Phase equilibrium calculation for clathrate hydrates based on a statistical thermodynamics model: An attempt to optimize the Kihara parameters for methane and ethane

An attempt was made to determine new Kihara parameters for methane and ethane with which the phase equilibrium pressure-temperature conditions for the simple methane and ethane hydrates can be accurately calculated based on the van der Waals-Platteeuw theory. The predictions with these new parameters were compared with those due to the other hydrate phase equilibrium prediction programs and the previously reported Kihara parameters as well as with the experimental values to examine the utility of the parameters. The results indicated that the phase equilibria for the simple methane and ethane hydrates are well reproduced with the new parameters determined in the present study, whereas the phase equilibria for the methane + ethane and methane + propane double hydrates were not well reproduced with the new parameters.