United States Office of Air Quality
Environmental Protection Rannfng and Standards
Agency Research Triangle Park, NC 27711
Air
EMB Report 93-UTL-3
May 1003
Electric Utility
Gas Fired Boiler
Emission Test Report
Houston Lighting and Power Company
Greens Bayou Unit - 5
Houston, Texas
^5r22^V
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GAS-FIRED BOILER EMISSION TEST REPORT
HOUSTON LIGHTING AND POWER COMPANY
GREENS BAYOU UNIT 5
HOUSTON, TEXAS
EPA Contract No. 68D20163
Work Assignment No. 1-34
Prepared by:
Research Division
Entropy, Inc.
Post Office Box 12291
Research Triangle Park, North Carolina 27709
Prepared for:
Lori Lay
U. S. Environmental Protection Agency
Emissions Measurement Branch
Research Triangle Park, North Carolina 27711
May 27, 1994
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DISCLAIMER
This document was prepared by Entropy, Inc. under EPA Contract No.
68D20163, Work Assignment No. 1-34. This document has not been reviewed by
the U. S. Environmental Protection Agency.
The opinions, conclusions, and recommendations expressed herein are
those of the authors, and do not necessarily represent those of EPA.
Mention of specific trade names or products within this report does not
constitute endorsement by EPA or Entropy, Inc.
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TABLE OF CONTENTS
1.0 INTRODUCTION 1
1.1 BACKGROUND 1
1.2 DESCRIPTION OF THE PROJECT 1
1.3 PROJECT ORGANIZATION 3
2.0 PROCESS DESCRIPTION AND SAMPLE POINT LOCATIONS 4
2.1 FACILITY DESCRIPTION 4
2.2 AIR POLLUTION CONTROL DEVICES 5
2.2.1 Nitrogen Oxide (NOJ Control 5
2.2.2 Sulfur Dioxide (S02) Control 5
2.2.3 Particulate Control 5
2.3 SAMPLE POINT LOCATION, UNIT 5 EXHAUST STACK 7
3.0 SUMMARY AND DISCUSSION OF RESULTS 9
3.1 OBJECTIVES AND TEST MATRIX 9
3.2 FIELD TEST CHANGES AND PROBLEMS 10
3.3 SUMMARY OF RESULTS 11
3.3.1 FTIR Results 11
3.3.1.1 Gas Phase Results 11
3.3.1.2 Sample Concentration Results 12
3.3.2 Instrumental and Manual Test Results 26
3.3.3 Process Results 31
3.3.3.1 Operating Conditions 31
3.3.3.2 Problems and/or Variations During Testing . . 31
4.0 SAMPLING AND ANALYTICAL PROCEDURES 39
4.1 EXTRACTIVE SYSTEM FOR DIRECT GAS PHASE ANALYSIS 39
4.1.1 Sampling System 39
4.1.2 Analytical System 40
4.1.3 Sample Collection Procedure . 40
4.2 SAMPLE CONCENTRATION 43
4.2.1 Sampling System 43
4.2.2 Analytical System 43
4.2.3 Sample Collection Procedure 45
4.3 CONTINUOUS EMISSIONS MONITORING 45
4.4 FLOW DETERMINATIONS 46
4.5 PROCESS OBSERVATIONS 47
4.6 ANALYTICAL PROCEDURES 47
4.6.1 Description of K-Matrix Analyses 47
4.6.2 Preparation of Analysis Programs 48
4.6.3 Error Analysis of data 49
4.6.4 Concentration Correction Factors 51
4.6.5 Analysis of Sample Concentration Spectra 51
n
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(Continued)
5.0 INTERNAL QUALITY ASSURANCE/QUALITY CONTROL ACTIVITIES 53
5.1 QC PROCEDURES FOR MANUAL FLUE GAS TEST METHODS 53
5.1.1 Sample Concentration Sampling QC Procedures 53
5.1.2 Manual Sampling Equipment Calibration Procedures ... 54
5.1.2.1 Temperature Measuring Device Calibration ... 54
5.1.2.2 Dry Gas Meter Calibration 54
5.2 QC PROCEDURES FOR INSTRUMENTAL METHODS 54
5.2.1 Daily Calibrations, Drift Checks, and System Bias
Checks 54
5.3 QA/QC CHECKS FOR DATA REDUCTION, VALIDATION, AND REPORTING . 55
5.3.1 Sample Concentration 56
5.3.2 Gas Phase Analysis 56
5.3.3 FTIR Spectra 57
5.4 CORRECTIVE ACTIONS 57
6.0 CONCLUSIONS AND DISCUSSION 58
7.0 REFERENCES 61
APPENDICES
A - Results and Calculations
B - Raw Field Data and Calibration Data Sheets
C - Analytical Data
D - EPA Methods and Protocol
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1.0 INTRODUCTION
1.1 BACKGROUND
The U.S. Environmental Protection Agency (EPA), Office of Air Quality
Planning and Standards (OAQPS), Industrial Studies Branch (ISB), and Emission
Measurement Branch (EMB) directed Entropy, Inc. to conduct an emission test
at Houston Lighting and Power Company's (HLPC) Greens Bayou electric
generating station, Unit 5, gas-fired boiler in Houston, Texas. The test was
conducted on May 20 and 21, 1993. The purpose of this test was to identify
which hazardous air pollutants (HAPs) listed in the Clean Air Act Amendments
of 1990 are emitted from this source. The measurement method used Fourier
transform infrared (FTIR) technology, which had been developed for detecting
and quantifying many organic HAPs in a flue gas stream. Besides developing
emission factors (for this source category), the data will be included in an
EPA report to Congress.
Before this test program, Entropy conducted screening tests using the
FTIR method at facilities representing several source categories, including
a coal-fired boiler. The screening tests were part of the FTIR Method
Development project sponsored by EPA to evaluate the performance and
suitability of FTIR spectrometry for HAP emission measurements. These tests
helped determine sampling and analytical limitations, provided qualitative
information on emission stream composition, and allowed estimation of the
mass emission rates for a number of HAPs detected at many process locations.
The evaluation demonstrated that gas phase analysis using FTIR can detect and
quantify many HAPs at concentrations in the low part per million (ppm) range
and higher and a sample concentration technique is able to detect HAPs at
sub-ppm levels.
Following the screening tests, Entropy conducted a field validation
study at a coal-fired steam generation facility to assess the effectiveness
of the FTIR method for measuring HAPs, on a compound-by-compound basis. The
flue gas stream was spiked with HAPs at known concentrations so that
calculated concentrations, provided by the FTIR analysis, could be compared
with actual concentrations in the gas stream. The analyte spiking procedures
of EPA Method 301 were adapted for experiments with 47 HAPs. The analytical
procedures of Method 301 were used to evaluate the accuracy and precision of
the results. Separate procedures were performed to validate a direct gas
phase analysis technique and a sample concentration technique of the FTIR
method. A complete report, describing the results of the field validation
test, has been submitted to EPA1.
This report was prepared by Entropy, Inc. under EPA Contract No.
68D20163, Work Assignment No. 1-34. The field test was performed under Work
Assignment 4 of the same Contract. Research Triangle Institute (RTI)
provided the process information given in Sections 2.1 and 3.3.3.
1.2 DESCRIPTION OF THE PROJECT
The FTIR-based method uses two different sampling techniques: (1) direct
1
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analysis of the extracted gas stream (hereafter referred to as "gas phase
analysis") and (2) sample concentration followed by thermal desorption. Gas
phase analysis involves extracting gas from the sample point location and
transporting the gas through sample lines to a mobile laboratory where sample
conditioning and FTIR analyses are performed. The sample concentration
system employs 10 g of Tenax® sorbent, which remove organic compounds from a
flue gas stream. Organic compounds adsorbed by Tenax® are then thermally
desorbed into the smaller volume of the FTIR absorption cell; this technique
allows detection of some compounds down to the ppb level in the original
sample. For this test, 850 to 1100 dry liters of flue gas were sampled
during each sample concentration run. Section 4.0 describes the sampling
systems.
Entropy operated a mobile laboratory (FTIR truck) containing the
instrumentation and sampling equipment. The truck was driven to the site at
Greens Bayou and parked directly beneath the sample location. The test was
performed over a two-day period.
Entropy tested the boiler exhaust gases at the stack. The furnace
burned natural gas. Section 2.0 contains descriptions of the process and the
sampling point location.
Gas phase analysis was used to measure sulfur dioxide (S02), nitrogen
oxides (NOJ, carbon monoxide (CO), carbon dioxide (C02), and ppm levels of
other species. EPA instrumental test methods were used to provide
concentrations of CO, C02, 02, and hydrocarbons. Sample concentration was
used to measure HAPs at ppb levels. Entropy conducted three 4-hour sample
concentration runs at the exhaust stack. Gas phase analysis was performed
concurrently with the sample concentration runs. Combustion gas volumetric
flows were calculated from fuel data provided by the facility. The test
schedule is given in Section 3.1.
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1.3 PROJECT ORGANIZATION
This testing program was funded and administered by the Industrial
Studies Branch (ISB) and the Emissions Measurement Branch (EMB) of the Office
of Air Quality Planning and Standards (OAQPS) of the U.S. EPA. An RTI
representative collected process data. The following list presents the
organizations and personnel involved in coordinating and performing this
project.
HLPC Corporate Contact:
Mr. Derek Furstenwerth (713) 945-8063
HLPC Greens Bayou:
Mr. Keith Nemec
(713) 458-3157
EMB Work Assignment
Managers:
Ms. Lori Lay (919) 541-4825
Mr. Dennis Holzschuh (919) 541-5239
ISB Contacts:
Mr. Kenneth Durkee
Mr. William Maxwell
(919) 541-5425
(919) 541-5430
Entropy Project Manager:
Dr. Thomas Geyer
(919) 781-3551
Entropy Test Personnel:
Mr. Scott Shanklin
Ms. Lisa Grosshandler
Dr. Laura Kinner
Mr. Greg Blanschan
Mr. Mike Worthy
Dr. Ed Potts
RTI Representative:
Mr. Jeffrey Cole
(919) 990-8606
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2.0 PROCESS DESCRIPTION AND SAMPLE POINT LOCATIONS
2.1 FACILITY DESCRIPTION
HLPC's Greens Bayou Unit 5 is located in Houston, Texas. Greens Bayou
Unit Five is a tangentially fired, tilting-burner, reheat boiler with
controlled circulation. It is capable of supplying 3,054,000 Ib/hr of steam
to a Westinghouse turbo generator that is rated at a design maximum load of
420 MW. The unit normally operates as a load-following unit, meaning that it
is operated according to electric demand (the plant load is varied during
normal operation from 90-350 MW). Unit 5 undergoes a planned outage every 2
years for a maintenance inspection.
During the test, the unit was operated, whenever possible, at a high MW
load (415 + 5 MW, approximately 90-100 percent capacity). This was done to
maintain consistency in the flue gas flow rates during the test runs. The
primary fuel source for Unit 5 is natural gas. Unit 5 is also capable of
using No. 6, No. 4, and No. 2 fuel oil as alternate fuels.
Two forced draft fans with motors rated at 3,500 hp each provide and
control the amount of preheated combustion air. The fans are located below
the stack (Figure 1), however, there is no direct connection to the stack at
this point. These fans push combustion air through the corner windboxes and
keep the unit under positive pressure. Windboxes are corner-mounted modular
firing units containing air nozzles, gas nozzles, and igniters. The fans
also provide the sealing air (through a separate duct) that prevents backflow
through the gas recirculation system.
In the combustion chamber, the preheated air and fuel are introduced
through four windboxes in the four corners of the furnace. Both fuel and
combustion air are projected from the corners of the furnace along a line
tangential to a small circle moving in a horizontal plane at the center of
the furnace. The fuel and combustion air are ignited by an electrical spark
from gas igniters. The flame zone extends from the corners of the furnace to
the center where the fireball swirls. This fireball location can be moved by
adjusting the tilting burners up or down in unison. This technique is used
to control furnace heat absorption in the superheater and reheater sections.
This action controls the furnace exit-gas temperature for variations in load.
Normal combustion flame temperatures are approximately 2,000 to 3,000 °F.
Exhaust gases from the combustion chamber pass through the furnace over
the primary superheater, secondary superheater, and secondary reheater. From
the secondary reheater, the gases pass through an opening in the rear of the
furnace wall into the convection pass. E-xhaust gases then pass over the
primary reheater and economizer to the air preheater and out the stack. The
gas recirculation system inlet is located after the economizer. Flue gas is
taken from the economizer outlet and re-introduced at the bottom of the
furnace. Recirculation of a portion of the flue gas through the furnace will
increase the steam temperature. Temperature control is obtained by
positioning dampers to regulate the amount of recirculated gas. Also, the
added flue gas flow is used to broaden the combustion zone so that it does
not concentrate in the burner area. Keeping the combustion zone spread
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throughout the furnace reduces NOX formation which would be higher if the
combustion zone were smaller and hotter.
2.2 AIR POLLUTION CONTROL DEVICES
2.2.1 Nitrogen Oxide (NOJ Control
Tangentially fired units, because of their design, are low NOX emitters.
These units provide for more complete mixing of fuel and air. Although the
gas recirculation installed on the unit tends to reduce NOX emissions, it is
used only as a means of reheat temperature control for the combustion
chamber.
2.2.2 Sulfur Dioxide (SO..) Control
Emissions of S02 are considered negligible for natural gas firing. When
the alternative fuel (fuel oil) is used, S02 emissions are controlled by the
use of low sulfur content oil, or split-firing of fuel oil and natural gas.
Current State regulations limit fuel oil sulfur content to 0.7 percent by
weight. Lower sulfur fuel oil (less than 0.3 percent sulfur) or split-firing
to achieve 150 ppm S02 is required as of July 31, 1993.
2.2.3 Particulate Control
Particulate and visible emissions are limited by the use of natural gas
as the primary fuel and utilization of No. 2 distillate oil as an alternate
fuel.
The process information provided in the section above was supplied by
Greens Bayou plant personnel.
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Secondary
Reheater
Secondary
Superheater
Primary
Reheater
Primary
Superheater
\
Combustion
Chamber
Comer-mounted
Windboxes (4)
Economizer
Stack
Hot, Clean
Combustion
Air
Gas Recirculation,
Sealing Air Duct
Cold, Clean
Combustion Air
Gas
Recirculation
Damper
Gas
Recirculation
Fan
Forced
Draft
Fans
Figure 2-1: Houston Light & Power - Greens Bayou Unit Five
Combustion Air & Flue Gas Flow
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2.3 SAMPLE POINT LOCATION, UNIT 5 EXHAUST STACK
The sampling was conducted at the rectangular exhaust stack,
approximately 8 ft. downstream of the air preheater outlet. Figure 2-2
indicates the position of the test location in relation to the furnace and
other components of the system. Figure 2-3 provides greater detail of the
test location. The measurement point on the stack is approximately 114 feet
above ground level. The stack dimensions are 11 ft. deep by 26.5 ft. wide.
Four 6-inch sampling ports are evenly spaced across the width of the stack.
For gas phase analysis, the location was reached using 150 feet of heated
Teflon line. The middle two ports were used for sampling.
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.5'
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6.6'
=4
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3.3'
~f
Gas Phase
Sample Port
Sample
• Concentration
Sample Port
50104 9/93 Figure 2-2. Houston Lighting and Power, Greens Bayou Unit 5 Exhaust Stack.
8
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3.0 SUMMARY AND DISCUSSION OF RESULTS
3.1 OBJECTIVES AND TEST MATRIX
The purpose of the test program was to obtain information that will
enable EPA to develop emission factors (for as many HAPs as possible) which
will apply to electric utilities employing gas-fired boilers. EPA will also
use these results to prepare a report for Congress.
The specific objectives were:
• Measure HAP emissions (employing methods based on FTIR
spectrometry) in two concentration ranges, 1 ppm and above
using gas phase analysis, and sub-ppm levels using sample
concentration/thermal desorption.
• Determine maximum possible concentrations for undetected HAPs
based on detection limits of instrumental configuration and
limitations imposed by composition of flue gas matrix.
• Measure 02, C02, CO, and hydrocarbons using gas analyzers.
• Obtain process information from Greens Bayou. This
information includes the rate of power production during the
testing periods.
Table 3-1 presents the test schedule that was followed at Greens Bayou.
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TABLE 3-1. FTIR TESTING SCHEDULE AT GREENS BAYOU STACK #5
SAMPLING PERIODS
Date
5/19/93
5/20/93
5/21/93
5/21/93
Run#a
Amb
1
2
3
Amb
Gas Phase
Analysis
1130-1416
1550-1936
1109-1316
Sample
Cone.
1740-1840
0930-1330
1530-1930
0945-1345
1415-1515
CEM Analyzers
O2,CO2,CO,HC
1016-1416
1417-1934
1106-1350
Thermal Desorption
Date
5/20
5/21
5/21
5/21
5/21
Time
2340-2354
2358-0021
0024-0046
1452-1508
1608-1624
Amb denotes an ambient sample.
3.2 FIELD TEST CHANGES AND PROBLEMS
Initially, the plan called for two 4-hour sample concentration runs on
May 20 and performing gas phase analysis concurrently for the entirety of the
two 4-hour periods. Instead, the first sample concentration run began as
soon as the sampling system was ready and the process was operating at full
load. The gas phase run started soon after the beginning of sample
concentration Run 1, continued^through the end of Run 1 and into Run 2, but
was stopped before the end of sample concentration Run 2. Gas phase analysis
was also performed for less than the 4 hours of sample concentration Run 3.
Orsat analysis provided data for the periods when the CEMs were not
operating. This plan was the best way to accomplish the test objectives
while completing the test runs within the originally planned time.
On the evening of May 20 (after Run 2 and before Run 3) Entropy
performed a spiking test using formaldehyde in an experiment unrelated to
this project. During the course of the experiment samples spiked with
formaldehyde were introduced to the sample conditioning systems. The
polymeric form (paraformaldehyde) readily condenses on the walls of the
PermaPure membrane. Because the membrane has a large surface area, extensive
purging is usually required to remove some compounds. Traces of formaldehyde
remained in the PermaPure system and contaminated three of the FTIR samples
from Run 3. The formaldehyde concentration in these FTIR samples was about
5 ppm. This contamination did not interfere with the FTIR analysis for any
other species.
10
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3.3 SUMMARY OF RESULTS
3.3.1 FTIR Results
Gas phase and sample concentration data were analyzed for the presence
of HAPs and other species. All spectra were visually inspected and
absorbance bands were identified. Spectra were analyzed, using procedures
developed by Entropy, to determine concentrations of any species detected.
These results are presented in Tables 3-2 and 3-3. Maximum possible
concentrations were calculated for undetected HAPs. These results are
presented in Tables 3-4 to 3-6.
3.3.1.1 Gas Phase Results -- Each gas phase FTIR spectrum was separately
analyzed for the presence of HAPs and other species. Compounds detected in
the gas phase samples were;
• Water vapor.
• C02 and CO.
• Nitric oxide (NO) was the largest component of the NOX emissions.
The NO stack concentration, from 51 to 79 ppm, could be measured in
hot/wet, condenser and PermaPure samples.
• N02 and N20 were detected, but not quantified because quantitative
reference spectra are not currently available.
A set of subtracted spectra was generated so that maximum possible
(minimum detectible) concentrations could be calculated for HAPs that were
not identified in the sample stream. Reference spectra of water vapor and C02
were multiplied by an appropriate scaling factor and subtracted from each of
the sample spectra. The remaining base lines were then analyzed for every
compound represented in the quantitative reference spectra library to
determine the maximum possible concentrations of HAPs that were undetected.
The calculations were performed according to the procedures described in
Section 4.6.3. Results for hot/wet and dry (treated with the condenser or
PermaPure dryers) spectra are presented in Tables 3-4 and 3-5 respectively.
The results are averages of the calculated values for all of the spectra over
the 3 sample runs.
The maximum possible concentrations for HAPs given in Table 3-4 for
hot/wet samples and Table 3-5 for condenser samples represent upper limits
for the in-stack concentrations. This means that, for a HAP to have been
present in the gas stream, its concentration must have been below the
calculated maximum possible concentration. The results presented in Tables
3-4 and 3-5 indicate how effectively these compounds could be measured by
FTIR analysis with the analytical system used for this test.
The hot/wet gas phase spectra are difficult to analyze because of strong
interference from water vapor. Even so, in results from the hot/wet gas
phase data, 96 compounds give maximum possible concentrations below 10 ppm,
of these 70 are below 5 ppm and 29 are 1 ppm or lower.
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Previously, Entropy developed analysis programs to analyze for HAPs in
FTIR spectra of samples extracted from a coal-fired boiler stack.
Statistical analyses snowed that the programs were successful in measuring
some HAPs in hot/wet and condenser samples.1 The major interferant species
detected at the coal-fired boiler are very similar to those that have been
identified at the gas-fired boiler (with the exception that S02 was not
detected in the gas-fired exhaust). Therefore, the same programs were used
to analyze the data obtained in this test. The results of the analyses are
presented in Appendix C.
3.3.1.2 Sample Concentration Results -- The sample concentration spectra
represent integrated samples over each 4-hour run. In addition to water
vapor, C02, CO, and NO, the following compounds were detected;
• Ammonia (NH3) was detected in the stack samples form all three runs
and in both of the ambient samples.
• Freon(ll) (CC13F) was detected in the stack sample from Run 1.
This has been identified in sample concentration spectra taken at
other emission sources and it is believed to be a contaminant.
• HC1 was detected in trace amounts in the post-test ambient sample.
• Evidence of hexane was observed in samples from all three runs and
also the ambient samples. Absorbencies similar to hexane are often
observed in spectra of desorbed samples. These features are due to
a mixture of alkane hydrocarbons, including hexane, the sum of
whose spectra gives absorbances which appear similar to hexane.
Table 3-3 shows calculated concentrations of HC1 and ammonia from all of
the test runs. The concentration of CC13F could not be determined because
quantitative reference spectra are not currently available. The
concentration for HC1 was near its limit of detection. The calculated value
is shown only for the spectrum where HC1 was detected. In-stack
concentrations were estimated by dividing the in-cell concentration by the
concentration factor (Section 4.6.4). The in-stack concentrations are based
on the volume of gas sampled and do not account for effects of the sampling
system or the adsorption/desorption efficiencies of HC1, NO and NH3.
Therefore, the values in Table 3-3 represent lower limits on the
concentrations for these species. Upper limits for NH3 and HC1 are provided
by the values given in the gas phase data (Tables 3-4 and 3-5) Table 3-6
gives maximum possible concentrations for species not detected using Tenax.
Other absorbance bands, which remain unidentified, were observed in the
sample from Run 2. None of these bands were attributed to HAPs for which
Entropy currently has reference spectra. When these bands are identified, it
should become clear whether they are due to emissions from the process or
were formed by conditions unrelated to the process (i.e. contamination). The
first ambient sample and spectra of samples from Runs 1 and 2 contain
negative absorbance features due to methane meaning that traces of methane
were in the cell when the single beam background spectrum was collected.
This minor contamination caused no difficulty with the analysis.
12
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Spectral analysis programs were also previously developed for the
validation of the sample concentration technique. The analysis programs were
used to evaluate the sample concentration data for HAPs. The results,
presented in Appendix C, give calculated concentrations only for those HAPs
that Entropy has proven in a field validation study can be measured using
Tenax.
13
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TABLE 3-2. FTIR RESULTS FROM ANALYSIS OF GAS PHASE SAMPLES
Date
5/20/93
Run
#
1.0
2.0
Sample
Time
1124-1127
1135-1138
1145-1147
1152-1155
1210-1212
1225-1227
1326-1328
1338-1342
1345-1348
1400-1404
1412-1415
1546-1549
1554-1555
1600-1602
1713-1715
1720-1724
1730-1740
1745-1800
1820-1831
1901-1903
1912-1914
1924-1926
1930-1932
Sampling System
to FTIR (a)
Hot/Wet
Condenser
Condenser
Perma-Pure
Hot/Wet
Condenser
H2O
(%)
17.0
17.0
-
Flow Rate
(DSCFM)
646,974
646,974
622,720
622,720
622,720
622,720
NO
ppm Ib/hr
77.8 235.1
73.4 221.8
78.1 236.1
75.7 228.8
68.9 208.2
74.6 225.5
71.7 216.7
72.0 217.6
70.4 212.8
78.9 238.5
78.1 236.1
75.5 219.6
74.2 215.9
73.9 215.0
74.9 217.9
75.7 220.2
73.5 213.8
74.2 215.9
74.2 215.9
60.1 174.8
58.1 169.0
59.6 173.4
64.1 186.5
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TABLE 3-2. (Continued)
Date
5/21/93
Run
#
3.0
Sample
Time
1108-1109
1113-1114
1120-1121
1131-1133
1143-1145
1150-1152
1158-1200
1205-1208
1220-1233
1236-1246
1250-1259
1302-1315
Sampling System
to FTIR
Hot/Wet
Condenser
Perma-Pure
H2O
(%)
17.0
Flow Rate
(DSCFM)
568,071
568,071
568,071
NO
ppm Ibs/hr
54.9 145.7
53.6 142.2
52.2 138.5
55.9 148.4
58.4 155.0
56.8 150.7
56.2 149.1
60.0 159.2
56.2 149.1
55.3 146.8
50.9 135.1
57.5 152.6
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TABLE 3-3. CONCENTRATIONS CALCULATED FOR SOME MAP'S THAT WERE
DETECTED IN SPECTRA OF CONCENTRATED SAMPLES EXTRACTED
FROM THE UNIT 5 STACK AT GREENS BAYOU GAS-FIRED BOLER.
Run*
1
2
3
Ambient 1
Ambient 2
Nitric Oxide (a)
In-Cell Flue Gas
(ppm) (c) (ppm) (d)
21.44
21.27
10.65
0.2079
0.1768
0.0595
0.0000
0.0000
Ammonia
In-Cell Flue Gas
(ppm) (ppm)
5.12
1.00
0.49
12.27
0.95
0.0496
0.0083
0.0027
0.0913
0.0071
Hydrogen Chloride
In-Cell Flue Gas
(ppm) (ppm)
1.78
0.0000
0.0000
0.0000
0.0000
0.0133
Hexane (b)
In-Cell Flue Gas
(ppm) (ppm)
2.03
1.82
1.95
1.14
1.30
0.0197
0.0151
0.0109
0.0085
0.0097
(a) Compounds detected on Tenax for which Entropy has obtained quantitative reference spectra.
Blank spaces indicate a non-detect.
(b) Probably a mixture of alkane hydrocarbons which may include hexane and together
give absorbancs similar to hexane.
(c) Concentration of detected compound in FTIR cell calculated using MCOMP analytical routine.
(d) Concentration of detected compound in flue gas calculated by dividing in-cell concentration by
the concentration factor (see Section 4.6.5).
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TABLE 3-4. CALCULATED MAXIMUM POSSIBLE (MINIMUM DETECTIBLE) CONCENTRATIONS:
HAPs NOT DETECTED IN SPECTRA OF HOT/WET SAMPLES EXTRACTED FROM
UNIT 5 STACK AT GREENS BAYOU GAS-FIRED BOILER.
LOCATION
Compound(a)
Acetonttnle
Acrolein
Acrylonitnle
Mlyl Chloride
Benzene
Bromoform
1,3-Butadiene
Carbonyl Sulfide
Chlorobenzene
Ethyl Benzene
Ethyl Chloride
Ethylene Oibromide
i-Hexane
Methyl Bromide
Methyl Chloride
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Methylene Chloride
2-Nitropropane
Propylene Dichloride
Styrene
Tetrachloroethylene
Toluene
1 , 1 ,2-Trichloroethane
Trichloroethylene
2,2,4-Trimethylpentane
Vinyl Acetate
Vinyl Bromide
Vinyl Chloride
i/inylidene Chloride
O-xylene
P-xylene
Carbon Oisulfide
Carbon Tetrachloride
Chloroform
Analytical Region (wni(b)
1041.40 - 1042.88
2636.11 - 2875.59
922.19 - 997.82
893.51 - 1002.22
3036.88 - 3063.07
1135.90 - 1154.20
870.00 - 1052.64
2029.21 - 2075.69
1012.42 - 1036.64
2866.13 - 2921.27
943.43 - 1000.16
1167.96 - 1208.92
2835.27 - 3005.43
2948.11 - 2972.53
1017.96 - 1020.72
1140.70 - 1222.63
2872.05 - 2994.95
1137.50 - 1232.04
1249.95 - 1285.66
831.47 - 868.50
996.86 - 1038.00
886.32 - 931.22
899.20 - 925.20
2862.00 - 2924.00
909.41 - 960.62
919.70 - 959.88
2861.57 - 3009.23
832.23 - 906.69
899.81 - 904.54
852.81 - 1056.06
1059.44 - 1113.01
2859.84 - 3095.04
2854.43 - 3083.14
2171.29 - 2184.68
793.89 - 800.58
758.21 - 781.25
STACK
RMSD(c)
1.29E-03
1.58E-03
5.58E-03
5.26E-03
1.37E-02
5.33E-03
6.05E-03
4.49E-02
7.30E-03
2.00E-03
5.57E-03
7.12E-03
5.80E-03
5.70E-03
2.31 E-03
7.29E-03
6.05E-03
1.08E-02
1.48E-01
5.15E-03
6.08E-03
4.09E-03
3.99E-03
1.97E-03
4.70E-03
4.72E-03
6.24E-03
4.49E-03
1.47E-03
6.12E-03
9.87E-03
1.07E-02
1.08E-02
2.56E-02
1.95E-02
3.51 E-02
Max. Con.
(ppmMd)
6.89
2.06
4.59
4.29
6.41
1.00
6.33
2.56
6.72
4.08
7.76
5.07
0.84
6.53
7.55
5.37
2.55
1.21
60.60
5.68
7.16
3.10
0.36
3.11
4.90
0.91
0.75
2.77
0.62
6.25
2.63
6.78
5.88
24.30
0.38
1.77
17
-------
TABLE 3-4. CALCULATED MAXIMUM POSSIBLE (MINIMUM DETECTIBLE) CONCENTRATIONS:
HAPs NOT DETECTED IN SPECTRA OF HOT/WET SAMPLES EXTRACTED FROM
UNIT 5 STACK AT GREENS BAYOU GAS-FIRED BOILER.
LOCATION
Compound(a)
Cutnene
1,2-Epoxy Butane
Ethylene Oxide
Methanol
Methyl Chloroform
Methyl Iodide
Methyl t-Butyl Ether
'ropylene Oxide
^-xylene
Acetone
Acetaldehyde
Acetophenone
Acrylic Acid
Aniline
Uenzotnchloride
Benzyl Chloride
3is(chloromethyl)ether
Chloroacelic acid
2-Chloroacteophenone
Chloromethyl methyl ether
Chloroprene
o-Cresol
m-Cresol
p-Cresol
1,2-Dibromo-3-chloropropane
1 ,4-Dichlorobenzene
Dichloroethyl ether
1 ,3-Oichloropropene
Dichlorvos
N.N-Diethyl aniline
Dimethyl carbamoyl chloride
Dimethyl formamide
1,1 -Dimethyl hydrazine
Dimethyl phthalate
1,4-Dioxane
Epichlorohydrin
Analytical Region (wn)(b)
1015.82 - 1063.57
902.37 - 919.70
866.90 - 875.00
2807.91 - 3029.40
1057.95 - 1105.30
1250.18 - 1253.53
1195.00 - 1210.00
2875.59 - 3097.75
2910.25 - 2952.78
1182.00 - 1255.03
2685.41 - 2744.40
874.88 - 1126.36
1104.89 - 1164.68
1102.90 - 1123.63
866.50 - 877.90
1262.87 - 1279.12
1068.78 - 1154.25
1094.97 - 1124.12
1274.39 - 1285.42
1111.02 - 1146.08
875.90 - 878.80
1092.80 - 1114.07
1139.68 - 1172.77
1159.10 - 1185.50
855.88 - 904.72
995.96 - 1031.06
1109.35 - 1155.04
768.00 - 791.00
835.77 - 876.95
2655.32 - 3156.07
889.55 - 917.52
2824.80 - 2873.60
856.12 - 974.09
1157.86 - 1254.16
2861.10 - 2864.80
943.52 - 981.73
STACK
RMSD(C)
7.18E-03
3.95E-03
1.69E-03
7.07E-03
9.44E-03
1.92E-03
4.76E-03
1.14E-02
4.04E-03
1.23E-02
1.54E-03
8.59E-03
6.32E-03
8.37E-03
1.56E-03
2.13E-01
8.09E-03
7.52E-03
9.48E-03
6.74E-03
1.59E-03
6.05E-03
3.52E-03
6.11E-03
3.15E-03
4.20E-03
6.58E-03
2.09E-02
4.98E-03
1.11E-02
3.35E-03
1.54E-03
5.03E-03
1.12E-02
1.17E-03
6.35E-03
Max. Con.
(ppm)(d)
17.71
2.87
0.41
5.68
1.66
1.74
0.75
7.20
2.46
5.35
2.53
7.14
0.79
2.66
0.29
96.56
0.86
1.60
1.74
0.97
0.28
2.51
0.63
0.66
5.36
1.80
0.73
4.17
0.57
6.34
0.82
0.95
4.06
5.83
0.18
5.08
18
-------
TABLE 3-4. CALCULATED MAXIMUM POSSIBLE (MINIMUM DETECTIBLE) CONCENTRATIONS:
HAPs NOT DETECTED IN SPECTRA OF HOT/WET SAMPLES EXTRACTED FROM
UNIT 5 STACK AT GREENS BAYOU GAS-FIRED BOILER.
LOCATION
Compound(a)
Ethyl Acrylate
Ethylene Bichloride
Ethylidene bichloride
Formaldehyde
Hexachlorobutadiene
Hexachlorocylcopentadiene
Hexachloroethane
Hexamethylphosphoramide
Hydrochloric Acid
Isophorone
Maleic Anhydride
Methyl hydrazine
Naphthalene
Nitrobenzene
N-Nitrosodimethylene
\l-Nitrosomorpholine
Phenol
aeta-Propiolactone
Propionaldehyde
1,2-Propylenimine
Quioline
Styrene Oxide
1 , 1 ,2,2-Tetrachloroethane
2.4-Toluene diisocyanate
a Toluidine
1 ,2,4-Trichlorobenzene
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Tnethylamine
Ammonia
Analytical Region (wni (b)
1181.93 - 1210.00
1227.88 - 1241.50
930.35 - 1126.16
2788.33 - 2842.20
976.90 - 997.70
1227.02 - 1240.42
995.46 - 1042.73
949.42 - 1019.53
2817.35 - 2823.26
2681.20 - 3130.60
885.27 - 905.56
2683.00 - 3061.78
779.31 - 783.55
841.70 - 861.39
928.00 - 1085.28
892.23 - 1024.64
879.40 - 882.40
860.13 - 957.64
2546.18 - 3114.35
817.57 - 821.31
800.19 - 803.73
861.39 - 903.93
794.92 - 824.07
885.61 - 905.31
2858.50 - 2951.85
1009.00 - 1198.39
1178.04 - 1204.16
856.27 - 863.36
2756.62 - 2839.34
893.10 - 926.00
STACK
RMSD(c)
6.55E-03
5.49E-03
9.45E-03
1.24E-03
2.78E-03
6.07E-03
6.73E-03
5.51 E-03
1.04E-03
1.12E-02
2. 14 E-03
7. 62 E-03
1.26E-02
5.84E-03
7.33E-03
5.18E-03
4.08E-04
4.35E-03
8.12E-03
2.20E-03
7.16E-03
3.09E-03
8.86E-03
2. 11 E-03
3.07E-03
1.09E-02
6.62E-03
2.23E-03
1.26E-03
3.83E-03
Max. Con.
(ppm)(d)
0.33
3.01
12.98
1.23
0.38
0.45
23.35
0.74
1.00
6.94
0.21
8.17
1.21
2.26
2.22
2.03
0.79
0.89
8.53
0.93
1.05
2.12
1.98
1.50
2.49
7.26
1.98
0.52
0.52
2.28
(a) HAP's for which Entropy has obtained quantitative reference spectra.
(b) Frequency region, in wavenumbers (1/cm) chosen for the analysis.
(c) Calculated root mean square deviation over the analytical region in spectra that were generated by
subtracting reference spectra of interferant species from the sample spectra.
(d) Maximum Concentration (in ppm) of undetected compound, that could have been present in FTIR samples,
calculated according to procedures discussed in Sections 4.6.3 and 3.3.1.
19
-------
TABLE 3-5. CALCULATED MAXIMUM POSSIBLE (MINIMUM DETECTIBLE) CONCENTRATIONS:
HAPs NOT DETECTED IN SPECTRA OF CONDENSED SAMPLES EXTRACTED FROM
UNIT 5 STACK AT GREENS BAYOU GAS-FIRED BOILER.
LOCATION
Compound(a)
Acetonrtrile
Acrolein
Acrylonitrile
Ally) Chloride
lenzene
Bromoform
,3-Butadiene
Carbonyl Sullide
Chlorobenzene
Ethyl Benzene
Ethyl Chloride
Ethylene Dibromide
n-Hexane
Methyl Bromide
Methyl Chloride
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
vlethylene Chloride
2-Nitropropane
'ropylene Dichloride
Styrene
fetrachloroethylene
Toluene
1 ,1 ,2-Trichloroethane
rrichloroetfiylene
2,2,4-Trimethylpentane
Wnyl Acetate
Vinyl Bromide
Vinyl Chloride
i/inylidene Chloride
O-xylene
P-xylene
Caiton Oisulfide
Carbon Tetrachloride
Chloroform
Analytical Region (wn)(b)
1041.40 - 1042.88
913.70 - 1000.35
92Z19 - 997.82
893.51 - 1002.22
3036.88 - 3063.07
1135.90 - 1154.20
870.00 - 1052.64
2029.21 - 2075.69
1012.42 - 1036.64
2866.13 - 2921.27
2916.56 - 3041.03
1167.96 - 1208.92
2835.27 - 3005.43
2948.11 - 2972.53
1017.96 - 1020.72
1140.70 - 1222.63
2872.05 - 2994.95
1137.50 - 1232.04
1249.95 - 1285.66
831.47 - 868.50
996.86 - 1038.00
886.32 - 931.22
899.20 - 925.20
3018.19 - 3054.70
909.41 - 960.62
826.25 - 860.91
2861.57 - 3009.23
832.23 - 906.69
899.81 - 904.54
852.81 - 1056.06
834.13 - 898.73
2859.84 - 3095.04
2854.43 - 3083.14
2171.29 - 2184.68
793.89 - 800.58
758.21 - 781.25
STACK
RMSD(c)
1.40E-03
3.15E-03
3.24E-03
3.18E-03
2.31 E-03
1.81E-03
3.23E-03
1.56E-02
2.44E-03
1.96E-03
3.08E-03
2.05E-03
3.21 E-03
1.87E-03
1.46E-03
2.28E-03
3.38E-03
3.06E-03
8.45E-03
1.86E-03
2.18E-03
2.46E-03
2.16E-03
2.77E-03
3.41 E-03
2.65E-03
3.28E-03
1.78E-03
1.05E-03
3.19E-03
1.73E-03
3.45E-03
3.46E-03
1.48E-02
5.11E-03
1.92E-02
Max. Con.
(ppm)(d)
7.47
2.00
2.67
2.59
1.08
0.34
3.38
0.89
2.24
4.01
2.29
1.46
0.47
2.14
4.78
1.68
1.42
0.34
3.45
2.05
2.57
1.86
0.20
1.31
3.55
0.41
0.39
1.10
0.44
3.26
1.10
2.19
1.89
14.12
0.10
0.97
20
-------
TABLE 3-5. CALCULATED MAXIMUM POSSIBLE (MINIMUM DETECTIBLE) CONCENTRATIONS:
HAPs NOT DETECTED IN SPECTRA OF CONDENSED SAMPLES EXTRACTED FROM
UNIT 5 STACK AT GREENS BAYOU GAS-FIRED BOILER.
LOCATION
Compound(a)
Cumene
,2-Epoxy Butane
Ethylene Oxide
Methanol
ilethyl Chloroform
Methyl Iodide
Methyl t-Butyl Ether
'ropylene Oxide
ri-xylene
Acetone
Acetaldehyde
Acetophenone
Acrylic Acid
Aniline
Jenzotrichloride
Benzyl Chloride
)n(chloromethyl)ether
Chloroacetic acid
2-Chloroacteophenone
Chloromethyl methyl ether
Chloroprene
o-Cresol
m-Cresol
p-Cresol
1 ,2-Dibromo-3-chloropropane
1 ,4-Dichlorobenzene
Dlchloroethyl ether
1 ,3-Dichloropropene
Dichlorvos
N.N-Diethyl aniline
Dimethyl carbamoyl chloride
Dimethyl formamide
1,1-Dimethyl hydrazine
Dimethyl phthalate
1,4-Dioxane
Epichlorohydrin
Analytical Region (wn)(b)
1015.82 - 1063.57
2859.05 - 3076.29
866.90 - 875.00
2807.91 - 3029.40
1057.95 - 1105.30
1250.18 - 1253.53
1195.00 - 1210.00
2875.59 - 3097.75
2910.25 - 2952.78
1182.00 - 1255.03
3006.20 - 3009.20
1140.40 - 1286.06
1104.89 - 1164.68
1102.90 - 1123.63
866.50 - 877.90
1262.87 - 1279.12
1068.78 - 1154.25
1094.97 - 1124.12
1274.39 - 1285.42
1111.02 - 1146.08
875.90 - 878.80
1092.80 - 1114.07
1139.68 - 1172.77
1159.10 - 1185.50
855.88 - 904.72
995.96 - 1031.06
1109.35 - 1155.04
768.00 - 791.00
835.77 - 876.95
2655.32 - 3156.07
889.55 - 917.52
1057.80 - 1103.90
856.12 - 974.09
1157.86 - 1254.16
2861.10 - 2864.80
943.52 - 981.73
STACK
RMSD(C)
3.32E-03
3.48E-03
9.48E-04
3.29E-03
429E-O3
9.98E-04
1.79E-03
3.54E-03
2.09E-03
3.41 E-03
6.41 E-04
5.02E-03
1.94E-03
1.90E-03
8.79E-04
9.31 E-03
3.63E-O3
2.19E-03
4.12E-03
1.75E-03
8.72E-04
2.19E-03
1.80E-03
1.95E-03
1.54E-03
2.00E-03
1.91 E-03
1.08E-02
1.85E-03
3.38E-03
1.76E-03
4.24E-03
2.94E-03
3.15E-03
8.33E-04
3.18E-03
Max Con.
(ppm)(d)
8.18
1.48
0.23
2.65
0.75
0.90
0.28
2.24
1.27
1.48
1.53
0.65
0.24
0.60
0.16
4.22
0.39
0.46
0.76
0.25
0.16
0.91
0.32
0.21
2.63
0.86
0.21
2.15
0.21
1.92
0.43
0.97
2.37
1.63
0.13
2.54
21
-------
TABLE 3-5. CALCULATED MAXIMUM POSSIBLE (MINIMUM DETECTIBLE) CONCENTRATIONS:
HAPs NOT DETECTED IN SPECTRA OF CONDENSED SAMPLES EXTRACTED FROM
UNIT 5 STACK AT GREENS BAYOU GAS-FIRED BOILER.
LOCATION
Compound(a)
Ethyl Acrylate
•thylene Bichloride
Ethylidene bichloride
Formaldehyde
Hexachlorobutadiene
Hexachlorocylcopentadiene
texachloroe thane
•lexamethylphosphoramide
Hydrochloric Acid
Isophorone
Maleic Anhydride
Methyl hydrazine
Naphthalene
Nitrobenzene
N-Nitrosodimethylene
vl-Nitrosomorpholine
Phenol
jeta-Propiolactone
Propionaldehyde
1 ,2-Propy lenimine
Quioline
Styrene Oxide
1 , 1 ,2,2-Tetrachloroethane
2,4-Toluene diisocyanate
o Toluidine
1 ,2,4-Trichlorobenzene
2,4.5-Trichlorophenol
2,4,6-Trichlorophenol
rriethylamine
Ammonia
Analytical Region (wn)(b)
1181.93 - 1210.00
1227.88 - 1241.50
930.35 - 1126.16
2788.33 - 2842.20
847.50 - 864.50
1227.02 - 1240.42
995.46 - 1042.73
949.42 - 1019.53
2817.35 - 2823.26
2681.20 - 3130.60
885.27 - 905.56
2683.00 - 3061.78
779.31 • 783.55
841.70 - 861.39
928.00 - 1085.28
892.23 - 1024.64
1162.67 - 1195.76
860.13 - 957.64
2546.18 - 3114.35
817.57 - 821.31
800.19 - 803.73
861.39 - 903.93
794.92 - 824.07
885.61 - 905.31
2858.50 • 2951.85
1009.00 - 1198.39
1178.04 - 1204.16
856.27 - 863.36
2756.62 - 2839.34
893.10 - 926.00
STACK
RMSD(c)
1.70E-03
1.67E-03
4.45E-03
1.25E-03
2.09E-03
1.77E-03
2.47E-03
2.63E-03
8.43E-04
3.37E-03
1.19E-03
3.08E-03
3.74E-03
1.85E-03
3.76E-03
3.13E-03
1.92E-03
2.79E-03
2.96E-03
1.41E-03
3.05E-03
1.57E-03
3.17E-03
1.19E-03
2.45E-03
4.62E-03
1.66E-O3
1.25E-03
1.22E-03
2.15E-03
Max. Con.
(ppm)(d)
0.08
0.92
6.12
1.23
0.19
0.13
8.56
0.35
0.81
2.09
0.12
3.31
0.36
0.71
1.14
1.23
0.29
0.57
3.11
0.60
0.45
1.08
0.71
0.85
1.99
3.08
0.50
0.29
0.51
1.28
(a) HAP's for which Entropy has obtained quantitative reference spectra.
(b) Frequency region, in wavenumbers (1/cm) chosen for the analysis.
(c) Calculated root mean square deviation over the analytical region in spectra that were generated by
subtracting reference spectra of interferant species from the sample spectra.
(d) .Maximum Concentration (in ppm) of undetected compound, that could have been present in FTIR samples,
calculated according to procedures discussed in Sections 4.6.3 and 3.3.1.
22
-------
TABLE 3-6. CALCULATED MAXIMUM POSSIBLE (MINIMUM DETECTIBLE) CONCENTRATIONS:
HAPs NOT DETECTED IN SPECTRA OF CONCENTRATED SAMPLES EXTRACTED FROM
UNIT 5 STACK AT GREENS BAYOU GAS-FIRED BOILER.
LOCATION
Compound(a)
Acetonitrile
Acrolein
Acrylonitrile
Ally! Chloride
tanzene
Bromoform
1.3-Butadiene
Carbonyl Sulfide
Chlorobenzene
Ethyl Benzene
Ethyl Chloride
Ethylene Dibromide
n-Hexane
Methyl Bromide
Methyl Chloride
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Methyl Methacrylate
Vlethylene Chloride
2-Nitropropane
Propylene Oichloride
Styrene
Tetrachloroethylene
Toluene
1 . 1 ,2-Trichloroethane
Frichloroethylene
2.2,4-Trimethylpentane
Vinyl Acetate
Vinyl Bromide
Vinyl Chloride
Vinylidene Chloride
O-xylene
P-xylene
Carbon Oisulfide
Carbon Tetrachloride
Chloroform
Analytical R
1041.40 - 1042.88
2636.11 - 2875.59
922.19 - 997.82
893.51 - 1002.22
3036.88 - 3063.07
1135.90 - 1154.20
870.00 - 1052.64
2029.21 • 2075.69
1012.42 - 1036.64
2866.13 - 2921.27
2916.56 - 3041.03
1167.96 • 1208.92
2835.27 - 3005.43
2948.11 - 2972.53
1017.96 • 1020.72
1140.70 - 1222.63
2872.05 - 2994.95
1137.50 - 1232.04
1249.95 - 1285.66
2875.79 - 3039.65
996.86 - 1038.00
886.32 - 931.22
899.20 - 925.20
2862.00 - 2924.00
909.41 - 960.62
919.70 - 959.88
2861.57 - 3009.23
919.53 - 1046.33
899.81 - 904.54
852.81 • 1056.06
1059.44 - 1113.01
2859.84 - 3095.04
770.61 - 819.06
2171.29 - 2184.68
793.89 - 800.58
758.21 - 781.25
STACK
RMSO(C)
4.55E-04
8.59E-04
-7.26E-03
6.81 E-03
6.33E-03
2.42E-03
6.08E-03
1.59E-02
3.03E-03
1.63 E-03
6.94E-03
3. 71 E-03
3.07E-03
2.52E-03
3.29E-04
5.18E-03
3.23E-03
5.61 E-03
1.55E-02
6.27E-03
2. 73 E-03
5.01 E-03
2.56E-03
1.67E-03
6.23E-03
6.00E-03
3.28E-03
6.61 E-03
2.35E-04
6.99E-03
7.66E-03
6.60E-03
3.75E-03
1.11E-02
5.68E-03
1.74 E-03
Max. Con.
(ppm)(d)
2.42
1.12
5.98
5.56
2.96
0.45
6.36
0.90
2.79
3.33
5.15
2.64
0.45
2.89
1.08
3.82
1.36
0.63
6.33
5.31
3.21
3.80
0.23
2.63
6.49
1.15
0.39
3.31
0.10
7.14
2.04
4.18
2.14
10.53
0.11
0.09
23
-------
TABLE 3-6. CALCULATED MAXIMUM POSSIBLE (MINIMUM DETECTIBLE) CONCENTRATIONS:
HAPs NOT DETECTED IN SPECTRA OF CONCENTRATED SAMPLES EXTRACTED FROM
UNIT 5 STACK AT GREENS BAYOU GAS-FIRED BOILER.
LOCATION
Compound(a)
Cumene
1,2-Epoxy Butane
Ethylene Oxide
riethanol
Methyl Chloroform
Methyl Iodide
Methyl t-Butyl Ether
'ropylene Oxide
vl-xylene
Acetone
Acetaldehyde
Acetophenone
Acrylic Acid
Aniline
3enzotrichloride
Benzyl Chloride
3is(chloromethyl)ether
Chloroacetic acid
2-Chloroacteophenone
Chloromethyl methyl ether
Chloroprene
o-Cresol
m-Cresol
p-Cresol
1 ,2-Dibromo-3-chloropropane
1 ,4-Dichlorobenzene
Oichloroethyl ether
1 ,3-Dichloropropene
Dichlorvos
N.N-Diethyl aniline
Dimethyl carbamoyl chloride
Dimethyl formamide
1,1 -Dimethyl hydrazine
Dimethyl phthalate
1,4-Dioxane
Epichlorohydrin
Analytical R
1015.82 - 1063.57
902.37 - 919.70
866.90 - 875.00
2807.91 • 3029.40
1057.95 - 1105.30
1250.18 - 1253.53
1195.00 - 1210.00
2875.59 - 3097.75
2910.25 - 2952.78
1182.00 - 1255.03
2685.41 - 2744.40
1140.40 - 1286.06
1104.89 - 1164.68
1102.90 - 1123.63
805.30 - 823.50
1262.87 - 1279.12
1068.78 - 1154.25
1094.97 - 1124.12
1274.39 - 1285.42
1111.02 - 1146.08
875.90 - 878.80
1092.80 - 1114.07
1139.68 • 1172.77
1159.10 - 1185.50
855.88 - 904.72
995.96 - 1031.06
1109.35 - 1155.04
768.00 - 791.00
967.79 - 1000.25
2655.32 - 3156.07
889.55 - 917.52
2824.80 - 2873.60
856.12 - 974.09
1157.86 - 1254.16
2861.10 - 2864.80
943.52 - 981.73
STACK
RMSD(C)
3.50E-03
2.61 E-03
2.82E-03
4.09E-03
7.72E-03
8.29E-04
1.72E-03
6.86E-03
2.16E-03
5.72E-03
6.80E-04
9.49E-03
3.55E-03
4.05E-03
2.04E-03
1.59E-02
5.44E-03
3.78E-03
8.12E-03
3.36E-03
4.83E-04
3. 21 E-03
2.42E-03
3.27E-03
3.34E-03
2.27E-03
3.18E-03
2.80E-03
3.48E-03
5.76E-03
2.49E-03
7.00E-04
6.68E-03
5.51 E-03
3.59E-04
7. 80 E-03
Max Con.
(ppm)(d)
8.64
1.90
0.68
3.29
1.35
0.75
0.27
4.34
1.31
2.48
1.12
1.22
0.45
1.29
0.23
7.19
0.58
0.80
1.49
0.49
0.09
1.33
0.43
0.35
5.69
0.97
0.36
0.56
0.48
3.28
0.61
0.43
5.39
2.86
0.05
6.24
24
-------
TABLE 3-6. CALCULATED MAXIMUM POSSIBLE (MINIMUM DETECTIBLE) CONCENTRATIONS:
HAPs NOT DETECTED IN SPECTRA OF CONCENTRATED SAMPLES EXTRACTED FROM
UNIT 5 STACK AT GREENS BAYOU GAS-FIRED BOILER.
LOCATION
Compound(a)
Ethyl Acrylate
Ethylene Oichloride
Ethylidene dichloride
:ormaldehyde
Hexachlorobutadiene
Hexachlorocylcopentadiene
Hexachloroethane
Hexamettiylphosphoramide
Hydrochloric Acid
sophorone
Maleic Anhydride
Methyl hydrazine
Naphthalene
Nitrobenzene
•J-Nitrosodimethylene
N-Nitrosomorpholine
•"henol
Deta-Propiolactone
Propionaldehyde
1 ,2-Propylenimine
Quioline
Styrene Oxide
1 , 1 ,2.2-Tetrachloroethane
2.4-Toluene diisocyanate
o Toluidine
1 ,2,4-Trichlorobenzene
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
rriethylamine
Ammonia
Analytical R
1181.93 - 1210.00
1227.88 - 1241.50
696.22 - 750.59
2788.33 - 2842.20
976.90 - 997.70
1227.02 - 1240.42
995.46 - 1042.73
949.42 - 1019.53
2817.35 - 2823.26
2681.20 • 3130.60
838.45 • 841.30
2683.00 - 3061.78
779.31 - 783.55
841.70 - 861.39
928.00 - 1085.28
892.23 - 1024.64
1162.67 - 1195.76
860.13 - 957.64
2546.18 - 3114.35
817.57 - 821.31
800.19 - 803.73
861.39 - 903.93
794.92 - 824.07
885.61 - 905.31
2858.50 - 2951.85
1009.00 - 1198.39
1178.04 - 1204.16
856.27 - 863.36
2756.62 • 2839.34
893.10 - 926.00
STACK
RMSD(c)
3.13E-03
2.00E-03
2.97E-02
6.98E-04
2.47E-03
1.95E-03
2.71E-03
6.15E-03
3.71 E-04
5.BOE-03
1.14E-03
4.70E-03
1.19E-03
6.93E-03
9.74E-03
6.33E-03
3.84E-03
5.40E-03
4.82E-03
4.42E-04
1.77E-03
2.80E-03
3.87E-03
1.82E-03
2.17E-03
9.32E-03
3.32E-03
1.54E-03
7.78E-04
2.52E-03
Max. Con.
(ppm)(d)
0.16
1.10
8.40
0.69
0.34
0.14
9.40
0.82
0.36
3.60
0.11
5.04
0.11
2.67
2.95
2.49
0.58
1.11
5.07
0.19
0.26
1.93
0.86
1.29
1.76
6.21
1.00
0.36
0.32
1.50
(a) HAP's for which Entropy has obtained quantitative reference spectra.
(b) Frequency region, in wavenumbers (1/cm) chosen for the analysis.
(c) Calculated root mean square deviation over the analytical region in spectra that were generated by
subtracting reference spectra of interferant species from the sample spectra.
(d) Maximum Concentration (in ppm) of undetected compound, that could have been present in FTIR samples,
calculated according to procedures discussed in Sections 4.6.3 and 3.3.1.
25
-------
3.3.2 Instrumental and Manual Test Results
Table 3-7 presents the results of the EPA Methods 3A and 10 tests as
described in Section 4-3. No HC data were available during the test because
the analyzer malfunctioned. But, judging from the FTIR data, the HC
concentration was below the detection limit of the HC analyzer. A summary of
the CEM results is presented in Table 3-8. All CEM results in the tables
were determined from the average gas concentration measured during the run
and adjusted for drift based on the pre- and post-test run calibration check
results (Equation 6C-1 presented in EPA Method 6C, Section 8). Although not
required by Method 10, the same data reduction procedures as that in Method
3A were used for the CO determinations to ensure the data quality. All
measurement system calibration bias and calibration drift checks for each
test run met the applicable specifications of the test methods.
26
-------
TABLE 3-7. RESULTS FROM GREENS BAYOU UNIT 5
Date
5/20/93
Run
#
1
2
Sample
Time
1124-1127
1135-1138
1145-1147
1152-1155
1210-1212
1225-1227
1326-1328
1338-1342
1345-1348
1400-1404
1412-1415
1546-1549
1554-1555
1600-1602
1713-1715
1720-1724
1730-1740
1745-1800
1820-1831
1901-1903
1912-1914
1924-1926
1930-1932
Sampling System
to FTIR (a)
Hot/Wet
Condenser
Condenser
Perma-Pure
Hot/Wet
Condenser
O2
(%d)
2.1
2.3
2.2
2.3
2.1
1.8
2.1
2.1
2.1
2.1
1.8
1.6
1.8
1.9
1.8
1.7
1.6
1.7
1.7
1.5
1.6
1.7
1.8
CO2
(%d)
10.7
10.6
10.6
10.6
10.7
10.8
10.7
10.7
10.7
10.7
11.0
11.1
10.8
10.8
11.0
11.0
11.1
11.0
11.1
11.1
11.1
11.1
11.0
CO
ppmd
0.0
0.0
0.0
0.0
0.0
1.6
0.0
0.0
0.0
0.0
14.0
4.7
1.1
0.0
0.2
3.4
6.3
4.9
5.9
13.0
10.3
4.7
4.1
Ib/hr
0.0
0.0
0.0
0.0
0.0
4.5
0.0
0.0
0.0
0.0
39.5
12.8
3.0
0.0
0.5
9.2
17.1
13.3
16.0
35.3
28.0
12.8
11.1
Flow Rate
(WSCFM)
779,487
779,487
750,265
750,265
750,265
750,265
Flow Rate
(DSCFM)
646,974
646,974
622,720
622,720
622,720
622,720
-------
TABLE 3-7. RESULTS FROM GREENS BAYOU UNIT 5 (Cont.)
Date
5/21/93
Run
#
3
Sample
Time
1108-1109
1113-1114
1120-1121
1131-1133
1143-1145
1150-1152
1158-1200
1205-1208
1220-1233
1236-1246
1250-1259
1302-1315
Sampling System
to FTIR
Hot/Wet
Condenser
Perma-Pure
O2
(%d)
1.9
1.9
1.8
2.0
1.9
1.9
1.9
2.0
1.9
1.9
2.0
2.1
CO2
(%d)
10.9
10.8
10.9
10.8
10.9
10.9
10.9
10.8
10.9
10.9
10.8
10.8
CO
ppmd
0.5
1.1
3.9
0.8
0.9
1.8
0.8
0.7
2.5
2.0
0.0
0.0
Ib/hr
1.2
2.7
9.7
2.0
2.2
4.5
2.0
1.7
6.2
5.0
0.0
0.0
Flow Rate
(WSCFM)
684,423
684,423
684,423
Flow Rate
(DSCFM)
568,071
568,071
568,071
IX)
00
(a) Sampling system descriptions are contained in Section 4.1. CEM procedures are
described in Section 4.3. Description of flow rate calculations is contained in Section 4.4.
-------
TABLE 3-8. SUMMARY OF CEM AND MANUAL TEST RESULTS AT GREENS BAYOU UNIT 5
DATE
5/20/93
5/21/93
RUN
#
1
2
3
SAMPLE
TIME
1124-1347
1400-1415
1546-1602
1713-1831
1901-1914
1925-1932
1108-1132
1143-1208
1220-1315
SAMPLING
SYSTEM
TO FTIR
Hot/Wet
Condenser
Condenser
PermaPure
Hot/Wet
Condenser
Hot/Wet
Condenser
PermaPure
02
(%d)
2.2
2.0
1.8
1.7
1.5
1.7
1.9
1.9
2.0
C02
(%*}
10.7
10.8
11.0
11.0
11.1
11.1
10.8
10.9
10.8
CO
Ppmd
0.0
3.0
6.8
4.3
11.8
4.0
1.2
2.4
0.9
Ib/hr
0.0
8.5
18.5
11.7
32.0
10.9
3.0
5.9
2.2
FLOW
RATE
(WSCFM)
779,487
750,265
684,423
FLOW
RATE
(DSCFM)
646,974
622,720
568,071
Each test run emission rate (expressed in units of Ib/hr) was computed
using the averaged concentration measurement for the test period, the flue
gas volumetric flow rate, and the appropriate conversion factors. The boiler
exhaust gas flow rates were determined using EPA Method 19 procedures and the
measured flue gas 02 and are presented in Table 3-9. The natural gas analysis
data were supplied by HLPC and are included in Appendix A. The sets of
analysis data were averaged and used with the fuel feed rates to the boiler
during the test periods to compute the heat consumption and Fd-factor needed
to determine the dry exhaust gas volumetric flow rate (in units of dry
standard cubic feet per minute, dscfm) for each test run. Wet basis flow
rates (wscfm) were computed based on 17% H20 in the flue gas.
TABLE 3-9. BOILER EXHAUST GAS VOLUMETRIC FLOW RATE DETERMINATIONS
RUN
NO.
1
2
3
GCV
(Btu/ft3)
1034
1034
1034
AVG. FUEL
FLOW
(mmft3/day)
93.8
92.3
83.3
HEAT
CONSUMPTION
(mmBtu/hr)
4044.7
3975.9
3589.2
Fd
(dscf/mmBtu)
8633
8633
8633
02
(%d)
2.1
1.7
1.9
FLUE
GAS
FLOW
(dscfm)
646,974
622,720
568,071
As a quality assurance check of the 02 and C02 data, F0 factors were
calculated for each test run. The calculated F0 results presented in Table
3-10 are within the range of acceptable values.
29
-------
TABLE 3-10. VALIDATION OF 0, AND CO, MEASUREMENT DATA
RUN NO.
1
2
3
02
(%d)
2.2
2.0
1.8
1.7
1.5
1.7
1.9
1.9
2.0
C02
(%d)
10.7
10.8
11.0
11.0
11.1
11.1
10.8
10.9
10.8
CALCULATED
F0
1.75
1.75
1.74
1.75
1.75
1.73
1.76
1.74
1.75
Calculated F0 = (20.9-%02) / %C02
EPA Method 3 acceptance criteria,
F0 range: 1.64 - 1.88 for natural gas
30
-------
3.3.3 Process Results
3.3.3.1 Operating Conditions -- The preheater outlet and inlet
temperatures, natural gas flow (mmBtu/hr), generator output (in megaWatts),
stack gas 02 concentration (in percent) are presented Table 3-11 and Figures
3-1 to 3-3.
3.3.3.2 Process Variations During Testing -- Variations and changes that
occurred with the process are listed below.
1) During Run 1 (9:30 a.m. to 1:30 p.m., 5/20/93), a cooling tower fan
(1 of 10) was turned off from 10:40 a.m.-11:07 a.m. and from 1:25
p.m. to the end of Run 1.
2) During Run 2 (3:30 p.m. to 7:30 p.m., 5/20/93), a "frozen shut"
high-pressure steam governor valve (1 of 8) was cycled twice and
freed. This action resulted in increases in all monitored data
except the oxygen reading. Subsequent decreases resulted when
plant personnel cycled the valve again and it remained closed.
3) During Run 3 (9:45 a.m. to 1:45 p.m., 5/21/93), the unit was
operated between 360 and 370 MW. This range was used to reduce the
possibility of damage from the "frozen" high-pressure steam
governor valve.
31
-------
TABLE 3-11 Process Data Sheet: Houston Lighting and Power Co., Greens Bayou, Unit Five
Date
Testl
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
Test 2
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
Time
9:30 AM
9:38 AM
9:46 AM
9:54 AM
10:02 AM
10:10 AM
10:18 AM
10:26 AM
10:34 AM
10:42 AM
10:50 AM
10:38 AM
11:06 AM
11:14 AM
11:22 AM
11:30 AM
11:38 AM
11:46 AM
11:54 AM
12:02 PM
12: 10PM
12: 18PM
12:26 PM
12:34 PM
12:42 PM
12:50 PM
12:58 PM
1:06 PM
1:14 PM
1:22 PM
1:30 PM
3: 30PM
3:38PM
3-.46PM
3:54PM
4:02 PM
4: 10PM
4: 18PM
4:26 PM
4:34 PM
4:42 PM
4:50 PM
4:58 PM
MW
Operating capacity
414.01
414.01
413.80
417.17
413.80
413.80
414.01
413.80
413.80
414.01
412.71
411.56
411.77
413.23
414.01
414.01
414.38
414.38
414.17
414.38
413.64
413.80
414.38
413.80
413.64
414.01
413.07
413.07
413.23
413.44
412.29
413.80
427.14
432.76
408.96
411.77
411.36
410.83
411.20
410.99
411.20
410.83
410.83
DegF
Preheater inlet temp.
657.80
657.43
657.80
658.02
658.10
657.88
657.80
658.02
657.88
657.88
657.58
657.80
658.02
657.88
657.80
658.02
658.70
659.00
658.93
658.63
658.18
658.10
657.80
656.68
656.60
657.13
656.83
656.83
656.98
657.43
657.88
654.20
656.98
661.70
659.68
656.98
655.77
654.80
654.80
655.02
655.02
654.73
654.27
DegF
Preheater outlet temp.
264.88
265.48
265.48
265.70
266.08
266.30
266.60
267.20
267.73
267.88
268.33
268.63
268.93
268.78
268.93
269.75
270.20
270.73
270.43
270.28
269.83
270.43
269.98
269.60
269.90
269.98
269.98
270.20
270.28
270.28
271.03
269.30
271.03
274.10
273.58
270.88
270.43
269.98
269.83
269.90
270.20
270.28
270.28
Percent
Oxygen
1.6287
1.7556
1.8305
1.7480
1.8457
1.7112
1.7274
1.7263
1.7871
1.6786
1.6916
1.7090
1.7068
1.7632
1.7600
2.0887
1.9726
2.0041
1.9325
2.0313
1.7730
1.8457
1.6211
1.5430
1.5972
1.5820
1.5592
1.5549
1.7665
1.8522
1.8609
1.4724
1.5451
1.4106
1.6504
1.7437
1.6015
1.6330
1.6265
1.6970
1.6265
1.4670
1.6211
Million Btu/hr
Natural Gas Flow
4052.2
4064.9
4060.3
4060.3
4057.1
4049.1
4051.2
4041.3
4037.5
4036.8
4039.7
4035.8
4040.5
4042.9
4045.5
4054.3
4048.3
4048.3
4048.5
4045.7
4041.6
4043.3
4037.8
4040.4
4043.9
4035.9
4024.8
4037.4
4037.1
4043.6
4039.9
4014.2
4139.6
4184.1
3876.3
3958.8
3963.4
3964.4
3965.1
3973.8
3958.5
3960.0
3963.2
32
-------
TABLE 3-11 Process Data Sheet: Houston Lighting and Power Co., Greens Bayou, Unit Five (Cont.)
Date
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
Time
5:06PM
5: 14PM
5:22 PM
5:30 PM
5:38 PM
5:46 PM
5:54 PM
6:02 PM
6: 10PM
6:18 PM
6:26 PM
6:34 PM
6:42 PM
6:50 PM
6:58 PM
7:06 PM
7: 14PM
|_ 7:22 PM
7:30 PM
MW
Operating capacity
410.99
410.99
410.63
411.36
410.99
410.99
410.99
411.56
410.99
411.56
411.93
411.20
411.20
411.93
411.36
411.56
411.20
411.36
411.77
•ta for 3D flow traverse (after Test 2)
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
7:38 PM
7:46 PM
7:54 PM
8:02 PM
8:10 PM
8:18 PM
8:26 PM
8:34 PM
8:42 PM
8:50 PM
8:58 PM
9:06 PM
9: 14PM
9:22 PM
9:30 PM
9:38 PM
9:46 PM
9:54 PM
10:02 PM
10: 10PM
10: 18PM
10:26 PM
10:34 PM
DegF
Preheater inlet temp.
654.73
655.33
655.18 ,
654.65
654.20
653.60
654.13
654.50
654.27
654.58
654.73
654.43
654.13
654.73
653.98
653.90
653.68
653.98
654.13
DegF
Preheater outlet temp.
270.88
270.50
270.13
269.98
269.68
269.68
269.38
269.83
269.60
269.98
269.90
269.60
269.83
269.68
269.08
268.70
268.93
268.70
268.93
Percent
Oxygen
1.5864
1.7545
1.7133
1.4279
1.4279
1.5028
1.4355
1.6601
1.5820
.6081
.5375
.5994
.6406
.5961
.3596
.3520
.3715
1.4160
1.5820
Million Btu/hr
Natural Gas Flow
3966.6
3969.3
3967.9
3959.8
3960.3
3974.3
3971.2
3965.4
3963.7
3977.3
3959.6
3952.6
3966.2
3972.7
3955.3
3954.6
3970.2
3963.6
3960.8
3959.2
3972.9
3844.2
3845.2
3862.1
3631.7
3722.7
3340.8
3069.2
2703.6
2701.6
2607.2
2707.2
2566.2
2544.3
2410.2
2469.7
2507.8
2494.2
2535.0
2599.0
2463.0
2300.0
33
-------
TABLE 3-11 Process Data Sheet: Houston Lighting and Power Co., Greens Bayou, Unit Five (Cont.)
Date
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
5/20/93
Test3
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
Tune
10:42 PM
10:50 PM
10:58 PM
11:06PM
11: 14PM
11:22PM
11:30PM
11:38 PM
11:46PM
11:54PM
12:02 AM
12:10 AM
12:18 AM
12:26 AM
12:34 AM
12:42 AM
9:44 AM
9:52 AM
10:00 AM
10:08 AM
10:16 AM
10:24 AM
10:32 AM
10:40 AM
10:48 AM
10:56 AM
11:04 AM
11:12 AM
11:20 AM
11:28 AM
11:36 AM
11:44 AM
11:52 AM
12:00 PM
12:08 PM
12:16 PM
12:24 PM
12:32 PM
12:40. PM
12:48 PM
12:56 PM
1:04 PM
1:12 PM
1:20 PM
1:28 PM
MW
Operating capacity
365.26
366.20
364.69
366.20
364.32
365.83
366.20
364.11
365.05
364.32
363.75
363.02
363.54
363.54
366.20
364.11
364.89
362.24
366.56
364.69
364.69
366.20
363.02
363.39
363.39
363.18
363.54
365.83
363.02
DegF
Preheater inlet temp.
642.20
642.73
642.80
642.58
641.38
642.13
642.27
642.50
642.43
642.20
642.43
641.90
642.50
643.02
642.88
642.13
642.20
642.43
643.02
642.88
642.43
643.02
642.20
642.20
642.73
643.10
642.43
642.80
643.33
DegF
Preheater outlet temp.
257.08
257.53
257.83
258.13
257.83
258.73
258.58
258.88
259.33
259.18
259.48
259.48
259.40
260.23
260.60
260.38
260.08
260.08
260.23
260.30
260.60
260.60
260.38
260.38
260.68
260.68
260.60
260.83
260.68
Percent
Oxygen
1.8316
2.0215
1.9585
1.7990
1.8110
1.8088
1.9184
1.9184
1.9336
1.7969
1.6471
1.7773
1.7969
1.8945
1.9227
1.7969
1.7914
1.7285
2.0551
1.6743
1.6547
1.9282
1.7990
1.8945
2.0085
1.9455
2.162S
1.8869
1.9282
Million Btu/hr
Natural Gas Flow
1894.8
1529.3
1535.0
1526.5
1521.0
1S38.1
1570.3
1594.5
1596.4
1525.9
1538.0
1480.5
1463.4
1518.5
1545.8
1555.1
3557.6
3598.6
3656.6
3588.9
3593.8
3628.6
3573.9
3573.9
3652.5
3568.3
3560.4
3562.9
3585.4
3572.4
3608.9
3586.8
3559.6
3539.2
3695.6
3561.9
3608.3
3648.3
3618.6
3556.0
3615.8
3574.5
3592.7
3574.5
3543.1
34
-------
TABLE 3-11 Process Data Sheet: Houston Lighting and Power Co., Greens Bayou, Unit Five (Cont.)
Date
5/21/93
5/21/93
Time
1:36 PM
1:44 PM
MW
Operating capacity
363.%
365.26
Data for 3D flow traverse (after Test 3)
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
5/21/93
1:52 PM
2:00 PM
2:08 PM
2:16 PM
2:24 PM
2:32 PM
2:40 PM
2:48 PM
2:56 PM
3.04PM
3:12 PM
3:20 PM
3:28PM
DegF
Preheater inlet temp.
643.70
642.80
DegF
Preheater outlet temp.
260.53
261.13
Percent
Oxygen
1.8989
1.7871
Million Btu/hr
Natural Gas Flow
3559.5
3548.2
3543.2
3570.3
3617.3
3508.7
3583.8
3543.2
3602.2
3606.5
3462.2
3505.7
3571.8
3523.8
3547.3
35
-------
GO
CD
418
417
416
415
414
413
412
411
630im 1002am. 1034 «m ll:06am. 11:38 im 12:10pm 1242pm. 1:14 pm.
g46am. 10:1ta.m. lOSOam 11:22
-------
CO
435
430
425
420
415
410
405
3:30pm. 402p.m. 4:34p.m. S:06p.m. S:36p.m. 6:10pm. 6:42p.m. 7:14p.m.
3:46 pm 4:IBp.m. 450pm. 5:22 p m. 554pm. 626pm. 658pm. 7:30 pn
Generator Output, Megawatts
Outlet Temp. (F)
276
274
272
270
268
266
264
664
330pm 4
-------
CO
00
367
366
365
364
363
362
844«m 1016am 1048am 1120a.m. 1152am. 1224pm. 1256pm 126pm.
1000am. 1032am. 1104am 11:36 am. 12.08pm. 1240pm 112pm. t:44pm.
2.2
2.1
2
1.9
1.8
1.7
1.6
644am. 10:18 am. 1048am 11:20 am. 11:52 am. 1224pm. 1258pm. 128pm
10:00im. 10:32am. 11:04 am 11:36i m. 1208pm. 12:40pm. 1:12pm 1:44 pin
Generator Output, Megawatts
Stack Gas Oxygen (percent)
Outlet Temp. (F)
262
261
260
259
258
257
256
Inlet Temp. (F) 3.750
646
3,700
645
644 3>65°
643 3,600
642
3,550
641
B:44«m 10:18 am 10:48 am 1120am 1152am 1224pm 1256pm 121pm.
lOOOam. 1032am 11.
-------
4.0 SAMPLING AND ANALYTICAL PROCEDURES
The FTIR analysis uses two different techniques. The first, referred to
as direct gas phase analysis, involves transporting the gas stream to the
sample manifold and directly to the infrared cell. This technique provides
a sample similar in composition to the flue gas stream at the sample point
location. Some compounds may be affected because of contact with the
sampling system components or reactions with other species in the gas. A
second technique, referred to as sample concentration, involves concentrating
the sample by passing a measured volume through an absorbing material
(Tenax®) packed into a U-shaped stainless steel collection tube. After
sampling, the tube is heated to desorb any collected compounds into the FTIR
cell. The desorbed sample is then diluted with nitrogen to one atmosphere
total pressure within the cell. Concentrations of any species detected in
the absorption cell are related to flue gas concentrations by comparing the
volume of gas collected to the volume of the FTIR cell. Desorption into the
smaller FTIR cell volume provides a volumetric concentration. This, in turn,
provides a corresponding increase in sensitivity for the detection of any
species that can measured using Tenax®. Sample concentration makes it
possible to achieve lower detection limits for some HAPs.
Infrared absorbance spectra of gas phase and concentrated samples were
recorded and analyzed. In conjunction with the FTIR sample analyses,
measurements of HC, CO, 02, and C02 were obtained using EPA instrumental test
methods. Components of the emission test systems used by Entropy for this
testing program are described below.
4.1 EXTRACTIVE SYSTEM FOR DIRECT GAS PHASE ANALYSIS
An extractive system was used to transport the gas stream from the stack
directly to the infrared absorbance cell. Figure 4-1 illustrates the
sampling system used for both FTIR gas phase analysis and EPA instrumental
test methods.
4.1.1 Sampling System
Flue gas was extracted through a stainless steel probe. A Balston®
particulate filter rated at 1 micron was installed at the outlet of the
sample probe. Heated 3/8-inch O.D. Teflon® sample line connected the probe
to the heated sample pump (KNF Neuberger, Inc. model number N010 ST.Ill)
located inside the mobile laboratory. A 150-ft length of Teflon® sample line
was sufficient to reach the FTIR truck. The temperature of the sampling
system components was maintained at about 300°F. Digital temperature
controllers were used to control and monitor the temperature of the transport
lines. All connections were wrapped with electric heat tape and insulated to
ensure that there were no "cold spots" in the sampling system where
condensation might occur. All components of the sample system were
constructed of Type 316 stainless steel or Teflon®. The heated sample flow
manifold, located within the FTIR truck, included a secondary particulate
filter and valves that allowed the operator to send sample gas directly to
the absorption cell or through a gas conditioning system.
39
-------
The extractive system can deliver three types of samples to the
absorption cell. Sample sent directly to the FTIR cell is considered
unconditioned, or "hot/wet." This sample is thought to be most
representative of the actual effluent composition. The removal of water
vapor from the gas stream before analysis was sometimes desirable; therefore,
a second type of sample was provided by directing gas through a condenser
system. The condenser employed a standard Peltier dryer to cool the gas
stream to approximately 38°F. The resulting condensate was collected in two
traps and removed from the conditioning system with peristaltic pumps. This
technique is known to leave the concentrations of inorganic and highly
volatile compounds very near to the (dry-basis) stack concentrations. A
third type of sample was obtained by passing the gas stream through a series
of PermaPure® dryers. This system utilized a network of semi-permeable
membranes. Water vapor was drawn through the membrane walls by a
concentration gradient, which was established by a counter flow of dry air
along the outside of the membrane walls. In addition to protecting the
absorption cell, water removal relieved spectral interferences, which could
limit the effectiveness of the FTIR analysis for particular compounds.
4.1.2 Analytical System
The FTIR equipment used in this test consists of a medium-resolution
interferometer, heated infrared absorption cell, liquid nitrogen cooled
mercury cadmium telluride (MCT) broad band infrared detector, and computer.
The interferometer, detector, and computer were purchased from KVB/Analect,
Inc., and comprise their base Model RFX-40 system. The nominal spectral
resolution of the system is one wavenumber (1 cm"1). Samples were contained
in a model 5-22H infrared absorption cell manufactured by Infrared Analysis,
Inc. The inside walls and mirror housing of the cell were Teflon® coated.
Cell temperature was maintained at 240°F using heated jackets and temperature
controllers. The absorption path length of the cell was set at 22 meters.
Figure 4-2 shows the arrangement of the FTIR instrumentation.
4.1.3 Sample Collection Procedure
During all three runs, gas phase and sample concentration testing were
performed concurrently at the stack. During a test run, flue gas was
continuously flowed through the heated system to the sample manifold in the
FTIR truck. A portion of the gas stream was diverted to a secondary manifold
located near the inlet of the FTIR absorption cell. The cell was filled with
sample to ambient pressure and the FTIR spectrum recorded. After analysis,
the cell was evacuated so that a subsequent sample could be introduced. The
process of collecting and analyzing a sample and then evacuating the cell to
prepare for the next sample required less than 10 minutes. During each run,
about 12 gas phase samples were analyzed.
40
-------
Vent
In-Slack
Particulate
Filter
Extractive
Probe
Heated
Pump
Heated
Transport
Lines
Hot/Wet
Perma-Pure
Dryer
Condenser
Heated
Manifold
FTIR
Cell
02
Analyzer
1
CO
Analyzer
50104 9/93
Figure 4-1. Direct extraction gas handling system.
-------
ro
To To
Vacuum Vent
Pump
Preheated
N2
50104 9/93
Figure 4-2. Top view of FTIR measurement system.
-------
4.2 SAMPLE CONCENTRATION
Sample concentration was performed using the adsorbent material Tenax®,
followed by thermal desorption into the FTIR cell. The sample collection
system employed equipment similar to that of the Modified Method 5 sample
train.
4.2.1 Sampling System
Figure 4-3 depicts the apparatus used in this test program. Components
of the sampling train included a heated stainless steel probe, heated filter
and glass casing, stainless steel air-cooled condenser, stainless steel
adsorbent trap in an ice bath, followed by two water-filled impingers, one
knockout impinger, an impinger filled with silica gel, sample pump, and a dry
gas meter. All heated components were kept at a temperature above 120°C to
ensure no condensation of water vapor within the system. The stainless steel
condenser coil was used to pre-cool the sample gas before it entered the
adsorbent trap. The trap was a specially designed stainless steel U-shaped
collection tube filled with 10 g of Tenax® and plugged at both ends with
glass wool. Stainless steel was used for the construction of the adsorbent
tubes because it gives a more uniform and more efficient heat transfer than
glass.
Each sampling run was conducted for 4 hours at approximately 0.12 to
0.17 dcfm for a total sampled volume between 30 and 40 dcf. The sampling
rate was close to the maximum that can be achieved with the sampling system
and collection times provided a volumetric concentration that is proportional
to the amount of gas sampled. The resulting increase in sensitivity allowed
detection to sub-ppm concentrations for some compounds.
4.2.2 Analytical System
Sample tubes were analyzed using thermal desorption-FTIR. The sample
tubes were wrapped with heat tape and placed in an insulated chamber. One
end of the sample tube was connected to the inlet of the evacuated FTIR
absorption cell. The same end of the tube that served as the inlet during
the sample concentration run served as the outlet for the thermal desorption.
Gas samples were desorbed by heating the Tenax® to 250°C. A preheated stream
of UPC grade nitrogen was passed through the adsorbent to carry desorbed
compounds into the FTIR absorption cell. About 7 liters of nitrogen at 240°F
was required to carry the desorbed gases to the cell and bring the total
pressure of the FTIR sample to ambient pressure. The infrared absorption
spectrum was then recorded. The purging process was repeated until no
evidence of additional sample desorption was noted in the infrared spectrum.
43
-------
Heated
Filter Box
J
Probe
T
Duct Wall
Gas
Flow
Thermocouples
(T) (T)
Heated
Teflon
Line
Air-Cooled
Condenser
Coil
Thermocouple
Bypass
Valve
9
Vacuum Line
Main Valve
50104 9/93
Figure 4-3. Sample concentration sampling system.
-------
4.2.3 Sample Collection Procedure
The sample concentration test apparatus was set up at the location after
the test team performed leak checks of the system. The sample flow,
temperature of the heated box, and the tube outlet temperature were monitored
continuously and recorded at 10-minute intervals during each run. At the end
of each run flow was interrupted and the charged collection tube was removed.
The open ends were tightly capped and the tube was stored on ice until it was
analyzed. In most cases, the tubes were analyzed within several hours after
the sample run.
4.3 CONTINUOUS EMISSIONS MONITORING
Entropy's extractive measurement system and the sampling and analytical
procedures used for the determinations of HC, CO, 02, and C02 conform with the
requirements of EPA Test Methods 25A, 10, and 3A, respectively, of 40 CFR 60,
Appendix B. A heated sampling system and a set of gas analyzers were used to
analyze flue gas samples extracted at the exhaust stack. The CO, C02, and 02
analyzers received gas samples delivered from the same sampling system that
supplied the FTIR cell with condenser sample. These gas analyzers require
that the flue gas be conditioned to eliminate any possible interference
(i.e., water vapor and particulate matter) before being transported and
analyzed. The HC analyzer received hot/wet sample. All components that
contact the gas sample were either Type 316 stainless steel or Teflon®.
A gas flow distribution manifold downstream of the heated sample pump
was used to control the flow of sample gas to each analyzer. A refrigerated
condenser removed water vapor from the sample gas analyzed by all the
analyzers except for the HC analyzer (Method 25A requires a wet basis
analysis). The condenser was operated at approximately 38°F. The condensate
was continuously removed from the traps within the condenser to minimize
contact between the gas sample and the condensate.
The sampling system included a calibration gas injection point
immediately upstream of the analyzers for the calibration error checks and
also at the outlet of the probe for the sampling system bias and calibration
drift checks. The mid- and high-range calibration gases were certified by
the vendor according to EPA Protocol 1 specifications. Methane in air was
used to calibrate the HC analyzer.
Table 4-1 presents a list of the analyzers that Entropy used during the
test program to quantify the gas concentration levels at the sample point
locations. Figure 4-1 is a simplified schematic of Entropy's reference
measurement system.
45
-------
TABLE 4-1. GAS ANALYZERS USED DURING THE TEST PROGRAM
PARAMETER (RANGE)
HC (0-10 ppmj
CO (0-100 ppmd)
C02 (0-20%d)
02 (0-25%d)
ANALYZER
Ratfisch Model RS255CA
Thermo Environmental
Model 48
Fuji Model 3300
Teledyne 320P-4
ANALYTICAL TECHNIQUE
Flame ionization
detector (FID)
Infrared gas filter
correlation (GFC)
Non-dispersive infrared
(NDIR)
Micro-fuel cell
A computer-based data acquisition system was used to provide an
instantaneous display of the analyzer responses, as well as compile the
measurement data collected each second, calculate data averages over selected
time periods, calculate emission rates, and document the measurement system
calibrations.
The test run values are determined from the average concentration
measurements displayed by the gas analyzers during the run and are adjusted
based on the zero and upscale sampling system bias check results using the
equation presented in Section 8 of Method 6C.
4.4 FLOW DETERMINATIONS
Because the measurement location on the stack does not satisfy EPA
Method 1 criteria, flue gas volumetric flow was determined using mass balance
calculations based on the natural gas fuel usage rate, fuel composition, and
exhaust gas diluent concentrations (see below). The flow rate calculations
are based on the use of F-factors as outlined in EPA Method 19 (40 CFR 60).
The natural gas feed rate to the boiler was a process parameter recorded
by the RTI representative during the test program. The rates were recorded
at 15-minute intervals and then averaged for each test run period. Greens
Bayou personnel supplied EPA with fuel analysis data so that the gross
calorific value (GCV, in units of Btu/ft3) and Fd-factor (in units of dry
standard cubic feet of combustion gas generated per million Btu of heat
input, dscf/mmBtu) could be determined for the computation of the flue gas
volumetric flow rates.
During the sampling runs, an S-type pitot tube was positioned adjacent
to the point where the sample concentration probe was inserted. Single point
AP values were recorded at 10 minute intervals to verify that flow
characteristics, at the sampling point, were not changing significantly
during the test run.
Heat consumption of the boiler was one of the process parameters
recorded by the RTI representative at 8-minute intervals during the test periods.
46
-------
The dry exhaust gas flow rate was calculated according to EPA Method 19
procedures:
DSCFH = F °9
20.9-%02d
where:
Fd = Dry basis F-factor (dscf/mmBtu) determined from fuel analysis
%02d = Dry basis concentration measurement from EPA Method 3A
HC = Heat consumption (mmBtu/hr)
4.5 PROCESS OBSERVATIONS
During the test, a representative from Research Triangle Institute (RTI)
monitored the process operations so that emissions test data could be
correlated with process data.
4.6 ANALYTICAL PROCEDURES
4.6.1 Description of K-Matrix Analyses
K-type calibration matrices were used to relate absorbance to
concentration. Several descriptions of this analytical technique can be
found in the literature2. The discussion presented here follows that of
Haaland, Easterling, and Vopicka3.
For a set of m absorbance reference spectra of q different compounds
over n data points (corresponding to the discrete infrared wavenumber
positions chosen as the analytical region) at a fixed absorption path length
b, Beer's law can be written in matrix form as
A = KC+E (2)
where:
A = The n x m matrix representing the absorbance values of the m
reference spectra over the n wavenumber positions, containing
contributions from all or some of the q components;
K = The n by q matrix representing the relationship between absorbance
and concentration for the compounds in the wavenumber region(s) of
interest, as represented in the reference spectra. The matrix
element !(„„ = banq, where anq is the absorptivity of the qth
compound at the nth wavenumber position;
C = The q x m matrix containing the concentrations of the q compounds
in the m reference spectra;
47
-------
E = The n x m matrix representing the random "errors" in Beer's law for
the analysis; these errors are not actually due to a failure of
Beer's law, but actually arise from factors such as
misrepresentation (instrumental distortion) of the absorbance
values of the reference spectra, or inaccuracies in the reference
spectrum concentrations.
The quantity which is sought in the design of this analysis is the
matrix K, since if an approximation to this matrix, denoted by K, can be
found, the concentrations in a sample spectrum can also be estimated. Using
the vector A* to represent the n measured absorbance values of a sample
spectrum over the wavenumber region(s) of interest, and the vector C to
represent the j estimated concentrations of the compounds comprising the
sample, C can be calculated from A* and K from the relation
5=[KtK]'1KtA* . (3)
Here the superscript t represents the transpose of the indicated matrix, and
the superscript -1 represents the matrix inverse.
K=ACt[CCt]
"1
The standard method for obtaining the best estimate K is to minimize the
square of the error terms represented by the matrix E. The equation
represents the estimate K which minimizes the analysis error.
Reference spectra for the K-matrix concentration determinations were de-
resolved to 1.0 cm"1 resolution from existing 0.25 cm"1 resolution reference
spectra. This was accomplished by truncating and re-apodizing the
interferograms of single beam reference spectra and their associated
background interferograms. The processed single beam spectra were recombined
and converted to absorbance (see Section 4.3).
4.6.2 Preparation of Analysis Programs
To provide accurate quantitative results, K-matrix input must include
absorbance values from a set of reference spectra which, added together,
qualitatively resemble the appearance of the sample spectra. For this
reason, all of the Multicomp analysis files included spectra representing
interferant species and criteria pollutants present in the flue gas.
A number of factors affect the detection and analysis of an analyte in
the stack gas matrix. One factor is the composition of the stack gas. The
major spectral interferants in the gas-fired boiler effluent are water and
C02. At C02 concentrations of about 10 percent and higher, weak absorption
bands that are not visible at lower concentrations can interfere with the
48
-------
spectral analysis if not accounted for. Some portions of the FTIR spectrum
were not available for analysis because of extreme absorbance levels of water
and C02, but most compounds exhibit at least one absorbance band that is
suitable for analysis. Measurable amounts of NO and N02 were also present
in the samples and these species needed to be accounted for in any analysis
program. A second factor affecting analyses is the number of analytes that
are to be detected.
A set of Multicomp program files had been previously prepared for
analysis of data collected at a coal -fired utility for the purpose of
performing statistical validation testing of the FTIR methods. Separate
programs were prepared to measure 47 different compounds. Four baseline
subtraction points were specified for each analytical region, identifying an
upper and a lower baseline averaging range. The absorbance data in each
range were averaged, a straight baseline was calculated through the range
midpoint using the average absorbance values, and the baseline was subtracted
from the data prior to K-matrix analysis.
Before K-matrix analysis was applied to data all of the spectra were
inspected to determine what species had been detected. Analysis program
files were constructed that included reference spectra representing the
detected species. The program files were then used to calculate
concentrations of the detected species. Sample concentration spectra were
also analyzed using program files that were shown by the validation testing
to be suitable for measuring their corresponding compounds.
4.6.3 Error Analysis of data
The principal constituents of the gas phase samples were water, C02, NO,
and N02. A separate multicomp program was prepared to quantify each of these
compounds. Other than these species and N20 no major absorbance features were
observed in the spectra. After concentrations of the four main constituents
were determined, the appropriate standard was scaled and subtracted from the
spectrum of the mixture. This helped verify the calculated values. New
spectra were generated from the original absorbance spectra by successively
subtracting scaled standard spectra of water, C02, NO, and N02. The resulting
"subtracted" spectra were analyzed for detectible absorbencies of any HAPs
and, for undetected species, the maximum possible concentrations that could
be present in the samples.
Maximum possible concentrations were determined in several steps, the
noise level in the appropriate analytical region was quantified by
calculating the root mean square deviation (RMSD) of the baseline in the
subtracted spectrum. The RMS noise was multiplied by the width (in cm"1) of
the analytical region to give an equivalent "noise area" in the subtracted
spectrum. This value was compared to the integrated area of the same
analytical region in a standard spectrum of the pure compound. The noise was
calculated from the equation:
RMSD =
1 «
-i) S (ArAM)
n
(5)
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where:
RMSD = Root mean square deviation in the absorbance values within a region.
n = Number of absorbance values in the region.
AJ = Absorbance value of the ith data point in the analytical region.
AM = Mean of all the absorbance values in the region.
If a species is detected, then the error in the calculated concentration is
given by:
_ SMSD X (*, - *.) (6)
ppm AreaR R
where:
Ennm = Noise related error in the calculated concentration, in ppm.
ppin
X2 = Upper limit, in cm"1, of the analytical region.
x, = Lower limit, in cm"1, of the analytical region.
AreaR = Total band area (corrected for path length, temperature, and
pressure) in analytical region of reference spectrum of compound of
interest.
CONR = Known concentration of compound in the same reference spectrum.
This ratio provided a concentration equivalent to measured area in the
subtracted spectrum. For instances when a compound was not detected, the
value Eppm was equivalent to the minimum detectible concentration of that
(undetected) species in the sample.
Some concentrations given in tables 3-4 to 3-6 are relatively high
(greater than 10 ppm) and there are several 'possible reasons for this.
• The reference spectrum of the compound may show low absorbance at
relatively high concentrations so that its real limit of detection
is high. An example of this may be acetonitrile.
• The region of the spectrum used for the analysis may have residual
bands or negative features resulting from the spectral subtraction.
In these cases the absorbance of the reference band may be large at
low concentrations, but the RMS deviation is also large (see Equation
7). Drier spectra give significant improvement because it is easier
to perform good spectral subtraction on spectra where absorbance from
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water bands Is weaker.
• The chosen analytical region may be too large, unnecessarily
including regions of noise where there is no absorbance from the
compound of interest.
In the second and third cases the stated maximum possible concentration
can be lowered by choosing a different analytical region, generating better
subtracted spectra or narrowing the limits of the analytical region. Entropy
has already taken these steps with a number of compounds. If more
improvements can be made, they will be included in the final report.
4.6.4 Concentration Correction Factors
Calculated concentrations in sample spectra were corrected for
differences in absorption path length between the reference and sample
spectra according to the following relation:
Ccorr -|^|x[^lxfCMlei (7)
where:
C00rr = the path length corrected concentration.
cc«ic = tne initial calculated concentration (output of the Multicomp program
designed for the compound)
Lr = the path length associated with the reference spectra.
L8 = the path length (22m) associated with the sample spectra.
T8 = the absolute temperature of the sample gas (388 K).
Tr = the absolute gas temperature at which reference spectra were recorded
(300 to 373 K).
Corrections for variation in sample pressure were considered, and found
to affect the indicated HAP concentrations by no more that one to two
percent. Since this is a small effect in comparison to other sources of
analytical, no sample pressure corrections were made.
4.6.5 Analysis of Sample Concentration Spectra
Sample concentration spectra were analyzed in the same manner as spectra
of the gas phase samples. To derive flue gas concentrations it was necessary
to divide the calculated concentrations by the concentration factor (CF). As
an illustration, suppose that 10 ft3 (about 283 liters) of gas were sampled
and then desorbed into the FTIR cell volume of approximately 8.5 liters to
give concentration factor of about 33. If some compound was detected at a
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concentration of 50 ppm in the cell, then its corresponding flue gar,
concentration was about 1.5 ppm. When determining the concentration factor
it was also important to consider that the dry gas meter was cool relative tc
the FTIR cell. Also, the total sampled volume was measured after most of the
water was removed. The total volume of gas sampled was determined from the
following relation:
where:
Vfiue = Total volume of flue gas sampled.
Vco, = Volume of gas sampled as measured at the dry gas meter after it
passed through the collection tube.
Tfiua = Absolute temperature of the flue gas at the sampling location.
Ted = Absolute temperature of the sample gas at the dry gas meter.
W = Fraction (by volume) of flue gas stream that was water vapor.
The concentration factor, CF, was then determined using Vf,ue and the
volume of the FTIR cell (Vce)|) which was measured at an absolute temperature
(TC8|I) of about 300 K:
CF '
cell
flue
Finally, the in-stack concentration was determined using CF and the
calculated concentration of the sample contained in the FTIR cell, Cce)l.
CF
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5.0 INTERNAL QUALITY ASSURANCE/QUALITY CONTROL ACTIVITIES
Quality assurance (QA) is defined as a system of activities that
provides a mechanism of assessing the effectiveness of the quality control
procedures. It is a total integrated program for assuring the reliability of
monitoring and measurement data. Quality control (QC) is defined as the
overall system of activities designed to ensure a quality product or service.
This includes routine procedures for obtaining prescribed standards of
performance in the monitoring and measurement process.
The specific internal QA/QC procedures that were used during this test
program to facilitate the production of useful and valid data are described
in this section. Each procedure was an integral part of the test program
activities. Section 5.1 covers method-specific QC procedures for the manual
flue gas sampling. Section 5.2 covers the QC procedures used for the
instrumental methods. QC checks of data reduction, validation and reporting
procedures are covered in Section 5.3, and corrective actions are discussed
in Section 5.4.
5.1 QC PROCEDURES FOR MANUAL FLUE GAS TEST METHODS
This section details the QC procedures that were followed during the
manual testing activities.
5.1.1 Sample Concentration Sampling QC Procedures
QC procedures that allowed representative collection of organics by the
sample concentration sampling system were:
• Only properly cleaned glassware and prepared adsorbent tubes that had
been kept closed with stainless steel caps were used for any sampling
train.
• The filter, Teflon® transfer line, and adsorbent tube were maintained
at ±10eF of the specified temperatures.
• An ambient sample was analyzed for background contamination.
The QC procedures that were followed in regards to accurate sample gas
volume determination are:
• The dry gas meter is fully calibrated every 6 months using an EPA
approved intermediate standard.
• Pre-test and post-test leak checks were completed and were less than
0.02 cfm or 4 percent of the average sample rate.
• The gas meter was read to a thousandth of a cubic foot for the
initial and final readings.
• Readings of the dry gas meter and meter temperatures were taken every
10 minutes during sample collection.
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• Accurate barometric pressures were recorded at least once per day.
• Post-test dry gas meter checks were completed to verify the accuracy
of the meter full calibration constant (Y).
5.1.2 Manual Sampling Equipment Calibration Procedures
5.1.2.1 Temperature Measuring Device Calibration -- Accurate temperature
measurements are required during source sampling. The bimetallic stem
thermometers and thermocouple temperature sensors used during the test
program were calibrated using the procedure described in Section 3.4.2 of EPA
document 600/4-77-027b. Each temperature sensor is calibrated at a minimum
of three points over the anticipated range of use against a NIST-traceable
mercury-in-glass thermometer. All sensors were calibrated prior to field
sampling.
5.1.2.2 Dry Gas Meter Calibration -- Dry gas meters (DGMs) were used in the
sample trains to monitor the sampling rate and to measure the sample volume.
All DGMs were fully calibrated to determine the volume correction factor
prior to their use in the field. Post-test calibration checks were performed
as soon as possible after the equipment was returned as a QA check on the
calibration coefficients. Pre- and post-test calibrations should agree
within 5 percent. The calibration procedure is documented in Section 3.3.2
of EPA document 600/4-77-237b.
5.2 QC PROCEDURES FOR INSTRUMENTAL METHODS
The flue gas was analyzed for CO, 02, C02, and HC. Prior to sampling
each day, a pre-test leak check of the sampling system from the probe tip to
the heated manifold was performed and was less than 4 percent of the average
sample rate. Internal QA/QC—checks for the instrumental test method
measurement systems are presented below.
5.2.1 Daily Calibrations, Drift Checks, and System Bias Checks
Method 3A requires that the tester : (1) select appropriate apparatus
meeting the applicable equipment specifications of the method, (2) conduct an
interference response test prior to the testing program, and (3) conduct
calibration error (linearity), calibration drift, and sampling system bias
determinations during the testing program to demonstrate conformance with the
measurement system performance specifications. The performance
specifications are identified in the following table.
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TABLE 5-1. INSTRUMENTAL TEST METHOD SPECIFICATIONS.
PERFORMANCE TEST
Analyzer Calibration Error
Sampling System Bias
Zero Drift
Upscale Calibration Drift
Interference Check
SPECIFICATION
± 2% of span for zero, mid-, and
high-range calibration gases
± 5% of span for zero and upscale
calibration gases
± 3% of span over test run period
± 3% of span over test run period
± 7% of the modified Method 6 result
for each run
A three-point (i.e., zero, mid-, and high-range) analyzer calibration
error check is conducted before initiating the testing by injecting the
calibration gases directly into the gas analyzers and recording the
responses. Zero and upscale calibration checks are conducted both before and
after each test run in order to quantify measurement system calibration drift
and sampling system bias. Upscale is either the mid- or high-range gas,
whichever most closely approximates the flue gas level. During these checks,
the calibration gases are introduced into the sampling system at the probe
outlet so that the calibration gases are analyzed in the same manner as the
flue gas samples. Drift is the difference between the pre- and post-test run
calibration check responses. Sampling system bias is the difference between
the test run calibration check responses (system calibration) and the initial
calibration error responses (direct analyzer calibration) to the zero and
upscale calibration gases. If an acceptable post-test bias check result is
obtained but the zero or upscale drift result exceeds the drift limit, the
test run result is valid; however, the analyzer calibration error and bias
check procedures must be repeated before conducting the next test run. A run
is considered invalid and must be repeated if the post-test zero or upscale
calibration check result exceeds the bias specification. The calibration
error and bias checks must be repeated and acceptable results obtained before
testing can resume.
Although not required by Methods 10 and 25A, the same calibration and
data reduction procedures required by Method 3A were used for the CO and HC
determinations to improve the quality of the reference data.
5.3 QA/QC CHECKS FOR DATA REDUCTION, VALIDATION, AND REPORTING
Data quality audits were conducted using data quality indicators which
require the detailed review of: (1) the recording and transfer of raw data;
(2) data calculations; (3) the documentation of procedures; and (4) the
selection of appropriate data quality indicators.
All data and/or calculations for flow rates, moisture content, and
sampling rates were spot checked for accuracy and completeness.
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In genera], all measurement data have been validated based on the
following criteria:
• Acceptable sample collection procedures.
• Adherence to prescribed QC procedures.
Any suspect data have been identified with respect to the nature of the
problem and potential effect on the data quality. Upon completion of
testing, the field coordinator was responsible for preparation of a data
summary including calculation results and raw data sheets.
5.3.1 Sample Concentration
The sample concentration custody procedures for this test program are
based on EPA recommended procedures. Because collected samples were analyzed
on-site, the custody procedures emphasize careful documentation of sample
collection and field analytical data. Use of chain-of-custody documentation
was not necessary, instead careful attention was paid to the sample
identification coding. These procedures are discussed in more detail below.
Each spectrum of a sample concentration sample has been assigned a
unique alphanumeric identification code. For example, TgrelSOA designates a
Tenax® spectrum of a sample collected during Run 1 at the stack using tube
number 30. The A means this is the spectrum of the first desorption from
this tube. Every adsorbent tube has been inscribed with a tube
identification number.
The project manager was responsible for ensuring that proper custody and
documentation procedures were followed for the field sampling, sample
recovery, and for reviewing the sample inventory after each run to ensure
complete and up-to-date entries. A sample inventory was maintained to
provide an overview of all sample collection activities.
Two ambient samples were prepared. One was obtained before test began
and a second after the test was completed. Ambient samples were run through
the identical trains used in the test runs. This provided a check for
contamination of the sampling train. The charged ambient tube was stored and
analyzed in the same manner as those collected in the test runs. The volume
of air drawn for the blanks was sufficient to verify that the sampling train
was clean and performing properly. If relatively minor contamination was
identified from the ambient sample, it was accounted for in the subsequent
analysis of the sample spectrum using spectral subtraction. Major sources of
contamination were not identified in any instance.
Sample flow at the dry gas meter was recorded at 10 minute intervals.
Results from the analyzers and the spectra of the gas phase samples provided
a check on the consistency of the effluent composition during the sampling
period.
5.3.2 Gas Phase Analysis
During each test run a total of 12 gas phase samples were collected and
analyzed. Each spectrum was assigned a unique file name and a separate data
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sheet identifying sample location and sampling conditions. A comparison of
all spectra in this data set provided information on the consistency of
effluent composition and a real-time check on the performance of the sampling
system. Effluent was directed through all sampling lines for at least 5
minutes and the CEM's provided consistent readings over the same period
before sampling was attempted. This requirement was satisfied any time there
was a switch to a different conditioning system. At times when the cell was
evacuating, the FTIR signal was continuously monitored to provide a spectral
profile of the empty cell. A new sample was not introduced until there was
no residual absorbance remaining from the previous one. The signal was also
monitored at times when the cell was being filled to provide a real-time
check for significant contamination in the system.
5.3.3 FTIR Spectra
For a detailed description of QA/QC procedures relating to data
collection and analysis, refer to the "Protocol For Applying FTIR
Spectrometry in Emission Testing." A spectrum of the calibration transfer
standard (CTS) was performed at the beginning and end of each data collection
session. The CTS gas was 100 ppm ethylene in nitrogen. The CTS spectrum
provide a check on the operating conditions of the FTIR instrumentation, e.g.
spectral resolution and cell path length. Ambient pressure was recorded
whenever a CTS spectrum was collected.
Two copies of all interferograms and processed spectra of backgrounds,
samples, and the CTS were stored on separate computer disks. Additional
copies of sample and CTS absorbance spectra were also stored for use in the
data analysis. Sample spectra can be regenerated from the raw inter-
ferograms, if necessary. FTIR spectra are available for inspection or re-
analysis at any future date.
Pure, dry ("zero") air was periodically introduced through the sampling
system to check for contamination. On two occasions water was condensed in
the FTIR manifold. The lines and cell were purged with zero air, or dry N2.
On one occasion, after the condensed water was removed, absorbance bands were
observed near 2900 cm"1 in the subsequent FTIR sample. It was determined that
these absorbances were not caused by anything in the flue gas, but were
attributed to contamination that had been carried into the cell during the
purging process and remained after the sample was pumped away. This was
corrected by taking a new background spectrum.
The position and slope of the spectral base line were monitored as
successive spectra were collected. If the base line within a data set for a
particular sample run began to deviate by more than 5 percent from 100
percent transmittance, a new background was collected.
5.4 CORRECTIVE ACTIONS
It was the responsibility of the project manager and the team members to
see that data collection procedures were followed as specified and that
measurement data met the prescribed acceptance criteria. No major corrective
actions were necessary
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6.0 CONCLUSIONS
Entropy performed an emission test using FTIR spectrometry at Greens
Bayou Unit 5 gas-fired boiler in Houston, Texas. Gas phase analysis and
sample concentration measurements were performed over two days. Gas
analyzers were used to measure CO, 02, C02, and hydrocarbons. Three 4-hour
sample concentrations run were performed at the stack. Gas phase analysis
and CEM measurements were performed during the sample concentration runs.
No significant levels of HAPs were measured using FTIR to analyze gas
phase samples, but NO was detected. NH3 and HC1 were detected in sample
concentration spectra. Other unidentified bands were observed in the sample
from sample concentration Run 2 and CFC13, which may be a contaminant, was
detected in the sample from Run 1.
A primary goal of this project was to use FTIR instrumention in a major
test program to measure as many HAPs as possible or to place upper limits on
their concentrations. Four other electric utilities were tested along with
the Greens Bayou facility. Utilities present a difficult testing challenge
for two reasons:
1) They are combustion sources so the flue gas contains high levels of
moisture and C02 (both are spectral interferants).
2) The large volumetric flow rates typical of these facilities can lead
to mass emissions above regulated limits even for HAPs at very low
concentrations. This places great demand on the measurement method
to achieve low detection limits. Furthermore, with natural gas as
the combustion fuel, concentrations of any HAPs formed in the process
would be expected to be very low.
This represents the first attempt to use FTIR spectroscopy in such an
ambitious test program. The program accomplished very significant
achievements and demonstrated important and fundamental advantages of FTIR
spectroscopy as an emissions test method:
• Using a single method quantitative data were provided for over 100
compounds.
• Software was written to analyze a large data set and provide
concentration and detection limit results quickly. The same or
similar software can be used for subsequent tests with very little
investment of time for minor modifications or improvements.
• The original data are permanently stored so the results can be
rechecked for verification at any time.
• A single method was used to obtain both time-resolved (direct gas)
and integrated (sample concentration) measurements of gas streams
from two locations simultaneously.
• The two techniques of the FTIR method cover different concentration
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ranges.
• Preliminary data (qualitative and quantitative) are provided on-site
in real time.
• With little effort at optimization (see below), detection limits in
the ppb range were calculated for 29 .HAPs and less than 5 ppm for 70
HAPs using direct gas phase measurements of hot/wet samples, which
present the most difficult analytical challenge. Sample
concentration provided even lower detection limits for some HAPs.
• A compound detect is unambiguous.
It is appropriate to include some discussion about the "maximum possible
concentrations" presented in Tables 3-4 to 3-6. These numbers were
specifically not labeled as detection limits because use of that term could
be misinterpreted, but they will be referred to as "detection limits" in the
discussion below.
In FTIR analysis detection limits are calculated directly from the
spectra (see Section 4.6.3 and the "FTIR Protocol"). These calculated
numbers do not represent fundamental measurement limits, but they depend on
a number of factors. For example:
Some instrumental factors
• Spectral resolution.
• Source intensity.
• Detector response and sensitivity.
• Path length that the infrared beam travels through the sample.
• Scan time.
• Efficiency of infrared transmission (through-put).
• Signal gain.
Some sampling factors
• Physical and chemical properties of a compound.
• Flue gas composition.
• Flue gas temperature.
• Flue gas moisture content.
• Length of sample line (distance from location).
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• Temperature of sampling components.
• Sample flow.
Instrumental factors are adjustable. For this program instrument settings
were chosen to duplicate conditions that were successfully used in previous
screening tests and the validation test. These conditions provide speed of
analysis, durability of instrumentation, and the best chance to obtain
measurements of the maximum number of compounds with acceptable sensitivity.
Sampling factors present the same challenges to any test method.
An additional consideration is that the maximum possible concentrations
are all higher than the true detection limits that can be calculated from the
1 cm'1 data collected at Greens Bayou. This results from the method of
analysis: the noise calculations were made only after all spectral
subtractions were completed. Each spectral subtraction adds noise to the
resulting subtracted spectrum. For most compounds it is necessary to perform
only some (or none) of the spectral subtractions before its detection limit
can be calculated. With more sophisticated software it will be possible to
automate the process of performing selective spectral subtractions and
optimize the detection limit calculation for each compound. (Such an
undertaking was beyond the scope of the current project.) Furthermore, the
detection limits represent averages compiled from the results of all the
spectra collected at the sampling location. A more realistic detection limit
is provided by the single spectrum whose analysis gives the lowest calculated
value. It would be more accurate to think of "maximum possible
concentrations" as placing upper boundaries on the HAP detection limits
provided by these data.
Another important sampling consideration is the sample composition. In
Table 3-3 benzene's detection limit is quoted as 6.41 ppm. This was
determined in the analytical region between 3036 and 3063 cm"1. Benzene
exhibits a much stronger infrared band at 673 cm"1 but this band was not used
in the analysis because absorbance from C02 strongly interfered in this
analytical region. At a lower C02 emission source an identical FTIR
measurement system would provide a benzene detection limit below 1 ppm for
direct gas analysis (even ignoring the consideration discussed in the
previous paragraph).
Any difficulties associated with measuring particular compounds are
related to the sampling conditions and not the FTIR analysis. The moisture
content of the flue gas was estimated to be about 17 percent. This should
have caused no problem with condensation in the sampling line. But water
soluble species are more difficult to measure at higher moisture levels and
a moisture content of 17 percent can present significant spectral
interferances for some compounds. FTIR techniques still offer a good way to
measure unstable or reactive species because FTIR spectrometry can be readily
used to monitor the sampling system integrity. That was not done in this
test because the primary goal was the general one of measuring as many
compounds as possible, not optimizing the measurement system for any
particular compound or set of compounds.
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7.0 REFERENCES
1) "FTIR Method Validation at a Coal-Fired Boiler," EPA Contract No.
68D20163, Work Assignment 2, July, 1993.
2) "Computer-Assisted Quantitative Infrared Spectroscopy," Gregory L.
McClure (ed.), ASTM Special Publication 934 (ASTM), 1987.
3) "Multivariate Least-Squares Methods Applied to the Quantitative Spectral
Analysis of Multicomponent Mixtures," Applied Spectroscopy, 39(10), 73-
84, 1985.
4) "Fourier Transform Infrared Spectrometry," Peter R. Griffiths and James
de Haseth, Chemical Analysis, 83, 16-25,(1986), P. J. Elving, J. D.
Winefordner and I. M. Kolthoff (ed.), John Wiley and Sons,.
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