Process for producing diaryl carbonate

Abstract

A process for producing diaryl carbonate of the present invention comprises steps of: (1) a diaryl carbonate production step of subjecting an aromatic monohydroxy compound and phosgene to condensation reaction at a temperature of 80 to 180° C. in the presence of an aromatic nitrogen-containing heterocyclic compound catalyst to obtain the diaryl carbonate; (2) a purification step of removing impurities from a hydrogen chloride gas by-produced upon the condensation reaction; (3) a chlorine recovery step of recovering chlorine usable for the production of phosgene from the purified hydrogen chloride gas; and (4) a phosgene production step of reacting the recovered chlorine with carbon monoxide to obtain phosgene usable in the diaryl carbonate production step. Such a process for producing diaryl carbonate by reacting an aromatic monohydroxy compound with phosgene using a catalyst comprising an aromatic nitrogen-containing heterocyclic compound has merits that the diaryl carbonate can be produced in an industrially advantageous manner even at a high conversion rate, and the by-produced hydrogen chloride is converted into chlorine and then is used in phosgene production process.

Dependencies are inferred from the claim text.