| 摘要 |
The present invention provides a process for the production of high purity methyl acetate from methanol and glacial acetic acid wherein the acetic acid functions both as a reactant and as an extractive agent. The process comprises countercurrently flowing approximately stoichiometric quantities of acetic acid and methanol through a single reactive distillation column in the presence of an acidic catalyst which is preferably sulfuric acid. The column provides intimate contact between the acetic acid and the methanol and between the acetic acid and the azeotropes (methyl acetate/water and methyl acetate/methanol) which are formed in the column. At preferred catalyst concentrations, the residence time in the column is at least about two hours. The process further comprises continuously removing high purity methyl acetate from the top of the column and continuously removing water from the bottom of the column. In preferred embodiments, the process further comprises removing intermediate boiling compounds, such as methyl propionate, methyl butyrate, isopropyl acetate, and mixtures thereof, from a vapor sidedraw stream. The invention further comprises in preferred embodiments the use of a temperature control scheme whereby the overhead and the bottoms compositions are controlled by using two temperature control loops. |
