THE ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM
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U.S. Environmental Protection Agency I ^y ^^ I 7"e BuSmeSS O/ Innovation
Illinois Clean Coal Institute
ETV Joint Verification Statement
TECHNOLOGY TYPE: Mercury Emissions Monitor
APPLICATION: Sorbent Trap Monitoring of Flue Gas Mercury
TECHNOLOGY
NAME: HG-324K System
COMPANY: Environmental Supply Company
ADDRESS: 2142 E. Geer Street PHONE: (919) 956-9688
Durham, NC 27704 FAX: (919) 682-0333
WEB SITE: www.environsupply.com
E-MAIL: esc@environsupply.com
The U.S. Environmental Protection Agency (EPA) has established the Environmental Technology Verification
(ETV) Program to facilitate the deployment of innovative or improved environmental technologies through
performance verification and dissemination of information. The goal of the ETV Program is to further
environmental protection by accelerating the acceptance and use of improved and cost-effective technologies.
ETV seeks to achieve this goal by providing high-quality, peer-reviewed data on technology performance to
those involved in the design, distribution, financing, permitting, purchase, and use of environmental
technologies. Information and ETV documents are available at www.epa.gov/etv.
ETV works in partnership with recognized standards and testing organizations, with stakeholder groups
(consisting of buyers, vendor organizations, and permitters), and with individual technology developers. The
program evaluates the performance of innovative technologies by developing test plans that are responsive to
the needs of stakeholders, conducting field or laboratory tests (as appropriate), collecting and analyzing data,
and preparing peer-reviewed reports. All evaluations are conducted in accordance with rigorous quality
assurance (QA) protocols to ensure that data of known and adequate quality are generated and that the results
are defensible.
The Advanced Monitoring Systems (AMS) Center, one of six technology areas under ETV, is operated by
Battelle in cooperation with EPA's National Exposure Research Laboratory. In collaboration with the Illinois
Clean Coal Institute, and with assistance from the Northern Indiana Public Service Company, the AMS Center
evaluated the performance of the Environmental Supply Company's HG-324K sorbent-based mercury sampling
system for determining mercury in stack gas at a coal-fired power plant. This verification statement provides a
summary of the test results.
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VERIFICATION TEST DESCRIPTION
The performance of the HG-324K was evaluated in terms of relative accuracy (RA), data completeness, and
operational factors (ease of use, maintenance and data output needs, power and other consumables use, reliability,
and operational costs). RA was determined according to Equation A-10 of Chapter 40 of the Code of Federal
Regulations Part 75 (40 CFR Part 75) Appendix A, by comparing HG-324K vapor-phase total mercury (HgT)
results to simultaneous results from American Society for Testing and Materials (ASTM) D 6784-02, the
"Ontario Hydro" (OH) method. Data completeness was assessed as the percentage of maximum data return
achieved by the HG-324K over its test period. Operational factors were evaluated by means of observations
during use and records of needed maintenance, vendor activities, and expendables use.
The HG-324K was verified at Unit 17 of the R.M. Schahfer Generating Station, located near Wheatfield, Indiana,
between June 12 and 15, 2006. Unit 17 burns pulverized Illinois sub-bituminous coal and has an electrostatic
precipitator and a wet flue gas desulfurization unit. During this period, twelve successive OH method runs, each
of 2 hours duration, were conducted on the Unit 17 stack using paired OH trains. Those reference samples were
collected and analyzed to determine elemental mercury and oxidized mercury, the sum of which is HgT.
QA oversight of verification testing was provided by Battelle and EPA. Battelle QA staff conducted a technical
systems audit, a performance evaluation audit, and a data quality audit of 10% of the test data.
This verification statement, the full report on which it is based, and the test/QA plan for this verification test are
all available atwww.epa.gov/etv/centers/centerl.html.
TECHNOLOGY DESCRIPTION
The following description of the HG-324K is based on information provided by the vendor. The information
provided below was not verified in this test.
The HG-324K system was designed to sample mercury emissions from coal-fired sources as specified in
Appendix K in 40 CFR Part 75. The system consists of a dual heated probe, knockout and drying impingers to
remove moisture, a connecting umbilical, and the HG-324K automated sampler. An integrated sample of vapor
phase mercury is captured on two parallel and independent sorbent traps that are placed in the stack on the front
of the sampling probe. Stack gas is drawn through each of the traps at a constant flow rate of approximately 500
cubic centimeters per minute. The traps and probe are heated to prevent condensation of moisture from the
sample gas. After exiting the probe, the sample gas passes through the knockout and drying impingers to remove
moisture and then is drawn into the HG-324K sampler for measurement of the sample volume. The HG-324K
provides proportional, integral, derivative flow control of the dual samples; records all temperatures including the
stack, probe, and condenser; controls the probe temperature; and measures the dry standard volume of sample gas
The HG-324K is controlled using an industrial data acquisition and control system with a removable
CompactFlash™ memory card for storing data files. The HG-324K may be connected to a plant network through
wireless or direct connection to allow program control and remote data access. It comes in a watertight, corrosion
proof case with 2-inch hard rubber transport wheels and a retractable extension handle. The outside dimensions
are 24-5/8 inches long by 19-1/2 inches wide by 14 inches deep.
The sorbent traps used with the HG-324K were prepared and analyzed for HgT by Frontier Geosciences.
Consistent with Appendix K, each trap incorporated a breakthrough section and a pre-spiked section to assess
mercury spike recovery.
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VERIFICATION RESULTS
The RA of the HG-324K for determining HgT was 29.5%, based on 11 OH runs, when the comparison was based
on HG-324K results corrected for trap blanks but not corrected for mercury spike recovery. For those 11 runs,
the overall average HgT value from the OH reference method was 0.821 microgram per dry standard cubic meter
((ig/dscm), whereas that from the HG-324K was 1.004 (ig/dscm, a difference of 0.183 (ig/dscm. When
comparing HG-324K results corrected for mercury spike recovery, the RA for 11 OH runs was 37.0%, and the
OH and HG-324K average values were 0.821 (ig/dscm and 1.064 (ig/dscm, respectively, a difference of
0.243 (ig/dscm.
The HG-324K sampled during all 12 OH runs conducted over four days with no delays, breakdowns, broken
traps, or sampling interruptions. The only problem encountered was that after Run 8 the post-test leak check
failed. As a result, only 11 of the 12 sampling runs (91.7% data completeness) were suitable for comparison to
the OH reference results.
The HG-324K was installed quickly and was operated by a vendor representative without serious problems. A
failed post-test leak check in one sampling run was the only difficulty encountered. The sorbent traps were
rugged and uniform in construction, so that no breakage occurred; no problems were encountered in placing the
traps into the end of the sampling probe or recovering them after sampling. The sampling probe used with the
HG-324K was simple and relatively light in weight, and was handled by a single operator in all sampling. The
HG-324K sorbent sampling system incorporated data acquisition and transfer capabilities, including magnetic
card recording media and wireless communication.
The cost of the HG-324K system as tested is $18,750. As used in this test, the cost per sorbent trap sample was
about $500, including preparation of the trap, pre-spiking the trap with mercury, and analyzing the four-section
trap after sampling.
Original signed by Gregory A. Mack 2/16/2007 Original signed by Sally Gutierrez
Gregory A. Mack Date
Vice President
Energy, Transportation, and Environment Division
Battelle
Sally Gutierrez
Director
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
4/4/2007
Date
NOTICE: ETV verifications are based on an evaluation of technology performance under specific,
predetermined criteria and the appropriate quality assurance procedures. EPA and Battelle make no expressed or
implied warranties as to the performance of the technology and do not certify that a technology will always
operate as verified. The end user is solely responsible for complying with any and all applicable federal, state,
and local requirements. Mention of commercial product names does not imply endorsement.
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