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...hydrogen has the highest energy to weight ratio of all fuels.
...hydrogen in an oxygen atmosphere can reach burning temperatures up to 3000°C (the highest reached burning temperature in air for methane is 2148°C and for propane 2385°C
The explosive regions for hydrogen and methane lie in the ranges 13% - 59% and 6.3% - 14% respectively. The explosive range for hydrogen is clearly much greater, whereas methane is already explosive at a much lower concentration. The diffusion coefficient for hydrogen at 0.61 cm3/s is 4 times as high as that for methane. Hydrogen therefore mixes in air considerably faster than methane or petrol vapor, which is advantageous in the open but represents a potential disadvantage in badly ventilated interiors. Since both hydrogen and natural gas are lighter than air they rise quickly. Propane and petrol vapor are in contrast heavier than air and remain on the ground, leading to a higher likelihood of explosion.
