Removal and recovery of compressed CO₂ from flue gas by a novel thermal swing chemisorption process

A synopsis of the published literature on removal of CO₂ from a flue gas is given. A novel thermal swing chemisorption (TSC) process concept is proposed for removal and recovery of compressed CO₂ from a flue gas without precompression, predrying, or precooling. The process uses Na ₂O promoted alumina as a reversible CO₂ selective chemisorbent in conjunction with the principles of rapid thermal swing adsorption for direct production of compressed CO₂ from a flue gas. Several complementary process steps are used in the design to compress the product CO₂ and to achieve high CO₂ recovery and sorbent capacity utilization. Judicious steam purge steps are used for highly efficient sorbent regeneration and to minimize the steam requirement. The CO₂ chemisorption characteristics of the sorbent are reviewed and a model simulation of the TSC process performance is reported.