Structured Foil Catalysts: A Road Map to Highly Effective, Compact Systems Aftertreatment 2007-01-4038
While emission standards are becoming more stringent with every new legislation level, the engineering of compact aftertreatment system is becoming extremely challenging. This paper outlines a road map for cost-effective, compact aftertreatment systems through use of catalysts with standard and structured foil substrates. The longitudinal-structure (LS) foil disrupts laminar flow regimes within channels enhancing mass transfer and gas reconditioning.
The presented results were applied to DOC catalyst functionality including parameters such as cross-section, substrate type and substrate volume.
The catalysts were degreend and tested on a production 15ltr ISX Cummins engine calibrated for US 1998 emissions. Various load points were selected to determine catalyst performance as a function of exhaust gas temperature, exhaust flow rate (space velocity) and exhaust gas composition. A HC injector system was used to characterize oxidation performance at various concentration levels.
The presented results show the trade-off between converter efficiency in mass transfer limited catalyst function and back pressure. The LS-Metalit showed superior performance with high potential for down sizing based on a high volumetric efficiency.