Effect of TBAB and SDS surfactants on the interfacial tension of CO2 Hydrate in water

Abstract

The interfacial tension rate is an important factor in the kinetic study of gas hydrate formation. In this study, the interfacial tension between CO2 hydrate and water was calculated at various temperatures, pressures and solution concentrations through measuring the induction time according to the Classical Nucleation Theory (CNT). Since the nucleation of hydrate is in part an interfacial phenomenon, interfacial properties such as the interfacial tension between gas and water may have a great influence upon the hydrate formation rate. Experimental data for pure water showed that, at constant temperature, with increasing pressure, the interfacial tension decreases from 2.92 to 1.67 mN/m, and at constant pressure with increasing temperature, interfacial tension increases from 3.92 to 4.7 mN/m. At constant temperature, with increasing TBAB concentration from 1% to 3% by weight, the induction time decreases from 60 to 36 seconds. At higher temperatures, addition of SDS 500 ppm decreased the induction time and interfacial tension from 4.61 to 2.32 m N/m. Finally, the relationship of nucleation intensity with the super saturation was obtained by fitting the experimental data. According to equations and graphs, the nucleation intensity is a function of temperature.