Process Simulation And Analysis Of Nylon 6 Manufacture Process

Process simulation and analysis of Nylon 6 manufacture process using Aspen Plus have been conducted. Firstly, the methods and models including thermodynamic property, mass transfer coefficient of caprolactam(CL) and solubility of cyclic dimer(CD) were studied. Then modeling blocks of major sections in Nylon 6 manufacture process, including leaching section, drying section and triple effect evaporation section had been built.Leaching model based on leaching kinetics were realized by connecting the existing models of Aspen Plus of CSTRs in series. After adjusting the models with industrial data, we determined the number of CSTR to be 8 and the Correction factor of CD to be 3.5×10-3. Analysis of the main process parameters of leaching section and some optimization suggestions had been conducted then.Drying model based on normalized drying kinetics were realized using the data acquired by TGA. It was verified that the calculated results was in good agreement with design value of industrial plant. The temperature distribution, water content distribution and drying rate distribution of the manufacture process were then analyzed based on the model.Triple effect evaporation model was built and then calibrated. After verifying the calculated results with the industrial plant, sensitivity analysis was carried out on the system. Then some optimization suggestions and the significance and problems in the practical application were discussed.Finally, a hierarchical model for the whole process was created following the theory of hierarchical mechanism based on the above models. With appropriate convergence method, the simulation will be realized and provide reference for later study.