Chemistry Reference
In-Depth Information
Fig. 16 Critical line of the
mixture of the system CO
2
plus hexadecane, projected
onto the
p
; T
plane
(pressure
p
and temperature
T
rescaled with the LJ
parameters of the effective
monomers of hexadecane as
usual,
p
0.4
0.3
ξ
=1
ξ
=0.9
q
c
=0.387
0.2
=1
q
c
=0.47
ξ
=1
ξ
=0.886
ξ
3
,
T
k
B
T=e
). Data are shown
for
q
c
0
; x
0
:
886 (
top
curve
),
x
0
:
9(
middle
curve
), and
x
1(
bottom
curve
).
Symbols
show the
simulation results for
q
c
pe=s
0.1
0
0.8
1
1.2
1.4
1.6
T*
47,
applying
x
1 in both cases.
From Mognetti et al. [
56
]
0
:
387 and
q
c
0
:
Fig. 17 Isothermal slice through the phase diagram of the CO
2
+C
16
H
34
system at
T
486 K
showing MC results for the model with
q
c
0
:
47 (
open circles
) and comparing them to the results
of the model with
q
c
886
(
asterisks
).
Squares
show two sets of experimental data [
271
] at two temperatures that bracket the
temperature used in the simulation.
Triangles
are MC estimates for the location of the critical
point. From Mognetti et al. [
56
]
0, showing both the choice
x
1(
closed circles
) and the choice
x
0
:
works exactly for our grossly simplified coarse-grained model, and thus correction
factors
x
that deviate from unity by 1 2% are physically reasonable.
This consideration is underlined by the analysis of isothermal slices through the
miscibility gap in the plane of variables pressure versus molar concentration of this
system (Fig.
17
). It is seen that the MC results that include the quadrupolar
interactions
ð
q
c
¼
0
:
47
Þ
and respect the Lorentz Berthelot rule
ðx ¼
1
Þ
fit to the
