Mechanical Engineering Commons^™

Experimental And Modeling Study Of Particulate Matter Oxidation Under Loading Conditions For A Scr Catalyst On A Diesel Particulate Filter, Abhishek Jadav

Dissertations, Master's Theses and Master's Reports

The heavy-duty diesel engines use a Diesel Oxidation Catalyst (DOC), a Catalyzed Particulate Filter (CPF), a Selective Catalytic Reduction (SCR) with urea injection and a Ammonia Oxidation Catalyst (AMOX), to meet the US EPA 2010/2013 particulate matter (PM) and NO_x emission standards. However, it is not possible to achieve the 2015 California low NO_x standards with this arrangement. Hence, there is a need to improve the existing aftertreatment system. This can be achieved by coating the SCR catalyst on a diesel particulate filter (DPF), thus combining the PM filtration and NO_x reduction functionality into a single device. …

The Emission And Particulate Matter Oxidation Performance Of A Scr Catalyst On A Diesel Particulate Filter With A Downstream Scr, Sagar Sharma

Dissertations, Master's Theses and Master's Reports

Selective catalytic reduction (SCR) systems along with a NH₃ slip control catalyst (ASC) offers NOₓ conversion efficiency >90 % with NH₃ slip < 20 ppm. However, future heavy duty diesel (HDD) engines are designed for higher engine-out NOₓ to improve fuel consumption. Consequently, there is a strong desire to further improve the NOₓ reduction performance of SCR systems, to meet the 2015 California Optional Low NOₓ Standard. SCR catalysts on a diesel particulate filter provide an effective solution to reduce NOₓ and PM using a single aftertreatment device. It also provides an opportunity to increase the SCR volume to achieve NOₓ conversion efficiency >95 %. A downstream SCR catalyst substrate can be used to get additional NO_x conversion by using the SCRF^® outlet NH₃ to increase the cumulative NOₓ conversion of the system.

In this study, NOₓ reduction, NH₃ slip and PM oxidation performance of a Cu-zeolite SCRF^® with a downstream Cu-zeolite SCR were investigated based on engine experimental data at steady state conditions. The experimental data were collected at varying SCRF^® inlet temperatures, space velocities, inlet …

A Scr Model Based On Reactor And Engine Experimental Studies For A Cu-Zeolite Catalyst, Xiaobo Song

Dissertations, Master's Theses and Master's Reports - Open

A NO_x reduction efficiency higher than 95% with NH₃ slip less than 30 ppm is desirable for heavy-duty diesel (HDD) engines using selective catalytic reduction (SCR) systems to meet the US EPA 2010 NO_x standard and the 2014-2018 fuel consumption regulation. The SCR performance needs to be improved through experimental and modeling studies. In this research, a high fidelity global kinetic 1-dimensional 2-site SCR model with mass transfer, heat transfer and global reaction mechanisms was developed for a Cu-zeolite catalyst. The model simulates the SCR performance for the engine exhaust conditions with NH₃ maldistribution and aging …