Patent ID: 8003817
Filing Date: 2011-08-23
Classification: B01D,C07C,Y02P

Abstract:
1. A process for the preparation of a mixture of at least one diaryl carbonate and at least one alkylaryl carbonate or a mixture thereof from at least one dialkyl carbonate and at least one aromatic hydroxy compound, which comprises (a) reacting the dialkyl carbonate(s) in the presence of at least one transesterification catalyst with the aromatic hydroxy compound(s) in at least one transesterification column containing at least one concentrating part in the upper portion of the column and at least one reaction zone beneath the concentrating part, which has at least two sections, (b) removing the vapor at the head of the transesterification column is condensed wholly or partially in at least one condenser, equipping at least one concentrating part of the transesterification column with at least one intermediate condenser, and the heat of condensation obtained by condensation in that intermediate condenser is fed directly or indirectly back into the process again; wherein the at least one diaryl carbonate is of the formula (I) wherein R, R′ and R″ independently of one another represent H, linear or branched, optionally substituted C R can further represent —COO—R′″, wherein R′″ can be H, optionally branched C wherein the at least one alkylaryl carbonate is of the general formula (IV) wherein R