热解条件对煤焦孔结构和反应性的影响  

Effects of Pyrolysis Conditions on the Pore Structure and Reactivity of Chars

作　　者：温雨鑫[1] 徐祥[1] 肖云汉[2] 

机构地区：[1]中国科学院先进能源动力重点实验室(工程热物理研究所),北京市海淀区100190 [2]中国科学院能源动力研究中心,江苏省连云港市222069

出　　处：《中国电机工程学报》2013年第29期63-68,9,共6页Proceedings of the CSEE

基　　金：国家863高技术研究发展计划项目(2006AA05A103);国家自然科学基金项目(51006106);科技部国际合作项目(2010DFB705602);中国科学院知识创新工程重要方向性项目(KGCX2-YW-348)~~

摘　　要：使用加压热重分析仪、马弗炉和常压滴管炉装置对褐煤、次烟煤、烟煤进行制焦,应用压汞法、低温N2和常温CO2吸附法测定煤焦孔结构参数,并通过扫描电镜观察煤焦表面形貌,测定了煤焦的CHN元素含量,利用热重分析仪测定焦900℃下的CO2气化反应活性,研究了压力、升温速率、高温停留时间对孔结构和气化反应性的影响。研究表明,慢速升温下提高热解压力会降低孔表面积和气化反应性;提高升温速率,降低高温停留时间,则微孔表面积降低,中孔显著增加,大孔的分形维数降低,化学反应活性提高;煤焦反应活性主要与残余挥发分含量相关,其次受到大、中孔表面积影响,而与微孔无关。Lignite, sub-bituminous and bituminous coals were pyrolyzed in pressurised thermogravimetric analyser （PTGA）, muffle furnace （MF） and drop-tube furnace （DTF）. The effects of pyrolysis conditions on the char properties were studied. Mercury porosimetry and N2, CO2 adsorption were used to obtain pore structures of chars. The CO2 gasification reactivity was determined by PTGA at 1 173K. Chars were also analyzed with scanning electron microscope and a CHN elemental analyzer. The results indicate that low pyrolysis pressure, high heating rate and short residence time under high temperature substantially increase the mesoporosity and CO2 gasification reactivity, but reduce both microporosity and the macropore fractal dimension. The reactivity of char is mainly influenced by the residual volatile matter content, the second is macroporosity and mesoporosity, and has no relation to microporosity.

关 键 词：煤焦 热解 孔隙结构 气化反应活性 

分 类 号：TK224[动力工程及工程热物理—动力机械及工程]