Keywords
crude oil dehydration
demulsification
scanning electron microscopy (SEM)
interfacial armored shells
water droplet coalescence
asphaltene-stabilized emulsions
surfactant composition
cottonseed soapstock
oil desalting
emulsion stability
petroleum processing.
How to Cite
Abstract
Water–oil emulsions formed during crude oil production and transportation represent one of the major technological challenges in petroleum processing due to their high stability and resistance to conventional separation methods. In the present study, the microstructural features and stability mechanisms of water–oil emulsions obtained from the Kokdumalak and Amu-Darya oil fields were investigated using scanning electron microscopy. Morphological analysis was performed with a Thermo Scientific Quattro S SEM scanning electron microscope, allowing visualization of the localization of water globules, mineral salts, and stabilizing particles within the dispersed system. SEM observations revealed that water droplets are surrounded by complex armored interfacial shells formed by asphaltenes, resins, finely dispersed mineral salts, and mechanical impurities. These shells significantly increase the stability of the emulsified system and hinder droplet coalescence during conventional dehydration processes. The introduction of the industrial demulsifier K- 1 promoted partial coagulation of water droplets; however, a significant fraction of finely dispersed droplets remained stabilized due to the strong protective interfacial structures. To intensify the destruction of stable water–oil emulsions, a demulsifying composition based on pre-saponified cottonseed soapstock (PSCS) combined with the industrial demulsifier K-1 was investigated. Experimental results demonstrated that the proposed composition effectively promotes droplet aggregation, accelerates coalescence processes, and enhances the removal of water, chloride salts, and mechanical impurities from crude oil. The optimal PSCS consumption was found to be 45–70 g/t of crude oil, which significantly reduced the residual water and salt content in commercial oil. The obtained results provide new insights into the microstructural mechanisms governing the stability of water–oil emulsions and demonstrate the potential of using surfactant compositions based on industrial by-products for improving the efficiency of crude oil dehydration and desalting processes in oil treatment facilities.References
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