CO2 capture performance of HKUST-1 in a sound assisted fluidized bed

Abstract

Among the CCS technologies, adsorption processes are attractive due to their low energy requirements, stimulating recent research to find suitable and highly specific adsorbents for removing CO2 from flue gas. Much attention has been focused on metal–organic frameworks (MOF), a new class of microporous materials that have potential applications in separation processes. As regards the handling of such fine materials, sound-assisted fluidization has been indicated as one of the best technological option to improve the gas–solid contact by promoting a smooth fluidization regime. The present work is focused on the CO2 capture by sound assisted fluidized bed of a specific MOF, HKUST-1. Tests have been performed in a laboratory scale experimental set-up at ambient temperature and pressure, pointing out the effect of sound parameters (intensity and frequency) and CO2 partial pressure. Effectiveness of CO2 adsorption has been assessed in terms of the moles of CO2 adsorbed per unit mass of adsorbent, the breakthrough time, the adsorption rate and the fraction of bed utilized at breakpoint. The results show the capability of the sound in promoting a more efficient adsorption process. Finally experimental tests have been carried out to find a possible regeneration strategy of the sorbent. The stability of the material has been assessed performing different chemico-physical characterizations (BET, XRD, TG, FT-IR and granulometric distribution) on a sample of HKUST-1 subjected to 10 CO2 adsorption/desorption cycles.