Effect of Operational Parameters on the Performance of a Multistage Fluidized Bed Adsorber

Fluidized bed adsorbers are particularly suited for treating large flow rates of dilute air streams such as VOC-laden air from automotive painting operations. This research investigates the effect of different operational parameters on the performance of a multistage fluidized bed adsorber for adsorption of a VOC (1,2,4-trimethylbenzene) on beaded activated carbon (BAC). A pilot-scale six-stage fluidized bed adsorber was tested to assess the effect of inlet VOC concentration, inlet gas flow rate, temperature, relative humidity, and adsorbent feed rate on VOC removal efficiency. The results showed that an increase in BAC feed rate could be effective up to a level beyond which there was no change in the removal efficiency of the adsorber. Increasing VOC concentration (100 to 300 ppm_v) resulted in a significant decrease (51%) in removal efficiency of the adsorber. Additionally, increasing inlet air flow rate (200 to 350 SLPM) reduced the removal efficiency by 20%. Increasing inlet stream temperature (20°C to 50°C) resulted in a small (<10%) decrease in removal efficiency. On the other hand, increasing the inlet stream humidity had negligible effect on removal efficiency. The obtained results help determining optimal conditions for operating a fluidised bed adsorber.