Authors: I.Y. Petrov, A.V. Osipov, K.Y. Ushakov, Bogomolov , B.G. Tryasunov

Title of the article: Catalytic liquefaction of coals - a promising way to produce motor fuels and valuable chemical compounds Part 3. factors influencing the processes of coal liquefaction: coal rank and coal composition

Year: 2021, Issue: 3, Pages: 58-73

Branch of knowledge: 05.17.07 Chemical technology of fuel and high-energy substances

Index UDK: (66.092.094.25.097+66.061):552.57

DOI: 10.26730/1999-4125-2021-3-58-73

Abstract: Characteristics of initial coal raw materials, such as coal rank (degree of coalification), petrographic composition and mineral components, have a huge impact on the yield and properties of the products formed during the liquefaction of solid fuels. The yield of liquid products depends on the type of coal used and its carbon content. The maximum yield of distilled liquids is observed at a carbon content of ~ 80-85%, which corresponds to bituminous coals. In case of low-grade coals (lignites, sapropelites, oil shale and other solid fuels), a fairly high degree of conversion is observed due to the increased oxygen content (~ 15-30%), but the amount of distilled liquid products decreases, and that of such products as CO, CO₂ and H₂O, on the contrary, increases. Among the petrographic components of coals, vitrinite and exinite (liptinite) are the most reactive materials that undergo rapid fragmentation reactions. Macerals of the inertinite type, characterized by lower H/C atomic ratios, with some exceptions, are much less reactive. Mineral substances (silicates, clays, pyrite, carbonates, etc.) contained in coals can act both as catalysts and inhibitors of liquefaction processes. Iron-containing minerals contribute to the hydrogenation and cracking reactions of coal matter, as well as to the products of its transformations. The presence of clay materials (for example, kaolin) in the composition of coal leads to an increase in the degree of its conversion, but at the same time, the reactions of aromatization, condensation and coke formation of liquefaction products are also accelerated. In low-ash coals, with an increase in the ash content (i.e., with a rise in the amount of mineral components), as a rule, both the total degree of coal conversion and the yield of liquid products increase, but in high-ash coals, changes in the ash contents do not seem to affect the total degree of coal conversion and yields of "coal liquids".

Key words: coal liquefaction degree of coalification H/C atomic ratio macerals mineral components of coal coal conversion

Receiving date: 27.05.2021

Publication date: 02.07.2021

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