Mini Bio-gas plant using food waste, decomposable organic material and kitchen waste

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Picture of Mini Bio-gas plant using food waste, decomposable organic material and kitchen waste
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
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Step 1:

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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:

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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:

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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:

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  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:

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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:

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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:

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

Step 8:

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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:

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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
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Hi! This is a very helpful instructable you have uploaded to share to others. Our schools in the Philippines would surely benefit from this. Please, can you also send me the details of how to construct this project? I know our students will appreciate this very much. Again, thank you for sharing this with us. My email address is

pednekarr made it!9 days ago
I have constructed the mini biogas unit and loaded it with the stuff. I am not interested in the gas but I am excited about it as waste disposer
antoniraj (author)  pednekarr5 days ago

good construction. Where are the feed pipe and outlet pipe...?

feed pipe is on the top and the outlet on the side. covered the sides with paper.
I have covered the feed pipe with a plastic bottle and the sides with paper to prevent foul smell if any. BTW, will there be any foul smell?
antoniraj (author)  pednekarr2 days ago

it is better to keep it in the open. there will be mild smell in the slurry but not much. how do you propose to use the gas ? Methane is odorless and highly explosive. so take care

I have kept it in open. I intend to release the gas when it builds up.
antoniraj (author)  pednekarr5 days ago

ok... nice

good.! :)

Hello sir, thank you for uploading such a specific plan! I wish to use this plan for a school project so could you please send me the details to ?Thank you!

antoniraj (author)  juyeonjaniekim3 days ago
Please see the attached file sent to your mail

hello sir i want to make biogas setup for home use for cooking .please send me the details to you

antoniraj (author)  rahul.vengattil4 days ago
please go through the attached files sent to your mail. you can also browse through my other instructables on biogas at the following links

i am so happy with your project,i am a social worker & I am planning for setting up a bio gas plant for our village but plant will be bigger i think so i am confused about layout. Can you please help and share me an idea to proceed further and plz help me with the details about layout and other things of the project?

my contect no. 09807557400;


antoniraj (author)  pradeep.aryaji5 days ago
I have mailed you construction plan of a Fixed Dome Biogas plant. Please go through the document.

Also, you can see my other instructable on constructing a medium sized Biogas plant here...
AbheyM5 days ago

I want to make it for my house .
Can you tell me how efficient this small plant is.
or can you please send me the layout of the more efficient plant of this size only

antoniraj (author)  AbheyM5 days ago
this is a prototype working model to show how Floating type Biogas plant functions. This will produce very little amount of gas which will burn in a Bunsen burner for few minutes. if you want to construct for your home, please go through my other instructable on constructing a medium sized Biogas plant at this link...
AbheyM AbheyM5 days ago

my mail is

RwijuP7 days ago

Dear sir,

We are trying to build a commercial biogas plant for food material.I wanted to know what are the waste that are generated. Is it a solid waste or a liquid waste which can be drained out

antoniraj (author)  RwijuP7 days ago
The out put generated is liquid slurry. It is not waste. It is a well composted material which can be diluted and used directly for plants.
jiguanya8 days ago

hello sir am happy to know how to make the biogass my question to you is,if i have enough gass ,will i be able to refill the ordinaly gass cillinder,please email me how if there is any way my mail adress,


antoniraj (author)  jiguanya8 days ago

you also require costly equipment for bottling Biogas in cylinders

antoniraj (author)  jiguanya8 days ago
No, you can not just refill ordinary gas cylinders (LPG) with biogas. Firstly you need to purify the gas, that is removing unwanted gases like carbon dioxide and Hydrogen Sulphide

do we need any permission from any govt department to install domestic boigas plant to replace lpg completely at homes

antoniraj (author)  amitsingharya8 days ago
I think no permission is required from any government department

hi sir ,

i am so happy with your project ,but i have some doubts on it,is it possible to get your contact no :u can catch me on 9052945121

kindly post your doubts here so that others can also get clarification from those comments and replies

MS89 days ago

hello sir ,

I want to construct fixed dome type biogas digester for my restaurant waste of 10 kg daily. how can i make it? please help?

antoniraj (author)  MS89 days ago

please go through construction plan sent to your mail

sir can u upload a video clip showing the working of the above explained plant

or mail me @

antoniraj (author)  akshay.sanaki9 days ago

it is a prototype... I did not have any video of its working. However you can find more information in my other instructable here...

freshp113 days ago

hello sir i want to make biogas setup for home use for cooking regular.please send me the details to you

antoniraj (author)  freshp111 days ago
Please see attached files sent to your mail. Also refer to my other instructables on Biogas here:
vijayC214 days ago

Wonderful job sir!! Kindy send me details for the project at

antoniraj (author)  vijayC214 days ago
Please go through attached files sent to your mail. Also refer to my other instructable on biogas at these links:
sourabhp14 days ago
Hii sir,

I want to know about your any need of chemical to mix in that waste?.and it is possible to produce only by kitchen waste .how much gas produced from how much waste?.pls reply at
antoniraj (author)  sourabhp14 days ago
No chemicals are to be mixed with the feed material... you can use all types of organic waste other than onion peels, egg shells, garlic peels and more fibrous substances (like coconut waste etc.)

For more information please also see my other instructables here:
PavanJ15 days ago

Dear sir this prototype biogas plant is very good but i confuse for what quantity produce of biogas and whats qty of dung used in per day basis.pls send the details of composition required and produce gas Qty. me this mail id " "

antoniraj (author)  PavanJ15 days ago
You can feed about 350 to 400 grams of cow dung in this plant. This is a prototype and the gas produced is very less. this model can be used for science fair projects, not for home use.

Please also go through my other instructables on biogas at the following links to get a clear idea about a medium sized biogas plant
Ehtisham9419 days ago

hello, i want to make this project but at a larger scale, therefore i have some doubts and question.kindly share me some more information at :

i would be very thankful to u, and once again, u have done a fine effort.

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