Levulinic acid production from wood with green solvents

In this work, protic ionic liquid, 1-methylimidazolium hydrogen sulfate (HMIMHSO4) and gamma-valerolactone (GVL) were explored with respect to their effects on levulinic acid production directly from cotton stalks and pine using the acidic catalyst, CrCl3.6H2O in a hydrothermal reactor. GVL as a biomass-derived solvent resulted in higher yields of levulinic acid compared to HMIMHSO4 which was attributed to the higher lignin depolymerization capacity of the solvent and GVL’s capability for stabilization of the solvated protons. The increasing water content of the media from 10% to 20% enhanced the production and the yields. GVL gave the maximum levulinic acid concentration and yield from pine; 21.4 g/L and 78%, respectively when the reaction was conducted at 180 °C and 10% biomass loading with 20% water and 0.1 M CrCl3.6H2O for 4 h.