Dear Ron and Nat and All Thanks for the updates and eyes open reports. Something I feel it is worth repeating is that the time taken to break down the oils necessarily means something has to be done to maintain the high temperatures needed to do this.
A month ago a class of stove students here in Ulaanbaatar tried two different coals which had different oil levels (hydrocarbons). One is from Baganuur which is a popular source for domestic heating and power station coal. The top levels of the coal are very young and hardly consolidated at all. Some of the coal resembled wood fibre board that has been soaked in water. Dreadful, weak and oily. The flame in an enclosed but large space is about a foot long. That is the 'time' taken to break down the long chain hydrocarbons. It is a distance but is really related to time and temperature. We were unable to get the traditional stove with its enclosed but relatively large internal space to break down the oil. it smoked slightly even if left for a long time (an hour). Only once the level of volatiles had dropped did it get completely clean. The CO/CO2 ratio during this time was about 2 to 3% indicating partial combustion of the carbon. Later we burned the same coal during the demonstration of a 9 kW downdraft stove that was based on a long 65mm steel pipe. The 'combustion chamber' is effectively a long 2-1/2 inch pipe. Thus constrained, and heated by the hot walls, the oil was able to completely break down immediately, meaning from seconds after being lit. The turbulence level is high and the CO/CO2 ratio dropped rapidly to less than 1% settling at 0.11% after less than 30 minutes from the match. It is interesting that a clean burn can be achieved with a very different technique which Nat is using: slow heating and relatively low velocity but good mixing when hot to ensure the oil breaks down before getting to the flame. Two very different approaches with good results! Love it! Regards Crispin -----Original Message----- Hi Nat and all: I am not too surprised to hear of the success with an oil seed cake. Only in the last year did I become aware of the ease in lighting up a single peanut (held with needle nose pliers). I recommend all observing how pyrolysis works nicely (lengthily) with such an oily fuel. (Remember Nat is only doing pyrolysis.). What a waste that this wonderful fuel has just been torched to get rid of it! Ron _______________________________________________ Stoves mailing list [email protected] http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org http://stoves.bioenergylists.org http://info.bioenergylists.org
