Fractionation of oil palm fronds (OPF) hemicellulose using dilute nitric acid for fermentative production of xylitol

摘要

Due to rapid expansion of palm oil industries, oil palm (Elaeis guineensis Jacq.) frond has become one of the most abundant agricultural residues for sustainable fermentation feedstock. This study investigated the potential usage of soluble products of oil palm frond (OPF) bagasse upon dilute-acid hydrolysis. An experimental screening of parameters such as the concentrations of nitric acid, temperatures, and contact time enabled the optimal liberation of xylose from OPF. The highest amounts of sugars recovered were 18.4 g xylose and 8.9 g glucose per 100 g OPF obtained from 4% (v/v) HNO3 at 130 degrees C for 20 min. The liquid fraction contained 22.1 g/L xylose, 8.9 g/L glucose and 4.6 g/L total inhibitors. A qualitative analysis showed significant structural changes of the OPF upon acid hydrolysis, The fermentability test conducted for xylitol production using the OPF hydrolysate revealed that the maximum yield of 0.35 g xylitol per g of sugars was obtained. This work lends evidence to the use of hydrolysis with dilute nitric acid as an effective and environmentally friendly approach for xylitol production based on biorefinery.