聚乙烯装置的流化床反应器开车方法优化

Optimization of start-up for fluidized-bed reactor of polyethylene plant

分析了聚乙烯装置在开车期间存在的主要问题,结合历年开车数据和生产经验,提出了具体的控制措施。回收利用蒸汽冷凝水至流化床反应器(R-401)的冷却系统,以提高循环冷却水温度;优化置换方法,细化R-401系统复位前的确认工作;优化R-401内床层料位、床层分配率和循环气体组分的浓度,以及超临界环管反应器内氢气浓度等的方法。减少了置换次数6次,缩短开车期间的排放时间9.0 h,缩短开车时间8.0 h,减少了氮气用量35 700 m3,减少开车期间乙烯、1-丁烯、丙烷和氮气排放量各1.5,0.1,14.5,19.9 t,增加产量510 t,达到预期效果。

The author analyzed the main problems during the start-up on the polyethylene plant. According to the historical start-up data and production experience, some controlling measures were taken, such as recycling condensate water to the cooling system of the fluidized-bed reactor R-401 in order to increase the cooling water temperature, optimizing method of substitution, defining confirmation items before R-401 system resetting, and optimizing controlling methods for fluidized-bed level, bed split and circulation gas ratio in R-401 and hydrogen concentra tion in the supercritical loop reactor. By the above effective measures, substitution was decreased by six times, discharge time was shortened by nine hours, start-up time was shortened by eight hours, nitrogen usage was reduced by 35 700 m3, discharge amounts of ethylene,1-butene, propane and nitrogen were reduced by 1.5, 0.1, 14.5 19.9 t, respectively. Consequently, the yield was increased by 510 t, and the desired effect was achieved.