乙烯装置原料轻质化改造后循环乙烷系统优化

OPTIMIZATION OF CIRCULATING ETHANE SYSTEM AFTER MODIFICATION OF ETHYLENE PLANT FOR LIGHTER RAW MATERIALS

辽阳石化裂解装置2019年完成原料轻质化改造,将2台裂解炉改造为加工液化气及芳烃尾气的裂解炉。气体炉的投用提高了乙烯收率,但因循环乙烷量大幅升高,导致裂解炉乙烷转化率降低,影响装置正常运行。通过流程优化,对循环乙烷进行二次分配解决了转化率低的问题,并通过降低乙烷汽化器出口压力,减少了乙烷液位高频繁排放火炬问题,优化了系统运行。

PetroChina Liaoyang Petrochemical Company completed the modification of its ethylene plant for lighter raw materials in 2019 and transformed two gas furnaces to process liquefied gas and aromatic tail gas.The operation of the gas furnaces improved the ethylene yield,but the amount of circulating ethane increased greatly,resulting in the decrease of ethane conversion rate of the cracking furnace and affecting the normal operation of the plant.The secondary distribution of circulating ethane through process optimization solves the problem of low conversion rate.By reducing the outlet pressure of ethane vaporizer,the problem of high-frequency emission of ethane to flare due to high liquid level is reduced,and the system operation is optimized.