118
Ind. Eng. Chem. Process
Des. D e V . 1082, 21, 118-127
Vapor-Liquid Equilibria by UNIFAC Group Contribution. Revision and Extension. 2 Jurgen Gmehllng' Lehrstuhl Technische Chemie 8, University of Dortmund, 46 Lbrtmund 50, West Germany
Peter Rasmussen and Aage Fredenslund' InsNtuffet
for Kemlteknlk, The Technical University of Denmark, DK 2800 Lyngby, Denmark
The UNIFAC group-contribution method may be used for predicting activity coefficients for many nonelectrolyte liquid mixtures of interest in chemical technology. The accuracy and the range of applicability of the method are dependent on the availability of group parameters based on reliable experimental data. I n this work, some of the gaps in the group-interaction parameter table have been filled, and parameters are reported for seven new groups not previously covered by UNIFAC. I t is shown that frequently the UNIFAC equation is more flexible for correlating vapor-liquid equilibrium data than its molecular counterpart, the UNIQUAC equation.
Introduction The UNIFAC (UNIQUAC Functional Group Activity Coefficients) group-contribution method is a reliable and fast method for predicting liquid-phase activity coefficients in nonelectrolyte, nonpolymeric mixtures at low to moderate pressures and temperatures between 300 and 425 K. I t has become widely used in practical chemical engineering applications, most notably in phase equilibrium calculations in cases where little or no relevant experimental information is available. The UNIFAC method was originally developed by Fredenslund et al. (1975). Later the method was revised and its range of applicability considerably extended (Fredenslund et al., 1977a,b;Skjold-Jargensen et al., 1979). The UNIFAC method is fully described in these references, and we do not here repeat the description. It is the aim of this work to report further extensions and revisions of the UNIFAC parameter tables. New Parameters (Extension) In this work we have extended the UNIFAC group-interaction parameter table by including experimental vapor-liquid equilibrium data published until the middle of 1980. The literature data have been collected and stored in the Dortmund Data Bank (Gmehling et al., 1977),which now contains over 10 000 vapor-liquid equilibrium data sets. Relevant, thermodynamically consistent data are automatically retrieved from the data bank and used directly in the parameter estimation procedure. Most of the group-interaction parameters presented in this work are estimated in the manner described by Fredenslund et al. (1977a). Some of them are estimated using a parameter estimation program based on the principle of maximum likelihood and described by Skjold-Jargensen (1980) and by Kem6ny et al. (1981). In the following two sections we report group-interaction parameters for new groups not previously covered by UNIFAC and parameters which fill some of the gaps in the parameter table by Skjold-Jargensen et al. (1979). New Groups Table I presents a supplementary list of group volume and surface area parameters, Rk and Q k , for seven new groups not previously covered by UNIFAC. Alkynes. New experimental data for alkanes with alkynes have recently been reported. This enables the 0196-4305/82/1121-0118$01.25/0
determination of a limited number of interaction parameters for mixtures containing the alkyne group. Dimethyl sulfoxide, acrylonitrile, trichloroethylene, and dimethylformamide are included, each as one separate group. These compounds are of significant importance in chemical technology, and hence a considerable number of vapor-liquid equilibrium data sets for mixtures including these components have been reported (Gmehling et al., 1977). As shown in Table I, diethylformamide may be built from one dimethylformamide group (DMF-2) and two CH, groups. Fluorinated Hydrocarbons (alkanes and aromatics) have been included. Only a small number of data sets for mixtures with fluorohydrocarbons have been published. While for chlorohydrocarbons it was possible to develop separate group-interaction parameters for the groups CC14, CC13, CCl,, and CC1, such a distinction was not possible for the groups CF,, CF2,and CF. Instead the groups CF,, CF2, and CF were defined as subgroups belonging to the same main group, "CF2". Thus their Rk and Qkvalues differ, but they have identical interaction parameters with any other group (e.g., uCFa,CH2 = uCF ,CH2). For subgroups belonging to the same main group, tke interaction parameters are equal to zero (e.g., uCF3,CF2 = oCF ,CF3 = 0). The group-interaction parameters for tke new groups are given in Table 11. Filling the Gaps Because of the increase of the number of data sets in the Dortmund Data Bank, it has been possible to determine some of the group-interaction parameters previously nonavailable because of lack of data. (These interactions are marked "ma." in Table I1 of Skjold-Jargensen et al., 1979). The results are shown in Table 111. Several of these parameters were determined on the basis of data recently measured by Smith and co-workers (see, e.g., Muthu et al., 1980). It has been found that the combinatorial part of UNIFAC alone describes the published vapor-liquid equilibrium data for the system 1,2-ethanediol-water. This e WH= U ~ H * @ means that for this system one may u ~ UH = 0. It may be pointed out that the availafie experimental data for the 1,2-ethanediol-water system are somewhat conflicting. Parameters describing the interactions between the groups C=C/CCOO and C=C/HCOO are now available. 0 1981 American
Chemical Society
Ind. Eng. Chem. Process Des. Dev., Vol. 21, No. 1, 1982 119
Table I. UNIFAC Group Volume and Surface Area Parameters for New Groups. R k and Q k group volume group surface parameter, area parameter main group
“C&”
CSH
“Me ,SO” ‘‘ACRY ’’ ‘TlCC” “ACF” “DMF”
Me,SO ACRY c1-( C=C) ACF DMF-1 DMF-2 CF, CF, CF
“CF,”
‘
sub group
e=
Rk 1.2920 1.0613 2.8266 2.3144 0.791 0.6948 3.0856 2.6322 1.406 1.0105 0.615
sample group assignment
Qk 1.088 0.784 2.472 2.052 0.724 0.524 2.736 2.120 1.380 0.920 0.460
1-hexyne: 1CH,, 3 CH,, 1 C=CH 2-hexyne: 2 CH,, 2 CH,, 1 C=C dimethyl sulfoxide: 1Me,SO acrylonitrile: 1 ACRY trichloroethylene: 1 CH=C, 3 C1-(C=C) hexafluorobenzene: 6 ACF dimethylformamide: 1DMF-1 diethylformamide: 2 CH,, 1 DMF-2 perfluorohexane: 2 CF,, 4 CF,
perfluoromethylcyclohexane: 1 CF,5 CF,, 1 CF
1.00
0.80 0.60
Y1
0.60
0.20 0 .a0
t
0,BO 0.60
Y1
0 ,LO
0,20
0.00
t
0,80
0.60
Yl 0.60
0.20 0 .oo
t
0.80 0.60
Yl 0.60
0.20 0.00
-
x1 x1x1Figure 1. Experimental and predicted x-y diagrams for 16 ketone-alkane mixtures.
Thus UNIFAC may be applied to systems with, for example, vinyl acetate.
Extensions by Other Authors The matrix of UNIFAC group-interaction parameters has recently been further extended by several authors. Hauthal et al. (1980) published more than 30 UNIFAC parameters for systems with lactam derivatives, acetic
x1
-
anhydride, multifunctional amino compounds, vinyl acetate, methylformate, and others. Kat0 (1980) reports UNIFAC parameters for the enol ring (defined as one group) together with alcohol and alkane groups. Kat0 shows that with these new parameters, UNIFAC is capable of describing chemical and physical equilibria in mixtures containing acetylacetone, its tautomers, and various organic solvents.
120
Ind. Eng. Chem. Process Des. Dev., Vol. 21, No. 1, 1982
Table 11. UNIFAC GroupInteraction Parameters for New Groups. amnrK main group main group
m
n
CH. C=k CH,CO CCN CNO, CH, ACH ACCH, OH CH,OH HZ0 CH,CO
e=
ccoo
CH,O cc1,
(3%
CCl, CH,SH DOH CH, HZ0 CCN CH,
c=c
ACH OH CH,OH CH,CO
ccoo
CH,O CCN COOH cc1 CCl, CCl, CNO, CS, CH, ACH ACCH, OH CH,OH CCl, CH,
c=c
ACH ACCH, OH CH,OH H,O CH,CO CH,O ACNH, CCl, CH,SH DOH
c=c
Me,SO
CH 2
CkC
c=c
e= CkC Me,SO Me,SO Me ,SO Me,SO Me,SO Me,SO Me, SO Me,SO Me, SO Me,SO Me ,SO Me,SO Me, SO Me ,SO ACRY ACRY ACRY ClCC ClCC ClCC ClCC ClCC ClCC ClCC ClCC ClCC ClCC ClCC ClCC ClCC ClCC ClCC ACF ACF ACF ACF ACF ACF DMF DMF DMF DMF DMF DMF DMF DMF DMF DMF DMF DMF DMF DMF DMF CF,
amnr
K
298.9 523.6 -246.6 -203.0 -27.70 526.5 169.9 4284. -202.1 -399.3 -139.0 -44.58 52.08 172.1 215.0 363.7 337.7 31.66 -417.2 689.0 160.8 81.57 -0.505 237.3 69.11 253.9 -21.22 -44.42 -23.30 145.6 -19.14 -90.87 -58.77 -79.54 -86.85 48.40 -47.37 125.8 389.3 101.4 44.78 -48.25 21 5.2 485.3 320.4 245.6 5629.0 -143.9 -172.4 319.0 -61.70 254.8 -293.1 498.6 78.92 302.2 -119.8 -97.71 -2.859
anm, K -72.88 -184.4 443.6 329.1 174.4 50.49 -2.504 -143.2 -25.87 695.0 -240.0 110.4 41.57 -122.1 -215.0 -343.6 -58.43 85.70 535.8 -165.9 386.6 -42.31 41.90 -3.167 -75.67 640.9 726.7 -8.671 -18.87 -209.3 298.4 2344. 201.7 85.32 143.2 313.8 167.9 -5.132 -237.2 -157.3 649.7 645.9 -124.6 -31.95 37.70 -133.9 -240.2 64.16 172.2 -287.1 97.04 -158.2 335.6 -186.7 -71.00 -191.7 6.699 136.6 147.3
Zarkarian et al. (1979) determined several new groupinteraction parameters on the basis of infinite dilution activity coefficients obtained from gas-liquid chromatography measurements.
New Interaction Parameters for the ACOH Group (Revision) Phenol may be constructed from 5 ACH groups and 1 ACOH group, see Table IV. This means that it is necessary to establish the values for the interaction parameters UACHhcOH and UACOHACH before any other parameters describing interactions with the ACOH group can be determined.
Table 111. UNIFAC Group-Interaction Parameters for Already Existing Groups, a,,,,,, K (Previously Marked “n.a., Non-available”). main group, main group, m n
c=c c=c c=c
ACH ACCH, ACCH, OH CH,OH CH,OH CH,OH CH,CO CH,CO CH,CO CHO
ccoo
HCOO CH,O CH,O CNH, CNH, CNH ACNH, ACNH, pyridine pyridine pyridine CCN COOH CCl CNO, CNO, H*O OH
ccoo HCOO ACCl CCl, (C),N ACNO , ACNO, (C),N ACNH, ACCl ACNH, pyridine ACCl CH,O DOH cc1, DOH Br (C),N cc1, (C)J CCN ACCl COOH
ca*
cc1, ACCl CCl, ACCl ACNO, I DOH CH,SH
am,, K
anm, K
71.23 468.7 959.7 -144.4 23.50 4448.0 157.1 53.90 335.5 17.12 937.9 165.1 174.5 304.1 -101.7 -287.2 -20.11 -202.3 -41.11 -99.81 -189.2 -216.8 699.1 -153.7 -351.6 -165.1 52.31 76.75 464.4 533.2 304.3 0.0 147.5a
269.3 91.65 -203.2 121.3 109.9 -127.8 561.6 -406.8 5.182 661.6 -399.1 -51.54 128.1 -7.838 152.0 488.9 9.207 736.4 38.99 261.1 865.9 617.1 323.3 -313.5 587.3 309.2 356.9 1346.0 -314.9 -85.12 64.28 0.0 461.6
a This parameter was misprinted in Skjold-JGrgensen et al. (1979).
E t h a n 0 1 -hexane
1.2-Dichloroetnane-benzene
Figure 2. Examples of binary mixtures which are constructed from two different main groups.
In the previous UNIFAC group-interaction parameter tables, the parameters aACHhCOH and aACOH,ACH were established on the basis of vapor-liquid equilibrium data for the benzene-phenol system. Unfortunately, only one, apparently not so reliable, data set was published for this
Ind. Eng. Chem. Process Des. Dev., Vol. 21, No. 1, 1982 121 Y1
Y1
.8
.8
.6
.6
.4
.4
.2
.2
0
0
.2
.4
Cyclohexane(1)
.8
.6
x1
- trichloroethylene(?)
at 1 am
.2
Hexane(1)
.4
.6
.8
x1
- tetrachloroethylene(2)
.6
.4
.2
.8
x1
Hexane(1) - trichloroethylene(2)
at 60 OC
at 60 OC
Figure 3. Experimental and predicted x-y diagrams for three chlorinated hydrocarbon-alkane systems. Y1
Y1
.8
.8
.6
.6
.4
.4
.2
.2
0 .2
.4
.6
.8
.2
X 1
E t h y l b e n z ~ (1) e - nitrobenzene 12) a t 100 OC
Propylhnzereil) - nitrobenzene(2) a t 1 0 0 OC
.6
.4
.E
x1
-
Butylbenzene(1) nitrobenzene(2) a t 100 OC
Figure 4. Experimental and predicted r-y diagrams for three alkylbenzene-nitrobenzene mixtures.
Figure 6. UNIFAC group-interaction parameters.
system. As a result, predictions for mixtures containing phenol, cresol, and other components with the ACOH group may be less reliable than is normally the case for UNIFAC predictions. For the system benzene (1) -cyclohexane (2), the selectivity of the solvent phenol (S) may be defined as the ratio of the infinite dilution activity coefficients of benzene and cyclohexane in phenol, i.e., y m p , s / y mKolbe l,~ et al. (1979) noted that while the experimental value of the selectivity for this system should
be somewhat larger than 2.1, UNIFAC with the parameter table of Skjold-Jargensen et al. (1979) yields the value 1.4. The number of published data sets for mixtures with phenol and either toluene, xylene, or cresol is relatively large. In this work, we have simultaneously determined the parameters ~ A C H A C O H , a ACOH,ACH, ~ A C C H ~ , A C O Hand aACOH,ACCHa on the basis of experimental data for these systems plus new data for the system benzene-phenol measured at the University of Dortmund. As a conse-
122
Ind. Eng. Chem. Process Des. Dev., Vol. 21, No. 1, 1982
Table IV. UNIFAC Group Volume and Surface-Area Parameters main group 1 “CH,”
2 “ClC”
subgroup
no.
Rh
CH, CH; CH C CH,=CH CH=CH CH,=C CH=C ACH AC ACCH, ACCH, ACCH OH
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
0.9011 0.6744 0.4469 0.2195 1.3454 1.1167 1.1173 0.8886 0.6605 0.5313 0.3652 1.2663 1.0396 0.8121
CH,OH
1.000
0.848 hexane: 0.540 2-methylpropane: 0.228 2,2-dimethylpropane: 0.000 1.176 1-hexene: 0.867 2-hexene: 0.988 2-methyl-1-butene : 0.676 2-methyl- 2-butene : 0.485 2,3-dimethylbutene-2: 0.400 benzene : 0.120 styrene: 0.968 toluene: 0.660 ethylbenzene: 0.348 cumene : 1.200 2-propanol:
1 CH,, 3 CH,, 1 CH,=CH 2 CH,, 2 CH,, 1 CH=CH 2 CH,, 1 CH,, 1 CH,=C 3 CH,, 1CH=C 4 CH,, 1 C=C 6 ACH 1 CH,=CH, 5 ACH, 1 AC 5 ACH, 1ACCH, 1CH,, 5 ACH, 1 ACCH, 2 CH,, 5 ACH, 1ACCH 2 CH,, 1 CH, 1 OH
16
1.4311
1.432
methanol :
1 CH,OH
H,O
17
0.92
1.40
water:
1 H,O
ACOH
18
0.8952
0.680
phenol :
5 ACH, 1 ACOH
CH,CO
19
1.6724
1.488
ketone group is 2nd carbon; 2-butanone:
1CH,, 1 CH,, 1 CH,CO
CH,CO CHO
20 21
1.4457 0.9980
1.180 0.948
ketone group is any other carbon; 3:pentanone: acetaldehyde:
2 CH,, 1 CH,, 1 CH,CO 1CH,, 1 CHO
CH,COO CH,COO HCOO
22 23 24
1.9031 1.6764 1.2420
1.728 butyl acetate: 1.420 butyl propanoate : 1.188 ethyl formate:
1 CH,, 3 CH,, 1 CH,COO 2 CH,, 3 CH,, 1CH,COO 1 CH,, 1CH,, 1 HCOO
CH,O CH,O CH-0 FCH,O CH,NH, CH,NH, CHNH, CH,NH CH,NH CHNH
25 26 27 28 29 30 31 32 33 34
1.1450 0.9183 0.6908 0.9183 1.5959 1.3692 1.1417 1.4337 1.2070 0.9795
1.088 0.780 0.468 1.1 1.544 1.236 0.924 1.244 0.936 0.624
dimethyl ether: diethyl ether diisopropyl ether: tetrahydrofuran: methylamine : propylamine : isopropylamine: dimethylamine: diethylamine: diisopropylamine :
1 CH,, 1 CH,O 2 CH,, 1CH,, 1 CH,O 4 CH,. 1CH. 1CH-0 3 CH;; 1 FCH,O 1 CH,NH, 1 CHI, 1 6H,, 1CH,NH, 2 CH,, 1CHNH, 1CH,. 1CH,NH 2 CH;: 1CH;, 1 CH,NH 4 CH,, 1 CH, 1 CHNH
CH,N CH,N
35 36
1.1865 0.9597
0.940 0.632
trimethylamine: triethylamine :
2 CH,, 1 CH,N 3 CH,, 2 CH,, 1 CH,N
ACNH, CAN CAN C A N CH,CN CH,CN COOH HCOOH CH,Cl CHCl CCl CH,Cl, CHC1, CCl, CHCl, CCl, CCl,
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53
1.0600 2.9993 2.8332 2.667 1.8701 1.6434 1.3013 1.5280 1.4654 1.2380 1.0060 2.2564 2.0606 1.8016 2.8700 2.6401 3.3900
0.816 2.113 1.833 1.553 1.724 1.416 1.224 1.532 1.264 0.952 0.724 1.988 1.684 1.448 2.410 2.184 2.910
aniline: pyridine : 3-methylpyridine : 2,3-dimethylpyridine : acetonitrile : propionitrile: acetic acid: formic acid: 1-chlorobutane: 2-chloropropane : 2-chloro-2-methylpropane : dichlorome thane : 1,l-dichloroethane: 2,2-dichloropropane: chloroform: l,l,l-trichloroethane: te trachloromethane:
5 ACH, 1 ACNH, 1 C.H,N 1 CH,; 1 C5H,N 2 CH,, 1 C,H,N 1 CH,CN 1 CH;, 1 CH,CN 1 CH,, 1 COOH 1 HCOOH 1 CH,, 2 CH,, 1CH,Cl 2 CH,, 1CHCl 3 CH,, 1 CCl 1 CH,Cl, 1CH,, 1 CHC1, 2 CH,, 1CCl, 1 CHC1, 1CH,, 1 CCl, 1CCl,
ACCl
54
1.1562
0.844
chlorobenzene :
5 ACH, 1 ACCl
CH,NO, CH,NO, CHNO, ACNO,
55 56 57 58
2.0086 1.7818 1.5544 1.4199
1.868 1.560 1.248 1.104
nitromethane: 1-nitropropane : 2-nitropropane : nitrobenzene :
1 CH,NO, 1CH,, 1 CH,, 1 CH,NO, 2 CH,, 1 CHNO, 5 ACH, 1 ACNO,
CS,
59
2.057
1.65
carbon disulfide:
1 cs,
CH, SH CH,SH
60 61
1.8770 1.6510
1.676 1.368
methane thiol : et haneth io1 :
1CH,SH 1 CH,, 1 CH,SH
furfural
62
3.1680
2.481
furfural:
1 furfural
c=c 3 “ACH” 4 “ACCH,” 5 “OH” 6 “CH,OH” 7 “H,O” 8 “ACOH” 9 “CH,CO” 10 THO” 11 “CCO 0 ” 12 “HCOO” 13 “CH,O” 14 “CNH,” 15 “CNH” 16 “(C),N” 17 “ACNH,” 18 “pyridine” 19 “CCN” 20 “COOH” 21 “CCl” 22 “CCl,” 23 “CCl,” 24 “CCl,” 25 “ACCl” 26 “CNO,” 27 “ACNO,” 28 “CS, ” 29 “CH,SH” 30“ “furfural”
sample group assignment
Qh
2 CH,. 4 CH, 3 CH;; 1CH’ 4 CH,, 1 C
Ind. Eng. Chem. Process Des. Dev., Vol. 21, No. 1, 1982 123
Table IV (Confinued) main group 31 “DOH” 32 “I” 33 “Br” 34 “GC” 35 “Me,SO” 36 “ACRY” 37 “ClCC” 38 “ACF” 39 “DMF” 40 VF,”
subgroup
no.
Rk
(CHZOH1,
63
2.4088
2.248
1,2-ethanediol:
I
64
1.2640
0.992
1-iodoethane:
Br CH& C=C Me,SO
65 66 67
68
0.9492 1.2920 1.0613 2.8266
0.832 1-bromoethane: 1.088 1-hexyne: 0.784 2-hex yne : 2.472 dimethyl sulfoxide:
ACRY
69
2.3144
2.052
acrylonitrile:
1 ACRY
C1( C=C)
70
0.7910
0.724
trichloroethylene :
1CH=C, 3 Cl(C=C)
ACF
71
0.6948
0.524
hexafluorobenzene :
6 ACF
DMF-1 DMF-2
72 73
3.0856 2.6322
2.736 2.120
dimethylformamide: diethylformamide :
1DMF-1 2 CH,, 1DMF-2
CF, CF, CF
74 75 76
1.4060 1.0105 0.6150
1.380 0.920 0.460
perfluorohexane :
2 CF,, 4 CF,
perfluoro methylcyclohexane :
1CH,, 5 CH,, 1CF
sample group assignment
Qk
Table V. UNIFAC Parameters for Interactions with the ACOH Group
C=C ACH ACCH, OH CH,OH H*O CH,CO
ccoo
pyridine CCl, DOH
547.4 1329.0 884.9 -259.7 -101.7 324.5 -133.1 -36.72 -341.6 10000.0 838.4
1665.0 25.34 244.2 -451.6 -265.2 -601.8 -356.1 -449.4 -305.5 1827.0 -687.1
quence, it was necessary to change all subsequent interaction parameters for the group ACOH. In this connection we have used new data for phenol-alkane systems measured a t the University of Dortmund. The new groupinteraction parameters for the ACOH group are given in Table V. Predictions for mixtures with phenol, cresol, etc., should now be more reliable. For example, the predicted value of the selectivity of phenol for the benzene-cyclohexane system now becomes 2.5, which is much closer to the experimental value than previously.
The Flexibility of UNIFAC Figure 1shows experimental and predicted x-y diagrams for 16 different binary alkane-ketone systems. Bearing in mind that all of these diagrams are produced using the -~ same two parameters ( U C H ~ , C H ~ C O= 476.4 K; UCH C O ~ C26.76 K), this in a qualitative way indicates the dexibifity of the UNIFAC model. A similar figure is shown by Gmehling et al. (1980) for alkane-alcohol systems, and many additional such figures are shown by Gmehling (1981). In this section we attempt somewhat more quantitatively to assess the flexibility of the UNIFAC model. We focus the attention on binary mixtures which may be constructed from two different main groups. Examples of such mixtures are shown in Figure 2. One may correlate a vapor-liquid equilibrium data set for, e.g., ethanol-hexane with the UNIQUAC equation and obtain two UNIQUAC parameters describing the molec-
1 CH,, 1CH,, 1I 1 CH,, 1 CH,, 1Br 1 CH,, 3 CH,, 1CHEC 2 CH,, 2 CH,, 1C=C 1Me,SO
Table VI. Comparison of Results from Correlating Binary, Isothermal Vapor-Liquid Equilibrium Data Using UNIFAC and UNIQUAC re1 sum of squares dev: temp, SSQ (UNIFAC)/ K SSQ (UNIQUAC) system ethanoloctane propanoldecane diethylamineheptane acetonecyclohexane acetonedecane 3-pentanoneheptane l-octenecyclohexane
348
0.27
363
0.85
328
1.09
328
0.89
318
0.94
363
0.78
313
0.94
The data were correlated using the programs based on the principle of maximum likelihood (Skjold-JQrgensen (1980)). SSQ (UNIFAC) and SSQ (UNIQUAC) are defined as
SSQ = Z[(
Xl(CdC)
- xl(exP)
)* +
OX
T(calc) - T(exp) (
UT
)2
+
3.’1(calc)- Yl(exP) )2
+
UY
g ( c d c ) - P(exP) OP
l21
In both cases, the following variances were used: ux = u y = 0.005; U T = 0.1 K; u p = 1.0 mmHg.
ular interactions in the mixture. One may also correlate this data set with the UNIFAC equation and obtain two UNIFAC parameters describing the group interactions in the mixture, i.e., uCH2,0H and u O H , C H . In this way we may compare the flexibility of UNIQUAe and UNIFAC models for describing binary mixtures. It may be shown (Maabe, 1979) that if a mixture can be described by no more than two different main groups and if the components have no main group in common, then UNIFAC reduces to UNIQUAC. This holds for the
124
Ind. Eng. Chem. Process Des. Dev., Vol.
21, No. 1, 1982
Table VII. UNIFAC Interaction Parameters' 1 2
3
4
5
6
7
8
61.13 340.7 0.0 -146.8 89.60 -50.00 362.3 25.34 140.1 n.a. 85.84 n.a. 52.13 -44.85 -22.31 -223.9 650.4 31.87 -22.97 62.32 4.680 121.3 288.5 -4.700 -237.7 10.38 1824.0 21.50 28.41 157.3 221.4 58.68 155.6 n.a. -2.504 n.a. -75.67 -237.2 -133.9 n.a.
76.50 4102.0 167.0
986.5 693.9 636.1 803.2 0.0 249.1 -229.1 -451.6 164.5 -404.8 245.4 191.2 237.7 -164.0 -150.0 28.60 529.0 -132.3 185.4 -151.0 562.2 747.7 742.1 856.3 246.9 341.7 561.6 823.5 461.6 521.6 267.6 501.3 721.9 n.a. -25.87 n.a. 640.9 649.7 64.16 n.a.
697.2 1509.0 637.3 603.2 -137.1 0.0 289.6 -265.2 108.7 -340.2 249.6 155.7 339.7 -481.7 -500.4 -406.8 5.182 -378.2 157.8 1020.0 529.0 669.9 649.1 860.1 661.6 252.6 n.a. 914.2 382.8 n.a. n.a. n.a. n.a. n.a. 695.0 n.a. 726.7 645.9 172.2 n.a.
1318.0 634.2 903.8 5695.0 353.5 -181.0 0.0 -601.8 47 2.5 23 2.7 10000.0 n.a. -314.7 -330.4 -448.2 -598.8 -339.5 -332.9 242.8 -66.17 698.2 708.7 826.7 1201.0 920.4 417.9 360.7 1081.0 n.a. 23.48 0.0 n.a. n.a. n.a. -240.0 386.6 n.a. n.a. -287.1 n.a.
1333.0 547.4 1329.0 884.9 -259.7 -101.7 324.5 0.0 -133.1 n.a. -36.72 n.a. n.a. n.a. n.a. n.a. n.a. -341.6 n.a. n.a. n.a. n.a. n.a. 10000. n.a. n.a. n.a. n.a. n.a. n.a. 838.4 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a.
1CH, 2 c=c 3 ACH 4 ACCH, 5 OH 6 CH,OH 7 H,O 8 ACOH 9 CH,CO 10 CHO 11 ccoo 1 2 HCOO 1 3 CH,O 1 4 CNH, 1 5 CNH 1 6 (C),N 1 7 ACNH, 18 pyridine 1 9 CCN 20 COOH 21 CCl 22 CCI, 23 CCl, 24 CCl, 25 ACCl 26 CNO, 27 ACNO, 28 CS, 29 CH,SH 30 furfural 3 1 DOH 32 I 33 Br 34 c=c 3 5 Me,SO 3 6 ACRY 37 ClCC 38 ACF 3 9 DMF 4 0 CF,
0.0 2520.0 -11.12 -69.70 156.4 16.51 300.0 275.8 26.76 505.7 114.8 90.49 83.36 -30.48 65.33 - 83.98 5339.0 -101.6 24.82 315.3 91.46 34.01 36.70 -78.45 -141.3 -32.69 5541.0 -52.65 -7.481 -25.31 140.0 128.0 -31.52 -72.88 50.49 -165.9 41.90 -5.132 -31.95 147.3 9
-200.0 0.0 -94.78 -269.7 8694.0 -52.39 692.7 1665.0 -82.92 n.a. 269.3 91.65 76.44 79.40 -41.32 -188.0 n.a. n.a. 34.78 349.2 -24.36 -52.71 -185.1 -293.7 -203.2 -49.92 n.a. 16.62 n.a. n.a. n.a. n.a. n.a. -184.4 n.a. n.a. -3.167 n. a. 37.70 n.a.
10
11
1 CH, 2 c=c 3 ACH 4 ACCH, 5 OH 6 CH,OH 7 H,O 8 ACOH 9 CH,CO 1 0 CHO 11 ccoo 1 2 moo 1 3 CH,O 14 CNH, 1 5 CNH 16( C P 1 7 ACNH, 18 pyridine 19 CCN 20 COOH 21 CCl 22 CCl, 23 CCl, 24 CC1, 25 ACCl 26 CNO, 27 ACNO, 28 CS, 29 CH,SH 30 furfural 3 1 DOH 32 I 3 3 Br 34 c=c 3 5 Me,SO
476.4 524.5 25.77 -52.10 84.00 23.39 -195.4 -356.1 0.0 128.0 37 2.2 n.a. 52.38 n.a. n.a. n.a. -399.1 -51.54 -287.5 -297.8 286.3 423.2 552.1 37 2.0 128.1 -142.6 n.a. 303.7 160.6 317.5 n.a. 138.0 -142.6 443.6 110.4
677.0 n.a. n.a. n.a. 441.8 306.4 -257.3 n.a. -37.36 0.0 n.a. n.a. -7.838 n.a. n.a. n.a. n.a. n.a. n.a. n.a. -47.51 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a.
232.1 71.23 5.994 5688.0 101.1 -10.72 14.42 -449.4 -213.7 n.a. 0.0 -261.1 461.3 n.a. 136.0 n.a. n.a. n.a. -266.6 -256.3 n.a. -132.9 176.5 129.5 - 246.3 n.a. n.a. 243.8 ma. -146.3 152.0 21.92 n.a. n.a. 41.57
0.0 25.82 -44.50 377.6 244.2 365.8 n.a. -170.0 n.a. 65.69 n.a. 223.0 109.9 979.8 49.80 -138.4 268.2 122.9 n.a. 33.61 134.7 375.5 -97.05 -127.8 40.68 n.a. 404.3 150.6 n.a. 291.1 n.a. -143.2 n.a. n.a. -157.3 -240.2 n.a. 12
13
741.4 468.7 n.a. ma. 193.1 193.4 n.a. n.a. n.a. n.a. 372.9 0.0 n.a. n.a. n.a. n.a. n.a. n.a. n.a. 312.5 n.a. n.a. 488.9 n.a. ma. n.a. n.a. n.a. 239.8 n.a. n.a. n.a. n.a. n.a. n.a.
251.5 289.3 32.14 213.1 28.06 -180.6 540.5 n.a. 5.202 304.1 -235.7 n.a. 0.0 n.a. -49.30 n.a. n.a. n.a. n.a. -338.5 225.4 -197.7 -20.93 113.9 n.a. -94.49 n.a. 112.4 63.71 n.a. 9.207 476.6 736.4 n.a. -122.1
14 391.5 396.0 161.7 n.a. 83.02 359.3 48.89 ma. n.a. n.a. n.a. ma. n.a. 0.0 108.8 38.89 n.a. n.a. n.a. n.a. n.a. n.a. n.a. 261.1 203.5 n.a. n.a. n.a. 106.7 n.a. n.a. ma. n.a. n.a. n.a.
15 255.7 273.6 122.8 -49.29 42.70 266.0 168.0 n.a. n.a. n.a. -73.50 n.a. 141.7 63.72 0.0 865.9 n.a. n.a. n.a. n.a. n.a. n.a. n.a. 91.13 -108.4 n.a. n.a. n.a. n.a. n.a. ma. n.a. n.a. n.a. n.a.
16 206.6 658.8 90.49 23.50 -323.0 53.90 304.0 ma. n.a. n.a. n.a. n.a. n.a. -41.11 -189.2 0.0 n.a. n.a. n.a. n.a. n.a. -141.4 -293.7 -126.0 1088.0 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a.
Ind. Eng. Chem. Process Des. Dev., Vol. 21, No. 1, 1982 125 Table VI1 (Continued) 9
10
11
12
n.a: -8.671 n.a. 97.04 n.a. 17
19
20
21
22
2 c=k 3 ACH 4 ACCH, 5 OH 6 CH,OH 7 H,O 8 ACOH 9 CH,CO 1 0 CHO 11 ccoo 1 2 HCOO 1 3 CH,O 1 4 CNH, 1 5 CNH 1 6 (C13N 1 7 ACNH, 18 pyridine 19 CCN 20 COOH 21 CCI 22 CCl, 23 CC1, 24 CCI, 25 ACCl 26 CNO, 27 ACNO, 28 CS, 29 CH,SH 30 furfural 31 DOH 32 I 33 Br 34 c=c 3 5 Me,SO 3 6 ACRY 37 ClCC 38 ACF 39 DMF 40 CF,
1245.0 n.a. 668.2 764.7 -348.2 335.5 213.0 n.a. 937.3 n.a. n. a. n.a. n.a. n.a. n.a. n.a. 0.0 n. a. 617.1 n.a. n.a. n. a. n.a. 1301.0 323.3 n.a. 5250.0 n.a. n.a. n.a. 164.4 n.a. n.a. n.a. n.a. n.a. n.a. n.a. 335.6 n.a.
287.7 n.a. -4.449 52.80 170.0 580.5 459.0 -305.5 165.1 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 0.0 134.3 -313.5 n.a. 587.3 18.98 309.2 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a.
597.0 405.9 212.5 6096.0 6.712 36.23 112.6 n.a. 481.7 n.a. 494.6 n.a. n.a. n.a. n.a. n.a. -216.8 -169.7 0.0 n.a. n.a. n.a. 74.04 492.0 356.9 n.a. n.a. 335.7 125.7 n.a. n.a. n.a. n.a. 329.1 n.a. -42.31 298.4 n.a. n.a. n.a.
663.5 730.4 537.4 603.8 199.0 -289.5 -14.09 n.a. 669.4 n.a. 660.2 -356.3 664.6 n.a. n.a. n.a. n.a. -153.7 n.a. 0.0 326.4 1821.0 1346.0 689.0 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 2344.0 n.a. n.a. n.a.
35.93 99.61 -18.81 -114.1 75.62 -38.32 325.4 n.a. -191.7 751.9 n.a. n.a. 301.1 n.a. n.a. n.a. n.a. n.a. n.a. 44.42 0.0 -84.53 -157.1 11.80 -314.9 n.a. ma. -73.09 -27.94 n.a. n.a. n.a. 1169.0 n.a. n.a. n.a. 201.7 n.a. n.a. n.a.
53.76 337.1 -144.4 n.a. -112.1 -102.5 370.4 n.a. -284.0 n.a. 108.9 n.a. 137.8 n.a. n.a. -73.85 n.a. -351.6 n.a. -183.4 108.3 0.0 0.0 17.97 n.a. n.a. n.a. n.a. n.a. n.a. n.a. -40.82 n.a. n.a. -215.0 n.a. n.a. n.a. n.a. n.a.
25
26
27
28
29
30
1 CH, 2 c=k 3 ACH 4 ACCH, 5 OH 6 CH30H 7 H,O 8 ACOH 9 CH,CO 1 0 CHO 11 ccoo 1 2 HCOO 1 3 CH,O 1 4 CNH, 1 5 CNH 1 6 (C),N 1 7 ACNH, 18 pyridine 1 9 CCN 20 COOH 21 CCl 22 CCl, 2 3 CCl, 24 CC1, 25 ACCl 26 CNO, 27 ACNO, 28 CS,
321.5 959.7 538.2 -126.9 287.8 17.12 678.2 n.a. 174.5 n.a. 629.0 n.a. n.a. 68.81 4350.0 -86.36 699.1 n.a. 52.31 n.a. 464.4 n.a. n.a. 475.8 0.0 794.4 n.a. n.a.
661.5 542.1 168.0 3629.0 61.11 75.14 220.6 n.a. 137.5 n.a. n.a. n.a. 95.18 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n. a. 490.9 -154.5 0.0 -85.12 n.a.
543.0 n.a. 194.9 4448.0 157.1 n.a. 399.5 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. -62.73 n.a. n.a. n.a. n.a. n.a. n.a. 534.7 n.a. 533.2 0.0 n.a.
153.6 76.30 52.07 -9.451 477.0 -31.09 887.1 n.a. 216.1 n.a. 183.0 n.a. 140.9 n.a. n.a. n.a. n.a. n.a. 230.9 n.a. 450.1 n.a. 116.6 132.2 n.a. n.a. n.a. 0.0
184.4 n.a. -10.43 n.a. 147.5 37.84 n.a. n.a. -46.28 n.a. n.a. 4.339 -8.538 -70.14 n.a. n.a. n.a. n.a. 21.37 n.a. 59.02 n.a. n.a. n.a. n.a. n.a. n.a. n.a.
354.5 n.a. -64.69 -20.36 -120.5 n.a. 188.0 n.a. -163.7 n.a. 202.3 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. -64.38 546.7 n.a. n.a. n.a. n.a.
1 CH.
n.a. -209.3 n.a. -158.2 n.a.
14
n.a. -18.87 n.a. n.a. n.a.
3 6 ACRY 37 ClCC 38 ACF 39 DMF 40 CF,
n.a. n.a. n.a. n.a. n.a.
13
n.a. n.a. n.a. n.a. n.a. 18
n.a. n.a. n.a. n.a. n.a.
15 n.a. n.a. n.a. n.a. n.a. 23 24.90 4584.0 -231.9 -12.14 -98.12 -139.4 353.7 n.a. -354.6 n.a. -209.7 -287.2 -154.3 n.a. n.a. -352.9 n.a. -114.7 -15.62 76.75 249.2 0.0
0.0 51.90 n.a. n.a. n.a. -26.06 n.a. 48.48 n.a. 21.76 n.a. n.a. -343.6 ma. 85.32 n.a. n.a. n.a. 31 3025.0 n.a. 210.4 4975.0 -318.9 n.a. 0.0 -687.1 n.a. n.a. -101.7 n.a. -20.11 n.a. n.a. n.a. 125.3 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 139.8 n.a. n.a.
16 n.a. n.a. n.a. n.a. n.a. 24 104.3 5831.0 3.000 -141.3 143.1 -67.80 497.5 1827.0 -39.20 n.a. 54.47 n.a. 47.67 -99.81 71.23 -8.283 8455.0 -165.1 -54.86 212.7 62.42 56.33 -30.10 0.0 -255.4 -34.68 514.6 -60.71 n.a. -133.1 n.a. 48.49 225.8 n.a. -58.43 n.a. 143.2 -124.6 -186.7 n.a. 32 335.8 n.a. 113.3 n.a. 313.5 n.a. n.a. n.a. 53.59 n.a. 148.3 n.a. -149.5 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 177.6 86.40 247.8 n.a. 304.3 n.a. n.a.
126
Ind. Eng. Chem. Process Des. Dev., Vol. 21, No. 1, 1982
Table VI1 (Continued) 29 CH,SH 30 furfural 31 DOH 32 I 33 Br 34 c=c 35 Me,SO 36 ACRY 37 ClCC 38 ACF 39 DMF 40 CF,
a
25
26
n.a. n.a. n.a. n.a. 224.0 n.a. n.a. n. a. n.a. n.a. n.a. n.a.
n.a. n.a. 481.3 64.28 125.3 174.4 n.a. n.a. 313.8 n.a. n.a. n.a.
33
34 298.9 523.6 n.a. n.a. n.a. n.a. n.a. n.a. -246.6 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. -203.0 n.a. n.a. n.a. n.a. n.a. n.a. -27.70 n.a. n.a. n.a. n.a. n.a. n.a. n.a. 0.0 n.a. n.a. n.a. n.a. 6.699 n.a.
1 CH, 479.5 2 c=k n.a. 3 ACH -13.59 4 ACCH, -171.3 5 OH 133.4 6 CH,OH n.a. 7 H,O n.a. 8 ACOH n.a. 9 CH,CO 245.2 10 CHO n.a. 11 ccoo n.a. 1 2 HCOO n. a. 1 3 CH,O -. 2 0 2.3 14 CNH, n.a. 15 CNH n.a. n.a. 16 (C),N 17 ACNH, n.a. 1 8 pyridine n.a. 1 9 CCN n.a. 20 COOH n. a. 21 CCl -125.9 22 CCl, n.a. n.a. 23 CCl; 24 CCl, 41.94 25 ACCl -60.70 26 CNO, 10.17 27 ACNO, n.a. n.a. 28 cs, 29 CH,SH n.a. 30 furfural n.a. 31 DOH n.a. n.a. 32 I 33 Br 0.0 34 c=c n.a. 35 Me,SO n.a. 36 ACRY n.a. 37 ClCC n.a. 38 ACF n.a. 39 DMF n. a. 40 CF, n.a. n.a. = not available.
27
28
29
n.a. ma. n.a. n.a. n.a. ma. n.a. n.a. 167.9 n.a. n.a. n.a.
0.0 n.a. n.a. n.a. n.a. n.a. 85.70 n.a. n.a. n.a. -71.00 n.a.
35
36
37
38
39
526.5 n.a. 169.9 4284.0 -202.1 -399.3 -139.0 n.a. -44.58 n.a. 52.08 n.a. 172.1 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 215.0 363.7 337.7 n.a. n.a. n.a. n.a. 31.66 n.a. -417.2 n.a. n.a. n.a. 0.0 n.a. n.a. n.a. 136.6 n.a.
689.0 n.a. n.a. n.a. n.a. n.a. 160.8 n.a. n.a. n.a. n.a. n.a. n.a. ma. n.a. n.a. n.a. n.a. 81.57 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 0.0 n.a. n.a. n.a. n.a.
-0.505 237.3 69.11 n.a. 253.9 -21.22 n.a. n.a. -44.42 n.a. -23.30 n.a. 145.6 n.a. n.a. n.a. n.a. n.a. -19.14 -90.87 -58.77 n.a. -79.54 -86.85 n.a. 48.40 n.a. -47.31 n.a. n.a. n.a. ma. n.a. n.a. n.a. n.a. 0.0 n.a. n.a. n.a.
125.8 n.a. 389.3 101.4 44.78 -48.25 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 215.2 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. 0.0 n.a. n.a.
485.3 320.4 245.6 5629.0 -143.9 -172.4 319.0 n.a. -61.70 n.a. n.a. n.a. 254.8 n.a. n.a. n.a. -293.1 n.a. n.a. n.a. n.a. n.a. n.a. 498.6 n.a. n.a. n.a. n.a. 78.92 n.a. 302.2 n.a. n.a. -119.8 -97.71 n.a. n.a. n.a. 0.0 n.a.
n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a.
mixture 172-dichloroethane-benzene(see Figure 2). Naturally, in this case UNIFAC and UNIQUAC are equally flexible. When the components have a main group in common (e.g., ethanol-hexane) the UNIQUAC and UNIFAC models differ. Two UNIFAC or two UNIQUAC parameters have been fitted to a number of binary vapor-liquid equilibrium data sets exemplified by the ethanol-benzene system. Table VI shows that as a correlating equation, UNIFAC is somewhat more flexible than UNIQUAC. This indicates that the assumptions underlying the solution of groups concept may be physically reasonable. Results Naturally, many results could be shown using the new UNIFAC group-interaction parameters. However, only two typical examples of such predictions will be shown here.
30 n.a. 0.0 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a.
31 n.a. n.a. 0.0 n.a. n.a. n.a. 535.8 n.a. n.a. n.a. -191.7 n.a.
32 n.a. n.a. n.a. 0.0 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a.
40 -2.859 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. ma. n.a. n.a. n.a. n.a. n.a. 0.0
In Figure 3, the same two group-interaction parameters (ac1.c~= c),C H ~and U C H ~ cl-(c , = c)) are used to calculate all three x-y diagrams. Figure 4 shows the predicted vapor-liquid equilibria for the homologous series ethylbenzene, propylbenzene, butylbenzene with nitrobenzene. In all of these systems the average deviation between experimental and predicted vapor phase compositions is less than 0.01 mole fraction. This is typical for cases where the group-interaction parameters are based on reliable experimental data. When the parameters are based on limited, poor data or when the molecules contain two strong functional groups close to each other, much larger average deviations may be expected. Glycols are examples of molecules having two strong functional groups (here two OH groups) close to each other. Skjold-Jerrgensenet al. (1979) found that glycols could not
Ind. Eng. Chem. Process Des. Dev. 1982, 27, 127-134
be described by using two OH groups. It was necessary to introduce a special glycol group. Similar “proximity effects” are discussed by Hauthal et al. (1980). Complete tables of Rk and Qkvalues and group-interaction parameters which include the extensions reported in this work are given in Tables IV and VII. As a result of the revisions and extensions of UNIFAC described in this work, UNIFAC now encompasses 40 different main groups and 76 subgroups. Figure 5 gives an overview of the available group-interaction parameters. The new parameter tables do not include the CCOH alcohol group introduced by Fredenslund et al. (1977). In our experience, the OH alcohol group (group no. 5 of Table VII) yields results which are as good as or better than the CCOH group. Supplement A list of references to the data on which the new UNIFAC parameters are based and a listing of a subroutine which incorporates the new UNIFAC parameter table in generating activity coefficients may be obtained from the authors. Acknowledgment The authors are grateful to Deutsche Bundesministerium fur Forschung and Technologie and the Danish Statens tekniske videnskabelige Forskningsrhd for support of
127
the UNIFAC project. In addition, we thank Professor U. Onken and our many other colleagues who in different ways have contributed to this work. Literature Cited Fredenslund, Aa.; Gmehllng, J.; Rasmussen, P. “Vapor-Liquid Equilibria Using UNIFAC”; Elsevler: Amsterdam, 1977a; Chapter 5. Fredenslund, Aa.; Gmehilng. J.; Michelaen. M. L.; Rasmussen, P.; Prausnitz, J. M. Ind. Eng. Chem. Process Des. D e v . 1977b. 16, 450. Fredenslund, Aa; Jones, R.; Prausnitz. J. M. A I C M J . 1975, 2 1 , 1086. Gmehling, J.; Onken, U.; Arlt, W. “Vapor-Liquid Equlibrlum Data Collectlon”; DECHEMA Chemistry Data Series, Vol. 1 (12 parts): Frankfurt, 1977. Gmehling, J.; Doctorlal Thesis, (Hebllitationsschrlft), University of Dortmund. BRD, under preparation, 1981. Gmehling, J; Rasmussen, P.; Fredenslund, Aa. Chem. Ing. Tech. 1980. 52(9), 724. Hauthai, W. H.; Schmelzer, J.; Qultzsch. K.; Mohle, L.; Figurski, G. 6th Int. Conf Thermodynamics Merseburg DDR , 1980. Kato, M. Ind. Eng. Chem. Fundem. 1980. 19, 253. Kemgny, S.; SkJoidJerrgensen,S.; Manczinger, J.; T6th, K. AIChE J . 1981 In press. Kolbe, B.; Gmehllng. J.; Onken, U. I.Chem. E . Symp. Ser. 1979, 56,1.31 23. Maalore, B.; M. Sc. Thesis, Instltuttet for Kemlteknik, The Technlcal University of Denmark, Lyngby, Denmark, 1979. Muhtu, 0.; Maher. P. J.; Smith, B. D. J . Chem. Eng. Data 1980, 2 5 , 163. SkjoidJerrgensen, S.; Ph. D. Dissertatlon, Instituttet for Kemlteknik, The Technical University of Denmark, Lyngby. Denmark, 1980. SkjoldJerrgensen, S.; Kolbe. B.; Gmehiing, J.; Rasmussen P. Ind. Eng. Chem. Process Des. Dev. lS79, 18, 714. Zarkarlan, J. A.; Anderson, F. E.; Boyd, J. A.; Prausnltz, J. M. Ind. Eng. Chem. Process Des. Dev. 1979, 18, 657.
.
I
Receiued for review December 4, 1980 Accepted June 30,1981
Density, Viscosity, and Surface Tension of Coal Liquids at High Temperatures and Pressures Shuen-Cheng Hwang and Constantine Tsonopoulos’ Exxon Research and Engineering Company, Fiorham Park, New Jersey 07932
John R. Cunnlngham Brigham Young University, Provo, Utah 84602
Grant 1111. Wllson Wiltec Research Company, Inc., Provo, Utah 84601
Density, viscosity, and surface tension of coal liquids have been experimentally determined at temperatures up to 850 O F and pressures up to 3200 psia. Measurements were made on liquids produced with the Exxon Donor Solvent process from Illinois and Wyoming coals. Several measurements were also made to determine the effect of dissolved hydrogen on the physical properties of coal liquids. These data were used to investigate the applicability of the existing physical property correlations to coaiderived liquids. Results indicate that the existing correlations are generally satisfactory for the temperature and pressure dependence of density but are unsatisfactory for the viscosity and surface tension of coalderlved liquids.
Introduction Coal liquefaction has drawn a lot of attention in the last few years. Several processes are currently being investigated, and in every case the process development has been 0196-4305/82/1121-0127$01.25/0
hampered by the unavailability of phase-equilibrium and physical property data at the conditions of interest. The first need has been addressed by Wilson et al. (1981). Here we are concerned only with the density, viscosity, and 0 1981 American
Chemical Society
