| 摘要 |
<p>The method involves introducing a reducing agent i.e. urea, into an exhaust pipe (2) of a combustion engine (1) when nitrous oxide concentration downstream from a catalytic reduction device (6) is lower than a limiting value, where the limiting value is equal to 5 parts per million or 2 parts per million or zero. The nitrous oxide concentration is measured by a sensor (12) placed downstream from the catalytic reduction device. An independent claim is also included for a system for reducing nitrogen oxide produced by a combustion engine.</p> |
