The “Hydrogen Ready Appliances Assessment Report” published by the Northwest Energy Efficiency Alliance (NEEA) in February, 2023, is one of the most recent studies on this topic. Several key items from the report pertaining to this question include the following:
1. “There appears to be growing consensus that blends of up to 20% or perhaps even 30% are…
Such a compressor should NOT be used for hydrogen. There are many issues with converting a compressor to hydrogen service. First and most important, this must be approved by the manufacturer. Examples of concerns for a non-hydrogen compressor used for hydrogen service include (but are not limited to):
The water vapor cloud formed from venting cold hydrogen gas from a liquid hydrogen tank will vary in size depending upon atmospheric conditions including ambient temperature and humidity. There is not a direct relationship between the water vapor cloud and the flammable could of hydrogen, but it’s often used as a proxy.
Initially upon release, it is possible that H2 vapor from…
Yes, although not as common as high-pressure gas releases, high-velocity cold H2 gas has ignited during rupture disc and relief valve activation.
The purity required will be a function of the end use application. There are a variety of grades of hydrogen that can be purchased. The H2 purity will also vary based on source (GH2 or LH2) and production method. CGA G-5.3, Commodity Specification for Hydrogen, lists several typical purities of both liquid and gaseous hydrogen. Standard GH2 available from most suppliers is 99.95% hydrogen.…
A design condition for vent stacks is to always assume that the hydrogen will ignite. The stack musts be designed such that it can withstand those conditions as well as minimize radiation to surrounding personnel and exposures. Although hydrogen fires have comparatively low radiation compared to hydrocarbon fuels, the radiation from large releases from vent stacks can be quite high. Documents…
Even if a small experiment is being run inside a fume hood, the best practice is to use a dedicated vent line for hydrogen which vents hydrogen to a safe location outside. This is especially recommended for planned venting. This practice avoids situations where flammable mixtures could develop. Each system is unique and should be evaluated and approved for use independently…
Hydrogen flames can be nearly invisible in daylight, especially at low flowrates. The concentration of hydrogen does not have much effect on the color of the flame. Many hydrogen incidents or fires will have a bright orange hue, or even yellow flames. The color is primarily caused by contaminants that is either naturally in the air in certain environments, swept into the air during the release…
Cylinders used within a laboratory can be used safely by meeting the requirements prescribed in NFPA 2,
Hydrogen Technologies Code, and NFPA 45, Standard on Fire Protection for Laboratories Using Chemicals.
Special consideration should be given to both safe handling and storage of cylinders. Regarding lecture
size cylinders, their small size can make them susceptible to damage and…
We are the leaders in the building industries and factories. We're word wide. We never give up on the challenges.