Electropolymerized carbonic anhydrase immobilization for carbon dioxide capture

Area of Science:

• Biotechnology
• Chemical Engineering
• Environmental Science

Background:

• Biomimetic carbonation using carbonic anhydrase (CA) accelerates CO2 capture in amine solutions like methyldiethanolamine (MDEA).
• Practical challenges include high costs and limited enzyme stability, hindering industrial application.
• Enzyme immobilization on solid supports is a key strategy to address these limitations.

Purpose of the Study:

• To investigate the efficacy of immobilizing carbonic anhydrase (CA) on a porous carbon foam support.
• To enhance the stability and reusability of CA in tertiary amine solvents for CO2 capture.
• To overcome the technical barriers of biocatalyst recovery and thermal instability.

Main Methods:

• Carbonic anhydrase (CA) was immobilized on a macroporous carbon foam support with 63% porosity.
• The performance and stability of the immobilized enzyme were evaluated in methyldiethanolamine (MDEA) solvent at 70 °C.
• Electropolymerization was used to create the enzymatic supports.

Main Results:

• The macroporous carbon foam support facilitated efficient CO2 supply and enzyme accessibility.
• Immobilized CA retained 40% of its initial activity after 42 days at 70 °C in the amine solvent.
• Free CA lost all activity within 1 hour under the same conditions.
• The electropolymerized enzymatic supports demonstrated significantly improved thermal stability.

Conclusions:

• Immobilization of CA on porous carbon foam effectively enhances enzyme stability and reusability in amine-based CO2 sequestration solvents.
• This approach overcomes critical limitations of free enzyme use, paving the way for more robust and cost-effective carbon capture technologies.
• The developed enzymatic supports show promise for practical applications in industrial CO2 capture.