Kinetic study of glucose conversion to levulinic acid over Fe/HY zeolite catalyst

Abstract

The glucose conversion using Fe/HY zeolite catalyst in a batch reactor has been investigated. The main products within the temperature range between 120 and 200°C were 5-hydroxymethylfurfural (5-HMF) and levulinic acid (LA). The highest LA yield of 66% was obtained from 100% glucose conversion at 180°C. After eliminating the influence of internal and external diffusions, a kinetic model was developed based on the pseudo homogeneous model. The kinetic model consisted of four key steps: (1) glucose dehydration to form 5-HMF; (2) glucose degradation to produce humins; (3) 5-HMF rehydration to form LA; and (4) 5-HMF degradation to form humins. The first-order model and the experimental data fitted-well. The reactions rates increased with temperature, and the activation energies of glucose conversion to 5-HMF and 5-HMF conversion to LA were 64 and 61kJmol-1, respectively, comparatively lower than previously reported values.