天然气和二氧化碳转化制合成气的研究　Ⅴ．甲烷脱氢积炭反应特征  

Studies of Reforming Natural Gas with Carbon Dioxide to Produce Synthesis Gas V.Characteristics of Carbon Deposition for Methane Dehydrogenation

作　　者：史克英[1] 徐恒泳[1] 范业梅[1] 商永臣[1] 徐国林[1] 

机构地区：[1]哈尔滨师范大学化学系

出　　处：《分子催化》1996年第1期41-47,共7页Journal of Molecular Catalysis(China)

基　　金：国家自然科学基金;黑龙江省自然科学基金

摘　　要：采用ＴＧ、ＸＲＤ、ＳＥＭ、ＥＤＡＸ和脉冲色谱技术，研究了Ｎｉ／Ａｌ２Ｏ３和Ｎｉ／ＡＲＭ催化剂的甲烷脱氢积炭反应特征。结果指出，甲烷脱氢反应的积炭行为与催化剂上镍的分散状态有关。Ｎｉ－２催化剂上Ｎｉ的分散度小，晶粒大，甲烷脱氢形成的炭丝较长，主要以石墨型炭游离存在：而Ｎｉ／ＡＲＭ催化剂上Ｎｉ的分散度大，镍晶粒小，甲烷脱氢形成的炭丝较短，主要覆盖在催化剂活性中心表面。甲烷脱氢主要产生无定型炭和石墨型炭，其中无定型炭可以被ＣＯ２部分消除。在催化剂制备时，通过提高镍在催化剂表面的分散度，减小镍的晶粒大小，不仅可以提高催化剂的活性，而且可以提高ＣＯ２对积炭的消炭性能。The carbon deposition of methane dehydrogenation was studied on the Ni/Al2O3 catalysts by using pulse-chromatographic apparatus as well as TG,XRD,EDAX and SEM techniques.The results show that the behavior of carbon deposition for methane dehydrogenation on the Ni/Al2O3 catalysts is related to the Ni dispersion and the crystal size of the catalysts.Since Ni-2 catalyst has bigger Ni crystal size and lower Ni dispersion than Ni-1 and Ni/ARM catalysts,the carbon filaments formed on the Ni-2 catalyst are longer than those on Ni-1 and Ni/ARM catalysts for methane dehydrogenation.In addition the carbon filaments on Ni-2 catalyst are usually present in the form of free graphite,but the carbon deposited on Ni/ARM catalyst is principally covered on the surface active site of nickel.According to the results of experiments,it was shown that the carbon deposition of methane dehydrogenation reaction principally formed two types of amorphous carbon and graphite.The amorphous carbon could partially be eliminated by carbon dioxide, but the graphite could not be eliminated by carbon dioxide.It was found that increasing Ni dispersion and decreasing Ni crystal size would increase not only the catalytic activity but also the ability of carbon dioxide elimination.

关 键 词：天然气 二氧化碳 转化 甲烷 脱氢 合成气 

分 类 号：TE665.3[石油与天然气工程—油气加工工程]