An accurate equation of state for carbon dioxide

Abstract

An equation of state for carbon dioxide is developed here that yields high accuracy in P-V-T calculations over wide ranges of temperatures (216–423 K) and pressures (to 310.3 MPa). It is particularly accurate around the critical region due to the use of “nonanalytical” terms to model the critical isotherm. Thus it is suited to applications in supercritical states. The density calculation is reliable to within 0.1-0.2 % outside the critical region, and to within 1% near the critical point. The equation has also been tested for vapor pressure and enthalpy calculations (with deviations less than 0.06%, and 2–5 J/g, respectively). Comparison with a number of existing equations of state shows that the present equation is more dependable. © 1985, The Society of Chemical Engineers, Japan. All rights reserved.