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Oil-immersed power transformers generate characteristic gases after failure,Therefore, it is necessary to analyse and monitor the soluble gases in transformer oil samples. In this study, the DFT calculation method was used to study the adsorption properties of H2, CO, C2H2, and C2H4 gases in oil on both intrinsic MoTe2 and Rh-doped MoTe2 films. In order to analyse the adsorption characteristics, this paper first obtains the most stable Rh-doped MoTe2 monolayer model through the modelling and computational analysis of different doping sites, then, the adsorption of these gases on the material surface is studied by analysing adsorption energy, charge transfer, total state density, parting density, energy band structure, differential charge density map, molecular front orbital and desorption time, and finally concludes that Rh-MoTe2 monolayer film is the ideal material for hydrogen sensing elements, due to the extremely long desorption time of CO gas, indicating that CO gas is hard to desorption on the surface of adsorbent,which shows that this process has played a certain role in promoting CO removal. Highlights Study focused on gas adsorption using DFT: Rh-MoTe2 ideal for hydrogen sensing and effective for CO removal, intrinsic MoTe2 ineffective and required metal doping. Rh doping enhanced conductivity and gas adsorption capacity in MoTe2. Rh-MoTe2 was suitable for detecting H2, C2H2, and C2H4 gases. Desorption times vary with temperature, with CO removal particularly effective at higher temperatures. Findings suggest potential applications for Rh-MoTe2 in gas sensing and removal. [ABSTRACT FROM AUTHOR]

Microporous organic polymers (MOPs) are a new type of porous materials, which have advantages of synthetic diversity, chemical and physical stability, microporous size controllability, etc. MOPs indicate broad applications in various fields such as heterogeneous catalysis, gas adsorption, separation, and storage. In recent years, MOPs have attracted an enormous attention in greenhouse gas capture due to their great potential in physisorptive gas storage. Carbazole and its derivatives have been studied extensively as Metal-Organic Polyhedra (MOPs) building blocks due to their unique structural features and versatile functionalization possibilities. This paper systematically reviews the synthesis, characterization and application of carbazole-based polymers, and relationship of structures and properties of these polymers. The application of the polymers in carbon dioxide (CO2) capture field is analysed taking advantage of their adjustable microporous structure and electron rich properties. This review also provides novel insights regarding functional polymer materials that have high ability of greenhouse gas capture and absorbing selectivity will be obtained by reasonable molecular design and efficient synthesis. [ABSTRACT FROM AUTHOR]

The paper demonstrates the prospects of using an approach for calculating adsorption isotherms of gases on micropore industrial zeolites based on the example of H2, CO2, CO, CH4, N2 adsorption on 13X and 5A zeolites using the Dubinin–Radushkevich–Astakhov (DRA) equation. Experimental adsorption isotherms of H2, CO2, CO, CH4, N2 gases on 13X and 5A zeolites of various manufacturers have been obtained, as well as ranges of the limiting adsorption volume and characteristic adsorption energy have been established. It made it possible to correctly calculate isotherms using the DRA equation in the temperature range 293–323 K and pressure range 0–30 atm. The paper proposes and solves the optimization problem of determining affinity coefficients, which allows the calculation of gas adsorption isotherms on zeolites using only one experimental isotherm of standard gas N2. The mismatch between the experimental isotherms and those calculated by the DRA equation is 14.69% for H2 (maximum) and 1.81% for CO2 (minimum). This approach makes it possible to significantly reduce the number of necessary expensive experiments in comparison with the traditional approach (using the Langmuir equations or equations derived from it), at the same time providing acceptable accuracy for practice. [ABSTRACT FROM AUTHOR]

Hydraulic fracture is a key technology for high-efficiency development of shale gas, and the flow mechanism of fractured well with Stimulated Reservoir Volume (SRV) is complex in shale gas. In this paper, an apparent permeability model is proposed, which can not only reflect the multi-scale flow characteristics in shale gas but also characterize the variation of permeability with effective stress. In addition, a composite model for a fractured well with SRV is established, which comprises multiscale, geomechanics and adsorption phenomenon. The object of this paper is to investigate some important impacts on a fractured well with SRV. The results reveal that the cumulative gas production will decrease sharply when the shale gas reservoir stress-sensitive coefficient increases. Additionally, the gas production rate and cumulative gas production will increase with the increase of SRV permeability. And, the adsorption phenomenon has an influence on shale gas seepage and sorption capacity, the larger Langmuir volume, the richer adsorption gas content in shale gas. And, more adsorbed gas will be exploited into free gas, which slows down the production decline of gas wells. The production of gas well will increase with the increase of perforation thickness of gas reservoir. [ABSTRACT FROM AUTHOR]

InN monolayer with graphene-like morphology and desirable electronic property is a promising candidate for gas sensing application. In this paper, we study the adsorption and sensing performances of the Rh-decorated InN (Rh–InN) monolayer upon two typical dissolved gases in the transformers oil, namely H2 and C2H2, to explore its potential to evaluate the working condition of the transformers. Rh atom conducts n-doping on the pristine InN surface with Eb of −2.01 eV. Also, chemisorption is determined for H2 and C2H2 adsorption on the Rh–InN surface given that the Ead of −0.88 and −2.15 eV, respectively. The opposite changing trend of Eg in H2 and C2H2 systems manifests the resistance-based sensing mechanism for selective detection of two gas species. The applied electric field supports the work function analysis that an Rh–InN monolayer possesses a strong potential for field-effect transistor sensor application in terms of H2 and C2H2 detection, wherein the charge-transfer in the gas systems is tunable by altering the voltage. Moreover, the excessive electric field is not considered to be suggestible since it can impact the geometric stability of the Rh–InN monolayer. This theoretical work is meaningful to exploit novel sensing 2D materials to guarantee the good operation of the power system. Highlights Rh-decorating behaviors upon InN monolayer is studied. Expound the potential of Rh-InN monolayer for dissolved gas analysis in transformers. Analyze the effect of applied electric field on gas adsorptions. [ABSTRACT FROM AUTHOR]

Iron-based catalysts can be used as de-NOx catalysts due to their good adsorption performance to gas molecules. However, the adsorption behaviours of NH3, NO, and O2 molecules on ferrous oxide surface are unclear. In this paper, the adsorption properties of NH3, NO, and O2 molecules over FeO (100) surface and oxygen-defected FeO (100) surface were studied by a density functional theory calculation. The Fe-top of the FeO (100) surface is the most active site. NH3 and NO can be adsorbed on the Fe-top sites by N terminal. The adsorption of O2 on the Hollow site of the FeO (100) surface has a larger adsorption energy. When oxygen-defected presents on the FeO (100) surface, the adsorption performances of NH3 and NO on the Fe-top sites are slightly decreased. NO and O2 can be adsorbed on the O-defected site, in which the adsorption energy of O2 is larger. For the adsorption of double molecules, O2 + NH3 or O2 + NO adsorbed on the FeO (100) surface have synergistic effects, respectively, which enhance the adsorption performance. Moreover, the co-adsorption behaviours of O2 + NH3 and O2 + NO on the O-defected FeO (100) surface also occur. [ABSTRACT FROM AUTHOR]

The Soochow University Beamline, located at the National Synchrotron Radiation Laboratory in China, is a Soft X-ray beamline designed for studying energy-related materials and devices. It operates in the energy range of 45 eV–1100 eV and is specifically tailored for investigating Li, B, C, N, O, F K-edges, and most L-edges of transition metals. The beamline offers various capabilities, including X-ray absorption, photon in photon out, and in situ/operando studies of energy materials and devices in gas/liquid environments. It has been successful in producing high-quality research papers and is open to users worldwide. The beamline is a collaborative effort between Soochow University and the National Synchrotron Radiation Laboratory, with funding from Soochow University. It is the first synchrotron radiation beamline in China to be funded by a university. [Extracted from the article]

The zoning of the coal seam gas is zonal, which has a significant impact on the prominent prediction indicators, resulting in different prediction results for the same prominent prediction indicators in the same coal seam soft and hard coal. In this paper, the hard coal and soft coal in the coal seam are highlighted. The adsorption and desorption rules of the soft coal and hard coal in the outburst coal seam and its influence on the sensitivity of the outstanding prediction index are studied. The results show that: (1) the initial desorption of soft coal is larger than that of hard coal; (2) the outstanding prediction index has an exponential function relationship with gas pressure; (3) the sensitivity of prediction indicators is different. And concluded that: (1) the initial desorption rate of soft coal is faster than that of hard coal; (2) the outburst prediction index K1 and Δh2 increase with the increase of gas adsorption equilibrium pressure; (3) outburst prediction index K1 is more reliable than Δh2. [ABSTRACT FROM AUTHOR]

In this article, the adsorption process of transition metal Fe-doped ZIF-67 material on characteristic gases in oil was investigated based on the first principles. The geometry optimisation model, adsorption parameters, energy band structure, TDOS and PDOS of each adsorption system were analysed and compared. The results showed that Fe-ZIF-67 chemically adsorbed all four characteristic gases in oil. And after doping, the adsorption energy of ZIF-67 material to CO gas can be greatly improved, but the adsorption energy to C2H2 gas is reduced. The adsorption performance ranking is CO > C2H2 > C2H4 > C2H6. This result shows that the addition of Fe enhances the selective absorption of characteristic gases in oil by ZIF-67 materials. The addition of Fe enhances the selective absorption of characteristic gases in oil by the ZIF-67 material. This article offers part of the theoretical evidence for the selective detectability and gas adsorption of characteristic gases in oil by ZIF-67 material. [ABSTRACT FROM AUTHOR]

In this paper, we present a brief review of what has been learned about the adsorption characteristics of various organic molecules at the surface of ice, from more than 15 years of computer simulation studies at the molecular scale. In particular, grand canonical Monte Carlo and molecular dynamics calculations were performed to determine the adsorption isotherms, the saturation coverage of the first molecular layer at the ice surface, the preferred orientations of the molecules in their adsorption sites, and the corresponding adsorption energies. The results of the simulations indicated that the main driving force for trace gas adsorption on ice is hydrogen bonding not only between the adsorbate and the water molecules of the ice surface, but also within the adsorbate. When possible, the comparison with available experimental data showed a close agreement, supporting thus the methodology used in the modelling. Finally, the present review demonstrates how computer simulation can nicely complement experimental approaches for studying interactions between trace gases and ice under tropospheric and interstellar condition [ABSTRACT FROM AUTHOR]

Molecular simulation was used to study methane adsorption and its effect on kaolinite swelling. The effects of temperature and pressure were also analysed. The comparisons which validate the force field and model in our paper were made between simulation and experiment. Simulation results demonstrate that adsorption behaviour of methane exhibit Langmuir adsorption behaviour. The temperature has a negative effect on gas adsorption, the adsorption amounts will decrease with increasing temperature at a given pressure. A quantitative relationship between the methane adsorption and the kaolinite swelling was provided. The kaolinite-methane interaction dominates and the methane-methane interaction contributes less than 20% to the total interaction energy. The first peak in the RDFs increases with the increasing pressure, illustrating that the system becomes less structured at higher pressure. Compared with the higher temperature, the first peaks at lower temperature increase as a higher amount of methane adsorbed indicating that the interaction between the kaolinite and methane increase with decreasing temperature. Methane is strongly adsorbed on the sites of the hydrogen and oxygen atoms in kaolinite molecules. [ABSTRACT FROM AUTHOR]

A cross-linked hybrid poly Schiff-base (PSB) was synthesized and characterized through spectroscopic, morphological, and structural approaches. The BET surface area (SBET) of the PSB is 20.33 m2/g, the pore volume (Vp) is 0.024 cm3/g, and the pore diameter (Dp) is 4.13 nm. The current study elucidates PSB's strong chemical and thermal stability, as well as the remarkable capacity to adsorb CO2 with perfect selectivity. This property is accomplished by the synergistic interaction of the polymer's physicochemical and structural features when exposed to CO2, N2 and CH4 molecules. This mesoporous polymer exhibits a CO2/N2 = 60 and CO2/CH4 = 10.5 selectivity, and can adsorb 3.22 mmol/g CO2 (at 298 K/1 bar). Furthermore, the isotherms of CO2 gas adsorption and desorption in the porous polymer are reversible. The use of PSB having effective imide, imine, and meta-hydroxyl functional groups in the adsorption and selectivity of CO2 gas produced excellent results, which make it a suitable candidate for CO2 storage and separation applications. [ABSTRACT FROM AUTHOR]

The present work reports the green synthesis and hydrogen storage capacities of porous biocarbon (CK-700) and, N/S doped biocarbon (ACK-1) prepared by green and sustainable carbonization methods from pistachio shells. The hydrogen uptake capacity of CK-700 and ACK-1 were investigated at −196 °C and in the pressure range of 5–50 bar. A green and sustainable route is described for the synthesis of N/S doped biocarbon (ACK-1) by using a combined hydrothermal carbonization and chemical activation process in which Na2S2O3 applied as an activating agent. The characterization of N/S doped biocarbon and raw biocarbon were investigated by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Scanning Electron Microscopy (SEM) and Brunauer-Emmett-Teller (BET) analyses. The hydrogen storage capacities of the green synthesized CK-700 and ACK-1 were measured by IGA dynamic gas adsorption analyzer. The hydrogen adsorption capacity of CK-700 and ACK-1 were measured and, the highest hydrogen adsorption capacity of ACK-1 was obtained to be 4.55 wt% under pressure of 50 and at 73 K, while the lowest hydrogen uptake capacity of CK-700 was obtained to be 2.24 wt% under pressure of 5 bar and at 73 K in raw biocarbon. Hydrogen storage capacity of the green synthesized porous biocarbon and N/S doped porous biocarbon were studied. Biocarbon nanoparticles were prepared via green and sustainable method. The addition of sodium thiosulfate as a nontoxic agents plays a synergetic catalytic role. Increase of pore sizes around 765 m2/g in porous N/S doped biocarbon essential for the enhanced hydrogen adsorption. [ABSTRACT FROM AUTHOR]

Gas is one of the most important factors which causes coal and gas outburst and can influence the mechanical characteristics of coal. Coal itself is a kind of elastic carbonaceous material which can swell and shrink under the influence of gas adsorption and desorption. Solid deformations influence the porosity of coal which also changes its adsorption and desorption capability. Gas pressure due to gas adsorption in porous materials is the cause of elastic deformation of coal, which can be assessed by direct experimental measurements. In this paper, briquette coal samples are made with different sizes of coal particles and the deformations are tested during the process of gas adsorption and desorption in samples under different gas pressures. The results show that coal swells during gas adsorption and shrinks during desorption. Deformation of different coal samples under different gas pressures is variable. It is further observed that deformation of coal is proportional to gas pressure and particle size. Also, deformation is not recoverable and residual deformation develops. The relationship between residual deformation and gas pressure is derived. This study helps to reveal the damage mechanism of pore gas in cola mass. [ABSTRACT FROM PUBLISHER]

In this paper, we report a comprehensive analysis of the adsorption of argon in cylindrical pores of finite length having different dimensions and adsorbent energies. We determine the mechanisms of adsorption and desorption in the hysteresis region, and use the recently introduced mid-density scheme, as an approximate method, to determine the equilibrium transition, which is found to lie wholly within the loop and closer to the desorption branch. For a given loading in the hysteresis region, we determine the microscopic behaviour of two metastable states (one on the adsorption branch and the other on the desorption branch) and the stable equilibrium state. The adsorption metastable state is characterised by a bulging adsorbed layer, while the desorption metastable state is characterised by a liquid bridge with a meniscus at each end in the shape of a long elliptical cone. The equilibrium state has a configuration that displays a liquid bridge with hemispherically shaped menisci having areas less than those of the two menisci in the desorption metastable state. [ABSTRACT FROM AUTHOR]

The Ru atomic catalyst-doped GaN (Ru-GaN) model was established by density functional theory (DFT), and the adsorption models of transformer oil dissolved gas (CO, H2, CH4, C2H2, C2H4 and C2H6) by a Ru-GaN monolayer were optimised. From the adsorption energy, differential charge density, electron state density, molecular orbital and desorption properties, the modification mechanism of Ru-GaN and the gas-sensitive response mechanism of Ru-GaN to CO, H2, CH4, C2H2, C2H4 and C2H6 were systematically studied. The introduction of metal Ru increases the defect state of GaN to provide the active site for the adsorption of gas molecules and reduces the adsorption barrier of GaN to gas molecules. The results show that Ru metal-doped GaN can adsorb CO, C2H2 and C2H4 by chemisorption, with Eads of −2.068 eV, −2.422 eV and −1.877 eV and Qt of −0.1696 e, −0.0671 e, −0.1222 e. In addition, charge redistribution leads to changes in the density of states, molecular orbitals and the conductivity of CO, C2H2 and C2H4 adsorption systems, indicating excellent gas sensitivity to the three gases. The desorption time further verified that Ru-GaN is an ideal CO and C2H2 gas scavenger and a recyclable material for C2H4 gas sensors. [ABSTRACT FROM AUTHOR]

Abandoned mines contain a large amount of residual coal and gas resources for development and utilization. In order to accurately establish the calculation model of gas reserves and lay a foundation for the exploitation of gas resources in abandoned mines, based on the analysis of temperature evolution of abandoned mines, gas adsorption experiments and molecular simulations were carried out at temperatures of 30, 60, 90, 120, 150 °C and five different adsorption equilibrium pressures (0.5∼2.5 MPa). The test results show that the attenuation rates of gas adsorption at 30∼60 °C, 60∼90 °C, 90∼120 °C, and 120∼150 °C are 8.53%, 7.89%, 5.55%, and 1.55%, respectively. High temperature inhibits the increase of gas adsorption by residual coal, but its inhibition has a certain limit. At high adsorption equilibrium pressure, the initial adsorption rate increases with the rise of temperature. When the pressure is 2.5 MPa, the initial adsorption rates at 30, 60, and 90 °C is 1.25, 2.22, and 2.32 ml▪g−1▪min−1, respectively. Temperature affects the gas adsorption characteristics of residual coal. Therefore, the influence of temperature should be considered when establishing the gas reserves model of abandoned mines. The inhibition effect of high temperature on adsorption is limited. Initial adsorption rate increases with the rising temperature at high pressure. The temperature factor should be added to the gas reserves model of abandoned mines. [ABSTRACT FROM AUTHOR]

Theoretical description of single gas and gas mixture adsorption equilibria can be achieved in many different ways depending on the kind of approach (microscopic or macroscopic) and on the physical assumptions related to the nature of the adsorbent–adsorbate systems studied as well as temperature and pressure conditions. In this paper, a detailed statistical thermodynamics development is presented. It leads to a generalized expression of adsorption isotherms for pure gases on homogeneous surfaces. The non-ideality of both gas and adsorbed phases are taken into account using the Redlich–Kwong equations of state (EOS) which is adapted for two-dimension phases. Such an approach leads to a symmetrical treatment of both phases resulting in similar expressions of their EOS and of their fugacity coefficients. It allows an easy extension to gas mixtures adsorption equilibria. We present adsorption isotherms calculated using our model, the influence of the non-idealities are presented and discussed. [ABSTRACT FROM AUTHOR]

Theoretical description of single gas and gas mixture adsorption equilibria can be achieved in many different ways depending on the kind of approach (microscopic or macroscopic). In this paper, we present a statistical thermodynamics approach for the calculation of mixed gas adsorption equilibrium data on uniform surfaces. The non-ideality of both the mixed gas phase and the adsorbed phase is considered by using the Redlich–Kwong EOS associated to the classic Lorentz–Berthelot mixing rules. This is an interesting way to extend the model presented in Part I and to predict multicomponent gas adsorption equilibria for highly non-ideal systems from parameters deduced from pure gas data. We present mixture adsorption isotherms and selectivity curves calculated using our model. [ABSTRACT FROM AUTHOR]

MD simulations were performed based on the cross-linking simulations to investigate the selectivity of the eight containing-oxygen molecules, O2, CO, CO2, NO, N2O, NO2, COS and SO2, identified by the gas-phase CHCl•– anion. Of the studied containing-oxygen molecules the O2, NO and SO2 had relatively high molecular selectivity toward CHCl•–, especially NO. Except for NO and N2O, which become C–N bonds, the C–O interaction was the main component of the CHCl•– interacted with O2, CO, CO2, NO2, COS and SO2 molecules, with the addition of CHCl•– having a significant impact on the interaction intensity. Based on interactions with CHCl•–, predictions suggest that the electron-rich material's adsorption of O2, NO2, SO2 and CO should be very significant and efficient, with the order of O2 > NO2 > SO2 > CO. The COS adsorption was determined by it's C/S atom rather than the O atom. The effective adsorption of the three gases CO2, NO and N2O should take place at high temperatures. We expected to shed new light on the role of the electron-rich in gas sensor response/recovery by simulating the pre-concentration process of CHCl•– probe molecules and enhancing the interfacial interactions between gases-probe molecules. [ABSTRACT FROM AUTHOR]

In this study, we developed a model of convective heat and mass transfer of an acoustically levitated slurry droplet that evaporates in an atmosphere of air, water vapor, and soluble gas. The advanced model considered the effects of acoustic streaming, forced convection, and non-isothermal gas absorption on the evaporation rate of a liquid droplet containing small solid particles. It is shown that the time of porous shell formation decreases with the increase of sound pressure level (SPL) and increases with the increase in frequency. Adding soluble gas to the gaseous phase shortens the time required for porous shell formation during slurry droplet drying. As shown by numerical calculations, in a gas mixture containing air with an ammonia content of 30%, at a temperature of 293 K and a humidity of 50%, with an acoustic field frequency of 2π·45 kHz and an SPL of 140 dB, the time of porous shell formation of a silica-water slurry droplet with the initial radius of 250 µm is about half shorter than that in a gas mixture not containing an active gas. The prediction of the developed model was in good agreement with the experimental results available in literature. [ABSTRACT FROM AUTHOR]

Chinese historic buildings are characterized by a wooden structure, which has caused serious results due to the ravages of frequent fire disasters. After the weathering by the natural environment, the fire risk of wood is highly enlarged. Fluorinated chemical gases are widely used for fire suppression at the early stage of a historic building fire. However, the effects of hydrogen fluoride (HF) released during fire suppression on historic buildings are unavailable. Presently, experiments were performed to study HF effects on the weathered timbers. Five traditional fluorinated chemical gases, H-37, FK-5-1-12, H-1323, H-2402, and H-1301, are employed to suppress a fixed flame. The weathered timber chips, acting as historic building materials, are located in the chamber to detail the influence of HF on the surface. The characteristic of gas production and elements variety of wood surface are discussed by FTIR and SEM-EDX, respectively. It is observed that flame enhancement takes place at the early stage of fire suppression and various types of fire agents. The total amount of HF during 50 min is highly dependent on the physical parameters of fluorinated chemical gases. The SEM results of weathered timber suggest the surface of the wood is porous, resulting in a strong gas absorption performance. The amount of deposited F on the wood surface is found to be positively correlated with the total amount of HF yielded during fire suppression. [ABSTRACT FROM AUTHOR]

The synthesis, characterization and modification of mesoporous silica (MS) were carried out and, drug removal and release studies were also performed. The synthesized MS has an ordered structure with high surface area and homogeneous pore size distribution, which was then modified with a Schiff base (S) ligand. The characterization of MS and Schiff base modified MS (S-MS) was accomplished with scanning electron microscopy (SEM), nitrogen gas adsorption, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and dynamic light scattering (DLS) analyses. The adsorption of diclofenac sodium (DS) and metformin HCl (MF), which were preferred as model drugs, onto MS and S-MS, was investigated in an aqueous solution with respect to pH, the amount of adsorbent and contact time. The maximum calculated values from the pseudo-second-order model for the adsorption of MF and DS were determined as 625.5 and 675.0 mg g‒1 for MS and 558.5 and 765.7 mg g‒1 for S-MS, respectively. In addition, the hybrid structures of MS and S-MS were prepared for use in the drug release studies, and their efficiencies in releasing drugs were then investigated. The releases of DS and MF from silica hybrid structures after 4 h were determined to be at around 30% and 70%, respectively. [ABSTRACT FROM AUTHOR]

Nowadays, detecting the more hazardous sulphur group of gases (H2S, SO2) is increasingly essential, and there is a need to find a readily fabricated, low-cost, high-performance 2D material. This study investigated the selective detection of H2S and SO2 by MoSe2 monolayers and Pt-doped MoSe2 monolayers using first-principles calculations. Our results show that the dopant dramatically enhances the activity of the material, creating solid interactions with the material surface and that Pt-doped MoSe2 monolayers have the potential to selectively detect these toxic gases because of their different conductive tendencies. This work provides insights into the potential application of unexplored TMDs as chemically resistant sensors for the detection of poisonous gases, which may be of importance for environmental monitoring and industrial manufacturing. [ABSTRACT FROM AUTHOR]

The adsorption properties of coal determine the economic benefits of coalbed methane (CBM) extraction. To investigate the gas adsorption behavior of raw coal after heating, gas adsorption tests and pore characterization tests were conducted. Meanwhile, the influence of high temperature on coal pore structure and polymorphic gas adsorption was analyzed. The results showed that the gas adsorption gradually increased with the increase of coal grade at the same temperature. For the same coal grade coals, the adsorbed gas content decreased 5.96%-21.53% and the non-adsorbed gas content increased 51.25%-95.47% with the increase of temperature. The high temperature has a dilating effect on coal pores, causing the proportion of tiny pores to decrease and the adsorbed gas storage capacity to become weaker, and the proportion of medium and large pores to increase and the non-adsorbed gas storage capacity to become stronger. This study can provide data support for coalbed methane heat injection extraction. [ABSTRACT FROM AUTHOR]

Employment of mesoporous silica nanostructures (MSNs) in the drug delivery field has shown a significant potential for improving the oral delivery of active pharmaceutical products with low solubility in water. Mirtazapine (MRT) is a tetracyclic antidepressant with poor water solubility (BCS Class II), which was recently approved as a potent drug used to treat severe depression. The principle of this research is to optimize the incorporation of Mirtazapine into MSNs to improve its aqueous solubility, loading efficiency, release performance, and subsequent bioavailability. The formulation was optimized by using of Box-Behnken Design, which allows simultaneous estimation of the impact of different types of silica (SBA-15, MCM-41, and Aluminate-MCM-41), a different drug to silica ratios (33.33%, 49.99%, and 66.66%), and different drug loading procedures (Incipient wetness, solvent evaporation, and solvent impregnation) on the MRT loading efficiency, aqueous solubility and dissolution rate. The optimized formula was achieved by loading MRT into SBA-15 at 33.33% drug ratio prepared by the incipient wetness method, which displayed a loading efficiency of 104.05%, water solubility of 0.2mg/ml, and 100% dissolution rate after 30 min. The pharmacokinetic profile of the optimized formula was obtained by conducting the in-vivo study in rabbits which showed a marked improvement (2.14-fold) in oral bioavailability greater than plain MRT. The physicochemical parameters and morphology of the optimized formula were characterized by; gas adsorption manometry, scanning electron microscopy (SEM), polarized light microscopy (PLM), Fourier-transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and X-ray powder diffraction (XRPD). [ABSTRACT FROM AUTHOR]

Conventional CO2 capture technologies are well-established for CO2 separation in power plants and carbon emission industries. However, the additional operating expenses under optimized conditions remain a problem that leads to increased production costs. Therefore, it is necessary to evaluate the viability of CO2 capture technologies based on their energy consumption and processability. This review focuses on the economic feasibility of membrane-based CO2 capture and comparison with existing technologies, with particular attention to the costs of CO2 capture and its removal efficiency. On this basis, technology limitations and challenges will be further discussed based on the operational configuration. The output of the technical and economic evaluations concluded that membrane gas absorption (MGA) is the most feasible, has relatively low operating costs, and is easy to operate at room condition, which implies the potential of MGA as an alternative approach to mitigate CO2 emissions. In addition, this review also clarifies the development of superhydrophobic membranes in MGA, so that MGA can reach another higher level in industrial-scale applications. [ABSTRACT FROM AUTHOR]

The adsorption properties of two kinds of metal–organic frameworks (MOFs), PCN-228ʹ and PCN-230, have been studied by the grand canonical Monte Carlo (GCMC) method for the absorption of N2, H2, CH4/H2 mixed gas. Their pore size distributions are analysed by the Horvath-Kawazoe (HK) method. The PCN-230 exhibits an outstanding volumetric density for hydrogen storage endowed by its ultralow density and promising pore volume. While the PCN-228ʹ shows a great selectivity of 70 towards adsorption of the CH4/H2 gas mixture at low pressure, this type of MOF presents strong CH4 adsorption capacity, which is suitable for CH4/H2 mixed gas separation and purification. [ABSTRACT FROM AUTHOR]

Gas adsorption is widely used in air pollution control, with mainly activated carbon and zeolites used as adsorbents. Although physical and chemisorption can be used, most air pollution applications involve physical adsorption, now also increasingly investigated for CO2 abatement from combustion gas. Empirical adsorption treatments have been presented since many decades, but solely rely on the comparison of adsorbate feed and exhaust concentrations of the adsorption bed. In-situ measurements, to study the absorbate/adsorbent interactions in real time, are compared in the present review when performed by a three-dimensional (3D) Positron Emission Tomography of an adsorbing 11CO2 radioactive tracer on activated carbon versus a zeolite adsorbent. The overall results are validated by conventional exit gas analysis. Results are defining both the time-dependent adsorption parameters, such as the progressing adsorption front and Mass Transfer Zone along the adsorbent bed length, and enable to assess previous semi-empirical adsorption correlations toward their optimum validity in predicting adsorption isotherms, kinetics and mechanisms. [ABSTRACT FROM AUTHOR]

Ships have become an important source of SO2 emission in coastal areas with the rapid development of maritime transport. It is of great significance to develop a marine scrubber for reducing SO2 emission of ships. In this study, numerical simulation of a full-scale marine spray scrubber is conducted to investigate two-phase flow pattern and SO2 absorption process in the scrubber. A desulfurization model based on seawater absorbent is coupled into the simulation, which considers the mass transfer between phases and seawater aqueous phase chemistry simultaneously. A distribution ring is introduced in the scrubber to enhance the desulfurization performance of the scrubber. The result of simulation shows that the distribution ring can optimize effectively the distribution of gas–liquid phases and enhance the SO2 absorption. Under vertical condition, the desulfurization efficiency could be promoted approximate 6% after installing a distribution ring. The inclined condition resulting from the ship swinging could lead to the uneven distribution of droplets and an obvious decrease (8.7%) of desulfurization efficiency, whereas the desulfurization performance of the scrubber could be ensured with a distribution ring installed even under an inclined condition. Finally, a spray scrubber design scheme has been developed and successfully applied in the exhaust gas cleaning system (EGCS) of a container ship. Test result shows the outlet average value of SO2/CO2 can be reduced to 3.55. Meanwhile, the consistency of test data and calculation result indicates the applicability of the numerical model established for the simulation and optimization of the scrubber in industrial applications also. Implications: EGCS is an effective method to reduce SO2 emission of marine industry. However, different from a land desulfurization tower, the application of a spray scrubber in EGCS faces more problems due to the different application scenarios and complex sea conditions (inclined condition resulting from ships swinging and so on) during sailing. In this work, a numerical model capable of investigating physical and chemical phenomena in the scrubber simultaneously is established, which can produce a great amount of data for the operation instruction of EGCS and the design and optimization of the marine spray scrubber. The distribution ring is introduced in the marine spray scrubber to intensify the SO2 absorption and enhance the desulfurization performance of the scrubber under different working conditions. [ABSTRACT FROM AUTHOR]

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To reveal the influence of water on the gas adsorption process of medium rank lump coals, four groups of medium rank coals were selected for the study, and pore analysis experiments and low-field nuclear magnetic resonance (NMR) isothermal adsorption experiments with different water contents were carried out. The microscopic pore structure characteristics of medium rank lump coals were characterized by the combined mercury-pressure method and nitrogen adsorption method; the gas adsorption process of water-bearing coal samples was quantitatively analyzed based on the NMR isothermal adsorption experimental platform, and the influence of the water endowment state on the gas content of lump coal reservoirs was discussed. The results show that medium grade coals are predominantly microporous and small pore, followed by mesoporous, with the least macrospores, and have good gas storage capacity and that the adsorption capacity increases with the degree of metamorphism. With the increase of adsorption time, the gas adsorption of the aqueous coal samples showed a trend of first increasing and then remaining constant, reaching the adsorption equilibrium within 9 h. The adsorption saturation, adsorption increment, and adsorption gas content all increased with the increase of metamorphism, while the non-adsorbed gas content decreased for the same moisture content coal sample. The saturation, increment, adsorption, and non-adsorption gas content decreased with increasing water content for the same coal sample. [ABSTRACT FROM AUTHOR]

Energy consumption in the world increases 5.6% every year, and alternative resources like shale gas, coal-bed methane (CBM), tar sand, and so on are strongly needed. Shale gas is an unconventional natural gas of enormous potential. Abundant shale gas resides in the form of adsorption gas. Desorption of shale gas is an important mechanism and power source of shale gas reservoir development. Based on the features of shale gas reservoirs, the adsorption/desorption mechanisms, and their influencing factors, high-temperature mixture gas flooding is proposed in this article. Combining the theories of surface chemistry, chemical thermodynamics, and physical chemistry, this article investigates the mechanisms of developing shale gas reservoirs by high-temperature mixture gas flooding, which are illustrated in the following aspects: (1) increasing temperature to accelerate desorption; (2) competitive adsorption, lowering partial pressure of CH4, and accelerating diffusion; (3) increasing moisture on the shale surface; (4) decreasing total organic content (TOC) and improving permeability; and (5) providing displacement energy. [ABSTRACT FROM PUBLISHER]

The microcellular foaming process consists of the saturation process for dissolving gas molecules into plastic and the subsequent foaming process for cell formation. Foaming characteristics of microcellular plastics (MCPs) such as foaming ratio and cell morphology are largely determined by the saturation conditions, particularly by the saturation pressure. In this study, we investigate the effects of saturation pressure on the foaming characteristics of MCPs, when the quantity of dissolved gas (or the weight gain) is kept constant. Because the weight gain of a specimen is an increasing function of saturation pressure, different desorption times are used in order to maintain the same weight gain across specimens from different saturation pressures. Contrary to the common belief, for specimens with the same weight gain higher saturation pressures lead to lower foaming ratios. A hypothesis for the underlying mechanism and a practical ramification of the phenomenon are discussed. [ABSTRACT FROM AUTHOR]

In this study, we designed an experimental system of surface potential during coal adsorption of gas to examine the characteristics of surface potential in this process. The results suggested that surface potential was generated in this process and that it was enhanced with the passage of time. In adsorption cycles, the higher the pressure, the greater the surface potential signals, and they increase exponentially. Thereby, research on surface potential during gas adsorption on coal holds great theoretical significance for understanding the physical properties of coal. [ABSTRACT FROM AUTHOR]

Absorption of hydrogen gas inside the metal hydride (MH)-based hydrogen storage system generates significant amount of heat. This heat must be removed rapidly to improve the performance of the system which can be accomplished by embedding a heat exchanger inside the MH bed. In this article, a tubular shape MH system, equipped with a heat exchanger consisting of copper tube and pin fin is presented. A detailed 3D mathematical model is developed using COMSOL Multiphysics 4.3b for the numerical study of absorption and desorption processes inside the storage system. Impact of various operating and geometric parameters on the charging time of the storage system has been examined. It is observed that these geometric and operating parameters influence the charging time of the storage system. In the last, the impact of heat exchanger material on the performance of the storage system is explored. It is found that aluminum made heat exchanger is the best for the storage systems. The absorption process is accomplished in 1152 s at the operating parameters of 15 bar, 298 K, and 6.75 lit/min. This numerical work suggests that the efficient design of storage system is very important for rapid absorption and desorption of hydrogen. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) have been well-known and extensively researched due to the high storage /good selectivity for gas molecules. Herein, the structures and electron paramagnetic resonance (EPR) spectra for dicopper paddle wheel MOF compound (Cu2(µ2-O2CCH3)4 with various gas molecule are theoretically investigated by density functional theory (DFT) calculations. The adsorption energies and isotherms (including pure gas molecules and the mixed ones) are calculated for the gas molecules interacting with the unsaturated Cu2(µ2-O2CCH3)4. Both quantities exhibit the roughly consistent orders (e.g. H2S > NH3 > CO2 > CO > H2O > N2 > NO > H2 for isotherms and H2S > NH3 > N2 > CO2 > NO > H2O > H2 > CO for adsorption energies), possibly suggesting that this material may act as a potential adsorbent of these gas molecules. The catalytic property of Cu2(µ2-O2CCH3)4 for oxidation of CO and NO into non-toxic molecules and splitting of H2O into H2 and O2 in the solvent condition are uniformly discussed. Simulation of Grand Canonical Monte Carlo (GCMC) in MS 8.0 and calculations in Langmuir model reveal that Cu2(µ2-O2CCH3)4 has good selectivity for CH4 in natural gas (CH4/CO2/N2) and SO2 in fog (SO2/NO/NO2/H2O/O2), which would exhibit potential environmentally friendly applications. [ABSTRACT FROM AUTHOR]

A two-layer cyclic pressure–temperature swing adsorption system was designed for effective water vapor removal from air or helium. The system consists of two fixed bed adsorption columns, each containing two layers of adsorbents consisting of silica gel and zeolite molecular sieves 13×. To gain in-depth insights about the process, a descriptive model considering mass, energy and momentum balances, along with kinetic and equilibrium equations has been developed. The results of computer simulation showed that the layered bed, containing silica gel and molecular sieves 13×, offers both a longer water breakthrough time and significantly enhanced two-layered bed desorption performance compared with those for the one-layered bed. The influence of total gas pressure during the adsorption step, and height of the adsorbent layers on the process efficiency were studied. The cyclic steady state cycles were obtained under various conditions by a cyclic iteration method. Condensation of desorbed water in the adsorbent bed during regeneration has been considered. Theoretical study indicated no water vapor condensation. [ABSTRACT FROM AUTHOR]

The aim of this work is to predict the adsorption of methane on various activated carbon using to intelligent models including Generalized Regression Neural Network (GRNN), and adaptive network-based fuzzy inference system (ANFIS). Methane is the major component of natural gas, coal bed gas, and some exhaust gases of petrochemical or chemical units. Therefore, a fundamental study on the adsorption was encouraged by engineering concerns. In this regards, the precise prediction of CH4 adsorption is of great interest and importance. The model is developed using a comprehensive database obtained from the literature. The outcomes of the model were compared with the experimental data. The values of the statistical parameters R2, RMSE, and AARD% reveal that the ANFIS model is more accurate. Results showed that the developed model accurately predicts CH4 adsorption on activated carbons with an overall R2 and AARD% values of 0.921% and 0.657%, respectively. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop and validate a simple, new and efficient method for the analysis of hydrogen sulphide (H2S) released from the effluents of phosphoric acid production units. H2S sampling was performed by absorption of the industrial gas into a cadmium acetate absorbing solution. The formed cadmium sulphide (CdS), as a result of a chemical reaction, was analysed by turbidimetry. A methodical validation study of the proposed method was performed according to the requirements of ISO 17025 standards. The proposed method was demonstrated to be precise, linear and accurate over a concentration range of 6.91–92.16 mg/l. Detection and quantification limits were equal to 5.09 mg/l and 6.91 mg/l, respectively. Sample analysis had to be performed within 48 h of the sampling step. The turbidimetry method was applied successfully to the industrial gaseous effluents and can be considered as an economical alternative to the iodometric method. [ABSTRACT FROM AUTHOR]

Selective absorption of H2S from gas mixture containing H2S and CO2 into aqueous solutions of 2–(tert–butylamino) ethanol (TBE) and 2–amino–2–methyl–1–propanol (AMP) at different temperature was investigated at high pressure by using a static gas absorption method. The influence of temperature and contact time on the absorption of H2S was investigated. The rates of absorption of H2S and the selectivity factor decreased with the increase of absorption temperature. With increasing contact time for both alkanolamine solutions, the selectivity factor increased at first and then decreased. [ABSTRACT FROM AUTHOR]

Microscopic pore structure and water distribution are important and fundamental parameters for coalbed methane reservoir characterisation. These are closely related to the calculation/interpretation of other critical parameters, such as permeability and flow capacity. In this study, scanning electron microscopy, low-pressure nitrogen gas adsorption, nuclear magnetic resonance spectroscopy, and theoretical calculations were used to study the pore structure characteristics and water distribution of Zhaozhuang coal mine in the southeastern Qinshui Basin, PR China. The results show that the pore radius ranges from 2.066 to 594.045 nm, mainly classified as micropores and transitional pores. The micropores significantly contribute to the total pore volume. The adsorption pores (micropores and transitional pores) contribute the most to the total specific surface area. The T2 spectrum distributions of saturated water samples show two peaks. The first T2 spectrum peak is related to adsorption pores, whereas the second T2 spectrum peak is related to seepage pores. The seepage pores were not well developed as the adsorption pores. Most adsorption pores are saturated with irreducible water that could not be discharged by centrifugation, whereas the seepage pores are saturated with movable water that could be completely discharged by centrifugation. The T2 cutoff method was used to calculate the irreducible water saturation, and the irreducible water saturation of the sample was ≥90%. The irreducible water was mainly distributed in the micropores, and some of the irreducible water was distributed in the transitional pores. The irreducible water that remains in the pores can cause reservoir damage. [ABSTRACT FROM AUTHOR]

We suggest a two-dimensional model of adsorption of trace atmospheric gases by mineral dust particles with origin from desert soils. The model is based on the application of theory of turbulent diffusion in the atmospheric boundary layer (ABL) in conjunction with the model of gas adsorption by porous solid particles. The numerical model is formulated using parameterizations based on eolian (by wind) dust emission experiments. The eolian field experiments were performed at a dust source (loess soil in Northern Negev, Israel) using a portable boundary layer wind tunnel to determine the emitted particulate matter (PM) fluxes for different wind speeds and varying soil conditions. The numerical analysis is performed for the adsorption of gas-phase HNO3 by dust PM. We determined numerically concentration distributions of the atmospheric dust PM, and trace gas using shear velocity and emitted dust flux from the soils employed in the experiments. Analysis was performed for the case of neutral and slightly stable stratification of ABL typical for dust storm events in the East Mediterranean. The numerical analysis showed that during dust events the slightly stable atmosphere is characterized by higher concentration of PM10 in the surface layer than the neutrally stable atmosphere. It is found that in the case of neutral stratification as well as for stable atmospheric stratification the concentration of nitric acid HNO3 strongly depends on concentration of atmospheric dust particles. The developed model enhances our capacity of quantification of atmospheric dust effects in climate models as well as health risk assessment. Copyright © 2019 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

To evaluate pore networks of the lower Cambrian Niutitang Shale in the Cen-gong Block, multiple techniques, including geochemical analysis, low-pressure gas (CO2 and N2) adsorption, mercury intrusion capillary porosimetry (MICP) and field-emission scanning electron microscope (FE-SEM), were performed to investigate pore structure, including pore-size distribution (PSD), pore volume and surface area of black organic-rich shales from two wells to better understand the mechanism of shale-gas accumulation. Geochemical analysis shows that equivalent vitrinite reflectance ranges from 2.1 to 3.5% and are overmature. Surface areas and pore volumes of micropores calculated from CO2 adsorption, which vary from 8.23 to 37.39 m2/g and from 3.06  10−3 to 10.89  10−3 cm3/g, respectively, can provide large amounts of adsorptive sites for shale-gas accumulation. N2 adsorption shows reversed S-shaped isotherms, which are classified into type H2 and H3 hysteresis loops, indicative of ink-bottle pores and slit-or plate-like pores. N2 adsorption and MICP analysis indicates that the inorganic-associated pores in shales may play a significant role in the storage and production of hydrocarbons. High-resolution FE-SEM analysis suggests that OM pores (OMPs) are common in Niutitang samples with a dominant diameter less 50 nm, but a sample with the highest total organic carbon (TOC) of 10.01 wt% has few OMPs, whereas a sample with the TOC of 7.51 wt% has more OMPs. The percentage of OMP area vs total organic matter area (Øs) ranges from 1.70 to 7.92%. The pore structure characteristics of TX1 well, calculated by multiple techniques, are better than samples from TM1 well. In addition, pore types are dominated by interparticle, intraparticle and organic matter pores, and the minor amounts of OMPs in TM1 well indicates that most of the organic matter may have lost the potential to generate hydrocarbons owing to the release of formation pressure with some graphitisation and high-angle fractures larger in the TX1 well. TOC content, mineral composition and tectonically related thermal maturity may be the main controlling factors of the pore structure and the lower Cambrian Niutitang Shale demonstrates the greatest potential for shale-gas production in South China. [ABSTRACT FROM AUTHOR]

We investigated the H2S/CO2 gas mixture absorption rate and selectivity of 2-(tert-butylamino)ethanol (TBE) and 2-amino-2-methyl-1-propanol (AMP) using a static gas absorption method. The H2S and CO2 gas mixture was pumped into a reaction kettle filled with sterically hindered amines solubilized in water. The influence of time on the H2S absorption rate and selectivity of the sterically hindered amine solutions was investigated. [ABSTRACT FROM AUTHOR]

Six renewable DESs prepared from choline chloride (CC) and phenols (guaiacol, GC; cardanol, CL) with molar ratios of phenols to CC of 3:1, 4:1 and 5:1 were investigated to absorb SO2 at 293.15-323.15 K and 0-1.0 bar. Results showed that DESs demonstrated satisfactory SO2 absorption performance, and GC-CC (3:1) exhibited the maximum absorption capacity of 0.528 g SO2 per g DES. The SO2 enriched DESs could be easily regenerated and recycled five times. Moreover, the DESs exhibited high selectivity of SO2/CO2. Present DESs seem to be promising absorbents for SO2 due to good performance. [ABSTRACT FROM AUTHOR]

On the bases of two different approaches (solid-state and quantum-chemical) adsorption of nitrogen atom and ammonia molecules on SiC substrate is considered. In the solid-state approach with the use of the Haldane- Anderson density of state model for the 4 H- and 6 H-SiC polytypes, it is shown that the binding energies for N and N2 are 6 and 3 eV correspondingly. In the quantum-chemical approach with the use of the surface molecule model for N the binding energy values are 6 eV for adsorption on C-face and 4 eV for adsorption on Si-face. It is demonstrated also that the charge transfer between adsorbate and substrate for all the cases considered are negligible. [ABSTRACT FROM AUTHOR]

In this study, the reaction mechanism for the selective catalytic reduction (SCR) of NOx by NH3 over rare earth concentrate (RE-concentrate) was investigated by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The catalyst sample was investigated by X-ray diffraction, Brunauer-Emmett-Teller and scanning electron microscope methods to characterize its crystal structure and surface topography. Some pore structures and the diffraction peaks of CeO2 appeared after the catalyst calcined at 500°C. Fe, Nd, La, and other metal elements well-dispersed inside the catalyst, which exist in the form of coexistence. Further, the presence of oxygen promoted the adsorption of NO. Moreover, the adsorption intensity of NOx on the RE-concentrate was higher than the pure metal oxidation (Fe2O3, CeO2, and La2O3). The result of the in-situ DRIFT shows that there are Lewis and Brønsted acidic sites on the surface of the catalyst. The presence of oxygen promotes the dehydrogenation of NH3. It is found that the selective catalytic reduction (SCR) reaction over RE-concentrate catalysts mainly followed the Langmuir-Hinshelwood mechanism. The decomposition of oxygen into active monomolecular oxygen (O(ad)) by the surface active sites and the adsorption of NO on the catalyst surface are the important steps in the NH3-SCR reaction. However, it is of great importance to reduce the oxidability of RE-concentrate and control further dehydrogenation of NH2 species, which could improve the N2 selectivity. [ABSTRACT FROM AUTHOR]

Several trace gases such as H2O, CO, CO2, NO, N2O, NO2and CH4strongly absorb in the mid-IR spectral region due to their fundamental rotational and vibrational transitions. In this work, we propose an evanescent field absorption gas sensor based on silicon/silicon dioxide slot waveguide at 3.39 μm for sensing of methane gas. These waveguides can provide the highest evanescent field ratio (EFR) > 47% with adequate dimensions. Higher EFR values often come at an expense of higher propagation losses. These waveguides have relatively higher losses as compared to conventional waveguides, such as rib and slab waveguides, as these fundamental losses are static and the proposed sensing mechanism is established on the incremental loss due to the absorption of the gas. Therefore, incident power can always be incremented to compensate the waveguide losses. [ABSTRACT FROM AUTHOR]

We use an all-atom molecular dynamics simulation to generate the dense porous structures of overmature type II kerogen with control microporosity. The structures mimic the organic part of Barnett shale under a typical reservoir condition of 365 K and 275 bar. First, we build an atomistic model of kerogen unit using the consistent valence force field and chemical structure proposed by Ungerer and his colleagues. Second, we generate kerogen structures by gradual cooling and compression of the initial low-density random configurations of kerogen units. During the structure generation, we use a dummy particle of varying size to introduce microporosity into the kerogen structures. We systematically characterise the microporous kerogen structures by calculating the geometric pore size distribution, pore limiting diameter, maximum pore size, accessible surface area, and pore volume and by analysing the pore network accessibility. Third, we employ grand canonical Monte Carlo (GCMC) to study the adsorption of two proxies of shale gas (pure methane and mixture of 82% of methane, 12% of ethane and 6% of propane) in the kerogen structures. The shale gas adsorptions are compared with GCMC simulation of CO2adsorption in the kerogen structures. Hydrocarbons are modelled using the all-atom optimized potential for liquid simulations (OPLS) force field while carbon dioxide is represented by the EPM2 model. We complement the adsorption studies by exploring accessibility of pore space of the kerogen structures using molecular dynamics simulation. Finally, we introduce a mesoscale pore void into a microporous kerogen structure and probe the adsorption behaviour of the hydrocarbon mixture in such a multiscale kerogen model. [ABSTRACT FROM PUBLISHER]