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. 2025 Jun 4;10(23):24675-24696.
doi: 10.1021/acsomega.5c01533. eCollection 2025 Jun 17.

Experimental and Theoretical Insights into CO2 and N2 Capture Using Natural Hydrophobic Deep Eutectic Solvents at High Pressures

Ahmad Al-Bodour  1 , Noor Alomari  1 , Shan Khai Liew  1 , Santiago Aparicio  2 , James Springstead  1 , Mert Atilhan  1
Affiliations

Experimental and Theoretical Insights into CO2 and N2 Capture Using Natural Hydrophobic Deep Eutectic Solvents at High Pressures

Ahmad Al-Bodour et al. ACS Omega. .

Abstract

This study explores three binary natural hydrophobic deep eutectic solvents (HDESs) for capturing carbon dioxide (CO2) and nitrogen (N2) at high pressures. The HDES systems, comprising linoleic acid (LnA) as a hydrogen-bond donor (HBD) and camphor (CAM), citral (CIT), or piperitone (PIP) as a hydrogen-bond acceptor (HBA), were synthesized and characterized for density, viscosity, conductivity, surface tension, and contact angle. High-pressure gas absorption experiments demonstrated CO2 and N2 capture, achieving absorption rates of ∼62%-92% within 100 s at 10-30 bar. At 25 bar, a mole fraction absorption of 0.47 matched the performance of aqueous monoethanolamine (MEA) at 25 °C. Among the HDESs, CAM-LnA (1:1) exhibited the highest CO2 selectivity at 2.5 and 5 bar, with values of 41.4 and 44.2, respectively. The conductor-like screening model for real solvents (COSMO-RSs) method predicted eutectic points and gas absorption, while molecular dynamics simulations assessed gas interactions at the molecular level. The results underscore the potential of HDES for high-pressure gas capture, providing insights into their production, characterization, and applications.

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Figures

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COSMO-RS eutectic composition and eutectic temperature predictions.
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Schematic representation of the high-pressure isochoric gas sorption system. , Reprinted (adapted or reprinted in part) with permission from [J. Environ. Chem. Eng. 2022, 10(5), 108237 and J. Mol. Liq. 2023, 390, 123114]. Copyright [2022, 2023] [Elsevier].
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(a) HDES density evolution profile with temperature change. (b) HDES thermal expansion coefficient profile as temperature functions.
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Experimental viscosity data of the natural HDES systems are temperature dependent.
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Ionic conductivity for the three HDESs.
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TGA data curves of the three LnA-based HDES systems.
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FTIR data curves of the prepared hydrophobic NADES.
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CO2 experimental absorption compared to (a) COSMO-RS predictions and (b) the conventional amine and DES system.
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Kinetics of CO2 solubility in the studied HDES systems.
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N2 experimental absorption data in comparison with the COSMO-RS predictions for the investigated NADES.
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N2 absorption process kinetics for the prepared HDES systems.
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Molecular structures of compounds used in this work for the considered DES (HBAs/HBD), CO2 and N2.
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Site–site radial distribution functions, g(r), for [HBAs]/[HBD], [HBA]/[HBA], and [HBD]/[HBD] sites in the reported DES (1:1) + CO2 systems at x CO2 = 0/0.05/0.1/0.3/0.5 (CO2 effect) (atom labeling is shown in Figure ).
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Site–site radial distribution functions, g(r), for [HBA]/[HBD], [HBA]/[HBA], and [HBD]/[HBD] sites in the reported DES (1:1) + N2 systems at x N2 = 0/0.05/0.1/0.3/0.5 (N2 effect) (atom labeling is shown in Figure ).
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Site–site radial distribution functions, g(r), for [HBA]/CO2 and [HB]/CO2 sites in the reported DES (1:1) + CO2 systems at x CO2 = 0.05/0.1/0.3/0.5 (atom labeling is shown in Figure ).
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Site–site radial distribution functions, g(r), for [HBA]/N2 and [HBD]/N2 sites in the reported DES (1:1) + N2 systems at x N2 = 0.05/0.1/0.3/0.5 (atom labeling is shown in Figure ).
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Average number of hydrogen bonds per HBD molecule, NH, for [HBA]/[HBD] interactions (O1–O2) in the reported DES (1:1) + CO2 from MD simulations at 293 K and 1 bar as a function of x CO2 (atom labeling as in Figure ).
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Average number of hydrogen bonds per HBD molecule, N H, for [HBA]/[HBD] interactions (O1–O2) in the reported DES (1:1) + N2 from MD simulations at 293 K and 1 bar as a function of x N2 (atom labeling is shown in Figure ).
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Spatial distribution functions, SDFs, of the corresponding centers-of-mass of LnA and CO2 around central [HBA] molecules for the reported DES (1:1) + CO2 as a function of x CO2 .
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Spatial distribution functions, SDFs, of the corresponding centers-of-mass of LnA and N2 around central [HBA] molecules for the reported DES (1:1) + N2 as a function of x N2 .
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Intermolecular interaction energies, Einter (sum of Lennard-Jones and Coulombic contributions), for the different interaction sites in the reported DES (1:1) + CO2/N2 from MD simulations at 293 K and 1 bar as a function of x CO2 /x N2 .
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References

    1. Le Quéré C., Jackson R. B., Jones M. W., Smith A. J. P., Abernethy S., Andrew R. M., De-Gol A. J., Willis D. R., Shan Y., Canadell J. G., Friedlingstein P., Creutzig F., Peters G. P.. Temporary Reduction in Daily Global CO2 Emissions during the COVID-19 Forced Confinement. Nat. Clim. Change. 2020;10(7):647–653. doi: 10.1038/s41558-020-0797-x. - DOI
    1. Peters G. P., Andrew R. M., Canadell J. G., Friedlingstein P., Jackson R. B., Korsbakken J. I., Le Quéré C., Peregon A.. Carbon Dioxide Emissions Continue to Grow amidst Slowly Emerging Climate Policies. Nat. Clim. Change. 2020;10(1):3–6. doi: 10.1038/s41558-019-0659-6. - DOI
    1. Karadas F., Atilhan M., Aparicio S.. Review on the Use of Ionic Liquids (ILs) as Alternative Fluids for CO2 Capture and Natural Gas Sweetening. Energy Fuels. 2010;24(11):5817–5828. doi: 10.1021/ef1011337. - DOI
    1. Zeng S., Zhang X., Bai L., Zhang X., Wang H., Wang J., Bao D., Li M., Liu X., Zhang S.. Ionic-Liquid-Based CO2 Capture Systems: Structure, Interaction and Process. Chem. Rev. 2017;117(14):9625–9673. doi: 10.1021/acs.chemrev.7b00072. - DOI - PubMed
    1. Huy P. Q., Sasaki K., Sugai Y., Kiga T., Fujioka M., Adachi T.. Effects of SO2 and pH Concentration on CO2 Adsorption Capacity in Coal Seams for CO2 Sequestration With Considerations for Flue Gas From Coal-Fired Power Plants. J. Can. Pet. Technol. 2009;48(10):58–63. doi: 10.2118/130067-PA. - DOI

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