N_2/CO_2气氛下内在矿物对煤焦反应活性的影响  

Influence of Included Minerals on the Intrinsic Reactivity of Chars Prepared Under N_2 and CO_2 Atmosphere

作　　者：张洪[1] 赵博[1] 陈佳宝[1] 王平[1] 李亚男[1] 陆超[1] 

机构地区：[1]中国矿业大学化工学院,徐州221008

出　　处：《燃烧科学与技术》2012年第5期393-397,共5页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(50676103);国家科技支撑计划资助项目(2006BAF02A24)

摘　　要：为研究富氧条件下矿物对煤焦反应性的影响,选取3种变质程度不同的煤,用浮沉法将其分选为不含矿物的低密度煤粉和含内在矿物的中等密度煤粉,在N2/CO2气氛下的1,450,℃滴管炉(DTF)中制焦,然后用BET、TGA分析和XRD分析对煤焦孔结构、反应活性及其形成机理进行研究.结果发现,与N2气氛下制备的煤焦相比,CO2气氛下制备的3组煤焦的反应性均较高,但变化趋势有所不同.低密度煤焦反应活性随煤化程度的降低而升高,而中等密度煤焦的反应活性变化趋势则相反.机理研究表明,煤焦的反应活性是煤焦比表面积和碳结构的结晶度综合影响的结果,而二者又由CO2较高的热容量、热解过程中间液相与内在矿物相互作用所致.The influence of included minerals on the intrinsic reactivity of chars under oxy-fuel conditions was studied in this paper. Organic-rich particles and organic particles with included minerals were first separated from each of three coals of different rank. And then they were devolatilized at 1 450℃ in a drop tube furnace （DTF） under N2 and CO2 atmosphere, respectively. The chars were subjected to nitrogen adsorption study, thermogravimetric analysis and XRD analysis. It was found that the char reactivity of all three pairs of chars were increased under CO2 atmosphere as compared with that under N2 atmosphere, but with differing trends. For the organic-rich samples, the reactivity increases with the decreasing rank. On the contrary, for the samples of organic particles with included minerals, the reactivity decreases with the decreasing rank. Mechanism analysis shows that the reactivity of chars is not a result of gasification but a combined result of changes in surface area and orderness of carbon structure, both of which, in turn, result from the higher heat capacity of CO2 and the interaction between metastable liquid phase and included minerals.

关 键 词：富氧 矿物 反应活性 煤焦 

分 类 号：TK16[动力工程及工程热物理—热能工程]