Complementary effects between NO oxidation of DPF and NO2 decomposition of SCR in light-duty diesel engine

Autor: Hyun Jo, Ocktaeck Lim, Youngmin Woo, Youngdug Pyo, Jinyoung Jang, Young Jae Lee, Ahyun Ko, Yongjin Jung
Rok vydání: 2019
Předmět:
Zdroj: Journal of Industrial and Engineering Chemistry. 80:160-170
ISSN: 1226-086X
DOI: 10.1016/j.jiec.2019.07.045
Popis: This study was conducted as part of the development process of the diesel oxidation catalyst, diesel particulate filter, and selective catalytic reduction systems of old diesel vehicles for particles and NOx reduction. While SCR plays the most important role in the reduction of NOx emissions, the contribution of the DOC and DPF cannot be ignored. The conversion, generation, and reduction of NO, NO2, and N2O emissions through DOC, DPF, and SCR were tracked for use as basic data for the development of the catalyst and control logic. The results of the experiment show that NO was converted to NO2 at over 300 °C by Pt catalytic oxidation reaction. The highest conversion rate appeared at 450 °C for DOC and at 350 °C for DPF. NO2 was converted to NO in the operating range of 150–300 °C by de-oxidation reaction. Under most operating conditions, NOx reduction efficiency in SCR was maximized when the NH3 to NOx ratio was 1, but the reduction efficiency was deteriorated by excessive NO2 conversion in DOC and DPF. In SCR, NO2 decomposition without NH3 could convert NO2 to NO, showing improved NO2 reduction efficiency under some operating conditions, where NO2 was excessively converted in DOC and DPF.
Databáze: OpenAIRE
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