Method for processing combustion exhaust gas containing soot particles and NOx

摘要

The invention relates to a system and a method for processing exhaust gas of an internal combustion engine such as a diesel engine. The disclosed system and method can be particularly suitable to the diesel engine that usually operates in a lean burn condition without the occurrence of a periodic high-load condition in view of its combustion characteristics. According to the system and method, an exhaust composition containing soot particles and gaseous components are processed to remove the soot particles and to reduce the amount of NOx compounds. The soot particles are first filtered with a filter that passes gaseous components of the composition and collecting the soot particles. The collected soot particles are oxidized in the presence of a light-activated redox catalyst to turn to smaller molecules that can pass through the filter. The NOx compounds are temporarily adsorbed by an adsorber and reduced in the presence of a light-activated redox catalyst to turn to N₂.