Patent ID: 7918082

Claim:
A method for desulfation of a nitric oxide trap and regeneration of a particle filter arranged in an exhaust line for treatment of the exhaust gas of an internal-combustion engine, comprising: evaluating the saturation rate of the trap and the clogging rate of the filter, initiating regeneration of the particle filter as soon as the clogging rate of the filter reaches a threshold value, and carrying out desulfation of the trap by increasing the fuel/air ratio of the exhaust gas to a value higher than 1 and by an alternation of exhaust gas lean mixture and rich mixture periods during desulfation of the trap, and initiating regeneration of the particle filter as soon as the saturation rate of the trap reaches a threshold value by increasing the fuel/air ratio of the exhaust gas without it reaching a ratio of 1, then carrying out desulfation of the trap by increasing the fuel/air ratio of the exhaust gas to a value higher than 1 and regulating the temperature of the particle filter by an alternation of exhaust gas lean mixture and rich mixture periods during desulfation of the trap.