Global kinetic modeling of low-temperature NH3-SCR for NOx removal using Cu-BEA catalyst

Abstract

The increasing energy demand and the need to reduce emissions have propelled the use of bioenergy and biofuels. Although carbon emissions can be significantly reduced using biofuels, an increase in the emissions of Nitrogen oxides (NOx) is inevitable. To address this issue, selective catalytic reduction (SCR) using ammonia (NH3) has played a significant role in curbing NOx emissions from the combustion of conventional and biofuels. The combustion usually occurs at low temperature (<350 °C), and hence copper exchanged zeolites have been demonstrated to be an excellent candidate for NOx removal via NH3-SCR. Among the many zeolites, beta (BEA), SSZ-13, and Silicoaluminophosphate (SAPO-34) have shown good SCR activity. To simulate the SCR activity, global kinetic modeling is followed in the literature. In this paper, kinetic modeling is carried out for simulating NH3-SCR using copper-beta (Cu-BEA) catalyst. The model is validated with the experimental data available from the literature. The SCR performance is analyzed for the variations in the feed concentrations of NH3, nitrogen oxide (NO), and oxygen (O2). The model results show that the required ratio of NH3 to NO in the feed is one, and the oxygen concentration above 6% is desired in the feed for excellent SCR activity.