Efficient Conversion of Oil Palm Trunk and Frond to Bioethanol and Biogas Using Two-Stage Steam Explosion Pretreatment

Abstract

Bioethanol and biogas production from oil palm trunk (OPT) and oil palm frond (OPF) investigated within a biorefinery concept. Firstly, bioethanol production from OPT and OPF pretreated two-stage steam explosion by comparing with enzyme hydrolysis and without enzyme hydrolysis in the SSF process, which used S. cerevisiae in fermentation. The amount of bioethanol increased rapidly, which was stable when the fermentation process entered 96 hrs, resulting in the highest amount of bioethanol produced from OPF and OPT equal to 0.31 and 0.40 g ethanol/g glucose of bioethanol yield, which was about 24.96% and 25.99% higher than the non-enzymatic fermentation of OPF and OPT. The total stillage from OPT and OPF distillation produced a methane yield of 164.38 ml/CH4 g COD at 30 days of HRT and an organic loading rate (OLR) of 12.45 g COD/L-day. Biofuels in the biorefinery concept of OPF/OPT material at 1,000 kg produced bioethanol, biogas, and solid residue as 49 L at 95% bioethanol, 7,116 L at 63.05% of methane composition, and 13 kilograms of solid residue.