Pyrolysis property of pulverized coal in an entrained flow reactor during coal reburning

Rapid pyrolysis of several kinds of Chinese pulverized coals under the different conditions of coal reburning was systematically investigated in an entrained flow reactor (EFR). The morphological changes of chars formed from the devolatilized coal particles were analyzed. The mass loss of coal particles and the release fraction of some elements such as carbon, hydrogen, and nitrogen in devolatilized coal at high-temperature flue gas were studied. The influences of coal types, pyrolysis temperature, devolatilized atmosphere, and coal particle size on pyrolysis properties were analyzed. The experimental results indicate that increasing the initial volatile matters of pulverized coal and pyrolysis temperature and decreasing the size of the coal particles, results in (1) increasing the percentage of coal mass loss and release fraction of carbon, hydrogen, and nitrogen in coal, and (2) increasing the H/C ratios in char. The release fraction of hydrogen is noticeably larger than the percentage of coal mass loss and release fraction of C and N, which is basically the same as the percentage of coal mass loss.