High-temperature CO2 capture cycles for CaO-based pellets with kaolin-based binders

Direct Gas–Solid Carbonation Kinetics of Steel Slag and the Contribution to In situ Sequestration of Flue Gas CO2 in Steel‐Making Plants

“…carbonation temperature for steel slag was 600 8C in this study, which was clearly higher than the optimal temperature for air pollution control system residues (400-500 8C) [27,30,31] but close to the optimal temperature for limestone or other CaO-based adsorbents (600-700 8C). [29,38,39] The influence of CO 2 concentration (Figure 3) and the presence of SO 2 ( Figure 4) on the carbonation conversion of steel slag was not as strong as that of temperature. As shown in Figure 3, all sequestration curves were similar over a reaction time of 1 h; the curve representing the carbonation between steel slag and 100 % CO 2 was slightly higher than the other three, and the uptake of CO 2 gradually increased as the CO 2 concentration increased in the simulated flue gases.…”

Enhanced CO2 capture by biomass-templated Ca(OH)2-based pellets

“…Maintaining a high make-up flow to replace the spent sorbents and elutriated materials has been found to negatively influence the economics of the process [12]. As a result, there have been extensive research efforts to improve the reactivity of the sorbent by chemical doping [10,[13][14][15], organic acid treatment [16][17][18][19], and hydration [20]. In some cases of doping CaO-based material with metals, doped sorbents exhibited low performance, even inferior to that of the undoped material, such as in the case of doping CaO with the alkali metal lithium [13].…”

“…However, these modification techniques risk being cost-ineffective due to the relatively high cost of chemicals and treatment procedures and require further development [22,23]. Pelletization still allows the possibility of sorbent doping but has also been proposed to improve the mechanical strength of the sorbent using different binders, such as bentonites [24], kaolin [25], alumina [25], and calcium aluminate cement [19,26].…”

Carbon dioxide removal using calcium aluminate carbonates on titanic oxide under warm-gas conditions

“…The sorbent stability can be significantly enhanced by incorporating suitable inert particles into CaO, yielding well-distributed oxides within the calcium oxides. Impregnating CaO with an inert particle helps to avoid the deterioration of the spent sorbent, for example, of CaO/ SiO 2 [10], Ca/Al-oxide [11], Zr/Ca complex [12], limestone/kaolin [13], CaO/aluminate cement [14], and extruded particles of Ca(OH) 2 /cement [15].…”