Investigating the application of enzyme carbonic anhydrase for CO2 sequestration purposes

Biological sequestration of carbon dioxide (CO(2)) in geological formations is one of the proposed methods to reduce the carbon dioxide released into the atmosphere. In this method, an enzyme is used to enhance the hydration and subsequent precipitation of CO(2). In the present work, the effect of bovine carbonic anhydrase on the hydration of CO(2), and its precipitation in the form of calcium carbonate, was studied. The enzyme enhanced the hydration reaction. The rate of hydration reaction increased with both the enzyme concentration and temperature. The precipitation of calcium carbonate was promoted in the presence of the enzyme. The concentration of the enzyme did not affect the precipitation; however, temperature impacted the precipitation of calcium carbonate. At higher temperatures, less calcium carbonate was formed. Also, in the presence of the enzyme, calcium carbonate settled more quickly. The enzyme activity was not influenced by the pH of the reaction mixture. In contrast, the formation of calcium carbonate was affected by the pH of the solution. A kinetic analysis was performed for the bovine carbonic anhydrase. Based on the experimental results, the activation energy and catalytic rate constant are estimated as 700.91 cal/mol and 0.65 s(-1), respectively.