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编号 1 (2023)
Articles
ПАМЯТИ ЮРИЯ ГАВРИИЛОВИЧА КРЯЖЕВА
3
Synthesis and Study of the Properties of Porous Carbon–Carbon Nanocomposites with Nitrogen-Containing Carbon Nanofibers
摘要
The possibility of synthesizing carbon–carbon nanocomposites with nanofibers embedded in a carbon matrix by two-stage dehydrochlorination (under the action of alkali followed by carbonization) of a carbon-chain chloropolymer has been shown. Chlorinated polyvinyl chloride was used as the initial chloropolymer, and nitrogen-containing carbon nanofibers (N-CNFs) were used as a nanoscale component. The structure of the resulting nanocomposites was examined by electron microscopy and the texture parameters were studied using low-temperature nitrogen adsorption–desorption. The introduction of N-CNFs into the carbon matrix and the activation of the resulting carbon–carbon nanocomposite in an atmosphere of CO2 contributed to the formation of a micro- and mesoporous material with a specific surface area of ~1100 m2/g. It was shown that the resulting nanocomposites were characterized by high energy capacity and energy efficiency when tested as electrodes of electrochemical supercapacitors.
4-12
Metal Content of Brown Coals from the Raichikhinskoe Deposit (Priamurie, Far East): Conditions of Accumulation and Distribution and Prospects for Development
摘要
The formation of metal-bearing coalfields of the Raichikhinskoe deposit in the conjugation zone of distributive provinces of the Bureya uplift and coal-accumulation areas of the Zeya–Bureya sedimentary basin was studied. It was established that it occurred under conditions of the successive extraction of ore components from weathering crusts of the Bureya uplift, transportation, and unloading in the paleodelta of the Bureya River. These processes proceeded synchronously with volcanic activity in the Sikhote-Alin orogenic belt, which is associated with the supply of volcanic ash. The association of these events made it possible to distinguish two types of enrichment of the Raichikha coals in rare earth elements and yttrium (REY): terrigenous with the supply of REY by surface waters and combined terrigenous volcanogenic associated with the shedding and leaching of acidic and alkaline volcanic ash. The cerium group lanthanides predominate in coals and their combustion products. The largest fraction of REY was contained in fly ash (0.11% on a total weight basis). The mechanisms of accumulation of ore components at the stage of peat deposits are considered from the standpoint of the localization of trace ore components as clastogenic mineral forms and under the conditions of interaction of ore solutions with the organic environment of peat bogs. The quality of REY was assessed, and the most enriched sections of the Verkhnii layer were identified. Prospects for the extraction of lanthanides from coal are considered from the standpoint of the possible recovery of a number of rare, nonferrous, and noble metals in this process.
13-31
Rare Earth Element Speciation in Miocene Brown Coals from the Sergeevskoe Deposit (Priamurie, Far East)
摘要
The concentration, speciation, and localization of rare earth elements in Miocene brown coals from the Sergeevskoe deposit (Amur oblast) have been studied. The total rare earth element content of the test coals (97.43 mg/kg) exceeds the clarke value by a factor of 1.5; the amount of light lanthanides (74.57 mg/kg) prevails over that of heavy ones (7.68 mg/kg). The main concentrators of lanthanides in Miocene brown coals are humic acids. The amount of rare earth elements in water-soluble, ion-exchange, silicate, and disulfide forms does not exceed 5% of the total content with the exception of scandium, 22% of which is associated with silicate minerals such as clays.
32-46
A Study of the GTL Process in Adiabatic Mode
摘要
Versions of the production of environmentally friendly components of motor fuels using the Fischer–Tropsch synthesis (FTS) are considered. The advantages and disadvantages of the used radial reactors are analyzed. Research on the development of a domestic technology for the production of synthetic liquid fuels from natural gas on a bench-scale process plant, which was used to solve the problems of hydrogen utilization, is described. Based on the results of this work, conclusions that allow the development of a promising scientific and practical direction were drawn.
47-51
Low- and High-Molecular-Weight Oxygen-Containing Compounds of the Organic Matter of Oil Shale from the Dmitrievskoe Deposit (Kuzbass)
摘要
Data on the composition and structure of aliphatic and aromatic fragments bound through oxygen in the molecules of resinous-asphaltene and oil components of bitumoid from the sample of Dmitrievskoe oil shale have been obtained.
52-57
Carbonization of Carbohydrates in an Atmosphere of Argon and under the Action of Calcium and Iron Chlorides
摘要
The carbonization of carbohydrates (glucose, sucrose, and starch) in an inert gas atmosphere of argon and under the action of calcium chloride and iron(III) chloride additives was studied. It was established that the addition of calcium and iron(III) chlorides exerted a peculiar catalytic effect on the carbonization process. Carbon production can be carried out at lower temperatures to 200°С. In traditional methods of synthesis, carbonization upon the decomposition of carbohydrates occurs at temperatures of 300–800°C. It was found that the process of carbon production was accompanied by the release of heat, which was confirmed by thermodynamic calculations of the chemical reaction of carbon production and experimental studies of the carbonization of carbohydrates by differential scanning calorimetry. A regular decrease in the yield of carbon, as compared to a maximum theoretically possible one, was observed in the order glucose > sucrose > starch. It was established that the heat of combustion of carbon obtained upon the carbonization of carbohydrates under the action calcium and iron chlorides reached 34 MJ/kg or more due to the presence of structural fragments that do not occupy energetically favorable positions compared to the graphite structure. The presence of the structural fragments of carbon was established by X-ray phase analysis of powder diffraction patterns.
58-65
Theoretical Method for Evaluating the Heat of Combustion of Sewage Sludge in the Lack of Air
摘要
A procedure based on the modification of the Mendeleev formula and the calculation of chemical equilibrium in an initial mixture is proposed for estimating the heat of combustion of sewage sludge (SWS) under conditions of lack of air. The equilibrium composition of a mixture is proposed to be calculated on the basis of applied programs or chemical equilibrium equations. For the second method, the initial equations and methods for their solution are given. Thus, two cases are considered. The first case is the absence of carbon from the equilibrium mixture and the second is the presence of carbon in the equilibrium mixture. A procedure is proposed for calculating an air deficiency coefficient at which carbon begins to appear in an equilibrium mixture. Test calculations were carried out for dry and wet SWS at a combustion temperature of 700°C using the NASA program and based on chemical equilibrium equations. A comparison between the calculation results obtained by both methods showed satisfactory agreement. For illustration, the calorific value of SWS was calculated at 700°C and an air deficiency coefficient of 0.5–1. The procedure can be used for fuels in which the contribution of sulfur to the heat of combustion of the fuel can be neglected.
66-72