Hydrogen ignition energy

Hydrogen has a wider range of flammability limits and a lower ignition energy than other fuels. 

Relationship between minimum ignition energy and equivalence ratio for hydrogen-air and methane-air mixtures. 

Several of the combustion-related properties of hydrogen in air, such as its wide flammability limits (4-75 vol%), wide detonation range (20-65 vol%), very low spark ignition energy (0.02 mJ), high heat of combustion (121 kJ/g) and high flame temperature (2050°C) combine to emphasise the high fire-related hazards of the... 

The product of sorbing hydrogen on to hot zirconium powder bums with incandescence when heated in air [1,2], Ignition and combustion properties of pyrophoric zirconium and zirconium hydride powder (< 10 p), and safety measures are discussed [3], Ignition energies for zirconium hydrides, ZrUx x = 0 — 2, in air have been studied in Japan [4],... 

Hydrogen is produced or used in gas or liquid form in a number of processes. Hydrogen is a colorless, odorless gas that is easily ignited over a wide flammable range. Hydrogen burns very rapidly and cleanly in air with a nearly invisible clear blue flame. It has flammable limits of 4-74% in air and minimum ignition energy of 0.02 mj, compared to 0.25 mj for typical hydrocarbons. 

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