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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal>Dear Friends of Clean Cooking<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have just reviewed another stove with a particulate production number that is very low. Any test result this clean is always suspect so hold the salt shaker, but we have more tests to analyse. <o:p></o:p></p><p class=MsoNormal style='background:white'><o:p> </o:p></p><p class=MsoNormal style='background:white'>The PM<sub>2.5</sub>/MJ<sub>NET</sub> is between 2 and 3 mg/MJ<sub>NET</sub>. That is lower than the claim from India for LPG which is 8 mg/MJ<sub>NET</sub>.<span style='font-family:"helvetica neue",serif;color:black;mso-fareast-language:EN-CA'><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>It is a pellet burner with power controllable across the range of 1 to 2.3 kW. That is calculated on a 3 minute smoothed average. The fuel is Albasia Pellets which is the only type available in Central Java. The moisture level is 5.6%. Sometimes it is a little higher, towards 8%. In the past few months it has always been between 5.5 and 6%.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The importance of this is not just this particular stove, it is the demonstration that biomass can be burned with extremely low emissions in a relatively inexpensive natural draft stove. Remember, this is the second stove seen recently that outperformed any fan stove I have seen. Fans tend to stir up particles, lofting them on the high velocity air giving elevated PM<sub>2.5</sub> and PM<sub>4</sub> readings. PM<sub>4</sub> is unusual in natural draft stoves.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The oft-repeated claim that a stove needs a fan in order to be ‘really clean’ seems to be the old thinking now. The reduction measured against the baseline (burning wood, not pellets) is over 99%. At this low level we have to quibble over the precision. Let’s just say that after 4 minutes from ignition the PM level is very low.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The test duration is about 80 minutes and involves replication the cooking behaviour in Central Java. The stove is made in Indonesia. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The system efficiency (energy in the fuel loaded v.s. the energy in the pot) is just over 30%. The thermal efficiency (energy in the fuel completely combusted v.s. the energy in the pot) is just over 43%. The average Heat Transfer Efficiency was 44.7%, with the low power average being 46.5%. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Just to give you a picture of CO, the CO/CO<sub>2</sub> ratio at low power was 1.0%, rising with firepower. The CO/MJ<sub>NET</sub> was between 3 and 4 g so it can still be improved.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Regards<o:p></o:p></p><p class=MsoNormal>Crispin in Accra with a pile of friends<o:p></o:p></p></div></body></html>