₦airaland Forum

Preparation of Digester Tank


The top portion of the digester tank also needs to be cut and removed. However, the width of cutting should be just enough for the free movement of gas tank

*Place the removed top portion of gas holder on top of digester tank

*Leave about 20 mm on all sides and mark the guide line for cutting

*Using a hacksaw, cut slots on top of projected portion of digester tank

*Now use a hacksaw blade to cut along the guide line and remove the top

*Finish the cut edges with sandpaper

More pictures

Preparation of Gas Holder Tank

The 500 liter capacity tank is required to be cut at the top. The visible top ridge will be used as guideline to cut the tank

Using a sharp knife make a slot along the line
Now you can insert a hacksaw blade in the slot and cut along the ridge
The hacksaw blade gets very hot. Wrap the end with a piece of cloth
Cut through the ridge and remove the top cut portion from the tank

DAY 2: Tools Required

You can see here that construction of this plant does not require many tools. These are list of tools I have used:

A hacksaw with frame

A single sided hacksaw blade

A sharp knife

A medium sized hammer

Set of spanners to tighten the gas pipe connectors

For crimping the connectors with the ends of gas pipes, I got assistance from the shop from where I bought the gas pipes. They helped me with their Hand crimping equipment as per my requirement.

Yes we'll meet. At the end of this training, you will be able to construct one yourself

Txonyi:
pls continue.
i am willing to even meet you in person
or even pay to learn

Please drop your comments. Thanks.

This training is 100% FREE!!!

Adhesives Used

For joining the parts of the gas plant, I have used the following adhesives

Araldite Epoxy Adhesive
M-Seal Epoxy Compound
PvC Solvent Cement

Last picture

More Material Pictures

Other Materials Required

In addition to the tanks, I have utilized the following PVC parts:

PVC Door elbow 120 mm dia one number to be used for feeding waste
PVC pipe 50 mm dia 300 mm long to be fitted with digester for slurry outlet
PVC pipes 32 mm dia 250 mm long 4 pieces to be fitted with digester for guide system
PVC pipes 32 mm dia 1000 mm long 4 pieces for guide system
PVC pipes 12 mm dia 1000 mm long 4 pieces for guide system and stabilizing gas tank
PVC pipe 120 mm dia one piece to be used for waste feeding
PVC cap 120 mm dia for the waste feed pipe
PVC pipe 50 mm dia about 5 meters for the slurry outlet system
PVC bend 50 mm dia one piece for the slurry outlet system
PVC 32 mm dia threaded couplers 4 pieces to be fitted with gas tank for guide system
PVC 32 mm dia plain couplers 4 pieces to be fitted with digester for guide system
PVC Elbow reducer 32 mm to 12 mm 4 pieces for the guide system

We'll get there soon Sir

EternalTruths:
Teach us about the electricity aspect using Generator.


Thanks

Selection of Tanks

This is my attempt at constructing a medium sized Biogas plant for home use as well for demonstration to students and others using a 750 liter capacity tank as digester and a 500 liter capacity tank as a gas holder, a floating type gas holder method. I have provided easy to understand step-by-step instructions on how to build the plant. Please go through this and feel free to post your comments and queries with respect to biogas.

Before selection of tanks, I need to consider how much of digestible kitchen and garden waste I could collect everyday for feeding the tank. In my case I can easily collect between 3.5 to 4 kilogram of waste from kitchen and home garden. This quantity will be sufficient for a biogas plant with 700 to 800 liter capacity digester tank. A simple thumb rule for biogas plant for home use is 5 kilograms of waste needs a 1000 liter capacity digester.

Now for the selection of gas holder tank, I need to consider the following before buying the tank:

The model I am building is with a floating type gas holder tank. That means the gas holder will move up and down based on the amount of gas inside. So, the gas holder tank should fit inside the digester and also should have minimum difference between their width as this will reduce in loss of gas through the sides.

During market search, I found that the 500 liters capacity tank will meet the requirement, having a width difference of about 100 mm, that means 50 mm on each side. So, I have decided to use the 500 liter tank as gas holder, which will have an up-and- down movement inside the digester using guides.

Some designs cater for a water seal between the digester and gas holder, but in my case that will considerably reduce the capacity of the digester. However, the gas loss through the sides will be very marginal with respect to providing a water seal and reducing the capacity of the digester.

In the above photographs, you can see the selection of my tanks. They are of very good quality three layered tanks that can withstand exposure to sunlight and acidic condition of the slurry inside.

Biogas Plant Using Kitchen and Food Waste

DAY 1: What is Biogas, What is Biogas Plant and How it Functions...?

What is Biogas...?

For those who are not familiar with the term Biogas :

Microorganisms who thrive in the absence of air digests the organic material and releases a mixture of gases. The gases thus produced contains mostly methane along with other gases like Carbon dioxide, Nitrogen and Hydrogen Sulphide in small quantities. This process is known as anaerobic digestion.

Methane is a colorless and odorless gas and is highly flammable. (It is Hydrogen Sulphide that smells bad) Methane is not poisonous.

Methane along with other gases occurs naturally in swamps, waste dumps and even in home toilets in the septic tank. Due to its highly flammable quality, it can be used as fuel. But capturing the methane from the atmosphere is very difficult as it is lighter than air. The Biogas Digester or Biogas Plant we see here is a device which helps us in collecting this gas and use it as fuel.

Biogas Plant

You can see the opened-up prototype of a Biogas plant in above photograph.

The Biogas plant consists of a digester tank, where the organic material is stored and the microorganisms work on them and release gas.
The gas thus produced is collected in a tank known as gas collector. In a floating type model, this tank is floating in the slurry and moves up-and-down based on the amount of gas stored in it
A guide pipe helps the gas collector tank to move up-and-down inside the digester tank.
Waste is fed through feed pipe inside the digester tank.
The fully digested slurry drains out through the outlet pipe. This can be collected, diluted and used as fertilizer for plants.
A gas pipe line from the Gas collector tank helps in utilizing the gas for cooking and lighting.

Now let's get down to business and construct a medium sized Biogas plant for home use

Welcome aboard

donstriker0:
Present too

Welcome aboard Sir

Candyrain:
Organic matter? Is that poo poo?

Bubu isn't interested in this. He just allocated some money for oil exploration in NE instead of looking for alternative source of energy.

Present btw

Sir i don't believe in impossibilities. As a matter of fact, those things possible today were actually impossible yesterday. Mobile phones/GSM was impossible in Nigeria like 40 years ago, but today it is possible.

mrvitalis:
Bro I am a mechanical engineer and I tell u... if we must get 24/day power this is not the way to go

Welcome aboard

uwa1:
Present.....

The world is moving away from fossil fuel to renewable energy, The earlier we tap into this the better.

mrvitalis:
This is not what we need in this country for now

Welcome aboard Sir

ayowhizi:
Interested

With due respect to the moderator of this section, i hope this is the right section to post this very useful material. Over the past three years, research has been ongoing on how to harness the power of BIOGAS. In the present scenario of dwindling petroleum resources and global warming, exploring other avenues for eco-friendly fuels became essential. Biogas which is a clean and environmental friendly fuel emerged as one of the potential alternative fuels.

In view of this, i have decided to take any person who might be interested in generating his/her (Cooking/Electricity) energy @ home by the hand on how to construct a 500L BIOGAS TANK for domestic consumption ONLY.

This lesson is made possible by my teacher in BIOGAS TECHNOLOGY, MR J. Antoni Raj. (Rtd) Civil Engineer, Uthamapalayam and Dr. S Ajmal Khan, M.sc, P.hd, Professor- Emeritus, Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai, India.

All lectures will be supported with pictures. I need 10 nairalanders to indicate interest before i proceed. PLS DON'T DROP YOUR EMAILS.

Sure, without the gas purified, Your gen will not be able to combust it. Q2. Yes it will help in breaking down solids more quickly.

bomeri:
Thanks op, nice read.......Q. Will this purifier help for gen use? Q2. Grinding to liquid will it help disgestion? Thanks in advance

Bottom Line

It is nearing a month after we installed the Biogas plant. The quality of gas has considerably increased compared to the initial output.To Now the plant produces gas which burns for about half an hour. The solids we introduced in the digester will take more time to get fully digested. The gas production will gradually increase and we may be able to get a regular supply of gas for about an hour's cooking in the following months. This will considerably reduce the consumption of LPG.

Now we do not throw away any organic waste from our home. What is more, we are getting free gas as well as free organic manure for our home garden.

To improve the quality of gas, fix a purifier to the gas outlet pipe. Attached is a purifier.

I hope my students are not too lazy to read this entire article

How the technology could contribute to socio-economic development and environmental protection

Both small and large scale biogas applications offer several direct and indirect benefits

Small scale applications

Social benefits

Smoke-free and ash-free kitchen, so women and their children are no longer prone to respiratory infections;
Women are spared the burden of gathering firewood;
Environmental and health benefits

Keeping manure and waste in a confined area and processing themin the digester reduces the amount of pollutants in the immediate environment and increases sanitation;
Households no longer need to extract wood for cooking, which can reduce deforestation levels where people heavily rely on woodfuel;
The sludge remaining after digestion is a good fertilizer, increasing land productivity (and farm incomes).
The release of methane is avoided thus contributing to climate mitigation. A single, small scale biodigester reduces between 3 and 5 tCO2-eq./year,

Economic benefits

Buying (fossil) fuel resources (e.g. kerosene, LPG, charcoal or fuel wood) is no longer needed
Switching from traditional biomass resources (e.g., in developing countries) or fossil fuels (e.g. in industrialised countries) to biogas fired generation capacity improves security of energy supply (locally as well as nationally or regionally) as the feedstock can mostly be acquired locally
Figure 1 shows the benefits of a domestic biodigester in Cambodia, based on an analysis in the frame of Cambodia’s National Biodigester Programme.

Sustainable development benefits of a biodigester in Cambodia
Figure 3: Sustainable development benefits of a biodigester in Cambodia (Source: Bunny and Besselink, 2006)

Possible negative aspects of the biogas installations are the possible reduction in soil fertility since animal dung is now used as feedstock for the biogas installation instead of for fertilisation. This aspect can be addressed by using the bioslurry that remains as a side-product of the biogas production process for soil fertilisation. Another potential problem is related to the possible build-up of pathogens (worms, protozoa and some fatal bacteria such as salmonella) in the biogas system. A study carried out for biogas systems in Nepal has shown that some pathogens were present in the bio-slurry. Studies have been undertaken to explore whether the biogas systems could enhance the breeding of mosquitoes. However, no direct relation was found between biogas production and mosquito breeding (Netherlands Ministry of Foreign Affairs, 2007).

Industrial scale digesters also offer a number of benefits

Biogas can contribute to replace fossil fuels, thus reducing the emission of GHGs and other harmful emissions;
By tapping biogas in a biogas plant and using it as a source of energy, harmful effects of methane on the biosphere are reduced;
Industrial estates can, by processing their waste in a biogas plant, fulfill legal obligations of waste disposal while at the same time, generate energy for production processes, lighting or heating;
Municipalities can use biogas technology to solve problems in public waste disposal and waste water treatment (GTZ, 1999);
It’s a natural waste treatment process;
Requires less land then anaerobic composting;
Reduces disposed waste volume and weight to be landfilled;
It generates high quality renewable fuel proven to be useful in a number of end-use applications
It significantly reduces GHG emissions
It maximizes recycling benefits
Considering the whole life-cycle, it is more cost-effective then other waste treatment options (IEA Bioenergy, Task 37, 2005).
Technology Needs Assessment(TNA) on Cooking by: Zambia, Georgia, Sudan, Cambodia, Kenya, Mali and Azerbaijan

Several countries discussed biogas for cooking in their TNA.The benefits the technology offers for the environment and health is recognized by all. The TNAs highlight how the use of biogas instead of firewood, may counteract uncontrolled harvesting of forests and improve health by providing a smoke-free and ash-free kitchen. Furthermore, they all appreciate that women and children are spared the burden of gathering firewood. Kenya presents methane capture from bio digesters as a top priority, because it provides clean energy for rural households

With regard to the challenges, the high initial investment costs are recognized by all. Azerbaijan, Kenya and Zambia mention the lack of awareness and appropriate financing and distribution mechanism as major constraints. Kenya specifically highlight the lack of confidence in the technology due to the negative image caused by failed biogas plants. Zambia states that the main challenge is cultural among the rural communities associated with the handling of animal and human waste.



Climate

Green gas or biogas offers several sustainable development benefits since it is a clean and GHG-neutral source of energy. Most of the biogas has a methane component of 50 to 60%, a CO2 component of 35 to 50%, and a relatively small amount of hydrogensulfide (H2S) and ammonia. In comparison, the methane component of natural gas could amount to over 80%. Applying the CDM to biodigester type of projects or programmes has proven, to be problematic for various reasons. First, a single biodigester reduces between 3 and 5 tCO2-eq./year, which makes bundling of project activities necessary in order to be able to cover transaction costs. Second, although small-scale methodologies for the accounting of GHG emission reductions have been applied to biogas projects in Nepal (see below), they have proven cumbersome to apply in the context of biodigester programmes and unpractical.

For calculation of these GHG emission reductions, it is recommended to apply the approved methodologies for thermal energy production with or without electricity, thermal energy for the user project (large scale activities) which has been developed under the Clean Development Mechanism of the UNFCCC Kyoto Protocol (CDM). This methodology helps to determine a baseline for GHG emissions in the absence of the project (i.e. business-as-usual circumstances), how emission reductions below this baseline can be calculated, and how these reductions can be monitored. General information about how to apply CDM methodologies for GHG accounting can be found at: http://cdm.unfccc.int/methodologies/PAmethodologies/approved.html.


Financial requirements and costs

The major cost categories for a biodigester are (GTZ, 1999):

Manufacturing or acquisition costs (production costs): all expenses and lost income which are necessary for the erection of the plant
operation and maintenance costs (running costs): acquisition and handling of the substrate (feedstock), if not acquired externally, feeding and operating of the plant; supervision, maintenance and repair of the plant; storage and disposal of the slurry; gas distribution and utilization;
The production costs of biogas plants are determined by the following factors:

purchasing costs or opportunity costs for land which is needed for the biogas plant and slurry storage;
model of the biogas plant;
size and dimensioning of the biogas unit
amount and prices of material
labor input and wages
the degree of participation of the future biogas user and his opportunity costs for labor.
A rough estimate of costs of a simple, unheated biogas plant, including all essential installations but not including land, is between 50-75 US$ per m3 capacity. 35 - 40% of the total costs are for the digester (GTZ, 1999). The Biogas for Africa initiative estimates the cost of a small household unit somewhat higher at 600-800 eur per unit (Biogas for Africa, 2007). For small scale applications in developing countries, the farmer typically contributes to financing the digester with payback periods depending on the price of otherwise purchased firewood/kerosene, as the digester has zero fuel costs. Only water and dung or leafy biomass material need to be collected.

For larger plants producing electricity from biogas, a rough estimate of capital costs of a digester and an engine of 0.3-10MW is between 3500 and 5500 US$/kWe (IEA Bioenergy, 2009).

Source: http://www.climatetechwiki.org/technology/biomass

[b]Biomass is an interesting option for electricity and heat production in parts of the world where supplies of residues from agriculture or the forest products industry are abundant. But the rapid development of second-generation liquid biofuel technologies to produce transport fuels could create competition for feedstocks between the two uses (IEA 2010).

Biomass combustion already provides around 12% of global energy requirements, including use for traditional cooking and heating. In 2006 biomass-based power and heat plants consumed a feedstock volume equivalent to 3.5 EJ, which represents a mere 7% of the global biomass used for energy purposes (IEA 2008). Consumption in the OECD countries accounted for 82% of this volume.

Worldwide, the installed capacity for biomass-based power generation was about 45 GW in 2006, with an estimated electricity production of some 239 TWh (IEA 2008). According to the IEA Bioenergy (2009), this power production occurs mostly in:

• “Co-firing plants for those countries with coal plants;

• Combustion-based CHP plants for countries that possess district heating systems (Nordic countries in Europe), large pulp and paper or food industries (e.g. Brazil, USA). At present, some 230 power and combined heat and power (CHP) plants use co-firing, mostly in northern Europe and the United States (Platts, 2011b), with a capacity of 50-700 MWe. Co-fi ring in CHP plants is currently the most competitive option to exploit the biomass energy potential for both electricity and heat production. Biomass feedstock’s include forestry and agriculture residues, animal manure, waste and dedicated energy crops.

• MSW incineration plants, although a large potential is still untapped;

• Stand-alone power plants where large amounts of residues are available (e.g. sugar-cane bagasse in Brazil);

• Anaerobic digestion units (e.g. in Germany) and landfill gas units (e.g. in the UK), as a result of increasingly strict environmental regulations on waste disposal and landfills at EU level”.

In the EU, 55 TWh of biomass-based electricity were produced in 2004, mainly based on wood residues and MSW. Finland produced 12% of its power consumption from biomass and wastes. In the United States some 85% of all wood process wastes (other than forest residues) are used for power generation (IEA Bioenergy, 2009).

At the same time, a proliferation of smaller-scale biomass-to-power or CHP projects has been ongoing in both developed countries and emerging economies. In these countries, biomass-based co-generation is well established in a number of agro-industries. China, Brazil, Latin America, Thailand, and India are all increasingly employing biomass power alongside other renewable resources (IEA 2007). In Asia, Indonesia, Thailand and Taiwan peat, wood chips, bark, vegetable oil and sludge are being directly co-fired with coal in industrial plants (IEA Bioenergy Task 32a, 2010). On the other hand, the CDM has supported the development of hundreds of biomass-based power generation projects of small and medium size (>35 MW) across the developing world, often using agricultural residues as main feedstock. The vast majority of these projects are located in Asia (>70%), followed by Latin America and only a few in Africa (IGES, 2010).[/b]

[size=15pt]Biogas for cooking and electricity[/size]

Pls kindly take your time to read this article, it is tremendously useful

Biogas is a gaseous mixture generated during anaerobic digestion processes using waste water, solid waste (e.g. at landfills), organic waste, and other sources of biomass. Biogas can be upgraded to a level compatible with natural gas (‘green gas’) by cleaning (removal of H2S, ammonia and some hydrocarbons from the biogas) and by increasing its methane share (by removing the CO2). The resulting green gas can subsequently be delivered to the natural gas distribution grids. In developing countries, biogas could be an interesting energy option, in particular for those countries that rely heavily on traditional biomass for their energy needs.

Introduction:
Biogas is a gaseous mixture generated during anaerobic digestion processes using waste water, solid waste (e.g. at landfills), organic waste, e.g. animal manure, and other sources of biomass (Welink et al., 2007). Anaerobic digestion is the biological degradation of biomass in oxygen-free conditions. In the absence of oxygen, anaerobic bacteria will ferment biodegradable matter into methane (40-70%), carbon dioxide (30-60%), hydrogen (0-1%) and hydrogen sulfide (0-3%), a mixture called biogas. Biogas is formed solely through the activity of bacteria. Although the process itself generates heat, additional heat is required to maintain the ideal process temperature of at least 35°C. In comparison, the methane component of natural gas could amount to over 80%. In nature, biogas is generated at the bottom of stagnated ponds, lakes, swamps or in the digestive system of animals (Jepma et al., 2006).

Biogas can be produced on a very small scale for household use, mainly for cooking and water heating or on larger industrial scale, where it can either be burnt in power generation devices for on-site (co)generation, or upgraded to natural gas standards for injection into the natural gas network as biomethane or for use directly as gaseous biofuel in gas engine-based captive fleets such as buses.

The feedstock, e.g. animal dung or sewage, is converted to a slurry with up to 95% water, and – for small-scale applications – fed into a purpose-built digester. Digesters come in many forms and sizes, which may range from 1 m3 for a small household unit to some 10 m3 for a typical farm plant and more than 1,000 m3 for a large installation (Larkin et al., 2004). Biogas production in such cases can be both continuous and in batches with digestion taking place for a period from ten days to a few weeks.

A small domestic biogas system will typically consist of the following components:

Manure collection: raw, liquid, slurry, semi-solid and solid manure can all be used for biogas production.
Anaerobic digester: The digester is the component of the manure management system that optimizes naturally occurring anaerobic bacteria to decompose and treat the manure while producing biogas.
Effluent storage: The products of the anaerobic digestion of manure in digesters are biogas and effluent. The effluent is a stabilized organic solution that has value as a fertilizer and other potential uses. Waste storage facilities are required to store treated effluent because the nutrients in the effluent cannot be applied to land and crops year round.
Gas handling: piping; gas pump or blower; gas meter; pressure regulator; and condensate drain(s).
Gas use: a cooker or boiler (EPA, 2010).
For applications on a larger scale, feedstocks such as sewage sludge from waste water treatment plants, wet agricultural residues and the organic fraction of municipal solid waste (MSW) can be collected and used. Biogas can be used for all applications designed for natural gas, given a certain upgrading of its quality (IEA Bioenergy Task 37, 2005).

Upgrading can be done to a level compatible with natural gas (‘green gas’) by cleaning (removal of H2S, ammonia and some hydrocarbons from the biogas) and by increasing the methane share (by removing the CO2). (Welink et al., 2007).

Feasibility of technology and operational necessities

Small scale applications

Small scale biogas for household use is a simple, low-cost, low-maintenance technology, which has been used for decades across the developing world. Such small-scale applications are mostly implemented through programmes supported by governments. In such cases, it usually concerns rural areas and communities without connection to the grid. Although some cattle would be needed to feed the digester (about seven) and water needs to be available as well, other requirements are rather low.

Data on biomass use is often hard to access and difficult to evaluate because of the diversity in consumption patterns, differences in units of measurement, the lack of regular surveys and the variation in heat content of the different types of biomass.

The switch to biogas in cooking is not without challenges. According to the IEA, with an increase in income, households do not simply switch from one fuel to another. The use of multiple fuels in parallel may enhance energy security compared to reliance on a single fuel or technology. Besides, traditional food preparation processes are not easily being overhauled because of taste preferences and the familiarity of cooking with traditional technologies. Nevertheless, in the long run and on a regional scale, households in countries that become more wealthy are generally projected to shift from cooking exclusively with biomass to using more efficient technologies, amongst which biogas can be one option (IEA, 2006, 2008).

Currently, low per-capita incomes and a lack of awareness of the benefits of more sustainable fuels provide an important barrier. Therefore, financing investments in biogas installations, especially in least developed countries, is a problem. Hence, financing programmes and additional incentives are clearly needed to deal with this general reluctance among the target group. In India, for example, many of the biogas plants are concentrated on wealthier farms with a relatively large number of cattle (Boyle, 2004).

Large-scale applications

Industrial applications are designed to process large amounts of feedstock into biogas, which requires a well-developed logistical system for feedstock collection and effluent disposal. Because of costs associated with feedstock collection, the viability of such plants depends on the availability of very cheap or free feedstock such as sewage sludge, manure, agricultural residues or organic fractions of municipal solid waste. Decentralized farm-size units are increasing productivity by supplementing their feedstock with agricultural residues or crops (IEA Bioenergy, 2009).

Status of the technology and its future market potential

Both small and large scale anaerobic digestion is a well established commercial technology. Today, the highest degree of market maturity can be found in the area of municipal sludge treatment, industrial wastewater purification and treatment of agricultural wastes (GTZ, 2009). Improvements still need to be achieved in the use of contaminated feedstock, where biomass pre-treatment and separation processes are needed to remove contaminants which may end up in the digestate, making it unsuitable as fertilizer and difficult to dispose of (IEA Bioenergy, 2009).

There are regional differences in the application of biogas technologies, depending on the local situation and infrastructure available. In rural Asia, mostly small-scale biodigesters are used, that generate enough energy for farmers to become self-sustaining. According to the Dutch development organisation SNV (personal communication), which manages a small-scale biogas installations programme in Vietnam, an average Vietnamese farmer’s family need about five pigs and two cows in order to produce enough biogas for cooking. In general, in developing countries, biogas is mostly used for cooking, heating and lighting with a strong emphasis on the former two.

At present, China is the biggest biogas producer in the world, with around 18 million farm households using biogas and about 3,500 medium to large-scale digester units (DEFRA 2007). The use of the technology in municipal wastewater treatment has increasingly been deployed in Asia (India in particular) and Latin America. Agricultural biogas plants in developing countries are usually promoted as part of the solution to energy and environmental issues, in particular where liquid manure from agriculture causes severe water pollution (GTZ, 1999). Large biogas for domestic use programs have been rolled out in several developing countries, notably in Nepal, where around 150.000 biogas installations have been build over ten years (Bajgain & Shakya, 2005). A number of biogas-based CDM projects exist.

In Europe, on the other hand, demand for biogas comes mostly from the power generation and industry sectors (grid-connected). Although a significant potential exists for using biogas for electricity generation, further improvements are yet to be realised for a large-scale introduction. In the UK, for example, in the mid-1990s the total installed capacity remained under 1 MW. The first large-scale plant in the UK was commissioned in 2002 and built on the basis of a German/Danish design. It uses 146,000 tonnes of slurry per year from 28 farms, together with wastes from food processors, to supply the heat input for a generating capacity of 1.43 MW. The total efficiency in such large-scale applications depends on how the generated heat is used in the process. In Europe, a typical biogas plant has an average capacity of 250 to 300 kW with a minimum recommended capacity of 200 to 250 kW. The electricity delivered by the plant to the grid provides an extra source of income. In the whole of Europe, 5.9 Mtoe of biogas were produced in 2007 (Eurobserv’ER, 2008).

Because biogas can make a positive contribution to multiple goals in government programmes, it has the potential to increasingly become one of the most efficient and economical sources of renewable fuel with anaerobic digestion an economically viable technology for both small-scale rural applications in developing countries and for a range of scales in the developed world (IEA Bioenergy, Task 37, 2005). Therefore significant growth is expected in the coming years.

Once your biogas is purified, simply buy a gas gen. set and follow the user manual.

abdulwasee:
@Dexpro. You are 1 in a million may God continue to be your guide and thank you for helping Nigeria grow though your innovation and creativity!
My own question is how can 1 use the Biogas to power electric generator? Many Thanks!

Afoskalex:
@Dexpro, sure for asking this question, are you and Engineer or a scientist because you have really impress us. There was a time a met with some that want to train me on biogas, I was expected to be prepared to pay for the training which is normal but without asking for anything, you gave us practical training in biogas though not one on one. I was to work on biogas during my undergraduate project but the project was changed because my supervisor left for another university. It has been my dream to work on renewable energy since then. Once again I say on behalf of other students in this forum thank you. I will be glad to be a disciple.

Thanks Sir for the compliments

rev2214:
Hello,
Just read some detail about biogas. My question is 1. What is the difference BTW Biogas and carbon nano tubes and what are the side effect?

I have space on my property for this but I want to consider children. Pls advice

Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure. These cylindrical carbon molecules have unusual properties, which are valuable for nanotechnology, electronics, optics and other fields of materials science and technology.

Meanwhile

Biogas typically refers to a mixture of different gases produced by the breakdown of organic matter in the absence of oxygen.

So how does CNTs relate with Biogas? CNTs is nowhere near Biogas.

Biogas has NO side effects. You can construct one bearing in mind to put all things away from the reach of children.

The Digested Slurry

Initially, I have added diluted cow dung slurry which covered slightly more than half of the digester tank. Periodical addition of about 3 to 4 kilograms kitchen waste and weeds from the garden everyday, gradually increased the slurry level inside the digester tank. Once your digester is full, you will find the digested slurry oozing out of the outlet pipe, whenever you feed the plant.

Place a bucket beneath the outlet and collect the slurry. This slurry does not have any odor and will not attract any flies. it is also an excellent organic fertilizer.

Dilute the slurry with water and feed your garden plants with the diluted slurry.

Test the Biogas

The gas initially produced may contain lots of impurities and [size=15pt]WILL NOT[/size] burn. I have emptied the gas holder tank three times before testing the gas. **(You don't necessarily need to empty yours thrice BUT YOU MUST EMPTY IT ONCE! )

Connect the gas inlet pipe and open the knob Slightly. Now you can hear the hissing noise of gas escaping through the burner. Hold a lighted match stick over the burner and voila, you have a flame...!!!

The gas still has lots of impurities, but it started burning. You can see the blue flame of methane burning here.

*Words or sentence in bold are for emphasis, Please note them.

DAY ELEVEN

Add Ballast on Top of Gas Holder Tank

Before testing the biogas in the stove, you need to check that the collected gas in the tank has enough pressure to flow through the gas pipe to the stove.

Methane is lighter than air. When you connect the gas pipe line and open the gas outlet valve, there are chances of negative pressure at the pipe end which may suck in the out side air into the tank. This is known as Flow back. This can be avoided by placing ballast on top of the gas holder tank.

Here I have added an old car tyre with a semi-inflated tube inside on top of the gas holder tank. The semi-inflated tube will prevent any rain water getting collected in the tyre and becoming a breeding ground for mosquitoes.

After placing the ballast, open the valve and check the gas flow. You can hear a hissing noise when the gas is flowing out. you can also feel the gas flow by placing your fingers in front of the valve opening.

We'll treat your question soon Sir

Afoskalex:
Dexpro, please I will want you to elaborate more on the discharge of slurry and other waste products from the digester.Thank you