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Dear Dr. Karve,<br>
</font><br>
On 12/5/2010 8:48 PM, Anand Karve wrote:
<blockquote
cite="mid:AANLkTimpp18ENx6Lt+9mkcBbQRF5spfc1xC4c5ouO0DP@mail.gmail.com"
type="cite">
<div>Dear Paul, [...]<br>
</div>
<div>I have not heard of a single accidental explosion or of a
fire arising from a biogas plant...</div>
</blockquote>
<br>
When I was doing research for the biogas handbook, I returned
repeatedly to the venerable Sewage Works Journal, one of the early
of the periodicals (if not the earliest) devoted to AD, in its case
dealing with municipal sewage. In several issues there were reports
of explosions-- this of course was in the twenties and thirties--
where workers would open large tanks without any precautions, and an
explosion would result. In some cases people simply disappeared-- no
recognizable fragments were found, according to the reports.<br>
<br>
<blockquote
cite="mid:AANLkTimpp18ENx6Lt+9mkcBbQRF5spfc1xC4c5ouO0DP@mail.gmail.com"
type="cite">
<div>There were even reports from South America of a
sausagelike biogas plant made out of relatively thin plastic
film. I don't think there has been an accident with any of
those, but something like that would never be allowed in Europe
or USA. <br>
</div>
</blockquote>
<br>
I've not seen any reports of explosions with plastic bag digesters
either. But in terms of their use in the US, actually in a series of
classes I have recently initiated about biogas, one of the key
aspects is that every participant leaves with a ~200 gal plastic
digester kit. These classes have been held from Hawaii to
Pennsylvania, soon in Los Angeles and Iowa, and we are negotiating
in a number of other places including Australia (maybe to meet
Paul?) and Guatemala. In any case the point, as may surprise you, is
that in fact there are no regulations of which I know in the US that
are <i>specific</i> to the use of (plastic bag or similar) small
digesters. Someone asked me about such regulations recently, and my
response was that (again, to the limits of my knowledge) any
regulations that would apply would be about other issues. For
example:<br>
<br>
<blockquote
cite="mid:AANLkTimpp18ENx6Lt+9mkcBbQRF5spfc1xC4c5ouO0DP@mail.gmail.com"
type="cite">
<div>There also appear to be rules about effluents from a biogas
plant. </div>
</blockquote>
Where human wastes, or other potentially environmentally or
medically harmful materials are used as substrates, there is indeed
a forest of regulations, federal, state and local, which would or
may apply. Thus, for example, if a small digester were to be fed
humanure, then a building inspector might reasonably classify it as
a septic tank, and apply the relevant building codes or health
regulations. Likewise, either out of ignorance or with some
justification (depending on how it has been constructed and how it
is being used), someone with a clipboard might decide that a small
digester was hazardous under some regulation or other, but again, I
feel fairly confident if not entirely certain that nowhere in the US
are there regulations which pertain to small biogas digesters as
small biogas digesters. If it is classified as something else-- a
septic tank or a hazardous gas storage unit, for example-- then some
regulations may pertain. In this instance, then, if one loses the
classification battle, one may lose the regulation war.<br>
<br>
<br>
<blockquote
cite="mid:AANLkTimpp18ENx6Lt+9mkcBbQRF5spfc1xC4c5ouO0DP@mail.gmail.com"
type="cite">
<div>Antibiotics were mentioned in one of the previous postings.
Do they really persist in the effluent? <br>
</div>
</blockquote>
<br>
Some antibiotics are indeed very persistent. See, for example, <a
href="http://info.ngwa.org/gwol/pdf/042379994.pdf">this paper</a>.<br>
<br>
<br>
<br>
d.<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>
</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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