New SwRI research consortium examines the effects of NOx controls on PM emissions

8 March 2001

San Antonio, TX-based Southwest Research Institute (SwRI) is forming a consortium to examine how technologies aimed at reducing oxides of nitrogen (NOx) from diesel engines affect the emissions of particulate matter (PM).

Titled, “The Effect of Emission Control Technologies on the Chemical and Physical Properties of Diesel Particulate”, the new consortium will research the impact of various current as well as novel NOx and PM control technologies on the chemical and physical characteristics of particles emitted from diesels. Emphasis will be placed on in-cylinder methods as well as post-combustion emissions reduction devices. For NOx reduction, exhaust gas recirculation (EGR) and water emulsions will be among methods considered.

In addition, NOx adsorbers and selective catalytic reduction (SCR) systems with urea will be included in the test matrix. For PM control, diesel oxidation catalysts (DOC) in combination with diesel particulate filters (DPF) will be investigated. The end result of combining these post-combustion systems together with in-cylinder controls is to achieve NOx/PM emission levels that approach those proposed by the US Environmental Protection Agency (EPA) for 2007.

The scope of work will include a detailed gaseous and PM chemical and physical characterization for a production engine. This work will not be limited to regulated emissions (hydrocarbons, carbon monoxide, NOx, and total PM), but will include a substantial list of unregulated emissions. From the chemical standpoint, the program will address soluble and insoluble fractions, sulfate and retained water, aldehydes and ketones, polycyclic aromatic hydrocarbons, cyanide, ammonia, nitrous oxide, hydrogen sulfide, trace metals and hydrocarbon speciation.

As for the physical characteristics of PM, a complete and thorough analysis of ultrafine and nanoparticle distribution will be conducted. This analysis will focus on particle count and size using specialized equipment such as the scanning mobility particle sizer (SMPS), electrical low pressure impactor (ELPI), micro-orifice uniform deposit impactor (MOUDI), and others, for both steady-state as well as transient engine operation.

This consortium will benefit engine manufacturers, petroleum companies and catalyst and emission control manufacturers. The fee to join the 19-month consortium is $100,000. For more information contact: Magdi Khair, staff engineer, Emissions Research Department, 210/522-5311, fax 210/522-3950, or email mkhair@swri.org.

Source: SwRI