Y
L .
.I
,
Binary \Systems Involving Ethvlene Chlorohydrin J
J
VAPOR-LIQUID EQUILIBRIA H. BEN SNYDER
AND
E. C. GILBERT
Oregon State College, Corvallis, Ore.
An Othmer type equilibrium still was used to obtain the vapor-liquid curves for the distillation of seven binary systems composed of ethylene chlorohydrin and various organic solvents. The solvents chosen are all commercially available, with boiling points which fall within the temperature range 68-178' C., and are immiscible with water. Of the seven systems described in this work, three show azeotropes. No system which contains a miscibility gap was found. Of the four systems which have no azeotrope, isopropyl ether and benzene produced the largest vapor pressure differential between solvent and chlorohydrin throughout the entire concentration range.
with the results of Othmer (8) on the benzene-acetic acid system. The ethylene chlorohydrin was that supplied by the Carbide and Carbon Chemicals Corporation 4s 98" purity; it was found by analysis for chlorine and also for the hydroxyl group (9)to be 98.6 per cent chlorohydrin. One sample was treated with anhydrous potassium carbonate, but this failed to change the refractive index, density, or boiling point more than could be observed. The alcohols were refluxed for 9 hours over calcium oxide and distilled; that portion with constant refractive index was used. The ethers were treated with calcium chloride to remove most of the water and alcohol present, if any. They were then refluxed over sodium and distilled. The P$'-dichlorodiethyl ether was used as supplied by Eastman Kodak Company, without further purification. Benzene and toluene were refluxed over sodium and distilled. The physical constants of the various reagents are shown in Table I. TABLIO I. PHYSICAL CONSTANTS OF REAGENTS
LTHOUGH the system ethylene chlorohydrin-water has been studied ( 6 ) , published data on the phase equilibria in other systems containing the chlorohydrin are scarce. The present work represents a study of the vapor-liquid equilibria between seven organic solvents and ethylene chlorohydrin. These solvents were chosen because of their commercial availability, immiscibility in water, and boiling temperature, as well as lack of chemical reactivity with chlorohydrin.
A
Experimental Procedure The equilibrium apparatus was essentially that of Othmer (8), modified slightly to avoid loss by volatilization and to
improve the ease of sampling. The thermometer was a shortstem type, suspended from the stopper and entirely surrounded by vapor. It was compared with a thermometer calibrated by the National Bureau of Standards. No barostatic control waa used, experiments being confined to periods when the pressure was 760 * 3 mm. The technique was essentially that described by Othmer. The behavior was tested by observations on the acetic acidwater system studied by Othmer in the original apparatus. The correlation is shown in Figure 1. For systems in which the boiling point of the second component was low compared to that of chlorohydrin, reliable temperature readings were more readily obtainable in an auxiliary ebulliometer (vacuumjacketed, with internal heating and short-stem thermometer completely in the vapor). This procedure was also compared
Substance Ethylene chlorohydrin 180 ropy1 ether Isogutyl alcohol n-Butyl aloohol n-Butyl ether Benzene Toluene p,p'-Diohlorodiethyl ether
n %4 1.4402 1.3660 1.3942 1.3977 1.3969 1.4980 1.4932 1.4548
Boiling Point,
c.
128.0 68.4 '107.5 117.2 141.7 80.0 110.6 177.4
Vapor Pressure dai: Reference 1.1961 (6) 0.7204 0.7985 (4) 0.8065 (4) 0.7641 (7) 0.8738 (1) 0.8610 (1) 1.2133 (5)
Analysis was made in an Abbe refractometer with temperature regulated a t 25' C.; the refractive index of mixtures was compared with standard curves previously obtained for known mixtures of the two components.
Equilibrium Data The vapor-liquid equilibria are shown in Table I1 as well as in graphical form (Figure 2), which is best adapted to illustrate the differences observed in the behavior of the various solvents. Two of the solvents, isobutanol and n-butanol, showed only relatively small deviations from Raoult's law, while benzene and isopropyl ether produced systems with considerable deviation. The system with n-butyl ether showed an azeotrope at 68 mole per cent chlorohydrin (123.0' C.), that withtoluene at 27 mole per cent chlorohydrin (106.9O C.), and that with &P'-dichlorodiethyl ether at 91.8 mole per cent chlorohydrin (128.2" C.). None of the systems gave evidence of the formation of immiscible pairs at the temperatures and pressure investigated. 1519
INDUSTRIAL AND ENGINEERING CHEMISTRY
1520
0
BO 100 20 40 GO W E I G H T PERCENT WATER I N L I Q U I D
FIGURE 1. LIQUID-VAPOR EQUILIBRIUM FOR SI-S~EAI B c ~ r r ACID-WATER. c
P I / P I X= I P y ~ / P l x letc. ,
20
0
20
60
80
40
60
80
40
60
IO0
THE
Excellent reproducibility was obtained, ab demonstrated in several of the graphs where the data of separate runs have been incorporated. Beatty and Calingaert ( 1 ) and more recently Carlsoii and Colburn ( 2 ) have given methods by which data of this type may be tested for reliability and consistency. Both methods are rather time consuming, but the latter investigators ( 2 ) have perhaps the advantage in this respect. Their procedure involves the integration of the theoretical Gibbs-Duhem equation expressing the relation between activity coefficients and mole fractions by means of equations derived by van Laar, Margules, or Scatchard and Hamer. Assuming that the vapors are perfect gases, y1 =
0
Vol. 34, No. 12
( 1)
Carlson and Colburn give expressions for log y1 and log y2 in terms of empirical constants A and B such that at 2 1 = 0, log y1= A , and a t x2 = 0, log y2 = B. Further, a t x1 = z2 =
,-.-
U.3,
log Yl B
=
log: " 2 A
(2)
I n order to use this met'hod for checking the reliability of experimental data, it is thus necessary to calculate y1and 7 2 . Plotting these quantities against z1 reveals immediately any lack of internal consistency as the points should lie on smooth curves. Systematic error will be shown by the failure of agreement between observed y and those calculated by means of the equations involving A and B. Choice of constants A and B is somewhat empirical, being governed chiefly by Equation 2 and the extrapolated values of the 7 - 2 curves. Unless the vapor pressure curves for the liquids are known, the method oannot be used. Furthermore, if the vapor pressure curve (and hence boiling point) for the liquid used does not agree exactly with that in the literature, an error is introduced which may be considerable. Some of the lack of agreement shown in our data is certainly due to this factor. For the sake of brevity only y2,experimental and calculated from the van Laar equations, is shown. The system ethylene chlorohydrin-n-butanol evidently comes very close to following Raoult's law (y = l), and the data are consistent. Only slight deviation is observed in the system chlorohgdrin-isobutanol. In both the benzene and toluene systems the agreement between experiment and calculation leaves something to be desired. The curve yz-x in both shods too great convexity toward the z coordinate, and though the theoretical curve can be shifted by change in constants A and B , com-
0
20
n O L E P E R C E N T C H L O R O H Y D R I N IN
FIGURE 2.
50
100
LIQUID
LIQUID-VAPOREQUILIBRIA FOR VARIOUSSYSTEMS
I. Ethylene ohlorohydiin-n-butanol 11. Ethylene chlorohydrin-isobutanol 111. Ethylene chlorohydrin-benzene (x,o iepresent independent runs). IV. Ethylene chlorohydrin-isopropyl ether V Ethylene chlorohydrin-0 P'-dichlorodiethyl ether ether (+, x, o represent VI: Ethylene chlorohydrin-;-butyl independent runs). VII. Ethylene chlorohydrin-toluene
plete agreement is not attainable. The yl-z curve (for the activity coefficient of toluene) is a quantitative check between calculation and experiment over the entire range, although this may be the result of chance. The failure of these two systems to stand up under this test as well as the others is difficult to explain in vie17 of the high reproducibility obtained
December, 1942
INDUSTRIAL AND ENGINEERING CHEMISTRY
1521
DATAFOR VARIOUS SYSTEMS WITH ETHYL EN^ CHLOROHYDRIN TABLE11. ANALYSISAND EQUILIBRIUM Temp. of
vapor, O
C.
7
126.0 123.2 120.8 119.5 119.0 118.6 118.3 118.0 117.5 125.7 119.6 116.5 113.3 112.2 111.0 110.2 109.8 109.3 108.3
-
114.0 98.8 96.0 92.8 88.2 86.2 84.4 83.5 82.0 81.7 81.2 80.5 ,--
106.0 105.3 97.0 89.3 83.5 77.8 76.0 74.5 73.1 72.7 70.7 70.0
Mole Fraction Refractive Index Chlorohydrin Y2 Liquid Vapor Liquid Vapor Exptl. Ethylene Chlorohydrin-n-Butanol 0.920 1.04 1.4356 0.949 1.4373 0.734 1.04 1.4257 0.820 1,4301 0.462 1.01 0.570 1.4181 1.4134 0.299 1.01 1.4071 0.384 1,4103 0.91 0.321 0.222 1,4079 1.4051 0.99 0,263 0.195 1.4058 1.4035 0.157 0.99 0.213 1.4041 1.4023 1,4023 1.4010 0.157 0.114 0.98 1,4000 1.3993 0.080 0.058 0.99 Ethylene Chlorohydrin-Isobutanola 1.02 0,970 0.931 1.4386 1.4362 0.847 0.695 1.06 1.4313 1.4229 0.576 1.11 0.736 1.4251 1 4169 0.395 1.11 1,4088 0,558 1.4161 0.476 0.324 1.11 1.4123 1.4058 0,376 0.241 1.08 1.4080 1.4026 0.318 0.198 1.07 1.4056 1.4010 0.168 1.06 1.3999 0.275 1.4039 0.136 1.07 1.3988 0.223 1.4019 0.114 0.060 0.98 1.3981 1.3962 Ethylene Chlorohydrin-Benzeneb 0.988 0.711 1.10 1.4422 1,4620 1.25 0.946 0.472 1.4448 1.4760 0.393 1.22 1.4801 0.922 1.4469 0.899 0.308 1.06 1.4489 1.4844 0.814 0.757 1.10 1.4550 1.4876 0,208 1.10 1.4893 0.746 1.4597 0.630 0.170 1.14 1.4670 1.4910 0.546 0.150 1.20 1.4719 1.4919 0.122 1.4932 0.338 1.70 1.4829 0.285 0.112 1.85 1.4855 1.4936 0,085 2.02 1.4947 0.201 1.4896 0.102 0.062 2.49 1,4940 1,4960 Ethylene Chlorohydrin-Isopropyl Ether 1.3920 0.979 0.432 1.4379 1.3918 0,972 0.430 1.4372 0,961 0.340 1.3859 1.4360 1.3774 0.926 0 1200 *. 1.4323 0.143 1.3741 0.873 1.4272 0.798 0.101 1,3717 1,4202 1.3708 0.738 0.085 1.4150 0.654 .. 1.3701 0.073 1.4082 0.561 0.059 1.3693 1.4012 0,052 1.3689 0.515 1.3978 0.037 1.3680 0.336 1.3856 0.277 0.033 1.3678 1.3820
....
.. .. .. .. ..
-
-
Ca?td.
O
7
.. .... .. .. .. .. .. ..
127.1 123.7 123.3 123.0 123.0 123.3 124.0 125.0 126.9 129 * 8 134.6
1.00 1.02 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.12 1.01 1.02 1.04 1.05 1.12 1.17 1.35 1.47 1.95 2.06 2.32 2.72
....
T$f$rPfC.
-
.... .. ....
.. .... .. ..
120.4 113.9 108.4 107.6 107.0 106.9 107.8 109.2 ,-Ethylene 128.3 128.2 128.2 128.2 128.4 128.8 130.4 133.0 135.6 139.4 144.6 152.2 160.8 167.0
Mole Fraction Refractive Index Chlorohydrin 72 Liquid Vapor Liquid Vapor Exptl. Ethylene Chlorohydrin-n-Butyl Ether" 1,4394 1.4333 1.4279 1.4220 1.4166 1.4122 1.4077 1.4043 1.4018 1.3996 1.3980 1.4409 1.4430 1.4468 1,4518 1.4559 1.4601 1,4644 1.4678 1.4710 1.4579 1.4779 1.4800 1,4818 1.4839 1.4858 1.4873 1.4889 1,4898 1.4910 1.4918 1.4405 1.4407 1,4409 1.4417 1,4428 1.4439 1.4461 1.4483 1.4501 1.4517 1.4629 1.4538 1.4543 1.4546
1.4372 1.4260 1.4220 1.4196 1.4178 1.4163 1.4141 1.4122 1,4100 1.4068 1.4026
0.992 0.921 0,849 0.755 0.649 0.549 0.427 0.313 0.210 0.115 0.048
0.968 0.822 0.755 0.710 0.674 0.643 0.595 0.589 0.491 0.400 0.243
1.01 1.02 1.04 1.10 1.21 1.36 1.58 1.94 2.45 3.36 4.45
Ethylene Chlorohydrin-ToJuened 1.4463 0.992 0.927 1.00 1 ,4572 0.967 0.770 .. 1,4670 0.920 0.630 1.4723 0.851 0.500 1.4749 0.790 0.444 1.05 1.4762 0.725 0.416 1 .4779 0.654 0.379 0.357 1.14 1 ,4788 0.591 1,4794 0,527 0.344 1.4807 0.422 0.313 1,4812 0,301 1.52 0.378 1.4818 0.330 0.286 1.4821 0.286 0.279 2.10 1.4829 0.233 0.254 1.4841 0.184 0.228 1.4850 0.147 0.206 1,4862 0.108 0.175 3.02 1.4871 0.084 0.151 1 ,4887 0.055 0.112 1.4899 0.034 0.082 4.30 Chlorohydrin-B,P'-Dichlorodiethyl Ether' 1.4409 0.980 0.960 1.00 1.4412 0.970 0.945 1.00 1.4414 0,934 0.960 1.00 1.4418 0.919 0.914 1.02 1.4421 0,899 1.06 0.863 1.4423 0,807 0,889 1.11 1.4428 1.24 0.681 0.863 1.43 1.4434 0.531 0.835 1.4440 0.803 1.76 0.392 1.4451 0.271 0.742 2.16 1.4466 0.171 0.650 2.60 1.4481 0.091 0.545 3.36 1.4502 0.044 0.383 3.93 1.4525 0.020 0.205 4.03
Y P
-
Calcd. 1.00 1.02 1.04
1.11
1.23 1.40 1.66 2.01 2.42 2.97 3.30
1.00
..
1.13 1.31 1.90 2.55 3.60 4.25 1.01 1.02 1.02 1.03 1.05 1.08 1.20 1.42 1.73 2.11 2.53 3.00 3.26 3.40
Using van Laar equations with A = 0.08 and B 0.057; in this instanoe 71agrees with calculated values better than ~ 2 . Using van Laar equations with A 0.9 and B = 0.5. Using van Laar equations with A = 0.72 and B = 0.54. d Using van Laar equations with A = 0.75 and B = 0.68' in this instance the agreement between calculated and experimental values for toluene (71) was quantitative: the effept was thus to throw all deviation into the chlorohydrin values. 8 Using van Laar equations with A 0.79 and B = 0.54. a b c
in the equilibrium runs, as shown in Figure 2. The difficulty may lie in the failure to measure true temperature. Excellent consistency and good agreement between calculation and experiment are shown in the systems involving chlorohydrin with @,@'-dichlorodiethyl ether and n-butyl ether, respectively. Only in the very dilute solutions where analysis becomes less exact does a drift become evident. No data for the vapor pressure of isopropyl ether above its boiling point were found; hence calculations were not made for this system. pl =
Nomenclature partial pressure = Py,mm. Hg
P = total pressure, mm. Hg PI, Pz = vapor pressures of pure components, mm. Hg zl,vt = mole fraction solvent in liquid and vapor, respectively z2,g2 = mole fraction chlorohydrin in liquid and vapor, respectively y1 = activity coefficient of liquid solvent ya = activity coefficient of chlorohydrin A , B = arbitrary constants of van Laar equations
Literature Cited (1) Beatty, H. A., a n d Calingaert, George, IND. ENQ.CHEW., 26, 904 (1934). (2) Carlson, H.C., a n d Colburn, A P., Ibid., 34,581 (1942). (3) Gallaugher, A. F., a n d Hibbert, H . , J . Am. Chem. SOC.,59,2521 (1937).
International Critical Tables, Vol. 111, p. 219, New York. McGraw-Hill Book Co., 1928. Kireev, V. A., Kaplan, S. I., and Zlobin, V. N., J . Applied Chem.
(U. 5. 9. R.),7, 1333 (1934). Kireev, V. A., a n d Nikiforova, V. A., J . Gen. Chem. (U. S . S . R.), 6. 75 11936). (7) Mathew;, J. 'H.. and Fehlandt, P. R., J . Am. Chem. SOC.,53, 3212 (1931). (8) Othmer,'D. F., IND. E N & CHEM., 20, 743 (1928). (9) Pennington, Lloyd, Dimick, K., and Christensen, B. E., IND. ENQ.CHEM.,ANAL.ED., 13, 821 (1041). AESTRACTBD from the master's thesis of H. Ben Snyder. Published with the approval of the Monographs Publication Committee, Oregon State College, as Research Paper No. 64, School of Science, Department of Chemistry.
Solubilization of Water-Insoluble Dye in Aqueous Solutions of Commercial Detergents-Correction In the above article by J. W. McBain and R. C. Merrill, Jr., in the August, 1942,issue, an error occurs in Table I1 on page 916. .The detergents Igepal C and Igepal CTA are manufactured by General DyestuE Corporation, not by Hart Products Corporation as erroneously listed.
