Enhanced Energy Savings from Simultaneous Triple Esterification of C4-C6 Alcohols in a Single Reactive Distillation Column

Abstract

This paper introduces multiple esterification reactions of three alcohols occurring in a single reactive distillation (RD) column and reports significant energy savings by combining three reactions in the single unit. To realize a feasible integration of the three reactions, the removal of the common water product from the unstable heterogeneous azeotrope should be possible through liquid-liquid decantation in the eight-component system. For this multireaction system, only the direct sequence can produce three esters with a purity higher than 99.0 mol % due to the behavior of liquid-liquid phase equilibrium. We demonstrate an economic evaluation of the direct sequence of a single RD column simultaneously producing the three esters by comparing the direct sequence with the two parallel RD sequences in the same design basis. The total annual cost of the triple esterification direct sequence is reduced by 21.3-25.2% compared to that of the parallel esterification system.