3-72: Comparison of the Enzymatic Hydrolysis of Ionic-Liquid Pretreated Energy Crops

The development of techniques that enable the efficient conversion of biomass into fermentable sugars is essential if lignocellulosic biofuels to be energetically and economically feasible.   The crystaline and fibrous nature of cellulose is one of the main factors affecting the rate of enzymatic hydrolysis of biomass into its component sugars by cellulases.  In order to increase the efficiency of this process, biomass is treated to open up the cellulose fibers.  Current pretreatment technologies typically require high temperature, pressure or extremes in pH, that can result in the formation of undesirable byproducts and also necessitate high capital costs.  A novel pretreatment technology that utilizes ionic liquids, salts that have a melting point of below 100C, has recently drawn a great deal of attention due to their ability to drastically increase the rate of enzymatic hydrolysis of crystalline cellulose. Some of these liquids have the ability to dissolve cellulose at relatively low temperatures and upon reconstitution, yield amorphous cellulose.  Complete saccharification of microcrystaline cellulose treated with the ionic liquid 1-ethyl-3-methyl imidazolium chloride was achieved in 2 hours using a commercial cellulase derived from the fungus Trichoderma reesei. To examine the widespread applicability of this pretreatment technology, the rate of hydrolysis and resulting sugar yields of 5 different herbaceous and woody biomasses, pretreated with the ionic liquid EMIM Acetate,  was examined.