Pretreatment of lignocellulosic palm biomass using a solvent-ionic liquid [BMIM]Cl for glucose recovery: An optimisation study using response surface methodology

The potential of oil palm frond (OPF) for fuel ethanol production was investigated in this current work. Pretreatment of lignocellulosic feedstock with the novel solvent ionic liquid (IL) BMIMCl was used to facilitate the conversion of OPF into fermentable sugar (glucose). The pretreatment was accomplished by first subjecting OPF to ionic liquid treatment, followed by regeneration of cellulose using an anti-solvent. Scanning Electron Microscopy showed a significant destruction of biomass structure after pretreatment with IL, which in turn reduced the crystallinity and improved the enzymatic digestibility of the biomass. The effects of several pretreatment variables, such as temperature, retention time and solid loading, were studied using Response Surface Methodology (RSM) based on a factorial Central Composite Design (CCD). These factors were further optimised using RSM. An optimum 100% glucose recovery was found with pretreatment conditions of 80 °C, a 15-min retention time and 10% solid loading.