Process for making dimethyl carbonate

摘要

An eco-friendly process for making dimethyl carbonate comprising contacting methanol with carbon dioxide in the presence of a solid, calcined catalyst derived from zirconium phosphonate catalyst having molecular formula: Zr(X)2-nYn.mH2O where X refers to phosphonate, Y refers to HPO42− or HPO32−, n varies from 0.2 to 1.8 and m varies from 0 to 5, is disclosed.

主权项

1. A process for making dimethyl carbonate in yield a greater than 40 wt % of catalyst and with 100 wt % selectivity wherein the process comprises the steps of:
(a) providing reusable, water-tolerant, solid, calcined catalyst consisting of zirconium pyrophosphate derived from zirconium phosphonate having a molecular formula:
Zr(X)2-nYn.mH2O wherein, X refers to phenyl phosphonate, Y refers to HPO42− or HPO32−, n varies from 0.2 to 1.8 and m varies from 0 to 5; (b) contacting methanol with carbon dioxide in the presence of the catalyst as provided in step (a) wherein the amount of the catalyst ranges from 0.5 to 5% by weight of methanol, pressure of carbon dioxide ranges from 1 to 60 bar and a molar ratio of methanol and carbon dioxide varies from 0.25:1 to 10:1; and (c) subjecting the reaction mixture as obtained in step (b) to a temperature in the range of 80 to 200° C. and for a period in the range of 3 to 12 hrs followed by lowering the temperature, venting out or recycling unreacted carbon dioxide and separating product dimethyl carbonate from the left out methanol, by-product water and catalyst.