Effect of metamorphic degree of bituminous coal on the pore and crystal structure of coal based porous carbon by flash Joule heating
WU Junchen;ZHANG Wenjun;ZHU Rongtao;LU Haozhi;SUN Yang;WANG Yajun
以不同变质程度的烟煤为原料,K2CO3为活化剂,采用焦耳热闪蒸法在不同电压下制备了多孔碳。通过场发射扫描电子显微镜(FESEM)、低温氮气吸附、拉曼光谱等表征手段考察了烟煤变质程度以及闪蒸电压对多孔碳的孔隙特征及晶体结构的影响。结果表明:焦耳热闪蒸方法产生的瞬间高温在有限空间内产生的压力效应和热膨胀效应是孔隙形成和扩展的驱动力;低变质程度的朔州煤在碱碳比3∶1,闪蒸电压80 V时,制备的多孔碳的比表面积为601.95 m2/g、总孔容为0.44 cm2/g,孔隙结构最发达;高变质程度的长治煤在碱碳比3∶1,闪蒸电压160 V时,制备的多孔碳的石墨化程度最高。
Porous carbon was prepared by bituminous coal with different metamorphism degree and used K2CO3 as activators by flash Joule heating under different voltage. The effects of metamorphism degree of the bituminous coal and flash voltage on pore characteristics and crystal structure of porous carbon were investigated and characterized by a series of methods such as field emission scanning electron microscopy (FESEM), low temperature nitrogen adsorption and Raman spectra. Results show that the pressure effect and thermal expansion effect caused by the instantaneous high temperature through the Joule heating in the limited space are the driving forces for the pore formation and expansion. When the alkali-carbon ratio is 3∶1 and the flash voltage is 80 V, the pore structure of the porous carbon prepared from low metamorphic Shuozhou coal is the most developed with the specific surface area is 601.95 m2/g and pore volume is 0.44 cm2/g. The graphitization degree of porous carbon prepared from Changzhi coal with high metamorphic degree is the highest when the alkali-carbon ratio is 3∶1 and the flash voltage is 160 V.
flash joule heating;metamorphic degree of bituminous coal;coal-based porous carbon;pore structure;crystal structure
0 引言
1 试验
1.1 试验材料
1.2 焦耳热闪蒸试验
1.3 样品表征分析
2 结果与讨论
2.1 焦耳热闪蒸装置
2.2 焦耳热闪蒸电压和温度的关系
2.3 烟煤焦耳热闪蒸多孔碳的孔隙结构
2.4 烟煤及其焦耳热闪蒸多孔碳的晶体结构
3 结论
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会