Typical heating values of combustible gases at 77°F (25°C)

Compound Lower heating value
(H2O gas in products)
Higher heating value
(H2O liquid in products)
Btu/lbm fuel kJ/kg fuel Btu/lbm fuel kJ/kg fuel
Acetylene, C2H2 - - 21 500 50 000
Blast furnace gas - - 1 170 2 720
Blue water gas - - 6 550 15 200
n-Butane, C2H10 - - 21 320 49 590
iso-Butane, C2H10 - - 21 270 49 470
Carb. water gas - - 11 350 26 400
Coal gas - - 16 500 38 400
Coke-oven gas - - 17 000 39 540
Ethane, C2H6 20 420 47 480 22 300 51 880
Hexane, C6H14 19 390 45 100 20 930 48 680
Hydrogen, H2 51 570 119 950 60 960 141 790
Methane, CH4 21 500 50 010 23 860 55 500
Natural gas) (15.8% C2H6) - - 24 100 56 100
Octane, C8H18 19 260 44 790 20 750 48 250
Producer gas - - 2 470 5 750
Propane, C3H8 - - 21 670 50 400