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<DIV><FONT face=Arial>Dear Stuart</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=kneebraceboy@yahoo.com.au
href="mailto:kneebraceboy@yahoo.com.au">stuart mather</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=kchisholm@ca.inter.net
href="mailto:kchisholm@ca.inter.net">Kevin C</A> ; <A
title=gasification@lists.bioenergylists.org
href="mailto:gasification@lists.bioenergylists.org">gasification@lists.bioenergylists.org</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, February 02, 2013 8:17
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [Gasification]
mycoremediation of tarry water</DIV>
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<B><SPAN style="FONT-WEIGHT: bold">From:</SPAN></B> Kevin C <<A
href="mailto:kchisholm@ca.inter.net">kchisholm@ca.inter.net</A>><BR><B><SPAN
style="FONT-WEIGHT: bold">To:</SPAN></B> stuart mather <<A
href="mailto:kneebraceboy@yahoo.com.au">kneebraceboy@yahoo.com.au</A>>;
Discussion of biomass pyrolysis and gasification <<A
href="mailto:gasification@lists.bioenergylists.org">gasification@lists.bioenergylists.org</A>>
<BR><B><SPAN style="FONT-WEIGHT: bold">Sent:</SPAN></B> Saturday, 2 February
2013 2:50 PM<BR><B><SPAN style="FONT-WEIGHT: bold">Subject:</SPAN></B> Re:
[Gasification] mycoremediation of tarry water<BR></FONT></DIV><BR><BR>Kevin
wrote:<BR> ....While I have not seen a report showing that blackwater
disposal is harmful to the environment, I have not seen one that says it is
not harmful either. However, a competent Gasifier Operator sent me pictures of
his blackwater dump site a few years after he stopped dumping blackwater
there, and the plants growing there seemed just as vigorous and healthy as
nearby plants outside teh dump zone.<BR>> <BR>> Best
wishes,<BR>> <BR>> Kevin<BR> </DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57>That's intriguing Kevin,</DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57>So I wonder why there seems to be a
general consensus that dumping tarry water in a pond amounts to environmental
vandalism. Not saying your gasifier correspondent was making it up. But you
would think the President of Myanmar would have better things to do than
declare black water gasification leach ponds toxic sites Military juntas
aren't well known for their environmental awareness. So why the concern about
tar ponds people?</DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57>Stuart.</DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57> </DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57><FONT face=Arial># A "Tar Pond" or
"Blackwater Disposal Pond" is a highly concentrated "disposal situation". Too
much of anything is almost certain to be a problem. One cannot grow carrots or
wheat in a pond used to dispose of distilled water, and ethanol alcohol is a
poison when taken in excess quantities at high concentrations, as an extreme
examples. The issues here are one of both toxicity and concentration. A
"Gasifier Tarpond" could indeed become qualified as a 'superfund site."
However, the same chemicals, if spread in dilute form over say 1, or 10, or
100 square miles may present no significant hazard, and may even yiled a net
benefit. </FONT></DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57><FONT face=Arial></FONT> </DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57><FONT face=Arial># I would say intuitively
that there is a combination of "toxicity and concentration" above which,
gasifire tar disposal is "bad", and that there are "toxicity and
concentration" combinations below which gasifier tars are not hazardous, and
may even be beneficial. I don't know all the compounds in gasifier tars,
and the concentrations below which they can be "generally considered as safe."
In my opinion, nobody can responsibly say for certain that "gasifier tars are
toxic" unless one specifies both the components and concentration. Neither can
anyone say for certain that "gasifier tars are safe" unless one has
a rational data base to support the statement. </FONT></DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57><FONT face=Arial></FONT> </DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57><FONT face=Arial># The process of smoking
fish, meat, and other food products can be looked on as a way to dispose of
"gasifier tars." :-) The fact that such "smoke tars" preserve foods proves
that such tars are toxic to some life-forms. Some studies suggest that smoked
foods are bad, while others suggest that while there may be some "cancer
deaths" as a result of eating such smoked foods, the benefits from
reducing deaths from pathogenic organisms that would otherwise be present
greatly exceed the "smoking detriments."</FONT></DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57><FONT face=Arial></FONT> </DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57><FONT face=Arial># "The way to eliminate
the gasifier tar problem is to eliminate tar formation in the first place."
This is not that difficult with properly designed and operated gasifiers. This
can be done, as is evidenced by the many gasifiers in operation fueling IC
engines, with no tar problems. Stratified downdraft gasifiers, and updraft
gasifiers are well known as "tarry gas producers." In some applications,
such gasifier systems can be very appropriate, because of their generally
lower capital cost, and their ability to handle a wider range of fuel
sizing and moisture content. Such gases can often be burned directly, without
need for tar removal. TLUD stoves, which are basically "an updraft gasifier
with a build-in burner to destroy the tars" are an excellent example of a
gasification system where tarry gas is not a problem. If one wants to
pipe such gas to a burner at a distance from the gasifier, then tar
build-up in piping is likely to be a problem. Water quenching of such gas will
remove many of the tars, ash and char that cause pipes to plug. Then one
has the problem and cost of dealing with the "blackwater." If the problem, and
cost of dealing with it are big enough, then it may be better to employ a
different gasifier, and different fuel preparation techniques, to produce
a gas with an acceptable tar level. </FONT></DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57><FONT face=Arial></FONT> </DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57><FONT face=Arial>Best wishes,</FONT></DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57><FONT face=Arial></FONT> </DIV>
<DIV
style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt"
class=yui_3_7_2_29_1359847868608_57><FONT face=Arial>Kevin</FONT></DIV>
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