Optimization of pulp concentration for bioethanol production from elephant grass (Pennisetum purpureum) using two commercial yeasts with addition of Tween 20

Abstract The higher consumption of fuel, especially fossil fuels, will lead to depletion of fuel reserves and high air pollution, which causes environmental pollution. Therefore, it is necessary to find alternative fuels that are environmentally friendly and abundant availability in nature, so-called biofuels. One type of biofuel is bioethanol. Raw materials that can be produced into bioethanol are biomass or lignocellulosic material. Elephant grass is one type of lignocellulosic material that has high cellulose content (40.85%). The objective of this study was to determine the optimum pulp concentration by adding Tween 20 to the saccharification process with two types of commercial yeasts (fermipan and mauripan) in the fermentation process. The pulp variations used were 20, 25 and 30% w/v with Tween 20 concentrations 0% and 1%/v. The results showed an increase in pulp concentration, and the addition of Tween 20 by 1% could increase the ethanol content compared to controls (Without Tween 20). The highest ethanol content was produced at 30% pulp concentration (13.09%) with addition 1% of Tween 20 in the saccharification process and fermipan yeast in the fermentation stage, and it could achieve ethanol content of 13.94%(v) when using Mauripan yeast.