biodiesel impact on engine oil performancewebpages.eng.wayne.edu/nbel/nbb-conference/cummins... ·...
TRANSCRIPT
AMMRE Mid-Year Review Form 2006
Biodiesel Impact on Engine Oil Performance
Howard L. Fang, Cummins Inc.
National Biodiesel Conf & Expo
Kissimmee, Florida
Feb. 4, 2008
AMMRE Mid-Year Review Form 2006
0
20
40
60
80
100
100 150 200 250 300 350 400
Temperature (C)
% R
eco
very
D-1
D-2
B100
DT=50C
§ Higher distillation temperature
§ Higher surface tension and higher specific gravity-larger fuel droplet size to condense on cylinder wall
§ Lower volatility and higher affinity toward oil additives-less likely to vaporize from crankcase oil
Biodiesel promotes fuel dilution
AMMRE Mid-Year Review Form 2006
Adverse biodiesel effects on engine oil
§ Methyl ester and its degradation products may compete with antiwear
ZDDP additive towards metal surfaces
-Wear/corrosion performance determines the limit for oil drain intervals
-Wear increase can be related to the film stability of the protection layer
§ Biodiesel promotes fuel dilution in oil particularly with late-injection
in aftertreatment regeneration
-SAE2006-01-3301 and SAE2007-01-4036
-High biodiesel dilution carries more water into the oil that may de-stabilize the overbased
detergents (Normally 1% fuel dilution will introduce 10 ppm additional water into the oil)
-Sludge derived from oxidation or interaction with additives can degrade piston cleanliness
AMMRE Mid-Year Review Form 2006
Beneficial effects on engine oil
§ Biodiesel and degradation products are potent friction modifiers
-Biodiesel blends assist fuel lubricity and can minimize the use of lubricity additives
-It needs to be verified
§ Dispersancy improvement by biodiesel soot
-Dispersancy improvement is caused by different PM morphology using biodiesel fuel
where more oxygenates are coupled into the soot structure resulting in a better soot
suspension by dispersant
-The dispersancy benefit can be evaluated by viscosity measurement
-It is important to determine the blending threshold for viscosity benefit
AMMRE Mid-Year Review Form 2006
Oil tracer approach on fuel dilution
174017601780180018201840
-0.07
-0.06
-0.05
-0.04
-0.03
-0.02
-0.01
0
Wavenumbers (cm-1)
Sig
na
l str
en
gth
7% Fuel Dilution
9% Fuel Dilution
4% Fuel Dilution
1% Fuel Dilution
For fuel tracer approach, including IR, GC and isotope labeling, the quantification of fuel dilution (FD) in oil is based on an appropriate calibration with ‘known’ amount of the biodiesel in engine oil. The unknown FD value is predicted through the slope of such calibration function. However, the exact concentration of biodiesel in the oil on cylinder wall is actually ‘unknown’ due to low distillation. Oil tracer approach is needed
AMMRE Mid-Year Review Form 2006
Sample selection
Sample
Soln -A: 2 % HPE in S150N
Soln -B: 4 % HPE in S150N
Soln -C: 5 % HPE in S150N
Soln -D: 8 % HPE in S150N
Soln -E: 2 % PE in S150N
Soln -F: 5 % PE in S150N
Soln -G: 8 % PE in S150N
ZDDP: Oloa 262
Baseoil : S150N
O
R-C-O
R-C-O
O
O-C-R
O
O
R-C-O
R-C-O
O
O-C-R
O
OH
OO-C-R
Partially esterfied pentaerythritol (HPE)Hydroxy # 60
Fully esterified pentaerythritol (PE)
AMMRE Mid-Year Review Form 2006
Hydroxy ester interaction with ZDDP
• Both nCOP (974 cm-1) and nP=S (652 cm-1) of ZDDP are sensitive to
environment
• Hydroxy ester (partially esterified species) can form complex with ZDDP
through hydrogen-bonding
• Under complex formation, the absorption strength of nCOP (974 cm-1) and
nP=S (652 cm-1) will be reduced following the hydroxy concentration
• Fully esterified esters should show little interaction with ZDDP
RO S S OR
P Zn P
RO S S OR
O H
H O
AMMRE Mid-Year Review Form 2006
Differential IR data of ZDDP in ester solutions
52.196
2.90117.008
Soln-G
(2% ZDDP in Soln-G) – (Soln-G)
31.889
2.94417.015
Soln-F
(2% ZDDP in Soln-F) – (Soln-F)
12.674
3.14917.582
Soln-E
(2% ZDDP in Soln-E) – (Soln-E)
41.001
2.64515.138
Soln-D
(2% ZDDP in Soln-D) – (Soln-D)
25.758
2.79815.757
Soln-C
(2% ZDDP in Soln-C) – (Soln-C)
20.403
2.84116.498
Soln-B
(2% ZDDP in Soln-B) – (Soln-B)
10.315
2.99817.221
Soln-A
(2% ZDDP in Soln-A) – (Soln-A)
Ester Cabonyl
(1789-1720 cm-1)
ZDDP nP=S
(690-620 cm-1)
ZDDP nCOP
(1050-910 cm-1)
Sample
52.196
2.90117.008
Soln-G
(2% ZDDP in Soln-G) – (Soln-G)
31.889
2.94417.015
Soln-F
(2% ZDDP in Soln-F) – (Soln-F)
12.674
3.14917.582
Soln-E
(2% ZDDP in Soln-E) – (Soln-E)
41.001
2.64515.138
Soln-D
(2% ZDDP in Soln-D) – (Soln-D)
25.758
2.79815.757
Soln-C
(2% ZDDP in Soln-C) – (Soln-C)
20.403
2.84116.498
Soln-B
(2% ZDDP in Soln-B) – (Soln-B)
10.315
2.99817.221
Soln-A
(2% ZDDP in Soln-A) – (Soln-A)
Ester Cabonyl
(1789-1720 cm-1)
ZDDP nP=S
(690-620 cm-1)
ZDDP nCOP
(1050-910 cm-1)
Sample
AMMRE Mid-Year Review Form 2006
ZDDP decay rates are faster in hydroxy
ester (HPE) than in full ester (PE)
14.5
15.5
16.5
17.5
18.5
0 2 4 6 8 10[Ester] % in S150N
ZD
DP
str
en
gth
@9
74
cm
-1
HPE (ZDDP@974)
PE (ZDDP@974)
2.5
2.7
2.9
3.1
3.3
3.5
0 2 4 6 8 10[Ester]% in S150N
ZD
DP
str
eng
th @
652 c
m-1
HPE (ZDDP@652)
PE (ZDDP@652)
At 8% concentration, the nCOP band drop is
12 % for HPE and only 3 % for PE
At 8 % concentration, the nP=S band drop is
12 % for HPE and only 2% for PE
AMMRE Mid-Year Review Form 2006
31P NMR data2°-ZDDP 1°-ZDDP
Sample Basic Neutral Basic Neutral
1% ZDDP in PAO 100.6 94.5 102.5 96.4 as is and @70ºC (14.2%) (61.6%) (12.8) (11.6%)
1% ZDDP in a mixture of 100.5 94.4 102.5 96.4
10% HPE/PAO @25°C (12.7%) (57.5%) (16.8) (13%)
1% ZDDP in a mixture of 100.5 94.3 102.5 96.4
10% HPE/PAO @50°C (9.9%) (58.2%) (17.5) (14.4%)
1% ZDDP in a mixture of 100.4 94.1 102.5 96.2
10% HPE/PAO @70°C (7.4%) (65.3%) (11.5%) (15.8%)
1% ZDDP in a mixture 100.3 94.0 * 96.1
10% HPE/PAO @90°C (4%) (63%) (16%)
*: area not integratible
AMMRE Mid-Year Review Form 2006
Electric Contact Resistance (ECR) data
ECR WSD
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0 0.01 0.02 0.03 0.04 0.05 0.06
Dose (fraction)
WS
D (
mm
)
WSD A
WSD F
WSD CD
CALC WSD A
CALC WSD F
CALC WSD CD
A: aged biodiesel F: fresh biodiesel CD: certified ULSD
Biodiesel aging was conducted by heating @110C for 20 hr under air flow
AMMRE Mid-Year Review Form 2006
High Frequency Reciprocating Rig (HFRR) data
HFRR WSD
0
50
100
150
200
250
300
350
400
0 0.01 0.02 0.03 0.04 0.05 0.06
Dose (fraction)
WS
D(m
icro
mete
r)CalcHFRR F CalcHFRR A
CalcHFRR CD WSD F
WSD A WSD CD
A: aged biodiesel F: fresh biodiesel CD: certified ULSD
AMMRE Mid-Year Review Form 2006
Four-ball wear test data
0
0.3
0.6
0.9
1% ULSD 1% Fresh SME 1% Aged SME
4-b
all w
ear
scar
(mm
)
1800 rpm
1600 rpm
40 kg load, 60 minute period, 120ºC with 1600 and 1800 rpm speed
AMMRE Mid-Year Review Form 2006
IR data of interaction between aged biodieseland ZDDP
0
0.3
0.6
0.9
16501700175018001850 cm-1
AB
S
fresh SME
aged SME
1780 1710
0
0.3
0.6
0.9
16501700175018001850 cm-1
AB
S
fresh RME
aged RME
0
0.3
0.6
0.9
16501700175018001850cm-1
AB
S
fresh palm
aged palm
1780 1700
1790 1720
0
0.3
0.6
0.9
55065075085095010501150 cm-1
AB
S
f resh SME
aged SME
0
0.3
0.6
0.9
55065075085095010501150 cm-1
AB
S
f resh RME
aged RME
0
0.3
0.6
0.9
55065075085095010501150cm-1
AB
S
f resh palm
aged palm
AMMRE Mid-Year Review Form 2006
Concentration dependence of wear scar on hydroxy ester as evaluated by four-ball
0.5
1.5
2.5
0 4 8 12
Ester Content (wt%) in PAO
Wear
Sca
r (m
m)
10% HE
10% Full Ester
AMMRE Mid-Year Review Form 2006
Dispersancy evaluation by KV100
4
5
6
7
8
0 0.2 0.4 0.6 0.8 1 1.2
[PM]% in PAO4 (300ppm dispersant)
KV
100
(cS
t)
B50
B20
ULSD
Break -off point of viscosity increase with [PM]
Dispersant: PIBSA/PAM (MW=5000m, 300 ppm in PAO4)
AMMRE Mid-Year Review Form 2006
Conclusions
§ Oil dilution by aged biodiesel may increase engine wear even at
concentration of 5% or less
§ Excessive fuel dilution of biodiesel can lead to complex formation
between oxidized biodiesel species and ZDDP
-Even under different tribological conditions, HFRR and four-ball give similar
results for oil containing aged biodiesel
§ Aged biodiesel causes wear increase while fresh biodiesel might
actually decrease wear
§ B50 seems to be the limit for soot suspension benefit when a level
of 300 ppm dispersant is used in PAO4
SAE2007-01-4141