Methane Digesters For Fuel Gas and Fertilizer With Complete Instructions For Two Working Models
by
L. John Fry
Santa Barbara, California
by
L. John Fry
Santa Barbara, California
Showing posts with label Best Biogas. Show all posts
Showing posts with label Best Biogas. Show all posts
A better biogas plant for your home
The use of waste food instead of dung as feedstock makes this biogas plant distinct and more practical to use by people in both rural and urban areas
What comes to your mind first when “a biogas plant” is mentioned? Does the picture include a large smelly tank attached to a gas stove used mostly in villages?
Well, you might have been correct if not for an innovative compact biogas plant that uses waste food rather than cattle dung as the feedstock! Brainchild of Dr Anand Karve, a Pune-based biologist, this biogas plant can be used both in rural and urban households, thanks to the source of energy.
The use of biogas – a mixture of mainly methane and some carbon dioxide – as an alternative to conventional fuels such as coal and LPG in rural households is not new. However, the size of the plant and its reliance on large quantities of cattle dung has acted as a dampener for urban households. Also, because of the dung’s low calorific value, the energy produced per kilogram of dung is low vis-à-vis waste food. It was this that made Dr Karve decide on replacing the traditional feedstock with waste food as the input. “It is known that methane gas can be produced from sugar, starch, cellulose and fat, and one kg of food waste (dry weight) – which contains starch, sugar, protein or fat – yields about 250 gms of methane. So I decided to replace dung used in a conventional biogas plant with waste food,” says Dr Karve, who runs Appropriate Rural Technology Institute (ARTI), an NGO. The result was an efficient and less cumbersome device that can also be used in urban households.
Since 2006, nearly 3,000 such plants have been installed both in India and abroad in rural and urban households and in commercial establishments such as hostels and hotels.
BenefitsSo why has this biogas plant aroused a lot of interest? There are several reasons behind this.
One, the conventional biogas plant produces 250 gms of biogas from 40 kgs of excreta in 40 days. In contrast, the new plant requires just 1 kg of sugar or starch – in the form of waste food from household or hotels, spoilt grain, overripe fruit, non-edible seeds, kitchen waste, etc. – to produce the same quantity of methane in just 24 hours. According to Dr Karve, through the use of this compact system it has been demonstrated that using feedstock having higher calorific value increases the efficiency of methane generation.
Two, the choice of feedstock facilitates its use in urban households. Reliance on cattle excreta has been one of the major restricting factors limiting its usage in urban homes. Traditional plants require approximately 40 kg of input on a daily basis, and have a high retention period of 40 days. The large quantity of input and the longer period require plenty of storage space, which is a major constraint in cities.
==============================================
How does it work?
The standard plant uses two tanks, which typically have a volume of 0.75 cu.m. and 1 cu.m. The smaller tank, which is the gas holder, is inverted over the larger one containing a mixture of feedstock and water. An inlet pipe is provided for adding feedstock and an overflow pipe for removing the digested residue.
A pipe takes the biogas to the kitchen, where it is used with a biogas stove.
The gas holder gradually rises as gas is produced, and sinks down again as the gas is used for cooking.
Initially the plant is fed with a starter mix, which contains either cattle dung mixed with water and waste flour or effluent from an existing biogas plant mixed with starch. The feeding of the plant is built up over a few weeks.
==================================================
hree, according to Dr. Karve the higher calorific value of the input results in better quality of gas thus produced. From the point of view of conversion of feedstock into methane, this system is 400 times more efficient than conventional system. He says, the biogas thus produced has all the virtues of LPG – it produces a clean blue flame, has the same intensity, provides finger tip control of flame, produces no soot and smoke, etc. As methane has the same calorific value as LPG, it becomes as efficient and cost effective too.
Source:http://www.dare.co.in/people/featured-innovation/a-better-biogas-plant-for-your-home.htm
What comes to your mind first when “a biogas plant” is mentioned? Does the picture include a large smelly tank attached to a gas stove used mostly in villages?
Well, you might have been correct if not for an innovative compact biogas plant that uses waste food rather than cattle dung as the feedstock! Brainchild of Dr Anand Karve, a Pune-based biologist, this biogas plant can be used both in rural and urban households, thanks to the source of energy.
 |
| Dr Anand Karve Appropriate Rural Technology Institute (ARTI) |
Since 2006, nearly 3,000 such plants have been installed both in India and abroad in rural and urban households and in commercial establishments such as hostels and hotels.
BenefitsSo why has this biogas plant aroused a lot of interest? There are several reasons behind this.
One, the conventional biogas plant produces 250 gms of biogas from 40 kgs of excreta in 40 days. In contrast, the new plant requires just 1 kg of sugar or starch – in the form of waste food from household or hotels, spoilt grain, overripe fruit, non-edible seeds, kitchen waste, etc. – to produce the same quantity of methane in just 24 hours. According to Dr Karve, through the use of this compact system it has been demonstrated that using feedstock having higher calorific value increases the efficiency of methane generation.
Two, the choice of feedstock facilitates its use in urban households. Reliance on cattle excreta has been one of the major restricting factors limiting its usage in urban homes. Traditional plants require approximately 40 kg of input on a daily basis, and have a high retention period of 40 days. The large quantity of input and the longer period require plenty of storage space, which is a major constraint in cities.
==============================================
How does it work?
The standard plant uses two tanks, which typically have a volume of 0.75 cu.m. and 1 cu.m. The smaller tank, which is the gas holder, is inverted over the larger one containing a mixture of feedstock and water. An inlet pipe is provided for adding feedstock and an overflow pipe for removing the digested residue.
A pipe takes the biogas to the kitchen, where it is used with a biogas stove.
The gas holder gradually rises as gas is produced, and sinks down again as the gas is used for cooking.
Initially the plant is fed with a starter mix, which contains either cattle dung mixed with water and waste flour or effluent from an existing biogas plant mixed with starch. The feeding of the plant is built up over a few weeks.
==================================================
hree, according to Dr. Karve the higher calorific value of the input results in better quality of gas thus produced. From the point of view of conversion of feedstock into methane, this system is 400 times more efficient than conventional system. He says, the biogas thus produced has all the virtues of LPG – it produces a clean blue flame, has the same intensity, provides finger tip control of flame, produces no soot and smoke, etc. As methane has the same calorific value as LPG, it becomes as efficient and cost effective too.
Source:http://www.dare.co.in/people/featured-innovation/a-better-biogas-plant-for-your-home.htm
Biogas Plants by Ludwig Sasse PDF
Biogas Plants by Ludwig Sasse
Content
Acknowledgments ................................................................................................ 1
Preface.................................................................................................................... 4
0.
Biogas as appropriate technology .............................................................. 5
1.
Benefits and costs of a biogas plant .......................................................... 7
2.
The digestion process.................................................................................. 9
3.
Biogas plants .............................................................................................. 12
4.
Scaling of biogas plants ............................................................................ 16
5.
Design of biogas plants ............................................................................. 28
6.
Biogas utilization ........................................................................................ 44
7.
Planning, design and construction ........................................................... 48
8.
Appendix ..................................................................................................... 57
Bibliography......................................................................................................... 64
Download Full E book (PDF) Biogas Plants by Ludwig Sasse
Content
Acknowledgments ................................................................................................ 1
Preface.................................................................................................................... 4
0.
Biogas as appropriate technology .............................................................. 5
1.
Benefits and costs of a biogas plant .......................................................... 7
2.
The digestion process.................................................................................. 9
3.
Biogas plants .............................................................................................. 12
4.
Scaling of biogas plants ............................................................................ 16
5.
Design of biogas plants ............................................................................. 28
6.
Biogas utilization ........................................................................................ 44
7.
Planning, design and construction ........................................................... 48
8.
Appendix ..................................................................................................... 57
Bibliography......................................................................................................... 64
Download Full E book (PDF) Biogas Plants by Ludwig Sasse
BIOGAS TECHNOLOGY: A TRAINING MANUAL PDF Download
BIOGAS TECHNOLOGY: A TRAINING MANUAL FOR EXTENSION
source: http://www.fao.org/docrep/008/ae897e/ae897e00.htm
TABLE OF TABLES
TABLE OF FIGURES
TABLE OF CHARTS
TABLE OF ANNEXES
ACRONYMS AND ABBREVIATIONS
RELEVANT UNITS AND CONVERSION FACTORS
INTRODUCTION TO MANUAL
SESSION ONE : SYSTEM APPROACH TO BIOGAS TECHNOLOGY
1.1 Introduction
1.2 Components of a Biogas System
1.4 Session Plan
1.5 Review Questions
1.6 References
1.7 Further Reading Materials
SESSION TWO : RELEVANCE OF BIOGAS TECHNOLOGY TO NEPAL
2.1 Introduction
2.2 Energy Situation in Nepal
2.4 Biogas Potential in Nepal
2.5 Uses of Biogas
2.7 Biogas and Forests
2.8 Biogas and Women
2.9 Health and Sanitation
2.10 Municipal Waste
2.11 Economy and the Employment
2.12 Session Plan
2.13 Review Questions
2.14 References
2.15 Further Reading Materials
SESSION THREE : BIOGAS PROGRAMMES
3.1 Introduction
3.2 Biogas Programmes in China
3.4 Biogas in Nepal
3.6 Review Questions
3.7 References
3.8 Further Reading Materials
SESSION FOUR : UTILIZATION OF SLURRY AS FEED AND FERTILIZER
4.1 Introduction
4.2 Inter-Relationship of Biogas Technology and Agriculture
4.3 Limitations of Chemical Fertilizer Use
4.4 Organic Fertilizer
4.5 Importance of Slurry for Crop Production
4.6 Characteristics of Digested Slurry
4.7 Utilization of Digested Slurry...
4.9 Quality Assessment of Compost and Digested Slurry
4.10 Influence of Slurry on the Yield of Crops and Vegetables
4.11 Field Experiment
4.12 Effluent as a Supplement in Ration of Animal and Fish
4.14 Session Plan
4.15 Review Questions
4.16 References
4.17 Other Reading Materials
SESSION FIVE : INSTALLATION COST AND FINANCIAL VIABILITY
5.1 Introduction
5.2 Financial Analysis
5.4 Financial Viability Assessment as Practiced by ADB/N
5.5 Indicators of Financial Viability of Biogas Plants
5.6 Economic Analysis
5.8 Review Questions
5.9 References
SESSION SIX : SUBSIDY AND INSTITUTIONAL FINANCING
6.1 Introduction
6.2 Definition of Subsidy
6.3 Rationale of Subsidy for Biogas Plant Installation
6.4 Subsidy and External Financing
6.5 Review of Subsidy on Biogas Programmes in Nepal
6.6 Institutional Financing
6.7 Flow of Funds
6.8 Procedure for Obtaining Loan and Subsidy with Technical Assistance
6.9 Session Plan
6.10 Review Questions
6.11 Reference
SESSION SEVEN : FIELD VISIT PROGRAMME
7.1 Introduction
7.2 Methodology
7.3 Themes for Observation
7.4 Information on Plants Visited in each of the Five Training
7.5 General Opinions and Impression about Field Visits
7.6 Review Questions
SESSION EIGHT : EXTENSION SUPPORT SERVICES FOR BIOGAS
8.1 Introduction
8.2 From a Single Plant to National Objectives and Strategy
8.6 Extension Methods
8.8 Relevant Questions
8.9 References
SESSION NINE : QUALITY STANDARDS
9.1 Introduction
9.2 The Need for Quality Control
9.3 Development of a System for Quality Control
9.6 Commissioning
9.7 After-Sale-Services
9.8 Mobile Team for Supervision, Follow up and Monitoring
9.9 Common Problems in Plant Operation
9.10 Session Plan
9.11 Review Questions
9.12 References
9.13 Further Reading Materials
SESSION TEN : MONITORING AND EVALUATION
10.1 Introduction
10.2 Definitions
10.3 Indicators and Data Base
10.4 M&E as Integral Part of Programme Implementation Process
10.5 M&E At Different Levels
10.7 Session Plan
10.8 Review Questions
10.9 References
APPENDICES
source: http://www.fao.org/docrep/008/ae897e/ae897e00.htm
TABLE OF CONTENTS
PREFACE TABLE OF TABLES
TABLE OF FIGURES
TABLE OF CHARTS
TABLE OF ANNEXES
ACRONYMS AND ABBREVIATIONS
RELEVANT UNITS AND CONVERSION FACTORS
INTRODUCTION TO MANUAL
SESSION ONE : SYSTEM APPROACH TO BIOGAS TECHNOLOGY
1.1 Introduction
1.2 Components of a Biogas System
1.2.1 Biogas1.3 Implications of Biogas System
1 2.2 Methanogenic Bacteria or methanogens
1.2.3 Biodigester
1.2.4. Inputs and their Characteristics
1.2.5 Digestion
1.2.6 Slurry
1.2.7 Use of Biogas
1.4 Session Plan
1.5 Review Questions
1.6 References
1.7 Further Reading Materials
SESSION TWO : RELEVANCE OF BIOGAS TECHNOLOGY TO NEPAL
2.1 Introduction
2.2 Energy Situation in Nepal
2.2.1 Tradition Sources of Energy2.3 Biogas in Other Countries
2.2.2 Commercial Sources of Energy
2.2.3 Sources of Alternative Energy
2.4 Biogas Potential in Nepal
2.5 Uses of Biogas
2.5.1 Cooking2.6 Biogas and Agriculture
2.5.2 Lighting
2.5.3 Refrigeration
2.5.4 Biogas-fueled Engines
2.5.5 Electricity Generation
2.7 Biogas and Forests
2.8 Biogas and Women
2.9 Health and Sanitation
2.10 Municipal Waste
2.11 Economy and the Employment
2.12 Session Plan
2.13 Review Questions
2.14 References
2.15 Further Reading Materials
SESSION THREE : BIOGAS PROGRAMMES
3.1 Introduction
3.2 Biogas Programmes in China
3.2.1 Use of Gas and Slurry3.3 Biogas programme in India
3.2.2 Training
3.2.3 Organization
3.4 Biogas in Nepal
3.4.1 Brief History of Biogas Development in Nepal3.5 Session Plan
3.4.2 Programmes of GGC and its Linkage
3.4.3 Support for the Development of a National Biogas Programme (FAO/TCP/NEP/4451-T)
3.4.4 Biogas Support Programme
3.4.5 Basic Features of BSP Third Phase
3.4.6 Biogas Companies
3.4.7 Need for Research and Development
3.6 Review Questions
3.7 References
3.8 Further Reading Materials
SESSION FOUR : UTILIZATION OF SLURRY AS FEED AND FERTILIZER
4.1 Introduction
4.2 Inter-Relationship of Biogas Technology and Agriculture
4.3 Limitations of Chemical Fertilizer Use
4.4 Organic Fertilizer
4.5 Importance of Slurry for Crop Production
4.6 Characteristics of Digested Slurry
4.7 Utilization of Digested Slurry...
4.7.1 Application of Slurry in Liquid Form4.8 Size of Compost Pit
4.7.2 Application of Slurry in Dried Form
4.7.3 Utilization of Slurry for Compost Making
4.9 Quality Assessment of Compost and Digested Slurry
4.10 Influence of Slurry on the Yield of Crops and Vegetables
4.11 Field Experiment
4.12 Effluent as a Supplement in Ration of Animal and Fish
4.12.1 Digested Slurry as a Feed to Animal4.13 Other Uses
4.12.2 Digested Slurry as a Feed to Fish
4.12.3 Improving the Quality of Feed
4.14 Session Plan
4.15 Review Questions
4.16 References
4.17 Other Reading Materials
SESSION FIVE : INSTALLATION COST AND FINANCIAL VIABILITY
5.1 Introduction
5.2 Financial Analysis
5.2.1 Project Life5.3 Discussion on Result of Financial Analysis
5.2.2 Benefits and Costs
5.2.3 Cash Flow Analysis
5.2.4 Time Value of Money and Discount Rate (Factor)
5.2.5 Net Present Value
5.2.6 Internal Rate of Return (IRR)
5.2.7 Benefit Cost Ratio
5.4 Financial Viability Assessment as Practiced by ADB/N
5.5 Indicators of Financial Viability of Biogas Plants
5.6 Economic Analysis
5.6.1 Economic Valuation of Firewood5.7 Session Plan
5.6.2 Economic Valuation of Kerocene
5.6.3 Economic Valuation of Labour
5.6.4 Value of Slurry
5.6.5 Investment Cost
5.8 Review Questions
5.9 References
SESSION SIX : SUBSIDY AND INSTITUTIONAL FINANCING
6.1 Introduction
6.2 Definition of Subsidy
6.3 Rationale of Subsidy for Biogas Plant Installation
6.4 Subsidy and External Financing
6.5 Review of Subsidy on Biogas Programmes in Nepal
6.6 Institutional Financing
6.7 Flow of Funds
6.8 Procedure for Obtaining Loan and Subsidy with Technical Assistance
6.9 Session Plan
6.10 Review Questions
6.11 Reference
SESSION SEVEN : FIELD VISIT PROGRAMME
7.1 Introduction
7.2 Methodology
7.3 Themes for Observation
7.4 Information on Plants Visited in each of the Five Training
7.5 General Opinions and Impression about Field Visits
7.6 Review Questions
SESSION EIGHT : EXTENSION SUPPORT SERVICES FOR BIOGAS
8.1 Introduction
8.2 From a Single Plant to National Objectives and Strategy
8.2.1 Building Government Commitment8.3 Institutions for Extension of Biogas Technology
8.2.2 Energy Related Objective of Eighth Five Year Plan
8.2.3 Objectives and Strategies of Perspective Energy Plan
8.3.1 Establishment of Biogas Companies and Biogas Related NGOs8.4 Factors Affecting Biogas Extension
8.3.2 Formation of Biogas Steering Committee
8.3.3 Proposed Alternate Energy Promotion Centre
8.4.1 Government Commitment8.5 Extension Approaches
8.4.2 Subsidy
8.4.3 Institutional Arrangements
8.4.4 Energy Pricing
8.4.5 Education and Access to Technology
8.4.6 Performance of Existing Plants
8.6 Extension Methods
8.6.1 Door-to-door Visits8.7 Session Plan
8.6.2 Use of Local Leaders
8.6.3 Exhibitions and Demonstration
8.6.4 Use of Mass Media
8.6.5 Occasional Publications
8.6.6 Audio-Visuals
8.6.7 Seminars and Workshops
8.6.8 Training
8.8 Relevant Questions
8.9 References
SESSION NINE : QUALITY STANDARDS
9.1 Introduction
9.2 The Need for Quality Control
9.3 Development of a System for Quality Control
9.3.1 Enforcement of Quality Control Measures9.4 Important Parameters for Quality Control
9.4.1 Design9.5 Appliances and Accessories
9.4.2 Deciding on the Size or Capacity of a Plant
9.4.3 Site Selection
9.4.4 Construction Materials and Trained Mason
9.4.5 Critical Stage of Construction
9.6 Commissioning
9.7 After-Sale-Services
9.8 Mobile Team for Supervision, Follow up and Monitoring
9.9 Common Problems in Plant Operation
9.10 Session Plan
9.11 Review Questions
9.12 References
9.13 Further Reading Materials
SESSION TEN : MONITORING AND EVALUATION
10.1 Introduction
10.2 Definitions
10.3 Indicators and Data Base
10.4 M&E as Integral Part of Programme Implementation Process
10.5 M&E At Different Levels
10.5.1 User Level10.6 The Logical Framework
10.5.2 Biogas Company Level
10.5.3 Programme Level
10.5.4 National Level
10.7 Session Plan
10.8 Review Questions
10.9 References
APPENDICES
Appendix - 1 Registration Form
Appendix - 2 Training Schedule (including field visit)
Appendix - 3 Evaluation Form (to be filled in by the participants)
Appendix - 4 Model of Certificate
Production of Biogas - Fixed Dome Type Biogas Plant
Production of Biogas - Fixed Dome Type Biogas Plant
Forms of biomass listed below may be used along with water:- Animal dung
- Poultry wastes
- Plant wastes ( Husk, grass, weeds etc.)
- Human excreta
- Industrial wastes(Saw dust, wastes from food processing industries)
- Domestic wastes (Vegetable peels, waste food materials)
Biogas is produced as a result of anaerobic fermentation of biomass in the presence of water.
The biogas plant is a brick and cement structure having the following five sections:
- Mixing tank present above the ground level
- Inlet chamber: The mixing tank opens underground into a sloping inlet chamber
- Digester: The inlet chamber opens from below into the digester which is a huge tank with a dome like ceiling. The ceiling of the digester has an outlet with a valve for the supply of biogas
- Outlet chamber: The digester opens from below into an outlet chamber
- Overflow tank: The outlet chamber opens from the top into a small over flow tank
- The various forms of biomass are mixed with an equal quantity of water in the mixing tank. This forms the slurry
- The slurry is fed into the digester through the inlet chamber. The temperature of the slurry must be maintained around 35 oC. Any drop in temperature will reduce the anaerobic activity and hence the yield of biogas
- When the digester is partially filled with the slurry, the introduction of slurry is stopped and the plant is left unused for about two months
- During these two months, anaerobic bacteria present in the slurry decompose or ferment the biomass in the presence of water
- As a result of anaerobic fermentation, biogas is formed, which starts collecting in the dome of the digester
- As more and more biogas starts collecting, the pressure exerted by the biogas forces the spent slurry into the outlet chamber
- From the outlet chamber, the spent slurry overflows into the overflow tank
- The spent slurry is manually removed from the overflow tank and used as manure for plants
- The gas valve connected to a system of pipelines is opened when a supply of biogas is required
- To obtain a continuous supply of biogas, a functioning plant can be fed continuously with the prepared slurry
- Requires only locally and easily available materials for construction
- Inexpensive
- Easy to construct
- Due to the above reasons, this plant is also called the Janata Gobar gas plant.
- As domestic fuel
- For street lighting
- For generation of electricity
- High calorific value
- Clean and excellent fuel containing upto 75% methane
- No residue produced
- No smoke produced
- Non - polluting
- The slurry is periodically removed and used as excellent manure which is rich in nitrogen and phosphorous
- Economical
- Can be supplied through pipe lines
- Burns readily - has a convenient ignition temperature Uses of Biogas
- Biogas is used
Review Of Bio-Gas Technology
Review Of Bio-Gas Technology
source: www.apo-tokyo.org
Download All chapters about Bio-gas:
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
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