铬系催化剂在气相法聚乙烯中试装置的稳定运行研究

Research on stable operation of chromium catalyst in gas phase polyethylene pilot plant

介绍了50 kg/h气相法全密度聚乙烯中试装置的工艺流程,分析了影响铬系催化剂在中试装置上稳定运行的因素,重点针对系统杂质和原料杂质、反应器床层料位、流化气速、氧气注入量与时机、细粉含量、系统压差及堵塞等因素,从系统置换效果、反应器料位和流化气速的调控、反应温度的控制及保证操作稳定性等方面提出了相应的预防和处理措施。从本质上保障反应系统的清洁,优化开工步骤,降低操作波动,可有效避免或减缓反应器分布板及流化回路堵塞,从而达到延长装置运行周期的目的。

This paper describes the process flow of the 50 kg/h gas phase full-density polyethylene pilot plant as well as the various factors that impact the stable operation of chromium catalyst in the plant, which include fluidizing gas velocity, fine powder content, impurities in feedstock and system, oxygen injection rate and timing, reactor bed level, system pressure difference and blockage. Preventive measures and treatment actions are offered in terms of the fluidized gas velocity and reactor material level regulation, operation stability and temperature control, system replacement effect. It can significantly prevent or slow the congestion of distribution board and fluidization reactor loop, prolong the operating cycle of the plant by means of ensuring the reaction system clean, optimizing the start-up steps, and reducing operation fluctuation essentially.