Study On The Synthesis Of Methyl Propyl Carbonate From Dimethyl Carbonate And Propanol Via Gas-phase Transesterification

The catalyitc synthesis of methyl propyl carbonate (MPC) using dimethyl carbonate (DMC) as methylating agent was studied under gas-solid-phase transesterification reaction conditions. Among various catalysts prepared and tested, TiO₂/Al₂O₃ with 5 wt% Ti loading calcined at 500 °C was the most active catalyst for the transesterification of DMC and propanol.The phase, structure and acid nature of the catalysts were changed due to the Ti loading and calcination treatment as indicated by X-ray diffraction (XRD). BET, NH3-TPD, pyridine/IR and X-ray photoelectron spectroscopy (XPS) characterization. It was observed that as the Ti content increased BET areas of TiO₂/Al₂O₃ decreased and anatase appeared. Ti(IV) species in monolayer dispersion was dominant below 1 wt% Ti loading.The influence of reaction parameters on the catalytic activity was investigated and the optimized reaction conditions was: tempearute 130℃, pressure 1.1 MPa, gaseous space velocity 360 h^-1, n (DMC)/n(propanol) 0.5. The conversion of DMC and the selectivity of MPC reached 57.27 % and 88.07 %, respectively under the above conditions and TiO₂/Al₂O₃ showed stable during a continuous test of 130 h.