摘要
为解决某石化公司1.2 Mt/a延迟焦化装置溢流冷焦过程中存在的冷焦水带油导致冷焦热水罐挥发性有机化合物(VOCs)含量较高的环保问题,将溢流冷焦工艺改造为泡焦冷焦工艺。通过在接触冷却塔回流罐罐顶挥发线上增加蒸汽抽空器,将焦炭塔冷焦过程中产生的蒸汽、油气抽至分馏系统,利用冷焦水的汽化潜热带走焦层中的热量,实现焦炭塔的泡焦冷焦。焦炭塔泡焦冷焦技术改造完成、投用后,焦炭塔冷焦时间在12 h内可以达到放水条件,对装置生产周期没有影响;冷焦过程中冷焦热水罐罐顶VOCs质量浓度从352.8 mg/m^(3)下降至1.6 mg/m^(3),冷焦水中油质量浓度从20~70 mg/L下降至1~10 mg/L;污油罐的污油量每天减少30 m^(3),说明冷焦过程中的油气较多地被回收至分馏系统,从而减少了随冷焦水带出的油气量;1.0 MPa蒸汽能耗增加4.13 MJ/t,电能耗减少2.04 MJ/t,总能耗增加2.09 MJ/t,对装置能耗影响较小;石油焦挥发分略有上升,能满足指标要求。焦炭塔采用泡焦冷焦工艺后,解决了原溢流冷焦过程中存在的环保问题,实现了装置的环保运行。
In order to solve the environmental problem of high content of volatile organic compounds(VOCs)in coke cooling hot water tank caused by oil entrainment of coke cooling water during overflow coke cooling process of 1.2 Mt a delayed coking unit in a petrochemical company,the overflow coke cooling process was transformed into coke soaking coke cooling process.By adding a steam extractor on the evaporator line at the top of the reflux tank of the contact cooling drum,the steam and oil gas generated in the coke cooling process of the coke drum were pumped to the fractionation system,and the heat in the coke layer was removed by utilizing the vaporization latent heat of the coke cooling water,so as to achieve coke soaking and coke cooling in the coke drum.The coke cooling time of the coke drum could reach the water discharging condition within 12 h after the process of coke soaking coke cooling was completed and put into operation,which had no impact on the production cycle of the unit.During coke cooling,the mass concentration of VOCs in the top of hot water tank decreased from 352.8 mg m 3 to 1.6 mg/m^(3),the mass concentration of oil in the coke cooling water decreased from 20-70 mg/L to 1-10 mg/L.The decrease of 30 m^(3) d in the waste oil tank indicated that more oil and gas in the coke process were recovered to the fractionation system,thus reducing the oil and gas carried out with the cold coke water.The steam energy consumption of 1.0 MPa steam increased by 4.13 MJ/t,the electrical energy consumption decreased by 2.04 MJ/t,and the total energy consumption increased by 2.09 MJ/t,which had little impact on the energy consumption of the unit.The volatile of petroleum coke increased slightly,which could meet the index requirements.The problem of environmental protection existing in the original overflow coke cooling process was solved,and the environmental operation of the unit was realized after the coke soaking coke cooling process was adopted in the coke drum.
作者
李林
宋福荃
杨万强
张剑
Li Lin;Song Fuquan;Yang Wanqiang;Zhang Jian(PetroChina Lanzhou Petrochemical Company,Lanzhou 730060)
出处
《石油炼制与化工》
CAS
CSCD
北大核心
2024年第5期26-30,共5页
Petroleum Processing and Petrochemicals
关键词
延迟焦化
冷焦水
泡焦冷焦
挥发性有机化合物
delayed coking
coke cooling water
coke soaking coke cooling
volatile organic compounds
