A steam-generating combustion system includes an oxygen enriched gas provided
as
at least part of an oxidant stream. A combustion chamber receives and combusts
a fuel in the oxidant stream and generate steam. The combustion chamber generates
flue gas having a flue gas volume which is smaller than a volume of flue gas generated
by the combustion chamber when operated with air as the oxidant stream. A flue
gas pollutant control system receives the flue gas from the combustion chamber
and reduces at least one of particulate matter, SOx, NOx,
and mercury. The reduction in flue gas volume allows the implementation of much
smaller pollutant control equipment, since the size of the pollutant control units
is mainly based on the volume or mass flow rate of flue gas to be treated. Moreover,
the system including oxygen-enriched gas in the oxidant will lead to concentrated
levels of the pollutants in the flue gas. The high concentrations of pollutants
will enhance their absorption in the different pollutant control systems, improving
removal efficiency for all species.