School of Chemical and Environmental Engineering,China University of Mining and Technology (Beijing),Beijing　 100083,China

利用分选、酸洗和添加矿物的方法制备出不同灰含量和矿物成分的褐煤煤样;使用沉降管反应器(DTR)和热重分析仪(TGA)研究内在矿物在800~1 200℃对褐煤热解的影响。结果表明,内在矿物可以降低褐煤的热解反应活性,增加低温(800℃)热解焦收率;碱金属和碱土金属(AAEM)是起主要作用的矿物成分。在高温条件下(≥1 000℃),内在矿物可通过催化原位水蒸气气化反应降低焦收率。焦收率的减少量正相关于煤样的灰分含量和内水含量,以及碱性金属总量。Raman光谱分析表明,内在矿物有延缓半焦微晶结构有序化和抑制交联键断裂的作用。内在矿物可促进半焦孔结构的形成,增大半焦的比表面积;钙为起主要作用的矿物成分。随热解温度的上升,过多的矿物会抑制半焦孔结构的进一步扩展。

In order to investigate the impact of inherent minerals on pyrolysis for lignite with high ash content,some py- rolysis experiments were conducted in Drop Tube Reactor and Thermogravimetric analyzer at 800 -1 200 ℃ . Lignite samples containing different ash and mineral compositions were prepared by separation,acid demineralization and min- eral addition. Results show that the inherent minerals could reduce the pyrolysis reactivity of lignite and increase the char yield at low temperature (800 ℃ );AAEM played a major role. While at high temperature (≥1 000 ℃ ),the in- herent minerals reduced the char yield by in-situ catalyzed steam-gasification. The reduction in char yield was directly related to the ash and internal water content of coal samples,as well as the total amount of basic metals. Raman analy- sis showed the inherent minerals can disorder the microcrystalline structure of char and inhibit the fracture of cross- linking bonds. The surface of char was increased by Ca as the main role of inherent mineral composition. With the py- rolysis temperature increasing,the excessive mineral will inhibit the further expansion of porosity for chars.

LI Changlun,WANG Yonggang,LIN Xiongchao,et al. Impact of inherent minerals on the yield and properties of char from pyrolysis of the lignite with high ash content[J]. Journal of China Coal Society,2017,42(8):2157-2163.