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 %.