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<div class="moz-text-html" lang="x-western"> <font face="Georgia"><br>
Dear friends,<br>
<br>
Excellent discussion lately. I was particularly impressed by the
article by Dr. Fulford about biogas burners. Best information
I've seen on this subject.<br>
<br>
<br>
I wanted to ask two questions just now, and I'll therefore be
sending another message to the list quite soon. Separating the
questions will allow the development of two different threads,
if there is much discussion about either question.<br>
<br>
The first question concerns pressure. Obviously AD is able to
generate biogas at pressure. Any vessel 33 feet deep will have
two atmospheres of pressure at the bottom, and there are a
number of digesters which are at least that deep. The gas
produced in deeper vessels-- if they are not stirred-- tends to
have a bit less carbon dioxide, because that gas dissolves
rather easily as compared with methane.<br>
<br>
But I am not familiar with any work that has been done regarding
the relationship between pressure and the rate of production.
That is, one would expect that at increasing pressure, less
biogas (measured, of course, at STP) would be produced. But what
is the relationship? How dramatic is the reduction in the rate
of production with deeper vessels?<br>
<br>
<br>
d.<br>
</font><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>www.completebiogas.com</a></code><br>
<em>Vahid Biogas</em>, an alternative energy consultancy <code><a>www.vahidbiogas.com</a><br>
<br>
</code></div>
<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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