CONTINUOUS PRODUCTION OF HYDROGEN FROM METHANE WITHOUT CARBON DIOXIDE PRODUCTION

对甲烷分解制氢不产生二氧化碳的生产工艺进行了研究。利用固定床反应器进行了一些开发催化剂的工作。在本研究中，为了连续生产氢气和碳素，对流态化系统进行了研究，制备了载体负载镍催化剂。反应温度为500~550℃。流态化床柱内径为12 mm。由于尺寸太小，不能确定工业上使用的流态化状态。然而，催化剂颗粒在反应器中发生了移动。采用硅胶、氧化铝和活性炭作催化剂载体，制得粒径约为60×10-6m的催化剂。二氧化硅负载催化剂的反应速率最高。单位重量镍的沉积碳随镍负载量的增加而增加。在固定床的情况下，120h后，催化剂上的积炭会堵塞反应器，而在沸腾床反应器中，没有观察到堵塞现象。为了保持良好的流态化质量作为反应器运行，考察了催化剂颗粒上积炭的流动性。30min后，破碎的二氧化硅载体的流动性下降。休止角随反应时间和碳沉积的增加而增大。破碎的二氧化硅支撑体的休止角的初始值很高。另一方面，球形氧化铝载体的价值较小，在反应9h内表现出良好的流动性。

The production technique in which hydrogen is produced from the methane decomposition without the production of carbon dioxide was studied. Some works using fixed bed reactor have been carried out to develop catalysts. In this study, in order to produce hydrogen and carbon continuously, the fluidized bed system was studied.Nickel catalyst supported on carriers were prepared. The reaction temperature was 500-550℃. The inner diameter of column used for a fluidized bed was 12 mm. Since the size was too small to establish the fluidizing state utilized industrially. However, the catalyst particle were moved in the reactor. The particle diameter was about 60 x 10-6 m.Silica, alumina and active charcoal were used as a catalyst supports. The highest reaction rate was obtained for silica supported catalyst. The deposition of carbon per unit weight of Ni increased with Ni loading. In the case of a fixed bed, the reactor was blocked by the deposited carbon on the catalyst after 120 h. However, the plugging was not observed for a fluidized bed reactor. This is one of the advantages of the fluidized bed utilization.Since to keep a good fluidization quality to operate as a reactor, the fluidity of the catalyst particles on which carbon deposited was investigated. The fluidity of crashed silica support decreased after 30 min. The angle of repose increase with reaction time and carbon deposition. The initial value of the angle of repose for the crashed silica support was high. On the other hand, the value of the spherical alumina support was small and the good fluidity was observed during 9 h reaction.