Appendix I

Some properties of hydrogen

 

•       Auto ignition temperature T_ig = 520°C (968°F)

•       Boiling point (1 atm) T_B = -252.7°C (-423.0°F)

•       Density r = 0.08342 kg/m3

•       Diffusivity k = 1.697 m2/hr

•       Flame temperature T = 2318°C (4202.4°F)

•       Flammable range 4-74% by vol in air

•       Freezing/melting point T_M = -259.2°C (-434.5°F)

•       Heat of combustion by mass DH = 28670 kcal/kg

•       Ignition energy 0.02 milli joules

•       Molecular weight M = 2.016

•       Specific gravity 0.0696 (air = 1)

•       Specific volume n = 11.99 m3/kg (191.98 scf/lb)

•       0.157 kcal/m hr K

•       Viscosity v = 33.84 x 10^-3 kg/m hr

•       Volumetric energy density r = 57.8 kcal/kg mole