Effect of subcritical water pretreatment on enzymatic digestibility of rice straw, corn stover and sugar cane bagasse (Thai)

Abstract

Currently, ethanol production from cellulosic material is an important process for alternative fuel production. This study focused on the pretreatment step of three agricultural wastes, i.e. rice straw, corn stover and sugar cane bagasse, using subcritical water at various temperatures (100, 150 and 200 ํC) for 10 min in a batch-type system. The results showed that at 200 ํC about 50 % of raw material degraded, resulting in a high level of reducing sugar. Corn stover gave the highest reducing sugar content in the pretreatment step (0.53 g reducing sugar/ g dry solid). In addition, pretreatment using subcritical water also improved the digestibility of all agricultural materials tested after digestion test with cellulase and cellubiase, especially at 200ํ ํC pretreatment.However, the pretreatment of rice straw gave the highest reducing sugar content (0.21 g reducing sugar/g dry solid) after enzymatic digestion.