Patent ID: 8058465

Claim:
A process for industrially producing a dialkyl carbonate and a diol in which the dialkyl carbonate and the diol are continuously produced through a reactive distillation system of taking a cyclic carbonate and an aliphatic monohydric alcohol as starting materials, comprising the steps of: continuously feeding the starting materials into a continuous multi-stage distillation column in which a catalyst is present; carrying out reaction and distillation simultaneously in said column; continuously withdrawing a low boiling point reaction mixture containing the produced dialkyl carbonate from an upper portion of the column in a gaseous form; and continuously withdrawing a high boiling point reaction mixture containing the diol from a lower portion of the column in a liquid form, wherein (a) said continuous multi-stage distillation column comprises a structure having a cylindrical trunk portion having a length L (cm) and an inside diameter D (cm) and having thereinside an internal with a number of stages n, and comprises a gas outlet having an inside diameter d 1 (cm) at a top of the column or in the upper portion of the column near to the top, a liquid outlet having an inside diameter d 2 (cm) at a bottom of the column or in the lower portion of the column near to the bottom, at least one first inlet provided in the upper portion and/or a middle portion of the column below the gas outlet, and at least one second inlet provided in the middle portion and/or the lower portion of the column above the liquid outlet, wherein (1) the length L (cm) satisfies the formula (1); 2100 â‰¦Lâ‰¦ 8000â€ƒâ€ƒ(1), (2) the inside diameter D (cm) of the column satisfies the formula (2); 180 â‰¦Dâ‰¦ 2000â€ƒâ€ƒ(2), (3) a ratio of the length L (cm) to the inside diameter D (cm) of the column satisfies the formula (3); 4 â‰¦/Dâ‰¦ 40â€ƒâ€ƒ(3), (4) the number of stages n satisfies the formula (4); 10 â‰¦nâ‰¦ 120â€ƒâ€ƒ(4), (5) a ratio of the inside diameter D (cm) of the column to the inside diameter d 1 (cm) of the gas outlet satisfies the formula (5); 3 â‰¦D/d 1 â‰¦20â€ƒâ€ƒ(5), and (6) a ratio of the inside diameter D (cm) of the column to the inside diameter d 2 (cm) of the liquid outlet satisfies the formula (6); 5â‰¦ D/d 2 â‰¦30â€ƒâ€ƒ(6).