Continuous production of levoglucosenone from levoglucosan over SO3H functionalized resin

Pyrolysis of cellulose produces substantial anhydrosugars, particularly levoglucosan (LGA), as the main product. In this study, liquid-phase continuous conversion of LGA was carried out over SO3H functionalized resin for the production of levogluosenone (LGO), which is a bio-renewable platform for fine and commodity chemicals. Factors including solvent, reaction temperature, catalyst dosage, initial LGA concentration and total flow rate were investigated on the influence of LGO yield, which was obtained with the highest yield of 38.4 % at 94.8 % LGA conversion at the optimized conditions. In addition, a stable catalytic performance without losing LGO yield was observed for 10 h long test. The use of glucose as substrate led to a decrease of LGO yield to 33.5 %, nevertheless, the use of bio-oil, derived from cellulose pyrolysis, as the substrate promoted LGO yield to 55.4 % due to the presence of other anhydrosugars. Density functional density calculations revealed that the free energy barrier was significantly decreased to 168 kJ/mol with the SO3H functionalized resin compared to that of 258 kJ/mol without catalyst.