Nonionic Demulsifier for Smart Demulsification of Crude Oil Emulsion at Room and Moderate Temperatures

This study reports the demulsification activity of a newly developed nonionic demulsifier (NID) via the condensation of glycolic acid ethoxylate lauryl ether with amine. The demulsification performance of the developed NID was assessed under room and moderate temperatures (25 and 60 °C), while the concentrations of NID were varied from 100 to 700 ppm at both temperatures in order to observe their oil-water separation efficiency. The demulsification mechanism was expatiated by determining the viscosity and elastic modulus of emulsion in the presence and absence of the NID. Adsorption at the oil and water interface was analyzed through a series of interfacial tension measurements. Accordingly, under the aforementioned temperatures, the optimal demulsification efficiency of the NID was 95% (25 °C) and 99% (60 °C) at 500 ppm. Viscosity determination at both temperatures revealed a drastic reduction in emulsion viscosity in the presence of NID, and the viscosity drop was of high magnitude at moderate temperatures (60 °C). Likewise, the elastic modulus measurements in bulk rheology revealed that the presence of NID in the emulsion weakened the elastic strength. Again, the interfacial modulus test exhibited the percolation of NID at the oil-water interface and the displacement of asphaltenes. Interfacial tension (IFT) measurements of the oil-water system at different NID concentrations showed that the particles were adsorbed at the oil-water interface. The IFT values of the oil-water system in the presence of NID ranged from 1.84 to 3.02 mN/m as compared to that of the NID-free oil-water system recorded as 16.11 mN/m. It is envisaged that this new nonionic demulsifier would be very useful in oilfields and petrochemical industries.