The thermal solution of coal at different metamorphic stages (from lignite to Zh coal) in the anthracene fraction of coking tar is studied. Up to 69% conversion of GZh and Zh coal with an elevated content of plastic mass and polyaromatic fragments is observed in thermal dissolution. It is shown that thermal dissolution is a selective process, in which quinoline-soluble pitch-like products are mainly formed, with little formation of gases and distillates.

The results of a study of the steam gasification of carbonized brown coal samples at 700°C depending on the composition of mineral components, textural properties, structural ordering of the organic matter, and the type of a gasifier are reported. It was found that the native calcium content is the main factor responsible for the reactivity of carbonized brown coal. Treatment with acid solutions led to the almost complete extraction of calcium, which was accompanied by a sharp decrease in reactivity upon gasification. It was hypothesized that the found behavior was associated with the participation of native calcium compounds (in oxide and/or carbonate forms) in the catalysis of carbon gasification reactions with water vapor.

The thermal dissolution of 1GZhR coal in model aromatic solvents and industrial polyaromatic solvents is analyzed. The following polyaromatic solvents are considered: coking tar, its anthracene fraction, and petroleum gas-oil. They are employed separately and in different combinations. The degree of conversion of the coal’s organic mass, the material balance, and the composition of the products and gases formed are determined. The efficiency of the solvents based on coal tar and its anthracene fraction is established in terms of the degree of conversion of the coal’s organic mass and the group composition of the products. The extractive products of thermal solution for the individual solvents (except for the petroleum gas-oil) and their mixtures take the form of a solid pitch-like mass (softening temperature 76–118°C). They have a high content (90–94%) of quinoline-soluble polyaromatic materials.

The thermal dissolution of grade 1GZh coal in different commercial paste-forming agents—coking tar, an anthracene fraction of coking tar, heavy semicoking tar, and petroleum gas oil—was studied. It was established that the presence of polycondensed molecules with a low degree of substitution of aromatic rings and compounds with hydrogen-donor and solvating activity in the solvent facilitated the efficient occurrence of the thermal dissolution of coal at a low temperature of 380°C. The highest yields of soluble pitch-like product (78–85%) were obtained in the processes performed in the anthracene fraction of coking tar and coking tar.

The thermal dissolution of two samples of 1GZhR and ZhR coal in the anthracene fraction of coal tar is studied. The yield of quinoline-soluble products increases considerably in the temperature range of coal softening. Optimal thermal-dissolution conditions are determined for selective production of quinoline-soluble pitch-like products. At 350–380°C, the yield of quinoline-soluble products is 70–73% after 1–2 h. The yields of the distillate fraction and the gas are 0.9% and 0.2%, respectively. The ash-free pitch-like product is a plastic mass with a softening temperature of 76–81°C. It consists mainly of polycyclic aromatic hydrocarbons with a few short alkyl substituents in the aromatic rings. The spatial structure mainly includes poorly structured polycyclic aromatic molecules of the γ component. The proportion of relatively ordered graphitelike packets is 31–37%. Each packet contains five stacked polycyclic aromatic molecules of diameter 17 Å. In terms of its composition and plasticity, the product is suitable as a source of alternatives to coal pitch.

The main process characteristics of the thermal dissolution of grade Zh coal in the anthracene fraction of coking tar depending on temperature and reaction time were determined. It was established that the effective extraction of quinoline-soluble products occurred in a temperature range of coal conversion into a plastic state. The process proceeded selectively; at 350–380°C, the yield of the quinoline-soluble products was 71–75%. In this case, the yield of toluene-soluble products did not exceed 10%, and the yield of gas was 0.5%. At a higher temperature and a long reaction time (>2 h), a sharp decrease in the characteristics of thermal dissolution occurred.

Изучен процесс термического растворения угля марки 1ГЖ в среде различных технических пастообразователей: в смоле коксования (СК), антраценовой фракции смолы коксования (АФСК), тяжелой смоле полукоксования (ТСПК) и нефтяном газойле (НГ).Установлено, что присутствие в растворителе поликонденсированных молекул с низкой степенью замещения ароматических колец и соединений, обладающих водорододонорной и сольватирующей активностью

The increased metal-bearing capacity of coals from the Salga-Tabakh area in the north of the Lena Basin was established. In terms of the composition of rare-earth elements, they can be attributed to the collectors of the most expensive yttrium group. A process flowsheet was proposed for the extraction of rare-earth elements from coal ashes; this flowsheet can be used both independently and as a part of coal conversion processes with the production of liquid fuels and other valuable chemical products.

The process of thermal dissolution of medium metamorphosed coals in anthracene oil to produce an alternative pitch binder was studied. The process was carried out at temperatures from 350 to 400°C and pressure not higher than 2.5 MPa, without the use of hydrogen and catalysts. It was determined that during thermal dissolution hard coal of gaseous-fat grade demonstrated a higher activity compared with less metamorphosed gaseous coal. Under optimal conditions at a temperature of 350-380°C yields of pitch tar containing product are 63-75%. With regard to their composition and the main technical characteristics the isolated pitches are at the level in the middle between the coal-tar and oil pitches. Based on the yield data analysis, technical and environmental characteristics of the isolated pitch products a conclusion was made on the prospects of thermal dissolution process as an alternative method for preparing extractive pitch- a substitute for coal-tar pitch produced by coking process.

The influence of hydrogenating upgrading of heavy semicoking tar from long-flame coal on its properties and composition is studied when it is used as the solvent in the thermal dissolution of bituminous gas coal (GZh coal). It was found that the concentration of oxygen-bearing compounds declines on catalytic hydrogenation of tar at 5 MPa and on combined treatment with two hydrogen donors: tetralin and the anthracene oil. After hydrogenating treatment, the heavy semicoking tar may be used as the solvent in the thermal dissolution of GZh coal so as to obtain pitch-like products.

The conversion of brown coals and sapropelic coal in toluene containing mixtures with co-solvents (water, ethanol and tetralin) was studied under sub- and supercritical conditions within the temperature range of 375-550°C and at pressures from 7 to 40 MPa. It was found that the extent of coal extraction in the toluene solvent medium, at 400°C, was significantly increased by the addition of small amounts of hydrogen-donor tetralin or ethanol co-solvents. The extract yield from sapropelic coal reached 79-83%, with the gas yield being small. The effect of process variables on extract yields under sub- and supercritical conditions was monitored. Coal extraction in the toluene-tetralin mixtures was found to depend mainly on the hydrogen donor ability of the tetralin co-solvent irrespective of sub-or supercritical toluene states. According to the composition, the bitumen extracted from coals can be used as a feedstock for pitch production. In the water containing mediums, aside from coal liquefaction, coal methanation, hydrolysis and oxidation reactions occurred resulting in the generation of large amounts of methane, hydrogen and carbon dioxide.

The composition and thermal properties of brown and black coals from a number of deposits in Mongolia were determined. Their reactivity in the process of steam gasification was studied. It was found that semicokes obtained from coals of the Baganuur, Khovil, Shivee Ovoo, and Bagakhangai exhibited comparatively high reactivity in this process. Deep conversion into combustible hydrogen-containing gas was achieved at a temperature of 750°C. As compared with the Mongolian coals, carbonization products from the brown coal of the Borodino deposit in the Kansk-Achinsk Basin exhibited increased gasification activity, which is related to the presence of a considerable amount of calcium compounds in its composition; these calcium compounds render catalytic action on the interaction of carbon with water vapor.

The structural properties of carbonization products obtained from different samples of initial and partially demineralized brown coals from the Borodino, Berezovo, and Kangalas deposits and the Yallourn deposit (Australia) were studied depending on the composition of the mineral matter of coal. Differences in the specific surface areas and the spatial structure characteristics of the organic matter of the test samples were found. It was shown that the carbonization products obtained from coals partially demineralized with the dilute solutions of acids, in comparison with the carbonization products of natural coals, were characterized by a lower concentration of an ordered graphite-like component (60–72% against 74–93%) but a higher degree of its graphitization (0.24–0.52 against 0.20–0.35). The dependence of these properties on the calcium content was revealed.

Определены состав и показатели реакционной способности угля Хоот Монголии в процессах пиролиза, газификации, термического растворения и получения пористых материалов. Установлено, что уголь отличается высокой активностью в реакциях деструкции. В процессе полукоксования выход жидкой смолы достигает 10%. Путем паровой активации карбонизатов получены высокопористые активные угли с величиной удельной поверхности до 900 м2/г и высокой сорбционной активностью. В процессе терморастворения в водорододонорном растворителе при 450°C без применения водорода из угля Хоот можно получать до 60.8% жидких продуктов при низком газообразовании.