[Federal Register Volume 61, Number 75 (Wednesday, April 17, 1996)]
[Notices]
[Pages 16773-16779]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-9467]
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ENVIRONMENTAL PROTECTION AGENCY
[FRL-5458-4]
Retrofit/Rebuild Requirements for 1993 and Earlier Model Year
Urban Buses; Approval of a Notification of Intent to Certify Equipment
AGENCY: Environmental Protection Agency.
ACTION: Notice of Agency Certification of Equipment for the Urban Bus
Retrofit/Rebuild Program.
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SUMMARY: The Agency received a notification of intent to certify
equipment signed September 6, 1996 from Johnson Matthey Inc. (Johnson
Matthey) with principal place of business at 460 East Swedesford Road,
Wayne, PA 19087-1880 for certification of urban bus retrofit/rebuild
equipment pursuant to 40 CFR 85.1401-85.1415. The equipment is
applicable to petroleum-fueled Detroit Diesel Corporation (DDC) two-
cycle engines originally installed in an urban bus from model year 1979
to model year 1993, exclusive of the DDC 6L71TA 1990 model year
engines, all alcohol fueled engines, and models which were manufactured
with particulate trap devices (see Table A). On December 13, 1995, EPA
published a notice in the Federal Register that the notification had
been received and made the notification available for public review and
comment for a period of 45-days (60 FR 64048). EPA has completed its
review of this notification, and the comments received, and the
Director of the Engine Programs and Compliance Division has determined
that it meets all the requirements for certification. Accordingly, EPA
approves the certification of this equipment.
The certified equipment provides 25 percent or greater reduction
in exhaust emissions of particulate matter (PM) for the engines for
which it is certified.
The Johnson Matthey notification, as well as other materials
specifically relevant to it, are contained in Public Docket A-93-42,
category XI, entitled ``Certification of Urban Bus Retrofit/Rebuild
Equipment''. This docket is located in room M-1500, Waterside Mall
(Ground Floor), U.S. Environmental Protection Agency, 401 M Street SW,
Washington, DC 20460.
Docket items may be inspected from 8:00 a.m. until 5:30 p.m.,
Monday through Friday. As provided in 40 CFR Part 2, a reasonable fee
may be charged by the Agency for copying docket materials.
DATES: The date of this notice April 17, 1996 is the effective date of
certification for the equipment described in the Johnson Matthey
notification. This certified equipment may be used immediately by urban
bus operators. Operators who have chosen to comply with program 1 or
program 2 can utilize this equipment or other equipment that is
certified for any engine that is listed in Table A that undergoes
rebuild.
FOR FURTHER INFORMATION CONTACT: Anthony Erb, Engine Compliance
Programs Group, Engine Program & Compliance Division (6403J), U.S.
Environmental Protection Agency, 401 M St. SW, Washington, D.C. 20460.
Telephone: (202) 233-9259.
SUPPLEMENTARY INFORMATION:
I. Background
By a notification of intent to certify signed September 6, 1995,
Johnson Matthey applied for certification of equipment applicable to
petroleum-fueled Detroit Diesel Corporation (DDC) two-cycle engines
originally installed in an urban bus from model year 1979 to model year
1993, exclusive of the DDC 6L71TA 1990 model year engines and models
which were manufactured with particulate trap devices or alcohol fueled
(see Table A). The notification of intent to certify states that the
equipment being certified is a catalytic exhaust muffler (CEM). The CEM
contains an oxidation catalyst developed specifically for diesel
applications, packaged as a direct replacement for the muffler. The
application demonstrates that the candidate equipment provides a 25
percent or greater reduction in emissions of particulate matter (PM)
for petroleum fueled diesel engines relative to an original engine
configuration with no after treatment installed. Certification is
applicable to engines that are rebuilt to original specifications, or
in-use engines that are not rebuilt at the time the CEM is installed
provided the engine meets engine oil consumption limits specified by
Johnson Matthey. According to Johnson Matthey, a 6V engine that uses
more than one quart of oil per 10 hours of operation, or an 8V engine
that uses more than 1.5 quarts of oil per 10 hours of operation, must
be rebuilt. Johnson Matthey is also certifying a 25 percent reduction
in PM for engines that are retrofit/rebuilt with certified new rebuild
kits that do not include after treatment devices. This will apply only
when the CEM is installed at the same time the retrofit/rebuild occurs.
Currently, this applies to the DDC retrofit/rebuild kit which was
certified on October 2, 1995 (60 FR 51472).
Certification of the Johnson Matthey CEM does not trigger any new
program requirements for applicable engines, as the requirement to use
equipment certified to achieve at least a 25% reduction has already
been triggered for these engines. Johnson Matthey stated that it would
offer the equipment for less than $2000 (in 1992 dollars).
The CEM contains an oxidation catalyst developed specifically for
diesel applications, packaged as a direct replacement for the muffler.
Using engine dynamometer testing in accordance with the Federal
Test Procedure for heavy-duty diesel engines, Johnson Matthey
documented significant reductions in PM emissions after retrofit. This
amounted to a 50% PM reduction in the pre-rebuild retrofit test and a
38% reduction in the post-rebuild retrofit test. The test data show
that engines with the certified retrofit equipment installed comply
with applicable Federal emission standards for hydrocarbon (H.C.),
carbon monoxide (CO), oxides of nitrogen (NO), and smoke emissions in
addition to demonstrating reductions in PM exhaust emissions.
[[Page 16774]]
Table A. Certification Levels
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PM level
Engine models Model year \1\ with Code Family
-----------------------------------------------------------------------CEM------------------------------------------------------------------------------
6V92TA MUI \2\ 1979-87 0.38 All All
1988-1989 0.23 All All
6V92TA DDEC I 1986-89 0.23 All All
6V92TA DDEC II 1988-91 0.23 All All
1992-93 0.19 All All
6V71N 1973-87 0.38 All All
6V71N 1988-89 0.38 All All
6V71T 1985-86 0.38 All All
8V71N 1973-84 0.38 All All
6L71TA 1988-89 0.23 All All
6LV71TA DDEC 1990-91 0.23 All All
8V92TA 1979-87 0.38 All 8V92TA
1988 0.29 All 8V92TA
8V92TA-DD 1988 0.31 All 8V92TA-DDEC II
8V92TA 1989 0.35 9E70 KDD0736FWH9
8V92TA 1989 0.29 9A90 KDD0736FWH9
8V92TA 1989 0.26 9G85 KDD0736FWH9
8V92TA DDEC 1989 0.31 1A KDD0736FZH4
8V92TA 1990 0.35 9E70 LDD0736FAH9
8V92TA DDEC 1990 0.37 1A LDD0736FZH3
8V92TA DDEC 1991 0.19 1A or 5A MDD0736FZH2
8V92TA DDEC 1992-93 0.16 1D NDD0736FZH1 & PDD0736FZHX
8V92TA DDEC 1992-93 0.22 6A NDD0736FZH1 & PDD0736FZHX
8V92TA DDEC 1992-93 0.15 5A NDD0736FZH1 & PDD0736FZHX
8V92TA DDEC 1992-93 0.19 1A NDD0736FZH1 & PDD0736FZHX
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\1\ The original PM certification levels for the 1991 6V92TA DDEC II, 6LV71TA DDEC and 8V92TA DDEC engine models are based on Federal Emission Limits
(FELs) under the averaging, banking and trading program. These limits are higher than the 1991 PM standard of 0.25 g/bhp-hr. The PM level listed in
this table for the engines that are equipped with the CEM provide at least a 25% reduction from the original certification levels. The 1992 to 1993
6V92TA DDEC II and 8V92TA DDEC engine models were also certified using FELs under the trading and banking program and likewise the PM levels for the
engines equipped with the CEM represent at least a 25% reduction from the original certification levels.
\2\ For 6V92TA MUI models that are rebuilt using a certified DDC emissions retrofit kit, Johnson Matthey is certifying the PM engine emissions to a
level of 0.22g/bhp-hr for the 1979 to 1987 models and to a level of 0.17 g/bhp-hr for the 1988-1989 models provided the CEM is installed at the same
time the rebuild with the DDC upgrade takes place. The DDC upgrade kit certification notification was published in the Federal Register on October 2,
1995 (60FR51472).
Under Program 1, all rebuilds of applicable engines must use
equipment certified to reduce PM levels by at least 25 percent. This
requirement will continue for the applicable engines until such time as
it is superseded by equipment that is certified to trigger the 0.10 g/
bhp-hr emission standard for less than a life cycle cost of $7,940 (in
1992 dollars).
Johnson Matthey has established PM certification levels as
specified in Table A for this equipment. Operators who choose to comply
with Program 2 and install this equipment, will use the specified PM
emission levels in their calculation of fleet level attained.
II. Summary and Analysis of Comments
EPA received comments from two parties on this notification. The
Detroit Diesel Corporation (DDC) had a number of comments in the
following areas: engines models covered by the application,
certification of equipment for use on different stages of engine
rebuild, test engine selection and extrapolation of test results,
certified emission levels and representivity of test data. The
Engelhard Corporation commented on the following areas: incomplete
parts list, modification of the manufacturers specification,
representivity of test data, and public health risk assessment.
DDC stated that certain engines that appear to be covered by
Johnson Matthey's certification request cannot be included in the final
certification, specifically 6V-92TA DDEC alcohol fueled engines for
urban bus applications and 1992 and 1993 engines which were certified
with particulate trap systems. EPA agrees that this is the case and
these engines are not covered under this certification. DDC also stated
that the 8V-92TA should not be included in the coverage under this
certification as they are too large for use in urban buses. EPA agrees
that engines this large will generally not be installed in urban buses.
However, if any of these engines are in fact installed in urban buses,
they are subject to the retrofit/rebuild requirements. Therefore, this
engine is included in the certification, but will only apply when the
8V-92TA is installed in an urban bus. DDC also notes that 6V-92TA DDEC
engines equipped with particulate traps do not appear to be included in
the certification request, and should not be included. EPA agrees that
Johnson Matthey did not intend to certify its equipment for use on 6V-
92TA engines with particulate traps.
In the notification, Johnson Matthey seeks to certify engines which
are not in need of rebuild based upon specified engine calibrations.
DDC has stated that certification should be approved only with respect
to engines that have been rebuilt to original specifications as the
retrofit/rebuild requirements do not apply until the operator rebuilds
an engine. DDC agreed that under program 2 operators could conceivably
install certified add-on equipment without rebuilding the base engine
and use the certified emission level in their fleet averaging, but
expressed concerns that the engine may have worn cylinders or fuel
injection components in need of rebuild, and as a result the engine out
PM emissions may be high. DDC stated that engine wear conditions would
create difficulty in achieving the
[[Page 16775]]
certification level when applying the CEM to an engine which has not
been rebuilt. DDC and Engelhard expressed concerns about the low
emission level of the pre-rebuild engine that was used in baseline
tests for this application.
DDC noted that it would not be appropriate to approve the
certification on engines which have been rebuilt using the DDC
certified emission upgrade kits as no reductions were made in the PM
emission levels stated in the notice. DDC stated its belief that the
addition of the CEM to an engine already rebuilt using the certified
DDC kit will provide incremental PM reduction, but that Johnson Matthey
must certify to a level that has been demonstrated using both the DDC
upgrade kit and the CEM. Further, Johnson Matthey had not provided the
emission performance warranty for this emission level and that Johnson
Matthey must accept all liability associated with this warranty. DDC
would warrant only for emission defects.
DDC's claim that program requirements do not start until an
operator rebuilds an engine is only partly correct. Operators choosing
to comply with program 1 are not required to take any action until an
affected engine is rebuilt or replaced. However, operators choosing to
comply with program 2 must ensure their fleet is equal to or less than
their target fleet level at all times. Thus, program requirements apply
continuously to program 2 operators. In addition, if an operator
desires to be able to change between programs, the regulations require
that both programs be complied with prior to the switch. Johnson
Matthey has supplied test data in the application which demonstrates
that engine rebuild is not necessary to ensure a 25% PM reduction with
the CEM installed, allowing program 2 operators to utilize this
equipment. Furthermore, Johnson Matthey has addressed the concern that
engine wear might prevent an engine from achieving the PM level to
which it is certified by providing an oil consumption criteria. Engines
which exceed this criteria are presumably worn, and must be rebuilt in
order to install the CEM to meet program requirements.
While it is true that program one requirements become effective
when the engine is rebuilt, EPA does not want to stop an operator from
taking the initiative to install certified equipment prior the time it
is actually required under the regulations. EPA believes that the
addition of the CEM would provide some incremental benefit to an in-use
engine prior to the time a rebuild is found necessary. Therefore, in
the interest of cleaner air, EPA will allow program one participants to
install certified equipment aftertreatment prior to time a rebuild is
found necessary in order to allow for an incremental reduction of PM
emission in the interim.
In regard to DDC's concerns that engine wear needs to be evaluated
prior to installing this equipment, Johnson Matthey has modified its
application to remove the language referring to calibrations which were
stated to be vague and unenforceable and will instead require that
operators determine the oil consumption rate for an engine prior to
installing the CEM in order to determine engine wear and condition. If
this rate of consumption exceeds 1.5 quarts of oil consumption per 10
hours of operation for 6V engines or 2.0 quarts of oil consumption per
10 hours of operation for 8V engines, Johnson Matthey will require that
the engine be rebuilt prior to CEM installation in order to address
these concerns. Furthermore, Johnson Matthey will be responsible for
meeting the performance warranty for a period of 150,000 miles on each
engine under this certification. EPA believes that operators will
rebuild engines when necessary in order to keep their fleet in
reasonable operating condition. The decision to rebuild will not be
affected by the option to install a catalyst. Rather, operators will
only choose to install the catalyst in order to reduce emissions, and
not in place of a needed rebuild. It is noted that the testing data
provided for a 50% reduction in the pre-rebuild engine and a 38%
reduction in the case where the engine was rebuilt. Based on these
levels of reduction, it is apparent there should be ample margin
between the in-use emissions of an engine that the operator finds is
not in need of a rebuild to reasonably project that the levels stated
in Table A can be met.
Both Engelhard and DDC commented on the low emission level of the
engine that was used for baseline testing. Johnson Matthey selected an
engine that was normally used in the transit industry. Although the
pre-rebuild level does appear low (0.44 g/bhp-hr PM), this engine was
not modified or adjusted prior to the baseline test. Further, nothing
in the engine's history indicates that it is not a representative urban
bus engine. Information from the transit company and Johnson Matthey
indicates that the engine was properly maintained in accordance with
industry practices. Therefore, EPA finds the data to be acceptable as
well.
With regard to the application of the Johnson Matthey CEM to
engines which were upgraded using DDC certified rebuild kits, Johnson
Matthey has provided revised language in the application to warrant the
emissions performance for these engines to reduced emission levels of
0.22 g/bhp-hr PM for the 1979 to 1987 engines and 0.17 g/bhp-hr for the
1988 and 1989 engines. These levels are included in Table A herein.
This should address the DDC concerns in this area.
With regard to the issues raised by DDC concerning test engine
selection and extrapolation of test results, DDC stated that the
testing was done on a used engine prior to rebuild and after rebuild
using DDC replacement parts. However, the rebuild was incomplete and
did not put the engine into any configuration which had been certified.
Since no testing was reported using either an unused engine or an in-
use engine that was newly rebuilt to its original configuration, DDC
has stated that it does not appear that Johnson Matthey fulfilled the
requirements of 40 CFR section 85.1406 (a)(v). Engelhard also commented
that it disputed whether the application represented a standard
rebuild.
In response to these issues, Johnson Matthey has provided
documentation that it attempted to rebuild the engine to a
configuration which would be normal for those engines currently in the
field. Since the original build date of the test engine a number of
changes were made in the field in accordance with DDC guidance. In
undertaking the rebuild, Johnson Matthey attempted to rebuild the
engine to the standard that exists for engines in the field. Johnson
Matthey has provided numerous pages from parts and engine references
which document that the parts installed are in accordance with
recommended field guidance. This documentation is included in the
docket.
It is noted that a change in horsepower was made during the engine
rebuild. This change in horsepower has evidently caused confusion
regarding the final engine rebuild configuration. After consultation
with EPA, during the rebuild the engine horsepower was modified to 277
horsepower vs. the 253 horsepower of the original engine. It was
believed that more urban bus engines exist in the field with 277
horsepower, and that this would be more representative of the existing
in-use urban bus fleet and this change was made simply to make the
engine more representative of the fleets that exist in the field.
Consequently, EPA believes that this change in horsepower caused the
apparent confusion relative to the rebuild status of this engine and
that Johnson Matthey has provided
[[Page 16776]]
documentation that the rebuild represents a standard rebuild for the
277 horsepower engine in accordance with the requirements of section
85.1406.
DDC commented that the certifier appears to be in conformance with
the requirements of EPA's ``worst case engine configuration''
requirements as stated in 40 CFR section 85.1406 (a)(2). However, DDC
also stated that EPA only considered trap technology in developing the
definition of worst case engine configuration, and noted that
particulate traps remove both the volatile and non-volatile particulate
components but that catalysts only reduce volatile particulate.
DDC stated that for catalyst technology, worst case should not be
based on total particulate but rather on the engine with the lowest
volatile particulate fraction and that EPA should modify the definition
in the regulations.
Trap technology was discussed in the preamble language to the Urban
Bus Retrofit/Rebuild rule. EPA also referenced aftertreatment devices
in this language and EPA obviously considers catalysts to be
aftertreatment devices. EPA, at this time, does not have information
that would break down engines into groups having the highest volatile
or lowest volatile composition and none was supplied with the comments.
Further, revision of the definition in the regulation will not take
place during this notification review, but would instead take place in
a regulatory amendment process based upon information received.
However, in the meantime, EPA will continue to interpret the worst case
definition to apply for both trap and catalyst technology.
With regard to certified emission levels, DDC commented that the
proposed certification levels do not represent a full 25% reduction,
and cited an example where only a 20% reduction was present in the
table for 1979 to 1987 for 8V-92TA engines. In addition, for the 1991
code 5A 8V92TA DDEC engine, the original certification testing yielded
a PM emission level of 0.20 g/bhp-hr and the proposed certification
level of 0.19 g/bhp-hr given in Table A represents only a 5% reduction.
The pre-rebuild levels listed in Sec. 85.1403(c)(1)(iii)(A) were
determined by EPA based on certification results or engineering data
and judgement. In Table A, Johnson Matthey has listed the PM levels it
is certifying to for listed models and years. In a number of instances
the certification level shown represents a 25% reduction from the
levels that were listed in Sec. 85.1403(c)(1)(iii)(A). In other
instances, the number reflects a 25% reduction from the level that was
certified by DDC during new engine certification. In the case of the
1979-1987 8V-92TA models, the certification level was not directly
listed in Sec. 85.1403 (c)(1)(iii)(A). However, there is a designation
for ``other engines'' which is listed as 0.50 g/bhp-hr PM.
In the case for the 1991 8V92TA DDEC engine the original
certification testing by DDC yielded a PM emission level of 0.20 g/bhp-
hr. However, DDC certified the engine to a level 0.37 g/bhp-hr level
under the averaging, banking and trading program. Therefore, the
proposed certification level of 0.19 g/bhp-hr PM provides for more than
a 25 % reduction from the original DDC certification level for this
engine. In the case of the 1979-1987 8V92TA engines, the level used by
Johnson Matthey was based on the level that was approved under a
previous application. In that application, the Engelhard Corporation
certified this engine model to a PM level of 0.40 g/bhp-hr level based
on what it projected to be a reasonable reduction. EPA accepted this
level and no comments were received on this during the review or post
certification time frame. However, based on DDC's comment and lacking
more specific information relative to the original emission levels of
this engine, Johnson Matthey has amended its application and Table A
has been revised to provide a certification level of 0.38 g/bhp-hr for
these engines. EPA will contact Engelhard with regard to a revision to
the certification level for this engine relative to its certification
as well. EPA has reviewed the certification levels in accordance with
DDC's request and believes that Table A represents at least a 25%
reduction in all instances. Further, based on the test data provided by
Johnson Matthey, EPA believes that the test data will in fact reduce
the PM emissions by 25% or more on these engines.
With regard to DDC's comments on representivity of test data,
Johnson Matthey's notification provides baseline testing data with a
particulate level of 0.44 g/bhp-hr even though the test engine had
accumulated 300,000 miles in service. In contrast, the table in
Sec. 85.1403 (c) (1)(iii)(A) of the regulations provides a baseline
value of 0.50 g/bhp-hr. In the case of DDC's own notification of intent
to certify the baseline certification testing yielded a value of 0.53
g/bhp-hr for this engine model. DDC questioned whether the blower that
was installed on this engine based on an in-field update was 100%
bypass blower. DDC noted that the injection timing was set at 1.460 for
the testing and not at 1.475 as would have been the case if the engine
were properly updated. Engelhard also questioned whether the injectors
were rebuilt and the injector height. According to DDC, the Johnson
Matthey pre-rebuild test configuration was not consistent with any DDC
certified configuration. According to DDC, because of this discrepancy,
the catalyst efficiency assessments would be expected to be higher,
than if testing had been performed using a properly rebuilt 1986 or
1987 engine. It was not clear whether the post-rebuild was intended to
reflect a standard rebuild or a rebuild using the certified DDC upgrade
kit. DDC and Engelhard noted that the parts listing in the application
did not include a blower, turbocharger cylinder heads or fuel
injectors, all of which were noted to be key components which are
subject to wear and must be replaced at rebuild. DDC also noted that
the cylinder kits were listed as part number 23503938. This part number
was noted by DDC to apply to a truck engine and are not the proper kits
for upgrading the engine to either a standard or upgraded bus engine
configuration. DDC noted that the 1.475 injection timing used in the
post-rebuild testing would have been proper for a standard rebuild, but
a timing change of 1.500 must be used with a DDC certified upgrade
rebuild. Johnson Matthey's post rebuild test level of 0.13 g/bhp-hr is
well below DDC's expectations and range of test experience for properly
rebuilt engines. DDC and Engelhard questioned the representivity of
such low test data.
According to Johnson Matthey, and as noted in testing documentation
in the application, pre-rebuild engine emissions were sampled on the
engine just as it came from the field. No changes were made to
components, settings or parts prior to testing. The engine history
indicates that the test engines went into revenue service on April 10,
1986. In May 1989, with 158,880 miles on the odometer, the engine was
serviced at an authorized DDC facility under a warranty claim. Warranty
repairs were made due to high oil consumption and smoke emissions.
Warranty repairs consisted of the replacement of the cylinder kit with
standard DDC parts. DDC authorized the replacement of the 83% blower
with a 100% blower. It is noted that this is the by-pass blower. Aside
from routine maintenance, the engine operated in regular service until
it was determined through maintenance records that the engine, due to
excess oil consumption was in need of a major engine overhaul. The
engine was removed from service
[[Page 16777]]
and sent to the Southwest Research Institute for certification testing.
It was determined through baseline testing that the engine was
consuming oil at a rate of 5 quarts per 12 hours. Testing was performed
at Southwest Research on the engine in its as received condition. The
engine was tested with T-70 injectors set a timing of 1.460. DDC
indicated that the injection timing should have been 1.475 if the
engine were properly updated. Based on the information presented, EPA
concludes that the pre-rebuild engine was tested in the configuration
that would represent the original configuration along with recommended
modifications for the engine in the field including the timing. Johnson
Matthey has provided EPA with detailed documentation that the engine
was tested in the original in-use configuration. Therefore, it is
apparent that the 1.460 timing would have been acceptable for the
original configuration, it would not have been acceptable for the
engine which had been updated in the field according to DDC. However,
this engine had not undergone the complete update and had been only
partially updated based on the warranty work performed in 1989.
Therefore, it is apparent that the 1.460 timing would be correct for
this engine since it had not undergone the update. Unfortunately, the
confusion was evidently caused by the fact that the blower was replaced
under warranty. But the additional changes necessary to update the
engine were not made at that time. Therefore, the engine was tested
with the original injection timing setting rather than the setting that
is specified for the updated rebuild.
In regard to the rebuilt engine presented for the post rebuild
testing, Johnson Matthey rebuilt the engine to the 277 horsepower
configuration as discussed earlier. The injectors for this horsepower
were the G-75 injectors set at the 1.475 timing. The documentation
submitted by Johnson Matthey indicates that this is the proper setting
according to printed field guidance and DDC commented that this would
be the correct timing for the standard rebuild. It is apparent to EPA
that the direction given in the field by DDC for a standard rebuild
updates the engine to the configuration which Johnson Matthey presented
for post rebuild testing. In regard to the parts list missing the
components noted, these parts were inadvertently left off the parts
list contained in the notification. Johnson Matthey has provided this
listing and it contains all the parts mentioned by the commenters as
being necessary for the rebuild and has been added to the docket. In
regard to the cylinder kits used in the rebuild, this part number was
provided in a printout of information from DDC's computerized service
information system identifying the listed cylinder kit part number to
be correct for this engine. In regard to this being a truck part
number, the servicer who performed the rebuild explained that there was
no bus engine designation at the time this engine was originally
manufactured, therefore the truck part number is referenced in the
guidance provided in the DDC printout. This printout is included in the
docket. Although the low level of PM that was generated in the post-
rebuild testing is lower than that seen for other rebuilt engines
tested under this regulation, the information presented by Johnson
Matthey indicates it was rebuilt to what would be a standard rebuild
configuration. Therefore, EPA believes it is acceptable for the purpose
of certification in the demonstration of a 25% reduction demonstration.
EPA notes that a low PM number for the pre-retrofit test does not seem
to be an advantage to the certifier when certifying a 25% reduction.
DDC noted that the maximum exhaust pressure limit for the 1986 6V-
92TA engine family limit was exceeded when the CEM was installed. The
backpressure was 3.4 inches Hg. on the pre-rebuild engine and 3.7
inches Hg. on the post rebuild engine. The maximum backpressure limit
for the 253 horsepower configuration is 2.5 inches Hg. and in the 277
horsepower configuration the maximum backpressure is 3.0 inches Hg. DDC
noted that an in-use catalyst which becomes partially plugged could
become more restrictive due to ash accumulations and cause still higher
levels of backpressure. DDC commented that the use of the same size and
configuration catalyst on 8V-92TA engines which have higher exhaust
flows would result in extremely high back pressures. DDC noted that
increased backpressure will cause increased engine out smoke and
increased non-volatile particulate levels. It would also cause
increased cylinder and exhaust temperatures and have a deleterious
effect on engine durability. DDC also commented that the life-cycle
cost should be modified to reflect an increased cost based on the fuel
economy shown in the post rebuild certification testing. The post
rebuild test with the CEM in place presented an exhaust backpressure of
3.7 inches Hg. (an increase of 1.3 inches Hg. over the baseline test
without the CEM) and brake-specific fuel consumption increased from
0.441 to 0.454 lb/bhp-hr when the CEM was added (an increase of 2.9%).
DDC stated its belief that the loss in fuel economy resulted from the
increased backpressure. Using the equation in 40 CFR section 85.1403
(b)(1)(ii)(C) DDC estimated the increased cost based on loss of fuel
economy to be $459 (1995 dollars). DDC believes that this component
must be included in the life-cycle cost analysis.
In response to the backpressure issue, Johnson Matthey noted that
the CEM that was used during certification testing was a prototype
which developed greater backpressure than the production models to be
manufactured. Johnson Matthey referenced SAE paper NO 930129
``Production Experience of a Ceramic Wall Flow Electric Regeneration
Diesel Particulate Trap'' which reports measured in-use back pressure
of 5.2 inches Hg. on a particulate trap system of the design approved
by DDC and certified by EPA for the DDC 6V92TA engine and noted that
the level experienced during Johnson Matthey's certification testing
was well below this level.
Johnson Matthey has also provided field data indicating that the
recent data collected shows backpressure experienced with CEMs in the
field is lower than that seen during the certification tests. It noted
that the certification test is designed to represent the standard
muffler in place on the exhaust system and the associated backpressure.
The CEM is designed to take the place of the muffler in the exhaust
system. Johnson Matthey has provided information indicating it will
design each CEM so that the backpressure due to the CEM will be less
than or equal to the muffler it replaces. Consequently, there will be
no incremental increase in backpressure due to the replacement of the
muffler with the CEM. Johnson Matthey provided field data from an
operator in which the backpressure readings were taken for buses during
``full stall''. Full stall is a procedure used in the field to evaluate
system backpressure. The information provided indicates that with
standard mufflers in place the backpressure ranged between 2.7 and 3.0
inches of Hg. For comparison purposes, Johnson Matthey also provided
data that the back pressure on an in-use bus was 2.4 inches Hg. at full
stall with a production CEM installed. Further, Johnson Matthey has
indicated that it will size each catalyst for the flow requirements of
the engine to minimize backpressure. Johnson Matthey has arranged for
production CEMs to be designed and fabricated by a major manufacturer
of urban bus mufflers. The
[[Page 16778]]
production CEMs currently in use in field tests were designed with this
company. Johnson Matthey has indicated that it will size the catalyst
element to accommodate engine flow. However, the conversion of PM will
never be compromised as the gas space hourly velocity (GHSV) will be
maintained. As noted by Johnson Matthey, the GHSV determines the
effectiveness and performance of the catalyst to convert PM. To
accommodate engines with greater exhaust flow, the catalyst volume will
be changed in accordance with the exhaust flow rate. Therefore, if the
engine flow rate is increased, a larger catalyst can be applied so long
as the GHSV is maintained. The resultant ability of the catalyst to
convert PM will be maintained.
Johnson Matthey also provided temperature data which documented
the exhaust temperatures with and without the catalyst. The peak
temperature difference between the two was between 10 to 15 degrees C
in the worst case. Johnson Matthey also noted that over the past six
years more than 1,000 buses in Europe have been equipped with CEMs and
there have not been any warranty claims resulting from CEM
backpressure. Based on the backpressure levels and the operating
temperatures noted during the test, EPA does not believe the
backpressure or temperatures experienced during testing will be
detrimental to engines if experienced in the field.
Based on the fact that Johnson Matthey has shown it will provide
catalysts to operators which are designed in tandem with a major
muffler producer to have equal or less backpressure than the mufflers
they will replace, while at the same time maintaining catalyst
efficiency, and in conjunction with the field data presented, EPA does
not find it would be appropriate at this time to consider a life-cycle
cost impact due to a fuel economy decrease which would be attributable
to increased backpressure. Therefore, life-cycle costs will not be
modified.
Since the requirements for trigger technology have already been
triggered for all engine models covered by this application, the life-
cycle cost calculation is not necessary from the standpoint of
triggering requirements. No new requirements will be placed on
operators based on this certification and no operator will be required
to specifically purchase this equipment. Rather, operators will be able
to select the equipment they will use. The Johnson Matthey equipment
may be used by operators choosing program 1 or program 2. However, this
certification will not be considered trigger technology, and will not
affect the emission levels for program 2. EPA encourages operators to
supply fuel economy or emissions data relative to this certification
directly to EPA, if fuel economy decreases or emission increases are
noted in the field. If in the future, EPA finds that based on the data
presented that the fuel economy or emissions have been affected, a
notice will be issued in the Federal Register.
DDC commented that EPA should seek assurances that the certified
hardware will be available for all engine bus combinations. Johnson
Matthey has indicated it will work with the operators to meet their
needs and is developing CEMs to be direct bolt in designs. This coupled
with the fact that other companies have already certified equipment for
the engines covered under this application should handle this concern.
DDC also commented that the CEM must be placed within six feet of
the turbine outlet as the testing data was developed with the catalyst
placed six feet from the turbine. DDC noted that the temperature and
conversion efficiency would be affected by the catalyst placement. If
the catalyst is placed nine feet from the turbine outlet, rather than
at six feet as positioned during the emissions test, the difference in
exhaust temperature between the two placements may affect the catalyst
efficiency. In the application, Johnson Matthey provided temperature
data indicating that the temperature change between the turbine outlet
and the catalyst was 10 degrees C over the six foot length and
projected that the difference in the additional three foot length would
amount to 5 degrees C. It is not thought that this temperature
difference will affect catalyst effectiveness.
Engelhard has raised a health effects issue concerning the
formulation of the catalyst. Specifically, Engelhard stated it's belief
that the Johnson Matthey CEM contains a catalyst that contains platinum
and vanadium. Engelhard noted that vanadium was toxic and was a real
concern in Europe. Engelhard stated that the combination of vanadium
and platinum raises the concern over increased aldehyde and oxygenate
emissions which would be expected to increase exhaust odor. Engelhard
stated that if the platinum and vanadium materials are being used,
Johnson Matthey should be required to supply test data proving no risk
to public health, welfare or safety. Engelhard did not provide any
documentation or references with its comments on this issue.
In order to gain a better understanding of the Engelhard comment,
EPA telephoned Engelhard to discuss its comment. EPA was told that the
primary concern was based on a technical report titled, ``Assessment of
Maleic Anhydride as a Potential Air Pollution Problem''. This report
dated January 1976 was generated under EPA contract number 68-02-1337.
Engelhard did not have a copy of the report on hand and sent EPA a
summary abstract which has been added to the docket. EPA obtained a
copy from the EPA Library. The report has been added to the docket as
well. The report indicates that maleic anhydride is a white crystalline
solid with a sharp irritating odor. It also states that the main method
of manufacture is the reaction between benzene vapor and air in the
presence of a vanadium catalyst. Benzene is listed by the American
Council of Governmental Industrial Hygienists as having a ``A1''
designation indicating that it is a confirmed human carcinogen. Maleic
anhydride has not received a designation from this group as no
experimental data has been reported. The report notes that maleic
anhydride is used in the production of esters, polyester resins, dye
intermediates, pharmaceuticals, agricultural chemicals and fumaric
acid. Health effects, physical chemical properties and measurement
techniques are also discussed in this report. Based on the report,
Engelhard concerns are focused on the fact that in a catalyst
containing platinum and vanadium, with benzene in the exhaust stream,
conditions may be present under which the benzene is converted to
maleic anhydride.
Johnson Matthey considers the presence or absence of vanadium in
the formulation of the catalyst used in the CEM to be proprietary
information and does not wish to disclose this information to its
competitors through public dissemination. To protect this proprietary
information, EPA will not discuss the formulation of the catalyst in
this notice. In any case, for the reasons given below, the presence of
vanadium would not affect the certification of the CEM in this
application.
EPA notes that the formation of maleic anhydride as discussed in
the report is under a controlled environment with the specific purpose
of producing maleic anhydride. In the process to manufacture maleic
anhydride, a benzene/air mixture is oxidized to maleic anhydride over a
vanadium catalyst at a pressure of 2 to 5 atmospheres at a temperature
of 400
[[Page 16779]]
to 450 degrees C. While benzene is present in the diesel exhaust, the
pressure in the exhaust will generally be at 1 atmosphere and the
temperature will usually be less than 400 degrees C. The average diesel
exhaust temperature ranges between 250 degrees and 350 degrees C. There
may be occasions where the diesel exhaust reaches 400 degrees C or
higher but this will represent peak temperatures of short duration for
the most part. For example, in the test engine for the post rebuild
test with catalyst installed, the exhaust temperature averaged
approximately 240 degrees C and the peak temperature was less than 330
degrees C. Additionally, the required pressure of 2 to 5 atmospheres
necessary for the specified conversion process will not be found in the
diesel exhaust. Therefore, the conditions specified to carry out the
conversion process as per the noted report will not be found in the
diesel exhaust system. Additionally, in the case of an oxidation
catalyst such as the CEM, volatile organic compounds such as maleic
anhydride are oxidized. Therefore, for the most part, any maleic
anhydride present would be converted to carbon dioxide and water by the
CEM. Johnson Matthey has provided test data that aldehydes and
oxygenate compounds were reduced by the catalyst used in the CEM.
After review of this matter, EPA does not believe that it has
sufficient information or test data at this time indicating that use of
the candidate equipment poses an unreasonable risk to public health and
welfare or safety.
However, EPA is interested in gathering additional information in
this area and requests that the public and industry provide information
with regard to the content of the diesel exhaust stream and the effect
oxidation catalysts may have upon exhaust stream components, especially
non-regulated components. Further, as benzene is present in the diesel
exhaust stream of all diesel engines, the possibility may exist for the
production of maleic anhydride with or without the presence of
vanadium. Therefore, the question raised here may pertain to all diesel
engines whether or not they are employing oxidation catalysts. Based on
this, EPA seeks information from the public and industry with regard to
diesel exhaust relative to increases or decreases in exhaust components
based on the use of oxidation catalysts which contain or do not contain
vanadium.
III. Certification Approval
The Agency has reviewed this notification, along with comments
received from interested parties, and finds that the equipment
described in this notification of intent to certify:
(1) Reduces particulate matter exhaust emissions by at least 25
percent, without causing the applicable engine families to exceed other
exhaust emissions standards;
(2) Will not cause an unreasonable risk to the public health,
welfare, or safety;
(3) Will not result in any additional range of parameter
adjustability; and,
(4) Meets other requirements necessary for certification under the
Retrofit/Rebuild Requirements for 1993 and Earlier Model Year Urban
Buses (40 CFR Sections 85.1401 through 85.1415).The Agency hereby
certifies this equipment for use in the urban bus retrofit/rebuild
program as discussed below in section IV.
IV. Operator Requirements and Responsibilities
This equipment may be used immediately by urban bus operators who
have chosen to comply with either program 1 or program 2, but must be
properly applied. Currently, operators having certain engines who have
chosen to comply with program 1 must use equipment certified to reduce
PM emissions by 25 percent or more when those engines are rebuilt or
replaced. Today's Federal Register notice certifies the above-described
Johnson Matthey equipment as meeting that PM reduction requirement.
Only equipment that has been certified to reduce PM by 25% or more may
be used by operators with applicable engines who have chosen program 1.
Urban bus operators who choose to comply with Program 1 may use the
certified Johnson Matthey equipment (or other certified equipment)
until such time as the 0.10 g/bhp-hr standard is triggered for the
applicable engines.
Operators who choose to comply with Program 2 and use the Johnson
Matthey equipment will use the appropriate PM emission level from Table
A when calculating their fleet level attained (FLA).
As stated in the program regulations (40 CFR 85.1401 through
85.1415), operators should maintain records for each engine in their
fleet to demonstrate that they are in compliance with the requirements
beginning on January 1, 1995. These records include purchase records,
receipts, and part numbers for the parts and components used in the
rebuilding of urban bus engines.
Dated: April 3, 1996.
Mary D. Nichols,
Assistant Administrator.
[FR Doc. 96-9467 Filed 4-16-96; 8:45 am]
BILLING CODE 6560-50-P