| 摘要 |
The invention relates to a method for desulfurising a catalyst system such as a NOx accumulating catalyst (12) and/or a particle absorbing catalyst (16), which is mounted downstream from an internal combustion engine (10) operated with a lean mixture. According to said method, the high temperatures required for desulfurization are obtained at least partially by means of regeneration of a particle filter (14) which is preferably mounted upstream from the catalysts (12, 16) in the exhaust gas pipe (20) in such a manner that a satisfactory thermal coupling is guaranteed. In order to reduce thermal losses, the particle filter (14) is preferably placed with the NOx accumulating catalyst (12) and/or the article absorbing catalyst (16) in a common housing (18). The optimum time for desulfurization is determined as follows: the sulphur loading of the NOx accumulating catalyst (12) and/or the particle absorbing catalyst (16) and/or the particle loading of the particle filter (14) are determined and compared to predetermined threshold values. When one of these threshold values is exceeded, regeneration of the particle filter (14) and hence desulfurization of the upstream mounted catalysts (12, 16) are triggered. The invention also relates to an exhaust gas scrubbing device for implementing the inventive method. The inventive method and device are particularly suited to direct injection internal combustion engines.
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