Process and device for reducing nitrogen oxides by using urea in the exhaust systems of internal combustion engines equipped with catalytic converters, especially for motor vehicles
A hydrocarbon compound is used as a support material having a melting point between predetermined ambient temperature of≥30 degrees C and a normal operating temperature range of 70 degrees C to 110 degrees C in the combustion engine. The hydrocarbon compound in the waste gas apparatus (1) is burnt at a temperature of 150 degrees C to 850 degrees C without residue or oxidized on the catalyst. The urea contained in waste gas reacts with the water in the waste gas to form ammonia and aids nitrogen oxide(s) reduction on the catalyst. The process of reducing nitrogen oxide using ammonia in the waste gas apparatus which contains a catalyst, includes using a mixture (3) composed of a support material and urea powder to dose in the waste gas apparatus (1) upstream of the catalyst. An Independent claim is included for urea-dosing apparatus for use in the above process.
