Process for the desulfation of a nitrogen oxide storage catalytic converter

A method for desulfurizing a nitrogen oxide storage catalytic converter is proposed, which is arranged in the exhaust gas cleaning system of an internal combustion engine, in particular a diesel engine used in motor vehicles, together with a particle filter. The desulfation takes place by heating the nitrogen oxide storage catalytic converter above a predetermined desulfation minimum temperature and then performing a lean-rich alternating operation of the internal combustion engine. DOLLAR A According to the invention, the heating takes place at least at times when the sulfur loading of the nitrogen oxide storage catalytic converter has exceeded a minimum value Smin and regeneration of the particle filter has been started and a lean-rich alternating operation of the internal combustion engine is then carried out if predetermined, determined by the internal combustion engine operation , Desulphation release conditions are met. DOLLAR A Application in motor vehicles, especially passenger cars with a diesel engine or a direct-injection gasoline engine.