Energy-efficient chemical regeneration of AMP using calcium hydroxide for operating carbon dioxide capture process

Abstract

To avoid the main disadvantage of the carbon dioxide (CO2) capture process, namely the large amount of energy consumed to regenerate the amine absorbent using current thermal methods, chemical regeneration has been introduced as a novel method to regenerate the amine. Chemical regeneration deploys a swing in the pH of the amine absorbent rather than the swing in temperature of typical thermal regeneration procedures, and hence reduces the regeneration energy. Here we tested calcium chloride (CaCl2) and calcium hydroxide (Ca(OH)2) as a calcium source for CO2 desorption and a pH swing agent for amine regeneration. After desorbing from the amine, CO2 in our procedures reacted with Ca2+ to form calcium carbonate (CaCO3). Forming precipitated CaCO3 is a permanent way to sequester CO2. Since carbonates have a low energy level compared to CO2, we expect the developed method to be an economical and energy-efficient process.