Highly selective and stable ZrO2–Al2O3 for synthesis of dimethyl carbonate in reactive distillation

Abstract

Reactive distillation is a strengthening process, which is widely used for the transesterification of propylene carbonate and methanol to synthesize dimethyl carbonate. In this paper, suitable catalysts of ZrO2–Al2O3 solid solutions were prepared for distillation column. The structure–property correlations were characterized by XRD, XPS, N2 adsorption–desorption, CO2-TPD, and NH3-TPD. The introduction of Al3+ replaced Zr4+ in zirconia forming a homogeneous solid solution, which generated strong basic sites and increased weak acid sites of the catalyst. It has shown excellent catalytic performance for the synthesis of dimethyl carbonate due to the synergistic effects of the acid–base sites. At the same time, the key parameters of the reactive distillation process were studied, and under optimized reaction conditions (feed alcohol ester ratio = 4, reflux ratio = 5:1, height of reaction section = 0.25 m, liquid space velocity of propylene carbonate = 0.26 h−1), the propylene carbonate conversion and selectivity to dimethyl carbonate were 98.14% and 99.96%, respectively.