Modeling And Simulation Of Industry Propylene Polymerization Process

The Spheripol-II propylene polymerization process has good advantages for itsproduction of high-quality and high-yield. The application of it is increasingly widespread, sothe study on the modeling and simulation of the industry equipment is very important for theincreasing of the economic efficiency. This paper is based on a Spheripol-II polypropyleneequip. The modeling study is carrying out on the reactor unit. Then steady and dynamicmechanism model of the main reactor is established. The steady model is established by usingHYSYS .In addition, the melt index predictive model are developed. The main work of thedissertation can be summarized as follows:This paper outlines the techniques principle of the Spheripol-II propylene polymerization.Then the techniques flow of each unit is introduced. The reaction mechanism and kinetics ofthe improved equip is analyzed in particular. On this basis, the main difficulties and problemsto be resolved of the production process modeling are concluded.According to the technical operation characteristic of the Spheripol-II reactor unit, it isassumed that the flow in each reactor is plug-like. Based on the kinetics of Z-N catalystpolymerization, mass balances and energy balances, the steady model of dual-loop reactor isestablished. Using the field data to solve the model, the model predict the distributionscharacteristics of materials in the loop reactor along the axial direction and technicalcharacteristics. It is validated the correctness of both model and the assumption. And it is alsobeneficial for the improvement of production conditions. In addition the steady simulation ofthe reaction unit is carried on by using the simulation software HYSYS. The simulationresults coincide with the yield results basically.Using the assumption on the above, we assume that the three reactors in react unit areCSTR. Dynamic concentration parameter model of dual-loop reactor in practical equipment isset up based on the mechanism analysis. Focus on the series structure of dual-loop reactor,combined with the yields, pilot study is carried on the consideration of the particular structureof the reactor. Aimed at the importance of the MI for the control of the production quality inthe process, the melt index inferential model was derived from the variables which effectedmelt index and were validated by process data. The model is simulated by using the yield data to identify its correctness. On this basis, the dynamic testing is carried to analyze the impactof the change of the production conditions on the dynamic characteristics of the dual-loopreactor. The simulation results inclined with the yield analysis basically to indicate that themodel can reflect the dynamic characteristics of the devices.