Authors: I.Y. Petrov, B.G. Tryasunov, A.R. Bogomolov

Title of the article: Catalytic liquefaction of coals: a promising way to produce motor fuels and valuable chemical compounds. Part 5. Factors Influencing the Processes of Coal Liquefaction: Coal Texture and Its Granulometric Composition

Year: 2021, Issue: 6, Pages: 27-39

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: 10.26730/1999-4125-2021-6-27-39

Abstract: The review article discusses the role of coal particle sizes and their textural characteristics in the direct liquefaction of solid fuels. According to most studies, the efficiency of the coal liquefaction process increases with decreasing particle size. However, in order to obtain reliable correlations between sizes of coal particles and their reactivities, it is recommended to determine not only the average particle sizes or the ranges of particle sizes, but also to carry out a complete detailed analysis of the entire particle size distribution of the coal under study. The texture of coals (porous structure and specific surface area) also has a significant effect on the liquefaction process. In case of non-catalytic liquefaction of coals, a general rule is usually observed: the higher the volume of macro- and micropores in the original coals, the higher their reactivity. Coal hydrogenation leads to the destruction of its original microporosity and an increase in the volume of mesopores and macropores. In liquefaction processes catalyzed by iron, with increasing temperature, coal conversion increases markedly, which is accompanied by a simultaneous rise in the yields of oil and asphaltenes. The textural characteristics of the resulting carbon residues (mainly meso- and macroporosity) change in parallel with both coal conversion and the yields of liquefaction products (oils and asphaltenes), increasing with an increase in temperature to 425°C, regardless of the nature of the catalytic precursor used (FeSO4 or red mud); at higher temperatures (and mainly at T = 500°C), both of these textural parameters decrease, which is probably due to blocking of porosity caused by repolymerization reactions.

Key words: coal liquefaction processes coal pore structure and texture coal particle size conversion liquefaction products

Receiving date: 08.11.2021

Approval date: 05.12.2021

Publication date: 24.12.2021

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