CO₂ Capture in Metal–Organic Framework Adsorbents: An Engineering Perspective

Abstract

CO 2 emission has raised worldwide concerns because of its potential effects on climate change, species extinction, and plant nutrition deterioration. Metal-organic frameworks (MOFs) are one class of crystalline adsorbent materials that are believed to be of huge potential in CO 2 capture applications because of their advantages such as ultrahigh porosity, boundless chemical tunability, and surface functionality over traditional porous zeolites and activated carbon. In terms of chemistry, there are already many studies devoted to the synthesis of new functional MOFs. Some of the synthesized MOFs have been evaluated for CO 2 capture at laboratory-scale. Several reviews have been published on this topic, but mainly from a chemistry and materials point of view. In this review, the authors focus on the engineering perspective on this topic, with emphases on material evaluation, performance judgment, and process design to address the engineering issues of these materials to be used as adsorbents in industrial CO 2 capture. The current engineering evaluation approaches for MOFs are summarized, in a manner that could also be applied to other adsorbent materials.

Ultra‐High Surface Area Nitrogen‐Doped Carbon Aerogels Derived From a Schiff‐Base Porous Organic Polymer Aerogel for CO2 Storage and Supercapacitors

“…The CO 2 uptake capacities of NCA‐900 still reach 16.7 wt% (3.8 mmol g −1 ) at 298 K and 1 bar (Figure S3, Supporting Information). Based on recent reviews about CO 2 capture using porous materials, a maximum gravimetric CO 2 uptake capacity of 26.7 wt% (6.1 mmol g −1 ) represents one of the best values compared to porous carbon aerogels, porous organic polymers, metal–organic frameworks, and porous electrospun fibers . Particularly, CO 2 uptake capacity of NCA‐900 in the typical condition of flue gas (CO 2 partial pressure = 0.15 bar, 298 K) is as high as 1.5 mmol g −1 , which is, e.g., superior to the values reported in the literature for commercial active carbons .…”

The Chemistry of Reticular Framework Nanoparticles: MOF, ZIF, and COF Materials

“…Permanent storage of, e.g., CO 2 gas due to Coulomb interaction is barely possible and mainly facilitated by van der Waals interactions. [272] Based on Coulomb interactions, the Pourbaix-enabled guest synthesis (PEGS) approach was successfully introduced that predicts guest confinement and synthesis inside MOF cavities for low temperature catalysis. [238] Often, reagents, such as catalysts are too large for direct incorporation within the host framework.…”

Easy Processing of Metal–Organic Frameworks into Pellets and Membranes

“…The resulting paste is then loaded into a syringe and heated, as depicted in Figure 3a. The processing of these materials into pellets were chosen due to two main reasons: it is a simple and inexpensive processing method, which can be advantageous to transpose to industry; and, in terms of engineering in industrial practice MOFs, are required to be pelletized and packed into columns for real gas capture and process studies [37]. Depending on the form of extrusion used, the materials can be processed into different sizes and shapes (Figure 4), and in large quantities, effortlessly.…”