is9
J. Chem. Eng. Data 1991, 36, 159-161
(2) Ashizawa, M.; Saltoh, A.; Sato, H. ROC. 17th CongeRem. 1087, 4 ,
tures from 275.65 to 440 K and pressures from 0.5 to 3.2 MPa with the uncertainty of f0.4% for the data below 420 K, f0.5% for the data at 430 K, and f0.8% for the data at 440 K, respectively. These C, data were correlated as a function of temperature and pressure, and saturated liquid C,' values were derived from the correlation.
350. (3) RAQ Saltoh. A.; Sato, H.; Watanabe, K. Int. J . 7bm@p. 1010, 10(3),
-_-.
(4) Saltoh, A.; Nakagawa, S.;Sato, H.; Watanabe, K. J . Chem. Eng. Dei% 1000, 35, 107. (5) Sato, H.; Uematsu, M.; Watanabe, K. Strojnlcky bsopls 1085, 38, 257.
(6) i i o , C . C . ; Sato, H.; Watanabe, K. Submitted for publication in J .
cham.E m . Data.
Acknowledgment
(7) Ta&awi,b.;-kabata, Y.; &to. H.; watanabe. K. J . hem. EW. h b p 1000. 35. 381. (8) Benning, A. F.; McHarness, R. C.; Markwood. W. H.; Smith. W. J., Jr. J . Ind. €179.Chem. 1040, 32(7), 976.
We acknowledge the assistance of Hideo Miyahara in the present measurements. We are also grateful to Asahi Glass Company, Tokyo, for kindly fumishing the sample of HCFC-123.
Ltterature Clted
Recehred for review July 24, 1990. Accepted November 26, 1990. The financial support from the Tokyo Electric Power Co.,Inc., k, greatly appreciated.
(1) Sato, H.; Sakate, N.; Ashizawa, M.; Uematsu, M.; Watanabe, K. Roc. 2nd A S K - J S M Therm. EW. Jdnt C M f . 1087. 4 . 350.
Vapor-Liquid Equilibrium Determination by Total Pressure Measurements for Three Binary Systems Made of 1,P-Dimethoxyethane with Toluene, Methylcyclohexane, or (Trifluoromethyl)benzene Kazunorl Alzawa and Masahiro Kato' Department of Industrial Chemistry, Faculty of Engineering, Nihon University, Koriyama, Fukushima 963, Japan ~
10.01 mmHg. The upper layer of the manostat is dibutyl phthalate, and the lower layer is ethylene glycol saturated with sodium nitrite. The prepared solution was then boiled. The temperature was controlled to the desired temperature by reducing the pressure. After attainment of steady state, the total pressure was measured with a Ruska 3850 quartz Bourdon gage with a precision of 10.02 mmHg. The experimental temperature was measured at 350 K with a Hewlett-Packard 2804A quartz thermometer calibrated at the triple point of water in a reference cell. The reproducibility of the thermometer temperature measurements was 10.01 K. The densities of the binary liquid mixtures were determined at 298.15 K with an Anton Paar M A 4 8 digltal density meter with a precision of 10.0001 g/cm3. Toluene was a special grade reagent supplied by Wako Pure Chemical Industries Ltd. 1,2-Dimethoxyethane, methylcyclohexane, and (trifluoromethy1)benzene were special grade reagents supplied by Tokyo Kasel Kogyo Co.,Ltd. Toluene and methylcyclohexane were used without further purltication. (Trifluoromethyl)benzene and 1,2dimethoxyethane were futher purified by distillation in an Oldershaw distillation column with 30 plates. The physical properties of the materials used are listed in Table I.
Total vapor pressures were measured for the three blnary systems made of 1,24methoxyethane wtth toluene, methylcyclohexane, or (trlfluoromethy1)benzene (benrotrtfluorlde) at 350 K. Dendtks of the mlxtures were measured at 298.15 K. The vapor-llquld equlllbrla were correlated by using the Wilson equatlon. Introduction Vapor-liquid equilibria (VLE) are required for engineering use such as in the design and operation of distillation equipment. I n the present study, isothermal total pressures P were measured by the ebulliometrlc method for the three binary systems made of 1,2dimethoxyethane with toluene, methylcycbhexane, or (trifluoromethy1)benzene (benzotrifiuoride) at 350 K. The densities of these mixtures were measured at 298.15 K, and the molar excess volumes V E were calculated.
Experimental Section The experimental apparatus previously reported by Kat0 et ai. ( 7 , 2) was modifled in the present study, as shown in Figure 1. The ebulliometer E has been described by Kat0 et ai. (3). The liquid volume in the ebulliometer is about 25 cm3. At the start of an experiment, a solution of desired composition was prepared by mMng each pwe substance, which was weighed by use of syrbrges and an automatic balance, sknilarly to the procedures of the previous works (3,4). The reproducibility of the composition was within 10.001 mole fraction. Cocks K,, K, and K, and solenoid valve V were opened, and K, and K, were closed. The system pressure was reduced by the vacuum pump near to the total pressure of the desired boiling point temperature. Next, cocks K, and solenoid valve V were closed, and the temperature was kept constant by use of the Williams (5) two-liquid manostat with a precision of 0021-9568/91/17360159$02.50/0
Results The experimental total pressures P for the three binary systems at 350 K are given In Table I1 and Figure 2. The experimental densities p for the three binary mixtures at 298.15 K are shown in Table 111. Figure 3 shows the molar excess liquid volumes V E calculated from VE =
v-
(x,V,
+ x,V,)
(1)
and correlated with the following equation: VE = x,x,[(Y
0
1991 American Chemical Society
+ @ ( x ,- x,)]
(2)
160 Jolmal of Chemical and Engineering Data, Vd.36,No. 2, 1991
Table I. Normal Boiling Points Tb, Densities p , and Refractive Indexes n of Materials Used Tb/K ~(298.15K)/ (g-cm-*) material exotl lit. exDtl lit. 1,2-dimethoxyethane 358.10 358.4 (10) 0.8612 0.8683" (IO) toluene 383.79 383.776 (12) 0.8622 0.862 32 (12) 0.7649 0.76511 (12) methvlcvclohexane 374.12 374.1 (12) - 0.76506 (13) 374.084 (13) 1.1814 1.1813 (10) (trifluoromethy1)benzene 375.19 375.20 (10) 375.200 (13) 1.18129 (13)
n~(298.15K) exDtl lit. 1.3775 1.379 P (10) 1.4941 1.49405 (12) 1.4207 1.4206 (12) 1.42058 (13) 1.4123 1.4114 (10) 1.412 25 (13)
'At 293.15 K. Table 11. Experimental Total Pressures P and Calculated Vapor-Phase Mole Fraction y Ifor the Three Binary Systems"at 350 K as a Function of the Liquid-Phase Mole Fraction x,,Wilson Coefficients A,, and Equations 3 and 4, and Standard Relative Deviations A r ( P ) P/mmHg Y1 X1 I I1 I11 I I1 I11 0.OOO 261.10 365.25 339.54 O.OO0 O.OO0 O.OO0 0.100 292.76 426.74 352.57 0.202 0.228 0.138 0.200 326.42 476.50 370.50 0.363 0.375 0.276 0.300 361.71 515.98 391.74 0.494 0.480 0.408 0.400 395.57 544.28 412.90 0.602 0.561 0.528 0.500 426.86 568.84 440.76 0.693 0.627 0.636 0.600 459.04 587.17 467.78 0.771 0.687 0.731 0.700 491.22 595.68 494.30 0.838 0.745 0.813 0.800 520.35 598.28 523.85 0.897 0.808 0.885 0.900 552.33 594.53 551.90 0.950 0.886 0.947 1.OOO 581.94 581.94 581.94 LOO0 1.OOO 1.OOO
I
"Systems: (I) 1,2-dimethoxyethane (1) + toluene (2), A12 = 1.6526, = 0.4762, Ar(P) = 0.0018; (11) l,2-dimethoxyethane (1) + methylcyclohexane (21, A12 = 0.9313, AZ1 = 0.4591, Ar(P) = 0.0023; (111) 1,2-dimethoxyethane (1) + (trifluoromethy1)benzene (2)., AIZ = 0.5347, AZ1 = 1.8698, Ar(P) = 0.0013.
A
Figwe 1. Experimental apparatus for measuring isothermal totai pressures: (A) vacuum pump; (6) trap; (C) condenser; (D)reservdr; (E) ebulliometer; (K) cock; (M)manostat; (P) pressure gage; (S) silica gel; (T) thermometer; (V) solenoid valve.
700 600
Table 111. Experimental Densities p for the Three Binary Systems' at 298.15 K as a Function of the Mole Fraction x, and Coefficients a and B, Eauation 2 P / (gem-? XI I I1 I11 0.7649 1.1814 O.OO0 0.8622 0.8624 0.100 0.7705 1.1538 0.8626 0.200 0.7768 1.1254 0.8628 0.7841 1.0962 0.300 0.7922 0.8628 0.400 1.0659 0.8627 0.500 0.8012 1.0346 0.8110 1.0022 0.8626 0.600 0.8624 0.700 0.8219 0.9688 0.8621 0.8338 0.9341 0.800 0.8617 0.900 0.8468 0.8983 0.8612 0.8612 0.8612 1.OOO
r---l
.' 0
500
1
;LOO 300
'
200 00
02
04
06
1
0.8
1.0
Mole Fraction of 1,2-Dimelhoxyelhane
'Systems: (I) l,2-dimethoxyethane (1)+ toluene (2), a = -0.50, j3 = -0.1; (11) 1,2-dimethoxyethane (1) methylcyclohexane (2), a = 4.12, fl = -0.3; (111) 1,2-dimethoxyethane (1) (trifluoromethyllbenzene (21, a = 0.05, j3 = 0.0.
Figwe 2. Experlmental total pressure P curves at 350 K: (-0-) 1,2dimethoxyethane toluene; (-A-)1,2dlmethoxyethane methylcyclohexane; (--) 1,2dimethoxyethane (trifluor0methyl)benzene.
The vapor-phase corrections In terms of the second molar virial coefficients Bu were estimated by the Hayden and 0'Connell (6) method, using the parameters (7-70) shown in
Table IV. The liquid volume change with pressure was neglected In the present study.
+
+
+
+
+
Table IV. Parameters Used to Calculate the Second Molar Virial Coefficients Bij by the Method of Hayden-O'Connell(6): Critical Pressure P,,Critical Temperature T,, Mean Radius of Gyration R', Molecular Dipole Moment p, and Association Factor 7 material 1,2-dimethoxyethane toluene methylcyclohexane (trifluoromethy1)benzene
Pc/atm 38.2 (9) 41.6 (7) 34.3 (9) 31.73"
TCIK 536 (9) 592.0 (7) 572.1 (9) 557.84"
R'/A
a/D
3.361* 3.443 (7) 3.823b 4.830b
1.79 (10) 0.36 (7) 0.00 (9) 2.56 (10)
Estimated from the Lydersen method. *Estimated from parachor.
Assumed.
v 0.W 0.00 (7) 0.00 (8) 0.W
Biil (cms-mol-l) -1145 -1499 -1682 -1900
Bijl
(cm3-mol-') -1251 -1316 -1452
Joumel of Chemical and Engineering Date, Voi. 36,No. 2, 1QQ1 101
1.0
calculated vapor phase mole fractions y , and the mean relatlve deviations in presswe Ar(P)are listed in Table 11. Vapor-lqu# equllibrlum relations are shown In Figure 4. The azeotroplc methylcyclocomposition of the 1,2dlmethoxyethane (1) hexane (2) system at 350 K is estimated to be xl(Az) = 0.826.
P-l
+
Acknowledgment 0.5
We thank Messrs. Kazuyuki Ueda and Kunihlko Takekawa for their help In the present experimental work.
Y '
Glossary 0.0
v.,
P T V VE X
~~
02
00
06
04
08
10
Y
Mole Fraction of 1.2-Dimelhoxyelhane
Figure 3. Experknental mder excess liquid volumes VE at 298.15 K: (-0-)1,24methOxyethane toluene; (-A-)1,2dhnethoxyethane
methylcyclohexane; (+) benzene.
+
1.2dimethoxyethane
+
+ (trlfluoromethylk
pressure, mmHg temperature, K molar liquid volume, ~ m ~ m 0 1 - l molar excess liquid volume, eq 1, cm3*mor1 liquid mole fraction vapor mole fraction
Greek Letters
4 Y
A Ar(P)
parameters in eq 2 activity coefficient Wilson parameter mean relative deviation, =1CIPc,llc - P,I/P, N number of experimental points)
(N,
Subscngts 1 2
1,2dlmethoxyethane toluene, methylcyclohexane, or (trifluoromethyllbenzene Rogblry No. 1,2dhnethoxyethane, 110-71-4; toluene, 108-88-3; methylcyclohexane, 10847-2; benrotrifluoride, 98-08-8.
Llterature Clted L q u d Mole Fraction 01 1.2-Dimethoxyelhane
Flgurr 4. Calculated vapor-liquid equilibria at 350 K: (-) 1,2dL methoxyethane toluene; (- -) 1,2dImethoxyethane methylcyclohexane; (- -) 1,2dimethoxyethane (tr1fluoromethyl)benzene.
+
+
+
The activity coefficients y, at constant temperature and pressure ( f a n d P , ) were correlated with the following Wilson ( 7 7) equations, almost similar to our previous paper (2). In y, = -In (x,
+ A12x2)+ x 2
In y2 = -in (x,
+
+ x1
The Wilson parameters A1, and A,, (Table 11) were determined to minimize the sum of squares of deviations in the absolute total pressures for all experimental data points. The
(1) Kato, M.; Tanaka, H. J . Chem. Eng. Data 1989, 34,206. (2) Kato, M.: Tanaka, H.; Alzawa, K. F/uMF?mseE m . 1990, 58, 181. (3) Kato, M.; Konlshl, H.; Hkata, M. J . Chem. Eng. Dam 1970, 15. 435,501. (4) Yoshlkawa, Y.; Takagl, A.; Kato, M. J . Chem. Eng. Dam 1980, 25, 344. (5) Williams, F. E. I d . Eng. Chem. 1947, 39. 779. (6) Hayden, J. G.; O'Connell, J. P. I d . Eng. Chem. Frocess Des. Dev. 1975, 14, 209. (7) Fredenslund, A.; Gmehllng, J.; Rasmussen. P. Vapw-LlpuM EquMx4 Using UNIFAC; Elsevier: Amsterdam, 1977. (8) Rausnitz. J. M.; Anderson, T. F.; &ens, E. A.; Eckert, C. A.; Hskh, R.; o'Cont~U,J. P. CaWHOns far v t Vepc~-l&uld end Llquld-Liquld E q m ; RentlceSlal: Engiewood Cllffs, 1980. (9) Reid, R. C.; Rausnitz, J. M.; Sherwood, T. K. The propertleg of Qases end L/q&, 3rd ed.; W a w H I I I : New York. 1977. (IO) Asahara, T.; Tokura, N.; Okawara, M.; Kumanotanl. J.; Senoo, M. solvent Handbook; Kodansha: Tokyo, 1976. (11) Wilson, 0. M. J . Am. Chsm. Soc. 1964, 86, 127. (12) Thnmermans, J. phycrico-Chemlcal Constants of Pve &pn& Compounds; Elsevier: New York, 1965; Vd. 2. (13) Rlddlck, J. A.; Bunger, W. B.; Sakano, T. &@nlc &/vents, 4th ed.; Wlley-Interscience: New York, 1986. Received for review January 8, 1990. Revised October 31, 1990. Accepted November 2, 1990.
