Specific Heat of Coal and Heat-treated Coal

Abstract

True and practical specific heat of coals (C% 70∼93) were measured continuously with adiabastic method. Practical specific heat includes heat of chemical reaction, heat of vaporization and heat of phase transition. The error of the measurments did not exceed over ±5 per cent. True specific heat increases with measuring temperature for individual coal and decreases as the rank of coal approaches to the graphite. The relation between true and practical specific heat shows that coal of C% 70 has exothermic reaction at the higher temperature range than 250°C. Especially, it shows maximum values at about 380 and 600°C. Coals of C% 75∼85 have exothermic reaction at 400∼500°C and at the higher temperature range than 600°C, and endothermic reaction at about 550∼600°C. Coal of C% 93 shows exothermic reaction at about 680°C and endothermic one at the higher temperature than 650°C. The mechanisms of reactions occuring at each temperature region were estimated from the decomposed gases and was examined if it is reasonable or not from the view point of the results obtained in this measurment.