Carboxylation of Propylene Oxide to Propylene Carbonate in Slurry and Trickle Bed Reactors

摘要

CO2 is naturally available carbon source and emitted from industrial processes, automobiles and petrochemical refineries. Catalytic conversion of CO2 to value added chemicals provides an alternative green, cheap and sustainable synthesis route for industrial chemicals, otherwise produced using toxic reagents such as phosgene. An important example is the carboxylation of propylene oxide (PO) to propylene carbonate (PC), a key intermediate for dimethyl carbonate and polycarbonates. These cyclic carbonates are widely used as aprotic solvents, antifoaming agents, antifreeze, plasticizers and monomer for various commodity polymers. Several studies are known on synthesis of cyclic carbonates by carboxylation of epoxides employing homogeneous and heterogeneous catalysts. Heterogeneous catalysts consisting of metal oxides, zeolites, polymer supported quaternary onium salts, ion exchange resins, and polymer supported ionic liquids have been studied with the goal of improving catalytic activity and selectivity. However, no efforts have been made to understand the intrinsic kinetics of carboxylation and the related reaction engineering studies. Here, we report an experimental study on (a) intrinsic kinetics of carboxylation of PO to PC using ion exchange resin catalyst in a batch slurry reactor, and (b) modeling of a trickle bed reactor with experimental validation.