VAPOR-LIQUID-EQUILIBRIA IN TERNARY MIXTURES OF WATER ALCOHOL NONPOLARGASES

The feasibility of alcohol dehydration by the use of light hydrocarbon solvents has been recently confirmed by pilot plant and bench scale e xperiments. In this regard the study of vapor liquid equilibria (VLE) for alcohol - water - non polar gas mixtures is of interest for the de hydration of alcohols by high pressure entrainers. The potential for w ater entrainment of a given gas can be obtained from binary informatio n alone; however, ternary data are required in order to know to wich e xtent the entrainment effect is affected by the presence of the alcoho l. Experimental studies carried out with propane, propylene and carbon dioxide, indicate that the water-gas relative volatility in mixtures with alcohol is poorly predicted by the group contribution equation of state (GC-EOS). In the present work new experimental data are present ed for the binary isopropanol-isobutane, and for the ternary isopropan ol-isobutane-water. An extension of the GC-EOS model is proposed for d ealing with the problem of associating mixtures.