Cocoa Pod Husk (CPH) for Biomass on Bioethanol Production
Syifa Afifah Rahman, Anja Meryandini, Ario Betha Juanssilfero, Fahrurrozi Fahrurrozi
Abstract
Cocoa pod husk (CPH) is an underutilized agricultural lignocellulosic biomass. CPH and its contents are considered suitable to be used as raw material in the production of 2G biofuels. Various hydrolysis methods and processing are still being developed and have not yet been well studied. This study aimed to investigate the efficiency of hydrolysis process using microwave irradiation AND the stress tolerance phenotype of yeast. The pretreatment of CPH biomass was carried out using hydrogen peroxide (H2O2). The chemical and structural component of CPH was analyzed before and after pretreatment. The results showed that H2O2 reduced up to 34% of lignin and increased the solubility of this component. Pretreated CPH powder was hydrolyzed by combining 1M H2SO4 and microwave-assisted hydrolysis, resulting in high glucose-xylose concentration within short reaction times. The highest glucose-xylose concentrations from CPH were 3.40 g/L - 0.94 g/L within 12 minutes at 180 °C. The oxidative-fermentative test showed that yeast Y003 could ferment xylose. The stress tolerance test showed that S. cerevisiae Y003 tolerance up to 40 °C temperature, up to 14% ethanol concentration, and up to pH 3 under pH stress. The highest glucose-xylose consumption by S. cerevisiae Y003 was observed under the treatment of E2 (93.59%), with ethanol production up to 1.85 g/L. Fermentation efficiency was 85 - 97%, indicating that this research succeeded in producing bioethanol from CPH biomass. Cocoa pod husk is a promising resource for further development of bioethanol production.