The challenges associated with heavy crude oil emulsions during hydrocarbon exploitation cannot be overemphasized. As such, water/crude oil separation in oil fields becomes necessary before conveyance to the refinery. In this study, we investigated new classes of pyridinium ionic liquids (ILs) demulsifiers, 1-butyl-4-methylpyridinium tetrafluoroborate, 1-butyl-4-methylpyridinium hexafluorophosphate, and 1-butyl-4-methylpyridinium iodide, designated as BMPT, BMPH, and BMPI, with unique anions (BF4 –, PF6 –, and I–), respectively. The effects of concentration dosages (100–1000 ppm) and anions of these ILs on the demulsification of produced emulsions were assessed using the bottle test technique at 75 °C. Viscosity and shear stress determination as well as interfacial tension (IFT) measurements were applied to affirm the effectiveness of these ILs to separate water/oil into phases. Bottle test results revealed that BMPT, BMPH, and BMPI demulsifiers removed water from the emulsion effectively, and the demulsification efficiency (% DE) increased with increasing dosage. BMPT, BMPH, and BMPI achieved the best % DE of 84%, 99%, and 59%, respectively, at 1000 ppm after 60 min. The highest water separation was recorded in PF6 – anion because of its high hydrophobic nature. Viscosity and shear stress time-sweep measurements indicated the reduction in viscosities and shear stresses after injection of the demulsifiers. Also, the dynamic IFT results showed that these demulsifiers could mix with water–oil at the interface, break asphaltenes and resins molecules, and reduced the IFT from 16.01 to 12.47 mN/m. Optical microscopic emulsion images before and after demulsifier injection and the demulsification mechanism describing the water/oil separation stages are also discussed.
Efficient demulsifiers for fast demulsification of asphaltene stabilized crude oil emulsions are currently in high demand. In this work, we evaluated the demulsification potential of ethyl cellulose (EC) demulsifiers with varying viscosities—4 cp, 22 cp, and 100 cp, designated as EC-4, EC-22, and EC-100. Demulsifcation efficiency (DE) of these demulsifiers to remove water from emulsions produced from distilled water, seawater, and different salts (NaCl, MgCl2, and CaCl2) solution were assessed using the bottle test technique at ambient and elevated temperatures (25 °C and 90 °C). The bottle test outcomes showed that EC-4 and EC-22 had better performance at the ambient conditions to demulsify the emulsions formed from distilled water with %DE of 85.71% and 28.57%, respectively, while EC-100 achieved 3.9% water removal owing to its high viscosity which inhibited its adsorption at the oil–water interface. At demulsification temperature (90 °C) under the emulsions from distilled water, the %DE of EC-4, EC-22, and EC-100 was 99.23%, 58.57%, and 42.85%, respectively. Seawater hastened the demulsification activities of these demulsifiers. Also, these demulsifiers demonstrated excellent demulsification in emulsions from various salts. The demulsification performance of the EC-4 demulsifier in the presence of any of these salts was approximately 98% while MgCl2 and CaCl2 accelerated the water/oil separation performance of EC-22 and EC-100 by promoting their diffusion and adsorption at the interface. Viscosity and shear stress measurements corroborated the results obtained from the bottle tests. Injection of EC demulsifiers led to a reduction in the viscosity and shear stress of the formed emulsion. Reduction in the shear stress and viscosity were highest in EC-4 and lowest in EC-100. Optical microscopic images of emulsion injected with EC-4 demulsifier were analyzed at various periods during viscosity measurements. Based on the optical images obtained at different durations, a demulsification mechanism describing the activity of the EC demulsifier was proposed.
Diesel-in-water emulsions have several applications in the upstream and downstream petroleum industry. The Diesel-in-water emulsions are not very well understood despite its numerous applications. In this work, water/diesel emulsions were prepared using octylphenol ethoxylate as an emulsifier at different mixing time and speeds, varying surfactant concentrations, and using different water/diesel ratios. The emulsion stability was evaluated using a bottle test method, droplet size distribution (microscope), and rheological measurements. It was found that emulsion stability not only depends on the concentration of surfactant, water, and diesel but also on mixing speed and time. The emulsion stability was enhanced by increasing the concentration of water, and the most stable emulsions were achieved when the water ratio was higher than 80. The emulsion stability significantly increased when the mixing speed was increased up to 1200. Further increase in the mixing rate did not affect stability. An optimum surfactant concentration was noted to get the most stable emulsions. Modeling results showed that the predicted and measured viscosities were very close with minimal marginal errors. The excellent predicted viscosity values are demonstrated by the considerable root mean square error (RMSE): 0.0873 and 2.5164 and mean absolute error (MAE): 0.0595 and 1.8675 for the training and testing dataset, respectively. The current study indicated that water to diesel ratio and mixing method could significantly affect the emulsion characteristics.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.