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<DIV>Regarding the activation of charcoal, I read somewhere that charcoal could
be reactivated in a micro wave oven, If this is the case any water trapped
within it would turn to superheated steam and push out impurities after which it
would simply evaporate. leaving the charcoal extremely hot??</DIV>
<DIV> </DIV>
<DIV>GF</DIV>
<DIV> </DIV>
<DIV>
<DIV>In a message dated 2/21/2012 7:00:10 A.M. Eastern Standard Time,
english@kingston.net writes:</DIV>
<BLOCKQUOTE
style="BORDER-LEFT: blue 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px"><FONT
style="BACKGROUND-COLOR: transparent" color=#000000 size=2
face=Arial>Darius,<BR>TLUD char is said to have good surface area and sorption
properties. Using the TLUD camp stove you may be able to enhance this by
simply increasing underfire air briefly at the end of the burn cycle. You will
loose a bit of yield but you will also spike the temperature and flush the
newly formed hot char with CO and CO2 which can have an activating
effect.<BR><BR>Page 34 of <A
title=http://www.biochar-international.org/sites/default/files/All-Biochars--Version2--Oct2009.pdf
href="http://www.biochar-international.org/sites/default/files/All-Biochars--Version2--Oct2009.pdf">http://www.biochar-international.org/sites/default/files/All-Biochars--Version2--Oct2009.pdf</A><BR>describes
a simple test that we have used to test our char. It seems to have some value
but more public data points would be useful. Although our char had only one
fifth the weight gain of a high quality AC they performed more equally in
a field trial to adsorb a toxin. Although our char is not made in a TLUD
it does experience a brief CO-CO2 flush at approximately 800C .<BR><BR>Thanks
to all for contributions to this thread.<BR>Alex English<BR><BR><BR>On
20/02/2012 11:06 PM, Bruno M. wrote:
<BLOCKQUOTE cite=mid:4F43183C.8020402@telenet.be type="cite">Hi
Anand,<BR><BR>i think you made a bunch of good ( & cheap) suggestions to
Darius,<BR>Calcium Chloride is probably one of the cheapest ( cheaper and
easier to get the K2CO3),<BR>since it is common used as a deicing salt on
roads ( up to -20°C) and also<BR>in household humidity absorbers ( &
odor eliminator) like eg: <A class=moz-txt-link-freetext
title=http://www.damprid.com/faq# href="http://www.damprid.com/faq#"
moz-do-not-send="true">http://www.damprid.com/faq#</A> ) <BR>but its
very hygroscopic, need to be stored dry and in closed containers,<BR>so i
guess you can't soak your biomass in a 25% solution and then hoping it to
dry in the sun<BR>( in an humid climate ), but 5% may do fine.<BR><BR><A
class=moz-txt-link-freetext
title=http://en.wikipedia.org/wiki/Calcium_chloride
href="http://en.wikipedia.org/wiki/Calcium_chloride"
moz-do-not-send="true">http://en.wikipedia.org/wiki/Calcium_chloride</A><BR>Safety:
Calcium chloride can get very hot when mixed ( concentrated) in water, and
the dust is an irritant.<BR><BR>But there are many sources of material to
make charcoal from and<BR>even so many ways to active those
carbons.<BR><BR>My guess is too, that for good activated carbon you need to
start from good char,<BR>that means char made at higher temperatures (
higher temp then normally needed for bio-char )<BR>800-900 °C. & you
like to have low ash content.<BR><BR>Maybe Darius this may also be of
interest to you:<BR><A class=moz-txt-link-abbreviated
title=http://www.vcharkarn.com/uploads/78/79040.pdf
href="http://www.vcharkarn.com/uploads/78/79040.pdf"
moz-do-not-send="true">www.vcharkarn.com/uploads/78/79040.pdf</A><BR><BR><A
class=moz-txt-link-freetext
title="http://revroum.getion.ro/wp-content/uploads/2010/RRCh_6_2010/Art 02.pdf"
href="http://revroum.getion.ro/wp-content/uploads/2010/RRCh_6_2010/Art%2002.pdf"
moz-do-not-send="true">http://revroum.getion.ro/wp-content/uploads/2010/RRCh_6_2010/Art%2002.pdf</A><BR><BR>Ones
you've done the activation step on your AC,<BR>you will not know HOW active
your char is, compared to <BR>commercial AC, & that also depends on your
purpose for this AC,<BR>so you'll need some testing of the AC.<BR>Here an
example of a big lab specific known for his AC testing service,<BR>with
price indication, just you know which kind of test could be done on
it.<BR><A class=moz-txt-link-freetext
title=http://pacslabs.com/activatedcarbon/actesting.php
href="http://pacslabs.com/activatedcarbon/actesting.php"
moz-do-not-send="true">http://pacslabs.com/activatedcarbon/actesting.php</A><BR><BR>An
example of analyzing different AC made from bagasse:<BR><CITE><A
class=moz-txt-link-abbreviated
title=http://www.waset.org/journals/waset/v34/v34-36.pdf
href="http://www.waset.org/journals/waset/v34/v34-36.pdf"
moz-do-not-send="true">www.waset.org/journals/waset/v34/v34-36.pdf</A><BR><BR></CITE>A
rather simple but much used test, is the 'iodine number' or 'iodine capacity
number',<BR>if you do this on a before and after the activation sample you
get a good impression<BR>of how much more active area has become
available.<BR>I guess this can be done on a small budget, and without
complex apparatus.<BR>Here is the ASTM Designation: D4607-94<BR><A
class=moz-txt-link-abbreviated
title="http://www.czsochem.com.cn/download/ASTM Iodine test.doc"
href="http://www.czsochem.com.cn/download/ASTM%20Iodine%20test.doc"
moz-do-not-send="true">www.czsochem.com.cn/download/ASTM%20Iodine%20test.doc</A><BR><BR>you
may need more tests.<BR><BR>When we know more of the purpose of your AC, and
the scale<BR>of your operation we may be able to give more precise advice
& tips, i guess.<BR><BR>Grts<BR>Bruno M.<BR>(
chemist)<BR></BLOCKQUOTE><BR><BR><BR>_______________________________________________<BR>Gasification
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