Large scale hydrogen production has been commercially practiced for decades.  Most large-scale hydrogen production facilities are based on the steam methane reforming (SMR) process to generate hydrogen. Historically, smaller plants have also been based on the SMR process and have been used in industrial applications as well. The small facilities typically are sited inside or adjacent to the hydrogen customer’s facility.  The only difference between plants is the size, not the operational method.

With the increased demand for hydrogen as a fuel for fuel cell electric vehicles (FCEVs), smaller hydrogen production facilities are becoming more common.  These facilities bring the source of hydrogen closer in proximity to fueling stations and other customers and can match the size of the facility with the fuel demand. While some of these production facilities are likely to be based on SMR technology, other technologies can also be utilized. As opposed to industrial sites for hydrogen production, these smaller plants and the loading facilities associated with them can be more visible and accessible to the public.  The end users of this hydrogen might have little or no experience in the chemical process industry. In addition, these facilities are more likely than large hydrogen plants to be operated unattended or partially attended (not around the clock).

As a result, the safety aspects associated with siting and operating small scale hydrogen plants are not currently addressed in existing publications for large HYCO (hydrogen, CO, and/or mixtures thereof) plants. CGA H-17, Guideline for Small Scale Hydrogen Production, addresses these issues.  CGA H-17 provides a single comprehensive set of safety and operating guidelines to address the multiple hazards associated with the operation of small-scale hydrogen production plants.

Some of the main issues that impact small scale hydrogen production facilities and the end users, to whom hydrogen may be new, are listed below:

• Mitigating process hazards from flammable, toxic, and high temperature gases, high voltage electricity, and hazardous process materials such as water treatment chemicals, catalysts, and adsorbents.
• Dealing with hazards from a bulk liquid hydrogen backup storage system, which may be large enough to require a plan to comply with OSHA Process Safety Management (PSM) and EPA Risk Management Program (RMP) regulations. For more details, see CGA H-5, Standard for Bulk Hydrogen Supply Systems, and CGA P-28, OSHA Process Safety Management and EPA Risk Management Plan Guidance Document for Bulk Liquid Hydrogen Supply Systems.
• Minimizing the impact of co-locating the production facility with a vehicle fueling station and dealing with public users of the fueling station, who may not understand the hazards of hydrogen or who may overestimate the hazards.
• Mitigating the safety concerns associated with a partially staffed (lone worker) or unstaffed production facility.