INDUSTRIAL AND ENGINEERING CHEMISTRY
1662
LITERATURE CITED
at any pressure up to saturation and the enthalpy a t zero presm e (B.t.u. per pound mole) divided by the critical temperature ( " R.) is plotted against reduced pressure. The curves calculated by Hougen and Watson (5)for viater are also shown for comparison. ACKNOWLEDGMENT
The authors wish to acknowledge the assistance of a fellowship provided by the Horace H. Rackham School of Graduate Studies of the University of Michigan, of the Dow Chemical Co. for assistance and the supply of the dichlorobenzene, and of P. Amin, R. Curtis, R. C. Parikh, S. 0. Shukla, F. C. Standiford, and M. M. Uppal for assistance and cooperation.
Vol. 46, No. 8
(1) Antoine, C., Compt. Rend., 107,681, 836, 1143 (1885).
(2) Herzog, R., ISD. ENG.CHEM.,36, 997 (1944). (3) Hougen, 0. A , , and Watson, K. M., "Chemical Process Principles," p . 495, John Kiley & Sons, 1947. (4) Konz, P. R., and Brown, G. G., IND. ENG.CHEM.,33, 617 (1941). ( 5 ) Neissner, H. P., Chem. Eng. Progr., 45, 149 (1949). (6) Meissner, H. P., and Redding, E. AI., IND. Esc. CHEX.,34, 521 (1942). ( 7 ) Roeser, Wm. T., and Weusel, H. T., S a t l . Bureau of Standards, Washington 25, D. C., Research Paper RP768. (8) Watson, K. M ~ IXD. , EBG.CHEIII.,23, 360 (1931). RECEIVED for reyieiv December 20, 1949.
ACCEPTED.ipril 19, 1954.
Ternary Liquid System, BenzeneHeptane-Die thylene Glycol GEORGE C. JOHYSOX AND ALFRED T. FRANCIS Research and Development Department, Socony-Vacuum Oil Co., Znc., Paulsboro, il; J .
B
ENZEXE and other aromatic hydrocarbons can be recovered effectively from hydrocarbon mixtures by solvent extraction with diethylene glycol (3, 8, 9). In the present work the phase diagrams and selectivity diagrams for the system benzene-heptane-diethylene glycol have been obtained a t temperatures varying from 25' to 175" C. The effect of water on this system also has been examined.
MATERIALS
Chemically pure benzene, melting point 5.40" C., was used The n-heptane, nz: 1.38179, mas certified by the Pr'ational Bureau of Standards. The diethylene glycol, n2,0 1.4476, was obtained from the Carbide and Carbon Chemicals Corp. The critical solution temperature with benzene was 88.8" C. The water content was 0.02 weight %, as determined by the use of the Karl Fischer reagent (6). PROCEDURE FOR PHASE DIAGRAMS
200
The mutual solubilities of heptane and diethylene glycol were measured as functions of temperature by making a series of 180
TABLEI. CLOUDPOINTS OF BIXBRYSYBTEM HEPTANE-
160
DIETHYLEKE
Heptane,
n-t. %
140
0.391 0.542 0.780 1.037 1.29 1.98 3.59 96.92 97.82 99,81 99.93
120
3
t: g
100
g
n
2
J
2.18
0.186 0.073
Cloud
Ppnt,
C.
