The real question is: should ethanol be the focus or will other sources be ignored in doing so. Right now, ethanol produced from only the kernels of corn yield about 370 gals/acre/yr. Diesel produced from soybeans produces 50 gals/acre/yr. Biodiesel from Palm Oil beats both with yields of 600 gals/acre/yr.
The promise of using the entire corn plant – which is referred to as “stover” and involves a more complex process in turning the cellulosic materials into ethanol – could produce 1,000 gals/acre/yr. Brazil is currently using sugar cane for its ethanol and produces about 650 gals/acre/yr. They are working on a “Super” cane that could produce 3,200 gals/acre/yr. So there is a range today of 50 to 600 gal/acre/yr for ethanol and diesel from biomass and the promise of 1,000 to 3,200 gal/acre/yr in the next 5 to 10 years for some of the other newer varieties of crops.
People in the energy business are looking for an oil that can be used to provide a feedstock to existing oil refineries. It might come from corn, oil crops, or algae. Don Paul, Chevron’s Chief Technology Officer, has referred to this as “super” crude, and should be viewed as an important goal of the biofuels industry. The advantage that biologists have in working on algae is that they can literally look for the right algae with oils that have carbon molecules with chains of 5 or 6 carbon atoms rather than the 12 – 15 carbons in most of the exiting biofuels. This would take advantage of the entire infrastructure already in place.