An Experimental Investigation into the Effect of NO2 and Temperature on the Passive Oxidation and Active Regeneration of Particulate Matter in a Diesel Particulate Filter

Development of a 2D SCR Catalyst on a Diesel Particulate Filter Model for Design and Control Applications to a Ultra Low NOx Aftertreatment System

“…With an increase in temperature from 490 to 590 o C the thermal PM oxidation rate increased from 92 to 96 % of the total PM oxidation rate and at the same time the passive oxidation reduced from 8 to 4%. Due to the presence of a di↵erent catalyst in the SCR® compared to a CPF [52] the passive oxidation rate contributed to 6% of the passive oxidation in the SCRF® in the place of 20% observed for the CPF during active regeneration. In the CPF due to the presence of a oxidation catalyst, the NO 2 consumed in the PM cake was regenerated in the wall and through back di↵usion supplied to the PM cake leading…”

“…A set of experiments were conducted using the SCR-F + SCR system described in Figure 7.2 consisting of a 2013 6.7 L Cummins ISB engine described in reference [51] and were modeled using the SCR-F model [49] and the SCR model [2]. Similarly, a set of experiments were performed as described in reference [52] with the production aftertreatment system described in Figure 1.2.…”

“…7. The contribution of NO 2 assisted PM oxidation during active regeneration was found to be 20 % for active regeneration experiments from the CPF experimental [52] compared to a contribution of 5 % in the case of active regeneration in the SCRF®. This change in reaction rate is attributed to the lack of backward di↵usion of NO 2 from substrate wall to the PM cake in the SCRF® due to a change in the catalyst used, from an oxidation to reduction catalyst.…”

AN EXPERIMENTAL INVESTIGATION INTO THE EFFECT OF PARTICULATE MATTER ON NOx REDUCTION IN A SCR CATALYST ON A DPF

“…The PM loading of the SCRF ® test procedure is similar to the procedure used in the past for baseline CPF testing [2]. The rail pressure was reduced by 30% to increase the engine-out PM and to load PM in a practical time (330 minutes).…”

“…At higher temperature of about 440 °C, NH3 slip is observed varying with PM loading in the SCRF ® . With PM loading, NO2 assisted oxidation increases the concentration of NO [2] and affects the NOx conversion efficiency.…”