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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Dear all,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Thank you very much for your feedback and
ideas. We will have to think more about David’s’ suggestion using
two flame traps.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Ken is right; I should have given a bit
more details on the project. I have to admit that we are at the very beginning...
The project is located in Kumasi, Ghana, and our local research partner is the
KNUST University of Science and Technology. The pilot plant shall be located at
the university campus and the feeding material will consist of organic
household waste or food waste from restaurants. In a first step, two Swiss
students will work on the project for 6 months (start in December), spending 4
months on site. Their task is to identify the suitable material, that’s
why I can’t give you the details on what exactly is available. At first,
I was also thinking about a shipping container (what about corrosion?), but
cement materials are also available as well as skilled workers. We will have to
compare the different options and costs.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>On principle, the idea is that such a
plant would be operated by the municipality or a private contractor (not by
farmers), as our focus is on municipal solid waste. There are still many open
questions, but my biggest concern was the security - if it is possible at all
to construct a simple digester which is safe...<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I think the students might contact some of
you directly for further questions later on.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Thank you,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Yvonne<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabindex=-1>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
digestion-bounces@lists.bioenergylists.org
[mailto:digestion-bounces@lists.bioenergylists.org] <b><span style='font-weight:
bold'>On Behalf Of </span></b>Ken Calvert<br>
<b><span style='font-weight:bold'>Sent:</span></b> Freitag, 29. Oktober 2010
09:48<br>
<b><span style='font-weight:bold'>To:</span></b> For Discussion of Anaerobic
Digestion<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [Digestion] Dry
fermentation in developing countries</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> Yvonne Hi! When you say developing
countries, what sort of construction materials are you thinking
of? Would old 20 tonne shipping containers be available?</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Are cement materias and tradesmen skilled in
cement plaster work readily available? What about PVC
tarpaulin cloth? Are there trucks on the roads that have waterproof
covers that can be strapped down over a load? What is
the local soil and terrain? Is it possible to dig say 2-3
metres deep in the soil and get a smooth surface, or is the
terrain too soft and sandy to hold to the shape of a cistern or
trench dug in the soil? Is it too rocky to allow any sort of digging
at all? If you can home in a little more on the country side
and local skills available I can make several different
suggestions. Sincerely, Ken Calvert. <a
href="http://www.coffee.20m.com">www.coffee.20m.com</a></span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> </span></font><o:p></o:p></p>
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<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> </span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>----- Original Message ----- <o:p></o:p></span></font></p>
</div>
<div style='font-color:black'>
<p class=MsoNormal style='background:#E4E4E4'><b><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial;font-weight:bold'>From:</span></font></b><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> <a
href="mailto:Yvonne.Voegeli@eawag.ch" title="Yvonne.Voegeli@eawag.ch">Voegeli,
Yvonne</a> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>To:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> <a
href="mailto:digestion@lists.bioenergylists.org"
title="digestion@lists.bioenergylists.org">digestion@lists.bioenergylists.org</a>
<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>Sent:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> Thursday, October
28, 2010 9:53 PM<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>Subject:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> [Digestion] Dry
fermentation in developing countries<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Dear all,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I like to start a new discussion on a different topic,
namely the dry-fermentation process (discontinuous) similar to the digesters
developed by the companies Bekon or Bioferm in Germany. The organic waste is
filled batch-wise into simple garage-like digesters for about 30-40 days.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Experts report that this process has a high potential for
application in developing countries as it has the simplest design and the solid
waste digesters are the least expensive ones. Also, substrates that lead to
operating problems during wet fermentation due to their structure or the
proportion of impurities they contain can still be processed using dry
fermentation methods. However, up to date, there is no experience with this
technology in developing countries. Therefore, our idea is to develop a
dry-fermentation biogas plant adapted to the situation in developing countries
using locally available material. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>After visiting a Bekon biogas plant in Switzerland,
I’m especially concerned regarding the opening of the digester for
emptying and refilling. Before opening the door, the digester has to be vented
in order to avoid a gas-air-mixture which is explosive. This installation seems
to me rather complicated.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>- Is anybody of you familiar with discontinuous
dry-fermentation systems and has an idea how the security can be assured in a
developing country context? Is it possible to install a simpler venting system?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>- Likewise, when removing the drum from a floating-drum
digester for emptying, how is ensured that at no time an explosive
gas-air-mixture occurs?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Thanks for your ideas,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Yvonne</span></font><font size=5><span style='font-size:
18.0pt'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=5 face="Times New Roman"><span style='font-size:
18.0pt'>°°°</span></font><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Yvonne Vögeli<br>
Eawag / Sandec<br>
Überlandstrasse 133<br>
P.O. Box 611<br>
8600 Dübendorf<br>
Switzerland<br>
Phone: +41 (0)44 823 54 20<br>
Fax: +41 (0)44 823 53 99<br>
yvonne.voegeli@eawag.ch<br>
</span></font><span lang=DE-CH><a href="http://www.sandec.ch"><font size=2
face=Arial><span lang=EN-US style='font-size:10.0pt;font-family:Arial'>http://www.sandec.ch</span></font></a>
</span><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center>
</span></font></div>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>_______________________________________________<br>
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<br>
for more information about digestion, see<br>
Beginner's Guide to Biogas<br>
http://www.adelaide.edu.au/biogas/<br>
and the Biogas Wiki http://biogas.wikispaces.com/<o:p></o:p></span></font></p>
</blockquote>
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