Pulsed and new-concept fluidized bed reactors: design, modeling and testing

Fluidized beds give high heat and mass transfer rates and handle solids in continuous operation. This is why they are used in catalytic cracking, polymerization, gasification, pyrolysis, and CO2 conversion. Their limits are also known: bubbles that let gas bypass the solids, segregation, attrition, and a scale-up that is still largely empirical. Pulsing the gas flow, vibrating the bed, or changing the distributor and internals modifies the bubble structure and the gas-solid contact, and opens operating windows that a conventional bed cannot reach. The MuRE group designs, builds, and models fluidized and spouted bed reactors at laboratory scale, from cold-flow units to reactive systems. The intern will work on one or more of three tracks, chosen according to background: - Design: reactor geometries, gas distributors and internals for pulsed, vibrated or structured fluidization, with drawings and operating windows. - Experiments: hydrodynamics in cold-flow units under steady and pulsed flow, using pressure fluctuation analysis, high-speed imaging, bed expansion and residence time measurements. - Modeling: CFD (two-fluid or CFD-DEM) and reduced-order models that link pulsation frequency and amplitude with bubble size, mixing, heat transfer and conversion, and scale-up rules based on dimensionless groups. The work feeds ongoing MuRE projects on the catalytic conversion of hydrocarbons, waste plastics and CO2, where the reactor sets the limit for scale-up. Mechanical engineering students are welcome.

- Design of a reactor geometry or internal configuration for pulsed or vibrated operation, with drawings and operating window. - Hydrodynamic data set (minimum fluidization, bed expansion, pressure fluctuation spectra, bubble statistics) under steady and pulsed flow. - CFD or reduced-order model validated with the data, with a parametric study of pulsation frequency and amplitude. - Scale-up criteria based on dimensionless groups. - Internship report and presentation; contribution to a peer-reviewed publication where results allow.