| 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 are 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 selectivity/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). Any process or apparatus for the mass production of a dialkyl carbonate and a diol in an industrial scale has not been disclosed yet. Thus, disclosed are: a continuous multi-stage distillation column having such a specific 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, at a selectivity of 95% or higher, preferably 97% or higher, more preferably 99% or higher; and a production process using the column. |