EXHAUST GAS PURIFICATION SYSTEM

摘要

Provided is an exhaust gas purification system which can suppress a decrease in engine torque during a desulfurization process applied to a NOx storage reduction catalyst. The exhaust gas purification system includes a NOx storage reduction catalyst (3) provided in an exhaust pipe (2) of an engine (E), and a desulfurization process control unit (8) that controls an amount of intake air introduced to the engine (E) to enrich the exhaust gas, and performs a desulfurization process to the NOx storage reduction catalyst (3). The desulfurization process control unit (8) is configured to gradually reduce an amount of intake air when the desulfurization process is commenced.