Estimation of kinetics parameters in Beckmann rearrangement of cyclohexanone oxime using genetic algorithm

Abstract

Beckmann rearrangement mechanism of cyclohexanone oxime, based on the characteristic of self-catalyzed reaction and polymorphism was proposed. According to the suggested mechanism, the basic approach was the rearrangement of OXH⁺ while the SO₃ acts as dehydrating agent and OXSO₃ can turn to CPLSO₃ ultimately. Considering self-catalyzed reaction between OXSO₃ and CPLH⁺, kinetic model for Beckmann rearrangement was established. Corresponding parameters were estimated by using float genetic algorithm (GA) and simulation results agree well with the experimental data below −19.3 °C. Industrial equipment was simulated and analyzed. Effects of key process parameters such as molar ratio of sulfuric acid to oxime and circulation ratio on the residual oxime are also discussed. The results show that the caprolactam exists as CPLH⁺ finally in oleum and the minimum molecular ratio of sulfuric acid to oxime can be 0.5 theoretically.

Keywords

Beckmann rearrangement / reaction kinetics / genetic algorithm / caprolactam