Anaerobic Digestion

 Anaerobic Digestion for Developing Countries with Cold Climates 


Utilizing solar heat to address technical challenges and facilitating dissemination through the use of carbon finance

Summary

A large proportion of the rural poor in developing countries have no access to a secure source of energy. The  rural poor  in developing  countries  rely  primarily on  traditional  biomasses,  such  as wood  and  charcoal.  The  reliance  on  traditional  biomasses  and  solid  fuels  result  in  substantial human, social and environmental cost. To  tackle  these costs a switch  to a clean  fuel  is required. One  of  the  solutions  is  anaerobic digestion  (AD)  of  manure  or  other  biodegradable matter  to produce a clean fuel: biogas.
The principle of AD has been known for 3-4 centuries and in 1920 the first digester was designed  for  house  on  site  biogas  production.  A  digester  is  a  technology which  converts  the commonly found wastes in rural areas, manures, in a controlled anaerobic environment to biogas and  an  excellent  fertilizer.   Biogas  is  a  clean,  convenient,  versatile  and  environmentally  benign fuel which  does  not  pollute  the  indoor  air.  Furthermore,  a  biogas  plant  has  several  additional benefits, such as replacing bought or collected wood (time or revenue savings), provision of light by biogas lamps, empowerment of women by relieving them of the drudgeries of  traditional fuel gathering. A toilet is in most cases attached to a digester which improves sanitation, a significant virtue  since  the majority  of  the  poor  lack  access  to  sanitation. The  effluent  from  the  digester, digestate,  has  a  high  fertilizer  value  comparable  to  chemical  fertilizers.  Digestate  is  also  an excellent fish feed and can enhance fish yields. The adoption of biogas digesters has considerable spillovers to the local, national and even to a global level. For instance, at local level, employment opportunities, skills development and reduced pressure on the forest. At  a national level, it leads to  less health costs, more employment, and potential  foreign exchange earnings and  at a global level: greenhouse gas emission mitigation. Consequently, the cumulative effects of these benefits alleviate poverty and contribute to achieve the Millennium Development Goals.
Download
 Anaerobic Digestion for Developing Countries with Cold Climates http://www.wecf.eu/download/2009/EricBuysman-AnearobicDigestionforDevelopingCountrieswithColdClimates-June2009-MasterThesis-Final.pdf

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biogas plants highlighted

Need for biogas plants highlighted

 

CANACONA: A ten-day training programme for masons from different talukas of Goa on construction of biogas plants, was organised by Directorate of Agriculture in association with the zonal agriculture office, Canacona, at Marlim-Tirval in Poinguinnim recently.
Master mason from Belgaum, Mr Kalappa Navregar was the resource person for the programme, informed Canacona ZAO, Mr Rajesh Desai.
Deputy director of agriculture, Mr Prajapati Tufani, who was also present during some of the sessions, spoke on the importance and significance of biogas and said that the compost that is derived from a biogas plant is devoid of weeds. He further said that, in order to sensitise the people and the farmers on the importance of biogas, a meeting was held at this very place.
He informed that biogas plants were constructed in four homes free of cost and that the construction of fifth plant is in progress.
The residents who got biogas plants constructed are Mr Shashikant Gaonkar, Mr Ram M Gaonkar and Mr Anand Gaonkar from Marlim and Mr Laxman Gaonkar from Tirval, while the fifth construction which is in progress is of Mr Mhablu Gaonkar of Tirval.
During the programme, the masons were also guided by Dr H Eshwarappa, professor and head of department of agricultural engineering, Bangalore, Dr K V Pathy, professor of agricultural engineering and Dr Kumar Gowda, project manager, biogas training centre.
During the programme, assistant zonal officers of all the talukas were present, informed ZAO Canacona, Mr Desai, who welcomed the function while assistant zonal officer, Ms Gauri Prabhudesai proposed the vote of thanks.

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Drying beds next to the expansion chamber

The digester slurry will flow from the expansion chamber to the drying beds (not filled in yet). The drying bed will have a layer of perforated bricks. The liquid will percolate down through the holes in the bricks into a layer of sand and then into a collection pipe (black pipe visible in the middle of the bed ) and out to an irrigation channel. The solids will remain on top for drying and will be removed manually and used as soil conditioner.(Photo: Jun - Jul 2010, GTZ/WSIP (N. Khawaja), Navin Well-Field Area, Herat)

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Banana peels to biogas

Banana peels to biogas - Peninsula News Review 

 

The Vantreight family farm is moving ahead in an attempt to create its own energy source while diverting compostable material from the waste stream.
Ryan Vantreight made a presentation to a meeting of all three Peninsula municipalities to explain the process.
“Vantreight Integrated Resource Management has been a process we’ve been looking at as well as a technology we’ve been researching that started about three years ago. We do, right now, aerobic composting, so it’s outdoor with forced air going through it,” said Vantreight.
“The first stage of this project is feed-stock. Getting the feed-stock. Household organics right now are going to be part of the landfill unless someone has a green thumb and does composting in their backyard,” he said.
The Vantreights propose to use bio-digesters for the anaerobic digestion of organic matter to create heat and energy for the farm and community. The contained composting creates heat and natural gas which would be used on the farm, while methane is collected, reducing green house gas emissions.
Their plan is to collect compostable material from Peninsula businesses and households biweekly in the winter and weekly during the summer months. The total cost per household is estimated at $95.52 per year. Vantreight said it would also reduce the amount of garbage being taken to the landfill by 35 to 40 per cent.
Up to 20 per cent of the compost created will be available to local farms for a fee, the other 80 per cent would be used on Vantreight Farm. The natural gas created by the process would also be made available for local hospitals and other public facilities that use natural gas.
“We have been approved in writing by the ALC (Agricultural Land Comission) to process up to 45,000 tonnes a year of organic matter on the farm as a farm use,” Vantreight said.
“We will not be using sewage sludge, municipal waste from the sewage treatment plant (for input) and our electricity and transport fuels (output) will be later. What we will be using the biogas for is heating greenhouses to be able to grow more food,” he said.
“We already have letters of interest from commercial and industrial facilities that want to be able to utilize this process for their organic waste stream. What we’re looking to fill in 10 to 15 per cent is Saanich Peninsula — Saanich basically — first-come-first-served. We have the capacity and as soon as we have those agreements in place we know how much we can build and we can then engineer that facility … December 31, 2012 is when we want to be able to have our operation up and running.”
Sidney councillor Mervyn Lougher-Goodey asked Vantreight what happens if residents who already compost do not want to participate. “From local municipalities you need 15,000 tonnes … if people don’t want to pay for that service, do they have to? Right now I pay for garbage, I do not want to have to pay for this because I have a composter in my backyard and that’s where it all goes and I’m sure there’s all sorts of folks like that living here,” he said.
“This is, I think, where the conversation begins, how that would be structured,” Vantreight answered.
“In North Saanich there are lots of people that have very large properties that actually already do their own organic processing and certainly there’s lots of farms … so it’s a bit of a trickier issue when you don’t have concentrated populations,” said North Saanich councillor Ruby Commandeur. “It might be a better focal point in Dean Park where we have a concentration of housing or in Sidney or in some parts of Central Saanich, but it might be difficult to do that as an entire municipality to say, ‘everybody has to be on board and pay that $95.’”
“At one point or another it won’t be a choice,” said Vantreight. “At one point or another organics will need to go somewhere. What we’re proposing is somewhere that would be able to utilize on farm to reduce green house gas emissions … How it’s structured within the municipalities may be challenging but it’s definitely something that’s coming.”
“It’s to a point where we either sink or swim. We need to be able to move forward with this and what we need to do is be able to have those long-term agreements. This is the start of the conversation and we will be going to the other municipalities to be able to make that organic tonnage. It wasn’t solely focus on Central Saanich North Saanich it will go first-come-first-served,” said Vantreight.
“You may find it more efficient to start at the CRD (Capital Regional District) level,” said Sidney Mayor Larry Cross. “It feels a little dodgy to me, to ask us as a community, to sign a supply agreement with you by September of this year, given what’s happening in the larger picture of the CRD … also our own agreements with our service providers in terms of collection.”
Vantreight said the tonnage and timeline are attainable goals if there is both public and political will to move forward. “The main goal is to get in front of the CRD organics ban — which is coming,” he said. The ban that was scheduled for  May 1, 2012 has now been postponed to 2013.

View the original article here

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Diesel to Biogas Engine Conversions

Omnitek Engineering Ramps Up Diesel to Biogas Engine Conversions in the Philippines

Omnitek Engineering says it expects demand in the Philippines for its diesel engine conversion technology that enables utilization of biogas fuel to gain momentum, particularly on hog farms in remote areas with an abundance of biogas sources and sometimes limited access to electricity.
Large hog farming operations in the Philippines are participating in Methane Recovery and Electricity Generation projects, which are being governed by the Clean Development Mechanism (CDM) - an article of the Kyoto Protocol which allows industrialized countries with a greenhouse gas reduction commitment to invest in emission reducing projects in developing countries and apply them to Kyoto targets.
Covered in-ground anaerobic digesters, which convert animal waste into biogas, are being financed by foreign firms, which subsequently sell the generated carbon credits through global carbon trading markets, such as the European Climate Exchange to offset green house gas emissions.
"High diesel fuel costs, an abundance of biogas and the financial burden of replacing diesel powered generators with new natural gas systems are strong incentives for farmers to adopt our diesel engine conversion technology," said Werner Funk, president and chief executive officer of Omnitek Engineering Corporation.
He noted that four Omnitek-converted biogas power generators are already operating in the Philippines. Estimated monthly savings to farmers are considerable, and the engine conversion cost can be recovered within a four-to-eight month period - depending upon the amount of electricity produced.
Funk added that Omnitek continues to experience solid demand for its diesel engine conversions for heavy- and medium-duty truck and bus applications in other parts of the world.
"Biogas fuel is an exciting opportunity to expand and we look forward to capitalizing on other global opportunities," he said.
Sales and marketing initiatives for Omnitek's diesel engine conversion technology for biogas and farming applications in the Philippines are being supported by the company's strategic relationship formed in 2009 with Philippine-based Alternative Bio-Energy Technologies Company (ABET) to address growing local market demand for biogas engine solutions.
Funk added that diesel engines have a service life of up to 20 years, which provides an additional incentive to convert.

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Methane Bio-Gas Digesters

Methane Digesters 


With gas and fuel oil prices on the rise, many people are tapping into the alternative energy market. Quite a few farmers and municipalities are turning sewage, manure, or garbage into fuel. What sort of fuel is it and what is the process that produces it? Well, the best answer is, its perfectly natural. When you bury garbage in a landfill, bacterial action decomposes and forms volatile gases. Over time those gases leak into the atmosphere and contribte to the greenhouse effect. Landfills in particular are being challenged to become emission free, by trapping and burning the "landfill gas". Landfill gas, or biogas, as it is now called, is composed of approsimately 65% methane, 30% carbon dioxide, and 5% other minor gases.
The process by which biogas is produced is anaerobic digestion; meaning without oxygen. This is not the same process as "composting" vegetation in your backyard. Composting requires aerating the mixture by turning; thereby exposing it to air (oxygen). The byproduct of this reaction is soil and predominantly carbon dioxide gas. Anaerboic digestion requires that the reaction take place in a container that is sealed or isolated from the outside air. The product is a large amount of methane, a little carbon dioxide, and a high grade fertilizer.

A simple digester is just a big balloon full of crap! Once placed in a sealed container, oxygen loving bacteria within the orginal product begins to break down the manure into simpler compounds; these are typically ammonia compounds. At this point, a fair amount of CO2 is given off. Once all of the oxygen is used up, other critters, ammonia loving bacteria, take over. The ammonia loving bacteria work to liquefy the material. Eventually, fodder for the a ammonia loving bacteria is used up and the next process begins; the production of methane. For this process to begin and proceed in a timely manner, the reaction requires two things, a neutral or slightly basic pH and an optimum temperature. A well buffered digester will be at around 8 to 8.5 on the pH scale. A digester is pretty much self buffering once it is started, but you can speed things up by starting it off on the right foot. The optimum temperature is 95 degrees F to 110 degrees F. While you will produce gas at lower temperatures, it will take a much longer period of time. Landfills don't begin producing methane gas until many years after they are sealed up.
There are different types of digesters; the two major types being batch and continuous feed. Each is exactly as its name denotes. The simplest is the batch digester and it can literally be as simple as putting some cow manure in a barrel and sealing it up. However, without adding some heat, there will be very little perceptible activity. Add a little heat in the form of a drum heater, as shown in the picture above, and voila - instant fuel. A little tubing and a few valves, and you have a simple digester. We have heard of running a small gasoline engine from a barrel typ type batch digester. However, it is very limited in the amount of methane it can produce. Typical life of a batch digester is around 45 to 60 days. At that point, you would have to dump the fully digested material and refill the container with fresh manure.
The most practical type of digester is the continuous feed digester, since it will provide a continuous output of gas instead of a large volume all at once. A small quantity of manure is fed into one end of the digester at regular intervals. With each feeding, the previous "slugs" are forced along the lenght of the digester until it comes to the outlet at the other end; sort of like a big instestine!
TAP Point:
When you plan for your digester, plan for a constant supply of manure and a way of disposing of the effluent. The continuous feed digester requires regular feeding and will produce lots of high quality fertilzer and lots of gas!
Most of the examples we see today are on the large corporate farms with sophisticated controls and people to tend the daily needs of the digester. What about the small farm? Well, a digester can be designed to be as large or as small as you like. Design it to suit your needs and budget.

How can I use the methane that I produce?

Methane can be burned to provide both heat and cold. Used in an absorption chiller, the heat produced by burning methane can be converted to cooling for buildings or processes. This is actually a very efficient system since for every BTU produced, you get a BTU back in cooling. No so with electric production. If you choose to produce electricity, the system efficiency is very low. This is mainly due to the fact that internal combustion engines are exremely inefficient, only about 25% so. Diesel engines are higher, around 35%. However, if you opt for a conventional engine generator set, then you are going to end up with a converted gasoline engine.

Using the gas directly for water heating is another very efficient use of the fuel. New hot water tanks are around 95% efficient. If you start off with a small digester, then plan for several independent usage methods. That way if demand is low, you can use all of the gas that you produce. If you have to store it by compression, then you will use a lot of teh gas you produce just to compress the rest. This will discussed in more detail later.

Another way of utilizing the fuel you make is to heat water to make steam and drive a turbine connected to a generator. Most back yard mechanics are not going to tackle this and industrial units are hideously expensive. Still, there are some interesting new micro-turbines being marketed today that would be perfect for small installation.

Each of these alternatives requires a constant supply of gas, but will not be able to tolerate oversupply. Correct sizing of the components is critical to maintain operation and to get the most from your unit. It is impossbile to accurately determine the rate at which gas will be produced because of all the variables - manure content, temperature, amount of water. If you have control over at least some of these parameters, you should be able to predict the flow of gas within a reasonable tolerance. However, you need to plan for a reserve that can act as a flywheel or capacitor and provide even flow to your engine/generator. 

As we discussed in Part 1 of this series on Methane Digesters, the proces of producing methane from animal manure is called anaerobic digestion (without air or oxygen). Anaerobic digestion occurs when organic material decomposes biologically in the absence of oxygen. The process must take place in the complete absence of oxygen and so the digester must be leak tight and should maintain a positive pressure inside of the digester to keep air out. If the vessel is to be pressurized then it must be able to withstand a certain amount of pressure.
While there are many different organic compounds that can be digested to produce Biogas, some are better than others. Straight cow, pig, or chicken manure will work very well and produce lots of usable fuel. The amount of biogas that is produced with each material is shown in the chart below:
Cow.........................................3-5 cu ft/lb of solids
Pig............................................6-8 cu ft/lb of solids
Chicken....................................6-13 cu ft/lb of solids
Use this information in conjunction with the TAP Methane Calculator to determine the output of a digester for various feed stock. This will help you properly size the digester and the componenets that will be used in conjunction with it so that things do not get out of hand. For given volume of feedstock, the calculator will determine:
1. The amount of gas that will be produced.
2. Energy potential of the gas.
3. Size of engine/generator set that will consume 100% of the gas.
4. Cost of the TAP methane generator system.
5. Estimated cost of the engine/generator set.
6. Value of electricity produced if the gas is consumed in an engine/generator set.
7. Value of propane if the gas produced is used to replace propane in a heating system.
8. Value of gasoline if the gas produced is used in an automobile.
Proper sizing of components will allow for efficient use of materials to prevent a "runaway" system.
As we stated previously, the process that makes methane out of manure is anaerobic digestion. It is not just one simple process, but a series of complex processes acting in concert with one another. At each step in the process, compounds are produced that are used in the next step of the process. Once started, if the proper care is taken, the digester will be "self buffering;" which means all of the processes within the digester will reach a state of equilibrium with one another. A well buffered digester will be able to correct small upsets and achieve equilibrium again with no intervention from the operator. The best practice is "patience". Rather than try to correct a poorly producing or stuck digester, the best practice is to leave it along and let if correct itself. Keep it warm and feed it regularly and it will pump out a continuous stream of gas.
When the digester is first loaded and sealed, there will be a lot of oxygen trapped in the digester housing. Before the process of methane production can start, the oxygen must go. This will be taken care of by the oxygen loving bacteria that reside wihtin the maure. The process is fermentation. If there are no leaks, then all of the oxygen will be consumed within the period of about 2 weeks. During that time, large quantities of CO2 (carbon dioxide) will be produced. This can be vented off or extracted and compressed for other uses. CO2 is a greenhouse gas and there may be credits or financial incentives given for trapping it.
During the initial phase of the anaerobic process, proteins, fats, and starches are broken down into simpler compounds by acid producing bacteria. These bacteria multiply rapidly and excrete the enzymes that break down and liquefy the material. One of the acids that will be produced is acetic acid. Most of the methane that will be produced will come from the conversion of acetic acid.
At this point the methane producing bacteria can develop. This phase of the process moves slowly and it can take some time before large quantities of methane are produced. Ina continuous feed digester, a balance is struck between the acid producing bateria and the acid consuming/methane producing bacteria. This balance is maintained by regular feeding of fresh material, in the right quantity. Over or underfeeding can slow down the process or bring it to a halt.
The digester must be kept at a constant temperature in the range of 90 degrees F to 110 degrees F. This is usually accomplished by circulating heated water through pipes running through the interior of the digester. The heat can come from a boiler fired by the methane being produced, solar collectors, or heat from an internal combustion engine. A stationary engine consuming the gas produced to generate electricity is the most common method. While not the most efficient use of gas, the internal combustion engine produces large mounts of waste heat that can be channeled back into the digester. This is a good example of an energy system where the individual components compliment and support each other. Additional information about applying engines with digesters to produce electricity will be discussed in future articles.
In a continuous feed digester, as material is added at the inlet, material is forced out of the outlet. The feed and drain can be arranged so that the material comes inot the digester below the level of the contained fluid to maintain a seal. I advocate using a mixing chamber on the inlet and pumping the material into the digester with a sludge pump. The incoming material should be the consistency of molasses. The bacteria will liquefy the material once digestion starts so do not add a lot of water. Too much water will increase the CO2 output. The incoming material should only be wet enough to pump or pour it.
The effluent coming off of the other end of the digester is a high quality fertilizer. It does not have the high odor like raw dung. SInce it is already broken down into simpler compounds it can be used directly by plants. Driend effluent can be bagged and sold for fertilizer or used as bedding for animals.
Biogas is approximately 65% methane, 32% CO2, and some other trace gases (nitrogen, hydrogen, carbon monoxide, oxygen, and hydrogen sulfide). The energy content is 600 BTU per cu ft. Compared to other gaseous fuels:

Biogas..................................................600 BTU/cu ft
Natural gas.........................................1050 BTU/cu ft
Propane..............................................2400 BTU/cu ft
Biogas can be used directly in gas range, gas furnance, gas hot water tank, gas space heaters, gasoline or diesel engines. Obviously the energy value needs to be considered. It would be difficult at best to use biogas as a substitute for gasoline in an unmodified engine. The low energy value would reduce the power and pre-ignition would occur because of the mismatch in the required compression ratio. Still, its not that it can't be used - it just won't have the same performance. A better alternative is to use it as a supplement in a diesel engine. This can be accomplished be feeding the gas right into the air intake of the engine. The governer will back off to reduce the amount of diesel fuel compensate automatically. A duel fuel alternative is a very good way to ulitize the gas you produce with very little added effort. TAP Energy will be experimenting with a simplified conversion kit for diesel engines.
Using the biogas directly for heating or cooking is the most efficient method of capitalizing on your new energy source. An example can be seen in the Bunsen burner pictured to the left. In a gas range, very little difference may be seen over natural gas and no modification is necessary. In a hot water tank, the heat cycle time will increase by 30%, but no modification is required to substitute biogas for natural gas. The trace of hydrogen sulfide inherent in biogas makes it easy to detect a leak. Use the same precations you would use if you were working with natural gas.

 source:http://tap-energy.com/

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Biogas project in Karatu Tanzania video

Biogas project in Karatu Tanzania video

he biogas project was firstly part of the "Sustainable Energy Project". Within this pilot project two prototype biogas plants were built in Slahhamo village. The construction of this efficient energy form were going hand in hand with training and human capacity building and awareness creation on the benefits that accrue in investing biogas plants.

After this pilot phase the biogas project was separated from the stove project, because the biogas was just affordable for farmers with enough cows. With the support of the United Nation Development Program (UNDP) the project continued and 25 biogas plants had been built in the district.

Aim of the project has been to utilize the energy, there potential are stored in the dung from the households cows. Cow dung can if it is broken down under anaerobic conditions release methane and create biogas. Biogas is an energy source, which can deliver clean and renewable energy to households, to meet these household energy needs for cooking and lighting.

The Project has developed and built biogas plant to test the possibilities for using biogas plant in the energy supply to households in the area, and for developing new construction principles for biogas plant in Tanzania.

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Biogas plant Information in urdu Voice,

Biogas plant Information in urdu Voice, Youtube video, Biogas plant at household level Voice Dr.Ashraf Sahibzada

Part one

Part Two

Biogas plant economic benefits Dr.Ashraf Sahibzada

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Making biogas Biogas tanks with 200 liters in detail.Thai Video

การทำไบโอแก๊ส Biogas ด้วยถัง 200 ลิตร อย่างละเอียด | Making biogas Biogas tanks with 200 liters in detail.

การทำไบโอแก๊ส Biogas ด้วยถัง 200 ลิตร อย่างละเอียด | Making biogas Biogas tanks with 200 liters in detail in Thai language

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How to Build Biogas Digester

How to Build Biogas Digester Video

Part 1 Introduction 

Part 2 Installation

Part 3 Using

The video is published under Vietnam EASE Programme which stands for Enabling Access to Sustainable Energy. This is the product of the project Biogas Market Development implemented by RCEE/CCRD. This biogas digester is the Improved VACVINA model technology.

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Biogas Video

Biogas: From Grass to Gas Video



Biogas technology is a new twist on an old tradition: using cow dung in a clean, efficient way to produce cooking and heating fuel in the form of safely produced methane gas.

Find out why biogas is the most cost-effective energy solution for India's rural population and find out how YOU can help -- by encouraging local governments to support biogas projects more enthusiastically, by supporting the technology financially, and even by aiding in the construction of the plants themselves!

You can get more information about the technology at saisanctuary.com!

Narrated by: Sandeep Prasanna (English/Kannada)
Written by: Karan Chhabra (English), BN Pemmaiah (Kannada)
Filmed by: Katie Swails
Special Thanks to: Pam and Anil Malhotra, SAI Sanctuary, Duke University Biology Department, Duke Center for Civic Engagement (DukeEngage)

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Build a biogas generator activity plan

Build a biogas generator activity plan  

How can we make and collect flammable methane?  Biogas is the name given to the gas th
can be collected from decaying bioma It is a mixture of about 60 per cent methane, 40 per cent carbon dioxide a trace amounts of hydrogen sulphide a nitrogen.  Building a biogas generator is simple a the diagram below shows you how to set one up. When your generator is complete, you will need to fill it with feedstock: this is the biomass that bacteria will break down to produce biogas.  When preparing and adding your feedstock to the generator you must wear rubber gloves, goggles and an apron.


Download  Build a biogas generator activity plan

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CONSTRUCTION OF HYBRID BIOGAS DIGESTER

INTRODUCTION TO CONSTRUCTION OF HYBRID BIO-DIGESTER – VACVINA

 INTRODUCTION TO CONSTRUCTION OF HYBRID BIO-DIGESTER – VACVINA

The objective of this book is to provide trainees with the process at each step as well as
echnical concept in building Vacvina bio-digester with its significant modification as follows  

• Study possible digester construction site on basis of geographical and soil condition;

•   Technical design in building and fixing underground tanks;

•   How to prepare and install equipments for Vacvina plant; and

•   Other factors to operate and maintain Vacvina tanks.

 Table of contents
 
1. How to Calculate Required Digester Volume ....................................................................................... 2
2. Preparation of Construction Materials and Appliances......................................................................... 3
3. Construction and Material Installation .................................................................................................. 4
3.1. Digester construction.......................................................................................................................................4
3.1.1. Digging.....................................................................................................................................................4
a. Construction site selection..........................................................................................................................4
b. Digging.......................................................................................................................................................4
3.2.2. Making digester foundation......................................................................................................................4
3.1.3. Bricklaying of the walls ...........................................................................................................................5
3.1.4. Mortar and cement liquid plastering.........................................................................................................5
3.1.5. Making digester concrete .........................................................................................................................6
a. How to assemble mold and install supporters of the mold to construct digester concrete..........................7
b. How to determine and make the technical hole during construction of top concrete.................................7
c. Preparing and casting iron rods ..................................................................................................................8
d. How to mix cement to construct top concrete 200B...................................................................................8
e. Concrete thickness......................................................................................................................................8
f. Concrete vibration and maintenance...........................................................................................................8
g. Making technical hole cover ......................................................................................................................9
3.1.6. Making concrete of worktop for cooking.................................................................................................9
3.2. Installation of appliances...............................................................................................................................10
3.2.1. Installation of inlets (siphon)..................................................................................................................10
3.2.2. Installation of outlet system ...................................................................................................................11
3.2.3. Installation of bottle safety valve ...........................................................................................................12
3.2.4. Installation of gas reservoir ....................................................................................................................12
a. How to install gas reservoir ......................................................................................................................13
b. Technique in tying gas reservoir ..............................................................................................................13

c. How to tie gas reservoir with plastic tube at its end .................................................................................13
d. Selection of place for gas reservoir ..........................................................................................................13
e. Operation..................................................................................................................................................13
3.2.5. Installation of biogas burners .................................................................................................................14
3.3. Filling soil around the digester ......................................................................................................................14
4. Attention for Operation and Maintenance of Biodigester – Vacvina Model....................................... 15
4.1. Feeding raw materials into digester...............................................................................................................15
4.1.1. First feeding of manure ..........................................................................................................................15
4.1.2. Daily feeding of manure.........................................................................................................................15
4.2. Operation of biodigester................................................................................................................................15
4.2.1. When reservoir is full of gas ..................................................................................................................15
4.2.2. When gas burners in operation...............................................................................................................16
4.2.3. When whole system in use .....................................................................................................................16
4.2.4. Warning of chemical into digester .........................................................................................................16
5. Appendix ............................................................................................................................................. 17
5.1. Practical exercise in calculation of total volume of a digester, construction materials and investment cost.17
5.1.1. Ouch Veasna family (Takeo province)...................................................................................................17
5.1.2. Thap Chaney (Kampong Speu province) ...............................................................................................19
5.2. Detail designs of biodigester system.............................................................................................................22
 
 Download PDF Book CONSTRUCTION OF HYBRID BIOGAS DIGESTER

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BIOGAS FOR A SUSTAINABLE FUTURE

Biogas for a sustainable future

by ALBERT FERNANDES
CANACONA: Biogas technology is being promoted in India chiefly under the aspect of energy. It is based on the anaerobic digestion of organic material to produce clean fuel for cooking, lighting and running machinery.
The bio-digested slurry besides providing plant nutrients, benefits the soil by bringing about physical, chemical and biological enrichment. In the days of energy crisis, biogas becomes handy for the farming community as it supplies gas for fuel and enriched bio-manure from cow dung.
Among the renewable sources of energy, biogas technology is the most mature in terms of use and number of units installed. Economically, too, biogas technology has the lowest financial input per kilo watt of output energy. It provides not only energy but also value added bio-fertilizer, in addition to providing other benefits like sanitation, cleaner environment with less pollution and better quality of life.
Looking beyond the years, it seems certain that we are moving to an era when the energy costs are going to rise and the pressure on fossil fuels and wood is going to become more and more acute.
The rising commercial energy demands worldwide also threaten the environment. Power sector growth is estimated to come mainly from fossil fuels, coal, oil, gas and large hydropower developments. Renewable energy resources and energy efficiency can help address some of the global growing energy needs without adverse environmental impacts.
So why should people today prefer biogas plants in their homes? Precisely because of its zero or low cost fuels, low gestation period, quicker benefits, social relevance and economic viability, besides providing security to developing economies. The biogas energy is comparatively cheaper as compared to conventional sources.
Biogas plants can be easily installed in remote tribal areas where electricity is not viable and/or available. It can also help in the reduction of indiscriminate felling of trees for fuel and consequent deforestation, besides improving rural sanitation and reducing the incidences of eye-diseases among the village women and children. biogas plants, if installed in the rural remote areas, offers huge employment for the less-skilled rural people.
Speaking to this reporter, the ZAO Canacona, Mr Rajesh Desai informed that biogas production, like the septic tank, is an anaerobic digestive process, which is the simplest and safest way for treating human excreta and animal manure to prevent the spread of diseases. He also informed that it converts these renewable resources to a clean fuel to replace other conventional fuels. When burnt, biogas gives a blue flame which may be used for cooking, lighting as well as alternative fuel for petrol and diesel engines.
Mr Desai points out that biogas technology also reduces the build-up of carbon dioxide in the atmosphere and reduces the smoke in the area. He further tells that a biogas plant is an asset to a farmer’s family, because it is based on the biological decomposition of organic materials in the absence of air. Since India has the largest cattle population in the world, this strategy can work and is viable to the Indian rural community in particular.
Mr Desai further informs that there shouldn’t be big trees near the selected sites for the installation of biogas plants since this may prevent the sun’s rays from falling on the plant. The roots, too, may cause damage.
The ground water level should be at least 2-3 metres below the surface and the selected site shouldn’t have in its vicinity a drinking water well, for at least 50 feet around. There should be enough space for storage of digested slurry pits or construction of compost pits, Mr Desai asserted.
Mr Desai also pointed out that septic tanks can be connected to biogas plants.  He confirmed that in Belgaum, most of the septic tanks have been connected to biogas plants.
Moreover, the government gives 90 per cent subsidy for the construction of a biogas plant. On an average per day, 15-25 kg of cow dung is sufficient to run a domestic biogas unit in one household.
Today, in Canacona taluka, there are more than 50 installations of biogas plants.

Source: http://www.navhindtimes.in/south-goa-monitor/biogas-sustainable-future

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Malaprabha Biogas Plant Diagram

Malaprabha Biogas Plant Diagram

Cut-away view of Malaprabha Biogas Plant (without gas tight cover on 1st chamber)

Perspective sketch of Malaprabha Biogas Plant with attached pour-flush toilets

View of Malaprabha Biogas Plant (without gas tight cover on 1st chamber)

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Electricity generated by biogas plants in Pune, india

 Electricity generated by biogas plants in  Pune, india

Pune, May 28: Electricity maked by processing organic household waste is being used to light up the streets of Maharashtra's Pune city.s many as 225 streetlamps have been lit up by power maked by biogas or gobar gas plants.

The initiative, which was taken by the local municipal corporation, has been aimed to set up five more power plants towards the end of 2011.

According to officials, biogas or gobar gas from organic waste can be effectively used to make electricity.

"The Municipal Corporation started this biogas or gobar gas plant a year ago in the city. Every day we supply about five tonnes of organic waste to the biogas or gobar gas plant, from which we can make near about 300 cubic metres of gas, and that gas can be utilized to run the genset (generators), gas engine to make electricity. After electricity generation, electricity is utilized to light up the streetlights," said Suresh Jagta, a systems engineer.

As much as 40 percent of domestic garbage is processed every day in 12 biogas or gobar gas plants in the city.

Statistics reveal the city produces 1,200-1,400 metric tonnes of waste, out of which only 200-250 tonnes is organic waste. Out of that, 50 metric tonnes of organic waste is processed to make electricity.

According to officials, the waste is collected from different sources for further treatment.

"The plant uses green waste from households, vegetable and markets, which is called wet waste. We collect it here for treatment," said Sanjay Nandre, a project developer.

The first biogas or gobar gas plant in the city was set up in 2009.

About 2,400 tonnes of organic waste has been processed since the project was started, and 48,000 kilowatts of power has also been maked.

India has an estimated two million biogas or gobar gas plants in use since 2000.

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KESC's biogas energy project

 Karachi Electric Supply Company biogas energy project 

BR Research met Evan Chrapko, CEO of Highmark Renewables and Omer Ghaznavi, General Manager Corporate Strategy & Business Development at KESC to discuss about the upcoming renewable power project base primarily on animal waste. Following are the edited transcripts of the conversation BR Research: How did the biogas idea come up in presence of the more fashionable renewable soures such as wind and solar energy?

Evan Chrapko & Omer Ghaznavi: We started the work on this project about 18 months ago. Initially the focus was on wind power, solar power and the regular stuff that we keep hearing about. But the problem with wind and solar was that the pricing was too high. There were a lot of technology issues, everything had to be imported, it was not proving to be economical enough for us for a variety of reasons.

The idea was to bring the prices down in the future instead of going up all the time. We started looking around for options and one project that we came across was the Landhi bio gas project. The project we have taken is the biggest in the world and dealing with 3000 tons of waste a day to produce 25 MW. To handle that, you need to know what you are doing and need to be able to prove that the thing will work because it is a matter of $60-70 million of investment.

BRR: What advantages does biogas energy have over more conventional sources and what expertise does Highmark offer? EC & OG: We spoke to a lot of German and North Americans firms in the beginning but most of them were hesitant to work in Pakistan back then. Then we heard about Highmark and a couple of projects that they were doing. We contacted them and started searching for different sites. Landhi was the best option as it is very concentrated and generates a lot of waste.

The waste which is dumped into the open sea has huge impact on the environment. The concept was to move to a more sustainable process without much dependency on imported material and equipment at a much lower price. The beauty of the model is that the majority of the equipment can be sourced locally, reducing the import dependency.

While the line work, layout and the engineering will be done remotely by Highmark, the implementation on the ground will be done by the local contractor. We have our options open for equipment, we can either source it locally or import it from US or Far East, whatever suits us.

We have now brought in a testing container to get an idea of what kind of and how much gas can be produced. We have three months of testing going on, after which we will work on design. At the same time, we are working on the financial close, the investors have shown interest but we obviously need the data to support the case.

We are hoping to reach the financial close by the end of the year. For financing, we are talking to a lot of international financing institutions like ADB. IFC etc. Local financing is a bit dicey and it makes almost impossible to look for that.

BRR: Is biogas energy any friendlier to the environment than the other renewable sources?

EC & OG: The good thing about the project is that other than producing power that will be environmental friendly we will also be producing 400 tons of organic fertiliser, which is only slightly smaller than Fatima Fertiliser.

It will not be a direct substitute to urea but will be a complimentary product. While urea is suitable for extracting more growth, this organic fertiliser would be used on eroded soil which has lost its utility and where urea won't be effective.

And Pakistan faces that soil problem a lot, so there is a market for organic fertiliser to be tapped. That is why we are hoping to talk to the likes of Fatima, Engro or the Faujis and let them deal with the fertiliser side of things.

There is no point KESC trying to become a fertiliser firm. The core thing that attracted towards Highmark was their capability to utilise all kind of waste like animal waste, metro waste etc.

BRR: Are there other sites in Karachi from where the raw material can be sourced?

EC& OG: Yes there are a few places near Sohrab Goth - but they won't be as big as Landhi. Landhis's advantage is its concentration and huge amount of waste which is why it is getting international attention.

The current largest project comparable in the world is 8-9 MW. So this project is going to be the largest in the world by a mile. We have a lot of interest on how much could be done socially and on humanitarian grounds. This is a high quality product and very sustainable and reliable in comparison to wind or solar which is very vulnerable and fluctuates highly.

This is energy plus fuel - so we are cleaning up the by-product in a way that allows the environment to stay clean. We are working with KESC because we see the strategic leadership and vision there - they are very serious and ken about the project which is why we are moving ahead swiftly.

All the solar and wind projects do generate electricity but the social and environmental aspect is largely ignored. It is not that we are doing some rocket science work - it is a combination of some very old and some relatively new laboratory technology and this combines in a unique way to get something that is very reliable.

BRR: Will it be local people working on the project or will it be a mix of foreigners and local both?

EC & OG: All construction, operation, everything will be locally done. The only thing that comes from Highmark is the design.

The idea behind it is not to deal with the load shedding issue with this project - it is to bring about a change in the local community over there. We will be working with our CSR team towards providing health and education services to the local community.

The biggest thing is that you need to collect 3000 tons of we waste from the sites every day, we will be picking waste form restaurants and even from the Sabzi Mandi - but the biggest chunk (95 percent) will be the animal waste and we will be mixing it altogether.

Our technology is unique that it will accept all kinds of organic waste. We have put in a lot of research to get to this technology as the waste here is not 'clean' and contains lots of impurities.

BRR: Will the electricity produced be attached to the national grid or will it be for Landhi only?

EC & OG: We will identify industrial users in Landhi, Korangi and nearby areas. We will try not to throw it on the grid in order to avoid line losses etc. The tariff for biogas is already set by Nepra at 8.5 cents per unit, which we hope will be feasible enough.

We do not want to be dependent on government doling out money - we plan to subsidise it form carbon credits and sale of fertilisers.

BRR: What is the project's estimated cost? Are there any plans to expand?

EC & OG: The project's estimated cost is $65-70 million. This is a KESC project but we don't want it to be confined to KESC only - we want the bigger players to come in and share. If we can show it successfully in Karachi - then it can work elsewhere in Pakistan too.

It may not resolve your 5000 MW shortage - but t it will get power to the remote areas and provide cleaner energy. And will also provide bio fertilisers which are very good for the farmland. It is certainly better than using raw manure.

KESC can only do Karachi but that is why we don't want to do it solely on our own, we want other partners to work with us. We are hoping that in the next decade we have three or four such facilities in Karachi as there are other waste sites in the city - where human or metropolitan waste could be used.

We have great incentives on renewable energy - there are no taxes - repatriation of money is easy. We are hoping to start generating electricity by 2013 - fingers crossed.

Source: http://www.brecorder.com/articles-a-letters/single/626/0/1192816/?date=2011-05-26

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Biogas in Mexico city

powerland mexico city a bold community built on trash 

MEXICO CITY — Energy can be harnessed from the most unexpected places. In Mexico, it now even comes from trash.

Recently, an enormous landfill in the east of Mexico City was sealed over and converted into a retail park, and underneath it, a unique system turns mountains of trash into megawatts of electricity.
Neza Uno was a 350-acre dump overflowing with twenty million tons of garbage, severely contaminating the air and water basins in this part of the city for over thirty years, where today over a million people live. Now transformed, the site is a modern complex bustling with life that houses a mall, hospitals, government offices and sports grounds.
Ciudad Jardín, the Garden City, is the result of a five-year, 200-million dollar collaboration between the local authorities and private developers. From early on, a biogas collection system was envisioned to tap the potential energy latent in the millions of tons of organic garbage. Construction firm GUCAHE, whose founder Heberto Guzman was the visionary behind the project, hired engineer Jorge Sanchez to devise and install the system.
His design involved laying three miles of pipes underground to collect the biogas emitted by the trash - basically carbon dioxide and methane, the two gases responsible for global warming. The gas is fed into the biogas plant where it is currently being incinerated, but in mid-2011, the generators that convert biogas into electricity will be installed, and the cycle of regeneration will be complete.
According to Sanchez’s calculations the site will be able to produce up to three megawatts of electricity for ten years, enough to power the entire park and service parts of the local community, where the power grid is severely lacking. The award-winning project, one of the first of its kind in the world, is already being adopted as a model for landfill regeneration in other parts of Mexico. As Jorge Sanchez says, “the days of simply covering a landfill with earth and abandonning it are over.”

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Biogas Digester

 Biogas Digester

 

It is estimated that 2 cows or 10 pigs provide enough manure to fuel a family’s daily cooked meals. By combining an ancient process with engineered concepts, we have set out to introduce and implement small bio-gas plants to provide a source of methane gas for use in cooking and to power small gas lanterns.

When organic material decomposes under anaerobic (lack of oxygen) conditions, it produces biogas which is a mixture of methane (CH4) and carbon dioxide (CO2) with small quantities of hydrogen, nitrogen, carbon monoxide and other compounds. Biogas can be used as a fuel source for cooking, heating, producing light or even fueling a generator. A methane (BioGas) digester is a device used to produce and capture this biogas. Organic materials hereinto refers to excreta, or manure, of any animal but also refers to kitchenscraps and gardening waste.

The benefits of converting a limitless supply of manure and other organics into biogas include the following:

• Biogas systems produce clean energy for household use.
• Cooking on biogas is quicker, easier, and more efficient than cooking on wood or charcoal.
• Biogas systems produce excellent nutrient-rich fertilizers for use on farms and gardens.
• Biogas systems help in the fight against global warming by allowing us to burn methane instead of a harmful release into the atmosphere.
• By utilizing a limitless supply of manure input, there will be no further necessity for costly resources such as propane, coal, or firewood and thus will allow for economical savings while supporting the regrowth of trees.

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Large digester, energy facility being built at Wyoming County dairy farm

This information came from CH4 Biogas

Wyoming County, NY -- A new mixed-waste anaerobic digester and renewable energy facility is being built at the 2,000-cow Synergy Dairy in the town of Covington.
CH4 Biogas, LLC is building the project. Four of the 16 digesters in New York state are located in Wyoming County.
CH4 Biogas said Synergy Biogas will be one of the largest on-farm digesters in the state — and the first independently owned and operated plant located on a dairy farm. Additionally, the Synergy facility will be the first biogas plant in New York state designed specifically for co-digestion of manure with food grade organic waste, said CH4 Biogas officials.
In addition to producing renewable energy, the facility will reduce greenhouse gas emissions from the farm, divert organic wastes from landfills, reduce manure odors and provide the farm with manure handling systems to more efficiently manage nutrients and protect the environment.
CH4 will build, own and operate the biogas facility that will produce renewable energy by anaerobically digesting manure from the dairy along with food grade organic waste from food processors in the region. As anaerobic digestion unlocks the energy value in manure, it reduces odors and greenhouse gas emissions and produces a nutrient-rich end product for use as fertilizer.
Synergy Biogas will provide more than 10,000 megawatt hours per year of renewable energy to the grid (electricity to power more than 1,000 homes) and reduce greenhouse gas emissions by the equivalent of 8,500 tons of carbon dioxide per year.

It is anticipated the Synergy Biogas Plant will begin operation in September.
CH4 Biogas is a renewable energy company that builds, finances, owns and operates biogas based renewable energy facilities on farms and at food processing plants.

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Massachusetts's first biogas power plant to come online

 Massachusetts's first biogas power plant to come online

The Jordan Dairy Farm in Rutland, Mass., will soon host the state’s first operating biogas power facility.
A ribbon cutting ceremony will be held on May 31 for the manure and food waste-to-energy plant, construction of which began in October of last year. Among those attending will be Massachusetts Gov. Deval Patrick, local farmers involved and other project partners.
The plant will allow dairy farmers to better manage their cow manure by utilizing it, as well as food scraps, to produce heat and electricity (2,280 megawatt hours) for farm operations and for sale to the utility grid. It is part of the AGreen Energy LLC venture, a plan to install five anaerobic digestion plants on small dairy farms (250 to 400 animals) in the commonwealth.
The AGE projects are being designed, built and monitored by Ohio-based quasar energy group; Casella Waste Systems will operate the digesters and provide liquid source separation organics through its wholly owned company New England Organics.
The AGE venture requires about a $3 million capital investment per farm. Each anaerobic digester will employ a complete-mix process with a modular design, and the systems will be entirely computer controlled, allowing for remote monitoring and control.

Source: http://www.biomassmagazine.com/articles/5561/massachusettss-first-biogas-power-plant-to-come-online

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Biogas power plant design and construction

 Biogas power plant design and construction

A Biogas, Bio bio gas, or gobar gas plant uses the process of biological fermentation to generate renewable electricity and heat. It ferments natural waste products and energy crops to generate green energy.

Biogas, Bio bio gas, or gobar gas plants have an important place in a sustainable energy policy. This is because they have some important advantages that other alternative forms of energy such as solar power and wind power do not have.

- Highest energy efficiency: Biogas, Bio bio gas, or gobar gas is converted in a combined heat-& power coupling (CHP), with an efficiency of 85%.
- Continuous operation: The anaerobic fermentation is a biological process that occurs continuously
- Waste: Various wet waste flows can be processed into energy
- Flexibility: Flows from different sources can be processed together

Input

The starting point for each project is always based on the input flows that are available on-site and in the region. There are many different input flows that can be fermented:

·         Energy crops such as corn, beet, ...

·         Manure from pigs, chickens, ...

·         Organic Biological Secondary flows and products

·         Organic sludge

All organic biodegradable flows in the plant can be inserted and that a similar Biogas, Bio bio gas, or gobar gas potential without hazardous waste to be.

Fermentation in the Biogas, Bio bio gas, or gobar gas power plant

Through parallel fermenters, the Biogas, Bio bio gas, or gobar gas can be derived from the composition of input streams. The Agri-bio power plant uses wet fermentation, which means that the input flow has a minimum humidity of 40% and the reactor contents has dry matter percentage of maximum 12%.

Output

As mentioned above, after fermentation the Biogas, Bio bio gas, or gobar gas plant generates 3 outputs(*).

Electricity: the electricity that is generated can lower or eliminate your energy bill. Excess electricity can be resold on the electricity grid. This means that a Agri-bio power plant can convert your waste into electricity!

Heat: the heat generated during the combustion of Biogas, Bio bio gas, or gobar gas can be used for use in other processes that require significant heat.

Digestate: The digestate can be transformed into pellets suitable for fertilization of the fields or energy. In this way nothing is lost and we can turn this flow into an economically valuable product.

(*) renewable CO2 is also possible, this means that the facility is eligable for CDM’s (clean development mechanisms)

Energy Alliance Agreement: innovative cooperation with benefits for both parties!

Apart from the obvious connection to the grid or the use of heat for the drying of the digestate, the En-Bio experience to draw up a so-called energy alliance. It is heat and / or electricity traded to a customer in the area, which both parties can obtain a more favorable rate.

Energy Alliance Agreement: innovative cooperation with benefits for both parties!

Apart from the obvious connection to the grid or the use of heat for the drying of the digestate, the En-Bio experience to draw up a so-called energy alliance. It is heat and / or electricity traded to a customer in the area, which both parties can obtain a more favorable rate.

Options

Option 1: After-treatment of the digestate

After fermentation of organic material remains on a digestate. It may also be appropriate for this digestate through after-treatment into economically valuable products, by drying or crushing.

Option 2: Injection of Biogas, Bio bio gas, or gobar gas in the natural gas network

Through a filtering installation, we can upgrade the Biogas, Bio bio gas, or gobar gas so that we obtain Biogas, Bio bio gas, or gobar gas with quality comparable to natural gas.

Option 3: Biofuel expansion

For a continuous supply of electricity and / or heat to ensure is often chosen for an extension with a dual fuel engine based on PPO.

Option 4: Use of Biogas, Bio bio gas, or gobar gas in transportation vehicle

Biogas, Bio bio gas, or gobar gas can also be used as fuel for vehicles. This allows your vehicles to driving on a renewable and ecological fuel that you produce yourself!

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