Home – Home – Jornals – Chemistry for Sustainable Development 2016 number 3

The article can be started with a reference to recent events with the participation of Prime Minister of Russia Dmitry Medvedev. During the meeting on the development of the coal industry in Novokuznetsk 4-5 April 2016, he said: "Coal Chemistry - is the future. We understand this, and we have this topic discussed with the governor. There is, however, she is weak. " At a meeting with activists of the "United Russia" party he said: "Coal Chemistry products and highly processed from coal - this is the future. Here and there can be no dispute. And the government understands this. But one of my orders will not be enough, although I do not refuse, I'm willing to give it. " The Prime Minister has promised to give the commission to develop a federal program for the development of technologies for processing coal into marketable products.

The necessity of new innovative production not limited to mining of natural resources is dictated today both by the requirements of the world market and by the desire to increase the innovation capacity of the branches dealing with raw materials. For Kuznetsk Basin, a large industrial and raw material centre, the problem of the introduction of technological innovations directly into the coal mining branch becomes especially significant. This problem may be solved through the organization of the manufacture of science-intensive coal chemical products, and it is coal mining industry that is able to become not only a base but also a driver of innovative development of regional economics. The introduction of promising technologies of fine processing of raw materials will allow one to go out of the framework of energy coal mining and to use so-called illiquid coal for the production of a broad range of relevant coal chemical products with high added value. Undoubtedly, this route of development is rather capital-intensive, and under modern conditions it requires consolidation of the efforts of the owners of coal-mining works, the state and the scientific community. Under these conditions, the Kuznetsky Basin with its substantial scientific and technological basis in the area of coal chemistry has a chance to become the first perspective ground for the introduction and successful realization of the joint projects of this kind. Analysis of the modern state of the leading branch of the economics of the Kemerovo Region is carried out, the outlooks for the introduction of coal chemical works for the goal of innovative development of the region are evaluated, the directions of the development of coal chemistry are considered. A conclusion is made stating the necessity to use innovative technologies in the facilities of coal companies, which would make it possible to decrease the "technological" losses of coal and provide the intense route of the development of regional economics.

The necessity of the development of coal chemistry is dictated by the existing limitations in the development of coal industry in the Kuznetsk Basin. At the same time, practical implementation of the projects of profound coal processing is hindered by the absence of Russian industrial technologies if coal chemistry, high cost of foreign technologies and current economic conditions. For the development of Russian coal chemistry, consolidation of the efforts of the scientific community, coal-mining companies and the state within the framework of the state-private partnership is necessary.

Results of gasification of low-grade coal and coal wastes in the filtration mode with superadiabatic heating are presented for brown coal, flue ash and cake as examples. Gasification of low-grade coal and coal wastes allows one to obtain combustible gas with the combustion heat 2 to 5 MJ/m3 and ensures high degree of coal combustion. In addition, it is possible to obtain up to 10 mass % liquid hydrocarbons with combustion heat 32 MJ/kg, which are valuable for chemical industry.

The role of active coal and adsorption technologies based on it in solving a broad range of problems in industry, environmental and human protection is demonstrated. New technologies of obtaining active coal on the basis of black coal are described, in particular those involving black coal of the Kuznetsk Basin. Results of their tests in a number of important branches of modern Russian Economics are presented, including drinking water supply, gold hydrometallurgy, and production of respiratory equipment.

Coal-tar pitch is a very important kind of raw material for obtaining industrial carbon materials. The dependence of the scale of its production and qualitative characteristics on the need for metallurgical coke and the conditions of coal coking requires the search for alternative kinds of raw material for carbon materials and the methods to govern their properties. The problems connected with obtaining raw matter for carbon materials on the basis of coal-tar resin processing and thermal dissolution of fossil coal are considered. Results of the works in this area carried out at the JSC “Eastern Research Institute of Coal Chemistry” and Postovsky Institute of Organic Synthesis, UrB RAS are described.

Review of the state of the problem connected with the preparation of substitutes for coal-tar pitch for the production high-quality carbon materials is presented. The possibilities of alternative methods of their preparation from petroleum raw material and the products of thermal and thermochemical coal processing are considered. The promising significance of the low-temperature process of coal thermal dissolution under soft conditions for obtaining extractive pitch is demonstrated. A comparison of the chemical composition and technical parameters of the obtained extractive pitch with the industrial coal-tar pitch and petroleum-based pitch is carried out. The obtained extractive pitch is close in composition, molecular structure and technical parameters to coal-tar pitch and petroleum-coal tar pitch. Using extractive pitch as a binder, an experimental sample of anode was manufactured. Its correspondence to the major technical requirements was demonstrated.

Russian and foreign works describing coal self-ignition during mining, during storage in stores, dumps of coal mines and open pits are generalized. The features of these processes are analyzed depending on metamorphism stages, petrographic composition, and porous structure of coal, water content and concentrations of mineral components. It was noted that self-ignition processes include mainly the oxidation of aliphatic structures containing oxygenated functional groups, branched aliphatic chains, methylene groups connected with aromatic rings. The highest tendency to self-ignition is exhibited by brown and black coal of low metamorphism degree. A definite effect on the tendency to self-ignition may be due to mineral substances present in coal. Fine porous structure of the organic mass defines mainly diffusion-kinetic regime of oxidation reactions. As a rule, the effect of diffusion stages is less essential in comparison with the effect of metamorphism degree and humidity of coal. It was noted that self-ignition of coal is due to the combined action of a large number of factors of different nature, including chemical, physical, mining and geological conditions. Their effects are manifested to different extents and are studied insufficiently. To establish physicochemical foundations of the reactions of coal with oxygen, reveal key stages of self-heating and ignition, elaborate reliable criteria for prediction, new data relying on thorough interdisciplinary studies involving modern chemical and physical methods are necessary. Taking into account the multifactor nature of self-ignition phenomena, endogenous fire events and explosions, it is reasonable to elaborate the criteria for coal and beds under specific mining and geological conditions similarly to the basin-related industrial classification of coal.

The distribution of toxic elements and toxic compounds in ash and slag wastes from the combustion of coal of the Kuznetsk Coal Basin was studied. Correlations between the concentrations of heavy metals in the gross and mobile forms were studied, as well as the interconnections between the concentrations of separate elements in ash and slag wastes. Correlation analysis of the data revealed a strong correlation of overall content with mobile forms for nickel, lead, manganese and cobalt (correlation coefficient is equal to 0.99, 0.96, 0.92 и 0.96, respectively), while for copper and zinc the correlation is weak. A strong interconnection of the total content of copper and chromium in ash and slag wastes was revealed (r = 0.84). For the mobile forms of elements, a connection between cobalt and nickel content (r = 0.85), fluorine and zinc (r = 0.59) was revealed.

Coal samples of different grades representing the sequence of metamorphic transformation were studied. It was established by means of NMR spectroscopy that the contribution from carbon in structural fragments of aromatic rings increases with an increase in coal maturity. The contribution from the end atoms of alkyl fragments and oxygen-containing groups decreases proportionally. The qualitative and quantitative composition of the individual representatives of the class of polycyclic aromatic hydrocarbons (PAH) in the organic extracts of black coal was determined by means of high-performance liquid chromatography. Coal of K and KS grades is characterized by the maximal total concentration of PAH - from 363.4 to 432.0 μg/kg. The regularity of the change of total PAH composition with an increase in coal maturity was revealed. The maximum of the curve corresponds to the samples with vitrainite reflectance factor equal to 1.185-1.310 %.

The changes in the petrographic composition of some coal samples of the same grade taken from different deposits of the Kuznetsk Basin (from north to south) were considered. It was revealed that the total content of the components of vitrinite and semivitrinite changes in a peculiar manner.

The characteristics of the catalysts of ozonolytic treatment of aromatic hydrocarbons were studied using physicochemical analysis methods (XPA, BET, TGA, SEM). The catalytic system Mg-Cr was determined to be the most efficient one in the reaction of ozonolytic desulphurization of hydrocarbons. It was established that carbon fragments are accumulated on the catalyst surface during ozonolytic desulphurization of the benzene fraction, which is connected with the adsorption of sulphur-containing molecules and with the oxidation of condensed hydrocarbon fragments of the raw material.

Caking properties of 22 black coal samples were studied for the purpose of determining a connection between the free swelling index SI and the stage of coal metamorphism (R_o.r). It was established that SI changes in the sequence of metamorphism of coal samples under study along a curve with the maximum in the region of R_o.r = 0.81-1.00 %. It was shown that SI increases linearly with an increase in the thickness of the plastic layer within the range у = 4-22 mm. The obtained correlation equation can be used to determine the calculated values of the free swelling index SI for coal with у < 22 mm.

The porous structure of high-temperature coke obtained on the basis of coal of different grade composition from the Kuznetsk Basin was studied. It was established experimentally that the specific surface of high-temperature coke decreases with an increase in the stage of coal metamorphism. It was determined that coke with the maximal relative volume of micropores is formed from low-metamorphosed and weakly caking coal. During the carbonization of coal at the medium stages of metamorphism, dominant development is exhibited by transport pores.

For the first time, 22 samples of black coal of different stages of metamorphism sampled at coal mining enterprises of the Kuznetsk Basin were studied by means of ¹³С NMR spectroscopy. Analysis of the analytical data showed that the degree of coal aromaticity (f_a) increases from 0.68 to 0.85 with an increase in the stage of metamorphism. It was established that an increase in aromaticity index (f_a) of the organic mass of coal is proportional to a decrease in the amount of aliphatic carbon in the structural fragments within the range 0-51 ppm.

The sorption of copper cations by native and modified humic acids obtained from brown coal of the Tisul deposit of the Kansk-Achinsk basin was studied using IR Fourier, ¹³С NMR spectroscopy in solid. The sorption capacity of humic acids was determined. It was shown that modification of humic acids by hydrogen peroxide causes the change of the functional composition and an increase in sorption capacity. The sorption of copper cations proceeds both via ion exchange mechanism and due to the formation of complexes with oxygen-containing groups and aromatic fragments.

The trends of the development of power engineering and coke chemistry, the major consumers of black and brown coal, were analyzed. A substantial potential of an increase in the fraction of coal used in power engineering was shown. Broad application of the technology of blowing up dust-coal fuel in coke chemistry for obtaining cast iron, on the one hand, decreases substantially the amount of metallurgical coke consumed, on the other hand, it requires substantial improvement of its quality. Possible directions of an increase in the quality of blast-furnace coke, improvement of the raw material basis of dust coal fuel for blast furnaces and the production of special kinds of coke are considered. New directions of obtaining synthesis gas were proposed on the basis of the working coke chemical and metallurgical plants by means of mixing the coke and converter gases, as well as by means of gasification of tar-water emulsions. The promising character of the Russian method of catalytic coking having no analogues in the world was demonstrated. Implementation of this method will allow one to develop the fundamental scientific approaches to making coal mixtures for coking, and to propose efficient methods of their preparation. A promising home technology of energy-technological processing of brown coal from the Kemerovo Region was developed on the basis of semi-coking using a solid heat carrier. A method to obtain pitch substitutes for the production of elite sorts of needle-like coke was developed; it includes soft thermal dissolution of a definite kind of coal in technical oil extracted from coke chemical tar. The advantages of the technology of preparation and combustion of water-coal fuel were demonstrated: 1) relative cheapness; 2) availability of the raw material; 3) ecological safety of combustion process; 4) the approved character of the process (transportation of the suspension along pipelines at a distance of 200-600 km was mastered, and about 600 thousand t of the fuel was processed). A method to prepare energy gas for underground coal gasification having no analogues in the world was developed; it allows a substantial (by 40 %) decrease in capital investment for the construction of the set-up and almost 2-fold decrease in the time of recoupment of capital investment. The proposals are aimed at the use of the potential of the unique coal basin situated in the Kemerovo Region.