Simultaneous removal of NO and SO2 from combustion fuel gases using supported copper oxide catalysts

Abstract

Nitrogen oxide (NOx) and sulphur dioxide (SO2) emissions produced by the combustion of fuel in
 stationary sources, such as power stations, industrial heaters or cogeneration plants, cause
 significant environmental problems. Selective catalytic reduction (SCR) is a well established
 process for the control of NOx emissions mainly due to its efficiency, selectivity and economics.
 High removal efficiencies for both NOx and SO2 can be achieved with the use of copper oxide
 catalysts, as they act as sorbents for the latter - forming copper sulfate - and catalyze the reduction
 of the former - to N2, in the presence of NH3. An added advantage is that these catalysts are
 relatively easy to be regenerated under reducing conditions.
 This study examines the deactivation and regeneration procedures of copper oxide
 catalysts/sorbents that are supported on Al2O3, SiO2, CeO2-Al2O3, in the presence of SO2 and
 identifies the appropriate conditions for the simultaneous removal of NO and SO2. The results
 obtained indicate that copper oxide supported on alumina, ceria-alumina and silica carriers, can be
 used as effective catalysts for the simultaneous removal of NO and SO2. Furthermore, they can be
 easily regenerated with a gas mixture of 1 % NH3/Ar at an optimum temperature of 673 K and they
 retain their initial activity. Thus, the use of regenerative fixed bed catalytic reactor appears as one
 of the most promising technologies however, further research focusing in new catalytic materials
 performance is necessary.