One pertinent reference is a Sandia National Laboratories paper by Schefer et al: Spatial and radiative properties of an open-flame hydrogen plume, Intl J. Hydrogen Energy, 31 (2006): 1332-1340. Information on this and other similar papers are available at https://h2tools.org/bibliography. Further information can probably be obtained from the author of this paper and other papers reporting…

There are many manufacturers of multiple  types of flame detectors and it’s best to seek their input for the advantages of different types for specific applications. Regarding flame detector technology, UV detectors have been prone to false alarms from outside sources such as sunlight, lightning, and welding/cutting torches. The newer triple-IR detectors that are specifically designed and…

The answer will depend on if it is only H2 measured or if VOCs are also included. The type of gas sensor may change since many detectors are limited to flammable gases. To provide feedback, the Panel would require more details on the sensors being used on the project and the failure modes. There are concerns about allowing hydrogen concentrations as large as 3.5% for the high level alarm.…

Liquid hydrogen is much less likely to pool than liquified natural gas (LNG) due to its low heat of vaporization. Very large facilities are often equipped with methods to enhance vaporization, such as crushed stone under tanks, as well as diversion systems to allow liquid hydrogen to spill and boil off in a safe area. Care needs to be taken that diversion systems do not create a hazardous…

By definition, liquid hydrogen can BLEVE, but this is highly unlikely. Liquid hydrogen is stored in a double wall tank with vacuum insulation. This protects the primary pressure vessel from direct impingement and the very cold liquid provides self-cooling of the vessel walls. Tanks are also equipped with redundant pressure relief systems that are sized for fire exposure.

Underground storage tanks can be either installed in a vault or directly buried. Both offer additional
protection from external impact and fire, but each has unique challenges. Vaults must be properly
ventilated and designed to not create an explosion or asphyxiation risk. Direct burial vessels should not
have any underground leak points and must be protected from corrosion. Both…

This can be a complex problem and response to insulation failure should be considered in the emergency response guidelines and procedures. 
First, a tank with an insulation failure may boil off at an elevated rate which applicable codes build into the relief device and vent system design.
Second, ice and oxygen enriched liquefied air can form where inadequately insulated surfaces…

This production rate of hydrogen of about 96 kg/h is quite significant, which depending upon the application might require a significant amount of storage. There will be a need to determine how many kg the project wants to store from this production rate in order to determine how much hydrogen ground storage is needed. Since the project is in Europe, look for pressure vessel manufacturers that…

Hydrogen cylinders contain pure hydrogen unless they are specifically manufactured for and marked as a mixture. The purity grade is usually between 99.5% and 99.9999%. The balance is typically inert gases (such as nitrogen) with just ppm levels of other contaminants, but this can vary depending upon the production source. When emptied, the residual is still the same purity of hydrogen, just at…

It is possible to store large quantities of gaseous hydrogen above ground, but it will likely require a large footprint due to its relatively low density even at high pressure. Also, if the quantity equals or exceeds 10,000 lb., the facility will need to comply with OSHA 1910.119 process safety management requirements if located in the US. Similar regulations exist in Europe and Asia that…