SEPARATION OF CARBON DIOXIDE (CO2) FROM GAS MIXTURES BY CALCIUM BASED REACTION SEPARATION (CARS-CO2) PROCESS

摘要

Carbon dioxide is selectively removed from a gas mixture to provide a gaseousstream depleted in CO sub 2 compared to the inlet stream The CO sub 2 isseparated from a gas mixture (e g flue gas/fuel gas) by its reaction withmetal oxides (such as calcium oxide) Calcium-based reaction separation for COsub 2 (CaRS-CO sub 2) consists of contacting a CO sub 2 laden gas with calciumoxide (CaO) in a reactor such that CaO captures the CO sub 2 by the formationof calcium carbonate (CaCO sub 3) Once "spent", CaCO sub 3 is regenerated byits calcination leading to the formation of fresh CaO sorbent and theevolution of a concentrated stream of CO sub 2 The "regenerated" CaO is thenrecycled for the further capture of more CO sub 2 A mesoporous CaCO sub 3structure that attains 90% conversion over multiple carbonation andcalcination cycles is identified Thermal regeneration (calcination) undervacuum proves a sorbent structure that maintains reproducible reactivitylevels over multiple cycles