automobile conventional for moveable .ppt

Hand gestures and conventional hand

1. Diesel Emissions and
Exhaust After-Treatment for
Modern Diesel Technology
National Biodiesel Board Technician Outreach Program
Rachel Burton & David Stehouwer 2009

2. Today’s Topics
Changes in diesel engine emissions
regulations
Basics of diesel engine emissions
Changes in hardware required by emissions
regulations
Interactions of fuels and fuel systems
Methods of exhaust aftertreatment
Exhaust aftertreatment & biodiesel
Resources

3. US On Highway Emissions Standards
1988
1990
1991
1994
1998
2000
2002
2010
0.80
0.33
0.134
0
2
4
6
8
10
12
N
O
x
,
g
/
k
W
-
H
r
P
a
r
t
i
c
u
l
a
t
e
,

g
/
k
W
-
H
r
8.058.05
6.76.76.76.7
5.45.4
3.33.3
1.51.5
0.0130.013
14
16
14.414.4
2007
0.270.27

4. Fuel technology
Combustion
technology
Aftertreatment
technology
Fuel system
technology
Better understanding
of combustion
Alternate Fuels
(Biodiesel)
Low sulfur
De-NOx
DOC
PM trap
Rate control
High pressure
Multi-injection
EGR technology
Others
Control
technology
Emission Reduction in Diesel Engines

5. 
Injection performance
Higher injection pressure 1600-2000+ bar
Multiple injection
•NOx, PM control
•Noise control
•Aftertreatment dosing, trap regen
Injection Rate Control
Soft SOI  Better BSFC/NOx tradeoff
Sharp EOI 　Better PM/smoke control

Precise injection control – minimum variation
Minimum emission variation
Tamper resistant
Stable over useful life (>8000 hours)
Summary of Requirements for
High Pressure Common Rail Fuel System
Time
N
e
e
d
l
e

l
i
f
t
P
r
e
s
s
u
r
e

a
t

n
e
e
d
l
e

s
e
a
t
Noise
NO
X
Aftertreatment
Soot
Increased injection pressure

6. Injection performance
Higher injection pressure 1600-
2000+ bar
Significant increases in fuel
economy
•At equivalent emissions
Summary of Requirements for
High Pressure Common Rail Fuel System (cont’d)
Increasing Injection Pressure
200 bar
2
4
6
8
Fuel Economy Improvement (%)
Increasing Injection Pressure
200 bar
2
4
6
8
Fuel Economy Improvement (%)
Time

7. Fuel properties effects on Common Rail FIE
• Startability
• Accurate SOI
• Controlled HR
•Leakage control
•Pressure control
•Durability/Fatigue
•Filter plugging
•Gumming, sticking
•Deposits
•Filter plugging
•Corrosion / Wear
Specified Fuel properties: chemical, contamination, physical
Cetane # Density
Aromatics
& Volatility
Sulfur Flash Pt
Hard Particle and ash
contamination
Water
contamination
Oxidation
Stability
Lubricity
Viscosity
Fatty Acid
Methyl Esters
•Pressure
control
•Quantity
control
•Elastomeric
compatibility
•Cavitation
damage
•Corrosion
•Acid oxidation
•Catalyst poisoning
•Smoke & Particulates
•Fire Hazard
•Spill
Hazard
•Spark
Hazard
•Wear
•Scuffing
•Seizure
•Gumming, sticking
•Deposits
•Filter plugging
•Corrosion & Wear
•Rough running
(misfire)
•Corrosion
•Wear
•Abrasive Wear
•Filter plugging
OTC and Refiner Additives
• Anticorrosion
• Cetane improvers
• Cold flow improvers
• Lubricity improvers
• Conductivity improvers
Refining process
contaminants
• Catalysts
• Desulfurization agents
• Cross contamination
Distribution and storage process
contaminants
• tank bottoms * pumps, pipes
• microbial * corrosion
• algae *varnish/sludge

8. Biodiesel Specifications Minimize Concerns

Oxidation Stability
Gumming and sticking
Fuel system deposits
Corrosion and wear

Total and Free Glycerin
Corrosion & Wear
Filter plugging
Water Content
Shortened injector life

9. Water in Fuel is a Problem
All non-dissolved water can cause
problems:
Serves as growth medium for
organisms that plug filters

Concentrates acids and ionic species
that cause corrosion and deposits
Freezes at cold temperatures and
reduces fuel flow
Reacts with some additives to form
precipitates and deposits

Plugs injector nozzles at extreme
conditions
Reduces fuel lubricity when in
emulsified form
0
50
100
150
200
250
300
Injector Life
(%)
251002004005007501000500010000
Amount of Water in Fuel
(ppm)
Effect of Water on Injector Life

10. Fuel-Water Removal More Difficult in Future

ULSD additive package lowers
interfacial tension making
removal more difficult
Biodiesels have lower interfacial
tension and hold more water,
again adversely impacting
removal
FWS more challenging as
biodiesel percentage in blends
increase
Solvency of biodiesel blends
makes coated cellulose media
option less effective
0
20
40
60
80
100
120
0 10 20 30 40
interfacial surface tension, dynes/cm
time weighted efficiency, %
original or
clay treated
fuel
additized
more
additized
ULSD
Biodiesel
B20 50

11. Exhaust Aftertreatment for Emissions Control

Diesel Particulate Filters (DPF)
Non-Catalyzed Traps
Catalyzed DPF
NOx Adsorber Technology
Solvent Catalyzed Reduction (SCR)

12. Diesel Particulate Filter (DPF) Maintenance
Carbon particulates are burned off with on-board
regeneration
Ash remains in the DPF and must be removed
periodically
This requires removal from vehicle

13. Catalyzed Diesel Particulate Filter (CDPFs)
Uses chemicals in exhaust to continuously
burn carbon in Soot Filter
Must still be removed to clean ash
NONO
2 2 Oxidizes Soot in FilterOxidizes Soot in Filter
2NO2NO
22 + C + C  CO CO
22 + 2NO + 2NO

ConvertsConverts
NO NO  2NO 2NO
22
Soot FilterSoot FilterPlatinum Catalyst
Exhaust Gas

14. NO
x
Adsorber Technology

Filter removes particles

LNA absorbs NOx on lean operation

Controls switch to rich operation to NOx to harmless Nitrogen

Filter regeneration and LNA regeneration are separate

Complex; costly; & fuel economy loss
Filter
Diesel
Injector
NO
x
Sensor
DOC
Valves
DOC
Diesel
Oxidation
Catalyst
LNA
Bypass
Reference: Volvo

15. Selective-Catalysts Reduction (SCR)
Aqueous
Urea
Solution
Tank
Ammonia
Slip
Catalyst
Engine
1
2
3
4
5
6
T
Air Induction
Pump and
Injector
Atomized
Urea
Solution
Catalyzed
Particulate
Filter
SCR Catalyst
Air to Air Cooler
C
Reference: DDC
Turbo-Charge
NO EGR

16. Selective-Catalysts Reduction (SCR)
Uses aqueous Urea instead of fuel to convert NOx
to Nitrogen
Requires extra tank etc.
Must add Urea distribution system to supply chain
Reduced EGR or no EGR
Fuel economy gains compared to NOx Adsorber

Proven durability for European applications
Favored by some for large truck and stationary
applications

17. How Does Biodiesel Effect
Emissions & Aftertreatment ?
Fuel System
Concern over deposits and corrosion
Addressed by ASTM specifications
Engine Emissions
Lower HC and Particulate
NOx emissions depend on duty cycle
Aftertreatment hardware / durability
Easier DPF regeneration
Studies at NREL / ORNL show no adverse effects
on hardware durability

18. What Will Be in the Marketplace?
All of the above!
Particulate Traps (or Soot Filters) were
across the board in 2007
NOx Adsorbers are on some pick-up truck
applications
SCR is favored for many HD truck and
stationary applications