Integrated process for the production of fermentable sugar and methane from rubber wood. (April 2020) - Charnnok, Boonya
Graphical abstract: Highlights: An integrated process based on organosolv pretreatment was developed. It was capable of co-producing fermentable sugars and methane. Organosolv pretreatment produced effective delignification beyond auto-hydrolysis. Intensive delignification enhanced the biochemical degradability of the rubber wood. Abstract: Pretreatment is required for the enhancement of the bioconversion of lignocellulosic biomass. This study aimed to develop an integrated process producing efficient biochemical conversion of rubber wood waste (RW) into co-biofuels, fermentable sugar and methane. The glucan conversion was enhanced to 93.8% with temperature (210 °C) and delignification by organosolv pretreatment (OS). Thereafter, anaerobic digestion of the residue left after enzymatic hydrolysis was conducted which further improved the methane yield (205.5 LCH4 /kg VS) by 33% over hydrothermal pretreatment (154.3 LCH4 /kg VS). Delignification during OS plays a key role in improving the degradability of RW resulting in efficient energy recovery (11.23 MJ/kg pretreated RW) which was clearly higher than an integrated process based on hydrothermal (HT) or HT plus process water. Scaled up to a biorefinery, the integrated process based on OS would economically produce fermentable sugar while other value-added chemicals might be produced from the process water.