Pre-treatment of lignocellulosic biomass using ionic liquids: wheat straw fractionation.

This work is devoted to study pre-treatment methodologies of wheat straw with 1-ethyl-3-methylimidazolium acetate ([emim][CH3COO]) and subsequent fractionation to cellulose, hemicellulose and lignin. The method developed and described here allows the separation into high purity carbohydrate and lignin fractions and permits an efficient IL recovery. A versatility of the established method was confirmed by the IL reuse. The fractionation of completely dissolved biomass led to cellulose-rich and hemicellulose-rich fractions. A high purity lignin was also achieved. To verify the potential further applicability of the obtained carbohydrate-rich fractions, and to evaluate the pre-treatment efficiency, the cellulose fraction resulting from the treatment with [emim][CH3COO] was subjected to enzymatic hydrolysis. Results showed a very high digestibility of the cellulose samples and confirmed a high glucose yield for the optimized pre-treatment methodology.