Effect of operating conditions on the CO2 recovery from a fine activated carbon by means of TSA in a fluidized bed assisted by acoustic fields

Abstract

CO2 temperature swing adsorption (TSA), consisting in adsorbing the CO2 and, then, inducing the sorbent regeneration and CO2 recovery by a temperature increase and gas purge, is a promising strategy for CO2 capture. With reference to the sorbent, commercially available adsorbent materials are generally available in the form of fine powders. A sound-assisted fluidized bed is capable of fully exploiting the potential and properties of fine sorbents, due to large gas–solid contact efficiency, high rate of mass/heat transfer and low pressure drops. This work is focused on the CO2 desorption process by TSA in a sound-assisted fluidized bed of fine activated carbon. The effect of desorption temperatures and N2 purge flow rate on the regeneration efficiency has been assessed in terms of CO2 recovery level and purity and desorption time. Both of them positively affect the desorption process in terms of enhanced desorption kinetics. Increasing temperatures also yield higher CO2 purities, whereas, no remarkable dilution effect has been observed when increasing the N2 flow rate. Finally, the activated carbon keeps its performances over 16 adsorption/desorption cycles, due to the stability of the regeneration process under sound-assisted fluidization conditions.