Dear Friends First a tip of the hat to Dean for pointing out that stoves can be designed to produce char or not.
I remind everyone to please look at the whole equation of a problem , not just a part and then make claims. In some cases one might want to create char and some not, for example when cooking at a low heat for a long time. >RWL - Crispin, being a climate denier, should not be taken as the final >word on these issues. Biochar in many places is giving a doubling of soil >productivity for centuries not just the first year, when there is a need >for twice as much fuel. I agree with Ron on this: there is a lot of support for the idea that char increases growth of plants. Alex English and I had a long conversation a couple of weeks ago and he report that some plant diseases are limited by an increased ability of the plant to cope with infections if there is char in the soil. Personally I think it has to be in the form of char, not carbon in general. I know some Permaculture stalwarts who think the answer lies in composting done correctly. The point I was making is that claims are being made for char making stoves to simultaneously save fuel, save trees and produce significant amounts of char. The energy and efficiency math does not support this, interesting as char is as a soil amendment. I have already pointed out that in order to get 'meaningful' (as promoted in the literature) quantities of char from a stove means fertilising a potted plant, not a field. > But as Nathan Mulcahy has been emphasizing, the fuels for pyrolyzing >stoves need not be wood at all. And for charcoal consuming stoves - >almost certainly obtained from wood, the gain of pyrolyzing stoves is >even greater. As AD Karve has shown, charcoal fuels can easily be made from agricultural waste and the whole system creates employment as well - basically out of nothing. Let us not toss that system aside too easily. >RWL The last part is indeed true - but I am pretty sure that trees >generally produce more than grasses on an annual basis. It is Roger who has conclusively shown that grasses significantly outperform trees. Melting permafrost allows for a huge increase in biomass per sq metre and the tree line used to be much farther north than it is now only 6000 years ago. One expects that this can also grow grasses for biofuel. Right Roger?? >But grasses are pretty hard to use in all but pyrolyzing stoves. Pelletized grass can be used in any pellet stove or furnace. It is also worth the energy to create the pellets which is harder to say about wood. Regards Crispin _______________________________________________ Stoves mailing list [email protected] http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org http://stoves.bioenergylists.org http://info.bioenergylists.org UNSUBSCRIBE HERE; http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org
