Liquid–vapour equilibrium in the krypton + methane system

Abstract

Experimental measurements of liquid–vapour phase equilibria in the system krypton + methane are reported for seven temperatures in the range 160.56–204.59 K and pressures to 5.25 MPa. The results for the three lower isotherms, below the methane critical temperature, have been used to estimate the excess Gibbs energy G^E. The mixture critical line has been located in (P, T, x) space. In all respects the system conforms very closely to the ideal model for liquid mixtures, exhibiting only very slight, positive departures from Raoult's law. The results of the experiments have been compared with the predictions of three equations of state, namely the Redlich–Kwong, Peng–Robinson and Deiters equations. The agreement is good for all three, with the Deiters equation performing particularly well, even in the methane supercritical region.