Interfacial tension measurements in water−methane system at temperatures from 278.15 K to 298.15 K and pressures up to 10 MPa

This paper reports the measurements of the interfacial tension in a water−methane system at temperatures from 278.15 K to 298.15 K and pressures up to 10 MPa. The measurements using the pendant-drop method were performed at various pressures lower than or, at the highest, nearly equal to the hydrate/liquid/gas equilibrium pressure corresponding to each of the following prescribed temperatures: 278.15 K, 283.15 K, 288.15 K, 293.15 K and 298.15 K. The obtained data show that at each temperature the interfacial tension decreases almost linearly with the increasing pressure, indicating that the observed decrease in the interfacial tension results from the promotion of methane adsorption onto the interface with the increasing pressure. •A set of new experimental data of water–methane interfacial tension was obtained.•Pressure dependence of the tension at five different temperatures was investigated.•The pressure was raised up to 10 MPa or the three-phase equilibrium pressure.•The tension exhibited nearly linear decrease with an increasing pressure.