On Thu, 19 Jul 2007 10:04:46 -0600, RomeoMike
wrote:



Jay Honeck wrote:


"Overall (farming, distillation), it takes 129,600 BTU to produce a
gallon of EtOH (ethanol), but the energy value of a gallon of EtOH is
only 76,000 BTU. In SI units [conversions in footnote 3]: it takes
45.7 MJ to produce a kilogram of EtOH, but the energy value of that
kilogram of EtOH is 26.8 MJ."

Does anyone know how much energy it takes to pump crude out of the
ground, ship it to a refinery, and the refine it to make a gallon of
gas? I don't, just asking for a comparison.

It's surprisingly inefficient, but using the same stuff for power
makes it relatively inexpensive.
I looked it up a while back and as I recall it was "cost of producing
alcohol compared to processing crude oil into gas" The biggest problem
I found is there is so much conflicting information out there that it
takes time (a lot of it) to filter out what is and is not both correct
and up-to-date. Even where studies are undertaken you really need to
know the criteria under which the studies were conducted.

*Probably* one of the least expensive fuels is hydrogen produced by
gasification of coal, but that process is not clean and produces a
tremendous amount of CO2 as a byproduct. OTOH the byproducts and be
recovered and sold while the CO2 can be sequestered.