Propylene Polymerization Process Simulation Based on Aspen
|School||Ocean University of China|
|Keywords||Aspen Plus Simulation software Spheripol polymerization process polypropylene|
Polypropylene (PP) is a kind of thermoplastic synthetic resin`with perfectproperties. It has the advantages of high strength, high melting point, high resistanceto wear, has been widely used in agriculture, daily life and the automotive industryand other fields. Because of the raw material sources, low price, easy to processingand molding, the perfect properties and wide range of uses, polypropylene hadbecome the fastest developing varieties of general resin since it was producedindustrially. Now there are various of polypropylene production processes. Thecapacity of polypropylene devices which use the Spheripol process accounts for about50%of the total production capacity. The modeling research of Spheripol process hasgreat significance to process improvement, capacity expansion, new productdevelopment and so on. In this paper, combined with the actual production data, itsimulated the propylene polymerization process on Aspen Plus software.The main content of the thesis, method of the research and the main resultsinclude the following:(1) On the basis of previous research, this paper simplified the mechanism ofpropylene polymerization, established the homopolymerization and copolymerizationmodel, and derived the calculation methods of polypropylene s physical properties.The calculated results of polymerization model which was proposed in this paper canmatch the actual production data well. It shows that the proposed model of propylenepolymerization can better simulate the propylene polymerization process, and canguide different factors effect on polymerization reaction.(2) This paper set up and simulated the loop reactor model of propylenepolymerization process in Aspen Plus software. Combined with the actual productionprocess parameters, the polypropylene EPS30R production process was simulated.And studied the effect of reactor s circulation ratio on the distribution of reactortemperature and material. Results show that the circulation ratio of reactor has a greatimpact on the distribution of reactor temperature and material. When the circulationratio of reactor is small, the temperature and material composition change a lot alongthe reactor tube, especially in propylene feed inlet. With the increase of circulation ratio, the material composition and temperature tends to be uniform, which isbeneficial to product quality control. The results verify the correctness of actualproduction process within the loop reactor using a higher circulation ratio.(3) Meantime this paper simulated the condition analysis of productive process.The results showed that different feeding condition had different effects on thesimulation result of polypropylene. when catalyst increases in feed, the productionand molecular weight distribution index of polypropylene rise, while the numberaverage molecular weight is reduced. When cocatalyst feed increases, the productionand molecular weight distribution index of polypropylene decreases, the numberaverage molecular weight increases. Hydrogen feed has a greater impact on thenumber average molecular weight of polypropylene, which decrease with the increaseof hydrogen feed. But hydrogen feed has no effect on the propylene conversion rate.Compared with results, it shows that catalyst feed has the greatest impact on thesimulation result of polypropylene, Especially for the influence of polypropyleneproduction.(4) The engineering analysis results can guide the development of newpolypropylene products. Based on the model of propylene polymerization and theattributes target of the new product, this paper finally obtained the feed conditions ofnew polypropylene after continuous adjustment, and the result can provide referencedata for developing the new polypropylene product NPP1.