[Digestion] size and cost of a small domestic biogas plant

[Anand Karve]

Dear Reuben,
being a biologist, I am rather ignorant about energy units like BTUs and
Joules. In biochemistry we use calories. Methane is supposed to have about
11000 kcal per kg. Biogas generally contains about 60 to 64% methane by
volume. So, 800 litres of biogas would measure about 24 cubic meters. It
would contain about 500 litres methane, weighing about 250 g, and energy
content of about 2750 kcal.
Yours
A.D.Karve

On Mon, Oct 4, 2010 at 2:57 PM, Reuben Deumling 9watts at gmail.comant about
BTU <9watts at gmail.comant%20about%20BTU> wrote:

> Thank you for helping to answer my earlier question. Can you translate the
> daily quantity of biogas produced in your example into units that are more
> familiar (BTUs, Joules, cubic feet...)?
>
> Thanks
> Reuben Deumling
>
>   On Sun, Oct 3, 2010 at 11:47 PM, Anand Karve <adkarve at gmail.com> wrote:
>
>>   Dear Members,
>> this question was raised in a recent flurry of messages. Instead of
>> repeating them, I  wish to state the following:
>>  Using daily 1 kg (dry weight) food waste produces daily about 700 to 800
>> kg biogas, which most small families (4 to 5 persons) find quite adequate
>> for cooking all their meals. Our biogas plant has a digester of 1000 litres
>> and a moving drum type of a gas holder having a capacity of about 750
>> litres. The  cost of complete biogas plant is about US$200, if it is
>> manufactured according instructions contained in our video which can be
>> downloaded from our web site www.arti-india.org by paying us US$10
>> through Pay Pal. The matter was also discussed if yeast had beneficial
>> effect on biogas production. Frankly, I do not see why and how yeast should
>> benefit the process. Yeast would actually act as a competitor of the
>> methanogens in that the sugar that would normally have produced
>> biogas, would be used by the yeast in producing alcohol. It is likely that
>> alcohol can act as substrate for the methanogens (glycerin, which is an
>> alcohol,  can be used by the methanogens as a substrate), but a lot of
>> energy would be wasted in this process in comparison to obtaining methane
>> directly from the sugars by using the methanogens.
>> Yours
>> A.D.Karve
>> --
>> ***
>> Dr. A.D. Karve
>> President, Appropriate Rural Technology Institute (ARTI)
>>
>> *Please change my email address in your records to: adkarve at gmail.com *
>>
>>
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-- 
***
Dr. A.D. Karve
President, Appropriate Rural Technology Institute (ARTI)

*Please change my email address in your records to: adkarve at gmail.com *
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