Can cellulose be a sustainable feedstock for bioethanol production?

Bioethanol is a promising substitute for conventional fossil fuels. The focus of this work was to convert commercial cellulose (Avicel® PH-101) to ethanol. In the first step, cellulose was selectively converted to glucose. Cellulose hydrolysis was carried out under microwave irradiation using hydrochloric acid as catalyst. Process parameters - acid concentration, irradiation time, and power consumption - were optimized. A yield of 0.67 g glucose/g cellulose was achieved under modest reaction conditions (2.38 M acid concentration, irradiation time - 7 min, 70% of power consumption). The glucose thus produced was then converted to ethanol by fermention with yeast (Saccharomyces cerevisiae). The speed, selective nature of the process and the attractive overall yield indicate that cellulose, a vast carbohydrate source, could indeed be a sustainable feedstock for bioethanol production.