THE EMISSION AND PARTICULATE MATTER OXIDATION PERFORMANCE OF A SCR CATALYST ON A DIESEL PARTICULATE FILTER WITH A DOWNSTREAM SCR
Author | : |
Publisher | : |
Total Pages | : |
Release | : 2017 |
ISBN-10 | : OCLC:1143740765 |
ISBN-13 | : |
Rating | : 4/5 ( Downloads) |
Download or read book THE EMISSION AND PARTICULATE MATTER OXIDATION PERFORMANCE OF A SCR CATALYST ON A DIESEL PARTICULATE FILTER WITH A DOWNSTREAM SCR written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Selective catalytic reduction (SCR) systems along with a NH3 slip control catalyst (ASC) offers NOx conversion efficiency >90 % with NH3 slip 90 % with NH3 slip 95 %. A downstream SCR catalyst substrate can be used to get additional NOx 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 NOx concentrations, NO2/ NOx ratios at ammonia to NOx ratios (ANR) between 1.02 to 1.10. The results demonstrated that the SCRF® with downstream SCR together can achieve NOx conversion efficiency > 98% at ANRs between 1.02 - 1.10 (which may have been due to measurement inaccuracies in downstream SCRF 98% at ANRs between 1.02 - 1.10 (which may have been due to measurement inaccuracies in downstream SCRF®/SCRdata), for the inlet temperature range of 200 - 370°C, space velocity in the range of 10 to 34 k/hr and inlet NO2/ NOx in the range of 0.3 - 0.5. However, NH3 slip from the SCRF® decreases and NOx concentration downstream of the SCRF® increases with the oxidation of PM in the SCRF®. The PM oxidation kinetics are affected by the deNOx reactions, hence, the SCRF® with urea dosing showed ~80 % lower reaction rates during passive oxidation when compared to the production CPF. The effect of varying fuel rail injection pressure on the primary particle diameter and on the Elemental Carbon (EC) and Organic Carbon (OC) fraction of the total carbon was also studied. The primary particle diameter was found to be in the range of 28-30 nm with no effect of the variation in fuel rail injection pressure on it. The OC part of the Total Carbon (TC) did not vary significantly with fuel rail injection pressure. The EC content increased with decrease in fuel rail injection pressure.