EQUATION OF STATE FOR BENZENE FOR TEMPERATURES FROM THE MELTING LINE UP TO 750 K WITH PRESSURES UP TO 500 MPA

摘要

An equation of state (EOS) is presented for the thermodynamic properties of benzene that is valid from the triple point temperature (278.6784 K) to 725 K with pressures up to 500 MPa. The equation is expressed in terms of the Helmholtz energy as a function of temperature and density. This formulation can be used for the calculation of all thermodynamic properties. Comparisons to experimental data are given to establish the accuracy of the EOS. The approximate uncertainties of properties calculated with the new equation are 0.1 % below T=350 K and 0.2 % above T=350 K for saturated vapour pressures and liquid densities, 1 % for saturated vapour densities, 0.1 % for densities up to T=350 K and p=100 MPa, and 0.1-0.5 % in density above T=350 K, 1 % for the isobaric heat capacities and saturated heat capacities, and 0.5 % for sound speeds. Deviations in the critical region are higher for all properties except saturated vapour pressures.