ABSTRACT

Biomass is a promising source of energy and has in recent years, gained special attention as a new raw material for biobutanol production. Biobutanol production from lignocellulosic biomass requires a pretreatment step and afterward enzymatic hydrolysis process to release sugars for fermentation to butanol. The aim of this study is to determine the conditions for optimal sugar yield through pretreatment. The feedstock characterized so as to determine hemicellulose, cellulose and lignin content utilizing standard laboratory analytical procedures for biomass analysis. From Response Surface Methodology tool (RSM), a Box-Behnken model was chosen to optimize the pretreatment conditions which were: the H2SO4 concentration (0-4wt. %), the reaction time (5-15 minutes) and the temperature (100-120°C). A total of Seventeen runs were carried out during the pretreatment using the pretreatment conditions. The experimental results were then optimized using Research Surface Methodology and an optimal sugar yield was obtained at 2wt% acid concentration and at a temperature of 120°C and reaction time of 15minutes. Pretreatment was then repeated at this condition and gave significant sugar yield as a result of lignin removal performed via alkaline pretreatment. The optimum sugar yield was at pH 5.0. The result showed that acid concentration and reaction influenced the response, in particular the best pretreatment yields was obtained at high value of concentration and low reaction time.