December 4, 2008	

Mr. Jaime Pagan

Energy Strategies Group

US Environmental Protection Agency

D243-01

Research Triangle Park, NC  27711

RE:	Resolution of Outstanding Issues in 40 CFR 60 Subpart IIII,
Standards of Performance for Stationary Compression Ignition Internal
Combustion Engines, as Applied to Larger CI engines. 

Dear Mr. Pagan:

	The Engine Manufacturers Association (EMA) represents the major
manufacturers of internal combustion engines used in stationary sources
that are now regulated by the recently promulgated Compression Ignition
(CI) NSPS (40 CFR 60 Subpart IIII).  EMA worked closely with you and
your office during the development of the proposed and final rules, and
EMA member companies are now working to ensure final compliance to the
standards established in the rule.  

Although EMA believes that the CI NSPS final rule generally adopts a
technically feasible level of control for most categories of stationary
CI engines, we have continuing concerns regarding the final NSPS rule as
it applies to very large engines, those over 30 liters per cylinder (30
l/cyl).  The requirements and emissions standards for those engines are
identified in Section 60.4204 (c) and Section 60.4205 (d) of the final
regulation.  Manufacturers’ concerns include several issues that
previously have been discussed with you in both written submittals and
meetings over the last years.  That correspondence included letters and
comments submitted by EMA and Euromot dated 29 September 2006, 27
November 2006, 13 April 2007, and 29 June 2007.  We last addressed the
issues at an EPA/EMA meeting at your offices on 27 August 2007.

Specifically, the previously identified issues that need resolution
include the following:

The NSPS establishes a single set of emission standards for engines
greater than 30 l/cyl that do not recognize nor address the broad and
diverse facility categories that utilize such engines.  Further, these
standards do not reflect best demonstrated technology.

The NSPS exemption related to the use of aftertreatment technology on
emergency engines also should apply to engines greater than 30 l/cyl.

The geographic areas where higher sulfur fuels are allowed or that are
subject to alternative emission requirements in the NSPS should be the
same as allowed in other NSPS regulations.

EPA Method 5 is not adequate to measure PM from engines larger than 30
l/cyl, and alternative methods are needed to improve accuracy.

The EPA should include provisions in the NSPS that incentivize and
promote engines with high energy efficiency.  EPA has included such
provisions in final NSPS rules for other combustion technologies such as
turbine and boilers.  This issue applies to all engines and not only
those with displacement greater than 30 l/cyl

The following text provides additional details and discussion on the
above issues.

The emissions standards for engines greater than 30 l/cyl are not Best
Demonstrated Technology and should be changed. 

EMA believes that some of the requirements imposed on engines greater
than 30 l/cyl go beyond EPA’s stated objective of the NSPS which is to
“require all new, modified, and reconstructed stationary CI ICE to use
best demonstrated systems of continuous emission reduction, considering
cost, non-air quality health, and environmental and energy impacts, not
just with add-on controls, but also by eliminating or reducing the
formation of these pollutants” (Final Rule, CI ICE NSPS, FR 71: 39154,
Summary).  As applied to very large engines, the final NSPS exceed that
objective by adopting emissions standards that require the use of
systems that are not best demonstrated technology or that significantly
adversely affect costs, non-air quality health, the effects of the
standards on local air quality, and energy impacts.  Specifically, the
final emission standards for engines over 30 l/cyl do not provide
flexibility to address local infrastructure, energy, or air quality
conditions but mandate costly aftertreatment control systems for PM and
NOx reductions. 

As mentioned above, EPA has established a single set of emission
standards for owners and operators for all stationary CI engines greater
than 30 l/cyl.  Owners and operators of such engines must reduce NOx
emissions by 90% or achieve an emissions standard of 1.6 g/kW-hr, and
must reduce PM by 60% or achieve an emissions standard of 0.15 g/kW-hr.
 Attaining the proposed standards will likely require the use of both
NOx and PM aftertreatment technology. The rule does not provide
sufficient transition time to develop and demonstrate the required
technologies for these very large engines.

Furthermore, the wide range of facility and engine sizes, the
application and location of a specific facility, the availability of
low-sulfur diesel fuel in territories, and operating conditions are
extremely varied.  Aftertreatment to meet the final standards may not
be technically or economically feasible under a given set of site
conditions.  Many remote applications that depend on very large
stationary diesel engines will be severely disadvantaged if products are
not available. 

As a solution for this issue, EMA proposes that the emission standards
for stationary engines greater than 30 l/cyl should be harmonized with
the recently approved International Maritime Organization (IMO)
emissions regulations.  Although there are technical differences between
very large marine engines and stationary engines created for specific
applications and duty cycles, there are correlations between the
required engine development and demonstration programs.  

First, the IMO, of which EPA is a key contributor and the US is now
signatory, has approved at MEPC58 on October 9th 2008 both Tier II
standards and Tier III aftertreatment forcing standards covering engines
of this size.  The Tier III NOx standards will mandate compliance
starting with new ship construction in 2016 to allow time for
development of the required technologies.  Engines and aftertreatment
systems will need to be developed and available at that time to meet the
IMO standards.  Secondly, a stand-alone US EPA proposed rulemaking is
currently underway for Marine engines greater than or equal to 30 l/cyl
(Reference the EPA Federal Register release.
 [EPA–HQ–OAR–2007–0121; FRL–8502–5]  RIN 2060–AO38
Control of Emissions From New Marine Compression-Ignition Engines at or
Above 30 Liters per Cylinder).  This US EPA proposed rulemaking is
expected to harmonize with IMO requirements as well.

	EMA believes a similar approach is warranted for very large stationary
engines, which are nearly all derived from those somewhat higher volume,
very large marine engines.  Often the same engine types (with different
turbo specifications) are used in both stationary and marine
applications.  One difference is that very large marine engines are IMO
certified using lighter fuels whereas very large stationary engines meet
World Bank/IFC standards using fuels available at the site.   Another
difference is that very large marine engines are developed with  a focus
on part-load performance and load-acceptance requirements and are
typically optimized at an 85- 90% Maximum Continuous Rating(MCR) load
range, whereas very large stationary engines are optimized for 100 % MCR
load with less development at partial loads.  One resulting difference
is that marine and stationary plant engines have different turbo charger
matching (different components in turbo chargers).

	Since manufacturers are now required to meet IMO regulations for very
large marine engines, the US is now a signatory to IMO, and EPA has
promoted the IMO regulations for several years, EMA believes that the
EPA should revise the NSPS for greater than 30 l/cyl engines to
harmonize with IMO requirements for stationary engines.  Engine
manufacturers make both marine and stationary versions of these engine
types.  If EPA were to harmonize the requirements, manufacturers will be
able to leverage development of solutions for both applications.

The NSPS exemption related to the use of aftertreatment technology on
emergency CI engines should be applied to engines greater than 30 l/cyl
to allow their use in emergency applications such as nuclear power
system back-up, firefighting, flood control, and national security.

In order to prevent potential performance and start-up problems when CI
engines are used for emergency power generation, the final NSPS does not
require owners or operators to use aftertreatment emissions control
equipment on emergency generators.  However, this critical exemption is
not applied to engines greater than 30 l/cyl in the current rule.

For example, the nuclear power generation industry must provide back-up
emergency power in order to assure the safe shut-down of the reactor in
case of an emergency or disruption of off-site power.  Due to their
excellent performance and reliability characteristics, large diesel
generators are the preferred option for such back-up power systems.  In
many cases, the nuclear industry requires back-up power sources capable
of generating 10 MW or more of power, and such generators will generally
require IC engines with a 30 l/cyl displacement.  However, in order to
meet the emissions standards for greater than 30 l/cyl engines
established in the final CI NSPS, aftertreatment controls for PM and NOx
will be needed.  As in the case of smaller engines, the addition of such
aftertreatment systems to meet current NSPS emission standards will
jeopardize the ability of the engines to meet their primary safety
function and performance standards required for emergency safety
systems.

The primary function of emergency generators is to guarantee the power
supply in case of loss of external electricity.  EMA believes it is
critical that the CI NSPS emissions standards do not interfere or
jeopardize this critical function or prevent the use of large CI engines
in emergency applications.  As in the case of smaller emergency
generators, large emergency generators will only be run for periodic and
required safety tests and in the case of an emergency.  

	Since EPA has adopted an exemption to the emissions limits for
emergency diesel generators where meeting the emissions limits would
require the use of aftertreatment devices and EPA has provided an
exemption from NOx emissions limits for combustion turbines used in
emergency situations, it follows that the same exemption should be
allowed for engines greater than 30 l/cyl that are used to provide
emergency back-up power.  In order to address this situation, the final
CI NSPS should be amended to establish emissions standards for emergency
engines with a displacement greater than 30 l/cyl that can be achieved
during emergency operating conditions and during limited maintenance &
readiness testing (as defined in the final CI NSPS paragraph 60.4211 e)
without the addition of aftertreatment PM or NOx controls.  As stated
above, EMA recommends harmonization with the IMO standards.  

For emergency-use stationary CI engines greater than 30 l/cyl, we
recommend that a slightly modified IMO Tier II standard be adopted and
become effective in January 2011 and that the IMO Tier 1standards be
adopted until that time    The current requirement in the CI NSPS (40
CFR 60.4213) to conduct tests within 10% of 100 percent peak load (or
the highest achievable load) is appropriate since it reflects the actual
operations and usage of the stationary engine.  EMA recommends that the
CI NCPS be amended to state that performance tests for slightly modified
IMO Tiers I and II also be conducted within 10 % of 100 percent peak
load or the highest achievable load of the engine.  The CI NSPS ruling
also requires an annual performance test to demonstrate compliance with
the set emission limits.  EMA recommends that the simplified measurement
method and allowances stipulated in Sections 6.3.11 and 6.4.15.2 of the
IMO MEPC58 Revised Marpol Annex VI October 2008 be used for emissions
measurements of engines at the site.  

The geographic areas allowed to use higher sulphur content fuels or that
are subject to alternative emissions requirements in the CI NSPS should
be the same as allowed in other NSPS regulations.

EPA has recognized that certain geographical areas, because of their
isolation from the mainland US or environmental conditions, warrant
exceptions to the provisions in the CI NSPS governing fuel quality or
permissible emissions.  For example, the CI NSPS excludes the American
territories of Guam, America Samoa and the Northern Mariana Islands from
the fuel sulfur content requirement.  Consequently, emissions standards
from engines in such locations should not be as stringent since the
quality of fuel in those locations is different.

Although EMA believes such exceptions are necessary and commendable, we
are concerned that various EPA NSPS rules are not consistent in defining
such areas or in allowing alternative emission standards for such areas.

	Specifically, in both the combustion turbine rule and the steam
generator boiler rule, the geographic areas defined as non-continental
or territories are expanded to include the Hawaiian Islands, Virgin
Islands, and Puerto Rico and offshore platforms.   The same definition
and allowances for different fuel quality available in those locations
should be applied to the CI NSPS as well, i.e., the geographic
exemptions should be the same in all rules and thus expanded in the CI
NSPS rule.

	In addition, EMA believes that remote areas that experience harsh
environmental conditions, such as remote areas in Alaska, require
additional exemptions from the fuel and emissions limits in the CI NSPS.
 The harsh environmental conditions in those locations make compliance
to the current NSPS emissions extremely problematic since they affect
the applicability of aftertreatment technology such as SCR systems.  In
those areas, EMA recommends that secondary abatement techniques not be
required due to the problems associated with reagent availability and
equipment and system freezing.  As an example, EPA established
alternative and less stringent emissions standards for gas turbines
operating north of the artic circle, in off-shore applications or
operating at temperatures below zero degrees F. 

	Similar provisions need to be incorporated into the CI NSPS. 
Alternative emissions standards should be adopted that are appropriate
and achievable given the harsh environmental conditions present.  As
recommended previously, EMA supports harmonization with IMO standards
for areas where higher fuel sulfur or fuels blended with used
lubrication oil are allowed.  In those areas, stationary CI engines >30
l/cyl should harmonize with a slightly modified IMO Tier II and Tier I
that reflects the design rating of stationary engines (testing at steady
state loads within 10 % of 100 percent peak load or the highest
achievable load). 

For the particulate limit we propose the same particulate limits (steady
state load within 10 % of 100 percent peak load  or the highest
achievable load of the stationary engine) of the EU LCP BREF document
(available at    HYPERLINK
"http://www.jrc.es/pub/english.cgi/d1254325/19Reference Documenton Best
Available Techniques for Large Combustion Plants (adopted July 2006)
-22Mb"  http://www.jrc.es/pub/english.cgi/d1254325/19Reference Document
on Best Available Techniques for Large Combustion Plants (adopted July
2006) -22Mb   page 405, table 6.47) 30 mg/Nm3 (15 % O2) for light fuel
oil and distillates and 50 mg/Nm3 (15 % O2) for heavy fuel oils with
measurement modified US EPA Method 5 or EPA 17.

EPA Method 5 is not an adequate method to measure PM from large engines.

EPA requires owners and operators of engines greater than 30 l/cyl to
use EPA Method 5 to measure PM for performance and compliance
demonstrations (NSPS Table 7(d) (IV)).  Method 5 requires that the PM
sample be taken at a cooled exhaust temperature of about 120 degrees C
(248 degree F).  The flue gas temperature of larger CI ICE is typically
in the range of 250-350 degree C (480 – 660 degree F).  Consequently,
owners and operators will have to cool flue gas from such engines in
order to reach the Method 5 described filter holder temperature. 
According to the CIMAC document this will result in large uncertainties
(non-reproducible sampling):   Appendix 2“. The cooling of the exhaust
gas cannot be considered as a controlled process and will not yield
reproducible sampling.  The main reason for this is the uncontrolled
condensation of semi-volatile components from the exhaust gas on the
cold surfaces needed to cool the gas.  According to ISO 9096 and EN
13284-1, more reproducible results are achieved if volatile compounds
are not trapped during sampling or further evaporated during sample
drying.  Considering the above issues it is concluded that to yield
repeatable particulate matter measurement data from the hot exhaust gas
of a diesel engine, the particulate sampling has to be performed at
exhaust gas temperature, i.e. using in-stack sampling”.  

Measurement methods EN 13284-1 (EU), JIS Z8808 (Japan) and ISO 9096
apply in-stack sampling of particulate in the case of flue gas
temperatures greater than 160 degree C (320 degree F).  US EPA Method 17
provides an option similar in principal to those methods.  In the case
of flue gas temperatures less than 160 degree C (320 degree F),
stack-out particulate sampling is used, and the filter holder
temperature is maintained at minimum 160 degree C (320 degree F) in
order to avoid risk of condensation and absorption of sulphur compounds,
water, etc. on the sampling filter.  

In order to avoid the problems associated with use of Method 5 for
engines greater than 30 l/cyl, EMA believes that the NSPS  should
provide flexibility and allow the use of Method 17 to measure
particulate matter.  EPA has allowed such flexibility in other rules,
specifically the NSPS rule for electric utility steam generating units
and industrial-commercial steam generating units as published in the
Federal Register on June 13, 2007.  In that rule, EPA has specified an
“own specific” particulate filter holding temperature and thus
approved a higher filter holder temperature than 120 +/- 14 degree C
(248 +/- 25 degree F) for the US EPA Method 5. The rule also provides
flexibility and the use of Method 17, and indicates that steam
generating units shall use particulate measurement methods 5, 5B or 17. 

Different prime mover technologies should have fair and equal treatment
under EPA regulations, and if flexibility and alternative filter holding
temperatures are provided for one prime mover technology, than a similar
and applicable requirement should be allowed for other prime mover
technologies.

EMA recommends that the requirements of the CI NSPS be amended to allow
owners and operators to use Method 17, and where engine stack
temperatures are less than 160 degree C (320 degree F) (in wet flue gas
desulphurization stacks, etc.)  to allow the use of Method 5B instead of
Method 5 in order to get reproducible measurement results and avoid
uncontrollable/difficult measuring conditions.  Such procedures also
align with applicable regulations in Japan and European countries.

EPA should encourage energy efficiency and fuel savings technology by
adding an energy efficiency provision in the CI NSPS.

The impact of EPA regulations on energy use should be a key
consideration when developing and finalizing emission standards as
described in the recent EPA ANPRM on greenhouse gas emissions.  The NSPS
should include provisions promoting energy and fuel efficiency, reducing
fuel use through the use of combustion sources with high fuel-energy
conversion rates is a key element of federal energy policy to reduce the
nation’s dependence on imported petroleum.  Further, the use of high
efficiency engines also results in lower greenhouse gas emissions and
can be an effective way to reduce greenhouse gas emissions.   

 

	EPA should include a provision within the CI NSPS that provides an
energy efficiency incentive allowing increases in the emission of
criteria pollutants for engines and generation systems that meet certain
thresholds of energy efficiency.  EPA has already adopted such
incentives for other technology in NSPS regulations governing steam
generator boilers, and stationary combustion turbines as follows:

US Steam-generating (boiler) unit NSPS,   page 32739: “For the
purposes of determining compliance with the emission limits in paragraph
60.45Da the owner or operator of generating unit which is also a
cogeneration unit shall  .. calculate emission rates based on electrical
output to the grid plus 75 percent of the equivalent electrical energy
(measured relative to ISO conditions) in the unit’s process stream.”
  Note paragraph 60.45Da is for the Hg emission, i.e., a 75 % bonus for
the recovered heat.

US stationary combustion turbine NSPS, page 38499: “… For
combined-cycle and combined heat and power complying with the
output-standard …gross energy output is calculated  as the sum of the
total electrical and mechanical energy generated by the combustion
turbine, the additional electrical or mechanical energy (if any)
generated by the steam turbine .. and 100 percent of the total useful
thermal energy output that is not used to generate additional
electricity or mechanical output expressed in equivalent MW ..”   

Note Emission bonus is applied on the regulated emissions: NOx and SO2, 
i.e., a 100 % bonus for the recovered heat and full bonus for extra
generated electrical/mechanical energy ( (e.g. a 30 % electrical + 60 %
heat recovery = 90 % efficiency ( emission limit 3 times higher compared
to the electricity production only case).

EMA requests that EPA develop and incorporate a similar efficiency
provision for CI engines.  Adoption of such as program will recognize
the importance of energy efficiency and the benefits of reducing fuel
use and greenhouse gas emissions.  Moreover, incorporating efficiency
considerations in the regulation will provide a level playing field for
engine-based systems compared to boilers and turbine that can already
take advantage of such energy efficiency provisions in NSPS regulations
governing those technologies.  EMA is prepared to work out an efficiency
provision together with US EPA.

Summary

EMA appreciates the opportunity to bring the above issues with the CI
NSPS to your attention and to provide some additional background
information on these topics.  With the finalization of the SI NSPS, we
believe it is an appropriate time to resolve these issues and ask that
EPA consider making the necessary revisions to the CI NSPS as soon as
possible.  We would be happy to discuss these items with you and suggest
that we set up a meeting date in January to discuss and resolve these
issues.

	

	Please feel free to call me if you have any questions.

		

								

Respectfully submitted,

										

								Joseph L. Suchecki

								

								Joseph L. Suchecki

								Director, Public Affairs   

     

 US EPA 2006.  Final Rule.  Standards of Performance for Stationary
Combustion Turbines.  Federal Register, 78: p 38497.

 CIMAC Recommendation 23.  Standards and Methods for Sampling and
Analyzing Emission Components in Non-automotive Diesel Engine Exhaust
Gases – Marine and Land-based Power Plant Sources.  CIMAC working
group on Exhaust Emissions, 2005.  	

 US EPA.   Federal Register Notice Final Rule Amendments to NSPS
Standards, June 13. 2007.  FR 72:  Page 32738.

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