The safety of the future hydrogen economy

Ignition and flame characteristics of cryogenic hydrogen releases

“…Cryogenic hydrogen dispersion can be affected by flashing, multi-phase flows, heat transfer, pool formation, ambient conditions (e.g., temperature, humidity, wind), ground effects, and obstacles/barriers. Extreme cold temperatures can also condense or even freeze ambient air during spills, which differentiates these releases from those of liquid natural gas and can result in unique hazards that likewise need to be understood [4][5]. A review of hydrogen system safety knowledge by Kotchourko et al [6] includes a detailed discussion of liquid hydrogen systems.…”

“…Based on the radiation heat flux measurements they created a safety distance guide which only corresponds to their hydrogen spillage rate. While these and several other large scale studies have looked at the pooling and vaporization of hydrogen [4][5][6][7][8], these experiments are sparsely instrumented with poor control of some boundary conditions. Accordingly, there is the risk that the use of improperly validated models to establish safety envelopes could be detrimental to the emergence of hydrogen as a transportation fuel.…”

Hydrogen production from hydrolysis of ammonia borane with limited water supply

“…Nevertheless, transportation, storage and supply of hydrogen still give rise to grave concerns, especially in safety, e.g. wide flammability range from 4 vol% to 75 vol% in air at 1 atm [6,7].…”

Experimental study on the characteristic stages of premixed hydrogen-air flame propagation in a horizontal rectangular closed duct

“…Serious ecological imbalance and environmental degradation resulting from excessive consumption of fossil fuel create an urgent need for long-term green energy resources and carriers [1,2]. Hydrogen has been getting more and more concern because of its zero carbon emission and low pollution character.…”

“…Besides, some other factors were also explored and scrutinized [1,29,30]. Generally speaking, the flame propagation in a tube depends on various parameters: initial pressure, equivalence ratio, chamber length, igniter geometry [17].…”