[Stoves] banana peels

[Anand Karve]

Dear Robert,
scientifically, the stem of banana is the underground rhizome. It contains
starch and it should yield a lot of gas. Ideally, Starchy and sugary
material yields about 1 kg biogas per kg dry weight. The volume of 940
litres per kg dry matter sounds a bit tall, because the rhizomes also
contain conductive tissue, having lignin and a relatively thick outer skin.
 It may be that the volume of biogas was measured at 35 degrees C, which
may explain its high volume. In scientific papers the gas volume is quoted
at standard temperature and pressure.
Yours
A.D.Karve


On Tue, Dec 6, 2011 at 5:07 PM, Robert Taylor <rt at ms1.hinet.net> wrote:

> **
> Dear Prof. Karve
>
> Thanks for adding the voice of experience. I was quoting, from my
> armchair, a New Zealand government leaflet passed on by Ken Calvert, which
> lists biogas yields from 20 different substrates. The table is entitled
> "Production of biogas from digestion of various materials at 35 deg C and
> suitable retention times with a loading concentration of 5% total solids".
> Top of the list is banana, fruit and stem (not "whole plant", as I
> misquoted from memory), yielding 940 liters of biogas (at 53% methane) per
> kg of total solids, retention time 15 days. Next are potato tuber at 880
> liters and sugarbeet root at 620. Bottom of this particular list are cattle
> and sheep manure, at 190/180 - 220 liters. I had thought some other
> tropical/subtropical crops such as cassava were also listed, but that must
> have been another source.
>
> Best regards
>
> Robert Taylor
>
>
>
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