Aqueous Pretreatments as a Key Process to Enhance the Hydrolysability of Kenaf Core Fibre for Sugar Production

Abstract

In this work, kenaf core fibre was introduced as a potential raw material for cellulosic alcohol production. To be more in line with the environmentally friendly approach, only pretreatment with minimum energy or chemical consumption was considered and applied prior to the enzymatic hydrolysis of kenaf core fibre. Thus, simple pretreatments (water, acid and alkali as media) with and without oxygen-alkali extraction process were employed and investigated in this study. Based on the obtained results, by adopting merely simple pretreatments, the total glucose yields of all the pretreated fibres were increased. On the other hand, it was interesting to note that when these pretreated fibres were further treated by oxygen-alkali extraction, the total glucose yields were increased remarkably to more than double of the one without extraction. The chemical composition analysis indicated that this phenomenon was related to the high removal of lignin and/or hemicellulose coupled with only little degradation of cellulose (<2.5%) in the fibre. Hence, oxygen-alkali extraction was an effective method that could enhance the enzymatic accessibility and hydrolysability of fibre.