Oil Consumption Pathway Impact on SCR-on-Filter Functional Performance and Lubricant Derived Ash Characteristics 2021-01-0578
SCR-on-filter, or SCRoF, is an emerging technology for different market segments and vehicle applications. The technology enables simultaneous particulate matter trapping and NOX reduction, and provides thermal management and aftertreatment packaging benefits. However, there is little information detailing the lubricant derived exposure effects on functional SCR performance. A study was conducted to evaluate the impact of various oil consumption pathways on a light duty DOC and SCRoF aftertreatment system. This aftertreatment system was aged utilizing an engine test bench modified to enable increased oil consumption rates via three unique oil consumption pathways. The components were characterized for functional SCR performance, ash morphology, and ash deposition characteristics. This included utilizing techniques, such as SEM / EDS, to evaluate the ash structures and quantify the ash elemental composition. Imaging techniques were also leveraged to provide ash deposition insights via non-destructive analysis.
Results from this study revealed that deterioration impacts from multiple oil ingestion locations are associated with the reduced high temperature NOX conversion performance. Specifically, the NOX conversion behavior was consistent with phosphorous poisoning on the DOC and SCRoF. The data also highlighted the differences in ash morphology relative to the oil ingestion pathway where higher temperature exposure caused ash sintering and resulted in differences in ash deposition.