Patent ID: 8071819
Filing Date: 2011-12-06
Classification: B01D,C07C,Y02P

Abstract:
1. An industrial process for the production of a high-purity diol in which a high-purity diol is produced by taking a cyclic carbonate and an aliphatic monohydric alcohol as starting materials, continuously feeding the starting materials into a continuous multi-stage distillation column A in which a catalyst is present, carrying out reactive distillation in said column A, continuously withdrawing a low boiling point reaction mixture A T containing a produced dialkyl carbonate and the aliphatic monohydric alcohol from an upper portion of the column A in a gaseous form, continuously withdrawing a high boiling point reaction mixture A B containing a produced diol from a lower portion of the column A in a liquid form, continuously feeding said high boiling point reaction mixture A B into a continuous multi-stage distillation column C, distilling off material having a lower boiling point than the diol contained in said high boiling point reaction mixture A B as a column top component C T and/or a side cut component C S so as to obtain a column bottom component C B , continuously feeding the column bottom component C B into a continuous multi-stage distillation column E, and obtaining the diol as a side cut component E S from a side cut outlet of the continuous multi-stage distillation column E, wherein: (a) said continuous multi-stage distillation column E comprises a distillation column comprising a stripping section having a length L (b) the enrichment section of said continuous multi-stage distillation column E has at least one chimney tray as an internal installed therein, said chimney tray having installed therein at least two chimneys each having an opening having a cross-sectional area S (cm and each of the chimneys being such that a height h (cm) from the opening of the chimney to a gas outlet of the chimney satisfies the formula (11): (c) the diol is continuously withdrawn in a liquid form from the side cut outlet, which is connected to a liquid collecting section of said chimney tray of said continuous multi-stage distillation column E.