Calcium looping (CaL) process is recognized as one of the most promising CO₂ capture technologies. However, the CaO-based sorbents will encounter serious sintering and elutriation problem. In this work, Al-stabilized CaO-based sorbents were synthesized by the impregnated layer solution combustion, and cigarette butt was selected as the porous reactive skeleton. The Al-stabilized CaO-based sorbent containing 15 wt% of Al₂O₃ exhibits the highly stable CO₂ capture performance. The CO₂ capture capacity after 20 cycles is almost the same as its initial sorption capacity, ~0.354 g/g. It is mainly attributed to the synergistic effect of thermal pretreatment (cigarette butt-assisted combustion) and incorporation of Al-based stabilizer (i.e., Ca₁₂Al₁₄O₃₃) provide an effective inert framework for the synthetic sorbents, ensuring their highly stable capability for CO₂ sorption during cycles. Further, graphite-moulding is a facile and energy-saving approach to make Al-stabilized CaO-based sorbent powders into pellet to enhance its resistance to elutriation. The produced sorbent pellets (85 wt % CaO/15 wt % Al₂O₃) exhibit excellent long-term CO₂ capture capacity (~0.248 g/g after 49 cycles) and high compression strength of 18.47±3.47 MPa. Therefore, the combined method involved of impregnated layer solution combustion and graphite-moulding is promising to produce highly efficient CaO-based sorbent pellets used in CaL for CO₂ capture.
 

CO2 capture ;Calcium looping; Sol-gel combustion synthesis