Patent ID: 7777067

Claim:
A process for the production of an aromatic carbonate containing a diaryl carbonate as a main product from a strating material comprising an alkyl aryl carbonate, which is obtainable through a transesterification reaction between a dialkyl carbonate and an aromatic monohydroxy compound, which comprises the steps of: (i) continuously feeding said starting material into a continuous multi-stage distillation column in which a catalyst is present; (ii) carrying out the reaction in the column to produce a dialkyl carbonate and the diaryl carbonate; (iii) continuously withdrawing a low boiling point reaction mixture containing said produced the dialkyl carbonate from an upper portion of the column in a gaseous form and continuously withdrawing a high boiling point reaction mixture containing the diaryl carbonate from a lower portion of the column in a liquid form, wherein said 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 (cm) and an inside diameter D (cm), and having an internal with a number of stages n thereinside, and comprises a gas outlet having an inside diameter d 1 (cm) at the top of the column or in an upper portion of the column near to the top, a liquid outlet having an inside diameter d 2 (cm) at the bottom of the column or in a lower portion of the column near to the bottom, at least one inlet provided in the upper portion and/or a middle portion of the column below the gas outlet, and at least one inlet provided in the lower portion of the column above the liquid outlet, wherein (1) said length L (cm) satisfies the following formula (1), 1500≦L≦8000 (1), (2) said inside diameter D (cm) of the column satisfies the following formula (2), 100≦D≦2000 (2), (3) a ratio of said length L (cm) to said inside diameter D (cm) of the column satisfies the following formula (3), 2 ≦L/D≦ 40 (3), (4) said number of stages n satisfies the following formula (4), 10≦n≦80 (4), (5) a ratio of said inside diameter D (cm) of the column to said inside diameter d 1 (cm) of the gas outlet satisfies the following formula (5), 2 ≦D/d 1 ≦15 (5), and (6) a ratio of said inside diameter D (cm) of the column to said inside diameter d 2 (cm) of the liquid outlet satisfies the following formula (6), 5 ≦D/d 2 ≦30 (6).