Fluidization behavior, fluid dynamics, and air pollutant abatement applications of gas–solid fluidized bed technology: A critical review

Owing to its excellent gas–solid contact efficiency, heat exchange rate, and mass transfer performance, gas–solid fluidized bed (GSFB) technology has attracted significant interest because it is adaptable for controlling diverse air pollutants. This review provides a comprehensive evaluation of GSFB systems, including bubbling, circulating, and dual-fluidized beds, for air pollutant abatement under different conditions. To address inherent hydrodynamic instabilities, diverse enhancement strategies, such as vortex flow, mechanical vibration, acoustic excitation, electromagnetic fields, and pulsed flow, are systematically evaluated regarding their impacts on fluidization behavior, hydrodynamics, and pollutant abatement efficiency. Particular emphasis is placed on pulsed fluidized beds for their ability to optimize bubble dynamics, particle mobility, and gas–solid interactions via both intermittent and repositioning pulse modes. Notably, the application of pulsed gas flow can reduce the minimum fluidization velocity by up to 66%, thereby significantly improving particle mobility and mitigating agglomeration without incurring additional pressure drop penalties. The effects of operational parameters, gas properties, and particle characteristics on bed behavior were analyzed, along with optimization strategies for fluidization regimes and reactor configurations. Recent advances in computational modeling and artificial intelligence (AI)-based control methods were reviewed for real-time adaptive optimization of GSFB reactors, with computational particle fluid dynamics emerging as a prominent tool for industrial-scale simulations. Future development should move beyond system-specific hydrodynamic improvements to address integrated multipollutant control, overcome high-frequency scale-up bottlenecks, and implement AI-driven intelligent control for dynamic, low-carbon operation in industrial environments.