Decentralized Power Production in Rural Communities

Andrea French

Nicole Munguia

November 21, 2006

Producer Gas

Methods for Biogas Production

Anaerobic Digestion Biomass Gasification

Fuel SourcesDecomposition Process

Processing Method

Various Applications:Mechanical, Thermal and Chemical Production

Anaerobic Digesters to Produce Biogas in Rural India

Feed Material Digestion Process Plant Design Applications Potential

http://www.biotank.co.uk/images/Feat11_picII-1.jpg

http://breathappeal.com/causes.htm

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.visakhaspca.org/programs/cowsanctuary.asp

http://www.worldofstock.com/closeups/TAN1242.php

Digestion ProcessSteps 3 & 4 Chemical Equation: CO2 + 4H2 → CH4 + 2H2O

Steps 3 & 4 Chemical Equations: CO2 + 4H2 = CH3COOH + 2H2O

CH3COOH → CH4 + CO2

http://www.biotank.co.uk/images/Feat11_picII-1.jpg

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

Average Composition of Biogas

Fixed Dome Designs

http://web1.msue.msu.edu/intext/biogas10.jpghttp://web1.msue.msu.edu/intext/blue%20bags.jpg

http://www.grameen-info.org/grameen/gshakti/programs.html

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

http://www.ashdenawards.org/winners/prakratik

http://www.repp.org/discussiongroups/resources/gasification/

http://www.oredaorissa.com/Photo.html

2 m3 biogas plant in a month could replace:

•26 kg if LPG,

•37 liters of kerosene,

•88 kg of charcoal,

•210 kg of fuel wood,

•or 740 kg of animal dung.

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/gotwattbig.jpg

Biomass Gasification

Characteristics of Fuel Sources Types of Gasifiers Cooling and Filtering Producer Gas Applications

Characteristics of Fuel Sources

High Energy Content/Bulk Density

Low Moisture Content

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 cubes256 5.4 0.2 3.24

Low Tar Production Low Ash Production

Rajvanshi, A.K., (1986)

Gasifier Design Updraft, Downdraft and Crossdraft Tailored to the Fuel Source Produce Minimal Dust and Tar

(Rajvanshi, 1986).

Updraft 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.htm2. http://www.unu.edu/unupress/unupbooks/80362e/80362E0j.htm3. http://web.archive.org/web/20041124201613/www.eere.energy.gov/consume

rinfo/factsheets/ab5.html?print4. Biogas: The Indian NGO Experience by AFPRO-CHF Network5. Energy, The Biomass Solution by Henry Bugay6. Rajvanshi, A.K., (1986). Biomass Gasification [Electronic version].

Alternative Energy in Agriculture, Vol.II, Ed.D, Chapter (No.4), 83-102.