2025 AIChE Annual Meeting

(291b) Magnetic Stabilization of Fluidized Beds for Enhanced Gas-Solid Contact

Authors

Ashin Sunny - Presenter, The Ohio State University
Danwyn Aranha, The Ohio State University
Rushikesh Narwade, The Ohio State University
Seth Apau, The Ohio State University
Krutarth Pandit, The Ohio State University
Pinak Mohapatra, The Ohio State University
Dawei Wang, The Ohio State University
Liang-Shih Fan, The Ohio State University
Conventional fluidized beds often suffer from bubble formation, which reduces gas-solid contact and limits mass transfer. Applying an external magnetic field to magnetically susceptible particles offers a promising approach to stabilizing fluidization by suppressing bubble formation. This approach also reduces pressure drop across the bed, prevents sorbent carry-over at high flow rates, and minimizes sorbent attrition. This study investigates the effect of an externally applied magnetic field on fluidized bed hydrodynamics to enhance stability, suppress bubbles, and improve gas-solid contact.

A current-carrying 8-coil cage was designed in COMSOL to generate a uniform magnetic field within the bed. The fabricated cage was installed around the fluidized bed setup, and hydrodynamic testing was conducted with Fe, Fe₃O₄, and Fe₂O₃ particles. The parametric study examined the effects of magnetic field strength, particle magnetic susceptibility, particle size, and gas velocity on key hydrodynamic properties, including bed pressure profiles and bed height. Regime maps of superficial gas velocity versus applied magnetic field strength were developed for different particles, with regime transitions identified through pressure fluctuation analysis and bed height measurements. Results showed a reduction in pressure fluctuations upon entering the stabilized regime compared to a conventional fluidized bed, confirming bubble suppression and improved gas-solid contact. Additionally, bed height steadily increased with gas velocity in the stabilized regime. A correlation was developed to predict the transition velocity from the stabilized to the bubbling regime.

The findings of this study demonstrate the potential of magnetic stabilization to enhance fluidized bed performance by suppressing bubble formation and improving gas-solid contact. The observed reduction in pressure fluctuations and fluidization regime maps under magnetic fields provide valuable insights for optimizing reactor design in industries such as carbon capture and chemical processing. The results pave the way for further advancements in magnetically assisted fluidized beds, offering a promising strategy for enhancing process efficiency in industrial applications.