Synthesis of HMF from fructose using Purolite ® strong acid catalyst: Comparison between BTR and PBR reactor type for kinetics data acquisition

5-hydroxymethyl-2-furfural (HMF) is an important furanic compound that can be obtained from renewable raw materials. HMF has wide application in the industry, acting as an intermediate in the production of fine chemicals, polymer, biofuels, and pharmaceuticals. In this research, HMF was obtained from the catalytic fructose dehydration. Purolite ® SGC650H, a gel-type strongly acidic resin, was applied as a catalyst using dimethylsulfoxide (DMSO) as a solvent. All experiments were carried out in a batch reactor (BTR) and a continuous packed bed reactor (PBR). The reactor performance data showed that increase in temperature resulted in higher HMF yield. In contrast, the higher the fructose concentration, the lower the HMF conversion. The HMF production rates in the PBR were higher because of the concentration of the catalyst. The rate constants were calculated by means of a pseudo-first-order reaction model, and the Arrhenius kinetic parameters obtained changed with regards to the reactants concentrations. The kinetic parameters displayed linear correlation in the Cremer-Constable diagram, which means that the system was under a kinetic compensation effect (KCE); therefore, the model was not suitable to represent the reaction. Langmuir-Hinshelwood (LHHW) models for rate equation were also tested. However all of them failed to adjust to the data, and thus a rate law was not determined. Due to the observed KCE, it was believed that there is at least a set of parallel dehydration reactions initiated from the different fructose isomers which has an influence on kinetic parameters.