Thermally Coupled Reactive Distillation System for the Separations of Cyclohexene/Cyclohexane Mixtures

Abstract

Because of the very close boiling points of cyclohexene and cyclohexane, their separation is extremely difficult with conventional distillation systems and reactive separation with water as reactive entrainer offers great economic incentives. In the current work, the synthesis and design of a flow-sheet with two reactive distillation columns (i.e., the hydration and dehydration reactive distillation columns) in series (FSTRDC) is first conducted subject to the minimization of total annual cost (TAC), and this leads to a process design with an excessive use of water. Although the process design facilitates the hydration of cyclohexene into cyclohexanol, it gives rise to a serious remixing effect in the hydration reactive distillation column and poses an unfavorable effect to the decomposition of cyclohexanol into cyclohexene and water in the dehydration reactive distillation column. For the suppression of these deficiencies, the hydration reactive distillation column was then modified to be heated directly...