CONTINUOUS PRODUCTION OF HYDROGEN FROM METHANE WITHOUT CARBON DIOXIDE PRODUCTION

研究了甲烷分解制氢而不产生二氧化碳的生产技术。已经进行了一些使用固定床反应器来开发催化剂的工作。本研究以流化床连续制氢和连续制碳为目的，制备了负载型镍催化剂。反应温度为500-550℃。用于流化床的柱的内径为12 mm，因为该尺寸太小而不能建立工业上使用的流化状态。然而，催化剂颗粒在反应器中移动。颗粒直径为约60 × 10-6 m。使用二氧化硅、氧化铝和活性炭作为催化剂载体。二氧化硅负载型催化剂的反应速率最高。单位重量Ni的碳沉积量随着Ni负载量的增加而增加。在固定床的情况下，反应器在120小时后被催化剂上的沉积碳堵塞。然而，对于流化床反应器没有观察到堵塞。这是流化床应用的优点之一。为了保持良好的流化质量以作为反应器操作，研究了其上沉积有碳的催化剂颗粒的流动性。反应30 min后，载体的流动性下降，休止角随反应时间的延长和积炭的增加而增大。破碎的二氧化硅载体的休止角的初始值高。另一方面，球形氧化铝载体的值小，并且在9 h的反应期间观察到良好的流动性。

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.