Abstract: Intrinsic data of N₂O catalytic decomposition over a K-promoted Co-Mn-Al mixed oxide prepared by the thermal treatment of a layered double hydroxide was used for the design of a pilot reactor for the abatement of N₂O emissions from the off-gases in HNO₃ production. A pseudo-homogeneous one-dimensional model of an ideal plug flow reactor under an isothermal regime (450 °C) was used for reactor design. A catalyst particle diameter of 3 mm is a compromise size because increasing the size of the catalyst particle leads to a decrease in the reaction rate because of an internal diffusion limitation, and particles with a smaller diameter cause a large pressure drop. A catalyst bed of 11.5 m³ was estimated for the target N₂O conversion of 90% upon the treatment of 30000 m³/h of exhaust gas (0.1 mol% N₂O, 0.005 mol% NO, 0.9 mol% H₂O, 5 mol% O₂) at 450 °C and 130 kPa.

Key words: nitrous oxide, catalytic decomposition, nitric acid production, emission abatement