Metal–Organic Frameworks for Separations

Kenji Sumida, David L. Rogow, Jarad A. Mason, Thomas M. McDonald, Eric D. Bloch, Zoey R. Herm, Tae-Hyun Bae, Jeffrey R. Long

Carbon Dioxide Capture in Metal–Organic Frameworks

The escalating level of atmospheric carbon dioxide is one of the most pressing environmental concerns of our age. Carbon capture and storage (CCS) from large point sources such as power plants is one option for reducing anthropogenic CO(2) emissions; however, currently the capture alone will increase the energy requirements of a plant by 25-40%. This Review highlights the challenges for capture technologies which have the greatest likelihood of reducing CO(2) emissions to the atmosphere, namely postcombustion (predominantly CO(2)/N(2) separation), precombustion (CO(2)/H(2)) capture, and natural gas sweetening (CO(2)/CH(4)). The key factor which underlies significant advancements lies in improved materials that perform the separations. In this regard, the most recent developments and emerging concepts in CO(2) separations by solvent absorption, chemical and physical adsorption, and membranes, amongst others, will be discussed, with particular attention on progress in the burgeoning field of metal-organic frameworks.

Carbon Dioxide Capture: Prospects for New Materials

Since the time of the industrial revolution, the atmospheric CO(2) concentration has risen by nearly 35 % to its current level of 383 ppm. The increased carbon dioxide concentration in the atmosphere has been suggested to be a leading contributor to global climate change. To slow the increase, reductions in anthropogenic CO(2) emissions are necessary. Large emission point sources, such as fossil-fuel-based power generation facilities, are the first targets for these reductions. A benchmark, mature technology for the separation of dilute CO(2) from gas streams is via absorption with aqueous amines. However, the use of solid adsorbents is now being widely considered as an alternative, potentially less-energy-intensive separation technology. This Review describes the CO(2) adsorption behavior of several different classes of solid carbon dioxide adsorbents, including zeolites, activated carbons, calcium oxides, hydrotalcites, organic-inorganic hybrids, and metal-organic frameworks. These adsorbents are evaluated in terms of their equilibrium CO(2) capacities as well as other important parameters such as adsorption-desorption kinetics, operating windows, stability, and regenerability. The scope of currently available CO(2) adsorbents and their critical properties that will ultimately affect their incorporation into large-scale separation processes is presented.

Adsorbent Materials for Carbon Dioxide Capture from Large Anthropogenic Point Sources

Combination of Advanced Oxidation Processes and biological treatments for wastewater decontamination—A review

Molecular modeling of HMS hybrid materials for CO2 adsorption

A variety of low rank coals have been treated by mechanical thermal expression (MTE). Under identical conditions, the percentage water removal decreased in proportion to the water content of the raw coals. Water removal was significant even for a sub-bituminous coal, provided sufficiently stringent conditions were used. The effect of MTE on inorganics removal varied markedly between coals. Large proportions of Na and Cl, but not other inorganics, were typically removed. The amount of organic carbon released to the product water was mainly influenced by processing temperature.

Dewatering Low Rank Coals by Mechanical Thermal Expression (MTE) and its Influence on Organic Carbon and Inorganic Removal

A polyethylenimine impregnated silica sorbent was evaluated for steam-assisted temperature vacuum swing desorption (TVSD) of CO2, adsorbed from 420 ppm of CO2 in N2. Results indicate that essential...

Desorption Process for Capturing CO2 from Air with Supported Amine Sorbent

Evaluation of methods for monitoring MEA degradation during pilot scale post-combustion capture of CO2

Mesoporous silica SBA-15 supported cobalt oxide composites prepared via the “double-solvent”, impregnation and adsorption techniques were characterized by diffuse reflectance UV–Vis (DR UV–Vis), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The potential of these cobalt modified composites to oxidize norbornene, benzyl alcohol and 1-phenylethanol was determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). SEM images indicated that, irrespective of cobalt content (Co-content), the integrity of the mesoporous channels remained intact for all methods. DR UV–Vis exhibited a red-shift which increased with Co-content for catalysts prepared by the double-solvent technique and is attributed to more extensive crystal growth. The morphology of the cobalt oxide species had a direct impact on the pore volume (Pv) and surface area (SA) of the composites and this, in turn affected the catalytic activity. For catalysts prepared by the double-solvent technique, the activity was in reverse proportion to the Co-content. This is attributed to reduced Pv which limits the active SA available.

Alan L. Chaffee

Papers

Molecular modeling of HMS hybrid materials for CO2 adsorption

Dewatering Low Rank Coals by Mechanical Thermal Expression (MTE) and its Influence on Organic Carbon and Inorganic Removal

Desorption Process for Capturing CO2 from Air with Supported Amine Sorbent

Evaluation of methods for monitoring MEA degradation during pilot scale post-combustion capture of CO2

Mesoporous Silica SBA-15 Supported Co3O4 Nanorods as Efficient Liquid Phase Oxidative Catalysts