In the present work, an industrial-scale experiment on ventilation air methane (VAM) utilization by a multibed thermal flow-reversal reactor (TFRR) is conducted in China. The influence of the inlet flow rate, feed methane concentration, and cycle time on the temperature distribution of the bed and heat recovery efficiency are investigated. The methane conversion in the studied cases exceeds 97%. The results show that the methane concentration during self-maintained operation of the TFRR without heat recovery should not be less than 0.22 vol % when the inlet flow rate is 103,000 Nm 3 /h and the cycle time is 300 s. As the inlet flow rate decreases, the lower concentration limit of automatic thermal maintenance increases. The peak temperature of the bed approaches the inlet side as the feed methane concentration increases and the cycle time decreases. The heat recovery efficiency increases linearly with increasing inlet flow rate, rises parabolically with an increasing feed methane concentration, and decreases weakly with increasing cycle time.

In the process of building a new power system with new energy sources as the mainstay, wind power and photovoltaic energy enter the multiplication stage with randomness and uncertainty, and the foundation and support role of large-scale long-time energy storage is highlighted. Considering the advantages of hydrogen energy storage in large-scale, cross-seasonal and cross-regional aspects, the necessity, feasibility and economy of hydrogen energy participation in long-time energy storage under the new power system are discussed. Firstly, power supply and demand production simulations were carried out based on the characteristics of new energy generation in China. When the penetration of new energy sources in the new power system reaches 45%, long-term energy storage becomes an essential regulation tool. Secondly, by comparing the storage duration, storage scale and application scenarios of various energy storage technologies, it was determined that hydrogen storage is the most preferable choice to participate in large-scale and long-term energy storage. Three long-time hydrogen storage methods are screened out from numerous hydrogen storage technologies, including salt-cavern hydrogen storage, natural gas blending and solid-state hydrogen storage. Finally, by analyzing the development status and economy of the above three types of hydrogen storage technologies, and based on the geographical characteristics and resource endowment of China, it is pointed out that China will form a hydrogen storage system of “solid state hydrogen storage above ground and salt cavern storage underground” in the future.

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Cu/Al2O3 modified by Mn and Ce catalysts for the catalytic combustion of low-concentration methane was studied by catalytic activity experiment and characterization. The results indicate that Mn improves the low-temperature (450–600 °C) catalytic activity. Compared with 10Cu/Al2O3, CH4 conversion of 3Mn–10Cu/Al2O3 is increased by 7% at 550 °C. This is because the interaction between Cu–Mn promotes the formation of CuMn2O4 and the dispersion of Cu, and increases the proportion of surface oxygen. Ce improves the high-temperature (600–700 °C) catalytic activity. Compared with 10Cu/Al2O3, CH4 conversion of 5Ce–10Cu/Al2O3 is increased by 8% at 700 °C. It is because Ce reduces Cu2+ to Cu+ with higher catalytic activity and inhibits CuAl2O4 production by Cu-support interaction. Cu–Mn–Ce three-component catalysts have the best catalytic activity. CH4 conversion of 3Mn–5Ce–10Cu/Al2O3 is increased by 11% at 600 °C. The synergy between Mn–Ce increases the proportion of surface oxygen and promotes the formation of the MnCeO x solid solution.