Frans,<br><br>When subjected to temperatures greater than 350 C, <br>are you saying that K2O melts but does not vaporize?<br>Are you saying that we end up with melted K2O?<br>If the original coffee husks contains 36% to 38%<br>
then the final biochar must contain at least twice that amount.<br>If this is correct, then coffee husk biochar must be quite valuable,<br>not only as a soil amendment but also as a fertilizer.<br>Surely this cannot be right.<br>
<br>The coffee husk contains some sort of oily substance<br>that begins to volatilize at temperatures as low as 170 C.<br>When gasified it produces a lot of black soot.<br>I tried many burner designs in the last few weeks to get rid of the soot and to turn orange flames into blue.<br>
Supplying hot premixed secondary air does not effectively consume this soot.<br>Sometimes it makes things worse.<br><br>A few days ago I cheated.<br>I mixed coffee husks and rice hulls in equal volumes.<br>(Note that the coffee husk has a bulk density of 180 kg/m3,<br>
while the rice husk has a bulk density of about 100 kg/m3.)<br>The flame at the base was blue and white.<br>
This is the first time I saw the color white in the gasification of coffee husks.<br>As the flame rose, it split into two parts:<br>one part vertical and the other part more horizontal.<br>The vertical part was blue/white and the more horizontal part was orange.<br>
But there were no streaks of black within the orange part of the flame and no visible soot.<br><br>The gasifier that I used looked like this:<br><a href="http://dl.dropbox.com/u/22013094/150%20Gasifier%20Drawings%20PDF/001%20-%20150%20Gasifier%20Assembly.pdf" target="_blank">http://dl.dropbox.com/u/22013094/150%20Gasifier%20Drawings%20PDF/001%20-%20150%20Gasifier%20Assembly.pdf</a><br>
Note the burner design: <br>it is a Belonio burner with two rings of burner holes, together with a burner housing.<br>This burner design gives by far the best result.<br>Secondary air is sucked up between the housing and the burner.<br>
It then moves from vertical to horizontal,<br>and from here it hits the two rings of holes that are offset from one another.<br><br>The best result, of course, is with 100% rice husks.<br>With the current burner design, the flame is totally blue right from the very beginning.<br>
<br>When I mixed rice hulls with coffee husks (half/half by volume),<br>not only does most of the soot disappear, <br>but the burn is quite consistent and steady from beginning to end.<br>
<br>Paul<br><br><br><div class="gmail_quote">On Sun, Oct 16, 2011 at 5:35 AM, Frans Peeters <span dir="ltr"><<a href="mailto:peetersfrans@telenet.be" target="_blank">peetersfrans@telenet.be</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<u></u>
<u></u>
<div link="blue" vlink="blue" lang="NL">
<div>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy">Dear Paul ,<u></u><u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy"> I did many times fusions with pure KOH
.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy">At 350° C it melts and is very aggesive to
dissolve ceramics Al2O3 and SiC powders . (Diamond recup. )<u></u><u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy">It is verry verry hygroscopic and the
hydroxyde airosols with water in the air gives your nose sense alcalic .<u></u><u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy">Your brain makes the link to urine . but
not the real potasium make it .<u></u><u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy">It goes not into gas but sputers airosols
has a special creep effect out of a creuset .! Even after cooling .<u></u><u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy">Also a battery and fuel cel with KOH . It
creeps in a isolated conductor for <u></u>20 cm<u></u> after years ,and destroys manny apparati
.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy">KOH Is colourless but Nickel gives yellow.salts
.<u></u><u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy">It does not become K2O2 becouse to destroy
SiC we must ad Na2O2 to oxydize the carbide .<u></u><u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy">Potasium is to measure with flame spectro
440 um purple colour in a hydrogen flame . (Sodium =yellow . Cupper =green Sr
=red<u></u><u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy">Sorry ,I drink no coffe ! But
have a friend who drinks pee ….<u></u><u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy">Regards<u></u><u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy">Frans<u></u><u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span style="font-size:10.0pt;font-family:Arial;color:navy"><u></u> <u></u></span></font></p>
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<p class="MsoNormal"><b><font face="Tahoma" size="2"><span style="font-size:10.0pt;font-family:Tahoma;font-weight:bold">Van:</span></font></b><font face="Tahoma" size="2"><span style="font-size:10.0pt;font-family:Tahoma">
<a href="mailto:stoves-bounces@lists.bioenergylists.org" target="_blank">stoves-bounces@lists.bioenergylists.org</a>
[mailto:<a href="mailto:stoves-bounces@lists.bioenergylists.org" target="_blank">stoves-bounces@lists.bioenergylists.org</a>] <b><span style="font-weight:bold">Namens </span></b>Paul Olivier<br>
<b><span style="font-weight:bold">Verzonden:</span></b> zaterdag 15 oktober
2011 9:07<br>
<b><span style="font-weight:bold">Aan:</span></b> <u></u>Discussion
of biomass cooking stoves<u></u><br>
<b><span style="font-weight:bold">CC:</span></b> Will Rutherford; loren
cardeli; CHRISTA ROTH<br>
<b><span style="font-weight:bold">Onderwerp:</span></b> [Stoves] why does
coffee husk biochar smell like urine?</span></font><u></u><u></u></p>
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<p class="MsoNormal"><font face="Times New Roman" size="3"><span style="font-size:12.0pt"><u></u> <u></u></span></font></p>
<p class="MsoNormal"><font face="Times New Roman" size="3"><span style="font-size:12.0pt">Christa,<br>
<br>
Do you have any idea why coffee husk biochar smells like urine?<br>
<br>
I just read that coffee husks contain 36% to 38% K2O.<br>
This supposedly accounts for the low melting point of its ash.<br>
That its ash has a low melting point makes sense to me,<br>
since, if I leave the fan on a bit too long after the gasification cycle is
finished,<br>
I see a stony yellowish/white ash at the bottom of the reactor.<br>
<br>
How is this possible that coffee husks could have so much K2O?<br>
What happens to the K2O when it is subjected to heat?<br>
I see that K2O has a melting point > <u></u>350C<u></u>.<br>
If subjected to heat does it turn into K2O2 or even KO2?<br>
At what point does it turn into a gas?<br>
<br>
Does the presence of K2O account for its urine smell?<br>
What does this urine smell mean with regard to the value of coffee husk
biochar?<br>
Would coffee husk biochar be rich in potassium?<br clear="all">
<br>
Paul<br>
-- <br>
Paul A. Olivier <br>
27C Pham Hong Thai Street<br>
Dalat<br>
Vietnam<br>
<br>
<u></u><u></u></span></font></p>
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<br></blockquote></div><br><br clear="all"><br>-- <br>Paul A. Olivier PhD<br>27C Pham Hong Thai Street<br>Dalat<br>Vietnam<br><br>Louisiana telephone: 1-337-447-4124 (rings Vietnam)<br>Mobile: 090-694-1573 (in Vietnam)<br>
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