Aqueous ammonia pretreatment of oil palm empty fruit bunches for ethanol production

Abstract

Oil palm empty fruit bunches (EFB) were pretreated by aqueous ammonia soaking for ethanol production. Pretreated EFB, which were pretreated at the optimal conditions of 60°C, 12h, and 21% (w/w) aqueous ammonia, showed 19.5% and 41.4% glucose yields during an enzymatic digestibility test for 96h when using 15 and 60FPU of cellulase, respectively. Using the pretreated EFB, simultaneous saccharification and fermentation for 168h with 5% (w/v) glucan loading and 60FPU of cellulase and 30CBU of β-glucosidase per gram glucan resulted in ethanol production of 18.6g/L titer, 65.6% of theoretical maximum yield, and 0.11g/L/h of productivity.