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>please sir send the pdf to my email jeebsontrust@gmail.com. Thank u very much</p>
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>
please see attached file sent to your mail
Sir can you send the pdf file to my mail - erganesk@gmail.com
<p>Dear Sir, </p><p>It is quite fascinating your ideas to simplify the bio-gas unit, could you please forward the pdf to nid2003r@gmail.com</p><p>Thanks and regards,</p><p>Nidhin</p>
<p>please check your mail</p>
<p>antoni raj sir can you please send this pdf to my gamil vragavender@gmail.com thanks in advance</p>
Please see attached files sent to your mail
<p>If you're thinking of DIY your own backyard bioplant and especially if you're going to produce electricity, there's no better blueprint online than <a href="http://biopowerplant.org/." rel="nofollow"> http://biopowerplant.org/</a></p><p>You will need to have a two small tanks, digester and colector where the gas will be stored for future burning. Once enough gas accumulates you simply run the generator with it. All you need to do is feed it with biodegradable waste from sewage, plant materials, fruit waste, manure, food waste or garden and lawn waste.</p><p>This way you get free electricity, potentially forever.</p>
You can go through my other instructable on constructing a medium sized Biogas plant at the following link :<br><br>http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/<br><br>The gas from this plant can be used for cooking, lighting or to run a biogas generator to produce electricity.
<p>sir you are so cool and your bio gas material was interesting, please send this pdf to my gamil also vraganvender@gmail.com</p>
<p>antoni raj sir can you please send this pdf to my gamil vragavender@gmail.com thanks in advance</p>
<p>Hi,</p><p>Can you please send these steps in a pdf to the below email id: sudersonsarathy@gmail.com.</p><p>We would want to have it for our entire flats in our community</p>
<p>Can't you go to &quot;Download&quot; above and do it yourself??..</p>
Please go through the attached files sent to your mail
It is so sweet, you folks are so polite and considerate, and also very eager to get involved in a good undertaking. I hope you undetstand that we Americans are sometimes amused, and sometimes frutrated with your use of English. But that is a minor matter, your hearts are so dear.
<p>What problem with English??... I read all of this and it was written in perfect English... ??</p>
<p>thank you...</p>
<p>dear sir, </p><p>can u send me all these pictures and more details to my mail id </p><p>cleanyog@gmail.com</p><p>waste of 4 people family is sufficient for this plant and how much gas is expected to generate?</p><p>regards</p><p>sudhakar shelke</p>
<p>Please see attached files sent to your mail for more information</p>
<p>Hi, i was wondering if there was a better way to filter out the excess gases rather than quickly opening and closing the value</p>
I am not clear about your query. I suppose you mean that instead of opening the valve and releasing the initial gas, there may be a better way to filter out the excess gas.<br><br>The gas produced initially contains very little methane and won't burn. So you have to release the initial gas 2 to 3 times before you get burnable gas
<p>Hi <a href="http://www.instructables.com/member/antoniraj" rel="nofollow">antoniraj</a>,</p><p>Very Interesting Intervention.</p><p>Can you please email a pdf of steps to us.(studio.mode@gmail.com) We would love to try it out. </p><p>Cheers </p>
please see attached files sent to your mail
Hi! Is it possible for you to send the instructions for making this biogas digester plant.<br>Email:- aditya.aryan333@gmail.com<br><br>Thanks in advance and Cheers for more projects for you! :)
Please see attached files sent to your mail
<p>hi sir,</p><p>am interested to follow your protocol to do plant for algae .is it possible? please suggest me.</p>
Plant for algae is some what different from the Biogas digester. Please go through some of the instructables at this link which will give you an idea about Algae cultivation and Bioreactor<br><br>http://www.instructables.com/howto/algae/
<p>Hi! Is it possible for you to send the instructions for making this biogas digester? </p><p>Email: mat_sumalinog@yahoo.com</p><p>Thanks in advance and Cheers for more projects for you! :)</p>
Please see the attached file sent to your mail
<p>i am interested to do a project of this biogas but how can it be applied in a septic tank? and i am planning to use the excess slurry to feed the seedlings.</p>
You need some arrangement to collect the gas from normal septic tank which does not have a dome to collect gas. The inlet and outlet of the tank are also to be modified in such a way that they discharge in and out inside the slurry to prevent gas loss. You can use a large balloon type arrangement to collect the gas through the vent pipe which is part of the septic tank.<br><br>You can use the digested slurry to feed seedlings
<p>Hi,</p><p>I am interested to use this in a school project.</p><p>could you please send me more detailed instructions to my email: noah.emery@yahoo.com.</p><p>I will really appreciate this </p><p>thanks</p>
<p>Please see attached files sent to your mail</p>
You are amazing, i understood this project easily by ur clear steps and appropriate pics. I was finding this system with easy techniques.
thank you...
<p>Hi, </p><p>I am highly <br>interested to try it for domestic use. I live in Colombia. Can you<br> send me more detailed instruction through my email. The email is 20.mauricio@gmail.com. I will really appreciate this. thanks</p>
Please see attached files sent to your mail
Please could you make a video on how it is done step by step.<br>My email is olaidemogaji@gmail.com<br>I am a physics student of the University of Lagos and the University is close to a slum which generates very large amount of waste but no one to tap into such abundance. We complain about lack of power supply but fail to tap into such golden oppourtunity.<br>It would be my utmost pleasure to have this video and carry such ingenious idea to the slum and bring them out of darkness.
I did not make any video. As I work alone in most of my projects, I prefer to take pictures. For taking pictures and videos also I need some assistance, otherwise it may not be possible.
<p>I'm still skeptic about how functioning of slurry outlet. It seems to be fixed a bit too high, does the slurry actually rise up that high, and does a single hole actually help in pushing out all of the waste? </p><p>And second, what's the use of the 64&quot; feeder pvc, when organic waste is being/can be directly poured into the digester tank(which is also easier and hassle free)??? </p>
it is very simple. You can fix the slurry outlet at any height, but the slurry can not be stored more than that height. Digested material float up to the top.and when you add more organic waste, the digested slurry at the top portion of the tank falls out through the outlet pipe.<br><br>Secondly, how can you pour the waste directly in to the digester tank when Gas holder is floating in it ? Do to that you have to remove the gas holder tank and loss all stored gas. You can not pour the waste through the sides

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 »
More by antoniraj:Ridge Gourd Skin Chutney Banana Halwa : A Sweet Dish Made From Over Ripe Bananas Deep-fried Cauliflower Fritters 
Add instructable to: