Emission control system and method of internal combustion engine

摘要

An emission control system for an internal combustion engine (1) includes a filter that collects particulates contained in an exhaust gas, and carries an NOx absorbent (17) thereon, filter regenerating means (9) for regenerating the filter by removing the particulates accumulated on the filter, S-poisoning determining means (9) for determining whether the NOx absorbent is in a condition of S poisoning due to absorption of SOx contained in the exhaust gas, and S-poisoning recovery means (9) for recovering the NOx absorbent from S poisoning. In the emission control system, when the S-poisoning determining means determines that the NOx absorbent is in the condition of S poisoning, the filter regenerating means is activated to remove the particulates, and the S-poisoning recovery means is then activated to recover the NOx absorbent from S poisoning after removal of the particulates.