Theoretical investigation of the possibility of using multicomponent (N2-O2-CH4-Y2O) clathrate hydrates for methane recovery from mine gas

Phase equilibria in a multicomponent ice-gas mixture-hydrate system are investigated for a mixture of nitrogen, oxygen, and methane, depending on the gas phase composition, pressure, and temperature. Equilibrium compositions of the formed hydrates are found, depending on the gas mixture composition. Calculations show that with increasing concentration ofmethane in gas phase the pressure of hydrate formation gradually decreases. It is shown that this pressure at considerable methane concentrations approximately corresponds to partial pressure of methane in the gas phase. Conditions of hydrate formation are calculated in the range of temperatures from 258 to 273 K, at pressures from 1 to 350 atm. The obtained results are in agreement with the known experimental data for hydrates of pure gases-nitrogen, oxygen, and methane.