Fluid-dynamic study on a multistage fluidized bed column for continuous CO2 capture via temperature swing adsorption

• Published in: Powder technology Vol. 316; pp. 528 - 534
• Main Authors: Zehetner, E., Schöny, G., Fuchs, J., Pröll, T., Hofbauer, H.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.07.2017; Elsevier BV
• Subjects: Adsorption; Bubbling bed; Cold flow; Cold flow model; Columns (process); Downcomer design; Fluid dynamics; Fluidized bed reactors; Fluidized beds; Gas flow; Multistage; Multistage fluidized bed; Recirculating systems; Solids; Studies; Temperature swing adsorption; Temperature swing adsorption; Cold flow model; Downcomer design; Bubbling bed; Multistage fluidized bed
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2016.11.065

The fluid dynamic operating behaviour of a multistage fluidized bed column was experimentally studied with the aid of a cold flow model. The model consists of a modular column that comprises four consecutive stationary fluidized bed stages with exchangeable gas distributor plates and weir plates for the internal downcomers. A solids recirculation system has been used to extract bed material from the bottom stage at a controlled rate and to redirect the material to the top stage. The focus of this work was to study the operation boundaries for different downcomer geometries with the aim to maximise the achievable solids flux through the downcomers. The maximum solids circulation rates were measured for several superficial gas velocities and the operating regimes resulting within the downcomers were monitored. Different mechanisms were identified to limit the stable operating range of the studied downcomer configurations that will be presented and discussed in this work. Finally, conclusions on the operability of the different downcomer configurations will be drawn and suggestions will be made for the design of internal downcomers of multi-stage fluidized bed columns. [Display omitted] •Experimental campaign with a multistage fluidized bed cold flow model•Investigation of different downcomer designs•Measurement of maximum solid circulation rates and solid fluxes•Identification of flow regimes and transport limitation mechanisms for downcomers