Utilization of biomass in the U.S. for the production of ethanol fuel as a gasoline replacement. I - Terrestrial resource potential. II - Energy requirements, with emphasis on lignocellulosic conversion

Abstract With relatively minor adjustments in the agricultural sector, large additional amounts of starch derived from feed corn, surplus and distressed grain, and set-aside land could presently be used for ethanol production. The quantity of ethanol that could be produced would be sufficient to replace anywhere from 5 to 27 per cent (5.5–30 billion gallons) of present gasoline requirements. Thus, the ethanol requirement for total gasohol use (10 per cent) in the U.S. could be met in the short period of time required for facility construction with no evident impact on food production. Increased supplies of ethanol will make feasible the introduction of ethanol fueled engines. High-yield sugar crops planted on new acreage could provide an additional 10 billion gal. of ethanol by the year 2000; conversion of the waste biomass from this crop to ethanol could also add substantially to this amount. Utilization of novel cellulose conversion technology can provide fermentable sugars from municipal wastes, agricultural and forest wastes, and ultimately, highly productive silvicultural operations. The wastes alone could yield over 36 billion gal. of 192° PR ethanol-fuel by the year 2000. Fast-growing woody species from silviculture are expected to yield a conservative average of 10 over-dry tons per acre per yr, convertible to 710 gal. of ethanol in a process that has 37 per cent yield. Advantages over sugar/starch crops include year-round harvesting, and use of marginal acreage. Commercial forest land presently suitable for silviculture is about 100 million acres in large tracts plus 200 million acres in small private tracts. The potential additional yield of ethanol from lignocellulosic biomass appears to be well in excess of liquid fuel requirements of an enhanced efficiency transport sector in the U.S. at present mileage demands. No conflict with food production would be necessary.