| abstract |
A reaction-based process has been developed for the selective removal of carbon dioxide (CO 2 ) from a multicomponent gas mixture to provide a gaseous stream depleted in CO 2 compared to the inlet CO 2 concentration in the stream. The proposed process effects the separation of CO 2 from a mixture of gases (such as flue gas/fuel gas) by its reaction with metal oxides (such as calcium oxide). The Calcium based Reaction Separation for CO 2 (CaRS-CO 2 ) process consists of contacting a CO 2 laden gas with calcium oxide (CaO) in a reactor such that CaO captures the CO 2 by the formation of calcium carbonate (CaCO 3 ). Once “spent”, CaCO 3 is regenerated by its calcination leading to the formation of fresh CaO sorbent and the evolution of a concentrated stream of CO 2 . The “regenerated” CaO is then recycled for the further capture of more CO 2 . This carbonation-calcination cycle forms the basis of the CaRS-CO 2 process. This process also identifies the application of a mesoporous CaCO 3 structure, developed by a process detailed elsewhere, that attains >90% conversion over multiple carbonation and calcination cycles. Lastly, thermal regeneration (calcination) under vacuum provided a better sorbent structure that maintained reproducible reactivity levels over multiple cycles. |