Low-cost cellulosic bioethanol production of oil palm empty fruit bunches using hydrothermal-alkaline pretreatments synergeticly

Abstract

The second generation of bioethanol has been developed by utilizing the residual products of crops such as oil palm empty fruit bunches (OPEFB). In this study, the OPEFB was carried out synergistically by applying two methods, namely hydrothermal and alkaline. This pretreatment is intended to improve the ability of the OPEFB delignification process. Hydrothermal pretreatment was carried out by annealing at 220o C for 30 minutes, while alkaline pretreatment was carried out by varying the concentration of NaOH, pretreatment time, and temperature. Based on the research results, it was found that hydrothermal pretreatment with the addition of DI water was effective in reducing hemicellulose levels from 21.54% to 1.11%. The combination of alkaline pretreatment using NaOH 2.0 M at 25o C for 60 minutes effectively reduced lignin levels from 47% to 26.6%, and increased cellulose levels to 83.04%. NaOH solution has been shown to dissolve lignin without affecting the stability of cellulose.