Empirical correlation for calculating the pure liquid water–methane hydrate–methane equilibrium pressure

Abstract

A new empirical correlation for calculating the pure liquid water–methane hydrate–methane equilibrium pressure in the temperature range of 273.15–301.70 K is obtained. This correlation was obtained on the basis of 398 experimental points taken from 44 sources. A statistical error analysis was carried out, as a result of which it was found that the obtained empirical correlation is the best of the currently existing empirical correlations for calculating the pure liquid water–methane hydrate–methane equilibrium pressure. The obtained empirical correlation is satisfied with a mean absolute percentage error of 1.55% and a coefficient of determination of 0.997. A theoretical analysis was carried out, as a result of which the general form of any empirical correlation for predicting gas hydrate equilibrium conditions in the water–gas system was established. It is shown that the form of such empirical correlation follows from the Clausius–Clapeyron equation.

Keywords

• Methane hydrate
• Phase equilibrium
• Empirical correlation
• Clausius–Clapeyron equation