Properties | Hydrogen | Comparison |
---|---|---|
Density (gaseous) | 0.089 kg/m3 (0°C, 1 bar) | 1/10 of natural gas |
Density (liquid) | 70.79 kg/m3 (–253°C, 1 bar) | 1/6 of natural gas |
Boiling point | –252.76°C (1 bar) | 90°C below LNG |
Energy per unit of mass (LHV) | 120.1 MJ/kg | 3x that of gasoline |
Energy density (ambient cond., LHV) | 0.01 MJ/L | 1/3 of natural gas |
Specific energy (liquefied, LHV) | 8.5 MJ/L | 1/3 of LNG |
Flame velocity | 346 cm/s | 8x methane |
Ignition range | 4–77% in air by volume | 6x wider than methane |
Autoignition temperature | 585°C | 220°C for gasoline |
Ignition energy | 0.02 MJ | 1/10 of methane |
Notes: cm/s = centimetre per second; kg/m3 = kilograms per cubic metre; LHV = lower heating value; MJ = megajoule; MJ/kg = megajoules per kilogram; MJ/L = megajoules per litre.
Source: The Future of Hydrogen: Seizing today’s opportunities, IEA, June 2019.