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

Abstract

Nitrogen oxide (NO x ) and sulphur dioxide (SO 2 ) 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 NO x emissions mainly due to its efficiency, selectivity and economics. High removal efficiencies for both NO x and SO 2 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 N 2 , in the presence of NH 3 . 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 Al 2 O 3 , SiO 2 , CeO 2 -Al 2 O 3 , in the presence of SO 2 and identifies the appropriate conditions for the simultaneous removal of NO and SO 2 . 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 SO 2 . Furthermore, they can be easily regenerated with a gas mixture of 1 % NH 3 /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.