Particulate Control Experience with GDI and GPFs Dr. Rasto Brezny Manufacturers of Emission Controls Association www.meca.org September 28, 2016 South Coast AQMD Diamond Bar, CA
Particulate Control Experience with GDI and GPFs
Dr. Rasto Brezny
Manufacturers of Emission Controls Association www.meca.org
September 28, 2016 South Coast AQMD
Diamond Bar, CA
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MECA Technologies Control Criteria and GHG Emission
Air Handling
Exhaust System Integration
OBD Sensors Waste Heat Recovery
Powertrain Electrification
Evaporative Controls
Filters & Substrates
Fuel Combustion Controls
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LEV III/Tier 3 Phase-In PN Implemented Soon for GDI Vehicles
0.0000.0100.0200.0300.0400.0500.0600.0700.0800.0900.1000.1100.120
'15 '16 '17 '18 '19 '20 '21 '22 '23 '24 '25
FTP NMOG+NOx LEV III Emissions, g/mi
PCs
0.030 NMOG+NOx (SULEV or Tier 2, Bin 2)
LDT2s
3 mg/mi PM phase-in
2017- 2021
1 mg/mi LEV III PM phase-in 2025-2028
LEV III Start
ARB PM Review
Euro 6c GDI PN limit (6 X 1011/km)
China PN limit (6 X 1011/km) India PN limit (6 X 1012/km)
India PN limit (6 X 1011/km)
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Understanding GDI PM Emissions • GDI fleet is growing; expected to reach 7 million per year by 2020 in U.S. • MECA has been studying GDI PM characteristics and GPF performance for
past 5 years. – PM/PN emissions are highest during cold start, transient and sub-
ambient temps – Vehicle cold-start strategy introduces PM variability – Fuel chemistry can affect GDI PM through PM Index – Lean GDI combustion exhibits range of EC and OC – Secondary organic aerosol emissions from GDI engines
• GPFs reduce variability in PM emissions caused by fuel, temperature and driving effects to lowest possible levels.
• Advanced fuel injection systems are delivering PM levels well below 1 mg/mile
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Engine and Injection Technology Impacts Particulate Emissions
FTP UC
Federal Test Procedure Unified Cycle
WG-DI SG-DI PFI FFV
Wall guided direct injection Spay guided direct injection Port fuel injected Flex fuel vehicle
CE-CERT, Karavalakis et al., ES&T, 2014
Ericsson, 2010
GDI PM Resembles Diesel PM
40 nm
9 nm
200 nm
GDI soot
100 nm
Diesel soot
ORNL, 2014
6 Source: CE-CERT, Karavalakis 2016
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Source : Anforderungen an Partikelfiltersysteme für Dieselmotoren, A.Mayer, TTM
Anatomy of a Wall-flow Particulate Filter
Engine Out
Emissions Alternately Open / Plugged Channels
Porous Ceramic Wall
Tailpipe Emissions
Soot Particles
• Effectively reduce: >95% PM, >99% UFP reduction
• Catalyzed filters capture and incinerate soot and associated toxics
• Experience with tens of millions of OE applications
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GPFs Designed to Minimize Back Pressure
HKIPT Conf, 10/15 8
• Thinner wall high porosity substrates optimized for back pressure and fuel economy
• Porosity allows higher catalyst loadings and lower thermal mass
• Higher cell density provide higher geometric surface area
• Ford SAE paper 2016-01-0941 concluded no impact on fuel economy from GPF after 150K miles.
GPF Effectively Reduces GDI Particle Emissions – MECA/Environment Canada Test Program
• GDI shows higher particle number emissions than PFI • Highest PM emissions during cold-start and acceleration • GPF efficiencies of around 85% • GPF regeneration under US06 • E10 vs. E0 – relatively small effects at normal ambient temps. • Both PFI and GDI emit ultrafine particles below 23 nm
SAE 2012-01-1727
Source: Environment Canada, 2016 9
-93% -96%
GPF Effectively Reduces Ultrafine Metal Oxide Ash Particulates
Met
al o
xide
em
issi
ons,
μg/
mi
US06
E0 E10
Met
al o
xide
em
issi
ons,
μg/
mi
FTP-75
E0
-80%
• Metal oxide ash particles have been shown to exhibited high oxidative stress response • These ultrafine particles are less than 10 nm • High concentrations observed under high-load (US06) • GPF demonstrated high removal efficiency.
Source: Environment Canada, 2012 10
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49% 16% 97% OC Removal
97% 79% > 99% EC Removal
89% 55% > 99% TC Removal
PM from Lean-burn GDI Engine MECA Program at Oak Ridge National Lab
ORNL: SAE 2016-01-0937 11
GPF Durability Demonstrated in Europe
SAE 2015-01-1073
Torque Power
Particle Number NEDC / WLTC / Artemis test cycle Criteria Pollutants
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CO2
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First Commercial GDI/GPF Tested
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RDE Testing of Catalyzed GPF
Euro 6c PN limit
Euro 6c PN limit
http://www.aecc.be/en/Publications/RDE%20PN_Technical_Seminar.html.
CE-CERT GDI Aerosol and PM Characterization
• SCAQMD/MECA program to characterize primary and secondary PM/PN • MECA demonstrating catalyzed GPF technology on two advanced technology vehicles • PM profile is vehicle technology and calibration specific • Study will characterize PAH emissions
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0.00
2.00
4.00
6.00
8.00
10.00
12.00
Accent Accord Soul Impala Mazda3 Mazda3w/ GPF
Carb
onac
eous
Aer
osol
(mg/
mile
) BC POA SOA
Source: CE-CERT, Karavalakis, 2016
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• GDI response time is longer than diesel • Stoichiometric operation poses challenges for sensor regeneration • Correlating PN and PM between vehicles
Electrode / Heater
Exhaust
Accumulator sensor
Electrostatic Sensor
Resistance
OBD Sensor Technology Being Developed for GPFs
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Summary and Conclusions • Vehicle combustion strategy, fuel and calibration affects PM and PN emissions.
• ARB has concluded that 1 mg/mile PM can be measured using existing test methods
• Fuel Injection and filter technologies demonstrated ability to meet EU PN standard and LEV III 1 mg/mile standard
• GPFs have demonstrated no measurable fuel economy impacts. First commercial introduction in 2015, more in 2017.
• Several OEMs have announced broad deployment of GPFs on tens of millions of vehicles by 2022 in Europe.
• Particle number regulations in Europe, India and China will demand best available technologies in 2017-2023 timeframe.
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