Taking a look accurately at the alteration of interfacial asphaltene film exposed to the ionic surfactants as demulsifiers

Abstract

The water droplets surrounded by a rigid interfacial asphaltene (ASP) film is one of the major setbacks in the petroleum industry. In this study, the properties of the interfacial ASP films around water droplets exposed to ionic surfactants as demulsifier were investigated. According to molecular dynamics (MD) simulation, the anionic surfactants are more effective than the cationic surfactant in the demulsification process since the anionic surfactants have the exact desire to localize not only near the ASP molecules but also near the water molecules. It has been found that it is likely to cause film changes and ruptures. Also, the MD simulation results for the desired surfactant, anionic surfactant, demonstrated that an increase in the surfactant concentration had an adverse effect on the system by hindering the change in the interfacial film. The increase in the temperature along with the enhancement in the adsorption rate of the surfactant results in the better performance of the demulsifier. Taking the MD and quantum results into account, the film deformation is a decisive factor in demulsification. The quantum computation has indicated that the electrostatic interactions play a significant role in selecting the attraction position and adsorption energy of the surfactant molecules.