Patent ID: 8250856

Claim:
An exhaust purification device of an internal combustion engine arranging an NOX selective reducing catalyst in an engine exhaust passage and feeding aqueous urea into the NOX selective reducing catalyst, using an ammonia generated from the aqueous urea to selectively reduce NOX contained in an exhaust gas, wherein moisture recovery means for recovering recoverable moisture in a vehicle, a water tank for storing the recovered moisture, an aqueous urea generation tank for generating aqueous urea fed to the NOX selective reducing catalyst and a high concentration aqueous urea tank storing high concentration aqueous urea having a higher urea concentration than a urea concentration of the aqueous urea fed to the NOX selective reducing catalyst are provided, and a feed control of moisture from the water tank to the aqueous urea generation tank and a feed control of high concentration aqueous urea from the high concentration aqueous urea tank to the aqueous urea generation tank are performed when an ignition switch is switched from on to off to allow time for generating the aqueous urea having a predetermined homogeneous concentration, the high concentration aqueous urea being diluted with a recovered moisture to thereby generate the aqueous urea to be fed to the NOX selective reducing catalyst in the aqueous urea generation tank.