Patent attributes
A method for regenerating a NOx absorbing catalyst includes: detecting a NOx value by a NOx sensor and determining whether to perform a regeneration mode or not based on a comparison of the sensed value and a predetermined upper limit; performing a first regeneration mode for a predetermined time period; if it is determined that the regeneration mode needs to be performed, determining a time period T2 for performing a second regeneration mode and performing the second regeneration mode for the determined time period T2; determining whether to perform a poisoning recovery mode based on the determination of whether a performance of the NOx absorbing catalyst has been deteriorated using an amount of exhausted NOx sensed after the performing of the second regeneration mode; and performing the poisoning recovery mode if it is determined that the poisoning recovery mode needs to be performed.
