Towards An Understanding Of Ionic Liquid Pretreatment Process Of Lignocellulosic Biomass: Recovery Of Ionic Liquid And Analysis Of Process Streams

摘要: Ionic liquids being non volatile, non-flammable, recyclable and designer friendly, are gaining wide recognition as green solvents and efficient reaction media in process industries as a potential replacement for volatile organic solvents. Unique solvating properties of ionic liquids have made them good solvents for cellulose and lignocellulosic substrates. During ionic liquid pretreatment process, the recalcitrance of biomass due to high crystallinity of cellulose and lignin sheathing was overcome leading to high yields of glucan and xylan conversions. Rates of enzymatic hydrolysis for pure cellulose pretreated by ionic liquids were found to be two orders of magnitude higher than that for untreated cellulose [1, 2]. Enhanced enzymatic hydrolysis yields of glucan to glucose and xylan to xylose were observed for ionic liquid pretreated ligocellulosic substrates like corn stover and poplar reaching theoretical yields for glucan. However, during pretreatment process of lignocellulosic biomass, various process interactions take place leading to alteration of biomass structure and generation of various desirable or undesirable compounds. Analysis of the pretreated biomass and the various compounds generated will give a proper insight towards a fundamental understanding of the ionic liquid pretreatment process. Besides that an efficient recovery of ionic liquid is necessary which will make the ionic liquid pretreatment process economically viable. This work focuses on understanding the ionic pretreatment process by analysis of various process streams and addresses the recovery of ionic liquids by different approaches.