Carbonic Anhydrase Promotes the Absorption Rate of CO2 in Post-Combustion Processes

• Published in: The journal of physical chemistry. B 2013-05, Vol.117 (18), p.5683-5690
• Main Authors: Vinoba, Mari, Bhagiyalakshmi, Margandan, Grace, Andrews Nirmala, Kim, Dae Hoon, Yoon, Yeoil, Nam, Sung Chan, Baek, Il Hyun, Jeong, Soon Kwan
• Format: Article
• Language: English
• Subjects: Animals; Applied sciences; Biocatalysis; Carbon Dioxide - chemistry; Carbon Dioxide - metabolism; Carbonic Anhydrases - chemistry; Carbonic Anhydrases - metabolism; Cattle; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; General studies of phase transitions; Materials science; Materials synthesis; materials processing; Metals. Metallurgy; Order-disorder and statistical mechanics of model systems; Physics; Powder metallurgy. Composite materials; Production techniques; Technology; Thermal properties of condensed matter; Thermal properties of crystalline solids; Thermodynamic properties; Thermodynamics
• ISSN: 1520-6106; 1520-5207
• DOI: 10.1021/jp401622c

The rate of carbon dioxide (CO2) absorption by monoethanol amine (MEA), diethanol amine (DEA), N-methyl-2,2′-iminodiethanol (MDEA), and 2-amino-2-methyl 1-propanol (AMP) solutions was found to be enhanced by the addition of bovine carbonic anhydrase (CA), has been investigated using a vapor–liquid equilibrium (VLE) device. The enthalpy (−ΔH abs) of CO2 absorption and the absorption capacities of aqueous amines were measured in the presence and/or absence of CA enzyme via differential reaction calorimeter (DRC). The reaction temperature (ΔT) under adiabatic conditions was determined based on the DRC analysis. Bicarbonate and carbamate species formation mechanisms were elucidated by 1H and 13C NMR spectral analysis. The overall CO2 absorption rate (flux) and rate constant (k app) followed the order MEA > DEA > AMP > MDEA in the absence or presence of CA. Hydration of CO2 by MDEA in the presence of CA directly produced bicarbonate, whereas AMP produced unstable carbamate intermediate, then underwent hydrolytic reaction and converted to bicarbonate. The MDEA > AMP > DEA > MEA reverse ordering of the enhanced CO2 flux and k app in the presence of CA was due to bicarbonate formation by the tertiary and sterically hindered amines. Thus, CA increased the rate of CO2 absorption by MDEA by a factor of 3 relative to the rate of absorption by MDEA alone. The thermal effects suggested that CA yielded a higher activity at 40 °C.