Fixed bed reactors are typical equipment in process engineering, e.g. for converting substances on catalysts or as an adsorber, for example for drying air.
The simulation of fixed bed reactors requires the determination of the flow in porous media, the diffusion in the bulk, the chemical or physical reaction (e.g. conversion, adsorption/desorption) and the thermal conduction.
In the project example shown, our customer wanted to determine the effect of different mixing points relating to precisely specified output variables. Two reactants (A+B) are to be mixed, resulting in a product (C). For the customer it was important to take into account the results in order to be able to provide a cooling/heating jacket if necessary. One of the most important target values was the exact length of the reactor.
In our experience, COMSOL Multiphysics is the best program on the market for this type of problem. It does not just allow you to depict all physical basic equations, but you can add your own equations too.
So here we were able to implement Langmuir isotherms confirmed experimentally by the customer just as easily as empirical temperature-dependent reaction constants.
Our task was complete once our customer saw that their model worked and was calculating the cases they required. They (unfortunately) did not want to tell us what exactly they were intending to do with it…