Department of Chemical and Biochemical Engineering

Electrolyte Solution Thermodynamics

PhD level course on Electrolyte Solution Thermodynamics and Separation Processes

This course is being offered as DTU course 28928 with lectures being given in the beginning of July and solutions to assignments submitted by the end of July.
The course can also be followed as a correspondence course for graduate students from other universities. You can sign up as a guest PhD student at DTU and get the 7.5 ECTS points transferred to your university. The students receive lectures and homework assignments by e-mail and submit their homework by email. 
A pre-requisite for the course is a basic understanding of and interest in Physical Chemistry/Applied Thermodynamics.
The aim of the course is to give an introduction to concepts important for understanding and working with electrolyte solution thermodynamics.
The course consists of a little over 100 pages of course material and exercises written by Kaj Thomsen. Solving the exercises is designed to be part of the learning process. The workload of the course corresponds to 7.5 ECTS credit points or approximately 180 work hours. The students receive grades based on their homework. 

The course material can be downloaded here: Electrolyte Solutions: Thermodynamics, Crystallization,Separation Methods 

Topics being discussed in the course include:

  • Concentration units and definitions of ideal solutions.
  • Freezing point depression and boiling point elevation of electrolyte solutions compared to those of ideal solutions.
  • Chemical potential and excess properties.
  • Symmetrical and unsymmetrical activity coefficients.
  • Molal, molar and mole fraction activity coefficients.
  • The measurement of Chemical Potentials in salt solutions.
  • Measurement of ionic activity coefficients.
  • The Nernst equation.
  • Measurement of solvent chemical potential: Freezing point depression, Boiling point elevation measurement, Vapor pressure methods, Isopiestic measurements, Osmotic coefficients.
  • Osmotic pressure.
  • The use of the Gibbs-Duhem equation for calculating mean activity coefficients from osmotic coefficients.
  • Short range and long range interactions between ions and molecules
  • Debye-Hückel theory - limiting and extended law.
  • Hückel equation.
  • Born equation.
  • Gibbs energy of transfer
  • Dielectric medium - relative permittivity
  • Mean spherical approximation (MSA).
  • Meisner model, Bromley model, Pitzer model, Extended UNIQUAC model, Electrolyte NRTL model.
  • Derivation of activity coefficients from fugacity coefficients.
  • Equations of state for electrolytes.
  • Speciation, solid-liquid, vapor-liquid, and liquid-liquid equilibrium calculations.
  • Mixed solvent approach versus novel approach for dealing with solutions containing non-electrolytes
  • Composition, temperature and pressure dependency of equilibrium.
  • Apparent molar properties.
  • Thermal properties: excess enthalpy and excess heat capacity. Heat of solution heat of dilution
  • Volumetric properties.
  • Phase diagrams
  • Phase rule and invariant points
  • Crystallization
  • Super saturation
  • The Kelvin equation for forming a crystal nucleus in a supersaturated solution
  • Fractional crystallization

You can follow this course by e-mail correspondence. Please contact

Last updated 11.08.2014