Efficient conversion of glucose to 5-hydroxymethylfurfural by synergetic catalysis of enzymes and chemical catalysts towards potential large-scale continuous operation

A continuous process to efficiently produce 5-hydroxymethylfurfural (HMF) from glucose by synergetic catalysis of enzymes and chemical catalysts was developed in dimethyl sulfoxide (DMSO)/water system under mild conditions. Sweetzyme IT Extra and Amberlyst 36 were used as heterogeneous catalysts for glucose isomerization and fructose dehydration, respectively, in packed bed reactors. Fructose yield of 50.9 % was obtained during glucose isomerization in 1:1 VDMSO/VWater medium at 60 °C and residence time of 30 min. Selective dehydration of fructose in glucose-fructose mixture was achieved in DMSO medium with fructose conversion of higher than 97 % and HMF yield of 87.2 % at 85 °C and a residence time of 40 min, where 93 % glucose unconverted. By adjusting the water content in the reaction system and recycling of water from isomerization and extraction units, the catalysts could keep good stability for 150 batches reuse without loss of activity. Based on the converted glucose, glucose conversion, HMF yield and selectivity reached 100 %, 81.5 %, and 81.5 %, respectively. This process showed great promise for production of HMF from glucose in continuous operation at large scale.