Reducing Lubricant Ash Impact on Exhaust Aftertreatment with a Oil Conditioning Filter
Sloan Automotive Laboratory
2009 Directions in Engine-Efficiency and Emissions Research (DEER) ConferenceAugust 6th, 2009
Simon A.G. Watson and Victor W. Wong, MITDarrell Brownawell
and Scott P. Lockledge, Lutek
LLC.Scott Harold, Ciba Specialty Chemicals
•
Ash negatively effects aftertreatment
systems:–
Increases fuel consumption and exhaust back pressure
–
Phosphorus may chemically deactivate catalysts
–
Periodic cleaning requirements and possible engine damage
Lubricant Derived Ash
Sloan Automotive Laboratory
Diesel Particulate Filter Ash Deposits:
(Aravelli, DEER 2006)
Inlet Outlet
(Sappok, 2009)
•
Lubricant additives are the source of most DPF ash:–
Detergents–
Zinc Dialkyldithiophosphate
(ZDDP)
•
Detergents contribute about 75% of ash found in DPF’s
(CaSO4
) •
Lower detergent levels significantly reduces DPF ash
Reducing Ash Accumulation in DPF’s
Sloan Automotive Laboratory
Typical DPF Ash Composition:
XRD analysis of DPF ash from a CJ-4 lubricant(Sappok, 2009)
Are there any alternatives for additives that do not contribute to DPF ash?
Sloan Automotive Laboratory
•
Strong Base Oil Filter–
Strong base is anchored in the filter–
Strong base in filter immobilizes acids–
Releases nothing–
Selectively sequesters acids only
•
Ashless
Antiwear–
Provides protection from wear without contributing to sulfated ash (ASTM D874)
Test Program
Sloan Automotive Laboratory
•
Long-duration steady-state testing to investigate the potential benefits of filter conditioning with reduced ash oils
•
Three long-duration tests:–
Test 2 –
Zero Detergent oil, Strong base filter -
300 hrs–
Test 3 –
Zero Detergent oil, Standard oil filter -
82 hrs–
Test 1 –
CI-4 PLUS oil, Standard oil filter -
318 hrs (Reference)
Load 100%FPSpeed 1800 rpmFuel 15 ppm Sulfur Diesel
Lubricants1. Experimental Zero Detergent
Formulation2. Fully Formulated (CI-4 PLUS)
Test Parameters
Experimental Zero-Detergent Oil Formulation
Sloan Automotive Laboratory
Component DescriptionBase Oil Blend of Americas Core Group I
Detergent NoneDispersant PIBSA/PAM (~10% of formulation)
Antiwear Ashless phosphorus and sulfur containing additives
Additional Corrosion Inhibitors None
Description of the Components in the Zero Detergent Oil:
Lubricant Properties
Sloan Automotive Laboratory
Element Zero Detergent CI-4 PLUS
Ca 0 3130Mg 0 10Zn 0 1350P 480 1490
Property Zero Detergent CI-4 PLUSSAE Grade 15W40 40WAPI Gravity 29.1 28.9
Viscosity @ 40°C [cSt] ~ 146Viscosity @100°C [cSt] 15.2 14.9Sulfated Ash [%] (D874) 0.057 1.35
TBN [mg KOH/g] (D2986) 5.5 10.2
Elemental Analysis (ASTM D4951):
Lubricant Properties:
Test Engine
Sloan Automotive Laboratory
•
Specifications:–
Single Cylinder–
Naturally Aspirated–
Air Cooled–
No EGR–
Maximum Power 5.5 kW–
Direct Fuel Injection–
Displacement 0.773 L–
Compression Ratio 15.5:1–
Sump Capacity 2.4 L
Lister Petter TR1 Generator Set
Test Procedure
Sloan Automotive Laboratory
•
Lubrication system cleaned with triple flush between tests•
Routine maintenance performed every 24 hours
•
Parameters measured every 24 hours:•
Oil Consumption (oil mass measurement)•
Fuel Consumption•
Oil Temperature•
Crankcase oil samples extracted every 48 hours:
•
For Tests 1 -
~17 g•
For Tests 2 and 3 -
~38 g •
Samples are extracted through the dipstick opening
0
400
800
1200
1600
2000
0 100 200 300 400Elapsed Operating Time (hours)
To
tal O
il C
on
sum
pti
on
Test 1 - CI-4+, Standard FilterTest 2 - Zero Detergent, Strong Base FilterTest 3 - Zero Detergent, Standard Filter
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 100 200 300 400Elapsed Operating Time (hours)
So
ot
(% w
Test 1 - CI-4+, Standard Filter
Test 2 - Zero Detergent, Strong Base Filter
Test 3 - Zero Detergent, Standard Filter
Oil Consumption and Soot Contamination
Sloan Automotive Laboratory
3.61 g/hr
5.93 g/hr
5.49 g/hr
Oil Consumption Soot Content
•
Mean oil temperatures of tests are equal•
Mean fuel consumption of tests are equal
y = 0.0028x + 0.9475R2 = 0.9791
y = 0.0088x + 1.1427R2 = 0.8841
y = 0.0028x + 0.5572R2 = 0.983
0.0
0.5
1.0
1.5
2.0
2.5
0 50 100 150 200 250 300 350Elapsed Operating Time (hours)
TA
N (
mg
KO
H/
Test 1 - CI-4+, Standard Filter, Colorimetric Titration
Test 2 - Zero Detergent, Strong Base Filter, Colorimeteric Titration
Test 3 - Zero Detergent, Standard Filter, Colorimetric Titration
Total Acid Number
Sloan Automotive Laboratory
Fully Formulated, Standard Filter
Zero-Detergent,Strong Base Filter
Zero-Detergent,Standard Filter
y = -0.0037x + 8.4521R2 = 0.7123
y = -0.0076x + 8.1965R2 = 0.9371
y = -0.0236x + 7.6R2 = 1
4.00
4.50
5.00
5.50
6.00
6.50
7.00
7.50
8.00
8.50
9.00
0 50 100 150 200 250 300 350
Elapsed Operating Time (hours)
pH
Un
it
Test 1 - CI-4+, Strong Base Filter
Test 2 - Zero Detergent, Strong Base Filter
Test 3 - Zero Detergent, Standard Filter
Lubricant Acidity
Sloan Automotive Laboratory
Fully Formulated, Standard Filter
Zero-Detergent,Strong Base Filter
Zero-Detergent,Standard Filter
0
2
4
6
8
10
0 50 100 150 200 250 300 350Elapsed Operating Time (hours)
TB
N (
mg
KO
H/
Test 1 - CI-4+, Standard Filter, ASTM D-5984Test 2 - Zero Detergent, Strong Base Filter, ASTM D-5984Test 2 - Zero Detergent, Strong Base Filter, ASTM D-2896Test 3 - Zero Detergent, Standard Filter, ASTM D-5984Test 3 - Zero Detergent, Standard Filter, ASTM D-2896
Total Base Number
Sloan Automotive Laboratory
Fully Formulated, Standard Filter
Zero-Detergent,Strong Base Filter
Zero-Detergent, Standard Filter
0
2
4
6
8
10
12
14
16
0 50 100 150 200 250 300 350Elapsed Operating Time (hours)
Mg
Co
nce
ntr
atio
n (
p
Test 1 - CI-4 PLUS, Standard Filter
Test 2 - Zero Detergent, Strong Base Filter
Test 3 - Zero Detergent, Standard Filter
Magnesium Concentration
Sloan Automotive Laboratory
Fully Formulated, Standard Filter
Zero-Detergent,Strong Base Filter
Zero-Detergent,Standard Filter
y = 0.0268x + 12.171R2 = 0.9721
y = 0.0241x + 18.064R2 = 0.3299
y = 0.2134x + 15.428R2 = 0.8306
7
12
17
22
27
32
37
42
47
0 50 100 150 200 250 300 350Elapsed Operating Time (hours)
Oxi
dat
ion
Nu
mb
er (
Ab
s
Test 1 - CI-4 PLUS, Standard Filter
Test 2 - Zero Detergent, Strong Base Filter
Test 3 - Zero Detergent, Standard Filter
Oxidation
Sloan Automotive Laboratory
Fully Formulated, Standard Filter
Zero-Detergent,Strong Base Filter
Zero-Detergent,Standard Filter
y = 0.278x + 13.795R2 = 0.9409
y = 0.0688x + 15.808R2 = 0.9807
0
5
10
15
20
25
30
35
40
45
0 50 100 150 200 250 300 350Elapsed Operating Time (hours)
Visc
osity
at 1
00C
(cSt
)
Test 1 - CI-4 PLUS, Standard Filter, ASTM D-445Test 2 - Zero Detergent, Strong Base Filter, ASTM D-445Test 3 - Zero Detergent, Standard Filter, ASTM D-445Linear (Test 3 - Zero Detergent, Standard Filter, ASTM D-445)Linear (Test 2 - Zero Detergent, Strong Base Filter, ASTM D-445)Linear (Test 1 - CI-4 PLUS, Standard Filter, ASTM D-445)
Viscosity
Sloan Automotive Laboratory
Fully Formulated, Standard Filter
Zero-Detergent,Strong Base Filter
Zero-Detergent,Standard Filter
0
20
40
60
80
100
120
140
160
0 50 100 150 200 250 300 350Elapsed Operating Time (hours)
Co
rrec
ted
Fe
Co
nce
ntr
atio
n ( Test 1 - CI-4+, Standard Filter
Test 2 - Zero Detergent, Strong Base FilterTest 3 - Zero Detergent, Standard Filter
Engine Wear
Sloan Automotive Laboratory
Fully Formulated, Standard Filter
Zero-Detergent,Strong Base Filter
Zero-Detergent,Standard Filter
0
10
20
30
40
50
60
70
80
90
0 50 100 150 200 250 300 350Elapsed Operating Time (hours)
Co
rrec
ted
Met
al C
on
cen
trat
ion
Test 1 - CI-4+, Standard Filter, Pb
Test 2 - Zero Detergent, Strong Base Filter, Pb
Test 3 - Zero Detergent, Standard Filter, Pb
Test 4 - CI-4+, Strong Base Filter, Pb
Bearing Wear Metals
Sloan Automotive Laboratory
T2, Pb
T3, Pb
T3, PbT1, Pb
Four Ball Wear Tests
Sloan Automotive Laboratory
0.00
0.20
0.40
0.60
0.80
1.00
Zero Detergent,Fresh Oil
CI-4+, Fresh Oil Test 1 - CI-4+,Standard Filter -
318 hours
Test 2 - ZeroDetergent,
Strong BaseFilter - 300
hours
Test 3 - ZeroDetergent,
Standard Filter -82 hours
Ave
rage
Wea
r Sca
r Dep
th (m
m)
Conclusions
•
Under the test conditions used in this study, the strong base filter had a significant and beneficial effect on the rate of oil degradation
•
The strong base filter reduced lubricant acidity by absorbing acidic contaminants in the lubricant
•
The filter performs an acid control function similar to that provided by over-based detergents, when used with a zero-
detergent oil
•
The zero-detergent oil (formulated with ashless antiwear additives) and the CI-4 PLUS oil provide similar levels of wear protection after aging with the strong base filter.
•
With more development, it may be possible use a zero detergent oil in combination with a strong base filter; providing adequate engine protection while minimizing lubricant ash effects on aftertreatment systems
Sloan Automotive Laboratory
Sloan Automotive Laboratory
•
Caterpillar•
Chevron
•
Ciba Specialty Chemicals•
Cummins
•
Detroit Diesel
This research is supported by the MIT Consortium to Optimize Lubricants and Diesel Engines for Robust Emission Aftertreatment
Systems
•
Komatsu•
Lutek
LLC.
•
Sud-Chemie•
Valvoline
•
Ford
We thank for the following organizations/companies for their support:
Acknowledgements
•
Department of Energy –
Vehicle Technologies Program