Study of the preparation of sugar from high-lignin lignocellulose applying subcritical water and enzymatic hydrolysis: Synthesis and consumable cost evaluation

This study concern sugars hydrolyzed from the high-lignin coconut coir dust using moderate subcritical water (SCW) hydrolysis at pressures 20-40 bar for 1 h and to evaluate the consumable costs driver generated. The SCW method produced two products, sugar liquid and solid (SCW-treated substrate). The solid was proceeded to prepare the sugar via enzymatic hydrolysis using pure cellulase. Yield of sugar hydrolyzed from lignocellulose by SCW technique was 0.25 gram sugar/gram cellulose +hemicellulose, or 0.09-gram sugar/gram lignocellulose at 160 °C and 40 bar. While, the maximum yield of sugar liberated enzymatically from SCW-treated solid was 0.35-gram sugar/gram cellulose+hemicellulose, or 0.13-gram sugar/gram SCW-treated solid. It was found that carbon dioxide gas was the highest cost driving in SCW hydrolysis.