[Default] On Thu, 3 Oct 2013 14:54:21 -0700,"Frank Shields" <[email protected]> wrote: >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.
My understanding is that the pyrolysis is only weakly exothermic between 330 and 450 but the reactions driving this are mostly cracking of pyrolysis products within the bits of wood. There may be small amounts of free oxygen from air in interstitial spaces of the wood that will react with nascent char and produce a small part of this heat but any oxygen already bound to the wood molecule will not contribute to oxidation overall as it is has already given up its bond energy. AJH _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org for more Biomass Cooking Stoves, News and Information see our web site: http://stoves.bioenergylists.org/
