Low Temperature Performance of Selective Catalytic Reduction of NO with NH 3 under a Concentrated CO 2 Atmosphere

Selective catalytic reduction of NO x with NH 3 (NH 3 -SCR) has been widely investigated to reduce NO x emissions from combustion processes, which cause environmental challenges. However, most of the current work on NO x reduction has focused on using feed gas without CO 2 or containing small amounts of CO 2 . In the future, oxy-fuel combustion will play an important role for power generation, and this process generates high concentrations of CO 2 in flue gas. Therefore, studies on the SCR process under concentrated CO 2 atmosphere conditions are important for future SCR deployment in oxy-fuel combustion processes. In this work, Mn- and Ce-based catalysts using activated carbon as support were used to investigate the effect of CO 2 on NO conversion. A N 2 atmosphere was used for comparison. Different process conditions such as temperature, SO 2 concentration, H 2 O content in the feed gas and space velocity were studied. Under Mn-Ce/AC conditions, the results suggested that Mn metal could reduce the inhibition effect of CO 2 on the NO conversion, while Ce metal increased the inhibition effect of CO 2 . High space velocity also resulted in a reduction of CO 2 inhibition on the NO conversion, although the overall performance of SCR was greatly reduced at high space velocity. Future investigations to design novel Mn-based catalysts are suggested to enhance the SCR performance under concentrated CO 2 atmosphere conditions.