Vapor-Liquid Equilibria Using Unifac

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.

Prefaces

Table of Contents

Chapter 1 Introduction

1.1 The Phase Equilibrium Problem

1.2 Origin and Range of Applicability of the UNIFAC Method

1.3 Organization of the Book

Chapter 2 Vapor Phase Nonideality

2.1 Fugacity Coefficients from the Virial Equation

2.2 Second Virial Coefficients

2.3 Fugacity Coefficients from the Chemical Theory

2.4 Computer Program for Fugacity Coefficients

Chapter 3 Liquid Phase Nonideality

3.1 Calculation of Reference Fugacities

3.2 Activity Coefficients

Chapter 4 The UNIFAC Group-Contribution Method

4.1 The UNIFAC Model

4.2 Group Interaction Parameters

4.3 Sample Predictions

4.4 Temperature Dependence of the UNIFAC Parameters

4.5 Alternative UNIFAC Parameters for Alcohols

4.6 Additional UNIFAC Parameters

Chapter 5 Determination of UNIFAC Parameters

5.1 The Dortmund Data Bank

5.2 Thermodynamic Consistency

5.3 Calculation of Activity Coefficients from Mutual Solubility Data

5.4 Estimation of UNIFAC Parameters

Chapter 6 Prediction of Vapor-Liquid Equilibria in Binary Systems

6.1 Sample Results from the Data Correlation

6.2 Sample Predictions

6.3 Predictions for Systems Containing Ethanol

Chapter 7 Prediction of Vapor-Liquid Equilibria in Multicomponent Systems

Chapter 8 Prediction of Phase-Splitting and Excess Enthalpy

8.1 Phase-Splitting

8.2 Excess Enthalpy

Chapter 9 Application of UNIFAC to Distillation Column Design

9.1 Multicomponent Distillation Calculations by Linearization

9.2 The Column Calculation Procedure

9.3 Examples of Distillation Calculations (Simplified Version)

9.4 Examples of Distillation Calculations (Full Version)

Appendix 1 Calculation of Fugacity and Activity Coefficients. The Consistency Test

SVIR

PHIB

YENWO

GAUSL

MLMEN

BIJ

Thermodynamic Consistency Test

Appendix 2 UNIFAC Programs

UNIFA

SYSTM

GRES

GREF

GCOMB

HCON

Calculation of Activity Coefficients

Prediction of Liquid-Liquid Equilibrium

UNIQUAC Parameters from UNIFAC

Appendix 3 Parameter Estimation Program

Appendix 4 Distillation Programs

Full Version

Simplified Version

Appendix 5 List of Phase Equilibrium Data used in the Determination of UNIFAC Parameters

Nomenclature