[Digestion] Small Scale Digester Heating

[Anand Karve]

Dear Takemoto,
the water circulation is passive. It uses a mechanism called heat siphon,
same as in a solar water heater. The insulation does not have to be rubber.
It can also be any synthetic spongy material. Such materials are used even
in winter sports clothing,
Yours
A.D.Karve

On Wed, Oct 3, 2012 at 7:05 PM, Takamoto <kyle at takamotobiogas.com> wrote:

> Dear Biogas List,
>
> I have been thinking about the biggest hurdles to producing more gas from
> small scale biogas systems (4 cubic meters to 12 cubic meters) and by far
> the biggest barrier is heat. From the literature I have read it seems that
> if you increase the temperature of the digester from about 18C (the
> temperature of our digesters) to 37C you can nearly double the gas yield
> per unit of input and nearly halve the retention time which would reduce
> the capital costs.
>
> Does anyone know of tests that have been done or ideas that have been put
> forth to heat small scale digesters in a controlled manner? (For the moment
> assume that such a process could be managed on many disparate, small scale
> biogas systems. That is the next challenge.) The processes I was thinking
> of were 1.) to heat the biogas system with biogas from the system itself or
> 2.) to bubble a very slight amount of air through the digester so that
> there was a slight anaerobic reaction that would produce heat and warm the
> digester. Or 3.) you could use sunlight to warm the digester if you can
> warm the digester and not the gas holder as warming the gas holder will
> only cause the gas to expand and no heat will be transferred to the slurry.
>
> These methods are probably most applicable to fixed dome and floating drum.
>
> Have either of these ideas been tried? Are there other ideas out there?
>
> Cheers,
> Kyle
>
>
>
>
> _______________________________________________
> Digestion mailing list
>
> to Send a Message to the list, use the email address
> Digestion at bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
>
> http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org
>
> for more information about digestion, see
> Beginner's Guide to Biogas
> http://www.adelaide.edu.au/biogas/
> and the Biogas Wiki http://biogas.wikispaces.com/
>
>
>


-- 
***
Dr. A.D. Karve
Trustee & Founder President, Appropriate Rural Technology Institute (ARTI)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/digestion_lists.bioenergylists.org/attachments/20121005/173d6fb0/attachment.html>