March 3 - 5,1999, Karlsruhe, Germany - FZK

the real ones [24], but the more advanced mixing
rules and the regression of their parameters also
contribute greatly to this considerable accuracy.
Figure 4.
10
0 -10-
® -15-
1 -20 H
-25 -
-30-
-35
spec. Volume at 250 bar
*•• spec. Volume at 300 bar
•*- Enthalpy at 250 bar
*- Enthalpy at 300 bar
Relative error when calculating properties
of the mixture H 20-C0 2 with
Xco2=0.05 by weighting the pure values
compared to reference data
i*0 530 580
Temperature [°C]
-•-VTBMSR
-+-RKS
Figure 5. Relative error on the enthalpy of the
Ff 20-C0 2 system (x CO2=0.05), 300bar
Conclusions
It has been shown that the proposed EOS, involving
a volume-translation, a sophisticated afunction
with polar parameters and more complicated
mixing rules, specifies reasonable accuracy for
the modeling of the thermodynamic behavior of
aqueous mixtures at elevated pressures and temperatures
- even in the supercritical region. Around
the critical points, their closeness to the real values
drop but only for small regions.
The structure of the EOS is relatively simple and
the parameters c,- and p-, can be related to density and
caloric properties, respectively, although there are
some interactions. Therefore, only slight effort is
required to predict the physical properties. This
enables the EOS to be deployed usefully in process
modeling and simulation.
Acknowledgement
The author would like to thank his former students
Jens-Martin Doering and Martin Junginger for
their major contribution to this work made by performing
the regressions and computing the results.
PR
650
630
110
References
1. Clifford, A.A. In: Clark, J.H. (ed.), "Chemistry of
Waste Minimization", 1995
2. Redlich, O; Kwong, J.N.S. Chem. Rev. 1949, 44,
233-244
3. Soave, G. Chem. Eng. Sei. 1972, 27, 1197-1203
4. Martin, J.J.; Ind. and Eng. Chem. Fundam. 1976,
15; 59-64
5. Peneloux, A.; Rauzy, E.; Freze, R. Fluid Phase
Equilibria, 1982, 8,7-23
6. Boston, J.F.; Mathias, P.M. In: Proc. of the 2 nd
Int. Conf. on Phase Equilibria and Fluid Prop, in the
Chem. Process Ind., West Berlin, 823-849,1980
7. Schwartzentruber, J.; Renon, FL, Ind. Eng. Chem.
Res., 1989,28, 1049-1055
8. Haar, L.; Gallagher S.; Kell S. "NBS/NRC Steam
Tables"; Hemisphere Publ. Corp.; Washington; 1984
9. Wagner, W.; de Rueck, K.M.; "International.
Tables of the Fluid State - 9: Oxygen"; IUP AC;
Pergamon Press, 1976
10. Sychev, V.V.; Vassermann A.A.; Kozlov A.D.;
Spiridonov, G.A.; Tsymarny, V.A.; "Thd. Properties
of Oxygen; Nat. Std. Ref. Data Service of the
USSR"; Hemisphere Publ. Corp.; Washington; 1987
11. Angus, S.; de Rueck, K.M.; Armstrong, B.; "Int.
Thermodynamic Tables of the Fluid State - 6: Nitrogen",
IUP AC, Pergamon Press, London, 1977
12. Angus, S.; de Rueck, K.M.; Armstrong, B.;
"International Tables of the Fluid State: Carbon
Dioxide", IUP AC, Pergamon Press, London, 1973
13. Gallagher, J.S.; Crovetto, R.; Levelt Sengers,
J.M.H. J. Phys. Chem. Ref. Data, 1993, 22(2), 431-
14. Gallagher J.S.; Levelt Sengers, J.M.H.; Abdulagatov,
I.M. NIST Technical Note 1404, 1993
15. Japas, M.L.; Franck, E.U. Ber. Bunsenges. Phys.
Chem., 1985, 89, 1268-1275
16. Japas, M.L.; Franck, E.U. Ber. Bunsenges. Phys.
Chem., 1985, 89, 793-800
17. Johns, A.I. et al., IntJ. Thermophys., 1988, 9(1),
3-19
18. Franck, E.U. Pure&Appl. Chem., 1985, 57(8),
1065-1070
19. Aspen Technology Inc., AspenPlus User's
Manual, Release 9, Cambridge, MA, USA
20. Peng, D.-Y.; Robinson, D.B. Ind. Eng. Chem.
Fundam., 1976, 15(1), 59-64
21. Dohm, R. Berechnung von Phasengleichgewichten,
Vieweg, Braunschweig, 1994
22. Rackett, H.G. J. Chem. Eng. Data., 1970, 15,
514-
23. Shaw R.W; Brill, T.B.; Clifford, A.A:; Eckert,
CA.; Franck E.U., Chemical Engineering News,
1991,69 (51)
24. Pilz, S.; Ph.D. Thesis; RWTH Aachen, to be
submitted in 1999