Stationary Source Enforcement Series
EPA 340/1-78-OOlb
APRIL 1978
JET ENGINE TEST CELLS -
EMISSIONS AND CONTROL
MEASURES: PHASE 2
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U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Enforcement
Office of General Enforcement
Washington, D.C. 20460
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EPA-340/1-78-001b
April 1978
JET ENGINE TEST CELLS -- EMISSIONS AND
CONTROL MEASURES: PHASE 2
by
John Kelly, Edward Chu
Contract No. 68-01-4142, Task 7
EPA Project Officer: James Her liny
Acurex Report TR-78-102
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Division of Stationary Source Enforcement
Technical Support Branch
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This report was furnished to the U.S. Environmental Protection Agency by
the Aerotherm Group of Acurex Corporation, Mountain View, California, in
fulfillment of Contract No. 68-01-3158. The contents of this report are
reproduced herein as received from the contractor. The opinions, find-
ings, and conclusions expressed are those of the author and not necessar-
ily those of the U.S. Environmental Protection Agency.
The Enforcement Technical Guideline series of reports is issued by the
Office of Enforcement, Environmental Protection Agency, to assist the
Regional Offices in activities related to enforcement of implementation
plans, new source emission standards, and hazardous emission standards to
be developed under the Clean Air Act. Copies of Enforcement Technical
Guideline reports are available as supplies permit -- from the Air
Pollution Technical Information Center, Environmental Protection Agency,
Research Triangle Park, North Carolina, 27711, or may be obtained, for a
nominal cost, from the National Technical Information Service, 5285 Port
Royal Road, Springfield, Virginia, 22161.
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ABSTRACT
Background information is provided on the environmental aspects of
uncontrolled and controlled military jet engine test cell operations. The
environmental impact of these operations is considered on both a source and
an air quality basis. Some of the uncontrolled jet engine test cell exhaust
plumes exceed local opacity regulations for stationary sources. However, the
air quality impact of uncontrolled operations is small.
Wet-packed scrubber, jet engine clean combustor, and ferrocene fuel-
additive test cell emissions control strategies are described. Clean
combustor technology and its associated cost of implementation are discussed
in detail. Wet-packed scrubber construction cost estimates are also examined
in detail. These control methods probably reduce jet engine test cell plume
opacity below local regulations. However, based on limited data, it is
estimated that for some jet engine tests, applying clean combustors can
cause NO emissions to rise above local stationary source regulations. The
A
air quality impact of controlled jet engine test cell emissions is small.
Jet engine and test cell emissions data collected during this study
are summarized in this document.
iii
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SUMMARY
The Navy, Air Force, and Army test jet engines in test cells as part
of routine maintenance procedures. When tested, some jet engines produce a
dark particulate test cell exhaust plume which is visible from a distance.
Recently, several military jet engine test cell facilities have been cited
for violation of local air pollution control district stationary source
opacity regulations. This study documents the results of the second phase of
a two-phase effort to provide background information to the Stationary Source
Enforcement Division of the Environmental Protection Agency on jet engine
test cell emissons and their control.
Jet engine clean combustor technology was examined as a means of
controlling jet engine test cell exhaust emissions, and plume opacity.
Considerable progress has been made in civilian jet engine clean combustor
technology. Gaseous emissions have been reduced, while exhaust opacity is
maintained at very low levels. Military jet engine clean combustor
technology has produced several afterburning and nonafterburning jet engines
with virtually invisible exhausts. Because of sparse data and variability
with engine model, the impact of military engine clean combustor technology
on gaseous emissions is not clear. The only consistent trend in the gaseous
emission data indicates that--N&y-eroissions are inrxea-s
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Performance and durability goals for military jet engines make it
difficult to simultaneously reduce all emissions and exhaust opacity by
applying clean combustor technology to new engines. Further, it is even more
difficult to reduce emissions and opacity by retrofitting clean combustors to
existing jet engines. However, the military now has a smoke standard for all
new engines and goals for lower emission levels have been established for
future engine procurements. The setting of smoke standards and emission
goals and the successes of the civilian and military clean combustor programs
are encouraging evidence that future military jet engines will be cleaner
than existing engines.
Several existing military jet engines have been made clean by
retrofitting clean combustors. Some engines originally scheduled to be
retrofit have not been altered. This is primarily due to problems in meeting
performance and durability goals, difficulties in achieving adequate designs
for reducing emissions and retirement schedules which make retrofitting some
older engines economically unjustifiable.
Currently, 28 percent of the Air Force and 40 percent of the Navy jet
engines are smokeless. By retrofitting old engines with clean combustors,
procuring new clean engines, and retiring old smoky engines, it is
expected that 40 percent of the Air Force engines will be smokeless by 1984
and 65 percent of the Navy engines will be smokeless by 1985.
In the Phase I study, three widely different wet-packed scrubber
control device cost estimates were received from the Navy and a private
contractor. These estimates were examined in detail to identify the source
of the difference and to determine if a single representative cost estimate
could be derived from the three estimates. Investigation showed that the
VI
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wide variations in the estimated costs were the result of assuming different
baseline test cell mass flowrates. By scaling the costs to a uniform test
cell mass flow of 660 Ibm/sec, most of the cost differences were reconciled.
Also, it was determined that the estimated cost for a wet-packed
scrubber is 1.3 million fiscal year 1975 dollars. This cost does not include
electric and other utility supply costs.
Available jet engine test cell information for the Alameda Naval Air
Rework Facility was used to assess the impact of test cell operations on the
environment. Impacts on source and air quality bases were considered. Since
jet engine test cell emissions data are sparse, the more available and
reliable jet engine exhaust data were used as the baseline uncontrolled jet
engine test cell emissions. These emission levels are probably higher than
test cell values and represent worst-case source conditions. Ground level
pollutant concentrations outside the air base perimeter were obtained by an
air quality model which incorporated worst-case meteorological data. These
weather conditions maximize ground level pollutant concentrations and
therefore represent worst-case air quality emission contributions.
On a source basis, worst-case Alameda jet engine test cell (JETC)
operations contribute very little (less than 0.26 percent) to the total nine
county Bay Area Air Pollution Control District (BAAPCD) emissions (unburned
hydrocarbons, carbon monoxide, nitrogen oxides, sulfur oxides, particulates)
inventory. Alameda JETC operations also represent less than 11 percent of
the emissions produced by military aircraft operations in the BAAPCD region.
Comparing worst-case Alameda JETC operations to base perimeter ambient
background levels of pollutants on a 24-hour basis, it is estimated that JETC
operations contribute, at most, 3 percent of particulates, 43 percent of
unburned hydrocarbons, 0.3 percent of carbon monoxide, 6 percent of nitrogen
vi i
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oxides, and 34 percent of surfur oxides. Contributions to the background
levels are much less than these maximum values at other locations.
Comparing worst-case individual Alameda JETC emissions with the BAAPCD
General Combustion Source Regulations, it is calculated that 40 percent of
Alameda JETC operations exceed the opacity regulations.
Applying wet-packed scrubber, clean combustor and ferrocene fuel
additive control strategies to jet engine test cells reduces the impact of
operations on ambient air quality in all respects except for NOX. Clean
combustors increase NOX by approximately 50 percent. However, the increase
is not large enough to alter the conclusion that JETCs contribute only
minimally to the BAAPCD source inventory. Comparing controlled individual
JETC emissions with General Combustion Source Regulations for the BAAPCD
indicates that all control strategies will reduce the plume opacity below or
near the stationary source opacity regulation. All control methods reduce
particulate concentrations. Since uncontrolled concentrations are below
regulations, controlled JETC particulate concentrations will be even further
below the standards. Wet-packed scrubber and ferrocene fuel additive control
strategies do not alter JETC gaseous emissions sufficiently to alter the
conclusion that all gaseous emissions are below BAAPCD General Combustion
Source Regulations. It is estimated that the T56 engine with clean combustors
will produce NOX emissions in excess of the regulation. If clean combustors
were applied to the T56 engine, 9 percent of Alameda JETC operations would
exceed the NO regulation.
A
Ferrocene added to the fuel is slightly toxic, but no more so than
the fuel itself. When burned, ferrocene fuel additive yields primarily iron
oxide, carbon dioxide, and water vapor. Taken alone, these substances are
not very toxic; however, it has been suggested that synergistic reactions
vm
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of iron oxide with combustion-produced polycyclic organic matter may produce
carcinogens or transport them into the human body. Further study is required
to prove or disprove this conjecture.
Controlled and uncontrolled JETC plume opacity, and gaseous and
particulate emissions data collected during this study are briefly described.
These data vary as a function of engine type, power level, and condition of
the engine. Furthermore, the test cell itself affects emissions, according
to the cell configuration, augmentor design and airflow, and quench water
flow. Also, stack exit areas are typically large and test cell configurations
generally create highly nonuniform distributions of stack exit velocity, which
makes accurate measurement of emissions very difficult.
Published JETC stack-exist emissions data are very sparse. Also, they
are limited since only a few (or one) sampling points are measured for a
large stack exit area. In addition, isokinetic particulate sampling rates
have not been maintained in some cases, casting doubt on the reliability of
the particulate data.
In this report, the JETC emissions data collected during this
study are briefly summarized. Comments on the reliability of the data and
details of the (1) engine and test cell unit tested, (2) test method for
opacity, particulates and gaseous emissions, (3) sampling locations, and (4)
test cell conditions, as well as the data are presented.
IX
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TABLE OF CONTENTS
Section Page
1 INTRODUCTION 1
2 CLEAN COMBUSTOR TECHNOLOGY 5
2.1 Current Civilian Aircraft Engine Emissions 6
2.2 Clean Combustor Technology 7
2.2.1 Pollutant Emission Characteristics of Jet Engines . 8
2.2.2 Overview of Current Low Emissions Technology ... 11
2.2.3 Application of Concepts to Current Civilian
Production Engines 16
2.3 Military Clean Combustor Programs 19
2.3.1 Low-Smoke Military Jet Engines 20
2.3.2 Military Goals for Gaseous Emissions 28
2.3.3 Implementation of Low-Smoke Combustor Programs by
the Military 33
3 WET-PACKED SCRUBBER COST ESTIMATES 39
4 JET ENGINE TEST CELL ENVIRONMENTAL IMPACT SUMMARY .... 51
4.1 Site Location 52
4.2 Uncontrolled Test Cell Emission Air Quality Impact . 54
4.2.1 Gaseous and Particulate Emissions 54
4.2.2 Uncontrolled Test Cell Plume Opacity 55
4.2.3 Comparison of Jet Engine Emissions Data 57
4.2.4 Comparison of Total Alameda JETC Source
Emissions with BAAPCD Source Inventory 62
4.2.5 Comparison with BAAPCD General Combustion Source
Regulations 64
4.2.6 Air Quality Comparison ..... 65
4.3 Controlled Test Cell Emissions Air Quality Impact . . 67
4.3.1 Gaseous and Particulate Emissions 68
4.3.2 Wet Packed Scrubber 68
4.3.3 Clean Combustors 70
4.3.4 Ferrocene Fuel Additive 73
4.3.5 Controlled Test Cell Emissions Air Quality Impact . 77
4.3.6 Comparison of Controlled Total JETC Emissions with
BAAPCD Source Inventory 78
4.3.7 Comparison of Controlled Emissions with BAAPCD
General Combustion Source Regulations 79
4.3.8 Controlled JETC Air Quality Impact 79
XI
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TABLE OF CONTENTS (Concluded)
Section Pa9.e
4.4 JETC Environmental Impacts on Water, Solids and
People 81
4.4.1 Uncontrolled JETC Water Quality Impact 81
4.4.2 Controlled JETC Water Quality Impact 82
4.4.3 People Impacts 83
4.5 Summary 84
4.5.1 Uncontrolled JETC Emissions 84
4.5.2 Controlled JETC Emissions 85
4.5.3 Impacts on Water and People 86
5 JET ENGINE TEST CELL EMISSIONS DATA 89
5.1 "Noise and Air Pollution Emissions from Noise
Suppressors for Engine Test Stands and Aircraft Power
Check Pads" . . . 90
5.2 "Preliminary Report: Jet Engine Test Cell Emissions" 90
5.3 "Turbojet Aircraft Engine Test Cell Pollution
Abatement Study" 91
5.4 "Jet Engine Test Cell TESI Augmentor-Scrubber System" 91
5.5 "A Survey of the Air Pollution Potential of Jet
Engine Test Facilities" 92
5.6 "Ferrocene Test for Test Cell Smoke Abatement" ... 93
5.7 "Jet Engine Test Cell Pollution Abatement Efficiency
Tests" 93
5.8 "A Study of Means for Abatement of Air Pollution Caused
by Operation of Jet Engine Test Facilities" 93
5.9 "Results of Air Samples from Electrostatic
Precipitator" 94
5.10 "Plume Opacity and Particulate Emissions from a Jet
Engine Test Cell" 94
5.11 "Gas Turbine Engine Particulate Measurement Technique,
Sunmary of Coordinating Research Council (CRC)
Programs" 95
5.12 "Aircraft Engine Emissions Catalog" 96
REFERENCES 97
APPENDIX A -- SCRUBBER RETROFIT COST ESTIMATE 103
APPENDIX B -- JET ENGINE IN TEST CELL EMISSIONS DATA ... 109
XII
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LIST OF ILLUSTRATIONS
Figure Page
1 Typical nonafterburning turbine engine emission trends . 9
2 Peak smoke levels General Electric (6E) engines ... 22
3 Smoke emission characteristics of TF39 engine using the
axial swirler combustor 24
4 J79 engine smoke levels 25
5 Smoke characteristics of advanced FlOl-type premixed
combustor 27
6 Comparison of current and future jet engine efficiency
goals 31
7 Comparison of current and future NOX jet engine emission
goals 32
8 Navy estimate of smokeless burner retrofit schedule ... 36
9 Tinker Air Force Base J79 engine test cell 53
10 Relationship between smoke number and soot density ... 58
11 Smoke number versus Ringelmann reading for a 14-foot
diameter stack 59
12 Theoretical and experimental opacity versus grain loading 60
xiii
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LIST OF TABLES
Table
1 Summary of Low-Emission Combustor Concepts ........ 13
2 Sunmary of Emission Levels (EPAP Values) Achieved with
the "Selected" Advanced Technology Combustor Concepts . . 18
3 Smokeless Military Engines
4 Comparison of Smoky and Smokeless Jet Engine Gaseous
Emissions ........................ 29
5 Percent of Low-Smoke Engines in the Military Engine
Inventory ........................ 33
6 Smoke Retrofit Cost Summary for Air Force Engines .... 34
7 Current Status of the Navy Retrofit Program and Retrofit
Costs .......................... 37
8 Scrubber Retrofit Cost Estimate ~ Naval Air Systems
Command ......................... 41
9 Scrubber Retrofit Cost Estimate ~ Jacksonville NARF ... 42
10 Comparison of Scrubber Cost Estimates .......... 43
11 Comparison of Scrubber and Cooling Tower Cost Estimates,
Scaled to a 660-1 bm/sec Flowrate ............. 45
12 Comparison of Water Delivery and Treatment Systems,
Electrical and Structural Cost Estimates, Scaled to a
660-1 bm/sec Flowrate .................. 47
13 Comparison of Total Scrubber System Costs Scaled to 660-
Ibm/sec Flowrate ........... ......... 50
14 Worst-Case JETC Source Strength Data for Alameda NARF . . 61
15 Comparison of Worst-Case Alameda JETC Emissions to Nine
County BAAPCD Emission Source Inventory and Military and
Civilian Aircraft Operations .............. 63
16 Percent Emission Contributions of BAAPCD Military Air
Bases .......................... 63
17 Comparison of Maximum Uncontrolled JETC Emissions to
Combustion Source Regulations .............. 54
xiv
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LIST OF TABLES (Concluded)
Table Page
18 Impact of Jet Engine Test Cell Emissions on Alameda
County Air Quality 66
19 Effect of Smokeless Combustor on J79 Percent Opacities . . 71
20 Percent Change in Emission Levels Due to Smokeless
Combustor Retrofit 73
21 Comparison of Three Control Methodologies Ringelmann
Opacity and Percent Change in Emissions 78
22 Effect of Controls on Total Emissions From Jet Engine Test
Cells at Alameda Naval Air Station 80
23 Comparison of Alameda Controlled and Uncontrolled JETC
Emissions with BAAPCD General Combustion Operating
Regulations 81
xv
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SECTION 1
INTRODUCTION
This report documents the results of the second phase of a two-phase
program conducted by Acurex/Aerotherm to provide background information on
jet engine test cell emissions and their controls to the Stationary Source
Enforcement Division of the Environmental Protection Agency. This program
was concerned primarily with military jet engine test cells in the United
States.
As part of routine maintenance procedures, military jet aircraft
engines are tested on stationary test stands or in test cells. The Navy, Air
Force and Army all maintain facilities devoted to engine maintenance and
testing. When tested, some jet engines produce a dark particulate plume
which is often visible from a considerable distance, and recently, several
military jet engine test cell facilities have been cited for violating local
air pollution control district stationary source opacity regulations.
The military services are aware of these problems, and have
established programs to characterize and control jet engine test cell
emissions. Several military studies are currently underway to assess the
effects of jet engine test cell emissions on ambient air quality.
Aerotherm's Phase I study on jet engine test cells, documented in
EPA report EPA-340/1-78-001 a (Reference 1), provided the following information:
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Physical descriptions of test cells and operating characteristics
which alter jet engine exhaust emissions
State-by-state location of military test cells
Critical review of existing jet engine test cell data and measurement
procedures for opacity, particulates and gaseous emissions
Discussion of test cell emissions control by electrostatic precipitators,
wet packed scrubbers, thermal converters, improvements in fuel
atomization and fuel additives
During the Phase 1 program, several areas of interest were identified
which were beyond the scope of the initial effort. A Phase 2 program was
then conducted to address these study areas. The results of the Phase 2
program, discussed in the following sections of this report, supplement the
information in the Phase 1 report with:
A survey of the state of the art of jet engine clean combustor
technology and the associated cost and implementation time table
of clean combustors by the military services
An examination of wet packed scrubber cost estimates to determine
the source of cost differential between Navy and private contractor
estimates
A brief summary of the environmental impact of controlled and uncontrolled
jet engine test cells, including summaries of the impacts on a
source and air quality basis
A tabulation of available jet engine test cell emission data for
both controlled and uncontrolled test cells
Currently, much activity is underway in all of these areas, and therefore,
some information in this report is based on conversations with people in the
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field rather than on published results. The cooperation of military and
government personnel in this regard is greatly appreciated.
The second section of this report discusses jet engine clean combustor
technology and military schedules for implementing these combustors. The
third and fourth sections discuss wet packed scrubber costs and the impact of
controlled and uncontrolled jet engine test cells on the environment. The
fifth section presents a tabulation of available jet engine test cell
emissions data.
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SECTION 2
CLEAN COMBUSTOR TECHNOLOGY
The January 1979 EPA emission standards for civilian aircraft jet
engines (Reference 2) have stimulated an extensive development program by
engine manufacturers and the government to produce advanced low-emission
engines for the commercial jet fleet. Although military aircraft are exempt
from compliance with the standard, the military services have actively moved
to assess and reduce emissions levels from their jet engines.
As part of its effort to set emission goals for its jet aircraft, the
Air Force's Aeropropulsion Laboratory has proposed gaseous emission goals to
be applied to future military aircraft procurements (Reference 3). While
lacking the force of legal limits, these goals provide substantial
encouragement for manufacturers to incorporate emission reductions on
military engines. For engine smoke emissions, the Air Force has promulgated
a smoke number goal for new procurements (Reference 4).
This section discusses how clean combustor technology is applied by
the military to reduce smoke, particulates and gaseous emissions from aircraft
jet engines. Because of large efforts to meet the mandated EPA standards,
the civilian emissions reduction program leads the military program.
Therefore, the following discussion on clean combustor technology will use
information generated for civilian aircraft applications. Because military
and civilian engine performance and durability goals are different,
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extrapolation of civilian technology to military engines is not straight-
forward. However, it is anticipated that much of the civilian technology
will be applicable to military jet engines.
In the following two subsections, current aircraft engine emission
characteristics and civilian clean combustor technology programs are
discussed. These subsections are followed by a description of military clean
combustor programs, including Air Force and Navy clean combustor retrofit
program schedules and costs. In addition, the impact of new procurements of
clean combustor engines on military aircraft emissions will be discussed.
2.1 CURRENT CIVILIAN AIRCRAFT ENGINE EMISSIONS
The January 1979 EPA standards for civilian aircraft jet engines
represent what the government believes is an achievable emissions goal.
These standards are used as a point of reference to determine how near
civilian aircraft jet engines come to meeting the standards, what current
combustor technology tests can achieve, and how far combustor technology must
be advanced to fully meet the standards.
The January 1979 EPA standards for civilian aircraft jet engines given
in Reference 2 are shown on the following page. Gaseous emission
characteristics are described by the EPA parameter (EPAP). The EPAP is a
measure of the total emissions of a particular pollutant produced by an
engine over a typical landing-takeoff (LTD) cycle normalized with respect to
the total impulse (for jet thrust engines) or total energy (for turboshaft or
turboprop engines) produced over that cycle. The EPA exhaust smoke limitation
is a specified smoke number.* This smoke number is a relative measure of
*A smoke number is obtained by filtering a known quantity of the stream through
a filter paper and measuring the reflectance of the soiled filter paper.
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exhaust visibility and may or may not be directly related to the
concentrations of participate emissions. Currently, no limitation is set to
control the particulate emissions from aircraft engines.
Class Tl
(Thrust level
Class T25
(Thrust level
<3000 lbf)
>8000 lbf)
THC EPAPa
1.6
0.8
CO EPAP
9.4
4.3
NOX EPAP
3.7
3.0
Nominal EPA
Smoke Number
Required
30
20
THC ~ Total unburned hydrocarbons
CO Carbon monoxide
NOX ~ Oxides of nitrogen
aEPAP parameter units are Ibm pollutants/1000 lbf thrust-hours/cycle.
bClasses higher than T2 have standards identical to the T2 class.
As can be seen in the above table, the smoke standards vary depending on
engine size. Reference 2 compares smoke and gaseous emission characteristics
of current civilian aircraft engines to the January 1979, EPA standards.
From this comparison, it can be concluded that almost all of the current civilian
aircraft engines meet the 1979 EPA smoke standards, but that none of the engines
meet the gaseous emission standards.
2.2 CLEAN COMBUSTOR TECHNOLOGY
Civilian programs to develop clean combustor technology were initiated
in the mid-sixties to reduce exhaust smoke, an obviously undesirable
emission visible to the public. During 1970, the potential degradation of
air quality due to the gaseous emissions from jet engines became a public
concern, and in 1972, standards to control the gaseous emissions from
civilian aircraft were promulgated by the EPA. These standards prompted the
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development of new technology to control both gaseous and smoke emissions
from jet engines.
This section describes the current status of civilian engine clean
combustor technology. The emission characteristics of jet engines are
briefly discussed to provide some background information on how design
parameters and engine operation modes affect emission levels. Following
this, a brief survey of combustor concepts with the potential to reduce
emissions are presented. Finally, the effectiveness of these emission
control concepts in reducing combustor emissions from current production
civilian engines is described.
2.2.1 Pollutant Emission Characteristics of Jet Engines
The emission characteristics of a typical civilian or military
non-afterburning engine are illustrated in Figure 1. As can be seen, the
greatest concentrations of pollutants are formed at the two extremes of the
engine operating power range: low-power idle and high-power takeoff. At
idle, CO and THC are the principal pollutants, while at takeoff, NOX and
smoke reach maximum levels.
The high levels of CO and hydrocarbons at idle are attributable to
the poor combustion conditions encountered. Problems with flame quenching,
fuel/air distribution, fuel atomization, and combustion intensity* work to
make combustion at idle inefficient and incomplete. At high power takeoff,
combustion efficiency is nearly 100 percent and only small amounts of CO and
THC are produced. However, the higher temperature and pressure levels within
the combustor lead to the generation of NOX. The cause of a high smoke
*Intense combustion occurs when there is rapid turbulent mixing of fuel
and air as well as vaporization and burning of fuel droplets.
8
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A-15615
-0
0 20 40 60 80 100
Engine power setting (X net thrust)
figure 1. Typical nonafterburnlng turbine engine emission trends (Reference 3).
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number at takeoff is primarily the high pressure level within the combustor.
This enhances the formation of soot particles. Because these particles
generally 1 micron in diameter or less are highly visible, the opacity of
the exhaust plume is high. At low power settings, particulates can also
occur by condensation of hydrocarbons. The condensed hydrocarbons tend to
agglomerate into particles larger than 10 microns (Reference 5), which are less
visible than those in the submicron range. Therefore, low smoke numbers are
often measured at low power settings even though particulate concentrations
may be significant.
CO and THC emissions at idle can be reduced by:
Improving fuel atomization and fuel/air distribution
Increasing overall equivalence ratio (ratio of fuel/air ratio to
stoichiometric fuel/air ratio)
Increasing residence time
These changes will have the effect of increasing combustion intensity and
uniformity, and allowing more time for fuel to react before it is cooled by
secondary airflow.
NOX emissions at takeoff can be reduced by:
Lowering flame temperature
Reducing residence time
Since NOX generation is a strong function of the time the combustion products
are at high temperature, reducing temperature and residence time will lower
NOX emissions considerably.
Smoke emissions can be reduced by:
Improving fuel atomization and thereby fuel/air distribution
Leaning out the local fuel-rich areas in the primary combustion
zone by improved fuel/air distribution
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Increasing residence time
Decreasing the number of rich zones will decrease the formation of soot
nuclei, and increasing the residence time will allow more of the soot to be
burned up.
It is apparent from the brief discussion above that design changes
made to reduce an emission at one operating condition could increase the
level of a different emission at another operating condition. Therefore,
reducing all emissions at all operating conditions is not a straightforward
task. Much work must go into the design of a new engine to achieve low
emission levels for all pollutants at once. Because of additional design
constraints, it is even more difficult to achieve low emission levels by
modifying an existing engine.
Very little information is presently available on pollutant emissions
from afterburning engines. However, general trends from some data on
afterburning engines (References 6 through 10) indicate possible significant
emissions of CO and THC, especially at the lower afterburner power settings.
Limited data also show that the amount of NOX produced in afterburners is
small due to relatively low pressures, small residence time and low flame
temperatures (Reference 11). Smoke emission levels during afterburner
operation are found to be low because of low pressure levels and slightly
lean local fuel/air mixtures. In fact, tests have shown that particulates
generated from the upstream main combustor were partially consumed in the
afterburner due to increased soot residence time at high temperature
(Reference 11).
2.2.2 Overview of Current Low Emissions Technology
Considerable testing of low emissions combustor concepts has been
conducted by manufacturers to develop clean engines that meet the 1979 EPA
11
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standards. These efforts have mainly focused on fuel preparation techniques,
especially in nozzle design. A summary and very brief discussion of the
concepts tested, extracted from Reference 12, is presented in Table 1. So
far, no single technique tested has been effective in simultaneously reducing
NOX, THC, and CO to the levels required by the 1979 EPA standards over the
entire operating range of an engine. Some of the concepts tested did,
however, demonstrate potential to meet the 1979 standards for a given
pollutant.
Some of the listed concepts can also reduce smoke levels, although
they are designed primarily for reducing gaseous emissions. As described
previously, smoke reduction can be achieved by improved atomization and
fuel/air distribution, which eliminates local fuel-rich regions in the
primary combustion zone. Hence, concepts listed in Table 1 that improve one
or both of these processes can be used to reduce smoke emissions.
The lean primary zone, water injection and rich primary concepts tested
can increase smoke emissions. In the first two concepts, a large quantity of
air or water is introduced into the combustion chamber to lower the flame
temperature and to reduce the rate of NOX formation. However, reducing the
flame temperature also causes combustion instability, resulting in flame
quenching and the formation of particulates. The rich primary concept was
designed to reduce CO and THC emissions by operating the reaction zone under
a richer condition than the normal fuel/air ratio. The high flame temperature
enhances the conversion of CO to C02 and the oxidation of hydrocarbons. However
the higher flame temperature also enhances NOV formation, and if the
X
equivalence ratio is greater than one, particulates may also start to form.
12
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TABLE 1. SUMMARY OF LOW EMISSION CONBUSTOR CONCEPTS
Category
Fuel
Preparation
Fuel
Distribution
Concept
Airblast
Air Assist
Preraix
*
Fuel
Atomization
Fuel
Staging
Approach
Engine pressure
differential used to
achieve high velocity
air jet which is
directed towards fuel
injectors. This helps
break up fuel droplets
and eliminate locally-
rich hot spots.
Same as above, except
to maintain airblast
at low power opera-
tion auxiliary air
compressors must be
installed.
Fuel and air are
mixed in a prechamber
prior to entering
primary combustion
zone. Premixing
allows stable combus-
tion at a leaner
primary zone fuel/air
ratio, thereby
reducing NOX formation.
Pressure differential
and fuel nozzle
geometry changes to
reduce droplet sizes,
increasing CO and UHC
burnup. However,
hotter mixture will
increase NOX.
Combustor divided into
pilot and main stages.
At low power only pilot
stage is used with an
optimum fuel /air ratio
to reduce CO and UHC.
At high power, staging
is optimized to reduce
NOX.
Impact on
Operations
Idle
Small
High
Some
Some
High
High
Power
High
High
High
High
High
Effects on Pollutant Emissions
CO
Reduction
Reduction
Reduction
Reduction
Reduction
UHC
Reduction
Reduction
Reduction
Reduction
Reduction
NOX
Uncertain
Uncertain
Reduction
Increase
Reduction
particulate
Smoke
Reduction
Reduction
Reduction
Reduction
Reduction
Effort
Required to
Implement
Minor
Major
(Heed auxiliary
compressor)
Major (Longer
coat) us tor)
Minor
"
Major (Two
sets of
fuel nozzles,
etc.)
T-530
-------
TABLE 1. Continued
Category
Fuel
Distribution
(Continued)
Air
Distribution
Concept
Nozzle
Design
Fuel
Sectoring
Lean
Primary
Rich
Primary
Delayed
Dilution
Approach
Modify fuel nozzle to
reduce wetting of
combustor wall and
thus UHC, while main-
taining adequate fuel/
air distribution.
Fuel injected
selectively at various
power levels to opti-
mize fuel/air distri-
bution for both idle
and high power.
A larger percentage of
combustor airflow is
introduced into the
primary reaction zone
creating a leaner
mixture which prevents
NOX. However, quench-
ing and CO emissions
are increased.
A smaller percentage of
combustor airflow is
introduced into the
primary reaction zone
creating a richer
mixture which promotes
the conversion of CO
to C02 and the consump-
tion of UHC. However,
primary zone is hotter,
which results in in-
creased NOX.
By delaying secondary
zone dilution air, a
longer combustion zone
at moderate tempera-
tures is produced.
This should result in
increased CO and HC
burnup with only
marginal increase in
NOX.
Impact on
Operations
Idle
High
High
Some
Some
Some
High
Power
High
Small
High
High
Some
Effects on Pollutant Emissions
CO
deduction
Reduction
Increase
Reduction
Reduction
UHC
Reduction
Reduction
Increase
Reduction
Reduction
NOX
Same
Same
Reduction
Increase
Increase
Particulate
Smoke
Reduction
Reduction
Increase
Increase
Reduction
i
Effort
Required to
Implement
Minor
Minor
Minor
Minor
Minor
_
-------
TABLE 1. Concluded
Category
Air
Distribution
(Continued)
Improvements
in Combust c^-
Operating
Conditions
Concept
Variable
Geometry
Idle Speed
Increase
Airbleed
Increased
Combustor
Length
Water
Injection
Approach
Airflow to primary
and secondary reaction
zones controlled by
mechanical means to
optimize fuel/air
distribution at both
idle and high power.
By increasing idle
speed, engine operates
in intermediate power
regime where NOX is
still low and CO and
UHC are much reduced.
Fuel consumption
increases.
Increased idle speed
with engine power
dissipated in com-
pressor by airbleed.
Same effect as above
concept.
Increased combust or
length allows more
burnup time for
CO and UHC. However,
larger residence
times tend to increase
NOX.
Injection of water
reduces primary zone
temperature and hence
NOX. Too much water
increases CO.
Impact on
Operations
Idle
High
High
High
Some
Some
High
Power
High
None
None
Some
High
Effects on Pollutant Emissions
CO
Reduction
Reduction
Reduction
Reduction
Increase
UHC
Reduction
Reduction
Reduction
Reduction
Increase
NOX
Reducti on
Increase
Increase
Increase
Reduction
Particulate
Smoke
Reduction
Reduction
Reduction
Reduction
Increase
Effort
Required to
Implement
Major
(Mechanical
control of
airflow over
full opera-
ting range)
Minor
Minor
Major
(Longer
engine, major
redesign)
Major
(Water supply,
deposits on
engine problem)
T-530
-------
2.2.3 Application of Concepts to Current Civilian Production Engines
As reported in Reference 12, some of the combustor concepts listed in
Table 1 were applied to civilian aircraft engine combustors. Experimental com-
bustor tests were performed to evaluate the effectiveness of each concept in
reducing gaseous as well as smoke emissions. The emission performance of the
best demonstrated combustor concepts were determined. These test results
were adjusted to reflect the emission characteristics of an entire engine in
its various operating modes. Comparing the adjusted combustor results to the
1979 EPA standards indicates that the NOX standard was achieved (without
water i nj ecti onpBy on]y~33|percent of the engines listed, while the CO and
THC standards were achieved by 54 percent and 75 percent of the engines,
respectively. Although the smoke emission data indicated smoke levels were
below the EPA smoke standards, none of the engines met all of the 1979 EPA
gaseous emissions standards. From these results, it can be concluded that
more than one concept will probably have to be applied to reduce all
pollutants to levels below the 1979 EPA standards.
In addition to the technology development described above, the
National Aeronautics and Space Administration (NASA) has also sponsored
programs to develop clean combustors for current commercial aircraft engines.
Their goal was to modify existing engines to meet the 1979 EPA standards
without sacrificing engine performance. The jet engines selected for
redesign included:
t CFG-50
JT9D-7
JT8D-17
16
-------
TFE731-2
501-D22A
The NASA programs are being conducted in three phases: Phase 1
consisted of experimental screening tests of low-pollution combustor
concepts; Phase 2 consisted of experimental test rig refinement of the most
promising combustor concepts; and Phase 3, currently in progress, consists of
incorporating and evaluating the best combustors as part of a complete
engine. Detailed information on the NASA programs can be obtained from
References 13 to 20.
Based on the Phase 2 experimental combustor rig test results, an
optimal low-pollution combustor concept was selected for each engine as
follows:
Double annular concept -- CF6-50 engine
Vorbix concept JT9D-7 engine
Vorbix concept -- JT8D-17 engine
Piloted-airblast concept TFE731-2 engine
Reverse flow concept 501-D22A engine
All of these concepts, except piloted airblast, used both fuel and air
distribution techniques (see Table 1); for piloted airblast, only fuel
preparation techniques were used.
The experimental results with these concepts were extrapolated to
actual engine conditions and compared with the 1979 EPA standards. As shown
in Table 2, advanced technology combustors have reduced aircraft engine
emissions significantly, although actual compliance with 1979 EPA standards
was achieved in only one case (501-D22A). Smoke emissions have increased some-
iwhat, but are still at the low levels characteristic of the baseline engines.
17
-------
00
TABLE 2. SUMMARY OF EMISSION LEVELS (EPAP VALUES) ACHIEVED WITH THE
"SELECTED" ADVANCED TECHNOLOGY COMBUSTOR CONCEPTS (Reference 13)
Emissions
Engines
CF6-50 Engine
(Double Annular Concept)
JT90-7 Engine
(Vorblx Concept)
JT8D-17 Engine
(Vorblx Concept)
TFE731-2 Engine
(P1loted-A1rb1ast Concept)
501-D22A Engine
(Reverse Flow Concept)
CO
Conv
Comb
10.8
14.3
16.1
17.5
31.5
Adv
Tech
3.0
6.3"
9.0a
10.1
4.6
EPA
Stds
4.3
4.3
4.3
9.4
26.8
THC
Conv
Comb
4.3
5.3
4.4
5.3
15.0
Adv
Tech
0.3
0.6
0.2
0.4
0.3
EPA
Stds
0.8
0.8
0.8
1.6
4.9
N°x
Conv
Comb
7.7
4.9
8.2
5.3
6.2
Adv
Tech
4.2
3.5
4.3
3.9b
7.3
EPA
Stds
3.0
3.0
3.0
3.7
12.9
Smoke requirements should be achievable for all concepts
"Lower values expected with further developments
Preliminary value
-------
Efforts to date indicate that applying these concepts to actual engines will not
increase smoke levels.
In summary, smoke reduction technology for civilian aircraft engines
is well defined. To reduce gaseous emissions below the 1979 EPA standards,
major combustor redesign, incorporating one or more of the above concepts,
will be required. In combustor rig tests, NASA has demonstrated clean
combustor technology which comes close to meeting the standards for five
commercial aircraft engines. However, NOX emissions still remain a problem.
Because civilian jet engine clean combustor programs have been
successful in reducing gaseous emissions while maintaining low smoke levels,
and because civilian and military jet engines are fundamentally similar, most
military jet engines probably can be made clean. However, applying these
civilian engine concepts to military engines is difficult because of the more
rigid military engine performance and durability constraints. This
difficulty is multiplied when an existing engine is modified to reduce
emissions. The success to date with attempts to apply clean combustor
techniques to existing military engines is mixed; many engines have responded
well, while some for reasons not fully understood -- have not been
successfully retrofitted. Also, some military engines have afterburners, and
none of the civilian combustor concepts apply to the afterburners of military
jet engines.
2.3 MILITARY CLEAN COMBUSTOR PROGRAMS
Military interest in reducing smoke from jet engines goes beyond
environmental considerations. Because visible smoke emissions can make
military aircraft easy to track in the sky and increase their vulnerability,
low-smoke combustor development programs were initiated by the military in
1965 (Reference 11). At the same time, smoke emissions from civilian
19
-------
aircraft became a concern of the public, since these emissions were visible
air pollution. The combined efforts of both military and civilian organizations
have developed the technology needed to design new jet engines which have
virtually invisible exhausts, yet adequate engine ignition and performance
characteristics.
In the following sections some low-smoke combustor concepts applied to
military engines are discussed. These concepts are similar to those applied
to civilian engines to reduce gaseous emissions while maintaining low smoke
levels. Next, a short compilation of smokeless engines and their percent of
total current Air Force and Navy inventory is given, followed by the future
engine emissions goals of the military. Finally, the military programs
currently underway to clean up engine emissions are described, along with
their associated costs.
2.3.1 Low-Smoke Military Jet Engines
Military low-smoke combustors employ techniques which are, in
principle, the same as those applied in civilian engines. The combustor is
redesigned to:
Lean-out local fuel-rich regions in the primary combustion zone
Improve fuel atomization and fuel/air distribution
These characteristics are achieved in practice by admitting the airflow into
the primary combustion zone with a strong swirl for enhanced mixing and
modifying the fuel nozzle pattern and shroud airflow to improve fuel
atomization. The more uniform fuel/air mixture created by these changes
permits a slight leaning-out of the primary zone mixture ratio. The impact
of these changes on engine smoke emissions is a strong function of combustor
type; some combustors respond more easily to these changes than others. For
the changes to be effective, it is essential that they be carefully tailored
20
-------
to the engine design. Also, it is much easier and more effective to incorporate
these changes into a new design than to modify an existing engine.
The success of low-smoke combustor design changes is illustrated in
Figure 2, a comparison of the exhaust opacity of several older, smoky engines
with new smokeless combustor military jet engines. Table 3 also compares
other smoky and smokeless military jet engines which are different models
of the same basic engine. Smoke levels for most of the smokeless engines
are reduced below the threshold of visibility.
TABLE 3. SMOKELESS MILITARY ENGINES
Engi nea
TF30
J52
J65
FIDO
TF34
SAE Smoke Number
Manufacturer Smokeless Smoky References
Pratt & Whitney
Pratt & Whitney
Curtiss-Wright Corp.
Pratt & Whitney
General Electric
15
30
11
36
12
78 21
63 21
21
3
3
aThe smoky and smokeless engines are different models of the same basic
engine.
General Electric's advanced annular combustor design is an example
of current low-smoke combustor technology. In this design, large amounts
of the combustor airflow are introduced through swirl cups containing
axial flow swirlers which surround each of the fuel nozzles. With this
approach, lean and relatively uniform primary zone fuel/air mixtures are
obtained as a result of the rapid and effective fuel/air mixing produced by
the air swirlers. Smoke levels are much reduced without significant
21
-------
PO
ro
;~77~7///7777
Visibility threshold ' '
0
10 15 20
Engine cycle pressure ratio
30
Figure 2. Peak smoke levels -General Electric (GE) engines (Reference 11).
-------
losses in ground ignition, altitude relight performance, or other combustor
performance characteristics. This design approach has been successfully
applied to the entire General Electric TF39 family of engines: TF39, LM2500,
and CF6. Note that the TF39 engine does not incorporate afterburners and the
CF6 is a commercial aircraft engine. The advanced TF39 smoke emission levels
are shown in Figure 3.
Significant smoke reductions can also be obtained from older engine
designs by retrofitting advanced clean combustors. The J79 engine previously
had a smoke number of 60 to 70 with kerosene fuel. A modified combustor
design was developed which renders its peak smoke level virtually invisible
at a smoke number of approximately 30. This reduction is achieved by
incorporating changes in the combustor's dome, liner and fuel nozzle to
improve combustion through better fuel/air mixing and the elimination of
fuel-rich areas. Many trial-and-error design changes had to be made to this
engine before an acceptable design was found. Figure 4 shows the smoke
emission levels of the improved J79 engines.
Incorporating this retrofit design approach into J79 engines is
expensive. According to an estimate by the Air Force, it is believed that
over $30,000 per engine in current dollars will be required to retrofit the
J79 engine with a smoke-reduction combustor (Reference 22). The Navy is in
the process of retrofitting 900 J79 engines at an estimated cost of $40,000
per engine in current dollars (Reference 23).
Other types of low-smoke emission combustor approaches for advanced
engines like the F101, TF34, and T700 also were developed at General Electric.
In these approaches, the fuel is injected at low pressure and is airblast-
atomized by part of the combustor airflow as it is delivered into the
primary combustion zone. Because of the very effective fuel atomization
23
-------
30
ro
t_
-------
ro
in
80-
70
60
50 4-
404
01
30-
20-
10-
i
Idle
Present engine
4
/
i
O
Q
-------
and fuel/air mixing attained with these airblast atomization techniques,
combustor designs of this kind were found to have low smoke emission levels.
As an example, the smoke emission characteristics of the F101 engine
ccmbustor are presented in Figure 5.
By applying this type of smoke reduction technology in retrofit and
new procurement programs, a significant portion of current military engine
inventory has been made smokeless. According to Air Force and Navy
personnel, 28 percent of Air Force engines and 40 percent of Navy engines
currently are smokeless. This achievement, coupled with the fact that most
current civilian jet engines are smokeless, is encouraging evidence that
eventually all non-afterburning military engines will be made smokeless.
Actual measurements of particulate concentrations at jet engine exits
for smoky and smokeless versions of the same engines are sparse. Typically,
smokeless combustor modifications are combined with performance improvement
modifications to produce an engine that has different emissions and performance
than the original engine. This makes a direct comparison of smoky/smokeless
combustor emissions difficult. One data source (Reference 24) indicates that
particulate concentrations, as well as smoke levels, are reduced by smokeless
combustors. In Reference 24, a J52 engine redesigned with new smokeless
combustors had particulate concentrations which were 25 percent lower than
the original engine. However, it was noted that the smokeless version of the
J52 was substantially changed from the original smoky engine. Use of known
smoky and smokeless engine smoke numbers and a correlation of particulate
concentration versus smoke number (see the environmental impact summary
section) indicates that smokeless combustors can reduce particulate
concentrations by 94 to 98 percent. However, the correlation is not precise
and may not be valid for comparing smoky and smokeless engines. Based on the
26
-------
ro
40
30
Visibility threshold
Y//////////////;
.o
Y///7)
70
80
Engine speed (%)
90
100
Figure 5. Smoke characteristics of advanced F101-type
premlxed combustor (Reference 11).
-------
above limited information, it is estimated that parti oil ate concentration
for smokeless combustor engines are reduced 25 percent below the baseline
smoky engine values.
The impact of low-smoke combustors on gaseous emissions was assessed,
based on the limited data on smoky versus smokeless engines given in Table
4. As shown by the table, there was no consistent pattern of peak THC and
CO emissions variation when low smoke combustors were applied to these four
engines. All smokeless engines had higher NOX emissions than the conventional
engines. Based on this data, an increase of roughly 50 percent in NOX is
estimated if smokeless combustors are used.
2.3.2 Military Goals for Gaseous Emissions
Goals to control gaseous emissions from nonafterburning military
engines have been established by the Air Force Aeropropulsion Laboratory
(AFAPL). Like EPA standards, these emissions goals are divided into two
levels: one for 1979, the other for 1981. These goals (described in
Reference 3) are summarized as follows:
1979 Goals 1981 Goals
Combustion Efficiency 99 percent for idle 99 percent for idle
at Idle pressure ratio pressure ratio
> 3:la > 3:1
98 percent for idle 98 percent for idle
pressure ratio pressure ratio
< 3:1 <3:1
NOX % Reduction from 25 percent without 50 percent without
Uncontrolled Level water injection water injection
75 percent with water injection
aCombustor pressure to ambient pressure at idle
28
-------
TABLE 4. COMPARISON OF SMOKY AND SMOKELESS JET ENGINE GASEOUS EMISSIONS
JT3D°
JT8D°
(Peak Values)
J79-GE15
(Peak Values)
TF39
(Peak Values)
Smoky
TOC
34.2
(EPAP)«
378
(PPM)»
350
(PPH)
9
(lb/k Ib
fuel)c
15
(lb/k Ib
fuel)
CO
40.8
(EPAP)
744
(PPM)
420
(PPM)
25.8
(lb/k Ib
fuel)
50
(lb/k Ib
fuel)
NOX
3.8
(EPAP)
70.4
(PPM)
110
(PPM)
9
(lb/k Ib
fuel)
38
(lb/k Ib
fuel)
Smoke
53
(SN)«
28
(SN)
80
(SN)
65
(SN)
80
(SN)
Smokeless
THC
18
(EPAP)
200
(PPM)
220
(PPM)
40
(lb/k Ib
fuel)
15
(lb/k Ib
fuel)
CO
26.2
(EPAP)
590
(PPM)
350
(PPM)
30
(lb/k Ib
fuel)
50
(lb/k Ib
fuel)
NOX
5.6
(EPAP)
70
(PPM)
180
(PPM)
18
(lb/k Ib
fuel)
40
(lb/k Ib
fuel)
Smoke
16
(SN)
60
:(SN)
33
(SN)
25
(SN)
5
(SN)
Reference
12
25
26
22
27
ro
vo
531
EPAP Parameter units are Ibm pollutant/1000 Ibf thrust-hours/cycle
PPM Parts per million
SN Smoke number
I
DThe JT3D and JT80 are cornierleal Jet aircraft engines, which have some design similarities with the J57 and J52 military
engines respectively.
cAbbrev1ation for pounds/thousand pounds of fuel
-------
Figures 6 and 7 show the emissions goals as they relate to the current
emission levels of military engines. One important provision of these goals
is that any emissions control design feature must not infringe upon the engine
design and operation to compromise engine effectiveness. These emissions
goals are still being examined by the Office of Secretary of Defense
at the present time, and have not yet been promulgated (Reference 28).
To meet military emissions goals for non-afterburning engines,
military engines (like civilian engines) will require significantly more
advanced combustors. These combustors will be produced in military-funded
programs that will make maximum use of available advanced combustor
technology for civilian engines (References 22 and 29).
Military engines such as the TF39, J52, and T56, are similar in design
to the CF6, JT8D, and 501 civilian aircraft engines upon which NASA-sponsored
advanced gaseous emission control technology has been experimentally
demonstrated. It is anticipated that if the NASA clean combustor technology
were applied to these engines, the gaseous emissions levels would fall below
*
or near the military emission goals. However, engine performance or
durability might degrade if these changes are directly applied. Only an
extensive design and test effort will demonstrate conclusively whether
civilian jet engine clean combustor technology can be applied to non-
afterburning military jet engines.
Furthermore, to reduce NOX emissions from nonafterburning engines to
levels comparable to the 1979 EPA standard requires an advance in control
technology beyond that currently available from the civilian sector.
30
-------
u>
Idle pressure ratio
3
4
u
0)
u 3
-------
200
100
O
in
80-
60 -
40 .
o~ 20
5 10
o
8
6
£ 4 -
2 . -
Combustor inlet temperature (°F)
400 600 800
1000
h-
1200
Present or
uncontrolled
N0 level
A - Engines w/o water injection
B - Engines w/water injection
N
M
sO
IA
400 500 600 700 300 900
Combustor inlet temperature (°K)
Figure 7. Comparison of current and future NOX jet engine
emission goals (Reference 3).
32
-------
2.3.3 Implementation of Low-Smoke Combustor Programs by the Military
Table 5 shows the current percentages of low-smoke engines in the
Air Force and the Navy engine inventories, as well as the projected numbers
for the future (References 29 and 30). The percentage of low smoke engines
will increase by:
Retrofitting some old engines with low-smoke combustors total
anticipated is on the order of thousands
Procuring new low-smoke engines on the order of several hundred
per year
Retiring older smoky engines
TABLE 5. PERCENT OF LOW-SMOKE ENGINES IN THE MILITARY ENGINE
INVENTORY
Percent of Low Smoke Engines
Air Force Navy
Current status 28 40
Future Projection 40 (1984) 65 (1985)
The Air Force currently has a program to retrofit both TF39 (C5
aircraft) and a small number of F100 engines (F15 and F16 aircraft) with
low-smoke combustors (Reference 30). The TF39 program, recently completed
in cooperation with General Electric, included retrofitting 343 in-service
engines and procuring 123 production engines at an estimated smoke reduction
cost of $1,659,101 and $1,236,060, respectively, in current-year dollars.
In addition to lowering smoke emissions, the new combustors have also
extended the overhaul time from 1000 service hours to 3000 service hours
(Reference 31).
33
-------
The F100 program, in cooperation with Pratt and Whitney Aircraft
Corporation, is just beginning and no detailed cost information has been
obtained. Also, the program is based on routine overhauls and no definite
program completion date can be forecast at this time (Reference 30).
As reported in 1974 (Reference 3), the Air Force has considered
retrofitting other engines. Table 6 lists these engines, along with an
estimated implementation cost. It was estimated that retrofit of the engines
listed would cost approximately $265 million (Reference 3). Of course, this
1974 estimate of total cost as well as the individual costs would be much
higher in terms of current dollars as a result of inflation and other cost
escalators.
The older, smoky engines will be phased out according to standard
retirement schedules.
TABLE 6. SMOKE RETROFIT COST SUMMARY FOR AIR FORCE ENGINES (REFERENCE 3)
Engine
J57
J79
T56
TF30
TF33
Inventory
10,475
4,709
3,533
2,672
1,831
Year Introduced
into Inventory
1956
1961
1958
1965
1961
Total Cost3
($ Million)
115
48
45
37
20
Total Projected Retrofit Cost: $265 million
aCosts estimated in 1974
34
-------
In 1972 the Navy tentatively scheduled six engines for retrofit with
low smoke ccmbustors (Reference 21). The retrofit schedule for these engines
is given in Figure 8. The proposed retrofit program was to have been completed
in 1976, but was never implemented. However, the Navy has made significant
progress in retrofitting smokeless combustors to previously Smoky engines.
Through contacts with Navy personnel (Reference 23), the status and costs
of the current Navy retrofit program were obtained. As shown in Table 7,
the J52 and TF30 retrofit programs are nearly complete. The J79 retrofit
program is moving ahead although it is behind the original schedule proposed
in 1972. The J57, TF41 and T56 engines have not been retrofitted due to a
number of factors, including:
t Problems in meeting performance and durability goals with some
engines, such as the TF41, has delayed consideration of modifications
to reduce smoke
Some engines, such as the J57, will be phased out and therefore
the capital investment to retrofit them is not economically justifiable
at this time
Sane design changes to reduce smoke levels have been unsuccessful
for certain engines
35
-------
o
O)
O
O)
t.
72
73
74 75
Fiscal year
76
71
O TF30
O J52
D J79
A J57
V T56
D TF41
Figure 8. Navy estimate of smokeless burner retrofit
schedule (Reference 21).
36
-------
TABLE 7. CURRENT STATUS OF THE NAVY RETROFIT PROGRAM AND RETROFIT COSTS
Engines to be Retrofit Cost Number of Engines
Retrofitted Per Engine Retrofitted Left
J52-P8A retrofitted
to P8B
TF30-P6C retrofitted
to P6E
J79-6E10/10A
retrofitted to
GE10B
$ 1,500
13,000
40,000
1135 6
343 17
200 700
In summary, 40 percent of Air Force and 65 percent of Navy jet engines
will be smokeless by 1985. These percentages reflect new "smokeless"
combustor engine procurements and a limited amount of retrofitting to older
engines. The Navy retrofit program has cost $6.2 million to date and will
cost roughly $38 million when completed around 1981 (Reference 29). The Air
Force TF 39 program is complete and has cost $2.9 million. Extensive retrofit-
ting of smokeless combustors and faster retirement of smoky engines could result
in much higher percentages of smokeless engine operations. However, the cost
of extensive retrofitting and early engine retirement is large.
37
-------
SECTION 3
WET-PACKED SCRUBBER COST ESTIMATES
In this section three widely different wet packed scrubber cost
estimates are examined to determine the source of cost differential between
these estimates.
The Aerotherm Phase I study (Reference 1) indicated that a wet
packed scrubber would effectively reduce jet engine test cell plume opacity
and particulate emissions. However, the scrubber is expensive to install
and operate. If a cost-versus-benefit analysis were to be made for the
scrubber system, accurate cost information would be required.
In Phase I, cost estimates for retrofitting scrubbers to type A*
test cells were requested both from the Navy and a private contractor.
The cost estimate was to be based on the following conditions:
a The scrubber was to be retrofitted to a Type A, permanent test
cell
A complete facility was to be provided including a scrubber,
a cooling tower, a water cleanup plant, all site modifications,
and installation of all equipment
Costs of bringing utilities (water, electric power) to the test
cell site were not to be included
*Large, permanent concrete structures capable of testing engines in the
20,000-lbf thrust class.
39
-------
Three cost estimates were received: two independent estimates from
the Navy, one estimate from a private contractor. The estimate prepared by
the Naval Air Systems Command (Reference 32) in early 1975 is shown in Table
8, and the estimate prepared in January 1976 by the Naval Air Rework Facility
(NARF), Jacksonville is shown in Table 9. A summary of the cost proposal
prepared by the original system contractor for the Jacksonville prototype
scrubber, Teller Environmental Systems, Incorporated, (TESI) is given in
Appendix A. Since these estimates were prepared in 1975 or the first month
of 1976, it has been assumed that the costs are in terms of fiscal year 1975
dollars.
A summary of bottomline costs is given in Table 10. These estimates
differ by roughly a factor of 3. This wide differential in estimated cost
prompted a critical examination of the cost estimates and conversations with
personnel involved in preparing the original cost estimates. The results of
our investigation are described below.
The TESI wet packed scrubbers consist of three main parts: (1) a jet
exhaust pretreatment section where water vapor condenses on particulates,
making them larger; (2) a packed-bed scrubber where the water-coated
particles are transferred to the scrubber irrigation water; and (3) a
water cleanup and sludge removal system. Since efficient transfer of
particulates to scrubber irrigation water requires a certain volume of
packed bed per cubic feet of test cell gas flowrate, scrubber volume
is directly proportional to test cell gas flowrate. The test cell gas
flowrate and corresponding mass flow is the sum of engine air and fuel
.flow, augmentor airflow, and quench water flow.*. For a fixed thrust level,
''Augmentor airflow and quench water flow are introduced into the jet exhaust
gases to cool them so that heat damage does not occur to test cell acoustic
baffles and concrete stack.
f
40
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TABLE 8. SCRUBBER RETROFIT COST ESTIMATE ~ NAVAL AIR SYSTEMS COMMAND
Item Cost
Packed scrubber $ 515,000
Cooling tower basin 160,000
Cooling tower 250,000
Water system for irrigation and quench 280,000
Water treatment plant 160,000
Exhaust stack modifications 50,000
Electrical work 100.000
Total $1,515,000
41
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TABLE 9. SCRUBBER RETROFIT COST ESTIMATE -- JACKSONVILLE NARF
Item
Cost
1. Cooling tower well
2. Water treatment system
3. Scrubber and quench water
system including cooling
tower
4. Cooling tower and water
treatment stairs
5. Water treatment building
(miscellaneous)
6. Columns, beams, and
miscellaneous for cooling
tower pipe support
7. Cooling tower and water
treatment building ~ general
construction work
8. Upper concrete work for
scrubber enclosure including
additional foundation
9. Addition piles for
building structure
31,138
250,000
731,000
21,995
1,560
60,450
251,515
250,000 (due to pollution abatement)
Prorated from a larger
figure
40,000 (due to pollution abatement)
Prorated from a larger
figure
10. Extra electrical work on
outside and inside of cell
TOTAL
307,077 (due to pollution abatement)
Prorated from a larger
figure
$1,944,735
42
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TABLE 10. COMPARISON OF SCRUBBER COST ESTIMATES
Complete Cost
Estimate One Cell Retrofit
Jacksonville NARF $1,944,735
Naval Air Systems Command 1,515,000
Teller Environmental Systems, Inc. 705,650
engine airflow can vary significantly, depending on whether the engine is
a jet with high average exhaust velocity (low mass flow! or a
with lower average exhaust velocity (high mass flow). Depending on test
cell and engine design, test cell airflow and the required scrubber volume
can vary significantly even for a fixed engine thrust. Assuming that
the scrubber cost is proportional to scrubber volume,''' the cost can vary
significantly with the test cell airflow. Based on this conclusion, we
reexamined the original cost estimates, using test cell flowrate as our
basis for comparison.
Teller Environmental Systems, Incorporated, based their cost estimate
for the scrubber on a J79 jet engine operating with maximum afterburner
(17,500-lbf thrust). The engine gas flowrate at this condition is roughly/
180 Ibm/sec. Turbofan engines such as the TF41 and TF30 have larger flow-
rates ~ roughly 260 and 240 Ibm/sec, respectively and would require
larger scrubbers. Also, future engines might be even larger, making the TESI
scrubber cost based on a J79 engine lower than the cost of the scrubber
required for a cell that tests all military engines.
In addition to basing their costs on a 079, TEST also included in
i
their estimate a modified augmentor which was projected to reduce the
tUninstalled costs of smaller units (10,000 to 20,000 cfm) vary with the 0.87
power of gas flowrate. For simplicity, a power of 1.0 is assumed to apply
for large scrubbers (Reference 33).
43
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augmentor to engine airflow ratio to 0.6. This would reduce the total test
cell gas flow, which, in turn, would minimize the size and cost of the
scrubber required to clean up the exhaust.
The Navy is currently constructing four new test cells with wet packed
scrubbers. These cells can handle engines producing test cell gas flows* of
up to 770 Ibm/sec. From conversations with Navy personnel who produced the
original cost estimates, it is apparent that these cost estimates were based
on these very large test cells. The estimate prepared by Jacksonville NARF
personnel is based on a test cell gas flowrate of 660 Ibm/sec (Reference 34).
The Naval Air Systems Command estimate is based on an engine flowrate of
approximately 350 Ibm/sec (Reference 35). Assuming that a reduced test cell
augmentor to engine air flow ratio of 1 can be achieved, the total test cell
flowrate for this system is then 700 Ibm/sec. Both test cell flowrates are
much larger than the flowrate used in the TESI estimate.
In these cost estimates, the most expensive component is the scrubber
and quench water system, including the cooling tower. Assuming that the
cost estimates for the scrubber and cooling tower system are directly
proportional* to the test cell flowrate, the estimate should be in the
ratio of the flowrates. When the costs are scaled to the Jacksonville
test cell flowrate of 660 Ibm/sec, good agreement is achieved for the
cost estimates for this portion of the system, as shown in Table 11.
*A11 flows will be given exclusive of quench water flows.
*This assumption should be adequate, since NASC and Jacksonville NARF flow-
rates are close and TESI cooling tower costs were based on prorating a
large single tower to two small test cells.
44
-------
TABLE 11. COMPARISON OF SCRUBBER AND COOLING TOWER COST ESTIMATES, SCALED
TO A 660 LBM/SEC FLOWRATE
Jacksonville
NARF
NASC
TESI
Test cell
flowrate (Ibm/sec)
Ratio of flowrates
to Jacksonville NARF test cell
flowrate
660
1.0
Information not supplied with estimate.
Includes contingency costs.
700
1.06
288
0.44
Original cost estimate ($1000)
Scrubber --a
cooling tower
Subtotal 731
Scaled cost based on 660 Ibm/sec ($1000)
Scrubber
Cooling tower
Subtotal 731
Percent difference
515
250
765
486
236
722
(-1%)
184b
138b
322b
41 9b
31 3b
732b
(+0%)
45
-------
Thus, the large difference in flowrates can account for the differences
in costs for the wet packed scrubber and cooling tower portion of the
costs. The cost differentials for the other components in the scrubber
system are not so easily reconciled.
Cost estimates for the water delivery and treatment, electrical, and
structural systems are scaled to a 660-1bm/sec scrubber system consistant
with the scrubber and cooling tower cost comparisons, and compared in
Table 12. These costs are scaled directly with the scrubber flowrate.
A more precise scaling approach is to make subcomponent cost proportional
to flowrate to seme exponential power which varies roughly between 0.6
and 1.0, depending on the subcomponent. This more precise approach was
not taken here, since a subcomponent breakdown was not available and only
broad component categories were given in the estimates.
The cost of water treatment depends upon the method used, and the
estimates do not contain enough information to determine the differences
between the water treatment systems. In addition, there is insufficient
information to establish the cost of the irrigation and quench water delivery
system for the Jacksonville NARF estimate. Keeping these caveats in mind,
costs for water delivery and treatment systems scaled to a 660-lbm/sec
scrubber system are compared in Table 12. The agreement between the scaled
costs is poor. The Jacksonville estimate is low since water delivery costs
were not included. However, an overall total system cost comparison which
includes water delivery will better demonstrate the consistency of these cost
estimates.
46
-------
TABLE 12. COMPARISON OF WATER DELIVERY AND TREATMENT SYSTEMS, ELECTRICAL
AND STRUCTURAL COST ESTIMATES, SCALED TO A 660-LBM/SEC FLOWRATE
Jacksonville
NARF NASC TESI
Ratio of flowrate 1.0 1.06 0.44
to Jacksonville NARF test cell
flowrate
Water Delivery and Treatment Systems
Original cost estimate ($1000):
Irrigation and quench ~a 280
treatment 272 160 _^
Subtotal 272 440 158b
Scaled cost based on 660 Ibm/sec ($1000) 272 415 359
(+53%) (+32%)
Electrical Systems
Original cost 307 100 93
estimate ($1000)
Scaled cost based on 660 Ibm/sec ($1000) 307 94 212
(-69%) (-31%)
Structural Costs
Original cost 635 50 Oc
estimate ($1000)
Scaled cost based on 660 Ibm/sec ($1000) 635 47 0
(-93%) (-100%)
Information not supplied with estimate.'
Includes contingency costs.
CA small structural cost is included in scrubber cost estimate.
47
-------
A comparison of electrical system costs for a 660-lbm/sec scrubber
system is also included in Table 12. This shows Jacksonville's estimate to
be much higher than the NASC and TESI figures. However, conversations with
Jacksonville personnel (Reference 34) have indicated that the cost for an
electrical substation has been included in their estimate. Also, the Jacksonville
estimate is based on prorated costs'for a new test cell and scrubber system.
Usually several contractors are involved in constructing a complete test cell
and scrubber system, so it is difficult to separate out the costs associated
with the scrubber from those of the test cell. (The prorating basis used
in the Jacksonville estimate is not known.) In light of these factors, the
large difference in costs between the Jacksonville and the other estimates
is not surprising.
Structural costs estimated by Jacksonville personnel also are much
higher than those estimated by NASC and TESI. The prorated Jacksonville
estimate has a much larger construction expense for the scrubber system than
NASC and TESI estimate. Expenses for concrete structures to house water
pumping and treatment equipment have been included in the Jacksonville
estimate, whereas only minor modification costs are included in the NASC
estimate and no separate costs for structures have been included in the
TESI estimate.* Jacksonville personnel believe that a significant amount
of structural expansion and modification are required to support and house
the scrubber equipment. Because it includes the electrical substation
costs and a substantial proration of structural expenses to the scrubber
system, the Jacksonville estimate is probably high relative to the other
*A small structural cost has been included in the scrubber cost estimate.
48
-------
estimates. Therefore, the Jacksonville electrical and structural expenses
have been removed from the original estimate and the total scaled costs
then compared with the other estimates.
In Table 13 the adjusted cost estimates are compared for a scrubber
system of 660-1bm/sec mass flow, and as anticipated, the Jacksonville adjusted
estimate is now lower than the others. However, the estimates are all within
30 percent of each other. Also included in Table 13 is a comparison of
the bottomline cost figures given in Table 10, scaled to a scrubber
system of 660-1bm/sec mass flow. By including substantial structural
and electrical substation costs, the Jacksonville estimate is once
again higher than the others, but all of the estimates are still within
30 percent of each other.
In summary, the wide differences noted between Navy and private
contractor scrubber cost estimates are based primarily on the difference
in test cell mass flow used for the estimates. Furthermore, the Jacksonville
estimate of scrubber cost contains electrical substation and structural
equipment housing charges prorated from new construction costs which were not
included in the NASC and TESI estimates. These costs are substantial and can
result in either a positive or negative 30-percent difference between the
estimates depending on whether these costs are included or deleted
in the Jacksonville estimate. Based on simple scaling of the original cost
estimate, it is believed that a 660-1bm/sec test cell gas flow scrubber
system which includes water treatment can be constructed for approximately
$1.3 million (fiscal year 1975 dollars). Inclusion of electrical substation
and other power source costs could increase this estimate by $0.1 million.
49
-------
TABLE 13. COMPARISON OF TOTAL SCRUBBER SYSTEM COSTS SCALED TO 660-LBM/SEC
FLOWRATE
Cooling tower and
Jacksonville
scrubber 731
Water delivery and treatment 272
Electrical
Structural
Bottom! ine costs
Scaled cost based
--
Total 1003
% difference
($1000) 1945
on 660 1 Dm/ sec ($1000) 1945
% difference
NASC
722
415
94
47
1278
(+27%)
1515
1429
(-27%)
TESI
732
359
212
0
1303
(+30%)
706
1605
(-18%)
50
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SECTION 4
JET ENGINE TEST CELL ENVIRONMENTAL IMPACT SUMMARY
In this section the impacts of jet engine test cell (JETC) operations
on the environment are discussed. JETC emissions data currently are limited
in quantity and quality, as well as highly dependent on engine type,
operation mode, test cell configuration, augmentation airflow, and method of
sampling. Therefore, jet engine exhaust emissions data are used to estimate
uncontrolled JETC emissions. The exhaust emissions data are more plentiful
and relatively more reliable than JETC emissions data, but they also ar-e^JV/
higher and, thus, represent maximum or worst-case conditions.
r
A mix of jet engine exit and JETC stack data is used to define
emissions reduction efficiencies for three emission control methods: wet
packed scrubbers, clean (smokeless) combustors, and ferrocene fuel additives.
These methods represent strategies for post-test cell cleanup, internal
engine combustion modification, and cleanup by altering fuel combustion
characteristics, respectively. The variability of jet engine and test cell
characteristics and the sparseness of emissions data for controlled jet
engines makes it difficult to assess the effectiveness of these control
techniques, and firm conclusions on controlled JETC emissions await better
emissions data.
Research on the air quality impact of test cells and military base
operations is currently being conducted by the Air Force and should be
51
-------
available in late 1977. The results of this study should be very valuable
in assessing the impact of JETCs on several Air Force and Navy bases.
Presently, it is not possible to arrive at broadly applicable
conclusions on the environmental impact of JETC operations since engines,
duty cycles, test cells, and sites vary. Therefore, this report focuses upon
one specific site: the JETCs of the Alameda Naval Air Rework Facility
(NARF), California. By analyzing this site, problem areas needing further
investigation are identified.
4.1 SITE LOCATION
To determine the environmental impacts of JETC operations, the Alameda
Naval Air Rework Facility (NARF) was chosen as a "worst-case" condition. The
Alameda NARF is a jet engine overhaul facility where extensive post-
maintenance jet engine testing is carried out. Since it is located in the
San Francisco Bay Area (population 4,781,000 in 1974), it has the potential
for impacting large numbers of people. The base is located on the East Bay
in a highly-developed area with a high level of pollution. The Oakland
Harbor, 1-80, 1-680, Oakland International Airport, Peralta College, College
of Alameda, Alameda City Administration buildings, and a residential section
of the city of Alameda are all in the vicinity of the base.
Fifteen test cells and one test stand (Reference 36) are located on
the base. Ten of the cells are depot-level cells and five are auxiliary
power unit cells. An example of a depot-level cell is given in Figure 9.
This type of test cell is used for testing engines after major maintenance
or overhaul. A complete description of test cell operation and characteristics
is given in the Phase I Aerotherm report (Reference 1). Based on a report
issued in 1975, Alameda JETC operations (on an average annual basis) consist
52
-------
en
to
Horizontal acoustical baffle
Acoustical ducts
Vertical acoustical baffles
Combustion air
Augmentor air
Exhaust
Vjetrr*~-
^ I I Aiinmpi
Figure 9. Tinker A1r Force Base J79 engine test cell (Reference 37)1
-------
of five and a half tests per day of 3 hours duration (Reference 36). These
tests consist of roughly 62-percent aircraft propulsion unit testing and 38-
percent auxiliary power unit testing. Air quality modeling data for Alameda
is available from the Navy (Reference 36), and the Air Force is in the
process of modeling this and other bases, using their sophisticated Air
Quality Assessment model. The results of these modeling efforts should
provide useful data to assess JETC emission impacts on the environment.
4.2 UNCONTROLLED TEST CELL EMISSION AIR QUALITY IMPACT
The ultimate impact of a pollution source is on air quality within the
entire region. However, regulations are applied on a source basis, because
individual source contributions can be monitored. Therefore, this study will
consider the environmental impact of JETCs on the basis of both source
emissions and ambient air quality.
4.2.1 Gaseous and Particulate Emissions
Documented emissions data are very sparse. The emphasis on emissions
data has been for aircraft operations rather than test cells, and as a
result, only limited testing has been conducted on actual cells. Limited
tests on JETCs indicates that the chemical composition of gaseous emissions
remains relatively unchanged and particulates are reduced from engine exit to
test cell stack exit (Reference 38). Several mechanisms are responsible for
reducing particulate stack emissions from jet engine exit values. Quench
water, which cools the exhaust, scrubs some particulate out of the exhaust
stream -- as much as 50 percent for a scrubber-equipped cell with roughly 20
percent more quench water flow than a typical cell (Reference 39). (It should
be noted that for some cells and some operating conditions no quench water is
used.) Agglomeration and subsequent fallout within the cell and plating out
on cell surfaces are additional modes of reduction (Reference 39).
54
-------
Participate emissions data obtained to date on JETC exhaust stacks
tend to be unreliable, primarily because the large stack area and
nonuniformity of flow velocities across the stack make isokinetic particulate
sampling difficult. Some test cells even have recirculating flow regions in
portions of the stack exit, making isokinetic sampling impossible or not
meaningful. Therefore, jet engine exhaust data are used to estimate
particulate emissions from uncontrolled JETCs. Other problems in measuring
particulate are discussed in the phase I JETC report (Reference 1).
Since the chemical composition of gaseous emissions are relatively
unchanged by the test cell, the engine exhaust gaseous emissions will be a
close estimate of JETC emissions on a mass-per-hour basis. The engine
exhaust particulate emissions are conservative because of the fallout of
particulate within the test cell, and therefore, engine data represent
worst-case particulate releases from test cells.
4.2.2 Uncontrolled Test Cell Plume Opacity
JETCs have been cited for noncompliance to local air pollution control
district opacity regulations. Therefore, a complete evaluation of the
environmental impact of JETC requires that plume opacities and their control
be examined.
Many factors influence the opacity of a JETC exhaust. For example,
augmentor and entrained air reduce opacity by diluting the stack
particulate/gas mixture. For the same particulate emissions, a large-
diameter test cell stack will provide a longer light-scattering path than a
small diameter stack thereby giving a higher apparent opacity (Reference 40).
Weather, sun angle, observer location, and other variables (Reference 40) can
introduce a variation in Ringelmann number (RN) for a given exhaust flow
particulate loading and size distribution.
55
-------
Actual exhaust opacity readings for "smoky" jet engines can be as high
as 2.5 RN (Reference 5). The diameters of the most effective light-scattering
particles (those that create high plume opacity readings) range from 0.2y to
2.0y (Reference 40). Smoky engines produce particle sizes in this range
during high power operations (References 5, 42). At low power settings,
measurements indicate that after the exit, condensed hydrocarbon particles
agglomerate to lOy in diameter (Reference 5). These particles contribute
little to the exhaust opacity.
At the JETC stack exit, particles range up to roughtly 2y in diameter,
20 to 30 percent by weight are less than ly in diamter and 80 to 90 percent
by number count are less than ly (References 43, 44). Most of the
particulate is in the highly visible range and stack exit opacity readings
can be as high as 3.0 RN for some "smoky" engines. In summary, because JETC
exhausts have particle sizes in the highly visible range, high plume opacity
readings result for test cell operations with "smoky" engines.
For a given uncontrolled JETC, exhaust opacity can be roughly
correlated with smoke number and particulate density. These correlations
indicate what change in particulate loading can be expected for a given change
in exhaust opacity. In this study, such correlations were useful in assessing
whether an exhaust opacity control device reduces the particulate loading
or simply alters the particulate size distribution to the less visible range.
This will be discussed further in the section on controlled JETC emissions.
The Navy has reported correlations (Reference 21) between SAE smoke
number, particle grain loading, and Ringelmann number for conventional and
smokeless engines (Figures 10 and 11). When grain loading data is not
available, the Navy uses these correlations to convert Ringelmann numbers to
56
-------
grain loadings (mg/cu meter). These correlations are for dry catch only and
are not valid at low power or idle where substantial condensed unburned
hydrocarbons exist.
The reliability of the Navy correlation is checked in Figure 12 by
plotting the Navy data with a curve based upon light-scattering theory. The
anchor point for the light-scattering curve was obtained in Reference 40 by
arbitrarily assigning an 85-percent opacity level to a 0.05 gr/scf
particulate plume of mean particle diameter of 2.5u from a power plant stack
with a 32.5-foot diameter. The rest of the sigmoid curve is generated by
applying the light-scattering theory for different grain loadings. The Navy
data and the theoretical line have similar slopes, which lends some
credibility to the use of the correlation.
4.2.3 Comparison of Jet Engine Emissions Data
The JETC emissions data used in this study and listed in Table 14 were
extracted from a Navy Aircraft Environmental Support Office (AESO) air
quality report (Reference 36). These data were originally obtained from the
Aircraft Engine Emissions Catalog, (Reference 45). These data are generally
within ±50 percent of published data for the J79 and J57 engines (Reference
41, 42), and within 15 percent for the TF30 engine (Reference 41). The AESO
values are conservative for particulate and nitrogen oxide (NOX) emissions,
while hydrocarbon (HC) and carbon monoxide (CO) emissions can be either
conservative or high, depending upon the engine type.
57
-------
100.0.
10.0
IS)
c
O)
o
o
t/1
1.0
0.1
<
20 40 60 80
SM smoke number (ARP 1179)
100
O T56 (501)
O J57-P-8
Q JT8D (conventional) J52-P-6A (conventional combustor) smoke number
A T400 (max particules) at max power
& T64-GE-413
Q T58-GE-10
Figure 10. Relationship between smoke number and soot density
(taken from Reference 21).
58
-------
5.0
A-l?487 0
4.0
VI
** 3.0
t.
J 2.0
o>
o>
1.0
Line of 1:1 correlation
4)
4>
G
20 40 60
SAE smoke number (engine)
TF 30-P-6
TF 30-P-8 (smokeless)
J 52-P-6A
J 52-P-8A (smokeless)
J 65 (clean)
T 56-A-10
J 57-P-8
80
100
80
60
u
S.
o
40
20
100
Figure 11. Smoke number versus Ringelmann reading for
a 14-foot diameter stack (taken from
Reference 21).
59
-------
>>
!-»
r*
u
Q.
O
01
o
100,
90-
80 -
70 -
60 -
50 -
40 -
30 -
20
10 -f
Theoretical
curve
Jet engine test cell data
~O~ Average engine
-0- J52
4 T56
I Coal-fired
power plan
gr/scf
Figure 12. Theoretical and experimental opacity versus grain loading (Reference 21, 40),
-------
TABLE 14. WORST-CASE JETC SOURCE STRENGTH DATA FOR ALAMEDA NARF
(REFERENCE 36)
Engine
J65
052
052
J52
T56
T56
TF34
TF34
TF41
TF30
6TCP
6TCP
GTCP
GTCP
T62
Percent
Operational Time 1n Mode
Idle
5
10
10
10
20
20
10
10
10
5
25
25
25
25
30
Military
70
65
65
65
50
50
50
50
70
65
55
55
55
55
45
Other A/B
25
25
25
25
30
30
40
40
20
30
20
20
20
20
25
Source Strength
(Ibs/hour)
CO NOX UHC Part SOX
53.6 37.2 1.4 19.9 52
12.1 60.7 9.3 176.1 52
12.1 60.7 9.3 176.1 52
12.1 60.7 9.3 176.1 52
11.0 16.7 4.1 1.1 12
11.0 16.7 4.1 1.1 12
13.6 25.5 3.8 8.8 115
13.6 25.5 3.8 8.8 115
33.9 150.0 17.9 127.3 72
18.9 121.0 7.4 113.6 72
9.7 1.4 5.7 0.6 2
9.5 1.3 5.6 0.6 2
9.7 1.4 5.7 0.6 2
9.5 1.3 5.6 0.6 2
3.7 0.4 2.2 1.3 13
61
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4.2.4 Comparison of Total Alameda JETC Source Emissions with BAAPCD Source
Inventory
The Alameda individual JETC data have been combined to establish the
total emissions from JETC operations. Consistent with the AESO report
(Reference 36), the five auxiliary power unit test cells have been combined
with the 10 depot-level cells to establish the emission source levels for
all test cell operations at Alameda. Each cell emission value is multiplied
by the number of tests per year and the duration of a test for each engine
type. The ton/day values are summed over all 15 cells to arrive at the
total emissions. It should be noted that the AESO report (Reference 36)
from which engine emissions and test schedule data were taken, focused on
worst-case conditions for air quality modeling. The total emissions given
here are probably greater than those found on an "average" day at Alameda.
Also SO emissions are based on the maximum allowable fuel sulfur content of
X
0.4 percent. The actual fuel sulfur content may only be a fraction of this
value.
Table 15 is a comparison of Alameda test cell emissions and source
emission values for the nine county Bay Area Air Pollution Control District
(BAAPCD) (Reference 46). The jet engine test cell emissions also are com-
pared with those from air carriers and military aircraft in this table. It
can be seen that JETC operations at Alameda contribute less than 0.01 per-
cent to UHC and CO, 0.07 percent to NO, 0.12 percent to SO and 0.26 per-
x x
cent to particulate in the total emissions inventory for the nine county
BAAPCD. Comparison with total military aircraft operations emissions indi-
cates that the Alameda NARF JETC operations contribute approximately 11
percent of particulate, 1 percent of UHC, 1 percent of CO, 10 percent of NO
A
and 56 percent of SOV emissions. It should be noted that of the four air
X
62
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bases in the nine-county area, Alameda has the lowest total percent emissions
as is indicated in Table 16.
TABLE 15. COMPARISON OF WORST-CASE ALAMEDA JETC EMISSIONS TO NINE
COUNTY BAAPCD EMISSION SOURCE INVENTORY AND MILITARY AND
CIVILIAN AIRCRAFT OPERATIONS
Part UHC CO NOX SOX
(ton/day) (ton/day) (ton/day) (ton/day) (ton/day)
- V .
Alameda (Reference 36)
1974 JETC
BAAPCD (Reference 46)
9 County Avtg.
Air Carriers*
Military Aircrafta
0.47
180
5.4
4.3
0.07
1000
10
8
0.17
4300
21.5
21.5
0.48
720
7.92
5.04
0.31
270
0.81
0.54
^Contributions of these categories to total county emissions
(% contribution x 9 county average)
TABLE 16. PERCENT EMISSION CONTRIBUTIONS OF BAAPCD MILITARY AIR BASES
Base
Alameda
Hamilton
Moffett
Travis
Percent
of Total
Emissions
8.6
12.6
30.2
48.6
100.0
Part
(percent)
10
13
30
47
100
HC
(percent)
11
16
29
44
100
CO
(percent)
13
20
28
39
100
NOX
(percent)
9
14
31
46
100
SOX
(percent)
33
67
100
63
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4.2.5 Comparison with BAAPCD General Combustion Source Regulations
Table 17 gives a comparison of JETC emissions with source regulations,
listing the local BAAPCD General Combustion Source Regulations and uncon-
trolled worst-case Alameda test cell emissions developed from Table 14
and Reference 36. The worst-case emission levels listed in Table 17 are
based on engines which produce the highest reported level of a specific
emission or opacity during an average test cycle, as given in Table 14.
TABLE 17. COMPARISON OF MAXIMUM UNCONTROLLED JETC EMISSIONS TO COMBUSTION
SOURCE REGULATIONS (REFERENCES 46, 36)
Emission
Opacity
Parti cul ate (gr/scf)
Total UHC (ppm)
NOX (ppm)
>(250 MBtu/hr) source
SOX (ppm)
Standard
BAPPCD"
RN £ 1
0.15
300
225
300
Alameda
RN - 3
0.04
107
174
58
Engine Type
J52
J52
T56
T56
T56
The parts-per-million concentrations include augmentation air and are
uncorrected for dilution. Because the values are averages for a test cycle
which includes idle, as well as military and other power settings, these
values are lower than peak values, and much lower than values corrected for
dilution. However, they do represent a duty-cycle emission, and dilution air
correction is not required by the BAAPCD. The opacity level is based on
observation of a smoky J52 engine operating in a JETC (Reference 21). It is
assumed that smoky J52 engines operating at Alameda would achieve the same
64
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level of opacity. The J52 engine is the highest (grains/scf) source of
participate and has the highest opacity of all engines tested at Alameda.
During JETC operations, the T56 has the highest level of NO (on a volume
A
basis) of all of the engines tested at Alameda.
Comparing the worst-case Alameda JETC opacity and emissions with
BMPCD regulations, it can be seen that only the opacity exceeds the general
combustion source regulations. The three engines which probably exceed the
opacity limit at Alameda are the J52, TF41, and TF30. Smokeless versions of
the TF30 and J52 would not exceed the opacity regulation. Based on Alameda
test cell operations reported in Reference 36, it can be concluded that
roughly 40 percent of Alameda JETC operations are above the BAAPCD opacity
regulations.
4.2.6 Air Quality Comparison
The Navy has applied the EPA "PTMPT" and "PTMAX" air quality models
(Reference 47) to determine the impact of Alameda NARF JETC operations on
local air quality (Reference 36). The models are Gaussian-based dispersion
techniques that determine the spread and dilution of pollutants from a point
source. The air quality models use as input the locations and strengths of
emission sources and weather data. Contributions from multiple sources are
superimposed to establish the total impact on ambient air quality. To obtain
worst-case results, weather parameters were selected to achieve maximum
ground concentrations outside the base perimeter. The results of this
worst-case study are summarized in Table 18, listing measured background
levels, calculated base perimeter maximum JETC contributions, and local and
Federal air quality standards.
65
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TABLE 18. IMPACT OF JET ENGINE TEST CELL EMISSIONS ON ALAMEDA COUNTY
AIR QUALITY.3
en
Emission
Part
UHC
"°x
CO
»K
Standards
ug/m1
BAAPCO
60e
100d
--
470b
11000f
46000b
105d
1310b
Fed Prim
75e
260d
160C
100*
40000b
365d
1310C
Alameda. ug/m*
Background
Level
105
6.5
70
2000
13
JETC Uncontrolled
max 1 hr
27.6
22.5
33.5
49.3
35.1
max 24 hr
3.5
2.8
4.2
6.2
4.4
JETC Controlled
Scrubber
1 hr
6.1
22.5
33.5
49.3
35.1
24 hr
1.8
2.8
4.2
6.2
4.4
Clean Combos tor
1 hr
.77
22.5
50.3
49.3
35.1
24 hr
21.8
2.8
6.3
6.2
4.4
Additives
1 hr
2.8
^22.5
33.5
49.3
35.1
24 hr
1.7
2.8
4.2
6.2
4.4
*Alameda Uncontrolled JETC values from AESO 111-75-8A, Table 4 (Reference 36)
1-hr concentrations not to be exceeded more than once per year
3-hr concentrations not be be exceeded more than once per year
24-hr concentrations not to be exceeded more than once per year
"Annual arithmetic mean
12-hr concentrations not to be exceeded more than once per year
-------
From Table 18 it can be seen that all JETC emission contributions are
beneath BAAPCD and Federal standards. For a duty-cycle normalized to a 1-
hour base, worst-case UHC and SOV emissions are greater than the background
A
levels by 3.5 and 2.7 times, respectively. (Background here refers to
ambient levels measured near the air base perimeter over a period of
many hours.) On a 24-hour air quality comparison, the maximum JETC
emissions represent the following percentages of local background levels: 3
percent of particulate, 43 percent of UHC, 0.3 percent of CO, 6 percent of
NOX, and 34 percent of SOX. Worst-case test cell operations appear to
contribute a large portion of UHC and SOX to the background levels. Ground-
level contributions upwind and downwind of this maximum point would be less.
4.3 CONTROLLED TEST CELL EMISSIONS AIR QUALITY IMPACT
If Alameda JETCs are considered as stationary sources, their operation
with "smoky" engines would be in violation of local BAAPCD standards for
stationary source opacity. Gaseous and particulate emissions would not
exceed local source regulations. However, if the cells were in certain local
regulating districts within the United States, which require emission
corrections for dilution air, then some engine tests also would exceed NO
/\
and THC regulations.
In this section the impact of three control methodologies wet
packed scrubbers, clean combustors, and ferrocene fuel additive on JETC
emissions are discussed. The wet packed scrubber is an example of a post-
engine-cleanup technique, whereas the clean combustor control method alters
the combustion processes to reduce the engine exhaust emissions. Ferrocene,
a fuel additive, chemically reduces JETC opacity and may reduce particulate
loading.
67
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Currently, these three control methods are used primarily to reduce
particulates and opacity. However, one method -- clean combustors --
alters gaseous emissions. A detailed discussion can be found in the
Aerotherm Phase 1 report (Reference 1) and the references cited in the
following sections.
4.3.1 Gaseous and Particulate Emissions
Controlled JETC emissions data are very sparse and show a lack of
consistency, which makes it difficult to assign a single reduction efficiency
for each pollutant to a particular control technique. Thus, a single
"average" efficiency for each pollutant has been applied to each control
technique. It is expected that these efficiencies will not apply to every
engine and test cell combination; however, since reasonable alternatives are
not available, this approach has been taken.
4.3.2 Met Packed Scrubber
A wet packed crossflow nucleation scrubber designed by Teller
Environmental Systems, Incorporated, is currently in operation at the
Jacksonville Naval Air Rework Facility. This scrubber removes particulates
by:
t Injecting water directly into the exhaust jet, superstaturating the
particle laden stream
Condensing the water on the particles at a downstream location,
making them grow in size
t Impacting the large water/particulate drops onto the stack-
mounted, packed-bed scrubber section, depositing both
water and particulate in the bed
Carrying the particulate and condesned water out of the test cell
by an irrigation water system
68
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Through the scrubbing process, a considerable amount of particulate is
removed, while some water vapor is added to the stream.
Some experimental emissions sampling has been conducted in the stack-
mounted scrubber (Reference 44). However, the data taken are not necessarily
representative of actual particul ate concentrations since isokinetic
conditions were not maintained during sampling. It is extremely difficult to
sample the large, low-velocity face of the scrubber, even when local wind
velocities are negligible. Because sampling is difficult and accurate
emissions data are needed, a 1/50-scale model scrubber was constructed and
attached to the Jacksonville Black Point No. 1 test cell which houses the
full-sized scrubber. With the model scrubber, sampling conditions were
carefully controlled and good data were obtained.
Details of the model scrubber sampling procedure are presented in the
Aerotherm Phase 1 report (Reference 1). From these tests it has been
concluded that the wet packed scrubber and quench water flow reduced the
particulate concentrations from a J79 jet engine by roughly 78 percent
(Reference 39). Also, no significant changes (less than 5 percent) in
concentrations of CO, C02, NO, and NOX across the scrubber were observed
(Reference 39).
Even though full-scale scrubber tests could not supply detailed
emission concentrations, they did provide relevant information on plume
opacity (Reference 44). Observations of scrubber test cell plumes of smoky
engines indicated that the wet packed scrubber can reduce plume opacity below
Ringelmann 1 levels. It should be noted that the scrubber produces a large,
dense white steam plume (ranging in size from several hundred up to 1500
feet) which may obscure a more dense particulate plume near the test cell
stack exit. However, by the time the steam plume dissipates, the exhaust
69
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plume also is greatly spread out and the particulate plume is not visible.
Besides obscuring particulate plumes, the steam plume might present a
nuisance through coating all objects in the vicinity of the test cell
with particle-laden drops (Reference 5). Nonetheless, wet packed scrubbers
reduce plume opacity levels below Ringelmann 1 at distances beyond the steam
plume.
Presently, four new scrubber-equipped test cells are under
construction at Jacksonville. These will be large test cells which can
handle engines with up to 350 pounds per second airflow. Each cell will be
equipped with water cooling and particulate removal systems which will allow
water to be recycled in a closed-loop. With the recycling system only 10
percent of the water flow needs to be made up while the system is operating.
It is estimated that a maximum pumping capacity of 14,000 gpm will be
required for these scrubbers, which translates into a significant energy
consumption of 1200 kW (1500 kva). The cost of this power is the major
nonlabor expense incurred by test cell operations. Annual electrical
operating costs for the scrubber should be approximately $18,000, based on
two engine tests per day, 250 operation days per year, maximum water
flowrate, and a cost of 3.5 cents per kilowatt-hour. Actual maintenance and
operating costs for the system would be several times this electrical cost.
4.3.3 Clean Combustors
This section focuses on the application of smokeless combustors to
current military jet engines. To reduce exhaust opacity and particulate
emissions from "smoky" engines, clean combustors use redesigned combustion
chambers that eliminate conditions favoring pollutant formation. Early
redesigns for military and civilian engines were directed twoards reducing
exhaust opacity, whereas more recent civilian engine redesigns seek to reduce
70
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gaseous emissions as well as exhaust opacity. Modifying an existing engine
to reduce emissions is far more difficult than designing a new engine with
low emissions, and the same modification can produce quite different results
on different engines. Therefore, engine modifications for pollutant reductions
must be carefully tailored to the individual engine.
Exhaust opacity measurements on J52, TF30, and J79 engines indicate
that smokeless combustors reduce plume Ringelmann numbers from a maximum of
2.5 to less than 1 (Reference 5). When all available opacity data are
examined, opacities ranging from 26 to 80 percent are reduced to a range
from 2.5 to 17 percent, an average reduction of 86 percent. As demonstrated
by the data presented in Table 19, smokeless combustors can reduce opacities
at all power levels.
TABLE 19. EFFECT OF SMOKELESS COMBUSTOR ON 079
PERCENT OPACITIES (REFERENCE 22)
Power Level
Idle
90*
95%
Military
Average
Smoky
(percent
opacity)
26
61
62
61
53
Smokeless
(percent
opacity)
2.5
3.0
8.0
17.0
7.6
Smoky/
Smokeless
Ratio
10.4
20.3
7.8
3.6
10.5
Reductions in particulate concentration accompany the reductions in
plume opacity. The smokeless combustor particulate data used in this study
consist of particulate measurements on "smoky" and "smokeless" J52 engines.
71
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Only a 21-percent reduction in particulate was reported for the J52 engine
(Reference 24). However, it was indicated in Reference 24 that considerable
differences in performance existed between the "smoky" and "smokeless" J52
engines, making a direct comparison of participate reductions difficult. The
opacity versus particulate correlation given in Figures 10 and 11 indicates
a 94- to 98-percent reduction of particulates for several engines (References
21, 5, 22). Although particulate acutally is reduced by only 21 percent, the
large apparent reduction indicates that clean combustors have probably
shifted the exhaust particle size distribution out of the highly visible
range. Extensive particulate and opacity data on smoky and smokeless
versions of the same engine are needed to confirm this hypothesis. For this
study, it is assumed that clean combustors reduce particulate concentrations
by 21 percent.
Presently, smokeless combustor gaseous emission data is sparse. For
this study, data from two commercial engines, JT3D, JT8D, and two military
engines, TF39 and J79, were used to estimate the impact of smokeless
combustors on gaseous emissions. The commercial engines, JT3D and JT8D,
have some design similarities with the military J57 and J52 engines
respectively, and these commercial engines exhibit uncontrolled gaseous
emission levels which are comparable to the military engines.
A summary of the effects of smokeless combustors on gaseous emissions
for the four engines are given in Table 20. The effect of "smokeless"
combustors on gaseous emissions does not appear to follow consistent trends:
unburned hydrocarbon and CO emissions seem to decrease or remain the same for
military engines, while most nitrogen oxide emissions are increased.
However, the increases in NOX are scattered over a range from -0.6 to +100
percent.
72
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TABLE 20. PERCENT CHANGE IN EMISSION LEVELS DUE TO SMOKELESS COMBUSTOR
RETROFIT
Engine
OT30
JT8D
JT8D
J79
TF39
, THC co NOX smoke
(percent) (percent) (percent) (percent)
-47
-47
-37
+344
0
-36
-21
-17
+404
0
+47
-0.6
+64
+100
+5
-70
-53
-59
-62
-94
Reference
12
25
26
22
27
To compare the clean combustor controls to wet packed scrubber and
fuel additive controls, a single clean combustor reduction efficiency is
assumed to apply to all engines for each pollutant. Due to wide scatter and
conflicting trends, it is assumed that THC and CO emissions are, on the
average, not altered by retrofitting smokeless combustors. For the increase
of smokeless combustor NOX emissions, a simple average of the percent
increases in Table 20 gives an increase of 50 percent.
4.3.4 Ferrocene Fuel Additive
Additions of ferrocene to jet fuel have been observed to reduce
opacity and particulate grain loadings of exhaust plumes (Reference 24).
Several chemical mechanisms may have caused these decreases (Reference 41):
1. Shift in the combustion reactions to favor the formation of a
low-visibility size range of particles. (In Reference 48 it was
hypothesized that the electrons from the metal in the additive
neutralizes ionic precursors of particulate material.)
73
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2. The iron in ferrocene serves as an oxidation catalyst
3. The ignition temperature of soot is lowered
4. Particle growth is limited
5. The refractive index of the particles is altered
Some or all of these mechanisms may be working in jet engines in which
ferrocene additives are used.
Depending on engine type, the weight percent of ferrocene additive in
fuel required to reduce opacity to 20 percent varies from 0.02 to 0.1
(Reference 1). Increases above 0.1 wt percent do not show proportionate
decreases in particulate emissions (References 24, 38). In one study, when
particulates were collected by both EPA and LA sampling trains (Reference
38), ferrocene at 0.042 wt percent reduced particulate loadings 53 percent.
Another study (Reference 24) showed that at higher power settings ferrocene
reduced particulate concentrations 64 percent, whereas at idle settings it
reduced particulate 45 percent. These values give an average reduction of 54
percent in particulates for ferrocene addition.
The trend of greater reduction at high thrust levels is also
substantiated by Reference 49. It may be hypothesized that ferrocene
addition only reduces soot formation, and therefore, the larger quantities
of condensed unburned hydrocarbons at low power levels will not be affected.
This mechanism is consistent with the lower effectiveness of ferrocene
at low power levels. To compare control methods, ferrocene is assumed
to reduce particulates 53 percent.
Ferrocene has been reported to eliminate visible plumes (References
48, 50). In Reference 41, ferrocene was reported to reduce jet engine plume
opacities from RN 2.5 to 0.25 (600 to 1000 ppm Fe added). From these data,
74
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it can be assumed that (for the purposes of comparing control methods),
ferrocene reduces jet plume opacities below RN 1.0.
None of the studies cited above listed both opacity and particulate
data. It was thought that using the Navy correlation might increase the
number of opacity and particulate readings upon which to draw a conclusion
(known opacities could be converted to particulate concentrations and vice-
versa). However, use of the correlation in this case does not appear to be
valid. It was interesting to find that the opacity and particulate
correlation presented in Figures 10 and 11 give unrealistically low
particulate concentrations when the opacity levels with ferrocene addition
are used. This indicates that the Navy correlation is not applicable
for ferrocene addition. It may be conjectured that ferrocene is shifting
the particle size distribution out of the highly visible range as well
as reducing particulate concentrations. This would reduce the opacity
beyond that expected by mass reduction alone.
Recent Alameda Naval Air Station tests have indicated that gaseou
emissions of CO, SOV, NOV, and UHC remains essentially unchanged with
A A
ferrocene addition (Reference 23).
Ferrocene Toxicity
Ferrocene is the common name for dicyclopentadienyl iron, an organo-
metallic compound with chemical formula Fe(C5H5)2. Ferrocene is a crystalline
material which breaks down thermally above 400°C and is soluble at 5 to 6
percent by weight in JP-5 fuel (Reference 51). As a control method,
ferrocene is dissolved in a solvent and introduced into the fuel so that it is
present during the combustion process.
The toxicity of ferrocene and its products has been of some concern.
Ferrocene is slightly toxic (Reference 51). Animal studies showed little,
75
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if any, ocular irritation; abraded and unabraded skin irrigation tests were
negative; and inhalation studies indicated no significant symptoms (Reference
51). Ferrocene is not toxic unless ingested. Ferrocene dissolved in xylene,
toluene, and JP-5 fuel did not demonstrate a higher rat LD5Q (50-percent
mortality) than that of the solvent alone. The oral and intraperitoneal
LD50's for a relatively pure sample of ferrocene are 1890 mg/kg and 1520 mg/kg,
respectively, which places ferrocene in the slightly toxic category (Reference 51
The primary combustion products of ferrocene are water, carbon
dioxide, and iron oxide. During combustion, the two cyclopentene rings
separate from the iron and react, forming products indistinguishable from
fuel combustion products.
The toxicity of the primary combustion products of ferrocene is minimal.
Fe^Oo is the least toxic oxide of all the fuel additive oxides; it is only
slightly toxic on an acute local basis, and is not toxic on a chronic basis
(References 52, 53).
Even though iron oxide by itself is not a real concern, i)t has been
hypothesized that iron compounds may serve as a transport mechanism into the
body for combustion-formed carcinogenic agents (Reference 54). Furthermore,
a recent EPA publication indicates that in boiler processes, iron may react
with polycyclic organic material (POM) to produce a potentially carcinogenic
substance (Reference 55). Another study on residual oil combustion (Reference
56) has indicated that POM's are reduced when ferrocene is used. At this
time, it is not clear whether ferrocene products have the potential to
*The ferrocene tested in this study was Arapahoe Chemical Company's Fe 55
Smoke Suppressant. The introperitoneal rat 1059 data presented here are
somewhat higher (indicating lower toxicity) than those reported by other
laboratories with other sources of ferrocene.
76
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transport carcinogenic ROM's into the body or ferrocene products and ROM's
react to form a different substance. Further research is needed into
combustion processes with ferrocene addition.
Effect of Ferrocene on Jet Engines
Ferrocene is stable in jet fuel at low temperatures. At high
temperature, (400-500°F) a solid is formed which may clog fuel lines (Ref-
erence 1). This prevents ferrocene from being used during in-flight opera-
tions, since the fuel is a coolant and can reach very high temperatures.
However, if the stationary JETC fuel supply system is properly designed,
the ferrocene can be used without clogging.
Jet engines which have used the ferrocene additive show red deposits
of varying thicknesses on the internal surfaces of the combustors. These
deposits are composed primarily of iron oxide. For short periods of testing,
on the order of 2 to 4 hours, the deposits do not affect the performance of
most engines (References 50, 5, 57). However, Naval Air Propulsion Test
Center studies of ferrocene addition have shown that out of eight engines,
two engines (the T56 and J79) experienced a problem with engine deposits
(Reference 57). Besides reducing engine performance, the deposits created
by ferrocene addition may lead to problems with engine durability and in-
flight safety of jet aircraft. These data indicate that ferrocene addition
must be carefully evaluated on an engine-by-engine basis.
4.3.5 Controlled Test Cell Emissions Air Quality Impact
In the section on uncontrolled test cell emission it was concluded
that several current military engines exceed local opacity regulations. In
this section, the control method efficiencies previously derived are applied
to the uncontrolled JETC emissions to determine the controlled emission
levels. These emissions are then compared to the regulations. In Table 21,
77
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opacity levels and emission reductions achieved by wet packed scrubber,
clean combustor and ferrocene fuel additive control methods are
summarized. All methods can decrease plume opacities to the Ringelmann
1 level, while they reduce particulate concentrations from 21 to
78 percent. The only definite change in gaseous emission level 1s an
increase in NOX concentration when.clean combustors are fitted to an engine.
TABLE 21. COMPARISON OF THREE CONTROL METHODOLOGIES - RINGELMANN OPACITY
AND PERCENT CHANGE IN EMISSIONS
Wet Scrubber
Clean Combustor
Ferrocene Fuel
Additive
Opacity
-------
4.3.7 Comparison of Controlled Emissions with BAAPCD General
Combustion Source Regulations
In Table 23, the worst-case Alameda controlled JETC emissions are
compared with BAAPCD local regulations. As in the uncontrolled case, gaseous
emissions are below general combustion source regulations. However, NO
A
concentrations under worst-case conditions for the clean combustor control
method are now slightly above the regulations. Controlled plume opacity
levels are roughly at or below the regulation level.
From the Alameda test cell operation schedule and emissions levels,
presented in Reference 36 it can be concluded that the scrubber and additive
control methodologies are able to meet the local emission regulations,
including opacity. The clean combustor control method for the T56 engine
meets all of the standards except NO concentrations. It is estimated that
j\
9 percent of Alameda JETC operations would exceed the NOV regulation if clean
j\
combustors were applied to the T56 engines.
4.3.8 Controlled JETC Air Quality Impact
I
As previously discussed, worst-case uncontrolled JETC operations make
a substantial contribution only to UHC and SOY ambient concentrations
X
(roughly 43 and 34 percent, respectively, on a 24-hour basis) as shown in
Table 18. Since these quantities are found to be unaffected by the control
methods discussed herein, the conclusions reached for the uncontrolled JETC
operations are also applicable to the controlled case. As can be seen in
Table 18, contributions of both controlled or uncontrolled Alameda JETC
operations to ambient air quality are far below BAAPCD or Federal regulations.
79
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TABLE 22. EFFECT OF CONTROLS ON TOTAL EMISSIONS FROM JET ENGINE TEST CELLS
AT ALAMEDA NAVAL AIR STATION
Emission
Part
UHC
CO
NOX
sox
Tons/Day
BAAPCD*
Average
180 '
1000
4300
720
270
OETC
Uncontrolled
0.47
0.07
0.17
0.48
0.31
JETC
Controlled
Wet Packed Clean " Fuel
Scrubber Combustor Additives
0.10
0.07
0.17
0.48
0.31
0.37
0.07
0.17
0.72
0.31
0.22
0.07
0.17
0.48
0.31
aCounty area average emissions, 1974
80
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TABLE 23. COMPARISON OF MAXIMUM ALAMEDA CONTROLLED AND UNCONTROLLED JETC
EMISSIONS WITH BAAPCD GENERAL COMBUSTION OPERATING REGULATIONS
JETC Alameda Controlled
Emissions Standard Uncontrolled Scrubber Combustor Additive
Opacity RN < 1 RN s 3.0 RN £ 1 RN ^ 1.1 RN < 1
S02 300 ppm 58 ppm 58 pptn 58 ppm ._58 ppm
Part. 0.15 gr/scf 0.04 gr/scf 0.009 gr/scf 0.032 gr/scf 0.019 gr
Total HC 300 ppm 107 ppm 107 ppm 107 ppm 107 ppm
NOX 225 ppm 174 ppm 174 ppm 261 ppm 174 ppm
4.4 JETC ENVIRONMENTAL IMPACTS ON WATER, SOLIDS AND PEOPLE
In addition to Impacts on air quality, JETC operations have impacts on
water and solid wastes which need to be considered. JETC operations also
have been the subject of several nuisance complaints filed by people residing
in the vicinity of military bases. To complete the environmental impact
summary, these areas are briefly discussed below.
4.4.1 Uncontrolled JETC Water Quality Impact
Water is used during operations to quench or reduce the temperature
of the jet exhaust so that the test cell acoustic baffles are not damaged.
The quantity of water used varies according to engine type, power level and
cell design. Quench water, particularly at idle, may not be used until stack
temperatures indicate a need for cooling water. Typically, up to 700 and
1000 gpm of quench water are used for normal rated and'military power levels,
respectively (Reference 39). At these levels, most of the quench water
exits via the stack as vapor or droplets. Ground release can occur at
low thrust levels, but as drips rather than flow (Reference 39).
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The quench water spary scrubs some particulate out of the gas stream
in addition to condensing unburned hydrocarbon vapors. Some limited chemical
analyses of quench water discharges have indicated that the filterable
residues are water salts resulting from heating water in the augmentor tube
(Reference 39). Nonfilterable residues are carbonaceous. The scrubber
water is colloidal, and the particles are hydrophobic, possibly as a result
of being coated with JP-5 or degraded JP-5 fuel (Reference 43).
Since actual water discharges are minor and can be contained without
discharging into a sewer or larger body of water, the impact of JETC on water
quality is insignificant.
4.4.2 Controlled JETC Water Quality Impact
Because the clean combustor control method has no water requirements
or discharges beyond those of uncontrolled JETCs, conclusions reached for
uncontrolled test cells apply to those controlled by clean combustors.
Wet packed scrubbers do not create any new problems of water
discharge, since the 16,000 to 17,000 gpm of scrubber irrigation water for
a production system is cleaned and recycled. The scrubber irrigation water
removes particulate from the packed bed, and helps condense the nucleation
water before it leaves the stack (Reference 39). The irrigation water
cleanup system reduces the collected particulate to sludge. Approximately
60 Ib/hr of sludge per test cell is produced when the scrubber is operating,
and the sludge is approximately 25-percent solids. Because it is formed
by coagulating particulate with calcium oxide (lime), the sludge is slightly
toxic. However, it appears that the solid waste is a minor impact.
In controls using ferrocene fuel additive, some small amounts
ferrocene could be introduced into the small amount of water discharge.
Since ferrocene is only slightly toxic, no major water pollution problems are
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introduced, beyond those of the uncontrolled cells. Products of ferrocene
combustion would be almost identical to fuel products, and therefore this
impact is minimal.
Federal and state water regulations are concerned with discharges into
navigable waterways. However, the water discharge from JETC's controlled or
uncontrolled, is so minor that it cannot be classified as a regulated
discharge.
4.4.3 People Impacts
Analyzing the impacts of JETC operations on the population is
difficult. Potential impacts can be identified and discussed, but quantifi-
cation of an impact is not straightforward. Keeping in mind that the
same problem source will impact people differently, two possible impacts of
jet engine test cell facilities are examined briefly below.
Visual
Uncontrolled JETCs show a visual plume during the average test.
Complaints have been filed with BAAPCD regarding a visual impact upon
the population in the area (Reference 58). Even if the test cell is con-
trolled for particulate opacity, a steam plume will persist whenever quench
water is being used. The color of this plume varies from white to black
according to power, test cell and engine type, control method, and quench
water flowrate.
Residents in the area have seen, and will continue to see, the steam
plume from controlled or uncontrolled test cells. If they interpret the
plume as a pollution source, then complaints will occur. By operating the
JETC during evening or early morning hours, fewer people see the plume.
However, the noise impact would be greater, and such scheduling may be
impossible.
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Noise
JETCs are a source of high sound levels relative to normal
conversation and high levels may persist for several hours during a test.
An estimate of sound levels at the perimeter of a base (where JETCs are
located near the center of the base) can easily be made. As a general
rule, sound drops by 6 dBA when distance from the sound source doubles.
Using the JETC data in Reference 43 (90 dBA at 250 feet from the test
cell), the sound level at the base perimeter (assumed to be 1000 yards)
would be 70 dBA, or approximately speech level. From this exercise it
can be concluded that if the JETCs do not directly border residential
areas, the noise impact should be acceptable for daytime operation. Be-
cause the JETCs are located away from populated areas at the Alameda NARF
(Reference 59), sound levels should be well below 70 dBA.
Aircraft Operations have more of an impact than JETCs. Noise
complaints by Alameda residents originally directed at JETC operations,
were found to be caused by night flights, not jet engine testing (Reference 60)
Noise is an impact to which Alameda residents are sensitive but JETCs
are not the source of the impact.
Using the scrubber will reduce noise levels further (Reference 43).
clean combustor and ferrocene fuel additive will have or no impact on noise
levels.
4.5 SUMMARY
This section summarizes the impact of uncontrolled and controlled JETC
on the environment, and includes impacts on air, water, and people.
4.5.1 Uncontrolled JETC Emissions
On a source basis, worst-case Alameda JETC operations contribute very
little (less than 0.26 percent) to the total nine county BAAPCD emissions
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(unburned hydrocarbons, carbon monoxide, nitrogen oxides, sulfur oxides,
particulates) inventory. Alameda JETC operations also represent less than 11
percent of the emissions produced by military aircraft operations in the BAAPCD
region. On an air quality basis, worst-case Alameda JETC operations contribute, at
at most, 3 percent of particulates, 43 percent of unburned hydrocarbons, 0.3
percent of carbon monoxide, 6 percent of nitrogen oxides and 34 percent of
sulfur oxides on a 24-hour comparison. Contibutions to the background levels
are much less than these maximum values at other locations.
Comparing worst-case individual Alameda JETC emissions with the BAAPCD
General Combustion Source Regulations, it is found that 40 percent of Alameda
JETC operations exceed the opacity regulations.
4.5.2 Controlled JETC Emissions
The impact of wet packed scrubbers, clean combustors, and ferrocene
fuel additive control strategies on JETC emissions has been assessed.
Wet packed scrubbers reduce JETC plume opacities below RN 1, and reduce
particulates 78 percent. Clean (smokeless) combustors also reduce plume
opacities below RN 1, but reduce particulates 21 percent. Ferrocene fuel
additive reduces plume opacity below RN 1 and reduces particulates by 53
percent. Gaseous emissions remain substantially unchanged with application
of wet packed scrubbers and ferrocene fuel additive; the only change in
gaseous emissions using clean combustors seems to be an increase in
nitrogen oxides of roughly 50 percent.
Using these control strategies, the impact of JETC operations on
ambient air quality is reduced in all respects except for NOX- NOX is
increased by clean combustors. However, the increase is not large enough
to alter the conclusion that JETCs contribute only minimally to the
BAAPCD source inventory. Comparing controlled individual JETC emissions with
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General Combustion Source Regulations for the BAAPCD indicates that all
control stragegies will reduce the plume opacity below or near the RN 1
regulation. All control methods reduce particulate concentrations. Since
uncontrolled concentrations are below regulations, controlled JETC
particulate concentrations will be even further below the standards.
Scrubber and additive control strategies do not alter JETC gaseous emissions
sufficiently to alter the conclusion that gaseous emissions are below BAAPCD
General Combustion Source Regulations. Application of clean combustors to
the T56 engine may produce NO concentrations in excess of the regulation.
J\
It is estimated that 9 percent of Alameda JETC operations would exceed the
NO regulation if clean combustors were applied to the T56 engine. Ferrocene
X
added to the fuel is slightly toxic, but no more so than the fuel itself.
When burned, ferrocene fuel additive yields primarily iron oxide, carbon
dioxide, and water vapor. Taken alone, these substances are not very toxic;
however, it has been suggested that synergistic reactions of iron oxide with
combustion-produced POMs may produce carcinogens or transport them into the
human body. Further study is required to prove or disprove this conjecture.
4.5.3 Impacts on Water and People
Controlled or uncontrolled JETCs have only minor water discharges
which can be released onto the ground and evaporated. Discharge water might
contain small amounts of degraded fuel and possibly ferrocene additive. The
wet packed scrubber control method produces a solid cake (60-lbm/hr) waste
from water treatment and recycling. Because of its lime content, this cake
is slightly toxic.
Complaints of plume visibility have been received at the BAAPCD
offices. These plumes are caused by both particulate matter and condensed
water vapor. Since applying control methods will not reduce water
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condensation, some plume will always be present at high-power operation.
However, control methods will reduce the opacity of the plume considerably.
Uncontrolled JETC operations are located sufficiently far away from
civilian populations that their sound levels are not a nuisance. Wet packed
scrubber controls can reduce these sound levels even futher.
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SECTION 5
JET ENGINE TEST CELL EMISSIONS DATA
The general validity of published JETC data and measurement techniques
was discussed in the Phase 1 study of JETC emissions (Reference 1). In this
section, available plume opacity, gaseous and particulate emissions data for
controlled and uncontrolled JETC are briefly described. Details of the (1)
engine and test cell unit tested, (2) test method for opacity, particulates
and gaseous emissions, (3) sampling locations, and (4) test cell conditions,
as well as the detailed data are presented in Appendix B.
To characterize the environmental impact of controlled and
uncontrolled JETC's, plume opacity, parti cul ate and gaseous emission
concentrations must be measured at the stack exit. These quantities vary as
a function of engine type, power level and condition of the engine.
Furthermore, the test cell itself affects emissions, according to the cell
configuration, augmentor design and airflow, and quench water flow. Also,
stack exit areas are typically large and test cell configurations generally
create highly nonuniform distributions of stack exit velocity. Therefore, to
characterize test cell emissions properly, extensive sampling must be
conducted at the stack exit area for several test cell engine combinations.
Published JETC stack-exit emissions data are very sparse. They also
are limited since only a few (or one) sampling points were measured for a
large stack exit area. In addition, isokinetic particulate sampling rates
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have not been maintained in some cases, casting doubt on the reliability of
the particul ate data.
In the following paragraphs the JETC emissions data sources found
during this study are briefly summarized. Comments on the reliability of the
data are included here, and details of the data, including test conditions,
are presented in Appendix B.
5.1 "NOISE AND AIR POLLUTION EMISSIONS FROM NOISE SUPPRESSORS FOR ENGINE
TEST STANDS AND AIRCRAFT POWER CHECK PADS" (Reference 61)
This report presents gaseous and particulate emissions data taken on
jet aircraft noise suppressors and a JETC. The noise suppressor data were
obtained at McClellan (California) and Hill (Utah) Air Force Bases; the JETC
data were obtained at McConnell (Kansas) Air Force Base. Based on multipoint
C02 concentration measurements, a single stack exit sampling point was
established at which "average" particulate and NOX concentration data were
collected. For particulate data, this "average" is somewhat suspect, since
the distribution of velocity across the stack exit was highly nonuniform.
Seme areas even experienced negative velocities. Based on carbon and water
balances, the overall accuracy of the multipoint gaseous data was estimated
by the author to be between 1 and 52 percent. Because NOX was sampled at a
single point and only small particulate sample volumes were collected (4.1 to
13.65 cu ft), a much greater sampling error probably results for these data.
Isokinetic sampling rates were maintained during particulate sampling.
Details of the data and the test conditions are given in
Appendix B-l.
5.2 "PRELIMINARY REPORT: JET ENGINE TEST CELL EMISSIONS" (Reference 42)
The primary purpose of this study was to demonstrate the feasiblity of
the JETC sampling procedure initiated at McClellan Air Force Base. Both
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gaseous and parti oil ate data were obtained, however, the JETC stack exit was
sampled at only a single point. Also, the J57 engine was only run at idle
conditions during the sampling limiting the usefulness of the data in
assessing the environmental impact of JETC's. The authors indicated that the
NOX concentration is probably low due to absorption in the sampling line and
tedlar sampling bags.
Details of the data and the test conditions are given in
Appendix B-2.
5.3 "TURBOJET AIRCRAFT ENGINE TEST CELL POLLUTION ABATEMENT STUDY"
(Reference 62)
In this study, the test cell data from "Air Pollution Source Emissions
Evaluation of Turbofan Jet Engine Test Facility at NAS, Albany, Georgia,"
Bibbens, R. N., et al., Report 64-037, May 1971, is presented. Emission
levels were measured at the base of the stack for a J79 engine at power
levels of idle, 95-percent thrust and afterburner. Stack exit particulate
concentrations might be less than the measured values, due to particulate
fallout within the stack. Since the original Albany NAS, report is
not available, the reliability of the data cannot be determined at this time.
Details of the emissions data and test method are given in
Appendix B-3.
5.4 "JET ENGINE TEST CELL TESI AUGMENTOR-SCRUBBER SYSTEM" (Reference 44)
This report presents the results of a study to determine how
effectively the TESI wet packed nucleation scrubber (used at the Jacksonville
NARF) reduced JETC particulate emissions and plume opacity. Three engines,
(J52, J79 and TF30), were tested. The scrubber system was found to reduce
plume opacity below Ringelmann 1 and grain loadings below or near 0.004
grains/cu ft. for all of the engines.
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The opacity readings are probably accurate. However, it was noted
in the report that the flow velocities at the scrubber face varied considerably
and in some locations the velocity was so low that the direction of the
flow could not be determined. Under these conditions, particulate sampling
rates were probably not isokinetic. In addition, manifolding of sampling
nozzles and lengthy sampling lines add uncertainty to the data. Because
particulate data were inconclusive, a model scrubber was constructed
and tested at Jacksonville NARF. The results of this model scrubber test
are presented in Section 5.7 and Appendix B-6.
Details on the data taken in the TESI report and the test conditions
are given in Appendix B-4.
5.5 "A SURVEY OF THE AIR POLLUTION POTENTIAL OF JET ENGINE TEST FACILITIES"
(Reference 21)
In this report JETC plume opacities observed by Alameda Naval Air
Rework Facility and BAAPCD personnel are presented. Data on seven engines
(TF30-P-6 and P-8 (smokeless); J52-P-6A and P-8A (smokeless); J65 (clean);
T56-A-10 and J57-P-8 are included, as shown in Figure 11. Within the bounds
of uncertainty of the Ringelmann opacity measurement technique, the data
appear to be valid. Also included in this report are J79 THC idle, and NOX
military power level data at the JETC stack exit, taken from the Naval Civil
Engineering Laboratory Report No. 64-037, May 1971, Port Hueneme, California
94043. Since this report is not available, the reliability of the data and
the measurement techniques cannot be determined. The quantitative values
given were 105-ppm THC and 5-ppm NOX. The NOX data seem low when compared
with USAF J79 stack measurements at McClellan Air Force Base (see
Section 5.1).
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5.6 "FERROCENE TEST FOR TEST CELL SMOKE ABATEMENT" (Reference 63)
This study investigated the feasibility of using a
fuel additive to reduce test cell exhaust smoke to an acceptable level.
Plume opacity readings for a J79 engine with and without ferrocene fuel
additive were recorded at the North Island NARF. These results indicated
that ferrocene is effective in keeping plume opacities below 20 percent at
all power levels. Because the readings were taken on an overcast day, some
uncertainty in the opacity levels may have resulted.
Details of the data and the test conditions are given in
Appendix B-5.
5.7 "JET ENGINE TEST CELL POLLUTION ABATEMENT EFFICIENCY TESTS"
(Reference 39)
This study reports the results of a test program to determine the
effectiveness of a model wet packed crossflow scrubber in reducing JETC
emissions. The study was prompted by the inconclusive data obtained on the
full size scrubber at Jacksonville NARF. The test methods and data obtained
during the study were judged by the EPA to be acceptable for determining scrub-
ber effectiveness. J52 and J79 gaseous and particulate emissions data were
obtained both upstream and downstream of the scrubber section. The model
scrubber was located in an auxiliary ground-level duct and emission levels at
the scrubber inlet may not be representative of stack exit values. However,
the data should be useful in assessing the effectiveness of wet packed
scrubbers in reducing JETC stack emissions.
Details of the data and the test conditions are given in Appendix B-6.
5 8 "A STUDY OF MEANS FOR ABATEMENT OF AIR POLLUTION CAUSED BY OPERATION OF
JET ENGINE TEST FACILITIES" (Reference 37)
Included in this report are some gaseous emission test cell data
obtained by the Navy. These data were extracted from "Pilot Tests for the
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Establishment of an Environmental Data Base for Naval Aviation Activities,"
Osgood, F. B., et al., Naval Air Rework Facility, NAS, North Island, San
Diego, California, August 1972. NOX, THC and CO emissions from a J79 engine
were measured at the base of a JETC stack over a wide range of power
settings. Since the original report is not available, no comments on the
reliability of the data or measurement techniques can be made. However, the
emission levels are somewhat consistent with other JETC data.
The details of the data and measurement techniques are given in
Appendix B-7.
5.9 "RESULTS OF AIR SAMPLES FROM ELECTROSTATIC PRECIPITATOR" (Reference 64)
This document presents a summary of the model electrostatic
precipitator emissions data obtained by United Engineers and Constructors at
the Jacksonville NARF. The format of the data is the same as that for
the wet packed model scrubber.
Since the electrostatic precipitator and scrubber data were obtained
on the same test cell and engine combination (see Section 5.7), these results
can be compared directly. All tests were performed at normal rated power.
Since only a summary of the data is presented, it is not possible to
comment on the reliability of the data. Although the data taken before the
model electrostatic precipitator may not be representative of JETC stack exit
values, the data are useful in assessing the effectiveness of electrostatic
precipitators in reducing JETC emissions.
Details of the data and the test conditions are given in Appendix B-8.
5.10 "PLUME OPACITY AND PARTICULATE EMISSIONS FROM A JET ENGINE TEST CELL"
(Reference 65)
The objective of this study was to determine the feasibility of
utilizing optical transmissometers as mass emission monitors for JETCs.
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JETC stack exit particulate emissions data as well as plime opacity
measurements were obtained for J57 and J75 jet engines. The JETC used in the
study is a reciprocating aircraft engine test cell which has been modified to
test jet engines. The stack exit area is roughly three times larger than the
largest test cell constructed for jet engine testing. Because of the large
difference in exit areas, the emission rates and opacities determined in this
study may not correspond with those obtained on more standard test cells.
The large stack areas of this cell also created some isokinetic
sampling problems. Stack exit velocities during lower power operation were
very low, and in seme locations even negative. This made isokinetic
particulate sampling very difficult at low power levels. Carbon dioxide
concentration data indicated that the measured and actual velocities could be
considerably different and even at higher power settings, velocity measurements
were still somewhat uncertain. These problems could result in considerable
errors in particulate mass concentration at low power settings.
Details of the data and the test conditions are given in
Appendix B-9.
5.11 "GAS TURBINE ENGINE PARTICULATE MEASUREMENT TECHNIQUE, SUMMARY OF
COORDINATING RESEARCH COUNCIL (CRC) PROGRAMS" (Reference 66)
One of the major objectives of this study was to identify changes
in parti cul ates between the rear engine face and the JETC stack exit.
To meet this objective, particulates were sampled at both the engine exit and
JETC stack exit, using both dry EPA and wet Los Angeles (LA) sampling
techniques. Since the LA method catches condensed hydrocarbons as
particulate, the LA method theoretically should yield higher particulate
levels than the EPA method for the same engine conditions. This was not the
case in this study. In addition, particulate data obtained by both the EPA
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and LA sampling trains lacked repeatability. Because of these problems, the
data obtained in this study cannot be considered very reliable.
Details of the data and the test conditions can be found in
Appendix B-10.
5.12 "AIRCRAFT ENGINE EMISSIONS CATALOG" (Reference 45)
Stack exit JETC particulate and gaseous emissions data for small
turboshaft engines have been obtained at North Island NARF. An EPA Method 5
sampling train was used for particulate data. The repeatability of the data
was not good. Data gathering time, which included two or three traverse
points, was limited to 5 minutes at each power setting. Therefore, a great
deal of confidence cannot be placed in the particulate data taken during this
study.
Details of the data and the test conditions are given in
Appendix B-ll.
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13. Rudey, R. A., "Status Review of NASA Programs for Reducing Aircraft
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14 Niedzwiecki, R. W., "The Experimental Clean Combustor Program Description
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16. Roberts, R., Peduzzi, A., and Niedzwiecki, R. W., "Low Pollution
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18. Roberts, R., Fiorentino, A. J., and Diehl, L., "The Pollution Reduction
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21. \ Lindenhofen, H. E., "A Survey of the Air Pollution Potential of Jet
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PE-3, October 1972.
22. Henderson, R. E., Air Force Aero Propulsion Laboratory, private
communi cation.
23. Longley-Cook, B., Naval Facilities Engineering Command, San Bruno,
private comnunication.
24. Kl airman, A. F., and Horling, J. E., "Parti cul ate Sampling from Gas
Turbine Engines," paper presented at International Conference on
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25. Bristol, C. W., Jr., "Gas Turbine Engine Characteristics and Future
Outlook," SAE Paper 710319, 1972.
26. Imbrogno, S. "Comparison of Exhaust Emissions of a Low-Time JT8D-
11 Engine: High-Smoke Versus Low-Smoke Combustion Chamber Configurations,"
Federal Aviation Administration Report FAA-RD-74-87, April 1974.
27. Naugle, D. F., Tyndall Air Force Base, private communication.
28. Muller, F., Office of Assistant Secretary of Defense for Health and
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31. Bourgeois, M. J., San Antonio Air Logistics Center, private communication.
r~--
32.\ Morhard, W. C., "Joint Navy-Air Force Jet Engine Test Cell Study, Phase
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33. Offen, G. R., Fulton, R. W., Maurer, R. E., Schreiber, R. J., Wolfe,
K. J., "A Summary of Fine Particle Control by Conventional Collection
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34. Kanen, R. J., Jacksonville NARF, private communication.
35. Foster, B., Naval Facilities Engineering Command -- Southern Division,
private communication.
"Air Quality Impact from Aircraft Engine Test Facilities at Naval Air
Station and Naval Air Rework Facility," Alameda AESO-111-75-8A, Point
Mugu AESO-111-75-11A, Mirimar AESO-111-75-15A, North Island --
AESO-111-75-16A, June 1975.
Ferner, J. A., et al.t "A Study of Means for Abatement of Air Pollution
Caused by Operation of Jet Engine Test Facilities," Naval Facilities
Engineering Command No. 5685-000, August 1973.
38. Klarman, A., "Gas Turbine Engine Particulate Measurement Technique ~
Summary of Coordinating Research Council Program," Interim Report, Naval
Air Propulsion Test Center, November 6, 1974.
39. Kemen, R. J., et al., "Jet Engine Test Cell Pollution Abatement
Efficiency Tests," Naval Air Rework Facility, Jacksonville, Florida,
March 1973 -- May 1974.
40. Weir, A., Jr., et al., "Factors Influencing Plume Opacity,"
Environmental Science and Technology, Vol. 10, No. 6, June 1976, 539-
544.
<<41>\ Robson, F. L., et al., "Analysis of Jet Engine Test Cell Pollution
X~J Abatement Methods," AFWL-TR-73-15, May 1973. Available from NTIS as
AD-763119.
/\^
ty2/\ Burnett, R. D., "Preliminary Report: Jet Engine Test Cell Emissions,"
^^Environmental Health Laboratory, McClellan Air Force Base, California,
AD-757-859, December 1970.
43. Teller, A., "Turbine Emission Control A Systems Approach," Teller
Environmental Systems, Inc., Worster, Massachusetts.
44 "Jet Engine Test Cell TESI Augmenter-Scrubber System," Teller
Environmental Systems, Inc., Contract No. N62467-70-C-0240, December
1971.
45 "Aircraft Engine Emissions Catalog," Aircraft Environmental Support
Office, North Island, Naval Air Rework Facility, San Diego, California.
46. "Air Pollution and the San Francisco Bay Area," BAAPCD, 10th Edition,
March 1976.
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47. Turner, D. B. and Busse, A. D., "User's Guide to the Interactive
Versions of Three-Point Source Dispersion Programs: PTMAX, PTDIS, and
PTMTP," National Environmental Research Centers, U. S. Environmental
Protection Agency, Research Triangle Park, N.C. 27711.
48. Salloja, K. C., "Burner Fuel Additives," Combustion, January 1973.
49. "Gas Turbine Engine Particulate Measurement Techniques," Work Unit Plan
No. NAPTC-633, Interim Report, May 10, 1976.
50. Shayeson, M. W., "Reduction of Jet Engine Exhaust Smoke with Fuel
Additives," presented at Aeronautic and Space Engineering and
Manufacturing Meeting, Los Angeles, California, SAE No. 670866, October
1967.
51. "Investigation of Ferrocene as a Smoke Suppressant Fuel Additive, Report
on Ferrocene Toxicity Study and Evaluation of Two Smoke Suppressant Fuel
Additives," NAVAIR Work Unit Assignment No. NAPTC-742-BP7-307, Interim
Report, April 2, 1973.
52. Finfer, E. Z., "Fuel Oil Additives for Controlling Air Contaminant
Emissions," Journal of the Air Pollution Control Association, Vol. 17,
No. 1, January 1967.
53. Martin, G. B., et al., "Effects of Fuel Additives on Air Pollutant
Emmissions from Distillate Oil-Fired Furnaces," EPA, Office of Air
Programs, Research Triangle Park, North Carolina, EPA-AP-87, Stock No.
5503-0021.
54. Sax, N. I., Dangerous Properties of Industrial Materials, 2nd ed.,
Rein hold Pub. Corp., New York, 1963.
55. "Control of Particulate Matter from Oil Burners and Boilers,"
Environmental Protection Agency, EPA-450/3-76-005, April 1976.
:56. Gianmar, R. D., et al., "The Effect of Additives in Reducing Particulate
Emissions from Residual Oil Combustion," ASME Paper No. 75-WA/CD-7.
!57. "Use of Smoke Suppressant Additive Ferrocene in Fuel for Gas Turbine
Engine Operaion; Recommended Test Procedure and Instructions," for NAVAIR
Work Unit Assignment No. NAPTC-742-BP7-307, Interim Report, April 2,
1973.
58. Thompson, P., BAAPCD, Radio Rm., personal communication, August 31,
1976.
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August 18, 1976.
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60. Creagh, Ron, City of Alameda Mayor's Office, private communication,
August 18, 1976.
61. "Noise and Air Pollution Emissions from Noise Suppressors for Engine
Test Stands and Aircraft Power Check Pads," Burnett, R. D., USAF
Environmental Health Laboratory Report 71M-19, January 1972.
"Turbojet Aircraft Engine Test Cell Pollution Abatement Study," Naval
Facilities Engineering Command, Naval Civil Engineering Laboratory
Report CR74.001, June 1973.
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Test Center, NAVAIRSYS COMPREPAC Project Order No. P. 0. 3-0124,
February 1975.
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Engineers and Constructors, Inc., for SOUDIVNAVFAC, June 1975.
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Grimes, B. C., Masters Thesis, University of California, Davis, March
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663. February 1973.
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APPENDIX A
SCRUBBER RETROFIT COST ESTIMATE
The following cost tables are extracted from the detailed Teller
Environmental Systems, Incorporated scrubber cost estimate. The complete
cost estimate is reproduced in the Phase 1 report (Reference 1).
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ESTIMATED COST FOR A TELLER ENVIRONMENTAL SYSTEMS, INC.
EMISSION CONTROL SYSTEM
FOR
A STANDARD JET ENGINE TEST CELL
(J-79 ENGINE)
14 January 1976
by Charles B. Wyman
Denis R. J. Roy
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1. INTRODUCTION
The size of the Nucleation scrubber system is predicated on testing
the J79 jet engine in its maximum afterburner mode (17,500-lbs. thrust).
Also, the use of a TESI designed augmenter is assumed in order to reduce
the amount of dilution air required.
Basis for the estimate is the prototype installation now operational at
the Black Point test cell number one (1) NARF-JACKSONVILLE, FLORIDA. The
estimate reflects refinements in material selection as well as improvements
in design developed from operation of the prototype unit.
The cost per cell was established using the following assumptions:
1. A common cooling tower is to be used for two test cells.
2. The Cooling Tower is located between the two test cells (est. 200
ft. between cells).
3. One solids treatment system would be required for two test cells.
4. Structural design no snow loads incorporated.
The flow sheet attached is representative of typical flow conditions
for gas and liquid streams.
106
-------
SUMMARY OF COSTS
SECTION TOTAL COST
TESI Augmenters $ 36,600
Nucleation Systems 526,200
Cooling System 336,000
Solids Treatment System 179,500
Subtotal $1,078,300
Contingency 10 Percent 108,000
Engineering and Royalty 225,000
TOTAL COST FOR INSTALLED SYSTEMS ON
TWO JET ENGINE TEST CELLS $1,411,300
EQUIVALENT COST PER TEST CELL $ 705,650
107
-------
BREAKDOW OF COSTS FOR ONE TEST CELL
(Prorated from Cost
of Two cells)
Nucleation Scrubber $ 167,600
TESI Augmenter 17,800
Cooling Tower 125,000
Solids Treatment System 50,600
Piping 70,500
Pumps 10,000
Instruments 19,900
Electrical 52,500
Miscellaneous 24,750
538,650
10-Percent Contingency 54,500
593,150
Engineering 112,500
$ 705,650
108
-------
APPENDIX B
JET ENGINE IN TEST CELL EMISSIONS DATA
B-l. DATA SUMMARY
Source: "Noise and A1r Pollution Emissions from Noise Suppressors for Engine Test Stands and
Aircraft Power Check Pads," Burnett, R. D., USAF Environmental Health Laboratory, Report
71M-19, McClellen Air Force Base. January 1972.
Unit Tested
Location:
Date Tested:
Cell Type:
Stack Area:
Stack Height:
McConnell AFB, KA
24-29 September 1971
A/F 32T-2 cell
242 sq ft
-20 ft
McClellan AFB, CA
7-11 September 1971
A/F 32A-13 supressor
120 sq ft
-22 ft
Hill AFB, UT
13-17 September 1971
A/F 32A-14 supressor
120 sq ft
-22 ft
Engine Tested
Unit:
Duty Cycle:
TF30-P, J79-17
Idle, military,
afterburner
TF30 (F111A)
Military, afterburner
F4C
Idle, military,
afterburner
Test Method
Particulates
Probe Type:
Method:
Probe Location:
Number of Points:
Volume Sampling Rate:
Isokinetic:
Opacity Measurement:
Opacity Type:
Gaseous Laboratory Analysis
Probe Type: Stainless steel
EPA Sampling Train
Wet -All condensibles at 70°F collected as partlculate
Stack exit
One "average" point
5.1-13.7 scf dry
0.75-1.03
Ringelmann
Idle RN < 1, military RN - 1, afterburner - water plume
NOX
CO
UHC
Phenol disulfonic acid method
Nondisperslve infrared analyzer
Gas chromatographic
Emissions Data
Table B-l
109
-------
TABLE B-1. DATA SUMMARY SHEET
F-111A TF-30
F-4C
J-79
Stack Gas Flow
Idle
Total (dry scfm)
scfm/1000 Ibs fuel
Military
Total (dry scfm)
scfm/1000 Ibs fuel
Afterburner (Zone 3)
Total (dry scfm)
scfm/1000 Ibs fuel
Max. Afterburner
Total (dry scfm)
scfm/1000 Ibs fuel
Particulate Emissions (Ib/lOOOlbs fuel)
Idle
Military
Afterburner (Zone 3)
Max. Afterburner
278000
139000
550000
68700
500000
21500
480000
12200
26.5*
8. 34
13.3
29.3
178000
178000
471000
70000
505000
28200
435000
10200
26.5
23.7
11.9
5. 36
135000
67500
339000
40900
::::
318000
10700
72.4
4.32
10.8
102000
96000
449000
52400
482000
15800
32.4
12.8
7. 18
* TF-30 data - no idle data taken during F-lllA test
-------
TABLE B-1. Continued
F-111A TF-30 F-4C J-79
Nitrogen Oxide Emissions, as NOg
(lb/1000 Iba fuel)
Idle
Military
Afterburner (Zone 3)
Max. Afterburner
* TF-30 data - no idle data taken during F-111A
Carbon Monoxide Emissions (lb/1000 Ibs fuel)
Idle
Military
Afterburner (Zone 3)
Max. Afterburner
Ethylene Emissions (lb/1000 Ibs fuel)
Idle
Military
Afterburner (Zone 3)
Max. Afterburner
\
Gaseous Hydrocarbons, as Hexane (lb/1000 Ibs
Idle
Military
Afterburner (Zone 3)
Max. Afterburner
6. 52*
26.9
9.62
9.0
test
81.4
4.39
40.6
6.39
3.62
0. 165
1.0
0.014
fuel)
15.8
Nil
2. 58
Nil
6.52
19.7
7,38
4.47
46.4
^3.04
52. 1
24.8
3.09
<0. 30
2. 70
<1.89
9.49
0.934
7.91
0. 14
6.75
12.7
-,
8.6
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
NM
5.14
13.8
....
5.08
62.5
2.73
31.9
2.07
<-0. 23
<0. 068
12.8
1.4
....
1.34
-------
TABLE B-l. Concluded
F-111A
TF-30
F-4C
J-79
Average Condensate Concentrations (rug/liter condensate)
Formaldehyde
Nitrates
Nitrites
Heavy Oils
Fuel Consumption (1000 Ibs/hr)
Idle
Military
Afterburner (Zone 3)
Max. Afterburner
45-73
24-44
3
10
1.0-1.5
6. 8-7.01
22.0-22. 3
37.2-38.4
9.5
23.0
1.0
6.9
0.999-1.5
6.725-7. 53
17.89-21.01
42. 59-43. 12
20-40
3-40
1.0
7.2
28.8
37.8
31.0
1.1
12.1
1.062-1.075
8. 370-8.574
30.5-30.6
-------
B-2. DATA SUMMARY
Source: "Preliminary Report: Jet Engine Test Cell Emissions," Burnett, R. D., USAF Environmental
Health Laboratory Report 70M-37, McClellan Air Force Base, California, December 1970.
Unit Tested
Location:
Date Tested:
Cell Type:
Stack Area:
McClellan Air Force Base
17 November 1970
Type A
253 sq ft
Engine Tested
Unit:
Duty Cycle:
Fuel Rate:
J57 engine
Idle only
1000 Ibm/hr
Test Method
Particulate:
Probe Type
Method
Probe Location
Number of Points
Isok1net1c
Stainless steel probe
In situ fiberglass filter, dry catch
Near stack wall at exit
One sampling point
0.95
Gaseous Laboratory Analysis
Probe Type
NOX
CO
UHC
Phenol disulfonic acid method
Infrared
Flame ionization; gas chromatography
Emissions Data
TEST CELL EMISSIONS (057 ENGINE AT IDLE)
Carbon Dioxide
Carbon Monoxide
Oxide* of Nitrogen lac NO.,)1**
Total Hydrocarbon! (a* C atom*)
Paraffins (an C alonii)
Aromaticn (a* C alum*)
Olcfinn <»* C atom*)
Ai'Clylpi"' {UK < alumni
PnrlirulaU-n ('»M. lunkinrtif)
PPM
Z.SSO
66
1.0
60
24
10
24.4
1.6
lb*/hr and
Ib«/I000 lb» fuel'
sic.s
Z.9
45.4
IB. I
7.6
1H. 5
1.2
2.07
» Fuel r»l<- 1000 ll.n/hr. limn emi»«iun« In Ibn/hr Inn/1000 In* fuel
et Colic. lr
-------
B-3. DATA SUMMARY
Source: "Turbojet Aircraft Engine Test Cell Pollution Abatement Study," Naval Facilities Engineer-
Ing Command. Naval Civil Engineering Laboratory Report CR74.001, June 1975. Data presented
extracted from "Air Pollution Source Emissions Evaluation of Turbofan Jet Engine Test Fa-
cility At NAS, Albany, Georgia," Bibbens, R. N., et al.. Report 64-037. May 1971.
Unit Tested
Location
Date Tested
Cell Type
Stack Area
NAS, Albany, Georgia
1971
Type A
138 sq ft
Engine Tested
Unit
Duty Cycle
J79
Idle, 95 percent thrust, afterburner
Emissions Data
Table B-2
B-4. DATA SUMMARY
Source: "Jet Engine Test Cell TESI Augmentor-Scrubber System," Teller Environmental Systems, Inc.,
Final Report, December 1971.
Unit Tested
Location
Date Tested:
Cell Type
Stack Area
Pollution Control
Equipment
NARF - JAX, Black Point Test Cell No. 1
December 1970 through May 1971
Type A
Scrubber face area, 960 sq ft
Prototype scrubber and augmentation system mounted on exhaust stack of
cell
Engine Tested
Unit
Duty Cycle
J79, TF30, J52
Idle, normal, military
Test Method
Particulates
Probe Type
Probe Location
Number of Points
Volume Sampling Rate
Isokinetic
Opacity Measurement
Type
Impingers, filters connected to fixed manifold at stack exit
Scrubber face
Six test points
11.5 to 26 I1ters/m1n
Attempted
Rlngelmann
Emissions Data
Tables B-3, B-4, B-5
114
-------
TABLE B-2. ALBANY, GEORGIA J79 TEST (A)
MNTICUIATIS HI WOX. "Of SOt CO MTBMCAWOWS'*' ClWlfllC «« JtT
rva st«« vr * NMW voc vot TO. v*
sent tt/M w/scr «i.j Kiowt m»«n IV*< wt» WM rw U/M w U/V« ww "' rr/ste
ieie 5*5 irt.ito tt o.oti to 0.5 - t 1*5 - j» . tto 1I.J
5* TMWt .»* 5«.«»» TO o.oi« 75 *.» ««J o ij . 1.5 J»o ty.1 ; T.J*
"1 JB.JTO (87.590 91 °.°'* 5« '-0 . 7 «5 HO - 13 JJ> ') T.»t»
en ID vim 500 CM OJCHCM wun
It) U HCUHC
()| STICK JO » 10 rtCT
ft) >OT couxTiMa vxtos m «UCMCM v«nn
(I it* touunoN jowict ptiuioxi or nweor*« Jtt CNCINC TCST f»tniTt »T MS. M.MMT.
O-037. MIT 1)71 BT M N BIB8CNS, J C KINO AND W V MkTSON
-------
TABLE B-3. PARTICULATE EMISSIONS FROM JET ENGINES IN TEST CELL
INLET TO CONTROL SYSTEM
EMISSIONS
6RAINS/SCF
Based on Solids
Collected in
ENGINE MODE ENV/ONE-1 NARF ENV/ONE-2(3) Scrubber Water,
(1.2)
J-79 IDLE 0.0092
NORMAL
MILITARY 0.021
AB 0.059
J-S2 IDLE 0.0034
NORMAL
MILITARY O.OOS9
TF-30 IDLE
NORMAL
MILITARY
0.0348
'(Does not include drain)
0.0153
0.0234
0.0388
Questionable
0.0044
0.0157
0.0126 0.0088
0.0079
0.0079
0.0054 0.0096
0.0029
0.0131
0.065
0.08
0.041
0.006
0.0083
0.054
I - Gas flow on which loading is based:
J-79
J-79
J-79
J-79
TF-30
TF-30
TF-30
J-S2
J-52
Mil
A/B
Normal
Idle
Mil
Normal
Idle
Mil
Normal
Idle
320,000
260,000
300,000
200,000
350,000
300,000
200,000
350,000
300,000
200,000
scfm TABLE 7-1
scfm TABLE 7-1
scfm Assumed
scfm Assumed
scfm TABLE 7-1
scfm Assumed
scfm Assumed
scfm Assumed
scfm Assumed
scfm Assumed
2 - Solids collected at base of stack were not measured.
3 - A portion of the particulates were collected prior to
this sample because of condensation in the stack and
the internal section of the scrubber. This is evi-
dent from the total black coating of the internals.
116
-------
TABLE B-4. DETAILED SAMPLE LEVELS AT OUTLET OF CONTROL SYSTEM
Mass Velocity Temperature
goint collected grams (fps) *F
J-79 Normal
Time Sampled
S Bin.
Min. AB
Time Sampled
4 Bin.
1
2
3
4
5
6
1
2
3
4
S
6
.0030
.0024
.0014
.0019
.0022
.0029
.0029
.0056
.0022
.0033
.0025
.0033
120
230
60
226
>260
165
130
260
98
165
>260
184
400
400
400
400
400
400
(Reported)
345
410
320
410
320
345
Max. AB
Time Sampled
4 Bin.
1
2
3
4
5
6
.0066
.0035
.0045
.0049
.0066
,0053
163
>260
105
165
>260
165
375
375
375
375
375
375
TABLE B-5. EMISSION LEVELS FROM TESI CONTROL SYSTEM
ENGINE
MODE
PARTICULATE
EMISSIONS
Grains/cu.ft.
RINGLEMAN
J-79
TF-30
J-79
Idle
Normal
Military
Idle
Normal
Military
Idle
Normal
Military
Max. A/B
0.0024
0.0029
0.0024
0.0019
0.0014
0.0018
0.0052
0.0029
0.0062
0.0033
Less than 1/2
These tests
are questio
-------
B-5. DATA SUMMARY
Source: "Ferrocene Test for Test Cell Smoke Abatement," Naval A1r Propulsion Test Center. NAVAIRSYS
COMREPAC Project Order No. P.O. 3-0124. February 1975.
Unit Tested
Location:
Cell Type:
Pollution Control
Equipment:
Engine Tested
Unit:
Duty Cycle:
Test Method
Opacity Measurement
Type:
Emissions Data
Pover
Con'Jition
North Island NARF, San Diego. CA
Type A
Ferrocene fuel additive
J79
Idle, military, afterburner
Visual Opacity
NORTH ISLAND J79 FERROCENE TEST
Visual Opacity
Without Ferrocene
Additive Concentration, Visual Op.-icity!
7. By Weigh: With Ferrocen.--
Idie
85?: ::ili:iry 302
Military 507.
A/B X'r.inuffl ^ 152
A/3 Ka-iniw. (2) 207,
.05
.04
20 %
20Z
(1) Blsck and UTiice (steis) plune.
(2) Stea^ plur.e.
* These readings pjde OP. overcast day.
118
-------
B-6. DATA SUMMARY
Source: "JETC Pollution Abatement Efficiency Tests," Jacksonville Naval Air Rework Facility Report.
March 1973 - Nay 1974.
Unit Tested
Location:
Date Tested:
Cell Type:
Stack Area:
Stack Velocity:
Stack Temperature:
Water Consumption:
Pollution Control
Equipment:
JAX NARP, Black Point No. 1, Model Scrubber
May 1963 - February 1974
Permanent, concrete
Model scrubber. 16 ft' at sampling positions 1 and 2
600-750 ft/mln at position 1 and 400-630 ft/m1n at position "2
-135 average
Quench water - 700 gal/m1n
Model scrubber designed by Plant Engineering Division and Materials
Engineering Division
Test Method
Partlculates
Probe Type:
Method:
Probe Location:
Number of Points:
Volume Sampling
Rate:
Isokinetic:
Opacity Measurement
Type
Gaseous
Probe Type
CO
UHC
CO-
Research appliance
Method 5, no cyclones, probe washed and residue collected
Up and downstream of scrubber
25 points x 5 min/point
125 min sampling 0.5-Inch probe nozzle
Yes
None
Chemiluminescence
None
Nondlspersive infrared
Flame ionization
Nondlspersive infrared
Turbidity of sump water was checked to determine amount of suspended participate.
Engine Tested
Unit
Power, thrust Ibf
Fuel rate, Ibs/hr
Quench water, gpm
Emissions Data
J52-P8B
NR
MIL
7800 8300
5600 6800
700 700
Tables B-6 throuqh B-17
NR
7500
5400
700
J79-10
MIL
MIN AB MAX AB
11000 13000 16000
9500 17000 32500
700 1000 1000
119
-------
TABLE B-6. SUMMARY OF EMISSIONS FROM AN EXPERIMENTAL MODEL WET SCRUBBER
AT JACKSONVILLE NAVAL AIR STATION
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-------
TABLE B-7. J-79 ENGINE DATA USING TELLERETTES
INLET
OUTLET
INLET
OUTLET
INLET
OUTLET
Date
No. ft. of packing
Engine operating condition
Flow at II Sump gal./mln.
Flow at 12 Sump gal./mln.
Vol. of dry gas sampled, SCF
Stack flow rate, SCFM, dry
Stack gas velocity, at stack
conditions, f.p.m.
Moisture, X by volume
Stack gas temp, degree F.
Isoklnetic. X
Participate Results
(a) Probe and filter catch
Gralns/SCF, dry, x 10-3
(b) Total Catch
.Gra1ns/SCF, dry, x 10-3
(c) Particulates from II Sump
Water sample gralns/SCF, x 10-3
Particulate Removal Efficiency
Based on air sample (a), X
Based on air sample (b), X
Based on total (air and water, a+c). X
Based on total (air and water, b+c), X
11-8
4
NR
15.2
86.3
87.87
8878.8
741.1
17.5
129.8
92.6
7.18
8.15
11-8
76.77
7356.4
547.4
10.4
110.8
97.6
3.14
3.99
11-9
4
Mil
10.9
84.6
87.79
7998.3
730.2
23.0
140.0
102.6
5.54
5.65
11-9
70.80
6545.8
516.8
13.6
121.6
101.2
3.83
4.96
11-12
4*
Mil
. 10.1
85.6
92.43
8580.8
.-. 767.8
22.2
139.8
100.7
7.10
9.88
11-12
72.78
6689.3
519.6
13.2
120.2
101.7
3.75
4.57
8.20
56.3
51.0
79.6
75.6
7.19
30.9
12.2,
69.9
61.4
10.31
58.8
53.7
80.7
77.4
Entrained Water Removal, X
57.2
61.0
58.3
-------
TABLE B-0. J-79 ENGINE DATA USING TELERETTES
INLET
OUTLET
INLET
OUTLET
OUTLET
Date
No. ft. of packing
Engine operating condition
Flow at II Sump ga1./m1n.
Flow at 12 Sump gal./m1n.
Vol. of dry gas sampled, SCF
Stack flow rate, SCFM, dry
Stack gas velocity, at stack '
conditions, f.p.m.
Moisture, % by volume
Stack gas temp, degree F.
IsoMnetlc, %
Partlculate Results
(a) Probe and filter catch
Grains/SCF, dry, x 10-3
(b) Total Catch
Grains/SCF, dry, x 10-3
(c) Partlculates from II Sump
Water sample grains/SCF, x 10-3
Partlculate Removal Efficiency
Based ,on air sample (a), %
Based on air sample (b), %
Based on total (air and water, a+c), %
Based on total (air and water, b+c), X
Entrained Water Removal, %
11-15
5
NR
12.3
86.0
72.19
6980.43
584.7
17.8
129.0
96.7
7.62
7.66
9.53
66.3
62.8
85.0
83.4
11-15
59.92
5409.81
392.5
8.8
105.0
103.6
2.57
2.85
11-16
5
NR
12.4
86.0
74.60
7028.6
599.5
18.8
130.0
99.3
7.27
7.62
11.02
52.1
54.3
81.0
81.3
11-16
61.01
5619.6
406.9 ' , .
8.3
104.6
101.5
3.48
3.48
i ii
11-19
5
NR
13.2
3.0
72.70
6935.4
577.3
17.1
128.8
99.0
7.37
8.03
12.34
63.6
65.2
86.4
86.3
11-19
67.20
5745.2
465.9
15.2
126.0
109.4
2.68
2.80
68.3
78.6
23.6
-------
TABLE B-9. J-79 ENGINE DATA USING TELLERETTES
IS3
CO
Date
No. ft. of packing
Engine operating condition
Flow at *1 Sump gal./min.
Flow at n Sump gal./min.
Vol. of dry gas sampled, SCF
Stack flow rate. SCFM, dry
Stack gas velocity, at stack
conditions, f.p.m.
Moisture, X by volume
Stack gas temp, degree F.
Isoklnetlc, I
Participate Results
(a? Probe and filter catch
Gralns/SCF, dry, x 10-3
(b) Total Catch
Grains/SCF, dry, x 10~3
(c) Particulates from II Sump
Water sample gralns/SCF, x 10-3
Partlculate Removal Efficiency
Based on air sample (a), %
Based on air sample (b), X
Based on total (air and water, a+c), X
Based on total (air and water, b+c), X
INLET
11-26
5
NR
13.2
.9
73.07
6978.3
586.2
17.7
130.4
97.9
8.56
8.56
14.58
62.0
62.0
65.9
85.9
OUTLET
11-26
63.84
5426.6
443.4
15.4
129.2
110.0
3.26
3.26
INLET
*MMMMH>M»
12-4
5
Mil
9.6
86.4
90.05
8031.1
732.0
22.8
141.3
104.9
8.57
8.57
12.73
49.0
49.0
79.5
79.5
OUTLET
12-4
72.94
6463.6
499-. 6
12.3
118.0
105.5
4.37
4.37
INLET
12-5
5
Nil
9.5
89.8
86.44
7707.9
705.7
22.9
141.2
104.9
9.50
9.71
13.07
' '58.7
53.4
82.6
80.1
OUTLET
12-5
71.09
6224.3
485.3
12.6
119.0
106.8
3.92
4.53
Entrained Water Removal, X
36.9
65.6
64.7
-------
ro
TABLE B-10. J-79 ENGINE DATA USING HEILE PACKING
i
INLET OUTLET INLET OUTLET INLET OUTLET
D«tc 1-30 1-30 1-31 1-31 2-1 AM 2-1 AM
No. ft. of packing 333
Engine operating condition NR NR NR
Flow at II Sump gal./mln. 12.3 16.2 14.7
Flow at §2 Sump gal./m1n. .2 .5 75.0
Vol. of dry gas sampled, SCF 73.04 62.75 91.46 85.15 91.89 75.01
Stack flow rate, SCFM, dry 6539.8 5448.0 8919.5 8075.4 9046.4 7510.6
Stack gas velocity, at stack
conditions, f.p.m. 542.4 437.1 746.1 638.8 : 760.4 566.4
Moisture, % by volume 16.6 14.1 17.4 12.9 17.7 10.!
Stack gas temp, degree F. 129.6 126.8 130.2 127.6 131.0 115.I
IsoMnetlc, % 104.4 107.7 95.9 98.60 95.0 93.4.
Participate Results
(a) Probe and filter catch *
Gralns/SCF, dry, x 10-3 6<90 3t0gu 6>6? 2 fi 3^
(b) Total Catch
Gralns/SCF, dry, x 10-3 7.27 3.41 6.85 2.68 7.06 3.74
(c) Particulates from IT[Sump
Water sample grains/SCF, x 10-3 io.69 9.33 9.30
Participate Removal Efficiency
Based on air sample (a), X 55.2 62.0 ''51.2
Based dh air sample (b), X 53>1 60 g 47'0
Based on total (air and water, a+c), X 82.4 84.2 79*8
Based on total (air and water, b+c), % 81.0 83.5 77 i *
S
Entrained Water Removal, X 42.5 75.3 57 0
-------
TABLE B-ll. J-79 ENGINE DATA USING HEILE PACKING
ro
en
Date
No. ft. of packing
Engine operating condition
Flow at fl Sump gal./min.
Flow at 12 Sump gal./min.
Vol. of dry gas sampled, SCF
Stack flow rate, SCFM, dry
Stack 335 velocity, at stack
conditions, f.p.m.
Moisture, X by volume
Stack gas temp, degree F.
Isok1ret1c, X
Participate Results
(a) Probe and filter catch
6r»1ns/SCF, dry, x 10-3
(b) Total Catch
Gnins/SCF, dry, x 10-3
(c) Partlculates from II Sump
Kater sample grains/SCF, x 10-3
Participate Removal Efficiency
Based 01 air sample (a), X
Based en air sample (b), X
Based sn total (air and water, a+c), X
Based at total (air and water, b+c), X
Entraired Water Removal, X
INLET OUTLET
2-1 2-1
3
NR
15.1
72.0
85. 8$ 77.46
8851.3 7760.1
738.1 581.9
17.3 10.3
129.8 114.2
90.7 93.3
6.46 3.22
7.21 3.66
8.86
50.1
49.3
79.0
77.2
65.9
INLET
2-5
3
NR
18.
1.0
71.36
12014.7
980.4
16.3
126.0
98.8
8.81
9.67
8.84
31.9
31.1
66.0
64.0
54.5
OUTLET
2-5
64.98"
11295.1
890.3
13.3
125.4
95.7
6.00
6.66
INLET
2-7
5
NR
13.3
80.5
93.94
9297.3
-. 77!-3
16.9
126.6
94.5
6.71
7.31
7.35
58.3
56.6
80.1
78.4
94.0
OUTLET
2-7
82.06
7562.0
562.5
8.9
115.*2
101.5
2.80
3.17
-------
TABLE B-12. J-79 ENGINE DATA USING HEILE PACKING
INLET
OUTLET
INLET
OUTLET
ro
01
Date
No. ft. of packing
Engine operating condition
Flow at #1 Sump gal./m1n.
Flow at 12 Sump gal./mln.
Vol. of dry gas sampled, SCF
Stack flow rate, SCFM, dry
Stack gas velocity, at stack
conditions, f.p.m.
Moisture* 5 by volume
Stack gas temp, degree F.
Isok1net1c, %
Partlculate Results
(a) Probe and filter catch
Grains/SCF, dry, x 10-3
(b) Total Catch
Grains/SCF, dry, x 10-3
(c) Particulates from II Sump
Water sample gra1ns/SCF, x 10-3
Partlculate Removal Efficiency
Based on air sample (a), %
Based on air sample (b), %
Based on total (air and water, a+c), X
Based on total (air and water, b+c), X
Entrained Water Removal, %
2-8
5
NR
14.2
.5
91.30
9348.9
772.9
16.4
127.6
91.3
5.46
5.81
8.60
43.7
46.5
78.1
78.4
2-8
86.02
8041.2
643.4
13.8
125.
100.0
3.08
3.11
2-11
5
NR
13.9
.6
95.32
9425.2
757.9
15.1
125.0
94.6
8.74
9.13
7.84
66.8
62.9
82.5
80.0
2-11
85.88
8072.5
632.5
13.0
122.8
99.5
2.90
3.39
INLET
OUTLET
39.7
37.8
-------
TABLE B-13. J-52 ENGINE DATA USING TELLERETTES
INLET
OUTLET
INLET
OUTLET
INLET
OUTLET
ro
vj
Date
No. ft. of packing
Engine operating condition
Flow at II Sump gal./m1n.
Flow at 12 Sump gal./m1n.
Vol. of dry gas sampled. SCF
Stack flow rate, SCFM, dry
Stack gas velocity, at stack
conditions, f.p.m.
Moisture, X by volume
Stack gas temp, degree F.
Isoklnetlc, X
Participate Results
(a) Probe and filter catch
Grains/SCF, dry, x 10-3
(b) Total Catch
Grains/SCF, dry, x 10-3
(c) Parti culates from
-------
TABLE B-14. J-52 ENGINE DATA USING TELLERETTES
ro
oo
Date
No. ft. of packing
Engine operating condition
Flow at II Sump gal./m1n.
How at 12 Sump gal./mln.
Vol. of dry gas sampled, SCF
Stack flow rate, SCFM, dry
Stack gas velocity, at stack
conditions, f.p.m.
Moisture, I by volume
Stack gas temp, degree F.
Isoklnetlc, %
Partkulate Results
(a) Probe and filter catch
Grains/SCF, dry, x 10-3
(b) Total Catch
SfTTnsTsCFT dry. x 10-3
(c) Partlculates from IT I Sump
Hater sample gralns/SCF, x 10-3
Partlculate Removal Efficiency
Based on air sample (a), %
Based on air sample (b), X
Based en total (air and water, a+c), X
Based c* total (air and water, b+c), X
Entrained Water Removal, X
INLET
1-2 AM
5
NR
17.6
1.0
85.64
8684.5
725.6
18.0
129.6
92.2
6.37
7.09
OUTLET
1-2 AM
71.57
6495.3
519.6
14.7
126.2
103.0
3.44
3.55
INLET
1-2 PM
5
M11 '
15.8
79.0
93.76
9262.6
797.5
19.8
134.6
94.7
7.62
8.01
OUTLET
1-2 PM
80.32
7547.1
560.3
10.1
113.6
99.5
2.78
3.22
INLET
2-15 AM
5
NR
15.7
71.0
94.93
9318.4
" 771.3
16.4
130.6
95.3
6.42
6.73
OUTLET
2-15 AM
88.50
8232.6
611.5
9.5
112.4
100.5
3.86
4.32
j 50
46.0
49.9
56.3
58.7
40.9
63.5
59.8
71.5
68.2
75.9
39.9
35.9-
52.9
49.3
54^7
-------
TABLE B-15. J-52 ENGINE DATA USING TELLERETTES
INLET OUTLET INLET OUTLET INLET OUTLET
Datc 2-20 PM 2-20 PM 2-15 PM 2-15 PM 2-20 AM 2-20 AM
No. ft. of packing 3 3 3
Engine operating condition MR NR NH
Flow at II Sump gal./mln. 14.2 16.7 15 i
Flow at 12 Sump gal,/mii, 80.0 .6 .6
Vol. of dry gas sampled, SCF 86.26 80.75 96.69 85.99 9s!go 86.38
Stack flow rate, SCFM. dry g297.9 7680.3 8927.2 7601.7 9295.4 7938.0
Stack gas velocity, at stack
conditions, f.p.m. 775.5 565.9 749.3 615.7 ' 774.8 637.7
Moisture, X by volume 17.1 9.1 17.3 14.8 17.0 14.4
- Stack gas temp, degree F, 129.6 110.0 131.6 128.0 1280 1238
Isoklnetlc, X 86.8 98.3 101.3 105.8 96.5 10K8
Partlculate'Results
(a) Probe and filter catch
Grains/SCF, dry, x 10-3 8.12 3.99 7.39 3.15 7 84 4 60
(b) Total Catch
Gra1ns/SCF. dry, x 10-3 g 16 5 36 ? ^
(c) Particulates from III Sump °'DI
Water sample gralns/SCF, x 10-3 i.ei 1.53 j^
Partlculate Removal Efficiency
Based on air sample (a), X 59.9 57.4 ' 41>3
Based on air sample (b), X 41.5 52.3 34^4
Based on total (air and water, a+c), X 59.0 64.7 50 4
Based on total (air and water, b+c), X 50.2 60.1 44 o
Entrained Water Removal, X 72.5 34.6 32.0
-------
TABLE B-16. J-52 ENGINE DATA USING HERE PACKING
CO
o
Date
No. ft. of packing
Engine operating condition
Flow at II Simp gal./mln.
Flow at 12 Sump gal./m1n.
Vol. of dry gas sampled, SCF
Stack flow rate, SCFM, dry
Stack gas velocity, at stack
conditions, f.p.m.
Moisture, X by volume
Stack gas temp, degree F.
Isoklnetlc, %
Partlculate Results
(a) Probe and filter catch
Grains/SCF, dry, x 10-3
(b) Total Catch
Grains/SCF, dry, x 10" 3
(c) Particulates from II Sump
Hater sample grains/SCF, x 10-3
Partlculate Removal Efficiency
Based 'on air sample (a), %
Based on air sample (b), X
Based on total (air and water, a+c), X
Based on total (air and water, b+c), X
Entrained Water Removal, X
INLET
1-8 AM
Demist
NR
17.8
.4
84.43
8225.2
660.1
14.7
125.5
96.0
4.80
5.23
1.48
45.5
40.3
58.3
53.4
OUTLET
1-8 AM
72.44
6717.7
527.4
13.0
123.8
100.8
2.62
3.13
INLET
1-8 PM
Demist
NR
17.8
.4
79.62
8178.7
668.6
16.1
127.8
91.0
5.55
6.27
1.31
42.2
38.8
53.2
49.3
OUTLET
1-8 PM
71.44
6693.7
531.3
13.9
125.4
99.8
. 3.21
3.84
INLET
1-11
3
NR
17.5
.4
79.60
7496.3
" 628.8
17.7
130.6
99.3
5.03
5.51
1.81
37.6
35.1
54.1
51.1
OUTLET
1-11
72.71
6597.1
t
534,8
l',J
12M
ioi.i
i .
y .
3\14
3.58
33.7
33.4
43.5
-------
TABLE B-17. J-52 ENGINE DATA USING HEILE PACKING
INLET OUTLET INLET OUTLET INLET
Date 1-14 1-14 1-25 1-25 1-28
No. ft. of packing .3 3 3
Engine operating condition NR ' NR NR
Flow at II Sump gal./m1n. 16.4 15.3 , 16.6
Flow at 12 Sump gal./mln. .4 53.0 71.5
Vol. of dry gas sampled, SCF 85.70 75.29 83.43 69.59 83.20 . '68.22
Stack flow rate, SCFM, dry 8066.0 6813.0 7755.9 6578.6 " 7963.1 6537.3
Stack gas velocity, at stack
conditions, f.p.m. 662.4 536.4 650.5 . 493.8 .' 668.4 481.8
Moisture, X by volume 16.8 13.5 17.9 10.5 '17.5 8.8
Stack gas temp, degree F. 128.6 125.4 130.8 115.4 130.6 ' 112.8
IsoMnetlc, X 99.4 103.3 100.6 98.9 97.7 . 97.6
Particulate Results
(a) Probe and filter catch
Gralns/SCF, dry, x 10-3 5.23 3.03 5.45 . 2.55 4.02 2.03
(b) Total Catch ' .
Gra1ns/SCF, dry, x 10-3 5.73 3.54 5.74 2.77 4.03 2.64
(c) Particulates from ITI Sump ' .
Water sample gralns/SCF, x 10-3 1.64 1 67 2>0g
Particulate Removal Efficiency
Based on air sample (a), X 42.1 53.3 49.4
Based on air sample (b), X 38.3 51.8 34.5
Based on total (air and water, a+c), X 55.9 , 64.2 , 66.5
Based on total (air and water, b+c), X . 52.0 62.7 . 56.6
Entrained Water Removal, X 48.1 68.4 88.6
-------
B-7. DATA SUMMARY
Source: "A Study of Means for Abatement of Air Pollution Caused by Operation of Jet Engine Test
Facilities," United Engineers and Constructors, Inc. Report, Naval Facilities Engineering
Command Contract N00025-72-C-0037, August 1973.
Unit Tested
Location
Date Tested
Cell Type
North Island NARF. San Diego, CA
Approximately August 1972
Type A
Engine Tested
Unit
Duty Cycle
J79-10 and J79-17
Idle, military, afterburner
Test Method
Probe Location
Number of Points
Gaseous
Probe Type
N0x
CO
THC
Bottom of JETC stack
One point
Chemiluminescence
Nondispersive infrared analyzer
Flame ionization detector
Emissions Data
DATA SUMMARY TABLE8
PollutanJX^
.X^Power
Level
N0x
CO
THC as CH4
Emissions, lbs/106Btu
Idle
0.1
2.3
0.43
100%
0.8
0.3
0.08
Afterburner
0.37
1.0
1.2
aAverage data for 11 tests on different J79-10 and
J79-17 engines
132
-------
B-B. DATA SUMMARY
Source: "Results of Air Samples from Electrostatic Predpltator," Memorandum on Electrostatic
Predpltator A1r Sampling Carried out by United Engineers and Constructors, Inc. for
SOUDIVNAVFAC, June 1975.
Unit Tested
Location
Date Tested
Cell Type
Stack Area
Pollution Control
Equipment
Jacksonville NARF, Blackpolnt No. 1
April 17 - April 18, 1975
Type A
Model scrubber, -16 ft2
Electrostatic precipitator
Engine Tested
Unit
Duty Cycle
J79
Normal rated
Test Method
Partlculates
Method
Probe Location
IsoMnetlc
EPA Method 5, dry
Upstream and downstream of precipitator
Yes
Emissions Data
Table B-18
133
-------
TABLE B-18. J-79 ENGINE DATA WITH ELECTROSTATIC PRECIPITATOR
CO
-p.
Date
Flow at 11 Sump gal./mln.
Vol. of dry gas snmpled, SCP
Stack flov rate, SCFM, dry
Stack gas velocity, at stack
conditions, f.p.m.
Moisture, 7. by volume
Stack gas temp, degree 7.
Isokinetlc, X
Particulnte Results
(a) Probe md Miter catch
Gralns/SCF, dry, x 10-3
(b) Total Catch
Grains/SCF, dry, x 10"3
(c) Partlculatea from fl Sump
Water snmple grains/SCF, x 10"'
Partlculate Removal Efficiency
Based on air sample (a), Z
Based on nir sample (b), Z
Baaed on total (air and water, a+c), X
Based on total (air and water b+c), Z
IKLET
4-17
9.66
92.79
9276.0
763.8
15.75
132
97.5
6.17
7.30
5.41
53.0
51.5
74.9
72.1
OUTLET
4-17
81,06
8149.4
665.8
15.15
131
97.6
2.90
3.54
'INLET
4-18 AM
9.89
87.99
8404.3
703.8
17.13
132
102.0
3.48
3.92
5.64
69.8 .
64.9
88.5
86.8
OUTLET
4-18 AM
83.31
7621.5
620.5
14.89
131
106.0
1.05
1.20
IHLET
4-18 JN
9.61
84.27
8607.6
693.0
16.66
132
95.0 ,.
3.14
3.21
5.14
66.6
60.4
87.3
84.8
OUTLET
4-18 ?X
B4.82
7920.2
698.3
15.39
131
1D4.3
1.05
1.27
Entrained Water Removal, 7. 11.5 44.8 22,7
-------
8-9. DATA SUMMARY
Source: "Plume Opacity dnd Paniculate Emissions from a Jet Engine Test Cell." Grimms. B C Masters
Thesis, University of California, Davis, March 1975. ' "
.Unit Tested
Location
Date Tested
Cell Type
Stack area
Stack Height
McClellan AFB, Sacramento, CA
1975
Modi fifed reciprocating engine test cell
700 sq ft
-15 ft
Engine Tested
Unit
Duty Cycle
J57-21, J75
Idle, military, afterburner
Test Method
Participates
Probe Type
Method
Probe Location
Number of Points
Isold net 1c
Opacity Measurement
Type
EPA Method 5
Dry
Stack exit
Two points
Attempted
Lear-Siegler RM-4 optical transmissometer
Emissions Data
Tables B-19. B-20
135
-------
TABLE B-19. PARTICULATE MASS CONCENTRATION
co
cr>
FUEL aow,
LB/HR
1,000
1,020
2,500
2,500
5,000
5,000
8,620
8,650
8,785
8,550
13.400C
CONCENTRATION,
Mg/M3
2.20
0.15
1.95
2.46
5.28
4.79
6.08
6.34
5.26 .
6.45
.10.4
SUBMICRON SUBMICRON SAMPLING VELOCITY AT SAMPLE
CONCENTRATION, CONCENTRATION, LOCATION SAMPLING PT., RATE, X
Mq/Ms * FT/SEC ISOKINETIC
1.85
0.15
1.61
a
4.51
- -
5.53
5.26
5.00
4.97
6.45
84
100
82.5
^^^^^M«W
85.5
^MM
91
83
95.5
77
62
7,5
5,1
4,4
7,6
7,1
1,6
7,5
7,5
5,1
7,5
7,5
11.8
4.3b
10.9
20.1
12.7
26.2
46.8
42.9
13.5
46.1
49.8
,81
299
79.4
96
33.9
72.6
118.7
82.6
195.0
160.2
111.9
OPACITY
X
2.5
3.5
12
11
28
27
36.5
36.5
36.3
35
36d
a. not measured
b. variable between -5 and +10 fps
c. J-75 d. adjusted for effects of
cooling water
-------
TABLE B-20. PARTICULATE EMISSIONS
Fuel Flow
Ib/hr
1.000
1.020
2.500
2,500
5,000
5,000
8,620
8,650
8,785
8,550
13,400
Emission Rate.-.
Kg/Hr
0.685
0.042
1.27
1.60
4.99
4.89
6.68
7.74 ~
5.42
7.65
12.3
Emission Factor
lb/1000 Ib. fuel
1.51
1.09
1.15
1.41
2.20
2.15
2.19
1.98
1.36
1.97
2.02
Emission Factor3
lb/106 BTU
0.08
0.005
0.062
0.075
0.118
0.115
0.117
0.106
0.073
0.106
0.108
a. based on 18,644 BTU/lb of fuel from 1967 CRC Fuel analysis
137
-------
B-10. DATA SUMMARY
Source: "Gas Turbine Engine Partlculate Measurement Technology," CRC Program, Klarman, A. F..
NAPTC-663, February 20, 1973.
Unit Tested
Location
Date Tested
Stack area
Stack Velocity
Pollution Control
Equipment
Trenton NAPTC
June 19. 1973
28 sq ft
- Idle -95 fps, normal rated -325 fps
Ferrocene fuel additive 1n some runs
Test Method
Partlculates
Probe Type
Method (wet & dry)
Probe Location
Number of Points
Isok1net1c
Opacity Measurement
Type
Gaseous
Probe Type
N0x
CO
UHC
CO,
LA AND EPA Methods
LA method actually caught less particulate
Data lacks repeatability 90 to 40 percent deviation
Exhaust tailpipe, stack exit
15 exhaust tailpipe, 6 stack exit
Yes
SAE smoke number ARP 1179
Eight points based on EPA standards
ARP 1256 chemiluminescence
ARP 1256 nondispersive infrared
ARP 1256 flame ionization detector
ARP 1256 nondispersive infrared
Engine Tested
Unit
Duty Cycle
Emissions Data
J57
Idle, normal rated
Tables B-21 through B-26
GASEOUS DATA SUMMARY TABLE
THC
Uncontrolled, ppm
Idle
119
Normal Rated
15
138
-------
CO
10
RUN
Ambient Conditions
Barometer (In Hg)
Temperature
Dry Bulb (*F)
Wet Bulb (*F)
Humidity (gr/lb Dry Air)
Engine Conditions
Power Mode
Air Flow (Ib/sec)
Fuel Flow (Ib/hr)
f/a
Exhaust Gaa Temperature (*F)
Ferrocene Concentration (g/1 JP-5)
Run Time (mln)
TABLE B-21. ENGINE AND AMBIENT CONDITIONS
1 2 3a 3b
30.11
30.11
30.07
30.05
29.96 30.02
29.96
72
69
102
Idle
A1.3
1077
0.00723
583
-
_
81
71
98
Idle
41.0
1088
0.00737
599
-
60
74
72
115
Normal
Rated
115.8
5100
0.0122
900
-
38
80
75
123
Normal
Raced
113.7
4964
0.0121
895
-
26
86
76
J
119
Normal
Rated
110.1
4811
0.0121
900
»
42
71
68
98
Normal
Rated
119.4
5100
0.0119
898
0.41
41
71
67
93
Normal
Rated
119.5
5168
0.0120
902
0.42
54
-------
TABLE B-22. EPA SAMPLING TRAIN
RUN
Tailpipe
1 (Idle)
2 (Idle)
3 (NR)
_. 4 (NR)
0 5 (NR with
Ferrocene)
6 (NR with
Ferrocene)
Stack
1 (Idle)
2 (Idle)
3 0«)
* (NR)
i (NR with
Ferrocene)
6 (NR with
Ferrocene)
FILTER
CATCH
(nig)
24.0
7.4
41.9
35.8
19.8
20.3
7.0
11.2
10.2
4.8
11.0
8.3
PROBE AND
LINE
WASHINGS
(n-B)
108.7
62.8
89.5
19.0
18.7
13.0
35.4
30.7
35.8
7.0
4.1
4.8
TOTAL
PARTICULATES
(mg)
132.7
70.2
131.4
54.8
38.5
33.3
42.4
41.9
46.0
11.8
15.1
13.1
TOTAL
VOLUME SAMPLED
(ft^) (liters (1))
51.47
14.09
4.05
11.17
8.17
14.79
75.71
66.85
33.69
33.36
34.40
35.13
1457.75
399.10
114.60
316.30
231.50
418.80
2144.15
1893.23
954.12
944.77
974.23
994.90
PARTICULA1
CONCENTRA'
(grains/ft^)
0.0398
0.0764
0.5006
0.0757
0.0727
0.0347
0.0086
0.0097
0.0211
0.0054
0.0068
0.0058
c_nwBdAi«, va>* a.n* a.W(*
(A - B) 1002
/I) AVC (AB)
o.cflio ,,.
i 1 f O
'0.1759
1.1466 W7
0.1732
0.1663
0.0795 7°
0.0198
0.0221 "
0.0482
0.0125 11T
0.015J
16
0.01)2
1
-------
TABLE B-23. LA SAMPLING TRAIN
mm
Inlet
1
2
J
4
5
6
Stacfc
1
2
3
4
S
6
T.llpl*
1
2
3
4
S
6 .
WATER
(f)
4.9
4.4
3.6
2.0
0.0
0.0
19.3
15.1
7.1
10.1
4.6
39.5
28.2
17.6
7.3
,11.7
19.1
SOLUBLE.
(S/l)
(X10-3)
2.50
2.72
3.76
2.55
0.00
0.00
11.2
8.15
5.76
13.6
6.93
~
22.0
18.8
-
6.70
19.3
13.1
PARTICULATKS
SOLVENT SOLUBLE
(X10-3)
23.4
2.6
3.9
2.6
3.3
1.7
6.8
5.1
9.0
3.2
1.8
57.2
39.1
5.5
6.3
18.5
7.7
11.9
1.61
4.08
3.32
4.47
1.51
3.95
2.75
7.29
4.32
2.71
"
31.8
26.0
_
5.63
16.4
3.29
INSOLUBLE .
(S) (-8/D
(XI 0-3)
3.9
1.4
2.1
2.3
0.0
0.3
9.1
18.4
15.3
8.2
2.1
"
21.4
9.0
39.8
27.2
12.9
21.1
2.00
0.86
2.20
3.19
0.00
0.27
5.29
9.93
12.4
11.1
3.16
-
11.9
6.00
_
24.3
11.4
14.5
TOTAL
PARTICULATES
32.2
8.4
9.6
7.1
3.3
2.0
35.2
38.6
31.4
21.5
8.5
118.1
76.3
62.9
41.0
53.1
47.9
TOTAL '
VOLUME SAMPLED
(ft3) (liters (1»
69.25
57.14
33.77
27.67
26.10
39.84
60.77
65.46
43.58
26.16
23.45
29.99
63.55
53.01
-
39.53
39.80
51.40
1960.9
1618.0
956.2
783.5
739.0
1128.1
1720.8
1853.6
1234.4
740.7
664.0
849.2
1799.5
1501.0
-
1119.3
1127.0
1455.4
CONCENTRATIOM
(trains/ft 3) te/1)
0.0072
0.0023
0.0044
0.0040
0.0020
0.0008
0.0089
0.0091
0.0111
0.0127
0.0056
0.0287
0.0222
-
0.0160
0.0205
0.0144
0.0164
0.0052
0.0100
0.0091
,' 0.0045
0.0018
0.0205
0.0208
0.0254
0.0290
0.0128
0.0656
0.0508
-
0.0366
4.0471
0.0329
FBtCCRT BEVIATM
{A - ) 100
AVC (AB)
103
9
86
2
13
_
23
36
-------
TABLE B-24. COMPARISON OF ENGINE AND STACK MEASUREMENTS
C02 (X) IDLE
NR
THC (ppm) IDLE
MR
EPA (mg/1) IDLE
NR
NR
(Ferrocene)
LA (mg/1) IDLE
NR
(Ferrocene)
ENGINE
1.28
2.53
295
25
9.35
17.32
12.29
5.82
3.66
4.00
STACK
0.48
0.80
119
15
2.10
3.04
1.44
2.07
2.72
1.26
RATIO (E/S)
2.66
3.16
2.48
1.66
4.45
5.68
8.53
2.81
1.35
3.13
142
-------
TABLE B-25. COMPARISON OF ENGINE AND STACK PARTICULATE
BREAKDOWN FOR LA METHOD
ENGINE STACK RATIO
Water Soluble (X1Q-3)
(mg/1)
1
2
3
4
5
6
AVG -----
22.0
18.8
-
6.70
19.3
13.1
11.2
8.15
5.75
13.6
6.93
-
--
1.96
2.31
-
.49
2.78
-
Solvent Soluble
1
2
3
4
5
6
Insoluble
1
2
3
4
5
6
AVG - -
TOTAL AVERAGE - - -
1.89
31.8
26.0
-
5.63
16.4
5.29
----------
11.9
6.00
-
24.3
11.4
14.5
3.95
2.75
7.29
4.32
2.71
-
* * *
5.29
9.93
12.4
11.1
3.16
-
8.05
9.45
-
1.30
6.05
-
2.25
.60
-
2.19
3.61
i
6.21
2 Ifi
* iL v
3.42
143
-------
TABLE B-26. REDUCTION IN PARTICULATES BY FERROCENE
EPA (mg/1) - without
- with
increase/(decrease) (Z)
ENGINE
17.32
12.29
(29)
STACK
3.04
1.44
(53)
LA (mg/1) - without
- with
increase/ (decrease) (2)
3.66
4.00
9
2.72
1.28
(53)
144
-------
B-ll. DATA SUMMARY
Source: "Aircraft Engine Emissions Catalog," Aircraft Environmental Support
Office, Naval Air Rework Facility, Naval Air Station, North Island,
San Diego, California
Unit Tested
Location
Stack Area
Engine Tested
Unit
Duty Cycle
Test Method
Parti oil ates
Probe Type
Probe Location
Number of Points
Isokinetic
Gaseous
Probe Type
NOX
CO
Total hydrocarbons
Number 10, Naval Air Rework Facility, Naval
Air Station, North Island, San Diego, California
9 sq ft
T64-GE-6B, T64-GE-413, T58-GE-8F/10
Idle, 75 percent, Shaft Horsepower, Military
Radar high volume sampler
Stack exit
Two or three points
Yes
C hem i luminescence
Nondispersive infrared
Flame ionization
145
-------
Emissions Data
DATA SUMMARY TABLE
Fuel Flow
(Ib/hr)
NOX
(lb/1000 Ib fuel)
CO
(lb/1000 Ib fuel)
UHC
(lb/1000 Ib fuel)
Parti culates
(mg/m3)
T64-6E-6B
Idle 75*
337 1039
4.0 8.9
48.4 4.7
13.1 0.8
2.6 6.3
Military
1390
11.2
2.3
0.7
8.6
T64-GE-413
Idle
267
3.1
47.1
12.2
5.0
/75% Mi
1487
9.8
2.2
0.6
26.4
litary
1908
11.8
1.2
0.5
25.1
DATA SUMMARY TABLE
Particulates9
(mg/m3)
Opacity
(Ringlemann)
T58-GE-8F
Idle 75%
11, 7 20, 36
1/4 1/2
Mi litary
36, 22
3/4
runs at same conditions
146
-------
Emissions Data
DATA SUMMARY TABLE
Fuel Flow
(Ib/hr)
NOX
(lb/1000 Ib fuel)
CO
(lb/1000 Ib fuel)
UHC
(lb/1000 Ib fuel)
Particulates
(mg/m3)
T64-6E-6B T64-GE-413
Idle 75% Military Idle 75% Military
337 1039 1390 267 1487 1908
4.0 8.9 11.2 3.1 9.8 11.8
48.4 4.7 2.3 47.1 2.2 1.2
13.1 0.8 0.7 12.2 0.6 0.5
2.6 6.3 8.6 5.0 26.4 25.1
DATA SUMMARY TABLE
Particulates3
(mg/m3)
Opacity
(Ringlemann)
T58-6E-8F
Idle 75% Military
11, 7 20, 36 36, 22
1/4 1/2 3/4
runs at same conditions
147
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA 340/1-78-001b
2.
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
Jet Engine Test Cells
Measures: Phase 2
-- Emissions and Control
6. REPORT DATE
April 1978
6. PERFORMING ORGANIZATION CODE
EPAOE; Project 7268
7. AUTHOR(S)
J. Kelly, E. Chu
B. PERFORMING ORGANIZATION REPORT NO
Acurex Final Report 77-261
10. PROGRAM ELEMENT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Acurex Corporation/Aerotherm Group
485 Clyde Avenue
Mountain View, CA 94042
11. CONTRACT/GRANT NO.
68-01-3158; Task 11
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
Division of Stationary Source Enforcement
Washington, D. C. 20460
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
Stationary Source Enforcement Series
16. ABSTRACT
Background information is provided on the environmental aspects of uncon-
trolled and controlled military jet engine test cell operations. The environ-
mental impact of these operations is considered on both a source and an air
quality basis. Some of the uncontrolled jet engine test cell exhaust plumes
exceed local opacity regulations for stationary sources. However, the air
quality impact of uncontrolled operations is small.
Wet-packed scrubber, jet engine clean combustor, and ferrocene fuel-
additive test cell emissions control strategies are described. Clean com-
bustor technology and its associated cost of implementation are discussed in
detail. Wet-packed scrubber construction cost estimates are also examined
in detail. These control methods probably reduce jet engine test cell
plume opacity below local regulations. However, based on limited data, it
is estimated that for some jet engine tests, applying clean combustors can
cause NOX emissions to rise above local stationary source regulations. The
air quality impact of controlled jet engine test cell emissions is small.
Jet engine and test cell emissions data collected during this study
are summarized in this document.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Jet engine test cells
Jet engines
Jet engine exhaust emissions
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Enforcement
Jet engine test cells
Air facilities
13B
14D
01E
8. DISTRIBUTION STATEMENT
Release unlimited
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
155
20..!
22. PRICE
EPA Form 2220-1 (9-73)
148
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