Hydrogen as Fuel for ICEs: State of Art and Technological Challenges

Table 4

Hydrogen, CNG, gasoline, diesel, and ammonia fuel properties at 298K and 1 atm.

Property	Hydrogen	CNG	Gasoline	Diesel	Ammonia
Density (kg/m^3)	0.08	0.70–0.72	720–760	820–845	0.73
Flammability limits (volume % in air)	4–75	4.3–15	1.4–7.6	0.6–5.6	15–28
Flammability limits (ø)	0.1–7.1	0.4–1.6	0.7–4	—	—
Autoignition temperature in air (K)	858	723	550	527	914
Minimum ignition energy (mJ)	0.02	0.28	0.24	0.25	8
Flame velocity (m/s)	1.85	0.38	0.37–0.43	0.2–0.8	0.015
Adiabatic flame temperature (K)	2480	2214	2580	2600	2070
Quenching distance (mm)	0.64	2.1	∼2	∼2	—
Stoichiometric fuel/air mass ratio	0.029	0.069	0.068	0.068	0.165
Lower heating value (MJ/kg)	119.7	45.8	44.79	42.78	18.8