Optimization-Based Design of a Reactive Distillation Column for the Purification Process of Cyclohexanone Using Rigorous Simulation Model and Validated Using an Experimental Packed Column

This paper presents a model for a reactive distillation column where 2-cyclohexen-1-one is eliminated from a mixture of cyclohexanone and cyclohexanol. In the purification of cyclohexanone, 2-cyclohexen-1-one must be removed to produce high quality caprolactam. A common practice in industry is to promote the condensation of 2-cyclohexen-1-one with cyclohexanone using NaOH as catalyst. However, it promotes the cyclohexanone self-condensation with the drawback of incurring raw material losses. The column model was developed using gPROMS and validated using a packed distillation column on laboratory scale at steady state. The kinetic model of involved reactions and the binary interaction parameters of NRTL equation were implemented. The model can predict adequately the concentration profile for the involved compounds. The model was used to optimize the operating industrial conditions to minimize the unitary total cost to produce high purity cyclohexanone. gPROMS algorithms were used to solve the resulting mixed-integer nonlinear problem.