APPARATUS FOR CLEANING INTERNAL COMBUSTION ENGINE EXHAUST GASES Russian patent published in 2015 - IPC F01N3/20 

FIELD: chemistry.

SUBSTANCE: cleaning apparatus includes a catalyst for producing NH₃, which is placed in the exhaust pipe of an internal combustion engine and produces NH₃; a catalyst for selective reduction of nitrogen oxides (hereinafter NO_x), which is placed in the exhaust pipe at the outlet side of the NH₃ producing catalyst and which selectively reduces NO_x; a reducing unit at the input, which removes sulphur contaminants from the NH₃ producing catalyst; a reducing unit at the output, which removes sulphur contaminants from the NO_x selective reduction catalyst after removing sulphur contaminants from the NH₃ producing catalyst using the reducing unit at the input. The reducing unit at the output removes sulphur contaminants by adding a certain amount of oxygen which enters the NO_x selective reduction catalyst over a certain period of time after sulphur contaminants are removed from the NH₃ producing catalyst by the reducing unit at the input. This amount of oxygen will be larger than the amount of oxygen entering the NO_x selective reduction catalyst at the end of a predefined period of time. A version of the apparatus for cleaning internal combustion engine exhaust gases is also described.

EFFECT: when there is another catalyst at the input side of the NO_x selective reduction catalyst, both catalyst are purified from sulphur contaminants accordingly.

8 cl, 8 dwg