Biodiesel Production Technology

advertisement
BIODIESEL PRODUCTION TECHNOLOGY
& FEEDSTOCKS FOR INDIA
Expert Lecture at Workshop on
Moving Toward Sustainable Energy Systems:
Exploring Global Pathways to a Common Destination
Organized by
UNIVERSITY OF MINNESOTA, OCTOBER 24,2006
PROF. NAVEEN KUMAR
COORDINATOR, BIODIESEL RESEARCH
DELHI COLLEGE OF ENGINEERING
DELHI, INDIA
Email: naveenkumardce@rediffmail.com
Phone : 27871248, 32924637 Mobile : 9891963530, 9810363530
What is
Biodiesel?
Biodiesel, a fuel composed of mono-alkyl esters of
long chain fatty acids derived from variety of
vegetable oils or animal fats, designated as B100,
and confirming to different quality standards e.g.
ASTM D 6751, EN14214 or IS 15607.
Transesterification Reaction
1 triglyceride + 3 alcohol
catalyst
3 ester alcohol + 1 glycerine
Me
O=
O
O=
O
O=
O
O=
3 MeOH
Me
O
O=
Me
O
O=
O
HO
HO
KOH
Catalyst
Triglyceride
HO
Glycerol
Biodiesel
(Methyl Ester Alcohol)
Molecular Structure
Fats and oils have quite big
molecules with a spinal of glycerol
on which are bond three fatty acid
rests.
By the transesterification, the fatty
acid rests are removed from the
glycerol and each is bond with
methanol.
The products are one mole glycerol
and three mole of fatty acid methyl
ester.
Issues Related to Base Catalyzed
Transesterification Process


Feedstock Issues
FFA
Water
Process Issues
Type of Alcohol
Molar Ratio
Catalyst
Reaction time & temperature
Agitation
Feedstock Issues
1. Free Fatty Acids (FFA)
Free Fatty acids in the oils react with alkaline
catalyst to form soaps.
R-OH + KOH
Acid + KOH
K-OR + H2O
Soap + water
It results in loss of catalyst and reduction in
yield
Feedstock Issues
2. Water
Water deactivates the catalysts. Drying of oil is required.
Water hydrolyses fats to form free fatty acids.
Free fatty acids react with alkali catalysts forms soaps
Soaps
semi solid mixture
glycerol separation
Process Issues
Type of Alcohol
• Methanol, Ethanol, Butanol etc
• Methanol –commercially used
• In methanolysis, emulsion forms and separated into
lower glycerol portion and upper ester portion.
Reaction time is small
• In ethanolysis, emulsions are stable and requires
more complicated separation and purification
process. Reaction time is large
• Typical alcohol: TG ratio is 6:1 for base catalyzed
reactions.
Catalyst?
“Chemical marriage brokers”
The presence of a catalyst facilitates reactions that would
be kinetically impossible or very slow without a catalyst
Homogeneous versus Heterogeneous
Homogenous
The catalyst, reactants
and products are all in
one phase, normally the
liquid
phase.
The
reactions proceed over
a intermediate complex
and are often highly
selective, but separation
of the products and the
catalyst is difficult.
Hetrogenous
The catalyst is in one
phase, normally solid,
while the reactants and
products are in another
phase. Separation of
catalyst and products is
easy, but the reaction is
often less selective,
because the catalyst
material
is
not
homogeneous
Various Catalysts used in Biodiesel
Production
Homogenous
• Base Catalysts: NaOH, KOH, NaMeO
• Acid Catalysts: H2SO4, PTSA, MSA, H3PO4, CaCO3

Typical base concentrations are :
NaOH/KOH – 0.3 to 1.5 %
Na MeO – 0.5 % or less
Heterogeneous
• Sulfated Zeolites & Clays
• Hetro-poly acids
• Metal Oxides, Sulfates
• Composite materials
Reaction time , Temperature & Agitation
 Transesterification



reaction will proceed at
ambient (30°C) temperatures but needs 4-8
hours to reach completion.
Reaction time can be shortened to 2-4 hours at
40°C and 1-2 hours at 60°C.
Higher temperatures will decrease reaction
times but require pressure vessels because
methanol boils at 65°C.
Better agitation should be adopted to accelerate
reaction.
Batch, Base Catalyzed Process
Alcohol
TG
Water
Water
Ester
Biodiesel
Alcohol
Dryer
Catalyst
Water
Alcohol
Batch Reactor
Wash
Water
Acid
Crude
Glycerol
Neutralized
Glycerol
10 Liters Biodiesel Unit
Stirrer
Water Cooled
Condenser
Cooling Water
Reaction
Vessel
Heating Element
Development Cost : US $ 1300
600 LITERS/DAY BIODIESEL UNIT
Control Panel
Motor & Gear Box
Skid
Oil Tank
Methaoxide
Vessel
Washing Vessel
Reaction Vessel
Vacuum Drier
Separating Vessel
Development Cost : US $ 7000
Motor& Gear Pump
High FFA Feed Stocks
 Biodiesel feed stocks are classified by the amount of
free fatty acids they contain:
• Refined vegetable oils < 0.05%
• Crude vegetable oil 0.5-5%
• Used Cooking Oil 2-7%
• Animal fat 10-30%
 Price decreases as FFAs increase but processing cost

also increase
Base Catalyzed Reaction not suitable for high FFA
feeds because of soap formation.
Most of the non-edible oils available in India contains high FFA (212%) & to decrease the cost of biodiesel, it is imperative to utilize
high FFA oil or fatty acids
Acid Catalyzed Processes
Acid catalyzed processes are used for direct
esterification of free fatty acids in a high FFA
feedstock
Limitations:
 Water formation by
FFA + methanol ==> methyl ester + water
 High alcohol: FFA ratio required – about 40:1
 Large amounts (5 to 25 %) catalyst may be
required

Preferred method for High FFA feeds: Acid
Catalysis followed by base catalysis
Use acid catalysis for conversion of FFAs to
methyl esters, until FFA < 0.5%.
 Acid esterification of FFA is fast (1 hour) but acid
catalyzed transesterification is slow (2 days at
60°C).
2. Then, add additional methanol and base catalyst
to transesterify the triglycerides.
1.
Air
SVO
P1
Methanol
+
H2SO4
SV2
P3
P2
Vaccum
Drier
Motor
SV3
P8
Settling Tank
1000 Ltrs.
Reactor 600 Ltrs.
Motor
Vegetable Oil
Storage
Tank
1500 Kg
Biodiesel
Storage
Tank
1000 Ltrs.
Design by
DCE
SV2
Biodiesel Unit
1tpd Capacity
P7
Vaccum
P6
Methanol
+
KOH
Storage
Tank
500 Ltrs.
P5
Drier
P4
Glycerol Storage
Tank 500 Ltrs.
Washing Column Separating Column
500 Ltrs./ Charge 500 Ltrs./ Charge
Transesterification
Reactor,
500Lts./Charge
Barriers to Homogeneous Catalyst






Sensitivity to FFA & water content of the
feedstocks
Removal of catalyst
Formation of soap with high FFA feedstock
Large quantity of effluent water as a result of
removal of catalyst
Necessities pre-treatment of oil in case FFA
content are higher
No scope for regeneration or re-utilization
Heterogeneous
Catalyst
Benefits - Heterogeneous Catalyst




Catalyst Regeneration – Decrease of Catalyst
Cost
Utilization of lower quality feed stocks for
biodiesel production
Simplification of separation process – Decrease
of production cost
Decrease of wastewater – Development of
environmental friendly process
Product Quality









Product quality is important – modern diesel
engines are very sensitive to fuel.
It is not biodiesel until it meets Quality Standards.
Reaction must be >98% complete.
Acid number – for degrading, oxidized fuel
Flashpoint – for residual methanol
Water & sediment – fuel fouling, deposits
Sulfated ash – for residual catalyst
Total glycerin – for incomplete conversion, detects
residual mono, di and tri glycerides
Free glycerin – inadequate fuel washing
Feed Stocks for India
Feed stocks used in different Countries
Feedstock
Countries
Rape seed , Sunflower EU
Soya bean
U.S.A.
Palm Oil
Malaysia
Coconut
Philippines
Linseed & Olive oil
Spain
Cotton Seed Oil
Greece
Jatropha Curcas Oil
Nicaragua
Used Cooking Oil
Japan
Beef Tallow
Ireland , USA
Used frying Oil
Australia
WHY JATROPHA THE SUITABLE
CHOICE ?











Thrives on any type of soil
Needs minimal inputs or management
Has no insect pests
Not browsed by cattle or sheep
Can survive long periods of drought
Propagation by seed/cutting is easy
Rapid growth
Yield from the 2nd year onwards
Yield from established plantations 5 tonne per
ha.
30% oil from seeds by expelling
Seed meal excellent organic manure
Target Output per Hectare
Estimated Biodiesel production
per Hectare = 3,000 litres/700Gal
2500 trees per hectare
produces
Seed
6.9 tonnes
Seedcake
4.2 tonnes
Vegetable Oil
2.7 tonnes
Glycerol
0.27 tonnes
Potential yields of 12 tonnes per
hectare and 55% oil Extraction are
also attainable
Anti-Erosive Properties
Reduces wind and water erosion of soil
Improved absorption of water by soil
Properties of press cake as
fertilizer
Quality
seedling
preparation
10 x 20 cm bag
Germination -3 days
3-6 months old seedlings
VIEW OF JATROPHA PLANT
NURSERY
Intercropping with Jatropha
Indian Biodiesel Program









Name of Biodiesel started making appearance at Indian
Conferences, Workshops & Seminars in 1999
‘Report of the Committee on Development of Biofuel’ –
Planning Commission, GOI in 2003
Stage I ‘Demonstration Project’ use Jatropha curcas on
400,000 ha (0.5 MMT BD) Nation-wide investment $ 300mn
Stage II – 11 mill ha (13 MMT biodiesel) for 20% blend.
Demonstration project started with initial grant of $11mn for
nursery raising rest is expected to be sanctioned late this year
First 10,000 TPA plant in Hyderabad about to start production
Garware100,000 TPA DMT plant modified for biodiesel
production
A 250,000 TPA plant is being setup in Vishakhapatnam , A.P.
A 100,000 TPA plant is coming up in Kakinada , A.P.
India’s target of bio-diesel production
5 % mixing of Biodiesel in HSD by 2007
 20 % mixing of Biodiesel in HSD by 2012

Diesel & Biodiesel Demand, Area Required under Jatropha
For Different Blending Rates
Year
Diesel Demand
(MT)
Biodiesel requirement for
blending (MMT)
@
5%
@
10%
@
20%
Area Requirement for
Blending
(Mha)
@
5%
@
10%
@
20%
2006-07
52.33
2.62
5.24
10.48
2.19
4.38
8.76
2011-12
66.90
3.35
6.69
13.38
3.35
5.58
11.19
Land requirement for different
blending percentages
Summary
 Biodiesel is an renewable fuel for diesel engines that
can be made from virtually any oil or fat feedstock.
 Biodiesel with a potential consumption of 15000
million litres can have a retail turnover of more than
US$ 9000 mn per year
 It can provide huge rural employment potential of 40 to
50 million families and transform the rural economy
 Remote village electrification and power for agriculture
application – Energy grown & used by village.
 The technology choice is a function of desired
capacity, feedstock type and quality, alcohol recovery,
and catalyst recovery.
Summary
 The dominant factor in biodiesel production is the
feedstock cost which around 70%, with capital cost
contributing only about 7 % of the product cost.
Therefore high FFA, lower quality feedstock should
be promoted for biodiesel production in India.
 For meeting energy security and electricity for all, it
is necessary to develop and commission small to
medium capacity biodiesel unit at village &
community level..
 Maintaining product quality is also essential for the
growth of the biodiesel industry in India.
Thank You all for
your precious time
Download