Process for acquiring a charged state of a nitrogen oxides storage catalyst arranged in an exhaust gas channel of a lean-burn internal combustion engine comprises determining the nitrogen oxides

摘要

Process for acquiring a charged state of a NOx storage catalyst (22) arranged in an exhaust gas channel (18) of a lean-burn internal combustion engine (10) comprises determining the NOx removal depending on a concentration of reducing agent in the exhaust gas downstream of the storage catalyst or a parameter derived from the reducing agent concentration. Preferred Features: The NOx removal is determined depending on a cumulated reducing agent leakage which is detected using an oxygen-sensitive measuring device (26) arranged downstream of the storage catalyst. The reducing agent consists of unburned hydrocarbons, carbon monoxide and/or hydrogen.