Fremgangsmåde til formindskelse af indholdet af nitrogenoxider i gasser.

摘要

The method comprises passing an N2O- and NOx-containing gas over a sequence of two catalyst beds, adding reducing agents for NOx and for N2O between the catalyst beds in such an amount that not only NOx but also a predetermined proportion of N2O is reduced. The reaction conditions are set so that the N2O content of the gas is reduced by not more than 95%, based on the N2O content at the entrance of the first catalyst bed, by decomposition to nitrogen and oxygen in the first catalyst bed and that not only chemical reduction of NOx but also chemical reduction of N2O occurs in the second catalyst bed so that the N2O content of the gas is reduced by at least 50%, based on the N2O content at the entrance of the second catalyst bed.