Advanced Aftertreatment System Meeting Future HD CNVII Legislation II

<div class="section abstract"><div class="htmlview paragraph">With the increasing clarity of the CNVII emission legislation, it is foreseeable that CNVII will further tighten the emission limits of major pollutants such as Nitrogen Oxide (NO<sub>x</sub>), Nitrous Oxide (N<sub>2</sub>O) and Particulate Number (PN). Together with the implementation of stage IV fuel consumption legislation in July 2025, which requires engine fuel consumption reduction or thermal efficiency improvement, it will lead to further deterioration of its pollutant emissions and reduction of exhaust temperature, posing greater challenges to the After-Treatment System (ATS) in terms of NO<sub>x</sub> removal, particularly during engine cold start and N<sub>2</sub>O formation suppression.</div><div class="htmlview paragraph">This study is an extension of our earlier investigation [<span class="xref">1</span>], and a novel copper-based corrugated SCR (Full Body-CuSCR, FB-CuSCR) technology was successfully applied. The results based on a modified CNVI medium duty engine indicated excellent dynamic response of the FB-CuSCR technology over cordierite which helped to improve the performance of the ATS in various test conditions, particularly during engine cold start. A single dosing system based on the same engine and catalyst technology was also studied. It required more measures such as higher urea consumption to have similar NO<sub>x</sub> and other pollutant emissions but in the meantime provided a potential cost-effective solution for certain applications for CNVII legislation. Various factors affecting the performance of single dosing and twin dosing systems were also discussed in this study.</div></div>