For use in fuel cell vehicles, hydrogen has to be free of any contaminants that could damage the fuel cell. Professor Andreas Schütze and his research team at Saarland University are collaborating with research partners—the Fraunhofer Institute for Solar Energy Systems ISE and Hydac Electronic GmbH—to develop a sensor system that can provide continuous in situ monitoring of hydrogen quality at hydrogen fueling stations.
The research team is developing an infrared measuring cell that will be installed inside the hydrogen filling station and that can measure reliably and accurately under extreme conditions. The very high pressures to which their sensors are exposed are in fact utilized by the team to further improve the sensitivity of their process.
The hydrogen fuel flows through a small tube in the cell.
We illuminate the gas passing through the tube with light from an infrared source and we collect the light passing out on the opposite side of the tube. If there has been a change in the chemical composition of the gas, the infrared spectrum will change accordingly. This allows us to detect the presence of unwanted additives or contaminants.—Professor Schütze
Members of the research team are currently conducting experiments and are assigning particular infrared absorption signals to the various contaminants. They are also determining which wavelengths of the infrared spectrum are most suitable for the measurements and are calibrating the system. These important preparatory stages need to be completed before this autumn, when the sensor system will be installed in a hydrogen refueling station for operational trials.
The research team from Saarbrücken will be at this year’s Hannover Messe starting 1 April, where they will showcase their high-pressure test rig at the Saarland Research and Innovation Stand (Hall 2, Stand B46).
One of the questions we’re studying at the moment is whether and how the intensity of the infrared spectrum we measure changes with pressure. The sensor system has to be able to reliably detect a range of contaminants at concentration levels significantly below what we find in oils.—Marco Schott, a doctoral student working on the hydrogen measuring cell
The project is being supported by the German Federal Ministry of Education and Research through a grant worth €2.5 million (US$2.8 million).