Exhaust gas depollution system and process

摘要

The invention is a depollution system and a depollution processor for eliminating pollutants from exhaust gas from spark-ignition internal combustion engines. A depollution system which processes exhaust gas from a spark-ignition internal-combustion engine in accordance with the invention comprises at least a first gas processing device including a three-way catalyst placed in an exhaust line, a second device in the exhaust line through which all the exhaust gas passes and are processed therein which eliminates alkynes in the exhaust gas which interfere with operation of the three-way catalyst in removing pollutants from the exhaust gas, the second device being placed upstream from the first device in relation to a direction of propagation of the gases in the exhaust line and which lowers a temperature at which the first device starts eliminating the pollutants by catalysis relative to a temperature at which the first device starts eliminating pollutants by catalysis when alkynes are present in the exhaust gas.