采用Ni-Mg-O复合氧化物催化剂进行了流化床甲烷催化裂解法制碳纳米管的中试实验，研究了主要操作变量对甲烷转化率、催化剂产碳率、产品团聚率及催化剂损失率的影响，得到了适宜的操作条件为：甲烷进气流速16~19 cm/s、催化剂粒径150~220 μm、催化剂加入量50~60 g、反应温度650~700 ℃、反应时间120~140 min。多批次重复性实验表明，在选定的操作条件下，甲烷转化率约为30 %，催化剂产碳率约为10 gCNTs/gCAT。对纯化后的产品进行SEM及TEM形貌表征显示，制得的碳纳米管管径均匀，中空结构明显，碳纳米管的外径为10~30 nm，内径为2~5 nm。

The Ni-Mg-O compound oxide catalyst and pilot scale fluidized bed reactor were used to prepare carbon nanotubes by catalytic pyrolysis of methane.Effect of main operation variables were studied，which could change the conversion rate of methane，carbon product rate of catalyst，rate of reunited product and loss rate of catalyst. Appropriate conditions were determin ed as follows: inlet velocity of methane was 16~19 cm/s，particle size of catalyst was 150~220 μm，dosage of catalyst was 50~60 g， reaction temperature was 650~700 ℃ and reaction time was 120~140 min.Multiple batches of repeated experiments results show ed that the conversion rate of methane was about 30% and the carbon product rate of catalyst was about 10 gCNTs/g CAT under the selected conditions.SEM and TEM morphological characterization of the purified products showed that the prepared carbon nanotubes had uniform diameter and obvious hollow structure，with outer diameter of 10~30 nm and inner diameter of 2~5 nm.