Bioethanol production from rice straw waste by enzyme catalyst using separated hydrolysis and fermentation (SHF) method

Abstract

Bioethanol produced through hydrolysis and fermentation processes has great potential for usage as a liquid biofuel to be combined with fossil fuels. Its use and presence as an energy source does not interfere with the availability of food sources, and it has the potential as biomass to produce biofuel, in this case, bioethanol, because it contains 29.63 percent cellulose, 17.11 percent hemicellulose, and 12.17 percent lignin, all of which can be used to produce glucose via the hydrolysis process. Straw was utilized in this study for bioethanol synthesis via Separate Hydrolysis and Fermentation or SHF. In the fermentation process, Saccharomyces cereviceae is used as an organism. The goal of this study was to investigate the effect of the catalyst used in this case, cellulolytic enzymes, specifically cellulase enzymes and a combination of cellulase cellobiose enzymes in the hydrolysis process that affects glucose production on the levels of bioethanol produced, cellulose and cellobiose enzymes are used because rice straw contains the highest concentration of lignocellulose. The results of the experiments revealed that the cellulase enzyme achieved the highest output of reducing sugar (12.70 g/L) at a concentration of 5% and an incubation duration of 72 hours, yielding 5.9% bioethanol. The cellulase cellobiose enzyme combination produced reducing sugar yield (15.21 g/L) at a ratio of 2:1 and incubation time of 72 hours and produced the highest bioethanol yield of up to 27.40 percent. Rice straw is a potential raw material for bioethanol production employing a mixture of cellulase cellobiose enzyme catalysts and can be used as a new and renewable energy source.