This paper describes the hazards connected with the reforming of natural gas at public refueling stations, identification of necessary measures to stop or mitigate the events and the safety functions required for such a system. This work was part of the EC Fifth Framework project Hydrofueler, in which a small-scale compact hydrogen reformer unit was developed. The reformer was based on novel compact plated reactor technology.

A HAZOP has been performed to identify hazardous events, possible causes and possible preventive actions for the process sections. A service station is a public domain and the risk must be acceptable to the public. Major hazards for this type of system are fire and explosion due to the existence of flammable gases. In order to avoid these hazards it is essential to use equipment that can maintain its integrity under all conditions. Using suitable materials and seals, protection against overpressure and high temperatures as well as the inclusion of shutdown systems increases the safety.

Safety functions must be defined to ensure the required functional safety for each determined hazardous event. Safety functions required for this type of system is developed in the project and the target safety integrity is based on a quantitative method described in the generic standard IEC 61508. This standard is the basis for the development of new safety instrumented systems in the Norwegian petroleum industry, where natural gas is the feedstock. This standard has therefore been considered relevant for hydrogen production systems. Recommendations based on IEC 61508 are given.