Challenges in hydrogen fuel sampling due to contaminant behaviour in different gas cylinders

Increasing deployment of fuel cell electric vehicles (FCEVs) has led to implementation of hydrogen quality regulations (ISO 14687:2019) to prevent FCEV loss of performance. Hydrogen refuelling stations operators must be able to send representative samples of hydrogen fuel for analysis. Stability of contaminants in sampling vessels needs to be known at ISO 14687:2019 thresholds. A 4-month stability study was carried out on mixtures of ISO 14687 contaminants at amount fractions close to the thresholds in two types of sampling cylinders (SPECTRA-SEAL® and SGS™ aluminium cylinders). SPECTRA-SEAL® cylinder allowed representative sampling of CO, CO2, CH4, C2H6, N2, Ar, He, Cl2CH2, H2O, O2, CH2O2 in hydrogen fuel for 2 months. SGS™ cylinder allowed representative sampling of CO, CO2, CH4, C2H6, N2, Ar, He, Cl2CH2, H2O, O2, H2S for 4 months. Further work is needed to allow representative sampling of ammonia and formaldehyde.