Kinetics of coal char gasification in a carbon dioxide medium

• Published in: Russian journal of physical chemistry. B Vol. 10; no. 4; pp. 576 - 581
• Main Authors: Korotkikh, A. G., Slyusarskiy, K. V., Ditts, A. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-07-2016; Springer Nature B.V
• Subjects: Activation energy; Anthracite; Argon; Bituminous coal; Carbon dioxide; Chemical reactions; Chemistry; Chemistry and Materials Science; Coal; Coal gasification; Diffusion layers; Diffusion rate; Fixed beds; Gas generators; Kinetics and Mechanism of Chemical Reactions. Catalysis; Lignite; Oxidation; Physical Chemistry; Pyrolysis; Reaction kinetics; Solid fuels; Thermogravimetry; Time measurement; carbon dioxide; pyrolysis; solid fuel; gasification; temperature; reaction rate; coal char; thermal analysis
• ISSN: 1990-7931; 1990-7923
• DOI: 10.1134/S1990793116040059

Solid fuel samples with different carbon contents are gasified by successively subjecting to pyrolysis in argon and oxidation in carbon dioxide at various temperatures to determine the rate of the chemical reactions and the activation energy required for simulating and optimizing the operation of gas generators. The samples were prepared from bituminous coal, lignite, and anthracite of the Kuznetsk and Kansk-Achinsk coal basins. The gasification of coal char samples in a carbon dioxide medium at 900–1200°C is analyzed by thermogravimetry. The temperature dependences of the weight change rate and gasification time of coal char samples are measured and used to calculate the preexponential factor and activation energy of the carbon oxidation reaction. It is found that, with increasing oxidizing medium temperature from 900 to 1200°C, the gasification time of the coal char samples obtained from anthracite and bituminous coal decrease 8- and 22-fold, respectively. A physicomathematical model of coal char gasification in a fixed bed, with the oxidizing gas diffusing through the ash layer formed, is proposed.