Thermal Resistance of Brown Coals from Various Deposits in Russia and Mongolia
Chemistry for Sustainable Development
||brown coals, thermogravimetric analysis, pyrolysis, flash point, petrography
Federal Research Center of Coal and Coal Chemistry, Siberian Branch of the Russian Academy of Sciences, Kemerovo, Russia
Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Thermogravimetric investigation of five brown coal samples from various deposits in Russia and Mongolia was carried out in the inert and oxidizing media. A comparative analysis of the data obtained allowed us to reveal that brown coal of the Kangalasskoe deposit has higher thermal stability. This is confirmed by a higher yield of solid residue from pyrolysis in the inert atmosphere, lower yield of volatile substances, and the shift of the maximum of thermochemical decomposition of coal substance to higher temperatures. Temperature limits (ignition temperature for particles and the final temperature at which the coke residue burns out) of thermal degradation of the organic mass of the studied brown coals in the oxidizing medium were determined. It was demonstrated that brown coal samples were characterized by increased reactivity with respect to oxygen. It was established that the ignition temperature increases with an increase in the carbon content (Сdaf) in the samples and a decrease in the yield of volatiles (Vdaf), while the final temperature of the oxidation process significantly correlates with the aromaticity index f a of the organic mass of coal.