FYI: In addition to being toxic when ingested (as previously discussed), some phorbol esters can activate tumors. Although compounds may break down during the normal cycle of the stove, they may not when it is being lit. When testing the toxicity of emissions from J stoves, we must test at the various times during pyrolysis. In my opinion we should be extremely cautious regarding the toxicity before promoting this stuff. If you are interested in literature on the toxicity of Jatropha, Harrinder Makkar at the University of Hoffenheim has published a significant amount.<br>
<br>Boston<br><br><br><div class="gmail_quote">On Tue, Aug 16, 2011 at 10:11 PM, Crispin Pemberton-Pigott <span dir="ltr"><<a href="mailto:crispinpigott@gmail.com" target="_blank">crispinpigott@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div link="blue" vlink="purple" lang="EN-CA"><div><p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">Dear Roger<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"><u></u> <u></u></span></p>
<div><div><p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 10pt; color: rgb(31, 73, 125);">></span><span style="font-size: 10pt;">I am curious if this "log" was an extruded or pressed product. <span style="color: rgb(31, 73, 125);"><u></u><u></u></span></span></p>
</div><p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">It is a pressed/extruded log (same thing) using no binder save the lignin in the material. The diameter is about 110 mm and the length about 250/300mm – will check.<u></u><u></u></span></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">The colour is ‘pine’ so I would say, golden.<u></u><u></u></span></p><p class="MsoNormal" style="margin-bottom: 12pt;">
<span style="font-size: 10pt; color: rgb(31, 73, 125);">>…</span><span style="font-size: 10pt;">The moisture content is known to be about 8%. <span style="color: rgb(31, 73, 125);"><u></u><u></u></span></span></p><p class="MsoNormal" style="margin-bottom: 12pt;">
<span style="font-size: 11pt; color: rgb(31, 73, 125);">It varies with storage. The production process dries the wood almost completely (hot) and it picks up some moisture after that.<u></u><u></u></span></p><div>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 10pt; color: rgb(31, 73, 125);">></span><span style="font-size: 10pt;">It is approx 8500 btu/lb, <span style="color: rgb(31, 73, 125);"><u></u><u></u></span></span></p>
</div><p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">That would be 8500 x 1055 x 2.2046 (lbs/kg) = 19.8 MJ per kg which is definitely a ‘dried’ energy content.<u></u><u></u></span></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">With 8% moisture it is about 17 MJ/kg for typical hardwood.<u></u><u></u></span></p><p class="MsoNormal" style="margin-bottom: 12pt;">
<span style="font-size: 10pt; color: rgb(31, 73, 125);">>…</span><span style="font-size: 10pt;">and gives a burn time of up to 12 hours (in our stove) <span style="color: rgb(31, 73, 125);"><u></u><u></u></span></span></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">It is important that you express this burn time together with a kW rating (or BTU if you can work that out instead).<u></u><u></u></span></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">A couple of contributors explained this before but here is a repeat:<u></u><u></u></span></p><p class="MsoNormal" style="margin-bottom: 12pt;">
<span style="font-size: 11pt; color: rgb(31, 73, 125);">8500 BTU’s / lb in the 2.2 kg log.<u></u><u></u></span></p><p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">That is 8500 x 1055 x 2.2 = 43,493,000 Joules total heat content (43.4 MJ)<u></u><u></u></span></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">One Watt is 1 joule per second of energy.<u></u><u></u></span></p><p class="MsoNormal" style="margin-bottom: 12pt;">
<span style="font-size: 11pt; color: rgb(31, 73, 125);">12 hours = 12 x 60 minutes x 60 seconds = 43,200 seconds.<u></u><u></u></span></p><p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">43,493,000 Joules / 43,200 seconds = 1007 Watts average heat output on a continuous basis. That is the same as saying ‘the power output is 1 kW’ average.<u></u><u></u></span></p>
<div><p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 10pt; color: rgb(31, 73, 125);">></span><span style="font-size: 10pt;">Funny thing is I get more smoke at a higher heat output than the medium to lower end. <span style="color: rgb(31, 73, 125);"><u></u><u></u></span></span></p>
</div><p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">That has to do with the availability of secondary air and the combustion environment (including its physical size).<u></u><u></u></span></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 10pt; color: rgb(31, 73, 125);">></span><span style="font-size: 10pt;">Estimated <span style="color: rgb(31, 73, 125);">[heat] </span>output at 27,000 high, 5,000 btu low output. <span style="color: rgb(31, 73, 125);"><u></u><u></u></span></span></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">Per what? Per hour? Per day? It is not clear. 5000 BTU’s is 5.275 MJ. If that was per hour, it is 1.465 kW. The 27,000 = 7.9 kW. If it takes 12 hours to burn the log, (and in fact there is still some coals left) it averages 1 kW heat output average.<u></u><u></u></span></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">An earlier point I was making about Mongolian space heating is that the homes need between 4 and 12 kW on a continuous basis. We would need to burn at about your ‘medium’ power level continuously to keep the place warm. The largest stoves we work with in homes are 20 kW, equivalent to about 1.3 kg of wood per hour (depending on the moisture content).<u></u><u></u></span></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">Any stove sold there has to be able to cook a 16 inch diameter wok, and to boil 9 litres of water (in the wok) in less than 1.5 hours from ignition (or it won’t be considered at all for the programme). Some stoves can boil it in 30 minutes, but 90 is the upper limit. Mass production facilities are available. It has to retail under $150.<u></u><u></u></span></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">Good luck with the EPA testing and alla that. Please keep us informed about how it goes.<u></u><u></u></span></p><p class="MsoNormal" style="margin-bottom: 12pt;">
<span style="font-size: 11pt; color: rgb(31, 73, 125);">Crispin<u></u><u></u></span></p></div></div></div><br>_______________________________________________<br>
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