Catalytic Synthesis of Glycerol Monoacetate Using a Continuous Expanded Bed Column Reactor Packed with Cation-Exchange Resin

Abstract

The selective and continuous production of monoacetin using an expanded-bed column reactor, in which the reactive fluid flows vertically upward and the catalyst is hydrodynamically floated, was studied. Acetic acid and glycerol were used as the substrates and the proton-type cation-exchange resin Amberlyst 16 was used as the catalyst. Batch reaction experiments under various conditions were first conducted to investigate the details of the heterogeneous catalytic reaction mechanism. The esterification of acetic acid with glycerol to produce the target product monoacetin was proved to proceed predominantly over the undesired consecutive esterification reactions to diacetin and triacetin. The intraparticle and extraparticle mass-transfer resistances for the catalytic resin were negligible. The Eley−Rideal-type catalytic reaction model was successfully applied to the experimental data for the various conditions. Next, the hydrodynamic correlation between the flow rate of the reactive fluid and the corresponding expanded-bed height on the continuous reactor was determined experimentally. Furthermore, the reaction and transport model for a continuous expanded-bed column reactor was constructed based on the kinetic model for the batch system. The numerical calculation simulated the experimental data well, and the optimum operating conditions were successfully determined by the theoretical analysis.