Preparation and characterization of biomass-based nanocatalyst for hydrolysis and fermentation of catalytic hydrolysate to bioethanol

Abstract

In this study, magnetic solid acid nanocatalyst was synthesized using Syzygium cumini seed powder and green synthesized magnetic Fe3O4 nanoparticles by wet impregnation method. The catalyst with a high acid density of 0.85 mmol g−1, the surface area of 466.905 m2 g−1, and pore volume of 0.191 cm3 g−1 was obtained. The prepared nanocatalyst Fe3O4–@C–SO3H was used to hydrolyze ultrasonic pretreated palmyra peel and corncob biomass in a magnetic stirrer. The total reducing sugar (TRS) of 97.6% and 90% was achieved for palmyra peel and the later for corncob under varied conditions of catalyst concentration and temperature. It is observed at 0.3-g catalyst concentration and 125 °C temperature gave the best yield for the palmyra peel sample within 1 h. And for corncob samples at 0.2-g catalyst concentration and 135 °C gave the best sugar yield within 1 h. The hydrolysate comprising high reducing sugar was further fermented using Saccharomyces cerevisiae. Bioethanol yields of 78.3% from palmyra peel and 62.7% from corn cob were quantified using gas chromatography technique.