Improvement CO2 absorption of calcium-based by zirconia/alumina

In the field of solid absorbents for CO₂, the use of calcium-based waste for CO₂ capture not only enables the resourceful use of waste but also reduces the cost of carbon dioxide capture. In this study, CaO was utilized as the calcium-based absorbent, while ZrO₂ and Al₂O₃ were employed as modifiers. The properties of ZrO₂/Al₂O₃/CaO composite absorber for cyclic CO₂ absorption was investigated. The findings indicated that the concurrent addition of ZrO₂ and Al₂O₃ could enhance the cyclic absorption stability and carbonation efficiency of CaO. The carbonation uptake efficiency of the absorber was enhanced by about 6% after the fifth absorption cycle compared with that without the addition of ZrO₂ and Al₂O₃. The incorporation of ZrO₂ and Al₂O₃ induced structural modifications in the calcium-based absorbent, providing support and separation between the CaO particles, thereby preventing void fusion. This enables the absorbent to maintain high activity and stability, while also delaying the sintering process of CaO.