Presurized HT PEM

Pressurized high temperature proton exchange membrane fuel cells for H2/O2 operation

A fuel cell is a device that, unlike combustion engines, is capable of directly converting the chemical energy stored in fuels into electricity through an electrochemical reaction with an oxidant (typically air). Several fuel cell types exist, operating in different temperature ranges and with a variety of fuels, which enable them to meet society’s application demands. As part of the renewable energy chain it is possible to store excess electricity, e.g. from windmills, as hydrogen by conversion through an electrolysis process. In periods of high energy demand, fuel cells may apply this stored hydrogen as a pollution-free fuel, producing only water, heat and electricity are the only products. Oxygen from the electrolysis process is typically considered as a residual by-product and is emitted to the atmosphere.

In my project, an alternative scenario is considered. If storing the oxygen instead of releasing it to the atmosphere, it may be used with advantage in fuel cells to enrich the oxidant, consequently increasing fuel cell performance. Additional performance increase can be obtained by pressurizing both fuel and enriched oxidant. Alternatively, this gain may be used to maintain performance while lowering the amount of expensive platinum that is necessary to catalyze the electrochemical reaction. However, it is uncertain to which extend oxidant enrichment and pressurization will result in accelerated degradation of the fuel cell materials. 

My main project goals are to determine optimum operating conditions with respect to pressurization and oxygen concentration relative to the amount of platinum applied while developing individual fuel cell components to better meet expected accelerated material degradations and component price.

Graph-LSD

Polarization curve showing increased performance obtained by oxidant enrichment

The PhD project is part of the LSD Project funded by Energinet.dk

For further info about the project see DTU Orbit

Contact

Stine Søndergaard
Former PhD student
PRO
http://www.pro.energy.dtu.dk/research/former-phd-projects/presurized-htpem
21 NOVEMBER 2017