Abstract:

As a low-energy regeneration process,mineralization-desorption has become the focus of carbon dioxide capture and storage（CCS） technology.In order to study the whole process of mineralization-desorption of CO₂-rich absorbent and its regeneration,12 characteristic peaks of potassium glycine solution and its CO₂ saturated absorption solution were assigned by ATR-FTIR.Then the characteristic peaks of reactants and products were selected and used to monitor the CaO mineraliza-tion-desorption of CO₂ absorbed by potassium glycine solution and its regeneration.The experimental results showed that the contents of protonic ammonia（—NH₃⁺）,carbamate（N—COO^-） and bicarbonate（HCO₃^-） decreased with the increase of the pH of the solution in the mineralization-desorption process.The amino content（—NH₂） in the solution was continuously generated,indicating that the potassium glycine absorbent was regenerated.Although —NH₃⁺ can completely regenerate back to— NH₂,part of N—COO^- remains in the absorbent solution.Therefore,calcium oxide mineralization-desorption cannot completely regenerate the potassium glycine absorbent which had absorbed CO₂.The results are helpful to further understand the reaction mechanism and kinetics of the CO₂ absorbers that have been trapped in the mineralization-desorption process.

Key words: glycine, carbon dioxide capture, mineralization-desorption