SYSTEM FOR PURIFYING EXHAUST GASES FOR REDUCTION EMISSIONS OF HYDROCARBONS DURING COLD STARTING-UP OF INTERNAL COMBUSTION ENGINES

摘要

The present invention is characterized in that hydrocarbon adsorption apparatus contains a mixture of adsorbents of Y-zeolite being fee of aluminium with Si/Al ratio above 40 and ZSM5 zeolite with Si/Al ratio above 20, whereby the adsorbent mixture weight ratio of both the zeolites is in the range of 1:10 to 10:1, and catalysts arranged beyond that mixture comprise an oxidation catalyst with platinum and/or palladium and a three-way catalyst with platinum and/or palladium and/or rhodium, whereby the oxidation catalyst contains at least 3.5 g of platinum and/or palladium per one liter of the catalyst volume. Another modification is characterized in that the hydrocarbon adsorber contains a mixture of adsorbents of Y-zeolite being fee of aluminium with Si/Al ratio above 40 and ZSM5 zeolite with Si/Al ratio above 20, whereby the adsorbent mixture weight ratio of both the zeolites is in the range of 1:10 to 10:1 and the farther arranged three-way catalyst contains platinum and/or palladium