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2001 Progress Report: Development And Demonstration Of Trace Metals Database

EPA Grant Number: R827649C001
Subproject: this is subproject number 001 , established and managed by the Center Director under grant R827649
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Center for Air Toxic Metals® (CATM®)
Center Director: Groenewold, Gerald
Title: Development And Demonstration Of Trace Metals Database
Investigators: Folkedahl, Bruce C. , Benson, Steven A. , Galbreath, Kevin C. , Hassett, J. , Holmes, Karen , Jensen, John , Laudal, Dennis L. , Miller, Stanley J. , Olson, Edwin S. , Pavlish, John H. , Zygarlicke, Christopher J.
Current Investigators: Folkedahl, Bruce C. , Beard, Roy B. , Benson, Steven A. , Galbreath, Kevin C. , Hanson, Paul R. , Hassett, J. , Holmes, Karen , Jensen, John , Laudal, Dennis L. , Maki, Andrew B. , Miller, Stanley J. , Olson, Edwin S. , Pavlish, John H. , Peck, Wes D. , Zygarlicke, Christopher J.
Institution: University of North Dakota
EPA Project Officer: Stelz, Bill
Project Period: October 15, 1999 through October 14, 2002
Project Period Covered by this Report: October 15, 2000 through October 14, 2001
Project Amount: Refer to main center abstract for funding details.
RFA: Center for Air Toxic Metals (CATM) (1998)
Research Category: Targeted Research

Description:

Objective:

The objective of the research conducted by the Center for Air Toxic Metals (CATM) is to address air toxic trace element emissions, which have become a matter of worldwide concern, as well as a regulatory issue in the United States. The goal of CATM is to develop key information on air toxic metal compounds to support development and implementation of pollution prevention and control strategies that will reduce air toxic metal emissions and releases to this environment.

Progress Summary:

This year, CATM research activities addressed several key issues related to air toxics. A summary of these research activities and accomplishments is provided in the report.

Fundamental Mechanisms of Mercury Species Formation in Coal Combustion Flue Gas

Bench-scale investigations using synthetic flue gas indicate that NO, NO2, hematite (-Fe2O3), and maghemite (-Fe2O3) promote the conversion of gaseous elemental mercury (Hg0) to gaseous oxidized mercury (Hg2+) and/or particle-associated mercury (Hg[p]) in simulated coal combustion flue gases. Injections of NO2 and -Fe2O3 had a different effect depending on coal type. HCl injection into the subbituminous coal combustion flue gas converted most of the Hg0 to Hg2+, whereas HCl injection into the lignitic flue gas converted most of the Hg0 and Hg2+ to Hg(p). Fabric filters impregnated with -Fe2O3 resulted in Hg0 and Hg2+ removal efficiencies of about 50 percent.

Development of Sampling and Analytical Tools for Oxidized Mercury Species

Research is underway to develop new analytical tools for the definitive determination of reactive oxidized mercury species in a vapor phase in combustion flue gas streams. Current methods for speciating vapor phase mercury do not distinguish the inorganic forms of Hg(II), but this information is needed to understand and accurately model the behavior of mercury in flue gas and in a control device. Analysis of HgCl2 was improved by derivatizing cryogenically trapped HgCl2, with diazomethane to form bischloromethylmercury, whose peak shape is very sharp in contrast to the very broad elution of HgCl2. Additionally, the chemistry of the gas chromatography-mass spectrometry (GC-MS) analysis of Hg(NO3)2 was elucidated. Several experiments were performed showing that the chromatography and unique spectra obtained for trapped, as well as standard Hg(NO3)2, resulted from on-column reaction of vapors of this highly reactive species.

Development of Mercury Control Technologies

Several new approaches were taken not only to achieve better sorbent performance, but also to better understand the complex physical and chemical process by which sorbents absorb, oxidize, and retain mercury. Carbon impregnation tests with various acids and ligands failed to result in an improved sorbent capacity with a full flue gas matrix. Similarly, carbon impregnation with iron(III) and iron(IV) compounds showed no improvement over the baseline carbon. Longer-term catalyst tests, in which the catalyst bed was exposed to real flue gas, showed that gold with the appropriate substrate and contact geometry can oxidize nearly 100 percent of the elemental mercury. A vanadium titanium catalyst was less effective, achieving 70 percent oxidation, but still may be effective enough to consider for some applications. Further testing of promising catalysts will continue next year.

Application of Database and Models to the Fundamental and Applied Study of Air Toxic Metals

The CATM database now contains more than 390,000 analytical measurements from more than 150,000 analyses from approximately 100 plants. The database also contains all usable data from the U.S. Environmental Protection Agency Information Collection Request. A theoretical model was developed to evaluate mercury-sorbent interactions and gas-phase mass-transfer rates to the sorbent. The model calculations qualitatively reproduced the correct trending of mercury capture with sorbent injection rates and time, as well as the effect of higher sorbent-to-mercury ratios. An empirical model for mercury speciation and transformations focused on developing a neural network to predict mercury emissions. The regression ratio between the actual data and predicted data set is 0.2259 (correlation, r2 = 0.9750), which is within good acceptability limits.

Stability of Mercury in Combustion By-Products

The project was designed to determine the mechanisms of mercury release from coal combustion by-products (CCBs) and biomass materials. The results of the project show that there is no clear evidence of the rate of mercury release compared to mercury concentration as determined by bulk analysis of the ash. The mercury release from six samples appears to be extraordinarily low--below 200 picograms per 100 grams of CCB for each 90-day equilibration period. This equates to a release of 4?109 pounds per ton in a 90-day period as a worst-case scenario, which is 1.6?108 pounds per ton per year. New tests are just beginning for biota experiments.

Investigation of the Fate of Mercury in a Coal Combustion Plume Using a Static Plume Dilution Chamber

Measurements of speciated forms of mercury have been made in combustion stacks and in ambient air. However, little is known about the mercury transformations that occur in the plume. A static plume dilution chamber (SPDC) designed to simulate plume conditions in the atmosphere was used to examine these reactions. Good mass balances were obtained for these tests (100 ? 25 percent). The data appear to indicate that some reduction of Hg2+ to Hg0 does take place in the SPDC. However, because of observed wall effects, the static SPDC may not be the best tool available to generate data to further understand mercury chemistry in combustion plumes.

Mercury Release from Crude Oil

Uncertainty continues over the amount of mercury released into the environment from the extraction, transport, refining, and consumption of crude oil and its products. The project focused on gathering relevant information from a broad range of possible sources and evaluating the information for accuracy, validity, and completeness. While some researchers indicate that there are crude oils with significant levels of mercury, others argue that the average values reported are biased by a sample population that is weighted toward samples high in mercury. In addition to the potential bias in the data from more frequent measurement of samples that are high in mercury, there also is uncertainty associated with sampling and measurement techniques. Sampling and handling issues can be associated with the large variety of mercury forms, difficulties in obtaining homogeneous samples, loss of volatile Hg0 to the headspace of sample containers, and loss of mercury to the sample containers. Analytical methods for the determination of Hg in hydrocarbons have improved dramatically in recent years, but improved quality assurance/quality control procedures need to be followed and documented to add further confidence in results.

Technology Commercialization, Education, and Publication

To facilitate the transfer of technical information produced by CATM, several communication venues are employed, including participation in conferences, symposia, workshops, and other educational programs; annual meetings and peer reviews; and the publication of a semiannual newsletter. The CATM Web Page was maintained throughout the year. Copies of the CATM Newsletter are available through this Web site. The EERC, through CATM, has organized and sponsored two Air Quality: Mercury, Trace Elements, and Particulate Matter Conferences held in 1998 and 2000. A third Air Quality Conference is planned for September 2002.

Future Activities:

Future research at CATM will focus on the following:

Education and peer-reviewed publications.


Journal Articles on this Report: 3 Displayed | Download in RIS Format

Other subproject views: All 33 publications 14 publications in selected types All 4 journal articles
Other center views: All 347 publications 110 publications in selected types All 52 journal articles

Type Citation Sub Project Document Sources
Journal Article Olson ES, Miller SJ, Sharma RK, Dunham GE, Benson SA. Catalytic effects of carbon sorbents for mercury capture. Journal of Hazardous Materials 2000;74(1-2):61-79. R827649 (2001)
R827649C001 (2001)
R827649C001 (Final)
 not available
Journal Article Sondreal EA, Benson SA, Hurley JP, Mann MD, Pavlish JH, Swanson ML, Weber GF, Zygarlicke CJ. Review of advances in combustion technology and biomass cofiring. Fuel Processing Technology. 2001;71(1-3):7-38. R827649 (2001)
R827649C001 (2001)
R827649C001 (Final)
 not available
Journal Article Timpe RC, Mann MD, Pavlish JH. Organic sulfur and hap removal from coal using hydrothermal treatment. Fuel Processing Technology 2001;73(2):127-141. R827649 (2000)
R827649 (2001)
R827649C001 (2001)
R827649C001 (Final)
 not available
Supplemental Keywords:

air, toxic, air quality, control, modeling, database, emissions, environment, hazardous, mercury, metals, pollutants, air pollution, sampling, measurement, species, transformations. , Ecosystem Protection/Environmental Exposure & Risk, Economic, Social, & Behavioral Science Research Program, Air, Scientific Discipline, RFA, Ecosystem/Assessment/Indicators, exploratory research environmental biology, decision-making, air toxics, Economics & Decision Making, Ecological Indicators, Environmental Engineering, Ecological Effects - Human Health, Environmental Chemistry, Chemical Mixtures - Environmental Exposure & Risk, Ecological Effects - Environmental Exposure & Risk, Ecosystem Protection, heavy metals, decision analysis, decision making, trace metals database, models, mercury, chemical databases, environmental decision making
Relevant Websites:

http://www.undeerc.orgexit EPA
http://www.undeerc.org/catm/catm_home.htmlexit EPA

Progress and Final Reports:
Original Abstract
2002 Progress Report
Final Report


Main Center Abstract and Reports:
R827649    Center for Air Toxic Metals® (CATM®)

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R827649C001 Development And Demonstration Of Trace Metals Database
R827649C002 Nickel Speciation Of Residual Oil Ash
R827649C003 Atmospheric Deposition: Air Toxics At Lake Superior
R827649C004 Novel Approaches For Prevention And Control For Trace Metals
R827649C005 Wet Scrubber System
R827649C006 Technology Commercialization And Education
R827649C007 Development Of Speciation And Sampling Tools For Mercury In Flue Gas
R827649C008 Process Impacts On Trace Element Speciation
R827649C009 Mercury Transformations in Coal Combustion Flue Gas
R827649C010 Nickel, Chromium, and Arsenic Speciation of Ambient Particulate Matter in the Vicinity of an Oil-Fired Utility Boiler
R827649C011 Transition Metal Speciation of Fossil Fuel Combustion Flue Gases
R827649C012 Fundamental Study of the Impact of SCR on Mercury Speciation
R827649C013 Development of Mercury Sampling and Analytical Techniques
R827649C014 Longer-Term Testing of Continuous Mercury Monitors
R827649C015 Long-Term Mercury Monitoring at North Dakota Power Plants
R827649C016 Development of a Laser Absorption Continuous Mercury Monitor
R827649C017 Development of Mercury Control Technologies
R827649C018 Developing SCR Technology Options for Mercury Oxidation in Western Fuels
R827649C019 Modeling Mercury Speciation in Coal Combustion Systems
R827649C020 Stability of Mercury in Coal Combustion By-Products and Sorbents
R827649C021 Mercury in Alternative Fuels
R827649C022 Studies of Mercury Metabolism and Selenium Physiology

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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