Design of Enzyme Loaded W/O Emulsions by Direct Membrane Emulsification for CO₂ Capture

Area of Science:

• Chemical Engineering
• Materials Science
• Environmental Science

Background:

• Membrane-based gas separation is crucial for a low-carbon economy, offering efficiency and reduced energy use.
• Enzyme immobilization within membranes can enhance selectivity for specific gas molecules.
• Supported liquid membranes (SLMs) offer tunable properties for gas separation applications.

Purpose of the Study:

• To develop and validate an emulsion-based supported liquid membrane (SLM) for improved carbon dioxide (CO2) and methane (CH4) separation.
• To immobilize carbonic anhydrase enzyme within a water-in-oil emulsion for enhanced CO2 capture.
• To demonstrate the feasibility of this approach for biogas purification.

Main Methods:

• Direct membrane emulsification was used to create stable water-in-oil (W/O) emulsions incorporating carbonic anhydrase.
• Optimized emulsions (2% Tween 80 in corn oil, 0.5 g/L carbonic anhydrase, 5% PEG 300) were impregnated onto a porous PVDF membrane.
• Gas permeability studies were conducted to evaluate CO2 and CH4 separation performance.

Main Results:

• The developed emulsion-based SLM demonstrated a ~15% increase in CO2 permeability.
• A significant ~60% decrease in methane (CH4) permeability was observed compared to control membranes.
• Corn oil was identified as a suitable, low-cost, and non-toxic bulk phase for the emulsion.

Conclusions:

• A proof-of-concept for an enhanced CO2 capture system using emulsion-based SLMs was successfully established.
• The enzyme-functionalized membrane shows significant potential for selective CO2 separation in biogas upgrading.
• This method offers a promising route for developing advanced membranes for low-carbon energy applications.