Simultaneous catalytic reduction of N2O and NOx for tertiary N2O abatement technology: A field study in a nitric acid production plant

To investigate the feasibility of the simultaneous abatement of N2O and NOx in a single reactor, this field study was performed in a nitric acid production plant. An Fe/BEA powder catalyst prepared by Fe ion-exchange with steam-treated BEA zeolite was extruded in pellets and honeycombs. In the simultaneous reduction of N2O and NOx, the pellet- and honeycomb-type catalysts showed more than a 90% and 95% conversion of N2O and NOx, respectively, at a reaction temperature between 350 degrees C and 380 degrees C which is typical for the DeNO(x) process. The catalytic performance of the pellets and honeycombs was also stable during the reactor operation period. With higher N2O and NOx conversions of over 90%, NH3 concentration in exhaust gas streams can be reduced to satisfy domestic regulations for air pollutant emissions. Accordingly, it is suggested that the simultaneous reduction of N2O and NOx in a single reactor with the Fe/BEA catalyst may be a reasonable option for a tertiary abatement technology for nitric acid production plants. Novelty or Significance: The simultaneous catalytic reduction of N2O and NOx in a tail gas from a nitric acid production plant was investigated with Fe/BEA catalysts prepared by Fe ion-exchange with steam-treated BEA zeolite. Pellet-and honeycomb-type catalysts were applied to abatement using NH3 as the reducing agent. Over 90% of N2O and NOx from the nitric acid production process was simultaneously removed from a single reactor at a reaction temperature between 350 degrees C and 380 degrees C. (c) 2018 American Institute of Chemical Engineers Environ Prog, 38: 451-456, 2019