Silicon assisted synthesis of high-purity Ca3Al2O6 carrier towards scale-up of Ca-based carbon dioxide capture materials

Aluminium-stabilized calcium-based materials are currently an excellent solution for capturing CO 2 directly from industrial flue gas . However, there is still no report on the technology of low-cost and large-scale assembly of Ca 3 Al 2 O 6 and CaO. In this study, we innovatively put forward a silicon-assisted strategy to facilely synthesize high-purity Ca 3 Al 2 O 6 and evaluate its cyclic performance for stabilizing uptake CO 2 after assembly. With regard to the Si/Al ratio of 0.2, Ca 3 Al 2 O 6 was prepared selectively among 850–900 °C, with only 5.2% CaO residually. The introduction of silicon inhibited the formation of Ca 5 Al 6 O 14 by-products and the mechanism of silicon at the calcium-aluminum interface was also explained by systematic characterization. The Ca 3 Al 2 O 6 modified sorbent with simple assembly showed extremely high cycle stability improvement compared with the pure precipitated calcium carbonate derived CaO. These works provide technical guidance for the industrial scale-up of the rational design of Al-stabilized calcium-based adsorption materials.