Axial Dispersion in Fixed-Bed Reactors from Numerical Analysis

Transport processes in packed reactors have transient behavior (e.g., adsorption, desorption, or Chemical-Looping) [1]. For reactors with a low tube-to-particle diameter ratio, particle resolved CFD simulations have been used extensively in the last years to accurately predict the steady-state conditions (see [2], [3] and [4]).

Simplified models rely on effective parameters like the effective thermal conductivity, the heat transfer coefficient, and the dispersion coefficient. A work flow based on particle resolved CFD and particle tracking is proposed to determine axial dispersion coefficients in fixed-bed reactors that can later be used in simplified models.

The effect of the bed morphology, Reynolds number, axial position, and tube-to-particle diameter ratio is thoroughly investigated.

References

[1] Adams et al. (2009) Int. J. Hydrogen Energy, 34, 8877-8891
[2] Wehinger et al. (2015) Chem. Eng. Sci., 122, 197-209
[3] Wehinger et al. (2016) AIChE J., 62(12), 4436-4452
[4] Wehinger et al. (2017) Ind. Eng. Chem. Res., 56(1), 87-99