Highly effective production of levulinic acid and γ-valerolactone through self-circulation of solvent in a continuous process

A sustainable and cost-competitive catalytic process for high yield production of levulinic acid (LA) and γ-valerolactone (GVL) from biomass-derived furfuryl alcohol (FOL) fluid was proposed with GVL as a self-circulation solvent. The innovative process eliminated the separation of the final product GVL and intermediate product LA from the solvent, and the actual concentration of FOL was improved enormously. A higher yield (90.5%) of LA was realized in the fixed-bed reactors than that in the conventional autoclave since the short residence time of the FOL solution could alleviate the polymerization of FOL in the continuous process. UV-Raman spectroscopy demonstrated that fewer polymers deposited on the catalysts, so superior stability of the zeolite was observed in the fixed-bed reactors. Moreover, an 89.4% high yield of GVL can be achieved since the integration of the tandem reaction of hydration and hydrogenation could substantially avoid side reactions in the fixed-bed reactors.