Visualising reaction complexes in amine-based unloaded and CO₂-loaded carbon capture solutions

Area of Science:

• Chemical Engineering
• Materials Science
• Environmental Science

Background:

• Carbon capture is vital for mitigating climate change, particularly in industries with unavoidable CO2 emissions.
• Aqueous amine blends are common carbon capture agents, relying on CO2 absorption and thermal regeneration.
• Understanding solute interactions is key to optimizing reactivity and reducing regeneration energy.

Purpose of the Study:

• To experimentally determine the atomically resolved structure of aqueous sodium and potassium glycinate.
• To investigate structural changes in these solvents upon CO2 loading.
• To provide a foundation for improved modeling and rational design of carbon capture solutions.

Main Methods:

• Utilized H/D isotopically varied neutron diffraction.
• Performed structural refinement on diffraction data.
• Employed Energy-based Potential of Rocks (EPSR) for analysis.

Main Results:

• Quantified the structure of aqueous sodium and potassium glycinate in both unloaded and CO2-loaded states.
• Determined the frequency and energetic stability of intermolecular interactions.
• Provided the first experimentally derived, atomically resolved structural data for these solvents.

Conclusions:

• The methodology offers unprecedented insight into carbon capture solvent structures.
• This work facilitates the large-scale modeling and rational design of advanced carbon capture agents.
• The approach is applicable to a wide range of other carbon capture solutions.