June 1953
INDUSTRIAL AND ENGINEERING CHEMISTRY Conclusions
*
Nomenclature
A simple method has been developed for predicting liquidliquid equilibrium data of sufficient accuracy to be used in engineering design calculations. The equilibrium data are predicted from mutual solubility data which may be easily and accurately determined by experimental means. The method of prediction is based on the assumptions that in hydrocarbonsolvent systems the hydrocarbons form ideal solutions in each other, and the activity coefficients of the several hydrocarbons are functions of the solvent concentration. Although this method of calculation is not rigorous, the results of this study indicate that phase equilibrium data of sufficient accuracy for engineering design calculations may be obtained. It is possible that predictions at temperatures close to the critical solution temperatures of any solvent-hydrocarbon pair may be inaccurate. Therefore, predictions within 20’ F. of a critical solution temperature should be experimentally verified. The results also indicate the assumption that aliphatic and naphthenic hydrocarbons form ideal solutions in each other is acceptable for liquid-liquid phase equilibrium calculations. This method of prediction has given good results for systems of aliphatic and naphthenic hydrocarbons in the solvents furfural, aniline, and methylcarbitol, and would probably give good results for the same hydrocarbons in similar solvents; however, this method of prediction should not be applied to other types of systems without first checking a few experimental points. Acknowledgment The authors wish to gratefully acknowledge the contributions His ideas and advice were of material aid in the successful completion of this project. The authors also wish to thank the Research and Development Department of Phillips Petroleum Go. for permission to publish this work. of K. H. Hachmuth to this study.
A
= constant in van Laar equations = activity = constant in van Laar equations
‘ i K = partition coefficient
= mole fraction in solvent phase or in solution if only one phase is present y = mole fraction in hydrocarbon phase y = activit coefficient In = logaritlm to the base e log = logarithm to the base 10 Subscripts h pertains to solvent phase i indicates component i j indicates component j Y pertains to hydrocarbon phase z
Literature Cited (1) Carlson, H. C., and Colburn, A. P., IND. ENG.CHEM.,34, 581 (1 942). (2) Colburn, A. P., and Schoenborn, E. M., Trans. Am. Inst. Chem. Engrs., 41, 421 (1945). (3) Darwent, B. de B., and Winkler, C. A., J. Phus. Chem., 47, 442 (1943). (4) Gibbs, J. W., “Collected Works,” New York, Longmans, Green, and Co., 1928. (5) Herbolsheimer, Glenn, dissertation, The Pennsylvania State College, 1942. ( 6 ) Hildebrand, J. H., and Scott, R. L., “Solubility of Nonelectrolytes,” 3rd ed., New York, Reinhold Publishing Corp., 1950 (7) Hunter, T. G., and Brown, T., IND. ENG.CHEM.,39,1343 (1947). (8) Lam, J. J. van, 2. phusik Chem., 72, 723 (1910); 83, 599 (1913). (9) Treybal, R. E., “Liquid Extraction,” New York, McGraw-Hill Book Co., 1951. (10) Varteressian, K. A., and Fenske, M. R., IND. ENU.CHEM.,29, 270 (1937). (11) Wohl, K., Trans. Am. Inst. Chem. Engrs., 42,215 (1946). RECEIVED for review December 12, 1952. ACCEPTEDFebruary 26, 1953. Presented st the Eighth Southwest Regional Meeting of the AMERICAN CHEMICAL SOCIETY, Little Rock, Ark., 1952.
Mass Transfer between Solid Wall and
Dextran-Correction In the Staff-Industry Collaborative Report, Dextran, by Gordon H. Bixler, G. E. Hines, R. M. McGhee, and R. A. Shurter [IND.ENG.CHEM.,45,692 (1953)J, the following sentence should be added on page 694, column 1, line 8: Dextran and gelatin are the only expanders accepted by the Council on Pharmacy and Chemistry of the American Medical Association. The caption for the photograph on page 701 should read: (Left) Vapor Compression Still Supplies 400 Gallons of PyrogenFree Water Each Hour. On page 705, in reference (la),the year should be 1915 instead of 1951.
Ion Exchange-Correction In the Unit Operations Review article on “Ion Exchange’’ [IND.ENG.CHEM.,45, 83 (1953)] the following changes should be made in the Literature Cited. (4) (25) (58) (99) (189) (398)
1377
Fluid Streams-Correction I n the article on “Mass Transfer between Solid Wall and Fluid Streams” [IND. ENG.CHEM., 45, 636 (1953)] the following changes should be made: Page 638, Equation 17 Page 638, Equation 18 Page 638, second column paragraph 3, line 3 Page 644, Figure 7
Change u t6 U Change CT to C? Change 5 t ~ < y +
< 33 to 5
