Analysis of the Purity of Hydrogen at Public Hydrogen Refuelling Stations

Contaminations in hydrogen have a strong impact on the long-term stability and thereby performance of proton exchange membrane (PEM) based fuel cells for mobile applications. While these influences have been intensively studied, particularly the purity of the hydrogen provided at public hydrogen refuelling stations (HRS) which is well-defined in ISO standards is rarely analyzed. We intend to take samples of hydrogen at HRS with a specially designed mobile refuelling module enabling the sampling at 70 MPa. With a method specifically developed and explicitly described in this paper, we seek to ensure that other sources of contamination can be excluded during the probe sampling. With analysis techniques able to determine concentrations of contaminants down to the parts per billion (ppb) level the hydrogen samples will be investigated in the laboratory. While single routes of contamination, such as the synthesis route, have been individually studied in detail elsewhere, the provision of hydrogen with different storage processes, as well as transport and compression at the HRS will be considered in these investigations as a holistic system. Finally, it can be stated whether the dispensed hydrogen meets the high-quality requirements of fuel cells for mobile applications