Vapour-liquid and liquid-liquid equilibria in the system methyl butenol-water

• Published in: Fluid phase equilibria 1992-07, Vol.74, p.253-270
• Main Authors: Raal, J.D., Brouckaert, C.J.
• Format: Article
• Language: English
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Liquid-vapor equilibria; Phase equilibria
• ISSN: 0378-3812; 1879-0224
• DOI: 10.1016/0378-3812(92)85066-H

Isobaric vapour liquid equilibrium data were measured for the system methyl butenol (MBE) - Water at pressures of 97,2 kPa and 30,0 kPa using a recirculating equilibrium still of unusual design adapted for systems of limited miscibility. For the water-rich region x 1 > 0,97, vapour composition measurement became problematical and the T-y curve was computed using an isobaric form of the coexistence equation. Liquid-liquid equilibrium data are presented for the temperature range 18°C to 84°C. Vapour pressure data for the MBE measured in the temperature range 16°C to 80°C compare well with existing data available only from 64°C to 106°C. The system behaviour is complex and there is evidence of a homogeneous as well as a heterogeneous azeotrope. The three parameter Margules and NRTL equations were found incapable of simultaneously representing VLE and LLE behaviour with a satisfactory degree of accuracy. Equation constants are reported which give a satisfactory representation of the MBE rich region up to the 2-liquid phase composition. This, together with graphicat LLE and activity coefficient data for the narrow water-rich region, provides an adequate representation of the entire system for separation process design.