E. I. Shkol’nikov

Study of the processes of steam-hydrogen mixture generation in a reactor for hydrothermal aluminum oxidation for power units

This work is devoted to the study of the processes of generation of steam-hydrogen gaseous mixtures formed in the hydrothermal oxidation of aluminum and its further utilization in power units. One of the main objects of this study is a reactor that generates steam-hydrogen mixtures, and the main problem is the continuous mode of its operation. Analytical calculations of thermodynamic parameters that are characteristic of the continuous hydrothermal oxidation of aluminum are reported together with the results of the experimental study of this mode. A combination of theoretical and experimental studies made it possible to determine the composition of aluminum-water suspensions and the range of thermodynamic parameters that are optimal for the continuous reactor of steam-hydrogen mixture generation.

Porous Pd-Containing Polypropylene Membranes for Catalytic Water Deoxygenation

Water deoxygenation has been studied in a catalytic membrane reactor in which oxygen is reduced with hydrogen fed into the hollow fiber of a porous polypropylene membrane containing palladium metal on its outer surface. Palladized fibers obtained by different methods and the initial fibers have been characterized by dynamic desorption porosimetry, gas permeability measurements, X-ray structure determination, and light microscopy. The possibility of efficient water deoxygenation at room temperature is demonstrated.

Thermodynamic calculation of the parameters of a reactor for oxidizing aluminum in wet saturated steam

A model is considered that represents a chemical reactor for oxidizing aluminum in wet saturated steam to obtain a high-temperature and high-head flow of steam-hydrogen mixture, as well as aluminum oxides and (or) hydroxides. The thermal gas-dynamic parameters of the reactor are analyzed using a combined calculated and theoretical approach, which made it possible to determine the region of considered parameters optimal in terms of the thermodynamic efficiency of the reactor.

Synthesis of high-purity α-Al2O3 from boehmite obtained by hydrothermal oxidation of aluminum

We demonstrate the possibility of obtaining high-purity aluminum oxide by successive processes of hydrothermal oxidation of aluminum and vacuum heat treatment of the solid oxidation product (boehmite). The results of studies of changes in the structural properties and chemical purity of alumina samples obtained in the different modes of vacuum heat treatment of boehmite are presented. Experiments have shown the ability to produce alumina with a purity of 99.997% (the total content of all impurities is approximately 30 ppm) of aluminum with a purity of 99.8%. It was shown that the chemical purity of the final product depends on not only the temperature and time of heat treatment but also a number of other parameters of the process.

Effect of the amount of F4 fluoroplastic binder in carbon electrodes on characteristics of supercapacitors

Effect of the amount of F4 fluoroplastic binder in activated carbon electrodes on characteristics of double-layer supercapacitors with both aqueous and organic electrolytes was studied. It was shown that, depending on requirements to the strength of the electrodes, it is possible to raise by 20% the content of fluoroplastic without any significant decrease in the capacity of an electrode.

A facility for studying the spatial and temporal characteristics of a plume produced by interaction of high-power CO2 laser pulses with a solid-state target in various gas environments

An experimental facility for studying the kinetics of molecular association formation from atoms produced by evaporation of the target material by powerful CO2 laser pulses is described. First experimental results are presented for the spectral and spatial-temporal characteristics of the spread of Al atoms produced in interactions of laser radiation with aluminum oxide Al2O3, followed by AlO formation in various low-pressure (0.1–0.3 Torr) atmospheres. Images of structurally similar forms condensed on a glass surface have been observed with an atomic-force microscope.

Distributed generation of heat and electricity on the basis of renewable energy sources with using aluminum as an intermediate energy carrier

The possibility of localized generation of heat and electricity (also for transport applications) on the basis of different aluminum oxidation methods is considered. Use of renewable energy sources for reproducing aluminum allows a closed energy cycle to be obtained and make it more environmentally clean and safe. Preliminary assessments of this method for distributing electric energy in comparison with alternative schemes are carried out.

Ways to form electrodes for supercapacitors with aqueous and organic electrolytes and specific features of these methods

Two methods (spraying and calendering) for fabrication of supercapacitor electrodes are considered. Results of tests of double-layer capacitors with aqueous (sulfuric acid) and organic (tetraethylammonium tetrafluoroborate dissolved in acetonitrile) electrolytes and electrodes fabricated from activated carbon are presented. It is shown that, depending on the type of the electrolyte, it is necessary to use different methods for fabrication of carbon electrodes.

Activated carbon for supercapacitor electrodes with an aqueous electrolyte

Activated carbons on the basis of wood are obtained; the carbons are characterized by the optimal characteristics necessary to apply in supercapacitors with a sulfuric acid-based electrolyte. The properties of activated carbon including detailed study of the porous structure by the limited evaporation technique, as well as their electrochemical parameters in the supercapacitor structure, are investigated comprehensively. For material synthesis, correlations between the regime factors, the porous structure, and the functional characteristics of the supercapacitors on that basis are found. Suppositions concerning the peculiarities of formation of the porous structure of activated carbons obtained by the thermochemical synthesis method with use of an alkali as the activator, as well as the influence of the synthesis parameters on the electrochemical characteristics of the supercapacitors, are proposed.

Acid-base properties of phenol formaldehyde sorbents

It is shown that at a temperature of 295 K, phenol groups of phenol formaldehyde sorbents are characterized by the value pK ∼ 13.0–13.7. It is found that raising the temperature to 343 K reduces the pK value by one. It is concluded that the reason for the lower acidity of phenol formaldehyde sorbents relative to phenol in an aqueous solution is the smaller amount of firmly bound water.