Application of acid catalytic hydrothermal reaction to conversion of carbohydrate biomass into valuable substances

摘要

Hydrothermal degradation of glucose in the presence of HCI, H2SO4 and H3PO4 were carried out with pH varying from 1.5-2.5, reaction time varying from 1 min to 10 min at 523 K, to investigate the effect of different acid catalysts and acid concentration on the production of 5-hydroxymethyl-2-fur-aldehyde (HW) and levulinic acid from glucose. At lower acid concentration, the yield of FMIF was considerably high. The increase in acid concentration accelerated the conversion of HW to levulinic acid. Among three acid catalysts, HCI is most effect for both conversion of glucose to HMF and further conversion of HMF into levulinic acid. But the decomposition of HMF is also fastest in the case of HCl catalysis. In the conditions used in this study, the highest yield of levulinic acid is about 55 %, which occurred at pH 1.5 for 5 min with HCl, and total highest yield of HMF and levulinic acid is about 50 %, which occurred at pH 2.6 for 5 min with H3PO4.