论文部分内容阅读
离子交换型Ca是准东煤中主要的原位催化介质,基于Ca的挥发特性、煤焦结构的变化以及Ca的赋存形态等特征,并结合煤焦反应性分布全面分析Ca的行为特征及对煤焦反应性的影响.结果表明:离子交换型Ca的挥发程度随热解温度的升高逐渐增强;热解后煤焦中Ca组分浓度随热解温度升高而逐渐增大,但煤焦反应性与其浓度并不存在完全对应关系,应同时考虑Ca分散性的影响;拉曼分析表明在600～700℃温度区间,Ca会改善煤焦结构特征而进一步提高煤焦反应性,而在800～1000℃较高热解温度下,Ca对煤焦结构只有轻微影响;Ca-Char化学分馏前后的反应性和Ca含量对比分析证明离子可交换型Ca经热解后主要转化为一种稳定且具有较强催化活性的赋存形式.实验结果将为后续催化气化研究提供参考.“,”Ion-exchangeable Ca species are considered as the main in-situ catalyst in Zhundong Coal. In this study, based on the behavior characteristics including the migration, the evolutions of char structure and the occurrence mode of Ca, the behavior of ion-exchangeable Ca species and its effects on the char reactivity were systematically studied, combining with the profiles of the char reactivity. The results indicated that the volatilization of ion-exchangeable Ca species gradually raised with the increase of temperature. The concentration of Ca species in char increased with increasing temperature, which was not corresponding to the char reactivity. The effects of Ca dispersion on the char reactivity should be taken into account. The Raman spectra of char showed Ca species would improve the structural characteristics of char at 600～700℃ temperature range, resulting in the further promotion of char reactivity. However, the char structure was affected slightly by Ca species at 800～1000℃ pyrolysis temperature range. Comparing the reactivity and Ca content between the Ca-Char and the resultant chars after chemical leaching proved that the ion-exchangeable Ca species were mainly transferred into one occurrence speciation that was stable and catalytic. The experimental results in this study would be helpful to provide important bases for the subsequent research of catalytic gasification.