The Influence of the Structural and Energetic Characteristics of the Microporous Structure of Carbon Adsorbents on Hydrogen Adsorption

Фомкин, А. А.; Прибылов, А. А.; Ткачев, А. Г.; Memetov, N. R.; Melezhik, A. V.; Kucherova, A. E.; Shubin, I.N.; Пулин, А. Л.; Школин, А. В.; Меньщиков, И. Е.; Zhedulov, S. A.; Murdmaa, K. O.; Artamonova, S. D.

doi:10.1134/s1061933x19050053

Cited by 11 publications

(3 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These materials are the most promising as universal sorbents for liquid and gaseous media, devices for storing and transporting gaseous fuels, catalysts, fertilizer carriers, fuel cells, solving environmental problems in such industries as petrochemistry, energy, radio electronics, medicine, and agriculture. This is explained, first of all, by the presence of a balanced combination of a developed system of micro-and mesopores, with a significant specific surface, corresponding accessible pores and their large volume, with the presence of sufficiently large transport pores that ensure rapid diffusion of sorbed substances, chemical inertness and stability in real conditions of using such materials [1][2][3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Features of implementation options for the process of high-temperature activation of carbon material

Shubin

Popova

2023

JAMT

View full text Add to dashboard Cite

The paper shows the relevance of research in the development of activated carbon materials with a high specific surface area and porosity, which can be used as materials for the separation or storage of various liquid and gaseous media. A plurality of approaches to the implementation of the activation process, characterized mainly by the accumulation of experimental data and laboratory studies, is noted. The possibility of realizing the process of carbonizate activation in two variants has been established: the first is high-temperature alkaline activation, the second is high-temperature alkaline activation with an additional activator in the form of water vapor. The most rational temperature regimes for the implementation of this activation process are determined, which are 750 °C for the first variant, and 600 °C for the second, as well as their key features are defined. The characteristics of the carbon material obtained as a result of two variants of activation -specific surface area and porosity -are analyzed, and their dependence on the temperature of this process is established. The possibility of industrial implementation of the considered activation options is substantiated, taking into account the peculiarities of their implementation to obtain an activated highly porous carbon material with a specific surface area of more than 2700 m 2 ⋅g -1 and a porosity in the micro-and mesosize range of more than 1.3 cm 3 ⋅g -1.Keywords: high-temperature activation; options for carrying out activation; characteristics of the carbon material; features of the technological design of the process.

show abstract

Section: Introductionmentioning

confidence: 99%

Features of implementation options for the process of high-temperature activation of carbon material

Shubin

Popova

2023

JAMT

View full text Add to dashboard Cite

show abstract

“…However, a number of works [12,[21][22][23][24][25][26][27][28][29][30][31][32] shows that the DRA equation can be used to quantitatively describe experimental isotherms also at temperatures above critical by more than 100-150 K on active microporous carbons, zeolites, silica gels, and molecular sieves. In particular, the DRA equation can be used to describe the adsorption of CH4, N2, H2 on Zeo-5A@MOF-74-1 zeolite at temperature T = 298 K and pressure P = 0-22 atm [12]; H2 on active carbons [23,24]; Ar on zeolite 13X [32]; CH4 on zeolites 13X, CaLSX, KLSX, LiLSX at T = 298-343 К and P = 0-1 atm [31]; CH4, N2 on zeolites Cu-BTC and MaxSorb at T = 298-303 К and P = 0-40 atm [30]; CO on zeolite 13X at T = 293-343 К and P = 0-1 atm [27]. Works [22,25] propose to replace the saturation pressure with standard pressures.…”

Section: Introductionmentioning

confidence: 99%

On the Issue of Using the Dubinin–radushkevich–astakhov Equation in Calculating Isotherms of H2, Co2, Co in the Pressureswing Adsorption Process for Hydrogenrecovery on Block Zeolites 13x

2022

Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.

View full text Add to dashboard Cite

The calculation of adsorption isotherms of synthesis gas components in the process of pres-sure swing adsorption (PSA) for hydrogen extractionon zeolite adsorbents is traditionally carried out using the Langmuir equation or equations derived from it. Its disadvantage consists in the necessity to obtain experimental adsorption isotherms for each gas in the gas mixture on the used adsorbent. This approach is expensive, especially in the case of multicomponent mixtures, such as synthesis gas. The paper demonstrates the prospects of an alternative method for calculating ad-sorption isotherms of H2, CO2, CO gases in the PSA process for hydrogen extracionfrom synthesis gas on block zeolites 13X using the Dubinin–Radushkevich–Astakhov (DRA) equation. Using zeo-lites 13X made by three samples, experimental adsorption isotherms of H2, CO2, CO at temperatures of 293 and 323 K, and adsorption isotherms of N2ata boiling point of 77.35 K were obtained. Using experimental isotherms, the problems of parametric identification were solved, and the parameters of the DRA equation for H2, CO2, CO gases on block zeolites 13X were determined. It has been found that the calculation of adsorption isotherms of H2, CO2, CO gases on zeolites 13X, the char-acteristics of which fall within the ranges of the limiting adsorption volume 0.258–0.296 cm3/g and the characteristic adsorption energy 10279–13395 J/mol, respectively, can be correctly carried out using the DRA equation in the temperature range of 293–323 K and the pressure range of 0–30 atm.In this case, the maximum value of the mismatch between the experimental gas isotherms and those calculated by the DRA equation is 14.69% for H2; the minimum value is 1.81% for CO2. Certain affinity coefficients make it possible to calculate the adsorption isotherms of H2, CO2, CO gases in the obtained ranges of the limiting adsorption volume and characteristic adsorption energy using only one isotherm of the standard gas (N2) on the zeolite 13X used. The versatility of the DRA equation can be used to calculate the adsorption isotherms of various gases, mixtures, and adsor-bents in cyclic adsorption processes.

show abstract

“…At the same time, in many respects, the available technologies of compressed (CNG) and liquified natural gas (LNG) fail to meet efficiency and safety requirements [6][7][8]. Therefore, new technological solutions are required to increase the energy density of NG, and an adsorbed NG (ANG) method seems to be the most effective one for accumulation and storage [9][10][11]. Based on a rich set of experimental data reported over the past twenty years [11][12][13][14][15][16][17][18], activated carbons and metal-organic framework structures are recognized as the most promising adsorbents for employing in ANG systems.…”

Section: Introductionmentioning

confidence: 99%

ZrBDC-Based Functional Adsorbents for Small-Scale Methane Storage Systems

Соловцова

Меньщиков

Школин

et al. 2022

Adsorption Science & Technology

View full text Add to dashboard Cite

Metal-organic frameworks (MOF), potentially porous coordination structures, are envisioned for adsorption-based natural gas (ANG) storage, including mobile applications. The factors affecting the performance of the ANG system with a zirconium-based MOF with benzene dicarboxylic acid as a linker (ZrBDC) as an adsorbent were considered: textural properties of the adsorbent and thermal effect arising upon adsorption. The high-density ZrBDC-based pellets were prepared by mechanical compaction of the as-synthesized MOF powder at different pressures from 30 to 240 MPa at 298 K without a binder and mixed with polymer binders: polyvinyl alcohol (PVA) and carboxyl methylcellulose (CMC). The structural investigations revealed that the compaction of ZrBDC with PVA under 30 MPa was optimal to produce the ZrBDC-PVA adsorbent with more than a twofold increase in the packing density and the lowest degradation of the porous structure. The specific total and deliverable volumetric methane storage capacities of the ZrBDC-based adsorbents were evaluated from the experimental data on methane adsorption measured up to 10 MPa and within a temperature range from 253 to 333 K. It was measured experimentally that at 253 K, an 100 mL adsorption tank loaded with the ZrBDC-PVA pellets exhibited the deliverable methane storage capacity of 172 m3(NTP)/m3 when the pressure dropped from 10 to 0.1 MPa. The methane adsorption data for the ZrBDC powder and ZrBDC-PVA pellets were used to calculate the important thermodynamic characteristic of the ZrBDC/CH4 adsorption system—the differential molar isosteric heat of adsorption, which was used to evaluate the state thermodynamic functions: entropy, enthalpy, and heat capacity. The initial heats of methane adsorption in powdered ZrBDC evaluated from the experimental adsorption isosteres were found to be ~19.3 kJ/mol, and then these values in the ZrBDC/CH4 system decreased at different rates during adsorption. In contrast, the heat of methane adsorption onto the ZrBDC-PVA pellets increased from 19.4 kJ/mol to a maximum with a magnitude, width, and position depended on temperature, and then it fell. The behaviors of the thermodynamic state functions of the ZrBDC/CH4 adsorption system were interpreted as a variation in the state of adsorbed molecules determined by a ratio of CH4-CH4 and CH4-ZrBDC interactions. The heat of adsorption was used to calculate the temperature changes of the ANG systems loaded with ZrBDC powder and ZrBDC pellets during methane adsorption under adiabatic conditions; the maximum integrated heat of adsorption was found at 273 K. The maximum temperature changes of the ANG system with the ZrBDC materials during the adsorption (charging) process did not exceed 14 K that are much lower than those reported for the systems loaded with activated carbons. The results obtained are of direct relevance for designing the adsorption-based methane storage systems for the automotive industry, developing new gas-power robotics systems and uncrewed aerial vehicles.

show abstract

The Influence of the Structural and Energetic Characteristics of the Microporous Structure of Carbon Adsorbents on Hydrogen Adsorption

Cited by 11 publications

References 14 publications

Features of implementation options for the process of high-temperature activation of carbon material

Features of implementation options for the process of high-temperature activation of carbon material

On the Issue of Using the Dubinin–radushkevich–astakhov Equation in Calculating Isotherms of H2, Co2, Co in the Pressureswing Adsorption Process for Hydrogenrecovery on Block Zeolites 13x

ZrBDC-Based Functional Adsorbents for Small-Scale Methane Storage Systems

Contact Info

Product

Resources

About