PREDICTION OF ETHANE AND CO2 SOLUBILITIES IN HEAVY NORMAL-PARAFFINS USING GENERALIZED-PARAMETER SOAVE AND PENG-ROBINSON EQUATIONS OF STATE

A study was made of the abilities of the Soave and Peng-Robinson equations to represent the phase behavior of ethane + n-paraffin and CO2 + n-paraffin systems. These equations are capable of describing the phase behavior of such systems; however, the level of precision obtained varies with the degree of complexity used in representing the interaction parameters in the mixing rules employed. For ethane/CO2 With n-paraffins extending from C3 to n-C44, an uncertainty of about 1 % is obtained for bubble point pressures (or about 0.005 mole fraction for solubilities) when two system-specific interaction parameters per isotherm are used. Simple generalized correlations are presented for the equation-of-state interaction parameters which allow prediction of the bubble point pressures with an expected uncertainty of about 5.7 % (0.014 in mole fraction).