[Stoves] [biochar] First report from Phnom Penh

[Anand Karve]

Dear Crispin,
the biogas plant filled with charcoal accepted three times the normal
quantity of feedstock and also produced daily three times as much
biogas. It did this for about three months, after which it suddenly
stopped producing any biogas. We tried giving it a rest for a view
weeks, but it did not recover. We reduced the feedstock quantity back
to 1g per litre, but it did not produce any biogas. Three g per litre
of digester capacity represent overfeeding under normal circumstances.
As long as the charcoal in the biogas plant was active, the plant
could accept the high dose of the feedstock. But at some point of
time, the charcoal became inactive and without realising it, we kept
feeding the system with three times the allowable quantity of
feedstock. I think that the pH of the substrate became acidic, causing
the biogas production to stop.
Yours
A.D.Karve

On Fri, Mar 22, 2013 at 8:27 AM, Crispin Pemberton-Pigott
<crispinpigott at gmail.com> wrote:
> Dear AD
>
> I too have a question: did the addition of 3g/litre still yield 3kg of gas
> per kg of input? That leads to the question, was the gas production rate
> dropping so you reduced the feed loading from 3 g to 2 g then 1 g, or was
> the gas production rate dropping?
>
> Thanks
> Crispin
>
>
> Dear Anand,
> What was the particle size of the char that you added to achieve this
> effect? Have you tried different sizes?
>
> Thanks,
> Alex
>
>
>
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-- 
***
Dr. A.D. Karve
Trustee & Founder President, Appropriate Rural Technology Institute (ARTI)