Study on morphology of chars from coal pyrolysis

Pyrolyses under different temperatures were carried out upon Yangquan anthracite, Huainan bituminous coal of medium volatile matter, Shenfu bituminous coal of high volatile matter, and various lithotypes from Yangquan and Shenfu coals. It shows that yields of the pyrolysis rise with the increase of pyrolytic temperature, rising especially rapidly from 673 to 773 K, resulting in a distinction between stages I and II of the pyrolysis. Afterward, they keep a mild increase at high temperatures above 1173 K. Kinetic parameters k 0 and E have been reached on the basis of mathematical calculation and numerical stimulation. The k 0 of the coals obtained in higher temperature varies between 4.86 x 10 4 and 15.16 × 10 4 s -1 , and E lies between 9.03 x 10 3 and 22.85 x 10 3 J mol -1 . Chars have been obtained at each of the pyrolytic temperatures. The morphology of chars was studied with a petrographic microscope. Furthermore, the specific surface area and pore volume of chars from various coals and lithotypes pyrolyzed at 1323 K were measured with an Auto-scan 33 Quantochrome.