Equation of State and Thermodynamic Properties of Pure Toluene and Dilute Aqueous Toluene Solutions in the Critical and Supercritical Regions

Published

September 9, 2001

Author(s)

Sergei B. Kiselev, James F. Ely, Ilmutdin Abdulagatov, Emil Bazaev, Joe W. Magee

Abstract

In this paper, we report new PVTx measurements for water + toluene binary mixtures at 11 near-critical and supercritical isotherms T = 623, 627, 629, 631, 633, 643, 645, 647, 649, 651, and 673 K and pressures up to 39 MPa at a fixed concentration of x = 0.0287 mole fraction of toluene. Using these PVTx data together with data obtained earlier by other authors, we developed a crossover Helmholtz free-energy model (CREOS) for pure toluene and dilute aqueous toluene solutions in a wide range of the parameters of state around the vapor–liquid critical points. In the temperature range 593 K less than or equal to} T less than or equal to} 680K and density range 100 kg&#8226m^-3 less than or equal to} ρ less than or equal to} 500 kg&#8226m^-3, the CREOS reproduces the PVT data for pure toluene with an average absolute deviation (AAD) of about 0.5%, the C_P data with an AAD of about 1%, and the sound velocity data with an AAD of about 2.6%. In water + toluene mixtures, the CREOS yeilds an adequate description of all available experimental data in the region bounded by 0.35ρ_c(x) ρ less than or equal to} ρ less than or equal to} 1.65ρ_c(x) and 0.98 T_c(x) less than or equal to} T less than or equal to} 1.15T_c(x) at x less than or equal to} 0.04 mole fraction of toluene. The possibility of extrapolating the CREOS model to lower temperatures, 0.93 T_c less than or equal to} T less than or equal to} less than or equal to}T_c, and higher densities and concentrations, up to ρ = 2ρ_c and x = 0.12, is also discussed.

Citation

Industrial and Engineering Chemistry Research

Issue

41

Pub Type

Journals

Citation

Kiselev, S. , Ely, J. , Abdulagatov, I. , Bazaev, E. and Magee, J. (2001), Equation of State and Thermodynamic Properties of Pure Toluene and Dilute Aqueous Toluene Solutions in the Critical and Supercritical Regions, Industrial and Engineering Chemistry Research (Accessed April 25, 2024)