Abstract: The sulfur-containing sewage generated at the top of the flare tower of the delayed coking unit has high oil content, serious emulsification, large amount of coke powder, and difficult to settle and separate oil and water. The traditional high-oil sewage treatment technology can no longer meet the national environmental protection requirements. The problem of efficient and environmental protection treatment of high oil wastewater needs to be solved urgently. Combined with the technology and operating characteristics of the flare tower system of a delayed coking unit, using the process optimization and equipment improvement, the coke powder washing capacity was improved, the oil-water separation effect was improved, and the sewage on the top of the vent tower is discharged up to the standard. The results show that the mass concentration of oil in sewage can be reduced to 179 mg/L without injecting chemicals, and 37,800 TPY heavy sewage oil can be redistilled continuously, 5,000 TPY non-condensable gas can be recovered. The requirements of environmental protection and economic benefits can be achieved.

Key words: delayed coking unit, flare tower, revamping, sulfur-containing sewage, low-temperature heat utilization, economic benefits

摘要： 延迟焦化装置放空塔顶产生的含硫污水油含量高、乳化严重、携带焦粉多、油水不易沉降分离,传统的高含油污水处理技术已经不能满足国家的环保要求,延迟焦化装置放空塔顶高油污水高效环保处理问题亟待解决。结合中国石化某延迟焦化装置放空塔系统的技术和运行特点,通过流程优化、设备改进,提高放空塔焦粉洗涤能力,改善油水分离效果,确保放空塔顶污水达标排放。技术改造结果表明,在不注入化学药剂的情况下,放空塔顶外排污水油质量浓度降低至179 mg/L,实现连续回炼全厂重污油37.8 kt/a,回收燃料气5.0 kt/a,达到了环保要求,增加了经济效益。

关键词: 延迟焦化装置, 放空塔系统, 改造, 含硫污水, 低温热利用, 经济效益