Ethanol Production from Cashew Apple Juice Using Immobilized Saccharomyces cerevisiae Cells on Silica Gel Matrix Synthesized from Sugarcane Leaf Ash

Abstract

Ethanol is considered to be a promising alternative fuel to meet ever growing energy demands. In the present work, immobilized yeast cells by Saccharomyces cerevisiae were used for ethanol production from cashew apple juice as the substrate. The support, silica gel, was derived from a novel precursor sugarcane leaf ash. Sugarcane leaf is chosen due to its abundant availability, low cost, and also as a means to remove the agricultural residue. Substrate concentration, pH, and temperature have been optimized to achieve maximum production of ethanol. Maximum ethanol production was obtained at a substrate concentration of 70% (v/v), pH 6 and a temperature of 30°C. Maximum ethanol production was found to be 16,200 mg/L. Ethanol purity was determined and was found to be 97.79% pure (water free). Continuous ethanol fermentation was carried out in a packed bed reactor.