Meeting Future Global Particulate Emission Standards Presentations/Day 1... · • The European Union chose a PN regulation and standard that will most likely require ... tec o og

Meeting Future Global Meeting Future Global Particulate Emission Particulate Emission

StandardsStandards

Cary Henry, Ph.D.Cary Henry, Ph.D.Cary Henry, Ph.D.Cary Henry, Ph.D.

©Copyright Southwest Research Institute ® 2014©Copyright Southwest Research Institute ® 2014

Southwest Research Institute® San Antonio, Texas©Copyright Southwest Research Institute ® 2014

Southwest Research Institute® San Antonio, TexasSouthwest Research Institute® San Antonio, Texas©Copyright Southwest Research Institute ® 2014

SwRI Confidential Information

Southwest Research Institute® San Antonio, Texas©Copyright Southwest Research Institute ® 2014

LEV-III PM Emission Standards More StringentStringent

• CARB LEV III starting in 2015• Additional reduction to criteria pollutants

• Aggressive PM reductions– 1 mg/mi starting in 2025 for LDV– 8 & 10 mg/mi in 2021 for MDV

• No plans for PN regulation• CARB: “want the best available technology installed on all vehicles”

• 150,000‐mile durability requirement

~90% PM Reduction

requirement


European Emission Legislation Focusing on Particle NumberFocusing on Particle Number

• PN regulation already in effect for compression ignition engines• PN regulation will go into effect in September 2014 for GDI engines

• No pending regulation for PFI enginesp g g g• Initial PN limit for GDI is 6 x 1012 particles/km in September 2014

• PN limit will be reduced to 6 x 1011 particles/km in September 2017


PM vs. PN Regulation is a Controversial Topic That is Still Being DebatedTopic That is Still Being Debated

• Nation Ambient Air Quality Standards (NAAQS) use mass basis for i t l it ienvironmental monitoring

• Most health studies in US have used PM mass basis for measurement• US regulatory agencies are hesitant to regulate on the basis of particle number because of no direct link between ambient air quality and health impactsbecause of no direct link between ambient air quality and health impacts

• The European Union chose a PN regulation and standard that will most likely require the use of wall flow filters on all direct‐injected vehicles

• PM emissions are difficult to measure at the levels legislated for LEV‐III and• PM emissions are difficult to measure at the levels legislated for LEV‐III and proposed for Tier 3 1

• The Particle Measurement Program (PMP) is used to quantify PN for the EU legislationg– This method is limited to particles larger than 23 nm, which includes some ultrafine particulates


1. Swanson, J., Kittleson, D., Dikken, D., “Quantification of Uncertainty and Techniques for Improving Filter Mass Measurements”, American Filtration and Separations Society Annual Conference, May 2009

New EPA GHG Legislation is Driving New TechnologiesTechnologies

• GHG emission limits based on vehicle h lb d t k idthwheelbase and track width

• All vehicles must reduce GHG emissions by about the same amount

• Separate targets for light trucks• Separate targets for light trucks

• CAFE standards regulate fuel economy, and are generally aligned with GHG emissionsemissions

• These new regulations are driving a shift in engines to GDI and diesel technologies


tec o og es

Turbocharged GDI Applications Have Increased PM and PN EmissionsIncreased PM and PN Emissions

SAE 2012SAE 2012--0101--17271727

• PFI engines have very low PN emissions– At or near Euro 6 legislated levels

• GDI technology substantially increases particulate emissions

• Majority of particulate emissions for gasoline engine technologies aregasoline engine technologies are classified as ultra‐fine (UFP)

• High UFP PN emissions are still very low in total mass emissions


• GDI engines are below Euro 6 PM, but substantially above PN regulation

PM/PN Emissions Vary by Phases of FTP-75

ppen

dix P, 2011.

• Diesel PM is if l hi h

rt Docum

ent, Apuniformly high

across all phases• GDI applicationsemit most PM/PN

Technical Sup

po

emit most PM/PN during cold start

• Gasoline PFI applications have

oard, LEV

III PM T

very low PM/PN emissions

• Application of a DPF t di l

Air R

esou

rces BoDPF to diesel

engines reduces PM/PN to less than Gasoline PFI


California A

Engine Managed PM/PN Reduction Strategies are PossibleStrategies are Possible

• Combustion strategies are under d l t t d PM/PN

SAE 2011SAE 2011--0101--12191219

development to reduce PM/PN emissions from GDI engines

• Goal is to manage PM/PN emissions without the need for a gasolinewithout the need for a gasoline particulate filter (GPF)

• Majority of PN emissions from GDI engines occur during cold start and high‐load transients

• Several strategies have been proposed and evaluated, including:

/– Dual PFI/GDI fuel systems– Multiple injections per cycle GDI (piezoinjectors)

SAE 2011SAE 2011--0101--12191219


New Engine Technologies Such as Cooled EGR Can Reduce PM and PNEGR Can Reduce PM and PN

SAE 2010SAE 2010--0101--03530353

3500 rpm 9.6 bar BMEP3500 rpm 9.6 bar BMEP

• Low temperature combustion (LTC) strategies can reduce formation of soot via reduced combustionsoot via reduced combustion temperature

• Cooled EGR has been shown to reduce particulate number

35003500 rpmrpm

pemissions directly via reduced combustion temperature

• Cooled EGR can also reduce PM/PN

13.513.5 bar BMEPbar BMEP

indirectly via reduced exhaust temperature

• Reduced exhaust temperature enables t i hi t i b ti hi h


stoichiometric combustion, which reduces PM emissions

SAE 2010SAE 2010--0101--03530353

Gasoline Fuel Composition Impact PM/PN EmissionsEmissions

• Studies have also been conducted to tif i t f f l PM/PN

SAE 2012SAE 2012--0101--04370437

quantify impact of fuel on PM/PN emissions

• Increasing ethanol content in gasoline has been observed to reduce PMhas been observed to reduce PM emissions from GDI applications

• PM is reduced for both lean and stoichiometric combustion, although , gimpact is greater for stoichiometric

• PM is reduced for both FTP‐75 and US06 drive cycles

©Copyright Southwest Research Institute ® 2014©Copyright Southwest Research Institute ® 2014SAE 2012SAE 2012--0101--04370437

• PN was also observed to decrease with increasing ethanol content

Gasoline Particulate Filters Can be Used to Treat PM and PN Emission from GDI Enginesg

• Most effective strategy for mitigating PM/PN i i f GDI i i

SAE 2012SAE 2012--0101--17271727

PM/PN emissions from GDI engines is GPF technology

• The application of a GPF to a light duty GDI engine has been shown to reduceGDI engine has been shown to reduce PN by ~90%

• The use of a GPF alone has the capability to reduce PN emissions of a GDI engine to Euro 6 legislated levels

• The GDI‐GPF application has PN emissions similar to PFI technology, with the added combustion benefits of

©Copyright Southwest Research Institute ® 2014©Copyright Southwest Research Institute ® 2014SAE 2012SAE 2012--0101--17271727

with the added combustion benefits of GDI

Off-Highway Regulations – U.S. Tier 4 Final

• Recent implementation of Tier 4 final standards have resulted in complex emission control strategiesemission control strategies

• Overall strategies vary substantially between and among OEMs• Several applications are using either SCR or DPF, but not both

com

com

w.d

iese

lnet

.cw

.die

seln

et.c

ww

ww

ww


Future Off-Highway Regulation

CARB has publicly voiced concern over utilizing best available technologies on ALL applicationsg pp• CARB has made public comments addressing Tier 4 applications without the use of a DPF

• CARB seems very hesitant to draft legislation regarding PN, and appears to only y g g g , pp yconsider more stringent PM regulation


“Ultrafine Particulate Matter and the Benefits of Reducing Particle Numbers in the United States”, www.meca.org

Southwest Research Institute®


Documents

Meeting Future Global Particulate Emission Standards Presentations/Day 1... · • The European Union chose a PN regulation and standard that will most likely require ... tec o og