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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Ron, and stovers,<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><snip><o:p></o:p></span></b></p><div><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><i><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>[Frank >] The only thing that matters is us all being able to come up with the same number. If we all have a TGA and its calibrated we should be able to send a sample to a bunch of labs and they all report back the same number for E450c. It’s this value we give to the fuel. If during the testing we use larger fuels pieces that take longer for them to reach 450c in the field it doesn’t matter. We go as long as the secondary flame is still there because when that goes out nothing happens no matter how much un-burned fuel is left. That just means the stove is designed for smaller pieces or different biomass or a re-design needed to handle the larger pieces. The efficiency goes down because of that. It’s the same as if the stove needs better insulation or a change in the gap. <o:p></o:p></span></i></b></p><p class=MsoNormal><b><i><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> <o:p></o:p></span></i></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>In most situations char is of secondary concern with the first being what the task of the secondary flame is being used for. If your main concern is char and its quality, that is a different task. You want to know the efficiency of making the best quality char. Meaning the E450c used from the pile (weight) to produce good quality char. So you determine the E450c used for different configurations and compare the different chars produced for quality. Then determine the E450c needed to produce that best char (task). <o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Regards<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Frank<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>Frank Shields<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>Control Laboratories; Inc.<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>42 Hangar Way<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>Watsonville, CA 95076<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>(831) 724-5422 tel<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>(831) 724-3188 fax<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>frank@biocharlab.com<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>www.controllabs.com<o:p></o:p></span></b></p></div><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><div><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white'> </span>That is as simple a measurement as you can find. Granted that most of the weight loss is before 450 C, the weight is NOT constant as you keep going higher in temperature You will have a fair shot at the temperature achieved by measuring the weights in and out. But temp is not the only variable, there is also the time at temperature, the size of the fuel etc. See material in the Gaur-Reed Chapter 8.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal> I know people are trying hard to determine the peak pyrolysis temperature from the characteristics of the char - besides weight differences, there is density, water-adsorbing properties, pH, and electrical conductivity in the "simple" (poor man) category. Some big changes in conductivity can occur above a certain temp. Many people would like to know the CEC characteristics, but I know nothing on that measurement.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal> I guess I am saying that the stove itself might serve as the "pipe" you are describing. If you have a good guess at the temperature of the produced char, you have a reasonable estimate of its remaining energy content, which is what I guess you are after. I don't have much hope that any test with a "pipe" is going to tell you much about a particular stove.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal> But mainly, I urge you to keep measuring the weight of the char. You will not understand much about a char-making stove if you don't know the weight of the produced char.<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> <o:p></o:p></p><div><div><p class=MsoNormal>On Oct 3, 2013, at 3:54 PM, Frank Shields <<a href="mailto:frank@compostlab.com">frank@compostlab.com</a>> wrote:<o:p></o:p></p></div><p class=MsoNormal><br><br><o:p></o:p></p><div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'>Greetings Stovers,</span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'> </span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'>Tom Reed coauthored a book tilted An Atlas of Thermal Data (link below) that explains the results of Thermogravimetric data on a wide variety of biomass under different conditions. The results show a rapid decrease in weight that then stabilizes around the 400c and mostly completed at 450c. Using Thermogravimetric analysis (TGA) on biomass can separate the fuel into two distinct and repeatable fractions. The one fraction between ambient temperature to 450c we know will be used during cooking as once this restively low temperature is reached it has volatilized. It needs no oxygen from outside and gets it all from the fuel to form a gas then secondary air to completely combust. The fraction of fuel left above 450c contains energy that may be used or left after cooking. To compare efficiencies of stoves it seems to me we just need to use the energy of the biomass fraction we know will be used and use that value as the energy provided. If a stove is designed to use some char as added energy all the better for that stove. We do not need to determine the char left in the stove. We need to decide to use HHV or LHV but since we are not testing for hydrogen and just using an agreed upon value it doesn’t matter – as I see it.</span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'> </span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'>The Rich Man:</span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'>Needs a (1) calorimeter to determine the total energy HHV of the fuel and then used to determine the energy of the char left (remaining in the TGA). The energy in the fraction volatilized below 450c. is then calculated. Rich people need a (2) TGA to get an accurate value of the weight fraction containing the energy used from the dry biomass. Very accurately heat to 450c in nitrogen then cool and char removed for calorimeter.</span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'> </span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'>The Poor Man:</span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'>Needs a (1) look-up table of the total energy of the fuel and a (2) pipe of fuel to heat up to determine the weight of fraction in the char left. The energy of the char is looked up in the look up table to be able to determine the energy fraction of the fuel that is used in the stove comparison. Notice in Tom Reeds book that after 400c the weight stabilizes so as long as the pipe is heated to 450c or higher there will be little error. Error relative to other methods suggested and everyone can do the tests. Except for those where a look-up table will not work like Richard’s briquettes or where mixed biomass is used will need the more expensive equipment. .</span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'> </span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'><a href="http://www.nrel.gov/docs/legosti/old/7965.pdf"><span style='color:purple'>www.nrel.gov/docs/legosti/old/7965.pdf</span></a></span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'> </span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'> </span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white'><a href="http://www.tainstruments.com/product.aspx?siteid=11&id=11&n=1"><span style='color:purple'>www.tainstruments.com/product.aspx?siteid=11&id=11&n=1</span></a></span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white'> </span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white'>Understanding the complete process of a stove and all the reactions taken place is well worth studying and should continue. But for the sake of comparing stoves we need a foolproof procedure – it seems to me.</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white'> </span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white'>Thanks</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white'> </span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white'>Frank</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white'> </span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><cite><span style='font-size:10.5pt;font-family:"Arial","sans-serif";color:#00802A;background:white;font-style:normal'> </span></cite><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Brussels","serif"'> </span></b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Brussels","serif"'> </span></b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif"'>Frank Shields</span></b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif"'>Control Laboratories; Inc.</span></b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif"'>42 Hangar Way</span></b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif"'>Watsonville, CA 95076</span></b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif"'>(831) 724-5422 tel</span></b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif"'>(831) 724-3188 fax</span></b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif"'><a href="mailto:frank@biocharlab.com"><span style='color:purple'>frank@biocharlab.com</span></a></span></b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif"'><a href="http://www.controllabs.com"><span style='color:purple'>www.controllabs.com</span></a></span></b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> <o:p></o:p></span></p></div><p class=MsoNormal style='margin-bottom:13.5pt'><span style='font-size:13.5pt;font-family:"Helvetica","sans-serif"'>_______________________________________________<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"><span style='color:purple'>stoves@lists.bioenergylists.org</span></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"><span style='color:purple'>http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org</span></a><br><br>for more Biomass Cooking Stoves, News and Information see our web site:<br><a href="http://stoves.bioenergylists.org/"><span style='color:purple'>http://stoves.bioenergylists.org/</span></a><o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p></div></div></body></html>