ITM Power, with its partners Mainova Aktiengesellschaft and NRM Netzdienste Rhein-Main GmbH, has injected hydrogen into the German gas distribution network from the Thüga Group’s power-to-gas demonstration plant. (Earlier post.) The ITM Power rapid response electrolyzer plant has been delivered and commissioned ahead of schedule and the compliance and permitting work has been completed to enable the incorporation of hydrogen via the compliant mixing plant.
The system worked as planned, so much so that we will go into trial operation in the very near future ahead of final commissioning at the start of 2014.—Michael Riechel, Member of the Board of Thüga AG
By the end of 2016, the partners will have gained experience of how the system works under real-world conditions. The project partners are badenova AG & Co. KG, Erdgas Mittelsachsen GmbH, Energieversorgung Mittelrhein GmbH, erdgas schwaben gmbh, ESWE Versorgungs AG, Gasversorgung Westerwald GmbH, Mainova Aktiengesellschaft, Stadtwerke Ansbach GmbH, Stadtwerke Bad Hersfeld GmbH, Thüga Energienetze GmbH, WEMAG AG, e-rp GmbH and Thüga AG, which acts as project coordinator.
The operational phase will be accompanied by scientific partners, whose involvement is being funded by the Hessian Ministry for the Environment, Energy, Agriculture and Consumer Protection.
The core of the system is an ITM Power proton exchange membrane (PEM) electrolyzer. A gas mixing plant ensures that the proportion of hydrogen in the natural gas stream does not exceed 2 vol%, the technically permissible maximum value when a natural gas filling station is situated in the local distribution network.
The electrolyzer supplies the hydrogen-methane mixture at the same pressure as the gas distribution network—3.5 bar—thus avoiding the need for a compressor and saving costs.
The plant is located on the premises of Mainova AG in Schielestraße in Frankfurt am Main. The project partners decided to deploy a PEM system, as this technology, in comparison with alkaline systems, uses water rather than a potassium hydroxide solution, and is therefore more environmentally friendly. In addition, the system can respond more quickly to changes in the electrical load.
A further advantage is the unit’s compact design (2.45m high, 6m long, 3.30m wide, weighing 10 tons). The power consumption of the electrolyzer is 315 kW. It produces about 60 cubic meters per hour of hydrogen and thus in one hour can feed 3,000 cubic meters of hydrogen-enriched natural gas into the network.
Following the first phase of this project, the partners will consider a second project, in which hydrogen will be generated and combined with carbon dioxide to form synthetic methane to be directly injected and stored in the natural gas grid.