CH4 Adsorption Research Articles

Comparative study of metal-organic frameworks synthesized via imide condensation and coordination assembly.

A series of metal-organic frameworks (1-XDI) have been synthesized by imide condensation reactions between an amine-functionalized pentanuclear zinc cluster, Zn4Cl5(bt-NH2)6, (bt-NH2 = 5-aminobenzotriazolate), and organic dianhydrides (pyromellitic dianhydride (PMDA), naphthalenetetracarboxylic dianhydride (NDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (HFIPA)). The properties of the 1-XDI MOFs have been compared with analogues (2-XDI) prepared using traditional coordination assembly. The resulting materials have been characterized by ATR-IR spectroscopy, acid-digested 1H NMR spectroscopy, elemental analysis, and gas adsorption measurements. N2 adsorption isotherm data reveal modest porosities and BET surface areas (30-552 m2 g-1). All of the new 1-XDI and 2-XDI MOFs show selective adsorption of C2H2 over CO2 while 2-PMDI and 2-BPDI exhibit high selectivity toward C3H6/C3H8 separation. This study establishes imide condensation of preformed metal-organic clusters with organic linkers as a viable route for MOF design.

DFT analysis of Re-modified WSe2 monolayers for adsorption of CO, C2H2, and C2H4

Abstract The sensing performances of the Rhenium (Re) doped Tungsten Diselenide (WSe2) monolayer for detecting small gas molecules such as carbon monoxide (CO), acetylene (C2H2), and ethylene (C2H4) have been analyzed in this paper. Density functional theory and non-equilibrium Green’s function have been used to examine the electrical and geometric structures of re-adorned WSe2 monolayer when subjected to dissolved gas analysis gases in the transformer oil. Hence, the electrochemical characteristics like Band diagram and density of states are detailed. Adsorption systems’ recovery capabilities, Mulliken population, and adsorption energy have been examined to determine their stability. Studies also show that Re-doped WSe2 monolayer exerts deformation and as a result, the band gap narrowed down. At ambient temperature (273 K–300 K), the Re-doped WSe2 exhibits better adsorption of C2H4 over C2H2 and CO as the C2H4 has higher adsorption energy compared to the C2H2 and CO. Besides, V–I characteristics of the Re doped WSe2 layer after adsorption of the CO, C2H2, and C2H4 are detailed which signifies the efficacy of the Re doped WSe2 monolayer.

Adsorption simulation of gas released during oxidation of bituminous coal

ABSTRACT The adsorption of gases released during coal oxidation have a significant impact on the accuracy of CSC prediction. However, there are few research on the adsorption of C2H4 and C2H6 by coal. Therefore, the adsorption characteristics of N2/CO2/C2H4/C2H6 released during the spontaneous combustion of bituminous coal were investigated by programmed heating experiment and molecular simulation. The results showed that the low-volatile coal exhibited a higher adsorption capacity for CO2, N2, and C2H4 compared to high-volatile coal. The sequence of adsorption capacity for both low-volatile coal and High-volatile coal was CO2 > C2H6. The electrostatic potential of oxygen functional groups was ranked as follows: Ph-OH > Ph-COOH > R-COOH > R-OH. The interaction energy of gases at the -COOH position was greater than that at the -OH position, indicating that -COOH is more likely to provide adsorption sites for gases.

Adsorption and sensing properties of Pd-doped Janus HfSSe monolayer for thermal runaway gases in lithium-ion batteries: A DFT study

Detecting thermal runaway gases in lithium-ion batteries (LIBs) is an effective means of identifying early battery failures and is significant in ensuring the safe operation of LIBs. This work investigated the adsorption characteristics of CO2, CO, H2, CH4, C2H2, C2H4, and H2O on intrinsic and Pd-doped HfSSe monolayers using density functional theory (DFT). Our calculations showed that all gases were physically adsorbed on the intrinsic HfSSe monolayer, but the Pd-doped HfSSe monolayer had an enhanced adsorption effect for gas molecules. Additional computations of the band structure, deformation charge density, density of states, and frontier molecular orbitals revealed that the Pd-HfSSe monolayer demonstrated superior CO and C2H4 adsorption and sensing capabilities. The analysis of recovery time revealed that Pd-HfSSe may be used as a gas sensor for identifying C2H4. This study provides a theoretical basis for applying Pd-HfSSe as a gas sensor to detect thermal runaway gases in LIBs.

Mechanistic study of carbon dioxide sequestration technology using molecular simulations to assess the adsorption of methane and carbon dioxide by different functional groups

To investigate the characteristics of CO2 and CH4 adsorption across various functional groups and to clarify their thermodynamic attributes, slit models of functional groups with different pore sizes and moisture contents were constructed using the Materials Studio software program. The analysis focused on the characteristics of CO2 and CH4 adsorption in six distinct models comprising different functional groups. The results showed that the adsorption activities of the six functional groups followed the order –CHO>–COOH>–OH>-O-CH3 > –CH3 > –CH2CH3. The average adsorption heat of the oxygen-containing functional groups exceeded that of the aliphatic groups for both the single- or two-component injections of CO2. As the moisture content increases, the maximum adsorption capacity of CH4 in the slit models with –CH2CH3, −O-CH3, –COOH, and –OH functional groups show a significant decreasing trend when injecting CH4 with two components. The absolute value of the adsorption energy of CO2 and CH4 decreases with increasing pore size. In the slit models with –CHO and –COOH functional groups, multiple peaks appear in the adsorption energy of CO2, indicating a greater number of adsorption sites. For the two-component injection of CO2 and CH4, the entropy of CO2 in each functional group was minimized at a pore size of 1 nm.

A mixed polynuclear clusters-based Y-MOF with an unprecedented (12, 12, 18)-c topology: highly efficient propylene/ethylene separation and iodine adsorption

The design and synthesis of highly stable metal–organic frameworks (MOFs) bearing unpredictable polynuclear clusters and new topologies are important for the development of novel and complicated MOFs. Herein, the polynuclear rare-earth (RE) clusters with more coordination modes and the small V-shaped ligand (2,5-thiophenedicarboxylic acid) were chosen, and subsequently JLU-MOF132 with three different yttrium clusters (two independent Y6 and one Y9 clusters) and a novel (12, 12, 18)-connected topology was successfully synthesized. Notably, JLU-MOF132 exhibits high porosity, excellent thermal, acid-base, and solvent stabilities. JLU-MOF132 shows considerable potential in methanol-to-olefins (MTO) products (C3H6 and C2H4) separation. The high ideal adsorbed solution theory C3H6/C2H4 selectivities (9.2, 10.6, and 15.1) and the breakthrough experiments results, including the high C2H4 purity (>99.9 %) and productivities (26.1, 73.1, and 101.0 L·kg-1), demonstrate its practical purification capability. Semi-empirical tight binding (xTB) quantum chemical calculations explain the mechanisms that differentiate C2H4 and C3H6 adsorption in JLU-MOF132. In addition, JLU-MOF132 also displays outstanding radioactive iodine adsorption performance, with an iodine uptake of 750 mg·g-1 in vapor and 153 mg·g-1 in cyclohexane solutions. Briefly, this work not only demonstrates the viability of employing the V-shaped ligand to increase the structural diversity of highly stable MOFs, but also enhances the application potential of MOFs in the fields of the MTO products separation and radioactive iodine adsorption.

A coordination polymer based on ionic-type ligand for efficient separation of C2H2/C2H4 and C3H4/C3H6 mixtures

C2–C3 alkyne/alkene adsorption and separation is a critical process in industrial production, but it remains challenging due to the similar size of gas molecules. Herein, based on an ionic-type ligand, a porous coordination polymer with inherent positive charged sites has been successfully constructed by 1D chains through non-conventional CH···O hydrogen bonds. The flexible framework shows adsorption ability for C2H2 while negligible adsorption of C2H4; and a much earlier steep increase for C3H4 isotherm compared to C3H6 isotherm in the low-pressure region. Ideal adsorbed solution theory further illustrated that the framework has the ability to separate C2H2/C2H4 and C3H4/C3H6 mixtures.

The behavior and model of methane adsorption on coal by ultrasonic enhancement

Ultrasonic technology can effectively improve the efficiency of coalbed methane (CBM) extraction and holds a broad application prospect. While the influence of the ultrasonic comprehensive effect on CBM output has been extensively studied, there is still a lack of in-depth discussion and detailed analysis of the specific influence of the single effect on methane adsorption. This article conducted an in-depth study of methane adsorption behavior in three different ways: ultrasonic comprehensive effect (UCE), thermal effect (UTE), and mechanical vibration effect (UMVE) by controlling the experimental conditions. The results indicated that CH4 adsorption was significantly inhibited by the UCE, and this inhibition was mainly influenced by the UTE. In contrast, the UMVE somewhat enhanced the adsorption of CH4. The moisture in the coal did not change the above trend. Furthermore, the promotion of CH4 adsorption by UMVE had an immediate effect, occurring only when UMVE was applied. The essence of promoting adsorption is that UMVE acts on the coal matrix and CH4 adsorption phase as an additional load, subsequently resulting in an increase in adsorption equivalent pressure. Based on the above understanding, the equivalent pressure parameter of CH4 adsorption under UMVE was proposed, and a mathematical model for CH4 adsorption under UMVE was constructed. In addition, a CH4 adsorption model under the UCE was established. The research results have certain reference significance for the application of ultrasonic in coalbed methane mining.

Synergistic catalysis in Pd/La-CeO2 enhanced CH4 oxidation: The role of water and reactive oxygen species

The catalytic oxidation of methane (CH4) stands as an essential strategy for curtailing greenhouse gas emissions. This study advances CH4 oxidation using Pd on La-doped CeO2, where water (H2O) boosts oxidation efficiency. The temperature for obtaining 50 % CH4 conversion on Pd/La-CeO2 catalyst was reduced from 288 °C (without H2O) to 260 °C (with H2O), while that on CeO2 was 570 °C both under conditions with and without H2O. Operando DRIFTS analysis reveals the reaction pathway and intermediates during CH4 oxidation. Ce cations provide adsorption sites for CH4, leading to the generation of CH3 adsorbed species with the help of surface O2–. La doping creates oxygen vacancies essential for oxygen activation and foster the formation of reactive hydroxide (OH) from adsorbed H2O and O. Pd contributes to the formation of more reactive oxygen species that facilitate OH generation at La cations and the oxidation of CH4 adsorption species to CO2 and H2O. The synergistic interplay between Pd and La-CeO2 is particularly noteworthy, with H2O also playing a role in the gasification of surface carbonates, thereby enhancing the overall performance of CH4 oxidation. A kinetic model based on the Langmuir-Hinshelwood mechanism is proposed, offering an insight into CH4 oxidation.

Construction of negative electrostatic sugared gourd pore within nickel-based metal-organic framework for one-step purification acetylene from ethylene and carbon dioxide mixture

The development of highly efficient adsorbents for purifying acetylene from multi-component mixtures is crucial in the chemical industry, yet the tradeoff between renewability and selectivity severely constrains practical industrial applications. This study introduces sugar gourd pore framework (SGPF-1), an innovative ultra-microporous framework synthesized using 1,2-di(4-pyridyl)ethylene (BPE), 4,4′,4′’-nitrilotribenzoic acid (NTA), and hexanitronickel under solvothermal conditions. The X-ray diffraction analysis has been used to prove the detailed structure and phase purity of SGPF-1. The structure of SGPF-1 was tailored for selectively adsorbing and separating the target compound, C2H2. The negative electrostatic effect, inspired by the natural sugared gourd structure, enhances the selectivity and adsorption capacity for C2H2, while minimizing the interaction with impurities like C2H4 and CO2. Experimental data show that SGPF-1 exhibits significantly higher adsorption of C2H2 compared to C2H4 and CO2 at 298 K and 100 kPa, demonstrating exceptional selectivity towards 50/50 C2H2/CO2 and 1/99 C2H2/C2H4 to be 7.33 and 15.46. Breakthrough experiments confirm its effectiveness in separating C2H2 from C2H4/CO2 mixtures, with C2H4 saturation reached within 5 to 15 min, while C2H2 retention time at 298 K was as long as 26 min. Theoretical calculations have revealed that SGPF-1 exhibits electrostatic compatibility with C2H2 while repelling C2H4 and CO2 through an electrostatic exclusion mechanism. This highlights the importance of rational pore engineering in optimizing the electrostatic properties of adsorbents for high-efficiency multi-component separations. The research aims to advance gas separation technologies and improve the purity of acetylene, a valuable industrial raw material.

Preparation of high quality carbon nanotubes by catalytic pyrolysis of waste plastics using FeNi-based catalyst

Plastic waste pollution is the serious environmental problem, and catalytic pyrolysis of waste plastics is an effective way to solve this problem. Carbon nanotubes (CNTs) are prepared by catalytic pyrolysis of low-density polyethylene (LDPE) waste plastics by one-stage method using iron nitrate and nickel nitrate as catalyst. The growth mechanism of CNTs is analyzed in detail. TPO, XRD, SEM and Raman analyses show that increasing Ni content contributes to the production of CNTs with good morphology and high graphitization degree. While the increasing Fe content contributes to improving the yield of CNTs. The outer and inner diameters of the FeNi12-CNTs-800 are about 21 nm and 8 nm with the length of 18.9 μm, respectively. LDPE pyrolysis gases are analyzed to determine that the primary carbon source required for CNTs growth is C2H4. The C2H4 adsorption and decomposition processes on FeNi alloys are performed to reveal the growth mechanism of CNTs, based on density functional theory calculation. Three kinds of the growth models are proposed to explain the difference of the CNTs tubular shape. FeNi12-CNTs-800 are used to remove microplastics from wastewater due to existence of magnetic. PVC can be quickly removed from wastewater with removal of 100 % at 20 min. This study provides an effective way for recycling and treatment of waste plastic.

Tuning oxygen vacancies via photoinduced defect engineering in plasma pre-treated TiO2 for efficient solar-light-driven oxidation of trace methane

Photocatalysis employing cost-effective commercial titanium dioxide offers an ideal solution for eliminating trace methane emissions from livestock and poultry farming. However, significant challenges such as the rapid recombination of photogenerated carriers, a limited light absorption spectrum, and weak adsorption capabilities considerably hinder the effectiveness of titanium dioxide in the photocatalytic treatment of trace methane. This study proposes a novel approach to activate plasma pre-treated N-doped commercial anatase TiO2 into dual-defect TiO2 (N-doped TiO2-x) featuring stable and controllable oxygen vacancies (OV) through photoinduced defect engineering. Characterizations of the photocatalyst confirm the successful creation of surface defects, further evaluated through solar-light-driven CH4 (ppm level) removal investigations. The yield of this N-doped TiO2-x in converting CH4 is 4.84 μmol h−1, 44 times greater than that of unmodified TiO2, significantly outperforming previous studies. UV–Vis diffuse reflection spectra, and photoluminescence indicate that the modified commercial anatase TiO2 possesses a narrower band gap, efficient photogenerated carrier separation, and enhanced charge transfer. Furthermore, density functional theory (DFT) calculations demonstrate that the synergistic effects of oxygen vacancies and N doping enhance the adsorption and activation of both O2 and CH4 in the rate-determining step of the reaction. This innovative strategy holds considerable promise for modifying various materials for more efficient photocatalytic applications.

Mechanistic study of transition metal loaded/doped Ni − MgO catalyzed dry reforming of methane: DFT calculations

In the context of carbon peaking and carbon neutrality goals, dry reforming of methane (DRM) offers both environmental and economic benefits and holds great promise for development. In this work, based on Ni loaded MgO, two structural models constructed by transition metal loading (TM+Ni − MgO, TM=Fe, Zr, Mo) and doping (Ni − TM/MgO) were used for DRM by density functional theory (DFT). And the adsorption of CO2 and CH4 on these structures was analyzed. The partial density of states (PDOS) and charge density difference (CDD) indicate that due to the presence of unfilled electron d − orbitals in the TM atoms, electron transfer occurs between them and the p − orbitals of the C and O atoms. It facilitates the interactions and enhances the adsorption between CO2 and MgO. On this basis, the DRM reactions on Fe and Ni loaded MgO (FeNi − MgO) and Ni − loaded, Fe − doped MgO (Ni − Fe/MgO) were screened for focused research. It was revealed that the addition of Fe lowered the energy barrier values for some of the elementary reaction steps, allowing the reaction to proceed more easily. And Ni − Fe/MgO showed greater advantages by possessing more stable energy barrier fluctuation intervals (ER1 − ER3) and the smallest CO2 dissociation energy barrier.

Methane Adsorption and Desorption on Continental Shaly Matrix: Implications for Shale Gas Condensate Exploration and Production.

Shale gas condensate is a burgeoning unconventional resource with adsorbed methane (CH4) as its dominant component. Successful evaluation of marine shale gas gives limited insights into the evaluation of continental shale gas condensate due to their different occurrence patterns of organic matter and inorganic minerals and resultant contributions to pore development and CH4 ad-/desorption capability. To address this issue, we employed an advanced low-temperature oxygen plasma (LTOP) technology to extract organic matter from the continental shaly matrix. Results showed that the continental shaly matrix contains more clay minerals and less quartz, and develops fewer pores and fractures than typical marine shaly matrix. The organic matter-hosted pores instead of inorganic mineral-hosted pores are more weighted to the pore development in the continental shaly matrix. However, the inorganic minerals of the continental shaly matrix contribute more to CH4 adsorption capability than the organic matter, which could be attributed to the higher density of available adsorption sites toward CH4. Besides, the CH4 ad-/desorption hysteresis is more pronounced for the organic matter-free continental shaly matrix than the raw continental shaly matrix, which is attributed to the remarkable CH4 adsorption-induced clay mineral swelling. Overall, the effects of inorganic minerals in CH4 adsorption and desorption, particularly clay minerals, are crucial for continental shale gas condensate exploration and production.

Synthesis of CHA zeolite in phenoxide media for CO2 capture

Synthesis of small-pore chabazite (CHA) zeolites in the absence of organic structure-directing agents (OSDA) has been proven difficult. A judicious mixed cation approach recently reported could expand the design space of CHA formation. In a seemingly opposite direction, we herein report an anion tuning approach for controlling the zeolite polymorphism in an OSDA-free system that effectively promotes hierarchical CHA formation in a competitive growth with MER. Phenoxide media, utilizing mild in-situ nucleophilic etching in cooperation with zeolite framework growth, allow beneficial kinetic control to facilitate CHA nucleation. Operando analyses reveal the crucial role of stabilized dimeric aluminate species as a key intermediate for CHA phase selection. The phenol-mediated CHA zeolites exhibit almost perfect 9 molecules per unit cell CO2 uptake capacity and no CH4 adsorption. This work offers an anion tuning strategy for controlling zeolite polymorphism as a supplement to the current phase-selection toolbox that utilizes mixed inorganic cations.

Microscopic Characterization of Deformation Behavior during Kerogen Evolution: Effects of Maturity and Skeleton Moisture Content.

The CH4 storage and seepage capacity of shale kerogen are the main controlling factors of the natural gas production rate, and the porosity and permeability of kerogen are greatly affected by kerogen deformation. Therefore, the study of the deformation rule and CH4 adsorption characteristics of kerogen at different maturities and skeleton moisture contents has an important impact on the proper understanding of the development potential of shale gas reservoirs. In this paper, kerogen maturity (II-A, II-B, II-C, and II-D) and skeleton moisture content (0.0, 0.6, 1.2, 1.8, and 2.4 wt %) were considered. The deformation of kerogen, the adsorption of CH4 after deformation, and the quadratic deformation induced by CH4 were studied by using Grand Canonical Monte Carlo (GCMC) and molecular dynamics (MD). The results show that the kerogen volume strain increases with increasing skeleton moisture content, following the order II-A < II-B < II-C < II-D for the same moisture content. The density of the kerogen matrix decreases, and porosity increases with rising moisture content. The void fraction of immature kerogen decreases with increasing water content, while the opposite is true for postmature kerogen. The presence of skeleton moisture decreases the CH4 adsorption capacity of immature kerogen and increases the CH4 adsorption capacity of postmature kerogen. The chemical structure of immature kerogen is relatively soft, making its volume more affected by CH4 adsorption compared with postmature kerogen. In the same water environment, postmature kerogen has greater CH4 storage, diffusion, and seepage capacity compared to those of immature kerogen, suggesting that reservoirs with high organic matter maturity should be prioritized for development.

Molecular simulation of the effect of water content on CO2, CH4, and N2 adsorption characteristics of coal

The objective of this work was to investigate the sorption behavior of gases, namely CO2, CH4, and N2, by molecules of coal sampled from Linglu mine under different water inclusion rates. To this end, the adsorption, diffusion, adsorption heat, and potential energy distribution characteristics of the gases in the coal pores at different water inclusion rates were analyzed using molecular dynamics and grand canonical ensemble Monte Carlo methods. The results showed that the adsorption relationship of the coal molecules on CO2, CH4, and N2 exhibited a downtrend followed by an uptrend when the water content was increased from 0 to 3.6%. The adsorption amount of CO2 was approximately twice as much as those of CH4 and N2, indicating that the competitive adsorption advantage of CO2 compared with those of CH4 and N2 was unaffected by the water content. The trend in the average heat of adsorption was generally consistent with the trend in the density of coal molecules under different moisture contents. Under the same conditions, the diffusion coefficient within a coal molecule was negatively related to the water content in the system. The layer spacing of the water molecules (2.875 Å) was greater than the liquid–water layer spacing, indicating the formation of a water molecule layer at this point, which inhibited gas adsorption. This study lays a theoretical foundation for further investigating the microscopic mechanism of coal–water interaction.

Zeolite-templated carbon synthesized with ion-exchanged FAU-zeolite using alkaline earth metal ions for the selective adsorption of C2 hydrocarbons over C1 hydrocarbon

In this study, zeolite-templated carbon (ZTC) was synthesized using ion-exchanged faujasite-Y (FAU, NaY) zeolites with different alkali earth metals (Mg2+, Ca2+, Sr2+, and Ba2+) to investigate the effects of these metals on the synthesis, characteristics, and C2/C1 hydrocarbon separation performance of ZTC. Thermogravimetric and temperature-programmed desorption of NH3 (TPD-NH3) analyses showed that carbon deposition tends to occur outside the pores because of the increasing number of moderate acid sites as the atomic number increases. In particular, in the case of FAU-ZTC(Ca) synthesized using CaY as the ZTC template, carbon accumulated inside the pores owing to the distribution of the appropriate acid strength, resulting in the highest specific surface area of 2,835 m2/g among the synthesized ZTCs. The combined X-ray photoelectron and Raman spectroscopy results confirm that these defect sites of ZTC act as adsorption sites for large molecules such as C2H4 and C2H6. The isothermal adsorption of CH4, C2H4, and C2H6 showed that FAU-ZTC(Ca) exhibited the highest adsorption capacity ratios of C2H4 and C2H6 to CH4, with a C2H6/CH4 ratio of 5.897 and C2H4/CH4 ratio of 5.288, respectively. The effective pore size ranges affecting the adsorption of CH4, C2H4, and C2H6 determined using linear regression analysis are 0.4 to 0.6 nm for CH4 and 0.6 to 1.1 nm for C2H4 and C2H6. Molecular simulations confirmed that the adsorption energy was maximized by the interaction between the hydrogen atoms of the hydrocarbons and the carbon atoms of ZTC. Furthermore, C2H4 and C2H6 require larger pores than CH4 adsorption because C2H4 and C2H6 prefer to lie horizontally rather than vertically in the pores of the ZTC.

High-vacuum-calcined multi-MOF mixed-matrix membrane for CH4/N2 separation

Methane/nitrogen (CH4/N2) separation remains a persistent challenge owing to the similar polarities, kinetic diameters, and boiling points of CH4 and N2. Herein, a novel method is proposed for enhancing the separation performance of CH4/N2 via vacuum resistance calcination, which uses surface-carbonized and hardened ZIF-8 (SCH-Z), MOF-74-Ni (SCH-M), and UiO-66-NH2 (SCH–U). The nanoparticles treated by vacuum resistance calcination remain the microporous characteristics of MOF, while introducing additional mesoporous structure and unsaturated metal sites. Such multistage pore structure and rich metal sites display a significant improvement in the CH4 adsorption over N2. In addition, the separation performance of multiple metal–organic frameworks (MOFs) mixed matrix membranes (MMMs) fabricated by homogeneously mixing the alkaline polymer polyvinylamine (PVAm) with SCH-M/SCH-Z and SCH-M/SCH–U was investigated, respectively. When the measured pressure was 0.1 MPa and the binary filler loading was 48 %, the PVAm/(SCH-M)0.7(SCH-Z)0.3/MPSf MMM exhibited outstanding CH4/N2 separation performance (CH4 permeance of 2888.48 GPU and selectivity of 4.38). Furthermore, when the loading of the binary filler was 45 %, the ideal CH4/N2 selectivity and CH4 permeance of PVAm/(SCH-M)0.67(SCH–U)0.33/MPSf MMM are 5.57 and 2263.94 GPU, respectively. This study provides a novel idea that introducing multi-MOF nanoparticles into MMMs for optimizing gas separation performance.

Adsorption of methane by modified-biochar aiming to improve the gaseous fuels storage/transport capacity: process evaluation and modeling.

The CH4 storage by adsorption on activated carbons for natural gas handling has gained interest due to the appearance of lightweight materials with large surface areas and pore volumes. Consequently, kinetic parameters estimation of the adsorptive process can play a crucial role in understanding and scaling up the system. Concerning its versatility, banana peel (BP) is a biomass with potential for obtaining different products, such as biochar, a solid residue from the biomass' thermal decomposition of difficult disposal, where through an activation process, the material porous features are taken advantage to application as adsorbent of gaseous substances. This research reported data for the CH4 adsorption kinetic modeling by biochar from BP pyrolysis. The activated biochar textural characterization showed particles with fine mesoporous structure (pore diameter ranging between 29.39 and 55.62Å). Adsorption kinetic analysis indicated that a modified pseudo-first-order model was the most suitable to represent the experimental data, with equilibrium adsorption of 28mgg-1 for the samples activated with 20.0% vol wt.-1 of H3PO4 and pyrolysis at 500°C. The equilibrium constant was consistent with the Freundlich isotherm model, suggesting a physisorption mechanism, and led to a non-ideal, reversible, and not limited to monolayer CH4 adsorption.