Browse
Submit Data
Databases
API
Help

Dataset Information

14 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Efficient Xe selective separation from Xe/Kr/N₂ mixtures over a microporous CALF-20 framework.

ABSTRACT: Capture and separation of xenon and krypton by adsorption are particularly important issues at room temperature in both industry and environmental security. Herein, hydrophobic zinc-based frameworks (CALF-20) were synthesized to separate mixtures of Xe, Kr and N₂, and adsorptive properties and stability of as-prepared samples were investigated in detail. CALF-20 with the 1,2,4-triazole and oxalate as the ligand and Zn metal centers showed a surface area of 442 m² g^-1 and average pore size of 6-7 Å, and exhibited excellent stability in a high-temperature acidic solution. The single and binary adsorption datum represented that CALF-20 has a high Xe uptake of 2.45 mmol g^-1 and Xe/Kr selectivity of 13.2, as well as high Xe/N₂ selectivity of 62 at 298 K and 1.0 bar. The initial adsorption heat and Henry's constant of Xe on the CALF-20 were determined to be 31.7 kJ mol^-1 and 21.77 mmol g^-1 bar^-1 by isotherms, indicating a suitable affinity for Xe capture and Xe/Kr separation. In addition, simulation results indicated that the simulated adsorption isotherms and adsorption heats are well-matched with experimental results, and the adsorption affinity from the C-H groups of 1,2,4-trizole ring for Xe is significantly stronger than that for Kr.

SUBMITTER: Wei Y

PROVIDER: S-EPMC9214609 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Microporous Metal-Organic Framework with Dual Functionalities for Efficient Separation of Acetylene from Light Hydrocarbon Mixtures.

Project description:Separating acetylene from light hydrocarbon mixtures like ethylene is a very important process for downstream industrial applications. Herein, we report a new MOF [CuL2(SiF6)] (UTSA-220, L = (1E,2E)-1,2-bis(pyridin-4-ylmethylene)hydrazine) with dual functionalities featuring optimal pore size with strong binding sites for acetylene. UTSA-220 exhibits apparently higher uptake capacity for C2H2 than those for other light hydrocarbons. The potential of this material for trace C2H2 removal from C2H4 has also been demonstrated by a dynamic breakthrough experiment performed with C2H2/C2H4 (1/99 v/v) under simulated industrial conditions. According to the dispersion-corrected density functional theory (DFT-D) simulation, SiF62- and azine moieties serve as preferential binding sites for C2H2, indicating the feasibility of the dual functionalities incorporated in UTSA-220 for adsorbent-based C2H2 separations.

| S-EPMC7923745 | biostudies-literature

Microporous metal-organic framework with dual functionalities for highly efficient removal of acetylene from ethylene/acetylene mixtures.

Project description:The removal of acetylene from ethylene/acetylene mixtures containing 1% acetylene is a technologically very important, but highly challenging task. Current removal approaches include the partial hydrogenation over a noble metal catalyst and the solvent extraction of cracked olefins, both of which are cost and energy consumptive. Here we report a microporous metal-organic framework in which the suitable pore/cage spaces preferentially take up much more acetylene than ethylene while the functional amine groups on the pore/cage surfaces further enforce their interactions with acetylene molecules, leading to its superior performance for this separation. The single X-ray diffraction studies, temperature dependent gas sorption isotherms, simulated and experimental column breakthrough curves and molecular simulation studies collaboratively support the claim, underlying the potential of this material for the industrial usage of the removal of acetylene from ethylene/acetylene mixtures containing 1% acetylene at room temperature through the cost- and energy-efficient adsorption separation process.

| S-EPMC4468854 | biostudies-other

Microporous Metal-Organic Frameworks with Hydrophilic and Hydrophobic Pores for Efficient Separation of CH<sub>4</sub>/N<sub>2</sub> Mixture.

Project description:Highly selective removal of N2 from unconventional natural gas is considered as a viable way to increase the heat value of CH4 and reduce the greenhouse effect caused by the direct emission of CH4/N2 mixture. In this work, a three-dimensional Cu-MOF with two different types of micropores was synthesized, exhibiting a high selectivity for CH4/N2 (10.00-12.67) and the highest sorbent selection parameter value (65.73) among the reported materials. The CH4 molecule interacts with the framework to form multiple van der Waals interactions both in hydrophilic and hydrophobic pores, indicated by density functional theory calculations to gain a deep insight into the adsorption binding sites. In contrast, the weak polarity feature of the hydrophobic pore and the occupied open-metal sites in the hydrophilic pore result in a very low adsorption uptake of N2. The excellent separation performance combining the good stability and regenerability guarantees this Cu-MOF to be a promising adsorbent for an efficient separation of the CH4/N2 mixture.

| S-EPMC6740180 | biostudies-literature

Exploiting equilibrium-kinetic synergetic effect for separation of ethylene and ethane in a microporous metal-organic framework.

Project description:Physisorption is a promising technology to cut cost for separating ethylene (C2H4) from ethane (C2H6), the most energy-intensive separation process in the petrochemical industry. However, traditional thermodynamically selective adsorbents exhibit limited C2H4/C2H6 selectivity due to their similar physiochemical properties, and the performance enhancement is typically at the expense of elevated adsorption heat. Here, we report highly-efficient C2H4/C2H6 adsorption separation in a phosphate-anion pillared metal-organic framework ZnAtzPO4 exploiting the equilibrium-kinetic synergetic effect. The periodically expanded and contracted aperture decorated with electronegative groups within ZnAtzPO4 enables effective trapping of C2H4 and impedes the diffusion of C2H6, offering an extraordinary equilibrium-kinetic combined selectivity of 32.4. The adsorption heat of C2H4 on ZnAtzPO4 (17.3 to 30.0 kJ mol-1) is substantially lower than many thermodynamically selective adsorbents because its separation capability only partially relies on thermodynamics. The separation mechanism was explored by computational simulations, and breakthrough experiments confirmed the excellent C2H4/C2H6 separation performance of ZnAtzPO4.

| S-EPMC7148085 | biostudies-literature

Computational Screening of Metal⁻Organic Framework Membranes for the Separation of 15 Gas Mixtures.

Project description:The Monte Carlo and molecular dynamics simulations are employed to screen the separation performance of 6013 computation-ready, experimental metal⁻organic framework membranes (CoRE-MOFMs) for 15 binary gas mixtures. After the univariate analysis, principal component analysis is used to reduce 44 performance metrics of 15 mixtures to a 10-dimension set. Then, four machine learning algorithms (decision tree, random forest, support vector machine, and back propagation neural network) are combined with k times repeated k-fold cross-validation to predict and analyze the relationships between six structural feature descriptors and 10 principal components. Based on the linear correlation value R and the root mean square error predicted by the machine learning algorithm, the random forest algorithm is the most suitable for the prediction of the separation performance of CoRE-MOFMs. One descriptor, pore limiting diameter, possesses the highest weight importance for each principal component index. Finally, the 30 best CoRE-MOFMs for each binary gas mixture are screened out. The high-throughput computational screening and the microanalysis of high-dimensional performance metrics can provide guidance for experimental research through the relationships between the multi-structure variables and multi-performance variables.

| S-EPMC6474094 | biostudies-literature

XGBoost: An Optimal Machine Learning Model with Just Structural Features to Discover MOF Adsorbents of Xe/Kr.

Project description:The inert gases Xe and Kr mainly exist in the used nuclear fuel (UNF) with the Xe/Kr ratio of 20:80, which it is difficult to separate. In this work, based on the G-MOFs database, high-throughput computational screening for metal-organic frameworks (MOFs) with high Xe/Kr adsorption selectivity was performed by combining grand canonical Monte Carlo (GCMC) simulations and machine learning (ML) technique for the first time. From the comparison of eight classical ML models, it is found that the XGBoost model with seven structural descriptors has superior accuracy in predicting the adsorption and separation performance of MOFs to Xe/Kr. Compared with energetic or electronic descriptors, structural descriptors are easier to obtain. Note that the determination coefficients R 2 of the generalized model for the Xe adsorption and Xe/Kr selectivity are very close to 1, at 0.951 and 0.973, respectively. In addition, 888 and 896 MOFs have been successfully predicted by the XGBoost model among the top 1000 MOFs in adsorption capacity and selectivity by GCMC simulation, respectively. According to the feature engineering of the XGBoost model, it is shown that the density (ρ), porosity (ϕ), pore volume (Vol), and pore limiting diameter (PLD) of MOFs are the key features that affect the Xe/Kr adsorption property. To test the generalization ability of the XGBoost model, we also tried to screen MOF adsorbents on the CO2/CH4 mixture, it is found that the prediction performance of XGBoost is also much better than that of the traditional machine learning models although with the unbalanced data. Note that the dimension of features of MOFs is low while the quantity of MOF samples in database is very large, which is suitable for the prediction by model such as XGBoost to search the global minimum of cost function rather than the model involving feature creation. The present study represents the first report using the XGBoost algorithm to discover the MOF adsorbates.

| S-EPMC8028164 | biostudies-literature

The structure of neuroglobin at high Xe and Kr pressure reveals partial conservation of globin internal cavities.

Project description:Neuroglobin (Ngb) is a hexacoordinate globin expressed in the brain of vertebrates. Ferrous Ngb binds dioxygen with high affinity and the O(2) adduct is able to scavenge NO. Convincing in vitro and in vivo data indicate that Ngb is involved in neuroprotection during hypoxia and ischemia. The 3D structure of Ngb reveals the presence of a wide internal cavity connecting its heme active site with the bulk. To explore the role of this "tunnel" in the control of ligand binding, we determined the structure of metNgb and NgbCO equilibrated with Xe or Kr. We show four docking sites for Xe (only two for Kr); two of the four Xe sites are within the large cavity. They are only partially conserved in globins, since the two proximal Xe sites identified in myoglobin (Xe1 and Xe2) are absent in Ngb, as well as in cytoglobin. The Xe docking sites in Ngb map a pathway within the protein matrix, leading to the heme, which becomes more accessible in the ligand-bound species. This may be of significance in connection with the redox chemistry that may be the primary function of this hexacoordinate globin.

| S-EPMC2741589 | biostudies-literature

An ab initio study on noble gas inserted halogenated acetylene: HNgCCX (Ng = Kr and Xe; X = halogen).

Project description:Although HNgCCX (Ng = Kr and Xe; X = F and Cl) have been identified in cryogenic matrices, similar Br and I analogues have not been prepared so far. In this paper, the nature of HNgCCX (Ng = Kr and Xe; X = F, Cl, Br and I) have been investigated by ab initio methods. The main characteristic absorption peak of HNgCCX is the v H-Ng, which decreases as X varies from F to I. Moreover, the H-Xe bond is stronger than the H-Kr bond. The v C≡C and v C-X exhibit red- and blue-shift characters, respectively, especially the C-X bond is abnormal blue-shift halogen bond. AIM results show that the H-Ng bond is essentially covalent bond and the covalent character of H-Xe bond is underestimated, and the trend of the covalent character is C-Cl > C-Br > C-F > C-I. Although HNgCCX is instable thermodynamically with respect to Ng + HCCX, it is kinetically stable with respect to the two-/three-body channels due to the relatively larger energy barriers. The three-body channels of HNgCCX is the main decomposition channel, and the kinetically stability of HXeCCX is more than its Kr analogues. This study is helpful for the preparation of new HNgCCX in cryogenic matrices.

| S-EPMC5579194 | biostudies-literature

Experimental measurements of Xe and Kr releases from UO2 and determination of their migration mechanisms - Release rate data.

Project description:We present the raw data obtained from release rate at 1300°C of Xe and Kr implanted in UO2, related to [1]. We performed different sample preparation (polishing treatment) on polycrystalline and monocrystalline UO2. Ion implantation were performed at various fluences between 9.5 × 1010 to 5 × 1014 i/cm2 in UO2 samples. Release rate of Xe and Kr are obtained at 1300°C under vacuum from desorption experiments performed on the PIAGARA plateform at the CENBG (Centre d'Etudes Nucléaires de Bordeaux-Gradignan). Since we made a variety of samples depending on multiple parameters (sample type, sample preparation, ion implantation type and fluence), these data represent a serious amount of work that could be saved for the scientific community that might use them for other purposes such as burst modelling.

| S-EPMC8640255 | biostudies-literature

Gram-Scale Synthesis of an Ultrastable Microporous Metal-Organic Framework for Efficient Adsorptive Separation of C2H2/CO2 and C2H2/CH4.

Project description:A highly water and thermally stable metal-organic framework (MOF) Zn2(Pydc)(Ata)2 (1, H2Pydc = 3,5-pyridinedicarboxylic acid; HAta = 3-amino-1,2,4-triazole) was synthesized on a large scale using inexpensive commercially available ligands for efficient separation of C2H2 from CH4 and CO2. Compound 1 could take up 47.2 mL/g of C2H2 under ambient conditions but only 33.0 mL/g of CO2 and 19.1 mL/g of CH4. The calculated ideal absorbed solution theory (IAST) selectivities for equimolar C2H2/CO2 and C2H2/CH4 were 5.1 and 21.5, respectively, comparable to those many popular MOFs. The Qst values for C2H2, CO2, and CH4 at a near-zero loading in 1 were 43.1, 32.1, and 22.5 kJ mol-1, respectively. The practical separation performance for C2H2/CO2 mixtures was further confirmed by column breakthrough experiments.

| S-EPMC8433756 | biostudies-literature