Demulsification of Water-Containing Crude Oil Driven by Environmentally Friendly SiO<sub>2</sub>@CS Composite Materials
Huaikui Yuan, Zejun Zhang, Yuanzhu Mi, Fan Ye, Wangfu Liu, Jiazhe Kuan, Xia Jiang, Yue Luo
Abstract
Relatively low cost, environmental friendly, and high-efficiency silicon dioxide/carbon sphere composite demulsifiers (SiO2@CS) were prepared via an in situ hydrothermal–calcination route. They were characterized by Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. The demulsifiers with different ratios of SiO2 and CS were systematically investigated. The effect of the temperature, standing time, and dosage of SiO2@CS on the demulsification performance was determined by the bottle test. The efficiency reached the highest value of 89.52% when the dosage, temperature, and standing time were 300 mg/L, 70 °C, and 150 min, respectively. Also, the pH value and salinity were inspected. It was encouraging to find that the demulsifier had good acid, alkali, and salt tolerance. Investigations of the wettability, dynamic interfacial tension, and self-assembly of the interfacial film and microexaminations were carried out to probe the possible mechanism. SiO2@CS exhibited good adsorption, flocculation, and coalescence abilities in the demulsification process. The current work is beneficial for the further understanding of the demulsification process and also provides a promising demulsifier to deal with the water-in-crude oil emulsion.