The recovery of metals and the regeneration of electrolytes become increasingly important. Thus the objective of this project focuses on the implementation of an industrial scale energy saving clean process for the recovery of metals by a reduction of ions using hydrogen. The process should allow the re-use of the deposited metals as well as the recycling of the purified liquids. This demands a long term stable gas diffusion electrode and a close process performance.
Due to their large specific surface area, three-dimensional electrodes, in particular packed bed electrodes, are very useful for the reduction of metal ions at very low concentrations. To reduce metal ions in a dilute solution, it is planned to use an electrochemical reactor consisting of a hydrogen gas diffusion electrode (GDE) in direct contact with a packed bed electrode where two electrochemical processes occur simultaneously and spontaneously. This electrochemical cell consists of two different electrodes (a gas diffusionand a bed electrode give the name to the cell) is called a GB-cell (GBC). No external power supply is necessary to reduce ions (e.g. Cu2+, CrO4-, Fe3+) with hydrogen. Any reduction process which is thermodynamically possible can be carried out in this reactor.
Present gas diffusion electrodes, which have been developed for application in fuel cells are loaded with high active catalysts, which are very sensitive to organic and inorganic pollutants. A less active catalyst would be preferable since the required rate of hydrogen oxidation is relatively low and these catalysts are less sensitive to poisoning.
A pilot plan will be designed, constructed and operated under industrial conditions.
Expected achievements and exploitation
At present, there is no experience with industrial process liquids in a GBCprocess. The project should lead to a detailed understanding of the complex interaction of galvanic baths, pollutants and electrochemical techniques. The work should result in a verification of the industrial possibilities of the GBC-process and in particular the hydrogen gas diffusion electrode. The results will be of great interest to a large number of companies, especially small and medium sized enterprises.
The complete GBC-process will be installed at the galvanic firms which are partners in the project. Exploitation will further focus on the production and operation of gas diffusion electrodes (GDE) for industrial operation. The application of GDEs is not restricted to the GBC-process. Dissemination of the results will be assisted by technology transfer coordinators.
Funding SchemeCSC - Cost-sharing contracts
5466 AL Veghel
5674 TL Nuenen
5600 MB Eindhoven
5943 AD Lomm
183 07 Taeby
5943 AD Arcen En Velden