Coke and Chemistry最新文献

By means of a mathematical model, the actual temperature of the heating wall is measured over the height of the coke oven. By the same means, the influence of the air excess and the hot-air temperature on the distribution of the actual wall temperature is investigated. A method of regulating the mean wall temperature is proposed and tested.

The large-scale transformation of Russian industry in response to Western economic sanctions calls for reassessments of the available resources and capabilities of existing enterprises. This is especially important for the fuel industry. The goal here is to show the changes in the structure and state of the fuel industry and to assess the condition of its basic component: the coal industry. The classification of the fuel industry within a normative framework is reviewed. A method is proposed for assessing the state of the coal industry in terms of the major enterprises: Oscar Properties Holding, SDS Ugol, Siberian Coal Energy Company (SUEK), Ural Mining and Metallurgical Company (UGMK), Mechel, and EVRAZ. The conclusions of this assessment are inconsistent, but the coal industry is not in crisis; the share value of some enterprises has increased. This is mainly associated with the emergence of exchange mechanisms, by which real price indices for coal sales may be formulated. The approach adopted here and the results may be used by coal enterprises to predict their capabilities and by government bodies for overall industry forecasts.

Methods and instruments for measuring the smokestack emissions of coke oven batteries are analyzed. Pollutant formation in the flue gases of heating systems is described. It is established that organic materials interfere with the accuracy of measurements made by gas analyzers with electrochemical cells. Recommendations are made regarding methods of determining the smokestack emissions of coke batteries.

Laboratory data permit analysis of how the clinkering and coking properties of EVRAZ NTMK production batch affect coke quality. To correct the composition of production batch, assessment of its plastic properties not only by the Sapozhnikov (y, x) method used at all Russian coke plants but also by the following supplementary parameters is proposed: the fluidity F_max, according to the Gieseler method; the swelling number Sw proposed by the Institute of Fossil Fuels (IGI) and VUKhIN; and the composite coking index CCI of the batch proposed by VUKhIN, which permits prediction of CSR and CRI with acceptable accuracy.

Previous articles in this series presented thermodynamic analysis of the reactions in the gasification of coke in the presence of H₂O and some parameters of this process in the laboratory. The sample porosity was estimated qualitatively (visually) and quantitatively by means of specialized image analysis software. The coke strength was assessed by the standard method of determining the postreactive strength CSR, introducing corrections as necessary if the sample size and mass were too small. In this final article, those results are discussed. The presence of moisture intensifies gasification, consequently decreasing its hot strength. For gasification by reaction with CO₂, CSR is significantly higher than in the presence of moisture; the difference is proportional to the H₂O content in the gas. In the future, for blast furnaces with a high hydrogen content, the method of determining CSR must be modified to take account of the influence of water vapor (formed in the reaction) on coke gasification.

Liquid and solid products obtained from Kaa-Khem coal by high-temperature pyrolysis and supercritical fluid extraction are compared. The results confirm that the process parameters significantly influence the product yield and composition. The chemical composition of the liquid and solid products is studied in detail by various analytical methods. High-temperature pyrolysis and supercritical fluid extraction are promising for the derivation of chemical products from Kaa-Khem coal.

The prospects for development of the coal mining industry are considered in the light of the gradual transition from commodity exports to manufacturing in Russian economic policy. In particular, the challenges to the financial stability of coal mining companies are identified. The following factors are considered in more detail: the erosion of energy self-sufficiency in Russia’s manufacturing sectors; and the reliance on irrational and expensive logistics. The influence of innovation at coal mining companies on emerging risks as a result of the structural changes in industrial production is highlighted. The decrease in financial stability is analyzed, and its negative influence on the economics of Russia’s coal sector is established. Investment projects in the coal mining industry are discussed; the capital investments in the medium term for the development of the sector are assessed. Calculations of investments in the industry from various sources permit the evaluation of predictions regarding the implementation of export-oriented projects.

Coal tar pitch, obtained as the residue in coal tar distillation, is an important binder in electrode production. Pitch from coal tar derived by low-temperature pyrolysis (semicoking tar) is of particular interest. Technology for the production of pitch from semicoking tar is of great practical interest, while the study of its properties is of both applied and theoretical importance. In the present work, a specific method is used to produce pitch from semicoking tar: toluene is used to extract pitch from the semicoking tar. The yield of pitch from the tar is determined. The fractional composition of the pitch is studied, as well as its yield of volatiles and ash content. The pitch from semicoking tar may be regarded as soft. The content of α₁ fraction is 0.5% or less, while the content of α fraction is lower than that of industrial electrode pitch.

The pyrolysis of lignite microparticles (0.5–63.0 μm) in tablet form (ρ = 1 g/cm³) under the action of pulsed periodic laser radiation (1064 nm, 14 ns, 6 Hz, 0.2–0.5 J/cm²) is studied, for samples with different ash content (A = 10.1 and 0.5%). The laser pulses produce ablation of the samples: coal particles (10–50 μm) are emitted, and carbon atoms evaporate from the surface. Laser radiation absorbed in the surface layer triggers thermochemical reactions that develop by a chain mechanism. The gaseous products H₂, CH₄, C₂H₂, CO, and CO₂ are produced in both types of samples. The yield and generation rate of the synthesis gas (H₂ and CO) increase with ash content of the samples. This indicates that mineral impurities have a catalytic effect on the gasification of lignite in laser pyrolysis.