abstract |
The object is to provide a specific process for production of a dialkyl carbonate and a diol using a cyclic carbonate and a monohydric aliphatic alcohol as raw materials, by a reaction distillation method in which the raw materials are fed continuously into a continuous multi-stage distillation column containing a catalyst to achieve both the reaction and the distillation simultaneously in the column, wherein the dialkyl carbonate and the diol can be produced stably for a long period in an industrial scale of 2 tons or more per hour and 1.3 tons or more per hour, respectively, with high selectivities and high yields. Although various process for production of a dialkyl carbonate and a diol by a reaction distillation method have been proposed, these are all relate to the production at a laboratory level (i.e., a small scale and a short production period). There has been no disclosure about a process or apparatus for the industrial-scale mass production of a dialkyl carbonate and a diol. Thus, disclosed are a specific continuous multi-stage distillation column having such a constitution that a dialkyl carbonate and a diol can be produced stably for a period of 1000 hours or longer, preferably 3000 hours or longer, more preferably 5000 hours or longer, in an industrial scale of 2 tons or more per hour and 1.3 tons or more per hour, respectively, and at a selectivity of 95% or higher for the both, preferably 97% or higher, more preferably 99% or higher; the raw materials are fed into a specific stage of the distillation column; and a production process using the distillation column. |