Study On The Properties Of The Self-stabilizing Micro-nano Emulsion And Its Application In Oily Sludge

Oilfield pollution is one of the major environmental original pollution in China.The oily sludge produced by mining of crude oil and natural gas in oilfield is rich in oil resources,but its residual poisonous substances do harm to the environment and human health.While the total amount of oily sludge is increasing,a simple and feasible method is urgently needed.In this paper,the self-stabilizing micro-nano emulsion was adopted to effectively recover the srude oil from two kinds of oily sludge and to reduce the environmental pollution.The separation process showed that the self-stabilizing micro-nano emulsion should contain H101 as dispersibility and anhydrous calcium chloride?CaCl₂?as density modifier.The effective separation of oily sludge could be achieved without auxiliary ultrasound.Through single factor experiment,the optimum process conditions for the separation of 1# oily sludge by the self-stabilizing micro-nano emulsion were obtained: the stirring temperature was 50 ?,the amount of anhydrous CaCl₂ was 3.02 g in 18.00 g H101 aqueous solution,the mass ratio of H101 and H₂ O was 1:3,the liquid to solid ration was 8.34?that was 2.52 g oily sludge in 21.02 g H101 salt solution?,the cooling temperature was 20?,the stirring speed was 600 r/min for 100 min.The optimum process conditions for the separation of 2# oily sludge: the stirring temperature was 70?,the amount of anhydrous CaCl₂ was 2.50 g in 18.00 g H101 aqueous solution,the mass ratio of H101 and H₂ O was 1?3,the liquid to solid ration was 8.10?that was 2.53 g oily sludge in 20.50 g H101 salt solution?,the cooling temperature was 20?,the stirring speed was 650 r/min for 120 min.From the Fourier Transform Infrared spectrum?FT-IR?,thermogravimetric?TG?curve and X-Ray Diffractomer?XRD?pattern results,it could be found that the self-stabilizing micro-nano emulsion could be effectively used in the separation of the two kinds of oily sludge and it was better for the extraction of saturated hydrocarbons.There were two obvious weight loss stages in the pyrolysis process of the two oily sludge: the first stage?105.0?³23.5??was the precipitation of bound water and the volatilization of oil organic matter with low boiling point;thesecond stage?420.7?⁴64.4? for 1# oily sludge,406.5?⁴64.5? for 2# oily sludge?was for the precipitation of the volatiles when the pyrolysis was intense.The main components of the two kinds of sludge separated from the two different oily sludges were both silica.Among the seven density modifiers,41.4 g anhydrous CaCl₂ which had the highest solubility could be dissolved in 25wt% H101 aqueous solution.The Dindal phenomenon of the self-stabilizing micro-nano emulsion varied with the mass fraction of H101 and the addition of anhydrous CaCl₂.The average particle size of the self-stabilizing micro-nano emulsion under the optimum process conditions was 20.7 nm.For the self-stabilizing micro-nano emulsion without density modifier,the cloud point decreased first and then increased with temperature increasing.For the self-stabilizing micro-nano emulsion with density modifier,the trend of cloud point was consistent with the above,but the corresponding values decrease d obviously.With the addition of anhydrous CaCl₂ increased,the cloud point of the self-stabilizing micro-nano emulsion gradually decreased and eventually tended to balance.When 5wt% H101 was added to H₂ O,the surface tension was decreased from 69.2 m N/m to 39.3 m N/m.The effect of anhydrous CaCl₂ on the surface tension of the self-stabilizing micro-nano emulsion was not significant.When the amount of anhydrous CaCl₂ was 8.45 g,the surface tension was 31.4 m N/m.The self-stabilizing micro-nano emulsion has good cycle performance.Under certain conditions,the self-stabilizing micro-nano emulsion separates 1500 tons 1# oily sludge from shengli oilfield,which can produce direct benefits of 4.83 million RMB.And it can save 15 million RMB in sewage charges.The processing technology of oily sludge by the self-stabilizing micro-nano emulsion has a prosperous developing foreground with strong practicality,operability,good environmental benefits and economic benefits.