The Peng-Robinson equation of state was used for predicting vapor-liquid equilibria for three binary groups-methane-hydrocarbons

carbondi-oxide-hydrocarbons

and hydrogen-hydrocarbons. The correlated interaction parameters were recommended for binary systems containing methane and carbon dioxide. Application of the conformal solution mixing rules and a proposed correction of the temperature dependent factor a to highly asymmetric hydrogen-containing binary system

led to a more accurate description of vapor-liquid equilibria than the original work of Peng-Robinson.