Study On High Gravity Technoilogy Intensifing Oil Solid Separation Process

A large amount of oil-solid mixed waste will be generated during the exploitation,transportation and refining of petroleum.The most representative ones are oil sludge and catalytic cracking oil slurry.The popular treatment method of oil sludge is thermochemical cleaning,and for oil slurry,it is settlement with chemical additives.The common characteristics of them is to add a certain amount of chemical additives to the oil-solid system,and mix them well,so that the chemical additives can react on the surface of solid particles to realize oil-solid separation.Nowadays,the mixing equipment used to treat oil sludge and oil slurry is stirred tank reactor(STR).But the oil sludge and oil slurry belong to the high viscosity system.The mixing and mass transfer efficiencies of oil sludge,oil slurry and chemical additives in STR are poor,which leads to poor separation effect,long treating time,high additives consumption.High gravity technology has high mixing and mass transfer performance,so we introduces the high gravity technology into the oil-solid separation process.In addition,the study of intensified oil-solid separation by high gravity technology was carried out,which includes screening of chemical additives and investigation of treating process parameters in RPB.The main works of this paper are as follows:1.For the oil sludge studied in this paper,the effective detergent solution consists of 5 wt%Na2SiO3,2 wt%water-soluble demulsifier B1 and 93 wt%H2O.Moreover,when feeding speed is 25.27 kg/h,the optimum operating parameters in RPB is recommended to be as follows:rotating speed is 500 rpm,oil sludge/detergent solution ratio is 1:2,cycle time is 30 min,cleaning temperature is 80℃,and settling time is 20 h.Under the optimal conditions,the oil content in the treated sludge can reach to 3.13%in RPB treatment process,and the oil removal rate up to 95%.Furthermore,compared with the traditional thermochemical method,thermochemical method in RPB can improve the separation efficiency by 43%and reduce the dosage of detergent solution by twice.2.For the oil sludge studied in this paper,the effective settling agent mainly consists of oil-soluble alkyl phenolic resin and polyether.And,when feeding speed is 20.69 kg/h,the optimum operating parameters in RPB is recommended to be as follows:rotating speed is 900 rpm,usage of settling agent is 400 μg/g,mixing temperature is 95℃,mixing time is 25 min,settling temperature is 95℃,settling time is 24 h.Under the optimal conditions,the ash content in the treated oil slurry can be reduced to 270 μg/g in RPB treatment process.Furthermore,compared with the traditional method,the treatment with chemical additives in RPB can improve the separation efficiency by 15.6%.And during the whole treatment process,the rotating speed is smaller than traditional method,the dosage of settling agent is reduced by 20%,and the mixing time is reduced by 16%.The results show that RPB can intensify the oil-solid separation process remarkably,which indicates that RPB has potential research and application value in the oil-solid separation process.