Process for desulfurizing a nitrogen oxide storage catalyst in a diesel engine comprises heating the catalyst above a determined lowest desulfurization temperature, and operating the engine in a lean-rich alternating method

摘要

Process for desulfurizing a nitrogen oxide storage catalyst arranged with a particle filter in the exhaust gas purification device of a diesel engine comprises heating the catalyst above a determined lowest desulfurization temperature; and operating the engine in a lean-rich alternating method. The heating is carried out up to a time when the sulfur charge of the catalyst has exceeded a lowest value and regeneration of the filter has started. The engine is operated in a lean-rich alternating method when prescribed desulfurizing releasing conditions determined by the engine are fulfilled. Preferred Features: The lean-rich alternating method is produced using alternating lean and rich phases for 3-20 seconds. Heating of the catalyst is carried out using a lean engine operation and with a subsequent post-injection of fuel into the combustion chamber of the engine following the main injection of fuel. After desulfurization, the particle filter is regenerated when the particle charge has exceeded a predetermined threshold value.