乙烯装置碳三阻聚剂低温结晶问题研究与优化

STUDY AND OPTIMIZATION OF LOW TEMPERATURE CRYSTALLIZATION OF C3POLYMERIZATION INHIBITOR IN ETHYLENE PLANT

某1000 kt/a乙烯装置分离工段所使用的A型阻聚剂抑制结焦效果良好,但在低温环境下存在结晶现象,易使阻聚剂输送管道堵塞,造成阻聚剂输送断流。经实验研究,在温度为-10℃,转速为120 r/min,溶解时长1 min,晶体与脱丁烷塔塔釜产物-CY溶液的质量比为1∶4的条件下可完全溶解晶体,且溶解后静置72 h无晶体析出。在实验结论基础上提出了连续加注CY溶液防止结晶方案和间断式加注CY溶液进行阻聚剂输送管道解堵方案。

The A-type polymerization inhibitor used in the separation unit of a 1,000 kt/a ethylene plant has good coking inhibition effect,but it was easy to crystallize at low temperature,thus blocking the polymerization inhibitor delivery line and cutting off the polymerization inhibitor flow.According to the research,with the addition of CY solution,which is the bottom product of debutanizer,the A-type crystal can dissolve completely and no crystal will precipitate after 72 h when the reaction temperature is-10℃,the speed is 120 r/min,the dissolution time is 1 min and the mass ratio of crystal to CY solution is 1∶4.Based on the experiment results,two plans are proposed including the continuous addition of CY solution to inhibit the crystallization of A-type polymerization inhibitor and the intermittent addition of CY solution to dredge the polymerization inhibitor delivery line.