Theoretical Assessment of Rigs for Accelerated Ash Accumulation in Diesel Particulate Filters

Renewable fuels from different feedstocks can enable sustainable transport solutions with significant reduction in greenhouse gas emissions compared to conventional petroleum-derived fuels. Nevertheless, the use of biofuels in diesel engines will still require similar exhaust gas cleaning systems as for conventional diesel. Hence, the use of diesel particulate filters (DPF) will persist as a much needed part of the vehicle’s aftertreatment system. Combustion of renewable fuels can potentially yield soot and ash with different properties as well as larger amounts of ash compared to conventional fossil fuels. The faster ash build-up and altered ash deposition pattern lead to an increase in pressure drop over the DPF, increase the fuel consumption and call for premature DPF maintenance or replacement. Prolonging the maintenance interval of the DPF for heavy-duty trucks, having a demand for high up-time, is highly desirable. Understanding the mechanisms of ash formation and build-up in the DPF, especially for renewable fuels, is therefore of uttermost importance. Techniques using accelerated ash accumulation methods offer a way to cut down on the costly and time consuming field tests, as well as offering a robust method to perform tests under conditions relevant for real-driving. This paper presents a literature review regarding accelerated ash accumulation methods by summarizing these methods and giving an overview of the various rigs found in literature. Moreover, the paper outlines the strengths and weaknesses of the different methods. Furthermore, it offers a simplistic route to choose between the different techniques based on the particular research question to be addressed.