Separation Of Water-in-Oil Emulsion With Microfiber Glass

As an important process in many production fields,oil and water separation has attracted public attention.Water removal from oil is a technical problem.It is crucial to employ suitable methods or materials as well as taking into account of economy,operability,energy saving and environmental protection for dealing with the problem.In this paper,microfiber glass was used to separate water from water-in-oil emulsions and the separation effect and mechanism of fiber coalescence were studied.The effects of influent water content,superficial velocity and bed properties（bed height,porosity,fiber diameter and bed arrangement）on the water removal were investigated.The results showed that the increase of influent water content is beneficial to the improvement of separation efficiency.Take the bed height of 15mm as an example,when the influent water content changed from 500mg/L to 2000mg/L,the separation efficiency increased from 85.0%to 92.8%.But when the influent water content was greater than 2000mg/L,the change of separation efficiency was less than 1%and remained at around 93%.Superficial velocity of 4.9×10^-3m/s was the critical value in this experiment.When the velocity was less than the critical value,the effluent water content was maintained below 300mg/L.Once the velocity exceeded the critical velocity,the effluent water content increased sharply and the coalescence effect deteriorated.When the velocity reached 7.3×10^-3m/s,the gap among the effluent water content of the fibrous bed with different height and porosity was less than50mg/L.It turned out that the effect of bed height and porosity became secondary.The pressure drop across the fibrous bed is in accordance with the Carman-Kozeny equation.The study of the bed properties showed that the increase of bed height enhanced the coalescence effect.When the bed height increased from 5mm to 15mm,the separation efficiency increased by 8.7%.While the bed height changed from 15mm to25mm,the efficiency increased by only 0.9%.The increase of bed porosity increased the effluent water content.When the porosity increased from 0.75 to 0.85,the separation efficiency decreased by less than 3%.When it increased from 0.85 to 0.95,the separation efficiency decreased by more than 25%.Fiber diameter is an important factor for oil and water separation.The addition of finer fiber in the bed enhanced the interception of the fibrous bed and the effluent water content was lower.In the bed arrangement experiments,the mixed bed which composed of three kinds fibers with different ratio（5%0.60μm+5%2.58μm+90%4.62μm）showed the best separation performance.The separation efficiency was 97.1%and the pressure drop was 48.4kPa.The results determine the appropriate fluid conditions and reasonable range of bed properties which provides a reference for the treatment of water-in-oil emulsion on a large-scale in the future.