Licensing Opportunity: CO2 Capture from Seawater by a Novel Contactor

Invention Reference Number: 202405629

Carbon capture from air typically requires large amounts of solvent and sorbent that are energetically costly to regenerate. It also suffers from degradation, is environmentally unsustainable, and very expensive. Direct ocean capture is an alternative approach that uses seawater as a sorbent for capturing carbon dioxide. One common method utilizes electrochemical means to extract carbon dioxide from seawater but relies on costly membranes and large amounts of electricity. This innovative technology is a direct approach for moving seawater through high surface area, low-cost polymer fibers without need for electrical current. The process makes use of a polymer membrane contactor with a selective ligand grafted onto the surface that functions as a pH-reversible carbon dioxide sorbent. This is the first energy efficient, and environmentally sustainable technology for scalable carbon dioxide capture from seawater.

Description

Seawater is a critical natural sink of carbon dioxide and has absorbed about 30% of anthropogenic carbon dioxide since the beginning of the industrial era. As the ocean becomes more acidic, its ability to absorb carbon dioxide and store it in the form of bicarbonate will decrease as it reaches a state of saturation. Developing effective methods for removing carbon dioxide from the ocean is imperative for maintaining its absorptive properties and protecting aquatic life. Efficiently capturing climate-affecting carbon dioxide from seawater for storage or other uses faces significant technical and economic challenges. This technology makes use of a polymer grafted membrane contactor and is the first process suitable for scalable and energy efficient carbon dioxide capture from seawater. This membrane contactor involves hollow fibers grafted with ligand-based polymers that can selectively adsorb carbon dioxide without the energetic demands of other approaches. The use of hollow fiber contactors enables high surface area that maximizes the potential for bicarbonate capture and can be integrated with preexisting water-treatment and desalination plants. It also eliminates concerns about fouling that plague electrochemical techniques. This facilitates the capture of a larger volume of bicarbonates for enhanced sorbent performance. The proposed contactor-based process provides high selectivity, capacity, and throughput.

Benefits

• Reduces greenhouse gas emissions


• Energy efficient – only energy required is to pump seawater


• Cost effective – no expensive equipment needed


• Can be integrated into existing desalination or water treatment plants


• More resilient than electrochemical-based technologies


• Bicarbonate specific ligands


• New chemistry for modifying solid PVDF materials heterogeneously


• Fibers are reusable


• Highly scalable

Applications and Industries

• Any company/industry interested in reducing carbon emissions


• Water treatment utilities


• Desalination plants

Contact

To learn more about this technology, email partnerships@ornl.gov or call 865-574-1051.