Enzymatic digestibility of pretreated dewaxed bamboo residues as feedstock for bioethanol production

Abstract

Due to abundant availability, biofuel production from bamboo residues is gaining popularity. Bamboo biomass and its residues are widely available in the north-eastern part of India, which can be sustainably exploited for green energy production. The aim of the present study was to evaluate the pretreatments of dewaxed bamboo residues with dilute alkali (NaOH), and dilute acid, and the effect of pretreatment on biomass hydrolysis was performed with a commercial enzyme (Zytex). Results showed that maximum fermentable sugars were 490 mg/g obtained from 10% biomass with 0.6% (w/v) of alkali, and acid pretreated biomass produced 320 mg/g of sugars from 2% (w/v) acid with 10% biomass. Changes in biomass structure during the pretreatment process are correlated with FTIR, SEM, and component analysis for lignin, cellulose, and hemicelluloses. Fermentation studies of the hydrolysate showed that the yield of ethanol was 77% of the theoretical maximum at 36 h. Results indicate the scope of utilization of bamboo residues as substrates for biofuels, and alkaline pretreatment is an effective pretreatment process for bioethanol production.