Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Chemical Engineering


The solubilities of argon and of three binary gas mixtures of nitrogen and methane, 25%CH$\sb 4$ - 75%N$\sb 2$, 50%CH$\sb 4$ - 50%N$\sb 2$ and 75%CH$\sb 4$ - 25%N$\sb 2$, in water have been measured at a temperature of 323K for pressures up to 124.1 MPa. The data have been correlated using the established forms of the Krichevsky-Kasarnovsky and Krichevsky-Ilinskaya equations and are in agreement with previous studies. The performance of the Krichevsky-Ilinskaya equation has been improved by using Wilson's equation in place of the two-suffix Margules equation to predict the non-ideality associated with the solute gas in the solution. A simple predictive method for ternary mixtures, based on an extension of the Krichevsky-Kasarnovsky equation, has been proposed. The thermodynamic properties of pure polar fluids, a preliminary to the treatment of aqueous solutions, have been studied using statistical mechanics. A perturbation theory using a nonspherical reference potential has been derived and results have been compared to other perturbation theories and computer simulation studies. The extension of this theory to use a nonspherical reference fluid is described but remains as yet untested. The thermodynamic properties of the reference fluids in the perturbation theories mentioned above have been determined by Monte Carlo computer simulation. A comparison of the results from the two sources suggests that the accuracy of the perturbation theories could be improved by a more accurate calculation of these reference properties.