Verenium operated a demonstration plant with a capacity to produce 1.4 million gallons of cellulosic ethanol from agricultural resiues for about two years. During this time, the plant was able to evaluate the technical issues in producing ethanol from three different cellulosic feedstocks, sugar cane bagasse, energy cane, and sorghum. The project was intended to develop a better understanding of the operating parameters that would inform a commercial sized operation. Issues related to feedstock variability, use of hydrolytic enzymes, and the viability of fermentative organisms were evaluated. Considerable success was achieved with pretreatment processes and use of enzymes but challenges were encountered with feedstock variability and fermentation systems. Limited amounts of cellulosic ethanol were produced.