HyStORM - Hydrogen Storage via Oxidation and Reduction of Metals

Low temperature fuel cells are technologically mature and numerous manufacturers are starting the mass production of fuel cell powered vehicles and stationary energy systems at the moment. One key factor for the success of this promising technology is the area-wide availability of affordable hydrogen at filling stations. Current hydrogen production is based on the centralized production of large quantities of hydrogen out of fossil fuels followed by truck transportation as compressed or liquefied hydrogen over long distances. Hydrogen compression and liquefaction are cost and energy intensive processes. Due to the low volume-based energy density of hydrogen its transportation by trucks also leads to a steep increase in traffic volume. Another big issue regarding the hydrogen infrastructure is the storage of large quantities of hydrogen. The storage of large amounts of liquid or compressed hydrogen requires very high investments in the existing infrastructure with unsolved problems regarding safety issues and gas losses in large scale storage devices. These described issues can be solved by the decentralized and demand-oriented production of hydrogen. As part of the scientific project HyStORM an innovative process to store hydrogen decentralized in a chemical storage system and to release compressed hydrogen will be developed. The storage charging is performed by reducing an iron oxide based contact mass with a synthesis gas. The synthesis gas is produced in a previous reforming process out of biofuels. The fully loaded storage media consists of elemental iron and can be easily stored without losses and safety issues. The discharge is performed by feeding water into the system. Water evaporates and oxidizes the iron by releasing pure hydrogen. The evaporation of water leads to a pressure build up in the system and the generated hydrogen is compressed without additional gas compressors. The project partners already showed the feasibility of the single process steps in preliminary tests, which are: (i) the reforming of liquid hydrocarbons, (ii) the storage charging with a synthesis gas and (iii) the release of compressed hydrogen at 25 bars. The aim of the project HyStORM is the development of an innovative hydrogen storage process which includes: • Conversion of renewable resources to a synthesis gas • The charging of the storage system with this synthesis gas • Discharging of the storage by producing pressurized pure hydrogen of up to 100 bars. In the final stage of the project the validation of the technology will be demonstrated in a small scale laboratory breadboard unit. The feasibility of the complete process will demonstrate the successful development and will enable an efficiency assessment of the process. The success of this project will be a substantial contribution to the development of an infrastructure for area-wide hydrogen supply.