J. Chem. Eng. Data 1986, 31, 45-47
.io
45
Acknowledgment Acknowledgment is made to Mr. E. Niessen for his contribution in the measurements. Registry No. 2-Propanol, 67-63-0; carbon dioxide, 124-38-9.
.05
Llterature Clted
e 0
4
0
I 2
z
.02
--Predicted with RKJZ1 Predicted with RKJZZ
.01 1
5
2
10
Pressure, MPa
Flgure 5. Experimental vapor-liquid ratio of mole fractions for 2propanol (K ratio) at 62 OC.
D i
1 K m X
binary molecular size-related parameter ith component property jth component property equilibrium vapor/liquid ratio of mole fractions (K ratio) mixture property mole fraction
(1) Wilhoit, R. C.; Zwolinski, B. J. J . Chem. fhys. Ref. Data 1973, 2 , (Suppl. 1). (2) Radosz, M. Postdoctoral Report, The Technical University of Norway, Trondheim, 1980. (3) Radosz, M.; Lydersen, A. Chem.-Ing.-Tech. 1980, 52,756 (Suppl.). (4) Gmehling, J.; Onken, U.; Ark, W. "Vapor-Liquld Equilibrium Data Collection"; DECHEMA: Frankfurt, 1977. (5) Sorensen, J. M.; Ark, W. "Liquid-Liquid Equilibrium Data Collection"; DECHEMA, Frankfurt, 1979. (6) Paulaitis, M. E.; Kander, R. G.; DiAndreth, J. R. Ber. Bunsenges. fhys. Chem. 1984, 88, 869. (7) Kander, R. G.; Paulaitis, M. E. AIChE Annual Meeting, San Francisco, 1984; American Institute of Chemical Engineers: New York; 84b. (8) Radosz, M. Ber. Bunsenges. fhys. Chem. 1904, 8 6 , 859. (9) Prausnitz, J. M.; Hu, Y. AIChE Annual Meeting, San Francisco, 1984; American Instltute of Chemical Engineers: New York; 102e. (IO) Brignole,, , E. A.; Skjold-Jorgensen, S.; Fredenslund, Aa. I n "Supercritical Fluid Technology"; Penninger, J. M. L. et al., Eds.; Elsevier: Amsterdam, 1985. (11) Tsang, C. Y.; Streett, W. B. J . Chem. Eng. Data 1981, 26, 155. (12) Soave, G. Chem. Eng. Sci. 1972, 27, 1197. (13) Peng, D. Y.; Robinson, D. B. Ind. Eng. Chem. Fundam. 1976, 75, 59. (14) Zudkevitch, D.; Joffe, J. AIChE J. 1970, 76, 112. (15) Gray, R. D. Jr.; HeMman, J. L. Jr.; Hwang, S. C.: Tsonopoulos, C. NuM Phase Equilib . 1983, 13, 59. (16) Heidman, J. L. Jr. "PHASER Regression Program"; Exxon Research and Engineering Co.: Florham Park, NJ, 1985. Received for review January 28, 1985. Accepted May 15, 1985. Acknowledgment is made to Exxon Research and Engineering Company for permission to publish this paper.
Excess Enthalpies of Binary Mixtures of n -Decane with Hexane Isomers Salah E. M. Hamam Department of Chemical Engineering, Kuwait Universm, College of Engineering and Petroleum, Kuwait
George C. Benson' Department of Chemical Engineering, University of Ottawa, Ottawa, Ontario, Canada K1N 984
Calorlmetrlc measurements of excess enthalples are reporled for each of the flve mlxtures (n-decane-an lsomerlc hexane) at 298.15 K. The results for equlmolar mlxtures, together wlth prevlously publlshed results for other ( n -alkane-lsomerlc hexane) mlxtures, are well correlated In terms of the acentrlc factors of the n-alkanes. Currently we are studying the variations in the excess thermodynamic properties of binary mixtures which result from isomeric changes in one of the components. I n this regard, we have been investigating systems formed by mixing an nalkane with the five isomeric hexanes: n-hexane (n-C6), 2methylpentane (2-MP), 3-methylpentane (3-MP), 2,2-dimethylbutane (2,2DMB), and 2,3dimethylbutane (2,3DMB). Previous papers have reported excess enthalpies for mixtures of each of these isomers with nheptane ( 7 ) , n-octane (2), and n d o decane (3). The present paper describes a similar study of 0021-9568/86/1731-0045$01.50/0
(n decane-isomeric hexane) mixtures. Excess enthalpies of (ndecane-nC6) mixtures have been studied several times in the past ( 4 - e ) , but we are unaware of previous measurements on any of the other mixtures.
Experimental Sectlon Excess molar enthalpies I-$,!, were determined at 298.15 K in an LKB flow microcalorimeter. Details of the equipment and its operation have already been described ( 1 , 7). For most of the measurements, the error in the determination of pmis estimated to be less than 0.5%. However, it may be somewhat higher for small h', (
