Augmented back equation of state for polar fluids

✍ Scribed by M. J. Lee; K. C. Chao

• Publisher: American Institute of Chemical Engineers
• Year: 1988
• Tongue: English
• Weight: 756 KB
• Volume: 34
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.690340512

✦ Synopsis

Augmented BACK Equation of State for Polar Fluids

The pressure of water is decoupled into a polar pressure and a nonpolar pressure, the latter being obtained from the BACK equation based on the size and nonpolar energy of the water molecule determined by Jorgensen and coworkers. The polar pressure is obtained upon subtracting the nonpolar pressure from the total pressure given by the steam table equation of Keenan et al. The polar pressure function thus obtained for water is generalized to augment the BACK equation for the general description of polar fluids.

Equation constants are reported for 26 substances. Calculated vapor pressure, liquid molal volume, and pressure-volume-temperature (PVT) behavior are compared with data. Mixing rules are introduced to express poles interacting with poles and dispersion modes interacting with dispersion modes, but not poles interacting with dispersion modes. PVT relationship, vapor-liquid equilibrium, and liquid-liquid equilibrium in mixtures of water and nonpolar substances are calculated.