Fuel Gases - Wobbe Index

The Wobbe Index indicates the interchange ability of fuel gases and is the best indicator of the similarity between natural gas and a specific propane-air mixture.

Fuel Gas	Upper Wobbe Index (kcal/Nm3)	Lower Wobbe Index (kcal/Nm3)
Hydrogen	11,528	9,714
Methane	12,735	11,452
Ethane	16,298	14,931
Ethylene	15,253	14,344
Natural Gas	12,837	11,597
Propane	19,376	17,814
Propylene	18,413	17,180
n-Butane	22,066	20,336
Iso-Butane	21,980	20,247
Butylene-1	21,142	19,728
LPG	20,755	19,106
Acetylene	14,655	14,141
Carbon Monoxide	3,060	3,060

Since the Wobbe index relates heating characteristics of blended fuel gases it can be used to obtain constant heat flows from gases of varying compositions.
Note! The Wobbe Index does not relate flame temperatures, heat transfer coefficients or temperature gradients