Modeling of high-pressure ethylene-vinyl acetate copolymer at autoclave reactor

• Main Author: 甘子葳
• Other Authors: 錢義隆
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/17374718142388141080

碩士 === 國立臺灣科技大學 === 化學工程系 === 91 === For EVA free radical copolymerization, a mathematical model is developed to simulate composition concentration and reaction heat profile in the high-pressure autoclave reactor. Furthermore the model predicts structural and physical properties of production in the reactor outlet. In the model, EVA kinetic model is simplified to homopolymerization by using pseudo kinetic rate constant method, moreover, the reaction mechanism include the long chain branching frequencies. The technique of moments is then used to find the average molecular weight of polymer. Due to nonideal mixing, the reactor is divided into seven reaction zones in sequence. In addition to initiator and monomer feeds, each zone has mutual back-mixing flow. It is shown that the predicting properties of the proposed model agree well with plant model results and actual manufacturing data. In order to predict the properties of production such as Production Rate, Melting Index, Comonomer Weight Percent for seven different grades, we try to obtain the optimal kinetic parameters set for the EVA model. First, the most important reactions that affect the properties of production are determined by quantitative and qualitative analysis, then a three-stage approach is deduced to obtain the optimal kinetic parameters in the model. From different Melting Indexes, two sets of optimal kinetic parameters are found. One applies to three grades of lower Melting Indexes; another applies to four grades of higher Melting Indexes.