Experimental Study of the Salt Effect in Vapor/Liquid Equilibria Using Headspace Gas Chromatography

• Published in: Chemical engineering & technology Vol. 22; no. 9; pp. 761 - 765
• Main Authors: Banat, Fawzi A., Abu Al-Rub, Fahmi A., Simandl, Jana
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.09.1999; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Liquid-vapor equilibria; Phase equilibria; Water; Ternary system; Ethanol; Binary system; Experimental study; Calcium Chlorides; Primary alcohol; Gas chromatography; Salt effect; Liquid vapor equilibrium; Headspace; Salting out; Phase equilibrium; Ammonium Chlorides; Sodium Chlorides
• ISSN: 0930-7516; 1521-4125
• DOI: 10.1002/(SICI)1521-4125(199909)22:9<761::AID-CEAT761>3.0.CO;2-U

The salt effect on vapor/liquid equilibrium for an ethanol/water system was studied at 70 °C using the Headspace Gas Chromatography technique. The azeotropic point of the system was eliminated in the presence of the salts studied. All the salts investigated in this work exhibited a salting out effect which followed the order of NH4Cl > NaCl > CaCl2 and which increased with increasing salt concentration. Good agreement with Furter's equation was observed for the experimental data with unsaturated NaCl salt. The salt effect parameter, determined from Furter's equation, was found to be a function of the liquid concentration. Reported are results on the further investigation of the effect of adding inorganic salts on the separation of ethanol/water using the Headspace Gas Chromatography (HSGC) technique. The use of HSGC in studying VLE of binary mixtures is simple, accurate, fast, and time‐saving, since equilibrium and sample analysis are done in the same apparatus. Using NH4Cl, NaCl, and CaCl2, good agreement with Furter's equation was observed.