Hi David
A person expends about 13 MJ per day or 150W. I still don’t understand why you relate this fact to the energy required for a rocket/gasification stove or a solar concentrator to boil water??? In either case the energy is coming from the Sun and not from people (people also expend stored up solar energy). The system could be made to automatically boil water without human intervention and something I’m working on. The CaCl2 can be put at any height (within reason) where it takes water out of the air and offers potential energy that can be exploited. Taking water out of the air is easy in a humid place like the Philippines, but it will take longer in an arid place like a desert with low relative humidity. It’s about the amount of CaCl2 present, relative humidity, and the target amount of water needed. In arid places we will need more CaCl2 (I don’t know how much) than in a place like the Philippines. In any case once we have CaCl2 we will never need more as long as the mixture isn’t spilled due to rain or whatever. We have CaCl2 in a lot of excess and the concentration wouldn’t be much affected when in use by emptying the concentrated CaCl2 solution back into the dilute solution. As a note I’ll use a rocket stove to start. We have a lot of coconut husks just laying around and I’ll probably get an award for burning them up. Have you heard about black soil which is just charcoal that an ancient culture had a lot of success growing crops in it? If you have gasification stove it would give you something to do with the resultant charcoal. Ken Gotberg --- On Tue, 8/10/10, David G. LeVine <[email protected]> wrote: From: David G. LeVine <[email protected]> Subject: Re: [Gasification] Can use some help with stoves To: "Discussion of biomass pyrolysis and gasification" <[email protected]> Date: Tuesday, August 10, 2010, 4:01 PM Okay, and the 1° C/1 gm/1 cal holds ONLY for water, not water mixed with CaCl2, nor does the boiling point stay constant with changing concentrations. Yes, the heat required to change water from fluid to gas at 100° C should be an approximation close to 2.2 MJ/L, but the temperature may need to be much higher, or the CaCl2 may have a different specific heat, let's use 2-3 MJ/L as an engineering approximation. At 2 MJ/L, you will need 8 MJ/person/day, at 3 MJ/L, 12 MJ/person/day. Is this correct? That looks like 3 KWH/person/day, assuming 100% efficiency, just to make water vapor. Then there is the cooling (since humans do not do well with 100° C live steam), which requires energy. For a family of 4 at 10 KWH/day/person means (with a solar efficiency of under 25%) 40 KWH/day/person, 160 KWH/day incident radiation. I bet your proposed system is less than 25% efficient and 160 KWH/day represents a large area. _______________________________________________ Gasification mailing list [email protected] http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org http://gasifiers.bioenergylists.org http://info.bioenergylists.org _______________________________________________ Gasification mailing list [email protected] http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org http://gasifiers.bioenergylists.org http://info.bioenergylists.org
