Direct Saccharification of Lignocellulosic Biomass by Using Deep Eutectic Solvent (DES): Fermentability of Sugar to Bioethanol
Bioethanol is an alternative product that can served to replace fossil fuel usage. Lignocellulosic biomass is an promising feedstock for the production of bioethanol because of economic feasbility and environment friendly. The process of bioethanol production will be start from pre-treatment, saccharification and fermentation. The current conventional saccharification methods such acid hydrolysis and enzymatic hydrolysis have its own draw back therefore new method is in research phase to overcome the drawback. Deep eutectic solvent has been introduced to replace ionic solvent in the saccharification process due to its properties such as non-flammability, cheap, non-toxicity and environmental-friendly. The feasibility of the deep eutectic solvent that made up with choline chloride and glycerol to direct saccharification of sugarcane bagasse have been justified and the optimum condition of the process have been determined. The feasibility have been justified but no other related research have be conducted. The quality of the hydrolysate and the yield of bioethanol through direct DES saccharification have yet to be conduct. The yeast growth in fermentation of DES hydrolysate have to be investigated. The objective of the study is to determine the composition of the hydrolysate ,the composition of the biomass using the optimum condition and the effect of DES concentration to the growth of yeast and bioethanol production. The direct DES saccharification process will be undergoes in optimum condition at 140℃, 90min reaction time and 2.2% w/v of solid loading The composition of biomass will determined by NRTL method while the composition of the hydrolysate will be determined by HPLC method. The yest strain, Saccharomyces cerevisiae is used and is cultured in an incubator shaker at 150rpm at 30℃. 2mL yeast will then be used for fermentation in different type of DES concentration (control without DES, 5%, 10%, 25%, 50%, and 100% of DES solution) at temperature of 30°C in 150 rpm for 10-14 hours. Around 85.3% composition of glucose is expected to be produced in the hydrolysate. The yield of the of the reducing sugar is expected to be round 20%. High-performance liquid Chromatography column will be used to determine the yield of the bioethanol. The growth of yeast will be determined by using a spectrophotometer. It is expected 90% to 50% of DES solution in water solution will increase the growth of yeast and ethanol yield. The future study for this research can be investigate the fermentability of hydrolysate on direct DES solution using different DES mixture.