I have been searching for some method of using the food waste, decomposable organic material and kitchen waste efficiently, and came across information on producing bio-gas from organic waste.

The bio-gas produced from food waste, decomposable organic material and kitchen waste, consisting of methane and a little amount of carbon di oxide is an alternative fuel for cooking gas (LPG). Also, the waste materials can be disposed off efficiently without any odor or flies and the digested slurry from the bio-gas unit can be used as an organic manure in the garden.

Components of the Bio-gas Plant

The major components of the bio-gas plant are a digester tank, an inlet for feeding the kitchen waste, gas holder tank, an outlet for the digested slurry and the gas delivery system for taking out and utilizing the produced gas.

This project is also useful for students to have a hands-on learning experience in constructing a Mini Bio-Gas Plant, using locally available material.

Material Required:

1. Empty PVC can 50 ltrs capacity: 1 No. (to be used as Digester Tank)
2. Empty PVC can 40 ltrs capacity: 1 no. (to be used as Gas Holder Tank) (Make sure the smaller can fits inside larger one and moves freely)
3. 64 mm dia pvc pipe: about 40 cm long (to be used for feeding waste material)
4. 32 mm dia pvc pipe: about 50 cm long (fixed inside gas holder tank as a guide pipe)
5. 25 mm dia pvc pipe: about 75 cm long (fixed inside the digester tank as a guide pipe)
6. 32 mm dia pvc pipe: about 25 cm long (fixed on digester tank to act as outlet for digested slurry)
7. M-seal or any water-proof adeshive
8. Gas outlet system: Please see Step 4 below for required materials and construction

Tools required

Do not require many tools here. A hack saw blade for cutting the cans & pipes and a sharp knife for cutting holes on the cans are all the tools we need.

Additional accessories

A single burner bio-gas stove or a Bunsen Burner used in school laboratories

Step 1:

Bought this 50 ltrs capacity PVC can, which will act as the digester unit and removed the top portion of the can, by cutting it with a hack saw blade:


Step 2:

The smaller white can, which will act as the gas holder fits inside the red one. Here, again removed the top of the white can, also with the help of a hack saw blade:

Step 3:

64 mm, 32 mm and 25 mm dia PVC pipes which  will be used for feeding the kitchen waste, guide pipe for the gas holder and guide pipe fixed with the digestion chamber respectively. A small piece of 32 mm dia pipe will be used as outlet for the slurry:

Step 4:

  1. items required for the gas delivery system: got these items from a hardware store

1. Ball valve : one no ( to adjust the gas flow)
2. 'T' joint : one no ( to connect the gas holder and the ball valve)
3. Cap to block one end of 'T' joint : one no
4. Coupling or Adapter : one no (to connect vertical end of 'T' in to the gas collector)
5. Nipple: one no (added to the coupling in to the gas collector)
6. Gas pipe (flexible) : two meters
7. Barb : one no (fitted with the gas pipe, to join with the Ball valve)
8. Clip : one no (used for crimping the barb with the gas pipe and make it leak-proof)
9. Teflon tape : one roll (used as thread tape in all joints)

Step 5:

Here I have marked the cuts to be made in the bottom of the gas collection tank. The smaller hole on the left for gas delivery system, center hole for fixing the 32 mm guide pipe and 64 mm hole for fixing the waste feeding pipe on the right side. Made these holes with the help of a sharp knife and hack saw blade.

The next image is Inside of the gas holder showing the 32 mm guide pipe (center) and the 64 mm feeding pipe fixed with M-seal

Step 6:

Top view of the gas holder showing the feeding pipe, central guide pipe and the gas delivery system: I have closed the feeding pipe withe an old lid  (red one). This will facilitate opening the feed pipe only during feeding the system.

Step 7:

Digestion tank fitted with the central guide pipe and the outlet pipe for the slurry:

Step 8:

Completed unit. I have removed the gas pipe, so that the joints will get cured without any stress:

Wait for a day or two before feeding the system, allowing all joints to get cured and become leak-proof.

Initially, cow-dung mixed with water will be fed in to the system, which will start the gas formation process. Subsequently, food waste, decomposable organic material and kitchen waste will be diluted with water and used to feed the system. The gas holder will rise along the guide pipes based on the amount of gas produced. We can add some weight on top of the gas holder to increase the gas pressure. When we feed the system, the excess digested slurry will fall out through the outlet pipe, which can be collected, diluted and used as organic manure.

Initial production of gas will consist of oxygen, methane, carbon di oxide and some other gases and will not burn. These gases can be released to the atmosphere by opening the ball valve at least three / four times.

Subsequent gas will consist of about 70 to 80 percent methane and the rest carbon di oxide, which can be used in a single bio-gas burning stove or a Bunsen burner.

Total cost of this proto-type system is about one thousand Indian Rupees (about 20 dollars)

This is a basic prototype of a Bio-gas system using the food waste, decomposable organic material and kitchen waste to produce gas. An one thousand litre capacity Digestion tank will be sufficient for a small household for daily cooking purpose. The bigger commercial models provide a water seal between the digestion tank and gas holder tank.

You can get further information on kitchen waste based mini Bio-gas plant at the following links:



Step 9:

Charged the digester tank with cow dung diluted with water. Placed the gas holder tank and left it for two three days. The cow dung slurry started the process of gas forming.

Gas formation started and the gas holder tank gets lifted up. I have placed two bricks on top of the gas holder to get more gas pressure.

Step 10:

Note for students who are doing this as their School Project:

1. Take guidance from your teacher while using the gas in a stove or Bunsen burner.
2. Collect surplus food and wastage during lunch, dilute and feed the system.
3. Fruit peels, extracted tea powder, waste milk and milk products  can also be used for feeding the system.
4. DO NOT USE eggshells, Onion peels or left-over bones in this system as they will affect the efficient functioning of the system
5. Plant some seedling
6. while feeding, collect the slurry from the outlet, feed the seedlings and watch them grow
<p>sir i would like to separate the co2 from biogas and i would like to use it as raw material for other industries is it possible ?</p>
<p>how the floating dome was fixed....without gas escaping??????</p>
Actually the floating dome was not fixed. You can place the floating drum without the central guide pipe also. In that case the floating drum may tilt to one side due to the gas pipe line.<br><br>Please go through my other instructable on constructing a medium sized Biogas plant at the following link, which will clarify your doubt<br><br>http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/
<p>how sir ? how can i use some part of biogas to heat the digester, by adding hot water in it?</p>
You can use biogas to heat water to be warm for mixing with waste material
<p>i also trying to make a small black colour plastic hut around the digester so that it can trap the sun heat and makes the digester around hotter. if any further requirement is needed please sir it my pleasure to take your advise to</p>
Please see this website where they have provided insulation to the plant from cold<br><br>https://www.researchgate.net/figure/281237562_fig4_Fig-5-Floating-drum-biogas-plant-for-Cold-climate-having-insulated-techniques
<p>govindsinghce@gmail.com </p><p>i want your pdf sir, and want to discuss my views with you on biogas </p>
you can download the pdf files from the following dropbox link<br><br>Dropbox link to Biogas Folder<br><br>https://www.dropbox.com/sh/hjpq1o8qbe3r8db/AAD63dDpvb3SMSCye_eXPeRca?dl=0
<p>sir i basically belong form Uttarakhand , where temp throughout out the year remains low , so how can we maintain temperature inside digester and efficiency of biogas plant , i am experimenting , like a cover of compost material outside the digester may be it can prevent the digester to loss its heat in winter and i want your suggestion also how can i make it more efficient without any other electrical source </p>
During the digestion process lot of heat is generated. You can bury the digester in soil which will keep the slurry in good temperature. Your experimenting with some short of cover outside the digester should also work. You can also use part of the biogas produced to keep the digester in good working temperature
<p>hello sir,</p><p>can i use aluminium dig ester coated with black co lour instead of FRP digester ? i think metal can increase the temperature inside the chamber</p>
I could not reply to you earlier as my system was down.<br><br>Using any metal bodies as digester or gas holder is not advisable. About 40 years back, during the initial stages of Biogas plants in India, they used metal sheets for the gas holder, but none of them are functioning now. The reason metal got eroded in the slurry and gas started leaking.
<p>sir the gas that this plant will produce ,can we use this gas in lpg gas stove or do we need to buy some other kind of stove</p>
No, you have to use a stove specially made for burning Biogas. Please see my other instructable here, where I have shown the Biogas stove also<br><br>http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/
<p>Please sir, is there any way the gas from biogas can be stored externally for mobility or transfer from the gas plant to other places?</p><p>Kindly send the information to dosmile2020@yahoo.co.uk</p>
You can use a car tyre tube to store and transfer Biogas from the plant other places
<p>hello sir,what would be the composition of dry and wet waste produced from our kitchen?</p>
You can use about one part dry waste with four to five parts of wet waste from your kitchen. More wet waste no problem.
<p>Hello sir, what amount of waste does mini biogas plant consumes per day?</p><p>i would be grateful for your answer.</p>
It depends on the size of the plant. you can feed about 250 grams of waste in 50 liters capacity digester
<p>Thanks so much sir, i got the pdf. Please ,i'll like to have your email address so i can contact you for advice as i plan to commence work on this as soon as possible.</p><p>Thanks</p>
<p>Hello sir, what amount of waste does mini biogas plant consumes per day?</p><p>i would be grateful for your answer.</p>
<p>Sir, can this process be continued to generate electricity? If yes, how? I really would love a step by step guideline.</p><p>dosmile2020@yahoo.co.uk</p>
you can not directly generate electricity from biogas. However, you can use a Generator specifically designed for running on Biogas for this. There are many types available in the market. So there should not be any problem for you to locate one in your place.
Can i get pdf of the same at my email please.i m planning of doing the same at my community ,email :31erickmutua@gmail.com
You can download the file from the following Dropbox link<br><br>Mini Biogas Plant<br><br>https://www.dropbox.com/s/6clbgna7sslm3x4/Bio-gas%20plant%20using%20kitchen%20waste.pdf?dl=0
Please sir can you e-mail the pdf file <br>tyagijashn@gmail.com <br>As soon as possible<br>Thanks <br>
it is uploaded on Dropbox. You can download it anytime from the following link<br><br>Mini Biogas Plant<br><br>https://www.dropbox.com/s/6clbgna7sslm3x4/Bio-gas%20plant%20using%20kitchen%20waste.pdf?dl=0
<p>I'm studying the biogas reactor design project,information such as mathematical simulation of need.If you can help me.thank you...forzamln1994@gmail.com</p>
<p>I have uploaded the files to Dropbox. You can download some articles from the following Dropbox links.</p><p>Mini Biogas Plant</p><p>https://www.dropbox.com/s/6clbgna7sslm3x4/Bio-gas%20plant%20using%20kitchen%20waste.pdf?dl=0</p><p>Biogas Plant</p><p>https://www.dropbox.com/s/dr1gl7n9pufb4aa/Biogas%20Plant%20Using%20Kitchen%20and%20Food%20Waste.pdf?dl=0</p><p>Designing Biogas System</p><p>https://www.dropbox.com/s/4v7s1vcbwg1uhti/Designing%20biogas%20system.pdf?dl=0</p><p>Balaji Biogas system</p><p>https://www.dropbox.com/s/dyzqhplp1bjtrnr/Balaji%20Biogas%20system.pdf?dl=0</p><p>Deenbandhu Biogas Design and Construction Manual</p><p>https://www.dropbox.com/s/yc1mql1aoyrvz92/Constrution%20manual%20Deenbandhu%20type%20Bio-gas%20plant.pdf?dl=0</p>
<p>Excuse me sir. I want to ask you some question. Do you need to mix the cow dung with fresh water to get into the process of producing bio-gas? And do you always have to feed the digester with water while feeding the food waste everyday to dilute the digester?</p>
<p>Yes, you have to dilute the cow dung or any other organic material you are feeding to the digester with water. Use about 3 to 4 liters of water per kilogram of waste.</p>
<p>hi, how did you stop the biogas produced from escaping from the bottom if the white can? would it be possible to seal the white can to the orange can?</p>
Biogas do not escape from the bottom of the white tank, rather it is stored in the inverted white tank. The white tank will rise with respect to the Biogas stored in it. However little amount of gas will escape through the sides between both tanks, which is negligible.<br><br>Do not seal the white can with orange can.
<p>this is lovely and very informative and challenging, please could you give me a step by step lesson on this ,(also any other alternative instruments/tools needed)I would like to introduce this in my home(Nigeria) and possibly on a larger scale when I get results of it in my home. Thanks </p>
Please go through my other two instructables on Biogas at the following links for more information<br><br>http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/<br><br>http://www.instructables.com/id/Make-Energy-From-Weeds/<br>
Very nicely presented. <br>Great content.<br>I want to start a company and make commercial scale biodigesters for installations in large housing socities at very reasonable cost price ( not to make profit but to make cities a livable place) . Pl. Suggest that how far ( both distance and height ) can the bio gas be delivered.<br>
<p>This is only a prototype. Please go through my other instructables on Biogas at following links :</p><p><a href="http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/">http://www.instructables.com/id/Constructing-a-Med...</a></p><p><a href="http://www.instructables.com/id/Make-Energy-From-Weeds/">http://www.instructables.com/id/Make-Energy-From-W...</a></p><p>How far you can deliver the biogas in both distance and height depends on the size of the plant and the gas pressure you are getting at the delivery point. In the Biogas plants installed at my home I have laid pipe line for about 30 feet with 40 kilograms of load placed over the gas holder tank. The vertical height is about 15 feet from the top of gas holder to the stove.</p>
<p>please sir send the pdf to my email jeebsontrust@gmail.com. Thank u very much</p>
Please go through the attached file sent to your mail
Could you please send this PDF to me sir? It would be much appreciated.
Please see the attached file sent to your mail
Dear sir, <br>Can you send the pdf file to my mail eranesk@gmail.com
Please see attached file sent to your mail
Dear sir, <br>Can you send the pdf file to my mail - erganesk@gmail.com
<p>Hi,</p><p>Antoni Raj sir can you please send this pdf to my gamil id: abumujeebali@gmail.com thanks in advance</p>

About This Instructable




Bio: I like to make things more simple with easily available resources. My favorite quote: A human being should be able to change a diaper, plan ... More »
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