Chemical Reaction Engineering Module Updates

For users of the Chemical Reaction Engineering Module, COMSOL Multiphysics® version 5.4 includes an updated interface for the Thermodynamics features, new functionality for reactions in chemical species transport, and automatic definition of equilibrium constants. Read more about these chemical reaction engineering features below.

Updated Thermodynamics Interface

Several updates to the Thermodynamics interface make it more user friendly, as shown in the following bullets and accompanying image.

  • You can now add customized species or edit database species
    • Thermodynamic systems can also contain any combination of user-defined and database species
  • Available phases are reflected in the name of the thermodynamic system
  • Mixture properties and equilibrium calculations are placed under a parent Mixture node
  • Phase-specific properties are placed under parent nodes for each phase
  • Species properties are placed in a parent node with the species name


Additional Thermodynamics User Interface Improvements

  • New user interface for controlling thermodynamic models and property models
    • Two settings, Liquid phase model and Gas phase model, are now used when the system includes two or more phases
    • All property models can be inspected and edited in a table
  • All binary interactions parameters currently in use can now be inspected and edited in a table
  • Extended integration with the Reaction Engineering interface
    • Equilibrium constants, for ideal or nonideal systems, can now be provided by the thermodynamic system

New Partition Condition Feature

The new Partition Condition feature can be used to prescribe the ratio between the concentration of a solute species in two adjacent phases. For example, you can use it to model conditions at the interface between two liquid phases, a gas-liquid interface, or the interface between a liquid phase and a porous medium. You can see this functionality demonstrated in the Separation Through Dialysis model.


Contaminant transport streamlines in a hollow fiber dialysis device. Partition conditions are used on both sides of the porous membrane in the middle. Contaminant transport streamlines in a hollow fiber dialysis device. Partition conditions are used on both sides of the porous membrane in the middle.

Fast Irreversible Surface Reaction

You can now model infinitely fast irreversible heterogeneous reactions. In this case, the reaction rate is limited by the species transport to the reacting surface. The new Fast Irreversible Surface Reaction feature prescribes the concentration of a rate-limiting species to zero, and balances the fluxes of all participating species according to the stoichiometry.

Equilibrium Reactions

A new feature for modeling equilibrium reactions in domains and on boundaries is now available for concentrated mixtures. The feature is called Equilibrium Reaction for domains and Surface Equilibrium Reaction for boundaries.

Automatic Definition of Equilibrium Constants

In reaction engineering, the equilibrium constant, which is used in an equilibrium reaction or a reversible reaction, can now be automatically defined in terms of the Gibbs free energy of the reaction. When coupled to a thermodynamic system, the equilibrium constant can automatically be defined using thermodynamics properties.

New Application