不同热解气氛煤焦结构及燃烧反应性  

Structure and combustion reactivity of coal char pyrolyzed in different atmospheres

作　　者：段伦博[1] 赵长遂[1] 李英杰[1] 屈成锐[1] 周骛[1] 陈晓平[1] 

机构地区：[1]东南大学能源与环境学院,南京210096

出　　处：《东南大学学报（自然科学版）》2009年第5期988-991,共4页Journal of Southeast University：Natural Science Edition

基　　金：国家重点基础研究发展计划(973计划)资助项目(2006CB705806);东南大学优秀博士学位论文基金资助项目

摘　　要：在水平管式炉上制得徐州烟煤在Ar,N2和CO2气氛下热解的煤焦,比较了其在元素组成、挥发分收率、化学组分、微观结构特性和孔分布特性方面的差异,并在热重分析仪上进行了燃烧试验,确定3种煤焦在O2+Ar,O2+N2和O2+CO2气氛下的燃烧动力学特性.结果表明:由于CO2对煤焦的气化作用,CO2气氛下煤热解较Ar或N2气氛下具有更高的挥发分收率;CO2气氛热解焦芳香族和烷基官能团含量均高于其他气氛热解焦,但羟基官能团含量比它们低;CO2气氛热解焦具有更丰富的2～4nm的小孔结构,比表面积是其他气氛热解焦的100倍左右,比孔容积约为其他气氛焦的1.5倍.燃烧的化学反应动力学分析表明,不同气氛下煤焦燃烧均为一级反应,CO2气氛热解焦具有最小的活化能和指前因子.The coal chars were made from Xuzhou bituminous coal pyrolyzd in Ar, N2 and CO2 atmospheres in a horizontal tube furnace. The elemental compositions, volatile yields, the chemical compositions, the morphologic features and pore distributions of the three kinds of char were measured and compared. The combustion experiments under O2 ＋ Ar, O2 ＋ N2 and O2 ＋ CO2 atmospheres were carried out with a thermogravimetry analyzer and their combustion kinetic parameters were determined. Results show that the volatile yield under CO2 atmosphere is greater than those under other atmospheres due to the gasification effect of CO2. Coal char under CO2 atmosphere contains more aromatic group and aliphatic group but less hydroxyl group than those under other atmospheres. The coal char under CO2 atmosphere has more small pores at around 2 to 4 nm. Its specific pore area is about 100 times and the specific pore volume is about 1.5 times of those in other atmospheres. The combustion kinetic parameters indicate that all the combustion reactions of coal chars under different atmospheres belong to the first order reactions, while coal char under CO2 atmosphere has the smallest activation energy and pre-exponential factor.

关 键 词：O2/CO2燃烧 热解 挥发分收率 表观特征 孔分布 燃烧动力学 

分 类 号：TQ038.1[化学工程]