https://doi.org/10.1016/j.ccst.2021.100011
“The spent K2CO3/Al2O3 adsorbent could be partially regenerated at 180°C and a temperature higher than 250-300°C was required for its complete regeneration due to the formed KAl(CO3)2(OH)2 byproduct (Zhao et al., 2012c; Zhao et al., 2012d). Sengupta et al. reported that CO2 removal of K2CO3/Al2O3 increased from 71.8% to 81.3% as the regeneration temperature increased from 130°C to 200°C (Sengupta et al., 2018). Jaiboon et al. concluded that a regeneration temperature of 350°C was preferable for the stable sorption-regeneration operation of K2CO3/Al2O3 in a bubbling fluidized-bed reactor (Jaiboon et al., 2015). To alleviate the adverse effect of the byproduct on cyclic stability of K2CO3/Al2O3, suggestions had been made to select α-Al2O3 as an alternative support or to stabilize the γ-Al2O3 support by thermal treatment and alkali treatment with hydroxide, and these would allow the regeneration of the spent adsorbent below 200°C (Lee, S.C. et al., 2013; Sengupta et al., 2014b). A higher heating rate for regeneration had benefited potassium-based adsorbents shortened cycle period while their regeneration conversions had not been significantly affected (Zhao et al., 2012c).”