Methane pyrolysis is a hydrogen-producing method that does not emit carbon dioxide. Additionally, solid carbon is one of the products formed that can be stored or used as a valuable by-product to improve economic effect. In this study, the characteristics of production of hydrogen and carbon by methane pyrolysis were investigated to develop a hydrogen mass production system. Methane pyrolysis was performed in a medium-sized reactor with a capacity of approximately 40 L under conditions of high methane flow rate using permalloy plate catalysts, which were inexpensive and more practical than the supported catalysts. Notably, a maximum methane conversion of 90% was observed with the permalloy plate catalyst. Methane conversion increased with reactor temperature; however, the conversion rate decreased with an increase in flow rate. The morphological analysis results showed that the carbon was agglomerated when recovered at a furnace temperature of 760 °C and methane inflow rate of 0.2 Nm³/h, with a spherical and fibrous carbon mixture. The compositional analysis results demonstrated that the generated carbon retained the metallic components of the catalyst, which was considered to have been removed from the catalyst surface. In addition, the amount of hydrogen generated, and the efficiency of methane decomposition significantly increased with the furnace temperature. Furthermore, the present study confirmed the optimal temperature and flow conditions for efficient methane decomposition. We deduced that the thermal decomposition of methane, including the gas-phase reaction, was more efficient at relatively high temperatures (above 800 °C), while specific flow rates could generate hydrogen with high efficiency in some systems. Thus, the results of this study can also be used as an indicator to determine the optimal conditions of methane pyrolysis.

甲烷热解是一种不排放二氧化碳的制氢方法。此外，固体碳是形成的产物之一，可以储存或用作有价值的副产品以提高经济效益。在这项研究中，研究了甲烷热解制氢和碳的特性，以开发氢气大规模生产系统。甲烷热解是在一个容量约为 40 L 的中型反应器中在高甲烷流速条件下使用坡莫合金板状催化剂进行的，这种催化剂比负载型催化剂便宜且更实用。值得注意的是，使用坡莫合金板状催化剂观察到的最大甲烷转化率为 90%。甲烷转化率随反应器温度升高；然而，转化率随着流量的增加而降低。³/h，具有球形和纤维状碳混合物。组成分析结果表明，生成的碳保留了催化剂的金属成分，这被认为已从催化剂表面去除。此外，产生的氢气量和甲烷分解效率随着炉温的升高而显着增加。此外，本研究证实了高效甲烷分解的最佳温度和流动条件。我们推断甲烷的热分解，包括气相反应，在相对较高的温度（高于 800 °C）下更有效，而特定的流速可以在某些系统中高效地产生氢气。因此，