Biogas is a renewable and environmentally friendly
alternative fuels. Biogas is produced from the fermentation
process which consists of mostly CH4 (50-75%) and CO2 (up
to 50%) and a smaller amount of H2, N2, O2, and H2S, in
which it varies from source. There are several related studies
about the characteristics of biogas combustion and external
combustion. This research focus on effects of CO2 as the most
abundant inhibitors in biogas towards its effects on external
combustion process. This research was conducted by burning
a stoichiometric mixture of fuel (CH4 and CO2% range 0-
50%) and oxygen in the external test equipment premixed
methane combustion with a 5 mm nozzle diameter. The
results showed that the level of CO2 affects the formation of
flame angle and flame height. The increase in CO2 content
within the fuel mixture will decrease the flame height and
moreover, more CO2 content also creates larger flame angle.
