Abstract
Electric dehydration is the most widely used physical technology for separating water from crude oil. However, natural surfactants stabilize the oil–water interface, resulting in low dehydration efficiency and failure of the electric dehydrator due to electric field collapse. To explore the physical methods of weakening the influence of surfactants on electric dehydration, this study synchronously increased magnetization during the electric dehydration. Based on high-speed microscopy experiments, it has been demonstrated that synchronous magnetization weakens the hindrance of surfactants to droplet coalescence during electric dehydration. Within the experimental conditions, the influence of magnetization on the growth coefficient C1 ranges from 2.9% to 26.6%. In addition, based on molecular dynamics simulation, the mechanism of magnetization weakening the influence of surfactants was studied at the molecular level. It was found that water molecules and surfactant molecules undergo significant molecular clusters after magnetization, reducing the influence degree of surfactants on unit area. When the surfactant concentration increases, the decrease in the influence degree is balanced by the increase in the number of molecules, which also explains the law that the improvement rate ΔC1 decreases with the increase in surfactant concentration. The results of this work will be potentially valuable for weakening surfactant barriers to demulsification and oil–water separation.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Gansu Province
Science and Technology Program of Gansu Province
doctoral research startup fund of Lanzhou University of Technology
Hongliu Excellent Young Talents Support Program of Lanzhou University of Technology
Subject
Condensed Matter Physics,Fluid Flow and Transfer Processes,Mechanics of Materials,Computational Mechanics,Mechanical Engineering