双峰聚乙烯生产技术的优化

Optimization of production technology of bimodal polyethylene

分析了双峰聚乙烯装置运行中存在的主要问题,根据双峰工艺技术特点,从流化床参数控制、产品牌号切换、催化剂切换、在线色谱分析等方面采取了优化措施。严格控制流化床的乙烯分压和乙烯分压的增长速率、1-丁烯的加入速率、流化密度、流化速率、气相反应器入口温度以及反应温度变化率,并对在线色谱进行改造,增加了一个旋风分离器。通过优化,提高了流化床参数控制的稳定性,避免了块料的产生,实现了长周期运行的目标。

This paper analyzed main problems occurred in operation of a bimodal polyethylene （PE） plant. Several optimized measures were taken in terms of the characteristics of the bimodal PE technology, involving parameter control of fluidized bed, transition of product grade, change-over of catalyst and application of on-line gas chromatograph. The partial pressure and its increasing rate of ethylene in the fluidized bed, feeding rate of 1-butane, fluidized density, fluidized velocity, inlet temperature of the gas reactor and changing rate of reaction temperature were strictly controlled. The on-line gas chromatograph was renovated and was operated in conjunction with a cyclone separator specially equipped. The optimization of the technology improved the stability in parameter control of the fluidized bed, avoided the phenomenon of product clumping and realized the target for long-term operation.