超声波电脱盐破乳技术的应用研究

The Application of Ultrasonic Demulsification in Electrical Desalting Process

长庆石化采用"超声波强化破乳技术",进行500×104t/a常减压装置电脱盐工业试验与应用,经过空白试验、降破乳剂、优化调整、重复试验等阶段,完成了原油超声破乳设备性能试验。超声波强化破乳技术利用超声波的物理作用方式,产生波动-位移效应,破坏油水乳化结构,增强水在电场与重力作用下的分离能力。应用实践表明,该工艺可实现不加破乳剂达到原油破乳后盐含量不高于3mg/L、含水不高于0.3%的指标要求,同时一级脱盐罐乳化减轻,电脱盐总排水COD值由约2000mg/L降至约1000mg/L;电脱盐总排水含油由300～400mg/L降至100mg/L以下。采用超声波完全替代破乳剂破乳,能够显著降低电脱盐电流,保证电脱盐装置稳定生产。与现有的破乳技术相比,该工艺是一种设计合理、成本低、效率高的原油破乳手段,同时具有无污染、零排放、低能耗、效果好的特点。

PetroChina Changqing Petrochemical Company introduced an enhanced ultrasonic demulsification technology in its 500 ×104t/a atmospheric and vacuum distillation unit under an industrial electrical desalting experiment and application program.After several stages including blank tests,reduced use of demulsifiers,optimization and adjustment and repeated experiments,the company completed the experiment on the performance of ultrasonic crude oil demulsification equipment.Utilizing the physical action of ultrasound,the enhanced ultrasonic demulsification technology can produce the volatility-displacement effect to damage the oil and water emulsification structure and enhance the separating capacity of water in electric fields and under the effect of gravity.Applications show that in this technology,the content of salt in demulsified crude oil does not exceed 3mg/L and water content does not exceed 0.3% when no demulsifier is used.In addition,apart from alleviated emulsification in the primary desalting tank,the COD value of the total drainage of the electrical desalting process dropped to some 1000mg/L from around 2000mg/L and the content of oil in the total drainage of the electrical desalting process dropped to less than 100mg/L from 300-400mg/L.Completely replacing demulsifiers with ultrasound can considerably reduce the current used in the electrical desalting process,therefore ensuring a stable operation of the electrical desalting unit.Compared with conventional demulsification technolo gies,the ultrasonic technology is a crude oil demulsification approach with excellent design and higher efficiency and involving lower cost investment.It is characterized by non-pollution,zero emission,high energy efficiency and good effect of use.