Measurement of the exhaust emissions from Otto-engines equipped with a three-way catalyst regarding the secondary emission of nitrous oxide

摘要

This paper presents measurements of vehicular nitrous oxide emission taken on a chassis dynamometer. The tested vehicles were equipped with a closed-loop three-way-catalyst. Tests were carried out in neutral gear and at constant velocities withdefined load of the dynamometer. The N{sub}2O-concentration was measured with a gas-chromatograph online in the hot moist exhaust gas. Measurements were taken in front of as well as behind the catalytic converter. The N{sub}2O-conccntration maxima infront of the catalytic converter reached approx. 5 ppm N{sub}2O, those behind the catalytic converter approx. 35 ppm N{sub}2O. The emitted amount of N{sub}2O was dependent on the air/fuel-ratio, on the catalyst inlet temperature and on mileage.