AN APPROACH FOR THE APPLICATION OF A CUBIC EQUATION OF STATE TO HYDROGEN HYDROCARBON SYSTEMS

This paper presents an approach for predicting the solubility of hydro gen in hydrocarbons using a cubic equation of state. Because the alpha function from the Soave-Redlich-Kwong and Peng-Robinson equations of state is inadequate at temperatures far above the critical temperature , the binary interaction parameters required for hydrogen-hydrocarbon systems using these equations are typically large and strongly depende nt on the temperature. An approach is proposed for developing a temper ature-dependent alpha function for hydrogen which minimizes the need f or interaction parameters. The minimization of the values of the binar y interaction parameters between hydrogen and heavy hydrocarbons is de sirable because this produces better predictions when the binary inter action parameters are not known and are set to zero. A universal proce dure is also presented for interconverting the binary interaction para meters between the new hydrogen alpha function developed in this work and the traditional Soave alpha function or any other type of alpha fu nction.