Prediction model of interfacial tension of H2/H2O and (N2+H2)/H2O systems using the linear gradient theory in combination with PR-EOS

Interfacial tension (IFT) is an important physical parameter to study the behavior of gas-liquid two-phase in microstructures. In this paper, the IFT values for hydrogen-containing binary and ternary systems are investigated, and the IFT values are measured and predicted for the H2/H2O and (N2 + H2)/H2O systems in the temperature range from 278.6 K to 368.2 K. A simplified linear gradient theory (LGT) coupled with a modified PREoS is utilized to solve the densities and IFT values of the H2/H2O and (N2 + H2)/H2O systems over the temperature range. In the process, a new empirical correlation equation is also proposed to determine the interaction coefficients of the ternary systems. The IFT values of the above binary/ternary systems decrease with increasing temperature over the whole temperature range, and the comparison with the experimental values shows that the predictive model exhibits predictive instability near the lowest and highest temperatures, and the overall average deviation of the predicted values from the experimental values is 1.02 %, which is in good agreement. The applicability of the above prediction models in pressure environments has also been briefly explained during the process of the study. The results of this study present for the first time the prediction model of interfacial tension for hydrogen-containing binary and ternary systems, which provides a theoretical basis for the study of gas-liquid two-phase behavior of hydrogen-containing systems.