Effect of interlayer anion on the CO2 capture capacity of hydrotalcite-based sorbents

A series of hydrotalcites (HTCs) samples with different compensating anions was prepared (several anions never used before). The physicochemical characterization of these materials was realized through several techniques (including XRD and SEM/EDS). The CO2 sorption capacities of the HTCs were assessed using a magnetic suspension balance (static tests) and CO2 breakthrough runs in a packed column (dynamic tests). The HTC-CO3 sample presents the highest CO2 sorption capacity (1.05 mmol.g(-1), @ p(CO2) = 1 bar and 300 degrees C) in comparison with the other materials. The sorption kinetics were analyzed from CO2 uptake measurements and two distinct contributions were observed. Besides, the effect of temperature on the CO2 sorption capacity was studied for HTC-CO3. The efficiency of the column (in the breakthrough tests) was higher for the HTC-CO3 formulation (20%).