Asphalt-derived high surface area activated porous carbons for carbon dioxide capture

Plastic Waste Product Captures Carbon Dioxide in Nanometer Pores

Plastic waste (PW) and increasing atmospheric carbon dioxide (CO₂) levels are among the top environmental concerns presently facing humankind. With an ambitious 2050 zero-CO₂ emissions goal, there is a demand for economical CO₂ capture routes. Here we show that the thermal treatment of PW in the presence of potassium acetate yields an effective carbon sorbent with pores width of 0.7-1.4 nm for CO₂ capture. The PW to carbon sorbent process works with single or mixed streams of polyolefin plastics. The CO₂ capacity of the sorbent at 25 °C is 17.0 ± 1.1 wt % (3.80 ± 0.25 mmol g^-1) at 1 bar and 5.0 ± 0.6 wt % (1.13 ± 0.13 mmol g^-1) at 0.15 bar, and it regenerates upon reaching 75 ± 5 °C. The CO₂ capture cost from flue gas via this technology is estimated to be <$21 ton^-1 CO₂, much lower than competing CO₂ capture technologies. Hence, this PW-derived carbon material should find utility in the capture of CO₂ from point sources of high CO₂ emissions while providing a use for otherwise deleterious PW.

Carbon Dioxide Capture through Physical and Chemical Adsorption Using Porous Carbon Materials: A Review

Due to rapid industrialization and urban development across the globe, the emission of carbon dioxide (CO2) has been significantly increased, resulting in adverse effects on the climate and ecosystems. In this regard, carbon capture and storage (CCS) is considered to be a promising technology in reducing atmospheric CO2 concentration. Among the CO2 capture technologies, adsorption has grabbed significant attention owing to its advantageous characteristics discovered in recent years. Porous carbon-based materials have emerged as one of the most versatile CO2 adsorbents. Numerous research activities have been conducted by synthesizing carbon-based adsorbents using different precursors to investigate their performances towards CCS. Additionally, amine-functionalized carbon-based adsorbents have exhibited remarkable potential for selective capturing of CO2 in the presence of other gases and humidity conditions. The present review describes the CO2 emission sources, health, and environmental impacts of CO2 towards the human beings, options for CCS, and different CO2 separation technologies. Apart from the above, different synthesis routes of carbon-based adsorbents using various precursors have been elucidated. The CO2 adsorption selectivity, capacity, and reusability of the current and applied carbon materials have also been summarized. Furthermore, the critical factors controlling the adsorption performance (e.g., the effect of textural and functional properties) are comprehensively discussed. Finally, the current challenges and future research directions have also been summarized.

Enhance pore structure of cyanobacteria-based porous carbon by polypropylene to improve adsorption capacity of methylene blue

Porous carbon obtained by co-pyrolysis of plastic and biomass has received a lot of attention due to its excellent adsorption properties, and the pore structure plays an essential role in adsorption performance, however, the pore structure is still not well understood. Herein, we synthesized cyanobacteria-based porous carbon derived from cyanobacteria and polypropylene plastic by one-step method. CPC-800-30% exhibited a high BET surface area (2140 m²/g), pore volume up to 1.44 cm³/g. PP not only improved the pore structure of porous carbon, but also enriched the types of functional groups, such as O-H, N-H, C=O, and -CH, due to dehydroxylation or amino group decreased, resulting in the hydrogen radicals increased, hence PP had positive effect for biomass during co-pyrolysis. Meanwhile, CPC-800-30% showed excellent methylene blue (MB) adsorption capacity (667 mg/g). This work provided a new strategy for enhancing porous carbon structure via using PP as additive.

A review on application of activated carbons for carbon dioxide capture: present performance, preparation, and surface modification for further improvement

The atmosphere security and regulation of climate change are being continuously highlighted as a pressing issue. The crisis of climate change owing to the anthropogenic carbon dioxide emission has led many governments at federal and provincial levels to promulgate policies to address this concern. Among them is regulating the carbon dioxide emission from major industrial sources such as power plants, petrochemical industries, cement plants, and other industries that depend on the combustion of fossil fuels for energy to operate. In view of this, various CO2 capture and sequestration technologies have been investigated and presented. From this review, adsorption of CO2 on porous solid materials has been gaining increasing attention due to its cost-effectiveness, ease of application, and comparably low energy demand. Despite the myriad of advanced materials such as zeolites, carbons-based, metal-organic frameworks, mesoporous silicas, and polymers being researched, research on activated carbons (ACs) continue to be in the mainstream. Therefore, this review is endeavored to elucidate the adsorption properties of CO2 on activated carbons derived from different sources. Selective adsorption based on pore size/shape and surface chemistry is investigated. Accordingly, the effect of surface modifications of the ACs with NH3, amines, and metal oxides on adsorption performance toward CO2 is evaluated. The adsorption performance of the activated carbons under humid conditions is also reviewed. Finally, activated carbon-based composite has been surveyed and recommended as a feasible strategy to improve AC adsorption properties toward CO2. The activated carbon surface in the graphical abstract is nitrogen rich modified using ammonia through thermal treatment. The values of CO2 emissions by sources are taken from (Yoro and Daramola 2020).

Pore Characteristics for Efficient CO2 Storage in Hydrated Carbons

Development of new approaches for carbon dioxide (CO₂) capture is important in both scientific and technological aspects. One of the emerging methods in CO₂ capture research is based on the use of gas-hydrate crystallization in confined porous media. Pore dimensions and surface functionality of the pores play important roles in the efficiency of CO₂ capture. In this report, we summarize work on several porous carbons (PCs) that differ in pore dimensions that range from supermicropores to mesopores, as well as surfaces ranging from hydrophilic to hydrophobic. Water was imbibed into the PCs, and the CO₂ uptake performance, in dry and hydrated forms, was determined at pressures of up to 54 bar to reveal the influence of pore characteristics on the efficiency of CO₂ capture and storage. The final hydrated carbon materials had H₂O-to-carbon weight ratios of 1.5:1. Upon CO₂ capture, the H₂O/CO₂ molar ratio was found to be as low as 1.8, which indicates a far greater CO₂ capture capacity in hydrated PCs than ordinarily seen in CO₂-hydrate formations, wherein the H₂O/CO₂ ratio is 5.72. Our mechanistic proposal for attainment of such a low H₂O/CO₂ ratio within the PCs is based on the finding that most of the CO₂ is captured in gaseous form within micropores of diameter <2 nm, wherein it is blocked by external CO₂-hydrate formations generated in the larger mesopores. Therefore, to have efficient high-pressure CO₂ capture by this mechanism, it is necessary to have PCs with a wide pore size distribution consisting of both micropores and mesopores. Furthermore, we found that hydrated microporous or supermicroporous PCs do not show any hysteretic CO₂ uptake behavior, which indicates that CO₂ hydrates cannot be formed within micropores of diameter 1-2 nm. Alternatively, mesoporous and macroporous carbons can accommodate higher yields of CO₂ hydrates, which potentially limits the CO₂ uptake capacity in those larger pores to a H₂O/CO₂ ratio of 5.72. We found that high nitrogen content prevents the formation of CO₂ hydrates presumably due to their destabilization and associated increase in system entropy via stronger noncovalent interactions between the nitrogen functional groups and H₂O or CO₂.

Novel Porous Carbons Derived from Coal Tar Rejects: Assessment of the Role of Pore Texture in CO2 Capture under Realistic Postcombustion Operating Temperatures

Activated carbons (ACs) are among the most commonly used sorbents for CO₂ capture because of their high surface areas and micropore volumes, which depend on precursor and activation methods. In this study, we evaluated different ACs obtained from a low-value fraction of liquid-derived coal pyrolysis, namely phenolic oil, which was used as gel precursor before carbonization and KOH activation. CO₂ capture performances were determined at temperatures between 25 and 120 °C, with CO₂ concentrations ranging from 5 to 90 vol %. The most efficient sample captured 2.86 mmol of CO₂/g AC at 25 °C and 1 bar, which is a highly competitive capture capacity, comparable to previously reported values for ACs without any modification/functionalization. Finally, their thermal stability and cyclability (i.e., for a minimum of six adsorption-desorption cycles) were evaluated. CO₂ uptake was not affected by desorption temperature after six adsorption-desorption cycles. On the basis of the results obtained in this work, the role of the textural properties into the CO₂ capture at realistic postcombustion temperatures and partial pressures was elucidated. In particular, we concluded that CO₂ adsorption performance was more related to the volume of the narrowest pores and to the average pore size than to the surface area.

Fabrication of glucose-derived carbon-decorated magnetic microspheres for extraction of bisphenols from water and tea drinks

Glucose-derived carbon-decorated magnetic microspheres were synthesized by an easy hydrothermal carbonization method and used as a high-efficiency adsorbent to extract bisphenols in water and tea drinks. The as-prepared carbon-decorated magnetic microspheres had a well-defined core-shell structure with a shell thickness of about 5 nm. The microspheres possessed high saturation magnetization at 60.8 emu/g and excellent chemical stability in aqueous solution. The experimental parameters affecting the extraction efficiency, including extraction time, pH, adsorbent dosage, desorption solvents, desorption time, and solution volume were evaluated. Electrostatic and π-π interactions were the major driving forces during extraction. Overall, a new magnetic solid-phase extraction method of determining bisphenols was developed on the basis of as-prepared magnetic microspheres. The method had a wide linear range, low limits of detection (0.03-0.10 µg/L), and high recoveries (85.4-104.6%).

Ultrahigh Surface Area N-Doped Hierarchically Porous Carbon for Enhanced CO2 Capture and Electrochemical Energy Storage

Facile synthesis of ultrahigh surface area porous carbons with well-defined functionalities such as N-doping remains a formidable challenge as extensive pore creation results in significant damage to the active sites. Herein, an ultrahigh surface area, N-doped hierarchically porous carbon was prepared through a multicomponent co-assembly approach. The resultant N-doped hierarchically porous carbon (N-HPC) possessed an ultrahigh surface area (≈1960 m²  g^-1 ), a uniform interpenetrating micropore (≈1.3 nm) and large mesopore (≈7.6 nm) size, and high N-doping in the carbon frameworks (≈5 wt %). The N-HPC exhibited a high specific capacitance (358 F g^-1 at 0.5 A g^-1 ) as a supercapacitor electrode in aqueous alkaline electrolyte with a stable cycling performance after10 000 charge/discharge cycles. Moreover, as a CO₂ absorbent, N-HPC displayed an adsorption capacity of 29.0 mmol g^-1 at 0 °C under a high pressure of 30 bar.

Porous carbons derived from polyethylene terephthalate (PET) waste for CO2 capture studies

Oxygen augmented carbon adsorbent has been developed using polyethylene terephthalate (PET) waste by first carbonizing at different temperatures (500-800 °C) and then chemically activating using different ratios of KOH: PET (mass ratio 1 to 4). The textural characterization divulges the effect of activation in terms of the development of the high surface area and micropore volume of 1690 m² g^-1 and 0.78 cm³ g^-1 respectively, for the optimum sample (PET-3-700). Elemental analysis of PET-3-700 illustrates the presence of 34.33% oxygen and XPS results confirmed the occurrence of oxygen moieties which enhance the basicity of the adsorbent and promote CO₂ capture. The CO₂ adsorption capacity of prepared carbons was determined thermogravimetrically under dynamic conditions, at different concentrations of CO₂ (6-100%) and temperatures. The maximum CO₂ uptake capacity of 2.31 mmol g^-1 was exhibited by PET-3-700 at an adsorption temperature of 30 °C under 100% pure CO₂ flow. Four adsorption-desorption cycles corroborate almost complete regenerability of the prepared adsorbent. Adsorption kinetics at all adsorption conditions was described best by fractional order kinetic model. Freundlich isotherm fit indicates the surface of adsorbent being heterogeneous and low values of isosteric heat shows physisorption behavior of the process. Negative values of thermodynamic parameters indicate exothermic and feasible nature of adsorption process.

Synthesis of biomass tar-derived foams through spontaneous foaming for ultra-efficient herbicide removal from aqueous solution

Pyrolysis is one of the most important approaches to convert waste biomass into renewable energy and biomaterials, and the tar is the inevitable by-product of this process. In this study, carbon foams were prepared innovatively with biomass tar as the precursor through spontaneous gas foaming approach and used for dicamba removal from aqueous solution. The results showed that prepared carbon foams had unique properties including rich microporous structure and high specific surface area (reaching 1667 m²/g). In addition, the prepared carbons had high thermal stability due to the high graphitic degree. The adsorption results indicated that pH showed a great effect on the adsorption of dicamba onto the prepared carbon foams. The carbon foam exhibited ultra-fast dicamba removal and ultra-high adsorption capacity of 891.74 mg/g at room temperature. The adsorption process was well described by pseudo-second-order kinetics and Langmuir isotherm models. The thermodynamic study indicated dicamba adsorption onto the prepared carbon foams was a spontaneous and exothermic process. In addition, the good reusability from recovery test demonstrated that the prepared carbon foams had promising potential for dicamba removal from aqueous solution.

Tuning Both Surface Chemistry and Porous Properties of Polymer-Derived Porous Carbons for High-Performance Gas Adsorption

In this study, we have prepared novel pyrrole-formaldehyde polymers through polymerizing pyrrole and formaldehyde in the mixture solvent of water and ethanol by using hydrochloric acid as a catalyst. The as-synthesized polymers possess a nitrogen content of 6.7 atom % and are composed of spherical particles with the diameter of approximately 1-3 μm. A series of nitrogen-doped porous carbons with high specific surface areas (680-2340 m² g^-1) were successfully obtained through the activation treatment of the polymer spheres. The porous properties and surface chemistry of the as-prepared porous carbons are tuned by choosing different activating agents and changing the activation temperature. The morphology, porous properties, and chemical composition of the obtained nitrogen-doped porous carbons are revealed by various characterization methods, such as scanning electron microscopy, nitrogen sorption measurement, and X-ray photoelectron spectroscopy. The as-prepared nitrogen-doped porous carbons as gas adsorbents display high carbon dioxide uptake capacities of 3.80-5.81 mmol g^-1 at 273 K and 1.0 bar. They also show excellent carbon dioxide adsorption capacities (2.40-3.37 mmol g^-1 at 1.0 bar) and good gas selectivities (CO₂/N₂ selectivities of 16.9-70.2) at 298 K.

Prediction of Carbon Dioxide Adsorption via Deep Learning

Porous carbons with different textural properties exhibit great differences in CO₂ adsorption capacity. It is generally known that narrow micropores contribute to higher CO₂ adsorption capacity. However, it is still unclear what role each variable in the textural properties plays in CO₂ adsorption. Herein, a deep neural network is trained as a generative model to direct the relationship between CO₂ adsorption of porous carbons and corresponding textural properties. The trained neural network is further employed as an implicit model to estimate its ability to predict the CO₂ adsorption capacity of unknown porous carbons. Interestingly, the practical CO₂ adsorption amounts are in good agreement with predicted values using surface area, micropore and mesopore volumes as the input values simultaneously. This unprecedented deep learning neural network (DNN) approach, a type of machine learning algorithm, exhibits great potential to predict gas adsorption and guide the development of next-generation carbons.

Structure Design of Low-Temperature Regenerative Hyperbranched Polyamine Adsorbent for CO2 Capture

A novel low-temperature regenerative hydroxy-functionalized hyperbranched polyamine adsorbent (0.16OH-HBPA) for CO₂ capture was readily prepared using glutaraldehyde to cross-link amino-terminated hyperbranched polymers (HBP) and functionalized with glycidol, followed by the reduction of the imino groups of 0.16OH-HBPA to alkyl aminos using NaBH₄. Here, the HBP has been prepared through the one-pot reaction between pentaethylenehexamine and methyl acrylate. The as-prepared 0.16OH-HBPA adsorbent showed a high adsorption capacity (4.05 mmol/g) for CO₂ (concentration, 10%) in the presence of water at 25 °C, and the alkyl amino utilization efficiency reached 73%. More importantly, the CO₂-adsorbed 0.16OH-HBPA showed excellent regenerative performance at low temperatures (85 °C, under pure CO₂ gas) due to the introduced hydroxyl that can cooperatively adsorb CO₂ via the amino groups to form stable carbamic acid. This process suppressed the formation of open-chain urea and cyclic urea and could overcome the disadvantages of high regeneration temperatures (≥90 °C, under pure inert gas) of CO₂-adsorbed traditional solid amine adsorbents.

Design and Preparation of Biomass-Derived Carbon Materials for Supercapacitors: A Review

The synthesis and application of biomass-derived carbon in energy storage have drawn increasing research attention due to the ease of fabrication, cost-effectiveness, and sustainability of the meso/microporous carbon produced from various biological precursors, including plants, fruits, microorganisms, and animals. Compared to the artificial nanostructured carbons, such as fullerene, carbon nanotube and graphene, the biomass-derived carbons may obtain superior capacitance, rate performance and stability in supercapacitor applications ascribing to their intrinsic nanoporous and hierarchical structures. However, challenges remain in processing techniques to obtain biomass-derived carbons with high carbon yield, high energy density, and controllable graphitic microstructures, which may require a clear understanding over the chemical and elemental compositions, and the intrinsic microstructural characteristics of the biological precursors. Herein we present comprehensive analyses over the impacts of the chemical and elemental compositions of the precursors on the carbon yield of the biomass, as well as the mechanism of chemical activation on the nanoporous structure development of the biomass-derived carbons. The structure–property relationship and functional performance of various biomass-derived carbons for supercapacitor applications are also discussed in detail and compared. Finally, useful insights are also provided for the improvements of biomass-derived carbons in supercapacitor applications.

Effect of Porosity Parameters and Surface Chemistry on Carbon Dioxide Adsorption in Sulfur-Doped Porous Carbons

In this work, a series of highly porous sulfur-doped carbons are prepared through physical activation methods by using polythiophene as a precursor. The morphology, structure, and physicochemical properties are revealed by a variety of characterization methods, such as scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and nitrogen sorption measurement. Their porosity parameters and chemical compositions can be well-tuned by changing the activating agents (steam and carbon dioxide) and reaction temperature. These sulfur-doped porous carbons possess specific surface area of 670-2210 m² g^-1, total pore volume of 0.31-1.26 cm³ g^-1, and sulfur content of 0.6-4.9 atom %. The effect of porosity parameters and surface chemistry on carbon dioxide adsorption in sulfur-doped porous carbons is studied in detail. After a careful analysis of carbon dioxide uptake at different temperatures (273 and 293 K), pore volumes from small pore size (less than 1 nm) play an important role in carbon dioxide adsorption at 273 K, whereas surface chemistry is the key factor at a higher adsorption temperature or lower relative pressure. Furthermore, sulfur-doped porous carbons also possess good gas adsorption selectivity and excellent recyclability for regeneration.

Facile synthesis of oxidized activated carbons for high-selectivity and low-enthalpy CO2 capture from flue gas

The oxidized activated carbon obtained using a facile synthetic approach shows high-capacity and low-enthalpy CO₂ capture with a selectivity of 48.5 toward flue gas, which is double that of the pristine activated carbon.

Waste wool derived nitrogen-doped hierarchical porous carbon for selective CO2 capture

In this work, N-doped hierarchical porous carbon has been successfully fabricated by KOH activation of waste wool. The optimal sample exhibits good CO₂ adsorption capacity under atmospheric pressure (1 bar), as well as excellent CO₂/N₂ selectivity.

Knitting polycyclic aromatic hydrocarbon-based microporous organic polymers for efficient CO2 capture

In order to achieve efficient CO₂ capture, four novel microporous organic polymers, based on distinct polycyclic aromatic hydrocarbons such as fluoranthene, binaphthalene, naphthalene and phenanthrene, were successfully prepared by the solvent knitting method. N₂ sorption isotherms indicate that these polymers are predominately microporous with ultrahigh BET surface area i.e., 1788 m² g⁻¹ for fluoranthene-based Polymer 1, 1702 m² g⁻¹ for binaphthalene-based Polymer 2 and objective CO₂ uptake capacity of 24.79 wt% and 20.19 wt% (273.15 K/1.00 bar) respectively. While compared with the former two polymers, though 1227 m² g⁻¹ and 978 m² g⁻¹ are moderate in surface area, however the naphthalene-based Polymer 3 and phenanthrene-based Polymer 4 still exhibit CO₂ adsorption of up to 17.44 wt% and 18.15 wt% respectively under the similar conditions. Moreover, the H₂ storage and CH₄ adsorption in these polymers can be 2.20 wt% (77.3 K/1.13 bar) and 2.79 wt% (273.15 K/1.00 bar). More significantly, the electron-rich PAHs are proved to be new building blocks that provide a wealth of chances to produce hypercrosslinked polymers with efficient gas adsorption capacity, which are greatly influenced by the porous nature of polymers. Given the merits including mild reaction conditions, low cost, high surface area, impressive gas absorption performance, high thermal stability, these polymers are considered to be promising candidates for CO₂ capture and energy storage under more practical conditions.

In order to achieve efficient CO₂ capture, four novel microporous organic polymers, based on distinct polycyclic aromatic hydrocarbons, were successfully prepared by the solvent knitting method.

Melamine formaldehyde–metal organic gel interpenetrating polymer network derived intrinsic Fe–N-doped porous graphitic carbon electrocatalysts for oxygen reduction reaction

Melamine formaldehyde metal organic gel interpenetrating networks for heteroporous Fe–N-doped carbon.

Unveiling anomalous CO2-to-N2 selectivity of graphene oxide

Graphene oxide (GO) exhibits anomalous increase in CO₂-to-N₂ selectivity with temperature rise utilizing CO₂-philic functional groups and large macropores.

Facile Carbonization of Microporous Organic Polymers into Hierarchically Porous Carbons Targeted for Effective CO2 Uptake at Low Pressures

The advent of microporous organic polymers (MOPs) has delivered great potential in gas storage and separation (CCS). However, the presence of only micropores in these polymers often imposes diffusion limitations, which has resulted in the low utilization of MOPs in CCS. Herein, facile chemical activation of the single microporous organic polymers (MOPs) resulted in a series of hierarchically porous carbons with hierarchically meso-microporous structures and high CO2 uptake capacities at low pressures. The MOPs precursors (termed as MOP-7-10) with a simple narrow micropore structure obtained in this work possess moderate apparent BET surface areas ranging from 479 to 819 m(2) g(-1). By comparing different activating agents for the carbonization of these MOPs matrials, we found the optimized carbon matrials MOPs-C activated by KOH show unique hierarchically porous structures with a significant expansion of dominant pore size from micropores to mesopores, whereas their microporosity is also significantly improved, which was evidenced by a significant increase in the micropore volume (from 0.27 to 0.68 cm(3) g(-1)). This maybe related to the collapse and the structural rearrangement of the polymer farmeworks resulted from the activation of the activating agent KOH at high temperature. The as-made hierarchically porous carbons MOPs-C show an obvious increase in the BET surface area (from 819 to 1824 m(2) g(-1)). And the unique hierarchically porous structures of MOPs-C significantly contributed to the enhancement of the CO2 capture capacities, which are up to 214 mg g(-1) (at 273 K and 1 bar) and 52 mg g(-1) (at 273 K and 0.15 bar), superior to those of the most known MOPs and porous carbons. The high physicochemical stabilities and appropriate isosteric adsorption heats as well as high CO2/N2 ideal selectivities endow these hierarchically porous carbon materials great potential in gas sorption and separation.

From Azo-Linked Polymers to Microporous Heteroatom-Doped Carbons: Tailored Chemical and Textural Properties for Gas Separation

Heteroatom-doped porous carbons with ultrahigh microporosity were prepared from a nitrogen-rich azo-linked polymer (ALP-6) as a precursor for gas separation applications. Direct carbonization and chemical activation of ALP-6 with ZnCl2 and KOH were successfully applied to obtain three different classes of porous carbons (ALPDCs). Synthetic processes were conducted at relatively mild temperatures (500-800 °C),which resulted in retention of appreciable levels of nitrogen content (4.7-14.3 wt %). Additionally, oxygen functionalities were found to be present in chemically activated samples. The resultant porous carbons feature a diverse range of textural properties with a predominant microporous nature in common. The highest CO2 uptake value of 5.2 mmol g(-1) at 1 bar and 298 K in ALPDCK600 was originated from well-developed porosity and basic heteroatoms (N and O) on the pore walls. The highest heteroatom doping level (12 wt % nitrogen and 20 wt % oxygen) coupled with the high level of microporosity (84%) for ALPDCK500 led to notable CO2/N2 (62) and CO2/CH4 (11) selectivity values and a high CO2 uptake capacity (1.5 mmol g(-1), at 0.15 bar) at 298 K. This study illustrates the effective use of a single-source precursor with robust nitrogen bonds in combination with diverse carbonization methods to tailor the chemical and textural properties of heteroatom-doped porous carbons for CO2 capture and separation applications.

Enhanced selective adsorption of CO2 on nitrogen-doped porous carbon monoliths derived from IRMOF-3

The N-doped porous carbon monoliths prepared by direct carbonization of IRMOF-3, through an in situ activation and self-templating process, were found to exhibit significantly enhanced performance for the selective adsorption of CO₂ compared to pristine IRMOF-3.

Development Trends in Porous Adsorbents for Carbon Capture

Accumulation of greenhouse gases especially CO2 in the atmosphere leading to global warming with undesirable climate changes has been a serious global concern. Major power generation in the world is from coal based power plants. Carbon capture through pre- and post- combustion technologies with various technical options like adsorption, absorption, membrane separations, and chemical looping combustion with and without oxygen uncoupling have received considerable attention of researchers, environmentalists and the stake holders. Carbon capture from flue gases can be achieved with micro and meso porous adsorbents. This review covers carbonaceous (organic and metal organic frameworks) and noncarbonaceous (inorganic) porous adsorbents for CO2 adsorption at different process conditions and pore sizes. Focus is also given to noncarbonaceous micro and meso porous adsorbents in chemical looping combustion involving insitu CO2 capture at high temperature (>400 °C). Adsorption mechanisms, material characteristics, and synthesis methods are discussed. Attention is given to isosteric heats and characterization techniques. The options to enhance the techno-economic viability of carbon capture techniques by integrating with CO2 utilization to produce industrially important chemicals like ammonia and urea are analyzed. From the reader's perspective, for different classes of materials, each section has been summarized in the form of tables or figures to get a quick glance of the developments.