Entrainer-Enhanced Reactive Distillation for the Production of Butyl Acetate

A new reactive distillation (RD) process using a mass separation agent (extraneous entrainer) for the efficient production of butyl acetate from butanol and acetic acid via an esterification reaction was proposed. Until now, butyl acetate, a product of the esterification reaction, has been used as an internal entrainer in the production of butyl acetate. It has also been accepted that a configuration consisting of a prereactor followed by a reactive distillation column is most suitable for the production of butyl acetate. The use of an internal entrainer may shift the reaction equilibrium to be favorable to the reverse reaction in the reactive section, limiting the reaction yield. However, an extraneous entrainer, such as cyclohexane, can resolve the problem. It can be used to break the water–alcohol azeotrope and remove water more efficiently from the reactive section. In this study, we proposed a single reactive distillation configuration without a prereactor and the use of an extraneous entrainer (cyclohexane) and investigated the influence of various parameters, such as entrainer composition, reboiler duty, feed location, and number of reactive stages, on process performance. We demonstrated that the use of an extraneous entrainer instead of the internal entrainer, butyl acetate, can significantly improve the process efficiency and achieve great energy savings and capital cost reduction compared to the use of a prereactor followed by RD with butyl acetate as an entrainer.