Prediction of methane-carbon dioxide-nitrogen gas hydrate equilibria: Recovery of methane from hydrate reservoirs and natural gas reservoirs

Because of the reported release of the CO2 emission into the atmosphere, it is needed to develop a new permanent CO2 method. In this study, the feasibility of a CO2 separation gas hydrate method has been tested and a new CO2 sequestration method in the form of hydrate slurry has been proposed. A program based on the Distortion model was used to predict equilibrium pressures of gas hydrates. Predicted values were obtained for three systems: carbon dioxide---nitrogen, methane---carbon dioxide, and methane---carbon dioxide---nitrogen. The equilibrium values for the CO2---N2 gas hydrate were obtained for a temperature interval of 273-283 K. These predicted values matched closely to published experimental results based on the phase diagram of N2-CO2 gas hydrate, the potential of a new separation method to remove from the flue gas has been verified Predicted hydrate-phase mole fractions for the CH 4---CO2 and CH4---CO2---N 2 systems give support to the feasibility of sequestering carbon dioxide in the hydrate structure. The results predict that methane may not be recovered from the hydrate. A new process of using hydrate slurry injection to recover natural gas from reservoirs was proposed as an alternative. This subject was explored with sample calculations, which can be improved if actual PVT conditions are known.