Phase Separation in Binary Systems: the Possibility of Gas-Gas Equilibrium at Subcritical Conditions

Abstract

The possibility of gases exhibiting limited solubility under subcritical conditions is analyzed and discussed. It is shown that a binary gas mixture will always behave like a regular solution and that phase splitting is theoretically feasible whenever the condition (Pdelta12)/(RT) > 2 is fulfilled where delta12 = 2B12-B11-B22. The value of delta12 required for phase splitting to occur is extremely large so that although the phenomena is theoretically possible, it will occur rarely or at all.