<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=iso-8859-1"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Helvetica;
panose-1:2 11 6 4 2 2 2 2 2 4;}
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman",serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.apple-tab-span
{mso-style-name:apple-tab-span;}
span.apple-converted-space
{mso-style-name:apple-converted-space;}
span.EmailStyle19
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>Dear Rob<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><a href="http://cgpl.iisc.ernet.in/site/Portals/0/Publications/ReferedJournal/PartIExperimentalstudiesonapulverisedfuelstove.pdf">http://cgpl.iisc.ernet.in/site/Portals/0/Publications/ReferedJournal/PartIExperimentalstudiesonapulverisedfuelstove.pdf</a><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>That has the (slow to load) article with a demonstration of how to burn sawdust with multiple vertical holes instead of the more common (VITA Handbook) single vertical with single side channel.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>There are charts of the gasification phase and combustion phase and it seems to me they ran it in TLUD and BLUD fashion. The burn rate seems to be TLUD because it is really constant at 0.11 g/s or 1.6 kW.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>They report the gas phase equivalence ratio but that is such a strange metric for solid fuel it will be better to try to interpret the gas charts and make other calculations.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>There is a very interesting and simple demonstration in Fig 4 of how to tell where the pyrolysis front moved to during 30 minute runs. I suggest anyone who is working on gasifiers look at how that was done with three sheets of paper. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>Then conducted pot swapping tests to detect the heat transfer efficiency under all power conditions (as per CSI-WHT and Indian test 13152). This same approach was used on pellet stoves by Penn Taylor using the Burn Out Test Protocol. See Fig 8.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>The CO measurement method (sample above the stove) like the PM measurements, depends on the room and its air turnover to get a number and that does not translate back to a stove performance metric. They also used a hood to get O2, NOx and O2. This is dangerous because such an approach means the CO2 has to be calculated <i>on the assumption that it is not making char</i>. So the calculated CO/CO2 ratio could be far different from what is assumed. For anyone who tries this, using a scale under the stove, be aware that detecting CO and O2 does not tell you what the CO/CO2 ratio is at any time unless you are burning whole fuel. That is rare in a solid fuel stove. Unfortunately trying to make an accurate mass balance calculation requires that one measures the CO2 as well. Done properly you need CO, CO2, O2 and H2O (vapour). <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>Regards<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>Crispin<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'> Stoves [mailto:stoves-bounces@lists.bioenergylists.org] <b>On Behalf Of </b>Robert Lerner<br><b>Sent:</b> Saturday, May 23, 2015 14:12<br><b>To:</b> Ronal W. Larson<br><b>Cc:</b> Discussion of biomass<br><b>Subject:</b> Re: [Stoves] gasifying sawdust<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks Ron. I posted a few photos here: <a href="https://plus.google.com/photos/112929397141178613286/albums/6074575146282561169">https://plus.google.com/photos/112929397141178613286/albums/6074575146282561169</a>.<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Sorry, I don’t have metrics or performance data. Pressure drop through sawdust can be considerable, so particle size matters. Planer shavings are easier than coarse sawdust. Fine sawdust (e.g. from sander or finish work) is all but impossible. Moisture content was very high (as are most things in the humid tropics!). I recall running exhaust from my Dodge truck through the load to heat-dry it to the point where it could sustain a flame. <o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>The big TLUD It was used to dry/prime an even bigger retort kiln (4M³) filled with damp coarse (up to 30cm dia.) forestry residues, so after pyrolysis we kept the blower going and oxidized the carbon as well, to wring all the heat out of it that we could. When the big retort finally took off, it was pretty amazing. Boys building things and burning stuff…<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>We recently looked at reviving the TLUD design to fire ceramic water filters for CATIS-Mexico (<a href="http://catis-mexico.org/">CATIS-Mexico</a>), but couldn’t fit the TLUD into our budget, so we’re going to fire the filters in a ceramics kiln chamber using a sawdust blower-burner.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Rob <o:p></o:p></p><div><div><div><div><div><div><div><p class=MsoNormal><span style='color:black'>~~~~~~~~~~~~~~~~~~~~~~~<br>Robert A. Lerner<br>Mexico cell: 415-101-4591<br>U.S. direct: 619-618-1248<br>Skype ID: bajarob<br>Rob's <a href="http://www.youtube.com/watch?v=SgwwV6YrWb0">Biochar TED talk</a><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='color:black'>Board member <a href="http://www.catis-mexico.org/">CATIS-Mexico</a><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='color:black'>~~~~~~~~~~~~~~~~~~~~~~~<o:p></o:p></span></p></div></div></div></div></div></div></div><p class=MsoNormal><o:p> </o:p></p><div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal>On May 22, 2015, at 10:16 PM, Ronal W. Larson <<a href="mailto:rongretlarson@comcast.net">rongretlarson@comcast.net</a>> wrote:<o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>Rob and list:<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><span class=apple-tab-span> </span>Sounds like an important advance. Congratulations<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><span class=apple-tab-span> </span>I’ll bet most on the list would like to see your pictures.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><span class=apple-tab-span> </span>What weight of sawdust? The fuel bed height? Times for the pyrolysis front to reach the bottom and for total combustion? Have to change to lots more “primary” after you had made the char? Can you guesstimate the several butterfly ratio settings? Power for the fan/blower? Might you have been able to save the sawdust char if the 4 m3 wood was dry? Any way to describe cleanness of the burns?<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Ron<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On May 22, 2015, at 6:06 PM, Robert Lerner <<a href="mailto:bajarob@gmail.com">bajarob@gmail.com</a>> wrote:<o:p></o:p></p></div><p class=MsoNormal><br><br><o:p></o:p></p><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal>We built a big (1M dia.) fan-forced sawdust TLUD gasifier in Costa Rica, designed by Nikolaus Foidl.<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Used one blower with two butterfly valves—one to balance primary:secondary air ratio, and the other to adjust total airflow. <o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Worked great, though we combusted the char too, because were using the TLUD to dry & prime a 4M³ retort kiln filled with high MC wood. I have pictures.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Rob Lerner<o:p></o:p></p></div><div><div><div><div><div><div><div><div><p class=MsoNormal>~~~~~~~~~~~~~~~~~~~~~~~<br>Robert A. Lerner<br>Mexico cell: 415-101-4591<br>U.S. direct: 619-618-1248<br>Skype ID: bajarob<br>Rob's <a href="http://www.youtube.com/watch?v=SgwwV6YrWb0">Biochar TED talk</a><o:p></o:p></p></div><div><p class=MsoNormal>Board member <a href="http://www.catis-mexico.org/">CATIS-Mexico</a><o:p></o:p></p></div><div><p class=MsoNormal>~~~~~~~~~~~~~~~~~~~~~~~<o:p></o:p></p></div></div></div></div></div></div></div><p class=MsoNormal><o:p> </o:p></p><div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal>On May 22, 2015, at 12:00 PM, <a href="mailto:stoves-request@lists.bioenergylists.org">stoves-request@lists.bioenergylists.org</a> wrote:<o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>Message: 1<br>Date: Thu, 21 May 2015 11:11:33 -0700<br>From: Tom Reed <</span><a href="mailto:tombreed2010@gmail.com"><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>tombreed2010@gmail.com</span></a><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>><br>To: "</span><a href="mailto:stoves@lists.bioenergylists.org"><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>stoves@lists.bioenergylists.org</span></a><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>"<br><span class=apple-tab-span> </span><</span><a href="mailto:stoves@lists.bioenergylists.org"><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>stoves@lists.bioenergylists.org</span></a><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>><br>Subject: [Stoves] Sawdust Gasification<br>Message-ID: <</span><a href="mailto:3B3D1B5B-91C0-408B-8FBE-38ADAE3896A2@gmail.com"><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>3B3D1B5B-91C0-408B-8FBE-38ADAE3896A2@gmail.com</span></a><span style='font-size:9.0pt;font-family:"Helvetica",sans-serif'>><br>Content-Type: text/plain;<span class=apple-tab-span> </span>charset=us-ascii<br><br>Dear List<br><br>One of the benefits of the TLUD stove working on wood chips is that it produces 20% charcoal, which can be sequestered, removing 38 tons of CO2 from circulation for each ton of wood gasified (20% due to formation of charcoal from the lignin and using the gas from the cellulose (renewable) in place of propane, natural gas of coal gas. <br><br>If we could gasify sawdust, it would bring another, typically dry, source of fuel into the picture. However, the particle size of sawdust does not permit TLUD operation. Does anyone have a suggestion of how to gasify sawdust?<br><br>TOM REED<span class=apple-converted-space> </span><br><br>Thomas B Reed<span class=apple-converted-space> </span><br>280 Hardwick Rd<br>Barre, MA 01005<br>508 353 7841</span><o:p></o:p></p></div></blockquote></div><p class=MsoNormal><o:p> </o:p></p></div></div><p class=MsoNormal style='margin-bottom:12.0pt'>_______________________________________________<br>Stoves mailing list<br><br>to Send a Message to the list, use the email address<br><a href="mailto:stoves@lists.bioenergylists.org">stoves@lists.bioenergylists.org</a><br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br><a href="http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org">http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org</a><br><br>for more Biomass Cooking Stoves, News and Information see our web site:<br><a href="http://stoves.bioenergylists.org/">http://stoves.bioenergylists.org/</a><o:p></o:p></p></blockquote></div><p class=MsoNormal><o:p> </o:p></p></div></div></div></div></blockquote></div><p class=MsoNormal><o:p> </o:p></p></div></div></body></html>