- Background
In the development of CCUS technologies, CO₂ adsorbents must fulfill two essential requirements: high adsorption efficiency and low-energy regeneration. Conventional amine-based absorbents exhibit strong affinity for CO₂ but suffer from high energy demand during regeneration and material degradation over repeated cycles. In this context, attention has turned to 2-hydroxyethyl acrylamide (HEAA), a water-soluble acrylamide monomer. Based on an interesting research report, we propose the application of HEAA as a CO₂ adsorbent for CCUS.
- Key Findings from the Study (Carrascal-Hernandez et al., Gels 2024)
- Methodology: Stability evaluation of CO₂–polymer complexes using DFT (ωB97X-D/6-311G(2d,p)).
- Compared materials: Chitosan, PVP, PEG, HEAA.
- Binding energies (∆E_b, kcal/mol):
- Chitosan: −5.41
- PVP: −4.83
- HEAA: −4.29
- PEG: −3.06
- All values fall within the physisorption range, indicating spontaneous CO₂ adsorption at room temperature.
- Free energy (∆G): HEAA −2.78 kcal/mol → Supports spontaneous adsorption at room temperature.
- Regeneration behavior: CO₂ desorption begins around 160 °C when ∆G reaches 0.
- Functional Characteristics of HEAA
- Molecular structure: Contains an amide group (–CONH–) and a hydroxyethyl group (–CH₂CH₂OH) → high polarity and hydrophilicity → suitable for hydrogel formation.
- Mechanism of CO₂ capture: Forms weak dipole–dipole and hydrogen bond-like interactions with CO₂ through amide N–H, carbonyl, and hydroxyl groups.
- Adsorption strength: Stronger than PEG, weaker than Chitosan and PVP → moderate adsorption capacity with excellent reversibility.
- Regenerability: Enables relatively low-energy desorption (around 160 °C).
- Advantages of Using HEAA for CCUS Applications
- High reversibility → Maintains performance over multiple adsorption–desorption cycles.
- Excellent processability → Supplied as a water-soluble monomer, easily processed into hydrogels, films, beads, or coatings.
- Industrial scalability → Simple synthesis process with stable quality.
- Design flexibility → Can copolymerize with a wide range of acrylate monomers to achieve tailored material properties. Adsorption performance can be further enhanced by copolymerization or blending with nitrogen-rich polymers (e.g., Chitosan, PVP).
- Proposed Next Steps in Development
- Conduct basic adsorption tests of HEAA-based gels and beads (0–1 bar, 25–100 °C).
- Design copolymers (HEAA + Chitosan derivatives or PVP) to strengthen affinity.
- Evaluate scalability through morphology control (membranes, particles, coatings).
- Verify long-term performance stability through cycle durability tests (100+ cycles).
We also offer a wide range of other functional monomers. Please feel free to contact us if you are interested.
