Metal hydride-based hydrogen production and storage system for stationary applications powered by renewable sources. (September 2022)

• Record Type: Journal Article
• Authors: Rangel, C.M.; Fernandes, V.R.; Gano, A.J.
• Is Part Of: Renewable energy. Volume 197(2022)
• Page Start: 398
• Page End: 405
• Publication Date: 2022-09
• Subjects: Hydrogen -- Production and storage -- Metallic hydrides -- Renewable energies; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2022.07.103
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: In this work, a compact and low-cost electrochemical laboratory prototype for the storage and production of hydrogen, based on metallic hydrides, with high reversibility in the charge/discharge process is demonstrated, using electricity either from the grid or by direct coupling to renewable energies as power source. The reactor is a 316 L stainless steel vessel with a capacity up to 15 bar internal pressure. It includes working electrodes of alloy LaNi4 .3 Co0.4 Al0 .3 and counter-electrodes of Ni foam in an electrolyte solution of 35% KOH. The reactor uses unicellular/multicellular configurations, so that the overall capacity of the system can be extended by increasing the number of working electrodes, resulting in a highly modular system. Results show excellent linearity, reversibility, and stability under cycling at room temperature and pressure, demonstrated either when powered by the grid or by off-grid renewable energy. Furthermore, criteria were established for the quantification of the state of full charge and full discharge. The system was integrated with a custom electronic system, developed in-house for monitoring and control the reactor and to optimize the performance and energy efficiency of the hydrogen storage and discharge processes. Highlights: LaNi4.3 Co0.4 Al0.3 alloy in KOH showed high reversibility for storage/production of H2 . Full H2 discharge criteria is associated to a cell potential rise of more than 1 V. Full charge criteria coupled to presence of residual H2 in reactor, limited to 1–2% vol. Reactor integration with PV power supply is demonstrated. Linearity of the process allows scalability resulting in a highly modular system.