F2008-06-022
Diesel Aftertreatment Technology and PM Measurement
Emission regulations for diesel vehicles in the U.S. and Europe are very stringent, especially for particulate matter (PM) and nitrogen oxides (NOx). The challenges to overcome in meeting the PM regulations include the use of highly efficient diesel particulate filters with high mileage durability, the need to measure very low PM mass at the tailpipe, and a potential need to measure particle number in Europe. The two leading technologies for high NOx reduction on diesel vehicles are Selective Catalytic Reduction (SCR) and Lean NOx Traps (LNT). LNTs have the advantage of requiring no new infrastructure, and do not pose any new customer compliance issues. However, Urea SCR has several technical advantages, including a high and durable NOx conversion in a wider temperature window, a lower equivalent fuel penalty, and lower system and operating costs. In this paper, high efficiency NOx and PM control are discussed. Additional information is provided on new PM measurement solutions. Mathematical simulations are used to come to sound, technical judgment for business decisions when all desired experimental data are not available.
Session: Exhaust Gas Aftertreatment