Stabilized Performance of Al‐Decorated and Al/Mg Co‐Decorated Spray‐Dried CaO‐Based CO₂ Sorbents

Abstract

The sharp loss-in-capacity in CO 2 capture as a result of sintering is a major drawback for CaO-based sorbents used in the calcium looping process. The decoration of inert supports effectively stabilizes the cyclic CO 2 capture performance of CaO-based sorbents via sintering mitigation. A range of Al-decorated and Al/Mg co-decorated CaO-based sorbents were synthesized via an easily scaled-up spraydrying route. The decoration of Al-based and Al/Mg-based supports efficiently enhanced the cyclic CO 2 capture capability of CaO-based sorbents under severe testing conditions. The CO 2 capture capacity losses of Al-decorated and Al/Mg co-decorated CaO-based sorbents were alleviated, representing more stable CO 2 capture performance. The stabilized CO 2 capture performance is mainly attributed to the formation of Ca 12 Al 14 O 33 , MgAl 2 O 4 , and MgO that act as the skeleton structures to mitigate the sintering of CaCO 3 during carbonation/calcination cycles.

Review of Carbonate-Based Systems for Thermochemical Energy Storage for Concentrating Solar Power Applications: State-of-the-Art and Outlook

“…For instance, TiO 2 and Al 2 O 3 were simultaneously used by Peng et al 186 187 In this case, Y 2 O 3 was selected to induce an enhancement of the cyclic stability, whereas MgO was selected to improve the CO 2 uptake capacity (by means of an increased porous space for the carbonation reaction to take place). A spray drying approach was, similarly, proposed by Sun et al 188 to produce Al 2 O 3 /MgO-stabilized CaO-based sorbents, obtaining good results in terms of both enhanced multicyclic CO 2 sorption performances and CO 2 uptake (which was found to be larger than that typical of Al 2 O 3 -stabilized CaO-based sorbents).…”

Big Data Analysis and Technical Review of Regeneration for Carbon Capture Processes

“…This concept is carried out by dispersion of CaO on an inert matrix (Ca x Al y O x +1.5 y , MgAl 2 O 4 , MgO, CaTiO 3 , etc. ), which is similar to supported catalysts by depositing active components on a catalyst support. − Hu et al screened 12 inert supports for CaO by using the same wet-mixing method. Among them, Y-based and Al-based CaO showed the best CO 2 cyclic performance .…”

“…Results showed that the CaO/Ca 9 Al 6 O 18 sorbent capacity decreased from 0.275 g of CO 2 /g of sorbent at the first cycle to 0.197 g of CO 2 /g of sorbent at the 21st cycle. Despite decent performance in a lab-scale test, the water removing step in sol–gel methods is time-consuming and energy-intensive, which could be issues at large scale. , …”

Review on the Development of Sorbents for Calcium Looping

“…When the mass ratios of Y 2 O 3 and MgO were 20 wt %, respectively, the synthetic sorbent achieved notably high CaO conversion (over 90%) at harsh conditions (carbonation, 650 °C, 15 vol % CO 2 , and 15 min; calcination, 900 °C, N 2 , and 8 min) and was stabilized at a CO 2 uptake of 0.311 g CO 2 /g sorbent even after 122 cycles. Similarly, Sun et al synthesized a range of Al 2 O 3 -supported and Al 2 O 3 /MgO co-supported CaO-based sorbents, respectively, using an easily scalable spray drying approach . They also found that the addition of Al 2 O 3 or Al 2 O 3 /MgO both effectively enhanced the cyclic CO 2 capture performance of the CaO-based sorbents, while the cumulative CO 2 uptake of Al 2 O 3 /MgO co-supported CaO-based sorbents was generally higher than that of Al 2 O 3 -supported sorbents.…”