Efficiency optimization of polymer electrolyte electrolyzers through temperature and pressure variation

Due to the low natural availability of the iridium used as a catalyst, a significant improvement in the mass-specific performance of acidic polymer electrolyte membrane (PEM) electrolyzers is required. This goal can be achieved, among other things, by reducing the membrane thickness, as the ohmic losses of the cells and cell stacks are reduced. At the same time, PEM electrolysers are operated at increased gas pressure in order to reduce the energy required for downstream gas drying and compression. Due to the real behavior of the membrane, there is a safety-critical, temperature and pressure-dependent gas transfer between the half cells. With the help of overall system modeling, these aspects are brought together in order to determine energetically preferred operating strategies. The cross-scale model takes into account the electrochemical characteristics of the functional layer system, thermodynamic processes and the processing of the product gases outside the electrolyser. Development targets can be derived and focused from the data obtained.

Literature

Fabian Scheepers, Markus Stähler, Andrea Stähler, Edward Rauls, Martin Müller, Marcelo Carmo, Werner Lehnert
Improving the Efficiency of PEM Electrolyzers through Membrane-Specific Pressure Optimization, Energies 2020, 13, 612
https://dx.doi.org/10.3390/en13030612

Fabian Scheepers, Markus Stähler, Andrea Stähler, Edward Rauls, Martin Müller, Marcelo Carmo, Werner Lehnert
Temperature optimization for improving polymer electrolyte membrane-water electrolysis system efficiency, Applied Energy 283 (2021) 116270
https://dx.doi.org/10.1016/j.apenergy.2020.116270