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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Ron,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I am not involved in the web site and my work is well beyond what is in it at the moment. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I was wrong in thinking the tongue depressor was a measure of heat. Rather a measure of percent pyrolyzed (or inverse torrefied) when surface area or weight is used. Other measurements are Color change (shades of gray) at low temperatures determine temperature, change in pressure to break with description of the break determine structure breakdown and , perhaps FTIR when I learn more about what it can do. So all the above can be calibrated using simple equipment (except FTIR). <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>It seems to me that to determine if it is worthwhile to torrefy before making char that we need to know which feature change occurs that may make it worthwhile. Plot a curve of trucking cost vs. weight of biomass. Or cost of energy making pellets vs. torrefication temperatures. Things like that. Then making the new partial torrefied biomass we plot the temperature/time needed against weight loss for transportation and degree of torrefaction required to make pellets at low cost. Then a smart person could overlap the expenses of doing all this and see if they overlap showing it worthwhile. Being able to control the temperature and time during the process will be a challenge IMO as so much happens between 250c and 450c. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The whole idea of torrefaction is confusing to me. Once wood loses weight after moisture it should be ‘torrefied’ up to weight becoming stabilized (~450c). where it is now biochar IMO. I’m just learning how to spell the words and trying to understand what they mean. That’s harder for me than developing a test to determine degree of torrefication. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>And any correction of my spelling and meaning of these words is very well appreciated. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Regards<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Frank<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Frank Shields<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>42 Hangar Way<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Watsonville, CA 95076<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>(831) 724-5244 tel<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>(831) 724-3188 fax<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>frank@bioCharlab.com<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> stoves-bounces@lists.bioenergylists.org [mailto:stoves-bounces@lists.bioenergylists.org] <b>On Behalf Of </b>rongretlarson@comcast.net<br><b>Sent:</b> Saturday, February 25, 2012 12:46 PM<br><b>To:</b> Discussion of biomass cooking stoves<br><b>Cc:</b> Hugh McLaughlin<br><b>Subject:</b> Re: [Stoves] Is there a role for combining torrefaction and char-making stoves?<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-family:"Arial","sans-serif";color:black'>Frank: (and ccs)<br><br> I'm enjoying this dialog. I see why you are thinking dimensions rather than weight - but change in total weight still seems to be a statistic of interest to torrefaction researchers.. Your suggestion (last time) for using tongue depressors for char-making stove development is very useful. <br><br> I have now (for the first time) wandered around your several test description pages. You have an amazingly diverse wet of tests and client-types. On this list, I think it OK for you to describe (promote) your business a little more, if I initiate the question.<br><br> Nowhere did I see the words "Torrefaction testing". Have you been describing in this thread the development of some new (independent lab) test needs for (I now see, presumably) many emerging torrefaction companies?<br><br> Any comments on the appropriateness in developing countries of torrefied (and maybe pelletized) materials for char-making stoves? Do you think it possible that women with such stoves could in some circumstances make rather than expend money while cooking? Or better to think that with unprocessed input fuels only (I'm thinking transport costs as well).<br><br>Ron<br><br><o:p></o:p></span></p><div class=MsoNormal align=center style='text-align:center'><span style='font-family:"Arial","sans-serif";color:black'><hr size=2 width="100%" align=center id=zwchr></span></div><p class=MsoNormal><b><span style='font-family:"Arial","sans-serif";color:black'>From: </span></b><span style='font-family:"Arial","sans-serif";color:black'>"Frank Shields" <<a href="mailto:frank@compostlab.com">frank@compostlab.com</a>><br><b>To: </b>"Discussion of biomass cooking stoves" <<a href="mailto:stoves@lists.bioenergylists.org">stoves@lists.bioenergylists.org</a>><br><b>Cc: </b>"Hugh McLaughlin" <<a href="mailto:wastemin@charter.net">wastemin@charter.net</a>><br><b>Sent: </b>Saturday, February 25, 2012 1:01:47 PM<br><b>Subject: </b>Re: [Stoves] Is there a role for combining torrefaction and char-making stoves?<br><br><br><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Ron,</span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><snip></span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I think shape is better as it can fine tune the variation in temperature along the TD. Also weights of tars that may collect on the stick will not be an error if size is the measure. </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>It seems from the links that it will come to a constant size (or weight) if given enough time. But for shorter burst of a temperature it will not be accurate (as you suggest). I guess it is an average temperature for a given time. </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Regards</span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Frank</span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Frank Shields</span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>42 Hangar Way</span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Watsonville, CA 95076</span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>(831) 724-5244 tel</span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>(831) 724-3188 fax</span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><a href="mailto:frank@bioCharlab.com">frank@bioCharlab.com</a></span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> </span><span style='color:black'><o:p></o:p></span></p><div><div><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-family:"Arial","sans-serif";color:black'>1. I agree that the tongue depressor changes in shape sound like a very useful (and cheap at not much more than 1 cent each) diagnostic tool at these low temperatures. Especially they seem useful in identifying temperature differences at different retort locations. But after that problem is solved, it would seem that weight loss (as opposed to dimensions) should be a fairly direct indicator of temperature. Have you tried and can report weights for some of your temperatures near torrefaction levels?<br><br>2. I have found a fairly robust (and free) technical literature on torrefaction. The first two I have read are:<br><br>a. <a href="http://www.bioenergytrade.org/downloads/grazkleinschmidtpaper2011.pdf" target="_blank">http://www.bioenergytrade.org/downloads/grazkleinschmidtpaper2011.pdf</a><br><br> Its Table 1 (I couldn't copy, sorry) shows significant (factor of 3?) potential benefits for torrefied pellets over charcoal in volumetric energy density terms. Also benefits over wood and wood pellets in other measures. Although not written for charcoal-making stoves, and specific temperatures are not recommended, I take this paper to be positive towards charcoal-making stove use.<br><br>b. <a href="http://www.dcf.ufla.br/CERNE/artigos/08-01-2010625209%20artigo%20686.pdf" target="_blank">http://www.dcf.ufla.br/CERNE/artigos/08-01-2010625209%20artigo%20686.pdf</a><br> <br> This one is much more technical - and show results for applied temperatures of 220, 250, and 280 degrees C. Exothermicity is not seen at 220, but is at 250 and more at 280. There is a good bit more weight loss at the higher temperature - and possibly there is some advantage in terms of pelletizing. But if one can avoid pelletizing (by starting with short pellet-shaped branch or chip material), It seems like the 250 C temperature could be fine as well - from the authors' perspectives.<br><br> Re Frank's tongue depressors, the change in weight (and dimensions) is seen to be dependent on time as well as temperature - so simply knowing weight loss is not going to provide a unique temperature. Still weight loss is a valuable start - and will give some data. If a retort wall temperature reads 250 C and there has been little weight loss, one will need to wait longer and/or reach a outside higher wall temperature..<br><br>3. I see lots of other responses (thanks) - going to next. (and so truncate this one) So far it lstill ooks like there could be a good application of torrefaction to char-making. Hope someone is trying it out.<br><br>Ron</span><span style='color:black'><o:p></o:p></span></p><div class=MsoNormal align=center style='text-align:center'><span style='font-family:"Arial","sans-serif";color:black'><hr size=2 width="100%" align=center></span></div><p class=MsoNormal style='margin-bottom:12.0pt'><b><span style='font-family:"Arial","sans-serif";color:black'>From: </span></b><span style='font-family:"Arial","sans-serif";color:black'>"Frank Shields" <<a href="mailto:frank@compostlab.com" target="_blank">frank@compostlab.com</a>><br><b>To: </b>"Discussion of biomass cooking stoves" <<a href="mailto:stoves@lists.bioenergylists.org" target="_blank">stoves@lists.bioenergylists.org</a>>, "Paul Olivier" <<a href="mailto:paul.olivier@esrla.com" target="_blank">paul.olivier@esrla.com</a>><br><b>Cc: </b>"Hugh McLaughlin" <<a href="mailto:wastemin@charter.net" target="_blank">wastemin@charter.net</a>><br><b>Sent: </b>Friday, February 24, 2012 1:01:54 PM<br><b>Subject: </b>Re: [Stoves] Is there a role for combining torrefaction and char-making stoves?<br><br>Dear Paul and stovers interest in torrefication or degree of torrefication,<br><br>I have been experimenting with my pipes filled with tongue depressors at<br>different temperatures. Still trying to get a way to verify the temperature<br>reached the range I want. I use McKesson Medi-Pak Standard 6" (15cm) X 0.69"<br>wide.<br><br><a href="http://www.allegromedical.com/browse/browseProducts.do?searchPhrase=tonque+d" target="_blank">http://www.allegromedical.com/browse/browseProducts.do?searchPhrase=tonque+d</a><br>epressors<br><br>These are amazing. They start to shrink at 250c and at 450c are a fraction<br>the size they started. Then they still shrink some and start to curl. But<br>they keep their shape so measurements (length and width) can be made. If the<br>furnace has uneven heat one end will be wider than the other. Best<br>temperature gauge within the torrefied range I have found. My plan is to add<br>one with each biomass or biochar I am charring. First I need to accurately<br>calibrate them. Meaning I need to make sure the ovens are at a constant<br>temperature of my chosen. Using these sticks are showing that is not as easy<br>as I thought with my old ovens. <br><br>Regards<br><br>Frank<br><br><br>Frank Shields<br>42 Hangar Way<br>Watsonville, CA 95076<br>(831) 724-5244 tel<br>(831) 724-3188 fax<br><a href="mailto:frank@bioCharlab.com" target="_blank">frank@bioCharlab.com</a><br><br><br>-----Original Message-----<br>From: <a href="mailto:stoves-bounces@lists.bioenergylists.org" target="_blank">stoves-bounces@lists.bioenergylists.org</a><br><a href="mailto:[mailto:stoves-bounces@lists.bioenergylists.org]" target="_blank">[mailto:stoves-bounces@lists.bioenergylists.org]</a> On Behalf Of Paul S.<br>Anderson<br>Sent: Thursday, February 23, 2012 6:23 PM<br>To: Discussion of biomass cooking stoves; Paul Olivier<br>Cc: Hugh McLaughlin<br>Subject: Re: [Stoves] Is there a role for combining torrefaction and<br>char-making stoves?<br><br>Ronal and all, ( I do not know if other Listservs should be sent a copy.)<br><br>Great topic. I have a little different twist to it.<br><br> <snip></span><span style='color:black'><o:p></o:p></span></p></div></div><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-family:"Arial","sans-serif";color:black'><br>_______________________________________________<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://www.bioenergylists.org/">http://www.bioenergylists.org/</a><o:p></o:p></span></p></div></div></body></html>