Synthesis and characterization of a corn oil based demulsifier for crude oil emulsion

Water in oil emulsion occurs at many stages in the production and treatment of crude oil. The presence of water causes several operational problems like corrosion in equipment and pipelines. It is also an environmental/health threat, can interfere with refining operations, and generally increases the cost of oil production. Therefore, for economic, environmental, and operational reasons, it is essential to separate the water from the oil before transporting or refining the latter. The most effective method for overcoming this problem is to demulsify the crude using chemical demulsifiers through the synthesis of a demulsifier. Some gaps remain through this process, including that chemical demulsifiers, though effective, are mostly petroleum-based and refractory organic polymers. They often subject the ambient ecosystem to more hazardous risks and use highly complicated preparation methods, greatly limiting their applications. No study has yet been conducted using a new mix design to identify the significant and optimum values of the variables which affect the synthesis of a demulsifier. The aim of this research was to synthesise a demulsifier for crude oil emulsion using materials based on natural products and by applying the design of experiments method. A corn oil–based demulsifier was successfully synthesised through the condensation reaction of corn oil with diethanolamine in the presence of a catalyst applied during separation via a water-in-oil (W/O) emulsion using response surface methodology (RSM). The significant parameters of synthesis, identified through design of experiments, included a temperature of 180 °C, a time of two hours, a 2.5% catalyst, and diethanolamine to corn oil (D/C) 1/3, v/v. The demulsifier was characterised by FTIR, GC-MS, NMR, LC-QTOF-MS, and IFT analyses. The surfactant’s separation efficacy was studied using the Sany-glass test. The results showed that the new product efficiently demulsified the W/O emulsion, with 98% separation achieved. The influence of the settling time, demulsifier dosage, temperature, and pH on the demulsification efficiency were investigated. The separation efficiency increased with increases in the settling time, demulsifier dose, and pH, while the temperature conditions accelerated the demulsification process. The interfacial tension decreased with an increased dosage of the demulsifier, and the central composite design (CCD) of the response surface methodology (RSM) was employed during the optimisation demulsification process. The optimisation process was performed using four factors (water content, demulsifier dosage, temperature, and pH). The optimum conditions for demulsification were achieved at water content 40%, dosage 3500 ppm, temperature 60 ºC, and pH 8. Finally, the validation of the results showed good agreement with the experimental data, while the new demulsifier demonstrated excellent performance and was deemed promising for demulsifying W/O emulsions