Interaction model for critical pressures of multicomponent methane-free aliphatic hydrocarbon mixtures

Abstract

An interaction model has been proposed to represent the critical pressure of a multicomponent aliphatic hydrocarbon system not containing methane. This model has been expressed mathematically as an expansion which for its definition requires the establishment of interaction coefficients. For a proper representation of the critical pressure, this expansion has been truncated beyond the fourth order interactions. Experimental critical pressures available in the literature for multicomponent systems have been utilized to establish the second and third order interaction coefficients. Due to the lack of sufficient experimental critical pressures on quaternary systems, the fourth order interaction coefficient cannot be established at this time. Using the second and third order interaction coefficients, the critical pressures of 120 compositions of binary, ternary, quarternary, and quinary methane-free aliphatic hydrocarbon mixtures were calculated and were compared with corresponding experimental values to produce an average deviation of 3·25 per cent.