A Comparison of Organosolv-Formic Acid and Continuous-Soda Delignification of Elaeis guineensis Empty Fruit Bunch for Optimizing Reducing Sugar Production

Current delignification procedures of biomass are usually performed at high temperature. To increase efficiency and to improve sugar recovery, it is essential to implement an effective pretreatment that can perform at modest temperature and high lignin removal percentage. Prior research demonstrated that a high temperature pretreatment may remove lignin effectively. This study aims to analyze modest pretreatment temperature by using organosolv-formic acid in the batch reactor and soda pretreatment in the continuous screw reactor. Subsequently, the process followed by enzymatic saccharification using cellulase Cellic®️ Ctec2 enzymes to produce reducing sugar. The pretreatment by using formic acid was conducted at varying temperatures of 80°C, 100°C, and 120°C with different concentrations of formic acid:water as a solvents (70%, 80%, and 90%), heated under an oil bath for 3 hours, followed by saccharification and fermentation processes. The residual lignin contents obtained after impregnation for 2 h and pretreatment were 3.27-28.97%. Meanwhile, the soda pretreatment was, after maceration for 24-48 h were 8-12%. Saccharification was carried out by adding pretreated pulp, buffer solution, and enzymes and incubated for 72 hours at 50°C. Reducing sugar were 9,6% and 6% for formic acid and soda pretreatment, respectively.