Chemistry Reference
In-Depth Information
300
T
= 462 K 43 K
623 K
250
200
150
100
50
0
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
Mole Fraction Liquid Methane
, x
1
FIGURE 9.4
Pressure versus liquid mole fraction for isotherms of methane with m-cresol.
Symbols for data from Simnick et al. (From J. J. Simnick, H. M. Sebastian, H. M. Lin, and
K. C. Chao, 1979a, Gas-Liquid Equilibrium in Mixtures of Methane+m-Xylene, and Methane-
Meta- Cresol,
Fluid Phase Equilibria
, 3, 145, With permission from Elsevier.) (⎯) Regression
of temperature dependence of Henry's constant in Equation 9.26. (- - -) Prediction using
Equation 9.34 with Henry's constant for methane in quinoline fitted to data of Simnick et al.
(From J. J. Simnick, H. M. Sebastian, H. M. Lin, and K. C. Chao, 1979b, Vapor-Liquid-
Equilibrium in Methane + Quinoline Mixtures at Elevated-Temperatures and Pressures,
Journal of Chemical and Engineering Data
, 24, 239.) Arrows indicate prediction at
T
= 462 K
is not accurate.
Examples of using this with good success for hydrogen in different solvents,
including for model coal liquids, based on a single reference solvent are given by
Campanella, Mathias, and O'Connell (1987) and O'Connell (1995). Treatment of
complex mixed solvents, including for actual coal liquids, is also described in those
references. This concept also works quite well for ILs (Abildskov, Ellegaard, and
O'Connell 2009; Ellegaard, Abildskov, and O'Connell 2010).
Figure 9.4 shows predictions of pressure versus liquid mole fraction for the
methane (1) and m-cresol system where the Henry's constant of Equation 9.26 was
obtained from fitting data directly (solid lines) or predicted with quinolone (dashed
lines) as the reference solvent in Equation 9.34. As the arrows show, the prediction
is not uniformly accurate in this case. Better results have been obtained with other
solutes, especially hydrogen, nitrogen, and carbon monoxide, including mixed sol-
vents, as shown by Campanella, Mathias, and O'Connell (1987). Figures 9.5 and 9.6
show similar results for a system containing hydrogen and an ionic liquid (Abildskov,
Ellegaard, and O'Connell 2009).
9.3.2 m
odels
B
ased
on
e
quaTions
oF
s
TaTe
For infinitely dilute solutions, the temperature independence of
A
Kr
at higher densi-
ties leads to the Henry's constant of Equation 9.26 by integrating Equation 9.24. The
relations are
