Fresh and Aged SCRT Systems Retrofitted on a MY 1998 Class-8 Tractor: Investigation on In-use Emissions West Virginia University

Format:

Conference/Event

Author/Creator:

Littera, Littera, author.

Contributor:

Besch, Marc

Carder, Daniel

Cozzolini, Alessandro

Gautam, Mridul

Kappanna, Hemanth

Oshinuga, Adewale

Sayres, Adam

Thiruvengadam, Arvind

Conference Name:

10th International Conference on Engines & Vehicles (2011-09-11 : Naples, Italy)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2011

Summary:

In order to comply with stringent 2010 US-EnvironmentalProtection Agency (EPA) on-road, Heavy-Duty Diesel (HDD) emissionsregulations, the Selective Catalytic Reduction (SCR) aftertreatmentsystem has been judged by a multitude of engine manufacturers asthe primary technology for mitigating emissions of oxides ofnitrogen (NOx). As virtually stand-alone aftertreatmentsystems, SCR technology further represents a very flexible andefficient solution for retrofitting legacy diesel engines as themost straightforward means of cost-effective compliance attainment.However, the addition of a reducing agent injection system as wellas the inherent operation limitations of the SCR system due torequired catalyst bed temperatures introduce new, unique problems,most notably that of ammonia (NH₃) slip. Even the most refinedsystems, while performing flawlessly during standardizedcertification tests, may encounter excursions during real-worldoperation, thereby leading to possible formation of secondaryemissions and emit unacceptable high NOx.The following study, funded by the South Coast Air QualityMeasurement District (AQMD) and supported by Johnson Matthey, wasinitiated to provide a better understanding of the performance andespecially durability of retrofit exhaust aftertreatment systemscomprising of Diesel Particulate Filter (DPF) and SCR devices.Specifically, two SCRT® systems retrofitted to a Class-8 Heavy-DutyDiesel (HDD) truck, whereof one was new and another been in on-roadoperation for the duration of 15 months, were evaluated on achassis dynamometer with regard to overall system performance,secondary emissions formation and NOx conversionefficiency deteriorations due to catalyst aging. SCR conversionefficiencies ranged between 67% to 71% and Particulate Matter (PM)filtration efficiencies above 90%, depending on vehicle test cycle.No statistical evidence for a reduction in SCR® efficiency over thecourse of a 15 months on-road operation period could be found atthe 5% significance level

Notes:

Vendor supplied data

Publisher Number:

2011-24-0175

Access Restriction:

Restricted for use by site license