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

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.