Effect of fluidization on adsorption of volatile organic compounds on beaded activated carbon.

摘要

Adsorption on activated carbon is a widely used technique for controlling emissions of volatile organic compounds (VOCs) from automotive painting booths; however, irreversible adsorption is a common challenge in this process. This research investigates the effect of adsorbent bed configuration on adsorption of VOCs on beaded activated carbon (BAC). Fixed and fluidized bed adsorption of a single compound (1, 2, 4 -- trimethylbenzene) and a mixture of nine organic compounds representing different organic groups were accomplished in five consecutive cycles. Adsorption tests were completed either in partial or full loading of the adsorbent. All regeneration cycles were completed in fixed bed arrangement. The results demonstrated similar adsorption capacities obtained in both configurations. However, 30 -- 42% lower heel formation was found using fluidized bed than in fixed bed in case of the VOCs mixture. Thermo -- gravimetric analysis confirmed less organic accumulation on BAC after regeneration for the bed loaded with the VOCs mixture in fluidized bed configuration. The lower irreversible adsorption obtained using fluidized bed adsorption could be due to improved mass transfer and more complete utilization of BAC's available pore volume in the fluidized bed, and non -- uniform adsorbate distribution on the BAC, and displacement of lighter compounds with heavier ones in the fixed bed.