Gas Uptake Research Articles

Shaping of MIL-53-Al and MIL-101 MOF for CO2/CH4, CO2/N2 and CH4/N2 separation

Metal-organic frameworks (MOF) are promising materials for gas storage and separation. The formulation and shaping of MOFs in mechanically stable bead forms is an essential requirement for their practical application as an adsorbent for gas and liquid mixture separations. In this work, MIL-53-Al and MIL-101 MOF beads are synthesized using sodium alginate as a binder, and calcium chloride as a gelling agent. The synthesized MIL-53-Al and MIL-101 MOF beads are characterized by powder X-ray diffraction (PXRD), BET surface area, porosity analysis from N2 uptake data at 77 K, FTIR, TGA, and scanning electron microscopy (SEM). The isothermal equilibrium adsorption uptake of CH4 and N2 gases is measured up to 10 bar pressure while the CO2 equilibrium uptake is measured up to 1 bar at 298 and 313 K respectively. The isotherm data of all adsorbates are fitted in Dual Site Langmuir (DSL) isotherm equations. The adsorption selectivity for CH4/N2, CO2/CH4, and CO2/N2 binary systems are predicted using the Ideal Adsorbed Solution Theory (IAST) method. The dynamic column breakthrough experiments are carried out on MIL-53-Al beads for CH4/N2 (30:70 and 50:50 v/v), CO2/CH4 (45:55 v/v) and CO2/N2 (15: 85 v/v) feed mixtures. The IAST selectivity and breakthrough time obtained under the same superficial velocity, pressure, and temperature conditions follow the order CO2/N2 > CO2 /CH4 > CH4/N2. The MIL-53-Al beads show higher CH4/N2, CO2/CH4, and CO2/N2 selectivity for the targeted mixtures than MIL-101 beads.

Tröger's Base-Enriched Conjugated Cyclopentannulated Copolymers: Prominent Adsorbents of CO2, H2, and Iodine.

Three copolymers with conjugated structures, PTB1-PTB3, were produced utilizing a palladium-catalyzed cyclopentannulation polymerization by reacting a specially designed diethynyl Tröger's base surrogate with different dihalogenated polycondensed aromatic hydrocarbons. Brunauer, Emmet, and Teller nitrogen gas adsorption investigation revealed the surface areas of the copolymers, attaining ∼365 m2 g-1. Gas uptake studies demonstrated a considerable carbon dioxide uptake for PTB2 of 44.41 mg g-1 at 273 K and a promising H2 gas uptake of 3.18 mg g-1 at 77 K. PTB1-PTB3 displayed a sizable iodine adsorption capacity, achieving 4000 mg g-1, and mechanistic investigations demonstrated the prevalence of a pseudo-second-order kinetic model. Recyclability experiments proved the effective regeneration of the copolymers, even after performing several adsorption and desorption tests.

Enhancing energy carrier gas storage: Novel MOF-decorated carbons with high affinity toward methane and hydrogen

The low volumetric density of alternative energy sources, like methane and hydrogen, makes their efficient storage challenging. This issue hinders their widespread adoption as clean energy carriers and limits their potential to address the energy crisis and reduce CO2 emissions. To overcome this limitation, a novel hybrid adsorbent was synthesised by incorporating MIL-101(Cr) and pitch-based activated carbon (AC), and its potential for methane and hydrogen adsorption was evaluated through experimental and molecular simulation methods. The adsorption capacity of CH4 and H2 on the MOF-doped ACs was simulated using Grand Canonical Monte Carlo (GCMC). Through the ex-situ method, varying amounts of MIL-101(Cr) were integrated onto the surface of AC, resulting in a nanocomposite with enhanced gas uptake properties. The AC/MIL-101(Cr) nanocomposite with 50 wt% MOF-doping exhibited superior methane loading performance (12.21 mmol.g-1) at room temperature and 35 bar, surpassing MIL-101(Cr) by approximately 20% (10.15 mmol.g-1). In terms of hydrogen adsorption, the AC/MIL-101 composites demonstrated advantageous gas uptake at low pressures (P ≤ 4.5 bar) due to a decrease in pore diameter (2.17 nm to 1.61 nm) and an increase in the number of micropores (60% to 78%). Conversely, at higher pressures, the dominant factor influencing H2 storage was the surface area.

A critical review and meta-analysis of xenon-on-carbon sputter yield data

A systematic review and meta-analysis of sputter yield data for xenon ions normally incident on graphite at energies below 2000 eV was undertaken to identify systematic errors, determine the best model parameter values to represent yield as a function of energy, quantify uncertainty, and determine if the data support differences in yields for different types of graphite. A critical examination of the 11 published data sets for high density graphite, pyrolytic graphite, and amorphous carbon showed that, in general, they were carefully controlled to minimize errors. The most significant quantifiable systematic errors were those caused by the neglect of doubly charged ions, chemical erosion, and the impact of secondary electron emission on ion flux measurements. The effects of gas uptake and outgassing on mass loss measurements and unrepresentative surface textures may have biased other experiments, but these effects could not be quantified. The semi-empirical Eckstein model for yield as a function of energy was fit to data for the three graphite types using a hierarchical Bayesian statistical model, producing recommended fit parameters and probability distributions representing uncertainty in yields. The results showed that differences in yield for high density graphite and pyrolytic graphite were not statistically significant. Apparent differences in yield for amorphous carbon disappeared when the single data set available for energies below 150 eV was corrected for reasonable values of double ion content. Recommended procedures to avoid systematic errors and additional experiments and modeling to fill in gaps in our understanding are included.

Atomic observation and structural evolution of covalent organic framework rotamers

Dynamic 3D covalent organic frameworks (COFs) have shown concerted structural transformation and adaptive gas adsorption due to the conformational diversity of organic linkers. However, the isolation and observation of COF rotamers constitute undergoing challenges due to their comparable free energy and subtle rotational energy barrier. Here, we report the atomic-level observation and structural evolution of COF rotamers by cryo-3D electron diffraction and synchrotron powder X-ray diffraction. Specifically, we optimize the crystallinity and morphology of COF-320 to manifest its coherent dynamic responses upon adaptive inclusion of guest molecules. We observe a significant crystal expansion of 29 vol% upon hydration and a giant swelling with volume change up to 78 vol% upon solvation. We record the structural evolution from a non-porous contracted phase to two narrow-pore intermediate phases and the fully opened expanded phase using n-butane as a stabilizing probe at ambient conditions. We uncover the rotational freedom of biphenylene giving rise to significant conformational changes on the diimine motifs from synclinal to syn-periplanar and anticlinal rotamers. We illustrate the 10-fold increment of pore volumes and 100% enhancement of methane uptake capacity of COF-320 at 100 bar and 298 K. The present findings shed light on the design of smarter organic porous materials to maximize host-guest interaction and boost gas uptake capacity through progressive structural transformation.

Enhanced CO2 hydrate formation using hydrogen-rich stones, L-Methionine and SDS: Insights from kinetic and morphological studies

One promising proposal for CO2 capture and storage is based on hydrate technology, which grapples with challenges related to stringent formation conditions and slow formation rates. In this study, the induction time, gas uptake and the rate of CO2 hydrate formation were measured with varying concentrations (ranging from 0.05 wt% to 0.2 wt%) of L-Methionine (L-Met) and sodium dodecyl sulfate (SDS). Remarkably, the novel additive hydrogen-rich stone significantly reduced the induction time by 89.74 % and 85.16 %, even under static conditions. The morphology analysis reveals that L-Met foster the creeping growth of hydrates, resulting in an approximate 41.89 % increase in the initial 1 h gas uptake. The efficient heat diffusion further enables the rapid formation of hydrates, resulting in a high gas uptake in a short period. L-Met outperforms SDS in terms of induction time and gas uptake, with the optimal choice for CO2 hydrate formation being 0.1 wt% L-Met. This study briefly describes the mechanisms of three different kinetic promoters for hydrate formation, which provides new ideas for subsequent studies on CO2 capture and storage via hydrate technology.

Carbon reserves on the soils of the Dmitrievsky village council of the Ufa district of the Republic of Bashkortostan

The research was carried out within the framework of the state task of the Ministry of Education and Science of the Russian Federation “Program for the creation and operation of a carbon landfill in the Republic of Bashkortostan “Eurasian carbon landfill” for 2022-2023 (Publication number: FEUR-2022-0001). Carbon deposition in the soil is an essential function arising from the interaction of ecological processes. Human activity influencing these processes leads to dehumidification or, conversely, deposition of soil carbon. The article presents the materials of the analysis of literary sources on the subject of carbon farming, as well as the content of organic matter in the soils of agricultural lands of the southern forest-steppe of the Republic of Bashkortostan in the conditions of a carbon landfill in the Ufa district (Russian Federation). This study aims to analyse carbon reserves in the humus-accumulative soil horizon of a carbon landfill on agricultural lands in the Dmitrievsky Village Council of the Ufa district of the Republic of Bashkortostan. An agrochemical analysis of the accumulation of soil organic matter was carried out, and the capacity of the humus horizon of the soils of this site was determined. Carbon reserves in the studied soils were determined according to the methodology for quantifying greenhouse gas emissions and uptake [Order of the Ministry of Natural Resources of Russia No. 371 dated 05/27/2022, Guidelines for Quantifying the volume of greenhouse gas uptake]. The carbon content in the organic matter of soils is assumed to equal 58%. The conversion to the stock of soil carbon was carried out, considering the density of the soil composition. The degree of saturation of the soils of the studied sites, including the carbon landfill, is calculated. The reserves of organic carbon under individual varieties of soils in the humus-accumulative horizon - 4616360 tons were estimated.

Highly efficient separation and equilibrium recovery of H2/CO2 in hydrate-based pre-combustion CO2 capture

Gas hydrate-based CO2 capture processes have attracted considerable attention due to their potentials for energy-efficient pre-combustion CO2 capture. Recent investigations have explored the use of tailored-wettability porous silica gels, highlighting benefits in thermodynamic and kinetic efficiencies, specifically characterized by low energy requirements and rapid formation. However, achieving high purity levels for both H2 and CO2 is crucial for practical implementation. Consequently, identifying and optimizing an effective separation route becomes imperative. In this study, we examined the thermodynamic stability, gas uptake, and separation factors of THF (5.56 mol%) + H2 + CO2 hydrates with varying compositions (H2:CO2 = 80:20, 60:40, 30:70, or 20:80 mol%) in C0 and C1 silica gel (functionalized by monofunctional alkylsilanes (X-(CH3)2-Si-Cn)) systems with SDS (0 or 500 ppm). Pressure-composition diagrams for THF + H2 + CO2 systems in C0 and C1 silica gel were meticulously measured. Notably, the C1 silica gel system without SDS demonstrated good thermodynamic stability, substantial gas uptake, and a significant separation factor. Based on the pressure-composition diagram of the C1 silica gel system, we proposed a highly efficient route for separating H2 and CO2. This proposed cyclic process involves a three-stage reactor and achieve to gas hydrate-based pre-combustion CO2 capture, yielding a purity of approximately 91 % H2 and 94 % CO2. The present findings provide valuable insights into optimizing the wettability of porous media and efficient separation routes, demonstrating the feasibility of a gas hydrate-based pre-combustion carbon dioxide capture process.

Novel core–shell and recyclable gas hydrate promoter for efficient solidified natural gas storage

The storage and transportation of gases, including hydrogen, methane, and carbon dioxide in the form of gas hydrates, have recently garnered considerable attention. The practical implementation of gas hydrates crucially depends on the development of efficient and reusable promoters. In this study, novel core–shell magnetic nanoparticles (CSNs) developed as recyclable promoter to enhance gas uptake. Hydrate formation experiments indicated that the storage capacity can reach up to 132.7 ± 1.4 v/v and 160.6 ± 2.5 v/v in CSNs and CSNs + SDS solutions, respectively. Compared to pure water and SDS solution, the initial methane consumption rate (0.5972 mol/h) of CSNs increased by 12.2 times and 1.08 times at 3000 ppm, respectively. CSNs exhibited favorable characteristics in terms of cycling ability and preventing foam formation during repeated methane hydrate formation and dissociation experiments. Furthermore, the combination of CSNs and SDS resulted in a 72 % reduction in hydrate nucleation induction time and a 58.3 % decrease in foam formation ability compared to the sole use of SDS. In comparison to pure water, the addition of CSNs increased the onset temperature of hydrate formation by 4 °C and reduced the driving force required for methane hydrate formation. Additionally, molecular dynamics simulation studies revealed that CSNs effectively improved the amount of the ordered water structure, hydrate cage formation, and the growth state of methane hydrates. These properties make CSNs promising for potential use in the storage and transportation of gas, considering the economic and environmental advantages associated with the use of promoters.

Construction of polyimide structures containing iron(ii) clathrochelate intercalators: promising materials for CO2 gas uptake and salient adsorbents of iodine from gaseous and liquid phases

Three novel imide-iron(ii) clathrochelate copolymers (ACP1–3) were synthesized via a microwave-assisted polycondensation reaction employing a specially designed diamine iron(ii) clathrochelate surrogate with various aromatic dianhydride derivatives.

Elucidating gas-surface interactions relevant to atmospheric particle growth using combined temperature programmed desorption and temperature-dependent uptake.

Understanding growth mechanisms for particles in air is fundamental to developing a predictive capability for their impacts on human health, visibility, and climate. In the case of highly viscous semi-solid or solid particles, the likelihood of impinging gases being taken up to grow the particle will be influenced by the initial uptake coefficient and by the residence time of the adsorbed gas on the surface. Here, a new approach that combines Knudsen cell capabilities for gas uptake measurements with temperature programmed desorption (TPD) for binding energy measurements of gases is described. The application of this unique capability to the uptake of organic gases on silica demonstrates its utility and the combination of thermodynamic and kinetic data that can be obtained. Lower limits to the initial net uptake coefficients at 170 K are (3.0 ± 0.6) × 10-3, (4.9 ± 0.6) × 10-3 and (4.3 ± 0.8) × 10-3 for benzene, 1-chloropentane, and methanol, respectively, and are reported here for the first time. The uptake data demonstrated that the ideal gas lattice model was appropriate, which informed the analysis of the TPD data. From the thermal desorption measurements, desorption energies of 34.6 ± 2.5, 45.8 ± 5.5, and 40.0 ± 5.6 kJ mol-1 (errors are 1σ) are obtained for benzene, 1-chloropentane, and methanol, respectively, and show good agreement with previously reported measurements. A multiphase kinetics model was applied to quantify uptake, desorption, and diffusion through the particle multilayers and hence extract desorption kinetics. Implications for uptake of organics on silica surfaces in the atmosphere and the utility of this system for determining relationships between residence times of organic gases and particle surfaces of varying composition are discussed in the context of developing quantitative predictions for growth of aerosol particles in air.

Boron-rich hybrid BCN nanoribbons for highly ambient uptake of H2S, HF, NH3, CO, CO2 toxic gases.

Nanomaterials-based gas sensors are widely applied for the monitoring and fast detection of hazardous gases owing to their sensitivity and selectivity. Hydrogen sulfide (H2S), hydrogen fluoride (HF), ammonia (NH3), and carbon monoxide/dioxide (CO/CO2) produced from petroleum fields, sewage, mines, and gasoline are harmful for both human life and environment. With an increase in the emission of these toxic compounds, their real-time monitoring and efficient adsorbent application and storage are very necessary. To this end, we investigated the adsorption characteristic and sensitivity factor of these five toxic gases on armchair and zigzag hybrid boron-carbon-nitride (BCN) nanoribbons with/without boron-rich (B-rich) defects using first principle calculation, where 25%, 33%, and 50% carbon concentration were considered. Our findings reveal that B-rich nanoribbons have strong adsorption energy, charge transfer, and structural deformation owing to the double acceptor of B-rich defects. Moreover, the zigzag and armchair forms of these hybrid BCN nanoribbons show physical adsorption, altering their band gap and phase transition after adsorbing these toxic gases, where B-rich nanoribbons possess high sensitivity to NH3 and CO among other gases. Furthermore, B-rich hybrid nanoribbons have higher CO2 adsorption energy than the standard free energy of CO2 at room temperature. This study suggests that hybrid BCN nanoribbons and B-rich defected structures can be good candidates for the uptake and storage of toxic gases, helping experimental groups to design efficient ambient gas sensors.

Water sorption studies with mesoporous multivariate monoliths based on UiO-66.

Hierarchical linker thermolysis has been used to enhance the porosity of monolithic UiO-66-based metal-organic frameworks (MOFs) containing 30 wt% 2-aminoterephthalic acid (BDC-NH2) linker. In this multivariate (i.e. mixed-linker) MOF, the thermolabile BDC-NH2 linker decomposed at ∼350 °C, inducing mesopore formation. The nitrogen sorption of these monolithic MOFs was probed, and an increase in gas uptake of more than 200 cm3 g-1 was observed after activation by heating, together with an increase in pore volume and mean pore width, indicating the creation of mesopores. Water sorption studies were conducted on these monoliths to explore their performance in that context. Before heating, monoUiO-66-NH2-30%-B showed maximum water vapour uptake of 61.0 wt%, which exceeded that reported for either parent monolith, while the highly mesoporous monolith (monoUiO-66-NH2-30%-A) had a lower maximum water vapour uptake of 36.2 wt%. This work extends the idea of hierarchical linker thermolysis, which has been applied to powder MOFs, to monolithic MOFs for the first time and supports the theory that it can enhance pore sizes in these materials. It also demonstrates the importance of hydrophilic functional groups (in this case, NH2) for improving water uptake in materials.

Trace SO2 capture within the engineered pore space using a highly stable SnF62--pillared MOF.

Developing reliable solid sorbents for efficient capture and removal of trace sulfur dioxide (SO2) under ambient conditions is critical for industrial desulfurization operations, but poses a great challenge. Herein, we focus on SNFSIX-Cu-TPA, a highly stable fluorinated MOF that utilizes SnF62- as pillars, for effectively capturing SO2 at extremely low pressures. The exceptional affinity of SNFSIX-Cu-TPA towards SO2 over CO2 and N2 was demonstrated through single-component isotherms and corroborated by computational simulations. At 298 K and 0.002 bar, this material displays a remarkable gas uptake of 2.22 mmol g-1. Among various anion fluorinated MOFs, SNFSIX-Cu-TPA shows the highest SO2/MF62- of 1.39 mmol mmol-1 and exhibits a low Qst of 58.81 kJ mol-1. Additionally, SNFSIX-Cu-TPA displays excellent potential for SO2/CO2 separation, as evidenced by its ideal adsorbed solution theory (IAST) selectivity of 148 at a molar fraction of SO2 of 0.01. Dynamic breakthrough curves were obtained to reveal the effective removal of trace SO2 from simulated flue gas (SO2/CO2/N2; v/v/v 0.2/10/89.8) with a high dynamic capacity of up to 1.52 mmol g-1. Furthermore, in situ TGA demonstrated the efficient and reversible capture of 500 ppm SO2 over 20 adsorption-desorption tests. This durable material presents a rare combination of exceptional SO2 capturing performance, good adsorption selectivity, and mild regeneration, thus making it a good candidate for a realistic desulfurization process.

Binding of carbon dioxide and acetylene to free carboxylic acid sites in a metal-organic framework.

The functionalisation of organic linkers in metal-organic frameworks (MOFs) to improve gas uptake is well-documented. Although the positive role of free carboxylic acid sites in MOFs for binding gas molecules has been proposed in computational studies, relatively little experimental evidence has been reported in support of this. Primarily this is because of the inherent synthetic difficulty to prepare MOF materials bearing free, accessible -COOH moieties which would normally bind to metal ions within the framework structure. Here, we describe the direct binding of CO2 and C2H2 molecules to the free -COOH sites within the pores of MFM-303(Al). MFM-303(Al) exhibits highly selective adsorption of CO2 and C2H2 with a high selectivity for C2H2 over C2H4. In situ synchrotron X-ray diffraction and inelastic neutron scattering, coupled with modelling, highlight the cooperative interactions of adsorbed CO2 and C2H2 molecules with free -COOH and -OH sites within MFM-303(Al), thus rationalising the observed high selectivity for gas separation.

ИЗМЕНЕНИЕ КОНЦЕНТРАЦИИ ГАЗОВ В ТЕХНОЛОГИЧЕСКОМ МОДУЛЕ В ПРОЦЕССЕ ВЫРАЩИВАНИЯ БРОЙЛЕРОВ

There is no information on poultry emissions in national reports on anthropogenic gas release and greenhouse gas uptake. Gaseous pollutants are formed as a result of poultry enteric fermentation and fecal decomposition; their concentration depends on the ventilation efficiency and speed, as well as on density of poultry planting. Determination of greenhouse gas emissions amount from industrial poultry farming is an urgent task. The relative greenhouse gases emissions produced by poultry at the poultry house is approximately 0,045 kg in CO2 equivalent. At the same time, there is no information on the greenhouse gases’ concentration quantitative changing at poultry growing process. The aim of the study is greenhouse gases concentration change determining throughout the broiler chickens growing entire process. Studies of gases concentration in developed experimental technological module for broilers’ growing on each level of a two level battery have been carried out. Broiler chickens of the ROSS-308 cross for 6 weeks were raised. Greenhouse gas concentrations at the end of each week were measured. Due to the fact that the necessary temperature and humidity in the module were automatically maintained, only the natural ventilation system worked until the third week of cultivation, as a result the gas concentration inside the module increased, but did not reach the maximum of permissible concentration’s values. With the forced ventilation system’s automatic activation, the gases concentration at this technological module to minimum values was decreased. The gases’ concentration inside the module within the following limits varying: carbon dioxide - from 1029,9 to 4826,5 mg/m3, ammonia - from 2,05 to 23,11 mg/m3, hydrogen sulfide - from 0,12 to 0,96 mg/m3, methane - from 64,6 to 246,1 mg/m3. The gases’ concentration outside the technological module varies within the limits: carbon dioxide - from 366,4 to 1461,6 mg/m3, ammonia - from 0 to 3,42 mg/m3, hydrogen sulfide - from 0 to 0,35 mg/m3, methane - from 65,2 to 263,1 mg/m3.

Cumulative occupational exposure to gases and fumes is associated with impairment in lung function and disease-related quality of life in a German COPD patient cohort

ObjectivesThe impact of occupational exposures on lung function impairments and quality of life (QoL) in patients with chronic obstructive pulmonary disease (COPD) was analysed and compared with that of smoking.MethodsData...

Size‐Selective Capture of Fluorocarbon Gases and Storage of Volatile Halogenated Organic Vapors with Low Boiling Points by Molecular‐Scale Cavities of Crystalline Pillar[n]quinones

AbstractFluorocarbon gases are regarded as one of the largest contributors to serious environmental problems such as ozone‐depletion and global warming, and thus, the development of reclamation technologies is in great demand for reducing emission of such harmful compounds. So far, porous materials such as zeolites, activated carbons, and metal‐organic frameworks (MOFs) have been examined as solid‐state absorbents for fluorocarbon gases. However, such porous materials often suffer from a lack of size‐selectivity in fluorocarbon gas uptakes due to the large‐sized cavities (>1 nm). Herein, it is reported that macrocyclic pillar[n]quinones (P[n]Q, n = 5 or 6) in crystalline state show size‐selective uptake for fluorocarbon gases owing to their molecular‐scale cavities (<1 nm). The P[n]Q also show uptake behaviors for volatile halogenated organic compounds (VHOCs), which are highly toxic. Interestingly, the volatilities of VHOCs within the 1D channels of P[5]Q are drastically reduced compared with those of the bulk VHOC solvents. Experimental results and computational analyses revealed that the excellent storage abilities of the crystalline P[n]Q are a synergic result of their electron‐deficient macrocyclic scaffolds and the basic carbonyl oxygen atoms on their rims.

Green and Sustainable Carbon Dioxide Capture in Aqueous l-Valine: Experimental Studies on Process Efficiency and Gas Uptake for Industrial Applications

Green and Sustainable Carbon Dioxide Capture in Aqueous <scp>l</scp>-Valine: Experimental Studies on Process Efficiency and Gas Uptake for Industrial Applications

Experimental investigation on the methane storage by forming sH hydrate

Methane storage via clathrate hydrates is a promising method, the structure H (sH) hydrate can be formed at more moderate conditions compared to structure I (sI) hydrate and has a larger storage capacity than structure II (sII) hydrate. In this work, CH4 storage by forming sH hydrate in the tert-butyl methyl ether (TBME) solution was explored at an initial pressure of 5.0 MPa and within the temperature range of 274.15– 278.15 K. The CH4/TBME hydrate phase equilibrium condition was first determined with the isochoric pressure searching method, and the results revealed that the measured equilibrium data of CH4/TBME hydrate at different TBME concentrations were almost consistent. The effect of TBME concentration (0– 4.29 mol%), promoter type and sub-cooling on the hydrate formation kinetics and gas uptake was systematically investigated. The results showed that the hydrate formation rate increased with the increase of TBME concentration. The CH4 uptake achieved 117.7 ± 3.6 v/vw (volume ratio of gas to water at standard condition) in the 4.29 mol% TBME system, which was significantly increased than that of pure water (44.1 ± 5.0 v/vw). The cocamidopropyl dimethylamine (CDA) further improved the CH4/TBME hydrate formation kinetics and gas uptake, the CH4 storage capacity attained 145.6 ± 1.7 v/vw, which was slightly higher than that of the sodium dodecyl sulfate (SDS) system (143.6 ± 3.0 v/vw). As the sub-cooling increased, the formation kinetic profiles of CH4/TBME hydrate changed from a two-step to a one-step drop, indicating that the shift of mixed sH and sI hydrates to single sH hydrate. Additionally, the time taken for hydrate growth in the presence of TBME was significantly decreased than the pure water system, and the adding of CDA and SDS further shorten it. The CH4 recovery in each test was above 95.0 % and no foam generated during hydrate dissociation for the CDA-contained system. The stability test of CH4/TBME hydrate indicated that around 86 % CH4 was still enclosed in the hydrate phase after one week. This study would contribute to the application of the hydrate-based methane storage technology in future.