Catalytic processes for the preparation of acetic esters

Abstract

An improved process for the preparation of acetic esters is disclosed. It comprises a fixed bed reaction and a catalytic distillation. The fixed bed reaction comprises the steps of: (a) charging acetic acid and alcohol into a fixed bed reactor under a predetermined reaction condition; and (b) reacting the esterification reactants in the fixed bed reactor. The fixed bed reactor contains acidic catalysts that are present in a solid phase, and the reaction condition is controlled such that (i) the reactants and the products co-exist in a gas-liquid two-phase equilibrium in the fixed bed reactor and that (ii) at least one component of the reactants is present in one phase and at least one component of the products is present in another phase. The catalytic distillation comprises the steps of: (1) charging acetic acid from top of a catalytic distillation column and the reaction products from the fixed bed reactor from the bottom of the catalytic column in a counter-flow manner; and (c) continuously removing acetic ester and water from the top of the catalytic distillation column, and continuously removing acetic acid from the bottom of the catalytic distillation column. The acetic acid removed from the catalytic distillation column is fed into the fixed bed reactor. Very high alcohol conversion and essentially alcohol free product can be obtained at substantially reduced height of the catalytic distillation column.