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Biological Metal–Organic Frameworks (Bio-MOFs) for CO 2 Capture
... The adsorption selectivity of CO 2 relative to CH 4 and N 2 was calculated using Henry's law before 0.1 bar. Based on Henry's law, the material shows CO 2 over N 2 or CH 4 adsorption selectivity (Figure 3b), ranking medi-MOF-1 as better porous adsorbents constructed from biomolecules for separating CO 2 from N 2 [50][51][52]. As we know, the separation of CO2 to CH4 and N2 by porous materials is favorabl in the environment. ...
... The adsorption selectivity of CO2 relative to CH4 and N2 was calculated usin Henry's law before 0.1 bar. Based on Henry's law, the material shows CO2 over N2 or CH adsorption selectivity (Figure 3b), ranking medi-MOF-1 as better porous adsorbents con structed from biomolecules for separating CO2 from N2 [50][51][52]. Ref. As we know, the separation of CO2 to CH4 and N2 by porous materials is favorable in the environment. ...
... The adsorption selectivity of CO2 relative to CH4 and N2 was calculated using Henry's law before 0.1 bar. Based on Henry's law, the material shows CO2 over N2 or CH4 adsorption selectivity (Figure 3b), ranking medi-MOF-1 as better porous adsorbents constructed from biomolecules for separating CO2 from N2 [50][51][52]. ...
Medi-MOF-1 is a highly porous Metal-Organic framework (MOF) constructed from Zn(II) and curcumin. The obtained crystal was characterized using powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). A micrometer-sized crystal with similar morphology was successfully obtained using the solvothermal method. Thanks to its high surface area, good stability, and abound pores, the as-synthesized medi-MOF-1 could be used as a functional porous material to adsorb different gases (H2, CO2, CH4, and N2) and iodine (I2). The activated sample exhibited a high I2 adsorption ability of 1.936 g g-1 at room temperature via vapor diffusion. Meanwhile, the adsorbed I2 could be released slowly in ethanol, confirming the potential application for I2 adsorption.
... There is little existing literature that reports on the performance of amino acid-based adsorbents, and none with a systematic or comprehensive review. It is worth mentioning that there is one recent publication signifying the potential of amino acids as promising ligands for synthesis of bio-based metal organic frameworks (Bio-MOFs) [49]. ...
... In the present review of amino acid-based adsorbents, the number of regeneration cycles for these adsorbents have been reported in several research articles (Tables 7 and 8). The highest number of cycles was 14 [79], and most adsorbents showed high stability with 10 regeneration cycles in average [25,41,49,54,59], advocating the potential application of AA-based adsorbents. However, these articles only discussed the regeneration performance without in-depth analysis of regeneration mode and reactor configuration. ...
... Most of the review papers discussed on the amino acids as a potential solvent for CO 2 capture. None of the papers reviewed on amino acid application in CO 2 adsorption, except for one recent publication [49] that briefly discussed the potential of amino acid as one of the ligands for the synthesis of bio-based metal organic frameworks (Bio-MOFs), which supports the relevance of the topic of the present review. Based on the keywords analysis and top ten most cited research articles, the hotspot area of research in this specific topic is the immobilisation of amino acid ionic liquids into solid porous materials. ...
The rise of carbon dioxide (CO2) levels in the atmosphere emphasises the need for improving the current carbon capture and storage (CCS) technology. A conventional absorption method that utilises amine-based solvent is known to cause corrosion to process equipment. The solvent is easily degraded and has high energy requirement for regeneration. Amino acids are suitable candidates to replace traditional alkanolamines attributed to their identical amino functional group. In addition, amino acid salt is a green material due to its extremely low toxicity, low volatility, less corrosive, and high efficiency to capture CO2. Previous studies have shown promising results in CO2 capture using amino acids salts solutions and amino acid ionic liquids. Currently, amino acid solvents are also utilised to enhance the adsorption capacity of solid sorbents. This systematic review is the first to summarise the currently available amino acid-based adsorbents for CO2 capture using PRISMA method. Physical and chemical properties of the adsorbents that contribute to effective CO2 capture are thoroughly discussed. A total of four categories of amino acid-based adsorbents are evaluated for their CO2 adsorption capacities. The regeneration studies are briefly discussed and several limitations associated with amino acid-based adsorbents for CO2 capture are presented before the conclusion.
... For environmental and process cost reasons, in the application of CO2 capture, the use of inexpensive renewable biolinkers for MOFs design, like in CaSyr-1, is preferred vs. those derived from non-renewable petrochemical feedstocks. 2 For adsorption-related applications, thermal stability plays an important role in ensuring the integrity of the MOF during the interaction with the adsorbate, as well as in the regeneration process of the material for further reuse. 26 Here, the thermal stability of CaSyr-1 was evaluated through thermogravimetric analysis (TGA) under N2 flow (Fig. S8). ...
... cell viability (%) = 100 × (ODS -ODB) / (ODC -ODB) [2] ...
A facile, fast and green strategy in ethanol is utilized to prepare a new bioMOF, namely CaSyr-1 , with the particular characteristics of full biocompatibility given by using just calcium and...
... Bio-ligands are categorized from numerous points of view, such as size, charge, and number of metal donated electrons. Bio-ligands are categorized into amino acids and peptides, nucleobases, proteins, saccharides, porphyrins, natural-based MOFs, and other biomolecule-based ligands [27]. Some examples of bio-ligands are shown in Fig. 5.3. ...
... Carboxyl groups provide various coordination modes and have strong coordination ability with metal ions due to their large negative charge density [30]. Examples of some bio-molecular organic ligands [27]. ...
Many challenges for developing new materials for the selective capture and separations of pollutants of energy industries were investigated. Bio-MOFs, which are biologically and environmentally compatible metal ions and bio-molecular ligands, have spurred the development of renewable and recyclable porous materials according to green chemistry principles. This chapter addresses the different bio-ligands for MOF structure and their use in energy industries by gas storage and CO2 capture as well as by combining multiple coordination sites and contain a variety of functional groups which may be suitable for binding metal ions that can help to control various interactions and chemical bonding, resulting in flexible structures. More so, current works and researches and challenges of incorporating bio-ligands such as amino acids, peptides, nucleobases, polysaccharides, porphyrins, and plant-based compounds are discussed and have afforded insights and new knowledge into this exciting subdiscipline of research to design new generation MOFs.
... For the latter, biomolecules collected from biomass, e.g., amino acids, peptides, bases and polysaccharides, can be used as linkers-replacing traditional organic linkers-to construct metal-biomolecule frameworks (bio-MOFs), in order to avoid the pollution caused by traditional organic linkers with toxicity [28][29][30]. For example, p-phthalic acid, the organic linker of MOF-5, is harmful to organisms; when exposed to humid air, MOF-5 with poor stability tends to decompose and dissolve into water [31]. ...
... Carbohydrates, including monosaccharides, disaccharides, oligosaccharides and polysaccharides [102], need to be oxidized before being used as linkers. The most common are α-CD, β-CD and γ-CD [29,103]. Among them, γ-CD has been extensively studied because of its better structural symmetry. ...
Metal–organic frameworks (MOFs) and their derivatives have delivered perfect answers in detection, separation, solving water and electromagnetic pollution and improving catalysis and energy storage efficiency due to their advantages including their highly tunable porosity, structure and versatility. Recently, MOF/biomass, bio-MOFs and their derivatives have gradually become a shining star in the MOF family due to the improvement in the application performance of MOFs using biomass and biomolecules. However, current studies lack a systematic summary of the synthesis and advancements of MOF/biomass, bio-MOFs and their derivatives. In this review, we describe their research progress in detail from the following two aspects: (1) synthesis of MOF/biomass using biomass as a template to achieve good dispersion and connectivity at the same time; (2) preparing bio-MOFs by replacing traditional organic linkers with biomolecules to enhance the connection stability between metal ions/clusters and ligands and avoid the formation of toxic by-products. This enables MOFs to possess additional unique advantages, such as improved biocompatibility and mechanical strength, ideal reusability and stability and lower production costs. Most importantly, this is a further step towards green and sustainable development. Additionally, we showcase some typical application examples to show their great potential, including in the fields of environmental remediation, energy storage and electromagnetic wave absorption.
... To introduce certain amino groups onto the surface of the nanofibrous membranes, ammonia plasma treatment was performed. The introduced amino groups could graft tannic acid onto the surface of the nanofibrous membranes with glutaraldehyde through aldehyde-amine and aldehydehydroxy reactions [57]. Tannic acid, with its multiple phenolic hydroxyl groups and highly potent reducing activity, facilitated the in situ chemical reduction of AgNO 3 to form AgNPs. ...
Background
Given the significant impact on human health, it is imperative to develop novel treatment approaches for diabetic wounds, which are prevalent and serious complications of diabetes. The diabetic wound microenvironment has a high level of reactive oxygen species (ROS) and an imbalance between proinflammatory and anti-inflammatory cells/factors, which hamper the healing of chronic wounds. This study aimed to develop poly(L-lactic acid) (PLLA) nanofibrous membranes incorporating curcumin and silver nanoparticles (AgNPs), defined as PLLA/C/Ag, for diabetic wound healing.
Methods
PLLA/C/Ag were fabricated via an air-jet spinning approach. The membranes underwent preparation and characterization through various techniques including Fourier-transform infrared spectroscopy, measurement of water contact angle, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, assessment of in vitro release of curcumin and Ag+, testing of mechanical strength, flexibility, water absorption and biodegradability. In addition, the antioxidant, antibacterial and anti-inflammatory properties of the membranes were evaluated in vitro, and the ability of the membranes to heal wounds was tested in vivo using diabetic mice.
Results
Loose hydrophilic nanofibrous membranes with uniform fibre sizes were prepared through air-jet spinning. The membranes enabled the efficient and sustained release of curcumin. More importantly, antibacterial AgNPs were successfully reduced in situ from AgNO3. The incorporation of AgNPs endowed the membrane with superior antibacterial activity, and the bioactivities of curcumin and the AgNPs gave the membrane efficient ROS scavenging and immunomodulatory effects, which protected cells from oxidative damage and reduced inflammation. Further results from animal studies indicated that the PLLA/C/Ag membranes had the most efficient wound healing properties, which were achieved by stimulating angiogenesis and collagen deposition and inhibiting inflammation.
Conclusions
In this research, we successfully fabricated PLLA/C/Ag membranes that possess properties of antioxidants, antibacterial agents and anti-inflammatory agents, which can aid in the process of wound healing. Modulating wound inflammation, these new PLLA/C/Ag membranes serve as a novel dressing to enhance the healing of diabetic wounds.
... Moreover, most of these ligands are toxic and unsuitable for large-scale production. In contrast, Bio-MOFs composed of biomolecules and metal ions have gained attention among various MOFs materials due to their low cost, low toxicity, good reproducibility, and adherence to the principles of green chemistry [43,44] . Inexpensive biomolecules, such as amino acids, proteins, peptides, and porphyrins, can serve as ligands for synthesizing Bio-MOFs [45,46] . ...
The use of porous solid adsorbents is an effective and excellent approach for the separation and purification of methanol-to-olefins product and methane (CH4). In this particular study, a series of adenine (AD)-based biological metal–organic frameworks (Bio-MOFs) {Their general formula is Cu2(AD)2(X)2 [X = formic acid, acetic acid (AA), and propionic acid]} were proposed, which exhibited remarkable efficiency in the purification of CH4 and the separation of C3H6 from methanol-to-olefins product, ultimately yielding purified C2H4. The experimental findings demonstrate that different terminal ligands induce alterations in the pore microenvironment, consequently leading to variations in adsorption capacities and stability. Specifically, Cu-AD-AA exhibits the highest adsorption capacity and selectivity among the three MOFs, as confirmed by static adsorption isotherm testing and theoretical evaluation using ideal adsorbed solution theory (IAST) simulation. At 298 K and 1 bar, Cu-AD-AA exhibits 786 and 10.9 selectivity for C3H8/CH4 and C3H6/C2H4, respectively, surpassing the majority of MOFs materials. Furthermore, breakthrough experiments conducted in ambient conditions reveal that Cu-AD-AA possesses commendable separation capabilities, enabling one-step purification of C2H4 at varying proportions (C2H4/C3H6 = 50:50, 50:20, and 90:10), along with satisfactory recycling performance. Importantly, the synthesis of Cu-AD-AA utilizes simple and easily obtainable raw materials, thereby offering advantages such as cost-effectiveness, low toxicity, and facile synthesis that enhance its potential for industrial applications.
... A significant use of employing Bio-MOF is to avoid the toxicity of organic linkers to ease the practical applicability of MOFs. 26,27 Notably, Nathaniel et al. have reported several Bio-MOFs, namely, bio-MOF-14, bio-MOF-11, bio-MOF-1, and many for different potential applications. 28−32 To note, the Bio-MOFs addressed in this article differ from those reported. ...
... Thanks to their large chemical varieties, high surface areas, and pore volumes, MOFs offer favorable adsorption sites for CO 2 molecules, and more importantly, their structures can be decorated with open metal sites and/or functional groups to achieve very high CO 2 uptakes. 17,18 For example, early experimental studies showed that several MOFs outperform commercial zeolite 13X (4.7 mol/kg) 19 and activated carbon Norbit RB2 (2.5 mol/kg) 20 because of their high CO 2 adsorption capacities in the ranges of 0.6−8.5 mol/kg at ambient conditions, even reaching record-breaking capacities of ∼50 mol/kg at 40 bar, 298 K. 21−23 Motivated by these findings, more and more MOFs have been synthesized and tested for CO 2 capture. Structures of synthesized MOFs are deposited into the Cambridge Structural Database (CSD), 24 and our search of this data center using ConQuest software 25 resulted in 122,738 MOFs as of October 2023. ...
The existence of a very large number of porous materials is a great opportunity to develop innovative technologies for carbon dioxide (CO2) capture to address the climate change problem. On the other hand, identifying the most promising adsorbent and membrane candidates using iterative experimental testing and brute-force computer simulations is very challenging due to the enormous number and variety of porous materials. Artificial intelligence (AI) has recently been integrated into molecular modeling of porous materials, specifically metal–organic frameworks (MOFs), to accelerate the design and discovery of high-performing adsorbents and membranes for CO2 adsorption and separation. In this perspective, we highlight the pioneering works in which AI, molecular simulations, and experiments have been combined to produce exceptional MOFs and MOF-based composites that outperform traditional porous materials in CO2 capture. We outline the future directions by discussing the current opportunities and challenges in the field of harnessing experiments, theory, and AI for accelerated discovery of porous materials for CO2 capture.
... In addition, transition metal ions that can coordinate with phosphorus-containing ligands can be used to enhance the flame-retardant properties of the MOF. Lu et al. synthesized an organic ligand containing P/N and combined it with Co to form a novel P-MOF [69] . The researchers found that adding the P/N-treated cobalt MOFs to the lignin-based epoxy resins (EP) significantly improved their flame retardancy, as demonstrated by reduced peak heat release rates and decreased total heat release. ...
This article presents a vision for advancing the development of next-generation flame-retardant materials through the utilization of metal-organic frameworks (MOFs). The proposed vision is centered on four key areas: industrialization, multifunctionality, ligand synthesis, and derivatives. By optimizing production processes, customizing MOFs for specific properties and applications, and developing novel ligands and derivatives, the effectiveness and versatility of MOFs as flame-retardant materials can be significantly enhanced. This vision represents a promising direction for the field that has the potential to address critical safety concerns across various industries.
... Metal-organic frameworks (MOFs) are porous materials composed of metal nodes and multi-site organic linkers connected by coordination bonds to form a periodic network structure [43][44][45][46][47][48][49][50]. The characteristic structure of MOFs can be used to build catalytic systems with multi-metal active centers because metal active centers may be distributed in both the metal nodes and organic linkages via coordination bonds at the atomic level. ...
Confined catalytic realms and synergistic catalysis sites were constructed using bimetallic active centers in two-dimensional metal-organic frameworks (MOFs) to achieve highly selective oxygenation of cycloalkanes and alkyl aromatics with oxygen towards partly oxygenated products. Every necessary characterization was carried out for all the two-dimensional MOFs. The selective oxygenation of cycloalkanes and alkyl aromatics with oxygen was accomplished with exceptional catalytic performance using two-dimensional MOF Co-TCPPNi as a catalyst. Employing Co-TCPPNi as a catalyst, both the conversion and selectivity were improved for all the hydrocarbons investigated. Less disordered autoxidation at mild conditions, inhibited free-radical diffusion by confined catalytic realms, and synergistic C–H bond oxygenation catalyzed by second metal center Ni employing oxygenation intermediate R–OOH as oxidant were the factors for the satisfying result of Co-TCPPNi as a catalyst. When homogeneous metalloporphyrin T(4-COOCH3)PPCo was replaced by Co-TCPPNi, the conversion in cyclohexane oxygenation was enhanced from 4.4% to 5.6%, and the selectivity of partly oxygenated products increased from 85.4% to 92.9%. The synergistic catalytic mechanisms were studied using EPR research, and a catalysis model was obtained for the oxygenation of C–H bonds with O2. This research offered a novel and essential reference for both the efficient and selective oxygenation of C–H bonds and other key chemical reactions involving free radicals.
... So far, several studies have shown that biological PCPs are promising candidates for industrial applications because they have the advantages of multiple coordination sites, a combination of rigid and flexible structural properties, durability, and cost effectiveness [50][51][52][53]. Herein, three isostructural chiral PCPs with functional biomolecular ligands, Co 2 (asp) 2 (bpy) (PCPs-asp, asp=L-aspartic acid, bpy=4,4'bipyridine), Co 2 (mal) 2 (bpy) (PCPs-mal, mal= L-malic acid) and Co 2 (mal) 2 (NH 2 -bpy) (PCPs-mal-n, NH 2bpy = 3-amino-4,4'-bipyridine) were designed and synthesized via pore-structure control for efficient selective C 2 H 2 /CO 2 separation ( Figure 1). ...
Physical adsorption separation of acetylene (C2H2) from carbon dioxide (CO2) on porous coordination polymers is a promising technique. However, it is still a particular challenge to realize the practical separation application of porous coordination polymers (PCPs) adsorbents with high separation performance, moderate adsorption heat, high stability and low cost. Herein, we demonstrate the efficient adsorption and separation of C2H2/CO2 from aspartate/malate anions columnar PCPs (namely PCPs-asp, PCPs-mal and PCPs-mal-n) exploiting the hydroxyl/amino sites within fine-tuning pore structures. Its one-dimensional (1D) chains and abundant hydroxyl/amino functional sites matched with target molecules, affording these anions columnar PCPs with not only high separation selectivity for C2H2/CO2, but also excellent gas capacity. Among them, PCPs-mal possesses an ultra-high C2H2 storage density of 655 g·L-1 under ambient conditions, and even close to the density of solid C2H2 at 189 K (729 g·L-1). PCPs-mal exhibits an IAST separation selectivity as high as 15.2 for the equimolar C2H2/CO2 binary mixture. The breakthrough experiments demonstrate that PCPs-mal realize efficient binary C2H2/CO2 separation with an acetylene dynamic adsorption capacity of 2.03 mmol·g-1. Theoretical calculations and GCMC simulations further provide critical insight into the separation mechanism at the molecular level. More importantly, the facile scaled synthesis, low adsorption enthalpy, and high separation performance make it cost-effective for real-world applications.
... [2][3][4] Impressive efforts have been invested to develop efficient CO 2 capture materials such as inorganic, [5][6][7] and organometallic porous materials. [8][9][10][11] As an emerging subclass of porous coordination polymers, metal-organic frameworks (MOFs) were widely studied for their remarkable features such as high specific surface areas, tunable porosity, thermal and chemical stability, and so forth. 12 The functionalization of these materials allows better interactions with guest molecules and improves their retention as well as their catalytic conversion, which makes MOFs promising materials for diverse applications. ...
In the context of porous coordination materials toward CO2 capture and separation, two new metal-organic frameworks termed IRH-6 and IRH-7 were synthesized with square and rhombic microchannel pores, respectively. These materials exhibit high CO2 uptakes of 2.67 mol/kg (IRH-6) and 2.78 mol/kg (IRH-7) at 100 kPa and 298 K. Grand Canonical Monte Carlo simulation demonstrated strong non-covalent interactions between the quadripolar CO2 molecules and these nitrogen-rich frameworks. CO2/CH4 (50:50), CO2/N2 (15:85), and CO2/H2 (15:85) gas mixtures were investigated by the ideal adsorbed solution theory and show excellent CO2 selectivity at ambient conditions for both porous materials. Particularly, a remarkable increase in the CO2 selectivity to 102 (IRH-7) over 31 (IRH-6) was observed for the CO2/CH4 binary mixture, which highlights the effect of pore aperture modification on the preferential CO2 uptake over other conventional gases.
... Among them, metal-organic frameworks (MOFs), a class of crystalline materials with periodic grid structures constructed from inorganic units and organic ligands, have attracted interest as possible nanoparticles supporter. MOFs have been applied in many areas to date due to their high specific surface area (usually 1000-10000 m 2 g -1 ), well-organized porous channels, and easily tunable composition and structure, especially in catalysis [31,32]. IRMOF-3, Co(BDC)-NH 2 , and ED/Cr-MIL-101 were successfully prepared to stabilize metal ions (Cu, Fe, Pd) for catalyzing drug synthesis and driving chemical reactions [33][34][35][36]. ...
The antibiotic florfenicol (FF) discharged into the aquatic environment may cause serious water pollution. Therefore, an effective way to eliminate FF antibiotics from the water bodies should be proposed. Herein, MIL-53(Al)-supported nano zero-valent iron ([email protected](Al)) was synthesized and applied to activate hydrogen peroxide (H2O2) to spark the Fenton reaction for FF antibiotics removal. The characterization results demonstrated the successful loading and good dispersion of NZVI onto MIL-53(Al). 100% FF antibiotics degradation could be achieved under the optimal reaction conditions, including an initial FF antibiotics concentration of 20 mg L⁻¹, initial solution pH of 3.0, [email protected](Al) dose of 25 mg L⁻¹, and H2O2 concentration of 0.2 mM. And after four cycles, the FF antibiotic degradation efficiency was still 81.18%. The lowest tolerance for HCO3⁻ was observed while the degradation activity was maintained at the presence of Cl⁻ and HA. EPR measurement and free radical quenching experiment showed that ·OH was the main reactive specie in the [email protected](Al)/H2O2 system. FF antibiotics degradation involved hydroxylation reactions (electrophilic substitution), dehalogenation, hydrolysis, and cleavage based on the UPLC-MS/MS analysis and DFT calculation. Noteworthy, 0.247 mg L⁻¹ of F⁻ and 1.2 mg L⁻¹ of Cl⁻ were detected in the solution after the reaction due to the breakage of the stable C–Cl bond and C–F bond. Finally, this work revealed that the [email protected](Al), with high stability and recyclability, could be a potential heterogeneous catalyst for treating antibiotic wastewater.
... In the recent decades, adsorption technologies attracted a significant attention in the view of environmental preservation and producing clean energy [25][26][27][28]. To this end, different classes of sorbents including zeolites [29], activated carbons [30], metal organic frameworks (MOFs) [31,32], metal oxides materials [33], silica [34], lithium zirconate [35], etc. [36], have been proposed for carbon capture and sequestration by adsorption, being crucial for large scale applications, to consider sustainability, stability, loading capacity, regeneration condition, density and hydrophobic/hydrophilic character, simultaneously [17]. ...
The persistent enhancement of greenhouse gases in the atmosphere originated from anthropogenic activities, especially CO2, resulted in several serious global challenges. In this way, employing biomass, biochar, etc., as a low-cost precursor for CO2 adsorbent is promising not only in the view of hydrophobic character and abundant resources, but also is an illustrious strategy for solid wastes management as a consequence of the exponential population expansion. Herein, key concepts on adsorption technology, waste management, and different activation techniques on raw carbons materials have firstly been discussed. Afterwards, almost all accomplished studies on cyclic adsorption processes e.g. PSA, TSA, VSA, etc., which employed biomass/biochar as a source of adsorbents have been extensively reviewed, that gives a precise knowledge for large scale application of these materials. Furthermore, in the last part of this work, biomass/biochar adsorbent based samples, which have already been studied for CO2 capture, but till now, they have not been evaluated at the bench/pilot scale by cyclic adsorption process, are introduced for future directions. Also for the reader’s of this work, key concepts of each section have been summarized in the form of simple figures and tables that will help to identify clearly the prominent accomplished works till now.
Synchronous boosting adsorption and desorption efficiency is a great challenge for CO2 adsorption capture, especially for metal–organic frameworks (MOFs) having high adsorption uptakes. Herein, a novel “self‐supporting foam” strategy is proposed to fabricate a thermally conductive MOFs@boron nitride nanosheets (BNNS) composite foam (MOFs@BNNS‐PEI) via polyethyleneimine (PEI) cross‐linkage. The “rebar” BNNS and the “aggregate” MOFs are packed against each other to form a self‐supporting structure, effectively reducing the reliance on polymers to maintain high MOFs loading. Furthermore, this approach enables the successful fabrication of three different types of typical MOFs, including HKUST‐1, MIL‐100(Fe), and ZIF‐8. This unique design maintains a high specific surface area (SSA) of the MOFs foam and generates nitrogen‐rich microporosity contributing to CO2 adsorption. Additionally, PEI serves as a thermal bridge to reduce the interfacial thermal resistance between BNNS and MOFs, accelerating the thermal desorption of CO2 within the MOFs foam. Benefiting from these advantages, the MOFs@BNNS‐PEI exhibits a higher CO2 adsorption capacity (1.35–1.42 times that of pure MOFs) and a significant increase in the desorption rate for CO2 (5.0–5.7 times that of pure MOFs). Thus, the thermally conductive MOFs foam can be a viable option for efficient CO2 capture in practical applications.
ZPD is a type of metal–organic framework based on zinc ions. Its structure contains 2,5 pyridine dicarboxylic acid as ligand, and it was synthesized by the hydrothermal method. Its metal–organic framework has a high surface area, suitable micropores, and a very regular crystalline structure. In this study, Biginelli reaction and chromene synthesis were realized using Cu@ZPD as a catalyst. The prepared products were obtained with high-to-excellent yield (80–96%). The mentioned catalyst was identified by Fourier transform infrared (FT-IR), Brunauer–Emmett–Teller (BET), thermogravimetric analysis (TGA), X-ray diffraction (XRD), field emission–scanning electron microscopy (FE-SEM), energy-dispersive X-ray (EDX) mapping, transmission electron microscopy (TEM), and inductively coupled plasma optical emission spectroscopy (ICP-OES) analyses. By using ICP-OES, Cu loading was detected at nearly 3 wt%. The prepared catalyst can be reused 6 times without significantly losing its catalytic activity. Also, ¹HNMR, ¹³CNMR, and FT-IR spectroscopy was used to identify the products.
The research aimed to evaluate the effectiveness of Cu-BDC MOF/CNFs hybrid sorbents in capturing CO2 in post-combustion processes. Various analytical techniques were used to analyze the adsorption materials, including XRD, FTIR, TGA, FE-SEM, EDS, BET, and elemental mapping. Capture performance evaluations were conducted using a fluidized-bed system and temperature swing adsorption on a laboratory scale. The Cu-BDC MOF/CNFs hybrids demonstrated their highest sorption capacity at 90 °C. Working capacity evaluations at a regeneration temperature of 120 °C consistently measured an average of 1.34 mol/kg, with a negligible standard deviation of 0.01 mol/kg. Cyclic tests were performed to assess the sorbents' performance, revealing efficient and rapid desorption of adsorbed CO2 within a short duration. Furthermore, 90 % of the sorption capacity was achieved within 5 min. These findings highlight the potential of Cu-BDC MOF/CNFs hybrid sorbents for CO2 capture in post-combustion processes.
Volatile organic compounds (VOCs) are present in the mixture of gases found in the exhaled human breath. Since their occurrence in the breath may indicate the presence of a disease, some VOCs are referred to as “biomarkers.” One of the most interesting types of gas sensors which have been thoroughly explored for VOCs detections is based on metal–organic frameworks (MOFs), which are crystalline porous coordination polymers assembled by following reticular chemistry rules. The aim of this review is to present a comprehensive summary of the latest MOF-derived composites that have been employed as VOCs biomarkers’ sensors. The study will first focus on reviewing the role of VOCs as disease biomarkers and then on the most prevalent methods used for analyte sensing by MOFs, including optical, electromechanical, and electrical sensing. The successive section examines some of the most recent reports on the use of five typical MOF families for sensing VOCs relevant as disease biomarkers. The basic structural features of these MOFs and their fundamental working principles as gas sensors will be highlighted in each sub-section through selected examples, emphasizing at the same time the correlation between the MOFs structure and functionalities, and their sensing properties. Finally, the study will be concluded with a discussion about a new class of MOFs called bio-MOFs, and their potentialities in VOCs sensing.
Metal–organic frameworks (MOFs) have attracted increasing attention due to their high porosity for exceptional gas storage applications. MOF-5 belongs to the family of isoreticular MOFs (IRMOFs) and consists of Zn4O⁶⁺ clusters linked by 1,4-benzenedicarboxylate. Due to the large number of atoms in the unit cell, molecular dynamics simulation based on density functional theory has proved to be too demanding, while force field models are often inadequate to model complex host–guest interactions. To overcome this limitation, an alternative semi-empirical approach using a set of approximations and extensive parametrization of interactions called density functional tight binding (DFTB) was applied in this work to study CO2 in the MOF-5 host. Calculations of pristine MOF-5 yield very good agreement with experimental data in terms of X-ray diffraction patterns as well as mechanical properties, such as the negative thermal expansion coefficient and the bulk modulus. In addition, different loadings of CO2 were introduced, and the associated self-diffusion coefficients and activation energies were investigated. The results show very good agreement with those of other experimental and theoretical investigations. This study provides detailed insights into the capability of semi-empirical DFTB-based molecular dynamics simulations of these challenging guest@host systems. Based on the comparison of the guest–guest pair distributions observed inside the MOF host and the corresponding gas-phase reference, a liquid-like structure of CO2 can be deduced upon storage in the host material.
The increase of carbon dioxide emissions and the global warming consequences is today a considerable environmental concern. On the contrary, the rapid growth in the energy consumption throughout the world has exacerbated the CO2 emissions to the atmosphere. Accordingly, carbon capture sequestration and utilization have been considered as a potential emission mitigation strategy. In this way, several strategies and technologies including: absorption, membranes, adsorption etc. have been proposed, which adsorption technology using solid sorbents due to the lower environmental side-effects also lower energy consumption is one of the most favorable strategies. However, despite the significant efforts made for developing novel solid adsorbents for CO2 mitigation, still the elements of cost and synthesis have remained as main challenges. To this end, biochar carbon materials have been employed as a source of adsorbent through CO2 capture and sequestration process not only to satisfy these factors but also as a pathway to the solid waste management. Herein, the key concepts on the carbon capture and sequestration also adsorption processes have been discussed. Next, the capability of biomass/biochar as a low-cost origin of potential adsorbent is extensively discussed.
The increasing threats of global warming and climate change from anthropogenic Carbon dioxide (CO2) emissions require a fundamental shift to a sustainable and environmentally friendly industry practise. Carbon Capture and Storage can reduce CO2 emissions (85–90%) from large point emission sources. The proposed review aims at realization of an integrated adsorption unit to capture, recover, and utilize this potentially harmful gas. For successful deployment of Carbon Capture and Storage, it is necessary to develop a cost and energy efficient CO2 capture and separation method along with the best reactor configuration which can be implemented as per our requirements. Adsorption-based CO2 capture has enjoyed considerable research attention in recent years. Most of the research efforts focused on sorbent development to reduce the energy penalty. However, the use of suitable gas–solid contacting systems is the key for extracting the full potential from the sorbent to minimize operating and capital costs and accelerate the commercial deployment of the technology. This review paper focuses on CO2 capture, its separation and utilization. It also focuses on different adsorbent materials with high selectivity and high capture capacity.
Biological metal-organic frameworks (BioMOF) formed by coordinating metal ions with biologically derived organic ligands have rising scientific stature owing to their superior functionalities. In the current work silver mandelate crystals (Ag(C8H7O3)), a silver-based bio-MOF are grown in hydrosilica gel medium activated with mandelate anions. XRD pattern of the powdered crystal confirmed the crystallinity of the crystals and the diffraction pattern is matched with the reported card data. Raman and FTIR spectra analyses confirmed the formation of the compound and ensured the presence of various functional groups in the crystal. Thermogravimetric analysis (TGA) revealed the chemical formula of the grown crystal and Differential Thermal analysis (DTA) stated that the compound is thermally stable. The single-stage thermal degradation over the temperature range of 160–350°C shows the- final degraded product is crystalline silver. The electronic spectral studies of the grown crystals show that the optical band gap energy is 4.36 eV. The dielectric behaviour is examined by studying the variation of dielectric constant, conductivity, and dielectric loss with the frequency of the applied field.
The ever-increasing atmospheric CO2 level is considered to be the major cause of climate change. Although the move away from fossil fuel-based energy generation to sustainable energy sources would significantly reduce the release of CO2 into the atmosphere, it will most probably take time to be fully implemented on a global scale. On the other hand, capturing CO2 from emission sources or directly from the atmosphere are robust approaches that can reduce the atmospheric CO2 concentration in a relatively short time. Here, we provide a perspective on the recent development of metal-organic framework (MOF)-based solid sorbents that have been investigated for application in CO2 capture from low-concentration (<10 000 ppm) CO2 sources. We summarized the different sorbent engineering approaches adopted by researchers, both from the sorbent development and processing viewpoints. We also discuss the immediate challenges of using MOF-based CO2 sorbents for low-concentration CO2 capture. MOF-based materials, with tuneable pore properties and tailorable surface chemistry, and ease of handling, certainly deserve continued development into low-cost, efficient CO2 sorbents for low-concentration CO2 capture.
A stable multifunctional Eu3+‐coordination polymer formulated as [Eu (Htzpia)(H2tzpia)]n (Eu‐CP‐1), has been successfully constructed by the reaction of Eu3+ ion with the new organic ligand 5‐(3‐(tetrazol‐5‐yl) phenyl) isophthalic acid (H3tzpia) under hydrothermal condition. Eu‐CP‐1 displays a 2D coordination network, in which 1D uniform chains with (μ‐COO)3 bridges are interlinked by the Htzpia and H2tzpia spacers. The 2D networks are associated into 3D architectures through hydrogen bonding interactions. Eu‐CP‐1 displays excellent luminescence property and exhibits good stability in water. Thus, Eu‐CP‐1 can be used to detect Fe3+ ions and MnO4‐ ions with high sensitivity and selectivity through luminescence quenching effect. Due to the presence of open metal sites, free oxygen/nitrogen atoms and ‐NH groups of tetrazole rings, Eu‐CP‐1 can act as an effective heterogeneous catalyst for the cycloaddition reaction of carbon dioxide with epoxides under eco‐friendly and solvent‐free conditions. Interestingly, Eu‐CP‐1 is highly recyclable and reusable for up to five cycles without an obvious loss in sensing or catalytic efficiency. In addition, the possible relevant mechanisms are also investigated. This work should aid in expanding potential application prospects of the lanthanide CPs in the fields of contaminated ions detection and CO2 cycloaddition..
This study aimed to improve the carbon dioxide (CO2) capture and kinetics performance for direct air capture (DAC) while demonstrating the amine grafting reaction principles and its constraints using N-(2-aminoethyl)ethanolamine (AEEA) to functionalize coordinatively unsaturated metal sites in MIL-100(Fe), UiO-66(Zr), and MIL-100(Cr). Grafting experiments indicated that the grafting process is the reaction between metal sites and secondary amines of AEEA, while MOFs with high surface area and low acidity can effectively promote amine grafting without destroying the active site. Moreover, the adsorbed CO2 amounts of MF-Cr-AEEA at 400 ppm were 1.91 mmol/g of -25 °C and 2.42 mmol/g of 0 °C, and the structural decomposition temperature exceeded 400 °C, demonstrating excellent thermal and cold stability. As a result of the better crystal and surface structure, the internal heat and mass transfer processes were accelerated, resulting in low semi-adsorption times below 21 min. Moreover, CO2 capture cycles were established at 25 °C for adsorption and 80 °C for desorption. The results show that the adsorption capacity of MF-Cr-AEEA remained 1.86 mmol/g after seven cycles, demonstrating low renewable energy consumption and high stability.
Ammonia capture is of great importance to environmental protection and resource conservation. In this work, two isoreticular bio-MOFs, Zn(3-AIN)(AD)•DMF and Zn(3-AIN)(AD)•DMA, were constructed with inexpensive, easily available and low/without toxic...
Hybridization of metal organic frameworks (MOFs) with graphene oxide (GO) is used to improve the CO2 adsorption performance of MOFs, but the underlying mechanism of this process is still unclear. This study provides a general framework to understanding the mechanism of CO2 adsorption and separation on GO/CuBTC and GO/UTSA-16 in order to optimize the synthesis of the desired material. For this purpose, molecular models mimicking the experimentally available hybrid materials were developed and studied by molecular simulations. Once the models were validated with available experimental data, a systematic study on the effect of different structure variables was performed, searching for the best hybridization procedure for this application, in a predictive manner. It has been confirmed that the interface between GO and MOFs produces strong interactions with CO2, which, together with the smaller pore sizes, significantly enhances the adsorption performance at low pressures. Moreover, the performance of the most promising hybrid GO/MOFs structures from pure CO2 adsorption isotherms for separating CO2 from nitrogen were predicted by GCMC based on binary mixtures (15CO2:85N2) and a temperature swing adsorption (TSA) process. Among the different materials/compositions explored, GO/CuBTC with the highest GO content (i.e., 65% wt.) and under the premise of no stacking of GO, shows the best results in terms of key performance indicators: CO2/N2 adsorption selectivity (120 at 313 K), working capacity (1.794 mmol/g at a desorption temperature of 443 K), and a specific energy consumption (0.534 GJ/tonne-CO2) comparable to amine scrubbing.
Li4SiO4 has been evaluated as one of the most promising CO2 absorbers to mitigate climate changes caused by excessive CO2 emissions. Li4SiO4 absorbents with a high specific surface area would hold higher CO2 capture capacity. However, with the lack of suitable SiO2 precursors, the synthesis of Li4SiO4 absorbents with a high specific surface area and a well-defined hollow sphere structure was still challenging. Here, a two-stream confined jet impingement continuous microchannel reactor was proposed to produce ultrahigh-quality mesoporous silica nanospheres (UHMSNs) with an ultrahigh specific surface area and a small particle size. The obtained UHMSNs possessed excellent water dispersibility, a uniform diameter (142–207 nm), tunable perpendicular mesopores (2.6–3.3 nm), a high surface area (1347∼1854 m2/g), and a large pore volume 0.86∼1.23 cm3/g). Moreover, MesoDyn simulation provided valuable information to optimize the nucleation stage and the crystallization stage of UHMSNs. Additionally, UHMSNs were used as the silicon source to synthesize the petal-like hollow structure of Li4SiO4 microspheres, which enhanced CO2 adsorption.
An efficient CO2 adsorbent with a hierarchically micro-mesoporous structure and a large number of amine groups was fabricated by a two-step synthesis technique. Its structural properties, surface groups, thermal stability and CO2 adsorption performance were fully investigated. The analysis results show that the prepared CO2 adsorbent has a specific hierarchically micro-mesoporous structure and highly uniformly dispersed amine groups that are favorable for the adsorption of CO2. At the same time, the CO2 adsorption capacity of the prepared adsorbent can reach a maximum of 3.32 mmol-CO2/g-adsorbent in the actual flue gas temperature range of 303–343 K. In addition, the kinetic analysis results indicate that both the adsorption process and the desorption process have rapid adsorption/desorption rates. Finally, the fitting of the CO2 adsorption/desorption experimental data by Avrami’s fractional kinetic model shows that the CO2 adsorption rate is mainly controlled by the intra-particle diffusion rate, and the temperature has little effect on the adsorption rate.
Thermolysis of a urethane end group was observed as a first time phenomenon during activation. This unzipping mechanism revealed a new amine tethering point producing a diamine-terminated oligourea ([10]-OU), acting as a green sorbent for CO2 capturing. The oligomer backbites its end group to form propylene carbonate (PC), as proved by in situ TGA-MS, which can reflect the polymer performance by maximizing its capturing capacity. Cross polarization magic angle spinning (CP-MAS) NMR spectroscopy verified the formation of the proven ionic carbamate (1:2 mechanism) with a chemical shift at 161.7 ppm due to activation desorption at higher temperatures, viz., 100 °C (in vacuo) accompanied with bicarbonate ions (1:1 mechanism) with a peak centered at 164.9 ppm. Fortunately, the amines formed from in situ thermolysis explain the abnormal behavior (carbamates versus bicarbonates) of the prepared sample. Finally, ex situ ATR-FTIR proved the decomposition of urethanes, which can be confirmed by the disappearance of the pre-assigned peak centered at 1691 cm-1. DFT calculations supported the thermolysis of the urethane end group at elevated temperatures, and provided structural insights into the formed products.
As alternatives to natural enzymes, nanostructured materials with enzyme catalytic properties named “nanozymes” have attracted a great deal of attention with widespread usage in industrial, medical, and biological fields. Focusing on the design of enzyme models based on supramolecular scaffolds provides new perspectives towards artificial enzyme research. Supramolecular chemistry is defined as the ability of molecules to self-organize into a highly complex chemical system based on noncovalent interactions. A thorough understanding of the catalytic mechanism will contribute to the rational design of highly efficient nanozymes. Since the biocatalytic functions of natural enzymes usually accompanied by a variety of structural complexities and limitations, supramolecular viewpoint provides an alternative strategies to unravel the mystery of enzyme mechanisms. In the current review, we introduce the classification of supramolecular scaffolds, discuss about artificial nanozymes from supramolecular point of view and cover recent research development of nanozymes in the field of medical diagnosis and treatment, biosensing, imaging, environmental protection and etc. We hope this review provides insights to researchers who study the field and contributes to the development of enzyme mimic research.
The outstanding properties of metal-organic frameworks (MOFs) have proven that this type of crystalline adsorbent has great potential in CO2 capture applications. Most of the MOF research studies on new functional MOFs are conducted to improve the performance of CO2 gas adsorption. Combined studies of material evaluation and process design on engineering issues in CO2 capture applications in industry are rarely carried out. In this study, the authors attempted to address engineering issues by developing a biometal-organic framework with the bioligand L-glutamic acid that has more practical fabrication cost than petrochemical MOFs. Herein, the demonstration of the prediction and optimization of CO2 adsorption capacity, selectivity, and heat of adsorption using a multiobjective genetic algorithm (MOGA) combined with an artificial neural network (ANN). The success of the Bio-MOF fabrication was evaluated by scanning electron microscopy, N2 adsorption-desorption isotherm analysis, thermal gravimetric analysis, X-ray diffraction, and Fourier transform infrared spectroscopy techniques. Furthermore, volumetric measurements were performed at several temperatures (27, 35 and, 50°C). The isosteric heat of adsorption was then evaluated by an indirect method with the Clausius-Clapeyron (C-C) and Chakraborty, Saha, and Koyama (CSK) equations. Then, CO2/N2 selectivity was analysed by IAST techniques by regressing the experimental data with the Langmuir-Freundlich isothermal equation. The computational study by ANN and MOGA also gives satisfying results in balancing three requirements criteria. Thus, this study paved the way for the development of low-cost scalable MOF fabrication in industry by applying the optimization and balancing principles of the three objective functions.
With the objective to realize efficient and selective oxidation of hydrocarbons with O2 to partial oxidation products, 2D metal-organic frameworks (2D MOFs) possessing bimetallic active centers (Co&Cu, Co&Zn, Cu&Zn) were prepared to construct confined catalytic domains and staged oxidation sites. All the 2D MOFs were characterized systematically through FT-IR, XPS, PXRD, SEM, TEM, EDS, BET and TG analyses. Applied to the partial oxidation of C-H bonds with O2, superior catalytic performance was observed in the employment of 2D MOF Co-TCPPCu as catalyst, in which both of the conversion and selectivity towards partial oxidation products were enhanced simultaneously. The superior performance of oxidation system employing Co-TCPPCu as catalyst was mainly because of the decreased disordered autoxidation at lower reaction temperature, suppressed free radical diffusion in the confined catalytic domains of Co-TCPPCu, and enhanced oxidation of C-H bonds with oxidation intermediate product R-OOH catalyzed by second metal center Cu(II). For the important and classical oxidation of cyclohexane in chemical industry, the conversion was increased from 4.39% to 5.31% with the selectivity towards partial oxidation products being enhanced from 85% to 95% compared with homogeneous metalloporphyrin T(4-COOCH3)PPCo as catalyst. The staged oxidation paths and catalytic mechanism were also explored systematically through control experiments, free radical capture and electron paramagnetic resonance (EPR) analyses. This work presented an intelligent and valuable reference not only for the selective and efficient oxidative functionalization of hydrocarbons with O2 in both of the industrial application and academic research, but also for other important chemical transformations involved in free radicals.
Heterogeneous MOFs catalysts have attracted great attention due to the efficient combination of heterogeneity (easy post-reaction separation and recyclability) and homogeneity (active sites and porosity), which inspire us to explore functional MOFs materials with higher catalytic activity on the chemical fixation of CO2 and deacetalization-Knoevenagel condensation. Herein, the self-assembly of Cd²⁺ and H6TDP under acidic solvothermal condition generated one cadmium-organic framework of {[(CH3)2NH2]2 [Cd2 (TDP) (H2O)2]⋅3DMF⋅2H2O}n (NUC-29, H6TDP = 2,4,6-tris(2,4-dicarboxyphenyl)pyridine) with nano-caged voids and hierarchical microporous channels, which were built on the combination of two kinds of mononuclear units of [Cd (1) (COO)3(H2O)] and [Cd (2) (COO)3(H2O)]. After the removal of solvent molecules by activation, NUC-29 possesses the coexistence of Lewis acid-base sites on the inner surface of channels including all exposed Cd²⁺ sites and Npyridine sites, which render it an excellent recyclable heterogeneous catalyst to facilitate the cycloaddition reaction of epoxides with CO2 and deacetalization-Knoevenagel condensation under mild conditions.
In the paper, we present a review of different types of CO2 capture, storage, transportation, and utilization (CCSTU) processes. We have also reviewed their further development by using machine learning (ML) methods. Some examples of carbon capture or separation technologies (CCT) are absorption, adsorption, membranes, chemical looping, pyrogenic carbon capture and storage (PyCCS), hydrates, and mineral sequestration, which we review here. We have also classified hybrid processes where multiple methods can be synergistically used for CO2 capture and utilization. ML methods have also been successfully utilized in CCSTU to enhance the efficiency of CCSTU by process optimization and incorporating new materials design. Based on the review, we have outlined some recommendations for future research, namely consideration of the carbon impact of AI-driven models, and more interactions among ML experts, experimentalists, and computational modelers, which will lead to a holistic approach rather than a competing attitude for rapid commercialization of low-carbon technologies. We also give examples of databases for future research.
Traditional methods of preparing metal-organic frameworks (MOFs) compounds have the disadvantages such as poor dispersion, inefficient and discontinuous process. In this work, microchannel reactor is used to prepare MOFs-derived zeolite-imidazole material via flash nanoprecipitation to form ZIF-67 + PEI(FNP), which reduces the MOF synthesis time down to millisecond time interval while keeping the synthesized ZIF-67 + PEI(FNP) highly dispersed. The [email protected](FNP)catalyst obtained by flash nanoprecipitation and carbonization has a higher Co content and thus more active sites for oxygen reduction reaction than the [email protected](DM) catalyst prepared by direct mixing method. Electrochemical tests show that the [email protected](FNP) catalyst prepared by this method has excellent oxygen reduction performance, good methanol resistance and high stability. The onset potential and half-wave potential of [email protected](FNP) are 0.92 VRHE and 0.83 VRHE, respectively, which are higher than that of [email protected](DM) (Eonset = 0.90 VRHE and E1/2 = 0.83 VRHE). Moreover, the Zn-air battery assembled with [email protected](FNP) as the cathode catalyst has high open circuit voltage, high power density and large specific capacity. The performance of these batteries has been comparable to that of Pt/C assembled batteries. Density functional theory (DFT) calculations confirm that the Co (220) crystal plane present in [email protected](FNP) have stronger adsorption energy than that of Co (111) crystal plane in [email protected](DM), leading to better electrocatalytic performance of the former.
This review discusses the design and syntheses of molecular-scale pillar[n]arene-based porous materials with promising applications and summarises the development of using pillar[n]arenes as the building blocks of porous materials. From the perspective of "role of participation" in the syntheses of molecular-scale pillar[n]arene-based porous materials, the content can be divided into pillar[n]arenes serving as supramolecular nanovalves on surfaces and as ligands for metal-organic frameworks and covalent organic polymers. By integrating pillararenes, which possess rigid pillar-like structures, electron-rich cavities and desirable host-guest properties, with porous polymers of large surface areas and abundant active sites, applications of the resulting materials in drug release platforms, molecular recognition, sensing, detection, gas adsorption, removal of water pollution, organic photovoltaic materials and heterogeneous catalysis can be realised simultaneously and efficiently. Finally, in the conclusions and perspectives part, we put forward the challenges and viewpoints of the current research on pillar[n]arene-based porous materials. We hope this article can provide a timely and valuable reference for researchers interested in synthetic macrocycles and porous materials.
In this work, a new type of solid amine sorbent was developed for low concentration CO2 capture at ambient temperature. Polyacrylonirtrile(PAN)-poly(methyl methacrylate)(PMMA) porous hollow fibers were firstly prepared by a wet-spinning process. Tetraethylenepentamine(TEPA) was then grafted onto the porous structure of the hollow fibers. The amine modified hollow fibers denoted as [email protected] were characterized by the Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis(TGA), Brunauer-Emmett-Teller(BET), and scanning electron microscopy(SEM) methods. Performance of the [email protected] for CO2 capture was evaluated by passing a 0.3% CO2-N2 gas mixture through the porous matrix of the hollow fibers at ambient temperature. The highest CO2 adsorption capacity reached up to 1.50 mmol g⁻¹ for dry feed, and 3.00 mmol g⁻¹ for wet feed, respectively. Cyclic CO2 adsorption-desorption test indicated that the [email protected] sorbents are stable and regenerable.
Power plants need efficient sustainable technology for carbon dioxide (CO2) capture in order to comply with environmental regulations. This chapter presents advances and challenges of metal-organic frameworks (MOFs) and biological MOFs (bio-MOFs) as adsorbents in postcombustion CO2 capture. Thermal, chemical, and hydrothermal stability of MOFs in harsh working conditions affect the cost of CO2 capture technology. The authors also introduce strategies for improving the abilities of MOFs to capture CO2. This chapter also includes information on the adsorption capacity, selectivity, and heat of adsorption for CO2 capture through modification of synthesis procedures, pore structures, shapes, or additions of functional groups to MOFs, as well as a brief discussion on the cost analysis of MOFs for CO2 capture.
A novel metal-organic framework based on naphthalenedicarboxylic acid is described. By solvothermal reaction method, 2,6-Naphthalenedicarboxylic acid, existing organic ligands that have never been used to support La-MOFs, was synthesized using acetic acid as the solvent and lanthanum nitrate hexahydrate as a metal source. So far, this type of metal-organic framework based lanthanum ion has not been investigated before. La-NDC MOFs were characterized to determine its functional groups contained in La-MOFs, morphology and particle size, crystallinity, optical and thermal stability by SEM (Scanning Electron Microscopy), FTIR (Fourier transform infrared) spectroscopy, XRD (X-ray Diffraction), UV-vis and TGA (thermogravimetric analysis) sequencely. The adsorption/desorption isotherms of N2 were measured at 77.4 K to know the specific surface area and pore volume of La-NDC MOF. BET (Brunauer-Emmet-Teller) equation was also applied to calculate the surface area of compounds.
Investigation of metal–organic frameworks (MOFs) for biomedical applications has attracted much attention in recent years. MOFs are regarded as a promising class of nanocarriers for drug delivery owing to well-defined structure, ultrahigh surface area and porosity, tunable pore size, and easy chemical functionalization. In this review, the unique properties of MOFs and their advantages as nanocarriers for drug delivery in biomedical applications were discussed in the first section. Then, state-of-the-art strategies to functionalize MOFs with therapeutic agents were summarized, including surface adsorption, pore encapsulation, covalent binding, and functional molecules as building blocks. In the third section, the most recent biological applications of MOFs for intracellular delivery of drugs, proteins, and nucleic acids, especially aptamers, were presented. Finally, challenges and prospects were comprehensively discussed to provide context for future development of MOFs as efficient drug delivery systems.
The Fluid Catalytic Cracking Unit process converts heavy vacuum gas oil into more valuable products in the presence of zeolite catalyst at 520 °C and 2.5 bar. The coke is burned off with air in the regenerator tower at 700 °C and 230 ton / h of flue gases are produced. The flue gases consist of CO2 (12.7% mole), N2 (66.2% mole), H2O (19.2% mole), O2 (1.7% mole), and SO2 (0.2% mole). In this study, the chemical absorption of CO2 in an absorption and desorption pilot plant was investigated and this process was simulated by Aspen Hysys. The pilot plant used has an absorber tower of 15 cm in diameter and a stripper tower of 10 cm. The towers were filled up to 1.5 m with 3-mm Raschig ring packing. A concentration of 30 wt% diethanolamine (DEA) solvent is used for CO2 absorption. Absorption was carried out at 1.1 bar, solvent temperature of 40 °C, flue gas temperature of 60 °C, and liquid to gas ratio (L/G = 3.7). Amine regeneration was carried out at 125 °C and 1.9 bar. The CO2 absorption efficiency in the pilot plant was obtained 96% and in Aspen Hysys simulation its 95%. The CO2 recovery efficiency in the stripper tower obtained 95% and CO2 purity is 94.6%. The overall efficiency of the chemical absorption with this process is 92%, and the regeneration energy in the stripper tower is 2.52 GJ/ton-co2. With this method, 1003 ton/day CO2 is captured from the FCCU flue gases and preventing emission to the atmosphere.
Aluminum trimesate-based MOF (MIL-96-(Al)) has attracted intense attention due to its high chemical stability and strong CO2 adsorption capacity. In this study, CO2 capture and selectivity of MIL-96-Al was further improved by the coordination of the second metal Ca. To this end, a series of MIL-96(Al)–Ca were hydrothermally synthesised by a one-pot method, varying the molar ratio of Ca²⁺/Al³⁺. It is shown that the variation of Ca²⁺/Al³⁺ ratio results in significant changes in crystal shape and size. The shape varies from the hexagonal rods capped in the ends by a hexagonal pyramid in MIL-96(Al) without Ca to the thin hexagonal disks in MIL-96(Al)–Ca4 (the highest Ca content). Adsorption studies reveal that the CO2 adsorption on MIL-96(Al)–Ca1 and MIL-96(Al)–Ca2 at pressures up to 950 kPa is vastly improved due to the enhanced pore volumes compared to MIL-96(Al). The CO2 uptake on these materials measured in the above sequence is 10.22, 9.38 and 8.09 mmol g⁻¹, respectively. However, the CO2 uptake reduces to 5.26 mmol g⁻¹ on MIL-96(Al)–Ca4. Compared with MIL-96(Al)–Ca1, the N2 adsorption in MIL-96(Al)–Ca4 is significantly reduced by 90% at similar operational conditions. At 100 and 28.8 kPa, the selectivity of MIL-96(Al)–Ca4 to CO2/N2 reaches up to 67 and 841.42, respectively, which is equivalent to 5 and 26 times the selectivity of MIL-96(Al). The present findings highlight that MIL-96(Al) with second metal Ca coordination is a potential candidate as an alternative CO2 adsorbent for practical applications.
Carbon dioxide capture by ammonia is considered one of the promising technologies for emission control in cement plants. This paper focuses on the experimental investigation of the factors affecting the chemical absorption process of carbon dioxide by ammonium hydroxide solution. The factors include ammonia concentration below 14%, reaction temperature below 20 °C and reaction time 30 min as the optimum parameters. The paper also highlights the economic and practical aspects to be taken into consideration when applying this technology to cement plants.
This article presents preliminary results of the methanation process using CO2 from amine scrubbing. The studies were carried out at the CO2-SNG pilot plant. The installation was built by TAURON Wytwarzanie S.A. at the Łaziska Power Plant in Poland. After the commissioning, the Institute for Chemical Processing of Coal (IChPW) was responsible for conducting research. Synthetic methane (SNG) is produced by the reaction of CO2 captured from flue gas (using amine absorption) with H2 obtained from water electrolysis. The methanation reaction takes place in a two-stage catalytic reactor. After the compression the SNG could be used as a fuel for internal combustion engines (CNG). This paper describes in detail the construction of the pilot plant as well as the guidelines for the methanation process. Furthermore, the impact of process gas flow, reactor temperature and system pressure on the conversion of CO2 to methane is presented. The tests were carried out at process gas flows in the range of 9.9–23.0 m³N/h, at pressures of 1.5–3.0 bara and temperatures of 280–350 °C. The maximum obtained CO2 conversion was 98%. The produced SNG consisted of about 82% of methane, 13% of hydrogen and 5% of CO2.
The concentration of CO2
in the atmosphere caused by fossil fuels, power plants, and transportation is
the most significant environmental issue in the world today. Intensive efforts have
been made to minimize CO2 levels to reduce global warming. Metal-organic
frameworks (MOFs), crystalline porous materials, exhibit great potential to
adsorb carbon dioxide. In the present study, research was conducted on the synthesis,
characterization, and adsorption isotherms of MIL-101. MIL-101, one type of
mesoporous MOF, can adsorb enormous amounts of CO2. The synthesis was
carried out using a fluorine-free hydrothermal reaction method. The porous
properties, structure, morphology, thermal stability, and chemical
functionalities of MIL-101 Cr were measured by N2
adsorption/desorption isotherms, X-ray diffraction (XRD), scanning electron microscope
(SEM), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy
(FTIR) analysis, respectively. The volumetric uptakes of CO2 were
experimentally measured at temperatures of 298-308 K and pressure of up to 600
kPa. The experimental result was correlated with the Toth isotherm model,
showing the heterogeneity of the adsorbent. The heat of adsorption of MIL-101
was determined from the measured isotherm data, indicating the strength between
the adsorbent and adsorbate molecule.
The separation of acetylene from ethylene is of paramount importance in the purification of chemical feedstocks for industrial manufacturing. Herein, an isostructural series of gallate‐based metal–organic frameworks (MOFs), M‐gallate (M=Ni, Mg, Co), featuring three‐dimensionally interconnected zigzag channels, the aperture size of which can be finely tuned within 0.3 Å by metal replacement. Controlling the aperture size of M‐gallate materials slightly from 3.69 down to 3.47 Å could result in a dramatic enhancement of C2H2/C2H4 separation performance. As the smallest radius among the studied metal ions, Ni‐gallate exhibits the best C2H2/C2H4 adsorption separation performance owing to the strongest confinement effect, ranking after the state‐of‐the‐art UTSA‐200a with a C2H4 productivity of 85.6 mol L⁻¹ from 1:99 C2H2/C2H4 mixture. The isostructural gallate‐based MOFs, readily synthesized from inexpensive gallic acid, are demonstrated to be a new top‐performing porous material for highly efficient adsorption of C2H2 from C2H4.
The discovery of naturally occurring linker‐based zirconium MOFs with permanent porosity and accessible functional groups remains a challenge. Using trans‐aconitic acid to assemble with Zr6 oxoclusters under green and scalable conditions, a novel microporous Zr‐aconitate framework has been prepared successfully with a high space‐time yield. This MOF is isostructural to the previously reported Zr‐fumarate, however with a smaller pore size and an abundant concentration of free acetic acid functional groups. This MOF shows an excellent chemical stability under various conditions, including boiling water, concentrated acids, and basic solution with pH below 12. Furthermore, this compound not only shows a higher carbon dioxide uptake compared to the Zr‐fumarate analogue but also exhibits a notably enhanced adsorptive selectivity for carbon dioxide over nitrogen in the entire pressure range.
Grand canonical Monte Carlo (GCMC) simulations are widely used with equilibrium molecular dynamics (EMD) to predict gas adsorption and diffusion in single-crystals of metal-organic frameworks (MOFs). Adsorption and diffusion data obtained from these simulations are then combined to predict gas permeabilities and selectivities of MOF membranes. This GCMC + EMD approach is highly useful to screen a large number of MOFs for a target membrane-based gas separation process. External field non-equilibrium molecular dynamics (NEMD) simulations, on the other hand, can directly compute gas permeation by providing an accurate representation of MOF membranes but they are computationally demanding and require long simulation times. In this work, we performed NEMD simulations to investigate H2/CH4 separation performances of MOF membranes. Both single-component and binary mixture permeabilities of H2 and CH4 were computed using the NEMD approach and results were compared with the predictions of the GCMC + EMD approach and experimental measurements reported in the literature. Our results showed that there is a good agreement between NEMD simulations and experiments for the permeability and selectivity of MOF membranes. NEMD simulations provided the direct observation of the mass transfer resistances on the pore mouth of MOF membranes, which is neglected in the GCMC + EMD approach. Our results suggested that once the very large numbers of MOF materials were screened using the GCMC + EMD approach, more detailed NEMD calculations can be performed for the best membrane candidates to unlock the actual gas transport mechanism before the experimental fabrication of MOF membranes.
CO2 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 CO2 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 CO2 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 CO2 capture. The current engineering evaluation approaches for MOFs are summarized, in a manner that could also be applied to other adsorbent materials.
Current advances in materials science have resulted in the rapid emergence of thousands of functional adsorbent materials in recent years. This clearly creates multiple opportunities for their potential application, but it also creates the following challenge: how does one identify the most promising structures, among the thousands of possibilities, for a particular application? Here, we present a case of computer-aided material discovery, in which we complete the full cycle from computational screening of metal-organic framework materials for oxygen storage, to identification, synthesis and measurement of oxygen adsorption in the top-ranked structure. We introduce an interactive visualization concept to analyze over 1000 unique structure-property plots in five dimensions and delimit the relationships between structural properties and oxygen adsorption performance at different pressures for 2932 already-synthesized structures. We also report a world-record holding material for oxygen storage, UMCM-152, which delivers 22.5% more oxygen than the best known material to date, to the best of our knowledge.
Carbon capture and storage (CCS) is broadly recognised as having the potential to play a key role in meeting climate change targets, delivering low carbon heat and power, decarbonising industry and, more recently, its ability to facilitate the net removal of CO2 from the atmosphere. However, despite this broad consensus and its technical maturity, CCS has not yet been deployed on a scale commensurate with the ambitions articulated a decade ago. Thus, in this paper we review the current state-of-the-art of CO2 capture, transport, utilisation and storage from a multi-scale perspective, moving from the global to molecular scales. In light of the COP21 commitments to limit warming to less than 2 °C, we extend the remit of this study to include the key negative emissions technologies (NETs) of bioenergy with CCS (BECCS), and direct air capture (DAC). Cognisant of the non-technical barriers to deploying CCS, we reflect on recent experience from the UK's CCS commercialisation programme and consider the commercial and political barriers to the large-scale deployment of CCS. In all areas, we focus on identifying and clearly articulating the key research challenges that could usefully be addressed in the coming decade.
One of the more recent and promising domains of the application of Metal Organic Frameworks (MOFs) is the biomedical one. To fulfil the keystone requirements of bioapplications, i.e. biosafety and activity, endogenous and/or bioactive motifs (cations, organic ligands or both) have been successfully used as constitutive building blocks to construct Metal Biomolecule Frameworks (also known as bioMOFs). This review highlights the latest advances in 3D bioMOF structures, from their synthesis to their biorelated activities in different biorelated areas including drug delivery, imaging, and sensing, classifying them by the nature of the active component.
We investigate the effect of pore size and shape on the thermal conductivity of a series of idealized metal-organic frameworks (MOFs) containing adsorbed gas using molecular simulations. With no gas present, the thermal conductivity decreases with increasing pore size. In the presence of adsorbed gas, MOFs with smaller pores experience reduced thermal conductivity due to phonon scattering introduced by gas-crystal interactions. In contrast, for larger pores (>1.7 nm), the adsorbed gas does not significantly affect thermal conductivity. This difference is due to the decreased probability of gas-crystal collisions in larger pore structures. In contrast to MOFs with simple cubic pores, the thermal conductivity in structures with triangular and hexagonal pore channels exhibits significant anisotropy. For different pore geometries at the same atomic density, hexagonal channel MOFs have both the highest and lowest thermal conductivities, along and across the channel direction, respectively. In the triangular and hexagonal channeled structures, the presence of gas molecules has different effects on thermal conductivity along different crystallographic directions.
In this report, the adsorption of CO2 on metal organic frameworks (MOFs) is comprehensively reviewed. In Section 1, the problems caused by greenhouse gas emissions are addressed, and different technologies used in CO2 capture are briefly introduced. The aim of this chapter is to provide a comprehensive overview of CO2 adsorption on solid materials with special focus on an emerging class of materials called metal organic frameworks owing to their unique characteristics comprising extraordinary surface areas, high porosity, and the readiness for systematic tailoring of their porous structure. Recent literature on CO2 capture using MOFs is reviewed, and the assessment of CO2 uptake, selectivity, and heat of adsorption of different MOFs is summarized, particularly the performance at low pressures which is relevant to post-combustion capture applications. Different strategies employed to improve the performance of MOFs are summarized along with major challenges facing the application of MOFs in CO2 capture. The last part of this chapter is dedicated to current trends and issues, and new technologies needed to be addressed before MOFs can be used in commercial scales.
The key challenge in post combustion capture from gas fired power plants is related to the low CO2 concentration in the flue gas (4 to 8% by volume). This means that conventional amine processes will result in a relatively high energy penalty while novel adsorbents and adsorption processes have the potential to improve the efficiency of separation. High-selectivity adsorbents are required to achieve relatively high CO2 uptake at low partial pressures, which means that the separation process should be based on either very strong physisorption or chemisorption with thermal regeneration. From the process point of view, the main challenge is to develop efficient separation processes with rapid thermal cycles. In this report we present a detailed overview of the methodology behind the development of novel materials and processes as part of the “Adsorption Materials and Processes for Gas fired power plants” (AMPGas) project. Examples from a wide variety of materials tested are presented and the design of an innovative bench scale 12-column Rotary Wheel Adsorber system is discussed. The strategy to design, characterise and test novel materials (zeolites, amine-containing MOFs, amine-based silicas, amine-based activated carbons and carbon nanotubes), specifically designed for CO2 capture from dilute streams is presented.
This paper, which is part of a special issue of the International Journal of Greenhouse Gas Control, gives an overview of the latest achievements in the pre-combustion decarbonisation route for the production of electricity with CO2 capture. Pre-combustion technologies applied to two different fuels are considered, natural gas and coal, since they cover most of electricity production from fossil fuels worldwide. The work first discusses in detail the different sections in which a power plant with pre-combustion CO2 capture can be divided. For each section, the available technologies with corresponding advantages and disadvantages are presented. Next, the plant lay-outs for natural gas and coal proposed in literature, including heat & mass balances and the economic assessment, are discussed. In general, research activity in pre-combustion decarbonisation for power production focused more on coal than on natural gas-based plant since in the latter case the plant complexity and costs are not competitive with post-combustion CO2 capture, which is a technology on the verge of commercialization. Finally the paper briefly discusses pre-combustion CO2 capture in industry especially those projects where CO2 is captured and stored or used for EOR.
While the bio-applications of Metal-Organic Frameworks (MOFs) recently emerged as a hot topic for the MOF community, examples of totally biocompatible porous solids, moreover exhibiting an established bioactivity are still extremely rare. We report here the synthesis of a microporous magnesium MOF built up from a naturally occurring phenolic ligand, together with the in vitro study of its toxicity and antioxidant activity. The title solid was prepared on the multigram scale (>15 g) solely from non toxic and bioavailable reagents (magnesium salt and gallic acid) and solvent (water). Its high biocompatibility was assessed by in vitro tests on three different cell lines. When poured in biological fluid, this solid slowly releases gallic acid, giving rise to a strong antioxidant activity, as demonstrated in vitro on the HL-60 cells line. Such combination of a high biocompatibility, adequate stability and microporosity makes this solid promising for various applications ranging from the capture of gases to the entrapment and release of small biological molecules.
Preface
The science of unit operations of chemical engineering is the foundation on which various problems associated with designs, fabrications, installation, operations and maintenance of facilities of processes are solved. The development of high throughput from production processes and optimum design of chemical engineering equipment determine not only the economic stability of any venture, but also its efficiency. This book addresses these features. Skills in solving practical engineering problems are obtained not only by theoretical fundamentals but also by experience.
Design problems are characterized by the fact that they are often complex, ill-defined and with no singular process model. Solving design problems requires system, procedural and strategic knowledge that students and practicing engineers need to develop for contextual thinking and decision making. The concept of the book came to my mind to present a pattern that can meet this need.
This book tries to help students and practicing design engineers to develop skills to an appropriate level, particularly in the discipline of solving chemical engineering design type problems. A framework for teaching students/engineers skills for solving design problems is developed and presented. The framework is presented in terms of elements/parameters constructively aligned with the cognitive process required in problem solving.
The book shows the concept of the basic chemical engineering processes and approach to solving design problems. The book is made up of seven chapters. Chapter one is on Applied Hydraulics. This chapter considers basic engineering principles required to handle fluid in plant operations. Detailed transfer phenomena are not presented here, but could be obtained in literature cited and Perry chemical engineers handbook. Pipeline hydraulic design procedures are presented. A typical design module for pressure vessel with the application of ASME CODES and PVELITE Software is presented in this chapter. Chapter two is on Mass Transfer, Absorption. The general subject of mass transfer may be divided into four broad areas of particular interest and importance: molecular diffusion in stagnant media, molecular diffusion in fluids in laminar flow, eddy diffusion or mixing in a free turbulent stream, and mass transfer between two phases. The chemical engineer’s interest in mass transfer comes primarily from his traditional role as a specialist in the design of separation processes. This chapter therefore considers the fundamental principles required by the chemical engineers for design separation processes. Chapter three is on Distillation. In this chapter the fundamental principles, relationships, formulas and methods of distillation and calculation of the number of stages required for both binary and multi-component systems are presented. Basic problems of design associated with physical, chemical properties and hydraulic phenomenon inside the unit are considered; incorporating the column internal configurations.
Chapter four of the book is on Adsorption. In this chapter the fundamentals of gas phase and liquid phase adsorptions are considered. Gas phase adsorption is a condensation process where the adsorption forces condense the molecules from the bulk phase within the pores of the adsorbent. The driving force for adsorption is the ratio of the partial pressure and the vapour pressure of the compound liquid phase adsorption is where the molecules move from the bulk phase to the pores of the adsorbent in a semi-liquid state. The driving force here is the ratio of the concentration to the solubility of the compound. Chapter five considers Extraction and Leaching. This chapter considers processes involved in extraction and leaching, factors influencing, the processes and parameters with graphical methods of solving problems associated with the process. The sixth chapter of the book is on Heat Transfer. The various modes of heat transfer and their applications to solving practical industrial problems are considered. The application of ASME CODES and PVELITE Software is presented in this chapter. The seventh chapter which is the last one for this volume one is on Separation Methods, Hydrodynamics of Fluidized Beds, Dimensionless Group Model for Centrifugal Separation.
In addition every chapter contains minimum of three practical questions and solutions. This is to provide basic procedures to give students of chemical engineering faculties in universities the approach in solving practical industrial problems. Most times students and practicing engineers are faced with challenges of finding solutions to problems of chemical engineering processes mathematically. The book becomes a guide to such practitioners.
The subsequent volume of this book will consider the following unit operations processes: Pumps, fans, Compressors; Drying; Evaporation, Crystallization; Refrigeration. This will form volume two of the book.
Chemical engineering practitioners, undergraduate students of chemical engineering schools will find this book very useful. Mechanical engineering practitioners and students alike who are involved in heat transfer and mass transfer operations will also benefit from the book.
Purification of propylene from the propyne (C3H4)/propylene (C3H6) mixture is a significant and challenging process in the chemical industry. Nowadays, the removal of propyne from propylene mainly relies on the energy-intensive hydrogenation catalyzed by noble metals. We herein report three gallate-based MOFs, namely M(II)-gallate (M = Ni, Mg, Co), which provide excellent performance in terms of removing propyne from propyne/propylene mixture (1/99, v/v). The C3H4 uptake capacities of Mg-, Co-, Ni-gallate can reach 3.75, 3.21 and 2.65 mmol/g, while the C3H6 uptake capacities are only 1.50, 1.49, and 0.9 mmol/g, respectively, at ambient conditions. Particularly, the productivity of 99.9999% pure C3H6 in Co-gallate and Mg-gallate was 1580 and 1420 mL/g, respectively, outperforming the state-of-the-art material USTA-200 (1400 mL/g). The adsorption mechanism was further investigated by using the first-principle DFT-D calculations, revealing the excellent C3H4/C3H6 separation ability of M-gallate originates from stronger supramolecular interactions and C-H…O interactions between the hydrogen atoms from C3H4 and oxygen atoms from M-gallate frameworks. Besides, the M-gallate materials also show excellent regeneration ability. Thus, this work demonstrates that the family of M-gallate materials shows industrially promising porous material for propylene purification by adsorption process.
A large part of the global energy is supplied through fossil-fuel power plants which release a high amount of CO2 into the atmosphere. As long as this energy pattern prevails in the world, concerns about climate change due to sudden rise in the content of green-house gasses (GHGs) might be alleviated only through retrofitting the power plants to CO2 capture units. Gas separation methods such as amine-based absorption could be suggested to hit this target but they could result in a costly and highly intensive process. This study analyzes the integration of a 600 MWe power plant with two promising methods, including membrane technology and enzymatic-absorption process. A techno-economic analysis is then carried out to demonstrate the technical viability and economic efficiency of these two methods compared to traditional separation processes. It is found that the electricity losses are estimated at 95 and 89 MW respectively, to capture 90% of the CO2 which is as low as 15% of the output power. This study also presents cost optimization results including capital and operation expenditures for each method. In comparison, enzyme-based absorption is more economically attractive and results in a lower CO2 capture cost. Overall, this study allows to recognize bottlenecks in each process and then proposes initiatives to improve the capture efficiency.
There have been many attempts to take advantage of innovative biomaterials for the practical development of pharmaceutical science. New generation of drug delivery systems that can exhibit multiple tasks in one delivery system has grown in attention in recent years. One class of hybrid porous materials that has proved its ability in multiple delivery applications is metal organic frameworks (MOFs). This class of materials is in attention due to its attracting structural features including targeted delivery, controllable release, high loading capacity, tunable pore size, biocompatibility, and many other features. This chapter describes and summarizes the newly developed MOFs as potential materials for pharmaceutical applications.
The separation of mixed C4-olefins is a highly energy-intensive operation in the chemical industry due to the close boiling points of the unsaturated C4 isomers. In particular, the separation of trans/cis-2-butene is among the most challenging separation processes for geometric isomers and is of prime importance to increase the added-value of C4-olefins. In this work, we report a series of isostruc-tural gallate-based metal-organic frameworks (MOFs), namely, M-gallate (M=Ni, Mg, Co), featuring oval-shaped pores, are ideally suitable for shape-selective separation of trans/cis-2-butene through their differentiation in minimum molecular cross-section size. Significantly, Mg-gallate displays the record high trans/cis-2-butene uptake selectivity of 3.19 at 298 K, 1.0 bar in single-component adsorption isotherms. These gallate-based MOFs not only exhibit the highest selectivity for trans/cis-2-butene separation but also accomplish a highly efficient separation of 1,3-butadiene, 1-butene, and iso-butene. DFT-D study shows that Mg-gallate interacts strongly with trans-2-butene and 1,3-butadiene along with short distances of CH-O cooperative supramolecular interaction of 2.57-2.83 Å and 2.45-2.79 Å respectively. In breakthrough experiments, Mg-gallate not only displays prominent separation perfor-mance for trans/cis-2-butene, but also realizes the clean separation of ternary mixture of 1,3-butadiene/1-butene/iso-butene and binary mixture of 1-butene/iso-butene. This work indicates that M-gallate are industrially promising materials for adsorption separa-tion of geometric isomers of C4 hydrocarbons.
The adsorption of CO2 by conventional liquid alkanolamine adsorbents does not meet the requirements for green-friendly development in industrial applications. In this work, we constructed NH2-β-CD-MOF for the first time through the amino-functionalization of the lowest-priced, readily available, and biocompatible β-CD. Subsequently, the samples were characterized by single-crystal X-ray diffraction, PXRD, SEM, DSC, TGA, EA, N2 adsorption/desorption. The CO2 adsorption capacity of NH2-β-CD-MOF was found to be 12.3 cm3/g, which is 10 times that of β-CD-MOF. In addition, NH2-β-CD-MOF has outstanding selective adsorption of CO2/N2 (947.52) compared to the reported materials. The adsorption mechanism of CO2 was analyzed by XPS and FT-IR. Furthermore, we have found that NH2-β-CD-MOF has better water stability relative to β-CD-MOF and γ-CD-MOF and has the ability to be recycled.
The environment sustenance and preservation of global climate are known as the crucial issues of the world today. Currently, the crisis of global warming due to CO2 emission has turned into a paramount concern. To address such a concern, diverse CO2 capture and sequestration techniques (CCS) have been introduced so far. In line with this, Metal Organic Frameworks (MOFs) have been considered as the newest and most promising material for CO2 adsorption and separation. Due to their outstanding properties, this new class of porous materials a have exhibited a conspicuous potential for gas separation technologies especially for CO2 storage and separation. Thus, the present review paper is aimed to discuss the adsorption properties of CO2 on the MOFs based on the adsorption mechanisms and the design of the MOF structures. In addition, the main challenge associated with using this prominent porous material has been mentioned.
Purification of ethylene from the ethylene (C2H4)/ethane (C2H6) mixture, one of the most important while challenging industrial separation processes, is mainly through the energy‐intensive cryogenic distillation. Herein we report a family of gallate‐based metal‐organic framework (MOF) materials, M‐gallate (M= Ni, Mg, Co), featuring three‐dimensionally interconnected zigzag channels, whose aperture sizes (3.47‒3.69 Å) are ideally suitable for molecular sieving of ethylene (3.28 × 4.18 × 4.84 Å3) and ethane (3.81 × 4.08 × 4.82 Å3) through actual molecular dimension differentiation. Particularly, Co‐gallate shows an unprecedented IAST selectivity of 52 for C2H4 over C2H6 with a C2H4 uptake of 3.37 mmol/g at 298 K and 1 bar, outperforming the state‐of‐the‐art MOF material NOTT‐300. Direct breakthrough experiments with equimolar C2H4/C2H6 mixtures confirmed that M‐gallate is highly selective for ethylene as evidenced by a significantly delayed breakthrough of ethylene as compared to ethane. The adsorption structure and mechanism of ethylene in the M‐gallate was further studied through neutron diffraction experiments. This work demonstrates that M‐gallate is an industrially promising adsorbent for adsorptive separation of ethylene and ethane.
A water resistant zirconium–porphyrin metal–organic framework PCN-222 was synthesized for selectively separating CO2/CH4 and CO2/N2. Isotherms of CO2, CH4 and N2 on PCN-222 at low and high pressure were respectively measured. At 298 K, CO2 uptakes at 100 kPa and 3000 kPa were 1.16 and 13.67 mmol/g, respectively. At 298 K and 100 kPa, CO2/CH4 (50:50, v/v) and CO2/N2 (50:50, v/v) adsorption selectivities separately reached up to 4.3 and 73.7. At 298 K and 3000 kPa, CO2/CH4 (50:50, v/v) and CO2/N2 (50:50, v/v) adsorption selectivities were 4.7 and 32.8, respectively. Importantly, breakthrough experiments confirmed that PCN-222 could achieve the effective separation of CO2/CH4 (both 50:50 and 10:90) and CO2/N2 (both 50:50 and 15:85) gas mixtures. The dynamic regeneration experiments showed that PCN-222 maintained its initial CO2 adsorption capacity after five cycles of CO2 adsorption-desorption. This work suggested that PCN-222 was a potential candidate for selectively separating CO2/N2 and CO2/CH4.
Toluene and tert-butanol mixtures are completely miscible for all compositions at the macroscopic scale. However tert-butanol forms a network of hydrogen-bonded clusters at the nanoscale which persist even in the tert-butanol-toluene binary liquid mixtures. Interpretation of neutron scattering experiments revealed phase separation of the mixture into a core-shell structure inside hydrophilic nanoporous solids, with a tert-butanol shell and a toluene core. The work carried out in this thesis is aimed at understanding the role played by competing intermolecular interactions (hydrogen-bonding, van der Waals) in driving phase separation in confinement. NMR experiments reveal the persistence of a hydrogen-bonding network in these binary liquids confined in silica nanopores even at very low concentrations of tert-butanol, providing evidence of a new kind of hydrogen bonded network under confinement. Vapour sorption isotherms of tert-butanol-toluene binary gas mixtures in silica nanopores helped explain higher affinity of polar silica walls for tert-butanol by a thermodynamic model. Replacing the host matrix by a hydrophobic analogue was found to reverse the selectivity, with toluene showing greater affinity for the pore surface. Effect of surface specific interactions was studied on spontaneous imbibition dynamics of these binary liquids through nanoporous silica network. Neutron radiography experiments revealed the separation of fluxes into a twocomponent flow, generally obeying the Lucas-Washburn law.
Owing to the progressive development of metal-organic-frameworks (MOFs) synthetic processes and considerable potential applications in last decade, integrating biomolecules into MOFs has recently gain considerable attention. Biomolecules, including lipids, oligopeptides, nucleic acids, and proteins have been readily incorporated into MOF systems via versatile formulation methods. The formed biomolecule-MOF hybrid structures have shown promising prospects in various fields, such as antitumor treatment, gene delivery, biomolecular sensing, and nanomotor device. By optimizing biomolecule integration methods while overcoming existing challenges, biomolecule-integrated MOF platforms are very promising to generate more practical applications.
MOFs have attracted significant attention as solid sorbents in gas separation processes for low-energy post-combustion CO2 capture. The parasitic energy (PE) has been put forward as a holistic parameter that measures how energy efficient (and therefore cost-effective) the CO2 capture process will be using the material. In this work, we present a nickel isonicotinate based ultra-microporous MOF, 1 [Ni-(4PyC)2⦁DMF], that has the lowest PE for post-combustion CO2 capture reported to date. We calculate a PE of 655 kJ/kg CO2, which is lower than that of the best performing material previously reported, Mg-MOF-74. Further, 1 exhibits exceptional hydrolytic stability with the CO2 adsorption isotherm being unchanged following 7 days of steam-treatment (>85% RH) or 6 months of exposure to the atmosphere. The diffusion coefficient of CO2 in 1 is also two orders of magnitude higher than in zeolites currently used in industrial scrubbers. Break-through experiments show that 1 only loses 7% of its maximum CO2 capacity under humid conditions.
Climate change, global warming, urban air pollution, energy supply uncertainty and depletion, and rising costs of conventional energy sources are, among others, potential socioeconomic threats that our community faces today. Transportation is one of the primary sectors contributing to oil consumption and global warming, and natural gas (NG) is considered to be a relatively clean transportation fuel that can significantly improve local air quality, reduce greenhouse-gas emissions, and decrease the energy dependency on oil sources. Internal combustion engines (ignited or compression) require only slight modifications for use with natural gas; rather, the main problem is the relatively short driving distance of natural-gas-powered vehicles due to the lack of an appropriate storage method for the gas, which has a low energy density. The U.S. Department of Energy (DOE) has set some targets for NG storage capacity to obtain a reasonable driving range in automotive applications, ruling out the option of storing methane at cryogenic temperatures. In recent years, both academia and industry have foreseen the storage of natural gas by adsorption (ANG) in porous materials, at relatively low pressures and ambient temperatures, as a solution to this difficult problem. This review presents recent developments in the search for novel porous materials with high methane storage capacities. Within this scenario, both carbon-based materials and metal−organic frameworks are considered to be the most promising materials for natural gas storage, as they exhibit properties such as large surface areas and micropore volumes, that favor a high adsorption capacity for natural gas. Recent advancements, technological issues, advantages, and drawbacks involved in natural gas storage in these two classes of materials are also summarized. Further, an overview of the recent developments and technical challenges in storing natural gas as hydrates in wetted porous carbon materials is also included. Finally, an analysis of design factors and technical issues that need to be considered before adapting vehicles to ANG technology is also presented. CONTENTS
Amine functionalized solid adsorbents are promising materials for the capture of CO2 because of their tunability and lower heat capacity compared to liquid amine solutions. This review focuses on recent advances in the use of solid-supported amines for CO2 capture, with emphasis on amine functionalized metal organic framework (MOF) materials. The recently reported diamine functionalized Mg-DOBPDC MOF demonstrates intriguing performance for CO2 capture, offering a unique adsorption mechanism with favorable energetics. Stable performance for CO2 capture under humid conditions and easy regenerability of the adsorbent are critical to the realization of practical CO2 adsorbents. Scalable regeneration methods such as temperature swing in a CO2 purge stream and temperature swing via steam stripping are discussed. Emerging gas-solid contacting strategies for CO2 capture with amine adsorbents are also discussed.
Oxy-fuel combustion is currently considered to be one of the major technologies for carbon dioxide (CO2) capture in power plants. The advantages of using oxygen (O2) instead of air for combustion include a CO2-enriched flue gas that is ready for sequestration following purification and low NOx emissions. This simple and elegant technology has attracted considerable attention since the late 1990s, rapidly developing from pilot-scale testing to industrial demonstration. Challenges remain, as O2 supply and CO2 capture create significant energy penalties that must be reduced through overall system optimisation and the development of new processes. Oxy-fuel combustion for power generation and carbon dioxide (CO2) capture comprehensively reviews the fundamental principles and development of oxy-fuel combustion in fossil-fuel fired utility boilers. Following a foreword by Professor János M. Beér, the book opens with an overview of oxy-fuel combustion technology and its role in a carbon-constrained environment. Part one introduces oxy-fuel combustion further, with a chapter comparing the economics of oxy-fuel vs. post-/pre-combustion CO2 capture, followed by chapters on plant operation, industrial scale demonstrations, and circulating fluidized bed combustion. Part two critically reviews oxy-fuel combustion fundamentals, such as ignition and flame stability, burner design, emissions and heat transfer characteristics, concluding with chapters on O2 production and CO2 compression and purification technologies. Finally, part three explores advanced concepts and developments, such as near-zero flue gas recycle and high-pressure systems, as well as chemical looping combustion and utilisation of gaseous fuel. With its distinguished editor and internationally renowned contributors, Oxy-fuel combustion for power generation and carbon dioxide (CO2) capture provides a rich resource for power plant designers, operators, and engineers, as well as academics and researchers in the field.
In this work, MIL-101-Cu and MIL-101-Ni were successfully synthesized via a microwave irradiation technique to enhance the adsorption capacity and adsorbent cyclability. The prepared adsorbents were characterized by various techniques such as XRD, FE-SEM, EDS, ICP, TEM and BET. TEM images clearly demonstrated that Cu and Ni NPs of 3–7 nm and 2–4 nm, respectively, were incorporated within the pores of the MIL-101 adsorbent. The CO2 adsorption capacity was measured by a volumetric method. The equilibrium CO2 adsorption capacities were measured as 9.7, 10.6, 11.8 and 12.4 mmol g−1 for the parent MIL-101, activated MIL-101, MIL-101-Cu and MIL-101-Ni adsorbents, respectively at 7.1 bar and 298.2 K. The initial isosteric heats of CO2 adsorption on the above mentioned adsorbents were estimated to be 22, 27, 31 and 38 kJ mol−1, respectively. Successive adsorption–desorption cycles were conducted to explore the cyclability of the adsorbents. The results confirmed that the adsorption capacity remained constant after 100 cycles. The equilibrium experimental data were well-fitted with a Freundlich isotherm model.
This review focuses on the separation of carbon dioxide from typical power plant exhaust gases using the adsorption process. This method is believed to be one of the economic and least interfering ways for post-combustion carbon capture as it can accomplish the objective with small energy penalty and very few modifications to power plants. The review is divided into three main sections. These are (1) the candidate materials that can be used to adsorb carbon dioxide, (2) the experimental investigations that have been carried out to study the process of separation using adsorption and (3) the numerical models developed to simulate this separation process and serve as a tool to optimize systems to be built for the purpose of CO2 adsorption. The review pointed the challenges for the post combustion and the experiments utilizing the different adsorption materials. The review indicates that many gaps are found in the research of CO2 adsorption of post-combustion processes. These gaps in experimental investigations need a lot of research work. In particular, new materials of high selectivity, uptake for carbon dioxide with stability for water vapor needs significant investigations. The major prerequisites for these potential new materials are good thermal stability, distinct selectivity and high adsorption capacity for CO2 as well as sufficient mechanical strength to endure repeated cycling.
Miniaturization of metal–organic frameworks (MOFs) results of great interest in order to integrate these materials in strategic applications such as sensing or drug delivery. This emerging class of nanoscaled MOFs (nanoMOFs), combining the intrinsic properties of the porous materials and the benefits of nanostructures, are expected to improve in some cases the performances of classical bulk crystalline MOFs. In the field of biomedicine, the benefits of MOF miniaturization have already been proved to be effective, not only because establishes a strong influence over the choice of the administration route but also governs their in vivo fate and therefore, their toxicity and/or activity.
The scope of this review focuses on the preparation of nanostructured MOFs and their related biomedical applications. We will cover all aspects concerning the various synthetic methods reported so far, as well as the shaping and surface engineering routes required for their use in biomedicine.
Written by an internationally-recognized author team of natural gas industry experts, the third edition of Handbook of Natural Gas Transmission and Processing is a unique, well-documented, and comprehensive work on the major aspects of natural gas transmission and processing. Two new chapters have been added to the new edition: a chapter on nitrogen rejection to address todays high nitrogen gases and a chapter on gas processing plant operations to assist plant operators with optimizing their plant operations. In addition, overall updates to Handbook of Natural Gas Transmission and Processing provide a fresh look at new technologies and opportunities for solving current gas processing problems on plant design and operation and on greenhouse gases emissions. It also does an excellent job of highlighting the key considerations that must be taken into account for any natural gas project in development. • Covers all technical and operational aspects of natural gas transmission and processing in detail. • Provides pivotal updates on the latest technologies, applications and solutions. • Offers practical advice on design and operation based on engineering principles and operating experiences.
Staring from β-cyclodextrins and Na salts, a new metal-organic framework with chiral helices, (C42O35H70)2(NaOH)4·H2O (CD-MOF-1), has been successfully synthesized. X-ray diffraction analysis reveals that CD-MOF-1 exhibits a 3D framework with left-handed helical channels running through the structure created by the ligation of Na ions to the primary and secondary faces of the β-cyclodextrins rings. Additionally, inclusion properties of CD-MOF-1 were also studied, and the result shows that the inclusion rate using CD-MOF-1 as inclusion materials is higher than that of β-cyclodextrins, which is expected to become a new type of green crystal material from edible natural products.
Widely used in adsorption, catalysis and ion exchange, the family of molecular sieves such as zeolites has been greatly extended and many advances have recently been achieved in the field of molecular sieves synthesis and related porous materials. Chemistry of Zeolites and Related Porous Materials focuses on the synthetic and structural chemistry of the major types of molecular sieves. It offers a systematic introduction to and an in-depth discussion of microporous, mesoporous, and macroporous materials and also includes metal-organic frameworks. Provides focused coverage of the key aspects of molecular sieves Features two frontier subjects: molecular engineering and host-guest advanced materials Comprehensively covers both theory and application with particular emphasis on industrial uses This book is essential reading for researches in the chemical and materials industries and research institutions. The book is also indispensable for researches and engineers in R&D (for catalysis) divisions of companies in petroleum refining and the petrochemical and fine chemical industries.
Oxyfuel combustion is one of the leading technologies considered for capturing CO2 from power plants with CCS. This involves the process of burning the fuel with nearly pure oxygen instead of air. In order to control the flame temperature, some part of the flue gas are recycled back into the furnace/boiler.Since the publication of the Special Report on CO2 Capture and Storage by the International Panel for Climate Change (IPCC, 2005), the development of oxyfuel combustion technology has progressed significantly and could be considered at par in terms of technology maturity as compared to other leading CO2 capture technologies.This paper presents an overview to the current state-of-the-art technology on the development of oxyfuel combustion applied to (a) PC and CFB coal fired power plants and (b) gas turbine based power plant. It should be noted that it is not the intention of this paper to provide a comprehensive review but to present what have been achieved in the past 10 years of RD&D efforts.For coal fired power plant using oxyfuel combustion, this paper primarily presents the different development aspects of the burners and boilers (combustion and heat transfer), emissions, operation of the plant (i.e. start-up and turndown) and its integration to the ASU and CPU.For gas turbine based power plant using oxyfuel combustion, the different GT cycles are described, looking at the different aspects in combustion, emissions, cycle efficiency and development of the turbomachineries.Also presented in this paper is a snapshot to what we have learned from the operation of the different large-scale pilot plants and development of large scale demonstration projects worldwide.The paper concludes by presenting the potential of this technology and highlighting the importance of realizing large scale demonstration plant as a necessary step to achieve its ultimate goal of technology commercialization.
Biological and artificial molecules and assemblies capable of supramolecular recognition, especially those with nucleobase pairing, usually rely on autonomous or collective binding to function. Advanced site-specific recognition takes advantage of cooperative spatial effects, as in local folding in protein-DNA binding. Herein, we report a new nucleobase-tagged metal-organic framework (MOF), namely ZnBTCA (BTC=benzene-1,3,5-tricarboxyl, A=adenine), in which the exposed Watson-Crick faces of adenine residues are immobilized periodically on the interior crystalline surface. Systematic control experiments demonstrated the cooperation of the open Watson-Crick sites and spatial effects within the nanopores, and thermodynamic and kinetic studies revealed a hysteretic host-guest interaction attributed to mild chemisorption. We further exploited this behavior for adenine-thymine binding within the constrained pores, and a globally adaptive response of the MOF host was observed.
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Environmental problems due to the discharge of gases, including NO and CO2, in addition, diseases caused by improper concentration of NO and CO2 in vivo must be resolved. In this study, Grand canonical Monte Carlo (GCMC) simulations are combined with density functional theory (DFT) to calculate the adsorption of NO and CO2 from a dual-component mixture to the Cu-BTC metal organic framework. The results show that the adsorption isotherms for various molar ratios of the gaseous mixture followed a Langmuir distribution. At higher pressures more CO2 than NO was adsorbed by Cu-BTC, with NO showing a tendency to desorb. However, better results for adsorption of NO were observed at lower pressures. For the different pressure and molar ratios of the gaseous mixture examined, more CO2 than NO was always adsorbed. Compared with three way-catalysts, Cu-BTC offers benefits to adsorption of CO2 and NO from gaseous mixtures without increased durability problems.
Bio-metal organic frameworks (Bio-MOFs), composed of biocompatible metal cations and linker molecules such as amino acids, nucleobases and sugars, are considered as promising candidates for gas storage and separation due to their permanent porosity, chemical functionality and structural tunability. In this study, detailed molecular simulations were performed to assess the potential of 10 different bio-MOFs in adsorption-based and membrane-based separation of CO2/CH4 mixtures. After showing the good agreement between experiments and molecular simulations for single-component adsorption isotherms of several gases in various bio-MOFs, adsorption selectivity and working capacity of these materials were predicted for CO2/CH4 separation. Membrane selectivity and gas permeability of bio-MOFs were computed considering flexibility of the structures in molecular simulations for the first time in the literature. Results showed that several bio-MOFs outperform widely studied MOFs and zeolites both in adsorption-based and membrane-based CO2/CH4 separations. Bio-MOF-1, bio-MOF-11 and bio-MOF-12 were identified as promising adsorbents and membranes for natural gas purification.
Metal–organic frameworks (MOFs) have emerged as an important family of compounds that have fascinating structures and diverse applications. But until now, targeted synthesis of MOFs with desired frameworks is still a challenge. In order to appreciate the properties and to design new frameworks, it is necessary to understand how to rationalize the design and synthesis of MOFs from a fundamental perspective. This highlight review will outline the recent advances in this topic from both our and other groups and provide an overview of the different factors influencing the structures of MOFs. These examples illustrate some of the present trends concerning the design of organic ligands and SBUs, coordination assemblies, and experimental conditions.