This study investigates the influence of CO2 gas on the treatment of single acidic gases (HCl, SO2, and NO2) using Mg[sbnd]Al layered double hydroxide intercalated with CO32− (CO3·Mg-Al LDH) as the adsorbent. The gas-removal kinetics is analyzed, and the reaction mechanisms are discussed. The coexisting CO2 gas decreased the removal rate of all three acidic gases. This is likely due to the exchange reaction between intercalated CO32− and gas-phase CO2, which inhibits the exchange between intercalated CO32− and HCl, SO2, or NO2. The HCl removal by CO3·Mg-Al LDH follows pseudo first order kinetics, suggesting that the main removal mechanism is chemisorption (chemical reaction between CO3·Mg-Al LDH and HCl). Meanwhile, the removal of SO2 and NO2 by CO3·Mg-Al LDH also follows pseudo first order kinetics. However, the corresponding adsorption mechanisms are classified as physisorption onto the Mg[sbnd]Al LDH.
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