All distillation is dependent on a heat source and a heat sink and the difference between their two temperatures. Multiple effect evaporators can have up to ten stages or more (if one can afford the hardware); fractional distillation usually requires high reflux rates. Vacuum exists to remove non-condensibles. It's the delta-T that, ultimately determines the overall efficiency; a sub-atmospheric operating pressures primarily makes heat exchange surfaces more efficient, according to Fourier's law which states that heat transfer across a given area is proportional to delta-T. Best, Mark
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of David G. LeVine Sent: Saturday, August 07, 2010 12:18 PM To: Discussion of biomass pyrolysis and gasification Subject: Re: [Gasification] Can use some help with stoves On 08/07/2010 01:33 PM, Bob Stuart wrote: > I'm wondering if vacuum distillation might be the best route to > efficiency for this. It is many times more efficient than just using > heat. Overall, the apparatus seems more economical than what is > needed to re-capture all waste heat. > > Bob Stuart That is a different technology and might be worth looking at. Saving even 1/2 MJ/L is useful! _______________________________________________ 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
