Blending municipal solid waste with corn stover for sugar production using ionic liquid process

Municipal solid waste (MSW) represents an attractive cellulosic resource for sustainable fuel production because of its abundance and its low or perhaps negative cost.  However, the significant heterogeneity and toxic contaminants are barriers to efficient conversion to ethanol and other products.  In this study, we generated MSW paper mix, blended with corn stover (CS), and have shown that both MSW paper mix alone and MSW/CS blends can be efficiently pretreated in certain ionic liquids (ILs) with high yields of fermentable sugars.  After pretreatment in 1-ethyl-3-methylimidazolium acetate ([C₂C₁Im][OAc]), over 80% glucose has been released with enzymatic saccharification.  We have also applied an enzyme free process by adding mineral acid and water directly into the IL/biomass slurry to induce hydrolysis after pretreatment.  With the acidolysis process in the IL 1-ethyl-3-methylimidazolium chloride ([C₂C₁Im]Cl), up to 80% glucose and 90% xylose are released for MSW.  There is a correlation between the mixture viscosity profile and hydrolysis efficiency.  Low viscosity of the hydrolysate after acidolysis generally corresponds to high sugar yields.  Overall, the results indicate the feasibility of incorporating MSW as a robust blending agent for biorefineries.