Second-Generation Ethanol from Sugarcane Industry Residues

Lignocellulosic residues such as bagasse, straw, and tops are generated by the sugarcane industry. Hence, the use of these residues for second-generation (2G) ethanol production could increase its viability. Cristiane Sanchez Farinas of the Federal University of São Carlos and the Embrapa Instrumentation in Brazil studied the use of the lignocellulosic residues from whole sugarcane lignocellulosic biomass from commercial varieties for 2G ethanol production.

Materials were pretreated, hydrolyzed and were fermented using an industrial strain of Saccharomyces cerevisiae. The susceptibility to enzymatic saccharification was highest for the tops while hydrolyzates from straw achieved the highest ethanol yields. Using a mixture of the different parts (bagasse-straw-tops, 1:1:1, dry-weight basis), it was possible to achieve higher enzymatic conversion and ethanol yield, compared to use of the bagasse alone. The variety of sugarcane was not significant factor in the 2G ethanol production.

Analysis showed that 2G ethanol production could be significantly improved by the combined use of bagasse, straw, and tops instead of using bagasse alone.