关键词: 二元相互作用参数, Peng-Robinson方程, 分子形状系数, 几何结合规则

Abstract: Based on the Mie potential function theory and London dispersion forces theory, and with the introduction of Leland’s molecular shape factors to modify the inadequacy of the two parameters corresponding states principle for complex fluids, a new correlation for binary interaction parameters of the equation of state was proposed.The pseudocritical rules of Joffee and Stewart were introduced to evaluate the molecular shape factors of mixtures in the deduction process.When Mie potential constant was set to be 3, the new correlation obtained could be used to evaluate the binary interaction parameters of paraffins mixture without back-calculation.The new correlation showed that besides the critical properties of components in paraffins mixture,the binary interaction parameters were the function of composition, temperature, molar volume, acentric factor and component’s ionization potential.Satisfying results with the maximum average absolute error of 2.40%, were achieved when the correlation was used in the Peng-Robinson equation of state to calculate the critical pressure of paraffins mixture.

Key words: 二元相互作用参数, Peng-Robinson方程, 分子形状系数, 几何结合规则