The catalytic effect of plasma sprayed coatings for improved combustion of gaseous fuels

toxic pollutants from combustion processes, emphasising the effect
of catalysts to reduce such emissions. One of the most frequently
used methods for reducing pollutants is the non-selective reduction
of nitrogen oxides, which can be carried out in the presence of
catalysts. This method uses CO from carbon-containing fuel
combustion to reduce nitrogen oxides. However, this process is
much more efficient in the presence of catalysts. The processes of
catalytic CO combustion and NOx reduction were carried out in a
model chamber by burning natural gas. The results show the
catalytic effect of plasma sprayed ceramic coatings on the catalysts
and surfaces bounding the combustion spaces on the exhaust gas
parameters.
The measurements of the natural gas combustion process
parameters in the presence of the catalytic coatings showed that the
coating based on a mixture of cerium oxide (CeO2) had the greatest
reduction effect, and the coating based on the mixture of vanadium
oxide (V2O5) had a smaller impact on reducing carbon monoxide
amounting to approximately 60%, and a nitrogen oxides reduction
rate of 35%. In contrast, the CO reduction rate for the catalysts
without the coating was 3%, and the degree of NOx reduction was
approximately 6%. The obtained results confirm the desirability of
the catalyst coating application for CO combustion and NOx
reduction.
Catalytic coatings sprayed in multi-layer coating systems can be
applied not only on the surfaces of catalysts but also on the surfaces
of heating devices, and they may not only have a catalytic effect but
can also extend the service life and improve the heating efficiency,
which confirms the scope and purposefulness of using the plasma
sprayed coatings.