Interfacial tension between (methane + ethane + propane) gas mixture and water from 283.2 K to 298.2 K under up to 10 MPa

This paper reports a study of the interfacial tension between natural gas (methane + ethane + propane gas mixture) and water. The composition of the (methane + ethane + propane) gas mixture was 89.95:7.05:3.00 and 95.0:3.5:1.5, in mole ratio. These measurements were performed using the pendant drop method at pressure and temperature conditions of up to 10 MPa and between 283.2 K and 298.2 K, respectively. These conditions were chosen to eliminate the possibility of clathrate hydrate formation. Interfacial tension in the (natural gas + water) system decreased with increasing pressure, but no temperature dependence was found for any of the at all conditions. The interfacial tension gradient with respect to pressure was found to depend on the composition of gas phase. The interfacial tension in a (natural gas + water) system was found to be smaller than that of a (methane + water) system.