Simulation And Optimization Of The Production Process Of Caprolactam

Caprolactam is an important organic material, which is widely used in various fields. In recent years, Caprolactam industry developed rapidy, but the demand of caprolactam in the field of high-end has been dependent on foreign imports due to the weakly technology. The production process of caprolactam, as one of the complicated production process in organic chemical industry, consequently how to optimize the process and technology of the production of domestic caprolactam to make it more competitive has became to a hotpot research these years. The traditional route of caprolactam production-- hydroxylamine route, is still the mainstream; and the newly cyclohexanone oxidation route is becoming the development trend in future.This paper takes the process of hydroxymine phosphat method which products 70000 tons of caprolactam for example, and the process simulation software of Aspen Plus is applied to create a simulation process of caprolactam. Including the separation process of the preparation of hydroxymine phosphate and caprolactam.On the base of the accurate simulation, firstly through analyzing the process, the maximizing the yield of caprolactam, minimizing the consumption of distilled towers' energy and minimizing the consumption of benzene are determined to be the opimization objectives. Then the operation and design parameters of each towers and usage of extractant are choosed to be the optmization variables. The restrains are determined by the process requirements. Non-dominated sorting genetic algorithm with elitist strategy(NSGA-II) is employed to solve the model. From analyzing the resulting Pareto front, the law impact of the benzene consumption and the energy consumption on the yield of caprolactam is revealed, which can provides reference for caprolactam separation process in design and operation optimization.The route of producing caprolactam by cyclohexanone oxidation is a green caprolactam production technology which was firstly developed in domestic, and then being developed rapidly. Firstly analyze and compare the difference between two processes of producing caprolactam in process flow and economy. Analyzes the dynamics of cyclohexanone oxidation and Beckmann rearrangement in liquid phase briefly, and then simulate these processes. The influence of mixture ratio and the reaction conditions on the yield of reaction is determined by sensitivity analysis. Then combined with the separation process, the process of producing caprolactam by cyclohexanone oxidation is obtained, which can establish foundation for the next step.Firstly, identified six important optimization indexes by analyzing the preparion of caprolactam of cyclohexanone oxidation process, contains the yield of cyclohexanone omixe, the yield caprolactam sulfonate, the cost of raw materials, separation effiency of towers, energy consumption of towers and the extractant consumption of toluene and benzene. And then intergrated these optimization indexes, the optimization model of the maximizing the economic benefits, minimizing the energy consumption is built and then solve it. Finally, from analyzing the resulting optimal front, the influence of the optimum variables on the yield and energy consumption of the optimized variables is revealed, which can provide reference for prepartion caprolactam of cyclohexanone oxidation process in design and operation optimization.