METHANE HYDROCARBON INTERACTION PARAMETERS CORRELATION FOR THE PENG-ROBINSON AND THE T-MPR EQUATION OF STATE

Generalized expressions for the interaction coefficients (k(ij)) of CH 4/hydrocarbon binary systems are presented for a modified and translat ed Peng-Robinson equation of state (t-mPR). The correlations involve t he acentric factor of the heavier hydrocarbon and cover the CH4/n-alka ne systems up to n-C-44 plus isomers and cycloalkanes. Typical errors in bubble point pressure predictions are below 5%, similar to those ob tained by fitting the T-P-x data. Successful predictions of saturated liquid and vapor volumes are also obtained. For the CH4/non-alkane sys tems average k(ij) values are recommended, since the lack of data for an adequate number of systems does not allow the development of a gene ralized correlation. The proposed correlations can be used with the Pe ng-Robinson equation of state as well.