Experimental study of particle emission characteristics of a heavy-duty diesel engine and effects of after-treatment systems: Selective catalytic reduction, diesel particulate filter, and diesel particulate and NO_x reduction

Abstract

This investigation focused on the particle emission characteristics of a heavy-duty diesel engine and the effects of after-treatment systems such as diesel particulate filter and selective catalytic reduction. The test engine was operated on the worldwide harmonized transient cycle mode, which is a new transient cycle for Euro 6, and the conventional European transient cycle mode. Four combinations of after-treatment systems, engine-out, selective catalytic reduction, diesel particulate filter, and diesel particulate and nitrogen oxide reduction, were evaluated for the transient cycles, respectively. The whole test procedure, as part of the Korea particulate measurement programme and the inter laboratory correlation exercise for domestic heavy-duty diesel engines, complied with the recommended method of particulate measurement programme. The particles that were extracted through the golden particle measurement system the constant volume sampler tunnel consisted of solid particles like carbonaceous fraction, metal ash, etc. The particles emitted from the tail-pipe, as analyzed by the differential mobility spectrometer, included volatile or soluble particles like sulphate fraction, nitrate fraction, and organic fraction. The test results showed that the particle number and size distribution depended on the catalytic activity or filtration efficiency of the after-treatment system. Compared to the accumulation mode, the nucleation mode was easily caught or oxidized by the after-treatment system. Additionally, the nucleation mode was sharply increased by excessive ammonia injection because nitrogen dioxide-assisted diesel particulate filter regeneration resulted in reduced conversion efficiency of the selective catalytic reduction.

Role of Alternative Fuels on Particulate Matter (PM) Characteristics and Influence of the Diesel Oxidation Catalyst

“…There are some exhaust conditions where catalytic reactions can be promoted and inhibited and are dependent on the presence and quantity of different species in the engine exhaust. DOC with high suitable loadings of a catalytic material, such as platinum and high cell density, could also physically trap and oxidize the volatile component of PM. ,, Furthermore, the majority of those studies are performed only for conventional diesel fuel − and the issues associated with particulate matter oxidation/reduction in DOC have not been addressed in depth. Therefore, the main objective of this study is to understand the combined effect of the fuel and DOC on the size, morphology, and microstructure of the soot agglomerates.…”

Evaluation of the time-resolved nanoparticle emissions and the vehicle performance characteristics for a turbocharged gasoline direct-injection vehicle with a metal-foam gasoline particulate filter

“…Moreover, the normal operating conditions of a GDI vehicle under a high exhaust gas temperature with a frequent fuel cut-off stage could supply sufficient oxygen for passive soot regeneration at pore sites in the GPF. 28,30,31,36,39–42…”

Experimental and kinetic modeling study for N2O formation of NH3-SCR over commercial Cu-zeolite catalyst

“…Selective catalytic reduction (SCR) of NOx by NH 3 is currently the most effective technology used for reducing NOx through selective reactions on the catalytic surface between NOx and adsorbed NH 3 . [1][2][3][4][5] The SCR of NOx with NH 3 has been studied extensively on various catalysts. [6][7][8][9][10][11][12][13] Ciardelli et al 6 studied the reactivity of NH 3 -SCR over a commercial V 2 O 5 -WO 3 /TiO 2 catalyst in a wide range of conditions and identified the reaction network at the different operating conditions.…”