Separation of Water-in-Crude Oil Emulsions by Non-Ionic Tweens and Coal Fly Ash Powder at Thermal Treatment and Centrifugation
Abstract
The study aimed to investigate the separation of water-in-crude oil emulsions by non-ionic Tweens and coal fly ash powder at thermal treatment followed by centrifugation. Two samples of crude oil from different oilfields of Kazakhstan were taken (sample1 and sample 2). For sample 1 the heating followed by centrifugation resulted in formation of intermediate layer emulsion. The use of Tweens for the sample 1 showed demulsifying ability close to 60 % and prevented the formation of an intermediate layer. The results of IR-spectroscopy confirm the mechanism of demulsification of coal fly ash based on an adsorption of stabilizing components of crude oil and their interaction with coal fly ash particles. The combination of coal fly ash and non-ionic amphiphile Tween 60 showed a slight increase of DE (68 %) for sample 1, and the formation of the intermediate layer emulsion was not observed. While for sample 2 the separation in the presence of coal fly ash and non-ionic Tween 60 was higher than 85 %, and 92 % for combination of Tween 80 and 2 % of coal fly ash. It has been shown that demulsification by fly ash and non-ionic surfactants depends on the nature and stability of crude oil emulsion.