神府烟煤水煤浆快速热解焦结构演化及其反应性的研究

利用高频热解装置对神府烟煤水煤浆及其原煤进行了600~1 200 ℃条件下的快速热解实验,考察了两者快速热解后的煤焦产率、焦-C产率随热解温度的变化规律.利用XRD、氮气气体吸附法、SEM等测试手段对比分析了水煤浆及煤粉热解后煤焦的微晶结构、孔隙特征及表观结构;在热重分析仪上进行CO₂气化反应活性的测定,对比了水煤浆和煤粉热解后煤焦的气化活性.实验表明,随着热解温度的升高,水煤浆和煤粉的热解焦产率、焦-C产率均逐渐降低,热解温度低于900 ℃时,两者热解焦产率、焦-C产率趋于一致,热解温度高于900 ℃时,水煤浆热解焦产率和焦-C产率明显低于煤粉热解焦;高温热解条件下,水煤浆热解焦的微晶有序化程度比煤粉热解焦略高,比表面积明显高于煤粉热解焦,水煤浆热解焦的气化活性优于煤粉热解焦.

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.