水素吸蔵合金は自身の1000倍の体積の水素を自身に取り込むことがてきます。 （一方，気体として水素を1/1000に圧縮するのは非常に難しいです。）現在この水素吸蔵合金を用いて水素ガス中の不純物を取り除きつつ水素を高密度で貯蔵する研究をしています。 この研究が実現すれば，一酸化炭素などの不純物を多く含む バイオマスや天然ガスから生成された水素を純化しながら貯められるカートリッジに応用できます。

Metal hydride can store hydrogen 1000 times as much as its volume. (Compressing hydrogen to 1000 atms is extremely difficult.) Our objective is storing and purifying hydrogen at the same time using metal hydride. Hydrogen derived from fossil fuel or biomass gas has a various kind of impurity which will damage fuel cells. If our idea comes true, a hydrogen cartridge which can store such hydrogen directly. That will provide improved efficiency and simplified system.

1. J. Shimogawa, S. Miao, N. Katayama, K. Dowaki, “Design and Temperature Analysis of a Metal Hydride Cartridge Using Exhaust Heat of a Fuel Cell for Electric-assisted Bicycles,” Journal of the Japan Institute of Energy, vol. 101, no. 8, pp. 152–161, Aug. 2022, doi: 10.3775/jie.101.152.
2. K. Dowaki, N. Katayama, T. Nagaishi, S. Kuroda, and M. Kameyama, “A System Analysis of Storage Alloy for Bio-H,” ,Journal of the Japan Institute of Energy,, vol. 96, no. 8, pp. 266–272, Aug. 2017.
3. S. Ashida, N. Katayama, K. Dowaki, and M. Kameyama, “Study on Metal Hydride Performance for Puri cation and Storage of Bio-H,” ,Journal of the Japan Institute of Energy,, vol. 96, no. 8, pp. 300–306, Aug. 2017.
4. S. Ashida, N. Katayama, K. Dowaki, and M. Kameyama, “Transient Impurity Concentration of Absorption and Desorption in Metal Hydride,” ,ECS Transactions,, vol. 83, no. 1, pp. 119–125, Feb. 2018.
5. N. Katayama, K. Dowaki, and M. Hayase, “Numerical Simulation of Hydrogen Absorption Process in Metal Hydride Cartridge for Mobile Devices,” ,ECS Transactions,, vol. 71, no. 1, pp. 173–177, Feb. 2016.
6. N. Katayama, K. Dowaki, and M. Hayase, “Purification of Hydrogen Containing Carbon Dioxide Using Metal Hydride,” presented at the ECS Transactions, 2015, vol. 65, no. 1, pp. 137–141.