Current status of the Functional-Segment Activity ... · UNIFAC COSMO-RS JCOSMO program COSMO-RS {...
Transcript of Current status of the Functional-Segment Activity ... · UNIFAC COSMO-RS JCOSMO program COSMO-RS {...
IntroductionF-SAC
Conclusions
Current status of the Functional-Segment ActivityCoefficient Model: F-SAC
Prof. Rafael de Pelegrini Soares
UNIVERSIDADE FEDERAL DO RIO GRANDE DO SULESCOLA DE ENGENHARIADEPARTAMENTO DE ENGENHARIA QUIMICALAB. VIRTUAL DE PREDICAO DE PROPRIEDADEShttp://www.enq.ufrgs.br/labs/lvpp
July 14, 2013
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
Summary
1 Introduction
2 F-SAC
3 Conclusions
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
Two families of predictive activity coefficient (γi ) models
Group contribution models,for instance:
COSMO-RS like models, forinstance:
UNIFAC (Do) – Group Contribution
According to revision 5 – Antje Jakob et al. In: Ind. Eng. Chem.Res. 45.23 (2006), pp. 7924–7933.
DOI:10.1021/ie060355c
COSMO-RS – Surface contacting teory
First, for each insulated molecule theCOSMOa method is applied and theapparent surface charges are determinedin a cavity
Several approximations are consideredhere:
The cavity consists of spheres of fixedradiiMolecules surrounded by a perfectconductorThe methods used contains otherapproximations: AM1, RM1, DFT, MP2,etc.The escaping charges need to becorrected. . .
aA Klamt and G Schuurmann. In: J. Chem. Soc., PerkinTrans. 2 (1993), pp. 799–805
COSMO-RS – Surface contacting teory
First, for each insulated molecule theCOSMOa method is applied and theapparent surface charges are determinedin a cavity
Several approximations are consideredhere:
The cavity consists of spheres of fixedradiiMolecules surrounded by a perfectconductorThe methods used contains otherapproximations: AM1, RM1, DFT, MP2,etc.The escaping charges need to becorrected. . .
aA Klamt and G Schuurmann. In: J. Chem. Soc., PerkinTrans. 2 (1993), pp. 799–805
COSMO-RS – Surface contacting theory
In the COSMO-RSa surface contactingtheory, the molecules are sequentially putin contact
For each contact, the conductor ispartially excluded
If each molecule is completely surroundedby others, the real solution would beobtained
aAndreas Klamt. In: The J. of Phys. Chem. 99.7 (1995),pp. 2224–2235
COSMO-RS – Surface contacting theory
In the COSMO-RSa surface contactingtheory, the molecules are sequentially putin contact
For each contact, the conductor ispartially excluded
If each molecule is completely surroundedby others, the real solution would beobtained
aAndreas Klamt. In: The J. of Phys. Chem. 99.7 (1995),pp. 2224–2235
IntroductionF-SAC
Conclusions
IntroductionUNIFACCOSMO-RSJCOSMO program
COSMO-RS – Surface contacting theory
For each surface pair contact, there is anenergy change
This results in different behavior fordifferent substances in solution
Clearly, there are many different possiblecontacting arranges and statisticalthermodynamics is necessary
For the F-SAC model, the COSMO-RSvariant known as COSMO-SACa is used
aShiang-Tai Lin and Stanley I. Sandler. In: Ind. Eng.Chem. Res. 41.5 (2002), pp. 899–913
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
IntroductionUNIFACCOSMO-RSJCOSMO program
Sigma profile – p(σ)
For the statisticalthermodynamics treatment,the 3D apparent surfacecharges are projected into asimple histogram
These pure compounddistributions, known assigma profiles – p(σ), arethe basis for computing theactivity coefficients inmixture
“It is always desirable to express the properties of a solution in terms that canbe calculated completely from the properties of the pure components.” –J. M. Prausnitz. Molecular thermodynamics of fluid-phase equilibria. Third.Prentice-Hall, 1999.
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
IntroductionUNIFACCOSMO-RSJCOSMO program
Sigma profile – p(σ)
For the statisticalthermodynamics treatment,the 3D apparent surfacecharges are projected into asimple histogram
These pure compounddistributions, known assigma profiles – p(σ), arethe basis for computing theactivity coefficients inmixture
“It is always desirable to express the properties of a solution in terms that canbe calculated completely from the properties of the pure components.” –J. M. Prausnitz. Molecular thermodynamics of fluid-phase equilibria. Third.Prentice-Hall, 1999.
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
IntroductionUNIFACCOSMO-RSJCOSMO program
JCOSMO program: sigma profile of pure substances
code.google.com/p/jcosmo/
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
IntroductionUNIFACCOSMO-RSJCOSMO program
JCOSMO program: activity coefficient and VLE predictions
code.google.com/p/jcosmo/
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
IntroductionUNIFACCOSMO-RSJCOSMO program
JCOSMO program: surface charges visualization
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
F-SAC: Motivation
Although COSMO-RS models have exceptional theoreticalcharacteristics, in general quantitative experimentalagreement is usually obtained by empirical modifications
The F-SAC1 model combines group contribution with theCOSMO-RS theory:
DOI:10.1021/ie400170a
1R.P. Soares and R.P. Gerber. “Functional-Segment Activity Coefficientmodel. 1. Model formulation”. In: Ind. Eng. Chem. Res. (2013). doi:10.1021/ie400170a.
IntroductionF-SAC
Conclusions
A new modelCurrent Status
Similarities/differences between COSMO-SAC and F-SAC
The model equations areidentical, the difference is inthe sigma profile
In the F-SAC model there isa neutral and two chargedpeaks per group
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
A new modelCurrent Status
Similarities/differences between COSMO-SAC and F-SAC
The model equations areidentical, the difference is inthe sigma profile
In the F-SAC model there isa neutral and two chargedpeaks per group
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
A new modelCurrent Status
Sigma profiles from group contribution
pi (σ) =∑
k ν(i)k pk (σ)
DOI:10.1021/ie400170a
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
F-SAC parameters
Parameters to be calibrated based on experimental data foreach group k :
Qk total group surface area, initial value fromCOSMO computations2
Q+k group positive area
Q−k group negative areaσ+
k surface charge density of the positive areaportion
Other parameters:
Q◦k = Qk − Q+
k − Q−k group neutral area
σ−k = σ+k Q+
k /Q−k surface charge density of the
negative area portion
2R.P. Gerber and R.P. Soares. In: Braz. J. of Chem. Eng. 30 (1 2013),pp. 1–11.
IntroductionF-SAC
Conclusions
A new modelCurrent Status
Parameter fit with experimental data
Currently there are parameters for 24 functional groupsdivided in 48 subgroups3.
The parameter estimation was accomplished using InfiniteDilution Activity Coefficient (IDAC) for more than 2000mixtures at different temperatures.
Additionally, VLE data for the ethanol/water system was alsoconsidered.
3R.P. Soares et al. “Functional-Segment Activity Coefficient model. 2.Associating Mixtures”. In: Ind. Eng. Chem. Res. (2013). doi:10.1021/ie4013979.
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
A new modelCurrent Status
F-SAC parameters
For the 24 grupos considered, only152 parameters were calibrated.
Only the hydrogen-bonding?
energies are pairwise
All other parameters are for puregroups alone, reducing the totalnumber of parameters
In order to represent the samemolecules in mixtures, 778parameters are used inUNIFAC (Do).
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
F-SAC parameters for Hydrogen-Bonding mixturesHB-acceptor is red (positive), HB-donor is blue (negative).
DOI:10.1021/ie4013979
F-SAC parameters for Hydrogen-Bonding mixtures
Only the hydrogen-bondingenergies are pairwisea
All other parameters are forpure groups alone
All F-SAC parameters have aphysical meaning, e.g. theestimated F-SAC water HBenergy is 21.84 kJ/mol and itshould beb in the range of 20.4to 23.3 kJ/mol.
aR.P. Soares et al. “Functional-Segment Ac-tivity Coefficient model. 2. Associating Mix-tures”. In: Ind. Eng. Chem. Res. (2013).doi: 10.1021/ie4013979
bK. Wendler et al. In: The J. of Phys. Chem.A 114.35 (2010), pp. 9529–9536
IntroductionF-SAC
Conclusions
A new modelCurrent Status
IDAC comparison for non-associating mixtures
-2 -1 0 1 2 3 4 5 6Logarithm of Experimental IDAC
-2
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m o
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odel
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AC
(e) F-SAC
-2 -1 0 1 2 3 4 5 6Logarithm of Experimental IDAC
-2
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AC
(f) UNIFAC (Do)
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
A new modelCurrent Status
IDAC comparison for associating mixtures (water excluded)
-2 -1 0 1 2 3 4 5 6Logarithm of Experimental IDAC
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-1
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(g) F-SAC
-2 -1 0 1 2 3 4 5 6Logarithm of Experimental IDAC
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AC
(h) UNIFAC (Do)
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
A new modelCurrent Status
IDAC comparison for aqueous mixtures
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20Logarithm of Experimental IDAC
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AC
(i) F-SAC
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20Logarithm of Experimental IDAC
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AC
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Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
A new modelCurrent Status
VLE predictions for non-associating mixtures
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0x1, y1
0.075
0.100
0.125
0.150
0.175
0.200
0.225
0.250
Pre
ssu
re[b
ar]
Exp. 298.2 K
F-SAC
UNIFAC(Do)
COSMO-SAC
(k) Chloroform/n-heptane
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0x1, y1
0.35
0.40
0.45
0.50
0.55
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
Pre
ssu
re[b
ar]
Exp. 323.15 K
F-SAC
UNIFAC(Do)
COSMO-SAC
(l) Acetone/cyclohexane
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
A new modelCurrent Status
VLE predictions for non-associating mixtures
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0x1, y1
2.00
2.25
2.50
2.75
3.00
3.25
3.50
3.75
Pre
ssu
re[b
ar]
Exp. 283.6 K
F-SAC
UNIFAC(Do)
COSMO-SAC
(m) Dimethyl ether/1-butene
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0x1, y1
0.65
0.70
0.75
0.80
0.85
0.90
0.95
1.00
1.05
1.10
Pre
ssu
re[b
ar]
Exp. 323.15 K
F-SAC
UNIFAC(Do)
COSMO-SAC
(n) Methyl acetate/1-hexene
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
A new modelCurrent Status
VLE predictions for associating mixtures
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0x1, y1
0.25
0.30
0.35
0.40
0.45
0.50
0.55
0.60
0.65
0.70
Pre
ssu
re[b
ar]
Exp. 298.15 K
F-SAC
UNIFAC(Do)
(o) diethyl-ether/chloroform
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0x1, y1
0.25
0.30
0.35
0.40
0.45
0.50
0.55
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
Pre
ssu
re[b
ar]
Exp. 380.15 K
Exp. 368.15 K
F-SAC
UNIFAC(Do)
(p) toluene/3-methyl,1-butanol
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
Predicting high-pressure VLE with SCMR
SRK with Mathias-Copeman α function and theSelf-Consistent Mixing Rule4 (SCMR) for propane-benzene,no parameter is adjusted for the mixture effects:
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0x1, y1
0
5
1 0
1 5
2 0
2 5
3 0
3 5
4 0
4 5
5 0
5 5
6 0
6 5
Pre
ssu
re[b
ar]
Exp. 310.93 K
Exp. 344.26 K
Exp. 377.59 K
Exp. 477.59 K
SRK(MC)+SCMR(FSAC)
4Paula B. Staudt and Rafael de P. Soares. In: Fluid Phase Equilibria 334(2012), pp. 76–88.
Possible representations for IL
According to the literature5, one of the following:
Meta-file: the IL is considered a single compound, theσ-profile is given by the sum of ions ⇐
Ion-pair: COSMO computations with the ion-pairElectroneutral mixture: independent ions in mixture in
equimolar proportion
5M. Diedenhofen and A. Klamt. In: Fluid Phase Equilib. 294.1-2 (2010),pp. 31–38.
IntroductionF-SAC
Conclusions
A new modelCurrent Status
F-SAC: formulation for IL
We have selected the meta-file approach for F-SAC: cationsand anions are the functional groups and the IL σ-profile isgiven by the groups addition:
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
A new modelCurrent Status
F-SAC: parameters for charged groups
The number of independent parameters per group is the same:
Qak first charged peak
Qbk second charged peakσa
k charge density of the first peak
The other parameters are:
z group charge (+1, -1, etc.)Q◦
k = Qk − Qak − Qb
k : neutral areaσb
k = (z/Qk − σak Qa
k )/Qbk : charge density of the
second peak
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
A new modelCurrent Status
Cations selected for the first study
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
A new modelCurrent Status
Anions selected for the first study
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
A new modelCurrent Status
IL tested
A databank was assembled with 1031 mixtures with 9different IL:
[EMIM]+[BF4]−
[BMIM]+[BF4]−
[HMIM]+[BF4]−
[OMIM]+[BF4]−
[EMIM]+[TCB]−
[HMIM]+[TCB]−
[OMIM]+[CL]−
[EMIM]+[MESO3]−
[EMIM]+[CF3SO3]−
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
A new modelCurrent Status
IDAC of 1031 mixtures (substances dissolved in IL)
The average deviation was 0,17 ln units, similar to theobserved for the neutral mixtures
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
ConclusionsOngoing researchLinks e more information
Conclusions
F-SAC is a new group contribution model
Its mathematical formulation is more complex (COSMO-RSbased), but it requires less parameters (and experimentaldata) than UNIFAC
When correlating a diverse IDAC database for non associatingmixtures, the F-SAC correlation deviated from experimentaldata by 0.073 ln units against 0.14 for UNIFAC (Do)predictions
For aqueous mixtures the F-SAC correlation deviated by0.338 while the UNIFAC (Do) predictions deviated by 1.23
Good predictions were also obtained for VLE data, notincluded in the parameter fitting process
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
ConclusionsOngoing researchLinks e more information
Ongoing research
The F-SAC model is currently being revised and extended
The number of groups is being extended
Now we are also considering VLE and LLE data in theparameter estimation process for improved parameter quality
Improved formulations for associating mixtures (hydrogenbonds) are being tested
Applications for polymer systems are being investigated
Parameters for light gases are being calibrated by means ofCEOs/GE mixing rules
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model
IntroductionF-SAC
Conclusions
ConclusionsOngoing researchLinks e more information
Thank you!
Download F-SAC demonstration code athttp://www.enq.ufrgs.br/labs/lvpp
Download the JCOSMO program, including source code, athttp://code.google.com/p/jcosmo/
DOI:10.1021/ie400170a DOI:10.1021/ie4013979
Prof. Rafael de Pelegrini Soares Current Status of the F-SAC model