Patent ID: 7744839

Claim:
A method for reducing the content of N 2 O and NO x in gases, comprising: a) passing the N 2 O- and NO x -containing gas over two catalyst beds, wherein the first catalyst bed contains a catalyst for decomposing N 2 O into nitrogen and oxygen and the second catalyst bed contains a catalyst for chemically reacting N 2 O and NO x with a reducing agent; b) selecting temperature, pressure, and space velocity in said first catalyst bed so that the decrease of N 2 O content of the gas is not more than 95%, based on the N 2 O content of the gas at the entrance of said first catalyst bed, and c) adding a reducing agent for N 2 O and a reducing agent for NO x between the first and second catalyst beds in an amount sufficient to chemically remove all of the NO x and at least 50% of the N 2 O, based on the N 2 O content of the gas at the entrance of said second catalyst bed.