CO2 absorption and sequestration as various polymorphs of CaCO3 using sterically hindered amine

Area of Science:

• Environmental Chemistry
• Chemical Engineering
• Materials Science

Background:

• Global warming necessitates reducing atmospheric CO2 from fossil fuel power systems.
• Sterically hindered amines offer potential for CO2 absorption.
• Enzymatic catalysis can enhance CO2 capture rates.

Purpose of the Study:

• To develop a method for reducing CO2 emissions.
• To investigate CO2 absorption by 2-amino-2-methyl-1-propanol (AMP).
• To accelerate absorption using carbonic anhydrase (CA) and convert CO2 to stable carbonates.

Main Methods:

• Investigated CO2 absorption into aqueous AMP.
• Assessed the catalytic effect of CA on absorption rates.
• Analyzed CO2-bicarbonate conversion using NMR spectroscopy.
• Performed carbonation of absorbed CO2 with various Ca(2+) sources (CaCl2, calcium acetate, calcium propionate).

Main Results:

• AMP efficiently absorbs CO2, forming bicarbonate species.
• CA significantly increases the catalytic efficiency of AMP for CO2 absorption.
• CO2 absorption capacities and enthalpy changes were quantified.
• Different Ca(2+) sources yielded varying CaCO3 polymorphs (calcite, vaterite) with specific yields.

Conclusions:

• AMP combined with CA is effective for CO2 absorption and sequestration.
• Calcium acetate and calcium propionate facilitate the formation of vaterite CaCO3.
• The developed method offers a viable route for CO2 capture and conversion into stable carbonates.