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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>Dear Roberto<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>It is unlikely that you will be able to burn charcoal without any CO2 at all. In the centre of a charcoal flame, under the middle of the pot, there is often a very high CO2 level, but it is so hot, excess C is available and it is absent of free oxygen so it breaks apart to make 2 CO. <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>If you can estimate the mass of CO2 and the mass of CO you can calculate the difference. C to CO2 is 33 MJ/kg (close enough) and C to CO is a bit more than 8. So you lose ¾ of the available heat energy if you fail to burn the CO to CO2.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>For 600m of char, (assuming 85% carbon) the loss would be 32.8 x 0.85 x 0.75 x 0.600 = 12.6 MJ loss<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Or 29.5 MJ/kg for the char x 0.6 kg to get the available heat = 17.7 MJ<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>And<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Subtract the CO loss: 0.600 kg x 0.85 carbon x 75% x 32.9 carbon heat = 12.6MJ loss, the same thing. Heat released by burning C to CO = 5.1 MJ. <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>If you have a portion of the gas as CO2 and another as CO, you can pro-rate the heat available as ‘yielded’ or ‘lost’ according to CO/(CO2+CO) and CO2/(CO+CO2) times the carbon mass times 32.9 MJ/kg.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>The CO loss is closer to 74.5 % of the CO2 energy if you really want to be picky.</span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Regards<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Crispin<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Hi,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>I want to know what is the difference in combustion efficiency between burning charcoal with secondary flame (burning CO) vs burning without secondary flame (CO escape to the chimney).<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>For example, burning 3 kg in a TLUD produce 600 grs of charcoal. Then if we decide to burn this charcoal, burning with secondary flame is more efficient than burning charcoal with no secondary flame.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>How can I measure this difference?<o:p></o:p></span></p><p class=MsoNormal><b><span lang=EN-US style='font-size:12.0pt;font-family:"Arial",sans-serif;color:#000099;mso-fareast-language:ES-CL'><o:p> </o:p></span></b></p><p class=MsoNormal><span lang=EN-US>Greetings<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Roberto Poehlmann<o:p></o:p></span></p></div></body></html>