PHASE I FINAL REPORT
HEAVY-DUTY ENGINE WORKING GROUP
MOBILE SOURCE TECHNICAL ADVISORY SUBCOMMITTEE
CLEAN AIR ACT ADVISORY COMMITTEE
APRIL 1997
-------
PHASE I FINAL REPORT
HEAVY-DUTY ENGINE WORKING GROUP
MOBILE SOURCE TECHNICAL ADVISORY SUBCOMMITTEE
CLEAN AIR ACT ADVISORY COMMITTEE
APRIL 1997
-------
Phase T Report
This report documents the staV.u^ of the EPA-Joint Industry Heavy
Duty Engine Work Group (HDEWG'} activity at the transition from
Phase I to Phase II of our cooperative program. Based on the
results of Phase I testing, the HDEWG has concluded that the
modified Caterpillar 3176 engine at Southwest Research Institute is
a valid test tool for evaluating the effects of fuel property
changes on NOx emissions at FTP NOx+NMHC level of 2.5 g/bhp-hr.
Based on these results and the guidelines established in the
"Intent of Initial Phase of Test Program" document, we recommend
moving forward with Phase II.
Background
The HDEWG was formed with the intent of contributing to EPA's 1999
technology review with an assessment of the relative merits of
achieving the 2.5 g/bhp-hr NOx + NMHC emission level by either:
Engine-system only
Engine-system + fuel modification
The Mission Statement of the HDEWG is given as Attachment 1. The
first activity of the work group was to tabulate a description of
data in the literature pertaining to fuel effects on heavy duty
engine emissions for reference, and to determine if any emissions-
fuel effects data is published at the 2.0 g/bhp-hr NOx level. This
tabulation, given as Attachment 2, indicates that no meaningful
data appears in the literature at the 2.0-3.0 g/bhp-hr NOx level .
The second work group activity was to design and conduct a low NOx
engine and fuel experimental study in four phases:
Phase I -- Validation of' "Transparent Test Tool" (2Q96-4Q96)
Phase II -- Fuels Matrix and Engine Variables Testing (4Q96-4Q97)
Phase III -- Fuel Effects Validation (4Q97-1Q98)
Phase IV -- Report (2Q98 target)
Phase I Results
The initial phase of the experimental study, "Validation of a
Transparent Test Tool", has been completed per the guidelines
established in the "Intent of Initial Testing" document (Attachment
3) . The agreed upon intent of this initial phase of the test
program was "to find out if the proposed "transparent test tool-"
has a similar overall response in emission performance to large
changes in fuel parameters as the "black box" engines - with all
engines demonstrating emissions capability at or near the 2.5
g/bhp-hr NOx + NMHC level."
The engine being proposed as a "transparent test tool" is a
Caterpillar 3176 with a cooled, low pressure EGR. The engine
features electronic unit injectors with 30 KSI injection pressure
capability. The engine operates at 17 bar BMEP at rated, 22 bar at
peak torque. Steady state 8 mode testing was employed because the
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configuration and control of the EGR system on this engine was
incapable of generating representative r- -sient emissions data.
Though there is confidence that steady .-late testing correlates
well with transient NOx results, there is not the same confidence
in steady state to transient particulate correlation. Therefore,
no particulate measurement was prescribed for this phase of
testing. Phase III of the test program is considered to be the
most appropriate place to evaluate particulate impact.
Three fuels were tested in Phase I: 1) a baseline commercial No. 2
diesel fuel; 2} a cetane enhanced version of the baseline fuel; and
3) a high (natural) cetane, low aromatic fuel. Fuel properties,
based on a round-robin analysis by eight labs, are summarized in
Table 1 and given in detail as Attachment 4.
Six engine manufacturers generated FTP and a prescribed steady
state synthesis (see Figure" 1) of FTP emissions data on these
fuels. "Black box" research engines which met a criteria of
operating at less than 3.0 g/bhp-hr NOx, and less than 0.5 g/bhp-hr
HC, and less than 0.15 g/bhp-hr particulate were used. Lab-to-lab
variability was not a significant factor since only percent change
versus the baseline fuel was being reported. The use of percent
change data allowed the engine manufacturers to protect their
proprietary research engine performance data. These engine tests
were all run in EPA compliant test facilities.
Comparisons of "black box" engine results with those of the
"transparent test tool" engine at SWRI are given in Tables 2 and 3
and are displayed in the accompanying graphics. A more detailed
listing of the "black box" engine data is given as Attachment 5.
The best correlation between the "black box" engines and the
"transparent test tool" was on NOx emissions. The engine
manufacturers report a 7.6 percent decrease in NOx from the
baseline fuel to the high cetane, low aromatic fuel, with a
standard deviation of 1.5 percent. The "transparent test tool"
generated a 7.0 percent decrease in NOx for the same fuel change.
Hydrocarbon results compare favorably in terms of order of
magnitude, but due to the very low levels being measured, percent
change and standard deviations are heavily influenced by extremely
small differences.
In terms of the response to cetane enhanced baseline fuel, NOx for
the black box engines increased by an average of 2.4 percent, with
the test tool generating a 3.4 percent increase. Hydrocarbon
measurements were highly variable again, with black box engines
reporting an average 11 percent decrease in hydrocarbon emissions,
as compared to no change with the test tool.
Discussion of Phase I Results:
While the primary objective of Phase I was to validate the SWRI
Caterpillar-3176 as a "transparent test tool", it was also used to
determine if the magnitude of fuel effects on low emission engines
were significant enough to move to Phase II of the program.
-------
The magnitude of the NOx change derived from high cetane, low
aromatic fuel of 7.6 percent correlates with tl findings of CRC
VE10 project. It is also in general agreement with the Chemkin
(chemical kinetics model) prediction of the change expected from
the aromatic or H/C ratio change discussed in an earlier HDEWG
meeting.
The negative or negligible impact of cetane enhancement (0.5% alkyl
nitrate} on emissions observed in Phase I was unexpected. "Black
box" results varied from a 5.3 percent increase to a 0.6 percent
decrease in NOx. Cetane enhancement is understood to affect NOx
formation primarily by reducing the amount of fuel burned in the
"premixed" combustion mode. Premixed (as opposed to diffusion
controlled) combustion yields high temperatures and pressures
associated with high rates of NOx formation. The combustion heat
release measurements taken by SWRI,in Phase I indicate that the
amount of fuel burned in the premixed combustion mode was reduced
by cetane enhancement, though by a smaller amount than expected.
Previously published data (1) suggests that increased cetane number
tends to reduce gaseous emissions. Effects on particulate matter,
"PM", are more variable, with a number of studies showing little or
no sensitivity of PM emissions to increased cetane number. Several
of these (notably SAE 950251) and other studies, have compared the
effect of natural vs. boosted cetane number on emissions, and
concluded that the effects of increased cetane number achieved
either through changes in base fuel composition or through
additives (alkyl nitrates, peroxides etc.) are equivalent. There
is little or no data in the published literature which suggests
that either fuel bound nitrogen or nitrogen contained in alkyl
nitrate ignition improvers makes a significant contribution to NOx
emissions from diesel engines. However, it should be noted that
these observations derive from assessment of fuel effects on heavy-
duty diesel engines {without EGR) calibrated to meet US 1998 or
earlier emissions standards. The influence of cetane (natural or
boosted) on engines designed to meet US 2004 emissions standards,
which - like the engine(s) used in the Phase I tests - are likely
to be equipped with EGR, has not been fully evaluated. Therefore,
the engine results in Phase I are inconsistent with our current
understanding of controlling phenomena, and it is recommended that
tests conducted in Phase II of this study include a thorough
evaluation of cetane effects on gaseous emissions.
References:
1. SAE: 902171, 922267, 930728, 932685, 932800, 941020, 950250,
950251, 961074.
The text of the SWRI report on Phase I is Attachment 6.
Phase I Conclusions
The modified CAT 3176 engine at Southwest Research Institute (SWRI)
responds to fuel property changes in a manner representative of
the "black box" research engines. Therefore, we have a valid
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test tool with which to proceed to Phase II.
Fuel effects on emissions on heavy duty diesel engines operating at
the 2.0-3.0 g/bhp-hr NOx level are significant enough to warrant
further study in Phase II.
During the analysis of the Phase I data, a number of questions
relative to the impact and interaction of engine EGR rates and
injection timing with fuel properties were discussed. Based on
these questions, EGR rates and injection timing will be
evaluated in Phase II.
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Table 1. Phase I Test Fuel Properties.
Baseline - "At the
Pump"
Cetane Enhanced
Baseline
High Cetane, Low
Aromatic
Cetane Number
46
52
57
SFC Aromatics,
%m
26
26
15
Density, g/cm3
.8564
.8564
.8233
Sulfur, ppr- !
310
315
180
Table 2. Comparison of emission response to high cetane, low aromatic fuel.
Black
Box
Engines
SWRI
FTP NOx
-7.6%
-
8-Mode
NOx
-7.6%
-7.0%
FTPHC
-35%
-
8-Mode
HC
-26%
-13%
FTP
Particulate
-16%
-
8-Mode
Particulate
*
-16%
-
FTP Fuel
Consumpfi
on
-2.2%
-
8-Mode
Fuel
Consumpti
on
-0.5%
-1.1%
*2 engine sample
Table 3. Comparison of emission response to cetane enhancement.
Black
Box
Engines
SWRI
FTP NOx
+1.5%
-
8-Mode
NOx
+2.4%
+3.4%
FTPHC
-33%
-
8-Mode
HC
-11%
-0.3%
FTP
Particulate
+0.3%
-
8-Mode
Particulate
+0.5%
,
-
FTP Fuel
Consumpti
on
-0.5%
-
8-Mode
Fuel
Consumpti
on
+1 .0%
+0.4%
*2 engine sample
50
Engine Speed (%)
100
Figure 1. Weighting Factors of 8-Mode FTP Synthesis
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Measured HC Emission Effect - High Cetane, Low
Aromatic Fuel vs. Baseline Fuel
0
-10
-20
o -30
D)
O
o>
-40
-50
-60
-70
-80
Transient
8-Mode
EMA Black Box Engines
Baseline Fuel
SWRI
8-Mode
CAT 3176
Black = Average
lwnt»Tai4i7.ppl
-------
Measured NOx Emission Effect - High Cetane, Low
Aromatic Fuel vs. Baseline Fuel
-2
x
O
o>
O>
ro -6
O
+*
Q) Q
O -O
0)
a.
-10
-12
Transient
8-Mode
EMA Black Box Engines
Baseline Fuel
Black = Average
SWRI
8-Mode
CAT 3176
-------
Measured Particulate Effect - High Cetane, Low
Aromatic Fuel vs. Baseline Fuel
Baseline Fuel
Black = Average
Transient
8-Mode
EMA Black Box Engines
bolK»7JZ14»7.|>flt
-------
Measured HC Emission Effect - Getane Enhance
Fuel vs. Baseline Fuel
10
o
o> -10
D)
o
"c
o
-60
m
Transient
8-Mode
EMA Black Box Engines
Baseline Fuel
Black = Average
SWRI 8-Mode
CAT 3176
-------
Measured NOx Emission Effect - Cetane Enhanced
Fuel vs. Baseline Fuel
Transient
8-Mode
EMA Black Box Engines
Black = Average
Baseline Fuel
SWRI
8-Mode
CAT 3176
ppt
-------
Measured Particulate Effect - Cetane Enhanced Fuel
vs. Baseline Fuel
0)
D)
c
CO
O
+rf
c
0
U
Q)
Q_
\£.
in -
I U
8_
6_
4_
-
-
A
-4 -
:,.-,.',:!: : :
•: '.'.'-.•:'.
_ ;:;;; ,_, |
Base
Black = Average
Transient
8-Mode
EMA Black Box Engines
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ATTACHMENT I
HDE Work Group Mission Statement
-------
Attachment 1
Heavy Duty Engine Work Group Mission Statement
Final 4/11/96
The work group will be comprised of representatives each from the heavy-duty
engine manufacturers and the petroleum refining industry. Representatives from
the Technical Advisory Subcommittee, other stakeholders, and EPA will also be
included as appropriate.
The work group is charged with developing emissions performance information
and with assessing the relative merits of approaches to achieve the 2.5 g/bhp-hr
NOx + NMHC emission level by either:
1. Engine-system only
2. Engine-system + fuel modification
It is recognized that the output of this work group will contribute to EPA's 1999
technology review and that cost, cost effectiveness, lead time and related factors
will be considered.
The timely assessment process will include evaluation of existing data on low
emission heavy-duty diesel engines, acquisition and testing of low emission
production viable diesel fuel formulas on prototype heavy-duty diesel engines
with production intent technologies capable of approaching the 2.5 g/bhp hr NOx
+ NMHC emission level.
The results of this work and any recommendations from the work group on
follow-up activities will be presented to the EPA and the Technical Advisory
Committee for their review and approval. The assessment should be completed
by October 31, 1997.
The work group will be co-chaired by a representative from the engine
manufacturers, the petroleum industry, and a "non-industry" representative from
the advisory subcommittee.
-------
Suggested Approach for Test Plan Development
1. Review current available information to direct.
a. Selection of engine NOx control technologies for evaluation.
b. Selection of fuel properties and range of values for evaluation.
2. Design test program using appropriate test matrix to eliminate engine
drifts and investigate non-linearity.
a. Engine-only emission control strategies using current low sulfur
diesel certification fuel.
b. Engine-fuel emission control strategies using engines equipped
with emission controls able to approach 2.5 g/bhp-hr NOx +
NMHC (on current low sulfur diesel certification fuel) and a fuel
matrix with production-feasible test fuels.
1. Develop engine baseline performance and emissions on
current commercial low sulfur diesel fuel.
2. Evaluate the impact of test fuels on emission performance.
3. Assemble test results in report usable to facilitate economic
evaluation of strategies.
-------
POSSIBLE STRUCTURE FOR EXPERIMENTAL PROGRAM
PHASE I (1996-2Q97):
Screen fuels with common engine at Southwest Research (Caterpillar
3176 fitted with exhaust gas recirculation; previously used for SWRI
clean diesel program).
PHASE 2 (2Q97):
Evaluate specific candidate fuels with in-house experiments at individual
engine manufacturer research laboratories.
Engine manufacturers are currently planning a "round-robin" test with
two fuels ("baseline" low-sulfur commercial diesel fuel; "low emission"
low-aromatic, high cetane experimental fuel) to confirm that the response
of the Caterpillar 3176 engine at SWRI to fuel modifications is
representative of current proprietary low-emission research engines.
-------
ATTACHMENT 2
Analysis of Current Literarture
-------
DATA REVIEW (1990-1996) - FUEL EFFECTS ON EMISSIONS FROM PRE-EGR HEAVY DUTY DIESEL ENGINES
Commentary and conclusions from a representative (but not exhaustive) review of literature concerning fuel effects on heavy duty (non-EGR) diesel engines
(see attachment 1) and data supplied by GARB on the quality and composition of diesel fuel in California (see attachment 2) are as follows:
1. Careful design of test fuel matrix is essential to minimise uncertainty in interpretation of results.
2. Changes in both fuel quality and engine design/calibration can influence emissions (and other aspects of performance such as power and fuel econony),
but In general fuel effects tend to be significantly smaller than engine effects.
• see SAE941020 and SAE950250 where fuel effects on emissions were assessed at two different engine timing settings.
« see SAE961074 where the effect of timing changes on NOx, Pm, power and fuel consumption was compared with changes in fuel quality
3. Different engines have different emissions responses to the same change in fuel quality
• see SAE941020 and SAE950250 where 2 different engines were tested over the US transient cycle on the same fuel matrix
• see SAE961074 where 5 different engines were tested over the EU steady state test on the same fuel matrix (different to above)
=> assessment of the air quality impact of changing fuel quality should be based on the fuel property/emissions sensitivity of a representative range of
engines
4. The same engine will give different absolute levels of emissions and may give different responses to fuel changes when tested on the same fuel matrix
over the US transient and the EU steady-state tests. This coupled with different emissions responses amongst engines makes it difficult to draw
comparisons between conclusions of US and European studies. The only published link between US and EU studies appears to be limited testing of 3
EPEFE fuels in a DDC Series 60 engine over the US transient cycle which suggests this engine is less sensitive (especially for NOx) to changes in fuel
quality over the US test cycle than EPEFE engines over the EU test cycle
• see reference to EPEFE report annex 7 in attachment 1
5. The majority of European studies pre-EPEFE focused on fuel effects on Pm. Since total aromatics were found to have no influence on Pm emissions
(supported by a number of more recent US studies eg: SAE941020), but there was uncertainly regarding the influence of polyaromatics, then the latter
was included as a key variable to be investigated in the EPEFE program.
EPEFE showed that polyaromatics can influence both NOx and Pm. The effect of monaromattcs was not studied, hence there remains uncertainty
regarding the relative importance on mono and polyaromatics on NOx emissions.
6. The majority of US studies have focused on the effects on cetane and total aromatics on NOx and Pm emissions. The separate effects of mono and poly
aromatics have not been systematically studied.
European studies have additionally included systematic study of other fuel properties - notably density, which has been found to have a significant
influence on engine performance and emissions in a number of engines, caused by physical interaction with the fuel injection system - influencing dynamic
timing and mass delivery but not affecting the combustion process itself.
page I
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7. Re-analysis of historic data in an attempt to investigate the significance of other fuel characteristics (eg: H/C ratio) is unlikely to lead to robust conclusions.
• Required information infrequently reported
• Uncertainty vs accuracy of data where it does exist (poor test method precision for H/C ratio)
8. A wide range of diesel fuel formulations have been certified by CARS* to have equivalent or better emissions than a reference fuel containing 10% total
aromatics. These fuel formulations include levels of total aromatics in excess of 27%, cetane numbers below 48 and sulphur levels up to 500ppm.
* in line with requirements of section 2282(g) of Title 13, California Code of Regulations.
page 2
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ATTACHMENT 1
I Source Engine Scope Cycle delta delta delta delta Comments
NOx Pm HC CO
SAE9O21?r
Ullman et al
SAE 912425
Lange
SAE 922267
McCarthy &
Slodowske
elal
SAE930728
Nikanjam
DDC Series 60 W protoype
11.1l;330hp
-------
1 Source Engine Scope Cycle delta delta delta delta Comments
NOx Pm HC CO
SAES32685
Unge&
Gaifingetal
SAE9028QO
Rosenthal et
al
SAE941020
Ullman et al
"
MB OM366L EURO 1
production engine
S; 177kWe2eOOrpm; TC;
1C; 01; mech inline pump
7.52g/kWhr NOx and
0 344g/kWhr Pm on 0.06%
S ceil fuel
Cummins N14*94
production engine
141; 3«*W (460hp)@?rpm
4 44g/brphr NOx and
O.OTSg/bhphr Pm on 0.05%
S cert fuel
DOC Series 60 94 prototype
11.1l;239t(Wei800rpm;
DI;TC;AC:EUI(std
calibration)
nominally 5g/bhphr NOx and
0. 1 g/brtphr Pm - no baseline
data on cert fuel given
12 fuel matrix
designed to study
fuel effects on
emissions.
especially NOx and
Pm
7 fuel matrix
designed to study
the influence of
H/C ratio, boiling
range and cetane
on emissions,
principally NOx and
Pm
1 1 fuel matrix
designed lo study
the effect of cetane,
total aromatic*
(SFC) and
oxygenates on
NOx, Pm, HC and
CO
EUECER49(13
mod* - steady
state)
Constant max
power for all fuels
US FTP
(transient) - hot
start only.
A ref fuel
transient
command cycle
used throughout
US FTP
(transient) - hot
and cold starts
A ref fuel
transient
command cycle
used throughout
no effect for
total (HPLC)
aromatlcs (28-
8%).
-0.358/kWhr
for+10CN(SO-
60)
-0.148g/bhphr
for -10% total
(FIA)
aromatlcs
-0. ICgJbfiphr
for+IOCN
-O.lg/bhphr for
-10% (30-20)
total aromatlcs
+OO39flJt>hphr
for +1% (0.25-
1.25) oxygen
-o.oeggAtiphr
for +1OCN (45-
551
•••••••••MP*i*J^B*^BV^Ba*a*ai
no effect for
total (HPLC)
aromatlcs (28-
8%).
-O.OCBg/kWhr
for-003%3
(0.06O.02)
-0.012flAWhr
for -C.02kg/l
density (0.84-
0.62)
-O.OIoVkWhr
for -2%
polyaromatics
0-1%)
-O02g/bfiphr
for -10% total
(FIA)
aromatlcs
no effect for-
10% (3O-20)
total aromattcs
•0.00eg/briphr
for +1% (0.25-
1 .25) oxygen
no effect for
HOCN (4&-5S)
P^B*^BPlW^BHi*JP^B*^Pi^iiPB
no effect for
-10% (30-20)
total aromatics
+aOQ6g/bhphr
for +1% (0.25-
1 .25) oxygen
no effect for
*1OCN (1&-55)
^^•^•••••••••••av^^^^^^vx
«O.O53g/bhphr
for -10% (30-
20) total
aromatics
•O.096g/bhphr
for +1 % (O.25-
1.25) oxygen
-O1g/bhphr for
*10CN (45-55)
Fuel effects determined by pairwise
comparisons within separate 3 sub-
matrices where parameters of interest
were decor related - plus regression
analysis of full 12 fuel test matrix
Significant Intercorrelatlon between
some properties, notably aromatics
and density - leading to uncertainty vs
assignment of emissions effects and
robustness of preferred models.
Aromatlcs measured by FIA and SFC
(MS and NMR given in full report).
Significant mtercorrelation between
total, mono, poly aromatics.
nb: 1 kW= 1.341 hp
page 4
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(Source Engine Scope Cycle delta delta delta delta Comments
NOx Pm HC CO
SAE94102D
Ullmanetal
SAE942022
Den Ouden
eta!
SAE960250
Spreen et al
DDC Series eo "94 prototype
11.1l;239kW@1800rpm;
Dl; TC; AC; EUI (timing
retarded from std calibration)
nominally 4g/bhphr NOx and
Pm slightly > 0. 1 g/bhphr - no
baseline data on cert fuel
given
5 different HD engines; all
01; TC; AC; mixture of mech
and electronic control;
pre EUR0 1; EURO land
USBI emissions calibrations
Navistar OTA466 ~94
prototype
7.61; 14SkW
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I Source Engine Scope Cycle delta delta delta delta Commenl^
NOx Pm HC CO •&.
SAE960250
Spreen et al
SAE060251
Ullman et al
Achen
Colloquium
Oct95
Navistar DTA466 "94
prototype
761; 143kW@2400rpm
TC; AC; 01 (3 deg in] retard);
oxidation catalyst
4.31 8/bhphr NOx and
0.12g/bhphr Pm on 'base'
fuel (0.06% S)
DDC Series 60 fXJ prototype
11.1l;242kWei800rpm
TC; AC; Ol; EUI
412g/bhpnr NOx and
O.O37g/bhphr Pm on 'base'
fuel
MAN D-0326LF production
engine
601; 169kWO2400rpm
TC; 1C; 01 mech Inline pump
nominally SgAcWhr NOx and
0 36g/kWhr Pm
1 1 fuel matrix
designed to study
the effect of cetane.
aromatlcs (SFC)
and oxygenates on
NOx. Pm, HC and
CO
1 1 fuel matrix
designed to study
the effect of cetane
on NOx. Pm. HC
and CO
13 fuel matrix
designed to study
fuel effects on
emissions -
principally Pm and
NOx
US FTP
(transient) - hot
and cold starts
A ref fuel
transient
command cycle
used throughout
US FTP
(transient) - hot
and cold starts
A ref fuel
transient
command cycte
used throuQhout
EUECER4B(13
mode -steady
state)
Constant max
power for all fuels
no effect for
-10% (30-20)
total aromatlcs
no effect for
+2% (0-2)
oxygen
-O.200g/bhphr
for +10CN (45-
55)
-0.164g/bnphr
for +10CN (45-
55)
•0.210/kWhr
for -10% (25-
15) total
(HPIC)
aromatics
-0.44g/kWrv
for +10CN (50-
60)
•OOOTg/bhphr
for -10% (30-
20) total
aromatlcs
•OOOSg/bhphr
for +2% (O-2)
oxygen
-0.013flA)hphr
for +10CN (45-
55)
-O.005g/bhphr
for +10CN (45-
55)
no effect for
total aromatlcs
-0.011 g/kWhr
for +10CN (50-
60)
-0066g/kWhr
for -0.15% S
(02-O.O5)
•WWm^^^"^^^^^^^™^"^^™l
no effect for
-10% (30-201
total aromatlcs
no effect for
+2% (0-2)
oxygen
-0.4B3g/bhphr
for +10CN (45-
55)
-0.06Bg/bhphr
for +10CN (45-
55)
no effect for
-1O% (30-20)
total aromatlcs
no effect for
+2% (0-2)
oxygen
-1 .26g/bhphr
for +10CN (45-
S6>
•O.iaeo/bhprtr
for +10CN (45-
55)
Aromatica measured by F . 3FC
(MS and NMR data given In .'• :
report).
Significant Intercorrelation between
total, mono, poly aromatics
The effects of density on emissions
were not studied In this program.
nb: 1 kW = 1 341 hp
page 6
-------
I Source Engine Scope Cycle delta delta delta delta Comments
NOx Pm HC CO
SAE961074
Signer et al
& final
EPEFE
report
SAE961074
Signer et al
& final
EPEFE
report
5 prototype engines which
meet EU 1996 emissions
limits of 7g/KWhr NOx and
0.1Sg/kWhrPm
5 prototype engines which
meet EU 1996 emissions
limits of 7g/kWhr NOx and
0.15g/kWhr Pm:
8.69; 6cyl;
222kW@2300rpm TC; !C
2.81; 4cyl;
64.5kW@3600rpm; TC; 1C
6.9; 6cyl;
162kW@2400rpm; TC; 1C
10.961; 6cyl;
2SOkW@1900rpm; TC; 1C;
.
6.21; 6cyl;
125kW@2500rpm;TC;IC
1 1 fuel matrix
designed to study
the effects of
density,
potyaromatics, T95
and CN on NOx,
Pm, HC and CO
1 1 fuel matrix
designed to study
the effects of
density,
potyaromatics, T96
and CN on NOx,
Pm, HC and CO
EU ECE R48 (13
mode - steady
state)
Engines set to
reference power
and tested on all
fuels without
adjustment
EUECER49(13
mode - steady
state)
Engines set to
reference power
and tested on alt
fuels without
adjustment
-0.245g/kWhr
for -0.027kg/l
density (0.855-
0.828)
-0.114g/kWhr
for -7%
polyarom (8-1)
-0.040g/kWhr
for +8CN (50-
58)
-0.120g/kWhr
for-45C
T9S(370-325)
+0.060410
-0.6511 g/kWhr
for -Q.027kg/l
density (0.856-
0.828)
-0.0483to
-0.194g/kWhr
for -7%
polyarom (8-1)
+0.0235 to
-0.0702g/kWhr
for +8CN (50-
58)
-0.0027 to
•O.2421g/kWhr
for-45C
T95(370-325)
^^^^PHVMIV^^^^^^^^M*^
no effect for
-0.027kg/!
density (0.855-
0.828)
-O.OD5g/kWhr
for -7%
polyarom (8-1 )
no effect for
+8CN (50-58)
no effect for
-45CT95
pTO-325)
+0.0034 to
XX0077g/kWhr
for -0.027kg/l
density (0.855-
0.828)
-0.000410
•O.OOSSg/kWhr
for -7%
polyarom (8-1 )
+0.001 3 to
-0.001 5g/kWhr
for +8CN (50-
58)
+0.0131 to
-0.0099g/kWhr
for-45C
T96(370-325)
+OO34g/kWhr
for -0.027kg/l
density (0.855-
0.828)
-O.OQ9g/kWhr
for -7%
polyarom (8-1)
-0.014g/kWhr
for +8CN (50-
58)
+0.031 g/kWhr
for-45C
195(370-325)
+0053710
+0.014g/kWhr
for -0.027kg/l
density (0.855-
0.828)
-0.0048 to
•0.018gAWhr
for -7%
polyarom (8-1 )
-0006110
-0.024g/kWhr
for +8CN (50-
58)
+0.0622 to
+0.0005g/kWh
rfor-45C
195(370-325)
+OO3g/kWhr
for -0.027kg/l
density (0.855-
0.828)
no effect for
-7% polyarom
(8-1)
-0.061 g/kWhr
for +8CN (50-
58)
+0.039g/kWhr
for-45C
T95(370-325L
+0.0962 to
-0.033g/kWhr
for -O.027kg/l
density (0.855-
0.828)
+O.0165to
•O.0098g^W
hrfor-7%
polyarom (8-1 )
•O.010210
-0.1H4g/kW
hr for +8CN
(5f>58)
+0.0801 to
-0.0234g/kW
hrfor-45C
195(370-325)
Emissions effects quoted are derived
from the global regression model for
the fleet of 5 engines
Emissions effects quoted are
maxlumum and minimum effects
derived from regression model for
each of the 5 individual engines.
nb: 1 kW = 1.341 hp
page 7
-------
(Source Engine Scope Cycle delta delta delta delta Comments
NO* Prn HC CO
SAE961074
and
EPEFE
Report -
table 10.2.2
EPEFE
Report -
Annex 07
5 prototype engines
(standard timing, fuel
delivery) which meet EU
1996 emissions limits of
7g/KWhrNOxand
O.ISg/kWhrPm:
8.65f; 6cyl;
222kW@2300rpm TC; 1C
2.81; 4cyt;
84.5M/v@3600rpm; TC; 1C
6.91; 6cyl;
162kW@2403rpm; TC; 1C
10.961; 6cyl;
250kW©19COrpm; TC; 1C;
6.21; 6cy1;
125kW©2500rpm; TC; 1C
DOC Series 60 '91 prototype
(at SwRi)
Two fuels
representing the
extremes of the
EPEFE matrix
-------
ATTACHMENT 2
California diesel fuel
GARB compliance sample test results
uo
en _
OU
cc .
cetane **
number cn
Oil ~
AK -
15)
A(\ .
X
•
•
A *•
V X A *
X ••
A
A A X X
X XX
... .1 ,
. -J
. S<25
S 25-100
A S 100-300
x S 300-500
10 20
aromatics %m
30
Data provided by GARB to EPA Heavy Duty Engine Working Group - Spring 1996
nb: all samples deemed to be in compliance with C ARB regulations
page1
-------
ATTACHMENT 3
HDE Work Group
Intent of Initial Phase of Test Program
-------
Attachment 3
Heavy Duty Engine Work
Intent of "Initial" Phase of Test Program
The purpose of this document is to define the intent of the "initial" phase of
testing to be carried out by members of the Heavy Duty Working Group.
Specific details of the test protocol (including engine test cycles, fuel analysis
and data reporting, etc.) Will be developed separately by representatives of the
key stakeholders (EMA, API, EPA).
1. The primary objective of the "initial" phase of the test program is to
validate the CAT 3176 of SwRI as a "transparent test tool" relative to
current research ("black box") engines in the laboratories of EMA
members. The intention is to find out if the "transparent test tool" has a
similar overall response in emission performance to changes in fuel
parameters as the "black box" engines - with all engines demonstrating
emissions capability at or near the "2.5 g/bhp-hr NOx + HC" level.
The second main objective of the "Initial" phase of testing is to establish
the emissions sensitivity to extreme fuel modifications for a range of
engines with such production intent technologies, and to establish options
for the main body of work to be carried out by the Heavy Duty Engine
Working Group.
2. The "initial phase of testing will therefore involve testing three fuels: 1)
current commercial No. 2-D diesel, 2) an 'extreme' No. 2 diesel fuel -
high cetane, low aromatics with all other properties allowed to 'float',
and 3) cetane-enhanced current commercial No. 2 diesel. These fuels
will be evaluated with the CAT 3176 at SwRI and current EMA research
("black box") engines with "2.5 g/bhp-hr NOx + HC" production intent
technologies. (Fuel 3 is a cetane-enhanced version of Fuel 1 using cetane
improver.)
It is recognized by all parties at the outset that the results of this "Initial"
phase of testing is intended to define the boundaries for fuel effects "2.5
g/bhp-hr NOx + HC" engines and not to define relative importance of
any specific fuel parameters.
-------
3. The Heavy Duty Engine Working Group will analyze the results of v'ais
program and the agreed conclusions will form an interim progress uport
to the Technical Advisory Subcommittee.
These agreed conclusions, together with those arising from the data
review process, will have significant implications for the direction of the
next phase of work to be developed and carried out by the Heavy Duty
Engine Working Group.
For example:
(1) All engines show the same relative sensitivity to NOx, PM,
and HC to the fuel changes. (Good transparent test tool)
(a) if this sensitivity is insignificant, then further work
on fuel effects will not be necessary
(b) if this sensitivity is "significant" then further work
is required to understand the relative importance of
individual fuel parameters and to determine whether
all engines respond in the same way (e.g., some
may be more sensitive to cetane, others to
aromatics, etc.)
Therefore...
(a) use the CAT 3176 at SwRI to examine effects of
individual fuel parameters in a jointly agreed to
fuels matrix
(b) use the CAT 3176 at SwRI to examine effects of
engine adjustments (e.g., different levels of EGR)
(c) validate findings from (a) & (b) by testing a sub set
of the fuels matrix defined in (a) on a range of
"black box" engines.
(2) Engines show different sensitivities to NOx, PM, and HC
to the fuel changes - need to understand why and identify
those technologies with give the minimum emissions
sensitivity to fuel modification jjiot an acceptable
transparent _test tool).
-------
ATTACHMENT 4
Round Robin Fuel Analysis Results - Phase 1
-------
PHASE1FS.XLS
HDDEWG Phase 1 Test Program
Test Fuel Inspection Data.
12/4/96
R. SobotowsKi
PARAMETER
DENSITY® 15 C,g/cm3
API GRAVITY @ 60F, deg. API
CETANE NUMBER
CETANE INDEX
CETANE INDEX
DISTILLATION, F IBP
5%
10%
20%
30%
40%
50%
60%
70%
80%
90%
95%
FBP
NMR, mol % AROMATICS
SATURATES
MS, %m PARAFFINS
MONOCYCLOPARAFFINS
DICYCLOPARAFFINS
TRICYCLOPARAFFINS
ALKYL BENZENES
INDANES / TETRALINS
INDENES
NAPHTHALENE
NAPHTHALENES
ACENAPHTHENES
'ACENAPHTHALENES
TRICYCLIC AROMATICS
TOTAL AROMATICS
SFC AROMATICS, %m 1 -RING
2-RING
3-RING
TOTAL
CARBON, %m
HYDROGEN, %m
NITROGEN, ppm
SULFUR, ppm
HOC, gross, btu/lb
MJ/kg
MJ/dm3
HOC, net, MJ/kg
MJ/dm3
VISCOSITY @40C,mm2/s
@ 100C, mm2/s
CLOUD POINT, F
POUR POINT, F
FLASH POINT, F
ALKYL NITRATE CONTENT, %v
TEST
METHOD
ASTM D4052
ASTM D4052
ASTM D6 13
ASTM D976
ASTM D4737
ASTM D86
ASTM D5292
ASTM D2425
ASTM D5 186
ASTM D5291
ASTM D5291
ASTM 04629
ASTM D2622
ASTM D4809
ASTM D445
ASTM D2500
ASTM D97
ASTM D93
Nalco GC
AMOCO-1
0.8564
33.6
45.9
45.0
44.4
365
408
432
456
476
495
513
530
550
571
601
628
649
18.1
81.9
34.33
20.35
5.84
3.42
14.06
11.07
3.34
0.81
2.48
2.24
1.20
0.86
36.06
26.6
poly 9.1
35.7
87.11
13.06
85
310
19460
45.26
38.76
42.49
36.39
2.74
1.13
0
_i
160
0.047
AMOCO-2
0.8564
33.7
52.4
45.4
45.0
350
405
430
456
476
494
513
530
549
570
602
630
646
18.4
81.6
-
26.2
poly 8.9
35.1
86.99
13.17
438
315
19411
45.15
38.67
42.36
36.27
2.72
1.13
t
„(
161
0.553
W-407
0.8233
40.3
56.9
56.2
59.3
397
436
454
472
487
499
511
522
536
553
584
612
630
9.8
90.2
60.9
17.57
5.9
2.81
5.02
3.7
1.2
0.2
0.9
0.7
0.5
0.5
12.84
15.5
poly 4.5
20.0
86.09
13.84
28
180
19817
46.10
37.95
43.16
35.53
2.72
1.15
i
j
181
< 1ppm
-------
PHASE 1FS.XLS
Table 3: Fuel W-407 Inspection Data.
HDDEWG Phase 1 Test Program
PARAMETER
DENSITY @ 15 C , g/cm3
API GRAVITY @ 60F, deg. API
CETANE NUMBER
CETANE INDEX
CETANE INDEX
DISTILLATION, F IBP
5%
10%
20V.
30%
40%
50%
60%
70%
80%
90%
96%
FBP
NMR, mol %C AROMATIC
SATURATE
MS, %m PARAFFINS
MONOCYCLOPARAFFINS
DICVCLOPARAFFINS
TRIG YCLOPARAF FINS
ALKYL BENZENES
INOANES / TETRALINS
INDENES
NAPHTHALENE
NAPHTHALENES
ACENAPHTHENES
ACENAPHTHALENES
TRICYCLIC AROMATICS
TOTAL AROMATICS
SFC AROMATICS, %m 1-RING
Z-RING
3-RING
TOTAL
CARBON, %m
HYDROGEN, %m
NITROGEN, ppm
SULFUR, ppm
HOC, gross, _ btu/lb
' MJ/kg
MJ/dm3
HOC, net, MJ/kg
MJ/dm3
VISCOSITY @40C, mm2/s
@ 100C, mm2/s
CLOUD POINT, F
POUR POINT, F
FLASH POINT, F
ALKYL NITRATE CONTENT. %v
TEST
METHOD
ASTM D4052
ASTM D4052
ASTMD613
ASTM D976
ASTM D4737
ASTM D86
ASTM D5292
ASTM D2425
ASTM DS186
ASTM D5291
ASTM 05291
ASTM D4629
ASTM D2622
ASTM D4809
ASTM 044S
ASTM D2500
ASTM D97
ASTM D93
ASTM D4046
ARCO
0.8228
40.4
57.5
56.6
-
397
440
457
512
594
634
635
"
•
15.8
poly 4.5
20.3
65.92
14.08
27
178
-
2.70
8
j
184
-
BP
0.8231
40.3
55.3
56.3
59.4
397
439
455
473
487
499
511
523
537
554
584
611
628
9.6
90.4
-
15.0
4.6
1.0
20.6
66.29
13.73
-
180
19948
46.40
38.19
43.43
35.79
2.74
1.17
6
0
185
"-$•**
MOBIL
0.8228
40.4
57.6(core)
-
-
401
459
513
583
€33
9.65
90.35
-
' Vt9^(««a)
85.63
14.18
'•-^~i-m
186
19811 (core
46.03
37.9
43.07
35.44
2.73
1.14
12
5
-
*&&3p«&
NAVISTAR
0.8236
40.3
56.2(swri)
56.0
56.9
393
451
469
488
493
509
524
537
553
581
636
«
-
^8,;Sf$w$l
86.82{swri
13.39(swr<
27(swri
190(swri
19780(swri
46.01
37.89
43.17
35.55
2.68
9(swri
' 5(swri
177
-
SHELL
0.8237
40.2
58.6
56.3
59.5
396
438
454
474
488
soo
512
524
537
555
584
611
628
10.0
90.0
60.87
17.57
5.91
2.81
5.02
3.70
1.24
0.24
0.86
0.70
0.54
0.54
12.84
17.4
poly 4.5
21.9
86.17
13.85
32
176
19792
46.04
37,92
43.10
35.50
2.73
1.14
S
i
184
r-^ijaa
SWRI
0.8234
40.3
55.1
-
-
407
432
454
473
489
500
512
523
537
555
585
609
624
*
-
14.7
poly 3.9
18.6
66.04
13.78
26
170
19756
45.95
37,84
43.03
35.43
2.73
1.14
10
5
183
< 1ppm *
76
PRODUCTS
COMPANY
0.8233
•
56.0
56.2
-
395
437
453
472
486
499
510
522
535
553
581
606
623
"
-
14.3
poly 4.1
18.4
55.70
13.90
27
17
•
2.7
h ' iOg
10
180
-
PHILLIPS
0.8235
•
58.5
55.8
-
388
432
448
470
485
497
507
519
532
550
577
601
629
"
-
-
86.15
13.85
-
186
-
-:-\\^9Q
j
5
174
-
AVERAGE
0.8233
40.3
56.9
S6.2
53.3
397
436
454
472
487
499
511
522
536
553
584
612
630
9.8
90.2
60.37
17.57
5.91
2.61
5.02
3.70
1.24
0.24
0.86
0.70
0.54
0.54
12.84
15.5
poly 4.5
20.0
86.09
13.84
28
180
19817
46.10
37.95
43.16
35.53
2.72
1.15
4
181
< 1ppm "
' Shell method. Claimed accuracy an order of magnitude better than D5291.
™ Nalco GC method
.".. Data not used in averaging !!!
' BP Infrared method
-------
PHASE1FS.XLS
12/4/96
Table 1: AMQCO-1 Fuel Inspection Data.
HDDEWG Phase 1 Test Program
PARAMETER
DENSITY @ 15 C , g/cm3
API GRAVITY @ 60F, deg. API
CETANE NUMBER
CETANE INDEX
CETANE INDEX
DISTILLATION, F IBP
5%
10%
20%
30%
40%
50%
60%
70%
80%
90%
95%
FBP
NMR, mol %C AROMATIC
SATURATE
MS, %m PARAFFINS
MONOCYCLOPARAFFINS
D1CYCLOPARAFFINS
TRICYCLOPARAFFINS
ALKYL BENZENES
INDANES/TETRALINS
tNDENES
NAPHTHALENE
NAPHTHALENES
ACENAPHTHENES
ACENAPHTHALENES
TRICYCLIC AROMATICS
TOTAL AROMATICS
SFC AROMATICS, %rn 1-RING
2 -RING
3 -RING
TOTAL
CARBON, Mm
HYDROGEN, %m
NITROGEN, ppm
SULFUR, ppm
HOC, gross, btu/lb
MJ/kg
MJ/dm3
HOC, net, MJ/kg
MJ/dm3
VISCOSITY @40C,mm2/s
@ 100C, mm2/s
CLOUD POINT, F
POUR POINT, F
FLASH POINT, F
ALKYL MTRATE CONTENT, %v
TEST
METHOD
ASTM D4052
ASTM D4052
ASTMD613
ASTM D976
ASTM D4737
ASTM D86
ASTM D5292
ASTM D2425
ASTM 051 86
ASTM DS291
ASTM DS291
ASTM D4629
ASTM D2622
ASTM D4809
ASTM D445
ASTM D2500
ASTM D97
ASTM D93
ASTM D4046
ARCO
0.8566
33.6
45.2
44.B
-
376
415
436
515
600
626
654
;
-
r;v%®
>;.>;:}«£
-
-
81
313
-
2.73
1.13
t
\
152
-
BP
0.8566
33.6
43.8
44.7
44.1
367
407
429
454
474
492
510
528
547
569
599
624
641
18.5
81.5
-
25.9
8.4
1.9
36.2
86.98
13.00
88
320
19590
45.57
39.03
42.8
36.67
2.76
1.15
-5
16
,094
MOBIL
0.6556
33.8
44.6{core)
-
-
367
436
515
606
646
16.63
83.37
-
25.7
9.1
1.7
36.5
87.53
13.38
-
333
19410(core
45.15
38.63
42.3
36.20
2.75
1.13
1 \ ; *€
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160
fcor&w*:
NAVISTAR
0.8566
33.6
49.5(swri)
44.7
43.7
361
427
454
473
492
510
528
548
565
593
646
;
-
_;^
66.80(swri
13.01(swri
83{swri
310{swri
19408(swri
45.14
38,67
42.38
36.30
2.70
0(swr
-6(swn
15
-
SHELL
0.8566
33.6
46.0
45.6
45.4
366
420
439
460
480
498
515
532
552
574
604
632
654
19.3
80.7
34.33
20.35
5.84
3.42
14.06
11.07
3.34
0.81
2.48
2.24
1.20
0.86
36.06
29.1
poly 8.54
37.6
87.117"
12.916"
82
283
19457
45.2
38.7
42.5
36.40
2.7
1.1
-4
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15
SWSfSWSSjiW
&H*S«*R!MW?
SWRI
0.8564
33.6
44.2
-
-
351
397
• 426
453
476
495
513
531
550
572
603
629
644
•
-
26.1
poly 7.54
33.6
87.10
13.00
84
300
19434
45.20
38.7
42.5
36.40
2.73
1.13
0
J
166
0.047 *
76
PRODUCTS
COMPANY
0.8564
33.7
48,3
45.2
-
367
403
430
458
478
496
514
532
551
572
602
629
656
•
-
26.2
poly 8.5
34.7
-
-
9
31
-
2.7
1.1
16
-
AVERAGE
0.8564
33.6
45.9
45.0
44.4
365
408
432
456
476
495
513
530
550
571
601
628
649
18.1
61.9
34.33
20.35
5.84
3.42
14.06
11.07
3.34
0.81
2.48
2.24
1.20
0.86
36,06
26.6
poly 9.1
35.7
87.11
13.06
85
310
19460
45.26
38.76
42.49
36.39
2.74
1.13
-5
160
0.047 "
' BP infrared method
'* Nalco GC method
'" Shell method. Claimed accuracy an order of magnitude better than D5291.
' Data not used in averaging !!l
-------
PHASE1FS.XLS
Tabls •;•: AMOCO-2 Fuel Inspection Data.
HDDEWG Phase 1 Test Program
PARAMETER
DENSITY @ 1S C , g/cm3
API GRAVITY @ 60F, deg. API
CETANE NUMBER
CETANE INDEX
CETANE INDEX
DISTILLATION, F IBP
6%
10%
20%
30%
40%
50%
60%
70%
80%
90%
95%
FBP
NMR, mol %C AROMATIC
SATURATE
MS, %m PARAFFINS
MONOCYCLOPARAFFINS
DICYCLOPARAFFINS
TRICYCLOPARAFFtNS
ALKYL BENZENES
INDANES/TETRALINS
INDENES
NAPHTHALENE
NAPHTHALENES
ACENAPHTHENES
ACENAPHTHALENES
TRICYCLIC AROMATICS
TOTAL AROMATICS
SFC AROMATICS, %m 1-RING
2 -RING
3 -RING
TOTAL
CARBON, %m
HYDROGEN, %m
NITROGEN, ppm
SULFUR, ppm
HOC, gross, btu/lb
MJ/kg
MJ/dm3
HOC, net, MJ/kg
MJ/dm3
VISCOSITY @ 40C, mm2/s
@ 100C, mm2/s
CLOUD POINT, F
POUR POINT, F
FLASH POINT, F
ALKYL NITRATE CONTENT, %V
TEST
METHOD
ASTM D4052
ASTM D4052
ASTMD613
ASTM D976
ASTM D4737
ASTM D86
ASTM DS292
ASTM D2425
ASTMDS186
ASTM D5291
ASTM D5291
ASTM D4629
ASTM D2622
ASTM D4809
ASTM D445
ASTM D2500
ASTM D97
ASTM D93
ASTM D4046
ARCO
0.8566
33.6
54.4
44.6
-
369
411
431
514
606
638
650
-
-
*-•??•&$
•• •••' •• 8 *
•••-;,!-••: ,*?<*
-
-
416
314
-
2.73
1.13
i
-5
162
-
BP
0.8567
33.6
52.9
45.1
43.9
342
406
426
454
474
492
510
528
547
568
598
624
639
18,1
81,9
-
26.1
8.6
1.1
35.8
86.96
13.07
412
320
19435
45.20
38.73
42.43
36.35
2.72
1.15
-11
169
MOBIL
0.8556
33.8
51 ,3(core)
-
-
338
428
515
605
642
18.79
81.21
-
26.1
8.9
1.4
36.4
87.37
13.42
-
365
19403(core
45.13
38.61
42.28
36.18
2.71
1.12
•.-•.-; ;, \iitg
-17
162
i$3@H
NAVISTAR
$$£14
•^.^sM
51 .6(swri)
46.7
46.2
358
430
454
476
494
512
527
547
' 568
595
647
_
-
vr^f*»*
87.24(swri
13.08{swri
480(swri
310(swri
19381(swri
45.08
38.38
42.30
36.02
2.71
0(swri
-6{swri
154
SHELL
0.8566
33.6
52.9
45.4
44.9
351
413
433
458
478
497
514
532
551
574
604
633
651
_
-
-
-
-
381
281
-
2.74
1.12
-
-
158
":.3£$m
SWRI
0.8565
33.6
52.0
-
-
341
397
429
455
475
494
513
531
549
570
602
628
645
-
-
26.2
poly 7.5
33.7
86.40
13.10
496
310
19427
45.19
38.70
42.4
36.32
2.73
1.12
-6
166
0.553 *
76
PRODUCTS
COMPANY
0.8565
33.7
51.5
45.1
-
353
396
433
459
477
495
513
531
550
572
601
629
650
_
-
26.2
poly 8.4
34.6
-
-
440
306
-
2.72
1.12
5
-1
154
-
AVERAGE
0.8564
33.7
52.4
45.4
45.0
350
405
430
456
476
494
513
530
549
570
602
630
646
18.4
81.6
-
26.2
poly 8.9
35.1
86.99
13.17
438
315
19411
45.15
38.67
42.36
36.27
2.72
1.13
-
161
0.553 "
* BP infrared method
Data not used in averaging !!!
" Nalco GC method
-------
ATTACHMENT 5
Summary of EMA Engine Test Results
-------
G. F. Keller 03/26/97
Engine Manufacturers Association
03:11 PM Revised Columns B&D
1
% CHANGE
from Baseline
Fuel
NOx
ENGINE MANUFACTURERS ASSOCIATION
I
TEST: Phillips DL 1500 Custom Blend
I
Convention: A negative change indicates a reduction vs. baseline.
| I
v. Baseline
!
1
ENGINE A B C DIE
F
1
! Percent Values ! !
Transient - 3 Hot -4.5 -9.3,' -9.6! -6.7! -11.7
% Sionilicance 99.9 1001 100J 100: 100
AVL t Mode -7.1 -7.9 -8 -9.91
% Significance ' 1 00 ! 1 00
-3.7
97.7
-5.3
99.9
PM iTransient-sHot -28.71 -15.7 1 -4.5! -9.6! -8.3! -30.9
ksiunifiance 1001 991 96.21 99.91 1001 99.9
! AVL 8 Mode -22.51 -9.61
% Siqnilfcance 99.8 '
HC iTr.n$ieni-3Hot -41.61 -17.9! -48.5! -15i -14.81 -70.5
i% Significance 100! 100 99.2 1 99.9! 97.3! 99.9
UvLiMode -37.6 i -9.8 j ! -18! -25.6! -39.7
NOx+NMHC
% Significance 100 1 100! 1001 99.9
T»ntieni - s Hot -8.2 1 -9.6! -14.1 -7.3!
% Significance 100! 100 I 99.9 !
I AVL i Mode -11.31 -7.91 -8.7:
ksignilicarce 100 1 !
-9.7
99.9
-12
99.9
Fuel Specific Emissions ] !
NOx/Gal
Trantient-3Hol
I AVL 1 Mode
PM/Gal
Trintlem - 3 Hot
-0.2 -13.4
-2.2 -12.2
-25.5
AVL a Mode -18.4
HC/Gal {Transient - 3 Hot -39.0
AVL 1 Mode -34.3
NOX+NMHO/GAL
Transient -3 Hot
1 AVL « Mode
Cycle Work {Transient - 3 Hot
1% significance
:AVLSMoOe
\% Significance
Observed Transient - 3 Hot
Fuel Consumption % significance
1 AVL a Mode
: % Signlf tance
-4.1
-6.7
-19.5
-21.6
-14.1
-13.6
-12.3
0.2 1 -0.2
52.8
-0.4
-4.3
97
0.3
99
-8.1 -10.91 -14.31 -7.1
I -13.31 -9.5
-2.9 -13.7! -10.31 -33.4
I
-47.6 -18.9i -17.4 1 -71.6
i -28.4
-12.6 -11.4
-42.4
-7.7
! -15.9
-1.1 -0.1 I -0.3
99.8 100 100
0 0
100 4
-1.11 -1.7 -3 -0.7
99.9 1 100| 96.3 99.5 95.9
-5;0
-0.9 1 4.8 -0.2
1001 100 0
-0.2
99.2
-2.2
97.6
-1.2
99.9
I
'
Averages
-7.6
99.6
-7.6
100.0
-16.3
99.2
-16.1
99.8
-34.7
99.4
-26.1
100.0
-9.8
99.9
-10.0
100.0
-9.0
-9.3
-17.6
-18.4
-36.0
-29.8
-9.9
-11.6
-0.3
91.5
-0.0
67.7
-2.2
98.2
-0.5
75.0
SD
2.9
0.9
1.5
0.0
10.1
1.4
6.5
0.0
20.8
1.0
11.4
0.0
2.3
0.0
1.7
0.0
4.7
4.3
10.0
19.4
10.3
3.5
3.8
0.4
17.3
0.2
45.0
1.2
1.7
3.1
43.3
Transient • 3 Hot
% Significance
AVL a Mode
•i. Significance
Tranttem - 3 Hot
% Significance
AVL B Mode
% Significance
Tranttem -3 Hot
% Significance
AVL a Mode
% Significance
Tranttem -3 Hot
% Significance
AVL a Mode
Transient - 3 Hot
AVL 6 Mode
Tranilent - 3 Hot
AVL 8 Mode
Tr»nt(*m-3Hot
AVL B Mode
Tranitont - 3 Hot
AVL 8 Mode
Trantiem -3 Hot
% Significance
AVL » Mods
% Significance
Trintienl - 3 Hot
% Significance
AVL 8 Mode
% Siqnificanc
NOi
PM
HC
NOi*NMHC
Noi Gat
PMGsl
HC/Gal
(NOX.NMHCJ/Gol
Cycle Wort
Fuel Consumed
k
.
gfk:\fueltest.wk4
Pagel
-------
G. F. Keller 03/26/97
Engine Manufacturers Association
03:11 PM Revised Columns B&D
t
ENGINE MANUFACTURERS ASSOCIATION
TEST: Amoc
o Cetane Enhanced v. ^Baseline
! I
% CHANGE Convention: A negative change indicates a reduction v. baseline.
from Baseline
Fuel
ENGINE ! A
!
B ; C
D
I
i ' i ;
E F
! j
' (percent Values
NOx 'Transient -3 Hoi !
6.21 -1.8 -1.9
'% Significance 93 .4 i 97 54.4
'AVL 8 Mode
i% SiamfearEn !
5.3 1 0.4;
100 i
0.4
56
4.4
I 96.6
-0.6 1 4.6
73
PM .Transient -3 Hot -5.5 1 -1.5! 11.3] 0.3
! % Significance £
lAVLsMode
% Significance
3.31 62 i 99.71 44
2.21
0.7
23
HC iTr.nn«it-3H« -23.9! -14.21 -53.5! -9.1
* Significance
100 1001 100
UvLiMoo* -22.3 20.71
•% Significance
NOX+NMHC jranslenl - 3 Hot
100 i
99
99.9
! -3.1
91.9
i -66.3
99.9
-8.3
92
3.1 -2.1 -7.8! -0.1
Insignificance :' 82.1 98 96.9!
AVL a Mode
I % Significance
Fuel Specific Emissions
NOx/Gal Transient . 3 Hot
1 AVL » Mode
PM/Gal
HC/Gal
[NOX+NMHC)/GAL
Cycle Work
Transient - 3 Hot
AVL V Mode
1.51 1.0!
100
8.1 -2 -3.4
6.4! 0.2
3.8! -1.7 9.5
33l
-32.4
99.9
-2.0
82.3
1.1
-2.6
96.1
0.5|
0.4
Tnmii.nt.3Hot -22.5 1 -1 4.4 j -54.31 -9
AVL « MOCM -21.41 20.4
Transient - 3 Hot
AVL 6 Mode
Transient -3 Hoi
% Significance 9
AVL a Mode
i% Significance
Observed
*uel Consumption
5.0 1 -2.4 1 -9.3
2.6 1 0.8!
0.8 1 0.1 -0.6
7.4I 65| 100
0.3 i 0.2 |
1 1001
Transient -3 Hot -3.2 0.2 i 1.6
X Significance i 86.0 90! 91.8
UvLlMode
% Significance
1.1 0.2:
98'
0.1
0
77
0
100
-1.3
4.1
4.6
-3.3
-66.4
-32.4
-2.2
-2.6
-0.1
89.8
i 0.2
95!
4.7
100
43.9
0
i
j • 1 ™"
Averages
1.5
79.5
2.4
91.0
0.3
78.2
1.5
23.0
-33.4
99.8
-10,6
97.3
-1.8
89.8
02
98.1
1.5
3.7
0.2
3.3
-33.3
-11.1
-1.8
0.3
0.0
85.8
-0.0
100.0
-0.5
81.3
1.0
99.0
SD
3.3
19.9
2.6
12.7
5.8
21.5
0.8
0.0
22.5
0.4
20.0
3.7
3.6
7.6
1.7
2.0
4.2
2.6
4.9
0.0
22.8
22.7
4.6
2.1
0.5
13.1
0.2
0.0
1.6
18.9
2.2
1.0
Transient • 3 Hot
% Significance
AVL a Mode
% Significance
Transient - 3 Hot
% Significance
AVL 8 Mode
% Significance
Transient - 3 Hot
% Significance
AVL B Mode
% Significance
Transient -3 Ho!
%Signiteance
AVLlUode
Trantient-JHot
AVL t Mode
Transient -3 Hot
AVL S Mode
TnntlMI-3Hot
AVL (Mode
Transmit • 3 Hot
AVL t Mode
Transient - 3 Hot
% Significance
AVL 1 Mode
% Significance
Transient - 3 Hot
% Significance
AVL 1 Mode
% Significance
NOi
PM
HC
NOx.NMHC
PM/Gal
(NOXtNMHCyGal
Cycle Work
Fuet Consumed
gfk:\fuertest.wk4
Page 2
-------
ATTACHMENT 6
SwRI Report on CAT 3176 Engine Test Results
-------
MEASUREMENT OF GASF^US EMISSIONS
FROM A CATERPILLAR 3176 ENGINE
(WITH EGR) USING THREE DIFFERENT FUELS
FINAL REPORT
Phase I
SwRI Project No. 03-8286
and
SwRI Project No. 08-7601
Prepared for:
Engine Manufacturers Association
401 North Michigan Avenue
Chicago, IL 60611 -5267
and
Environmental Protection Agency
2565 Plymouth Road
Ann Arbor, Ml 48105
Prepared by:
Douglas Leone
Thomas W. Ryan, III
April 10,1997
Approved:
Nigel
Engine
ice President
Vehicle Research Division
In the event Client distributes any report
issued by SwRI on this Project outside its
own organization, such report shall be used
in its entirety, unless SwRI approves a
summary or abridgement for distribution.
\
I
-------
EXECUTIVE SUMMARY
In July of 1995, the Environment Protection Agency (EPA), tne California Air Resources
Board (CARB), and the heavy-duty engine (HDE) manufacturers signed a Statement of Principles
(SOP) outlining a potential regulatory control program for 2004 and later model year HDEs. Central
to that agreement was a 2.4 g/Bhp-hr NMHC+NOX emission standard. EPA formally proposed this
standard on June 27, 1996.
The SOP also included a provision that acknowledged that along with engine hardware
modifications, fuel composition has a significant effect on emissions, and that changes in the quality
and characteristics of diesel fuel may be needed to make the engine technology necessary to meet the
standards feasible and, otherwise, appropriate under the Clean Air Act. The SOP identifies potential
evaluation of the emission sensitivity of several diesel fuel parameters.
In response to these provisions, EPA established a HDE Working Group composed of API
and EMA members to work with the EPA in its assessment of the sensitivity of 2004-era diesel engine
technology to diesel fuel quality. The work described in this report forms part of the Phase 1 testing
program designed and conducted by this Group.
The objective of the work described in this report was to determine if a CAT 3176 engine
(with EGR) gave the same emissions response when tested on 3 different diesel fuels as prototype
engines being developed by original equipment manufacturers (OEMs) to meet the 2004 SOP. Results
of the prototype engine testing are described elsewhere. Three fuels were tested: a baseline
commercial No. 2 diesel fuel; a cetane enhanced version of the baseline fuel; an 'extreme' No. 2 diesel
fuel with high cetane and low aromatics. Identical AVL, steady state, 8 mode tests were run on all
fuels to estimate FTP NO,, HC, CO, and BSFC based on weighted results. Paniculate matter was
not measured because steady-state generated Pm is a poor predictor of FTP Pm. The baseline fuel
was run three separate times and the other fuels were run twice each.
The CAT 3176 engine was run in 1994 OEM configuration, except for the addition of a low
pressure loop exhaust gas recirculation (EGR) system. EGR is a technology expected on 2004 diesel
engines. The level of EGR at the 8 discrete load/speed points was set to obtain an 8-mode weighted
result of approximately 2.7 g/bhp-hr NO, with the baseline fuel.
Relative to the baseline fuel, the average 8-mode weighted results were as follows:
• The high-cetane, low aromatic fuel reduced NO^ by 7 percent, HCs by 12.7 percent
and BSFC by 1.1 percent.
• The cetane enhanced baseline fuel increased NOX 3.4 percent but made no statistically
significant change in BSFC or HCs.
The results obtained with the high-cetane, low-aromatic fuel and the cetane enhanced baseline
fuel indicates that cetane number may not be the only factor affecting the NOX emissions from engines
employing this technology. Future work should include examination of the importance of cetane
number, both naturally occurring as well as through the use of cetane improvers.
iii
-------
ACKNOWLEDGEMENTS
The authors would like to thank Christine Hobbs of Cummins Engine Company for
her help in coordinating this effort. Mike Ross, Mike Wood, and Jerry Chessher provided help in
setup and operation of the engine, test cell, and the emissions carts. Janet Buckingham of SwRI
provided assistance with the statistical analysis. Cherian Olikara helped in the initial setup of the
project. Lee Dodge helped edit the report, and Susie Schliesing helped in report preparation. We
would also like to thank Caterpillar for their support in this project and for allowing SwRI the use
of their CAT 3176 engine.
IV
-------
TABLE OF CONTENTS
Page
1.0 BACKGROUND 1
2.0 OBJECTIVE 2
3.0 ENGINE CONFIGURATION 3
3.1 Engine History 3
3.2 Engine Overview 3
4.0 EMA TEST PLAN AND EPA WORK ASSIGNMENT 4
4.1 Test Cell Modification (EPA Funded) 4
4.2 Test Engine Modification (EPA Funded) 5
4.3 Engine Testing (EMA and EPA Funded) 5
4.4 Fuel Purge Procedure 7
5.0 ENGINE TEST RESULTS AND ANALYSIS 9
6.0 STATISTICAL ANALYSIS OF EMISSIONS RESULTS 18
7.0 SUMMARY AND CONCLUSIONS 22
8.0 RECOMMENDATIONS 23
9.0 REFERENCES 24
APPENDIX A: SUMMARY EMISSIONS DATA FOR FUELS TESTED
APPENDIX B: LOW-SPEED DATA FOR FUELS TESTED
APPENDIX C: SUMMARY HIGH-SPEED DATA
APPENDIX D: HIGH-SPEED PLOTS FOR FUELS TESTED
APPENDIX E: EMA TABLE DATA
-------
LIST OF ILLUSTRATIONS
Page
1 WEIGHTED NOX VERSUS FUEL TYPE CAT 3176 11
2 WEIGHTED HC VERSUS FUEL TYPE CAT 3176 12
3 WEIGHTED BSFC VERSUS FUEL TYPE CAT 3176 13
4 % CHANGE IN NOX FOR CHANGE IN FUEL CAT 3176 14
5 % CHANGE IN HC FOR CHANGE IN FUEL CAT 3176 15
6 % CHANGE IN BSFC FOR CHANGE INFUEL CAT 3176 16
7 HIGH-SPEED DATA RESULTS FOR FUEL EFFECTS
STUDY ON NOX CAT 3176 17
8 AVERAGE NOX BY FUEL 19
9 AVERAGE HC BY FUEL 20
10 AVERAGE BSFC BY FUEL 21
VI
-------
LIST OF TABLES
able Page
1 LOW-SPEED MEASUREMENTS 4
2 CALIBRATION OR VERIFICATION SCHEDULE FOR CELL 07 5
3 AVL 8-MODE TEST MATRIX BASED UPON A 600 rpm IDLE SPEED .. 6
4 ORDER OF AVL 8-MODE TESTING 6
5 TOLERANCES FOR CONTROLLED PARAMETERS 6
6 ORDER OF FUELS TESTED 7
7 FUEL ANALYSIS OF THE TEST FUELS 8
8 AVL 8-MODE EGR SCHEDULE 9
VH
-------
1.0 BACKGROUND
In July of 1995, the Environment Protection Agency (EPA), the California Air Resources
Board (CARS), and the heavy-duty engine (HDE) manufactures signed a Statement of Principles
(SOP) outlining a potential regulatory control program for 2004 and later model year HDEs. Central
to that agreement was a 2.4 g/Bhp-hr NMHC+NOX emission standard, which is approximately a 50%
reduction in the NOX levels from the 1998 standard. EPA formally proposed this standard on
June 27, 1996.
The SOP also included a provision that acknowledged that along with engine hardware
modifications, fuel composition has a significant effect on emissions, and that changes in the quality
and characteristics of diesel fuel may be needed to make the engine technology necessary to meet the
standards feasible and, otherwise, appropriate under the Clean Air Act. The SOP identifies potential
evaluation of the emission sensitivity of several diesel fuel parameters.
In response to these provisions, EPA established a HDE Working Group composed of API
and EMA members to work with the EPA in its assessment of the sensitivity of 2004-era diesel engine
technology to diesel fuel quality. The work described in this report forms part of the Phase 1 testing
program designed and conducted by this Group.
-------
2.0 OBJECTIVE
The objective of the work described in this report was to determine if a CAT 3176 engine
(with EGR) gave the same emissions response when tested on 3 different diesel fuels as prototype
engines being developed by original equipment manufacturers (OEMs) to meet the 2004 SOP.
Results of the prototype engine testing are described elsewhere.
-------
3.0 ENGINE CONFIGURATION
3.1 Engine History
A Caterpillar 3176 engine was provided to SwRI to support the Clean Heavy-Duty Diesel
Engine (CHDDE) program. The engine was included in the CHDDE program since the Caterpillar
3176 engine incorporated the technology necessary to achieve 1994 on-highway emissions levels.
This specific engine was used throughout the CHDDE program with excellent results.
3.2 Engine Overview
The Caterpillar 3176 engine is an in-line 6-cylinder engine that incorporated the following
design features:
Rating of 261 kW (350 hp) @ 1800 RPM
Peak torque of 1830 N-m (1350 Ib-ft) at 1200 RPM
• 125 mm x 140 mm (4.92" x 5.51") bore and stroke
• Direct injection
• Electronically controlled unit injectors
Mechanically actuated unit injectors
• Turbocharged with air to air aftercooling
• Uni-flow cylinder head configuration (exhaust and intake ports on same side of
engine)
Four (4) valves per cylinder
Quiescent combustion system
• Shallow bowl, Mexican hat designed piston crater
• High top ring position
• Articulated piston with steel crown and aluminum skirt
SwRI has modified the Caterpillar 3176 engine to incorporate an EGR system designed by SwRJ.
This EGR system incorporates optional EGR cooling and is designed with very long lines. Therefore,
Caterpillar has the opinion that this system is suitable only for steady-state emissions testing. The
long EGR lines will compromise the transient operation of the engine.
The Caterpillar 3176 engine is also representative of 1998 on-highway emissions levels with
the appropriate fuel injection timing.
-------
4.0 JMA TEST PLAN AND EPA WORK ASSIGNMENT
The following work was performed as a part of the project:
4.1 Test Cell Modification (EPA Funded)
An intake air conditioning system was installed. This system controlled intake air temperature
to 25"C ± 3°C (77°F ± 5°F) and humidity to 75 grains water / Ib dry air ± 5 grains water / Ib dry air.
Test cell calibration or verification was performed on all low-speed measurement devices. The
low-speed parameters to be measured/recorded are shown in Table 1. Table 2 shows the frequency
of calibration and verification during the engine testing.
TABLE 1. LOW-SPEED MEASUREMENTS
Run#
Year
Day
Barometer
Relative Humidity (outside)
Temperature (outside)
LFE in Temperature
Intake air Relative Humidity
Intake Air Dew Point Temp.
Intake Air Humidity ratio
Engine Speed
Torque
Brake Power
SAE Correction Factor
SAE Power
SAE BSFC
SAEBMEP
SAEBTE
A/F Ratio Dry (Mechanical)
Dry Air How
Fuel Flow
Coolant In Temp.
Coolant Out Temp.
Oil Sump Temp.
Fuel Inlet Temp.
Fuel Outlet Temp.
Compressor Out Temp,
Intake Manifold Temp.
Exh. Cylinder 1 Temp.
Exh, Cylinder 2 Temp.
Exh. Cylinder 3 Temp.
Exh. Cylinder 4 Temp.
Exh. Cylinder 5 Temp.
Exh. Cylinder 6 Temp.
Exh. Manifold Front Temp.
Exh. Manifold Back Temp.
Exhaust Stack
EGR Coolant Return Temp.
EGR Inlet Temp.
Oil Gallery Pressure
Fuel Pressure
Intake Manifold Pressure
Exhaust Back Pressure
Compressor Outlet Pressure
Exhaust Manifold Pressure
Compressor In Pressure
Emissions A/F Ratio (Spindt)
Emissions A/F Ratio (EPA)
Bosch Smoke
Carbon Monoxide
Carbon Dioxide
Oxygen
Unburned Hydrocarbons
Background Carbon Dioxide
Intake Carbon Dioxide
EGR
-------
TABLE 2. CALIBRATION OR VERIFICATION SCHEDULE FOR CELL 07
ParameteL.^
Engine speed
Torque
Pressure transducers
Engine coolant out temperature (verified)
Fuel supply temperature (verified)
Rektive humidity sensor temperature (verified)
LFE temperature sensor (verified)
Cal. Schedule
Every day of testing
Every day of testing
Weekly
Weekly
Weekly
Weekly
Weekly
4.2 Test Engine Modification (EPA Funded)
The turbocharger was replaced with a new turbo from Caterpillar. During preliminary testing,
the new turbocharger was damaged by improper engine operation (due to a malfunctioning engine
speed sensor). Therefore, the original turbocharger was installed and run on the engine, but its
performance was measured and considered acceptable compared to the new turbocharger.
The EGR cooler was inspected for EGR contamination and its performance was verified for
control of EGR temperature to meet intake manifold temperature specifications. The engine oil and
filter were changed.
The cylinder pressure and push rod transducers were removed, calibrated and reinstalled. The
dedicated high-speed data acquisition system was connected to the engine and checked out. A
procedure to transfer high-speed data from the system to a PC for data analysis were determined.
The procedure for calculation of injection pressure on the PC was developed. The high-speed data
were acquired in 0.5 crank angle degree intervals, and averaged over 50 engine cycles. The cylinder
pressure data were analyzed by the first-law heat release analysis to estimate apparent heat release
rate. The estimated premised burn fraction was computed from the heat release rate curve.
4.3 Engine Testing (EMA and EPA Funded)
The EGR calibration for the CAT 3176 engine was determined to achieve a transient
equivalent emissions value of 2.5 to 2.8 g/HP-hr NOX with the baseline fuel The fuel injection timing
strategy was maintained at the 1994 configuration as supplied by Caterpillar. The transient emissions
bvel was estimated by running an AVL 8-mode steady-state test and weighting the results. At two
of the test points, the engine measurements were acquired three times to determine significance of
the data. The 8 AVL test points and weighting factors are provided in Table 3. The AVL 8-mode
tests were run in the order shown in Table 4. The tests were run while controlling several engine
parameters within specified tolerances. The controlled parameters along with tolerances are provided
in Table 5.
-------
TABLE 3. AVL 8-MODE TEST MA
BASED UPON A 600 rpm IDLE SPEED
AVL MODE #
1 (repeated three times)
2
3
4
5
6 (repeated three times)
7
8
% speed
0
11
21
32
100
95
95
89
% load
0
25
63
84
18
40
69
95
Target
rpm
600
732
852
984
1800
1740
1740
1668
Target
ft-lbs
24
175
554
962
184
425
733
1061
WF
0.4168
0.0755
0.0346
0.0398
0.1000
0.1244
0.1215
0.0874
TABLE 4. ORDER OF AVL 8-MODE TESTING
I AVL Mode*
4 1 3
1 6 (3 times)
7
8
1 3
1 2
1 (3 times) U
TABLE 5. TOLERANCES FOR CONTROLLED PARAMETERS
Intake Restriction (can be checked at rated speed
only)
Exhaust Restriction (can be checked at rated speed
only)
Engine coolant temperature
Fuel supply temperature
Fresh Air temperature
Fresh Air humidity
Barometric pressure throughout day (if nearly done
with testing just note deviation)
Engine Speed
Torque
EGR
Intake Manifold
381 ± 51 mm Hp (15 ± 2 in 1^0)
76±8mmHg(3±0.3inHg)
88±3°C(190±5°F)
40±3°C(104±5°F)
25±3°C(77±5°F)
75 ± 5 grains HjO / Ib of dry air
± 25 mm Hg (± 1 in. Hg) of first day of testing
±2%
±2%
±2% of value
35°C ± 2°C (95 ± 4°F)
-------
Once the baseline performance was checked, the '. ,?.ine was tested with various fuels over
identical AVL 8-mode tests as shown in Table 6. A totaV "''_ :;e fuels were tested: the baseline fuel,
the cetane-enhanced baseline fuel and the high-cetane, low aromatic fuel. The baseline fuel was
tested a total of three times, the cetane-enhanced baseline and high-cetane, low-aromatic fuels were
both tested twice. Fuel analysis for the three fuels is provided in Table 7.
TABLE 6. ORDER OF FUELS TESTED
Baseline
High-Cetane, Low Aromatic
Cetane Enchanced Baseline
Baseline
High-Cetane, Low Aromatic
Enchanced Baseline
Baseline
4.4 Fuel Purge Procedure
Between tests on each fuel, a formal procedure was followed and documented for each
change in fuel. This procedure was as follows:
1. The fuel lines and day tank were drained.
2. The fuel filter was changed.
3. The new fuel was connected.
4. The engine was run for 10 minutes
5. The fuel lines and day tank were drained.
6. The fuel filter was replaced.
-------
TABLE 7. FUEL ANALYSIS OF THE TEST FUELS
PARAMETER
DENSITY @ 15 C, g/cm3
API GRAVITY @ 60F, deg. API
CETANE NUMBER
CETANE INDEX
CETANE INDEX
DISTILLATION, F IBP
5%
10%
20%
30%
40%
50%
60%
70%
80%
90%
95%
FBP
NMR, md% AROMATICS
SATURATES
MS, %m PARAFFINS
MONOCYCLOPARAFFINS
DICYCLOPARAFFINS
TRICYCLOPARAFFINS
ALKYL BENZENES
INDANES/TETPAUNS
INDENES
NAPHTHALENE
NAPHTHALENES
ACENAPHTHENES
ACENAPHTHALENES
TRICYCUC AROMATICS
TOTAL AROMATICS
SFC AROMATICS, %m 1-RING
2-RING
3-RtNG
TOTAL
CARBON, %m
HYDROGEN, %m
NITROGEN, ppm
SULFUR, ppm
HOC, gross, btu/lb
MJ/kg
MJ/dm3
HOC, net, MJ/kg
MJ/dm3
VISCOSITY 9 40C, mm2/s
© 100C, mm2/s
CLOUD POINT, F
POUR POINT, F
FLASH POINT, F
ALKYL NITRATE CONTENT, %v
TEST
METHOD
ASTM D4052
ASTM D4052
ASTM D613
ASTM D976 .
ASTM D4737
ASTM D86
ASTM D5292
ASTM D2425
ASTM D5186
ASTM D5291
ASTM D5291
ASTM D4629
ASTM D2622
ASTM D4809
ASTM D445
ASTM D2500
ASTM D97
ASTM D93
Nalco GC
BASELINE
FUEL
0.8564
33.6
45.9
45.0
44.4
365
408
432
456
476
495
513
530
550
571
601
628
649
18.1
81.9
34.33
20.35
5.84
3.42
14.06
11.07
3.34
0.81
2.46
2.24
1.20
0.83
36.06
26.6
poly 9.1
35.7
87.11
13.06
85
310
19460
45.26
38.76
42.49
36.39
2.74
1.13
0
-5
160
0.047
CETANE R '.NCED
BASE? ,EL
0.8564
33.7
52.4
45.4
45.0
350
405
430
456
476
494
513
530
549
570
602
630
646
18.4
81.6
•
26.2
poly 8.9
35.1
86.99
13.17
438
315
19411
45.15
38.67
42.33
36.27
2.72
1.13
2
-9
161
0.553
HIGH-CETANE, LOW
AROMATIC FUEL
0.8233
40.3
56.9
56.2
59.3
397
436
454
472
487
499
511
522
536
553
584
612
630
9.8
90.2
60.9
17.57
5.9
2.81
5.02
3.7
1.2
0.2
0.9
0.7
0.5
0.5
12.84
1S.S
poty4.5
20.0
86.09
13.84
28
180
19817
46.10
37.95
43.16
35.53
2.72
1.15
8
4
181
< 1ppm
-------
5.0 ENGINE TEST RESULTS AND ^ANALYSIS
The first step in performing the testing was to determine the appropriate levels of EGR
required to produce a weighted AVL 8-Mode (transient equivalent) NOX emissions level of 2.5 to 2,8
g/HP-hr with the baseline fuel. The EGR schedule shown in Table 8 resulted in a weighted 8-Mode
result of 2.68 g/Bhp-hr NO^, and was selected based on previous experience at SwRI with this engine
configuration. The 2.8 gm/Bhp-hr level was achieved using a test fuel available at SwRI. During the
two repeat tests of the baseline fuel, the weighted 8-Mode results were 2.75 and 2.72 g/HP-hr NOV
TABLE 8. AVL 8 MODE EGR SCHEDULE
AVL Mode #
1
2
3
4
5
6
7
8
EGR %
50%
12.5%
0%
0%
20%
16%
6%
4%
A summary of the weighted emissions results for all fuels tested is provided in Figures 1, 2,
and 3. Summary emissions data for individual modes is provided in Appendix A for all tests. Low-
speed data is provided in Appendix B. Summary modal high-speed data are provided in Appendix
C and the graphs in Appendix D. Appendix E is a compilation of the modal emissions data in EM A
specified format.
Percentage change of the weighted NO,, unbumed HC and BSFC for the change in fuel
compared to the baseline fuel is shown in Figures 4, 5, and 6. The high-cetane, low-aromatic fuel
decreased the NOX approximately 7 percent, while the cetane-enhanced baseline fuel increased NOX
approximately 3.4 percent. The high-cetane, low aromatic fuel decreased the HCs approximately 13
percent, whib the cetane-enhanced baseline fuel had a negligible effect on the HCs. The high-cetane,
low-aromatic fuel decreased the BSFC approximately 1.1 percent, while the cetane-enhanced baseline
fuel increased the BSFC approximately 0.4 percent.
The increase in NO, noted for the cetane enhanced baseline fuel relative to the baseline fuel
was unexpected. Previously published data ^ suggests that increased cetane number tends to
reduce gaseous emissions, including NOr Effects on Pm are more variable, with a number of studies
showing little or no sensitivity of Pm emissions to increased cetane number. Several of these (notably
-------
SAE 950251) and other studies, have compared the effect of natural versus boosted cetane number
on emissions, and concluded that the effects of increased cetane number achieved either thr •; ;.i
changes in base fuel composition or through additives (alkyl nitrates, peroxides, etc.) are equivalent.
There is little or no data in the published literature, which suggests that either fuel bound nitrogen or
nitrogen contained in alkyl-nitrate ignition improvers make a significant contribution to NOX emissions
from diesel engines. However, it should be noted that these observations derive from assessment of
fuel effects on HD diesel engines (without EGR) calibrated to meet US 1998 or earlier emissions
standards. The influence of cetane (natural or boosted) on engines designed to meet US 2004
emissions standards, which like the engine(s) used in the Phase 1 tests are likely to be equipped with
EGR, has not been fully evaluated. Therefore, it is recommended that tests conducted in Phase 2 of
this study include a thorough evaluation of cetane effects on gaseous emissions.
The increase in cetane number for the cetane-enhanced fuel and the high-cetane, low-aromatic
fuel was expected to decrease the ignition delay and, therefore, reduce the premix burn fraction. The
premix burn produces a significant amount of the NOX and reduction in this burn should reduce NOX
emissions. Shown in Figure 7 is the premix bum fraction computed for all the fuels. It is apparent
from this figure that the premix burn fraction for both the cetane-enhanced fuel and the high-cetane,
low-aromatic fuel was reduced compared to the baseline fuel. It is also clear that the high-cetane,
low-aromatic fuel resulted in consistently lower premix burn fraction than the cetane-enhanced fuel.
10
-------
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-------
3.00
2.50
2.00
1.
1.1
0.50
0.00
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-------
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2.00
0.00
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-4.00
-6.00
-8.00
-10.00
HIGH-CETANE
LOW AROMATIC
-6.99
CETANE ENHANCED
3.44
FIGURE 4. % CHANGE IN NOX FOR CHANGE IN FUEL CAT 3176
-------
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0.00
-2.50
-5.00
-7.50
-10.00
-12.50
.00
HIGH-CETANE,
LOW AROMATIC
CETANE ENHANCED
-0.28
-12.66
FIGURE 5. % CHANGE IN HC FOR CHANGE IN FUEL CAT 3176
-------
HIGH-CETANE,
LOW AROMATIC
CETANE ENHANCED
LU
Z
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o
'f<'\
-1.08
FIGURE 6. % CHANGE IN BSFC FOR CHANGE IN FUEL CAT 3176
-------
0.800
0.700
D Baseline 1
Baseline 2
3
• Cetane Enh. 1
• Cetane Enh. 2
H Hi CN 1
HICN2
o 0.500
2
6783
AVL Mode Number
FIGURE?. HIGH-SPEED DATA RESULTS FOR FUEL EFFECTS STUDY ON NOX CAT 3176
-------
6.0 STATISTICAL AN SIS OF EMISSION RESULTS
In order to compare the performance of the three tested fuels on emissions and BSFC, an
analysis of variance (ANOVA) statistical procedure was performed. The ANOVA compares the
average weighted NOX, HC and BSFC between the three fuels to determine if they are significantly
different. A total of seven tests were run: three on the baseline fuel, two on the high-cetane, low-
aromatic fuel and two on the cetane enhanced baseline fuel. The ANOVA used fuel type as the only
independent factor.
The results of the ANOVA for NO, indicate that there is a significant difference (p-value =
0.0013) in the average NOX among all three of the fuels tested. P-values less than 0.05 demonstrate
a significant difference in the averages in at least two of the fuels. A post-hoc multiple comparison
procedure was then performed to determine which averages were significantly different from the
others. The method used in this analysis was Fisher's least significant difference (LSD) procedure.
The results of the NO^ analysis are shown graphically in Figure 8. The average NO x is plotted for
each of the three fuels along with its 95 percent LSD confidence interval. If two of the averages are
statistically the same, their intervals will overlap 95 percent of the time., As can be seen in Figure 8,
all three fuels are significantly different from one another with respect to their average NOX. The
cetane enhanced baseline fuel had higher average NOX than the baseline, whereas the high-cetane,
low-aromatic fuel had a lower average NOX.
ANOVA results for HC and BSFC were similar and are illustrated in Figures 9 and 10,
respectively. There was a significant difference in the average HC (p-value = 0.0467) and BSFC (p-
value = 0.0015) between the high-cetane, low-aromatic and the baseline fuels, but not between the
cetane enhanced baseline and the baseline fuel The 95 percent LSD intervals shown in Figures 9 and
10 demonstrate the statistically lower average HC and BSFC for the high-cetane, low-aromatic fuel.
18
-------
2.9
95% LSD CONFIDED INTERVALS
2.8
£ 2.7
Q.
OQ
E
& 2.6
x
O
2.5
2.4
J 1
HIGH-CETANE
LOW AROMATIC
BASELINE
CETANE
ENHANCED
FUEL
FIGURES. AVERAGE NO* BY FUEL
19
-------
95% ISO CONFIDENCE IN ,VALS
0.15
0.14
S3
ut
O
0.13
0.12
0.11
i r
I I
HIGH-CETANE
LOW AROMATIC
BASELINE
CETANE
ENHANCED
FUEL
FIGURE 9. AVERAGE HC BY FUEL
20
-------
0.375
0.373
u. 0.371
CO
ffi
0.369
0.367
95% ISO CONFIDENCE INTERVALS
HIGH-CETANE
LOW AROMATIC
BASELINE
FUEL
CETANE
ENHANCED
FIGURE 10. AVERAGE BSFC BY FUEL
21
-------
7.0 SUMMARY AND CONCLUSIONS
The Caterpillar 3176 was utilized as a representative engine of future diesel engine technology
to test three fuels: a baseline fuel, a octane-enhanced baseline fuel, and a high-cetane, low-aromatic
fuel The engine was calibrated with a 1994-year fuel injection timing strategy. A low-pressure EGR
system was calibrated to provide an AVL 8-mode weighted (transient emission predicted) of 2.7
g/hp-hr NOX. An intake air conditioning system was installed to control intake air temperature and
humidity.
The following conclusions were reached from the data acquired and analyzed during the
performance of the project:
For high-cetane, low-aromatic fuel:
• Reduced NO^ 7 percent, reduced BSFC 1.1 percent, and reduced HCs 12.7 percent
compared to the baseline fuel
• All changes are considered significant based upon the statistical analysis performed
• Reduced the measured p remix burn fraction compared to the baseline fuel
For the cetane-enhanced fuel:
Increased NO^ 3.4 percent compared to the baseline fuel, an increase that is
considered statistically significant
Had no significant impact on HCs or BSFC compared to the baseline fuel
Reduced the premix bum faction compared to the baseline fuel
22
-------
8.0 RECOMMENDATIONS
The results obtained with the high-cetane, low-aromatic fuel and the cetane enhanced baseline
fuel indicates that cetane number is not the only fuel property that affects the NOX emissions from
advanced technology engines. It is likely that this lack, or at least significant reduction, of the
sensitivity to cetane number is due to the fact that these engines have significantly reduced premixed
burn fraction relative to the old technology engines. Future work should include examination of the
effects of cetane number, both natural and additized, on the emissions from this type of engine.
23
-------
9.0 REFERENCES
1. UUman, Terry L., "Investigation of the Effects of Fuel Composition on Heavy-Duty Diesel
Engine Emissions," SAE Paper No. 892072, SAE International Fuels and Lubricants Meeting
and Exposition, Baltimore, MA, Sept. 25-28, 1989.
2. Ullman, Terry L., Robert L. Mason, and Daniel A. Montalvo, "Effects of Fuel Aromatics,
Cetane Number, and Cetane Improver on Emissions from a 1991 Prototype Heavy-Duty
Diesel Engine," SAE Paper No. 902171, SAE International Fuels and Lubricants Meeting and
Exposition, Tulsa, OK, Oct. 22-25, 1990.
3. Ullman, Terry L., Kent B. Spreen, and Robert L. Mason, "Effects of Cetane Number, Cetane
Improver, Aromatics, and Oxygenates on 1994 Heavy-Duty Diesel Engine Emissions," SAE
Paper No. 941020, SAE International Congress & Exposition, Detroit, MI, Feb. 28 - March
3, 1994.
4. Spreen, Kent B., Terry L. Ullman, and Robert L. Mason,. "Effects of Cetane Number,
Aromatics, and Oxygenates on Emissions From a 1994 Heavy-Duty Diesel Engine with
Exhaust Catalyst," SAE Paper No. 950250, SAE International Congress & Exposition,
Detroit, MI, February 27 - March 2,1995.
5. Ullman, Terry L., Kent B. Spreen, and Robert L. Mason, "Effects of Cetane Number on
Emissions from a Prototype 1998 Heavy-Duty Diesel Engine," SAE Paper No. 950251, SAE
International Congress & Exposition, Detroit, MI, February 27 - March 2, 1995.
6. Ryan IE, Thomas W., Jirnefl Erwin, Robert L. Mason, and David S. Moulton," Relationships
Between Fuel Properties and Composition and Diesel Engine Combustion Performance and
Emissions," SAE Paper No. 941018, SAE International Congress & Exposition, Detroit, MI,
Feb. 28 - March 3, 1994.
24
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