[Stoves] Dung based Biogas Plants

[Keith Addison]

>Dung or slurry from an operating biogas plant serve as the intial inoculum.
>But once methane starts to emanate, only the non-dung feedstock is used.
>Yours
>A.D.Karve

Thankyou.

Best wishes

Keith Addison


>----- Original Message -----
>From: Keith Addison <keith at journeytoforever.org>
>To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>
>Sent: Monday, May 14, 2007 1:38 PM
>Subject: Re: [Stoves] Dung based Biogas Plants
>
>
> > Dear Dr Karve
> >
> > Thankyou for this information.
> >
> > For sugar, starch, fats and proteins, is an initial inoculation required?
> >
> > Best wishes
> >
> > Keith Addison
> > Journey to Forever
> > KYOTO Pref., Japan
> > http://journeytoforever.org/
> >
> >
> >
> > >I started experimenting with biogas generation only in 2003. But as a
> > >biologist, I was always interested in this technology. A bit of
>information
> > >that I obtained in 1983 in the course of a presentation that I attended
>at
> > >The Institute of Biology II, Freiburg University, Germany, helped me
>greatly
> > >in understanding this process. It was a presentation by two Germany
> > >researchers. They claimed that practically any organic substance could be
> > >converted into methane, even benzene or petroleum. The researchers used a
> > >long, spirally laid plastic tube filled with a dilute emulsion of dung.
>They
> > >introduced, at a time, only one specific organic material as the
>substrate,
> > >and passed it slowly through this tube. It took several weeks for the
>system
> > >to get adapted to the substrate, but after the system had started to
>produce
> > >methane, they found that the bacteria conducting a specific step in the
> > >conversion, occupied a specific zone within the tube. Thus, if the
>substance
> > >had to go through conversion stages from A to F, the bacteria in the
>first
> > >section would convert A to B. then came the zone in which B was converted
>to
> > >C, followed by zones of conversion from C to D, D to E and E to F. The
> > >methanogenic zone was always the last one. With this system they could
>show,
> > >that if a substance was not directly digestible by the methanogens, the
> > >concerned substance was degraded, step by step, by several other species
>of
> > >bacteria, that conducted the intermediate stages of conversion, before
> > >offering it to the methanogens. The main theme of the presentation was
> > >conversion of mother liquor from a paper factory into methane, but the
> > >experiments with the long plastic tube not only impressed me, but also
> > >helped me in understanding the process of biomethanation. It also raised
> > >several questions in my mind. Since our intestines also represent a
>tubular
> > >system, does the plastic tube model mimic the intestine? Are there zones
>in
> > >our intestine that are occupied by a particular species of bacteria? Is
>this
> > >nature's way of detoxifying material that is not directly digestible by
>the
> > >animal system?
> > >My experiments later on showed that the methanogens can directly digest
> > >sugar, certain polysaccharides like starch, mucilages, etc., and also
>fats
> > >and proteins. All the above substances yield roughly 250 g methane from a
>kg
> > >of substrate. When one uses cellulose, the methane production is just
>half
> > >as much as from sugar or starch, and the reaction time is doubled,
>because
> > >the material must first be digested by cellulolytic organisms, before the
> > >methanogens can take over.
> > >All the facts mentioned above, and even the plastic tube experiment, may
>be
> > >quite well known to persons who have systematically studied
>biomethanation.
> > >But I thought that the above information might be of interest to
>neophytes.
> > >Yours
> > >A.D.Karve
> >
> > <snip>