化学清洗技术在10.0 Mt/a常减压装置中的应用

介绍了化学清洗技术在中国石油天然气股份有限公司独山子石化分公司10.0 Mt/a常减压装置应用情况.从成本、蒸汽和新水消耗以及停工时间等方面对化学清洗中水基清洗和油基清洗两种技术进行了对比,最终选择油基清洗技术与热水循环冲洗撇油结合的方法来对常减压装置进行清洗,其中油基清洗以FCC柴油作为溶剂载体并经除臭及钝化清洗.应用结果表明,装置吹扫时没有发现异味现象,打开设备检测的硫化氢质量分数小于10 μg/g（实测硫化氢质量分数均为0）;打开设备人孔后没有发生硫化亚铁自燃现象,塔盘和填料表面有金属光泽,说明装置钝化和清洗效果良好.整个停工处理过程中,该清洗未对污水预处理系统造成任何冲击,化学清洗技术有效解决了蒸馏装置大型化后重油系统停工时不易彻底处理干净的难题,节约成本并缩短了停工及检修时间,实现了装置安全、环保、高效的绿色停工.

Application of chemical cleaning in a 10.0 MM TPY atmospheric-vacuum distillation unit

The application of chemical cleaning technology in the 10.0 MM TPY atmospheric-vacuum distillation unit in PetroChina Dushanzi Petrochemical Company was introduced.The advantages and disadvantages of water-based cleaning and oil-based cleaning in chemical cleaning were compared in respect of costs,consumption of steam and water and time required for unit shutdown.The combination process of oil-based cleaning and hot water recycle cleaning was finally selected.In oil-based cleaning,the FCC diesel was used as solvent carrier.The application showed that there was no bad smell during the cleaning.The hydrogen sulfide in opening equipment was lower than 10 ppm （the actual measured hydrogen sulfide was zero）.There was no auto-ignition of ferrous sulfide after opening of manhole.All trays and packings had metal luster,which indicated that the unit was good in passivation and cleaning.In the whole process of unit shutdown for treatment,the cleaning had no impingement on the operation of waste water treatment system.The chemical cleaning technology has provided a good solution to the difficulty in cleaning the heavy oil system of large crude oil distillation unit during the unit shutdown,and saved the costs and shortened the time required for unit shutdown and overhaul.Safe,environmentally friendly high-efficiency green unit shutdown has been realized.