Catalytic conversion of sucrose to 5-hydroxymethylfurfural in green aqueous and organic medium

Abstract

5-Hydroxymethylfurfural (HMF) is one of the promising chemicals, which can serve as a platform chemical to produce various energy chemicals. HMF can be produced from different lignocellulosic biomass derived sugars employing different catalytic processes. In this study, the synthesis of HMF was investigated from excessively available sucrose using environment friendly and cost-effective technology. Among the various solvents applied, dimethyl sulfoxide (DMSO) was found as an efficient organic solvent medium. The results elucidated the combination of p-toluenesulfonic acid (pTSA) and chromium chloride (CrCl3.6H2O) as the best dehydrating catalyst. A relatively higher HMF yield of 55% was achieved at a lower temperature (120 ℃) while at 150 ℃ (higher temperature) oxalic acid with higher concentration of CrCl3.6H2O gave a maximum yield of 59.21%. The time, temperature, and concentrations affected the yields. The positive impact was found with a rise in temperature from 100 to 120 ℃ in pTSA while oxalic acid affected the yield until 150 ℃. HMF yields were reported in descending order as pTSA > oxalic acid > maleic acid > malonic acid > succinic acid > blank at 120 ℃. It was observed that the isomerization of glucose to fructose is the major barrier to achieve the high process yield. Therefore, more efforts should be made to achieve the high rate of isomerization of glucose (part of sucrose disaccharide) in order to improve the HMF selectivity by depressing the humin formation.