Carbonic anhydrase textile structured packing for efficient CO₂ absorption in methyldiethanolamine solvent

Carbonic anhydrase (CA) is an attractive biodegradable catalyst for CO₂ absorption in solvent-based CO₂ capture. However, maintaining the stability of CA as a homogeneous component of the solvents is a challenge. Solvent regeneration temperature typically exceeds the enzyme thermal tolerance, which leads to CA deactivation. To reduce the need for frequent CA replenishment and to avoid inactive CA accumulation in the solvent, this work shows the benefits of an immobilization strategy where CA is fixed in a second-generation design of textile structured packing (CATSP-2) modules. The enzyme-immobilized packing showed 1.5 times better performance in CO₂ separation compared with traditional structured packing with a corresponding increased CO₂ loading in the rich solvent. The modules exhibited good CA activity retention of ~80% during the tests without any CA replenishment. Applying CATSP-2 could potentially decrease the packing height and absorber column size for a lower cost per amount of CO₂ captured.