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Methane adsorption on a recuperated activated carbon, AR-V, was studied over the temperature range of 213–393 K and at pressures up to 10 MPa from the perspective of its potential application for adsorption-based storage and separation technologies. The porous structure, phase and chemical compositions of AR-V were examined by nitrogen adsorption at 77 K, x-ray diffraction, and scanning electron microscopy. The amount of adsorbed methane increased with pressure up to 6.3 mmol/g at 243 K and fell dramatically to ~ 1 mmol/g with a temperature rise to 393 K. The molar differential isosteric heat of methane adsorption on AR-V was evaluated from the linear isosteres within the studied P,T-range; the effects from the non-ideality of a gaseous phase and the AR-V non-inertness were considered. The maximal summarized contribution from the AR-V thermal expansion and directly measured adsorption-induced deformation to the molar differential isosteric heat of methane adsorption turned out to be less than that from the gas compressibility. The initial drastic changes in the thermodynamic state functions of the adsorption system were attributed to the binding methane molecules with non-uniformly distributed high-energy adsorption sites. When methane molecules occupied all high-energy adsorption sites, the subsequent variations in the thermodynamic functions were governed by the intensifying attractive forces between methane molecules upon methane adsorption resulting in the formation of adsorption clusters. The temperature dependence of the isosteric heat capacity of the methane/AR-V system varied during adsorption; its value exceeded 2–3 times the isochoric heat capacity of the equilibrium methane gaseous phase.

Adsorbed natural gas (ANG) storage systems are based on nanoporous adsorbents with a tailored porous structure. Activated carbons are among the most promising and widely used candidates for this application, which is explained by the availability and abundance of raw material resources. In the present work, several series of activated carbons prepared from various precursors (coconut shell, peat, polymers, silicon carbide, and mineral coal) by different routes of physical and thermochemical activation were considered in the context of the adsorbed natural gas storage applications. Based on the Dubinin theory of volume filling of micropores and BET method, the porous structure of these adsorbents was evaluated from standard adsorption isotherms. The XRD, SAXS, and SEM measurements revealed variations in the textural and morphological properties of the adsorbents and their dependence on the precursor and synthesis procedure. The pore sizes evaluated from the adsorption and SAXS data were compared. Experimental data on methane adsorption at the temperature of 303 K and pressures of 0.1, 3.5, and 10 MPa made it possible to identify the most effective adsorbents. It was shown that the adsorption properties of ACs prepared from peat and mineral coal are determined by surface chemistry inherited from the precursor and activating agent. In contrast, the adsorption performance of ACs from polymer and coconut shell depends solely on the pore volume and pore dimensions. The adsorption effectiveness of each AC varies with pressure as a function of textural properties. Thus, a selection of an optimal adsorbent should be adjusted for thermodynamical coditions of ANG system.

Using the main statements of the Dubinin theory of volume filling of micropores (TVFM) the amount of adsorbed ethane was estimated at pressures up to 4 MPa in the temperature range lower and higher than the critical temperature (303–333 K) on the superactive microporous carbon adsorbent with the bimodal micropore size distribution and a total micropore volume of 1.44 cm3 g−1. Two approaches were applied for comparison of the accuracy of calculations: the approach based on the calculation of “standard states” of adsorption and pressure and the approach taking into account the property of linearity of adsorption isosteres of gases in broad ranges of thermodynamic parameters. Both thermodynamic approaches showed good agreement of the results with experimental data and can be recommended for precalculations of adsorption equilibria of gases and vapors on the basis of the minimum physicochemical information about the adsorbent and adsorptive. The high agreement of the experimental and calculated data provides the basis for using the adsorption characteristics obtained in the framework of the TVFM for the calculation of differential molar isosteric heats of adsorption.

The present study is aimed at the development of scientific and technological approaches to the production and exploitation of adsorption systems for natural gas storage at low temperatures. In this work, a monolithic microporous carbon adsorbent is proposed for the accumulation of natural gas; the comprehensive investigations of its structure and properties were carried out. The proposed adsorbent was used for filling up a mobile adsorption natural gas storage reservoir (an adsorber) equipped with the internal and external heat exchangers which provided different modes of fueling/delivery process. The adsorber endured the integrated reliability testing under isothermal, adiabatic and low-temperature conditions of gas fueling/delivery modes. The adsorption characteristics were determined at the pressures up to 10 MPa and within the temperature range from 238 to 293 K; the energy consumptions upon the processes of gas fueling and adsorber cooling were accessed depending on the fueling mode; the temperature variations occurring in the adsorber upon the gas fueling/delivery processes were studied within the pressure range from 0.05 to 10 MPa. Cyclic testings of the mobile adsorber of natural gas were performed to determine an influence of the cyclic loading on the adsorption capacity of the adsorbent.

Using numerical and analytical methods, a model for microporous carbon adsorbents with slit-shaped pores of different widths was developed. Such pores are formed during activation procedure by the removal of the hexagonal carbon layers burnt out in a graphite-like crystallites. Dubinin’s theory of volume filling of micropores was used to calculate methane adsorption equilibria on these model adsorbents. Isobaric dependences of methane adsorption on pore width, specific micropore volumes, and the specific surface were plotted in the range of pressures from 1 to 10 MPa. It was found that the isobaric adsorption curves had a maximum the position of which depends on both the structural-energy characteristics of the adsorbent and thermodynamic conditions chosen to operate the adsorption system. As pressure increased, the maximum of adsorption shifts to the porous systems with wider pores and larger micropore volume.

Adsorption-induced deformation of microporous carbon adsorbents AUK and AR-V with different genesis was measured in conditions of methane adsorption (temperature 273, 313, 353, 393 K; pressure 0–6 MPa). Thermal deformation of carbon adsorbents AUK and AR-V was measured in the temperature range of 273–573 K. Coefficients of linear thermal expansion (CTE) of carbon adsorbents were calculated in the temperature range of 273–573 K: for AUK, aT = (3 ± 0.15)·10–6 K–1; for AR-V, T = (8.4 ± 0.6)·10–5 K–1. A comparative analysis of the CTE of adsorbents and crystal graphite was implemented.

The efficiency of pyrometallurgical plants is determined by their thermal performance. The thermal processes in processing secondary copper-containing materials such as brass scrap are analyzed. The main goal of this research was to take the heat balance and to analyze the most significant heat inputs and outputs. The main heat inputs are from burning gas and exothermic reactions such as the oxidation of zinc and iron. The heat outputs are mouth, lining, and waste-gas losses.

Adsorption of methane on twelve microporous carbon adsorbents of different origin and structural and energy characteristics was studied at the pressures up to 20 MPa. Specific capacities have been calculated for methane adsorption storage systems. The effectiveness of adsorption accumulation was analyzed in terms of structural and energy characteristics, packing density and thermodynamic parameters of methane adsorption. Differential molar isosteric heats of adsorption and absolute efficiency of adsorption accumulation systems were evaluated. The effects of increased packing density and proper shape of adsorbent material on the adsorption accumulation efficiency were considered. It was shown that a selection of an adsorbent with the most optimal porous structure and density should be adjusted for thermodynamic parameters of accumulation system.

Results are presented from a study made of the hydrodynamics of the liquid bath in a TROF converter to find efficient operating parameters for conducting the blow through an unsubmerged lance. The study was performed on a cold physical model. Investigation of the character of development of the blast jet in the bubbling zone made it possible to establish the main forces associated with the mass of the liquid, friction, and buoyancy and to thus determine the hydrodynamics of the liquid bath.

A technique for the measurement of the equilibrium absolute adsorption of gases, in particular, of natural gas (methane), at pressures up to 10 MPa, is proposed. A plant for use in performing the measurements by means of a volumetric method is described. Estimators of the measurement errors are presented. Adsorption isotherms of methane by AU-1Sh miroporous carbon matter in the range of pressures 10–7–10 MPa and temperatures in the range 178–360 K are obtained by means of the proposed technique.

Aspects of the hydrodynamics of the bath of a furnace equipped with a submersible lance are studied by cold modeling. The model was made of plexiglass on a 1:12 scale. The main objective was to determine the relationship between the injection rate and the geometric parameters of the lance, as well as the relationship between the geometric parameters of the gas jet and its parameters at the outlet of the lance. This information will be used to design an optimized model of a unit equipped with a submersible lance and develop recommendations on selecting the optimum blast regimes.

Block diagrams are considered for two-channel and three-channel meters for determining the parameter of a parabolic characteristic for an electronic component or device. The accuracy in measuring the exponent is examined. Possible applications of the meters are indicated.

A block diagram of an instrument for measuring the parameter of the symmetrical parabolic characteristics of a radio-electronic component or device is considered. The results of an analysis of the error in measuring the exponent of the parabola are presented. Areas of a possible application of the measuring instruments were indicated.

A regular procedure is proposed for deriving approximate equations of motion of straight thin rotating jets of a viscous incompressible fluid, and similarity parameters of such flows are established. The problem of the stability of free steady motion of a finite jet is considered in the framework of a model that takes into account in the zeroth approximation the effects of viscosity, the rotation of the jet, and capillarity.

1. With the aid of photography we have determined the phase contact surface in a model bubble reactor as a function of gas velocity. Simultaneously we have carried out measurements of the rate of mass-transfer in the process of sodium sulfite oxidation in aqueous solution. 2. The true mass-transfer coefficients, calculated from experimental data, coincide satisfactorily with those calculated from the theoretical dependence.