Structure changes and gasification reactivity of CWS char from Shenfu coal rapid pyrolysis

The rapid pyrolysis of the CWS and raw coal from Shenfu coalfield was carried out in a high-frequency furnace. The pyrolysis temperature ranged from 600 ℃ to 1 200 ℃ with an interval of 100 ℃. The effects of temperature on the yields of char and char-C were investigated. The structure of chars obtained were characterized by using XRD, N₂ gas adsorption method and SEM; and the CO₂ gasification reactivity of chars was examined using TGA (thermogravimetric analyzer). The results show that with the increasing of pyrolysis temperature, the yields of char and char-C for both CWS and raw coal decrease. When the pyrolysis temperature is lower than 900 ℃, the yields of char and char-C for CWS are nearly the same as that for raw coal, and when the pyrolysis temperature is higher than 900 ℃,the yields of char and char-C for CWS become much lower than those for raw coal. The degree of graphitization and the regularity of microcrystal structure of CWS chars are slightly higher than that of raw coal chars, and the specific surface area of CWS chars is also much higher than that of raw coal chars. The gasification reactivity of CWS chars is greater than that of raw coal chars.