Borstar双峰聚合反应产品性质分析及模型建立

通过对Borstar双峰聚合反应过程产品性质实验分析,Borstar双峰聚乙烯技术超临界环管反应器生产聚合物熔融指数相对于分子量呈指数规律变化,气相反应器生产的聚合物熔融指数随分子量增加而呈一定规律的减少,聚合物分子量继续增加聚合物熔融指数减少趋势缓慢;在实验分析的基础上,基于聚合反应机理应用MATLAB软件建立工业装置聚合过程聚乙烯熔融指数及密度等产品性质计算模型和确定模型参数,通过模型拟合值和实际值的比较,模型能够准确预测熔融指数和密度的变化趋势,有关聚乙烯在环管中的熔融指数、在流化床内的熔融指数和密度的质量模型相对平均误差分别为2.4%,0.5%和0.3%。通过产品质量预测模型的推导和分析,环管部分熔融指数主要受温度、H2]/C2H4]影响;而气相部分熔融指数既受环管聚合物来料性质影响,又受气相反应器温度和H2]/C2H4]和C4H8]/C2H4]的影响

Analysis and simulation of resin quality of bimodal polymerization process in Borstar technics

The resin quality experimental data in Borstar bimodal polymerization process show that melt index is exponentially relative to the molecular weight changing for polymer in loop reactor, the polymer melt index in the gas fluidized bed reactor is the reduction of certain law and the reduction trends change slowly with molecular weight increasing. The resin quality model for Borstar bimodal polymerization process is developed by using kinetic mechanism and experimental result, the model parameters are confirmed by plant data using MATLAB software. The comparison of calculated values with plant data for the MI and density of polymer in the loop reactor and gas fluidized bed reactor show that the predicted data are all close to actual values, verifying that the model accurately describes the changing trend of plant production quality. The model deviations of MI for polymer in loop reactor and gas fluidized bed reactor and of density for polymer in gas fluidized bed reactor are respectively less than 2.4%, 0.5% and 0.3%. Derivation and analysis of product quality prediction model, the melt index of loop reactor is mainly affected by temperature, the ratio of H 2 ] and C 2 H 4 ], melt index of gas fluidized bed reactor is affected not only by incoming nature from the loop tube polymer, but also by the gas phase reactor temperature and the ratio of H 2 ] and C 2 H 4 ] and the ratio of C 4 H 8 ] and C 2 H 4 ].