Steady-State condition for CADET Process

Chromatography Modeling
1

Hi,

I would like to know if we can use the CADET Process in a steady-state condition, meaning without the effect of time, or in other words, at infinite time when the simulated moving bed reaches steady-state.

Thank you,
Fazlollah

2

Hi Fazlollah,

welcome to the forum!

You can use CADET-Process for that. Here’s the documentation for cyclic stationarity and steady state recycling. If you have further questions feel free to let me know.

Best wishes,
Ron

3

Thank you for your reply. I understand that we can specify the cycle numbers or different criteria to reach/define a steady-state condition. However, all the equations are still solved in a time-dependent manner. Is there a mode in CADET Process where we can remove the time dependency from the mass balance equations (i.e., assume dc/dt = 0) to reduce simulation times? This would be extremely helpful for complex SMB systems with multiple columns.

4

Hi Fazlollah,

no, we currently do not provide such solutions and I’m not even sure how this would work for some very limited cases with strong assumptions (e.g. linear isotherms, rapid equilibrium, no dispersion etc). Otherwise, \frac{\partial c}{\partial t} is a function of time and space and is not equal to 0.

But maybe we’re missing something, so if you have additional information, we could have a look.

Best

Johannes

5

There are several ways to directly calculate the cyclic steady state without following the exact trajectory over time, e.g. as described by He at al. (2018). However, these methods are not (yet) implemented in CADET-Process.