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

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Step 8:

Picture of
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:

http://e-biogas.blogspot.in/

http://www.samuchit.com/index.php?option=com_content&view=article&id=8&Itemid=10
 
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How long does it take before useful gas is generated? a week? a month?

How long does an initial "feed" last? How often do you need to add waste?
antoniraj (author)  bigattichouse1 year ago
It will take about a week to get useful gas. Initial gas produced in the first few days may contain impurities and may not burn properly, which needs to be released to the atmosphere.

The initial feed of cow-dung slurry is to start the process. Once the gas formation has started, you can add waste regularly everyday.
If you feed it regularly from this size of a container, how much gas do you get out? Looks like it could hold 2-3 cu feet at time, how long does it usually take to "refill" the gas resevoir?
antoniraj (author)  bigattichouse1 year ago
this one is a working model of the real system... to get any useful gas, you should have a minimum 500 ltrs capacity digester tank.. I am not clear about your query " how long does it usually take to "refill" the gas reservoir?".. can you be more specific..?
Suppose I built this model and I get it to the point where it makes useful (burnable) gas. With the small floating resevoir, I use the little amount of gas in it, and it floats back down to the surface. How long until the reservoir refills? A day? a week? I'm trying to get an idea of how much gas you get, but also how long it takes to generate that gas for a model this size.
antoniraj (author)  bigattichouse1 year ago
The anaerobic digestion process in all Bio-gas plants are continuous and you can get burnable gas everyday. The feed material for this small size of plant is about 500 grams per day and you will get about 100 to 150 grams of methane gas.
Thanks!