Thermodynamics of phase equilibria in aqueous-organic systems with salt

Journal Article · Fri Apr 01 04:00:00 EST 1994 · AIChE Journal (American Institute of Chemical Engineers); (United States)

DOI:https://doi.org/10.1002/aic.690400411· OSTI ID:7255850

Zerres, H; Prausnitz, J M ^[1]

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1. Univ. of California, Berkeley, CA (United States). Chemical Engineering Dept. Lawrence Berkeley Lab., CA (United States). Chemical Sciences Div.

A semiempirical thermodynamic method is developed to establish a framework for calculating vapor-liquid and liquid-liquid equilibria in ternary systems containing water, an organic solvent, and a salt. Careful attention is given to precise definition of standard states. Short-range ion-solvent forces are taken into account primarily by a chemical-equilibrium method based on stepwise ion solvation; however, physical contributions also contribute. Water-cosolvent nonideality is described by an extended equation of the van Laar form. Long-range electrostatic forces between ions are taken into account by an extended Debye-Hueckel equation with corrections for transferring from a McMillan-Mayer to a Lewis-Randall framework. The new method is illustrated with results for several systems including saturated aqueous mixtures of LiBr or LiCl with methanol where the salt concentration exceeds 20 molal. The method developed here is of particular interest for process calculations in extractive crystallization, a low-energy operation for producing salt from aqueous solution.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 7255850
• Journal Information: AIChE Journal (American Institute of Chemical Engineers); (United States), Journal Name: AIChE Journal (American Institute of Chemical Engineers); (United States) Vol. 40:4; ISSN 0001-1541; ISSN AICEAC
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALCOHOLS
ALKALI METAL COMPOUNDS
BROMIDES
BROMINE COMPOUNDS
CHLORIDES
CHLORINE COMPOUNDS
CRYSTALLIZATION
EQUATIONS
EQUILIBRIUM
HALIDES
HALOGEN COMPOUNDS
HYDROXY COMPOUNDS
LITHIUM BROMIDES
LITHIUM CHLORIDES
LITHIUM COMPOUNDS
LITHIUM HALIDES
METHANOL
ORGANIC COMPOUNDS
PHASE STUDIES
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
SALTS
THERMODYNAMIC PROPERTIES