close

Вход

Забыли?

вход по аккаунту

?

acs.iecr.7b03513

код для вставкиСкачать
Article
Cite This: Ind. Eng. Chem. Res. XXXX, XXX, XXX-XXX
pubs.acs.org/IECR
Heat Transport Properties of CO2‑Expanded Liquids: n‑Hexane,
n‑Decane, and n‑Tetradecane
Kourosh Kian and Aaron M. Scurto*
Department of Chemical & Petroleum Engineering and Center for Environmentally Beneficial Catalysis, University of Kansas,
Lawrence, Kansas 66045, United States
ABSTRACT: A number of processes involve liquids saturated with
significant quantities of gases at elevated pressures, e.g., processes in gasor CO2-expanded liquids (GXLs, CXLs), particle formation from gas or
supercritical antisolvent methods (GAS, SAS, etc.), CO2 capture and
sequestration, and enhanced oil recovery (EOR). In order to engineer
these systems, the thermodynamic and transport properties are
required. This contribution is one of the first reports for the heat
transport properties of gas-expanded liquids at elevated pressures. The
thermal conductivity, thermal diffusivity, and heat capacity are presented
for binary systems of CO2 and the n-alkanes, n-hexane, n-decane, or ntetradecane, at 25, 40, and 55 °C and pressures up to 106 bar. Equation
of state modeling of literature vapor−liquid equilibrium data was used to determine the compositions at the conditions of the
experimental heat transport measurements. All measured properties decrease with increasing composition of CO2 (pressure) in a
relatively linear manner until a CO2 composition of approximately 70 mol %. The Prandtl number, Pr, is calculated and decreases
with increased CO2 composition for all systems. However, as the fluid viscosity decreases with increased CO2, the heat transfer
coefficient, h, in pipe flow would actually increase in a turbulent flow regime.
1. INTRODUCTION
Numerous applications in chemistry and engineering involve
liquid phases containing significant quantities of dissolved
gases. As more of the gaseous component dissolves, the liquid
phase can develop different properties over the pure liquid.
These changes in properties may be tuned or exploited for
different applications. “Gas-expanded liquids” (GXLs) is a term
for a mixture of a liquid solvent (usually organic, ionic liquid, or
mixed aqueous solvent) with significant quantities of a
compressible gas (such as CO2 and ethane).1 CO2-expanded
liquids (CXLs) are the most common type of GXLs due to the
usually high liquid solubility, safety (fire suppression, etc.), and
economic advantages of CO2. CXLs have properties that range
between the pure organic liquid and supercritical CO2. For
instance, the viscosity of the liquid phase decreases with
increasing gas composition,2,3 the solubility of other gases can
increase in the expanded liquid phase,4 and the mass transfer
rate of other reaction gases into the liquid increases.5 While not
completely eliminating the use of organic solvents, the needed
volume of solvent for a GXL significantly decreases.
CXLs can be utilized for the preparation of uniform, fine
particles, especially for pharmaceutical compounds. The gas
antisolvent technique (GAS) sprays a liquid mixture containing
the target solvent into compressed CO2. As the CO2 dissolves
in the liquid droplet, it expands and decreases the solubility of
the solute (i.e., acts as an antisolvent) leading to the formation
of particles.6 Supercritical carbon dioxide can also be used as an
antisolvent in a mechanism known as supercritical antisolvent
(SAS) precipitation.
© XXXX American Chemical Society
Other examples of liquids with large quantities of dissolved
gas are found in CO2 capture and sequestration including
enhanced oil recovery. Some types of CO2 capture occur at
elevated pressures in both physically and chemically absorbing
solvents, e.g., the Rectisol, monoethanolamine (MEA)
solutions.7 The properties of the solvent change as larger
amounts of CO2 are absorbed. These processes undergo
thermal cycling as heat and lower pressures are used to desorb
the dissolved CO2. Recently in a new application, a suspension
of solid particles of n-tetradecane in water were used to
enhance CO2 capture by hydrate formation by using the
particles to absorb the enthalpy of hydration leading to the
melting of the particles into a liquid−liquid suspension.8 CO2expanded liquids are also exploited in enhanced oil recovery
(EOR) and geologic CO2 sequestration.9 Compressed CO2 is
injected into a depleted petroleum reservoir to increase the
amount of crude oil that can be produced and provide a
disposal area for CO2.10 We have recently investigated the
viscosity of several n-alkanes saturated with CO2.3 The viscosity
dramatically decreases with high quantities of CO2.
For development of any of these applications both
thermodynamic and transport properties are needed. Phase
equilibrium thermodynamic data are most often studied for
these systems. However, experimental data of the transport
properties (viscosity, thermal conductivity, and diffusivity) are
Received:
Revised:
Accepted:
Published:
A
August 24, 2017
September 29, 2017
September 29, 2017
September 29, 2017
DOI: 10.1021/acs.iecr.7b03513
Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
house using 316 stainless steel and sapphire windows with
appropriate O-ring seals. It has a 165 mL internal volume.
Temperature is controlled via a heat jacket connected to a
circulation heater with an integrated pump, which transfers the
heating material to the heat exchanger and back to the heating
unit. In order to make sure CO2 is well mixed in the solvent,
agitation is performed via a stirbar within the cell and a
magnetic stirring plate (Ika Werke, GmbH, Germany), PN
RET Basic C). The unit is placed on a heavy bench with low
vibrations (to prevent convection during measurement).
Pressure for the CO2 is provided by an ISCO 250-D syringe
pump (Teledyne-Isco, Inc., USA). A high precision digital
pressure gauge, Omega DPG7000, with an error band of
±0.05% of full scale (FS = 3000 psi; ±0.1 bar), is utilized to
accurately measure the pressure values.
The LAMBDA instrument works on a transient hot-wire
method standardized to ASTM D2717. A long cylindrical
source of heat (platinum filament with radius r0) introduces a
heat flux, q [mW/m], at a given time into the fluid sample. The
heat flux will generate a temperature profile inside the fluid
which is a function of time, t, and radial distance from the
source of heat, r. By using the energy balance for a Newtonian
fluid with constant density and applying appropriate initial and
boundary conditions, thermal conductivity, λ, can be related to
the temperature change by an analytical solution:
often significantly lacking. For instance, the authors are not
aware of any study measuring the thermal transport properties
of any liquid system with dissolved compressed gas despite the
numerous applications where temperature needs to be known,
controlled, or predicted with different heat transfer scenarios.
In this study, the thermal conductivity (λ), thermal diffusivity
(αT), and heat capacity (Cp) are measured for three binary
alkane mixtures of n-hexane, n-decane, or n-tetradecane
saturated with CO2, at three different isotherms (25, 40, and
55 °C) and pressures to 106 bar. In order to determine the
composition of the mixtures at the various temperatures and
pressures, equation-of-state modeling of phase equilibrium data
has been performed. These properties allow various dimensionless groups used for thermal engineering, such as the Prandtl
number, to be determined. These properties can have positive
implications for the thermal engineering of CXLs for various
applications.
2. EXPERIMENTAL SECTION
2.1. Measurement and Calculation of Thermal
Conductivity, Thermal Diffusivity, and Heat Capacity.
The thermal conductivity, thermal diffusivity, and heat capacity
were measured using a Flucon Fluid Control GmbH
(Germany) LAMBDA cell with a modified high-pressure
equilibrium cell. A schematic picture of the probe and
equilibrium cell is depicted in Figure 1. The measuring head
T (r , t ) − T0 = −
q ⎛ r2 ⎞
Ei⎜ −
⎟
4πλ ⎝ 4αT t ⎠
where λ is the thermal conductivity and αT is the thermal
diffusivity. The Ei(−x) function is called the exponential
integral function and is defined as follows:
−Ei( −x) =
∫x
∞
exp( −u) du
u
The exponential integral function can be expanded as a Taylor
series:
−Ei( −x) = −γ − ln(x) +
x
x2
x3
−
+
− ...
1·1!
2·2!
3·3!
where γ is the Euler constant and is equal to 0.5772. At
relatively long times, one can use the following approximation
to calculate the temperature profile at different points:
t≫
r2
4αT
T (r , t ) − T0 = −
⎤
⎡ r2
q
+ 0.5772⎥
ln⎢
4πλ ⎣ 4αT t
⎦
(1)
λ=
⎛t ⎞
ln⎜ 2 ⎟
8π (T2 − T1) ⎝ t1 ⎠
q1 + q2
(2)
From measurements at two different times, the value of
thermal conductivity is independent of the wire diameter. The
thermal diffusivity can be obtained by solving for eqs 1 and 2 as
follows:
Figure 1. (a) Thermal conductivity probe and (b) windowed highpressure equilibrium vessel with water jacket.
contains a cylindrical shape platinum wire with small
dimensions: diameter d = 0.1 mm and length L = 35 mm.
The platinum wire is welded to platinum lead terminals. The
lead terminals are supported by a circular Teflon plate, which
has a diameter of 24 mm and a thickness of 5 mm. The probe
has a built-in temperature Pt-1000 RTD probe as seen next to
the wire in Figure 1. The equilibrium cell was constructed in-
a=
⎛ 4πλ
⎞
r0 2
exp⎜
T + 0.5772⎟
4t
⎝ q
⎠
(3)
The heat capacity, Cp, requires knowledge of the fluid mass
density (ρ) or molar volume (V) at any given temperature,
pressure, and composition. For molar and specific heat capacity,
respectively:
B
DOI: 10.1021/acs.iecr.7b03513
Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
Table 1. Equation of State Parameters and Mixing Rule Interaction Parameters from Ref 3
CO2
n-hexane
n-decane
n-tetradecane
CAS No.
Tc [K]
Pc [bar]
ω
k(1)
ij
k(2)
ij
l(1)
ij
l(1)
ij
124-38-9
110-54-3
124-18-5
629-59-4
304.21
507.60
617.70
693.00
73.83
30.25
21.10
15.70
0.223621
0.301261
0.492328
0.643017
−
0.0046
−0.7354
−0.1806
−
0.0003
0.0013
0.0011
−
−0.6463
−1.3106
−3.5176
−
0.0020
0.0022
0.0129
Table 2. Comparison of Ambient Pressure Thermal Conductivity and Heat Capacity Data of the n-Alkanes: This Study vs
Literature
a
n-hexane
n-decanea
n-tetradecaneb
a
T [°C]
λexpt [mW/m·K]
λlit. [mW/m·K]
% diff
Cpexpt [J/mol·K]
Cplit. [J/mol·K]
% diff
25
40
55
25
40
55
25
40
55
126.51
121.57
116.43
130.10
127.88
124.81
140.67
137.19
134.27
126.18
121.18
116.34
129.48
125.62
121.83
141.90
137.90
134.20
0.26
0.33
0.07
0.48
1.80
2.45
0.87
0.51
0.05
195
193
190
297
298
296
424
421
419
194
200
206
312
320
328
419
401
383
0.58
3.70
7.81
4.79
6.99
9.73
1.20
5.02
9.53
Reference 12. bReference 13.
Cp =
V̲ λ
α
Cp̂ =
λ
ρα
reported values of thermal conductivity, diffusivity, and heat
capacity are the averages of 10 data points. The standard
deviation is reported as the precision of the measurement. The
standard deviation of thermal conductivity values tend to be
larger at higher temperatures and higher pressures, i.e.,
generally lower liquid density. Hence, one would expect to
see the largest deviations at 55 °C and around the critical
conditions. As density (molar volume) data is needed for the
heat capacity calculation, interpolation errors propagate
through these measurements. In this work we have assumed
an average error of 5% in the values of interpolated molar
volumes and, based on that, we have obtained the error
propagation for heat capacity values. An average error of 5% in
interpolated molar volumes will result in average standard
deviations in the heat capacities equal to 12, 10, and 6 J/mol·K
for n-tetradecane/CO2, n-decane/CO2, and n-hexane/CO2
mixtures, respectively.
2.4. Materials. Coleman Instrument grade carbon dioxide
(99.999% purity) was obtained from Matheson Gas Products.
n-Decane (CAS No. 124-18-5) 99+% was purchased from
Acros, and n-tetradecane (CAS No. 629-59-4) 99+% was
purchased from Alfa-Aesar. n-Hexane (CAS No. 110-54-3) 95+
% was purchased from Sigma-Aldrich. All materials were used
without further purification.
(4)
2.2. Procedure. Approximately 5−40 cm3 of n-alkane (nhexane, n-decane, and n-tetradecane) is initially charged into
the vessel, and enough time is given for the system to reach the
preset equilibrium temperature (25, 40, and 55 °C). A constant
pressure of CO2 is set and the liquid is stirred for about 15 min.
The software then measures the thermal conductivity every 90 s
to track the progress toward thermal and phase equilibria,
which occur within 30 min for all systems studied. After an
additional 15 min, 10 measurements are made and the average
and standard deviation are reported. The stirrer is shut off for
several minutes prior to measurement. Care must be taken to
minimize vibrations and anything that could cause convection.
Natural convection is minimized by allowing the liquid to come
into thermal equilibrium with the equilibrium cell over
appropriate times and the fact that the probe is at the
centerline of the relatively wide vessel away from the walls
where natural convection most often occurs. A new pressure is
set for the CO2 and the procedure is repeated up to a maximum
of 106 bar. It is important to know the volume expansion of the
CO2-expanded mixture as the probe wire must be completely
covered in the liquid phase, but the volume expansion should
not encompass the entire volume of the cell. The windowed
vessel allows general confirmation of the liquid level. As such,
often several initial charges of the n-alkane are needed to
measure the entire pressure range desired, i.e., smaller initial
volumes of the n-alkane at the highest pressure (highest CO2
compositions due to the highest volume expansion), etc.
Calibration is only required initially to set some of the
internal parameters of the instrument. The calibration fluid is
only required to be within an order of magnitude of the
mixtures of interest. In order to calibrate the instrument, liquid
n-hexane at 25 °C and atmospheric pressure is utilized. The
reference density and thermal conductivity values are obtained
from the NIST Standard Reference Database, REFPROP.11
2.3. Uncertainty in Measurements. The pressure gauge is
accurate to ±0.1 bar and the RTD has an uncertainty of ±0.01
°C. Thermal control of the fluid is approximately ±0.1 °C. The
3. EQUATION OF STATE MODELING
The direct measurements involve determining the liquid
thermal conductivity at various temperatures and pressures.
However, these conditions lead to different CO2 compositions
in the liquid phase. In order to understand the composition
effect on the thermal conductivity with CO2 in the alkane
liquid, equation of state modeling is used to calculate the
equilibrium compositions. The Peng−Robinson equation of
state with van der Waals two-parameter mixing rules was used
to predict the liquid compositions. The model was
implemented in the ASPEN Plus V9 thermodynamics package.
The physical properties of each component and the equation of
state (EoS) parameters used in this study are shown in Table 1.
In this study, the van der Waals two-parameter mixing rule,
vdW2, was employed with two binary interaction parameters, kij
C
DOI: 10.1021/acs.iecr.7b03513
Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
possible.14−17 According to the classification scheme of Scott
and van Konynenburg,17 the n-hexane/CO2 system has been
characterized as a type I system, n-decane is a type II system,
and n-tetradecane/CO2 is a type III system.15,16,18,19 This
implies that the upper pressure limits to maintain two-phase
vapor−liquid equilibrium for n-hexane at 25 °C will be the
vapor pressure of pure CO2, beyond which will be miscible
liquids. For the temperatures at 40 and 55 °C, the mixture
critical pressure will be the maximum limit. For n-decane, the
UCEP is at very low temperatures and, thus, VLE will terminate
at the pure CO2 vapor pressure at 25 °C. For n-tetradecane, the
VLLE pressure will be the maximum pressure for two-phase
conditions; this is within a few bar from the vapor pressure of
pure CO2. At 40 and 55 °C for both n-decane and ntetradecane, the mixture critical point will be the maximum
pressure possible. Without knowledge of the general phase
behavior and the use of view cells for the pressurized system,
incorrect or mislabeled results could occur for the measurement
of transport properties.
For the n-alkane systems with CO2, a large number of
literature reports exist for the vapor−liquid equilibrium at
various isotherms.20−28 Few of these studies were measured at
the exact temperatures and pressures of the thermal
conductivity data discussed below. For several systems,
interpolations of reliable data at the same isotherm would
have been possible. However, as the majority of the data were
at different conditions, it was decided to use equation of state
modeling to predict the compositions at the conditions of
interest for all of the thermal conductivity studies. Here only
experimental vapor−liquid equilibrium (VLE) data was used
and no data involving VLLE, LLE, etc. The Peng−Robinson
equation of state with van der Waals two-parameter mixing
rules (PR-vdW2) was used with temperature dependent
interaction parameters as shown in eqs 5 and 6. The linear
model was found to have a very good correlation with the
fewest number of parameters yielding an average absolute
relative deviation (%AARD) in the liquid composition data for
all isotherms of 1.2% with a maximum of 1.9%. The model was
then used to predict the liquid CO2 compositions for each of
the three n-alkanes and three temperatures. Figure 2 illustrates
the CO2 solubility in n-hexane, n-decane, and n-tetradecane at
55 °C. At any given temperature and pressure, the CO2
solubility is highest in n-hexane/CO2 and lowest in ntetradecane/CO2 mixtures. As expected, the CO2 solubility
decreases with increasing temperatures (not shown).
and lij, for the attractive parameter (am) and covolume
parameter (bm), respectively. These parameters are generally
a function of temperature to have a quantitative fit with
experimental data. In our previous study,3 we have used a linear
temperature model which produces the best fit with the lowest
number of fitted parameters:
kij = kij(1) + kij(2)T
lij = lij(1) + lij(2)T
kij = kji
lij = l ji
(5)
(6)
The fitted parameters are reported in Table 1.
4. RESULTS AND DISCUSSION
In this work, we have measured the thermal conductivity,
thermal diffusivity, and heat capacity values for binary mixtures
of n-hexane/CO2, n-decane/CO2, and n-tetradecane/CO2 at
three isotherms (25, 40, and 55 °C) and at different pressures.
Using literature data, we have correlated the solubilities of CO2
in the n-alkanes to determine the corresponding composition
for the thermal conductivity data. The phase behavior was
previously investigated and confirmed for these systems.
4.1. Pure n-Alkane Thermal Conductivity Measurements and Literature Comparison. Thermal conductivity
values of all pure n-alkanes under investigation in this study are
first measured at ambient pressure and at the temperatures of
interest. The experimental results are compared with the
reported data in the literature, and the deviations are shown in
Table 2. It should be noted that n-hexane was used as a
calibration fluid for the instrument’s internal calculation
method of thermal conductivity. Thus, a run-to-run uncertainty
for the instrument is on average ±0.22% based on at least three
measurements. As demonstrated, a very good agreement exists
with the literature thermal conductivity data. The percent
average absolute relative deviation from all of the data is 0.76%
with the largest error of 2.45%. The heat capacity measurements contained higher deviations, 5.5% on average. As these
measurements are calculated from both thermal conductivity
measurements and density/molar volume interpolated from
literature data, they are sensitive to error propagation especially
in the molar volume. As the molar volumes (density) are
interpolated, we assume a nominal 5% error in these quantities,
which we believe to be highly conservative. A high-precision,
high-pressure calorimeter would be able to obtain better
precision and accuracy. However, we believe that reporting
these values for systems that currently do not have any heat
capacity data will be helpful for both their qualitative trends and
at least an accuracy of ∼6% but believed to be better.
4.2. Phase Behavior, Equilibrium, and Equation of
State Modeling. The goal of the investigation was to measure
thermal conductivity in the CO2-saturated liquid phase.
However, n-alkane systems with CO2 and other compressed
gases are known to have multiple liquid phase and single-phase
equilibrium behavior at various temperatures and pressures. We
have recently investigated the phase behavior and vapor−liquid
equilibrium for the systems investigated and give an overview
here.3 Understanding the conditions of these transitions are
required for proper experimental measurement; e.g., two liquid
phases in contact with the thermal conductivity probe would
yield erroneous results. Regions of vapor−liquid−liquid
equilibrium (VLLE), liquid−liquid equilibrium (LLE), and
mixture critical points (V = L, L = L, upper critical end point
(UCEP), lower critical end point (LCEP)) are also
Figure 2. Vapor−liquid equilibrium prediction from EoS model CO2/
n-hexane, CO2/n-decane, and CO2/n-tetradecane at 55 °C.
D
DOI: 10.1021/acs.iecr.7b03513
Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
measured data point of approximately 95% CO2 to 100%. This
may indicate that the liquid structure and mechanism of
thermal conductivity is governed mostly by n-hexane with CO2
filling mostly free volume. This also indicates that simple
“mixing rules” to predict mixture thermal conductivity based on
pure component values, such as a mole/mass fraction average
of conductivities of pure liquid alkane and pure liquid CO2, etc.,
would not be accurate or appropriate especially for the highCO2 liquid compositions.
4.4. Thermal Conductivities of CO2/n-Decane and
CO2/n-Tetradecane. The liquid thermal conductivities of
binary mixtures of n-decane and n-tetradecane saturated with
CO2 were measured at 25, 40, and 55 °C and are listed in
Tables 4 and 5, respectively. As shown in Figure 5a, increasing
pressure/composition of CO2 decreases the liquid thermal
conductivities of n-decane and n-tetradecane mixtures. The
compositions were computed using the modeling results
described above at each temperature and pressure point of
the thermal conductivity measurements. With an increase in
CO2 composition, the liquid thermal conductivity decreases in
a generally linear manner until a very high composition of CO2.
A comparison of the thermal conductivities of the three
different n-alkanes saturated with CO2 is shown in Figure 6. In
general, there is a relatively linear decrease in the thermal
conductivity with increased composition of CO2. By increasing
the CO2 composition in liquid phase, thermal conductivity
increases in the order n-hexane, n-decane, and n-tetradecane.
The only noticeable difference in the slope occurs at higher
compositions of CO2 at conditions that are approaching phase
transitions, such as VLLE transitions, near the vapor pressure of
CO2 itself, etc. Both n-decane and n-tetradecane transition from
VLE to VLLE and as shown in the plot have similar qualitative
curvatures at the higher compositions. However, n-hexane
becomes miscible with CO2 at the vapor pressure at 25 °C and
seems to continue on a more linear trend. Similar trends are
observed in the thermal diffusivity (a measure of thermal
“inertia”) versus composition of CO2 as demonstrated in Figure
7.
4.5. Heat Capacities of Binary CO2/n-Alkane Systems.
The heat capacities are calculated from the experimental
thermal conductivity and diffusivity values and values for the
mixture molar volume (density). In order to calculate the heat
capacity, one needs to know the value of the density (molar
volume) of the mixture. In this work, the molar volume values
are interpolated from experimental data in the literature. The
calculated results for all systems are reported in Tables 3−5. A
comparison of the heat capacities of the three different nalkanes saturated with CO2 is shown in Figure 7 at 25 °C. In
general, there is a relatively linear decrease in the heat capacity
with increased composition of CO2. As can be seen in Figure 7,
as the composition of CO2 in the liquid phase approaches
unity, the heat capacities of the binary mixtures converge.
4.6. Heat Transfer Properties and Implications. The
thermal conductivity/thermal diffusivity and heat capacity
(along with density and viscosity) are required for a number
of heat transfer characterizations and calculations. These are
often accomplished through dimensionless groups. One of the
most important is the Prandtl number (Pr), which is defined as
As discussed in the Experimental Section, the heat capacity is
a calculation from our direct measurement of the thermal
conductivity and thermal diffusivity, and the molar volume of
the liquid mixture. Molar volume and related volume expansion
were not directly measured in these studies. However, ample
density data (molar volume data) are available for each of the
systems in the literature at either the exact temperatures and
pressure range or temperatures that bracket those used in these
studies.29−34 Interpolation is used to determine the molar
volume at each temperature, pressure, and composition. Figure
3 illustrates the change in molar volume of n-hexane with the
Figure 3. Molar volume of CO2/n-hexane versus pressure at various
temperatures interpolated from ref 30.
increase in CO2 pressure and composition. For this system, the
molar volume decreases rather linearly with CO2 composition.
As the composition of CO2 in the liquid phase increases, the
density (g/cm3) of the mixture slightly increases due to the
increase in solubility being slightly larger than the increase in
volume expansion (not shown). These interpolated molar
volume values at the pressures of the heat transport
measurements are found in Tables 3−5. The systems with ndecane and n-tetradecane behave qualitatively similarly.
4.3. Thermal Conductivity of CO2/n-Hexane. The liquid
thermal conductivity of n-hexane saturated with CO2 was
measured at 25, 40, and 55 °C until approximately the vapor
pressure or mixture critical points and listed in Table 3. As
shown in Figure 4a, increasing pressure of CO2 decreases the
liquid thermal conductivity at each temperature. At 25 °C, the
thermal conductivity decreases by about 12.9% between
ambient pressure and 60 bar (at 25 °C, Pvap = 64.3 bar12).
Again, this decrease is not a hydrostatic pressure effect but a
composition effect. Using the modeling results described above,
the compositions were predicted at each temperature and
pressure point. Figure 4b now illustrates the thermal
conductivity with composition of CO2. With an increase in
CO2 composition, the liquid thermal conductivity decreases in
a generally linear manner. Thermal diffusivities have similar
trends. However, despite these decreases in thermal transport
properties in CO2-expanded liquids, the actual heat transfer
rates may increase as will be discussed below. The thermal
conductivity of pure saturated liquid CO2 at 25 °C (and at the
vapor pressure of 64.3 bar) is 80.8 mW/m·K.12 Outside of the
measured data there would be a substantial decrease in thermal
conductivity as the composition of CO2 goes from the last
Pr =
E
η/ρ
ηV̲
ν
=
=
αT
λ /(Cpρ)
αT
(7)
DOI: 10.1021/acs.iecr.7b03513
Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
Table 3. Experimental Thermal Conductivity (λ) and Thermal Diffusivity (α) of CO2-Saturated Liquid n-Hexane at Various
Pressures with Predicted Compositions (xCO2), Molar Volume (VL), and Calculated Heat Capacity (Cp)
P [bar]
xCO2a
VLb [cm3/mol]
ηc [mPa·s]
λ [mW/m·K]
−
11.0
20.9
31.4
40.6
51.8
60.4
0.000
0.147
0.287
0.435
0.573
0.793
0.963
131.6
120.1
109.2
97.4
86.1
70.2
59.9
0.298
0.279
0.250
0.217
0.189
0.166
0.158
126.5
124.7
120.6
118.2
115.7
112.0
110.2
−
10.7
20.9
30.5
41.4
50.1
61.3
70.5
0.000
0.119
0.234
0.343
0.466
0.571
0.723
0.876
134.5
122.5
113.4
104.8
95.1
86.7
75.5
65.9
0.259
0.242
0.226
0.194
0.167
0.152
0.144
0.131
121.6
119.7
117.7
114.8
112.2
109.2
105.3
101.7
−
11.7
20.5
31.0
41.1
50.8
60.0
69.9
80.4
0.000
0.111
0.195
0.293
0.387
0.479
0.570
0.676
0.803
137.5
120.8
114.1
106.9
100.0
93.1
86.5
78.5
68.4
0.227
0.209
0.198
0.178
0.151
0.137
0.128
0.119
0.104
116.4
113.4
111.6
108.6
107.4
103.7
99.9
97.8
92.7
±λ
25 °C
0.6
0.7
0.8
0.7
0.9
1.0
1.0
40 °C
0.7
1.1
0.9
1.3
1.5
1.3
1.6
1.7
55 °C
0.9
0.8
1.0
1.3
1.9
2.0
2.0
2.0
1.8
αT × 104 [cm2/s]
±αT × 104
Cpd [J/mol·K]
±Cpe
Pr
8.538
8.520
8.482
8.460
8.436
8.402
8.387
0.003
0.001
0.001
0.002
0.001
0.001
0.001
195
176
155
136
118
94
79
1
9
8
7
6
5
4
5.3
4.9
4.4
3.7
3.1
2.6
2.5
8.491
8.474
8.455
8.428
8.404
8.378
8.341
8.308
0.003
0.001
0.002
0.002
0.002
0.003
0.002
0.002
193
173
158
143
127
113
95
81
7
9
8
7
7
6
5
4
4.8
4.3
4.0
3.4
2.8
2.5
2.3
2.1
8.444
8.415
8.399
8.371
8.361
8.326
8.292
8.272
8.227
0.002
0.003
0.002
0.002
0.003
0.001
0.002
0.002
0.003
190
163
152
139
128
116
104
93
77
16
8
8
7
7
6
6
5
4
4.3
3.7
3.5
3.1
2.6
2.3
2.1
2.0
1.7
From PR-vdW2 prediction. bMixture value interpolated from literature data.30 cInterpolated from ref 3. dComputed from α, λ, and predicted VL.
From error propagation assuming the error in molar volume is approximately 5%.
a
e
Figure 4. Thermal conductivity of CO2/n-hexane (a) versus pressure and (b) versus composition.
where η is the dynamic viscosity and ν is the kinematic
viscosity. Pr is the ratio of the viscous diffusion rate versus the
thermal diffusion rate. The Prandtl number is related to the
relative thickness of the momentum and thermal boundary
layers. When Pr is much less than 1 (e.g., many types of gases,
liquid mercury), the heat will diffuse (conduct) quickly
compared to the velocity or momentum mechanism for heat
transfer. The Nusselt number for heat transfer, Nu, is the ratio
of convective to conductive heat transfer and is defined as
Nu =
hL
λ
(8)
where h is the heat transfer coefficient (in units of power per
area per degree of temperature), L is the characteristic length
scale (e.g., L = pipe diameter for developed flow in a pipe). A
related dimensionless group is the Biot number, Bi, which is
identical to the Nusselt number except that the thermal
conductivity is that of the solid body in contact with a fluid. Bi
is used to determine whether the temperature inside a solid
body will vary to any large extent over time.
F
DOI: 10.1021/acs.iecr.7b03513
Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
Table 4. Experimental Thermal Conductivity (λ) and Thermal Diffusivity (α) of CO2-Saturated Liquid n-Decane at Various
Pressures with Predicted Compositions (xCO2), Molar Volume (VL), and Calculated Heat Capacity (Cp)
P [bar]
xCO2a
VLb [cm3/mol]
ηc [mPa·s]
λ [mW/m·K]
−
11.3
21.4
30.8
40.4
50.0
60.3
0.000
0.136
0.250
0.350
0.451
0.554
0.686
195.7
175.3
158.7
144.3
130.1
115.6
97.4
0.874
0.793
0.691
0.606
0.516
0.440
0.354
130.1
129.1
128.1
126.2
123.0
119.8
117.6
−
9.5
20.3
30.9
40.9
51.3
60.6
70.7
0.000
0.097
0.200
0.295
0.377
0.463
0.535
0.615
199.0
184.5
169.0
155.0
143.0
130.5
119.8
108.4
0.699
0.610
0.550
0.474
0.383
0.307
0.289
0.237
127.9
125.8
124.5
121.3
119.5
117.5
115.5
114.8
−
10.5
22.0
31.9
40.6
50.5
60.8
71.4
81.8
90.8
100.1
0.000
0.092
0.187
0.263
0.325
0.393
0.460
0.526
0.588
0.638
0.684
202.4
188.7
174.3
162.8
153.5
143.3
133.2
123.4
114.3
107.0
100.3
0.583
0.512
0.430
0.358
0.295
0.235
0.208
0.177
0.159
0.148
0.141
124.8
122.6
120.1
118.4
116.3
114.7
112.4
111.4
107.1
105.3
104.3
±λ
25 °C
0.6
0.7
0.8
0.9
1.0
0.9
1.0
40 °C
0.8
0.7
1.1
0.9
1.1
1.3
1.5
1.9
55 °C
1.0
1.0
1.1
1.2
1.3
1.2
1.5
1.7
1.7
1.9
2.2
αT × 104 [cm2/s]
±αT × 104
Cpd [J/mol·K]
±Cpe
Pr
8.571
8.562
8.553
8.535
8.504
8.475
8.454
0.001
0.007
0.001
0.001
0.000
0.001
0.002
297
264
238
213
188
163
136
15
13
12
11
10
8
7
14.0
12.6
10.9
9.5
8.1
6.8
5.4
8.550
8.531
8.518
8.489
8.472
8.453
8.435
8.428
0.006
0.001
0.001
0.002
0.002
0.003
0.002
0.003
298
272
247
222
202
181
164
148
22
14
13
11
10
9
8
8
11.4
9.9
8.9
7.6
6.1
4.9
4.6
3.7
8.521
8.501
8.477
8.462
8.443
8.428
8.407
8.397
8.358
8.341
8.332
0.004
0.002
0.002
0.002
0.001
0.002
0.001
0.009
0.002
0.001
0.002
296
272
247
228
212
195
178
164
147
135
125
32
14
13
12
11
10
9
9
8
7
7
9.7
8.5
7.1
5.9
4.9
3.9
3.4
2.9
2.6
2.4
2.3
a
From PR-vdW2 prediction. bMixture value interpolated from literature data.29,31,33−35 cInterpolated from ref 3. dComputed from α, λ, and
predicted VL. eFrom error propagation assuming the error in molar volume is approximately 5%.
the conditions for the measurements in this contribution by
interpolating the data of our previous viscosity study at similar
conditions. As seen in Tables 3−5, the Prandtl numbers for all
the binary mixtures at all isotherms decrease as the
concentrations of CO2 in the mixtures increase. Figure 8a
illustrates the relatively linear decrease in Prandtl numbers with
CO2 composition for CO2/n-hexane mixtures. Similar trends
are observed for each of the n-alkanes at 25 °C in Figure 8b and
similarly at the other temperatures. Above about a CO2
solubility of approximately 0.7 mole fraction, the rate of
decrease becomes smaller. It is worth noting that the decrease
in Prandtl number for CO2/n-tetradecane mixtures is the
greatest (on an absolute and percentage basis) while this drop
is the least for CO2/n-hexane systems.
In all these cases, the Prandtl number values are greater than
1.0 which means, in all binary mixtures, the momentum
diffusivity dominates the heat transfer mechanism compared to
the thermal diffusivity. By increasing the concentration of CO2
in the mixtures and by increasing the equilibrium temperature,
the Pr decreases significantly. From our calculations, it can also
be concluded that, for each binary mixture, the percentage of
drop in Prandtl number increases at elevated temperatures. For
instance, for CO2/n-tetradecane systems, the decreases in
Prandtl numbers at 25, 40, and 55 °C are 67, 76, and 87%,
respectively.
These changes in the Prandtl number can have real practical
implications for the equipment design of any gas-expanded-
The heat transfer coefficient between two phases (usually to/
from fluid and metal wall) is often the most important
parameter to determine heat transfer rates and design a number
of different process equipment, such as heat exchangers and
reactors. The heat transfer coefficient is obtained through the
Nusselt number which is a function of the Prandtl number, and
the Reynolds number (or Rayleigh number for natural
convection) and sometimes with additional parameters. The
functional form of the Nusselt number depends on the flow
regime, flow geometry, aspect ratio, etc.
For fully developed laminar flow in a pipe, the Nusselt
number is a constant. If the surface has constant heat, then Nu
= 4.36; if it has a constant temperature, then Nu = 3.66. Thus,
the Reynolds and Prandtl numbers have no bearing on the heat
transfer coefficient for this flow regime. However, for turbulent
flow in a pipe, the Dittus−Boelter correlation for the heating of
a fluid in the turbulent flow regime within a tube (and Pr > 0.7)
is given as
Nu =
hD
= 0.023Re 0.8Pr 0.4
λ
(9)
where D is the pipe diameter. Thus, the Prandtl number is
needed to properly quantify the heat transfer rate in a pipe.
For the systems of CO2/n-alkanes investigated here, the fluid
viscosity is needed to calculate the Prandtl number. We have
recently measured the viscosity for these CO2/n-alkane systems
at similar isotherms.3 In Tables 3−5, the viscosity is reported at
G
DOI: 10.1021/acs.iecr.7b03513
Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
Table 5. Experimental Thermal Conductivity (λ) and Thermal Diffusivity (α) of CO2-Saturated Liquid n-Tetradecane at
Various Pressures with Predicted Compositions (xCO2), Molar Volume (VL), and Calculated Heat Capacity (Cp)
P [bar]
xCO2a
VLb [cm3/mol]
ηc [mPa·s]
λ [mW/m·K]
−
11.8
21.9
31.6
40.1
50.9
60.7
0.000
0.127
0.225
0.310
0.381
0.465
0.541
261.1
233.6
209.8
193.1
175.4
159.1
144.4
2.150
1.943
1.649
1.417
1.263
0.976
0.732
140.7
138.7
137.3
133.1
130.9
128.4
123.7
−
11.4
20.4
31.5
41.1
50.0
61.5
71.2
80.2
0.000
0.103
0.177
0.261
0.326
0.382
0.449
0.500
0.540
265.0
242.3
225.1
207.3
191.7
180.4
166.2
154.9
145.9
1.612
1.499
1.313
1.139
0.889
0.713
0.654
0.472
0.397
137.2
136.6
135.0
129.3
126.4
124.9
122.4
120.5
118.0
−
10.2
21.4
31.2
41.6
50.8
61.7
69.4
80.6
91.2
101.1
105.5
0.000
0.079
0.160
0.223
0.285
0.336
0.390
0.425
0.472
0.512
0.543
0.554
268.9
252.6
234.6
220.6
206.5
195.3
183.3
175.5
164.9
156.1
149.2
146.6
1.264
1.194
1.025
0.920
0.701
0.588
0.481
0.407
0.300
0.222
0.195
0.170
134.3
131.6
129.2
125.3
124.2
122.6
121.3
119.7
116.5
113.2
111.6
110.5
±λ
25 °C
0.8
1.0
0.8
1.0
1.1
1.2
1.1
40 °C
0.7
1.0
0.9
1.0
1.4
1.1
1.2
1.3
1.8
55 °C
1.3
1.5
1.6
1.4
1.3
1.4
1.2
2.0
1.8
1.8
2.0
2.1
αT × 104 [cm2/s]
±αT × 104
Cpd [J/mol·K]
±Cpe
Pr
8.671
8.652
8.639
8.599
8.579
8.555
8.511
0.001
0.001
0.001
0.001
0.002
0.001
0.001
424
374
334
299
268
239
210
5
19
17
15
14
12
11
32.6
29.3
24.5
21.1
18.5
14.3
10.8
8.638
8.632
8.617
8.564
8.536
8.522
8.499
8.481
8.458
0.001
0.002
0.001
0.001
0.001
0.001
0.001
0.001
0.001
421
384
353
313
284
264
239
220
204
20
19
18
16
15
13
12
11
11
24.9
23.1
20.1
17.4
13.5
10.8
9.9
7.1
6.0
8.610
8.585
8.563
8.526
8.516
8.501
8.488
8.474
8.444
8.414
8.399
8.389
0.001
0.001
0.001
0.001
0.003
0.001
0.002
0.002
0.001
0.001
0.001
0.001
419
387
354
324
301
282
262
248
227
210
198
193
36
20
18
17
15
14
13
13
12
11
11
10
19.9
18.9
16.2
14.5
11.0
9.2
7.5
6.3
4.7
3.4
3.0
2.6
From PR-vdW2 prediction. bMixture value interpolated from literature data.31−33 cInterpolated from ref 3. dComputed from α, λ, and predicted VL.
From error propagation assuming the error in molar volume is approximately 5%.
a
e
Figure 5. Thermal conductivity versus composition of (a) CO2/n-decane and (b) CO2/n-tetradecane.
liquid system. For laminar flow in a tube of diameter D, the
heat transfer coefficient, h, will be directly proportional to the
thermal conductivity. Figure 9 illustrates the percent change of
h at constant flow velocity and pipe diameter with various
compositions of CO2 for n-decane at 25 °C. As shown, the heat
transfer coefficient, h, decreases over pure n-decane by
approximately 10% at a CO2 composition of ∼70%. For
turbulent flow, the heat transfer coefficient, h, in a pipe could be
calculated from eq 7 as Pr is greater than 0.7 at all CO2
compositions and conditions investigated. For constant pipe
diameter and flow velocity, the percentage change in the heat
transfer coefficient between the pure n-alkane and the CO2/
alkane mixture can be determined. These calculations use the
actual Re and Pr numbers at the indicated compositions of CO2.
As seen in Figure 9, the heat transfer coefficients can increase
up to 35% over the pure n-alkane at these conditions using the
H
DOI: 10.1021/acs.iecr.7b03513
Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
Figure 6. Comparison of thermal conductivities (a) and thermal diffusivities (b) of CO2/n-alkane mixtures at 25 °C.
Figure 7. Comparison of heat capacities of the liquid phase for alkane/
CO2 mixtures at 25 °C.
Figure 9. Percent change of the heat transfer coefficient, h, for CO2/ndecane for laminar and turbulent flow in a pipe at the same flow
velocity and pipe diameter using eq 9 at 25 °C.
same fluid velocity and pipe diameter for n-decane at 25 °C.
This is despite the fact that the thermal conductivity decreases
and the Prandtl number decreases in the mixture with CO2
over the pure n-alkane value. Similar trends are seen at the
other temperatures and the other n-alkanes. What is responsible
for the increase in heat transfer rate despite slower conductivity
is the increase in the Reynolds number. The Reynolds number
increases as the dynamic and kinematic viscosities decrease with
increasing composition of CO2. While this trend is for a specific
heat transfer scenario and in the turbulent regime, this
qualitative trend of increase heat transfer rates for CXLs will
hold for other correlations where the exponent of the Reynolds
number is generally greater than that for the Prandtl number.
For heat exchanger design especially determining the required
surface area, knowledge of the pipe/tube and the heat transfer
medium (steam, water, heat transfer fluids, etc.) is required.
However, the surface area required for any application of a CXL
with n-alkanes will be slightly larger in the laminar regime and
markedly lower in the turbulent regime. However, it should be
noted that the moderate pressure of CXLs would generally
Figure 8. Prandtl number with CO2 composition of (a) n-hexane at 25, 40, and 55 °C and (b) each n-alkane at 25 °C.
I
DOI: 10.1021/acs.iecr.7b03513
Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
(7) Sreedhar, I.; Nahar, T.; Venugopal, A.; Srinivas, B. Carbon
capture by absorption − path covered and ahead. Renewable
Sustainable Energy Rev. 2017, 76, 1080−1107.
(8) Chen, B.; Xin, F.; Song, X.; Li, X.; Azam, M. Z. Kinetics of carbon
dioxide hydration enhanced with a phase-change slurry of ntetradecane. Energy Fuels 2017, 31 (4), 4245−4254.
(9) Uemura, S.; Tsushima, S.; Hirai, S. In Use of Carbon Dioxide in
Enhanced Oil Recovery and Carbon Capture and Sequestration; John
Wiley & Sons, Inc.: 2014; pp 287−300.
(10) Kuuskraa, V. A.; Van Leeuwen, T.; Wallace, M.; DiPietro, P.
Improving Domestic Energy Security and Lowering CO2 Emissions with
“Next Generation” CO2-Enhanced Oil Recovery (CO2-EOR); National
Energy Technology Laboratory: Pittsburgh, PA, 2011.
(11) Lemmon, E. W.; Huber, M. L.; McLinden, M. O. NIST Reference
Fluid Thermodynamic and Transport Properties - REFPROP version 8.0;
National Institute of Standards and Technology: Gaithersburg, MD,
2007.
(12) Lemmon, E. W.; Huber, M. L.; McLinden, M. O. NIST
Standard Reference Database 23. NIST Reference Fluid Thermodynamic
and Transport Properties - REFPROP version 9; National Institute of
Standards and Technology: Gaithersburg, MD, 2010; p 55.
(13) Kroenlein, K.; Muzny, C.; Kazakov, A.; Diky, V.; Chirico, R.;
Magee, J.; Abdulagatov, I.; Frenkel, M. NIST/TRC Web Thermo Tables
(WTT), NIST Standard Reference Subscription Database 3Professional
Edition, version 2-2012-1-Pro; Thermodynamics Research Center
(TRC), National Institute of Standards and Technology: Boulder,
CO, 2011.
(14) Bolz, A.; Deiters, U. K.; Peters, C. J.; De Loos, T. W.
Nomenclature for phase diagrams with particular reference to vapourliquid and liquid-liquid equilibria. Pure Appl. Chem. 1998, 70 (11),
2233−2257.
(15) Galindo, A.; Blas, F. J. Theoretical examination of the global
fluid phase behavior and critical phenomena in carbon dioxide + nalkane binary mixtures. J. Phys. Chem. B 2002, 106 (17), 4503−4515.
(16) Hottovy, J. D.; Luks, K. D.; Kohn, J. P. Three-phase liquidliquid-vapor equilibriums behavior of certain binary carbon dioxide-nparaffin systems. J. Chem. Eng. Data 1981, 26 (3), 256−258.
(17) Van Konynenburg, P. H.; Scott, R. L. Critical lines and phase
equilibria in binary van der waals mixtures. Philos. Trans. R. Soc., A
1980, 298 (1442), 495−540.
(18) Scheidgen, A. L.; Schneider, G. M. Fluid phase equilibria of
(carbon dioxide + a 1-alkanol + an alkane) up to 100 MPa andt = 393
k: Cosolvency effect, miscibility windows, and holes in the critical
surface. J. Chem. Thermodyn. 2000, 32 (9), 1183−1201.
(19) van der Steen, J.; de Loos, T. W.; de Swaan Arons, J. The
volumetric analysis and prediction of liquid-liquid-vapor equilibria in
certain carbon dioxide + n-alkane systems. Fluid Phase Equilib. 1989,
51, 353−367.
(20) Chen, D.; Chen, W. Phase equilibria of n-hexane and n-octane
in critical carbon dioxide. Huaxue Gongcheng 1992, 20, 66−69.
(21) Lay, E. N.; Taghikhani, V.; Ghotbi, C. Measurement and
correlation of CO2 solubility in the systems of CO2+ toluene, CO2+
benzene, and CO2+ n-hexane at near-critical and supercritical
conditions. J. Chem. Eng. Data 2006, 51 (6), 2197−2200.
(22) Li, Y. H.; Dillard, K. H.; Robinson, R. L., Jr Vapor-liquid phase
equilibrium for carbon dioxide-n-hexane at 40, 80, and 120/sup 0/c. J.
Chem. Eng. Data 1981, 26 (1), 53−55.
(23) Ohgaki, K.; Katayama, T. Isothermal vapor-liquid equilibrium
data for binary systems containing carbon dioxide at high pressures:
Methanol-carbon dioxide, n-hexane-carbon dioxide, and benzenecarbon dioxide systems. J. Chem. Eng. Data 1976, 21 (1), 53−55.
(24) Wagner, Z.; Wichterle, I. High-pressure vapourliquid
equilibrium in systems containing carbon dioxide, 1-hexene, and nhexane. Fluid Phase Equilib. 1987, 33 (1), 109−123.
(25) Jiménez-Gallegos, R.; Galicia-Luna, L. A.; Elizalde-Solis, O.
Experimental vapor−liquid equilibria for the carbon dioxide + octane
and carbon dioxide + decane systems. J. Chem. Eng. Data 2006, 51 (5),
1624−1628.
increase the required wall thickness, although to a much lower
extent than supercritical fluid processes (i.e., 100−300 bar).
5. CONCLUSIONS
The thermal conductivity, thermal diffusivity, and heat capacity
were measured for binary systems of CO2-saturated n-alkanes
(n-hexane, n-decane, or n-tetradecane) at 25, 40, and 55 °C and
pressures up to 106 bar. Phase behavior and equilibrium are
discussed to determine the appropriate areas of study to
maintain vapor−liquid conditions and for determining needed
properties such as CO2 solubility and liquid molar volume/
density. Equation of state modeling of literature vapor−liquid
equilibrium data was used to determine the compositions at the
conditions of the heat transport measurements. Increasing
pressure (i.e., increasing composition) of CO2 results in a
relatively linear decrease in the liquid thermal conductivity,
thermal diffusivity, and heat capacity of the binary mixtures.
The Prandtl numbers are calculated and used to estimate the
change in heat transfer coefficients. The required heat transfer
areas would decrease with mixtures of CO2 systems over the
pure n-alkane for turbulent flows and slightly increase for
laminar flow.
■
AUTHOR INFORMATION
Corresponding Author
*Tel.: (785) 864-4947. Fax: (785) 864-4967. E-mail ascurto@
ku.edu.
ORCID
Aaron M. Scurto: 0000-0001-7214-1871
Notes
The authors declare no competing financial interest.
■
ACKNOWLEDGMENTS
This work was supported by the U.S. National Science
Foundation (CBET-0731244), the DOT:KU Transportation
Research Institute (TRI) (DOT No. DT0S59-06-G-00047),
and the KU General Research Fund. We would like to thank
Anas Alanqar for some initial scouting work in VLE modeling.
■
REFERENCES
(1) Scurto, A. M.; Hutchenson, K.; Subramaniam, B. Gas-expanded
liquids: Fundamentals and applications. In Gas-Expanded Liquids and
Near-Critical Media; ACS Symposium Series 1006; American Chemical
Society: Washington, DC, 2009; pp 3−37. DOI: 10.1021/bk-20091006.ch001.
(2) Sih, R.; Dehghani, F.; Foster, N. R. Viscosity measurements on
gas expanded liquid systemsmethanol and carbon dioxide. J.
Supercrit. Fluids 2007, 41 (1), 148−157.
(3) Kian, K.; Scurto, A. M., Viscosity of compressed CO2-saturated nalkanes: n-hexane, n-decane, and n-tetradecane. J. Supercrit. Fluids
Accepted for publication, 2017.
(4) Xie, Z. Z.; Snavely, W. K.; Scurto, A. M.; Subramaniam, B.
Solubilities of co and h2 in neat and CO2-expanded hydroformylation
reaction mixtures containing 1-octene and nonanal up to 353.15 k and
9 MPa. J. Chem. Eng. Data 2009, 54 (5), 1633−1642.
(5) Ahosseini, A.; Ren, W.; Scurto, A. M. Hydrogenation in biphasic
ionic liquid−carbon dioxide systems. In Gas-Expanded Liquids and
Near-Critical Media; ACS Symposium Series 1006; American Chemical
Society: Washington, DC, 2009; pp 218−234. DOI: 10.1021/bk-20091006.ch011.
(6) Fusaro, F.; Haenchen, M.; Mazzotti, M.; Muhrer, G.;
Subramaniam, B. Dense gas antisolvent precipitation: A comparative
investigation of the GAS and PCA techniques. Ind. Eng. Chem. Res.
2005, 44 (5), 1502−1509.
J
DOI: 10.1021/acs.iecr.7b03513
Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Article
Industrial & Engineering Chemistry Research
(26) Reamer, H.; Sage, B. Phase equilibria in hydrocarbon systems.
Volumetric and phase behavior of the n-decane-CO2 system. J. Chem.
Eng. Data 1963, 8 (4), 508−513.
(27) Wang, L. S.; Lang, Z. X.; Guo, T. M. Measurement and
correlation of the diffusion coefficients of carbon dioxide in liquid
hydrocarbons under elevated pressures. Fluid Phase Equilib. 1996, 117
(1), 364−372.
(28) Jiménez-Gallegos, R.; Galicia-Luna, L. A.; Elizalde-Solis, O.
Experimental vapor−liquid equilibria for the carbon dioxide + octane
and carbon dioxide + decane systems. J. Chem. Eng. Data 2006, 51 (5),
1624−1628.
(29) Cullick, A. S.; Mathis, M. L. Densities and viscosities of mixtures
of carbon dioxide and n-decane from 310 to 403 k and 7 to 30 MPa. J.
Chem. Eng. Data 1984, 29 (4), 393−396.
(30) Kaminishi, G.-I.; Yokoyama, C.; Shinji, T. Vapor pressures of
binary mixtures of carbon dioxide with benzene, n-hexane and
cyclohexane up to 7 MPa. Fluid Phase Equilib. 1987, 34 (1), 83−99.
(31) Kariznovi, M.; Nourozieh, H.; Abedi, J. Phase composition and
saturated liquid properties in binary and ternary systems containing
carbon dioxide, n-decane, and n-tetradecane. J. Chem. Thermodyn.
2013, 57, 189−196.
(32) Kato, M.; Aizawa, K.; Kanahira, T.; Tanaka, H.; Muramatsu, T.;
Ozawa, T.; LU, B. C.-Y. A new experimental method for measuring gas
solubilities in nonvolatile liquid mixtures. Sekiyu Gakkaishi 1992, 35
(4), 318−323.
(33) Nourozieh, H.; Kariznovi, M.; Abedi, J. Measurement and
correlation of saturated liquid properties and gas solubility for decane,
tetradecane and their binary mixtures saturated with carbon dioxide.
Fluid Phase Equilib. 2013, 337, 246−254.
(34) Zúñiga-Moreno, A.; Galicia-Luna, L. A.; Camacho-Camacho, L.
E. Compressed liquid densities and excess volumes of CO2+ decane
mixtures from (313 to 363) k and pressures up to 25 MPa. J. Chem.
Eng. Data 2005, 50 (3), 1030−1037.
(35) Ren, W.; Scurto, A. M. High-pressure phase equilibria with
compressed gases. Rev. Sci. Instrum. 2007, 78 (12), 125104.
K
DOI: 10.1021/acs.iecr.7b03513
Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX
Документ
Категория
Без категории
Просмотров
2
Размер файла
2 237 Кб
Теги
acs, 7b03513, iecr
1/--страниц
Пожаловаться на содержимое документа