First of all, is 300 million tons of biomass to ethanol equals 96 mil. gal with existing or cellulosic refining?he is assuming stoichiometry and no products other than ethanol and CO2; I laid it out in this comment.In other words, you can not do any better without transmuting something.For the energy figures, I took numbers out of the Rubber Bible: 12780 BTU/lbm for ethanol, 20460 BTU/lbm for gas