Effective Extraction of Lignin from Elephant Grass Using Imidazole and Its Effect on Enzymatic Saccharification to Produce Fermentable Sugars

Elephant grass (Pennisetum purpureum Schum.) is an energy crop ready to be used as a source of fermentable sugars. Imidazole was proposed as a new solvent for biomass fractionation to facilitate disruption of the lignocellulosic matrix and production of a polysaccharide lignin-free material highly susceptible to enzymatic saccharification. Approximately 82% w·w^-1 of lignin was extracted from elephant grass under the optimized operational condition (135.6 °C for 308.4 min). For similar conditions the recovered polysaccharide-rich materials demonstrated enzymatic digestibility with glucan to glucose yields as high as 80.6 mol %.