Enzymatic properties of immobilized carbonic anhydrase and the biocatalyst for promoting CO2 capture in vertical reactor

Present investigation entails carbonic anhydrase (CA) immobilization and its influence on accelerating CO2 absorption in post-combustion CO2 capture. CA was immobilized in alginate polymers with the glutaraldehyde cross-linking method, subsequently maintained 56.3% of its original activity. The pH and thermal stabilities of the immobilized CA were significantly greater than their free counterparts. The immobilized CA also had improved resistance to chemical impurities typically found in flue gas scrubbing liquids. Batch-scale studies with immobilized CA revealed that the rate of CO2 absorption was promoted by the addition of immobilized CA. The gas flow was the main factor affecting CO2 absorption with low enzyme load, while the enzyme load became the main parameter with the increase of gas flow. The catalytic absorption of CO2 with immobilized CA was remarkable with the gas flow of 650 mL min−1 and enzyme load of 1 mg in vertical reactor. The immobilized enzymes showed better operational stability, and the surface of immobilized CA was characterized with porous structure through scanning electron microscope. It was concluded that immobilized CA in alginate polymers would have the potential for CO2 capture by biomimetic route.