Learning Forum

[jonnathan.aguilar]

Hello, I am trying to simulate the adsorption process on a laboratory scale, for this the experiments were done in a flask in which the mixture and the adsorbate were added and the movement was generated with an orbital shaker.

So far I have proposed:
1) the motion of the orbital through the components of the gravitational force
2) VOF model for the mixture-air interface.
3) transport of species for adsorption

The third step is where I don't know how to simulate adsorption.

Below I leave an image of the flask and the fluid multiphase domain

[Prashanth]

Hello: can you add more background to what process you are looking to simulate?

[jonnathan.aguilar]

Hello, in itself is an adsorption process that is performed at laboratory scale, in which the solution with the adsorbate is added to a flask, in this case it is a drug and a certain amount of adsorbent is added, the stirrer (150 RPM) keeps the solid in suspension and mass transfer occurs. From the experiment an adsorption isotherm and adsorption kinetics are obtained.

I have added the motion of the orbital shaker as is in the following link: /forum/forums/topic/simulating-an-orbital-shaker/

The fluid domain occupies the entire interior of the flask, since it is multiphase, it is composed of the mixture and the air for which the VOF model was used. Then a new region is created that corresponds to the mixture and through path the corresponding volume fraction =1 is added. Up to that point the simulation takes a long time, 1% took me around 12h, I tried to do it in axisymmetric 2d, but this time was reduced to 8h for the same 1%. 

I reviewed the information on adsorption but all cases are carried out on a wall, in this case it would be in the entire volume of the mixture since it is assumed that the solid is uniformly distributed.

[Prashanth]

Adsorption is a surface phenomena. If you need to model adsoption on the unifromly distributed solids surface, you can use Eulerian multiphase model with heterogeneous reaction setup in the phase interaction panel.