Investigation of the Effects of Ionic Liquid 1-Butyl-3-methylimidazolium Acetate Pretreatment and Enzymatic Hydrolysis of Typha capensis

Pretreatment of Typha capensis (TC) with ionic liquid (IL) 1-butyl-3-methylimidazolium acetate [BMIM(OAc)] shows that the structural integrity-like degree of polymerization, polydispersity index, and lignin were altered, providing easy access to enzymes, and improved its digestibility to fermentable sugars. Hydrolysis of pretreated samples by a pre-optimized mixture of cellulose enzymes achieved an optimal reducing sugar yield (RSY) of 82.4 g/100 g after 6 h of pretreatment incubation. Because the costs of ILs are high, pre-hydrolysis and recycling are used to improve the economics. Pre-hydrolysis steps using sodium hydroxide followed by IL treatment were found to be better than sulfuric acid pre-hydrolysis followed by IL. Pre-hydrolysis treatment with alkali reduced pretreatment time from 6 h to 15 min, and total solid (TS) was increased from 5 to 10% without significant reduction in the glucose and RSYs. During solvent recycling, about 10% of initial lignin at each cycle was being accumulated into the l...