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A hybrid absorption-adsorption method to efficiently capture carbon.

Liu H, Liu B, Lin LC, Chen G, Wu Y, Wang J, Gao X, Lv Y, Pan Y, Zhang X, Zhang X, Yang L, Sun C, Smit B, Wang W - Nat Commun (2014)

Bottom Line: We show that this approach may give a more efficient technology to capture carbon dioxide compared to conventional technologies.Most importantly, the sorption enthalpy is only -29 kJ mol(-1), indicating that significantly less energy is required for sorbent regeneration.In addition, from a technological point of view, unlike solid adsorbents slurries can flow and be pumped.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, P. R. China.

ABSTRACT
Removal of carbon dioxide is an essential step in many energy-related processes. Here we report a novel slurry concept that combines specific advantages of metal-organic frameworks, ion liquids, amines and membranes by suspending zeolitic imidazolate framework-8 in glycol-2-methylimidazole solution. We show that this approach may give a more efficient technology to capture carbon dioxide compared to conventional technologies. The carbon dioxide sorption capacity of our slurry reaches 1.25 mol l(-1) at 1 bar and the selectivity of carbon dioxide/hydrogen, carbon dioxide/nitrogen and carbon dioxide/methane achieves 951, 394 and 144, respectively. We demonstrate that the slurry can efficiently remove carbon dioxide from gas mixtures at normal pressure/temperature through breakthrough experiments. Most importantly, the sorption enthalpy is only -29 kJ mol(-1), indicating that significantly less energy is required for sorbent regeneration. In addition, from a technological point of view, unlike solid adsorbents slurries can flow and be pumped. This allows us to use a continuous separation process with heat integration.

No MeSH data available.


Related in: MedlinePlus

Ab(d)sorption solubility and enthalpies.(a) The comparison of CO2 solubility coefficients in ZIF-8/glycol–mIm slurry at 303.15 K with that in ZIF-8/glycol at 293.15 K and that reported in the literature ((MEA (mass fraction 30%), MDEA (mass fraction 30%), TEA (mass fraction 30%), DEAE (mass fraction 30%)) at 313.15 K, ([p5mim][bFAP], [bmim][PF6]) at 298.15 K)420212223, (b) sorption enthalpies of CO2 in glycol–mIm liquid and ZIF-8/glycol–mIm slurry at 303.15 K (c) isotherms of CO2, CH4, N2 and H2 at 303.15 K in ZIF-8/glycol–mIm slurry.
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f3: Ab(d)sorption solubility and enthalpies.(a) The comparison of CO2 solubility coefficients in ZIF-8/glycol–mIm slurry at 303.15 K with that in ZIF-8/glycol at 293.15 K and that reported in the literature ((MEA (mass fraction 30%), MDEA (mass fraction 30%), TEA (mass fraction 30%), DEAE (mass fraction 30%)) at 313.15 K, ([p5mim][bFAP], [bmim][PF6]) at 298.15 K)420212223, (b) sorption enthalpies of CO2 in glycol–mIm liquid and ZIF-8/glycol–mIm slurry at 303.15 K (c) isotherms of CO2, CH4, N2 and H2 at 303.15 K in ZIF-8/glycol–mIm slurry.

Mentions: Though we have obtained promising CO2 selectivities, Fig. 3a indicates that, as in most application the partial CO2 pressure is low, the solubility coefficient of ZIF-8/glycol slurry at these conditions is too low for practical applications. We further tuned the absorbent by adding 2-methylimidazole (mIm) to the glycol. The solubility of CO2 in glycol–mIm (3:2) solution is 0.64 mol l−1 at 303.15 K and 1 bar (see Fig. 3a) and the selectivity of CO2 over N2 is higher than 200 (Supplementary Table 11). The CO2 absorption enthalpy in glycol–mIm solution is only about −34 kJ mol−1 at 303.15 K (Fig. 3b), which can lead to a much lower regeneration cost compared with many of the aqueous alkanolamines (around −100 kJ mol−1)12 and ion liquids19.


A hybrid absorption-adsorption method to efficiently capture carbon.

Liu H, Liu B, Lin LC, Chen G, Wu Y, Wang J, Gao X, Lv Y, Pan Y, Zhang X, Zhang X, Yang L, Sun C, Smit B, Wang W - Nat Commun (2014)

Ab(d)sorption solubility and enthalpies.(a) The comparison of CO2 solubility coefficients in ZIF-8/glycol–mIm slurry at 303.15 K with that in ZIF-8/glycol at 293.15 K and that reported in the literature ((MEA (mass fraction 30%), MDEA (mass fraction 30%), TEA (mass fraction 30%), DEAE (mass fraction 30%)) at 313.15 K, ([p5mim][bFAP], [bmim][PF6]) at 298.15 K)420212223, (b) sorption enthalpies of CO2 in glycol–mIm liquid and ZIF-8/glycol–mIm slurry at 303.15 K (c) isotherms of CO2, CH4, N2 and H2 at 303.15 K in ZIF-8/glycol–mIm slurry.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4214418&req=5

f3: Ab(d)sorption solubility and enthalpies.(a) The comparison of CO2 solubility coefficients in ZIF-8/glycol–mIm slurry at 303.15 K with that in ZIF-8/glycol at 293.15 K and that reported in the literature ((MEA (mass fraction 30%), MDEA (mass fraction 30%), TEA (mass fraction 30%), DEAE (mass fraction 30%)) at 313.15 K, ([p5mim][bFAP], [bmim][PF6]) at 298.15 K)420212223, (b) sorption enthalpies of CO2 in glycol–mIm liquid and ZIF-8/glycol–mIm slurry at 303.15 K (c) isotherms of CO2, CH4, N2 and H2 at 303.15 K in ZIF-8/glycol–mIm slurry.
Mentions: Though we have obtained promising CO2 selectivities, Fig. 3a indicates that, as in most application the partial CO2 pressure is low, the solubility coefficient of ZIF-8/glycol slurry at these conditions is too low for practical applications. We further tuned the absorbent by adding 2-methylimidazole (mIm) to the glycol. The solubility of CO2 in glycol–mIm (3:2) solution is 0.64 mol l−1 at 303.15 K and 1 bar (see Fig. 3a) and the selectivity of CO2 over N2 is higher than 200 (Supplementary Table 11). The CO2 absorption enthalpy in glycol–mIm solution is only about −34 kJ mol−1 at 303.15 K (Fig. 3b), which can lead to a much lower regeneration cost compared with many of the aqueous alkanolamines (around −100 kJ mol−1)12 and ion liquids19.

Bottom Line: We show that this approach may give a more efficient technology to capture carbon dioxide compared to conventional technologies.Most importantly, the sorption enthalpy is only -29 kJ mol(-1), indicating that significantly less energy is required for sorbent regeneration.In addition, from a technological point of view, unlike solid adsorbents slurries can flow and be pumped.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, P. R. China.

ABSTRACT
Removal of carbon dioxide is an essential step in many energy-related processes. Here we report a novel slurry concept that combines specific advantages of metal-organic frameworks, ion liquids, amines and membranes by suspending zeolitic imidazolate framework-8 in glycol-2-methylimidazole solution. We show that this approach may give a more efficient technology to capture carbon dioxide compared to conventional technologies. The carbon dioxide sorption capacity of our slurry reaches 1.25 mol l(-1) at 1 bar and the selectivity of carbon dioxide/hydrogen, carbon dioxide/nitrogen and carbon dioxide/methane achieves 951, 394 and 144, respectively. We demonstrate that the slurry can efficiently remove carbon dioxide from gas mixtures at normal pressure/temperature through breakthrough experiments. Most importantly, the sorption enthalpy is only -29 kJ mol(-1), indicating that significantly less energy is required for sorbent regeneration. In addition, from a technological point of view, unlike solid adsorbents slurries can flow and be pumped. This allows us to use a continuous separation process with heat integration.

No MeSH data available.


Related in: MedlinePlus