California Agriculture

Cellulosic biomass, which includes agricultural and forestry residues and woody and herbaceous plants, is the only low-cost resource that can support the sustainable production of liquid fuels on a large enough scale to significantly address our transportation energy needs. The biological conversion of cellulosic biomass to ethanol could offer high yields at low costs, but only if we can improve the technology for releasing simple sugars from recalcitrant biomass. We review key aspects of cellulosic ethanol production, including pretreatment and enzymatic hydrolysis technologies that present the greatest opportunities to lower processing costs. Although several companies seek to introduce cellulosic ethanol commercially, innovative measures are needed to help overcome the perceived risks of first applications.