ET^
Greenhouse Gas Technology Verification Center
A USEPA Sponsored Environmental Technology Verification Organization
Testing and Quality Assurance QA Plan for the
ANR Pipeline Company
Parametric Emissions Monitoring System (PEMS)
Prepared By:
Southern Research Institute
Greenhouse Gas Technology Verification Center
Research Triangle Park, NC USA
Telephone: 919/403-0282
For Review By:
ANR Pipeline Company 1^1
The Oil and Gas Industry Stakeholder Group 1^1
USEPA Quality Assurance Team ^
1^1 indicates comments are integrated into Plan
July 1999
-------
TABLE OF CONTENTS
1.0 BACKGROUND AND INTRODUCTION
2.0 PEMS TECHNOLOGY DESCRIPTION 3
2.1. PRINCIPALS 01 PEMS TECHNOLOGY 3
2.2. ANR PEMS DESCRIPTION 4
2.3. ANR PEMS SET-UP ACTIVITIES 6
3.0 DESCRIPTION OF THE TESTING SITE 8
3.1. SITE SELECTION AND DESCRIPTION 8
4.0 VERIFICATION PARAMETERS AND THEIR DETERMINATION 10
4.1. RELATIVE ACCURACY DETERMINATIONS 11
4.2. OPERATIONAL PERFORMANCE EVALUATIONS 15
4.2.1. PEMS Prediction Capabilities During Abnormal Engine Operation 15
4.2.2. PEMS Response to Sensor Failure 18
4.2.3. Assessment of PEMS Diagnostic Capabilities 19
5.0 FIELD TESTING PROCEDURES 20
5.1. OVERVIEW 20
5.2. SAMPLE HANDLING AND TESTING METHODS 21
5.2.1. Sample conditioning and handling 21
5.2.2. Calibrations 23
5.2.3. Reference Method 3A - Determination of Oxygen & Carbon Dioxide
Concentrations 23
5.2.4. Reference Method 7E - Determination of Nitrogen Oxides Concentration.... 24
5.2.5. Reference Method 10A - Determination of Carbon Monoxide
Concentration 24
5.2.6. Reference Method 25A - Determination of Total Gasseous Organic
Concentration 25
5.2.7. Reference Method 19 - Determination of Emission Rates 25
5.3. DATA ACQUISITION 26
6.0 DATA VALIDATION AND QUALITY 27
6.1. DATA VALIDATION 27
6.2. DATA QUALITY 27
7.0 VERIFICATION REPORT 29
7.1. OVERVIEW 29
7.2. PRELIMINARY VERIFICATION REPORT OUTLINE 30
8.0 PROJECT ORGANIZATION AND SCHEDULE 30
8.1. ORGANIZATION 30
8.2. SCHEDULE 31
9.0 HEALTH AND SAFETY PLAN 32
10.0 BIBLIOGRAPHY 37
Page
.... 1
-------
APPENDIX
APPENDIX A - Field Data Log Forms and Data Acquisition System Outputs
11
-------
ACRONYMS / ABREVIATIONS
ANR
ATDC
bhp
°BTDC
CEMS
cfh
CFR
CH4
CO
C02
DQO
DP
EPA
ETV
ft3
Ft-lbs
gm
H20
Hp
hr
inches Hg
KEA
KV
Lb
Mbtu
Msec
NOx
02
PEMS
ppm
ppmvd
PSIG
QA
RA
RPM
SCF
SRI
THC
The Center
WC
°F
ANR Pipeline Company
After Top Dead Center
Brake Horsepower
Before Top Dead Center
Continuous Emissions Monitoring System
Cubic Feet Per Hour
Code of Federal Regulations
Methane
Carbon Monoxide
Carbon Dioxide
Data Quality Objective
Differential Pressure
United States Environmental Protection Agency
Environmental Technology Verification
Feet Cubed
Foot-Pounds
Gram
Water
Horsepower
Hour
Inches Mercury
Kilkelly Environmental Associates
Kilovolt
Pounds
Million British Thermal Units
Milli second
Nitrogen Oxides
Oxygen
Parametric (also Predictive) Emissions Monitoring Systems
Parts Per Million
Parts Per Million Volume Drybase
Pounds Per Square Inch Gauge
Quality Assurance
Relative Accuracy
Revolutions Per Minute
Standard Cubic Foot
Southern Research Institute
Total Hydrocarbons
Greenhouse Gas Technology Verification Center
Water Column
Degrees F
111
-------
1.0 BACKGROUND AND INTRODUCTION
The Environmental Technology Verification (ETV) program was established by the United States
Environmental Protection Agency (EPA) in response to the belief that there are many viable
environmental technologies which are not being used for the lack of credible third-party
performance testing. With the performance data developed under the program, technology buyers
in the United States and abroad will be better equipped to make informed environmental
technology purchase decisions. In late 1997, EPA selected Southern Research Institute to manage
one of twelve ETV verification entities: The Greenhouse Gas Technology Verification Center (the
Center). Eleven other ETV entities are currently operating throughout the United States conducting
third-party verifications in a wide range of environmental media and industries.
In March of 1997, the Center met with members of the Executive Stakeholder Group. In that
meeting, it was decided that the oil and gas industries were good candidates for third-party
verification of methane mitigation and monitoring technologies. As a consequence, in June of
1998 the Center hosted a meeting in Houston, Texas with operators and vendors in the oil and
natural gas industries. The objectives of the meeting were to: (1) gauge the need for verification
testing in these industries, (2) identify specific technology testing priorities, (3) identify broadly
acceptable verification and testing strategies, and (4) recruit industry stakeholders. Industry
participants voiced support for the Center's mission, identified a need for independent third-party
verification, and prioritized specific technologies and verification strategies. Since the Houston
meeting, a 19 member Oil and Gas Industry Stakeholder Group was formed, vendors of GHG
mitigation devices were solicited in several technology areas, and verification testing of six gas
industry-related technologies are in various phases of evaluation.
Natural gas transmission companies often use large gas-fired IC engines to drive gas compressors
that transport gas through the transmission network in the United States. A parametric emissions
monitoring system (PEMS) for gasseous emissions from large gas-fired internal combustion
engines, has been developed by ANR Pipeline Company (ANR) of Detroit, Michigan. The
patented (US Patent #5,703,777) PEMS approach provides an alternative to instrumental
continuous emissions monitoring systems (CEMS), and has a potential to be a more cost-effective
approach. In addition to monitoring emissions of carbon dioxide (C02), carbon monoxide (CO),
total hydrocarbons (including methane) (THC), oxygen (02), and nitrogen oxides (NOx), the ANR
PEMS provides feedback on engine operating conditions which influence continuous emissions.
This may facilitate appropriate operator response to maintain operating conditions that result in
1
-------
lowered fuel consumption and emissions. The parametric approach to determining air emissions is
provided for in 40CFR64, and with over 13,000 natural gas compressors operating in the United
States alone, the potential applicability of this system is significant.
ANR Pipeline Company has requested ETV verification be conducted, and a test of the ANR
PEMS is scheduled to begin in July 1999 on an engine located at an ANR compressor station. This
Test Plan describes the technology to be tested, and outlines the Center's plans to conduct the
verification in a field setting.
The ANR PEMS will be tested over a full range of normal and off-normal engine operating
conditions, after which a draft Verification Test Report will be issued. There are two classes of
verification parameters to be evaluated: (1) emission monitoring relative accuracy determinations,
and (2) PEMS operational performance determinations. The seven verification parameters
associated with these areas are listed below, along with a brief statement of the approach that will
be used to assess each parameter.
Relative accuracy determinations: PEMS emission prediction values are compared to emissions
measured directly by in-stack instruments
C02 relative accuracy
NOx relative accuracy
CO relative accuracy
THC relative accuracy
PEMS operational performance: PEMS ability to respond to adverse engine operating conditions
PEMS prediction capabilities during abnormal engine operation
PEMS ability to respond to sensor failure
PEMS diagnostic capabilities (using data from evaluations above)
The parameters listed above will be assessed through observation, collection and analysis of
emissions data generated by the PEMS, comparative instrumental gas measurements, use of engine
data logs, and evaluation of ANR-supplied data used to characterize engine operations. PEMS
emission prediction performance capabilities will be assessed under normal engine operating
conditions, and then challenged by simulating "poor' engine performance episodes and evaluating
PEMS emission predictions during these episodes. The PEMS ability to provide the information
2
-------
needed for plant personnel to identify, diagnose, and then rectify problems that may produce poor
emission performance (e.g., actual poor engine operation or sensor failures) will be addressed
during the evaluation of the first six verification parameters listed above.
The remainder of this document provides descriptions and explanations of the PEMS and the
planned verification. The document is organized as follows:
Section 2 provides an overview of PEMS principals and describes the ANR
PEMS design, set-up, and operation;
Section 3 describes the testing site;
Section 4 discusses the verification parameters and approach;
Section 5 describes the testing and analysis procedures to be used;
Section 6 describes the data validation process and quality assurance goals;
Section 7 provides a draft outline of the Verification Report;
Section 8 presents the project team organization and schedule information;
Section 9 outlines health and safety issues associated with this test; and
Section 10, the Bibliography, provides references relevant to this Test Plan,
including references for detailed, step-by-step procedures for the Reference
Methods to be used.
Certain limitations to this test must be stated. First, this evaluation is not intended to characterize
PEMS Relative Accuracy when the host engine is operating abnormally, although performance
data will be collected during abnormal operating conditions. Also, this verification is not intended
to represent all types of engines operating under a wide range of conditions; i.e., performance
results are specific to the host site engine tested, and any extrapolation of these results to other
engines and operating conditions should be carefully considered.
2.0 PEMS TECHNOLOGY DESCRIPTION
2.1. PRINCIPALS OF PEMS TECHNOLOGY
The PEMS approach to monitoring exhaust emissions is based upon establishing relationships
between engine operating parameters, as determined by commonly used sensors, and exhaust
3
-------
emissions. As such, PEMS are fundamentally computerized algorithms that describe the
relationships between operating parameters and emission rates, and which estimate emissions
without the use of continuous emission monitoring systems.
2.2. ANR PEMS DESCRIPTION
The ANR PEMS is applicable to large gas-fired IC engines, and because different engines have
unique operating characteristics, the parameterization of a PEMS is engine specific. Each engine
produces unique relationships between emissions and engine operational functions, and the PEMS
used in this verification contains relationships unique to the host site engine. These relationships
are a function of engine speed and engine load (as torque), but other operational parameters are
also used including: engine efficiency (calculated fuel consumption/actual fuel consumption),
ignition timing, combustion air manifold temperature, and combustion air manifold pressure.
Relative humidity is not applicable to reciprocating engines, so therefore is not an operational
parameter being considered.
Figure 1 illustrates several important ANR PEMS prediction features. The figure indicates that
engine speed and torque are primary determinants of emissions, and that with values for speed and
torque, the "baseline" emissions for an engine are defined. Baseline emissions are representative
of a normally functioning and well-tuned engine, but as engine operational changes occur,
indicators of engine efficiency, ignition timing, air manifold temperature, and air manifold pressure
are used to adjust emission values. Within the ANR PEMS, monitored and estimated values for
these five key parameters are used to increase or decrease predicted emission from the baseline
level as shown in Figure 1. Table 1 describes the engine sensors from which values for these
operational parameters are derived. During the verification testing, the Center will not check the
calibration of these individual engine sensors, but calibration records will be obtained from ANR
and will be included in the final Verification Report.
Figure 2 illustrates general PEMS operational steps and outputs. As the figure shows, the ANR
PEMS contains several different functionalities including the prediction of continuous emissions,
the reporting of total emissions and high emission alarms/alerts, the monitoring of engine sensor
performance, and the reporting of potential sensor malfunctions.
4
-------
Figure 1. ANR PEMS Operational Features
Engine Speed and Torque
Figure 2. Simplified PEMS Diagram
PEMS Reports a
Potentially Faulty
Sensor Alarm
PEMS Reporting:
~ Emissions Values
~ Emissions Alerts
Out of Limit Alarms
5
-------
As Figure 2 also suggests, the ANR PEMS uses redundant engine monitoring sensors. Redundant
sensors are used for those engine parameters that ANR has found influence emissions the most
including fuel flow, combustion air temperature, and combustion air pressure. This redundancy
facilitates the assessment of sensor drift and the identification of failed or malfunctioning sensors.
Table 1. Engine Parameters/Sensors Used by PEMS
Sensor
Model
Specified
Accuracy
Calibration
Check
Operating
Range
Ignition timing
feedback
Altronic
#DI-1401P
± 1% of full
scale
Annual
45° BTDC
to 45° ATDC
Fuel DP (flow)
Rosemount #1151DP-4-S-12-
MI-B1 transducer
± 0.25%
Annual
0-100" wc
Fuel temperature
Rosemount
#444RL1U11A2NA RTD
± 0.25%
Annual
0-125 °F
Air manifold
pressure
Electronic Creations #EB-
010-50-1-0-40/N transducer
± 0.25%
Annual
0-25 PSIG
Air manifold
temperature
Rosemount 0068-F-l l-C-30-
A-025-T34 RTD
± 1%
Annual
0-150 °F
Alarms and alerts are set to give the engine operator knowledge when one or more key operating
parameters is out of specification. These alarms/alerts are set by ANR personnel specifically for
their desired operating rates. Key parameters that have alarm/alert functions include: efficiency
(high and low), ignition deviation from set point, air fuel deviation from set point, and exhaust gas
temperature absolute value (high and low). Three sensors have redundant units. These are: air
manifold temperature, air manifold pressure, and fuel delta P.
2.3. ANR PEMS SET-UP ACTIVITIES
The PEMS will be set-up and parameterized in the field at the site described in Section 3. As a first
step, the engine is determined to be well-tuned and operating normally, including all sensors. Once
this is done, data are collected to support the development of emission relationships. This is done
by first operating under a variety of normal engine speed and torque conditions while
simultaneously measuring the emissions of NOx, CO, 02, THC, and C02 Emission measurements
are collected with calibrated continuous emission monitors, and these data are used to determine
baseline, or normal, emission relationships for various speed and torque conditions. Because small
deviations in engine speed and torque can result in changes in engine operation and emissions,
6
-------
interpolation between the measured values is necessary and accomplished through linear regression
techniques.
To build relationships which predict emissions at other than normal conditions, engine operation is
forced to change by overriding automated engine control systems. This allows off-spec operations
to be simulated and their impact on emissions characterized. Engine operating parameters varied in
this step include combustion air temperature, combustion air pressure, engine operating efficiency
(calculated fuel consumption/actual fuel consumption), and ignition timing. Each parameter is
raised and then lowered from a normal condition until an alarm occurs (i.e., emissions exceed a
specified limitation or engine efficiency has degraded to unacceptable levels). As the engine
moves in and out of normal operation, continuous monitors simultaneously measure and record the
emissions of NOx, CO, 02, THC, and C02.
The ANR PEMS develops relationships between all key operating parameters. From these
relationships, emission levels are predicted when multiple operating parameters are outside of their
individual set points. The PEMS determines and responds to the highest emission-level resulting
from a particular combination of set point conditions. The PEMS defaults to the sensor that is
indicating the higher NOx emission rate.
ANR will complete the installation and set-up of the PEMS and establish acceptable correlation
between engine operating conditions and actual emissions of the designated gasses to the
atmosphere. Specific procedures necessary to establish these correlations and report emission
values are fundamental to the PEMS, and are not an element of the performance verification testing
to be conducted. An independent contractor working for ANR will conduct emission testing for the
set-up process. The ANR test contractor, Mechanical Equipment Company of El Paso, Texas, will
remain on site after the set-up process is complete, and will concurrently collect emissions data
with the verification testing team in order to establish equivalency of the emissions data against
which the PEMS was calibrated. Center staff will collect and evaluate the concurrent data from
both parties. Should a significant discrepancy (greater than 10 percent) exist between the data
collected, the cause of the discrepancy will be investigated and corrected prior to proceeding with
the PEMS verification tests. As the test set-up is being performed, an assessment will be made to
ensure that any other parameters that may be a factor are considered.
7
-------
3.0
DESCRIPTION OF THE TESTING SITE
3.1. SITE SELECTION AND DESCRIPTION
The PEMS approach to exhaust emissions determinations requires engine specific verification of
the PEMS to account for the design and operating characteristics of each engine type upon which it
is installed. Thus, engine characteristics are not a significant restriction or limiting factor for the
PEMS verification test. With this level of flexibility, ANR claims that the PEMS is appropriate to
most types and sizes of internal combustion engines. This allowed a level of flexibility in site
selection. The engine/compressor selected for this evaluation is shown in Figure 3. It is a
reciprocating, 4-cycle internal combustion (IC) engine, utilizing natural gas as a fuel. The engine
is an Ingersoll-Rand (model KVR-616: 16 cylinder, 6000 Hp), and is equipped with six
reciprocating compressors. As with the engine selection, site location was somewhat flexible. The
primary area of concern was any limitation on engine operation due to extremes of weather.
Accordingly, extremes of environment, very hot or very cold, were avoided. The site selected is a
mid-western gas transmission station operated by ANR Pipeline Company.
Based on data from ANR Pipeline staff, measurements collected during several compliance tests
suggest that the maximum and expected emission levels will be:
C02-7%Max., 5.8% anticipated
NOx - 2500 ppm Max., 2027 ppmvd anticipated
CO - 350 ppm Max., 226 ppmvd anticipated
THC - 900 ppm Max., 756 ppmvd anticipated
02 13% Max., 11.7% anticipated
Automated data acquisition systems exist at the plant which coordinate, collect, and record engine
operating variables monitored by various engine sensors. The system samples each variable at 5-
second intervals, and can report/record one-minute average values. To be consistent with the
concentrations measured by the CEMS, 30-second average values will be collected and stored.
Digital files containing 30-second average values for each monitored parameter will be collected
and stored throughout the sampling period. Values relevant to the verification will be reported in
the final Verification Report. The parameters monitored include those listed below.
8
-------
Speed - (Measured digitally) - RPM
Torque, Calculated - (Derived from compression work) - Ft-lbs
Torque, Fuel - (Derived from fuel consumption) - Ft-lbs
Air Manifold Pressure - (Charge pressure going into the cylinder)- inches Hg
Exhaust Manifold Pressure - (Pressure in the common exhaust manifold, post
ports and pre turbocharger) - inches Hg
Ignition Timing - (Measured value of #1 cylinder ignition and compared to
computer assumed value) - °BTDC
Efficiency - (Calculated fuel divided by actual fuel) - %
Air Manifold Temperature - (Charge temperature going into cylinder) - °F
EGT Std. dev. - Exhaust gas temperature, standard deviation. (Usually taken
at each cylinder port. Infers good "balance" all the cylinders producing the
same amount of power) - °F
Fuel Flow - (Orifice type fuel measurement system using redundant DP
sensors. Is the basis for calculating efficiency.) - inches Hg
Turbocharger Speed - RPM
Turbocharger Outlet Air Temperatures - (Both pre and post intercooler)- °F
Turbocharger Inlet and Outlet EGTs - Exhaust gas temperature in and out of
the turbocharger - °F
Turbocharger "bypass" - (A proportional valve around the hot wheel of the
turbocharger, which controls Air to Fuel ratio of the engine) % Open
Hickok Ignition Monitor - (Measures break down voltage and glow duration
of each spark plug) - kV & Msec.
Vibration - (Multi-points)
Fuel Manifold Pressure - PSIG
Oil & Coolant Temperatures - °F
Suction & Discharge, Pressure & Temperatures - PSIG & °F
9
-------
Figure 3. Photograph of Test Engine
4.0 VERIFICATION PARAMETERS AND THEIR DETERMINATION
A test of the ANR PEMS is scheduled for mid July 1999, and will be carried out on a large gas-
fired IC engine located at an ANR compressor station in the Midwestern United States. This
section describes the analysis methods that will be used to address each of the seven verification
parameters listed below. Specific testing strategies and matrices are presented, and key
calculations and instrumental testing methods planned for use are identified. Section 5 describes
the instrumental methods planned for use in the field.
The ANR PEMS will be tested over a full range of normal and off-normal operating conditions,
during which two classes of verification parameters will be evaluated. In the first class, PEMS
emission prediction values will be compared to emissions measured directly by instrumental
methods, allowing the determination of the Relative Accuracy for each gas reported by the PEMS.
In the second class, a number of important PEMS performance features will be evaluated including
10
-------
its ability to respond to abnormal engine operation conditions and failed or drifting sensors. PEMS
ability to facilitate the identification and mitigation of abnormal engine operation will also be
examined.
The seven verification parameters listed below are described individually in the following sections.
Relative accuracy determinations:
C02 relative accuracy
NOx relative accuracy
CO relative accuracy
THC relative accuracy
PEMS operational performance:
PEMS prediction capabilities during abnormal engine operation
PEMS ability to respond to sensor failure
PEMS diagnostic capabilities (using data from evaluations above)
4.1. RELATIVE ACCURACY DETERMINATIONS
As the PEMS approach to air emissions monitoring is a new technology, it is in limited use. As
such, formalized performance demonstration procedures specific to PEMS have not been
established to date.
Instrumental monitoring systems have been developed to the level that they are a primary means
for monitoring gasseous emissions from industrial processes for regulatory compliance purposes.
This recognition has led to EPA's development of Performance Specification Test procedures to
confirm the precision and accuracy of instrumental monitoring systems. With some
augmentations, these EPA Performance Specification Tests can also be used to determine PEMS
performance, and as such, EPA's Performance Specification Tests are the primary basis used to
assess the ANR PEMS monitoring performance. EPA has prepared example specifications and
evaluation procedures for assessing PEMS performance (Emission Measurement Center, USEPA),
and these guidelines have been followed here.
EPA's Performance Specification Tests require the use EPA Reference Test Methods to collect
actual emissions data for comparison with PEMS values. The list below identifies the individual
Performance Specification Tests planned for use, and their accompanying Reference Test Method.
11
-------
Performance Specification Test 2 for NOx:
Performance Specification Test 3 for C02 & 02:
Reference Method 7E
Reference Method 3A
Reference Method 10A
Reference Method 25A
Performance Specification Test 4 for CO:
Performance Specification Test 8 for THC:
In general, PEMS emission predictions will be compared with EPA Reference Method values.
These comparisons will be made after PEMS and CEMS values are placed on a common basis
(e.g., common moisture and temperature), and after each have been carefully time-matched. To
facilitate time-matching, synchronization of the PEMS and EPA Reference Method data
acquisition clocks will be done daily, and sampling system lags associated with the Reference
Method Sampling Train response time will be measured and integrated into the time-matching.
Reference Method 19 will be used to relate measured gas concentrations to mass rates.
For each of the five gasses listed above, the parameter that will be used to represent the result of
the PEMS/Reference Method comparison is Relative Accuracy. Relative Accuracy will be
calculated in accordance with the four-step process outlined below.
First, calculate the arithmetic mean of the difference, d, for all runs conducted as in Equation 1
below:
d
Where:
n = number of runs
d, = difference between Reference Method and PEMS output for a run
12
-------
Second, calculate the standard deviation associated with all runs, Sd, as shown in Equation 2
below:
f ¦ b J
Sd - ^ n-n0 <2>
Third, calculate the 2.5 percent error confidence coefficient (one-tailed), cc, as shown in Equation 3
below:
§
s
CC t 0 .975 / ( ^ )
n
Where: to.975 = t-value (see Table 2).
TABLE 2: t-Values
n*
to.975
n*
to-975
n*
To* 975
2
12.706
7
2.447
12
2.201
3
4.303
8
2.365
13
2.179
4
3.182
9
2.306
14
2.160
5
2.776
10
2.262
15
2.145
6
2.571
11
2.228
16
2.131
The values in this table are already corrected for n-1 degrees of freedom. Use
n equal to the number of individual values.
And finally, fourth, calculate the Relative Accuracy, RA, for all runs as shown in Equation 4
below:
RA = \d + cc |]
100
I RM
(4)
13
-------
Where:
d = Absolute value of the mean differences (from Eq. 1)
\cc\ = Absolute value of the confidence coefficient (from Eq. 1)
RM = Average Reference Method value
Recall that engine speed and torque are primary determinants of engine emissions. Collection of
the emissions and other data needed to perform Relative Accuracy determinations will occur while
the engine operates under normal speed and torque conditions, and when it is in a we 11-tuned state.
Engine operators at the site will determine when these conditions are met, and thus, when Relative
Accuracy testing can begin. The test engine normally operates within a range of torque values of
between 75 to 100 percent of capacity. To achieve these torque values, engine speed (RPM) is
maintained in the range of 75 to 100 percent of maximum. Although the engine/compressor is
capable of operating with loads and speeds as low as 50 percent, operation at loads and/or speeds
of less than 70 percent occurs only during start-up or severe process interruption. This engine
operates at loads/speeds of 85 percent to 100 percent approximately 90 percent of its operating
time. The other ten percent of the time it operates at 70 percent to 85 percent of load/speed.
A series of normal operating conditions have been specified for the Relative Accuracy
determinations, and these are shown in the testing matrix presented in Table 3. The individual
speed/load values in the matrix are nominal values that will be attempted in the field, but slight
variations may occur as a result of compressor demand and other conditions occurring during
testing. A series of 3 runs will be conducted at each operating condition, and each run will occur
for a 21 to 30 minute period after stable emissions readings have been observed via the Reference
Method monitors.
Table 3. Relative Accuracy Test Matrix1
Nominal Engine Speed %
Nominal Engine Load (%)
50-75
75-90
90 - 100
50-75
Not normal
Not normal
Not normal
75-90
Not normal
3 runs
3 runs
90 - 100
Not normal
3 runs
3 runs
1 All runs will be a minimum of 15 minutes after stable operating conditions are attained.
14
-------
Emission data from the Reference Methods and the PEMS will be complied for C02, NOx, THC,
and CO, under the conditions above. Results and relative accuracys will be presented on both a
concentration basis (ppm or percent) and for the pollutants, on an emission factor basis (gram/brake
horsepower-hour). This will result in two sets of results with 12 results each.
In accordance with EPA Performance Specification Test procedures, a minimum of nine runs are
required for use in determining Relative Accuracy, so up to 3 may be removed (although all 12
may also be used). If any of the 12 runs are eliminated, it will be done to eliminate runs that
contain a high degree of poor or unexplainable quality data. In no case will all three runs from one
operating condition be eliminated. Runs exhibiting a high difference between the Reference
Method and PEMS emissions outputs may also be eliminated keeping with this often used practice
in Relative Accuracy Tests for CEMS. The individual runs selected may vary, depending on the
gas being evaluated, but results from all 12 runs will be provided in the final Verification Report.
Relative Accuracys that are 20 percent or less are generally considered acceptable for CEMS used
for regulatory purposes.
The procedures and instrumentation associated with the execution of specific Reference Methods
and other sampling tasks are described later in Section 5.
4.2. OPERATIONAL PERFORMANCE EVALUATIONS
Operational performance evaluations will be conducted to assess the PEMS ability to respond to
sensor drift, failure, and abnormal engine operating conditions. Both are discussed individually in
the following three sections. Data from these two evaluations can be used to assess how PEMS
outputs and alarms may be used to identify and diagnose engine/sensor operational problems.
4.2.1. PEMS Prediction Capabilities During Abnormal Engine Operation
In Section 4.1, procedures for evaluating the PEMS under normal engine operating conditions were
described. These conditions are where the engine operates most often, but mechanical engine
changes, changes in fuel properties, and changes in ambient conditions can change engine
performance and emissions relative to normal operation. To examine how the ANR PEMS
responds to off-normal engine operating conditions, a series of tests will be conducted while
physically perturbing key engine operating characteristics. According to ANR, the most significant
engine operating features impacting emissions are pollutant specific but from a general perspective,
15
-------
the most significant parameters, in approximate order, are: (1A) air manifold pressure, (IB)
exhaust manifold pressure, (2) ignition timing, (3) engine efficiency, (4) air manifold temperature,
(5) exhaust manifold temperature, and (6) relative humidity. The operating parameters planned for
perturbation include all those parameters above which can be physically perturbed on the engine.
This excludes ambient humidity, where perturbations can not be easily simulated, and exhaust gas
pressure and temperature, which can not be altered in a predictable manner. The parameters to be
varied, the physical methods planned to vary them, and the measurements planned for each
condition are summarized below.
Combustion air manifold temperature and pressure - Air manifold
temperatures will be varied by manually changing the temperature setting,
causing the engine to increase or decrease combustion air flow through the
heat exchanger (turbocharger jacket). Both high and low temperatures that are
close to the upper and lower air temperature alarm levels will be established,
and runs of 21 to 30 minute duration will be started once the conditions are
reached, and measured pollutant concentrations have become relatively stable,
manifold pressure changes will be accomplished by increasing and decreasing
combustion air flow.
Engine efficiency - Engine efficiency is a function calculated from: calculated
fuel consumption/actual fuel consumption. Overriding the engine computer
and manually changing the engine horsepower value will vary this operating
parameter. This will, in-turn, cause the engine to change fuel flow without a
true need for a fuel change (i.e., the actual demand on the engine is changed).
With the engine consuming non-optimal fuel, efficiency will be changed. By
increasing and decreasing the horsepower setting, efficiency will be raised to
an optimum level, and then reduced to a point where the engine efficiency or
some other related engine alarm occurs. Runs of 21 to 30 minute duration will
be started once each condition is reached, and measured pollutant
concentrations are relatively stable.
Ignition timing - Ignition timing will be manually adjusted to vary this
operating parameter. As above, values just short of upper and lower alarm
values will be established, and 21 to 30 minute runs will be conducted at both
conditions.
Depending on the engine torque and speed, emission changes occurring as a result of changes in
the operating parameters above may vary in their significance. Thus, the evaluations above will be
conducted under a number of different torque and speed conditions, resulting in the execution of 24
individual runs. Evaluation of off-normal operations will focus on those speed and torque operating
ranges that occur most often for the engine. A matrix summarizing the tests planned is presented
as Table 4. Guidelines for the establishment of low and high alarm conditions required for each
test are shown in Table 4a.
16
-------
The adequacy of the PEMS response to an off-normal condition will be determined by comparing
the concentration obtained from the Reference Method with the concentration obtained from
PEMS. The difference and percent difference between these two values will be presented in the
Verification Report.
Table 4. Off-Normal Engine Operating Conditions to be Tested1
Operational Parameter/Alarm Condition
Nominal Engine Speed/Torque (%)
100/100
75/100
100/75
Efficiency
High
X
X
X
Low
X
X
X
Ignition Timing
High
X
X
X
Low
X
X
X
Air Manifold Temperature
High
X
X
X
Low
X
X
X
Air Manifold Pressure
High
X
X
X
Low
X
X
X
Low
X
X
X
Low
X
X
X
X = 1 run. All runs will be a minimum of 15 minutes after stable conditions are attained.
Table 4a. Engine Sensor Alarm and Alert Levels
Alert
Alarm
Efficiency
High
105%
110%
Low
95%
90%
Ignition Deviation from
Set Point
0.5%
1.0%
Air Manifold Temperature
(Redundant Transmitter
Deviation)
2°F
4 °F
Air Manifold Pressure
Deviation from Set Point
0.3 psi
0.5 psi
Air Manifold Pressure
Redundant Transmitter
Deviation
0.2 psi
0.3 psi
17
-------
4.2.2. PEMS Response to Sensor Failure
This will be the first test conducted on-site to ensure the PEMS responds appropriately to changes
in engine sensor inputs. Objectives of this test are to demonstrate the performance of PEMS when
engine sensor failure occurs, and to document PEMS ability to identify potentially failed engine
sensors.
ANR has designed the PEMS to provide conservative emission predictions when sensor drift or
failure occurs. When failure occurs, and dual sensors are used to monitor the engine parameter, the
PEMS uses the sensor input that results in the highest predicted emission rate. If the predicted
emissions are higher than a pre-set emission level; usually the maximum permitted emissions for
the operating engine, the PEMS alarms. When sensor failure occurs, operators use the PEMS
alarm, if the alarm level has been reached and/or the sensor alarms on the engine control system, to
diagnose and resolve failed sensors. For engine parameters that do not have redundant sensors
(i.e., energy efficiency and ignition timing), erroneous readings from failed sensors can also result
in high emissions indications and alarms at some point within the failure period.
The performance of PEMS during engine sensor failure will be examined by verifying PEMS
responses to simulated sensor failures. To accomplish this, the PEMS emission predictions will be
documented while artificially (electronically) simulating engine sensor outputs that correspond to a
failed sensor. The process will start by establishing steady state engine operation at torque and
speed levels that are within 75 to 100 percent of maximum. The steady-state CEMS and PEMS
concentrations prior to sensor perturbation will then be recorded to establish comparability. Next,
sensor perturbation will be simulated by manually adjusting sensor output signals for each PEMS
sensor including: ignition timing, exhaust manifold pressure, engine efficiency (fuel flow related
sensors), air manifold temperature, and air manifold pressure. Sensors will be perturbed one at a
time, and each will be changed by slowly adjusting the sensor output signal until the transmitter
alarm level is reached. Throughout this perturbation period, the data below will be recorded.
Default or conservative emission value used by PEMS,
Perturbed sensor signal values,
All other sensor values,
PEMS concentrations and emission rates for all pollutants,
Alarm/alert conditions reported by the PEMS and engine computer, and
Reference Method concentrations and emission rates for all pollutants.
18
-------
These data will be used to verify how PEMS predictions change as sensors drift toward the alarm
level, and, if appropriate information is available for operators to identify a failed sensor condition.
The simultaneous CEMS data will allow a direct comparison of actual emissions with PEMS
emissions, and will demonstrate how the two values diverge as sensor failure approaches. The
entire procedure will be repeated for low- and high-level alarm regimes, and with all five sensors.
A total of 10 tests will be conducted with run durations of 21 to 30 minutes, or as needed to achieve
stable PEMS concentrations at multiple sensor settings (3 sensor setting or higher).
Finally, to assess the impact of multiple failed sensors, the procedure above will be repeated for
pairs of simulated sensor failures. Specifically, two sensors monitoring different engine parameters
(e.g., combustion air temperature and exhaust pressure) will be artificially perturbed to the sensor
alarm level. As above, the values listed earlier will be recorded, then the procedure will be
repeated for all combinations of sensor pairs and low/high alarm levels. This will result in the
execution of 20 individual runs.
4.2.3. Assessment of PEMS Diagnostic Capabilities
Data collected as described in the previous two sections (Sections 4.2.1 and 4.2.2) will be used to
assess how well PEMS provides diagnostic information that engine operators can use to identify
and rectify engine operating and sensor problems that may negatively impact emissions.
Section 4.2.1 described how data would be collected when actual engine malfunctions are
occurring. These data will be used to assess PEMS ability to warn of poor engine performance
and subsequent emission increases. For example, when efficiency perturbations are simulated by
increasing horsepower as described earlier, PEMS alerts and alarms for parameters such as
efficiency, fuel flow, and fuel temperature could be indicative of engine efficiency problems. The
occurrence of these alarms and alerts, and other indications that may assist in diagnosing engine
efficiency (e.g., other engine system data), will be recorded as described earlier, and will be
evaluated with the assistance of ANR engine operators. These data and findings will be
summarized in the final Verification Report, but any conclusions will be qualified, since the
methods chosen to perturb engine operation were chosen for convenience, and other perturbation
mechanisms could cause different PEMS alarm responses. For example, high humidity could
impact efficiency, just like the planned horsepower adjustment, but in this case, different PEMS or
engine alarms may occur.
19
-------
PEMS alarms and alerts recorded under the sensor failure analyses described in Section 4.2.1 will
be used to qualify how well PEMS alerts operators to the existence of failed sensors, or the
possibility that a sensor is drifting significantly.
5.0 FIELD TESTING PROCEDURES
5.1. OVERVIEW
The test procedure described in this section has been developed to provide the framework for
testing the ANR PEMS during both normal and off-normal engine operation. It is based upon EPA
Performance Specification Test guidelines for CEMS and the document "Example Specifications
and Test Procedures for Predictive Emission Monitoring Systems" provided by EPA's Emission
Measurement Center (Emission Measurement Center, 1999).
The test procedures to be utilized in this verification are Federal Reference Methods. Reference
Methods are well documented in the Code of Federal Regulations, include detailed procedures, and
generally address the elements listed below (40CFR60, Appendices A and B).
Applicability and principle
Range and sensitivity
Definitions
Measurement system performance specifications
Apparatus and reagents
Measurement system performance test procedures
Emission test procedure
Quality control procedures
Emission calculations
Bibliography
Each of the selected methods utilizing an instrumental measurement technique includes
performance-based specifications for the gas analyzer used. These performance criteria cover span,
calibration error, sampling system bias, zero drift, response time, interference response, and
calibration drift requirements.
An overview of each test method planned for use is presented in this section, with emphasis on the
type of monitors used, the monitor range, the sampling system configuration, and general
calibration plans. The entire method reference will not be repeated here, but will be available to site
20
-------
personnel during testing, and can be viewed in the Code of Federal Regulations (40CFR60,
Appendix A). Field log forms that will be used to conduct calibrations and other field activities are
presented in Appendix A. CEMS output formats and summaries are presented later in Section 5.3.
5.2. SAMPLE HANDLING AND TESTING METHODS
5.2.1. Sample conditioning and handling
A schematic of the sampling system to be used is presented as Figure 4. In order for some of the
instruments used to operate properly and reliably, the flue gas must be conditioned prior to
introduction into the analyzer. The gas conditioning system is designed to remove water vapor
and/or particulate from the sample. All interior surfaces of the gas conditioning system are made of
stainless steel, Teflon, or glass to avoid/minimize any reactions with the sample gas components.
Gas is extracted from the gas stream through a heated stainless steel probe, filter, and sample line
and transported to two ice bath condensers on each side of the sample pump. The condensers
remove moisture from the gas stream. The clean, dry sample is then transported to a flow
distribution manifold where sample flow to each analyzer is controlled. Calibration gasses can be
routed through this manifold to the sample probe by way of a Teflon line. This allows
calibration and bias checks to include all components of the sampling system. The distribution
manifold also routes calibration gasses directly to the analyzer when linearity checks are made on
each of the analyzers.
21
-------
Figure 4. Gas Sampling and Analysis System
The system response time between sample collection and actual monitoring (i.e., the system
response time) will be determined to ensure that a time-matched comparison of PEMS and CEMS
outputs are made. The sampling system response time will be measured at the beginning of field
testing. The procedure will include the following stepwise process: (1) initiate a flow of zero
concentration calibration gas at the probe and wait for steady-state readings to occur, (2) introduce
a high concentration calibration gas while simultaneously recording the start time, (3) record the
time at which the gas concentrations due to the step increase are at 95 percent of their expected
level, and (4) repeat the procedure going from high to zero and record the system response time as
the longer of the two.
22
-------
5.2.2. Calibrations
Calibrations will be conducted on all monitors using Protocol No. 1 calibration gasses. Protocol
No. 1 gasses comply with requirements for traceability to the National Institute of Standards and
Technology.
Each monitor will be calibrated with a zero concentration gas. In addition, each will be calibrated
with a suite of gasses, selected to cover the monitor operating ranges specified later in Section 5.
The NOx, C02, and 02 monitors will be calibrated with two additional gas concentrations each.
One concentration will be 40 percent to 60 percent of span and one will be 80 percent to 100
percent of span. Maximum and actual concentrations anticipated for the test engine can be found in
Section 3. The CO and THC monitors will be calibrated with three additional gas concentrations.
For CO, the concentrations will include one each at approximately 30 percent, 60 percent, and 90
percent of span. For THC methane will be used, consistent with the basis PEMS uses to report
THC. The calibration concentration ranges for THC includes the following: 25 to 35 percent, 45 to
55 percent, and 80 to 90 percent of span.
All monitor calibrations will be conducted daily, before sampling begins. Calibrations will start by
routing calibration gasses directly to each monitor, and then adjusting the monitors to read the
appropriate calibration gas values. After adjustments are made to the analyzers, a final linearity
test is conducted by introducing each gas to the analyzers and recording responses while making no
adjustments. Acceptable results are within two percent of span for each gas. Following this and
after each test run, zero concentration and mid-span gasses will be passed through the entire
sampling system, and the values that are measured will be recorded. Differences between the
initial calibration and these system calibrations will be used to determine system bias and drift
values for each run and analyzer drift over the duration of each run. These bias and drift values are
used to adjust CEMS concentrations after field operations are completed.
Regarding engine sensor calibrations, SRI will obtain for the report copies of the most recent
calibration records for all of these sensors.
5.2.3. Reference Method 3A - Determination of Oxygen & Carbon Dioxide Concentrations
For carbon dioxide and oxygen, a continuous sample will be extracted from the emission source
and passed through instrumental analyzers. For determination of C02 a Milton Roy 3300 non-
23
-------
dispersive infrared (NDIR) analyzer will be used. NDIR measures the amount infrared light that
passes through the sample gas versus a reference cell. As C02 absorbs light in the infrared region,
the light attenuation is proportional to the C02 concentration in the sample. Based on the site-
specific data contained in Section 3, the C02 monitor range will be set at or near 0 to 20 percent.
Oxygen will be analyzed using a Teledyne 320A fuel cell-analyzer. This analyzer uses electrolytic
concentration cells that contain a solid electrolyte to enhance electron flow to the 02 as it permeates
through the cell. The fuel-cell technology used by this instrument determines levels of 02 based on
partial pressures. The electrode is porous (zirconium oxide) and serves as an electrolyte and as a
catalyst. The sample side of the reaction has a lower partial pressure than the partial pressure in the
reference side. The current produced by the flow of electrons is directly proportional to the 02
concentration in the sample. Based on the site-specific data contained in Section 3, the 02 monitor
range will be set at or near 0 to 25 percent.
5.2.4. Reference Method 7E - Determination of Nitrogen Oxides Concentration
Nitrogen oxides will be determined on a continuous basis, utilizing a Thermo Environmental
Model 10S chemilumenescence analyzer. This analyzer catalytically reduces nitrogen oxides in the
sample gas to NO. The gas is then converted to excited N02 molecules by oxidation with 03
(normally generated by ultraviolet light.) The resulting N02 emits light ("lumenesces") in the
infrared region. The emitted light is measured by an infrared detector and reported as NOx. The
intensity of the emitted energy from the excited N02 is proportional to the concentration of N02 in
the sample. The efficiency of the catalytic converter in making the changes in chemical state for
the various nitrogen oxides is checked as an element of instrument set up and checkout.
Based on the site-specific data contained in Section 3, the NOx monitor range will be set at or near
the 0 to 500 ppm range.
5.2.5. Reference Method 10A - Determination of Carbon Monoxide Concentration
For Reference Method 10A, a Thermo Environmental Model 48 gas filter correlation analyzer
utilizing an optical filter arrangement will be used. This method provides high specificity for CO.
Gas filter correlation utilizes a constantly rotating filter with two separate 180-degree sections
(much like a pinwheel.) One section of the filter contains a known concentration of CO, and the
other section contains an inert gas without CO. The sample gas is passed through the sample
24
-------
chamber containing a light beam in the region absorbed by CO. The sample is then measured for
CO absorption with and without the CO filter in the light path. These two values are "correlated",
based upon the known concentrations of CO in the filter, to determine the concentration of CO in
the sample gas.
Based on the site-specific data contained in Section 3, the CO monitor range will be set at or near
the 0 to 2,500-ppm range.
5.2.6. Reference Method 25A - Determination of Total Gasseous Organic Concentration
Total hydrocarbons vapors in the exhaust gas will be measured using a JUM Model VE-7 flame
ionization analyzer. This method passes the sample through a hydrogen flame. The intensity of the
resulting ionization is amplified and measured and then converted to a signal proportional to the
concentration of hydrocarbons in the sample. Unlike the other methods, the sample stream going to
the JUM analyzer does not pass through the condenser system, so it can be kept heated until it is
analyzed. This is necessary to avoid loss of the less volatile hydrocarbons in the gas sample.
Because all combustible hydrocarbons are being analyzed and reported, the emission value must be
calculated to some base (methane or propane). The calibration gas for THC will be either methane
or propane; which ever is consistent with the basis on which PEMS reports THC values.
Based on the site-specific data contained in Section 3, the THC monitor range will be set at or near
the 0 to 1,000 ppm range (as methane).
5.2.7. Reference Method 19 - Determination of Emission Rates
Method 19 provides procedures for converting concentration values of various flue gasses to
emission rate values. This is accomplished by determining the flow rate of the flue gas and then
calculating the emission rate from the concentration and volume data. The fundamental principle of
this method is based upon "F factors". F factors are the ratio of combustion gas volume to the heat
content of the fuel. F factors are calculated as a volume/heat input value, (e.g., standard cubic feet
per million Btu). This method applies only to combustion sources for which the heating value for
the fuel can be determined. The F factor can be calculated from either C02 or 02 values, on either a
wet or dry basis, as dictated by the measurement conditions for the gas concentration
determinations. This method includes all calculations required to compute the F factors and
guidelines on their use. The F factor for natural gas will be calculated from ANR supplied pipeline
25
-------
gas quality measurements (elemental analyses and heat contents). ANR monitors pipeline gas
quality and heat content daily using a calibrated gas chromatograph.
Two sets of emission rates will be determined based on pollutant concentration values supplied by
both the PEMS and CEMS. Other parameters include "F factors" determined from the flue gas
composition and ANR supplied fuel quality data, fuel flow measured by ANR's fuel flow
monitoring system (pressure and temperature based), and calculated engine brake horsepower
(calculated by ANR from engine speed and torque readings). The step-by-step calculations
involved are listed below.
Step 1. Calculate pounds of pollutant per million BTU of heat input.
Lb/Mbtu = concentration from CEMS or PEMS converted to mass basis using molecular weights
(Lb/scf) x f-factor from above (scf/Mbtu)
Step 2. Calculate the engine heat consumption rate in million BTU per hour.
Mbtu/hr = fuel rate determined from AGA-3 flow meter and temperature gauge (cfh) x fuel heating
value (Mbtu/ft3)
Step 3. Calculate the pounds per hour of pollutant.
Lb/hr = Lb/Mbtu (from step 1) x Mbtu/hr (from step 2)
Step 4. Calculate the grams per brake horsepower hour (bhp-hr) using ANR supplied bhp values,
gm/bhp-hr = Lb/hr (Step 3) x 453.59 gms/Lb = gm/hr III gm/hr / bhp = gm/bhp-hr
5.3. DATA ACQUISITION
Output from each of the instruments will be transmitted to a personal computer-based data
acquisition system. This system receives signals from all of the instruments every two seconds, and
time integrates those values over a pre-specified averaging period. During all tests, a 30-second
averaging period will be used for each monitored parameter, and these values will be stored for
later analysis and reporting purposes. Average values will also be determined over the time
associated with each run, and these values will be stored and used to determine run-average
emissions for Relative Accuracy and other determinations. Excel spreadsheets will be used to
calculate calibration results, and make corrections to the data for calibration, system bias, and drift
values.
Data will also be collected on engine performance parameters, and these data will be provided by
ANR's data acquisition system. These data will be needed to calculate some verification
parameters, identify alarm/alert conditions, and interpret verification results. Data will be
26
-------
recorded at 30-second intervals, and the specific parameters collected and stored are described in
Section 3.
6.0 DATA VALIDATION AND QUALITY
6.1. DATA VALIDATION
Calibrations and quality control checks for each measurement were presented in Section 5. Upon
review, all data collected will be classified as valid, suspect, or invalid. In general, valid results are
based on measurements that meet data quality goals, and that were collected when an instrument
was verified as being properly calibrated.
Often anomalous data are identified in the process of data review. All outlying or unusual values
will be investigated daily in the field using test records, test crew and engine operator interviews,
and log forms. Anomalous data may be considered suspect if no specific operational cause to
invalidate the data are found. All data, valid, invalid, and suspect will be included in the final
report. However, report conclusions will be based on valid data only. The reasons for excluding
any data will be justified in the report. Suspect data may be included in the analyses, but may be
given special treatment as specifically indicated.
All engine sensor and CEMS data will be reviewed on a daily basis including those listed below.
Run average comparison of CEMS and PEMS data for agreement based on
arithmetic mean, standard deviation, and Relative Accuracy for each measured
parameter
Daily CEMS calibration results and run-specific zero and mid-span calibration
results
6.2. DATA QUALITY
As a consequence of using EPA Reference Methods to verify PEMS performance, measurement
methodologies and data quality determinations are defined. In past verifications conducted by the
Center and EPA's Office of Research and Development, measurement methodologies have been
selected to ensure that desired level of data quality occurs in the final results. Since sampling
27
-------
methods, calibration methods, and data quality checks are clearly specified in the Reference
Methods, the Center's ability to change these strategies and adjust data quality is limited.
Reference Method procedures ensure that run-specific quantification of instrument and sampling
system drift and bias occurs, and that runs are repeated if specific performance goals are not met.
Furthermore, the Methods require adjustments be made to all measured concentrations based on
run-specific measurements of instrument and sampling system response to calibration checks.
Normally, measurements of these data quality indicators would be used to quantify the data quality
achieved during testing, but in this case, these data are used to adjust measured values to ensure the
highest possible representativeness and quality exists in the final results. Given this, the Relative
Accuracy and other determinations conducted here are considered to be of acceptable quality if all
Reference Method calibrations, performance checks, and concentration corrections specified in the
Reference Methods have been successfully conducted. As such, the Data Quality Objective for all
runs is to ensure that this has occurred. Evidence of the successful execution of these requirements
will be documented in the Verification Report, along with run- and pollutant-specific calibration
results.
Specific data quality indicators are discussed below including indicators for completeness,
precision, and bias. These apply to all of the verification parameters that will be assessed.
A summary of the data quality indicator goals is shown in Table 5.
1. Completeness will be 100 percent for the Relative Accuracy determinations. This means that
data will be collected, which meets the DQO above, for all 12 runs identified earlier in the
Relative Accuracy test matrix (Table 3). The completeness goal for the off-normal engine
operating tests identified in Table 4 will be 85 percent. This goal is lower than 100 percent to
account for potential difficulties that may occur in (1) establishing abnormal engine operating
conditions planned for this series of tests, and (2) measuring potentially large and dynamic
pollutant concentration profiles in a manner that meets the DQO. Finally, the completeness
goal for the sensor drift tests is 100 percent, which means that all runs will be conducted, as
outlined in 4.2.2, that meet the DQO above.
2. System accuracy or bias assessments will be conducted at the beginning of each day using the
protocols defined in each Reference Method. This will be accomplished by routing a suite of
calibration gasses, described earlier in Section 5, directly into each monitor. For each
calibration gas concentration examined, a data quality indicator goal of ± 2 percent of the
analyzer span value will be used for 02, C02, NOx, and CO. A goal of ± 5 percent of the
calibration gas value will be used for THC. Daily accuracy values determined from these
evaluations will be reported in the final Verification Report to document the Center's ability to
achieve the accuracy indicator goals specified above. These accuracys will be determined in
28
-------
the field, and if deviations from the goals are observed, sampling will be halted by the Center
until corrective action is taken.
3. System precision or bias will be determined for the combined sampling system and analyzer at
the beginning and end of each run using the protocols defined in each Reference Method. This
will be accomplished by routing zero concentration and mid-span gasses, described earlier in
Section 5, through the sample collection lines and monitor systems, and comparing the
measured concentrations with the certified calibration values. System bias, determined in this
manner, will be measured before and after each run to determine if the run is acceptable for
use. A drift of greater than ± 3 percent of analyzer span (difference between the before or after
system bias) will be considered unacceptable, and the run will be repeated. If a drift of less
than 3 percent occurs, which is the data quality indicator goal for precision, the average of the
before and after system bias values will be used to correct the measured concentrations in each
of the Methods. All system bias values and calculated drift values will be reported in the final
Verification Report on a run-specific and gas specific basis as a means to document that this
data quality indicator goal has been achieved.
Table 5. Data Quality Indicator Goals
Data Quality
Indicator
Type of Verification Test
Relative Accuracy
Off-Normal Engine
Sensor-Failure
Completeness
100%
85%
100%
Precision
Drift < ± 3% of span
Drift < ± 3% of
span
Drift < ± 3% of span
Accuracy
± 2% of span3
± 5% of cal. conc.b
± 2% of span3
± 5% of cal. conc.b
± 2% of span3
± 5% of cal. conc.b
a. 02, C02, NOx, and CO
7.0 VERIFICATION REPORT
7.1. OVERVIEW
A draft Verification Report will be prepared within 6 weeks of completing the field work. This
report will be submitted first to ANR for review, and after modifications are made, will be
submitted simultaneously to three Oil and Gas Industry Stakeholder Group representatives and the
USEPA Quality Assurance Team.
The final Verification Report will contain a Verification Statement, which is a 3 to 4 page summary
of the PEMS system, the test strategy used, and the verification results obtained. When the final
draft is prepared, officials from USEPA's Office of Research and Development and the GHG
29
-------
Center will sign the Verification Statement. The Verification Report will summarize the results
obtained from the verification test, and will contain sufficient raw data to support findings and
allow others to assess data trends, completeness, and quality. Clear statements will be provided
which characterize the performance of the PEMS on the seven verification parameters identified
earlier in Section 4.
7.2. PRELIMINARY VERIFICATION REPORT OUTLINE
Verification Statement
Section 1: Verification Test Design and Description
Description of the ETV program
PEMS system and site description
Overview of the verification parameters and evaluation strategies
Sampling and analytical procedure overview
Quality assurance and quality control results
Section 2: Verification Results and Evaluation
Relative accuracy determinations
Operational performance determinations
Other performance related findings
Data quality assessment
Section 3: Additional Technical and Performance Data (optional) supplied by ANR Pipeline
Company
References
Appendices: Raw Verification and Other Data
8.0 PROJECT ORGANIZATION AND SCHEDULE
8.1. ORGANIZATION
This Section defines project organization and key responsibilities for different organizations. The
project team organization chart is presented in Figure 5. This chart identifies the functions,
responsibilities, and lines of communication between the organizations and individuals associated
with this verification test.
Southern Research Institute's Greenhouse Gas Technology Verification Center has overall
responsibility for planning and ensuring the successful implementation of this verification test.
ANR Pipeline Company is providing the PEMS technology in working order, and is providing the
30
-------
engine/compressor system at which all testing will be conducted. EPA's APPCD is the sponsor of
this ETV Greenhouse Gas Pilot and is providing broad oversight and QA support for this
verification. ANR is using a contractor, Mechanical Equipment Company of El Paso, Texas, to
conduct the on-site monitoring needed to install and parameterize the PEMS. The Center is
contracting with an independent testing company, Kilkelly Environmental Associates (KEA) of
Raleigh, North Carolina, to provide on-site monitoring services for the verification.
ANR and the Center have signed a formal agreement (documented in the Letter of Commitment
and associated documents) specifying details of financial, technical, and managerial
responsibilities. These details are not repeated here.
Should a situation arise during the test that could affect the health or safety of any personnel, Brian
Phillips (Field Test Leader), after consultation with the Center's on-site CEM Expert, Bill
Chatterton, will have full authority to suspend testing.
8.2. SCHEDULE
Figure 6 presents the schedule of activities for verification testing of the ANR PEMS. Activities
prior to the date of this plan have been completed in conformance with this schedule, and
significant delays are not anticipated in completion of the remaining activities. The draft of the
Verification Report is scheduled for completion and review by mid-August. The finalized report
and Verification Statement will be ready for distribution by the end of September.
The July 12 start of test to be done before end of July target is significant, so as to avoid the late
summer months. As ambient temperatures become higher, the engine will be limited in its ability to
achieve full load operation. This is because internal combustion engines lose operating efficiency
as ambient air temperature and moisture rises in the late summer months.
31
-------
Figure 5. Project Organization
ANR and the Center will coordinate field activities such that KEA and ANR's contractor are
together on-site for 1 day before testing begins. During this time simultaneous calibrations will be
conducted by both firms to demonstrate comparability. SRI is coordinating with ANR to schedule
verification testing of the PEMS immediately after its installation is complete.
Although not expected, delays may occur for various reasons, including mechanical failures at the
site, weather, significant changes in gas demand on the pipeline, and operational issues. Should
significant delays occur, the schedule will be updated and all participants will be notified.
9.0 HEALTH AND SAFETY PLAN
This Section applies to Center personnel only. Other organizations involved in the project have
their own health and safety plans specific to their roles in the project.
Since the site is part of a pipeline facility, ANR's safety policies are regulated, in part by the US
Department of Transportation. The Center previously provided a similar scope of work to a
professional DOT compliance management company (National Compliance Services). Their
assessment was that the Center's on-site job function is not covered by the Research and Special
32
-------
Programs Administration, DOT Pipeline Safety Regulations requirements in 49CFR Parts 192,
193, and 195. If the scope of work changes, this determination will be re-evaluated.
SRI staff will comply with all ANR, state, local, and Federal regulations relating to safety at
ANR's compressor station. This includes use of personal protective gear (e.g., flame resistant
clothing, safety glasses, hearing protection, safety toe shoes) as required and completion of site
safety orientation (e.g., site hazard awareness, alarms and signals).
Other than normal industrial hazards, the most significant hazard at this ANR station is the
potential for explosive concentrations of natural gas. If any measurements are required inside the
compressor building or any other location where hazardous levels of natural gas might accumulate,
Center personnel will only use intrinsically safe apparatus. Where use of equipment not so rated is
required, Center staff will not use this equipment until the area has been evaluated for gas
concentration and ANR site personnel advise that it is safe to do so.
33
-------
\D_
1
~~2
~3~
4
5
6
7
8
9
TF
17
12
77
77
75
16
17
uary February March April May
Task Name
1/10 1/24 2/7 2/21 3/7 3/21 4/4 4/18 5/2 5/16 5/30 6/13 6/27 7/11 7/25 8/8 8/22 9/5 9/19
June July
August September
C02 PEMS Evaluation
Site selection and strategy
Test Plan Development/Review
Develop test plan
ANR review
Peer/EPA QA review
Field Testing/Data Reduction
Pre-test site survey
Test mobilization
PEMS set-up
Field evaluation/data reduction
Verification Report & Statement
Data analysis/verification
Draft development
ANR review
EPA QA and peer review
Final development
]
¦
¦ ¦
IZZh
Figure 6.0 Project Schedule
34
-------
10.0 BIBLIOGRAPHY
Buchop, Thomas Robert, et al. "Parametric Emissions Monitoring System Having Operating
Condition Deviation Feedback." United States Patent Number 5,703,777. United States Patent
Office. Washington, DC. December 30, 1997.
Code of Federal Regulations, Title 40, Part 60 (Appendices A and B). United States
Environmental Protection Agency. Washington, DC. 1999.
Code of Federal Regulations, Title 40, Parts 64 (Appendix C) and 75 (Appendix E). United States
Environmental Protection Agency. Washington, DC. 1999.
Collins, W. Michael and Keith B. Terhune. "A Model Solution for Tracking Pollution".
Environmental Engineering Supplement, Chemical Engineering. McGraw-Hill, Inc., New York,
NY. June, 1994.
"Example Specifications and Test Procedures for Predictive Emission Monitoring Systems."
Emission Measurement Center. United States Environmental Protection Agency. Research
Triangle Park, NC. 1999. Document can be obtained from the following Internet location
www. epa. gov/ttn/emc/cem .html.
35
-------
APPENDIX A
Field Data Log Forms
and
Data Acquisition System Outputs
36
-------
FIELD DATA
LOG FORMS
37
-------
PEMS INSTALLATION/SET-IJP CHECKIJST
Completed by:
Date:
Complete
Y/N/na
ACTIVITY/ITEM
REMARKS
(if needed, continue on reverse side by item #)
Software installation and
checkout completed
Verify critical sensors - number,
model
Sensor input present on engine
computer, correct range
Verify and document engine I.D.
Verify PEMS printouts available
and include identification of
engine, date, time, all emission
values, and alarms
NOTES:
38
-------
TESTING SET-TJP/PREPARATTON CHECKIJST
Completed by:
Date:
Complete
Y/N/na
ACTIVITY/ITEM
REMARKS
(if needed, continue on reverse side by item #)
Identify test team participants and
team leader
Identify contact person for PEMS
and engine operation
Identify test team CEMS system
- model, serial number, wet or
dry basis
Identify operating range and
calibration gasses - contents,
concentrations, cylinder s/n
calibration certificate
Verify interference tests
documented or completed
Verify and document results of
NO2 to NO conversion test
Verify DAS printout is complete
Verify stratification testing and
document results
Verify integrity of the sampling
system, multi-point sampling, and
document location of calibration
gas injection
Document system leak check
NOTES:
39
-------
TESTING SET-TJP/PREPARATTON CHECKIJST
(con't)
Complete
Y/N/na
ACTIVITY/ITEM
REMARKS
(if needed, continue on reverse side by item #)
Document system response times
Manually check DAS calculations
Document any data points
requiring manual data collection
and transfer list to "Test Run
Observation Checklist"
NOTES:
40
-------
TEST RUN OBSERVATION CHECKLIST
(Note: Complete a checklist for each test run)
Completed by:
Date:
Complete
Y/N/na
ACTIVITY/ITEM
REMARKS
(if needed, continue on reverse side by item #)
Document planned test conditions
(from test matrix)
Pre-test calibrations on CEMS
completed? Documented?
Atmospheric conditions
Temperature Barometric
Press. RH
Wind speed/direction /
Start time for test run
Test Start
Document actual test conditions
Verify PEMS and CEMS are
collecting required data points
Verify all manually collected data
are documented
End time for test run
Test end
Post-test calibration of CEMS
completed
Bias determined and applied to data
NOTES:
41
-------
TEST RUN OBSERVATION CHECKLIST
(con't)
Complete
Y/N/na
ACTIVITY/ITEM
REMARKS
(if needed, continue on reverse side by item #)
Copy of CEMS test run data obtained
Verify completeness
Copy of PEMS test run data obtained
Verify completeness
Document all anomalies and
unexpected events/conditions
DAS output obtained?
Obtain gas composition data from
ANR?
NOTES:
42
-------
SAMPLE
REFERENCE METHOD
DATA ACQUISITION SYSTEM
OUTPUTS
43
-------
P L AN T N A M E
U N IT #
L O C A T IO N
DA T E
"run#
START
TIME
END
TIME
R
p p m d NO
EFERENCE METHOD
; : lb NOx/
x .. % w C O 2 f ill ill B tu
C O N T IN U
p p m d NOx.
O U S M O
% w C O 2
N IT O R IN G
; lb N O x /
m m B tu
p p m d NO
DIFFERENCE
x r % w C O 2 /
lb NOx/
m m B tu
1
0:0 0
0:3 0
2 6 8.8 0
: 1 3.2 8 0.4 3 5
2 6 5.0 5 :
1 3 .0 8
T 0.436
3.7 5
: 0.20 ;
-0.0 0 1
2 *
1 2 :0 1
1 2:3 1 '
2 7 4 .2 3
13.34 : ' 0 .4 4 2
2 6 4 .4 5 ;
1 3 .0 5
Y" 0 .4 3 6
9 .7 8
. .. ^ 9 -
0.006
3
12:4"
13:17
2 7 9 .6 3
T" 13.21 0.4 55
2 6 1.9 0
1 3 .0 3
0.4 3 2
r'7".7 3
O". 1 8
0.0 2 3
4""
13 :3 0
14 :0 0
2 7 5.2 1
1 3^3 5 0 .4 4 3
2 6 4.5 0
1 3 .0 3
i ' 0 .4 3 6
1 0 .7 1
0.32
0.007
5
1 4:15
14 :4 5
2 7 2.0 2
1 3 .2 7 ; "" 0.441
2 6 2.8 5
1 2.9 7
0 .4 3 6
9.1"
0.3 0 :
0.005
6
1 5:0 0
1 5 :3 0
2 7 2.5 8
1 3 ".2 7 T 0.4 4 1
2 5 9.7 5 ;
1 3 .0 3
: 0.4 2 8
1 2.8 3
1 0.24 '
0.0 1 3
7
15 :4 5
16 :1 5
2 6 8.3 4
13^2 5 0 .4 3 5
2 5 3.4 0
1 2 .9 4
0 . 4 2 1
1 4 .9 4
0 .3 1
0.0 14
8
16:30
17:0 0
2 7 1 .5 2
13.28 V 0.439
2 5 4.5 0
1 2.9 4
0 .4 2 3
17 .0 2
1 0.34 r
0.0 16
.1.
9
10
17 :3 0
1 8 :0 0
2 6 8 .6 1
13.28 ! 0.435
2 5 2.7 5 :
1 2^9 9
; 0.4 1 8
15 .8 6
: 0.29
0.0 17
-
11
1 2
T e
t Mean:
2 7 2.3 3
1 3.2 8 0.4 4 1
2 5 9.9 1
1 3 .0 1
0.430
NOx Conversion Factor:
F c - F a c to r:
1 .1 9 4 E -0
18 0 0
7 ;lb NOx / SCF - ppmNOx
S C F / mmBtu
S T
MEAN D
AND A R D
IFFERENCE:
D E V IA T IO N :
1 2 .4 2
"4 .5 2
T" 0.2 7
; 0.06 '
0 .0 1
0 .0 1
C O N F ID E N C E C
OEF FICIENT:
3' . 4 7
| 0.0 4 :
0 .0 1
Bias Adjustment Factor =
(1
+ d / C EM
)
R E L AT IV E A C
C U R A C Y (% ):
5.8 4
II 2,9
3.8 1
WHERE:
d = Mean of the Differences
CEM = Mean ofthe Source Monitor's
DataValues
B IA S A D
JUSTME
N T F ACTOR:
rT -VALUE:
1.026
2 .3 0 6
* Runnotincluded in Re la tiv e Accuracy Calcula tio n s
44
-------
Reference Method Values Corrected for Bias & Drift
PLANT NAME
UNIT#
RUN #
START TIME
END TIME
DATE:
CAL GAS VALUE
INITIAL CAL
FINAL CAL
AVERAGE CAL
0.00
ppm S02
4.15
2.69
3.42
443.00
ppm S02
435.41
439.80
437.61
0.00
ppm NOx
1.22
0.73
0.98
463.60
ppm NOx
437.36
439.80
438.58
0.00
%02
0.18
0.43
0.31
12.12
%02
12.15
12.27
12.21
0.00
% C02
0.15
-0.05
0.05
1 1.50
% C02
1 1.38
1 1.48
1 1.43
Raw Data:
223.1 1
ppm S02
257.27
ppm NOx
6.41
% 02
13.19
% C02
o
o
o
o
% H20
CORRECTED VALUES: 224.15 ppmw S02
271.52 ppmw NOx
13.28 %w C02
0.439 lb NOx / mmBtu
6.22 %d 02
13.28 %d C02
CONVERSION FACTORS:
NOx = 1.1 94E-07 lb NOx / SCF - ppm NOx
Fc - FACTOR = 1 8 00 SCF / mmBtu
SAMPLE CALCULATIONS:
CORRECTED VALUES = Cma * (C - Co) / (Cm - Co)
WHERE: C = MEAN REFERENCE MEASUREMENT
Co = MEAN ZERO CALIBRATION RESPONSE
Cm = MEAN MID OR UPSCALE CALIBRATION RESPONSE
Cma = ACTUAL MID OR UPSCALE CAL GAS CONCENTRATION
EMISSION RATE = (ppm)(Conversion Factor)(Fc-Factor)(100 / % C02)
45
-------
System Bias & Drift Calculations
PLANT NAME
UNIT #
RUN #
START TIME
END TIME
DATE:
ANALYZER SPAN:
1000.00 ppm S02
1000.00 ppm NOx
25.00 % 02
20.00 % C02
INITIAL
FINAL
i VALUE
CAL ERROR
CAL ERROR
SYSTEM BIAS CHECK
SYSTEM BIAS CHECK
DRIFT
RESPONSE
( % OF SPAN )
RESPONSE
(% BIAS)
RESPONSE
(% BIAS)
(% OF SPAN)
ppm S02
1.10
-0.11
4.15
0.31
2.69
0.16
-0.15
ppm S02
451.53
-0.85
435.41
-1.61
439.80
-1.17
0.44
ppm S02
956.04
0.01
ppm NOx
0.73
-0.07
1.22
0.05
0.73
0.00
-0.05
ppm NOx
468.13
-0.45
437.36
-3.08
439.80
-2.83
0.24
ppm NOx
860.81
0.00
% 02
-0.18
0.72
0.18
1.44
0.43
2.44
1.00
% 02
12.15
-0.12
12.15
0.00
12.27
0.48
0.48
% 02
20.70
-0.24
% C02
0.05
-0.25
0.15
0.50
-0.05
-0.50
-1.00
% C02
11.67
-0.85
11.38
-1.45
11.48
-0.95
0.50
% C02
17.53
-0.15
ION ERROR = (( R-A ) / S ) * 100
R = CALIBRATION GAS VALUE
A = REFERENCE ANALYZER RESPONSE
S = ANALYZER SPAN VALUE
YSTEM BIAS = (( C - A ) / S ) * 100
C = SYSTEM CAL RESPONSE
A = ANALYZER CAL RESPONSE
S = ANALYZER SPAN VALUE
DRIFT = (( Cf - Ci ) / S ) * 100
Cf = FINAL SYSTEM CAL RESPONSE
Ci = INITIAL SYSTEM CAL RESPONSE
S = ANALYZER SPAN VALUE
46
-------
Volumetric Flow Rate Determination
PLANT NAME
UNIT #
RUN #
START TIME
END TIME
DATE
TEST DATA
Test
Delta P
Temperature
Stack Diameter (D)
367.00
Pnint
(in HTi)
0>S F)
Stack Area (A)
105,784
A-l
0.530
126
Barometric Pressure (Pbar)
29.70
A-2
0.520
126
Static Pressure (Pg)
-0.480
A-3
0.530
127
Percent 02 (% 02)
6.22
A-4
0.490
129
Percent C02 (% C02)
13.28
A-5
0.530
128
Percent Nitrogen (% N2)
80.50
A-6
0.520
128
Pitot Tube Coefficient (Cp)
0.84
A-l
0.500
123
Meter Box Delta H (dH)
1.94
A-8
0.450
125
Meter Box Factor (Y)
0.9800
B-l
0.530
128
Average Meter Temp. (Tm)
67.300
B-2
0.530
129
Gas Meter Volume (Vm)
23.838
B-3
0.520
128
Impinger (V^
62
B-4
0.470
125
Silica Gel (W)
3.6
B-5
0.540
125
B-6
0.520
125
B-7
0.510
125
Root Mean Sq. Delta P (Pavg)
0.5077
B-8
0.440
125
Mean Stack Temperature (Ts)
126.38
MAX.
0.540
129
MIN.
0.440
123
. 02
. C02
. N2
CALCULATIONS
Vm(std) = (Vm)(Y)(17.64((Pbar)/(Tm + 460))
Vm(std) =
23.211
dscf
Vwc(std) = (V)(. 04707)+ (W)(. 04715)
Vwc(std) =
3.0834
cubic ft.
% H20 = [Vwc(std) / (Vwc(std) + Vm(std))] x 100
% H20 =
11.726
% H20
Mfd = 1 - (%H20 / 100)
Mfd =
0.883
Ps = Pbar + (Pg / 13.6)
Ps =
29.665
in. Hg
Md = 0.44(% C02) + 0.32(% 02) + 0.28(% N2)
Md =
30.374
lb/lb-mole
Ms = (Md)(Mfd)+ 0.18(% H20)
Ms =
28.931
lb/lb-mole
Vs = 85.49 (Cp) x SQRT[(Pavg)(Ts + 460) / (Ps)(Ms)]
Vs =
42.29
ft/sec
Qsd = (60 / 144)(Mfd)(Vs)(A)(Ps / Pstd)(Tstd / (Ts + 460))
Qsd =
1.469E+ 06
DSCFM
Qs = (3600 / 144)(Vs)(A)(Ps / Pstd)(Tstd / (Ts + 460))
Qs =
9.985E+ 07
SCFH
Qaw = (60 / 144)(Vs)(A)
Qaw
1.864E+ 06
ACFM
1664.1
Kscfm
47
-------
ENGINE SYSTEM
DATA ACQUISITION SYSTEM
OUTPUTS
48
-------
NO*
ppm
2B00FS
CO
[;cm
THC
fifim
O
V= CO!
PtMS «Ox
gn'UHP hr
FI-fr'SND*
Iwhr
H
PEMSCO
gp'BH F-J'r
0.00
O.OO
isao.DD
tigs
5T2
PEWS CD
Ibs^hr
PEWS THC
gr/BHf'-hr
PEUS THC
Ifca'ir
AIR Flin
nrviATION
PSI
Right Rsnk.
Air Man.
PSI
L«R Hank
Air Man.
F£l
Righ: Bans*
Air Men.
r
Lefl bSank:
Air IVtei'*
F
-0.21
19,71
19.74
11T.7
117.2
Fuel
DP 01
in H20
Fjet
DP 02
in H20
Fad
Flaw
MSCFjWR
Ermine
Fue Effic
u*
Ejt". Tamp.
Stand. LWv
¦'F
bngine
Spewl
RPM
rrrwjlns
Power
B"HP
EAJ1»;
Torque
%
7S.99
75.81
43.37
100.0
ir.4
344
SM.7
39.43,
RELm-VE
HLJMIDI'fY
AWblEMT
TTFvlf'.
t"
b&w&K*
Ptt RM «CK-
rr
r
jr?eiiP-hr
r t
:
¦ FHA WC '"
U-Hfe AMP
49
------- |