Book contents
- Frontmatter
- Contents
- Preface
- 1 What is thermodynamics?
- 2 Defining our terms
- 3 The first law of thermodynamics
- 4 The second law of thermodynamics
- 5 Getting data
- 6 Some simple applications
- 7 Ideal solutions
- 8 Fugacity and activity
- 9 The equilibrium constant
- 10 Real solutions
- 11 The phase rule
- 12 Redox reactions
- 13 Equations of state
- 14 Solid solutions
- 15 Electrolyte solutions
- 16 Rock–water systems
- 17 Phase diagrams
- 18 Process modeling
- Appendices
- References
- Index
18 - Process modeling
- Frontmatter
- Contents
- Preface
- 1 What is thermodynamics?
- 2 Defining our terms
- 3 The first law of thermodynamics
- 4 The second law of thermodynamics
- 5 Getting data
- 6 Some simple applications
- 7 Ideal solutions
- 8 Fugacity and activity
- 9 The equilibrium constant
- 10 Real solutions
- 11 The phase rule
- 12 Redox reactions
- 13 Equations of state
- 14 Solid solutions
- 15 Electrolyte solutions
- 16 Rock–water systems
- 17 Phase diagrams
- 18 Process modeling
- Appendices
- References
- Index
Summary
Introduction
In this chapter we will have a brief look at how equilibrium thermodynamics is used in dealing with processes, that is, reacting systems, rather than just systems at equilibrium. Realistically, this should mean including the science of chemical kinetics with our thermodynamics, and we should also include other factors, such as fluid flow, temperature and pressure gradients, and surface reactions, to build increasingly realistic models of complex natural phenomena involving the movement and chemical reactions of fluids in soils and rocks in the Earth's crust.
That is all a bit too ambitious for this book. Computational models including all these subjects are at the forefront of research in several areas. What we will attempt in this chapter is first, to outline the rudiments of chemical kinetics, and then show how equilibrium thermodynamics simulates chemically reacting systems without using kinetics. The reason for discussing kinetics is that process modeling in thermodynamics has some points in common with kinetics, because both sciences consider the problem of chemical reactions proceeding from start to finish, and both use the progress variable. In simulating reactions in thermodynamics, however, we use the progress variable but not the real time variable, with which it is closely connected in kinetics. The use of a real time variable is what distinguishes kinetics from thermodynamics.
- Type
- Chapter
- Information
- Thermodynamics of Natural Systems , pp. 542 - 573Publisher: Cambridge University PressPrint publication year: 2005