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Friends,<br>
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<br>
On 10/25/2010 1:28 PM, Markus Schlattmann wrote:
<blockquote cite="mid:4CC5E87F.5090702@schlattmann.de" type="cite">
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I still don't believe in those 540 m³ from 1000 kg dung....</blockquote>
<br>
A sensible analysis. Maybe the key to the conundrum is the
statement:<br>
<br>
<blockquote cite="mid:4CC5E87F.5090702@schlattmann.de" type="cite">...the
biogas plant in Wardha... accepts 1000 kg cattle dung as a
one-time load and produces daily 3 cubic meter biogas continuously
over a period of 180 days...</blockquote>
<br>
It is well known that batch digestion does not produce the same
amount of biogas every day. Obviously it takes some time for the
ecology of the digester to get established (during which time, of
course, gas production is low), and it is surely something
approaching a law of biology that the more digestible components of
the substrate will be used up first, and then some of the more
recalcitrant materials will-- eventually-- be digested. The
succession of these stages offers a well-known curve, which is
either bell-shaped, if it plots daily production, or a long S (ogee)
curve if we are plotting cumulative production.<br>
<br>
In sum, I have no doubt that biogas is produced, and that for a
period of time production is good. Thus I would accept that the
reported plants produce well for a time, but not that they produce
the same amount every day, continuously for six months. But surely
the statement as quoted has to do with genuine enthusiasm, and
should not be taken as a rigorous mathematical description. <br>
<br>
<br>
While my search turned up a number of references to the organization
in Wardha in connection with biogas, none provided any reference to
these batch digesters, unless they are very large clay pots, as one
reference mentions. It would be salutary to have some literature on
the subject, if any has been produced.<br>
<br>
<br>
<br>
<div class="moz-signature">-- <br>
<div style="" ;=""><span style="font-size: 110%;">David William
House<br>
</span>
<div style="padding-left: 3em; font-size: 80%;">"The Complete
Biogas Handbook" <code><a href="www.completebiogas.com">www.completebiogas.com</a></code><br>
<em>Vahid Biogas</em>, an alternative energy consultancy <code><a
href="www.vahidbiogas.com">www.vahidbiogas.com</a><br>
<br>
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<div style="padding-left: 2em;">"Make no search for water.
But find thirst,<br>
And water from the very ground will burst."
<div style="padding-left: 2em; font-size: 80%;">(Rumi, a
Persian mystic poet, quoted in <em>Delight of Hearts</em>,
p. 77) <br>
<br>
<a class="moz-txt-link-freetext" href="http://bahai.us/">http://bahai.us/</a></div>
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