Comparative Optimization of Acid and Alkaline Pretreatment of Cassava Bagasse for Optimum Yield of Fermentable Sugar for the Production of Biobutanol

Abstract

The constantly growing population of the world and its accompanying energy utilization as well as the search for cleaner and sustainable energy sources for various activities of mankind has pioneered various research work in the field of biofuels over the years. This study compared the effects of both acid and alkaline pretreatment methods on lignocellulosic biomass (cassava bagasse) by comparing their yields of fermentable sugar for the production of biobutanol. The Response Surface Methodology (RSM) tool was used to ascertain the optimum conditions for both pretreatment methods by optimizing the input variables which are acid/alkaline concentration, temperature, and time of pretreatment. Using a central composite design (CCD), the maximum fermentable sugar yield obtained from the acid pretreatment was 798.52 mg/L at 117.35 ℃, 30.98 minutes, and 2.1 % (w/w) H2SO4, while that of the alkaline pretreatment was a sugar yield of 1382.36 mg/L, at 115.41℃, 32.84 minutes and an alkaline concentration of 2.32% (w/w) NaOH. Overall, the results show that both pretreatment methods are effective for cassava bagasse but with alkaline having a higher yield