A saturated liquid density equation in conjunction with the Predictive-Soave-Redlich-Kwong equation of state for pure refrigerants and LNG multicomponent systems

An equation and a set of mixing rules for the prediction of liquid density of pure refrigerants and liquified natural gas (LNG) multicomponent systems have been developed. This equation uses the parameters of Mathias and Cope man [P.M. Mathias, T.W. Copeman, Fluid Phase Equilib. 13 (1983) 91-108] tem perature dependent term for the Predictive-Soave-Redlich-Kwong [T. Holderba um, J. Gmehling, Fluid Phase Equilib. 70 (1991) 251-265] equation of state and hence it could be used together with this equation. The equation uses a characteristic parameter for each refrigerant; however, if it is not avail able, a value of zero is recommended. This model gives an average of absolu te errors less than 0.42% for the prediction of liquid density of 28 pure r efrigerants consisting of 2489 data points and 0.33% for 18 multicomponent LNG systems involving 132 data points. The model parameters were determined from pure component properties and reported. These parameters were then us ed without any adjustment to predict liquid density of multicomponent LNG m ixtures and excellent results were obtained. The model was also compared wi th other available methods. (C) 1998 Elsevier Science B.V. All rights reser ved.