Research About Modeling And Simulating Of Acrylonitrile Polymerization Reactor Based On Mechanism Analysis Method

In the industrial production processes with polymerization reaction, making a mathematical model including polymerization reactor, which can successfully reflect to both the polymerization reaction kinetics mechanism and the industrial performance of reactor running, is very important and indispensable. Modeling combining with polymerization reactor is not only helpful to master the inherence of the polymerization process, but also the basis of optimizing the production process, switching production type and enhancing the production efficiency. Due to its complexity of the polymerization kinetics mechanism and the practical industrial polymerization processes, modeling for a polymerization process becomes a problem of polymer reaction engineering.In this paper, the process of free-radical aqueous suspension copolymerization of Acrylonitrile (AN) and Vinyl Acetate (VA) using NaClO3-NaHSO3 as initiator was studied. Combining mechanism analysis method and polymerization reactor's characteristic, we respectively established the steady-state model and dynamic model of Acrylonitrile polymerization reactor. Depending on industrial production historical date, rate constant of steady-state model was fitted by random optimum seeking method. The materiel concentration in reactor, monomer conversion rate and average molecular weight were calculated and simulated using materiel residence time as a variable. The complicated steady-state model was predigested by approximate stationary state in order to prepare to establish dynamic model of Acrylonitrile polymerization reactor.The dynamic mathematical model of polymerization reaction in Continuous Stirred-Tank Reactor (CSTR) was constructed depending on conservation of materiel and conservation of energy. The dynamic mathematical model was simulated to investigate start-up process of polymerization reactor using the datum of production process. The results intuitively reflected the variety characteristic of each materials concentration, monomer conversion rate, average molecular weight and reaction temperature in CSTR. The influence factors of polymerization were investigated and simulated using the dynamic model. At last, we made a mathematical analysis of the thermal stability and steady-state operating point; furthermore, we gave simulation of the dynamic response about reactor temperature and the analysis result for steady-state operating point.