Decentralized Power Production
in Rural Communities
Andrea French
Nicole Munguia
November 21, 2006
Methods for Biogas Production
Anaerobic Digestion
Biomass Gasification
Fuel Sources
Decomposition Process
Processing Method
Producer Gas
Various Applications:
Mechanical, Thermal and Chemical Production
Anaerobic Digesters to Produce Biogas in
Rural India
 Feed Material
http://breathappeal.com/causes.htm
 Digestion Process
 Plant Design
 Applications
 Potential
http://www.biotank.co.uk/images/Feat11_picII-1.jpg
Feed Material
Type of Feedstock
Biogas per kg
Feedstock (m3)
Cows or Buffalo Dung
0.023-0.040
Pig Dung
0.040-0.059
Poultry Dung
0.065-0.116
Human Dung
0.020-0.028
Pre-treated Crop residue
and Water Hyacinth
0.037-0.045
http://www.repp.org/discussiongroups/resources/gasification/
http://news.bbc.co.uk/2/hi/south_asia/4205506.stm
http://www.worldofstock.com/closeups/TAN1242.php
http://www.visakhaspca.org/programs/cowsan
ctuary.asp
Digestion Process
Steps 3 & 4 Chemical Equation:
 CO2 + 4H2 → CH4 + 2H2O
Steps 3 & 4 Chemical Equations:
 CO2 + 4H2 = CH3COOH + 2H2O
CH3COOH → CH4 + CO2
Average Composition of Biogas
Matter
%
Methane, CH4
55-75
Carbon Dioxide, CO2
25-45
Carbon Monoxide, CO
0-0.3
Nitrogen, N2
1-5
Hydrogen, H2
0-3
Hydrogen Sulfide, H2S
0.1-0.5
Oxygen, O2
Traces
http://www.biotank.co.uk/images/Feat11_picII-1.jpg
Fixed Dome Designs
http://www.grameeninfo.org/grameen/gshakti/prog
rams.html
http://web1.msue.msu.edu/intext/blue%20bags.jpg
http://web1.msue.msu.edu/intext/biogas10.jpg
Fixed Dome Diagram
http://www.fao.org/docrep/T0541E/T0541E0E.GIF
Design Parameters
Design of Biogas Plant
Number of Cows
4
Assuming 1 Cow Produces
10 kg of dung/day
Amount of Dung Produced by 4 Cows
40 kg
Amount of Gas Produced by 1 kg of Dung
0.05 m3
Amount of Gas Produced by 40 kg of Dung
2 m3
Daily Requirement of Gas for Cooking/Lighting for 1
Person
0.5-0.6 m3
2 m3 of Gas per Day Will Provide Cooking and Lighting for
2/0.6 to 2/0.5 = 3 or 4 persons
Anaerobic Decomposition BioGas
Applications
 Effluent Use
Fertilizer
 Soil conditioner
 (Destroys Pathogens)
 Lighting
 Cooking

2 m3 biogas plant in a month
could replace:
http://www.oredaorissa.com/Photo.html
http://www.repp.org
/discussiongroups/r
esources/gasificatio
n/
•26 kg if LPG,
•37 liters of kerosene,
•88 kg of charcoal,
•210 kg of fuel wood,
•or 740 kg of animal dung.
http://www.ashdenawards.org/winners/prakratik
Potential for India
 260 million cows
 10 kg dung per day
 75% collection rate
 ~2 million tons of dung
daily
 40 kg dung produces 2
m3 biogas
 40 million 2 m3 plants
http://www.nrcs.usda.gov/news/images/got
wattbig.jpg
Biomass Gasification
 Characteristics of Fuel Sources
 Types of Gasifiers
 Cooling and Filtering Producer Gas
 Applications
Characteristics of Fuel Sources
 High Energy Content/Bulk
 Low Tar Production
Density
 Low Moisture Content
 Low Ash Production
Excellent
Fuels
Bulk Density
(kg/m^3)
M.C. (%)
Ash (%)
Tar (g/m^3)
Coconut Shells
crushed
435
11.8
0.8
3
Peach Pits
474
10.9
0.9
1.1
Corn Cobs
304
11
1.5
7.24
Prune Pits
514
8.2
0.5
0
Walnut Shells
cracked
337
8
1.1
6.24
Wood Blocks
5cm cubes
256
5.4
0.2
3.24
Rajvanshi, A.K., (1986)
Gasifier Design
 Updraft, Downdraft and Crossdraft
 Tailored to the Fuel Source
 Produce Minimal Dust and Tar
Updraft
(Rajvanshi, 1986).
Downdraft
Crossdraft
Downdraft Reactor
Cooling & Filtering Producer Gas
 Filter out impurities
 Cool producer gas to ambient temperature
Schematic Producer Gas Plant (Rajvanshi, 1986)
Applications
 Power Applications
 Generators for Electricity
 IC engines for Agricultural Equipment
 Pump for Irrigation Purposes
 Thermal Application
 Boil Water
 Cooking & Grain Drying
 Steam generation: Cogeneration or Residential Space
Heating
 Chemical Production
 Methanol: Oxidize Methane
 Hydrogen Gas: Water-Gas Shift Reaction/Steam
Reforming
QUESTIONS????
References:
1. http://www.fao.org/sd/EGdirect/EGre0022.htm
2. http://www.unu.edu/unupress/unupbooks/80362e/80362E0j.htm
3. http://web.archive.org/web/20041124201613/www.eere.energy.gov/con
sumerinfo/factsheets/ab5.html?print
4. Biogas: The Indian NGO Experience by AFPRO-CHF Network
5. Energy, The Biomass Solution by Henry Bugay
6. Rajvanshi, A.K., (1986). Biomass Gasification [Electronic version].
Alternative Energy in Agriculture, Vol.II, Ed.D, Chapter (No.4), 83-102.