生物质与煤混合热解特性的研究

采用热重分析法(TGA)对几种常见天然生物质(麦秆、棉秆和杨木屑)、两种不同变质程度的煤以及两者混合物的热解特性进行了研究。试验升温速度5℃/min,终温850℃。结果表明:生物质热解温度低,热解速度快,而煤相对热解速度慢,热解温度高,随煤变质程度提高,TG曲线向高温区移动,热解温度升高,最终失重率减小,试验无烟煤和烟煤的最终失重率分别为17%和30.07%。生物质与煤混合热解时,总体热解特性分阶段呈现生物质和煤的热解特征,但从实际微分曲线与按比例折算后的曲线比较结果看,400℃之前,生物质对煤的热解影响不明显,在400℃之后,生物质的加入对煤的热解产生抑制作用,煤的热解速率降低,煤的挥发分越低,抑制作用越强。

Study on the Co-pyrolysis of Biomass and Coal Blending

Thermo-gravimetric analysis (TGA) method has been used to investigate the pyrolysis characteristics of the natural biomass (including wheat stalks, cotton stalks and poplar scraps), different kinds of coals respectively and the blending of coal and biomass mixed in different proportions.The conditions were:heating rate 5℃/min; final temperature 850 ℃.The results showed that:the maximum pyrolysis rate was high and its corresponding temperature was low enough for the biomass, but the coal was quite the contrary.With the deepness of coalification, TG curve removed to a higher temperature, which meant that the pyrolysis temperature of coal was higher with a higher degree of coalification.In this experiment, the weight losses of anthracite and bituminite at the final temperature were 17% and 30.07% respectively.When the biomass and coal were mixed and pyrolyzed together, the general characteristics were basically the superposition of each component, and agreed with the individual pyrolysis characteristics of the biomass or the coal at different periods.However, the comparison of the differential thermo-gravimetric curves (DTG) with the calculated curves for the co-pyrolysis of biomass samples and coal in different proportions revealing that the biomass had no obvious influence on the pyrolysis of coal before 400℃ , nevertheless, after 400℃ , the addition of biomass had an inhibition on the pyrolysis of coal, the pyrolysis rate of coal decreased, the lower of the coal's volatile, the stronger of the inhibition affection.