By using the DFT and TD-DFT method, the potential of B12N12 nanocage to adsorb and detect of cyanogen fluoride (FCN) as a toxic gas molecule in the present of 1H+, 2H+, and 3H+ ions field and static electric field (SEF) were investigated at the WB97XD level of theory at the 6-31G (d, p) basis set. The structural and electrical parameters, adsorption energy, quantum descriptor, quantum theory of atom

Among the adsorption-based separation processes for gaseous mixtures, those exploiting pressure variations, so-called Pressure Swing Adsorption (PSA) processes, are the most popular. In this work, we focus on the specific PSA configuration known as Dual Reflux-Pressure Swing Adsorption (DR-PSA) given its ability to achieve sharp separations. In the case of binary mixtures, an analytical approach based

The zero length column technique has been developed over the past 30 years as a versatile experimental method to measure adsorption equilibrium and kinetics. In this review we discuss in detail the theory that forms the basis for the technique in order to understand how to design and operate efficiently a system. Experimental checks that should be performed to ensure the correct interpretation of the

This paper provides a set of comprehensive guidelines for the use of dynamic column breakthrough experiments to measure single and multi-component equilibria and kinetics. Recommendations are made for the design of the experimental rig, experimental procedures, and data processing methods to minimize errors and increase data reliability. Designing experiments to identify the transport mechanism, and

The scale of smelting ferronickel by RKEF (Rotary kiln—electric furnace) process is increasing these years, these untreated ferronickel slags will occupy a large area as accumulation and cause ecological damage. On the other hand, the CO2 emission and global warming are urgent problems to be solved as they have resulted in severe climate change. Carbon Capture and Storage (CCS) technology is considered

2H solid-state NMR represents a reliable method for probing the dynamics of the molecules in confined geometries, including microporous and mesoporous materials such as zeolites or metal–organic frameworks (MOFs). Dynamic characteristics derived from analyses of 2H NMR line shape and spin relaxation for adsorbed deuterated molecules can be related with translational motions along the porous framework

We present the development and application of X-ray Computed Tomography (CT) for the determination of the adsorption properties of microporous adsorbents and the study of breakthrough experiments in a laboratory fixed-bed adsorption column. Using the model system \(\text {CO}_2/\text {helium}\) on activated carbon, equilibrium and dynamic adsorption/desorption measurements by X-ray CT are described

Sorption processes are incorporated in a wide range of applications. A heat and mass transfer model which calculates the temperature distribution and pressure in a sorption cell is desired for developing any sorption system. In this paper, we present a one-dimensional dynamic numerical model for closed sorption cell systems, which is based on adsorption isotherm measurements of the working pair. The

The problem of measuring sorption kinetics in microporous adsorbents and distinguishing experimentally between surface resistance and internal diffusion is discussed and reviewed with reference to several commonly used experimental techniques; direct uptake rate measurements, zero length column (ZLC), frequency response, PFG NMR and interference microscopy.

To match the dynamics of a linear driving force model and the diffusion equation is of great practical importance in the design and optimization of adsorption separation processes. A frequency response analysis is applied to show that it is not possible to arrive at an equivalence based on a single parameter. Using this as the basis, a universal equivalence for the linear problem is constructed and

One primary measurement of open porosity uses physical adsorption isotherm, amount adsorbed versus gas pressure. Classical treatments, including the BET, cannot fit the isotherm for its full range, therefore standard curves have been created from non-porous materials for comparison. This classical method yields three output parameters, two surface areas, pore and external, relative to the standard

Based on the molecular understanding of the interplay of diffusion and adsorption, new membrane materials can be developed and the operational conditions of gas separation membranes can be optimized. Therefore, numerous diffusion and adsorption studies are conducted to optimize membrane materials. However, in an opposite way, transport or Fickian diffusion coefficients DT can be derived from membrane

The use of clay minerals for the decontamination of liquid radioactive waste generated during the work of nuclear energy enterprises remains currently relevant. The effect of the surface hydration of a montmorillonite nanocrystal on the adsorption of cesium and strontium ions from dilute solutions was studied. As opposed to the generally accepted mechanism of the adsorption of cesium and strontium

The insolubility of graphene nanosheets in aqueous media has been a limitation for the practical applications of this unique material. The non-covalent functionalization of graphene with mixed surfactants is an effective procedure for preparation of stable graphene dispersions. Physical adsorption of surfactants onto graphene surfaces is a significant stage in the dispersion of graphene nanosheets

Batch adsorption experiments are carried out by adding a known amount of adsorbent to a liquid solution at a known initial concentration and following the evolution in time of the concentration of the adsorbate. This is a very common method to obtain equilibrium and kinetic information in liquid systems, but in most cases kinetic results are analysed on the basis of empirical models. Two phenomenological

This paper reports the results of an international interlaboratory study led by the National Institute of Standards and Technology (NIST) on the measurement of high-pressure surface excess methane adsorption isotherms on NIST Reference Material RM 8850 (Zeolite Y), at 25 °C up to 7.5 MPa. Twenty laboratories participated in the study and contributed over one-hundred adsorption isotherms of methane

Adsorption and desorption of hydrocarbons in a realistic model (2496 atoms) of ZSM-5 zeolite (MFI), including an external surface and a reservoir for molecules, have been studied using classical molecular dynamics, with special focus on surface barriers. Different degrees of surface blocking have been modeled according to experimental observations. Using previous molecular dynamics results, from the

We had performed GCMC simulations to study the adsorption isotherms, the isosteric heats of argon, methane, nitrogen, carbon dioxide, methanol and water adsorption on molecular models of activated carbons at their boiling points in order to understand the contributions of the different functional groups of the adsorbent sites in the adsorption process. We had found that the values obtained from the

High magnetic fields (up to 17.6 T) in combination with large magnetic field gradients (up to 25 T/m) were successfully utilized in pulsed field gradient (PFG) NMR studies of gas and liquid diffusion in nanoporous materials. In this mini-review, we present selected examples of such studies demonstrating the ability of high field PFG NMR to gain unique insights and differentiate between various types

Gas separation by adsorption processes such as pressure swing adsorption (PSA) presents an attractive alternative for upgrading biogas to biomethane. A new vacuum pressure swing adsorption (VPSA) cycle is proposed for a unit designed to purify pre-cleaned biogas (40% CO2 and 60% CH4) in industrial conditions (feed flow rate more than 500 Nm3/h and large-volume equipment). The process simulations performed

Many decisions must be made when determining design and operation of a chromatographic process. Such decisions should optimize the performance, including product purity, recovery, productivity, and desorbent consumption. For this problem, model-based optimization has been shown to be a powerful approach, aided by recent developments in modeling of chromatographic processes. In this article, past studies

In this work, direct air capture (DAC) via adsorption is studied through the design and analysis of two temperature–vacuum swing adsorption (TVSA) cycles. In the first part, a novel way of describing the adsorption of \({\hbox {CO}}_{2}\) in presence of water vapor is proposed for co-adsorption kinetic and thermodynamic data gathered from the literature. Secondly, two TVSA cycle designs are proposed:

In this work a number of computational methods have been applied to study the adsorption of dimethylmercury (DMM) on the (ZnO)6 cluster and the influences of the supports (MgO, SBA-15) and external ions (Cl−, OH−) on the adsorption process: the energy and electronic properties were calculated using Geometry, Frequency, Noncovalent, eXtended Tight Binding method; global minimum was found by using the

A theoretical study was performed on the adsorption of propylthiouracil (PTU) on the outer surface of boron nitride nanotube (BNNT). In this investigation, the BNNTs with (5,5), (6,6) and (7,7) chiralities were selected. The PTU molecule was located on the outer surface of BNNT in perpendicular and parallel modes. After the relaxation of whole system, the energy values and optimum distances in two

In this work, at first, in order to find the most stable conformers of the two types of anticancer cytarabine (CYT) and gemcitabine (GEM) drugs, the potential energy curves for rotation around the C1′-N bond were explored at M06-2X/6–311 + + G(2d,2p) level of theory. Adsorption of the most stable conformers of CYT and GEM drugs on the BNNT surface was explored. Depending on the orientation of CYT and

Multiple Sorption Model (MSM) is used to simulate sorption isotherms and the effect of the multiplicity of physicochemical parameters is reduced by introducing an invariant procedure using a few sorbates that are small molecules. This study presents the use of water, methanol, carbon dioxide and methane as test molecules to determine the structure and texture of coal and energy parameters. Parallel

The existence of a skin resistance for adsorbate mass transport at the surface of a pelletized adsorbent particle or at the surface of adsorbent crystals within a particle has been proven by many macroscopic and microscopic experiments. An isothermal and isobaric column dynamic test method may be used to approximately estimate the relative magnitude of the skin resistance.

Two types of zeolites (type X and type A) were synthesized from fly ash of two Brazilian coal based power plants via hydrothermal treatment after ash fusion with NaOH. The synthesized zeolites were characterized by means of XRF, XRD, SEM and gas adsorption (N2 and CO2 adsorption/desorption at − 196 and 0 °C, respectively). Pure CO2 and N2 adsorption equilibrium isotherms were performed at 50, 70 and

The adsorption behavior of AgNPs-DNA nanocomposites on 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dimyristoyl-sn-glycero-3-phosphoserine (DMPS) lipid monolayers has been investigated by analyzing adsorption dynamic process, surface pressure-area isotherms (π-A), excess mean area (\({\Delta \mathrm{A}}_{\mathrm{e}\mathrm{x}\mathrm{c}}\)), excess Gibbs free energy (\(\Delta {\mathrm{

Carbon dioxide permeation studies were conducted on polyether-sulfone (PES) microspheres fabricated using phase-inversion technique by loading various amine-functionalized imidazolium cation ILs with a common anion bis-trifluoromethylsulfonylamide ([TF2N]−) on PES-polymer matrix. The cations include: Aminopropyl-butyl-imidazolium [APBIM], Diethyl-aminoethyl-imidazolium [DEAEBIM], Diaminopropyl-butyl-imidazolium

A detailed investigation has been carried out of the pre-polymerisation modification of the polymer of intrinsic microporosity PIM-1 by the addition of two methyl (Me) groups to its spirobisindane unit to create a new chemically modified PIM-1 analogue, termed MePIM. Our work explores the effects of this modification on the porosity of PIM-1 and hence on its gas sorption properties. MePIM was successfully

Rapid cycle pressure swing adsorption (RCPSA) characterized by short cycle time permits adsorbents to be used more frequently and increases process productivity. A rotary valve multi-bed RCPSA process is proposed to improve the performance of miniature oxygen concentrator. The RCPSA air separation system is highly integrated by four adsorbent beds and a rotary valve. The effects of process parameters

Enantioselective chromatography is nowadays a reliable tool for single enantiomer production from a racemate. The recovery of the distomer by racemization and recycling is a promising method to tackle the 50% yield constraint and to increase the productivity. In this paper three process configurations are compared. The production of enantiopure mandelic acid and methionine enantiomers exploiting different

Measurement of molecular diffusion in nanoporous host materials, which are typically inhomogeneous and anisotropic, often involves an intricate web of factors and relations to be taken into account since the associated diffusivities are a function of the diffusion path of the guest molecules during a given observation time. Depending on the observation time, therefore, the result of the experimental

The high conductivity of nanoprous carbons has a significant effect on adsorption of polar molecules; however, the mechanisms underlying this effect are not well-understood, and this effect is generally not considered in adsorption modeling. To investigate the impact of high host conductivity on the adsorption properties of vertical stacks of the graphene sheet, phenol vapor has been chosen as a simple

The adsorption of a methoxy radical (\(\hbox {OCH}_3\)) on the low-energy flat gold surfaces Au(111), Au(100) and Au(110) and on surface defects (adatoms) was compared with those of methanethiol (\(\hbox {SCH}_3\)) and methylamine (\(\hbox {NHCH}_3\)) radicals. Using dispersion-corrected DFT, we showed that the adsorption energy of \(\hbox {OCH}_3\) on gold is significantly lower than that of \(\hbox

In order to accomplish efficient CO2 capture, poly(ethyleneimine) (PEI) and tetraethylenepentamine (TEPA), with commonly used and inexpensive, was codispersed into the as-prepared SBA-15 (SBA-15(p)) to prepared blended amine functionalized adsorbent. The influence of the mass ratio of PEI to TEPA on the adsorption property was investigated. The promoting effects of TEPA on CO2 capture property were

A commercial gravimetric sorption analyzer, which is based on a magnetic-suspension balance, was significantly improved to reduce the uncertainty in adsorption measurements. In a previous paper, we investigated the force-transmission error (FTE) of the instrument’s magnetic-suspension coupling, and we analysed the uncertainty of the density measurement. In the present paper, equations for the determination

This paper analyses the effect of an adsorbed layer of variable curvature during the course of adsorption. To this end the capillary condensation and evaporation verified in pores endowed with elliptical geometry is studied. An adsorption potential within the pore walls is defined and it is numerically derived in accordance with the curvature of the pores and the attraction between the adsorbate and

A recently developed universal isotherm model was used in this work for the study of zirconium-added mesoporous silicas, focusing on the dehydration of low humidity gaseous streams. This modeling was chosen for its capability of calculating an energy distribution profile of the adsorption sites. This study was based on a systematic approach to evaluate three variables: the amount of zirconium substitution;

Abstract The determination and description of adsorption equilibria is critical for the design of several separation processes. In some instances, the dependence of the solid phase loading on the fluid phase concentration is complex and it is difficult to find a suitable functional form to represent the adsorption equilibria. This difficulty can be overcome by the use of discrete equilibrium data,

Abstract Efficient and stable supercapacitor electrodes must possess large surface area, excellent conductivity and electrochemical stability. In this regard, conductive carbon loaded metal oxide composites are of particular interest. Herein, Ru–Mn oxide loaded graphene was synthesized with different graphene oxide (GO) proportion using simple solution chemistry method. Morphological and compositional

Abstract Elevated temperature pressure swing adsorption (ET-PSA) is a novel process for hydrogen purification. By operating steam rinse and purge at conditions beyond the dew point will significantly improve the recovery rate of the product gas. Moreover, since cooling and reheating processes are not needed in ET-PSA, the sensible heat of the incoming gas could also be preserved. In this study, a seven-column

The adsorption of CO2 and CH4 on graphitic carbon nitride (g-C3N4) functionalized with four boron atoms (g-C43N4B4) were investigated by using the density functional theory for adsorption and separation of the CO2/CH gas molecules. The calculated Eads values showed that the CO2 molecule, in comparison with the CH4 molecule, has favorable interaction with the boron cluster hosted in the sheet. The capacity

Activated carbon fibres with a range of pore sizes, prepared from pre-oxidized acrylic fibre by physical activation in CO2 at different temperatures and times, were investigated as adsorbents for the inhalation anaesthetic isoflurane (2-chloro-2-(difluoromethoxy)-1,1,1-trifluoroethane). Adsorption–desorption isotherms of isoflurane were determined at 293 K and were analysed by the αS method using reference

The pore size distribution (PSD) is an important property of the porous materials, but an accurate and reliable PSD is very difficult to obtain. Quenched Solid Density Functional Theory (QSDFT) is widely used to analyze the pore size distribution. Here, a series of unclosed and closed isotherms of activated carbon were measured and compared. The experimental results revealed the appearance of an artefact

h-BN monolayer as a novel 2D nanomaterial has raised great attention for sensing application in recent years. In this work, we using DFT method investigate the Pd-doping behavior on the pristine h-BN monolayer as well as related adsorption and sensing performance upon three SF6 decomposed species to explore its sensing potential. Our results indicate that n-typing doping is identified after Pd atom

Capillary condensation within the pore space formed by a hexagonal arrangement of carbon nanorods is investigated using a thermodynamic model. Numerical solution of the corresponding non-linear differential equations predicts two characteristic equilibrium phase transitions corresponding to liquid-bridge formation between adjacent rods, and the subsequent filling of the entire pore space with liquid

The first principles calculations were performed to study the adsorption of NO/NO2 molecules on carbon nanotubes (CNTs) doped with different number of aluminum atoms. Calculations show that upon the aluminum doping, the adsorption distance is decreased while the charge density, adsorption energy and charge transfer are increased dramatically, indicating that the adsorption of NO/NO2 on CNTs could be

Pollution during rapid industrialization process is a serious environmental problem that seriously affects people's lives and livelihoods. Among them, the pollution of excessive heavy metals in wastewater has attracted wide attention. The current study proposes a novel effective and low-cost silica@polyacrylamide composites (SP-C) to capture cadmium ion (Cd2+) from wastewater contaminated by heavy

The aim of this work is to develop insights into adsorption of hydrogen and carbon dioxide in a zeolitic imidazolate framework, ZIF-8, using high-pressure adsorption studies, adsorption isotherm model fitting, and DFT investigation of preferential adsorption sites and binding energies. The robustness of ZIF series metal–organic frameworks has drawn interest towards its utility in large scale applications

There is still a growing interest in CO2 conversion into useful compounds. Plasma technology is a highly promising alternative due to its non-equilibrium nature, crucial for CO2 dissociation processes. In this study we present, the non-thermal plasma-assisted catalytic CO2 reduction to CO on 2D Zn-containing paddle wheel structures based on TCPP. The catalytic efficiency of this MOF material is shown

Elevated temperature pressure swing adsorption is a newly developed gas purification technology, wherein the product gas recovery rate can be significantly improved by adding a steam rinse and purge. Furthermore, high temperature industrial syngas can be directly purified at elevated temperatures, so the temperature variation during purification process is not as large as that in Selexol, Rectisol

Synthesis and application of layered nanomaterials are known as emerging field in nanotechnology. Inorganic layered nanomaterials with nanometer scale, high aspect ratios, and large-surface area generate various scientific and technological interests in several potential areas of application such as separation technology, medical sciences, chromatography drug delivery, and catalysis. In this research

MIL-88A metal-organic framework with the unsaturated Fe metal coordination sites has demonstrated to be a promising material for gas storage and capture. However, the hydrogen storage capacity of MIL-88A has to be improved to meet the practical level at the ambient conditions. In this research, we elucidated the effects of transition metal substitution on the hydrogen storage capability of MIL-88A

How to remove radionuclides from the radioactive wastewater quickly and efficiently is of great significance for mitigating the adverse effects of nuclear accident. Our previous researches have shown that metallic radionuclides (Cs+, Sr2+, and Ba2+) can be chemisorbed on monolayer 2H-MoS2. To enhance the adsorption capacity of the monolayer 2H-MoS2 to the metallic radionuclides, the effects of phase

In the present study, an all-atomic molecular dynamic simulation was used to investigate adsorption of copper ions (Cu (II)) by carbon nanotube and hybrid graphene–carbon nanotube in aqueous solution. In order to study oxygenated functional groups effect including hydroxyl (–OH) and carboxyl (–COOH), these nano-structures were functionalized with OH and COOH groups. To this end, oxygenated functional