Betriebsverfahren für eine Abgasnachbehandlungseinrichtung, welche einen Stickoxid-Speicherkatalysator und stromab einen SCR-Katalysator aufweist, sowie Verwendung des SCR-Katalysators zur Entfernung von Schwefelwasserstoff

摘要

Exhaust gas post treatment unit (2) comprises a nitrogen oxide storage catalyst (7) and an SCR catalyst (8). In a desulfurizing operating mode of the internal combustion (I.C.) engine with a reducing exhaust gas composition, the exhaust gas leaving the nitrogen oxide storage catalyst is introduced to the SCR catalyst for removing hydrogen sulfide formed during desulfurization. An Independent claim is also included for a process for operating an exhaust gas post treatment unit. Preferred Features: The SCR catalyst contains vanadium pentoxide, tungsten oxide and/or titanium dioxide. The exhaust gas post treatment unit additionally contains a particle filter (6) connected to an oxidation catalyst (5). The nitrogen oxide storage catalyst is arranged in the exhaust gas post treatment unit upstream of the oxidation catalyst and downstream of the particle filter.