Patent ID: 7531616
Filing Date: 2009-05-12
Classification: B01D,C07C,Y02P

Abstract:
1. A process for the production of an aromatic carbonate containing a diaryl carbonate as a main product from a dialkyl carbonate and an aromatic monohydroxy compound as a starting material, which comprises the steps of: (i) continuously feeding said starting material into a first continuous multi-stage distillation column in which a catalyst is present; (ii) carrying out the reaction in said first column to produce an alcohol and an alkyl aryl carbonate; (iii) continuously withdrawing a first column low boiling point reaction mixture containing a produced alcohol from an upper portion of said first column in a gaseous form while continuously withdrawing a first column high boiling point reaction mixture containing an alkyl aryl carbonate from a lower portion of said first column in a liquid form; (iv) continuously feeding said first column high boiling point reaction mixture into a second continuous multi-stage distillation column in which a catalyst is present and which is connected to said first column while carrying out the reaction in said second column to produce a dialkyl carbonate and a diaryl carbonate; (v) continuously withdrawing a second column low boiling point reaction mixture containing said produced dialkyl carbonate from an upper portion of said second column in a gaseous form while continuously withdrawing a second column high boiling point reaction mixture containing said produced diaryl carbonate from a lower portion of said second column in a liquid form; wherein (a) a molar ratio of the dialkyl carbonate to the aromatic monohydroxy compound in said starting material which is fed continuously into said first continuous multi-stage distillation column is in a range of from 0.1 to 10; (b) said first continuous multi-stage distillation column comprises a structure having a pair of end plates above and below a cylindrical trunk portion having a length L (1) said length L (2) said inside diameter D (3) a ratio of said length L (4) said number of stages n (5) a ratio of said inside diameter D (6) a ratio of said inside diameter D (c) said second continuous multi-stage distillation column comprises a structure having a pair of end plates above and below a cylindrical trunk portion having a length L (1) said length L (2) said inside diameter D (3) a ratio of the length L (4) said number of stages n (5) a ratio of said inside diameter D (6) a ratio of said inside diameter D