| abstract |
This invention provides a specific method for separating on a commercial scale by-product alcohols from a large amount of low-boiling reaction mixture containing alcohols as by-products produced in mass production on a commercial scale of aromatic carbonates by transesterification of a dialkyl carbonate with an aromatic monohydroxy compound in the presence of a catalyst in a reaction distillation column, that is, a continuous multistage distillation column having a specific structure. The above method can overcome drawbacks of the prior art that, despite a number of proposals on production processes of aromatic carbonates by a reaction distillation method, all the conventional proposed production processes are for production on a small scale for a short period of time, i.e., on an experimental scale, and there have been no disclosure of any specific method and apparatus which can realize mass production on a commercial scale in a stable manner for a long period of time, and no disclosure of specific method and apparatus in which alcohols as by-products in the production of aromatic carbonates on a commercial scale by a reaction distillation method can be separated on a commercial scale of not less than 200 kg per hr in an efficient and stable manner for a long period of time. |