The interaction of Na2CO3 with CaO-based sorbents in CO2 capture processes at high temperature

Addressing greenhouse gas constraints and the reliance on fossil fuels, Carbon Dioxide Capture and Storage (CCS) technology plays a vital role. This study enhances cyclic CO2 absorption using CaO-based sorbents with Na2CO3 doping under harsh conditions. Limited studies have explored alkali metal doping in CaO sorbents, often under mild conditions not practical for real-world application. Synthesized via sol-gel method, sorbents were characterized using XRD and TGA, confirming Na-Ca double carbonate formation in CO2 presence. Low Na2CO3 concentrations (<1 wt%) improved cyclic performance, while higher levels reduced efficacy. Na-Ca double carbonates exhibited stability in CO2-rich environments, melting above 800°C and partially decomposing into Na2CO3-CaCO3. Reference material Na2Ca(CO3)2 had lower melting points, exacerbating sorbent sintering. This study highlights Na's role in stabilizing sorbent structure, boosting CO2 absorption. Future research may explore double carbonate influence on sorbent properties, advancing CCS technology. Collaboration with ETH Zurich will continue to advance this field.