Optimization on acid hydrolysis conditions of coconut husk fiber for reducing sugar production as bioethanol feedstock

Abstract

Bioethanol is an appealing biofuel that can be used to replace petrol. Bioethanol consist of several generations which are from food crops and lignocellulosic materials. This study focusing on second generation of biofuel which is lignocellulosic material. Lignocellulosic material usually being possess by plant material and successfully fulfil the impractical gap of the first generation. However, to produce bioethanol from lignocellulosic material, it must undergo several treatments in order to yield reducing sugar. The purpose of this study is to optimize the acid hydrolysis conditions of coconut fibre for reducing sugar production. The conditions are reaction time, concentration of H2SO4 and temperature. The screening process was done by using OFAT to minimize the range before using the DOE software. The first manipulated parameter was the reaction time (30 min-150 min, 100oC, 0.6 M), followed by concentration of H2SO4 with the optimum reaction time (120 min,0.2M-1.0 M, 100oC) and temperature with the optimum reaction time and concentration of H2SO4 (120 min, 0.2 M, 60oC-140oC). The best OFAT analysis was under condition of 120 min, 0.2 M and 120oC with the amount of reducing sugar 48.92 g/l, 33.95 g/l and 45.32 g/l. Central Composite Design (CCD) which is under Response Surface Methodology (RSM) by using Design of Expert (DOE) software was used to identify the most optimum condition in acid hydrolysis pre-treatment in order to produce the highest concentration of reducing sugar.