The use of blast
furnace gas (BFG) as a fuel provides an alternative
for waste stream valorization in the steel industry, enhancing the
sustainability and decarbonization of its processes. Nevertheless,
the implementation of this solution on an industrial scale requires
a continuous control of the combustion due to the low calorific value
of BFG. This work analyzes the combustion behavior and monitoring
of BFG/CH
4
blends in a laboratory premixed fuel burner.
We evaluate several stable combustion conditions by burning different
BFG/CH
4
mixtures at a constant power rate over a wide range
of air/fuel equivalence ratios. In addition, relevant image features
and chemiluminescence emission spectra have been extracted from flames,
using advanced optical devices. BFG combustion causes an increase
in CO
2
and CO emissions, since those fuels are the main
fuel components of the mixture. On the other hand, NO
x
emissions decreased because of the low temperature
of combustion of the BFG and its mixtures. Chemiluminescence shows
that, in the case of CH
4
combustion, peaks associated with
hydrocarbons are present, while during the substitution of CH
4
by BFG those peaks are attenuated. Image flame features extracted
from both ultraviolet and visible bandwidths show a correlation with
the fuel blend and air/fuel equivalence ratio. In the end, methodologies
developed in this work have been proven to be valuable alternatives
with a high potential for the monitoring and control of BFG cofiring
for the steel industry.