Development of a carbonate absorption-based process for post-combustion CO₂ capture: The role of biocatalyst to promote CO₂ absorption rate

An Integrated Vacuum Carbonate Absorption Process (IVCAP) for post-combustion carbon dioxide (CO₂) capture is described. IVCAP employs potassium carbonate (PC) as a solvent, uses waste or low quality steam from the power plant for CO₂ stripping, and employs a biocatalyst, carbonic anhydrase (CA) enzyme, for promoting the CO₂ absorption into PC solution. A series of experiments were performed to evaluate the activity of CA enzyme mixed in PC solutions in a stirred tank reactor system under various temperatures, CA dosages, CO₂ loadings, CO₂ partial pressures, and the presence of major flue gas contaminants. It was demonstrated that CA enzyme is an effective biocatalyst for CO₂ absorption under IVCAP conditions.