SPG聚丙烯工艺流程模拟研究和优化

采用ASPEN PLUS的Polymer Plus对SPG聚丙烯技术中本体淤浆聚合工段和气相卧釜工段的两个关键的技术进行了较深入的研究。模拟结果表明,淤浆聚合反应收率在52%～58%时,聚丙烯总收率最高。淤浆反应温度提高,聚丙烯总收率和淤浆反应收率都提高。随着气相反应温度提高,气相反应收率先下降随后缓慢提高。加入少量氢气可以使聚丙稀数均分子量快速下降,聚合物分散度快速增加,而当氢气超过一定量以后,这种变化趋缓。为了确保反应器体积的充分利用和催化剂活性基本消耗完,要确定淤浆反应器体积和气相釜的体积和反应温度的匹配关系。根据反应热分布相应采用非均匀冷凝回流的方法,可以解决采用均匀冷凝回流方式时卧釜温度控制比较困难的问题。最后,提出了一些优化卧釜气相聚合流程的建议。

Simulation and Optimization of SPG Polypropylene Technology

The pivotal slurry and gas-phase polymerization workshop sections of SPG polypropylene (PP)technology were simulated by ASPEN Polymer Plus.The results showed that PP yield reached tiptop when the slurry yield was 52%-58%.The total PP yield and the PP yield in the slurry reaction both increased when the slurry temperature was increased,while the gas-phase polymerization yield first decreased then increased slowly with gas temperature increasing. The molecular weight of PP decreased and polymer distribution index of PP increased quickly when a little hydrogen was added, and then varied slowly when the amount of H_2 was above some value.The appropriate relation of the volume of slurry reactor and gas-phase reactor to the reaction temperature was determined in order to insure that the reaction volume was made full use and the catalyst activity was worked out.The difficulty of controlling the temperature of the horizontal reactor was overcome by adopting even condensation refluence in the place of uneven condensation refluence and some suggestions were put forward to optimize the gas-phase polymerization flow.