Method and apparatus for the desulphurisation of a NOx storage catalyst and the regeneration of a particulate filter

The process involves measuring the rate of saturation of a nitric oxide trap (22) and the rate of blockage of a particle filter (24). The trap and the filter are arranged in an exhaust line of an internal combustion engine. The desulphation of the trap and the regeneration of the particle filter are performed using rich and poor mixtures of exhaust gas, respectively if one of the rates attains the value. An independent claim is also included for a device for desulphation of a nitric oxide trap and regeneration of particle filter.