Process Reform And Operation Parameter Optimization Of Electric Desalination System

With the deep exploitation of crude oil and the potential improvement of oil field,the properties of crude oil into the refinery become worse and worse.Most of the inferior crude oil contains a lot of suspended mechanical impurities,which are closely combined with crude oil and difficult to separate.The low quality of crude oil,especially emulsification,makes the operation of electrodesalination more and more difficult.In the case that the crude oil salt in the 3.5 million tons/year atmospheric and vacuum pressure unit of Daqing Refining and Chemical Company was unqualified for 2 consecutive years,the plant technicians upgraded and reformed the electrodesalination system,which greatly reduced the salt content of the crude oil after removal,so that the salt content of the crude oil after removal can meet the anti-corrosion requirements of the refining unit process and provide effective guarantee for the long cycle operation of the unit.This paper mainly describes the contents and key points of the transformation of the electrodesalination system of the 3.5 million tons/year atmospheric and vacuum unit in Daqing Refining and Chemical Company,and optimizes the process operation parameters after the transformation.Through the analysis of the temperature,pressure,oil-water boundary,mixed pressure difference,electric field strength,water injection and other parameters that affect the operation of the electrodesalination system,the optimum parameters of the operation of the electrodesalination system are determined.The temperature of the desalting tank is 135℃,the pressure is 0.75-0.85 MPa,the mixing strength is 55-65 k Pa,the boundary is30-40%,the current is 22-25 A,and the water injection is 5-6%.The optimized desalting crude oil salt content can reach the standard continuously and stably,which effectively reduces the corrosion problems of the equipment of its own equipment and subsequent equipment.