Ionic Liquids
*************

COSMO-RS Ionic Liquids Activity coefficient Henry's law constant Gas
solubility VLE


Using the ADF COSMO-RS ionic liquid database
============================================

Ionic liquids (ILs), usually consisting of a large organic cation and
a small inorganic polyatomic anion, have attracted considerable
attention due to their unique thermophysical properties. The low vapor
pressure and high conductivity of these molten salts combined with
highly tunable properties, have resulted in highly diverse
applications across many different fields in chemistry, materials
science (battery electrolytes), chemical engineering (gas sorption and
purification), and many more.

To calculate thermodynamic properties of ionic liquids with COSMO-RS,
the IL may be described either as a single ion pair or as discrete
cations and anions. The latter method will be mainly used here. The
COSMO-RS ionic liquid database ADFCRS-IL-2014 contains 80 cations and
56 anions. This ADFCRS-IL-2014 database consists of ADF COSMO result
(.coskf) files, from standard ADF quantum mechanical calculations, as
described in the tutorial: COSMO result files. The user can create new
anions and cations using that same approach and add them to the List
of Added Compounds.

The ADFCRS-IL-2014 database is part of the ADFCRS-2018 COSMO-RS
database. Install the ADFCRS-2018 database if it is not yet installed,
see the tutorial: The COSMO-RS compound database.

SCM gratefully acknowledges Prof. Zhigang Lei's research group (State
Key Laboratory of Chemical Resource Engineering, Beijing University of
Chemical Technology, China) for providing the ionic liquid database,
the corresponding tutorial, and the reparameterization of COSMO-RS for
ionic liquids (ADF Lei 2018).


Reparameterization of COSMO-RS for ionic liquids
------------------------------------------------

In Ref. [617] Han, Lei and coworkers present a reparametrization of
COSMO-RS parameters for ionic liquids within the ADF framework. The
extensive training set consisted of 2283 activity coefficient data
points at infinite dilution and 1433 CO_2 solubility data points that
were collected from literature references.

The authors use the refitted parameters to predict CO_2 solubility in
pure ionic liquids at low temperatures (<273.2 K) and the CO_2
solubility in mixed ionic liquids over a wide temperature and pressure
range.

Their refitted optimal values for the misfit energy constant a', the
hydrogen bond coefficient c_hb, and the effective contact surface area
of a segment a_eff can be used by selecting *ADF Lei 2018*:

   Select **SCM → COSMO-RS**
   Select **Method → COSMO-RS**
   Select **Method → Parameters**
   Select 'ADF Lei 2018' in the popup menu Use COSMO-RS parameters

However, in this Tutorial we will use the original COSMO-RS
parameters.

   Select **Method → COSMO-RS**
   Select **Method → Parameters**
   Select 'ADF combi2005' in the popup menu Use COSMO-RS parameters


References
----------

Some of the work of Zhigang Lei group based on the COSMO-RS model
using the ADF software is listed as follows:

611. Z. Lei, C. Dai, J. Zhu, B. Chen, Extractive distillation with
     ionic liquids: A review,  AIChE Journal 60, 3312 (2014)

612. Z. Lei, C. Dai, B. Chen, Gas solubility in ionic liquids,
     Chemical Reviews 14, 1289 (2014)

613. Z. Lei, J. Han, Q. Li, and B. Chen, Process Intensification on
     the Supercritical Carbon Dioxide Extraction of Low-Concentration
     Ethanol from Aqueous Solutions,  Industrial &  Engineering
     Chemistry research 51, 2730 (2012)

614. Z. Lei, J. Han, B. Zhang, Q. Li, J. Zhu, and B. Chen, Solubility
     of CO_2  in Binary Mixtures of Room-Temperature Ionic Liquids at
     High Pressures,  Journal of Chemical Engineering data 57, 2153
     (2012)

615. Z. Lei, C. Dai, X. Liu, L. Xiao, and B. Chen, Extension of the
     UNIFAC Model for Ionic Liquids,  Industrial &  Engineering
     Chemistry research 51, 12135 (2012)

616. Z. Lei, C. Dai, Q. Yang, J. Zhu, and B. Chen, UNIFAC model for
     ionic liquid-CO (H_2 ) systems: An experimental and modeling
     study on gas solubility,  AIChE Journal 60, 4222 (2014)

617. J. Han, C. Dai, G. Yu, Z. Lei, Parameterization of COSMO-RS model
     for ionic liquids,  Green Energy & Environment 3, 247 (2018)


Ionic liquid volumes and densities
==================================

Ionic liquid densities may be estimated from the molecular volume and
molar mass (MW) of the constituent cations and anions. The COSMO
volume is stored in the coskf file and is displayed, together with the
MW, when a compound is selected in the COSMO-RS GUI.

   Click on the search button in the compounds field
   Select 'IL_cation_1-butyl-3-methyl-imidazolium'
   Click 'OK'
 [image]

Volumes and molar mass of other cations and anions can be similarly
found. Data for a few compounds are listed below.

+-----------------------------------+-----------------------------------+-----------------------------------+
|                                   | COSMO Volume (Å ^3)               | MW (g/mol)                        |
|===================================|===================================|===================================|
| cations                           |                                   |                                   |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C4MIM 1-butyl-3-methyl-           | 197.181                           | 139.124                           |
| imidazolium                       |                                   |                                   |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C6MIM 1-hexyl-3-methyl-           | 241.003                           | 167.155                           |
| imidazolium                       |                                   |                                   |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C8MIM 1-octyl-3-methyl-           | 282.855                           | 195.186                           |
| imidazolium                       |                                   |                                   |
+-----------------------------------+-----------------------------------+-----------------------------------+
| anions                            |                                   |                                   |
+-----------------------------------+-----------------------------------+-----------------------------------+
| BF_4   tetrafluoroborate          | 72.489                            | 87.003                            |
+-----------------------------------+-----------------------------------+-----------------------------------+
| PF_6   hexafluorophosphate        | 103.495                           | 144.964                           |
+-----------------------------------+-----------------------------------+-----------------------------------+
| NTF_2                             | 213.173                           | 279.917                           |
| bis(trifluoromethylsulfonyl)amide |                                   |                                   |
+-----------------------------------+-----------------------------------+-----------------------------------+

The molecular liquid density could be approximately calculated as (V
in Å^3  and MW in g/mol) using Avogadro's number:

      density = (MW_cation  +   MW_anion )/[0.6022*(V_cation  +   V_anion )]


density (g cm^-3)
^^^^^^^^^^^^^^^^^

+-----------------------------------+-----------------------------------+-----------------------------------+
| ionic liquid                      | expt [621]                        | calculated                        |
|===================================|===================================|===================================|
| C4MIMBF_4                         | 1.208                             | 1.392                             |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C6MIMBF_4                         | 1.148                             | 1.346                             |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C8MIMBF_4                         | 1.109                             | 1.319                             |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C4MIMPF_6                         | 1.37                              | 1.569                             |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C6MIMPF_6                         | 1.293                             | 1.505                             |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C8MIMPF_6                         | 1.237                             | 1.462                             |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C4MIMNTf_2                        | 1.429                             | 1.696                             |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C6MIMNTf_2                        | 1.37                              | 1.635                             |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C8MIMNTf_2                        | 1.32                              | 1.591                             |
+-----------------------------------+-----------------------------------+-----------------------------------+

As can be seen from this table, the calculated densities are
systematically overestimated by approximately 15%. Thus, the   COSMO
volumes underestimate the volume of a single compound, if   they are
used for estimating the liquid densities.


References
----------

621. C. Ye and J.M. Shreeve,   Rapid and Accurate Estimation of
     Densities of   Room-Temperature Ionic Liquids and Salts,  Journal
     of Physical   Chemistry A 111, 1456 (2007)


Activity coefficient calculation
================================

The activity coefficient of a compound solvated in an ionic liquid is
an important thermodynamic property. The cation and anion, which have
been treated separately, will be used in equal amounts to ensure an
electroneutral mixture in the COSMO-RS calculation.

In other applications cation-anion pair have been treated as one
molecule, however, in the COSMO-RS calculations below we will treat
the cation and anion as two separate molecules. To be able to compare
to experimental activity coefficients in which the cation-anion pair
is treated as one compound, we will also make one compound. However,
in the calculation this compound only has the dissociated form.

   Select **Compounds → Compound with multiple forms**
   Select 'IL_cation_1-ethyl-3-methyl-imidazolium' for dissociated compound d1.A
   Select 'IL_anion_tetracyanoborate' for dissociated compound d1.B
   Press 'Save' at the top of the left window
   In the file select box, choose 'IL_Emim_Tcb' as name for your file and click 'Save'
 [image]

   Select **Properties → Activity Coefficients**
   Select '1 component' in the popup menu next to Solvent
   Select 'IL_Emin_Tcb' for the first component in Solvent
   Enter 1.0 for the Mole fraction of the first component
   Enter '308.15' for 'Temperature Kelvin'
   Check the '+' button to add 'Hexane', 'Heptane', 'Octane', and 'Decane'
   Press 'Run'
 [image]

If one does not supply a density of the solvent in the input, the
program calculates the density of the solvent by dividing the mass of
a molecule with its COSMO volume. Note that the calculated activity
coefficients do not depend on this density. The result of the
calculation is given in the form of a table.

[image]

In the next figure the results of the calculated activity coefficients
at different temperatures are compared to experiment.

[image]

In this figure activity coefficients at infinite dilution of n-alkenes
in [EMIM]^+ [TCB]^-  are shown for different temperatures ranging from
298 K to 358 K. The scattered points are experimental data from Ref.
[633]. The points that are connected with a line are calculated
numbers with ADF COSMO-RS. For example, for Hexane, the calculated
values T = 308.15 K are:   1000/308.15 = 3.245, ln(30.219) = 3.41.
Note that the calculated numbers in this figure are calculated with an
older version of COSMO-RS. These will not change much if you use a
newer COSMO-RS version.


References
----------

631. Z. Lei, C. Dai, J. Zhu, B.   Chen, Extractive distillation with
     ionic liquids: A   review,  AIChE   Journal 60, 3312 (2014)

632. Z. Lei, C. Dai, B. Chen,   Gas solubility in ionic liquids,
     Chemical Reviews   14, 1289 (2014)

633. U. Domańska, M. Królikowska,   W.E. Acree Jr., G.A. Baker,
     Activity coefficients at infinite   dilution measurements for
     organic solutes and water in the ionic   liquid
     1-ethyl-3-methylimidazolium tetracyanoborate,    The Journal   of
     Chemical Thermodynamics 43, 1050 (2011)


Henry's law constants
=====================

In this tutorial, we will calculate Henry's law constants for   CO_2
in different ionic liquids. Henry's law constant   reflects the
solubility of a gas in a solvent, and one way to   define it is

   H_i = \gamma_i^\infty  P_i^S

where H_i  is the ratio between the partial vapor   pressure of a
compound *i* in the gas phase and its molar fraction in the liquid
phase, \gamma_i^\infty is the   the activity coefficient of the
compound at infinite dilution, and P_i ^S  is the saturated pure
compound vapor pressure of the gas.

The familiar Antoine and Wagner equations can be used to   calculate
the vapor pressure below the critical temperature   T_c , if one knows
the coefficients. Above   T_c , they can be extrapolated as a
hypothetical vapor   pressure. If the experimental saturated vapor
pressures of a gas   is not available, then it can be estimated by
COSMO-RS.

The saturated vapor pressure of CO_2  at 298.15 K can be   calculated
by the following Antoine equation:

      ln P_CO_2 ^S  (MPa) = 12.3312 -   4759.46/(T(K)+156.462)

The saturated vapor pressure of CO_2  at 298.15 K is   6.436 MPa (=
64.36 bar) according to this equation. The Antoine   equation can also
be written as:

      {}^{10}log P_CO_2 ^S    (bar) = 6.35537 - 2067.0/(T(K)+156.462)

The activity coefficients of infinitely diluted carbon dioxide in
[HMIM]^+ [Tf2N]^-  will now be calculated.

   Select **Compounds → List of Added Compounds**
   Search on the left side 'Carbon dioxide' and click on it
   Enter 6.35537 for the Antoine coefficient A on the right side
   Enter 2067.0 for the Antoine coefficient B
   Enter 156.462 for the Antoine coefficient C
   Select **Compounds → Compound with multiple forms**
   Press 'Clear' at the top of the left window
   Select 'IL_cation_1-hexyl-3-methyl-imidazolium' for dissociated compound d1.A
   Select 'IL_anion_bis(trifluoromethylsulfonyl)amide' for dissociated compound d1.B
   Press 'Save' at the top of the left window
   In the file select box, choose 'IL_Hmim_Tf2N' as name for your file and click 'Save'
   Select **Properties → Activity coefficients**
   Select '1 component' in the popup menu next to Solvent
   Select 'IL_Hmin_Tf2N' for the first component in Solvent
   Enter 1.0 for the Mole fraction of the first component
   Enter '298.15' for 'Temperature Kelvin'
   Check the '+' button to add 'Carbon dioxide' (Remove the alkanes if they are still present)
   Press 'Run'
 [image]

The results of the activity coefficients.

[image]

Henry's law coefficient is \gamma^\infty times the saturated vapor
pressure of CO_2  at 298.15 K (64.36 bar). For CO_2  in [HMIM]^+
[Tf2N]^- the calculated H = 0.5065*64.36 = 32.6 bar. Applying the same
calculations for more ionic liquids gives these results:


H (bar)
^^^^^^^

+-----------------------------------+-----------------------------------+-----------------------------------+
| ionic liquid                      | expt [644]                        | calculated                        |
|===================================|===================================|===================================|
| BMIM PF_6                         | 53.4±0.3                          | 53.1                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| BMIM Tf_2 N                       | 33.0±0.3                          | 35.4                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| HMIM Tf_2 N                       | 31.6±0.2                          | 32.6                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| HMPY Tf_2 N                       | 28.4±0.2                          | 314                               |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C6F9MIM Tf_2 N                    | 27.3±0.1                          | 33.8                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C8F13MIM Tf_2 N                   | 25.2±0.2                          | 31.0                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| HMIM eFAP                         | 25.2±0.1                          | 27.1                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| HMIM pFAP                         | 21.6±0.1                          | 25.8                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| C5MIM bFAP                        | 20.2±0.1                          | 25.2                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| Et_3 NBH_2 MIM Tf_2 N             | 33.1±1.2                          | 30.5                              |
+-----------------------------------+-----------------------------------+-----------------------------------+

[image]

There are many different definitions of Henry's law constant.
Henry's law constant as calculated directly by COSMO-RS,   k_H
(mol/(L atm)), is defined as the ratio between the   liquid phase
concentration of a compound and its partial vapor   pressure in the
gas phase. The relationship between k_H    and H is:

      H = k_H,inv ^px  = 1/(k_H    V_solvent )

where V_solvent  is the molar volume of the ionic   liquid. If no
densities for the cation, anion, or solvent are   given, COSMO-RS will
use the COSMO volume for calculating the   molar volume of the ionic
liquid, which is 0.2735 L/mol   (=(241.00+213.17)*0.6022/1000) for
[HMIM]^+ [Tf2N]^- , if the usual convention is   followed, that a pair
of a cation and an anion is treated as one   molecule. Thus in this
case H = 1.01325/(0.1136 * 0.2735) = 32.6   bar, where a conversion
factor from atm to bar is included.

Note that k_H  does not depend on whether one treats a cation and an
anion as separate molecules, or if a pair of a cation and an anion is
treated as one molecule. H = k_H,inv ^px  does depend on this
definition.


References
----------

641. P.G.T. Fogg and W. Gerrard,   Solubility of gases in liquids: A
     critical evaluation of   gas/liquid systems in theory and
     practice, New York: John   Wiley & Sons, Inc., 1991.

642. J.L. Anthony, J.L. Anderson,   E.J. Maginn, J.F. Brennecke, Anion
     Effects on Gas Solubility   in Ionic Liquids,  Journal of
     Physical   Chemistry B 109, 6366 (2005)

643. J.L. Anderson, E. J. Maginn and   J. F. Brennecke, Measurement of
     SO_2  Solubility in   Ionic Liquids,  Journal of Physical
     Chemistry B 110, 15059 (2006)

644. M.J. Muldoon, S.N.V.K. Aki,   J.L. Anderson, J.K. Dixon, J.F.
     Brennecke, Improving Carbon   Dioxide Solubility in Ionic
     Liquids,  Journal of Physical   Chemistry B 111, 9001 (2007)

645. B.H. Culbertson, S. Dai, H.   Luo, D.W. DePaoli, Low-Pressure
     Solubility of Carbon Dioxide   in Room-Temperature Ionic Liquids
     Measured with a Quartz Crystal   Microbalance,  Journal of
     Physical   Chemistry B 108, 721 (2004)

646. Y. Hou and R.E. Baltus,   Experimental Measurement of the
     Solubility and Diffusivity of   CO2 in Room-Temperature Ionic
     Liquids Using a Transient   Thin-Liquid-Film Method,  Industrial
     &  Engineering Chemistry research 46, 8166   (2007)

647. A. Finotello, J.E. Bara, D. Camper and R.D. Noble, Room-
     Temperature Ionic Liquids: Temperature Dependence of Gas
     Solubility Selectivity, Industrial & Engineering Chemistry
     research 47, 3453 (2008)


Gas solubility and selectivity in ionic liquids
===============================================

In this example the solubility of carbon dioxide in ionic liquids is
calculated and compared to experimental data.

First we use the experimental Antoine coefficients for CO_2.

   **(Skip this part if you have just done COSMO-RS tutorial 6.4)**
   Select **Compounds → List of Added Compounds**
   Search on the left side 'Carbon dioxide' and click on it
   Enter 6.35537 for the Antoine coefficient A on the right side
   Enter 2067.0 for the Antoine coefficient B
   Enter 156.462 for the Antoine coefficient C

Next we make the ionic liquid as one compound and calculate CO_2
solubilities.

   Select **Compounds → Compound with multiple forms**
   Press 'Clear' at the top of the left window
   Select 'IL_cation_1-butyl-3-methyl-imidazolium' for dissociated compound d1.A
   Select 'IL_anion_bis(trifluoromethylsulfonyl)amide' for dissociated compound d1.B
   Press 'Save' at the top of the left window
   In the file select box, choose 'IL_Bmim_Tf2N' as name for your file and click 'Save'
   Select **Properties → Solubility in Mixture**
   Select '1 component' in the popup menu next to Solvent
   Select 'IL_Bmin_Tf2N' for the first component in Solvent
   Enter 1.0 for the Mole fraction of the first component
   Enter '8' for 'Temperature: number of steps'
   Enter '282.0' for 'Temperature from'
   Enter '322.8' for 'Temperature to'
   Change the popup menu next to Solutes to 'Gas'
   Enter '3' for 'Pressure: for solubility gas: number of steps'
   Use 'MPa' units for the pressure
   Enter '0.5' for the pressure 'from'
   Enter '2.0' for the pressure 'to'
   Check the '+' button to add 'Carbon dioxide'
   Press 'Run'
 [image]

From the results we will use the calculated mole fractions at 282.0 K,
297.3 K, and 322.8 K.

[image]

In this example we also calculated the solubility of carbon dioxide at
relatively high pressures. In such cases, for more accurate results,
we also need to take the nonideal behavior of the gas into account,
the gas fugacity.

      f_gas  = P_gas  \Phi (T,P)

where f_gas  is the gas fugacity at the system temperature and
pressure, and \Phi (T,P) is the fugacity coefficiency of the gas. We
will approximate the fugacity coefficients with:

   \Phi (T=282.0 K,P) & \approx (1 - 0.06 (P/MPa)) \\ \Phi (T=297.3
   K,P) & \approx (1 - 0.05 (P/MPa)) \\ \Phi (T=322.8 K,P) & \approx
   (1 - 0.04 (P/MPa))

Note that these values are only approximate, and certainly not
applicable for higher pressures. We can use the same solubilities as
calculated before but plot them against fugacity instead of pressure.

+-----------------------------------+-----------------------------------+-----------------------------------+
| Temperature                       | f (MPa)                           | P (MPa)                           |
|===================================|===================================|===================================|
| 282.0                             | 0.50                              | 0.52                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 282.0                             | 1.00                              | 1.07                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 282.0                             | 1.50                              | 1.67                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 282.0                             | 2.00                              | 2.32                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 297.3                             | 0.50                              | 0.51                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 297.3                             | 1.00                              | 1.06                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 297.3                             | 1.50                              | 1.63                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 297.3                             | 2.00                              | 2.25                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 322.8                             | 0.50                              | 0.51                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 322.8                             | 1.00                              | 1.04                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 322.8                             | 1.50                              | 1.60                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 322.8                             | 2.00                              | 2.19                              |
+-----------------------------------+-----------------------------------+-----------------------------------+

The results can be compared with experimental values from Ref.[651].
Note that the calculated numbers in this figure are calculated with an
older version of COSMO-RS. These will not change much if you use a
newer COSMO-RS version.

[image]

For low pressures one can estimate gas solubility using Henry's law
constants:

   x = P_{gas} \Phi (T,P)/H_{gas}

For low pressures \Phi (T,P) will be close to 1. Calculating Henry's
law constants has been described in COSMO-RS Tutorial 6.4, and
following this procedure for CO_2 in [HMIM][Tf_2 N], results in H =
2.24 MPa at T = 282 K, H = 3.20 MPa at T = 297.3 K, and H = 5.51 MPa
at T = 322.8 K.

Gas selectivity in ionic liquids can be defined as

      S_i/j  = H_i /H_j

where S_i/j  is the selectivity between gas i and j in   ionic
liquids; H_i  and H_j  are Henry's law   constants of gas i and j,
which can be calculated using the   methods as described in the COSMO-
RS Tutorial 6.4.


References
----------

651. M.B. Shiflett and A. Yokozeki,   Solubility of CO_2  in Room
     Temperature Ionic Liquid   [hmim][Tf_2 N],  Journal of Physical
     Chemistry B 111, 2070 (2007)


VLE for systems containing ionic liquids
========================================

In this example a vapor-liquid diagram of Acetone in   [EMIM][Tf_2 N]
at 353.15 K is calculated and compared to   experiment. The
experimental saturated pure compound vapor   pressure is used for
Acetone.

   Select **Compounds → List of Added Compounds**
   Search on the left side 'Acetone' and click on it
   Enter '2.1516' in the 'Pure compound vapor pressure' field
   Enter '353.15' in the 'at temperature' field
   Select **Compounds → Compound with multiple forms**
   Press 'Clear' at the top of the left window
   Select 'IL_cation_1-ethyl-3-methyl-imidazolium' for dissociated compound d1.A
   Select 'IL_anion_bis(trifluoromethylsulfonyl)amide' for dissociated compound d1.B
   Press 'Save' at the top of the left window
   In the file select box, choose 'IL_Emim_Tf2N' as name for your file and click 'Save'
   Select **Properties → Binary Mixture VLE/LLE**
   Select 'Acetone' for the first compound
   Select 'IL_Emim_Tf2N' for the second compound
   Enter '20' for 'Number of mixtures'
   Select 'Isotherm' from the Isotherm, isobar, flash point popup menu
   Use 'Kelvin' as units for the temperature
   Enter '353.15' for 'Temperature'
   Press 'Run'
 [image]

+---------------------------+---------------------------+---------------------------+---------------------------+
| x                         | P (kPa)                   | x                         | P (kPa)                   |
+---------------------------+---------------------------+---------------------------+---------------------------+
| **calc**                  | **calc**                  | **expt** [661]            | **expt** [661]            |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.000                     | 0.000                     | 0.0133                    | 1.139                     |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.002                     | 0.144                     | 0.0383                    | 3.485                     |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.01                      | 0.726                     | 0.0539                    | 4.825                     |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.05                      | 3.741                     | 0.0683                    | 6.073                     |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.10                      | 7.774                     | 0.0949                    | 8.509                     |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.15                      | 12.135                    | 0.1521                    | 14.884                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.20                      | 16.863                    | 0.2081                    | 21.660                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.25                      | 22.005                    | 0.2735                    | 30.115                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.30                      | 27.616                    | 0.3393                    | 39.811                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.35                      | 33.760                    | 0.4022                    | 50.263                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.40                      | 40.511                    | 0.4647                    | 61.862                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.45                      | 47.960                    | 0.5249                    | 74.281                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.50                      | 56.210                    | 0.5839                    | 87.870                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.55                      | 65.386                    | 0.6369                    | 101.46                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.60                      | 75.637                    | 0.6846                    | 114.73                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.65                      | 87.133                    | 0.7264                    | 127.22                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.70                      | 100.07                    | 0.7631                    | 138.75                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.75                      | 114.68                    | 0.7948                    | 149.16                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.80                      | 131.18                    | 0.8222                    | 158.37                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.85                      | 149.74                    | 0.8455                    | 166.29                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.90                      | 170.04                    | 0.8653                    | 173.07                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.95                      | 192.70                    | 0.8967                    | 183.75                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.99                      | 210.80                    | 0.9376                    | 196.92                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 0.998                     | 214.30                    | 0.9671                    | 205.80                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| 1.000                     | 215.16                    | 0.9844                    | 210.74                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
|                           |                           | 0.9933                    | 213.25                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
|                           |                           | 0.9972                    | 214.40                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
|                           |                           | 0.9990                    | 214.94                    |
+---------------------------+---------------------------+---------------------------+---------------------------+
|                           |                           | 1.0000                    | 215.16                    |
+---------------------------+---------------------------+---------------------------+---------------------------+

Comparing the calculated and experimental vapor pressure of acetone in
[EMIM][Tf2N] in a graph:

[image]

**References**

661. M. Döker, J. Gmehling,  Measurement and prediction of vapor-
     liquid equilibria of  ternary systems containing ionic liquids,
     Fluid Phase Equilibria 227 (2005), 255
