Application of a Loop Reactor in the Investigation of Furfural Oxidation Kinetics on an Acidic Ion Exchange Catalyst

Catalytic oxidation of furfural with hydrogen peroxide is an important reaction among environmentally friendly biomass-based technologies to provide precursors for the chemical industry. Biobased furfural is obtained from the hydrolysis of hemicelluloses to monomeric sugar molecules and their subsequent dehydration. Valorization of furfural via liquid-phase oxidation yields primarily succinic and maleic acids, both molecules of significant interest for the polymer industry. In this study, the oxidation of furfural with hydrogen peroxide was investigated on the strongly acidic Amberlyst-15 catalyst. Experiments under different operating conditions in an aqueous environment were conducted in a packed bed loop reactor. The effects of various operation conditions such as temperature, reagent concentrations, volumetric flow rates, and catalyst loadings were investigated. An improved reaction network compared with existing literature was developed, with additional pathways explaining the routes for the succinic acid formation. The system was modeled using the transient axial dispersion model for the packed bed and parameter estimation was carried to fit the model to the experimental data and to obtain the pre-exponential factors and activation energies of the rate constants. The model was able to reproduce the experimental data very well.