Ultrasonic Pretreatment of Woodchips for the Conversion of Cellulose to Glucose for Bioethanol Production

Abstract

In this study, lignocellulosic biomass i.e. the woodchips of Albacia tree (Paraserianthes falcataria) were given different pretreatment methods, ie. chemical (acid) and physical (ultrasonic). The pretreatment was given in order to convert the cellulose to glucose for the production of bioethanol. 1% H2SO4 was applied for the acid pretreatment. Ultrasound pretreatment was carried out at varied time (10, 20 and 30 minutes) at 600 W, 20 kHz before or after the acid pretreatment. Enzymatic attack of the pretreated sample was also applied to enhance the saccharification process of cellulose. The objective of the research was to determine the most effective ultrasonic duration and the best combination of method for enzymatic hydrolysis of the woodchips. The data showed that the highest yield of glucose was achieved at 20 minutes ultrasonic time. It was also found that substantial amount of hydrolysis of cellulose to glucose occur during the ultrasonic stage even without the presence of acid or cellulose enzyme. It is likely that the highly energetic ultrasonic process alone could assist in enhancing rate of hydrolysis of lignocellulosic cellulose into glucose