Methane adsorption on a microporous carbon adsorbent in the precritical and hypercritical regions

Chkhaidze, é. V.; Фомкин, А. А.; Serpinskii, V. V.; Tsitsishvili, G. V.; Dubinin, M. M.

doi:10.1007/bf00954246

Cited by 16 publications

(9 citation statements)

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“…4 together with the experimental data for the adsorption system consisting of polymer-derived active carbon (PAC) and methane which were measured over wide ranges of pressure and temperature (10). It can be seen that the calculated values are in close agreement with the experimental data.…”

Section: Modified Dr/da Equationssupporting

confidence: 71%

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Modified Dubinin–Radushkevich/Dubinin–Astakhov Adsorption Equations

Jakubov

Mainwaring

2002

Journal of Colloid and Interface Science

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Section: Modified Dr/da Equationssupporting

confidence: 71%

“…Differentiating [12] with respect to temperature as an implicit function and remembering that the parameters E and n in general also depend on temperature, and taking into account relation [10], we obtain after simplification…”

Section: Modified Dr/da Equationsmentioning

confidence: 99%

Modified Dubinin–Radushkevich/Dubinin–Astakhov Adsorption Equations

Jakubov

Mainwaring

2002

Journal of Colloid and Interface Science

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“…According to [ 32 ], which summarized the thermodynamic functions of a large number of gas/microporous material adsorption systems, in most cases, the C a ( T ) dependence exhibited a local maximum at elevated temperatures. When adsorption achieved the high values, this maximum shifted towards lower temperatures, as was the cases of Xe [ 69 ] and CH 4 adsorption [ 70 , 71 ] in NaX zeolites, and CH 4 adsorption in the microporous silicon carbide-derived activated carbon labeled as AUK [ 33 ]. Therefore, we suggest that these regularities are general and will be observed in the studied adsorption systems with the increase in the values of methane adsorption, pressure, and temperature.…”

Section: Resultsmentioning

confidence: 99%

Thermodynamics of Adsorbed Methane Storage Systems Based on Peat-Derived Activated Carbons

et al. 2020

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Two activated carbons (ACs) were prepared from peat using thermochemical K2SO4 activation at 1053–1133 K for 1h, and steam activation at 1173K for 30 (AC-4) and 45 (AC-6) min. The steam activation duration affected the microporous structure and chemical composition of ACs, which are crucial for their adsorption performance in the methane storage technique. AC-6 displays a higher micropore volume (0.60 cm3/g), specific BET surface (1334 m2/g), and a lower fraction of mesopores calculated from the benzene vapor adsorption/desorption isotherms at 293K. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and small-angle X-ray scattering (SAXS) investigations of ACs revealed their heterogeneous morphology and chemical composition determined by the precursor and activation conditions. A thermodynamic analysis of methane adsorption at pressures up to 25 MPa and temperatures from 178 to 360K extended to impacts of the nonideality of a gaseous phase and non-inertness of an adsorbent made it possible to evaluate the heat effects and thermodynamic state functions in the methane-AC adsorption systems. At 270 K and methane adsorption value of ~8 mmol/g, the isosteric heat capacity of the methane-AC-4 system exceeded by ~45% that evaluated for the methane-AC-6 system. The higher micropore volume and structural heterogeneity of the more activated AC-6 compared to AC-4 determine its superior methane adsorption performance.

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“…Therefore, a practical engineering solution for the ANG facilities must consider the thermal effects of adsorption/desorption [ 34 , 35 , 36 , 37 , 38 , 39 ]. In this context, thermodynamic functions of adsorption systems, operating under conditions of high pore filling with adsorbate at high pressures, i.e., the HEAS conditions are of particular interest [ 40 , 41 ]. In this case, the isosteric heat of adsorption is an essential parameter, the correct evaluation of which defines the success of using particular mathematical models for calculating the characteristics of a scaled ANG system [ 42 , 43 ].…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic Behaviors of Adsorbed Methane Storage Systems Based on Nanoporous Carbon Adsorbents Prepared from Coconut Shells

et al. 2020

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The present work focused on the experimental study of the performance of a scaled system of adsorbed natural gas (ANG) storage and transportation based on carbon adsorbents. For this purpose, three different samples of activated carbons (AC) were prepared by varying the size of coconut shell char granules and steam activation conditions. The parameters of their porous structure, morphology, and chemical composition were determined from the nitrogen adsorption at 77 K, X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), and scanning electron microscopy (SEM) measurements. The methane adsorption data measured within the temperature range from 178 to 360 K and at pressures up to 25 MPa enabled us to identify the most efficient adsorbent among the studied materials: AC-90S. The differential heats of methane adsorption on AC-90S were determined in order to simulate the gas charge/discharge processes in the ANG system using a mathematical model with consideration for thermal effects. The results of simulating the charge/discharge processes under two different conditions of heat exchange are consistent with the experimentally determined temperature distribution over a scaled ANG storage tank filled with the compacted AC-90S adsorbent and equipped with temperature sensors and heat-exchanger devices. The amounts of methane delivered from the ANG storage system employing AC-90S as an adsorbent differ from the model predictions by 4–6%. Both the experiments and mathematical modeling showed that the thermal regulation of the ANG storage tank ensured the higher rates of charge/discharge processes compared to the thermal insulation.

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Methane adsorption on a microporous carbon adsorbent in the precritical and hypercritical regions

Cited by 16 publications

References 1 publication

Modified Dubinin–Radushkevich/Dubinin–Astakhov Adsorption Equations

Modified Dubinin–Radushkevich/Dubinin–Astakhov Adsorption Equations

Thermodynamics of Adsorbed Methane Storage Systems Based on Peat-Derived Activated Carbons

Thermodynamic Behaviors of Adsorbed Methane Storage Systems Based on Nanoporous Carbon Adsorbents Prepared from Coconut Shells

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