Thermo-gravimetric studies on the low temperature pyrolysis of bituminous coal

Studies on the thermal decomposition of a washed bituminous coal from Raniganj coalfields were carried out at steady temperatures ranging from 410°-456°C by means of a thermal balance. The experiment percentage loss versus time curves follow equation of the type,where Y = percentage loss in weight, X= time in minutes, C = the intercept on Y-axis at the assumed zero time and "a" and "b" are constants. The limiting losses at various temperatures, calculated from the horizontal asymptote of the curves, when plotted versus temperature fall on a straight line whose equation is L = mt + C where L = the maximum or limiting loss at any temperature, t=the temperature in degrees centrigrade and "m" and "C" have the usual significance. From this equation, the maximum loss at any intermediate temperature can be found by intrapolation within the experimental range. The activation energy of the thermal decomposition of this coal is found to be 50 K./cals/gm mole and the frequency factor is 1.15 x 1013. (Mr. P. Prabhakaram, Junior Scientific Officer; Mr. H.P.S. Murthy, Senior Scientific Officer, National Metallurgical Laboratory)