(585av) Designing Pellet Shapes for the Dynamic Catalytic Methantion in Fixed-Bed Reactors Using Particle-Resolved CFD Simulations
AIChE Annual Meeting
2017
2017 Annual Meeting
Liaison Functions
Poster Session: General Topics on Chemical Engineering II
Wednesday, November 1, 2017 - 3:15pm to 4:45pm
Typically, the exothermic methanation reaction (âH = â165.0 kJ/mol) is carried out in catalytic fixed-bed reactors characterized by a small tube-to-pellet-diameter ratio (N). This is due to a desired low pressure drop and likewise a good radial heat transfer to guarantee for a smooth temperature profile. These special arrangements of fixed beds are characterized by wall channeling and local interactions of transport phenomena and local kinetics. However, most of the available models in literature are based on plug flow and pseudo-homogeneous kinetics. Recently, we presented an approach which spatially resolves the pellets in the bed and calculates transport in the gas phase and pellet phase including detailed surface kinetics [2-4].
In this paper we investigate the methanation reaction under transient operation in catalytic low N fixed-bed reactors by using the particle-resolved CFD approach. Different pellet shapes are simulated and their effect on pressure drop, heat transfer characteristics, and reaction performance is quantified. Promising pellet shapes will be 3D printed and will be tested in the lab to validate the findings of the virtual design approach. This procedure has the potential to speed up catalytic pellet shape development and strengthen the understanding of dynamic operations of fixed-bed reactors.
References
[1] Delucchi & Jacobson (2011) Energy Policy, 39, 1170-1190
[2] Wehinger et al. (2015) Chemical Engineering Science, 122, 197-209
[3] Wehinger et al. (2015) Chemie Ingenieur Technik, 87(6), 734-745
[4] Wehinger et al. (2016) AIChE Journal, 62(12), 4436-4452