Gases – Properties and Combustion Requirements

 

SubstanceMolecular WeightRelative Density (Air = 1)Specific Volume (cu.ft./lb. at 32°F)G.C.V. (B.t.u./cu. ft.)
Air—112.39—
Oxygen (O₂)32.0001.10511.21—
Hydrogen (H₂)2.0160.0695178.2325
Nitrogen (N₂)28.0160.97212.75—
Carbon Monoxide (CO)28.010.96712.82322
Carbon Dioxide (CO₂)44.011.5298.10—
Methane (CH₄)16.040.55522.351013
Acetylene (C₂H₂)26.040.90613.681499
Ethylene (C₂H₄)28.050.97512.711614
Ethane (C₂H₆)30.071.04911.811792
Sulphur Dioxide (SO₂)64.062.2645.47—
Hydrogen Sulphide (H₂S)34.081.19110.41647
Carbon (C)12.01——14093 B.t.u./lb
Sulphur (S)32.06——3983 B.t.u./lb

Note: Air by weight consists of 76.8% Nitrogen and 23.2% Oxygen.

 

 

Combustion RequirementsCombustion Products with Theoretical Air Quantity
lb/lbmols/mollb/lbmols/mol
O₂AirO₂AirCO₂H₂ON₂SO₂CO₂H₂ON₂
———————————
7.9434.340.52.38—8.9426.41—1.01.88—
———————————
0.572.470.52.381.57—1.9—1.01.88—
3.9917.272.09.532.742.2513.28—1.02.07.53
3.0713.32.511.913.380.6910.22—2.01.09.41
3.4214.813.014.293.141.2911.39—2.02.011.29
3.7316.123.516.682.931.8012.39—2.03.013.18
———————————
1.416.101.57.15—0.534.691.88—1.05.65
2.6611.531.04.763.66—8.86—1.0—3.76
1.04.291.04.76——3.292.0—3.761.0

Note: Air by volume consists of 79.0% Nitrogen and 21.0% Oxygen.