Effect of porosity on hydrogenation kinetics of Mg-3Ni-2MnO_2 nanocomposite powder reaction bed  

作　　者：张文丛 史菲 

机构地区：[1]School of Materials Science and Engineering, Harbin In stitute of Technology (Weihai)

出　　处：《中国有色金属学会会刊：英文版》2009年第3期606-610,共5页Transactions of Nonferrous Metals Society of China

基　　金：Projects(2006126, 2006130 and 2008GG10007004) supported by the Science & Technology Plan of Shandong Province, China

摘　　要：Hydrided Mg-3Ni-2MnO2 composite powders were fabricated by reactive ball milling with hydrogen, and accumulative hydrogenation kinetics and temperature field of reaction bed with various porosities (0.37, 0.53 and 0.63) were measured. The results show that the accumulative hydrogenation kinetics of Mg-3Ni-2MnO2 powder reaction bed depends strongly on the effect of heat transfer, mass transfer and intrinsic reaction together. The reaction bed with the porosity of 0.53 exhibits the largest hydrogenation rate. During the hydrogenation process, the temperature of reaction bed rises quickly due to the fast release of heat, and the temperature difference between center and wall with 0.53 porosity can keep high even for a long time, which promotes fast heat transfer. The further analysis indicates that more emphases should be put on heat transfer rate rather than the only improvement of the effective thermal conductivity.Hydrided Mg-3Ni-2MnO2 composite powders were fabricated by reactive ball milling with hydrogen, and accumulative hydrogenation kinetics and temperature field of reaction bed with various porosities （0.37, 0.53 and 0.63） were measured. The results show that the accumulative hydrogenation kinetics of Mg-3Ni-2MnO2 powder reaction bed depends strongly on the effect of heat transfer, mass transfer and intrinsic reaction together. The reaction bed with the porosity of 0.53 exhibits the largest hydrogenation rate. During the hydrogenation process, the temperature of reaction bed rises quickly due to the fast release of heat, and the temperature difference between center and wall with 0.53 porosity can keep high even for a long time, which promotes fast heat transfer. The timber analysis indicates that more emphases should be put on heat transfer rate rather than the only improvement of the effective thermal conductivity.

关 键 词：反应动力学 加氢动力学 纳米复合粉体 反应床 孔隙率 镁 有效导热系数 快速传热 

分 类 号：TB383.1[一般工业技术—材料科学与工程]