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Listers, Hello,<br>
<br>
The URL for Professor Melvin S. Finstein's paper is <a
href="http://www.microbemagazine.org/index.php/04-2010-home/1503-anaerobic-digestion-variants-in-the-treatment-of-solid-wastes">www.microbemagazine.org/index.php/04-2010-home/1503-anaerobic-digestion-variants-in-the-treatment-of-solid-wastes</a>,
if anyone wants to follow this up. He offers a critique of the
classic CSTR design of reactor and compares it with the IBR
(Indeuced bed reactor), an adaptation of the UASB design.<br>
<br>
Best wishes,<br>
<br>
David F.<br>
<br>
On 16/01/2011 21:37, <a class="moz-txt-link-abbreviated" href="mailto:finstein@envsci.rutgers.edu">finstein@envsci.rutgers.edu</a> wrote:
<blockquote
cite="mid:50111.184.13.7.182.1295213870.squirrel@webmail.envsci.rutgers.edu"
type="cite">
<pre wrap="">All,
Re: CSTR at Beltsville
Historically, CSTR was designed based on aerobic thinking before it was
understood that the microbiology of aerobic and anaerobic (methanogenic)
systems are entirely different. It is now understood that to realize
maximal rates of treatment one must preserve the integrity of microbial
associations rather than smash them apart - as in CSTR. I'd include here
the URL to a brief publication summarizing a rather involved - but very
well established - story, but believe such inclusions get weeded out by
the list serve. You may contact me if interested.
The best to All,
Mel Finstein
Melvin S. Finstein, Ph.D.
Professor Emeritus of Environmental Science
Rutgers, the State University of New Jersey
105 Carmel Road
Wheeling, WV 26003
(304) 242-0341
Email: <a class="moz-txt-link-abbreviated" href="mailto:finstein@envsci.rutgers.edu">finstein@envsci.rutgers.edu</a>
</pre>
<blockquote type="cite">
<pre wrap="">
On 13 Jan 2011, at 17:16, <a class="moz-txt-link-rfc2396E" href="mailto:armoss@umd.edu"><armoss@umd.edu></a>un wrote:
Charles-
There's at least one small-scale digester of that size currently
operating in the U.S. - at the USDA Beltsville Agricultural Research
Center in Beltsville, MD. The dairy's herd size is roughly 125-130,
with ~100 milking and producing manure at any given time (dry cattle
are let out to pasture). The digester was built in 1994 and was
constructed as a continuous stirred-tank reactor. I have tentative
plans to conduct research on this digester simultaneously with a
low-cost, pilot-scale digester project operating on the same
waste-stream that's being constructed by our lab group at the
University of Maryland. I don't have intimate knowledge of the USDA
CSTR's history, but I can tell you what I know.
The digester was originally constructed for odor control as an
upright, cylindrical concrete tank (I'm not sure enough of the
designed HRT to give you information on it), and was later insulated
with gunnite-coated styrofoam. It operates on mechanically
screw-press separated, scraped waste, and utilizes the biogas produced
to power a boiler that circulates hot water through a conveyance
system installed within the digester for heating; a combined heat and
power electric generator was installed in the mid-2000s, but it has
never been brought online. The digester's had a number of problems
come up, including repeated clogging of the supply lines (originally
3-4" ID, now 6"), the break down of the screw-press separator and
supply pumps, and the corrosion of the boiler due to inadequate
scrubbing. To be fair, many of the problems associated with the
digester are the result of fluctuating research interest, funds,
management, and the lack of an effective biogas scrubbing system, but
they exist all the same. Currently, the digester is up and
operating... although obviously not ideally.
Although most of the digestion systems are covered lagoons, the AgSTAR
website contains a link to a Excel file detailing the digesters
currently registered in the EPA's system (look under "Farm Project
Profiles"). A few of them approximate the herd numbers you're
interested in.
As a side note, our research at the University of Maryland, together
with research at Ohio State and the University of Wisconsin, is
attempting to introduce smaller-scale, lower-cost systems in the U.S.
I gave a presentation in October on small-scale digestion and some of
the current efforts that you can find here.
Good luck hunting!
-Andy
Andrew R. MossSustainable Agriculture Research & Education
FellowUniversity of Maryland Dept. of Environmental Science and
Technology1445 Animal Sci./Ag. Engineering (Bldg. 142)University of
Maryland, College Park, MD 20742Phone: (865) 363-5535
</pre>
</blockquote>
<pre wrap="">
_______________________________________________
Digestion mailing list
to Send a Message to the list, use the email address
<a class="moz-txt-link-abbreviated" href="mailto:Digestion@bioenergylists.org">Digestion@bioenergylists.org</a>
to UNSUBSCRIBE or Change your List Settings use the web page
<a class="moz-txt-link-freetext" href="http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org">http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org</a>
for more information about digestion, see
Beginner's Guide to Biogas
<a class="moz-txt-link-freetext" href="http://www.adelaide.edu.au/biogas/">http://www.adelaide.edu.au/biogas/</a>
and the Biogas Wiki <a class="moz-txt-link-freetext" href="http://biogas.wikispaces.com/">http://biogas.wikispaces.com/</a>
</pre>
</blockquote>
<br>
<div class="moz-signature">-- <br>
<p align="center">********************************************************************<br>
Dr David Fulford CEnv MEI, 15, Brandon Ave, Woodley, Reading RG5
4PU <br>
<a href="mailto:d.j.fulford@btinternet.com">d.j.fulford@btinternet.com</a>,
Tel: +44(0)118 326 9779 Mob: +44(0)7746 806401 <br>
Kingdom Bioenergy Ltd, <a href="http://www.kingdombio.com">www.kingdombio.com</a>,
<a href="mailto:davidf@kindombio.com">davidf@kindombio.com</a> </p>
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