Advanced Diesel Particulate Filter Technologies for Next Generation Exhaust Aftertreatment Systems

The regulative environment is poised for ultra-low emissions in the 2024+ time frame with ultra-low NOx proposals from CARB and PN PEMS testing requirements from EU. GHG emissions limits are getting tighter in the next few years along with extended full useful life (FUL) requirements. Diesel Particulate Filters (DPF) will be an integral part of all diesel exhaust aftertreatment systems for the next several years and will need advanced technology solutions to meet the challenges above, without compromising on high performance requirements, namely, low lifetime pressure drop, high filtration efficiency, high durability (extended FUL), increased service intervals or lifetime filter solutions (high ash storage capacity). This paper discusses the primary challenges associated with meeting these future demands and possible technological solutions to address them. Data from on-road vehicle testing and impact of duty cycle (vocational/line haul) on lifetime aftertreatment performance has been discussed. Key drivers for pressure drop reduction over product lifetime are illustrated and used to develop the next generation of diesel particulate filters. The complex relationship between DPF geometry and operation history (flow, temperature, soot emissions, regeneration frequency, etc.) on ash accumulation pattern has been explored for both real-world applications as well as accelerated bench studies. The improvement in performance of advanced, high ash storage designs versus current commercial products have been demonstrated. These results provide a promising pathway towards optimizing aftertreatment design while realizing future emissions requirements across global markets.