Review Of Bio-Gas Technology
source: www.apo-tokyo.org
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GP Option for Community Development
GP Option for Community Development
Prepared for Asian Productivity Organization
3.1 Bio-Gas Technology
Bio-gas technology is the transformation of solid waste through anaerobic digestion process
to obtain bio-gas such as methane.
3.1.1 Process Microbiology
The biological conversion of the organic fraction of municipal solid waste under anaerobic
conditions is thought to occur in three steps. The first step involves the enzyme-mediated
transformation (hydrolysis) of higher-molecular-mass compounds into compounds suitable
for use as a source of energy and cell tissue. The second step involves the bacterial
conversion of the compounds resulting from the first step into identifiable lower-molecular-
mass intermediate compounds. The third step involves the bacterial conversion of these
intermediate compounds into simpler end products, principally methane and carbon dioxide.
In the anaerobic decomposition of wastes, a number of anaerobic organisms work together to
bring about the conversion of the organic portion of wastes into a stable end product. One
group of organism is responsible for hydrolyzing organic polymers and lipids to basic
structural building blocks such as fatty acids, monosaccharides, amino acids, and related
compounds. A second group of anaerobic bacteria ferments the breakdown products from the
first group to simple organic acids, the most common of which is acetic acid. This second
group of microorganisms, described as nonmethanogenic, consists of facultative and obligate
anaerobic bacteria that are often identified in the literature as “acidogens” or “acid formers”.
A third group of microorganisms converts the hydrogen and acetic acid formed by the acid
formers to methane gas and carbon dioxide. The bacteria responsible for this conversion are
strict anaerobes, called methanogenic, and are identified in the literature as “methanogens” or
“methane formers”. Many methanogenic organisms identified in landfills and anaerobic
digesters are similar to those found in the stomachs of ruminant animals and in organic
sediments taken from lakes and river. The most important bacteria of the methanogenic
group are the ones that utilize hydrogen and acetic acid. They have very slow growth rates;
as a result, their metabolism is usually considered rate-limiting in the anaerobic treatment of
an organic waste. Waste stabilization in anaerobic digestion is accomplished when methane
and carbon dioxide are produced. Methane gas is highly insoluble, and its departure from a
landfill or solution represents actual waste stabilization.
group are the ones that utilize hydrogen and acetic acid. They have very slow growth rates;
as a result, their metabolism is usually considered rate-limiting in the anaerobic treatment of
an organic waste. Waste stabilization in anaerobic digestion is accomplished when methane
and carbon dioxide are produced. Methane gas is highly insoluble, and its departure from a
landfill or solution represents actual waste stabilization.
3.1.2 Environmental Factors
To maintain an anaerobic treatment system that will stabilize an organic waste efficiently, the
nonmethanogenic and methanogenic bacteria must be in a state of dynamic equilibrium. To
establish and maintain such a state, the reactor contents should be void of dissolved oxygen
and free of inhibitory concentrations of free ammonia and such constituents as heavy metals
and sulfides. Also, the pH of the aqueous environment should range from 6.5 to 7.5. As the
methane bacteria cannot function below this point, sufficient alkalinity should be present to
ensure that the pH will not drop below 6.2. When digestion is proceeding satisfactorily, the
alkalinity will normally range from 1000 to 5000 mg/L and the volatile fatty acids will be less
than 250 mg/L. Values for alkalinity and volatile fatty acids in the high-solids anaerobic
digestion process can be as high as 12,000 and 700 mg/L, respectively. A sufficient amount
of nutrients, such as nitrogen and phosphorus, must also be available to ensure the proper
growth of the biological community. Depending on the nature of the sludges or waste to be
digested, growth factors may also be required. Temperature is another important
environmental parameter, with optimum temperature in the mesophilic, 30 to 38°C (85 to
100°F), and the thermophilic, 55 to 60°C (131 to 140°F) range.
3.1.3 Gas Production
The general anaerobic transformation of solid waste can be described by means of the
following equation.
Organic matter + H2O + nutrients → new cells + resistant organic matter + CO2 + CH4 + NH3
+ H2S + heat
3.1.4 Bio-Gas
Bio-gas is a gas generated from the anaerobic digestion of organic waste. It consists of CH4
(50-70%), CO2 (30-50%) with the remaining gases being: H2, O2, H2S, N2 and water vapor.
To ensure optimal Bio-gas production, the three groups of micro-organisms must work
together. In case of too much organic waste, the first and second groups of micro-organisms
will produce a lot of organic acid which will decrease the pH of the reactor, making it
unsuitable for the third group of micro-organisms. This will result in little or no gas
production. On the other hand, if too little organic waste is present, the rate of digestion by
micro-organisms will be minimal and production of Bio-gas will decrease significantly.
Mixing could aid digestion in the reactor but, too much mixing should be avoided as this
would reduce bio-gas generation. Table 3.1 shows the amount of bio-gas generated from
animal waste and agriculture residue.
ensure that the pH will not drop below 6.2. When digestion is proceeding satisfactorily, the
alkalinity will normally range from 1000 to 5000 mg/L and the volatile fatty acids will be less
than 250 mg/L. Values for alkalinity and volatile fatty acids in the high-solids anaerobic
digestion process can be as high as 12,000 and 700 mg/L, respectively. A sufficient amount
of nutrients, such as nitrogen and phosphorus, must also be available to ensure the proper
growth of the biological community. Depending on the nature of the sludges or waste to be
digested, growth factors may also be required. Temperature is another important
environmental parameter, with optimum temperature in the mesophilic, 30 to 38°C (85 to
100°F), and the thermophilic, 55 to 60°C (131 to 140°F) range.
3.1.3 Gas Production
The general anaerobic transformation of solid waste can be described by means of the
following equation.
Organic matter + H2O + nutrients → new cells + resistant organic matter + CO2 + CH4 + NH3
+ H2S + heat
3.1.4 Bio-Gas
Bio-gas is a gas generated from the anaerobic digestion of organic waste. It consists of CH4
(50-70%), CO2 (30-50%) with the remaining gases being: H2, O2, H2S, N2 and water vapor.
To ensure optimal Bio-gas production, the three groups of micro-organisms must work
together. In case of too much organic waste, the first and second groups of micro-organisms
will produce a lot of organic acid which will decrease the pH of the reactor, making it
unsuitable for the third group of micro-organisms. This will result in little or no gas
production. On the other hand, if too little organic waste is present, the rate of digestion by
micro-organisms will be minimal and production of Bio-gas will decrease significantly.
Mixing could aid digestion in the reactor but, too much mixing should be avoided as this
would reduce bio-gas generation. Table 3.1 shows the amount of bio-gas generated from
animal waste and agriculture residue.
Table 3.1 Amount of bio-gas generated from animal waste and agriculture residue
animal gas produced
L/kg-solid
Pig
Cow
Chicken
Horse
Sheep
Straw
Grasses
Peanut shell
Water Hyacinth
340-550
90-310
310-620
200-300
90-310
105
280-550
365
375
3.1.5 Factor Affecting Gas Generation
To ensure a constant generation of gas, the following factors should be considered :
• Organic waste should be sufficient at all time.
• Daily input of waste should conform with reactor size. Too much input will reduce the
gas generation rate.
• Digestion period (retention time) should be about 60-80 days
Digestion period =
waste of input Daily
reactor of Volume
• pH within reactor should be about 7.0-8.5. Too low a pH will inhibit gas production.
3.1.6 Benefit of Bio-Gas Technology
The following benefits will be obtained from bio-gas technology:
• Energy
Bio-gas could be used as a fuel alternative to wood, oil, LPG and electricity.
• Agriculture use
Sludge from the bio-gas reactor could be used as compost. Organic nitrogen from waste will
be transformed into ammonia nitrogen, a form of nitrogen which plants can uptake easily.
• Protect environment
Using bio-gas technology on animal waste treatment will reduce risk of infection from
parasite and pathogenic bacteria inherent in the waste. Odor and flies will be significantly
reduced in the area, and water pollution created by the dumping of waste can also be
prevented.
_-------------------------------------------------------------------------------------------------------
Introduction
Before Building Anything!
Biogas Notes 652Kb Introduction to biogas
What Biogas Can Do For You
Biogas Design
Mega Biogas Compilation 42Mb
2 Designs for Methane Digesters For Fuel Gas and Fertilizer 43.3Mb (168 pages)
Anaerobic Digester Calculator calculator to assist with your design
ARTI Biogas System 287Kb How to build
Balaji Biogas Plant 264Kb Short article on Indian style concrete digester made with steel mould.
Biogas and Waste Recycling - The Philippine experience 13Mb
Biogas Plants UN-ECDC 18.6Mb (270 pages very informative)
Biogas Sanitation 4.5Mb
Biogas: Community Development 2.3Mb
Biogas Utilization Handbook 3.9mb
Biogas Cogeneration Manual 12.7Mb (over 300 pages)
Biogas Plants - Ludwig Sasse 1.1Mb (detailed)
Biogas Systems in India 11.9Mb
Compost, Fertilizer and Biogas Production from Human and farm Waste in China 8Mb
Design of a Biogas Digester 231Kb
Digester Basic Design and Theory 114Kb
FAO Biogas 1 516Kb
FAO Biogas 2 494Kb
FarmWare - Link to FarmWare which is an analytical tool designed to provide a preliminary assessment on the benefits of integrating anaerobic digestion into an existing or planned dairy or swine manure management system.
Fuel Gas From Cow Dung 8.8Mb
Nepal Biogas Plant 630Kb
Peace Corps - Biogas 1.5Mb
Planning and Construction of Biomass Plants 97Kb
Planning - Steps To Take 59Kb
Plastic Tube Biodigester Installation Manual 605Kb
Polyethylene Tube Biodigesters 331Kb
Polyethylene Biogas Dome 540Kb
Purification of Biogas - 410Kb Removing hydrogen sulphide from biogas
Selecting and Sizing Biogas Units 546Kb
Understanding Biogas 252Kb
Biogas Plant Construction
Running a Biogas Programme: Handbook 18.2Mb
School Projects
Build Your Own Biogas Generator 722Kb - short extract
Methane Biogas Production 497Kb
Home Size Plants
2 Designs for Methane Digesters For Fuel Gas and Fertilizer 43.3Mb (168 pages)
3 Cubic Meter Plant 722Kb
ARTI Biogas System 94kb (Indian home system)
ARTI Biogas System 287Kb How to build
Basic Small Scale Drum Plan 1.1Mb
Biogas Digesters in India 773K
Biogas Digest 1.94Mb (80 pages very informative)
Biogas Plants UN-ECDC 18.6Mb 270 pages very informative
Biogas Digester Installation Manual 924Kb Plastic tube digester
Chinese Biogas Digester 2.3Mb
Chinese Biogas Manual 12Mb
Compost, Fertilizer and Biogas Production from Human and farm Waste in China 8Mb
Construction Manual for Rural Families 294Kb
Fuel Gas From Cow Dung 8.8Mb
Home Biogas Construction Photos 356Kb
Methane Biogas Production 497Kb
Low Cost Tubular Digester 1.1Mb
Low Cost Plastic Tube 29.9Mb A compedium of low cost solutions
Mini Biogas Plants For Households 1.2mb
Nepal Biogas Plant 630Kb
Polyethylene Tube Biodigesters 331Kb
Plastic Tube Biodigester Installation Manual 605Kb
PVC Biogas Digester 359Kb Bladder type, successful
Small Homebuilt Digester Construction 775Kb
Village Size Plants
Biogas For Overseas Volunteers 123Kb
Biogas Systems in India 11.9Mb
Biogas Digesters in India 773Kb
Biogas: Community Development 2.3Mb
Biogas Plants - Ludwig Sasse 1.1Mb (detailed)
Biogas Unit - Developing Countries 1.1Mb
Biogas Utilization Handbook 3.9mb
Chinese Biogas Digester 2.3Mb
Chinese Biogas Manual 12Mb
Biogas Utilization Handbook 3.9mb
Mixed Flow Digesters 759Kb
Plug Flow Digesters 4.3Mb
Agriculture
agSTAR Biogas Handbook 3.4MB (The guide identifies the states with the greatest opportunity to cost effectively install and operate biogas recovery systems using dairy and swine manure.)
agSTAR Biogas Program 3.4Mb (The program encourages in USA the use of biogas capture and utilization at animal feeding operations that manage manures as liquids and slurries.)
Agricultural Anaerobic Digestion 356kb
Biogas From Fish Farms 569Kb
Biogas Unit - Developing Countries 1.1Mb
Biogas at Vanith Farm 893Kb
Biomethane from Dairy Waste 4.1Mb
Biogas In Animal Husbandry 17.6 Mb (157 pages)
Colorado Technology Assessments 279Kb
Dairy Waste Anaerobic Digestion Handbook 1.2Mb
Farm Scale Biogas Plants 433 kb
Haubenschild Farms Digester 707Kb
Low Cost Biodigesters - small scale 316Kb
Pig Waste Management 25.3Mb (322 pages)
Polyethylene Tube Biodigesters 331Kb
Rokel Pig Farm Demonstration 1.8Mb
Selecting and Sizing Biogas Units 546Kb
Wisconsin Biogas Casebook 2.3Mb
Case Studies
Biogas Digesters in India 773Kb
Biomethane from Dairy Waste 4.1Mb
Chinese Biogas Digester 2.3Mb
Dairy, Reinfold Farm 2Mb digester designed for 1,000 cows
Fixed Film Anaerobic Digester at Farber Farm: Case Study
Haubenschild Farms Digester 707Kb
Wisconsin Biogas Casebook 2.3Mb
Reports
Biogas In Animal Husbandry 17.6 Mb (157 pages)
Biogas Technology in The 3rd World 14.7Mb
Biogas and Waste Recycling - The Philippine experience 13Mb
Cogeneration: A Worshop Manual 13.0Mb
Danish Centralised Biogas Plants 1.3Mb
Feasibility Study Domestic Biogas - Bangladesh 3.8Mb
IEA Biogas Technologies 1.3Mb
IEA Energy Crops 681Kb
Micro Turbine Power Generation 268Kb
Biogas Processes For Sustainable Development 1.30Mb
Market Opportunities for Biogas Recovery Systems 3.1Mb
Techno Economic Feasibility Report 465kb Indian Community Biogas
UNEP Converting Waste Agricultural Biomass Into A Resource 5.1Mb
Landfill Gas
Landfill Gas California 2.2Mb
Landfill Gas Handbook - International Solid Waste Association 1.9Mb
Landfill Gas Design, Construction, Operation - PowerPointPresentation 1.9Mb
Design Of Landfill Gas Systems - Power Point Presentation 5.8Mb
Landfill Gas Soils and Foundations Handbook 3.7Mb
Misc
Chinese Biogas Manometer 69Kb
CO2 Content by Syringe Protocol 12Kb
Biogas as Vehicle Fuel 712Kb
Engines For Biogas 1.2Mb (132 pages detailed info)
Solar Gas Turbines 2.9mb
Biogas For Heat Recovery 1.0Mb
Biogas Production and Micro turbines 306Kb
Capstone C30 Biogas Turbine 167Kb
Purification of Biogas - 410Kb Removing hydrogen sulphide from biogas
Roman Engineering of Roads, Bridges, Tunnels - Power Point 26.3Mb
animal gas produced
L/kg-solid
Pig
Cow
Chicken
Horse
Sheep
Straw
Grasses
Peanut shell
Water Hyacinth
340-550
90-310
310-620
200-300
90-310
105
280-550
365
375
3.1.5 Factor Affecting Gas Generation
To ensure a constant generation of gas, the following factors should be considered :
• Organic waste should be sufficient at all time.
• Daily input of waste should conform with reactor size. Too much input will reduce the
gas generation rate.
• Digestion period (retention time) should be about 60-80 days
Digestion period =
waste of input Daily
reactor of Volume
• pH within reactor should be about 7.0-8.5. Too low a pH will inhibit gas production.
3.1.6 Benefit of Bio-Gas Technology
The following benefits will be obtained from bio-gas technology:
• Energy
Bio-gas could be used as a fuel alternative to wood, oil, LPG and electricity.
• Agriculture use
Sludge from the bio-gas reactor could be used as compost. Organic nitrogen from waste will
be transformed into ammonia nitrogen, a form of nitrogen which plants can uptake easily.
• Protect environment
Using bio-gas technology on animal waste treatment will reduce risk of infection from
parasite and pathogenic bacteria inherent in the waste. Odor and flies will be significantly
reduced in the area, and water pollution created by the dumping of waste can also be
prevented.
_-------------------------------------------------------------------------------------------------------
Introduction
Before Building Anything!
Biogas Notes 652Kb Introduction to biogas
What Biogas Can Do For You
Biogas Design
Mega Biogas Compilation 42Mb
2 Designs for Methane Digesters For Fuel Gas and Fertilizer 43.3Mb (168 pages)
Anaerobic Digester Calculator calculator to assist with your design
ARTI Biogas System 287Kb How to build
Balaji Biogas Plant 264Kb Short article on Indian style concrete digester made with steel mould.
Biogas and Waste Recycling - The Philippine experience 13Mb
Biogas Plants UN-ECDC 18.6Mb (270 pages very informative)
Biogas Sanitation 4.5Mb
Biogas: Community Development 2.3Mb
Biogas Utilization Handbook 3.9mb
Biogas Cogeneration Manual 12.7Mb (over 300 pages)
Biogas Plants - Ludwig Sasse 1.1Mb (detailed)
Biogas Systems in India 11.9Mb
Compost, Fertilizer and Biogas Production from Human and farm Waste in China 8Mb
Design of a Biogas Digester 231Kb
Digester Basic Design and Theory 114Kb
FAO Biogas 1 516Kb
FAO Biogas 2 494Kb
FarmWare - Link to FarmWare which is an analytical tool designed to provide a preliminary assessment on the benefits of integrating anaerobic digestion into an existing or planned dairy or swine manure management system.
Fuel Gas From Cow Dung 8.8Mb
Nepal Biogas Plant 630Kb
Peace Corps - Biogas 1.5Mb
Planning and Construction of Biomass Plants 97Kb
Planning - Steps To Take 59Kb
Plastic Tube Biodigester Installation Manual 605Kb
Polyethylene Tube Biodigesters 331Kb
Polyethylene Biogas Dome 540Kb
Purification of Biogas - 410Kb Removing hydrogen sulphide from biogas
Selecting and Sizing Biogas Units 546Kb
Understanding Biogas 252Kb
Biogas Plant Construction
Running a Biogas Programme: Handbook 18.2Mb
School Projects
Build Your Own Biogas Generator 722Kb - short extract
Methane Biogas Production 497Kb
Home Size Plants
2 Designs for Methane Digesters For Fuel Gas and Fertilizer 43.3Mb (168 pages)
3 Cubic Meter Plant 722Kb
ARTI Biogas System 94kb (Indian home system)
ARTI Biogas System 287Kb How to build
Basic Small Scale Drum Plan 1.1Mb
Biogas Digesters in India 773K
Biogas Digest 1.94Mb (80 pages very informative)
Biogas Plants UN-ECDC 18.6Mb 270 pages very informative
Biogas Digester Installation Manual 924Kb Plastic tube digester
Chinese Biogas Digester 2.3Mb
Chinese Biogas Manual 12Mb
Compost, Fertilizer and Biogas Production from Human and farm Waste in China 8Mb
Construction Manual for Rural Families 294Kb
Fuel Gas From Cow Dung 8.8Mb
Home Biogas Construction Photos 356Kb
Methane Biogas Production 497Kb
Low Cost Tubular Digester 1.1Mb
Low Cost Plastic Tube 29.9Mb A compedium of low cost solutions
Mini Biogas Plants For Households 1.2mb
Nepal Biogas Plant 630Kb
Polyethylene Tube Biodigesters 331Kb
Plastic Tube Biodigester Installation Manual 605Kb
PVC Biogas Digester 359Kb Bladder type, successful
Small Homebuilt Digester Construction 775Kb
Village Size Plants
Biogas For Overseas Volunteers 123Kb
Biogas Systems in India 11.9Mb
Biogas Digesters in India 773Kb
Biogas: Community Development 2.3Mb
Biogas Plants - Ludwig Sasse 1.1Mb (detailed)
Biogas Unit - Developing Countries 1.1Mb
Biogas Utilization Handbook 3.9mb
Chinese Biogas Digester 2.3Mb
Chinese Biogas Manual 12Mb
Biogas Utilization Handbook 3.9mb
Mixed Flow Digesters 759Kb
Plug Flow Digesters 4.3Mb
Agriculture
agSTAR Biogas Handbook 3.4MB (The guide identifies the states with the greatest opportunity to cost effectively install and operate biogas recovery systems using dairy and swine manure.)
agSTAR Biogas Program 3.4Mb (The program encourages in USA the use of biogas capture and utilization at animal feeding operations that manage manures as liquids and slurries.)
Agricultural Anaerobic Digestion 356kb
Biogas From Fish Farms 569Kb
Biogas Unit - Developing Countries 1.1Mb
Biogas at Vanith Farm 893Kb
Biomethane from Dairy Waste 4.1Mb
Biogas In Animal Husbandry 17.6 Mb (157 pages)
Colorado Technology Assessments 279Kb
Dairy Waste Anaerobic Digestion Handbook 1.2Mb
Farm Scale Biogas Plants 433 kb
Haubenschild Farms Digester 707Kb
Low Cost Biodigesters - small scale 316Kb
Pig Waste Management 25.3Mb (322 pages)
Polyethylene Tube Biodigesters 331Kb
Rokel Pig Farm Demonstration 1.8Mb
Selecting and Sizing Biogas Units 546Kb
Wisconsin Biogas Casebook 2.3Mb
Case Studies
Biogas Digesters in India 773Kb
Biomethane from Dairy Waste 4.1Mb
Chinese Biogas Digester 2.3Mb
Dairy, Reinfold Farm 2Mb digester designed for 1,000 cows
Fixed Film Anaerobic Digester at Farber Farm: Case Study
Haubenschild Farms Digester 707Kb
Wisconsin Biogas Casebook 2.3Mb
Reports
Biogas In Animal Husbandry 17.6 Mb (157 pages)
Biogas Technology in The 3rd World 14.7Mb
Biogas and Waste Recycling - The Philippine experience 13Mb
Cogeneration: A Worshop Manual 13.0Mb
Danish Centralised Biogas Plants 1.3Mb
Feasibility Study Domestic Biogas - Bangladesh 3.8Mb
IEA Biogas Technologies 1.3Mb
IEA Energy Crops 681Kb
Micro Turbine Power Generation 268Kb
Biogas Processes For Sustainable Development 1.30Mb
Market Opportunities for Biogas Recovery Systems 3.1Mb
Techno Economic Feasibility Report 465kb Indian Community Biogas
UNEP Converting Waste Agricultural Biomass Into A Resource 5.1Mb
Landfill Gas
Landfill Gas California 2.2Mb
Landfill Gas Handbook - International Solid Waste Association 1.9Mb
Landfill Gas Design, Construction, Operation - PowerPointPresentation 1.9Mb
Design Of Landfill Gas Systems - Power Point Presentation 5.8Mb
Landfill Gas Soils and Foundations Handbook 3.7Mb
Misc
Chinese Biogas Manometer 69Kb
CO2 Content by Syringe Protocol 12Kb
Biogas as Vehicle Fuel 712Kb
Engines For Biogas 1.2Mb (132 pages detailed info)
Solar Gas Turbines 2.9mb
Biogas For Heat Recovery 1.0Mb
Biogas Production and Micro turbines 306Kb
Capstone C30 Biogas Turbine 167Kb
Purification of Biogas - 410Kb Removing hydrogen sulphide from biogas
Roman Engineering of Roads, Bridges, Tunnels - Power Point 26.3Mb
