Advanced analytical methods for the study of lubricant-derived ash and associated impacts on engine aftertreatment components 2019-01-2293
Catalytic and non-catalytic engine aftertreatment components, such as the diesel oxidation catalyst (DOC), selective catalytic reduction on filter (SCRF), the gasoline particulate filter (GPF) and the diesel particulate filter (DPF) are complex, multifunctional emissions control technologies that are robustly designed for extended use in harsh automotive exhaust environments. Over the useful component lifetime, lubricant-derived inorganic and incombustible ash accumulates in and/or on the surface of the aforementioned aftertreatment components, resulting in degraded performance and other potential problems. In order to better understand effects of ash in such components, a multiscale analytical approach is necessary, requiring a variety of experimental tools. This paper will briefly present a decade of analytical experience at the Sloan Automotive Laboratory at the Massachusetts Institute of Technology and at Kymanetics, Inc., specific to the fundamental understanding of the accumulation of lubricant-derived ash in engine aftertreatment components. Several key experimental tools and techniques will be reviewed including focused ion beam milling (SEM), in-situ X- ray diffraction (XRD), atomic force microscopy (AFM), ultra-high resolution X-ray computed tomography (CT), X-ray fluorescence (XRF), environmental scanning electron microscopy with backscattered electrons (ESEM-BSE), and ultra-small angle X-ray scattering (USAXS), among others.