Dear Tom and Frank
>Unless there is further interest from the stoves community this discussion should move to the biochar list. There is a desperately needed set of data which directly relates to stoves. We do not have a clue what the composition of the fuel is as it degrades from wood to pure (?) charcoal at, say, 650 C. Frank I was wondering last night if you could do a set of simple experiments with your perforated pipes, some wood species and the CN analyser. If you heat something in a furnace, the penetration rate of heat into steel is about 1 inch per hour at 900 C. Keeping that in mind, you can easily put some samples into the oven at 100, 200, 300, 400 and so on then run a CN analysis on it. The point is to find out when leaves the fuel and when. If the biochar people come back with a typical analysis for good performance under certain conditions, we will have a head start on producing that they want. See the recent message looking for a much larger pyrolysis unit. So, what do you think? The importance for me is this: with a combination of your total C analysis at each stage, and a separate test for 'volatiles remaining' it will be possible to deduce some of the composition of the fuel as it burns. The analyses I have seen so far are limited to the 'coal type' assessments of volatiles and 'fixed carbon'. So they are basically useless because they contain nearly no information about elemental composition. Because we know the H2 content of the biomass to begin with, then loss of mass is related to the loss of H2, O2 and C. You have to start with dry fuel (100% dry) and get the mass. After that we can do clever things with the mass and the total C remaining. You can publish it! Regards Crispin
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