While a satisfactory description of liquid-vapour equilibria in binary and multi-component systems had been developed by the end of the fifties, a similar situation has only been attained for liquid-liquid equilibria in the last ten years. There are several reasons for this, the most important of which is the necessity to employ more complex thermodynamic models for a quantitative description of liquid-liquid equilibria. These models require very sophisticated calculation techniques that cannot be carried out without the assistance of a computer. The authors have attempted to provide a theoretical description of liquid-liquid equilibria at a level permitting routine chemical engineering applications similar to those common for liquid-vapour equilibria. Consequently, a great deal of attention is paid to the calculation of parameters for heterogeneous and homogeneous binary systems, and to the qualitative evaluation of the suitability of the most frequently used thermodynamic models.

This booklet is designed to bridge the gap between handbooks and technical literature and aims at graduate students or experienced readers. Commercial flow sheeting simulation software is increasingly available and is used in the early steps of process design in industry. As to this, more sophisticated and precise models based on activities instead of concentrations should be used. After an introductory chapter there is in Chapter 2 an intensive discussion of reactive phase equilibria of ionic and non-ionic solutes based on chemical potentials. Chapter 3 introduces to multicomponent diffusion and mass transfer. However, the main focus is on the reactive mass transfer on rigid and mobile surfaces where the interfacial reaction, molecular diffusion and adsorption layers are decisive. The respective extraction of zinc with a cation exchanger and of acetic acid with an anion exchanger is discussed as case studies. Since adsorption layers and surfactants have a major impact on liquid-liquid extraction efficiency, the final chapter reviews several tech niques which make use of polymeric species in an extractive process. A short review is also given on extraction apparatus and the hydrodynamics (hydraulic design, droplet populance balances) of columns. Much of the booklet is based on the PhD works of C. Czapla (2000), G. Modes (2000), H. Klocker (1996), T. Kronberger (1995), M. Marters (2000), M. Roos (2000), M. Traving (2000) and B. Wachter (1996) who I wish to thank for their fruitful contributions.

Vapor-Liquid Equilibrium, Second Edition covers the theoretical principles and methods of calculation of equilibrium conditions from various experimental data and the elements of measuring technique, as well as the instruments for the direct determination of the equilibrium compositions of the liquid and vapor phases of the system. The book discusses the relations necessary for the thermodynamic treatment of the equilibrium between the liquid and vapor phase of a system; the concept of an ideal solution and auxiliary thermodynamic functions; and the activity and the activity coefficient. The text also describes vapor-liquid equilibrium in real systems (electrolytes and non-electrolytes) and in systems whose components (i.e. temperature, pressure, and composition of phases) mutually react according to several stoichiometric equations. The criteria of purity of substances and the methods of measuring temperature; low, medium, and high pressures; the pressures of the saturated vapors at given temperatures; and the boiling points at given pressures used in laboratory work in the field of vapor-liquid equilibrium are considered. The book also tackles the methods for the direct determination of equilibrium data (distillation, circulation, static, dew and bubble point, and flow methods). The text concludes with a review of the literature on the systems whose vapor-liquid equilibrium data had been measured and reported to the beginning of 1954. Workers in the chemical industry who deal with problems of distillation and rectification will find the book useful.

Vapor-Liquid Equilibria Using UNIFAC: A Group-Contribution Method focuses on the UNIFAC group-contribution method used in predicting quantitative information on the phase equilibria during separation by estimating activity coefficients. Drawing on tested vapor-liquid equilibrium data on which UNIFAC is based, it demonstrates through examples how the method may be used in practical engineering design calculations. Divided into nine chapters, this volume begins with a discussion of vapor and liquid phase nonidealities and how they are calculated in terms of fugacity and activity coefficients, respectively. It then introduces the reader to the UNIFAC method and how it works, the procedure used in establishing the parameters needed for the model, prediction of binary and multicomponent vapor-liquid equilibria for a large number of systems, the potential of UNIFAC for predicting liquid-liquid equilibria, and how UNIFAC can be used to solve practical distillation design problems. This book will benefit process design engineers who want to reliably predict phase equilibria for designing distillation columns and other separation processes.

This book provides a comprehensive overview of ionic liquid based separation techniques. The glimpse of thermodynamic predictive models along with global optimization techniques will help readers understand the separation techniques at molecular and macroscopic levels. Experimental and characterization techniques are coupled with model based predictions so as to provide multicomponent data for the scientific community. The models will focus more on the a-priori based predictions which gives higher emphasis on hydrogen-bonded systems. Particle Swarm Optimization (PSO) technique will also eventually help the readers to apply optimization technique to an extraction process. The overriding goal of this work is to provide pathways for leading engineers and researchers toward a clear understanding and firm grasp of the phase equilibria of Ionic Liquid systems.

Reviews the latest developments in a subject relevant to professionals involved in the simulation and design of chemical processes - includes disk of computer programs.

Working Guide to Vapor-Liquid Phase Equilibria Calculations offers a practical guide for calculations of vapor-phase equilibria. The book begins by introducing basic concepts such as vapor pressure, vapor pressure charts, equilibrium ratios, and flash calculations. It then presents methods for predicting the equilibrium ratios of hydrocarbon mixtures: Wilson's correlation, Standing's correlation, convergence pressure method, and Whitson and Torp correlation. The book describes techniques to determine equilibrium ratios of the plus fraction, including Campbell's method, Winn's method, and Katz's method. The remaining chapters cover the solution of phase equilibrium problems in reservoir and process engineering; developments in the field of empirical cubic equations of state (EOS) and their applications in petroleum engineering; and the splitting of the plus fraction for EOS calculations. - Includes explanations of formulas - Step by step calculations - Provides examples and solutions