不同升温速率下树皮体的热重特征变化

Thermogravimetric Characteristic Variation of Barkinite under Different Heating Rates

中国特有煤种——树皮煤,因具有高氢、高挥发分及高焦油产率等特点而备受关注,而其中富含的特殊显微组分——树皮体,其热性质一直未得到深入研究,直接影响树皮煤的合理利用。采用热重分析仪对不同升温速率下树皮体、镜质体及原煤(树皮煤)的热解失重特征进行了对比研究,并结合工业分析和元素分析结果,讨论了树皮体的化学性质。研究表明:随着升温速率的增加,树皮体、镜质体和树皮煤的TG和DTG曲线均不同程度的向右侧高温区移动,最大失重速率相应减小,升温速率对树皮体的DTG曲线变化影响较大。尽管使用的升温速率不同,而树皮体的DTG曲线峰形均具有窄而尖的特点,说明树皮体的受热变化比较剧烈。同时,树皮体的总失重量均大于镜质体和树皮煤。

The bark coal, a Chinese proper coal rank has been aroused general concern because of its high hydrogen, high volatile mat？ter contents and high tar yield characteristics. But the thermal properties of the rich special maceral—barkinite have not been studied further all the time, thus directly impacted the rational use of bark coal. Using thermogravimetric analyzer carried out comparative study of barkinite, vitrinite and raw coal （bark coal） pyrolytic weight loss characteristics under different heating rates, combined with proximate and ultimate analyses results discussed chemical properties of barkinite. The study has shown that along with the increasing of heating rate, the TG and DTG curves of barkinite, vitrinite and bark coal are all migrating to right side high temperature zone in vary？ing degrees;maximum weight loss rate decreasing correspondingly;heating rate has greater impact on barkinite DTG curves. Though under different heating rates, barkinite DTG curve peaks are all distinguished by narrow and acuminated shapes thus explained the rather acute barkinite heating variation. Moreover, the total weight loss of barkinite is greater than both vitrinite and bark coal.