Screening the Effect of Water Vapour on Gas Adsorption Performance: Application to CO₂ Capture from Flue Gas in Metal–Organic Frameworks

Abstract

A simple laboratory-scale protocol that enables the evaluation of the effect of adsorbed water on CO uptake is proposed. 45 metal-organic frameworks (MOFs) were compared against reference zeolites and active carbons. It is possible to classify materials with different trends in CO uptake with varying amounts of pre-adsorbed water, including cases in which an increase in CO uptake is observed for samples with a given amount of pre-adsorbed water. Comparing loss in CO uptake between "wet" and "dry" samples with the Henry constant calculated from the water adsorption isotherm results in a semi-logarithmic trend for the majority of samples allowing predictions to be made. Outliers from this trend may be of particular interest and an explanation for the behaviour for each of the outliers is proposed. This thus leads to propositions for designing or choosing MOFs for CO capture in applications where humidity is present.

Solution‐reprocessable microporous polymeric adsorbents for carbon dioxide capture

“…The trapping of polar solvents in hPIM‐1 (revealed by TGA curves) prompts us to test the water uptake capacity and hydrophobicity of these polymers, as the CO 2 uptake capacity from wet flue gas (containing 5–10 vol % water vapor) of hydrophilic adsorbents is often largely jeopardized (80–100% loss in CO 2 uptake capacity) because of the competitive adsorption of H 2 O over CO 2 . As shown in Figure and Table , the water contact angle of PIM‐1 (85°) agrees well to the literature values, and is higher than that of hPIM‐1 (72°).…”

“…The industrial benchmark adsorbents, represented by zeolites (5A, 13X), have inherent drawbacks to be overcome such as negligible CO 2 uptake capacity under wet conditions . Similarly, emerging metal‐organic frameworks (MOFs) typically suffer from the same problem . In addition, the complex and energy‐intensive regeneration processes of MOFs often jeopardize their structural integrity and thus lead to declined overall separation efficiency …”

Data-driven design of metal–organic frameworks for wet flue gas CO2 capture

“…The capture capacity of these reference materials lies between that of Al-PyrMOF and Al-PMOF in dry flue gases; however, unlike our MOFs, their performance reduces considerably in humid flue gases. Although our materials do not have the highest reported working capaci-ties 14 , it is encouraging tosee that, in wet flue gases, Al-PMOF outperforms commercial materials such as zeolite 13X and activated carbon.…”

“…For example, some MOFs have open metal sites at which amines can be attached, taking advantage of the specific amine chemistry that is also used in conventional amine scrubbing [10][11][12][13] . A previous screening study 14 investigated whether MOFs could adsorb CO2 in the presence of water, and the results suggested that such MOFs could be de novo designed. In this work, we develop a systematic strategy for the design and preparation of custom-made MOFs that can capture carbon from wet flue gases.…”

Computational development of the nanoporous materials genome

“…give an idea of their permanence in water 66 , investigating chemical pathways to water degredation can be extremely computationally expensive for a single material [151][152][153][154] . While accurate calculations of water stability are currently too expensive for these materials databases, creative development of chemical descriptors that correlate well with observed water degradation trends would fill an important knowledge gap.…”