(364e) Pilot-Scale Multistage Fluidized Bed Adsorber

Fluidized bed adsorbers offer several advantages when treating large gas flow rates, including low

pressure-drop and high mass and heat transfer. This research systematically investigates the effect of

design parameters on a multistage fluidized bed adsorber’s efficiency for capturing volatile organic

compounds (VOC). Specifically, the effects of number of stages, weir height, and solid/gas ratio on the

adsorber removal efficiency were investigated using 1,2,4-trimethylbenzene (TMB) as a test adsorbate

and beaded activated carbon (BAC) as adsorbent. The BAC and the TMB-laden air stream flowed

counter-currently. The results indicated a non-linear increase in overall TMB removal efficiency by

increasing the number of stages, which is due to using more adsorption capacity of the BAC through

the adsorber because of higher overall BAC retention time. However, this is effective only if the BAC

overall retention time does not exceed the BAC saturation time inside the adsorber. Additionally

increasing the weir height increased the removal efficiency of the adsorber due to increase in BAC

retention time on each stage. However, better performance was obtained when increasing the number

of stages and keeping the same overall retention time (i.e. increasing the number of stages while

decreasing the weir height). Finally, increasing the solid/gas ratio increased the adsorber removal

efficiency.