Mk. PENGELOLAAN SDALH
BIODRYING
SOLID WASTE MANAGEMENT
SUSTAINANBLE ENERGY
http://www.epem.gr/waste-c-control/database/html/Biodrying-05.htm
Dikoleksi oleh: smno.psdl.ppsub.2013
Biodrying adalah proses dimana
limbah biodegradable dengan cepat
dipanaskan melalui fase-fase initial
pengkomposan untuk menguapkan
air dari limbah sehingga
mengurangi bobotnya
(Choi , Richard , Ahn, 2001).
Dikoleksi oleh: smno.psdl.ppsub.2013
BIODRYING
-
BIODEGRADABLE WASTE
Biodrying is the process by which biodegradable waste is
rapidly heated through initial stages of composting to remove
moisture from a waste stream and hence reduce its overall
weight.
Biodegradable waste is a type of waste, typically originating
from plant or animal sources, which may be broken down by
other living organisms. Waste that cannot be broken down by
other living organisms may be called non-biodegradable.
Biodegradable waste can be commonly found in municipal
solid waste (sometimes called biodegradable municipal
waste, or BMW) as green waste, food waste, paper waste,
and biodegradable plastics. Other biodegradable wastes
include human waste, manure, sewage, slaughterhouse
waste.
Pengolahan Limbah
Through proper waste management, it can be converted into
valuable products by composting, or energy by waste-toenergy processes such as anaerobic digestion and
incineration. As part of an integrated waste management
system, waste-to-energy processes reduces the emission of
landfill gas into the atmosphere.
http://www.spiritus-temporis.com/biodegradable-waste/treatment.html……
diunduh 17/3/2012
BIODRYING
In biodrying processes, the drying rates are augmented by biological
heat in addition to forced aeration. The major portion of biological
heat, naturally available through the aerobic degradation of organic
matter, is utilized to evaporate surface and bound water associated
with the mixed sludge. This heat generation assists in reducing the
moisture content of the biomass without the need for supplementary
fossil fuels, and with minimal electricity consumption (Navaee-Ardeh ,
Bertrand , Stuart, 2006)
It can take as little as 8 days to dry waste in this manner.
This enables reduced costs of disposal if landfill is charged on a cost
per tonne basis. Biodrying may be used as part of the production
process for refuse-derived fuels. Biodrying does not however greatly
affect the biodegradability of the waste and hence is not stabilised.
Biodried waste will still break down in a landfill to produce landfill gas
and hence potentially contribute to climate change.
Choi HL, Richard TL, Ahn HK (2001). "Composting high moisture materials: biodrying
poultry manure in a sequentially fed reactor". Compost Sci. and Util. 9 (4): 303–11.
http://www.biocycle.net/CSUContents/2001/Autumn/303.html.
Navaee-Ardeh S, Bertrand F, Stuart PR (2006). "Emerging biodrying technology for the
drying of pulp and paper mixed sludges". Drying Technology 24 (7): 863–78.
http://www.informaworld.com/smpp/content~content=a748750739?words=biodrying.
Sugni M, Calcaterra E, Adani F (August 2005). "Biostabilization-biodrying of municipal solid
waste by inverting air-flow". Bioresour. Technol. 96 (12): 1331–7.
http://en.wikipedia.org/wiki/Biodrying…… diunduh 7/3/2012
LIMBAH YANG DAPAT DIDEGRADASI SECARA
BIOLOGIS
Biodegradable waste is a type of waste, typically originating
from plant or animal sources, which may be degraded by
other living organisms. Waste that cannot be broken down by
other living organisms are called non-biodegradable.
Biodegradable waste can be commonly found in municipal
solid waste (sometimes called biodegradable municipal
waste, or BMW) as green waste, food waste, paper waste,
and biodegradable plastics.
Limbah-limbah biodegradable lainnya,
termasuk limbah manusia, kandang ternak,
rumah potong hewan, limbah dapur.
Dalam kondisi tidak ada oksigen, libah-limbah
ini akan mengalami perombakan anerobik
menghasilkan gas methan.
http://en.wikipedia.org/wiki/Biodegradable_waste…… diunduh 7/3/2012
BIODEGRADASI
Biodegradation or biotic degradation or biotic decomposition is the
chemical dissolution of materials by bacteria or other biological
means.
The term is often used in relation to ecology, waste management,
biomedicine, and the natural environment (bioremediation) and is
now commonly associated with environmentally friendly products
that are capable of decomposing back into natural elements.
Organic material can be degraded aerobically with oxygen, or
anaerobically, without oxygen.
A term related to biodegradation is biomineralisation, in which
organic matter is converted into minerals.
Biosurfactant, merupakan surfaktan
ekstraseluler yang dihasilkan oleh mikroba,
dapat memacu proses biodegradasi.
http://en.wikipedia.org/wiki/Biodegradation…… diunduh 7/3/2012
BIODEGRADABLE MATTER
Biodegradable matter is generally organic material such as plant and
animal matter and other substances originating from living organisms,
or artificial materials that are similar enough to plant and animal
matter to be put to use by microorganisms.
Some microorganisms have a naturally occurring, microbial catabolic
diversity to degrade, transform or accumulate a huge range of
compounds including hydrocarbons (e.g. oil), polychlorinated
biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), pharmaceutical
substances, radionuclides and metals.
Major methodological breakthroughs in microbial biodegradation
have enabled detailed genomic, metagenomic, proteomic,
bioinformatic and other high-throughput analyses of environmentally
relevant microorganisms providing unprecedented insights into key
biodegradative pathways and the ability of microorganisms to adapt
to changing environmental conditions.
Ada kalanya produk yang dipasarkan dengan label
“BIODEGRADABLE” ternyata juga mengandung
bahan yang non-biodegradable
http://en.wikipedia.org/wiki/Biodegradation…… diunduh 7/3/2012
BAHAN ORGANIK
Organic matter (or organic material, Natural Organic Matter, or
NOM) is matter that has come from a once-living organism; is capable
of decay, or the product of decay; or is composed of organic
compounds. The definition of organic matter varies upon the subject
for which it is being used.
Organic matter is broken down organic matter that comes from plants
and animals in the environment.
Organic matter is a collective term, assigned to the realm of all of this
broken down organic matter. Basic structures are created from
cellulose, tannin, cutin, and lignin, along with other various proteins,
lipids, and sugars.
It is very important in the movement of nutrients in the environment
and plays a role in water retention on the surface of the planet. These
two processes help to ensure the continuance of life on Earth.
"Natural Organic Matter," GreenFacts, 22 Apr, 2007
<http://www.greenfacts.org/glossary/mno/natural-organic-matter-NOM.htm
http://en.wikipedia.org/wiki/Organic_material…… diunduh 7/3/2012
BIOMASA
Biomass, as a renewable energy source, is biological material from
living, or recently living organisms. As an energy source, biomass can
either be used directly, or converted into other energy products such
as biofuel.
In the first sense, biomass is plant matter used to generate electricity
with steam turbines & gasifiers or produce heat, usually by direct
combustion. Examples include forest residues (such as dead trees,
branches and tree stumps), yard clippings, wood chips and even
municipal solid waste.
In the second sense, biomass includes plant or animal matter that can
be converted into fibers or other industrial chemicals, including
biofuels.
Industrial biomass can be grown from numerous types of plants,
including miscanthus, switchgrass, hemp, corn, poplar, willow,
sorghum, sugarcane, and a variety of tree species, ranging from
eucalyptus to oil palm (palm oil).
T.A. Volk, L.P. Abrahamson, E.H. White, E. Neuhauser, E. Gray, C. Demeter, C.
Lindsey, J. Jarnefeld, D.J. Aneshansley, R. Pellerin and S. Edick (October 15–19,
2000). "Developing a Willow Biomass Crop Enterprise for Bioenergy and
Bioproducts in the United States". Proceedings of Bioenergy 2000. Adam's
Mark Hotel, Buffalo, New York, USA: North East Regional Biomass Program.
Industri biomasa dapat berupa Hutan Tanaman,
Perkebunan, Pertanian, Agroforestry dan lainnya
http://en.wikipedia.org/wiki/Biomass…… diunduh 7/3/2012
RDF = REFUSE-DERIVED FUEL
Refuse-derived fuel (RDF) or solid recovered fuel/ specified
recovered fuel (SRF) is a fuel produced by shredding and dehydrating
solid waste (MSW) with a Waste converter technology.
RDF consists largely of combustible components of municipal waste
such as plastics and biodegradable waste.
RDF processing facilities are normally located near a source of MSW
and, while an optional combustion facility is normally close to the
processing facility, it may also be located at a remote location.
SRF can be distinguished from RDF in the fact that it is produced to
reach a standard such as CEN/343 ANAS.
Velis C. et al. (2010) Production and quality
assurance of solid recovered fuels using
mechanical—biological treatment (MBT) of
waste: a comprehensive assessment
http://en.wikipedia.org/wiki/Refuse-derived_fuel…… diunduh 7/3/2012
RDF PROCESSING METHODS
Non-combustible materials such as glass and metals are removed
during the post-treatment processing cycle with an air knife or other
mechanical separation processing. The residual material can be sold
in its processed form (depending on the process treatment) or it may
be compressed into pellets, bricks or logs and used for other purposes
either stand-alone or in a recursive recycling process.
Advanced RDF processing methods (pressurised steam treatment in
an autoclave) can remove or significantly reduce harmful pollutants
and heavy metals for use as a material for a variety of manufacturing
and related uses. RDF is extracted from municipal solid waste using
mechanical heat treatment, mechanical biological treatment or waste
autoclaves.
The production of RDF may involve some but not all of the following
steps:
1. Preliminary liberation (not required for autoclave treatment)
2. Size screening (post-treatment step for autoclave treatment)
3. Magnetic separation (post-treatment for autoclave treatment)
4. Coarse shredding (not required for autoclave treatment)
5. Refining separation
Ref.: Williams, P. (1998) Waste Treatment and Disposal. John Wiley and Sons,
Chichester
http://en.wikipedia.org/wiki/Refuse-derived_fuel…… diunduh 7/3/2012
Biological processing
The "biological" element refers to either:
Anaerobic digestion
Composting
Biodrying
Anaerobic digestion harnesses anaerobic microorganisms to break down the biodegradable
component of the waste to produce biogas and soil improver. The biogas can be used to
generate electricity and heat.
Biological can also refer to a composting stage. Here the organic component is broken down by
naturally occurring aerobic microorganisms. They breakdown the waste into carbon dioxide and
compost. There is no green energy produced by systems employing only composting treatment
for the biodegradable waste.
In the case of biodrying, the waste material undergoes a period of rapid heating through the
action of aerobic microbes. During this partial composting stage the heat generated by the
microbes result in rapid drying of the waste. These systems are often configured to produce a
refuse-derived fuel where a dry, light material is advantageous for later transport combustion.
By processing the biodegradable waste either by anaerobic digestion or by composting MBT
technologies help to reduce the contribution of greenhouse gases to global warming.
Usable wastes for this system:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Municipal solid waste
Commercial and industrial waste
Sewage sludge
Possible products of this system:
Renewable fuel (biogas) leading to renewable power
Recovered recycable materials such as metals, paper, plastics, glass etc.
Digestate - an organic fertiliser and soil improver
Carbon credits – additional revenues
High calorific fraction refuse derived fuel - Renewable fuel content dependent upon biological
component
10. Residual unusable materials prepared for their final safe treatment (e.g. incineration or
gasification) and/or landfill
Further advantages:
1. Small fraction of inert residual waste
2. Reduction of the waste volume to be deposited to at least a half (density > 1.3 t/m³), thus the
lifetime of the landfill is at least twice as long as usually
3. Utilisation of the leachate in the process
4. Landfill gas not problematic as biological component of waste has been stabilised
5. Daily covering of landfill not necessary
http://en.wikipedia.org/wiki/Mechanical_biological_treatment…… diunduh 7/3/2012
REFUSE DERIVED FUEL (RDF)
Refuse Derived Fuel (RDF) is classified as an innovation of waste-to-energy technology
created by shredding and drying out municipal solid waste material. The raw material
mostly used for conversion is the combustible fraction of waste which usually consists of
plastics and biodegradable matter.
Refuse-derived fuel facilities are usually located near landfills and dumpsites for efficiency
of access and acquisition of waste materials and less transportation cost.
Refuse Derived Fuel production starts by collection and transportation of raw materials,
and then comes the separation and sorting of municipal solid waste. In this process, the
noncombustible and recyclable materials are removed since it does not have the potential
to be converted to energy. The noncombustible can still be useful after taking treatment
to improve their value. It can be recycled and reserved for use in other purposes.
Compression is a good way to reduce the amount of space need for the storage and
transportation of the noncombustible. The combustible components on the other hand
are prepared to undergo the conversion process. In the conversion process, the RDF is
extracted and removed from Municipal Solid Waste (MSW). The process is performed by
using any of the three methods: autoclaves, applying extreme mechanical heat treatment,
or using mechanical biological treatment. Pressurized steam treatment can also be used
to remove the existence of heavy metals and other hazardous elements from the raw
material.
The conversion process is divided into five stages. The process may be divided into five
stages: Preliminary Liberation, size screening, magnetic separation, coarse shredding
where shredding and compression comes to make it easier to dissolve the waste to
energy, and refining separation. Electricity Generation is the primary use of Refuse
Derived Fuel. It helps resolve the underlying concerns due to consumption of energy
means. Refuse derived fuel process is also classified as a type of green energy as the
production of Refuse Derived Fuel use waste which also lessens and eliminates raw
materials in exchange for a clean energy source. It is considered as one of the great
innovation of our present time because it resolves both waste management and energy
dilemmas. This process lessens the emission of gas in the air, and it lessens the waste in
the dumpsites and landfills worldwide. The use of this technology is expected to pave the
way for the salvation of our mother earth and the insurance of a stable and sustainable
future for the upcoming generations.
http://www.spectrumbluesteel.com/blog/2011/08/09/refuse-derived-fuel-rdf-process/ ……
diunduh 7/3/2012
Specified Recovered Fuel or Solid Recovered Fuel
(SRF)
Refuse-derived fuel (RDF) is a kind of fuel that is produced from
municipal solid waste or MSW. It is also known as Specified
Recovered Fuel or Solid Recovered Fuel (SRF) which is derived from
the process it originated. Refuse-derived fuel (RDF) is made up of
domestic or residual trash after the recoverable materials had been
collected separately.
The main process in producing RDF is thru shredding and dehydrating
or burning the solid waste materials. The waste materials included are
mainly plastics and biodegradable trash. These waste materials are
treated and processed to have a product that consists of high calorific
value.
RDF dapat digunakan sebagai bahan bakar langsung
sendirian , atau dicampur dengan bahan bakar
lainnya.
Beneficiation of RDF
The use of mechanical screening to produce a very highquality RDF in terms of a reasonably high heating value, a
low moisture content, and a low ash content .
http://www.spectrumbluesteel.com/blog/2011/08/03/rdf-turning-waste-into-good-use/ ……
diunduh 7/3/2012
REFUSE-DERIVED FUEL
RDF is produced by processing MSW to increase the fuel value of the waste.
The processing removes incombustible materials such as dirt, glass, metals,
and very wet organics, and it makes RDF more consistent in size than raw
MSW. RDF can be burned for fuel by itself or cofired with other fuels.
In addition, the data presented in this section cover only new facilities.
Emissions and energy balances for older facilities might differ from those
presented here.
Teknologi Produksi RDF
Typical Processes. All RDF processes typically begin with shredding MSW to a
finer size; many then separate the fuel fraction from the residue. In plants
where no additional preparation is included, the operation is called a "shredand-burn" RDF facility.
Frequently, however, the separated fuel fraction is further processed to
recover metals and sometimes glass. The normal sequence of RDF preparation
is shredding, air classifying/screening, magnetic separation, and sometimes
eddy current separation for nonferrous metal recovery. Many variations of the
process have been developed, each of which has certain advantages.
RDF
Refuse-derived fuel (RDF) is a fuel produced by shredding
municipal solid waste (MSW). Once the non-combustible
materials such as glass and metals are removed the RDF material
consists largely of organic, plastic and biodegradable waste. The
residual material can be sold in its processed form or it may be
compressed into pellets, bricks or logs and used for other
purposes either stand-alone or in a recursive recycling process.
http://infohouse.p2ric.org/ref/11/10516/refuse.html …… diunduh 7/3/2012
BIO-DRYING
Biological Drying: Increasing the Calorific Value of Organic
Combustibles
http://comp-any.com/company/index.php?id=56 …… diunduh 7/3/2012
BAHAN BAKAR HAYATI
Biofuel is a type of fuel whose energy is derived from biological
carbon fixation.
Biofuels include fuels derived from biomass conversion, as well as
solid biomass, liquid fuels and various biogases.
Although fossil fuels have their origin in ancient carbon fixation, they
are not considered biofuels by the generally accepted definition
because they contain carbon that has been "out" of the carbon cycle
for a very long time.
Biofuels are gaining increased public and scientific attention, driven
by factors such as oil price hikes, the need for increased energy
security, concern over greenhouse gas emissions from fossil fuels, and
support from government subsidies.
Bahan bakar hayati semakin penting
terkait dengan masalah-masalah:
1. Harga minyak yang mahal
2. Keamanan energi
3. Emisi gas rumah kaca,
4. Subsidi minyak
http://en.wikipedia.org/wiki/Biofuel …… diunduh 7/3/2012
BIO ETHANOL
Bioethanol is an alcohol made by fermentation, mostly from
carbohydrates produced in sugar or starch crops such as corn or
sugarcane.
Cellulosic biomass, derived from non-food sources such as trees and
grasses, is also being developed as a feedstock for ethanol
production.
Ethanol can be used as a fuel for vehicles in its pure form, but it is
usually used as a gasoline additive to increase octane and improve
vehicle emissions. Bioethanol is widely used in the USA and in Brazil.
Current plant design does not provide for converting the lignin
portion of plant raw materials to fuel components by fermentation.
Biomasa Selulosik
Biomasa lignin
fermentasi
Bio-etanol
Bioethanol itu apa?
The principle fuel used as a petrol substitute for road transport vehicles is
bioethanol. Bioethanol fuel is mainly produced by the sugar fermentation process,
although it can also be manufactured by the chemical process of reacting ethylene
with steam.
The main sources of sugar required to produce ethanol come from fuel or energy
crops. These crops are grown specifically for energy use and include corn, maize
and wheat crops, waste straw, willow and popular trees, sawdust, reed canary
grass, cord grasses, jerusalem artichoke, myscanthus and sorghum plants. There is
also ongoing research and development into the use of municipal solid wastes to
produce ethanol fuel. (http://www.esru.strath.ac.uk/EandE/Web_sites/0203/biofuels/what_bioethanol.htm)
http://en.wikipedia.org/wiki/Biofuel …… diunduh 7/3/2012
BIODIESEL
Biodiesel is made from vegetable oils and animal fats.
Biodiesel can be used as a fuel for vehicles in its pure form, but it is
usually used as a diesel additive to reduce levels of particulates,
carbon monoxide, and hydrocarbons from diesel-powered vehicles.
Biodiesel is produced from oils or fats using transesterification and is
the most common biofuel in Europe.
Hielscher - Ultrasound
Technology
Basically, making biodiesel from
oil, methanol (or ethanol) and
catalyst, is a simple chemical
process. The problem lies in the
chemical reaction kinetics. The
conventional transesterification
of the triglycerides to fatty
methyl esters (FAME) and
glycerin is slow and not
complete.
During the conversion process
not all fatty acid chains are
turned into alkyl esters
(biodiesel).
This reduces your biodiesel
quality and yield, significantly.
http://www.hielscher.com/ultrasonics/biodiesel_processing_efficiency.htm…… diunduh
7/3/2012
BIODIESEL
Spesifikasi biodiesel tergantung pada minyak nabati yang
digunakan sebagai bahan baku dan kondisi operasi pabrik
serta modifikasi dari peralatan yang digunakan. Biodiesel
sebagai bahan bakar motor diesel dapat dikatakan layak
karena angka cetannya minimal 47, sedangkan minyak
diesel angka cetan sekitar 50. Apabila angka biodiesel
terlalu dapat merusak motor (TEKNOLOGI PROSES
PRODUKSI BIODIESEL, Martini Rahayu.
http://www.oocities.org/markal_bppt/publish/biofbbm/bir
aha.pdf)
http://www.oocities.org/markal_bppt/publish/biofbbm/biraha.pdf …… diunduh 17/3/2012
PRODUKSI BIODIESEL
Blok Diagram Proses Biodiesel
(TEKNOLOGI PROSES PRODUKSI BIODIESEL, Martini Rahayu.
http://www.oocities.org/markal_bppt/publish/biofbbm/biraha.pdf)
Teknologi proses biodiesel yang umum digunakan
pada skala komersial yaitu transesterifikasi antara
minyak nabati dan metanol menggunakan katalis
basa NaOH atau KOH.
Sebaiknya digunakan minyak nabati dalam hal ini
CPO yang kadar asam lemak bebas (ALB)-nya
rendah (< 1%). Apabila ALB lebih, maka perlu
dilakukan pretreatment karena dapat
mengakibatkan efisiensi proses rendah.
http://www.oocities.org/markal_bppt/publish/biofbbm/biraha.pdf…… diunduh 18/3/2012
TRANS-ESTERIFIKASI
In organic chemistry, transesterification is the process of exchanging the
organic group R″ of an ester with the organic group R′ of an alcohol.
These reactions are often catalyzed by the addition of an acid or base catalyst.
The reaction can also be accomplished with the help of enzymes (biocatalysts)
particularly lipases (E.C.3.1.1.3).
Strong acids catalyse the reaction by donating a proton to the carbonyl group,
thus making it a more potent electrophile, whereas bases catalyse the reaction
by removing a proton from the alcohol, thus making it more nucleophilic.
Transesterification: alcohol + ester → different alcohol + different ester
Reaksi Transesterifikasi Triolein
Apabila triolein dalam minyak nabati beraksi dengan methanol akan
menghasilkan 3 molekul methil oleat inilah yang disebut sebagai biodiesel dan
satu molekul gliserol
(TEKNOLOGI PROSES PRODUKSI BIODIESEL, Martini Rahayu.
http://www.oocities.org/markal_bppt/publish/biofbbm/biraha.pdf)
.
http://en.wikipedia.org/wiki/Transesterification …… diunduh 7/3/2012
PRODUKSI BIODIESEL
Produksi biodiesel adalah proses memproduksi biofuel, biodiesel, baik
melalui transesterifikasi atau alkoholisis.
Ini melibatkan reaksi minyak nabati atau lemak hewan SECARA
katalisis dengan alkohol alifatik rantai pendek (biasanya metanol atau
etanol).
USDE: The Alternative Fuels and
Advanced Vehicles Data Center
(AFDC)
Biodiesel can be produced using a
variety of esterification
technologies. The oils and fats are
filtered and preprocessed to
remove water and contaminants. If
free fatty acids are present, they
can be removed or transformed
into biodiesel using special
pretreatment technologies. The
pretreated oils and fats are then
mixed with an alcohol (usually
methanol) and a catalyst (usually
sodium hydroxide or potassium
hydroxide). The oil molecules
(triglycerides) are broken apart and
reformed into methyl esters and
glycerin, which are then separated
from each other and purified.
Roughly speaking, 100 pounds of
oil or fat are reacted with 10
pounds of a short-chain alcohol
(usually methanol) with a catalyst
to form 100 pounds of biodiesel
and 10 pounds of glycerin.
http://www.afdc.energy.gov/afdc/fuels/biodiesel_production.html….. diunduh 7/3/2012
TAHAPAN SITENSIS BIODIESEL
The major steps required to synthesize biodiesel are as follows:
Feedstock pretreatment
If waste vegetable oil (WVO) is used, it is filtered to remove dirt, charred food, and other
non-oil material often found. Water is removed because its presence causes the
triglycerides to hydrolyze, giving salts of the fatty acids (soaps) instead of undergoing
transesterification to give biodiesel.
Determination and treatment of free fatty acids
A sample of the cleaned feedstock oil is titrated with a standardized base solution in order
to determine the concentration of free fatty acids (carboxylic acids) present in the waste
vegetable oil sample. These acids are then either esterified into biodiesel, esterified into
bound glycerides, or removed, typically through neutralization.
Reactions
While adding the base, a slight excess is factored in to provide the catalyst for the
transesterification. The calculated quantity of base (usually sodium hydroxide) is added
slowly to the alcohol and it is stirred until it dissolves. Sufficient alcohol is added to make
up three full equivalents of the triglyceride, and an excess of usually six parts alcohol to
one part triglyceride is added to drive the reaction to completion.
Pemurnian Produk
Produk reaksi tidak hanya mencakup biodiesel, tetapi juga produk
sampingan, sabun, gliserin, alkohol berlebih, dan sedikit air. Semua
produk sampingan tersebut harus dihilangkan, meskipun urutan
penghilangannya tergantung pada proses. Kepadatan gliserin lebih
besar daripada biodiesel, dan perbedaan sifat ini dimanfaatkan
untuk memisahkan produk sampingan gliserin. Sisa metanol
biasanya dikeluarkan melalui penyulingan dan digunakan kembali,
meskipun dapat dicuci (dengan air) sebagai limbah. Sabun dapat
diambilatau diubah menjadi asam. Sisa air harus dikeluarkan dari
bahan bakar.
http://en.wikipedia.org/wiki/Biodiesel_production …… diunduh 7/3/2012
REAKSI TRANS-ESTERIFIKASI
Transesterifikasi
Triglycerides (1) are reacted with an alcohol such as ethanol (2) to
give ethyl esters of fatty acids (3) and glycerol (4):
Animal and plant fats and oils are typically made of triglycerides which are esters
containing three free fatty acids and the trihydric alcohol, glycerol. In the
transesterification process, the alcohol is deprotonated with a base to make it a
stronger nucleophile. Commonly, ethanol or methanol are used. As can be seen,
the reaction has no other inputs than the triglyceride and the alcohol.
Normally, this reaction will proceed either exceedingly slowly or not at all. Heat,
as well as an acid or base are used to help the reaction proceed more quickly. It is
important to note that the acid or base are not consumed by the
transesterification reaction, thus they are not reactants but catalysts.
Almost all biodiesel is produced from virgin vegetable oils using the basecatalyzed technique as it is the most economical process for treating virgin
vegetable oils, requiring only low temperatures and pressures and producing over
98% conversion yield (provided the starting oil is low in moisture and free fatty
acids). However, biodiesel produced from other sources or by other methods may
require acid catalysis which is much slower. Since it is the predominant method
for commercial-scale production, only the base-catalyzed transesterification
process will be described below.
REAKSI TRANS-ESTERIFIKASI
Biodiesel dapat dibuat dengan proses esterifikasi jika minyak
nabati yang digunakan mengandung asam lemak bebas tinggi.
Asam lemak bebas dan alkohol dapat dikonversi menjadi ester
(biodiesel) dan air dengan katalis asam sesuai reaksi :
RCOOH + CH3OH ------------- RCOOCH3 + H2O
Asam lemak Metanol
Metil ester Air
Adapun mekanisme reaksinya adalah
Reaktor, Vol. 12 No. 1, Juni 2008, Hal. 19-21
KAJIAN AWAL PEMBUATAN BIODIESEL DARI MINYAK DEDAK PADI DENGAN PROSES
ESTERIFIKASI (Aprilina Purbasari dan Silviana. 2008).
An example of the transesterification reaction equation, shown in skeletal formulas:
http://en.wikipedia.org/wiki/Biodiesel_production …… diunduh 7/3/2012
REAKSI ESTERIFIKASI
Since natural oils are typically used in this process, the alkyl groups of
the triglyceride are not necessarily the same. Therefore,
distinguishing these different alkyl groups, we have a more accurate
depiction of the reaction:
R1, R2, R3 : Alkyl group.
Esterification is a reversible reaction. Esters undergo hydrolysis
under acid and basic conditions. Under acidic conditions, the
reaction is the reverse reaction of the Fischer esterification. Under
basic conditions, hydroxide acts as a nucleophile, while an alkoxide is
the leaving group. This reaction, saponification, is the basis of soap
making. (http://en.wikipedia.org/wiki/Ester)
http://en.wikipedia.org/wiki/Biodiesel_production …… diunduh 7/3/2012
KATALISATOR PROSES ESTERIFIKASI
During the esterification process, the triglyceride is reacted with
alcohol in the presence of a catalyst, usually a strong alkali (NaOH,
KOH, or Alkoxides).
The main reason for doing a titration to produce biodiesel, is to find
out how much alkaline is needed to completely neutralize any free
fatty acids present, thus ensuring a complete transesterification.
Empirically 6.25 g / L NaOH produces a very usable fuel.
One uses about 6 g NaOH when the WVO is light in colour and about
7 g NaOH when it is dark in colour.
Alkohol bereaksi dengan asam lemak untuk
membentuk ester mono-alkil (atau biodiesel)
dan gliserol mentah.
Reaksi antara biolipid (lemak atau minyak)
dan alkohol adalah reaksi reversibel sehingga
alkohol harus ditambahkan berlebih untuk
mendorong reaksi ke arah kanan dan
memastikan konversinya lengkap.
http://en.wikipedia.org/wiki/Biodiesel_production …… diunduh 7/3/2012
Base-catalysed transesterification
mechanism
The transesterification reaction is base catalyzed. Any strong base
capable of deprotonating the alcohol will do (e.g. NaOH, KOH, Sodium
methoxide, etc.). Commonly the base (KOH, NaOH) is dissolved in the
alcohol to make a convenient method of dispersing the otherwise
solid catalyst into the oil. The ROH needs to be very dry. Any water in
the process promotes the saponification reaction, thereby producing
salts of fatty acids (soaps) and consuming the base, and thus inhibits
the transesterification reaction. Once the alcohol mixture is made, it
is added to the triglyceride. The reaction that follows replaces the
alkyl group on the triglyceride in a series of steps.
Karbon pada ester dari trigliserida memiliki
muatan positif, dan oksigen karbonil
memiliki muatan negatif. Polarisasi dari
ikatan C = O inilah yang menarik RO- ke situs
reaksi.
Ini menghasilkan tetrahedral intermedier
yang memiliki muatan negatif pada oksigen
karbonil
http://en.wikipedia.org/wiki/Biodiesel_production …… diunduh 7/3/2012
ENERGI DARI SAMPAH DOMESTIK
Municipal Solid Waste (MSW) contains organic as well as inorganic matter.
The latent energy present in its organic fraction can be recovered for gainful
utilisation through adoption of suitable Waste Processing and Treatment
technologies. The recovery of energy from wastes also offers a few additional
benefits as follows:
1. The total quantity of waste gets reduced by nearly 60% to over 90%,
depending upon the waste composition and the adopted technology;
2. Demand for land, which is already scarce in cities, for landfilling is reduced;
3. The cost of transportation of waste to far-away landfill sites also gets
reduced proportionately; and
4. Net reduction in environmental pollution.
Oleh karena itu, logis bahwa, segala upaya harus
dilakukan untuk meminimalkan produksi limbah
dan mendaur ulang & menggunakan kembali
limbah itu sebanyak mungkin, pilihan recovery
Energi dari Limbah juga harus dipertimbangkan.
Kalau memungkinkan, pilihan ini harus
dimasukkan dalam skema Pengelolaan Sampah.
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
BASIC TECHNIQUES OF ENERGY RECOVERY
Energy can be recovered from the organic fraction of waste (biodegradable as
well as non-biodegradable) basically through two methods as follows:
(i) Thermo-chemical conversion : This process entails thermal decomposition of organic matter to produce either heat energy or fuel oil or
gas; and
(ii) Bio-chemical conversion: This process is based on enzymatic
decomposition of organic matter by microbial action to produce methane
gas or alcohol.
The Thermo-chemical conversion processes are useful for wastes containing
high percentage of organic non-biodegradable matter and low moisture
content. The main technological options under this category include
Incineration and Pyrolysis/ Gasification.
BIOMETHANASI
The bio-chemical conversion processes are preferred for wastes having high
percentage of organic bio-degradable (putrescible) matter and high level of
moisture/ water content, which aids microbial activity. The main technological
options under this category is Anaerobic Digestion (Biomethanation).
Methanogenesis (bacteria) The microbial formation of methane, which is
confined to anaerobic habitats where occurs the production of hydrogen,
carbon dioxide, formic acid, methanol, methylamines, or acetate—the major
substrates used by methanogenic microbes (methanogens). In fresh-water or
marine sediments, in the intestinal tracts of animals, or in habitats engineered
by humans such as sewage sludge or biomass digesters, these substrates are
the products of anaerobic bacterial metabolism. Methanogens are terminal
organisms in the anaerobic microbial food chain—the final product, methane,
being poorly soluble, anaerobically inert, and not in equilibrium with the
reaction which produces it.
(http://encyclopedia2.thefreedictionary.com/Biomethanation)
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
PARAMETERS AFFECTING ENERGY RECOVERY
The main parameters which determine the potential of Recovery of Energy
from Wastes (including MSW), are:
· Quantity of waste, and
· Physical and chemical characteristics (quality) of the waste.
The actual production of energy will depend upon specific treatment process
employed, the selection of which is also critically dependent upon (apart from
certain other factors described below) the above two parameters. Accurate
information on the same, including % variations thereof with time (daily/
seasonal) is, therefore, of utmost importance.
The important physical parameters requiring consideration include:
1. Size of constituents
2. Density
3. Moisture content
Smaller size of the constituents aids in faster decomposition of the waste.
Wastes of the high density reflect a high proportion of biodegradable organic
matter and moisture. Low density wastes, on the other hand, indicate a high
proportion of paper, plastics and other combustibles.
High moisture content causes biodegradable
waste fractions to decompose more rapidly
than in dry conditions.
It also makes the waste rather unsuitable for
thermo-chemical conversion (incineration,
pyrolysis/ gasification) for energy recovery as
heat must first be supplied to remove moisture.
PARAMETERS AFFECTING ENERGY RECOVERY
The important chemical parameters to be considered for determining the energy
recovery potential and the suitability of waste treatment through biochemical or thermochemical conversion technologies include: 1. Volatile Solids
2. Fixed Carbon content
3. Inerts,
4. Calorific Value
5. C/N ratio (Carbon/Nitrogen ratio)
6. Toxicity
The desirable range of important waste parameters for technical viability of
energy recovery through different treatment routes is given in the Table 15.1. The
parameter values indicated therein only denote the desirable requirements for adoption
of particular waste treatment method and do not necessarily pertain to wastes generated
/ collected and delivered at the waste treatment facility. In most cases the waste may
need to be suitably segregated/ processed/ mixed with suitable additives at site before
actual treatment to make it more compatible with the specific treatment method.
This has to be assessed and ensured before hand. For example, in case of Anaerobic
digestion, if the C/N ratio is less, high carbon content wastes (straw, paper etc.) may be
added; if it is high, high nitrogen content wastes (sewage sludge, slaughter house waste
etc.) may be added, to bring the C/N ratio within the desirable range.
What is Calorific Value?
Calorific value (CV) is a measure of heating power and is dependent upon
the composition of the gas. The CV refers to the amount of energy released
when a known volume of gas is completely combusted under specified
conditions.
The CV of gas, which is dry, gross and measured at standard conditions of
temperature and pressure, is usually quoted in megajoules per cubic metre
(MJ/m3).
Gas passing through the National Grid pipeline system has a CV of 37.5
MJ/m3 to 43.0 MJ/m3, with the exception of Stornoway which receives
liquid petroleum gas.
(http://www.nationalgrid.com/uk/Gas/Data/misc/reports/description/)
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
Desirable range of important waste parameters for technical
viability of energy recovery:
METHANOGENS
“Methanogens are the only living organisms that produce methane as a way
of life. The biochemistry of their metabolism is unique and definitively
delineates the group. Two reductive biochemical strategies are employed:
an eight-electron reduction of carbon dioxide to methane or a two-electron
reduction of a methyl group to methane. All methogens form methane by
reducing a methyl group. The major energy-yielding reactions used by
methanogens utilize substrates such as hydrogen, formic acid, methanol,
acetic acid, and methylamine. Dimethyl sulfide, carbon monoxide, and
alcohols such as ethanol and propanol are substrates that are used less
frequently “ (http://encyclopedia2.thefreedictionary.com/Biomethanation).
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
ASSESSMENT OF ENERGY RECOVERY POTENTIAL
A rough assessment of the potential of recovery of energy from MSW
through different treatment methods can be made from a knowledge of its
calorific value and organic fraction, as under:
In thermo-chemical conversion all of the organic matter, biodegradable as well
as non-biodegradable, contributes to the energy output :
Total waste quantity : W tonnes
Net Calorific Value : NCV k-cal/kg.
Energy recovery potential (kWh) = NCV x W x 1000/860 = 1.16 x NCV x W
Power generation potential (kW) = 1.16 x NCV x W/ 24 = 0.048 x NCV x W
Conversion Efficiency = 25%
Net power generation potential (kW) = 0.012 x NCV x W
If NCV = 1200 k-cal/kg., then Net power generation potential (kW) = 14.4 x W
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
KONVERSI BIOKIMIA
In bio-chemical conversion, only the biodegradable fraction of the
organic matter can contribute to the energy output :
In general, 100 tonnes of raw MSW with 50-60% organic matter can
generate about 1- 1.5 Mega Watt power, depending upon the waste
characteristics.
Calorific value.
The calories or thermal units contained in one unit of a
substance and released when the substance is burned.
Calorific value : the quantity of heat produced by the complete
combustion of a given mass of a fuel, usually expressed in joules
per kilogram
(http://www.thefreedictionary.com/calorific+value)
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
TECHNOLOGICAL OPTIONS
There are various technological options which can be employed for recovery of
energy from MSW (Fig. 15.1). While some of these have already been applied
at a large scale, some others are under advanced stages of development. A
brief on these technologies is given below.
Anaerobic Digestion (AD)
In this process, also referred to as bio-methanation, the organic fraction of
wastes is segregated and fed to a closed container (biogas digester) where,
under anaerobic conditions, the organic wastes undergo bio-degradation
producing methane-rich biogas and effluent/ sludge. The biogas production
ranges from 50- 150m3/tonne of wastes, depending upon the composition of
waste. The biogas can be utilised either for cooking/ heating applications, or
through dual fuel or gas engines or gas / steam turbines for generating motive
power or electricity. The sludge from anaerobic digestion, after stabilisation,
can be used as a soil conditioner, or even sold as manure depending upon its
composition, which is determined mainly by the composition of the input
waste.
Fundamentally, the anaerobic digestion process can be divided into three
stages with three distinct physiological groups of micro-organisms:
Stage I: It involves the fermentative bacteria, which include anaerobic and
facultative micro-organisms. Complex organic materials, carbohydrates,
proteins and lipids are hydrolyzed and fermented into fatty acids, alcohol,
carbon dioxide, hydrogen, ammonia and sulfides.
Stage II: In this stage the acetogenic bacteria consume these primary
products and produce hydrogen, carbon dioxide and acetic acid.
Stage III: It utilizes two distinct types of methanogenic bacteria. The first
reduces carbon dioxide to methane, and the second decarboxylates acetic acid
to methane and carbon dioxide.
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
PROSES ANAEROBIK
Factors, which influence the Anaerobic Digestion process, are
temperature, pH (Hydrogen Ion Concentration), nutrient
concentration, loading rate, toxic compounds and mixing. For start-up
a good innoculum such as digested sludge is required. A temperature
of about 35-38oC is generally considered optimal in mesophilic zone
(20-45oC) and higher gas production can be obtained under
thermophillic temperature in the range of 45-60oC. Provision of
appropriate heating arrangements and insulation may become
necessary in some parts of the country.
Anaerobic Digestion (AD) of MSW offers certain clear
advantages over the option of Aerobic process, in terms
of energy production/ consumption, compost quality
and net environmental gains:
1. AD process results in net production of energy.
2. The quality of the digested sludge (compost) is better
as Nitrogen is not lost by oxidation.
3. Its totally enclosed system prevents escape of
polluted air to atmosphere.
4. The net environmental gains are positive.
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
MAIN STEPS IN ANAEROBIC TREATMENT OF MSW
Pre-treatment: to remove inerts and non-biodegradable
materials,
upgrade and homogenise the feedstock for digestion and to
promote downstream treatment processes.
Anaerobic Digestion: and to produce biogas for energy to deodorise, stabilise and disinfect the feedstock.
Post-Treatment: to complete the stabilisation of the digested
material and to produce a refined product of suitable
moisture content, particle size and physical structure for the
proposed end-use as organic manure.
Effluent Treatment: to treat the liquid effluent to specified
standards before final disposal.
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
Different Designs and Configurations of AD Systems
Different designs and configurations of AD systems have been developed by
various companies to suit different total solid concentration in the feed and
microbial activity i.e. single phase, bi-phasic, multi-phasic. The more popular
ones are broadly categorised as low/ medium and high solids, two phase and
leach bed systems.
(i) Low / Medium Solid Digestion Systems:
A large number of systems presently available worldwide for digestion of solid
wastes are for low (< 10%) or medium (10-16%) solid concentrations. Some of
these systems, when applied to MSW or Market Waste, require the use of
water, sewage sludge or manure.
(ii) High Solid Continuous Digestion Systems:
These systems have been developed since the late eighties principally for the
organic fraction of municipal solid waste but have also been extended to other
industrial, market and agricultural wastes. The digestion occurs at solid content
of 16% to 40%. These systems are referred to as ‘Dry Digestion’ or Anaerobic
Composting when the solid concentration is in the range of 25-40% and free
water content is low. Systems in this category vary widely in design and include
both completely mixed and plug-flow systems.
(iii) Two Stage Digestion Systems:
In these systems the hydrolysis, acidogenesis and acetogenesis of the waste
are carried out separately from the methanogenesis stage. Since each step is
optimised separately, so that each of the reactions (i.e. acidogenesis,
methanogenesis, etc.) is operated closer to its optimum, the rate of digestion
is significantly increased. However, requirement of two reactors and more
process controls may lead to higher capital costs and system complications.
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
(iv) Dry Batch Digestion/ Leach Bed Process
This design concept is closest to the processes occurring naturally in a
landfill. The reactor containing the organic material is inoculated with
previously digested waste from another reactor, sealed and allowed to digest
naturally. The leachate from the bottom of the reactor is re-circulated and
heated, if required, to promote the degradation process.
In Leach Bed systems also referred to as SEBAC systems (Sequential Batch
Anaerobic Composting) this leachate is treated in a wastewater digester prior
to recirculation, and thus the solid phase digester essentially acts like a
hydrolysis / acid forming stage of a two phase system. This approach has the
distinct advantage of reduced materials handling but overall degradation of the
organic matter can be lower than other systems.
A great deal of experience with biomethanation
systems already exists in India, but a large part of
this is related to farm-scale biogas plants and
industrial effluents. There is little experience in the
treatment of solid organic waste, except sewage
sludge and animal manure. However, several
schemes for bio-methanationof MSW and Vegetable
Market Yard Wastes, are currently planned for some
cities of the country .
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
REFUSE-DERIVED FUEL (RDF) BASED POWER PLANTS:
In an RDF plant, waste is processed before burning. Typically, the
noncombustible items are removed, separating glass and metals for recycling.
The combustible waste is shredded into a smaller, more uniform particle size
for burning. The RDF thus produced may be burned in boilers on-site, or it may
be shipped to off-site boilers for energy conversion. If the RDF is to be used
off-site, it is usually densified into pellets through the process of pelletisation.
Pelletisation involves segregation of the incoming waste into high and low
calorific value materials and shredding them separately, to nearly uniform size.
The different heaps of the shredded waste are then mixed together in suitable
proportion and then solidified to produce RDF pellets. The calorific value of
RDF pellets can be around 4000 kcal/ kg depending upon the percentage of
organic matter in the waste, additives and binder materials used in the
process, if any. Since pelletisation enriches the organic content of the waste
through removal of inorganic materials and moisture, it can be very effective
method for preparing an enriched fuel feed for other thermo-chemical
processes like Pyrolysis/ Gasification, apart from Incineration. Additional
advantage is that the pellets can be conveniently stored and transported.
RDF plants involve significantly more sorting and handling than Mass
Burn facilities and therefore provide greater opportunity to remove
environmentally harmful materials from the incoming waste prior to
combustion. However, it is not possible to remove the harmful
materials completely.
Several years ago RDF was used mainly along with coal fired boilers but
now, because of the stricter restrictions w.r.t. air emissions, it is usually
burned in dedicated boilers designed and built specially for the RDF. In
case of RDF Pellets too, it needs to be ensured that the pellets are not
burned indiscriminately or in the open, but only in dedicated
Incineration facilities or other well designed combustion systems,
having all the necessary pollution control systems.
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
PROSES ANAEROBIK
Schematic diagram of complete anaerobic digestion of complex polymers.
Names in brackets indicate the enzymes excreted by hydrolytic bacteria.
Numbers indicate the bacterial groups involved:
1. Fermentative bacteria
2. Hydrogenproducing acetogenic bacteria
3. Hydrogenconsuming acetogenic bacteria
4. Aceticlastic methanogenic bacteria
5. Carbon dioxidereducing methanogenic bacteria
Anaerobic digestion of organic solid waste for energy production
Satoto Endar Nayono. 2009…… diunduh 8/3/2012
LIMBAH UNTUK ENERGI
Schematic diagram of a “waste to energy” concept which is applied in the city
of Karlsruhe
Bagasse Calorific Value
Gross calorific value, also known as the higher calorific value (HCV) of bagasse, is
calculated from the following formula:
HCV=[19 605 - 196,05(moisture % sample) - 196,05(ash % sample) - 31,14(brix %
sample)]kJ.kg-1
The net calorific value, also known as the lower calorific value (LCV), assumes that the
water formed by combustion and also the water of constitution of the fuel remains in
vapour form. In industrial practice it is not practicable to reduce the temperature of
the combustion products below dew point to condense the moisture present and
recover its latent heat, thus the latent heat of the vapour is not available for heating
purposes and must be subtracted from the HCV. By ASTM standards the HCV is
calculated at atmospheric pressure and at 20°C. LCV of bagasse is calculated by the
formula:
LCV=[18 309 - 207,6 (moisture % sample) - 196,05 (ash % sample) - 31,14 (brix %
sample)] kJ.kg-1
(http://www.sugartech.co.za/extraction/bagasseCV/index.php)
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
ANAEROBIC DIGESTION
Anaerobic digestion is described as a series of processes involving
microorganisms to break down biodegradable material in the absence of
oxygen. The overall result of anaerobic digestion is a nearly complete
conversion of the biodegradable organic material into methane, carbon
dioxide, hydrogen sulfide, ammonia and new bacterial biomass (Veeken .,
2000; Kelleher , 2002; Gallert and Winter, 2005).
Buswell (1952 as cited in Gallert and Winter, 2005) proposed a generic formula
describing the overall chemical reaction of the anaerobic fermentation
process of organic compounds which can be used for the prediction of biogas
production:
In the anaerobic digestion process different types of bacteria degrade the
organic matter successively in a multistep process and parallel reactions.
The anaerobic digestion process of complex organic polymers is commonly
divided into three inter related steps: hydrolysis, fermentation (also known as
acidogenesis), ßoxidation (acetogenesis) and methanogenesis which are
schematically illustrated in figure
(Stronach ., 1986; Pavlosthatis and Giraldo Gomez, 1991).
http://urbanindia.nic.in/publicinfo/swm/chap15.pdf…… diunduh 8/3/2012
TEMPERATURE
Temperature is one of the major important parameters in anaerobic digestion.
It determines the rate of anaerobic degradation processes particularly the
rates of hydrolysis and methanogenesis. Moreover, it not only influences the
metabolic activities of the microbial population but also has a significant effect
on some other factors such as gas transfer rates and settling characteristics of
biosolids (Stronach ., 1986 and Metcalf & Eddy Inc., 2003).
Anaerobic digestion commonly applies two optimal temperature ranges:
mesophilic with optimum temperature around 35°C and thermophilic with
optimum temperature around 55°C (MataAlvarez, 2002).
Influence of temperature on the rate of anaerobic digestion process.
Optimum temperature for mesophilic around 30 – 40 °C and for thermophilic 50 – 60 °C
(Source: MataAlvarez, 2002)…… diunduh 7/3/2012
September 9th, 2011 by Cars Centre
SUSTAINABLE ENERGY
Sustainable energy is the sustainable provision of energy that meets
the needs of the present without compromising the ability of future
generations to meet their needs.
Technologies that promote sustainable energy include renewable
energy sources, such as hydroelectricity, solar energy, wind energy,
wave power, geothermal energy, and tidal power, and also
technologies designed to improve energy efficiency.
Sustainable energy Sources
People are constantly keeping
an eye out for new sources of
fuel because of the constantly
high price of gasoline. Drivers
are generally upset that they
pay more every time they fill at
the gas pump.
Sumber:
http://carscentre.com/tag/sour
ces-of-energy
http://en.wikipedia.org/wiki/Sustainable_energy …… diunduh 7/3/2012
EFISIENSI ENERGI
Energy efficiency and renewable energy are said to be the twin pillars of sustainable
energy. Some ways in which sustainable energy has been defined are:
"Effectively, the provision of energy such that it meets the needs of the present without
compromising the ability of future generations to meet their own needs. ...Sustainable
Energy has two key components: renewable energy and energy efficiency." – Renewable
Energy and Efficiency Partnership (British)
"Dynamic harmony between equitable availability of energy-intensive goods and
services to all people and the preservation of the earth for future generations." And,
"the solution will lie in finding sustainable energy sources and more efficient means of
converting and utilizing energy." – Sustainable energy by J. W. Tester, et al., from MIT
Press.
"Any energy generation, efficiency & conservation source where: Resources are
available to enable massive scaling to become a significant portion of energy
generation, long term, preferably 100 years.." – Invest, a green technology non-profit
organization.
"Energy which is replenishable within a human lifetime and causes no long-term
damage to the environment." – Jamaica Sustainable Development Network
This sets sustainable energy apart from other renewable energy terminology such as
alternative energy and green energy, by focusing on the ability of an energy source to
continue providing energy. Sustainable energy can produce some pollution of the
environment, as long as it is not sufficient to prohibit heavy use of the source for an
indefinite amount of time. Sustainable energy is also distinct from Low-carbon energy,
which is sustainable only in the sense that it does not add to the CO2 in the atmosphere.
Green Energy is energy that can be extracted, generated, and/or consumed without any
significant negative impact to the environment. The planet has a natural capability to
recover which means pollution that does not go beyond that capability can still be
termed green.
Green power is a subset of renewable energy and represents those renewable energy
resources and technologies that provide the highest environmental benefit. The U.S.
Environmental Protection Agency defines green power as electricity produced from
solar, wind, geothermal, biogas, biomass, and low-impact small hydroelectric sources.
Customers often buy green power for avoided environmental impacts and its
greenhouse gas reduction benefits.
TEKNOLOGI ENERGI TERBARUKAN
Renewable energy technologies are essential contributors to sustainable energy as they
generally contribute to world energy security, reducing dependence on fossil fuel
resources, and providing opportunities for mitigating greenhouse gases. The International
Energy Agency states that:
Conceptually, one can define three generations of renewables technologies, reaching back
more than 100 years . First-generation technologies emerged from the industrial
revolution at the end of the 19th century and include hydropower, biomass combustion,
and geothermal power and heat. Some of these technologies are still in widespread use.
Second-generation technologies include solar heating and cooling, wind power, modern
forms of bioenergy, and solar photovoltaics. These are now entering markets as a result of
research, development and demonstration (RD&D) investments since the 1980s. The
initial investment was prompted by energy security concerns linked to the oil crises (1973
and 1979) of the 1970s but the continuing appeal of these renewables is due, at least in
part, to environmental benefits. Many of the technologies reflect significant
advancements in materials.
Third-generation technologies are still under development and include advanced biomass
gasification, biorefinery technologies, concentrating solar thermal power, hot dry rock
geothermal energy, and ocean energy. Advances in nanotechnology may also play a major
role.
—International Energy Agency, RENEWABLES IN GLOBAL ENERGY SUPPLY, An IEA Fact
Sheet
First- and second-generation technologies have entered the markets, and third-generation
technologies heavily depend on long term research and development commitments,
where the public sector has a role to play.
A 2008 comprehensive cost-benefit analysis review of energy solutions in the context of
global warming and other issues ranked wind power combined with battery electric
vehicles (BEV) as the most efficient, followed by concentrated solar power, geothermal
power, tidal power, photovoltaic, wave power, coal capture and storage, nuclear energy,
and finally biofuels.
…… diunduh 7/3/2012
ENERGY EFFICIENCY
Moving towards energy sustainability will require changes not only in the way energy is
supplied, but in the way it is used, and reducing the amount of energy required to deliver
various goods or services is essential. Opportunities for improvement on the demand side
of the energy equation are as rich and diverse as those on the supply side, and often offer
significant economic benefits.
Renewable energy and energy efficiency are sometimes said to be the “twin pillars” of
sustainable energy policy. Both resources must be developed in order to stabilize and
reduce carbon dioxide emissions. Efficiency slows down energy demand growth so that
rising clean energy supplies can make deep cuts in fossil fuel use. If energy use grows too
fast, renewable energy development will chase a receding target. Likewise, unless clean
energy supplies come online rapidly, slowing demand growth will only begin to reduce
total emissions; reducing the carbon content of energy sources is also needed. Any
serious vision of a sustainable energy economy thus requires commitments to both
renewables and efficiency.
Renewable energy (and energy efficiency) are no longer niche sectors that are promoted
only by governments and environmentalists. The increased levels of investment and the
fact that much of the capital is coming from more conventional financial actors suggest
that sustainable energy options are now becoming mainstream.
Climate change concerns coupled with high oil prices and
increasing government support are driving increasing
rates of investment in the sustainable energy industries,
according to a trend analysis from the United Nations
Environment Programme.
ENERGI HIJAU = Green energy
Green energy includes natural energetic processes that can be
harnessed with little pollution.
Anaerobic digestion, geothermal power, wind power, small-scale
hydropower, solar energy, biomass power, tidal power, wave power,
and some forms of nuclear power (which is able to "burn" nuclear
waste through a process known as nuclear transmutation, and
therefore belong in the "Green Energy" category).
Some definitions may also include power derived from the
incineration of waste.
The goal of green energy is generally to create power with
as little pollution as possible produced as a by-product.
Every form of energy collection will result in some pollution,
but those that are green are known to cause less than those
that are not. Most people who advocate greener sources of
energy claim that the result of worldwide use of green
energy will result in the ability to preserve the planet for a
longer time. Greenhouse gases, a by-product of traditional
sources of energy such as fossil fuels are thought to be
causing global warming, or the process of the Earth heating
up at an accelerated pace.
…… diunduh 7/3/2012
ENERGI HIJAU
Some people, including George Monbiot and James Lovelock have
specifically classified nuclear power as green energy (Lovelock, James
, 2006. The Revenge of Gaia. Reprinted Penguin, 2007).
Others, including Greenpeace disagree, claiming that the problems
associated with radioactive waste and the risk of nuclear accidents
(such as the Chernobyl disaster) pose an unacceptable risk to the
environment and to humanity. However, newer nuclear reactor
designs are capable of utilizing what is now deemed "nuclear waste"
until it is no longer (or dramatically less) dangerous, and have design
features that greatly minimize the possibility of a nuclear accident.
Green energy is energy that is produced in a manner that
has less of a negative impact to the environment than
energy sources like fossil fuels, which are often produced
with harmful side effects.
“Greener” types of energy that often come to mind are
solar, wind, geothermal and hydro energy. There are
several more, even including nuclear energy, that is
sometimes considered a green energy source because of
its lower waste output relative to energy sources such as
coal or oil.
http://www.wisegeek.com/what-is-green-energy.htm…… diunduh 7/3/2012
GREEN ELECTRICITY
In several countries with common carrier arrangements, electricity retailing
arrangements make it possible for consumers to purchase green electricity
(renewable electricity) from either their utility or a green power provider.
When energy is purchased from the electricity network, the power reaching
the consumer will not necessarily be generated from green energy sources.
The local utility company, electric company, or state power pool buys their
electricity from electricity producers who may be generating from fossil fuel,
nuclear or renewable energy sources. In many countries green energy
currently provides a very small amount of electricity, generally contributing
less than 2 to 5% to the overall pool.
In some U.S. states, local governments have
formed regional power purchasing pools using
Community Choice Aggregation and Solar
Bonds to achieve a 51% renewable mix or
higher, such as in the City of San Francisco (San
Francisco Community Choice Program Design,
Draft Implementation Plan and H Bond Action
Plan, Ordinance 447-07, 2007).
…… diunduh 7/3/2012
GREEN ENERGI
Green energy consumers either obligate the utility companies to increase the
amount of green energy that they purchase from the pool (so decreasing the
amount of non-green energy they purchase), or directly fund the green energy
through a green power provider.
If insufficient green energy sources are available, the utility must develop new
ones or contract with a third party energy supplier to provide green energy,
causing more to be built. However, there is no way the consumer can check
whether or not the electricity bought is "green" or otherwise.
The Green Energy Future
Green Energy means producing renewable energy and fuels, and a lot more.
1. Saving energy through good decision-making.
2. Reducing waste by capturing energy value from by-products.
3. Generating valuable by-products.
4. Contributing to Ontario's energy supplies in an environmentally
sustainable manner.
5. Creating rural economic development opportunities and partnerships.
6. Reducing greenhouse gas emissions.
Efisiensi energi merupakan titik-awal dari “energi
Hijau”. Petani, pengolah pangan, pedagang dan
pemukim dapat mereduksi penggunaan energinya
dnegan jalan memperbaiki lampu penerangan, motor,
ventilation, pemanas ruangan, peralatan dan
insulation, serta menerapkan teknologi konservasi
energi yang tersedia.
http://www.omafra.gov.on.ca/english/engineer/facts/grenergy.htm…… diunduh 7/3/2012
GREEN ENERGY
Farm fields are natural energy collectors. Energy is captured from the soil, sun,
wind and water:
1. Soil and sun combine to produce energy crops and biomass for fuel.
2. Sun and wind present energy opportunities to harvest power.
3. Water is also an energy resource in the form of untapped streams that flow
through farms. Dams can be used to tap this resource.
Farms and food processors can be more than energy collectors; they can
produce energy in marketable products such as switchgrass pellets, biodiesel,
ethanol and electricity.
Green Energy Opportunities - Energy efficiency, producing renewable energy, production
opportunities across the province, economic development opportunities, waste recycling
and using renewable energy by-products.
SUMBER: http://www.omafra.gov.on.ca/english/engineer/facts/grenergy.htm…… diunduh 7/3/2012
LISTRIK ENERGI SURYA
The World Wide Fund for Nature and several green electricity labelling
organizations have created the Eugene Green Energy Standard under which
the national green electricity certification schemes can be accredited to ensure
that the purchase of green energy leads to the provision of additional new
green energy resources (Eugene Green Energy Standard, Eugene Network.
Retrieved 2007-06-07)
Production of electricity from solar energy
Heating the coolant directly with solar rays turns water into steam, which then
turns the turbo-alternator to produce electricity.
Sumber: http://visual.merriam-webster.com/energy/solar-energy/production-electricity-from-solarenergy.php…… diunduh 17/3/2012
Bioenergy
Bioenergy is stored energy from the sun contained in materials such as plant
matter and animal waste, known as biomass. Biomass is considered renewable
because it is replenished more quickly when compared to the millions of years
required to replenish fossil fuels. The wide variety of biomass fuel sources
includes agricultural residue, pulp/paper mill residue, urban wood waste,
forest residue, energy crops, landfill methane, and animal waste.
Biomass is any organic matter, particularly cellulosic or lingo-cellulosic matter,
which is available on a renewable or recurring basis, including trees, plants and
associated residues; plant fiber; animal wastes; industrial waste; and the paper
component of municipal solid waste .
Plants store solar energy through photosythesis in
cellulose and lignin cells. Cellulose is defined as a polymer,
or chain, of 6-carbon sugars; lignin is the substance, or
“glue,” that holds the cellulose chain together . When
burned, these sugars break down and release energy
exothermically, giving off CO2, heat and steam.
The byproducts of this reaction can be captured and
manipulated to create electricity, commonly called
biopower, or fuel known as biofuel. (Both short for
"biomass power" and "biomass fuel" respectively) .
http://www.repp.org/bioenergy/index.html …… diunduh 8/3/2012
SIKLUS KARBON
Biomass is considered to be a replenishable resource—it can be replaced
fairly quickly without permanently depleting the Earth’s natural
resources. By comparison, fossil fuels such as natural gas and coal require
millions of years of natural processes to be produced. Therefore, mining
coal and natural gas depletes the Earth’s resources for thousands of
generations. Alternatively, biomass can easily be grown or collected,
utilized and replaced.
Courtesy of NASA at http://rst.gsfc.nasa.gov/Sect16/carbon_cycle_diagram.jpg
http://www.repp.org/bioenergy/link1.htm …… diunduh 8/3/2012
Courtesy of ORNL at http://bioenergy.ornl.gov/papers/misc/bioenergy_cycle.html
In order to curb CO2 emissions, we must take active strides to reduce our
emissions. At present, the United States is responsible for 25% of the world's
emissions, and is currently dedicated to a policy which actually encourages the
release of more carbon dioxide into the atmosphere, claiming it to be an
indication of economic growth.
Burning biomass will not solve the currently unbalanced carbon dioxide
problem. However, the contribution that biomass could make to the energy
sector is still considerable, since it creates less carbon dioxide than its fossilfuel counterpart.
Conceptually, the carbon dioxide produced by biomass when it is burned will
be sequestered evenly by plants growing to replace the fuel. In other words, it
is a closed cycle which results in net zero impact (see diagram below). Thus,
energy derived from biomass does not have the negative environmental
impact associated with non-renewable energy sources.
…… diunduh 8/3/2012
ENERGI BIOMASA
Biomass is an attractive energy source for a number of reasons.
First, it is a renewable energy source as long as we manage vegetation
appropriately. Biomass is also more evenly distributed over the earth's surface
than finite energy sources, and may be exploited using less capital-intensive
technologies. It provides the opportunity for local, regional, and national
energy self-sufficiency across the globe. It provides an alternative to fossil
fuels, and helps to reduce climate change. It helps local farmers who may be
struggling and provides rural job opportunites.
Energy from Biomass
Farmers and food processors produce or manage large volumes of energy-rich
organic materials, which can be further processed to obtain usable forms of energy.
There are several ways farmers and other businesses can tap into the energy
potential found in biomass.
Production of New Energy Crops
Ontario farmers can grow new energy crops such as switchgrass and specialized corn
silage for anaerobic digesters, depending on the location and type of operation they
have. These crops may fit into existing rotations and may be harvested by available
equipment.
Local Value-added Opportunities
Energy crops or agriculture and food biomass can be processed locally before
shipping. Local pelletizing of switchgrass or crop residues can produce a value-added
product that can be easily transported for use in other markets.
On-site Production of Energy
Renewable energy systems can produce energy in the following ways:
Anaerobic Digesters produce biogas by using manure and other organic inputs (such
as energy crops and food processing by-products). Biogas can be used as a
replacement for natural gas to produce heat, electricity and/or transportation fuel.
Biomass Combustion Systems that burn energy crops, crop residues, wood and other
cellulosic inputs produce heat, power or bio-oils with very low emissions. The heat
can be sold locally to another business, farm or community.
http://www.omafra.gov.on.ca/english/engineer/facts/grenergy.htm…… diunduh 8/3/2012
KONVERSI ENERGI BIOMASA
Bioenergy conversion requires a comparison with other energy sources that are displaced
by the bioenergy. Thus, biomass for power must be compared to coal, natural gas, nuclear,
and other power sources including other renewables. While comprehensive data is not
available, one study by REPP shows that emissions from biomass plants burning waste
wood would release far less sulfur dioxide (SO2), nitrogen oxide (NOx) and carbon dioxide
(CO2) than coal plants built after 1975.
The comparison with combined cycle natural gas power plants
is more ambiguous, since biomass releases far more sulfur
dioxide, similar levels or greater levels of nitrogen oxide, but
far less carbon dioxide than combined cycle natural gas plants.
There are five fundamental forms of biomass energy use.
1.
2.
3.
4.
5.
the "traditional domestic" use in developing countries (fuelwood, charcoal and
agricultural residues) for household cooking (e.g. the "three stone fire"), lighting
and space-heating. In this role-the efficiency of conversion of the biomass to
useful energy generally lies between 5% and 15%.
the "traditional industrial" use of biomass for the processing of tobacco, tea, pig
iron, bricks & tiles, etc, where the biomass feedstock is often regarded as a "free"
energy source. There is generally little incentive to use the biomass efficiently so
conversion of the feedstock to useful energy commonly occurs at an efficiency of
15% or less.
"Modern industrial." Industries are experimenting with technologically advanced
thermal conversion technologies which are itemised below. Expected conversion
efficiencies are between 30 and 55%.
newer "chemical conversion" technologies ("fuel cell") which are capable of bypassing the entropy-dictated Carnot limit which describes the maximum
theoretical conversion efficiencies of thermal units.
"biological conversion" techniques, including anaerobic digestion for biogas
production and fermentation for alcohol
http://www.fao.org/docrep/T1804E/t1804e06.htm…… diunduh 18/3/2012
TYPES OF BIOMASS
Domestic biomass resources include biomass processing residues including
pulp and paper operation, agricultural and forestry wastes, urban wood
wastes, municipal solid wastes and landfill gas, animal wastes and terrestrial
and aquatic crops grown solely for energy purposes, known as energy crops.
In large quantities, the biomass source is called a feedstock. Making use of the
waste is more productive than allowing it to sit and decompose on its own,
which is sometimes even more hazaradous to the surrounding environment.
Below is a more detailed description of each of these types.
Producing Biofuels from Renewable Sources
Like biomass energy systems, solid and liquid biofuels production from
crops can reduce reliance on fossil fuels. Unlike fossil fuels, biofuels are
considered "carbon neutral" because no net carbon is introduced into
the atmosphere through their use (i.e. they capture the same amount
of carbon dioxide in their growth as utilizing them creates). Local
biofuels production could also increase rural economic development.
Fuel Types include:
Grain Ethanol: Ethanol for fuel is mostly created from fermented corn.
Cellulosic Ethanol: Cellulosic ethanol will be produced from high-volume
specialized crops (e.g. switchgrass), crop residues and other forms of organic
matter.
Biodiesel: Biodiesel can be created from a variety of agricultural materials,
including canola and soybeans, and from food processing by-products.
Raw Biomass: Heat and electricity can be produced by burning grains, crop
residues or dedicated energy crops in burners or boilers.
Pelletized Biomass: Switchgrass and other high-growth crops can be harvested
and pelletized for ease of transportation, storage and use as a solid biofuel,
primarily in heating systems.
Biogas: Refined biogas can directly replace natural gas.
http://www.omafra.gov.on.ca/english/engineer/facts/grenergy.htm
http://www.repp.org/bioenergy/link2.htm …… diunduh 8/3/2012
BIOMASS PROCESSING RESIDUES.
All processing of biomass yields byproducts and waste streams collectively
called residues, which have significant energy potential. Not all residues can be
used for electricity generation, some must be used to replenish the source
with nutrients or elements. Still, residues are simple to use because they have
already been collected.
Forest residues, which includes wood from forest thinning operations that
reduce forest fire risk, biomass not harvested or removed from logging sites in
commercial hardwood and softwood stands as well as material resulting from
forest management operations such as pre-commercial thinnings and removal
of dead and dying trees.
There are four main supply chains of forest residues
Recovery of forest residues
Forest residues consist of small trees, branches, tops and un-merchantable
wood left in the forest after the cleaning, thinning or final felling of forest
stands, used as fuel without any intermittent applications. Three main sources
of forest residues can be distinguished: slash from final fellings, slash and small
trees from thinnings and cleanings, and un-merchantable wood. In Sweden for
example, slash from final fellings constitutes the largest share (over 71% in
1996 and even more dominating in 2003).
1. Terrain chipping
2. Chipping at a landing (generally roadside chipping)
3. Terminal chipping
4. Chipping at plant.
(sumber: http://www.eubia.org/191.0.html .... diunduh 17/3/2012
http://www.repp.org/bioenergy/link2.htm …… diunduh 8/3/2012
BIOMASA SISA PANEN TANAMAN
Agricultural or Crop Residues are the leftovers of harvesting. They can be collected with
conventional harvesting equipment while harvesting the primary crop or afterwards into
pellets, chips, stacks or bales .
Agriculture crop residues include corn stover (stalks and leaves), wheat straw, rice straw
and processing residues such as nut hulls. With approximately 80 million acres of corn
planted annually, corn stover is expected to become a major biomass resource for
bioenergy applications .
In some areas, especially dry climates, the residues must be left to replenish the soil with
nutrients for the next season and can not be completely utilized . The soil can not take out
all the nutrients from the residues, which translates to rotting and wasted energy sitting
on top of the fields.
Forest chips harvesting methods integrated into wood raw material harvesting (
Source: Alakangas, VTT)
http://www.eubia.org/191.0.html…… diunduh 8/3/2012
LIMBAH TERNAK
Animal waste, such as cattle, chicken and pig manure, can be converted to gas
or burned directly for heat and power generation. In the developing world,
dung cakes are used as a fuel for cooking .
Furthermore, most animal wastes contain high levels of methane. Thus, this
method is very unsafe, as the levels of harmful chemicals given off by the
biomass is hazardous to the health of users, causing 1.6 million deaths annually
in the developing nations . Since, animal wastes farms and animal processing
operations create large amounts of animal wastes that constitute a complex
source of organic materials with environmental consequences, utilizing the
manure to produce energy properly lowers the environmental and health
impacts.
These wastes can be used to make many products and
generate electricity through methane recovery methods and
anaerobic digestion.
Anaerobic reactors are generally used for the production of
methane rich biogas from manure (human and animal) and
crop residues. They utilise mixed methanogenic bacterial
cultures which are characterised by defined optimal
temperature ranges for growth. These mixed cultures allow
digesters to be operated over a wide temperature range i.e.
above 0°C up to 60°C.
http://www.fao.org/docrep/T1804E/t1804e06.htm…… diunduh 18/3/2012
LIMBAH DOMESTIK
Municipal Solid Waste. Residential, commercial, and institutional postconsumer wastes contain a significant proportion of plant derived organic
material that constitute a renewable energy resource. Waste paper, cardboard,
wood waste and yard wastes are examples of biomass resources in municipal
wastes. The International Energy Agency (IEA) is conducting research on
municipal wastes and their use in creating bioenergy.
BIOGAS
Generally biogas refers to a gas, which is produced by the biological
breakdown of organic matter in the absence of oxygen. And biogas
originates from biogenic material and is a type of biofuel.
http://www.inverter-china.com/blog/articles/green-energy/Definition-of-biogas.html……
diunduh 17/3/2012
TANAMAN ENERGI
Energy crops are bioengineered to be fast-growing plants, trees or other
herbaceous biomass which are harvested specifically for energy production
use. These crops can be grown, cut and replaced quickly. For a complete list of
potential plants which may be used as energy crops, please see the Handbook
of Energy Crops.
Herbaceous Energy Crops
Herbaceous energy crops are perennials that are harvested annually after
taking two to three years to reach full productivity. These include grasses such
as switchgrass, miscanthus (Elephant grass), bamboo, sweet sorghum, tall
fescue, kochia, wheatgrass, and others. These crops are generally grown for
fuel production.
Woody Energy Crops
Short-rotation woody crops are fast growing
hardwood trees harvested within five to eight
years after planting.
These include hybrid poplar (seen below), hybrid
willow, silver maple, eastern cottonwood, green
ash, black walnut, sweetgum, and sycamore.
…… diunduh 8/3/2012
Industrial Crops
Industrial crops are being developed and grown to produce specific industrial
chemicals or materials. Examples include kenaf and straws for fiber, and castor
for ricinoleic acid. New transgenic crops are being developed that produce the
desired chemicals as part of the plant composition, requiring only extraction
and purification of the product.
Agricultural Crops
These feedstocks include the currently available commodity products such as
cornstarch and corn oil; soybean oil and meal; wheat starch, other vegetable
oils, and any newly developed component of future commodity crops. They
generally yield sugars, oils, and extractives, although they can also be used to
produce plastics and other chemicals and products.
Aquatic Crops
A wide variety of aquatic biomass resources
exist such as algae, giant kelp, other seaweed,
and marine microflora. Commercial examples
include giant kelp extracts for thickeners and
food additives, algal dyes, and novel
biocatalysts for use in bioprocessing under
extreme environments .
…… diunduh 8/3/2012
BAHAN BAKAR HAYATI
Biofuel is a renewable energy source that are produced from recently living
organisms or their byproducts. The term itself is most commonly used to refer
to liquid biofuels. They are fuels developed from specifically grown agricultural
products.
Before World War II, biofuels were seen as providing an alternative to
imported oil in European countries. After the war, cheap Middle Eastern oil
lessened interest in biofuels. But since the 21st century, rising oil prices,
concerns over the potential oil peak, global warming, and instability in the
Middle East are pushing renewed interest in biofuels.
Indonesia's rich biodiversity and vast potential
for development of the bioenergy utilization,
together with the integrated strategy and
incentives for investment developed by the
government, favorably position the country to
maximise the promise of sustainable longterm returns from the biofuel economy.
http://www.biofuelindonesia.com/about.html …… diunduh 8/3/2012
ASAL-USUL BIOFUEL
The most common types of biofuel are originated from specifically grown agricultural
products. This include:
- Corn and Soybeans, primarily in the United States;
- Flaxseed and Rapeseed, primarily in Europe;
- Sugar Cane in Brazil;
- Palm Oil in South-East Asia;
- Jatropha Curcas, primarily in India.
Biofuel can also come from biodegradable outputs from industry, agriculture, forestry
and households. This include straw, timber, manure, rice husks, sewage, biodegradable
waste, and food leftovers. They are converted to biogas through anaerobic digestion.
Biomass used as fuel often consists of underutilized types, like chaff and animal waste.
Indonesia is currently focusing on developing Liquid Biofuel derived from Jatropha
Curcas, Palm Oil, and Sugar Cane.
Vegetable oil is used in several old diesel engines that have indirect injection
systems. This oil is also used to create biodiesel, which when mixed with conventional
diesel fuel is compatible for most diesel engines. Used vegetable oil is converted into
biodiesel. Sometimes, water and particulates are separated from the used vegetable
oil and then this is used as a fuel.
Biodiesel is a famous biofuel in Europe. Its composition is just like mineral diesel.
When biodiesel is mixed with mineral diesel, the mixture can be used in any diesel
engine. It is observed that in several nations, the diesel engines under warranty are
converted to 100% biodiesel use. It has also been proved that most people can run
their vehicles on biodiesel without any problem.
Bioalcohols are biologically produced alcohols. Common among these are ethanol and
rare among these are propanol and butanol. Biobutanol can be used directly in a
gasoline engine and hence is considered a direct replacement for gasoline. The
butanol can be burned straight in the existing gasoline engines without any alteration
to the engine or car. It is also claimed that this butanol produces more energy. Also,
butanol has a less corrosive effect and is less soluble in water than ethanol.
Ethanol fuel is the most commonly used biofuel in the world and particularly in Brazil.
Ethanol can be put to use in petrol engines as a substitute for gasoline. Also, it can be
mixed with gasoline in any ratio. The contemporary automobile petrol engines can
work on mixtures of gasoline and ethanol that have 15% bioethanol. This mixture of
gasoline and ethanol has more quantity of octane.
(http://biofuel.org.uk/types-of-biofuel.html)
http://www.biofuelindonesia.com/about.html …… diunduh 8/3/2012
BIODIESEL
Biodiesel & Green Diesel
Biodiesel is a renewable liquid fuel that can be produced locally, thus helping
to reduce Indonesia's dependence on imported crude.
The processed biodiesel fuel is derived from Palm Oil, Jatropha Curcas,
Coconut Oil, or Soybean Oil.
Biodiesel can be readily used in diesel-engine vehicles either as a substitue for
Diesel, or as an additive. It provides power similar to that produced by
conventional diesel fuel.
Bioethanol
Bioethanol comes from anhydrous alcohol produced from the fermentation of
sugar cane, cassava, or corn. Green Diesel is a blend of Plantation Oil and
Crude Oil, processed in an oil refinery without adding methanol.
The processed bioethanol fuel can be utilized for transportation vehicles as an
additive to fuel, up to 15% of total composition without the need for any
special equipment.
Pure Plant Oil (PPO) & Straight Vegetable Oil (SVO)
Pure Plant Oil and Straight Vegetable Oil are those that has not undergone
chemical change from its original characteristics.
Palm Oil, Straight Jatropha Oil (SJO) and Soybean Oil can all be used as an
additive for Diesel fuel (15% PPO, 85% Diesel) without needing any special
equipment. However, with the use of convertor, PPO can be used to purely
replace Diesel fuel (up to 100% of the composition), resulting in discontinue
need for Diesel fuel.
PPO can also be used to replace Kerosene (20% PPO, 80% Diesel) and Marine
Fuel Oil (up to 100% PPO without special equipment).
…… diunduh 8/3/2012
TANAMAN ENERGI
Bio-Fuel menjadi primadona dengan kemasan yang ramah lingkungan.
Walaupun ada juga pihak yang menentang BioFuel dengan alasan
akan adanya pertarungan antara Food untuk manusia dan Food untuk
Kendaraan bermotor dan Industri.
Apa komoditi dan bahan baku utama Bio-Fuel?
Ada 4 bahan baku utama yang saat ini digunakan:
1.
2.
3.
4.
Palm: atau juga dikenal dengan Kelapa Sawit
Jatropa Curcas: atau Jarak Pagar
Sugar cane: atau tanaman Tebu
Cassave: atau Ubi Kayu
http://www.praj.net/agri_services.asp
http://don85.wordpress.com/2008/01/16/biofuel-development-di-indonesia/…… diunduh
8/3/2012
PRODUK DARI BIO-FUEL
Bio-Ethanol: digunakan sebagai pengganti BBM (Gasoline) pada
transportasi, dengan target 10%. Bahan bakunya adalah dari Sugar
cane (Tanaman Tebu) dan Cassava (Ubi Kayu).
Bio-Diesel: akan menjadi pengganti Bahan Bakar Diesel (Solar) yang
akan digunakan untuk Transportasi (10%) dan Power Plant (50%).
Bahan Bakunya adalah dari Kelapa Sawit dan jarak Pagar.
Bio-Oil mempunyai 3 turunan yaitu:
Bio-Kerosin: sebagai pengganti Minyak Tanah di rumah tangga
(10%) dengan berbahan baku Kelapa Sawit dan Jarak Pagar
Bio-Oil: sebagai pengganti Automotive Diesel Oil (ADO) untuk
transportasi (10%) dan Power Plant (10-50%), dan Bio-Oil sebagai
pengganti Industry Diesel Oil (IDO) untuk Transportasi Laut dan
Kereta Api (10%), juga bahan baku yang sama dengan BioKerosin.
Bio-Oil: sebagai pengganti Minyak Bakar (Fuel Oil) untuk Industry
sebanyak 50%. Bahan baku nya adalah Kelapa Sawit dan Jarak
Pagar.
Bio-Diesel: sebagai pengganti Bahan Bakar Solar pada
Transportasi (10%) dan Power Plant (50%). Bahan bakunya
adalah Kelapa Sawit dan Jarak Pagar.
http://don85.wordpress.com/2008/01/16/biofuel-development-diindonesia/…… diunduh 8/3/2012
TARGET PENGEMBANGAN BIOFUEL
Pemerintah Indonesia sendiri, dalam kerangka pengembangan BIOFUEL
ini, ini mempunyai target untuk tahun 2010 sebagai berikut:
1.
2.
3.
4.
Menciptakan lapangan pekerjaan bagi 3.5 juta orang
Meningkatkan pendapatan petani minimal menyamai UMR
Mengembangkan tananaman bahan Biofuel di 5.5 juta hektar tanah
Terbentuknya 1000 Daerah yang-Self-Sufficient-Energy (DESA
MANDIRI) dan 12 daerah khusus BIOFUEL
5. Mengurangi ketergantungan akan Fossil Fuel paling tidak 10%
6. Menghemat Valuta Asing sampai US$10 Milliar
7. Memenuhi kebutuhan BIOFUEL dalam enegri dan eksport.
Biodiesel
Biodiesel is created through mixture of an organic oil, most commonly vegetable oil,
and an alcohol. This process of converting oils to biodiesel is known as
transesterification. While plant-based oil is the most common ingredient in
biodiesel, other types of oils can be used such as animal fat or algae. Biodiesel is a
substance very similar to diesel however modern diesel engines cannot use it
readily as an energy source without slight modifications to the engine. The
biodiesel available at gas stations is mixture of 5% biodiesel and 95% ordinary
diesel fuel. However, more biodiesel friendly vehicles are being produced, chief
amongst them are railway cars which can run on up to a 20% biodiesel mixture.
Some hobbyists also convert diesel to complete biodiesel powered vehicles.
The only problem with biodiesel is the fact that, while bioalcohols use any biomass
to produce energy, biodiesel must be produced from oil rich crops, which require
large amounts of fertile land. This is a problem as it increases the costs of biodiesel
and uses land that could have been used for food production or other purposes.
(http://renewableenergyindex.com/renewable-energy-sources/biologicalenergy/types-of-biofuels)
BAHAN BAKAR HAYATI = BIOFUEL
Bahan bakar hayati atau biofuel adalah setiap bahan bakar baik padatan, cairan ataupun
gas yang dihasilkan dari bahan-bahan organik. Biofuel dapat dihasilkan secara langsung
dari tanaman atau secara tidak langsung dari limbah industri, komersial, domestik atau
pertanian. Ada tiga cara untuk pembuatan biofuel: pembakaran limbah organik kering
(seperti buangan rumah tangga, limbah industri dan pertanian); fermentasi limbah basah
(seperti kotoran hewan) tanpa oksigen untuk menghasilkan biogas (mengandung hingga
60 persen metana), atau fermentasi tebu atau jagung untuk menghasilkan alkohol dan
ester; dan energi dari hutan (menghasilkan kayu dari tanaman yang cepat tumbuh sebagai
bahan bakar).
Proses fermentasi menghasilkan dua tipe biofuel: alkohol dan ester. Bahan-bahan ini
secara teori dapat digunakan untuk menggantikan bahan bakar fosil tetapi karena kadangkadang diperlukan perubahan besar pada mesin, biofuel biasanya dicampur dengan
bahan bakar fosil. Uni Eropa merencanakan 5,75 persen etanol yang dihasilkan dari
gandum, bit, kentang atau jagung ditambahkan pada bahan bakar fosil pada tahun 2010
dan 20 persen pada 2020. Sekitar seperempat bahan bakar transportasi di Brazil tahun
2002 adalah etanol.
Biofuel menawarkan kemungkinan memproduksi energi tanpa meningkatkan kadar
karbon di atmosfer karena berbagai tanaman yang digunakan untuk memproduksi biofuel
mengurangi kadar karbondioksida di atmosfer, tidak seperti bahan bakar fosil yang
mengembalikan karbon yang tersimpan di bawah permukaan tanah selama jutaan tahun
ke udara. Dengan begitu biofuel lebih bersifat carbon neutral dan sedikit meningkatkan
konsentrasi gas-gas rumah kaca di atmosfer (meski timbul keraguan apakah keuntungan
ini bisa dicapai di dalam prakteknya). Penggunaan biofuel mengurangi pula
ketergantungan pada minyak bumi serta meningkatkan keamanan energi.
Ada dua strategi umum untuk memproduksi biofuel. Strategi pertama adalah menanam
tanaman yang mengandung gula (tebu, bit gula, dan sorgum manis) atau tanaman yang
mengandung pati/polisakarida (jagung), lalu menggunakan fermentasi ragi untuk
memproduksi etil alkohol. Strategi kedua adalah menanam berbagai tanaman yang kadar
minyak sayur/nabatinya tinggi seperti kelapa sawit, kedelai, alga, atau jarak-pagar. Saat
dipanaskan, maka keviskositasan minyak nabati akan berkurang dan bisa langsung dibakar
di dalam mesin diesel, atau minyak nabati bisa diproses secara kimia untuk menghasilkan
bahan bakar seperti biodiesel. Kayu dan produk-produk sampingannya bisa dikonversi
menjadi biofuel seperti gas kayu, metanol atau bahan bakar etanol.
http://www.biofuelindonesia.com/about.html …… diunduh 8/3/2012
BIODIESEL
Biodiesel merupakan biofuel yang paling umum di Eropa. Biodiesel diproduksi
dari minyak atau lemak menggunakan transesterifikasi dan merupakan cairan
yang komposisinya mirip dengan diesel mineral. Nama kimianya adalah methyl
asam lemak (atau ethyl) ester (FAME). Minyak dicampur dengan sodium
hidroksida dan methanol (atau ethanol_ dan reaksi kimia menghasilkan
biodiesel (FAME) dan glycerol. Satu bagian glycerol dihasilkan untuk setiap 10
bagian biodiesel.
Biodiesel dapat digunakan di setiap mesin diesel kalau dicampur dengan diesel
mineral. Di beberapa negara produsen memberikan garansi untuk penggunaan
100% biodiesel. Kebanyakan produsen kendaraan membatasi rekomendasi
mereka untuk penggunaan biodiesel sebanyak 15% yang dicampur dengan
diesel mineral. Di Eropa, campuran biodiesel 5% sudah banyak digunakan
secara luas dan tersedia di stasiun bahan bakar umum.
Di USA, lebih dari 80% truk komersial dan bis kota
beroperasi menggunakan diesel. Oleh karena itu
penggunaan biodiesel AS bertumbuh cepat dari
sekitar 25 juta galon per tahun pada 2004 menjadi
78 juta galon pada awal 2005. Pada akhir 2006,
produksi biodiesel diperkirakan meningkat empat
kali lipat menjadi 1 milyar galon.
http://id.wikipedia.org/wiki/Biofuel…… diunduh 8/3/2012
BAHAN BAKAR HAYATI - FOTOSINTESIS
Pentingnya fotosintesis dalam produksi bio-fuel.
http://solarbiofuels.org/consortium.php…… diunduh 8/3/2012
FOTOSINTESIS PENTING DALAM PRODUKSI BIO-FUEL
Fotosintesis memainkan peran sentral dalam proses produksi bio-fuel karena
merupakan langkah pertama dalam konversi energi surya (cahaya) menjadi
energi kimia dan OLEH karenanya bertanggung jawab untuk mendorong
produksi stok pakan yang diperlukan untuk sintesis bahan bakar: proton &
elektron (untuk bio-H2), gula & pati (untuk bio-etanol), minyak (untuk biodiesel) dan biomassa (untuk BTL & bio-metana).
Consequently, any increase in photosynthetic efficiency will enhance the
competitiveness of bio-fuel production in general.
In higher plants and green algae, light is captured by specialised Light
Harvesting Complex proteins, referred to here as LHCI and LHCII, which confer
the ability to adapt to changing light levels. The excitation energy is then
funnelled to the photosynthetic reaction centres of photosystem I (PSI) and
photosystem II (PSII). PSII uses this energy to drive the photosynthetic water
splitting reaction, which converts water into protons, electrons and oxygen.
The electrons are passed along the photosynthetic electron transport chain via
plastoquinone (PQ), cytochrome b6f (Cyt b6f), photosystem I (PSI), and
ferredoxin (Fd) and on to NADPH. Simultaneously, protons are released into
the thylakoid lumen by PSII and the PQ/PQH2 cycle.
This generates a proton gradient, which drives ATP production via ATP
synthase. The protons and electrons are recombined by ferredoxin-NADP+
oxidoreductase (FNR) to produce NADPH. NADPH and ATP are used in the
Calvin cycle and other biochemical pathways to produce the sugars, starch, oils
and other bio-molecules (which collectively form biomass) that are required to
produce bio-ethanol, bio-diesel, bio-methane- and BTL-based bio-fuels.
Alternatively in some photosynthetic micro-organisms like the green alga
Chlamydomonas reinhardtii the protons and electrons extracted from water
(or starch) can be fed to the hydrogenase (HydA) via the electron transport
chain to drive the direct production of bio-H2
http://solarbiofuels.org/consortium.php…… diunduh 8/3/2012
Algae is the third and latest generation biofuel and so it has an
integral role to play in the future of biofuels.
It earned that distinction by being environmentally friendly (biodegradable) and more
effective than the alternatives (30X more energy per acre as compared to Soybeans).
Third generation was preceded by second generation biofuels (attractiveness comes from
its use of non food material such as wheat stalks and wood) and first generation biofuels
(ethanol and biodiesel).
The ethanol used in first generation biofuels is produced through fermentation of sugars
extracted from plants (sugar extracting methods can be applied to almost any kind starchbased material). Drawback of first generation's bioethanol: gas powered vehicles can only
run on a mixture of at most 15% bioethanol. A biofuel is by definition renewable material
since the matter within it must be at least 80% renewable.
Algenol's Algae-to-Ethanol
Delivers 67% to 87%
Reduction in CO2
Michael Graham Richard
Technology / Clean
Technology
October 25, 2010
SUMBER:
http://www.treehugger.com
/clean-technology/algenolsalgae-to-ethanol-delivers67-to-87-reduction-inco2.html
http://grmike.blogspot.com/2011/08/biofuels-getting-heavy-investment-from.html……
diunduh 8/3/2012
THE BENEFITS OF MAKING ETHANOL FROM ALGAE
Algae have many important advantages over other oil-producing
crops, like corn, canola and soybeans. It can be grown in almost any
enclosed space and it multiplies rapidly and requires very few inputs
to flourish - mainly just sunlight, water and carbon dioxide. "Because
algae has a high surface-area-to-volume ratio, it can absorb nutrients
very quickly, and its small size is what makes it mighty." The EROI Energy Returned is much higher than Energy Invested or required to
produce algae ethanol.
http://www.odec.ca/projects/2008/adit8i2/benefit.html…… diunduh 17/3/2012
BIODIESEL FROM ALGAE
Problems with Biodiesel from Algae
1. Not enough CO2 in the atmosphere to produce enough
2. Temperature of water needs to be right on
3. Open ponds and algae become choked with invasive species
4. Very Expensive
Benefits of using algae
· In the right conditions, algae can double its volume overnight
· Unlike other biofuel products, algae can be harvested day after day
· Up to 50% of an alga’s body weight is made of oil = more fuel
· Algae is expected to produce 10,000 gallons per acre per year
· Algae can double its volume overnight
· Algae can grow in brackish water like the water that’s in the desert in the southwest
· Algae can be grown using land and water unsuitable for plant or food production, unlike
some other first- and second-generation biofuel feedstocks.
· Select species of algae produce bio-oils through the natural process of photosynthesis.
Growing algae consume carbon dioxide; this provides greenhouse gas mitigation benefits.
· Bio-oil produced by photosynthetic algae and the resultant biofuel will have molecular
structures that are similar to the petroleum and refined products we use today.
· Algae have the potential to yield greater volumes of biofuel per acre of production than
other biofuel sources. Algae could yield more than 2000 gallons of fuel per acre per year
of production. Approximate yields for other fuel sources are far lower:
- Palm — 650 gallons per acre per year
- Sugar cane — 450 gallons per acre per year
- Corn — 250 gallons per acre per year
- Soy — 50 gallons per acre per year
1.
2.
Algae used to produce biofuels are highly productive. As a result, large quantities of
algae can be grown quickly, and the process of testing different strains of algae for
their fuel-making potential can proceed more rapidly than for other crops with longer
life cycles.
If successful, bio-oils from photosynthetic algae could be used to manufacture a full
range of fuels including gasoline, diesel fuel and jet fuel that meet the same
specifications as today’s products.
https://reich-chemistry.wikispaces.com/Parry.Saulenas…… diunduh 15/3/2012
ALGAE FOR BIODIESEL AND ETHANOL
GreenFuel Technologies Corporation that is based in Cambridge, Massachusetts
is based upon cultivating and producing algae that can produce high numbers of
biodiesel and ethanol.
Not having enough CO2 in the atmosphere was going to be a problem for us to
face with Algae biofuel production but there is a solution. This solution could
also be a solution for preventing all the output of harmful stuff into the
atmosphere that is destroying the ozone. What would make algae production
cheaper and more efficient is putting it next to a big factory. These factories let
off CO2 and gases into the atmosphere. The CO2 let off from these factories
would sometimes go up and stay in the atmosphere and be harmful to the ozone
and our atmospheric protection. Being beneficial to the environment and
needing a lot of CO2, the factories could channel their output into the algae
plant. Having this is very efficient since it both gets factory discharge and
produces energy for us.
CO2 digunakan dalam memproduksi energi ini menyebabkan
outputnya menjadi lebih sedikit CO2 terutama dari pabrik-pabrik,
dibandingkan dnegan sumber energi terbarukan lainnya. Ganggang
tumbuh lebih cepat dengan semua CO2 yang berasal dari cerobong
pabrik. Produksi Ganggang ini dikatakan menyebabkan penurunan
jumlah CO2 atmosfir sebesar 40% , berarti lebih sedikit emisi oksidanitrous dari pabrik-pabrik.
https://reich-chemistry.wikispaces.com/Parry.Saulenas…… diunduh 15/3/2012
ALGAE
untuk BIODIESEL & ETHANOL
GreenFuel Technologies Corporation that is based in Cambridge,
Massachusetts is based upon cultivating and producing algae that
can produce high numbers of biodiesel and ethanol.
Bioalcohols
The main bioalcohol fuels used today are ethanol and to a lesser extent methanol.
Methanol is the simpler and less energy-rich fuel of the two. It is most commonly
produced by gasification of biomass into a hydro-carbon rich gas called “syngas”
from which methanol is then obtained. While the process itself is not costly nor
complicated, it is only suitable for large scale production due to the large quantities
of biomass needed. Methanol has approximately half the energy content of gasoline
while at the same time costing much, much less and producing about 20% less toxic
emissions.
Ethanol is more energy rich when compared to methanol although it is still slightly
less energy rich than gasoline itself. The most popular method of production of
ethanol is simple fermentation of sugar. Sugar can come from a number of crops
depending on the geographical location. Currently, the gasoline used in many
countries around the world contains up to 10% of ethanol to offset the price. Ethanol
is particularly popular in Brazil where many cars have a so called “Flex” engine which
can be run on pure ethanol or gasoline or a mixture of both.
(http://renewableenergyindex.com/renewable-energy-sources/biologicalenergy/types-of-biofuels)
https://reich-chemistry.wikispaces.com/Parry.Saulenas…… diunduh 15/3/2012
ALGAE untuk
BIODIESEL & ETHANOL
Five resources are required to turn algae into fuel: sunlight, brackish or salt
water, desert or other marginal land, carbon dioxide and algae. We have
plenty of all five and too much of one — carbon dioxide. But through
photosynthesis, we can take carbon dioxide pollution out of the atmosphere
and convert it into algae-based gasoline and fuel
Algae had a lot going for it as a potential source of biodiesel: When
exposed to sunlight, algae rapidly reproduce and photosynthesize,
converting carbon dioxide into sugar. The sugar is metabolized into lipids,
or oil. The oil is then mixed with alcohol, such as ethanol, to produce
biodiesel. Additionally, certain strains of algae naturally produce as much as
60 percent of their biomass as oil, while others are powerfully resistant to
extreme heat, salinity or acidity.
https://reich-chemistry.wikispaces.com/Parry.Saulenas…… diunduh 15/3/2012
Sumber: http://climatelab.org/Biofuels ...... diunduh 10/3/2012
BIO-ALCOHOLS
Ethanol is a volatile, flammable, and colorless alcohol derived from sugars and
starches in biomass such as sorghum, wheat, rice, or yard clippings; in the United
States it is typically made from corn. Ethanol can be combined with gasoline in
varying concentrations, usually to be used in gasoline engines. E10, which contains
10% ethanol and 90% unleaded gasoline, can be used in almost all conventional
gasoline engines and is covered under warranty by every major U.S. automobile
manufacturer. E85, or 85% ethanol, is considered an alternative fuel under the Energy
Policy Act of 1992. This blend can only be used in E85-capable flexible fuel vehicles
(FFVs), which are available in a variety of models from U.S. and foreign automakers.
Ethanol produces fewer emissions of CO2 and benzene than gasoline, but its
emissions and energy balance vary based on feedstock. According to the EPA cornbased ethanol generates about 30 percent more energy than the fossil fuel energy
used to produce it, and over its life cycle reduces petroleum use more than 90% over
gasoline.3 Still, other ethanol feedstocks may offer significant environmental benefits
over corn. For example the World Bank estimates that sugarcane biodiesel produced
in Brazil reduces gasoline emissions by about 90 percent, whereas US corn ethanol
lowers gas emissions by 10-30 percent.
Biobutanol can be produced from any type of biomass. It offers advantages over
ethanol as it has a higher energy density, can be blended with gas in any
concentration to be used in conventional gasoline engines, and can be transported
through existing pipeline infrastructure. While biobutanol has not been produced
successfully on a large scale the technology has received significant investment,
specifically through a joint venture being undertaken by the DuPont corporation and
British Petroleum (BP).
Cellulosic ethanol has the same chemical composition as first-generation ethanol but
is based from the cellulose and hemicelluloses in woody fibers. Cellulosic technology
has strong appeal since cellulose presents a ubiquitous and renewable resource, but it
is not yet in wide use.
Life Cycle of Medium to Large Scale, Agri-based Biofuels
Life cycle analysis (LCA) is a tool used to account for inputs and
outputs to complex systems. In essence, it is a budgeting process
that accounts for all inputs (raw materials and energy) and outputs
(products, waste materials, and environmental impacting
components such as CO2). Some effective models have been
developed for life cycle analysis, including these for biodiesel.
Biofuel Life Cycle Analysis accounts for inputs and outputs
associated with feedstock production through to biofuel end use.
Setting appropriate system boundaries can be challenging. U.S.
Dept. of Energy Biomass Program
http://www.extension.org/pages/26614/life-cycle-analysis-for-biofuels……
diunduh 17/3/2012
BIO OILS: BIODIESEL
Biodiesel is a cleaner-burning alternative to petroleum diesel that can be
produced from virtually any fat or vegetable oil. Through a chemical
process called transesterification, heavy glycerol molecules are swapped
with a lighter alcohol (most often methanol) under very high temperatures,
which lightens the fuel so that it runs through any ignition-compression
vehicle without modifications to the engine. Pure biodiesel (B100) can be
blended with petroleum diesel in any proportion.
In the United States biodiesel has traditionally been made from soybeans,
but animal fats and other agri-crops such as rapeseed, flax and canola have
become increasingly common. In countries across Central and South
America, Asia and Africa, biodiesel may also be produced from Jatropha oil
from the Jatropha Csucas tree.
Biodiesel tersedia secara luas di banyak negara Eropa dalam
bentuk B100, namun karena sebagian besar adalah mandat
negara , bahan ini paling banyak dijual di Amerika Serikat
sebagai B2 (2% biodiesel) atau B5 (5% biodiesel ).
Biodiesel harus mematuhi standar yang ketat (ASTM D7651)
agar dapat dijual untuk digunakan di jalan raya di Amerika
Serikat.
http://climatelab.org/Biofuels…… diunduh 8/3/2012
BIO OILS: VEGETABLE OIL
Straight vegetable oil, including "virgin" oils or recycled oils, can be
converted into biodiesel or used in diesel engines that have undergone a
conversion process. The conversion creates a second tank intended for
vegetable oil, while the first tank holds diesel or biodiesel fuel. The driver
starts the car drawing fuel from the first tank, then switches to the second
tank when the engine has heated and the oil has sufficiently thinned.
Algal biofuel can be derived from aquatic plants raised in open ponds or
incubating units. Algae produces vastly more oil per acre than traditional
feedstocks; the limiting factor is actually access to carbon dioxide. As a
result, current technologies face significant cost limitations. The DOE
estimates that algal biofuel produced with currently-available technology
would cost over $8 per gallon, while the price of soy biodiesel today hovers
around $4 per gallon.
It is generally agreed that biodiesel fuel offers a superior
emissions profile to standard petroleum diesel. According to the
National Renewable Energy Laboratory (NREL), a vehicle
powered by B20 reduces life-cycle petroleum consumption by
19%, carbon dioxide emissions by 16%, and further reduces
hydrocarbon emissions by 20%.
Higher blends mean even greater emissions reductions.
However there have been questions concerning biodiesel's
nitrogen oxide (NOx) emissions, with studies by EPA and
NREL showing both higher and lower NOx levels as compared to
diesel emissions.
http://climatelab.org/Biofuels…… diunduh 8/3/2012
BIOFUEL FROM SOLIDS AND GASES
Solid Biofuel refers to any type of solid biomass or other matter that can be
burned directly, such as wood, agricultural waste, energy crops and biochar.
Burning solids releases heat that can be harnessed for energy, as well as liquids
and solids that can be used as biofuel.
Biogas can be produced through the anaerobic digestion of biodegradable
materials such as biomass, manure or sewage. It consists mostly of methane
and carbon dioxide mixed with other trace gases, and can be used to generate
electricity or compressed for use as a transportation fuel. Biodigesters are
often viewed as ideal partners for farms that produce animal waste, as the
digester doubles as an energy source and sanitation device.
Syngas ("synthetic gas") is produced by heating
and compressing any material that contains
carbon, such as biomass or coal, and is comprised
of carbon monoxide, carbon dioxide and
hydrogen.
It can be made into transportation fuels such as
methane gas or synthetic diesel fuel, and the ash
that is generated as a sidestream can be used as
fertilizer.
http://climatelab.org/Biofuels…… diunduh 8/3/2012
ROUNDTABLE ON SUSTAINABLE BIOFUELS
The Roundtable on Sustainable Biofuels (RSB) was initiated in 2007 to create a
standard for biofuels production and processing that would ensure
environmental, social, and economic sustainability, while reducing the impact
of biofuels on global climate change. RSB principles and criteria are currently
being developed through a consultative, multi-stakeholder process, with public
comment periods following the ISEAL best practices.
A key provision in the RSB 2008 draft is:
Principle 3: Biofuels shall contribute to climate change mitigation by
significantly reducing GHG emissions as compared to fossil fuels. Standard
methods for measuring the life-cycle GHG impact of biofuels (Life Cycle
Analysis, LCA) will be developed under this principle to even the playing field
and remove any subjectivity from the process. (RSB 2009)
The RSB recognizes that GHG impacts of biofuels production exist both on the
farm, where producers control practices, and off the farm, where market
forces may compromise compliance with Principle 3. The current version of the
standard focuses on practices that a producer can actually control. Producers
are advised on strategies to minimize the risk of iLUC by:
1. Maximizing use of waste and residues as feedstocks; marginal, degraded or
previously cleared land; improvements to yields; and efficient crops;
2. International collaboration to prevent detrimental land use changes; and
3. Avoiding the use of land or crops that are likely to induce land conversions
resulting in emissions of stored carbon.
The RSB also attempts to deal with biological diversity, conservation and
expects to include a deforestation cut-off date in the final standard.
http://climatelab.org/Biofuels…… diunduh 8/3/2012
Bioresour Technol. 2011 Aug;102(16):7443-50. Epub 2011 May 23.
Effects of biodrying process on municipal solid waste
properties.
Tambone F, Scaglia B, Scotti S, Adani F.
ABSTRACT
In this paper, the effect of biodrying process on municipal solid waste
(MSW) properties was studied. The results obtained indicated that
after 14d, biodrying reduced the water content of waste, allowing the
production of biodried waste with a net heating value (NHV) of
16,779±2,074kJ kg(-1) wet weight, i.e. 41% higher than that of
untreated waste.
The low moisture content of the biodried material reduced,
also, the potential impacts of the waste, i.e. potential selfignition and potential odors production. Low waste impacts
suggest to landfill the biodried material obtaining energy via
biogas production by waste re-moistening, i.e. bioreactor.
Nevertheless, results of this work indicate that biodrying
process because of the partial degradation of the organic
fraction contained in the waste (losses of 290g kg(-1) VS),
reduced of about 28% the total producible biogas.
http://www.ncbi.nlm.nih.gov/pubmed/21664812 …… diunduh 11/3/2012
Chemosphere. 2011 Jun;84(3):289-95. Epub 2011 May 7.
PCDD/F enviromental impact from municipal solid waste biodrying plant.
Rada EC, Ragazzi M, Zardi D, Laiti L, Ferrari A.
The present work indentifies some environmental and health
impacts of a municipal solid waste bio-drying plant taking into
account the PCDD/F release into the atmosphere, its
concentration at ground level and its deposition. Four
scenarios are presented for the process air treatment and
management: biofilter or regenerative thermal oxidation
treatment, at two different heights.
A Gaussian dispersion model, AERMOD, was used in order to
model the dispersion and deposition of the PCDD/F emissions
into the atmosphere. Considerations on health risk, from
different exposure pathways are presented using an original
approach. The case of biofilter at ground level resulted the
most critical, depending on the low dispersion of the
pollutants. Suggestions on technical solutions for the
optimization of the impact are presented.
http://www.ncbi.nlm.nih.gov/pubmed/21550632 …… diunduh 11/3/2012
Biostabilization–biodrying of municipal solid waste by inverting
air-flow
Mara Sugni, Enrico Calcaterra, Fabrizio Adani.
Bioresource Technology
Volume 96, Issue 12, August 2005, Pages 1331–1337
ABSTRACT
The process of biodrying could be a good solution for municipal solid waste
management, allowing the production of fuel with an interesting energy
content. Previous work (Adani, F., Baido, D., Calcaterra, E., Genevini, P.L., 2002.
The influence of biomass temperature on biostabilization–biodrying of
municipal solid waste. Bioresource Technology 83 (3), 173–179) has indicated
that appropriate management of the processing parameters (air-flow rate and
biomass temperatures) could achieve biomass drying in very short times (8–
9 days). However, the data of that work also evidenced that if the conditions
do not consider pile turning, and the air-flow is always from one direction,
temperature gradients arise within the biomass, resulting in a lack of
homogeneity in the moisture and energy content of the final product.
Therefore, a new laboratory study was conducted on municipal solid waste
biodrying–biostabilization in an effort to obtain homogeneous final products.
Our proposal to solve this lack of homogeneity is to periodically invert the airflow direction. Thus, in line with a previous study, two trials, A and B, were
carried out, dividing the biomass into three layers to study temperature and
moisture gradients throughout the process, and a third trial (C) simulating airflow inversion at regular intervals was introduced.
The results suggest that the daily inversion of air-flow eliminates marked
temperature differences and leads to a homogeneous final product.
http://www.sciencedirect.com/science/article/pii/S0960852404004109 …… diunduh
11/3/2012
Drying Technology: An International Journal . Vol 28, Issue 10, 2010
BIODRYING OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTES
Agnieszka Zawadzka, Liliana Krzystek, Paweł Stolarek & Stanislaw
Ledakowicz. pages 1220-1226
ABSTRACT
The effect of air flow rate on the change of biomass (organic waste material)
temperature and moisture content during an autothermal drying process is
discussed. The laboratory-scale experiments were performed using a 240dm3 horizontal composting reactor equipped with an air supply system,
biomass temperature measuring system, and air humidity and temperature
sensors. An organic fraction of municipal solid waste with the addition of a
structural material was used as a substrate in this process.
As a result of the autothermal biodrying process, the initial moisture
content of organic waste ranging from 0.8 to 0.9 kgH2O/kg of raw waste mass
decreased by 50%. Water balances were calculated before and after
biodrying, and the difference was less than 10%. The heat of combustion
and the calorific value of dried wastes ranged respectively from 6,750 to
12,280 kJ/kg and from 8,050 to 10,980 kJ/kg.
The biodrying efficiency varied from 0.73 to 0.97, depending on process
conditions. Energy balances showed that average biological energy
production rates varied between 1.66 and 6.90 W/kg of raw waste mass.
http://www.tandfonline.com/doi/abs/10.1080/07373937.2010.483034
Effect of air-flow rate and turning frequency on bio-drying of
dewatered sludge
Ling Zhao, Wei-Mei Gu, Pin-Jing He, , Li-Ming Shao
Water Research. Vol. 44, Issue 20, December 2010, Pages 6144–6152
Sludge bio-drying is an approach for biomass energy utilization, in
which sludge is dried by means of the heat generated by aerobic
degradation of its organic substances. The study aimed at
investigating the interactive influence of air-flow rate and turning
frequency on water removal and biomass energy utilization. Results
showed that a higher air-flow rate (0.0909 m3 h−1 kg−1) led to lower
temperature than did the lower one (0.0455 m3 h−1 kg−1) by 17.0%
and 13.7% under turning per two days and four days. With the higher
air-flow rate and lower turning frequency, temperature cumulation
was almost similar to that with the lower air-flow rate and higher
turning frequency. The doubled air-flow rate improved the total water
removal ratio by 2.86% (19.5 g kg−1 initial water) and 11.5%
(75.0 g kg−1 initial water) with turning per two days and four days
respectively, indicating that there was no remarkable advantage for
water removal with high air-flow rate, especially with high turning
frequency. The heat used for evaporation was 60.6–72.6% of the total
heat consumption (34,400–45,400 kJ). The higher air-flow rate
enhanced volatile solids (VS) degradation thus improving heat
generation by 1.95% (800 kJ) and 8.96% (3200 kJ) with turning per
two days and four days. With the higher air-flow rate, heat consumed
by sensible heat of inlet air and heat utilization efficiency for
evaporation was higher than the lower one. With the higher turning
frequency, sensible heat of materials and heat consumed by turning
was higher than lower one.
http://www.sciencedirect.com/science/article/pii/S0043135410004707…… diunduh
11/3/2012
Drying Technology: An International Journal . Vol. 24, Issue 7, 2006.
Emerging Biodrying Technology for the Drying of Pulp and Paper
Mixed Sludges.
Shahram Navaee-Ardeh, François Bertrand & Paul R. Stuart. pages 863-878.
ABSTRACT
Effective sludge management is increasingly critical for pulp and paper mills
due to high landfill costs and complex regulatory frameworks for options such
as sludge landspreading and composting. Sludge dewatering challenges are
exacerbated at many mills due to improved in-plant fiber recovery coupled
with increased production of secondary sludge, leading to a mixed sludge with
a high proportion of biological matter that is difficult to dewater. Various
drying technologies have emerged to address this challenge of sludge
management, whose objective is to increase the dryness of mixed sludge to
above critical levels (≈42% dryness) for efficient and economic combustion in
the boiler for steam generation. The advantages and disadvantages of these
technologies are reviewed in this article, and it is found that many have
significant technical uncertainties and/or questionable economics. A biodrying
process, enhanced by biological heat generation under forced aeration, is
introduced that has significant promise. A techno-economic analysis of the
batch biodrying process at a case study mill showed an annual operating cost
savings of about $2 million, including the elimination of landfilling practices
and supplemental fuel requirements in the boiler. It was shown that if a
biodrying residence time of less than 4 days can be achieved, payback periods
of 2 years or less can result in many mills.
The potential for the development of a continuous biodrying reactor and the
fundamentals of its mathematical modeling are thus presented. Compared to
the batch reactor configuration, it is expected that the continuous process
would result in improved process flexibility and controllability, lower
investment and operating costs due to shorter residence times, and an
improved potential to fit into the crowed pulp and paper mill site.
http://www.tandfonline.com/doi/abs/10.1080/07373930600734026…… diunduh
11/3/2012
Influence of turning and air-flow temperature on
aerobic bio-drying of MSW .
Dandan Huang; Wenxiong Huang; Ran Yin; Zhiyun Qu; Song Yuan
Electrical and Control Engineering (ICECE), 2011 International
Conference on 16-18 Sept. 2011 . page(s): 5978 - 5982
Taking high moisture-content MSW collected in a
mixing way as object, influences of turning and airflow temperature on bio-drying process were
studied using a self-designed experimental
equipment.
The results showed that turning could
further improve bio-drying effect
better with intermittent ventilation.
When the air-flow temperature is 40°C,
the moisture-content of materials
could be decreased from 61.6% to
23.7%, after 18d of bio-drying process.
And the heat value advanced 198.2%.
http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=6058147…… diunduh 11/3/2012
Journal of Environmental Sciences 2010, 22(5) 752–759
Release of volatile organic compounds during bio-drying of
municipal solid waste
Pinjing He, Jiafu Tang, Dongqing Zhang, Yang Zeng, Liming Shao
ABSTRACT
Three treatments were tested to investigate the release concentrations of
volatile organic compounds (VOCs) during the bio-drying of municipal solid
waste (MSW) by the aerobic and combined hydrolytic-aerobic processes.
Results showed that VOCs were largely released in the first 4 days of bio-drying
and the dominant components were: dimethyl disulfide, dimethyl sulfide,
benzene, 2-butanone, limonene and methylene chloride. Thus, the combined
hydrolytic-aerobic process was suggested for MSW bio-drying due to fewer
aeration quantities in this phase when compared with the aerobic process, and
the treatment strategies should base on the key properties of these prominent
components. Malodorous sulfur compounds and terpenes were mainly
released in the early phase of bio-drying, whereas, two peaks of release
concentrations appeared for aromatics and ketones during bio-drying. Notably,
for the combined hydrolytic-aerobic processes there were also high
concentrations of released aromatics in the shift from hydrolytic to aerobic
stages.
High concentrations of released chlorinateds were observed in the later phase.
For the VOCs produced during MSW bio-drying, i.e., malodorous sulfur
compounds, terpenes and chlorinateds, their release concentrations were
mainly determined by production rates; for the VOCs presented initially in
MSW, such as aromatics, their transfer and transport in MSW mainly
determined the release concentrations.
www.jesc.ac.cn/jesc_cn/ch/reader/create_pdf.aspx?file_no...…… diunduh
11/3/2012
AUTOTHERMAL BIODRYING OF MUNICIPAL SOLID WASTE WITH HIGH
MOISTURE CONTENT
Agnieszka Zawadzka, Liliana Krzystek;Stanisław Ledakowicz.
2010. Chemical Papers. Vol. 64, No.2. p. 265-268
ABSTRACT
To carry out autothermal drying processes during the composting of
biomass, a horizontal tubular reactor was designed and tested. A biodrying
tunnel of the total capacity of 240 dm3 was made of plastic material and
insulated with polyurethane foam to prevent heat losses. Municipal solid
waste and structural plant material were used as the input substrate.
As a result of autothermal drying processes, moisture content decreased
by 50 % of the initial moisture content of organic waste of about 800 g
kg−1. In the tested cycles, high temperatures of biodried waste mass were
achieved (54–56°C). An appropriate quantity of air was supplied to
maintain a satisfactory level of temperature and moisture removal in the
biodried mass and high energy content in the final product.
The heat of combustion of dried waste and its calorific value were
determined in a calorimeter. Examinations of pyrolysis and gasification of
dried waste confirmed their usefulness as biofuel of satisfactory energy
content.
Pyrolysis is a thermochemical decomposition of organic material at elevated
temperatures without the participation of oxygen. It involves the simultaneous
change of chemical composition and physical phase, and is irreversible. The word
is coined from the Greek-derived elements pyr "fire" and lysis "separating".
Pyrolysis is a case of thermolysis, and is most commonly used for organic
materials, being, therefore, one of the processes involved in charring. The pyrolysis
of wood, which starts at 200–300 °C (390–570 °F), occurs for example in fires
where solid fuels are burning or when vegetation comes into contact with lava in
volcanic eruptions. In general, pyrolysis of organic substances produces gas and
liquid products and leaves a solid residue richer in carbon content, char. Extreme
pyrolysis, which leaves mostly carbon as the residue, is called carbonization.
(http://en.wikipedia.org/wiki/Pyrolysis)
http://lw20.com/201109172717046.html…… diunduh 11/3/2012
Wikipedia, the free encyclopedia
ABSTRACT
Biodrying is the process by which biodegradable waste is rapidly heated
through initial stages of composting to remove moisture from a waste stream
and hence reduce its overall weight. In biodrying processes, the drying rates
are augmented by biological heat in addition to forced aeration. The major
portion of biological heat, naturally available through the aerobic degradation
of organic matter, is utilized to evaporate surface and bound water associated
with the mixed sludge. This heat generation assists in reducing the moisture
content of the biomass without the need for supplementary fossil fuels, and
with minimal electricity consumption. It can take as little as 8 days to dry waste
in this manner. This enables reduced costs of disposal if landfill is charged on a
cost per tonne basis.
Biodrying may be used as part of the production process for
refuse-derived fuels.
Biodrying does not however greatly affect the biodegradability
of the waste and hence is not stabilised. Biodried waste will still
break down in a landfill to produce landfill gas and hence
potentially contribute to climate change.
In the UK this waste will still imact upon councils LATS
allowances. Whilst biodrying is increasingly applied within
commercial mechanical biological treatment (MBT) plants, it is
also still subject to on-going research and development.
Journal of Environmental Sciences 20(2008) 1534–1540
BIODRYING OF MUNICIPAL SOLID WASTE WITH HIGH WATER
CONTENT BY COMBINED HYDROLYTIC-AEROBIC TECHNOLOGY
ZHANG Dongqing, HE Pinjing, SHAO Liming, JIN Taifeng, HAN Jingyao
The high water content of municipal solid waste (MSW) will reduce
the efficiency of mechanical sorting, consequently unfavorable for
beneficial utilization. In this study, a combined hydrolytic-aerobic
biodrying technology was introduced to remove water from MSW.
The total water removals were proved to depend on the ventilation
frequency and the temporal span in the hydrolytic stage.
The ventilation frequency of 6 times/d was preferable in the
hydrolytic stage. The hydrolytic span should not be prolonged more
than 4 d. At this optimal scenario, the final water content was 50.5%
reduced from the initial water content of 72.0%, presenting a high
water removal efficiency up to 78.5%.
A positive correlation was observed between the
organics losses and the water losses in both
hydrolytic and aerobic stages (R = 0.944, p < 0.01).
The evolutions of extracellular enzyme activities
were shown to be consistent with the organics
losses.
Drying Technology: An International Journal
Volume 28, Issue 10, 2010
Biodrying of Organic Fraction of Municipal Solid Wastes.
Agnieszka Zawadzka, Liliana Krzystek, Paweł Stolarek & Stanislaw Ledakowicz. p.
1220-1226
ABSTRACT
The effect of air flow rate on the change of biomass (organic waste
material) temperature and moisture content during an autothermal
drying process is discussed. The laboratory-scale experiments were
performed using a 240-dm3 horizontal composting reactor equipped
with an air supply system, biomass temperature measuring system,
and air humidity and temperature sensors. An organic fraction of
municipal solid waste with the addition of a structural material was
used as a substrate in this process.
As a result of the autothermal biodrying process, the initial moisture
content of organic waste ranging from 0.8 to 0.9 kgH2O/kg of raw
waste mass decreased by 50%. Water balances were calculated before
and after biodrying, and the difference was less than 10%. The heat of
combustion and the calorific value of dried wastes ranged
respectively from 6,750 to 12,280 kJ/kg and from 8,050 to
10,980 kJ/kg.
The biodrying efficiency varied from 0.73 to 0.97, depending on
process conditions. Energy balances showed that average biological
energy production rates varied between 1.66 and 6.90 W/kg of raw
waste mass.
http://www.tandfonline.com/doi/abs/10.1080/07373937.2010.483034……
diunduh 11/3/2012
Composting Strategies for High Moisture Manures
Tom L. Richard, Ph.D. (Department of Agricultural and Biosystems Engineering,
Iowa State University )
One of the significant challenges to composting high moisture materials like manure is
supplying adequate bulking material to provide porosity for oxygen transport through the
pile. This added material, such as cornstalks, sawdust, or straw, often cost significant money
or time to acquire, and can increase the volume requiring processing by several times, thus
increasing materials handling and application costs.
Recently several strategies have been developed which take advantage of the biological
drying that naturally occurs during thermophilic composting to reduce bulking amendment
requirements dramatically.
The composting process
The composting process involves four main components: organic matter, moisture, oxygen, and
bacteria.
Organic matter includes plant materials and some animal manures. Organic materials used for
compost should include a mixture of brown organic material (dead leaves, twigs, manure) and green
organic material (lawn clippings, fruit rinds, etc.). Brown materials supply carbon, while green
materials supply nitrogen. The best ratio is 1 part green to 1 part brown material. Shredding,
chopping or mowing these materials into smaller pieces will help speed the composting process by
increasing the surface area.
For piles that have mostly brown material (dead leaves), try adding a handful of commercial 10-10-10
fertilizer to supply nitrogen and speed the compost process.
Moisture is important to support the composting process. Compost should be comparable to the
wetness of a wrung-out sponge. If the pile is too dry, materials will decompose very slowly. Add water
during dry periods or when adding large amounts of brown organic material. If the pile is too wet,
turn the pile and mix the materials. Another option is to add dry, brown organic materials.
Oxygen is needed to support the breakdown of plant material by bacteria. To supply oxygen, you will
need to turn the compost pile so that materials at the edges are brought to the center of the pile.
Turning the pile is important for complete composting and for controlling odor.
Wait at least two weeks before turning the pile, to allow the center of the pile to "heat up" and
decompose. Once the pile has cooled in the center, decomposition of the materials has taken place.
Frequent turning will help speed the composting process.
Bacteria and other microorganisms are the real workers in the compost process. By supplying organic
materials, water, and oxygen, the already present bacteria will break down the plant material into
useful compost for the garden. As the bacteria decompose the materials, they release heat, which is
concentrated in the center of the pile.
In addition to bacteria, larger organisms including insects and earthworms are active composters.
These organisms break down large materials in the compost pile.
(http://urbanext.illinois.edu/compost/process.cfm)
http://infohouse.p2ric.org/ref/21/20974.htm …… diunduh 17/3/2012
Composting Strategies for High Moisture Manures
Tom L. Richard, Ph.D. (Department of Agricultural and Biosystems Engineering,
Iowa State University )
Composting as traditionally practiced achieves a moderate level of
drying, with manure usually blended with bulking materials to an initial
moisture content of 65% (wet basis), and the subsequent heating,
evaporation, and air movement reducing the moisture content to 45%
or less over a period of weeks or months.
This process is quite simple in its essence: manure (and amendments)
contain energy, aerobic decomposing microorganisms are only about
60% efficient at converting that energy to cell synthesis or metabolic
work, and the remaining 40% is transformed to "waste" heat.
Air moving through the compost pile (either by forced ventilation or
passive convection and diffusion) gets hot and evaporates water from
the surfaces of particles.
How long does it take?
The amount of time needed to produce compost depends on
several factors, including the size of the compost pile, the types of
materials, the surface area of the materials, and the number of
times the pile is turned.
For most efficient composting, use a pile that is between 3 feet
cubed and 5 feet cubed (27-125 cu. ft.). This allows the center of
the pile to heat up sufficiently to break down materials.
(http://urbanext.illinois.edu/compost/process.cfm)
http://infohouse.p2ric.org/ref/21/20974.htm …… diunduh 17/3/2012
Composting Strategies for High Moisture Manures
Tom L. Richard, Ph.D. (Department of Agricultural and Biosystems Engineering,
Iowa State University )
There are two aspects to reconfiguring the traditional composting
process for high-moisture manures. First, the linkage between
microbial heat generation and evaporation must be explicitly
recognized and optimized.
A detailed discussion of this optimization problem has been
presented elsewhere (Richard and Choi, 1996), but will be briefly
reviewed here. Second, and perhaps more revolutionary, is a change
in the materials handling system. Almost all composting is operated as
a batch process, where materials are mixed together initially and then
proceed through the process as a "batch". The suggested alternative,
which can be considered as a sequencing batch or semi-continuous
process, starts out as a batch but then get repeated sequential
additions of more high-moisture manure.
Richard, T.L., and H.-L. Choi. 1996. Optimizing the
composting process for moisture removal:
theoretical analysis and experimental results. ASAE
Paper No. 964014. Presented at the ASAE 1996
International Meeting in Phoenix, AZ. ASAE, St.
Joseph, MI.
http://infohouse.p2ric.org/ref/21/20974.htm …… diunduh 17/3/2012
Composting Strategies for High Moisture Manures
Tom L. Richard, Ph.D. (Department of Agricultural and Biosystems Engineering,
Iowa State University )
Theoretical Analysis and Optimization
Biodrying of a composting material results from the interaction of physical and
biological processes. The physical processes include airflow rate, vapor transfer
rates from the substrate to the airstream, inlet and outlet conditions of
temperature and relative humidity, and the reactor configuration as it affects
the balance between conductive and convective energy losses.
The biological process of principal importance is the degradation rate, which
releases energy and is itself a function of temperature as well as moisture and
oxygen concentration. For the purposes of this analysis we assume moisture
and oxygen concentration are not limiting, since by definition we are starting
with a high moisture mixture and utilizing high airflow rates to remove heat.
Effective heat removal typically requires approximately an order of magnitude
more airflow than is needed to satisfy aerobic reaction stoichiometry (Finstein
et al., 1986).
Finstein, M.S., F.C. Miller and P.F. Strom. 1986. Waste
treatment composting as a controlled system. pp. 363398. In: Biotechnology: a comprehensive treatis in 8 vol. ,
H.-J. Rehm and G. Reed (eds.), Vol. 8. Microbial
degradations, W. Schönborn (vol. ed.). VCH
Verlagsgesellschaft (German Chemical Society),
Weinheim, FRG.
http://infohouse.p2ric.org/ref/21/20974.htm …… diunduh 17/3/2012
Composting Strategies for High Moisture Manures
Tom L. Richard, Ph.D. (Department of Agricultural and Biosystems Engineering,
Iowa State University )
The removal of water from a composting reactor can be
accurately predicted through psychrometric analysis if the
inlet and outlet temperatures and relative humidities as well
as the airflow rate are known.
The details of the psychrometric equations and their use
have been presented elsewhere (Albright, 1990).
Albright, L.D. 1990. Environment Control for
Animals and Plants. ASAE Textbook No. 4. ASAE, St.
Joseph, MI. 453 pp.
What is compost?
Compost is decomposed organic material. Compost is made with material
such as leaves, shredded twigs, and kitchen scraps from plants.
To gardeners, compost is considered "black gold" because of its many
benefits in the garden. Compost is a great material for garden soil. Adding
compost to clay soils makes them easier to work and plant. In sandy soils,
the addition of compost improves the water holding capacity of the soil.
By adding organic matter to the soil, compost can help improve plant
growth and health.
(http://urbanext.illinois.edu/compost/process.cfm)
http://infohouse.p2ric.org/ref/21/20974.htm …… diunduh 17/3/2012
Composting Strategies for High Moisture Manures
Tom L. Richard, Ph.D. (Department of Agricultural and Biosystems Engineering,
Iowa State University )
Meskipun pemodelan aspek fisik penguapan air relatif mudah,
aspek biologinya jauh lebih kompleks. Beberapa peneliti telah
mengembangkan model yang menggambarkan efek suhu pada
kinetika degradasi, dengan hasil yang bervariasi (Richard and Choi,
1996).
Dalam contoh ini, secara teoritis laju biodrying akan digambarkan
dengan menggunakan model Andrews dan Kambhu (1973), yang
menggunakan persamaan yang mirip dengan bentuk klasik
Arrhenius yang digunakan dalam teknik kimia dan biokimia.
Using their parameters, the model has a temperature optimum at
57°C, decreasing to near zero at 68°C, which roughly corresponds
to the results of several experimental studies.
http://infohouse.p2ric.org/ref/21/20974.htm …… diunduh 17/3/2012
where
Composting Strategies for High Moisture Manures
Tom L. Richard, Ph.D. (Department of Agricultural and Biosystems Engineering,
Iowa State University )
Given the relationships between temperature, moisture removal and
decomposition rate, the optimization problem requires us to look for the
temperature at or above the peak in the temperature kinetic function where
the change in moisture removal rate with temperature is zero.
This can be expressed:
Where
Untuk kondisi inflow udara yang konstan, dan dengan
asumsi tidak ada perubahan suhu substrat di dalam
timbunan, hal ini dapat mengurangi masalah steady
state. Masalah ini dapat dipecahkan dengan
menetapkan generasi panas (ditentukan dengan
hubungan kinetika dan stoikiometri) sama dengan
pembuangan panas (ditentukan oleh hubungan
psychrometric) untuk menentukan suhu optimum
penguapan air.
http://infohouse.p2ric.org/ref/21/20974.htm …… diunduh 17/3/2012
Composting Strategies for High Moisture Manures
Tom L. Richard, Ph.D. (Department of Agricultural and Biosystems Engineering,
Iowa State University )
The figure plots the calculated rate of moisture removal at five different
maximum decomposition rates (kmax), which span the range of most manure
composting mixtures. At the highest decomposition rate, the model predicts
moisture removal rates of over 1 kg H2O per kg volatile solids (VS) per day.
For comparison with units more typically presented in experimental results, if
we assume VS = total solids (TS), a moisture removal rate of 1 kg H2O per kg VS
per day is equivalent to a reduction from 70% moisture to 57% moisture in 24
hours, while a moisture removal rate of 1.5 kg H2O per kg VS per day is
equivalent to a reduction from 70% moisture to 45% moisture in 24 hours.
Effect of maximum degradation rate on moisture removal rate, using the
model of Andrews and Kambhu (1973).
http://infohouse.p2ric.org/ref/21/20974.htm …… diunduh 17/3/2012
Composting Strategies for High Moisture Manures
Tom L. Richard, Ph.D. (Department of Agricultural and Biosystems Engineering,
Iowa State University )
Biodrying of high moisture organic residuals is a natural
corollary to the composting process. Systems designed for
the sequential addition of wet organic materials can
significantly reduce bulking amendment requirements while
simultaneously achieving high decomposition rates.
This mode of operation can alternatively be viewed as a
sequential batch reactor, recycling the bulking amendment
for multiple batches of compost, with a very high proportion
of recycled compost in each mix.
This high rate of recycle can reduce or eliminate the lag time
associated with composting system startup, further
increasing decomposition and moisture removal rates.
http://infohouse.p2ric.org/ref/21/20974.htm …… diunduh 17/3/2012
Water Res. 2010 Dec;44(20):6144-52. Epub 2010 Jul 13.
Effect of air-flow rate and turning frequency on bio-drying of
dewatered sludge.
Zhao L, Gu WM, He PJ, Shao LM.
ABSTRACT
Sludge bio-drying is an approach for biomass energy utilization, in which
sludge is dried by means of the heat generated by aerobic degradation of
its organic substances. The study aimed at investigating the interactive
influence of air-flow rate and turning frequency on water removal and
biomass energy utilization.
Results showed that a higher air-flow rate (0.0909m(3)h(-1)kg(-1)) led to
lower temperature than did the lower one (0.0455m(3)h(-1)kg(-1)) by
17.0% and 13.7% under turning per two days and four days. With the
higher air-flow rate and lower turning frequency, temperature
cumulation was almost similar to that with the lower air-flow rate and
higher turning frequency. The doubled air-flow rate improved the total
water removal ratio by 2.86% (19.5gkg(-1) initial water) and 11.5%
(75.0gkg(-1) initial water) with turning per two days and four days
respectively, indicating that there was no remarkable advantage for water
removal with high air-flow rate, especially with high turning frequency.
The heat used for evaporation was 60.6-72.6% of the total heat
consumption (34,400-45,400kJ).
The higher air-flow rate enhanced volatile solids (VS) degradation thus
improving heat generation by 1.95% (800kJ) and 8.96% (3200kJ) with
turning per two days and four days. With the higher air-flow rate, heat
consumed by sensible heat of inlet air and heat utilization efficiency for
evaporation was higher than the lower one. With the higher turning
frequency, sensible heat of materials and heat consumed by turning was
higher than lower one.
http://www.ncbi.nlm.nih.gov/pubmed/20673952 …… diunduh 17/3/2012
Bioresour Technol. 2008 Dec;99(18):8796-802. Epub 2008 Jun 3.
Bio-drying of municipal solid waste with high water content by
aeration procedures regulation and inoculation.
Zhang DQ, He PJ, Jin TF, Shao LM.
ABSTRACT
To improve the water content reduction of municipal solid waste with
high water content, the operations of supplementing a hydrolytic
stage prior to aerobic degradation and inoculating the bio-drying
products were conducted. A 'bio-drying index' was used to evaluate
the bio-drying performance. For the aerobic processes, the inoculation
accelerated organics degradation, enhanced the lignocelluloses
degradation rate by 10.4%, and lowered water content by 7.0%.
For the combined hydrolytic-aerobic processes, the inoculum addition
had almost no positive effect on the bio-drying efficiency, but it
enhanced the lignocelluloses degradation rate by 9.6% and
strengthened the acidogenesis in the hydrolytic stage.
Compared with the aerobic processes, the combined processes had a
higher bio-drying index (4.20 for non-inoculated and 3.67 for the
inoculated trials). Moreover, the lowest final water content occurred
in the combined process without inoculation (50.5% decreased from
an initial 72.0%).
http://www.ncbi.nlm.nih.gov/pubmed/18511273 …… diunduh 17/3/2012
Bioresour Technol. 2009 Feb;100(3):1087-93. Epub 2008 Oct 1.
Effect of inoculation time on the bio-drying performance of combined
hydrolytic-aerobic process.
Zhang DQ, He PJ, Yu LZ, Shao LM.
ABSTRACT
The study aimed at investigating the effects of inoculation time on
the bio-drying performance of combined hydrolytic-aerobic
process. Results showed that the addition of inoculating material
at different time exhibited various effects not only on the
degradation rate of total organics, but also on the performance of
water removal and water content reduction. The beginning of
aerobic stage (day 5) was suggested to be the optimal time for
inoculation. Under this operational condition, 815 g/kg-W(0)
(W(0)=initial water content) was removed and the water content
reduced from the initial 72.0% to 48.5%. Adding inoculating
material at the start of hydrolytic stage (day 0) reduced water
removal and water content reduction rates.
The addition of inoculating material at day 7 or 9 could not
improve the bio-drying performance significantly. Additionally,
the inoculation at days 0, 5, 7 and 9 enhanced lignocelluloses
degradation rate by 3.8%, 11.6%, 7.9% and 7.7%, respectively.
http://www.ncbi.nlm.nih.gov/pubmed/18835776 …… diunduh 17/3/2012
Water Res. 2011 Mar;45(6):2322-30. Epub 2011 Jan 22.
Biodegradation potential of bulking agents used in sludge bio-drying
and their contribution to bio-generated heat.
Zhao L, Gu WM, He PJ, Shao LM.
ABSTRACT
Straw and sawdust are commonly used bulking agents in sludge composting or
bio-drying. It is important to determine if they contribute to the biodegradable
volatile solids pool. A sludge bio-drying process was performed in this study using
straw, sawdust and their combination as the bulking agents.
The results revealed that straw has substantial biodegradation potential in the
aerobic process and sawdust has poor capacity to be degraded. The temperature
profile and bio-drying efficiency were highest in the trial that straw was added, as
indicated by a moisture removal ratio and VS loss ratio of 62.3 and 31.0%,
respectively. In separate aerobic incubation tests, straw obtained the highest
oxygen uptake rate (OUR) of 2.14 and 4.75 mg O(2) g(-1)VS h(-1) at 35 °C and 50
°C, respectively, while the highest OUR values of sludge were 12.1 and 5.68 mg
O(2) g(-1)VS h(-1) at 35 °C and 50 °C and those of sawdust were 0.286 and 0.332
mg O(2) g(-1)VS h(-1), respectively.
The distribution of biochemical fractions revealed that soluble fractions in hot
water and hot neutral detergent were the main substrates directly attacked by
microorganisms, which accounted for the initial OUR peak. The cellulose-like
fraction in straw was transformed to soluble fractions, resulting in an increased
duration of aerobic respiration. Based on the potential VS degradation rate, no
bio-generated heat was contributed by sawdust, while that contribution by straw
was about 41.7% and the ratio of sludge/straw was 5:1 (w/w, wet basis).
http://www.ncbi.nlm.nih.gov/pubmed/21306753 …… diunduh 17/3/2012
Bioresour Technol. 2002 Jul;83(3):173-9.
The influence of biomass temperature on biostabilization-biodrying of
municipal solid waste.
Adani F, Baido D, Calcaterra E, Genevini P.
Abstract
A laboratory study was carried out to obtain data on the influence of
biomass temperature on biostabilization-biodrying of municipal solid waste
(initial moisture content of 410 g kg wet weight (w.w.)(-1)). Three trials were
carried out at three different biomass temperatures, obtained by airflow
rate control (A = 70 degrees C, B = 60 degrees C and C = 45 degrees C).
Biodegradation and biodrying were inversely correlated: fast biodrying
produced low biological stability and vice versa. The product obtained from
process A was characterized by the highest degradation coefficient (166 g kg
TS0(-1); TS0(-1) = initial total solid content) and lowest water loss (409 g kg
W0(-1); W0 = initial water content). Due to the high reduction of easily
degradable volatile solid content and preservation of water, process A
produced the highest biological stability (dynamic respiration index, DRI =
141 mg O2 kg VS(-1); VS = volatile solids) but the lowest energy content (EC
= 10,351 kJ kg w.w.(-1)). Conversely, process C which showed the highest
water elimination (667 g kg W0(-1)), and lowest degradation rate (18 g kg
TS0(-1)) was optimal for refuse-derived fuel (RDF) production having the
highest energy content (EC = 14,056 kJ kg w.w.(-1)). Nevertheless, the low
biological stability reached, due to preservation of degradable volatile
solids, at the end of the process (DRI = 1055 mg O2 kg VS(-1)), indicated that
the RDF should be used immediately, without storage.
Trial B showed substantial agreement between low moisture content (losses
of 665 g kg W0(-1)), high energy content (EC = 13,558 kJ kg w.w.(-1)) and
good biological stability (DRI = 166 mg O2 kg VS(-1)), so that, in this case,
the product could be used immediately for RDF or stored with minimum
pollutant impact (odors, leaches and biogas production).
http://www.ncbi.nlm.nih.gov/pubmed/12094790 …… diunduh 17/3/2012
Bioresour Technol. 2005 Aug;96(12):1331-7. Epub 2005 Jan 20.
Biostabilization-biodrying of municipal solid waste by inverting airflow.
Sugni M, Calcaterra E, Adani F.
ABSTRACT
The process of biodrying could be a good solution for municipal solid
waste management, allowing the production of fuel with an interesting
energy content. Previous work (Adani, F., Baido, D., Calcaterra, E.,
Genevini, P.L., 2002. The influence of biomass temperature on
biostabilization-biodrying of municipal solid waste. Bioresource
Technology 83 (3), 173-179) has indicated that appropriate management
of the processing parameters (air-flow rate and biomass temperatures)
could achieve biomass drying in very short times (8-9 days). However, the
data of that work also evidenced that if the conditions do not consider
pile turning, and the air-flow is always from one direction, temperature
gradients arise within the biomass, resulting in a lack of homogeneity in
the moisture and energy content of the final product.
Therefore, a new laboratory study was conducted on municipal solid
waste biodrying-biostabilization in an effort to obtain homogeneous final
products. Our proposal to solve this lack of homogeneity is to periodically
invert the air-flow direction. Thus, in line with a previous study, two trials,
A and B, were carried out, dividing the biomass into three layers to study
temperature and moisture gradients throughout the process, and a third
trial (C) simulating air-flow inversion at regular intervals was introduced.
The results suggest that the daily inversion of air-flow eliminates marked
temperature differences and leads to a homogeneous final product.
http://www.ncbi.nlm.nih.gov/pubmed/15792579 …… diunduh 17/3/2012
Bioresour Technol. 2009 Jun;100(11):2747-61. Epub 2009 Feb 11.
Biodrying for mechanical-biological treatment of wastes: a review of
process science and engineering.
Velis C.A, Longhurst P.J, Drew G.H, Smith R, Pollard S.J.
ABSTRACT
Biodrying is a variation of aerobic decomposition, used within
mechanical-biological treatment (MBT) plants to dry and partially
stabilise residual municipal waste.
Biodrying MBT plants can produce a high quality solid recovered fuel
(SRF), high in biomass content. Here, process objectives, operating
principles, reactor designs, parameters for process monitoring and
control, and their effect on biodried output quality are critically
examined. Within the biodrying reactors, waste is dried by air
convection, the necessary heat provided by exothermic decomposition
of the readily decomposable waste fraction.
Biodrying is distinct from composting in attempting to dry and preserve
most of biomass content of the waste matrix, rather than fully stabilise
it. Commercial process cycles are completed within 7-15 days, with
mostly H(2)O((g)) and CO(2) loses of ca. 25-30% w/w, leading to
moisture contents of <20% w/w. High airflow rate and dehumidifying of
re-circulated process air provides for effective drying. We anticipate this
review will be of value to MBT process operators, regulators and endusers of SRF.
http://www.ncbi.nlm.nih.gov/pubmed/19216072 …… diunduh 17/3/2012
Bioresour Technol. 2011 Aug;102(16):7443-50. Epub 2011 May 23.
Effects of biodrying process on municipal solid waste properties.
Tambone F, Scaglia B, Scotti S, Adani F.
ABSTRACT
In this paper, the effect of biodrying process on municipal solid waste
(MSW) properties was studied.
The results obtained indicated that after 14d, biodrying reduced the
water content of waste, allowing the production of biodried waste with a
net heating value (NHV) of 16,779±2,074kJ kg(-1) wet weight, i.e. 41%
higher than that of untreated waste.
The low moisture content of the biodried material reduced, also, the
potential impacts of the waste, i.e. potential self-ignition and potential
odors production. Low waste impacts suggest to landfill the biodried
material obtaining energy via biogas production by waste re-moistening,
i.e. bioreactor.
Nevertheless, results of this work indicate that biodrying process because
of the partial degradation of the organic fraction contained in the waste
(losses of 290g kg(-1) VS), reduced of about 28% the total producible
biogas.
http://www.ncbi.nlm.nih.gov/pubmed/21664812 …… diunduh 17/3/2012
Water Res. 2002 Apr;36(8):2124-32.
Kinetics of the aerobic biological degradation of shredded municipal
solid waste in liquid phase.
Liwarska-Bizukojc E, Bizukojc M, Ledakowicz S.
Abstract
The organic fraction of municipal solid waste (OFMSW) should be
utilised by means of biological methods. The biodegradation of solid
wastes can be intensified owing to application of the bioreactors.
Estimation of the optimum values of the organic load is one of the most
important tasks for the aerobic biodegradation processes.
The kinetic model of biological oxidation of the organic wastes has been
presented in this paper. The experiments were carried out in batch 6-l
working volume stirred tank bioreactors at constant temperature of 25
degrees C. Initial total solids have been at the levels of 15, 19, 34, 55 and
66 g l(-1). The kinetics of microbial decomposition of organic substances
was described by means of an unstructured model.
The satisfactory time courses for substrate chemical oxygen demand in
the solid (CODs) and liquid phase (CODL) and biomass concentration
(RNA) have been achieved. Also, the influence of the initial TS on the
kinetics of the biodegradation process was investigated and the
optimum value of initial TS for this type of processes was estimated at
34-55 g l(-1).
http://www.ncbi.nlm.nih.gov/pubmed/12092587 …… diunduh 17/3/2012
J Biotechnol. 2003 Mar 6;101(2):165-72.
Estimation of viable biomass in aerobic biodegradation processes of
organic fraction of municipal solid waste (MSW).
Liwarska-Bizukojc E, Ledakowicz S.
ABSTRACT
2-(p-Iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride (INT)
dehydrogenase test and RNA assay were introduced to evaluate
biomass in the processes of aerobic biodegradation of the organic
fraction of municipal solid waste (MSW) in bioreactors.
It was found that RNA quantification by KOH/UV method delivered
reliable and repeatable results. Relative standard deviation (RSD) for
INT test was significantly higher than for RNA assay and achieved values
of 3-15%.
Moreover, it occurred that the optimum temperature for the growth of
autochthonic biomass, which takes part in the biodegradation process,
was in the range from 25 to 37 degrees C.
http://www.ncbi.nlm.nih.gov/pubmed/12568745 …… diunduh 17/3/2012
Water Res. 2002 Apr;36(8):2124-32.
Kinetics of the aerobic biological degradation of shredded municipal
solid waste in liquid phase.
Liwarska-Bizukojc E, Bizukojc M, Ledakowicz S.
Abstract
The organic fraction of municipal solid waste (OFMSW) should
be utilised by means of biological methods. The
biodegradation of solid wastes can be intensified owing to
application of the bioreactors. Estimation of the optimum
values of the organic load is one of the most important tasks
for the aerobic biodegradation processes. The kinetic model of
biological oxidation of the organic wastes has been presented
in this paper. The experiments were carried out in batch 6-l
working volume stirred tank bioreactors at constant
temperature of 25 degrees C. Initial total solids have been at
the levels of 15, 19, 34, 55 and 66 g l(-1). The kinetics of
microbial decomposition of organic substances was described
by means of an unstructured model.
The satisfactory time courses for substrate chemical oxygen
demand in the solid (CODs) and liquid phase (CODL) and
biomass concentration (RNA) have been achieved. Also, the
influence of the initial TS on the kinetics of the biodegradation
process was investigated and the optimum value of initial TS
for this type of processes was estimated at 34-55 g l(-1).
http://www.ncbi.nlm.nih.gov/pubmed/12092587 …… diunduh 17/3/2012
Waste Manag. 2008;28(7):1188-200. Epub 2007 Jul 3.
Modelling of moisture-dependent aerobic degradation of solid waste.
Pommier S, Chenu D, Quintard M, Lefebvre X.
Abstract
In landfill, high temperature levels come from aerobic reactions inside the
waste surface layer. They are known to make anaerobic processes more
reliable, by partial removal of easily biodegradable substrates. Aerobic
biodegradation of the main components of biodegradable matter (paper
and cardboard waste, food and yard waste) is considered. In this paper,
two models which take into account the effect of moisture on aerobic
biodegradation kinetics are discussed. The first one (Model A) is a simple,
first order, substrate-related model, which assumes that substrate
hydrolysis is the limiting step of the process. The second one (Model B) is
a biomass-dependant model, considering biological growth processes.
Respirometric experiments were performed in order to evaluate the
efficiency of each model. The biological oxygen demands of shredded
paper and cardboard samples and of food and yard waste samples
prepared at various initial water contents were measured. These
experimental data were used to identify model parameters.
Model A, which includes moisture dependency on the maximum amount
of biodegraded matter, is relevant for paper and cardboard
biodegradation.
On the other hand, Model B, including moisture effect on the growth rate
of biomass is suitable to describe food and yard waste biodegradation.
http://www.ncbi.nlm.nih.gov/pubmed/17611099…… diunduh 17/3/2012
Waste Manag Res. 2001 Feb;19(1):58-69.
The role of aerobic activity on refuse temperature rise: II. Experimental and
numerical modelling.
Lanini S, Houi D, Aguilar O, Lefebvre X.
ABSTRACT
The biodegradation of a model waste is studied in a 300-litre pilot.
The aim is to better understand the role of biochemical processes on
the temperature rise, in relation to landfill management protocols.
The variations of temperature and gas composition distributions in
the waste are accurately measured and analysed. The observations
confirm that biological consumption of the oxygen diffusing through
the waste is the main source of heat.
A theoretical modelling of coupled heat and oxygen transfers in fresh
refuse is then proposed. Numerical results are in good agreement
with experimental data, but it appears that biochemical kinetics
should account for the carbon availability limitation.
Finally, a prediction of the temperature field in a landfill is presented.
http://www.ncbi.nlm.nih.gov/pubmed/11525476…… diunduh 17/3/2012
BIODRYING OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTE
Stanisław Ledakowicz, Agnieszka Zawadzka, Liliana Krzystek
Department of Bioprocess Engineering, Faculty of Process and Environmental Engineering,
Technical University of Lodz, Wolczanska Str. 213, 90-924 Lodz, Poland
ABSTRACT
The effect of air flow rate on the change of biomass (organic waste
material) temperature and moisture content during an autothermal
drying process was discussed in this paper. The laboratory-scale
experiments were performed using a 240 dm3 capacity, horizontal
composting reactor (insulated with polyurethane foam), equipped with
an air-supply system, compost temperature measuring system, and air
humidity and temperature sensors.
An organic fraction of municipal solid waste with the addition of
structural material was used as a substrate in this process.
As a result of the autothermal biodrying process, moisture content
decreased by 50% at the initial moisture content of organic waste ranging
from 800 to 900 gH2O/kg wet weight. Water balances were calculated
before and after the composting and drying process. Very good
agreement of the calculated water balances was obtained. The heat of
combustion of dried waste and its calorific value were 12.28 kJ/g and
10.98 kJ/g, respectively.
http://158.170.80.141/wcce8/offline/techsched/manuscripts%5C0gqfjc.pdf…… diunduh
17/3/2012
Potential for Biodrying Manure
Peter Wright
Senior Extension Associate . PRO-DAIRY
Agricultural and Biological Engineering Department, Cornell University
Abstract
Studies have shown that spreading liquid manure when soils are near saturation or
when they are likely to become saturated before crop uptake of nutrients can occur,
can result in significant nutrient and bacterial discharges to the water through tile
lines and runoff. Often nutrient management plans designed to protect water
quality prescribe manure storage. Stored liquid manure can produce significant
objectionable odors both during storage and when spread. Catastrophic failure of
liquid systems is a risk that many farms want to avoid.
Biodrying as described in this paper is a system that has the potential to improve
water quality by increasing the likelihood of nutrient export. It can provide a
stabilized solid for spreading on hay ground during the growing season. Biodrying
will meet the farm's need for odor control. Smaller farms' desire for a solid based
treatment system would be addressed as well.
The design of a Biodrying process on an 85 cow dairy farm in the NYC Watershed
will be described. This work has been funded by a grant from NYSERDA and is being
constructed in the spring of 2001. This will include designing and building a
composting shed, installing a forced air system that will be controlled to optimize
the composting and drying of the manure. If managed carefully, the heat generated
by aerobic composting can provide the energy to reduce 12% dry matter (DM)
manure to a 60% DM residual. The compost would be reduced one half in volume
and to one fifth the weight of the original manure due to water loss and solid
conversion to gasses.
Preliminary analysis shows that the cost of operating the system minus the cost of
additional benefits including off site sales is less than the cost of conventional liquid
storage and land spreading that would meet the environmental goals for the farm.
If successful, this system would have application on many dairy farms.
http://www.manuremanagement.cornell.edu/Pages/General_Docs/Papers/Potential_for_Bi
odrying_Manure_Wright_2002.pdf…… diunduh 17/3/2012
Potential for Biodrying Manure
Peter Wright
Senior Extension Associate . PRO-DAIRY
Agricultural and Biological Engineering Department, Cornell University
Description of Biodrying
If managed carefully, the heat generated by aerobic composting can
provide the energy to reduce 12% DM manure to a 60% DM residual.
Forced air composting, under a roof, with the air flow controlled carefully
would optimize this process. Composting works best with an initial
moisture content below 70%. Recent applications of composting
operations have shown the feasibility of this process by using forced air to
compost six foot high layers of manure in 21 days. Recycled compost or a
mix of compost and sawdust, or other amendment, at 40% dry matter
could be spread in the cow alleys about 3 inches thick to absorb one days
production of 12% DM manure.
The mixture could be scraped into a shed, piled 6 feet deep and aerated to
produce 40% DM compost in 3 weeks.
The figure shows a side view, plan view and cross section of the biodrying
shed. The building was designed with a high overshot roof, open walls,
and four foot eaves to provide good ventilation while keeping the process
protected from precipitation. Manure and recycled compost can be
loaded from either side, although preliminary trials have shown that a
side delivery manure spreader can build a six foot pile 40 feet long.
http://www.manuremanagement.cornell.edu/Pages/General_Docs/Papers/Potential_for_Bi
odrying_Manure_Wright_2002.pdf…… diunduh 17/3/2012
Potential for Biodrying Manure
Peter Wright
Senior Extension Associate . PRO-DAIRY
Agricultural and Biological Engineering Department, Cornell University
Proposed Biodrying Building.
http://www.manuremanagement.cornell.edu/Pages/General_Docs/Papers/Potential_for_Bi
odrying_Manure_Wright_2002.pdf…… diunduh 17/3/2012
Potential for Biodrying Manure
Peter Wright
Senior Extension Associate . PRO-DAIRY
Agricultural and Biological Engineering Department, Cornell University
The air flow calculated for this system compares with various air flows form
the literature. Table 1 shows different air flows that were successful in
composting the listed ingredients. A control system can be developed to run
the fans that will optimize the composting operation (Hall).
Comparison of air flows and ingredients for various composting operations.
http://www.manuremanagement.cornell.edu/Pages/General_Docs/Papers/Potential_for_Bi
odrying_Manure_Wright_2002.pdf…… diunduh 17/3/2012
Effect of temperature and air flow rate on carbon and nitrogen compounds
changes during the biodrying of swine manure in order to produce
combustible biomasses
Antonio Avalos Ramirez, Stéphane Godbout, François Léveillée, Dan Zegan, Jean-Pierre
Larouche.
Journal of Chemical Technology and Biotechnology
Article first published online: 1 MAR 2012 | DOI: 10.1002/jctb.3744
ABSTRACT
Manure is the main waste of raising livestock, when spreading in soils can cause
surface and ground water pollution. The management of manure is associated
with emissions of greenhouse gases and odours. Dry manure contains at least
45% of carbon. This is an attractive characteristic for energetic valorisation. To use
manure in the production of energy, it must be previously dried.
Wet solids from swine manure containing 30% of dry matter were dried
in laboratory scale biodryers. Four levels of aeration rate from 0.4 to 4 L
min−1 kg and five levels of temperature from 25 to 65 °C were tested.
The highest emissions of CO2, NH3 and N2O occurred at the highest air
flow rate of 4 L min−1 kg. For all operating conditions, the high calorific
power had a mean value of 15 ± 0.4 MJ kg.
The dried biomass obtained had an energetic potential to valorise by
combustion.
The bed temperature and aeration rate have an effect on carbon and
nitrogen bio-cycles. These operating parameters can also control the
release quantity and gaseous form of nitrogen. Several problems
related to swine manure management can be solved by using
biodrying, an economic and environmental friendly technology.
http://onlinelibrary.wiley.com/doi/10.1002/jctb.3744/abstract;jsessionid=BE1F12F253ECD925D4F2DB9E4E
C6DF64.d03t01?systemMessage=Wiley+Online+Library+will+be+disrupted+17+March+from+1014+GMT+%280610+EDT%29+for+essential+maintenance&userIsAuthenticated=false&deniedAccessCustomisedMessage=…
… diunduh 17/3/2012
Environment Protection Engineering . Vol. 35 2009 No. 3
AGNIESZKA ZAWADZKA, LILIANA KRZYSTEK, STANISŁAW LEDAKOWICZ.
AUTOTHERMAL DRYING OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTE
ABSTRACT
In order to take advantage of heat released during composting, the
autothermal drying process requires the maintenance of adequate air
flow combined with temperature. The aim of this paper was to
construct a drying tunnel enabling the automatic control and
regulation of the basic process parameters for biomass drying
(organic fraction of municipal solid waste together with plant
structural material) to obtain biofuel. In the course of investigations,
various constructions of a drying tunnel were tested.
The best results were accomplished for a horizontal reactor with the
automatic regulation of air flow. About 50% reduction of moisture
content and dry mass on the level of 0.53 kgdry mass/kgwet weight
were obtained.
The heat of combustion of dried waste and its calorific value were
12.28 kJ/g waste and 10.98 kJ/g waste, respectively.
http://epe.pwr.wroc.pl/2009/Zawadzka_3-2009.pdf…… diunduh 17/3/2012
Environment Protection Engineering . Vol. 35 2009 No. 3
AGNIESZKA ZAWADZKA, LILIANA KRZYSTEK, STANISŁAW LEDAKOWICZ.
AUTOTHERMAL DRYING OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTE
Schematic diagram of autothermal drying tunnel No 1: 1 – Drying tunnel, 2 –
Polyurethane foam, 3 – Cover with holes, 4 – Inlet air, 5 – Outlet air, 6 –
Biofilter, 7 – Stand
http://epe.pwr.wroc.pl/2009/Zawadzka_3-2009.pdf…… diunduh 17/3/2012
Environment Protection Engineering . Vol. 35 2009 No. 3
AGNIESZKA ZAWADZKA, LILIANA KRZYSTEK, STANISŁAW LEDAKOWICZ.
AUTOTHERMAL DRYING OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTE
Schematic diagram of drying tunnel No. 2: 1 – Polyurethane foam, 2
– Cover with holes, 3 – Metal bar, 4 – Outlet air, 5 – Inlet air, 6 –
Biofilter, 7 – Engine, 8 – Stand
http://epe.pwr.wroc.pl/2009/Zawadzka_3-2009.pdf…… diunduh 17/3/2012
Environment Protection Engineering . Vol. 35 2009 No. 3
AGNIESZKA ZAWADZKA, LILIANA KRZYSTEK, STANISŁAW LEDAKOWICZ.
AUTOTHERMAL DRYING OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTE
Schematic diagram of the autothermal drying tunnel No. 3:
1 – Composted biomass, 2 – Drying tunnel, 3 – Polyurethane foam, 4 – Duct
heater, 5 – In-line duct fan, 6 – Inlet air, 7, 8 – Temperature sensors of
composted biomass, 9 – Temperature sensor of biomass over compost, 10 –
Biofilter, 11 – Outlet air, 12 – Exhaust fan, 13 – Temperature and moisture
sensors of outlet air
autothermal drying tunnel
http://epe.pwr.wroc.pl/2009/Zawadzka_3-2009.pdf…… diunduh 17/3/2012
Environment Protection Engineering . Vol. 35 2009 No. 3
AGNIESZKA ZAWADZKA, LILIANA KRZYSTEK, STANISŁAW LEDAKOWICZ.
AUTOTHERMAL DRYING OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTE
Duration of the composting and drying cycle in reactor No. 1 was 11 days. The
initial moisture of waste attained the value of 0.86 kgH2O/kgwet weight. The final
moisture value was equal to 0.53 kgH2O/kgwet weight, (Table 1). In this test cycle one
could observe a decrease of moisture by about 30%. Figure 4 shows the temperature
mean values of composting biomass in reactor 1.
Within the first three days of the drying process an increase of temperature can be
noticed. The highest temperature recorded during the process was 33 °C. It must be
added that it was attained on the 2nd and 3rd day of the process. After four days the
temperature decreased to 28 °C. Afterwards, the repeated increase by 2 °C was observed.
On the 8th and 9th day the temperature started to decrease to the value of 26 °C.
On the 11th day of the process the repeated increase in temperature was observed and
its value was 32 °C. Low temperatures obtained in this test series and high final
moisture of biomass as well as the observed increase in the temperature were probably
caused by a lack of the appropriate mixing and air flow.
http://epe.pwr.wroc.pl/2009/Zawadzka_3-2009.pdf…… diunduh 17/3/2012
Environment Protection Engineering . Vol. 35 2009 No. 3
AGNIESZKA ZAWADZKA, LILIANA KRZYSTEK, STANISŁAW LEDAKOWICZ.
AUTOTHERMAL DRYING OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTE
Temperature in composting biomass in reactors No. 1 and 2
On the 1st day of the process the
temperature in the reactor No. 2 was 25 °C. On the 3rd day one could observe an increase
in temperature up to 39 °C. On the 4th day of the process a decrease in temperature
to 35 °C was noticed. The highest temperature in this test cycle (40 °C) was
obtained on the 5th day. On subsequent days a decrease in temperature can be noticed.
On the last day of the investigations the temperature of biomass reached the value of 28
°C. It is highly probable that the observed increase in temperature, similarly to
reactor 1, is caused by a lack of the appropriate mixing and air flow.
In reactor 2, analogously to reactor 1, a similar level of decrease in moisture content
of waste mass (about 20%) was obtained. Nonetheless, higher temperatures were
recorded (40 °C), which was due to the better process conditions for composting than
in reactor 1. Notwithstanding, those results are not satisfactory due to the fact that the
final waste moisture content was very high.
http://epe.pwr.wroc.pl/2009/Zawadzka_3-2009.pdf…… diunduh 17/3/2012
Environment Protection Engineering . Vol. 35 2009 No. 3
AGNIESZKA ZAWADZKA, LILIANA KRZYSTEK, STANISŁAW LEDAKOWICZ.
AUTOTHERMAL DRYING OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTE
Temperature in the top and bottom of waste mass layer in reactor No. 3
On the first days of the composting process, the temperature in the bottom layer was
higher and amounted to about 23 °C, while temperature of the top layer was about 21
°C. On the 6th day of the process, a temperature growth was observed in both layers.
The highest temperatures, reaching 53 °C, were obtained in the bottom waste layer.
The temperature in the top layer was lower by about 2 °C in this period. At the end of
the process, a decrease of temperatures in both layers to the level close to inlet air
temperatures, i.e. 21 °C to 23 °C, was observed. The temperature of the top layer was
23 °C, while that of the bottom layer about 25 °C. On the 10th day of the cycle,
temperature of the bottom layer was on a higher level. The difference of temperature
of the bottom and top layer was not too high and attained the values ranging from 2 °C
to 5 °C, which indicates a satisfactory level of homogeneity in the moisture and energy
content of the final product.
http://epe.pwr.wroc.pl/2009/Zawadzka_3-2009.pdf…… diunduh 17/3/2012
Environment Protection Engineering . Vol. 35 2009 No. 3
AGNIESZKA ZAWADZKA, LILIANA KRZYSTEK, STANISŁAW LEDAKOWICZ.
AUTOTHERMAL DRYING OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTE
Temperature and humidity of outlet air in reactor No. 3
Air humidity at the beginning of the composting process was kept on the level
of about 52%. The highest value of this parameter reaching 75–79% was
obtained after 3 days of the process. At the end of the process, air humidity
dropped to the value ranging from 37% to 39%. Initially, the outlet air
temperature was 21 °C to 23 °C. The highest value of this parameter − about
33 °C, was obtained on the last days of the process. During the tested
processes no high temperatures of the outlet air were found which could be
due to temperature of the composting waste.
http://epe.pwr.wroc.pl/2009/Zawadzka_3-2009.pdf…… diunduh 17/3/2012
Environment Protection Engineering . Vol. 35 2009 No. 3
AGNIESZKA ZAWADZKA, LILIANA KRZYSTEK, STANISŁAW LEDAKOWICZ.
AUTOTHERMAL DRYING OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTE
The elementary analysis of composting waste was
performed and the heat of combustion and calorific
value were determined.
The heat of combustion (ΔHc0) is the energy released as heat when a compound
undergoes complete combustion with oxygen under standard conditions.
The chemical reaction is typically a hydrocarbon reacting with oxygen to form
carbon dioxide, water and heat. It may be expressed with the quantities:
1. energy/mole of fuel (kJ/mol)
2. energy/mass of fuel
3. energy/volume of fuel
The heat of combustion is conventionally measured with a bomb calorimeter. It
may also be calculated as the difference between the heat of formation (ΔfH0) of
the products and reactants.
(http://en.wikipedia.org/wiki/Heat_of_combustion)
http://epe.pwr.wroc.pl/2009/Zawadzka_3-2009.pdf…… diunduh 17/3/2012
Waste Manag. 2010 Jul;30(7):1165-70. Epub 2010 Jan 27.
Bio-drying and size sorting of municipal solid waste with high water content for
improving energy recovery.
Shao LM, Ma ZH, Zhang H, Zhang DQ, He PJ.
Abstract
Bio-drying can enhance the sortability and heating value of municipal solid
waste (MSW), consequently improving energy recovery. Bio-drying followed by
size sorting was adopted for MSW with high water content to improve its
combustibility and reduce potential environmental pollution during the followup incineration. The effects of bio-drying and waste particle size on heating
values, acid gas and heavy metal emission potential were investigated.
The results show that, the water content of MSW decreased from 73.0%
to 48.3% after bio-drying, whereas its lower heating value (LHV) increased
by 157%. The heavy metal concentrations increased by around 60% due to
the loss of dry materials mainly resulting from biodegradation of food
residues.
The bio-dried waste fractions with particle size higher than 45 mm were
mainly composed of plastics and papers, and were preferable for the
production of refuse derived fuel (RDF) in view of higher LHV as well as
lower heavy metal concentration and emission. However, due to the
higher chlorine content and HCl emission potential, attention should be
paid to acid gas and dioxin pollution control. Although LHVs of the waste
fractions with size <45 mm increased by around 2x after bio-drying, they
were still below the quality standards for RDF and much higher heavy
metal pollution potential was observed.
Different incineration strategies could be adopted for different particle
size fractions of MSW, regarding to their combustibility and pollution
property.
http://www.ncbi.nlm.nih.gov/pubmed/20106649 …… diunduh 17/3/2012
Waste Manag. 2011 Aug;31(8):1790-6. Epub 2011 May 4.
Evolution of heavy metals in municipal solid waste during bio-drying
and implications of their subsequent transfer during combustion.
Zhang DQ, Zhang H, Wu CL, Shao LM, He PJ.
Abstract
Bio-drying has been applied to improve the heating value of municipal solid
waste (MSW) prior to combustion. In the present study, evolution of heavy
metals in MSW during bio-drying and subsequent combustion was studied
using one aerobic and two combined hydrolytic-aerobic scenarios.
Heavy metals were concentrated during bio-drying and transformed between
different metal fractions, namely the exchangeable, carbonate-bound, ironand manganese-oxides-bound, organic-matter-bound and residual fractions.
The amounts of heavy metals per kg of bio-dried MSW transferred into
combustion flue gas increased with bio-drying time, primarily due to metals
enrichment from organics degradation. Because of their volatility, the
partitioning ratios of As and Hg in flue gas remained stable so that bio-drying
and heavy metal speciation had little effect on their transfer and partitioning
during combustion.
Sebaliknya, rasio partisi Pb, Zn dan Cu cenderung
meningkat setelah bio-drying, yang kemungkinan
meningkatkan potensi emisinya selama
pembakaran.
http://www.ncbi.nlm.nih.gov/pubmed/21543217 …… diunduh 17/3/2012
Waste Manag. 2010 Jul;30(7):1165-70. Epub 2010 Jan 27.
Bio-drying and size sorting of municipal solid waste with high water
content for improving energy recovery.
Shao LM, Ma ZH, Zhang H, Zhang DQ, He PJ.
Abstract
Bio-drying can enhance the sortability and heating value of municipal solid
waste (MSW), consequently improving energy recovery. Bio-drying
followed by size sorting was adopted for MSW with high water content to
improve its combustibility and reduce potential environmental pollution
during the follow-up incineration. The effects of bio-drying and waste
particle size on heating values, acid gas and heavy metal emission potential
were investigated.
The results show that, the water content of MSW decreased from 73.0% to
48.3% after bio-drying, whereas its lower heating value (LHV) increased by
157%. The heavy metal concentrations increased by around 60% due to the
loss of dry materials mainly resulting from biodegradation of food residues.
The bio-dried waste fractions with particle size higher than 45 mm were
mainly composed of plastics and papers, and were preferable for the
production of refuse derived fuel (RDF) in view of higher LHV as well as
lower heavy metal concentration and emission. However, due to the higher
chlorine content and HCl emission potential, attention should be paid to
acid gas and dioxin pollution control. Although LHVs of the waste fractions
with size <45 mm increased by around 2x after bio-drying, they were still
below the quality standards for RDF and much higher heavy metal
pollution potential was observed.
Different incineration strategies could be adopted for different particle size
fractions of MSW, regarding to their combustibility and pollution property.
http://www.ncbi.nlm.nih.gov/pubmed/20106649 …… diunduh 17/3/2012
Waste Manag. 2009 Nov;29(11):2816-23. Epub 2009 Jul 15.
Sorting efficiency and combustion properties of municipal solid waste
during bio-drying.
Zhang DQ, He PJ, Shao LM.
Abstract
One aerobic and two combined bio-drying processes were set up to investigate
the quantitative relationships of sorting efficiency and combustion properties
with organics degradation and water removal during bio-drying.
Results showed that the bio-drying could enhance the sorting efficiency of
municipal solid waste (MSW) up to 71% from the initial of 34%. The sorting
efficiency was correlated with water content negatively (correlation
coefficient, r=-0.89) and organics degradation rate positively (r=0.92). The
higher heating values (HHVs) were correlated with organics degradation
negatively for FP (i.e. the sum of only food and paper) (r=-0.93) but positively
for the mixing waste (MW) (r=0.90), whereas the lower heating values (LHVs)
were negatively correlated with water content for both FP (r=-0.71) and MW
(r=-0.96). Other combustion properties depended on organics degradation
performance, except for ignition performance and combustion rate.
The LHVs could be greatly enhanced by the combined
process with insufficient aeration during the hydrolytic
stage.
Compared with FP, MW had higher LHVs and ratios of
volatile matter to fixed carbon.
Nevertheless, FP had higher final burnout values than MW.
http://www.ncbi.nlm.nih.gov/pubmed/19608397 …… diunduh 17/3/2012
. Lower Heating Value Dynamics during Municipal Solid Waste Bio-Drying
E. C. Rada, A. Franzinelli, M. Taiss, M. Ragazzi, V. Panaitescu & T. Apostol
Environmental Technology
Volume 28, Issue 4, 2007
pages 463-469
Abstract
In agreement with the new European Union directives concerning the
valorization of materials and energy recovery, Municipal Solid Waste (MSW)
management is, in general based on an integrated approach characterized by a
combination of different treatment processes.
The bio-mechanical treatment (BMT) of MSW is an increasing option in Europe
either as a pre-treatment before landfilling or as a pre-treatment before
combustion. In this context the research on the bio-drying process is not fully
developed. In the present paper the Lower Heating Value (LHV) dynamics
during MSW bio-drying has been assessed. Measurements were made using a
pilot scale bio-dryer that allows the recording of data as air flow, temperature
(at the entrance, at the exit and inside the waste), and weight loss. An initial
characterization of the MSW completes the input data.
Results give information on the dynamics
of the main process parameters
(humidity, volatile solids, ammonia, Lower
Heating Value) and also of additional
parameters.
http://www.tandfonline.com/doi/abs/10.1080/09593332808618807 …… diunduh
17/3/2012
The influence of biomass temperature on biostabilization–biodrying of
municipal solid waste
Adani, Fabrizio; Baido, Diego; Calcaterra, Enrico; Genevini, Pierluigi
Bioresource Technology. Vol. 83. Issue 3. July, 2002. Pages 173-179
Abstract
A laboratory study was carried out to obtain data on the influence of biomass temperature on
biostabilization–biodrying of municipal solid waste (initial moisture content of 410 g kg wet
weight (w.w.) −1). Three trials were carried out at three different biomass temperatures, obtained
by airflow rate control ( A=70 °C, B=60 °C and C=45 °C). Biodegradation and biodrying were
inversely correlated: fast biodrying produced low biological stability and vice versa.
The product obtained from process A was characterized by the highest degradation coefficient
(166 g kg TS 0−1; TS 0−1=initial total solid content) and lowest water loss (409 g kg W 0−1; W
0=initial water content). Due to the high reduction of easily degradable volatile solid content and
preservation of water, process A produced the highest biological stability (dynamic respiration
index, DRI=141 mg O 2 kg VS −1; VS=volatile solids) but the lowest energy content (EC=10,351 kJ
kg w.w. −1).
Conversely, process C which showed the highest water elimination (667 g kg W 0−1), and lowest
degradation rate (18 g kgTS 0−1) was optimal for refuse-derived fuel (RDF) production having the
highest energy content (EC=14,056 kJ kg w.w. −1). Nevertheless, the low biological stability
reached, due to preservation of degradable volatile solids, at the end of the process (DRI=1055
mg O 2kgVS −1), indicated that the RDF should be used immediately, without storage.
Trial B showed substantial agreement between
low moisture content (losses of 665 g kg W 0−1),
high energy content (EC=13,558 kJ kg w.w. −1) and
good biological stability (DRI=166 mg O 2kgVS −1),
so that, in this case, the product could be used
immediately for RDF or stored with minimum
pollutant impact (odors, leaches and biogas
production).
http://discover-decouvrir.cisti-icist.nrc-cnrc.gc.ca/eng/article/?id=1572893 …… diunduh 17/3/2012
J Environ Sci (China). 2010;22(5):752-9.
Release of volatile organic compounds during bio-drying of municipal
solid waste.
He P, Tang J, Zhang D, Zeng Y, Shao L.
Abstract
Three treatments were tested to investigate the release concentrations of
volatile organic compounds (VOCs) during the bio-drying of municipal
solid waste (MSW) by the aerobic and combined hydrolytic-aerobic
processes.
Results showed that VOCs were largely released in the first 4 days of biodrying and the dominant components were: dimethyl disulfide, dimethyl
sulfide, benzene, 2-butanone, limonene and methylene chloride. Thus, the
combined hydrolytic-aerobic process was suggested for MSW bio-drying
due to fewer aeration quantities in this phase when compared with the
aerobic process, and the treatment strategies should base on the key
properties of these prominent components. Malodorous sulfur
compounds and terpenes were mainly released in the early phase of biodrying, whereas, two peaks of release concentrations appeared for
aromatics and ketones during bio-drying. Notably, for the combined
hydrolytic-aerobic processes there were also high concentrations of
released aromatics in the shift from hydrolytic to aerobic stages.
High concentrations of released chlorinateds were observed in the later
phase. For the VOCs produced during MSW bio-drying, i.e., malodorous
sulfur compounds, terpenes and chlorinateds, their release
concentrations were mainly determined by production rates; for the VOCs
presented initially in MSW, such as aromatics, their transfer and transport
in MSW mainly determined the release concentrations.
http://www.ncbi.nlm.nih.gov/pubmed/20608513 …… diunduh 17/3/2012
Experimental Study on the Bio-Drying Characteristics and its Influencing
Factors of Paper Mill Sludge
Xun An Ning, Qing Lin Chen, Jian Bo Zhou, Zuo Yi Yang, Jing Yong Liu
Advanced Materials Research, 204-210, 88. 2011.
ABSTRACT
The bio-drying characteristics and its influencing factors of paper mill sludge
(PMS) were investigated detailedly, by means of the heat generated by aerobic
degradation of the organic substances in the PMS. In the orthogonal
experiments, the good results were achieved with the followed optimization
technics: starch (25.0g/500.0g), sawdust (40.0g/500.0g), inoculation
(15.0mL/500.0g) and KH2PO4 (5.0g/500.0g).
During bio-drying, the matrix temperature increased to 47.2℃
within 12-24h rapidly under the given operation parameters,
and the maximum was about 48.0℃. In the whole process the
pH changed in the range of 6.11-7.87. The quantity of
amylolytic bacteria reduced to the minimum in the first day,
and the amylolytic bacteria grew well until the process of biodrying finished. The ATP content was increased drastically in
the first day and peaked in the fifth day, with the maximum ATP
content was about 6.4×10-6μmol/g. When bio-drying of PMS
was finished, the VS content and moisture content (MC)
reduced from 58.4% to 49.5% and 62.2% to 50.3% respectively.
http://www.scientific.net/AMR.204-210.88 …… diunduh 17/3/2012
Estimation of the energy content of the residual fraction refused by
MBT plants: A case study in Zaragoza’s MBT plant
Alfonso Aranda Usón, , Germán Ferreira, David Zambrana Vásquez,
Ignacio Zabalza Bribián, Eva Llera Sastresa.
Journal of Cleaner Production. Vol. 20, Issue 1, January 2012, Pages 38–
46.
Abstract
The proper estimation of the energy content of the residual fraction from
mechanical–biological treatment (MBT) plants is essential for planning and
promoting different methods to decrease its environmental impact, to lower
the consumption of energy resources, and to reduce economic costs.
Currently, in many countries, the residual fraction from these plants is disposed
of in a landfill with few recovery actions. This paper proposes a methodology
for estimating the energy content of the aforementioned fraction. To validate
it, the methodology is applied to a MBT plant in Zaragoza that collects residual
household waste from municipal solid waste (MSW) from 62 municipalities in
four regions of Aragon – Zaragoza, Ribera Baja del Ebro, Campo de Cariñena,
and Campo de Belchite.
An energy potential of 17929.24 kJ/kg of
the residual fraction from this MBT plant
is estimated, which is equivalent to
100.18 ktoe per year.
http://www.sciencedirect.com/science/article/pii/S0959652611002782 …… diunduh
17/3/2012
. Investigations of biological processes in Austrian MBT plants
J. Tintner, E. Smidt, , K. Böhm, E. Binner.
Waste Management. Vol. 30, Issue 10, October 2010, Pages 1903–1907
Abstract
Mechanical biological treatment (MBT) of municipal solid waste (MSW) has
become an important technology in waste management during the last
decade. The paper compiles investigations of mechanical biological processes
in Austrian MBT plants. Samples from all plants representing different stages of
degradation were included in this study. The range of the relevant parameters
characterizing the materials and their behavior, e.g. total organic carbon, total
nitrogen, respiration activity and gas generation sum, was determined. The
evolution of total carbon and nitrogen containing compounds was compared
and related to process operation.
The respiration activity decreases in most of the plants
by about 90% of the initial values whereas the
ammonium release is still ongoing at the end of the
biological treatment. If the biogenic waste fraction is
not separated, it favors humification in MBT materials
that is not observed to such extent in MSW.
The amount of organic carbon is about 15% dry matter
at the end of the biological treatment.
http://www.sciencedirect.com/science/article/pii/S0956053X10003181 …… diunduh
17/3/2012
Aerobic and Anaerobic Digestion and Types of Decomposition
Aerobic Digestion
Aerobic digestion of waste is the natural biological degradation and
purification process in which bacteria that thrive in oxygen-rich environments
break down and digest the waste.
During oxidation process, pollutants are broken down into carbon dioxide (CO2
), water (H 2 O), nitrates, sulphates and biomass (microorganisms). By
operating the oxygen supply with aerators, the process can be significantly
accelerated. Of all the biological treatment methods, aerobic digestion is the
most widespread process that is used throughout the world.
Advantages of Aerobic Digestion
Aerobic bacteria are very efficient in breaking down waste products. The result
of this is; aerobic treatment usually yields better effluent quality that that
obtained in anaerobic processes. The aerobic pathway also releases a
substantial amount of energy. A portion is used by the microorganisms for
synthesis and growth of new microorganisms.
http://water.me.vccs.edu/courses/ENV149/lesson4b.htm …… diunduh 17/3/2012
DEKOMPOSISI BAHAN ORGANIK SECARA AEROBIK
A biological process, in which, organisms use available organic matter to
support biological activity. The process uses organic matter, nutrients, and
dissolved oxygen, and produces stable solids, carbon dioxide, and more
organisms.
The microorganisms which can only survive in aerobic conditions are known as
aerobic organisms. In sewer lines the sewage becomes anoxic if left for a few
hours and becomes anaerobic if left for more than 1 1/2 days. Anoxic
organisms work well with aerobic and anaerobic organisms. Facultative and
anoxic are basically the same concept.
http://water.me.vccs.edu/courses/ENV149/lesson4b.htm …… diunduh 17/3/2012
DEKOMPOSISI BAHAN ORGANIK
Decomposition occurs most rapidly in well aerated soils. When organic plant
residues are incorporated into such a soil, three general reactions occur:
Carbon compounds are enzymatically oxidized to produce carbon dioxide,
water, energy, and decomposed biomass.
Elements essential to plant nutrition, such as N, P, and S, are released and/or
immobilized by a series of specific reactions that are relatively unique for each
element.
Compounds very resistant to microbial action are formed.
Factors Influencing rate of Organic Matter Decomposition
In addition to the composition of organic matter, nature and
abundance of microorganisms in soil, the extent of C, N, P and
K., moisture content of the soil and its temperature, PH,
aeration, C: N ratio of plant residues and presence/absence of
inhibitory substances (e.g. tannins) etc. are some of the major
factors which influence the rate of organic matter
decomposition.
(http://agriinfo.in/?page=topic&superid=5&topicid=170)
http://www.landfood.ubc.ca/soil200/interaction/orgmatter_air.htm…… diunduh 17/3/2012
PROSES PENGERINGAN (DRYING)
“Secara umum drying dapat diartikan sebagai proses untuk
mengurangi sebagian kadar air dalam material menggunakan aerasi.
Dalam beberapa kasus misalnya kadar air dapat dikurangi secara
mekanis dengan menggunakan pressing, sentrifugasi, dan metode
lainnya”
(Geankoplis,1993: hal 559).
“Teknologi pengeringan umumnya mengurangi kandungan uap (MC )
dari matriks kandungan sampah tersebut dengan menggunakan udara
panas panas, oleh karena itu air menguap ke fase udara (uap), dan
menghasilkan keluaran samapah kering dari karakteristik yang
diinginkan”
(Dufour, 2006).
Drying is a mass transfer process consisting of the removal of water or another
solvent by evaporation from a solid, semi-solid or liquid. This process is often
used as a final production step before selling or packaging products. To be
considered "dried", the final product must be solid, in the form of a continuous
sheet (e.g. paper), long pieces (e.g. wood), particles (e.g. cereal grains or corn
flakes) or powder (e.g. sand, salt, washing powder, milk powder). A source of
heat, and an agent to remove the vapor produced by the process are necessary.
In bioproducts like food, grains, and pharmaceuticals like vaccines, the solvent to
be removed is almost invariably water.
In the most common case, a gas stream, e.g., air, applies the heat by convection
and carries away the vapor as humidity. Other possibilities are vacuum drying,
where heat is supplied by conduction or radiation (or microwaves) while the
vapor thus produced is removed by the vacuum system.
Another indirect technique is drum drying (used, for instance, for manufacturing
potato flakes), where a heated surface is used to provide the energy and
aspirators draw the vapor outside the room. In turn, the mechanical extraction of
the solvent, e.g., water, by centrifugation, is not considered "drying".
(http://en.wikipedia.org/wiki/Drying)
http://www.scribd.com/doc/79843316/Proposal-La …… diunduh 17/3/2012
BIODRYING
BIODRYING
“Biodrying adalah proses dimana matriks sampah biodegradable dengan
cepatdipanaskan memalui tahap-tahap awal pembuatan kompos untuk
menghasilkan uap air dari aliran dan limbah dan dengan demikian mengurangi
berat keseluruhan”
( http://en.wikipedia.org/wiki/Biodrying … 18 Maret 2012)
Reaktor Biodrying menggunakan proses teknik fisik dan biokimia.
Desainreaktor meliputi wadah digabungkan dengan sistem aerasi, wadah atau
tangki dapat berupa tertutup atau terbuka, atau tabung seperti drum. Di sisi
biokimia, aerobik biodegradasi bahan organik mudah terjadi perurain. Di sisi
fisik, penghilangankelembaban konvektif dicapai melalui pengendalian aerasi
yang berlebih.
( http://www.epem.gr/waste-c-control/database/html/Biodrying-00.htm …
16 Maret 2012)
Biodrying (biological drying) is an option for the bioconversion reactor in
mechanical–biological treatment (MBT) plants, an alternative for treating residual
municipal solid waste (MSW).
Waste treatment plants defined as MBT integrate mechanical processing, such as
size reduction and air classification, with bioconversion reactors, such as composting
or anaerobic digestion.
The term "biodrying" was coined by Jewell et al. (1984) whilst reporting on the
operational parameters relevant for drying dairy manure.
IN MSW management, the term "biodrying" denotes:
(1) the bioconversion reactor within which waste is processed;
(2) the physiobiochemical process, which takes place within the reactor; and
(3) the MBT plants that include a biodrying reactor: "biodrying MBT".
Typically, the biodrying reactor within MBT plants receives shredded unsorted
residual MSW and produces a biodried output which undergoes extensive
mechanical post-treatment. Within the biodrying bioreactor the thermal energy
released during aerobic decomposition of readily degradable organic matter is
combined with excess aeration to dry the waste .
(http://www.epem.gr/waste-c-control/database/html/Biodrying-00.htm)
PROSES BIODRYING
Biodrying berbeda dari pengomposan dalam hal tujuan dari setiap proses.
Komposting menghasilkan “kompos'' seperti humus yang bermanfaat dan
aman digunakan pada lahan. Pengkomposan juga digunakan untuk
menstabilkan bahan organik biodegradable dari sampah domestik sebelum
ditimbun di TPA, hal ini dapat meminimalkan lindi dan pembentukan gas
sampah di TPA.
Schematic of biodrying box with process air circulation
and dehumidification.
(1) enclosed box; (2) air forced through the waste matrix, heated by the exothermic aerobic
biodegradation of readily decomposable waste fragments; (3) leachate collection and circulation
system; (4) forced aeration system with partial air recirculation, mixing ambient air and conditioned
process air; (5) heat exchanger; (6) cooling tower; (7) water (vapour condensate); (8) exhaust air
treatment through biofilter or regenerative thermal oxidation (RTO).
Appropriate conditions for microbial activity allow for the biodegradation of the waste placed within
the bioreactor, providing the necessary heat to evaporate moisture from the waste fragments.
Evaporated moisture is removed by the air convection, achieved by forced aeration. The exhaust air
is going through various treatment stages that improve its drying capacity (ability to carry moisture)
before it is partly re-circulated into the reactor, after being mixed with ambient air.
(technology by Herhof Environmental, schematic as reported by C.A. Velis, P.J. Longhurst, G.H. Drew, R.
Smith, S.J.T. Pollard, “Biodrying for mechanical–biological treatment of wastes: A review of process science
and engineering”, Bioresource Technology, 2009)
http://www.epem.gr/waste-c-control/database/html/Biodrying-00.htm …… diunduh 17/3/2012
OPTIMAL BIODRYING
In biodrying, the main drying mechanicsm is convective evaporation, using heat from the aerobic
biodegradation of waste components and facilitated by the mechanically supported airflow.
The Moisture Content (MC) of the waste matrix is reduced through two main steps:
(1) water molecules evaporate (i.e., change phase from liquid to gaseous) from the surface
of waste fragments into the surrounding air; and
(2) the evaporated water is transported through the matrix by the airflow and removed
with the exhaust gasses.
Limited amount of free water may seep through the waste matrix and be collected at the
bottom of the biodrying reactor as leachate.
Thus in biodrying, air convection and molecular diffusion are the main transport mechanisms
responsible for moisture flow through the matrix. Air convection, induced by engineered airflow
through the matrix, is almost exclusively responsible for the water losses. Here, air carries the
water evaporated from the surface of matrix particles (free moisture) with which is in contact.
Removal of water content from the waste matrix (desorption) by convective evaporation is
governed by the thermodynamic equilibrium between the wet waste matrix (solid state) and the
air flowing through the matrix (gaseous phase).
Optimal biodrying can be achieved through effective reactor design and conditioning of the input
material, combined with suitable process monitoring and control. Control can be exercised by
adjusting the level of operational variables (suitable to directly manipulate), informed by process
state variables (suitable to monitor and evaluate). Typical design and operational choices involve:
1.
2.
3.
4.
5.
6.
7.
matrix conditioning through mechanical pre-processing, e.g., comminution and/or mixing,
affecting the physical properties of the matrix, such as the resistance to airflow;
type of containment of waste matrix, e.g., in enclosed boxes (or ‘‘bio-cells”) (Fig. 1) or
piling in tunnel windrow systems, affecting drying mechanisms including insulating effect
and degree of compaction;
use of mixing/agitation/rotation of the waste matrix in dynamic reactors to homogenise it,
i.e., achieve uniform conditions: e.g., by rotating drum reactors (Fig. 2B) however, most of
the existing commercial designs are static;
aeration system design: inverted aeration systems have been tested (Fig. 2A), intending to
reduce gradients experienced in prevalent unidirectional desings
management of the aeration rate of the waste matrix, by control of the inlet airflow rate
(Qair), to remove water vapour and offgasses and control state process parameters, such
as substrate temperature and oxygen availability;
external systems for controlling the psychrometric properties of the inlet air (e.g.,
temperature, due point, relative humidity), by cooling and dehumidifying of the process air
to enhance its capacity to hold water vapour, combined with partial process air
recirculation; and,
residence time within the reactor, affecting the degree of completion of biochemical and
physical processes. Typical residence times are in the range of 7-15 days.
http://www.epem.gr/waste-c-control/database/html/Biodrying-00.htm …… diunduh 17/3/2012
In biodrying, the MC can be reduced from ca. 35–55% w/w to 20–10% w/w ar. During
aerobic biodegradation around 0.5–0.6 g of metabolic water is produced per g of VS
decomposed. However, water losses during biodrying are much greater than the gains of
metabolic water, resulting in a dried matrix. Mass balance of MC should include both
metabolic water gains and evaporation–convection losses. Overall weight losses of 25%
w/w are considered as typical.
Simplified schematics of bench/pilot-scale biodrying reactor designs, among else aiming to mitigate the
uneven drying of matrix. Reactor A: static enclosed hall. The central perforated pipe (C2) alternates
between blowing and pulling air through the matrix, whilst the peripheral pipes (C2, C3) operate
conversely. Reactor B: cylindrical rotating drum with one perforated pipe. Certain monitoring points are
shown: T: temperature: 1–7 internal, out: exhaust air; P: pressure; rH: relative humidity; Q: air flowrate.
BL: blower. (Schematics as reported by C.A. Velis, P.J. Longhurst, G.H. Drew, R. Smith, S.J.T. Pollard,
“Biodrying for mechanical–biological treatment of wastes: A review of process science and engineering”,
Bioresource Technology, 2009)
http://www.epem.gr/waste-c-control/database/html/Biodrying-00.htm …… diunduh 17/3/2012
Process Mass Flow Diagram
This is a general mass flow diagram often adopted in MBT plants that
incorporate a biodrying reactor. Under the MBT description three
variations will be presented.
MC of the waste matrix is the single most important variable for evaluating
the performance of biodrying processes. In waste management the MC is
typically measured by gravimetric water content methods and expressed as
a percentage of water for the wet weight of the material (wet basis: ar).
In biodrying, the MC can be reduced from ca. 35–55% w/w to 20–10% w/w
ar. During aerobic biodegradation around 0.5–0.6 g of metabolic water is
produced per g of VS decomposed. However, water losses during biodrying
are much greater than the gains of metabolic water, resulting in a dried
matrix.
Mass balance of MC should include both metabolic water gains and
evaporation–convection losses. Overall weight losses of 25% w/w are
considered as typical.
http://www.epem.gr/waste-c-control/database/html/Biodrying-00.htm …… diunduh 17/3/2012
STRUKTUR KARBOHIDRAT KOMPLEKS
Cellulose
Selulosa merupakan polimer dari β-D-Glukosa, yang berbeda dengan pati,
berorientasi dengan gugusan -CH2OH bergantian di atas dan di bawah bidang
molekul selulosa, sehingga menghasilkan rantai panjang tidak bercabang. Tidak
adanya rantai samping memungkinkan molekul selulosa untuk berdekatan dan
membentuk struktur yang kaku. Selulosa adalah bahan struktural utama dari
tumbuhan.
Wood is largely cellulose, and cotton is almost pure cellulose.
Cellulose can be hydrolyzed to its constituent glucose units by microorganisms that
inhabit the digestive tract of termites and ruminants. Cellulose may be modified in the
laboratory by treating it with nitric acid (HNO3) to replace all the hydroxyl groups with
nitrate groups (-ONO2) to produce cellulose nitrate (nitrocellulose or guncotton) which is
an explosive component of smokeless powder.
Partially nitrated cellulose, known as pyroxylin, is used in the manufacture of collodion,
plastics, lacquers, and nail polish.
Cellulose Gum or Carboxymethyl Cellulose (CMC) is a chemical derivative of
cellulose where some of the hydroxyl groups (-OH) are substituted with
carboxymethyl groups (-CH2COOH). The properties of cellulose gum depend on the
degree of substitution and the length of the cellulose chains.
The degree of substitution (DS) is the number of carboxymethyl groups per glucose
unit and may vary in commercial products from 0.4 to 1.5. Cellulose gum is nontoxic and becomes very viscous when combined with water. It is used as a
thickener for foods and as an emulsion stabilizer in products like ice cream.
Cellulose gum is also used in personal lubricants, diet pills, water-based paints,
detergents and paper coatings.
http://www.scientificpsychic.com/fitness/carbohydrates2.html …… diunduh 17/3/2012
STRUKTUR KARBOHIDRAT KOMPLEKS
Hemicellulose
The term "hemicellulose" is applied to the polysaccharide components of plant cell
walls other than cellulose, or to polysaccharides in plant cell walls which are
extractable by dilute alkaline solutions. Hemicelluloses comprise almost one-third
of the carbohydrates in woody plant tissue. The chemical structure of
hemicelluloses consists of long chains of a variety of pentoses, hexoses, and their
corresponding uronic acids. Hemicelluloses may be found in fruit, plant stems, and
grain hulls. Although hemicelluloses are not digestible, they can be fermented by
yeasts and bacteria. The polysaccharides yielding pentoses on hydrolysis are called
pentosans. Xylan is an example of a pentosan consisting of D-xylose units with
1β→4 linkages.
Arabinoxylan
Arabinoxylans are polysaccharides found in the bran of grasses and grains such as wheat, rye, and
barley. Arabinoxylans consist of a xylan backbone with L-arabinofuranose (L-arabinose in its 5-atom
ring form) attached randomly by 1α→2 and/or 1α→3 linkages to the xylose units throughout the chain.
Since xylose and arabinose are both pentoses, arabinoxylans are usually classified as pentosans.
Arabinoxylans are important in the baking industry. The arabinose units bind water and produce
viscous compounds that affect the consistency of dough, the retention of gas bubbles from
fermentation in gluten-starch films, and the final texture of baked products.
http://www.scientificpsychic.com/fitness/carbohydrates2.html …… diunduh 17/3/2012
STRUKTUR KARBOHIDRAT KOMPLEKS
Chitin
Chitin is an unbranched polymer of N-Acetyl-D-glucosamine. It is found in fungi and
is the principal component of arthropod and lower animal exoskeletons, e.g., insect,
crab, and shrimp shells. It may be regarded as a derivative of cellulose, in which the
hydroxyl groups of the second carbon of each glucose unit have been replaced with
acetamido (-NH(C=O)CH3) groups.
Pectin
Pectin is a polysaccharide that acts as a cementing material in the cell walls of all
plant tissues. The white portion of the rind of lemons and oranges contains
approximately 30% pectin. Pectin is the methylated ester of polygalacturonic acid,
which consists of chains of 300 to 1000 galacturonic acid units joined with 1α→4
linkages. The Degree of Esterification (DE) affects the gelling properties of pectin.
The structure shown here has three methyl ester forms (-COOCH3) for every two
carboxyl groups (-COOH), hence it is has a 60% degree of esterification, normally
called a DE-60 pectin. Pectin is an important ingredient of fruit preserves, jellies,
and jams.
Pectin is a polymer of α-Galacturonic acid with a variable number of
methyl ester groups.
http://www.scientificpsychic.com/fitness/carbohydrates2.html …… diunduh 17/3/2012
STRUKTUR KARBOHIDRAT KOMPLEKS
Starch
Starch is the major form of stored carbohydrate in plants. Starch is composed of a
mixture of two substances: amylose, an essentially linear polysaccharide, and
amylopectin, a highly branched polysaccharide. Both forms of starch are polymers
of α-D-Glucose. Natural starches contain 10-20% amylose and 80-90% amylopectin.
Amylose forms a colloidal dispersion in hot water (which helps to thicken gravies)
whereas amylopectin is completely insoluble.
Amylose molecules consist typically of 200 to 20,000 glucose units which form a helix as a result
of the bond
Amylopectin differs from amylose in being highly branched. Short side chains of
about 30 glucose units are attached with 1α→6 linkages approximately every
twenty to thirty glucose units along the chain. Amylopectin molecules may contain
up to two million glucose units.
http://www.scientificpsychic.com/fitness/carbohydrates2.html …… diunduh 17/3/2012
REAKTOR BIODRYING
Biodrying reactors use a combination of engineered physical and biochemical processes.
Reactor design includes a container coupled with an aeration system; containers can be
either enclosed , or open tunnel-halls, or rotating drums . On the biochemical side, aerobic
biodegradation of readily decomposable organic matter occurs. On the physical side,
convective moisture removal is achieved through controlled, excessive aeration. Whilst the
general reactor configuration and physiobiochemical phenomenon is similar to composting,
the exact way in which it is operated is significantly different.
DEKOMPOSISI AEROBIK DALAM BIODRYING
Dalam proses biodrying, prinsip proses drying yang didukung dengan
panas biologis akibat aktivitas mikroba dengan bantuan aerasi. Bagian
utama dari panas biologis secara alami tersedia melelui degradasi aerobic
bahan organic, digunakan untuk menguapkan air yang terkandung dalam
matrik sampah tersebut. Ada empat tahap biologi dan kimia sebagai kunci
proses dekomposisi aerob dalam biodrying :
1.Hidrolisis. Proses hidrolisis adalah proses pemecahan polimer organik
kompleks dengan berat molekul yang besar menjadi monomer penyusunnya
dan melarutkannya ke dalam larutan, misalnya air.
2.Acidogenesis. Proses acetogenesis adalah proses konversi senyawa
monomer senyawa organik seperti glukosa, asam amino dan asam lemak,
menjadi etanol dan asam asetat. Pada proses ini juga dihasilkan senyawa
amonia, CO2, dan uap air.
3.Asetogenesis. Proses asetogenesis adalah proses konversi etanol dari
proses acidogenesis menjadi asam asetat oleh mikroba asetogen.
4.Methanogenesis. Proses methanogenesis adalah proses konversi asam
asetat yang dihasilkandari proses sebelumnya, menjadi gas methane dan
karbon dioksida.
http://www.epem.gr/waste-c-control/database/html/Biodrying-00.htm …… diunduh 17/3/2012
DEKOMPOSISI
AEROBIK
HIDROLISIS ENSIMATIK
Dalam dekomposisi aerobik, bakteri dapat mengubah polimer rantai panjang
seperti karbohidrat, rantai ini dipecah menjadi bagian yang lebih kecil, yaitu
molekul monomernya, seperti glukosa.
Proses memecah rantai karbon menjadi molekul-molekul yang lebih kecil dan
larut dalam larutan, disebut hidrolisis. Oleh karena itu, hidrolisis senyawa yang
berat molekulnya tinggi ini merupakan proses awal yang diperlukan dalam
dekomposisi aerobik.
Melalui hidrolisis molekul organic kompleks seperti pati, lemak, dan protein
dipecah menjadi gula sederhana, asam amino, dan asam lemak.
Asam asetat dan hydrogen yang dihasilkan pada proses hidrolisis dapat
digunakan langsung oleh bakteri methanogen. Molekul lainnya seperti asam
lemak volatile (VFA)dengan memiliki rantai panjang dari asam karboksilat
harus dipecah menjadi senyawayang lebih kecil, yang dapat langsung
dimanfaatkan oleh bakteri methanogen. Produk dari fermentasi VFA adalah
amonia, methane disulfide, keton, benzene, hydrogen sulfide serta produk
lain.
The hydrolysis of polysaccharides to soluble sugars is called "saccharification". Malt
made from barley is used as a source of β-amylase to break down starch into the
disaccharide maltose, which can be used by yeast to produce beer. Other amylase
enzymes may convert starch to glucose or to oligosaccharides. Cellulose is
converted to glucose or the disaccharide cellobiose by cellulases. Animals such as
cows (ruminants) are able to digest cellulose because of symbiotic bacteria that
produce cellulases.
Sucrose.
The glycoside bond is represented
by the central oxygen atom, which
holds the two monosaccharide
units together.
http://en.wikipedia.org/wiki/File:Sucrose-inkscape.svg …… diunduh 17/3/2012
ASETO-GENESIS
Asetogenesis - Methanogenesis
Tahap ke tiga dalam proses dekomposisi aerobik adalah asetogenesis.
Setelah molekul sederhana hasil fermentasi secara asetogenesis lebih lanjut
dicerna oleh bakteri acetogen untuk menghasilkan asam asetat serta karbon
dioksid dan hydrogen.
Tahap terakhir dekomposisi aerobic adalah proses biologis methanogenesis.
Bakteri methanogen memanfaatkan produk dari tahapan sebelumnya dan
mengubah menjadi gas methane, karbon dioksida dan air.
Metana yang dihasilkan dari proses metanogenesis merupakan komponenkomponen yang membentuk sebagian besar gas yang dihasilkan oleh system.
Methanogenesis merupakan proses yang sensitive terhadap pH dan terjadi
antara pH 6,5 – 8.
Simplified schematic illustrating the methanogenic degradation of organic matter. Circled
numbers indicate the metabolic group of microbes involved in the particular stage of
degradation. 1: initial hydrolysis of polymeric carbon; 2: fermentation of monomers to low
molecular weight compounds; 3: aceticlastic methanogenesis and 4: CO2-reducing
methanogenesis from fermentation intermediates.
(http://ese.mines.edu/research_projects/biogenic_methane.html)
…… diunduh 17/3/2012
PARAMETER OPERASIONAL BIODRYING
ALIRAN UDARA MELALUI MATRIKS
Udara pengeringan (atau pengeringan penyimpanan massal) menggunakan
aliran udara melalui butir sampah atau residu di bagian dalam bed untuk
pengeringan dan mengawetkan sampah (Nellist, 1998).
Suhu matrix sampah mencapai 5ºC di atas suhu lingkungan.
Operasional kritis dan parameter terkait matrix sampah MC (moisture content),
MC equilibrium, waktu penyimpanan, dan tahan tekanan terhadap aliran
udara) dan udara (tingkat dan sifat aliran udara psychrometric, yaitu sifat yang
mengacu pada hubungan termodinamika dan fisik antara udara dan air uap,
seperti relatif humudity, temperatur, dll).
The process of evaporation is used in the arts for increasing the density of liquids by
boiling down, for drying wet materials, and for cooling purposes. The vaporization
of the liquid may be accomplished by adding more heat to it, or by lessening or
removing the atmospheric pressure upon it. Air may be partially dried by cooling it
to a low temperature. The vapor accompanying it will be condensed and thrown
down as water, and when the air is afterwards warmed it will be correspondingly
dry.
The efficiency of a drying apparatus which uses hot air as the drying medium will
depend upon several factors, as follows:
1. The dryness of the air before it is heated.
2. The degree of heat that is given to the air.
3. The amount of surface of wet material from which evaporation can readily
take place.
4. The volume of the air-current.
5. The thorough distribution of the fresh dry air over the evaporating surfaces.
6. The promptness with which the moistened air is removed.
Read more: http://chestofbooks.com/architecture/Building-ConstructionV4/Evaporation-And-Drying.html#ixzz1pSJSjFSq
http://chestofbooks.com/architecture/Building-Construction-V4/Evaporation-And-Drying.html…… diunduh
17/3/2012
Effect of air-flow rate and turning frequency on bio-drying of dewatered sludge.
Ling Zhao, Wei-Mei Gu, Pin-Jing He, Li-Ming Shao
Water Research (2010)
Volume: 44, Issue: 20, Publisher: Elsevier Ltd, Pages: 6144-6152
ABSTRACT
Sludge bio-drying is an approach for biomass energy utilization, in which sludge
is dried by means of the heat generated by aerobic degradation of its organic
substances. The study aimed at investigating the interactive influence of airflow rate and turning frequency on water removal and biomass energy
utilization. Results showed that a higher air-flow rate (0.0909m(3)h(-1)kg(-1))
led to lower temperature than did the lower one (0.0455m(3)h(-1)kg(-1)) by
17.0% and 13.7% under turning per two days and four days.
With the higher air-flow rate and lower turning frequency, temperature
cumulation was almost similar to that with the lower air-flow rate and higher
turning frequency. The doubled air-flow rate improved the total water removal
ratio by 2.86% (19.5gkg(-1) initial water) and 11.5% (75.0gkg(-1) initial water)
with turning per two days and four days respectively, indicating that there was
no remarkable advantage for water removal with high air-flow rate, especially
with high turning frequency. The heat used for evaporation was 60.6-72.6% of
the total heat consumption (34,400-45,400kJ).
The higher air-flow rate enhanced volatile solids (VS) degradation thus
improving heat generation by 1.95% (800kJ) and 8.96% (3200kJ) with turning
per two days and four days. With the higher air-flow rate, heat consumed by
sensible heat of inlet air and heat utilization efficiency for evaporation was
higher than the lower one. With the higher turning frequency, sensible heat of
materials and heat consumed by turning was higher than lower one.
http://www.mendeley.com/research/effect-airflow-rate-turning-frequency-biodrying-dewatered-sludge/……
diunduh 17/3/2012
REAKTOR BIODRYING
Reaktor biodrying bertujuan untuk pre-treatment limbah pada waktu tinggal
terendah dalam hal untuk menghasilkan SRF kualitas tinggi.
Hal dapat ini dicapai dengan:
1. Peningkatan kandungan energi (EC) (Adani et al., 2002) dengan
memaksimalkan penghilangan kelembaban dalam matriks sampah dan
melestarikan sebagian dari nilai kalor kotor dari senyawa kimia organik
melalui biodegradasi yang minimal,
2. Memfasilitasi penggabungan dari sebagian kandungan biogenik
diawetkan ke SRF;
3. Membuat output lebih sesuai untuk pengolahan mekanik dengan
mengurangi kelengketan.
Biodrying membuat materi yang lebih cocok untuk penyimpanan jangka
pendek dan transportasi yang baik oleh sebagian biostabilising dan
mengurangi MC di bawah ambang batas yang diperlukan
untuk berlangsungnya biodegradasi
Drying biomass material Reduction in the moisture content of biomass
material may be required to achieve a number of purposes in energy
applications.
Biomass may be dried before and/or after harvesting and harvested for
reduced moisture content.
Any moisture content must be driven off before combustion can take place,
either in advance before storage or as part of the combustion process
(which then uses part of the energy of the fuel); in either case this reduces
the overall energetic efficiency.
Equally, gasification also requires relatively low moisture content (<1015%).
(http://www.biomassenergycentre.org.uk/portal/page?_pageid=75,17305&_dad=portal
&_schema=PORTAL)
…… diunduh 17/3/2012
PENGUAPAN KONVEKTIF
Dalam biodrying, yang mekanisme pengeringan utama adalah konvektif
penguapan, menggunakan panas dari aerobik biodegradasi komponen
limbah dan didukung aliran udara.
Kandungan kelembaban (MC) dari matriks limbah dikurangi melalui dua
langkah utama:
(1) molekul-molekul air menguap (yaitu, perubahan fasa dari cair ke
gas) dari permukaan fragmen limbah ke udara sekitarnya, dan
(2) air menguap diangkut melalui matriks dengan aliran udara dan
dihilangkan dengan saluran gas buang.
Jumlah terbatas air bebas yang dapat merembes melewati matriks
limbah dan dikumpulkan di bagian bawah reaktor biodrying sebagai
lindi.
Effect of Flow rate of air
This is in part related to the concentration points above. If fresh air is
moving over the substance all the time, then the concentration of the
substance in the air is less likely to go up with time, thus encouraging
faster evaporation.
This is the result of the boundary layer at the evaporation surface
decreasing with flow velocity, decreasing the diffusion distance in the
stagnant layer.
(http://en.wikipedia.org/wiki/Evaporation)
…… diunduh 17/3/2012
FENOMENA BIO-DRYING
Dalam proses biodrying, konveksi udara dan difusi molekular adalah
transportasiutama untuk mekanisme pengaliran uap air melalui matriks (Frei dkk.,
2004b). Konveksi air, disebabkan oleh aliran udara yang direkayasa melalui
matriks. Udara membawa air yang menguap dari permukaan partikel matriks
(kelembaban bebas) dengan adanya kontak. Penghilangan kandungan air dari
matriks sampah (desorpsi)dengan penguapan konvektif diatur oleh keseimbangan
termodinamika antara matriks sampah basah (solid state) dan udara mengalir
melalui matriks (fasa gas). Kapasitas vapour-carrying dari udara terbatas pada
masing-masing T (udara) dan dicapai pada titik jenuh, setelah kondensasi yang
terjadi. Pada tingkat tertentu kelembaban relatif (RH) udara (rH udara) massa uap
air udara dapat terus meningkat dengan suhu.
rH udara telah telah digunakan di dekat keadaan lingkungan
pemodelan pengeringan untuk memperkirakan jarak dari saturasi titik inlet
udara, yaitu dengan sederhana dapat dianggap sebagai pengukuran pengganti
dari potensial pengeringan.
In a typical phase diagram, the
boundary between gas and liquid
runs from the triple point to the
critical point.
Regular drying is the green arrow,
while supercritical drying is the red
arrow and freeze drying is the blue.
(http://en.wikipedia.org/wiki/Drying)
…… diunduh 17/3/2012
Udara dan suhu matriks yang optimal untuk biodrying
ALIRAN UDARA DAN SUHU SUBSTRAT
Dalam proses biodrying, tingkat pengeringan yang lebih tinggi (volume
kelembaban yang dihilangkan per waktu) dicapai dengan tingkat aliran
udara yang lebih tinggi.
Titik penyetelan suhu substrat lebih rendah (45º C, dibandingkan dengan
55 º C dan 65 º C) mengakibatkan pengeringan yang lebih efektif .
Proses biodrying paling komersial beroperasi di rentang suhu 40-70 º C
untuk lubang udara Tout, untuk sebagian besar waktu tinggal berlaku
Tout kontrol bertahap, yang terdiri dari empat fase lebih dari satu
minggu:
1.Start up dan aklimatisasi biomassa: 40 º C;
2.Degradasi: 40-50 º C;
3.Sanitisation dan pengeringan: 50-60 C;
4.Pendingin menuju suhu ruang 60 ºC menuju T lingkungan (Nicosia et
al., 2007).
…… diunduh 17/3/2012
Aktivitas mikroba
Proses mikroba selama biodrying harus sesuai untuk
memanfaatkan dari panasyang diperlukan untuk
pengeringan yang efektif, bersama dengan
biodegradasisubstrat limbah yang terbatas.
Suhu substrat adalah faktor yang paling penting yang
mempengaruhi mikroba pertumbuhan (Miller, 1996),
karena antara lain, menyediakan kondisi ideal untuk
proliferasi jenis tertentu mikro organisme, misalnya,
mesofilik atau termofilik
…… diunduh 17/3/2012
AKTIVITAS MIKROBA DALAM BIODRYING
MIKROBA - BIODRYING
Selama biodrying dari matriks kandungan kelembaban tinggi lumpur
pulp dankertas, Roy dkk. (2006) mengidentifikasi tiga tahap
pengeringan yang terpisah, yang berkorelasi dengan periode
pertumbuhan mikroba:
1.Aklimatisasi mikroba mengakibatkan peningkatan eksponensial
tingkat pengeringan;
2.Penurunan eksponensial dari tingkat pengeringan karena
ketersediaan nutrisitidak cukup untuk konsumsi mikroba, dan
3. Pengeringan konstan, sesuai dengan fluktuasi Q Udara tersebut.
Jika dinamis serupa berlaku untuk substrat kering yang banyak sisa
MSW itu akan menunjukkan bahwa setelah beberapa titik biodrying
kurang tergantung pada aktivitasmikroba, semakin terhambat oleh
stres air, menjadi bukan hanya proses fisik (udara konveksi).
Hal ini jelas tidak akan mempengaruhi keseimbangan energidari
proses.
…… diunduh 17/3/2012
Nanda Gayuk Candy. 2012.”
Pengelolaan Sampah Kota dalam Rangka Pencapaian Pembangunan Millenium
(MDGs) . ”.(online)http://lifestyle.kompasiana.com/urban/2012
01/11/pengelolaan-sampah-kota-dalam-rangka-pencapaian-pembangunanmillenium-mdgs/, diakses 16 januari 2012Suwarno, 2011.
“Sampah di kota Malang 400 ton perhari”
http://mediacenter.malangkota.go.id/2011/02/10/sampah-di-kota-malang400-ton-perhari/
(diakses, 20 janiari 2012)
Velis C.A., Longhurst P.J.t, Drew G.H. and Smith R, Pollard S.J.T. 2009.
“Biodryingfor mechanical-biological treatment of wastes: a review of process
science andengineering” Volume 100. Bioresource Technology,
Cranfield University.
Mihaela Negoi Ramona, Ragazzi Marco, Apostol Tiberiu, Cristina Rada
Elena,Marculescu Cosmin. 2009. Bio-Drying Of Romanian Municipal Solid
Waste: AnAnalysis Of Its Viability. Vol. 71.-Haug, R.T., 1993. The practical
handbook of compost engineering, Boca Raton USA:CRC Press, Lewis
Publishers.
Frei, K.M., Stuart, P.R., Cameron, D., 2004. Novel drying process using
forcedaeration through a porous biomass matrix. Finland : Dry. Technol.
…… diunduh 17/3/2012