Ultra-Low Cost Ionic Liquids for the Delignification of Biomass

摘要

Low-cost pretreatment of lignocellulosic biomass is an essential next step toward large-scale deployment as renewable liquid fuels, materials or chemicals. Ionic liquids (ILs) are highly effective at pretreatment, but high IL cost has hindered commercial viability. We have recently developed low-cost (ca. $l/kg) ILs, such as triethylammonium hydrogen sulphate, for pretreatment. In this chapter we discuss the fractionation of the grass Miscanthus x giganteus, wherein we deconstruct the lignocellulosic matrix into a cellulose-rich pulp, a recovered lignin fraction and an organic distillate. More than 80% of the lignin and quantitative hemicelluloses are removed during extraction. This results in 70-90% glucose release during enzymatic saccharification. The IL can also be successfully recovered and reused, with>99% IL recovery and minimal effects on efficiency of extraction. A detailed mass balance of all components and subsequent economic analysis revealed this efficient pretreatment with an ultra-low cost IL could result in an economically viable pretreatment process.