Regenerating nitrogen oxides storage catalyst in exhaust gas channel of lean-burn I.C. engine involves using extrapolated oxygen-dependent signal

摘要

Process for regenerating a NOx storage catalyst (18) in the exhaust gas channel (14) of a lean-burn I.C. engine comprises extrapolating an oxygen-dependent signal from an oxygen-sensitive measuring device (20) during NOx regeneration; determining a time point based on the extrapolated signal which does not exceed a prescribed signal threshold value; and determining the end of the regeneration, in which a time spread corresponding to an exhaust gas running time between the engine and the catalyst is subtracted from the theoretical time point. An Independent claim is also included for a device for regenerating a NOx storage catalyst arranged in the exhaust gas channel of a lean-burn I.C. engine. Preferred Features: The oxygen-dependent signal is extrapolated using actual operating parameters of the engine and/or exhaust gas purification device (12).