<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content="text/html; charset=utf-8" http-equiv=Content-Type>
<META name=GENERATOR content="MSHTML 8.00.6001.19019">
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px">
<DIV><FONT size=2 face=Arial>"""""""""""""""""</FONT><BR>I am new on this list
serve, I have a question regarding the danger of H2S, I have been reading
about this gas and its dangers, I am developing a project in a rural community
in Mexico, I'm helping to develop 5 tubular PE- biodigesters, I am still
working on solve the <EM>Hydrogen sulfide issue, I don't want to put people's
life on risk; so, any help on the manage or elimination of
</EM><EM>Hydrogen sulfide</EM> on Bio-gas systems will be helpful, </DIV>
<DIV><FONT size=2 face=Arial>"""""""""""""""""""""""""""""""</FONT></DIV>
<DIV><FONT size=2 face=Arial>If you control the biogas appropriately, you will
mitigate the risk of the hydrogen sulfide. </FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>However, there are ways to scrub the
biogas on the way out of the digester (exposure to rusty steel wool,
lathe turnings,shredded sheetmetal etc) or</FONT><FONT size=2
face=Arial> it can be collected in the digester by admitting a small
amount of oxygen to the digester which causes the Sulfur to collect as less
dangerous forms within the digester, eventually passing out with the
effluent. Sulfur has become an important plant nutrient
in these days of decreasing powerplant sulfur emissions here in the USA and
elsewhere in the developed world. The amount of oxygen would have to be
regulated to stay below the level where the mixture becomes flammable.
Not quite so simple a technology as the poly tube digester you are working
with. </FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>As part of your training for the operators of the
digesters, you must emphasize that the digester is a very dangerous
place. Not that a poly tube digester is somewhere a person might ever
go. This is not only because of hydrogen sulfide, but also because of
the carbon dioxide and methane. Every year or two, someone (and
sometimes several "rescuers" as well) is killed when they enter a pit or
other place where the biogas/manure gas has accumulated or is being liberated
rapidly enough to reach dangerous concentrations.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Jim</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>James R Rankin, DVM</FONT></DIV>
<DIV><FONT size=2 face=Arial>Cedarcrest Farms, Inc</FONT></DIV>
<DIV><FONT size=2 face=Arial>Faunsdale, Alabama
USA</FONT></DIV></BLOCKQUOTE></BODY></HTML>