PROGRAM AREA OVERVIEW --

11. ENVIRONMENTAL TECHNOLOGY AND SUPPORT FOR EXISTING FOSSIL ENERGY FACILITIES

The use of coal in energy utilization and conversion systems suffers from a number of considerations with respect to the fuel itself. Coal is a solid fuel containing components that are precursors of environmental pollutants or materials that are potentially damaging to downstream components. Further, coal contains mineral matter that is converted into ash, which can lead to suspended particulates in air, erosion of or deposition in downstream components, and problems of solid waste disposal. This topic seeks to mitigate the environmental disadvantages of coal utilization, including its potential impact on water quality and availability, through improvements in various aspects of the coal utilization cycle. The research is expected to provide high-quality scientific information on present and emerging environmental issues for use in regulatory and policy decision-making. Environmental considerations and the concomitant need for low-cost compliance options are the primary drivers of the current research program.

In addition, this topic addresses two other requirements for coal power systems: (1) the use and disposition of by-products from coal combustion and gasification, and (2) the further development of micro-sensors that can withstand the harsh conditions of advanced power generation systems. Grant applications are solicited only in the following subtopics:

a. Continuous Measurements of Mass Concentration and Chemical Composition of Primary PM 2.5 Emitted from Coal-Fired Utility Boilers—Continuous (or near-continuous) emission monitors (CEMs) for primary PM 2.5 (particulate matter with an aerodynamic diameter less than 2.5 µm) mass and composition would be more desirable than filter-based methods. However, due to continuing concerns over the complexity, high cost, and uncertain field reliability of these monitors, they have not been readily adopted by the utility industry. Furthermore, currently-available CEMs for PM 2.5 mass are expected to perform even less reliably in the cooler, moister conditions characteristic of flue gas released from wet flue gas desulfurization (FGD) systems. Technology for continuously measuring the chemical composition of primary PM 2.5 emissions from exhaust stacks is even less well-developed; none of the prototype instruments designed for this purpose have been applied to coal-fired utility boilers. Therefore, grant applications are sought to identify novel concepts and technologies for measuring, in near-real-time, the mass concentrations and chemical composition of primary PM 2.5 emitted from coal-fired utility boilers with and without wet FGD systems. Proposed concepts and technologies must demonstrate the promise of being more reliable and more cost-effective than currently-available CEMs for PM 2.5 mass and composition measurements. It also should be noted that experimental dilution sampling devices and plume aging chambers have already been developed to simulate the changes in PM 2.5 mass and composition that may occur within the boiler exhaust plume. Therefore, proposed concepts and technologies may be designed for use with or without the use of such devices; however, grant applications that further refine or develop sampling protocols for dilution samplers or plume aging chambers are not of interest, nor are grant applications that seek to further refine or develop existing PM 2.5 CEMs.

b. Water Usage in Electric Power Production—Power generated from fossil fuels is dependent on water. On average, approximately 21 gallons of water are required for each kWh of power produced. Thermoelectric power production uses approximately 195 billions of gallons of water per day. In power generation, the largest single use of water is for cooling the low-pressure steam from the turbine. Under the Clean Water Act, section 316(b), the EPA has developed new regulations to reduce this cooling usage of water and improve cooling water intake structures. Research opportunities exist for reducing or eliminating the need to use water for cooling purposes. Air has been considered as an alternative, but air-cooled systems (sometimes referred to as dry systems) can have associated capital-cost and energy-inefficiency penalties, particularly in retrofit applications. Non-potable water is another option for cooling purposes, but there may be negative impacts on existing cooling towers. Other water-related issues associated with power plants involve their wastewater streams, including cooling tower blow-down water and flue gas desulphurization wastewater; these waste streams are often large volume, low concentration waters that are expensive to treat on a per-contaminant basis. Therefore, grant applications are sought to identify novel concepts and technologies to reduce both the amount of water used in coal power generation and the potential impact on water quality. Grant applications must be directed toward one of the following areas of interest: (1) reducing the amount of water used in power generation, (2) water quality improvements in power generation, (3) improvements in wet or dry cooling towers, (4) novel, low-cost treatment technology to allow for the use of wastewater as process water in power plants, or (5) novel, low-cost treatment technologies for power plant wastewater.

c. High Volume Utilization of Coal Combustion By-Products—More than half of the electricity generated in the U.S. is produced by coal-fired facilities. In January of 2004, the EPA published draft regulations to control mercury emissions from coal-fired electric utilities. One of the proposed technologies to control mercury involves the addition of activated carbon to the flue gas. The activated carbon would be collected with the fly ash via electrostatic precipitators or fabric filters. Currently, fly ash is considered a non-hazardous material for disposal; however, the increased levels of mercury, from the addition of the mercury-impregnated activated carbon, could change this status. Preliminary research suggests that the addition of activated carbon to the fly ash could make the fly ash unmarketable or increase the cost of disposal. Simultaneously, the EPA published another draft regulation that targets both sulfur dioxide and nitrogen oxide emissions from power plants. To comply with this regulation, it is anticipated that more units will be equipped with flue gas desulfurization (FGD) technology. In fact, FGD production in the U.S. may increase by an order of magnitude to almost 200 million tons, thus exceeding the production of all other coal combustion products.

In the wake of these regulations, grant applications are sought to: (1) develop novel high volume utilization technologies for fly ash that contains very high concentrations of either unburned or activated carbon from mercury control technologies, and (2) develop high volume utilization technologies of flue gas desulfurization materials in novel applications (excluding wallboard production).

d. Engineering Needs for Micro Sensors in Coal-Based Power Systems—The DOE, along with other government agencies and sensor developers, have put forth a significant effort to develop micro-electric-mechanical-systems-based and other types of micro-sensors for measuring physical parameters (pressure, temperature, strain, etc.) and detecting gases in coal-based power systems. Research and development has focused on sensors for high temperature (300-1000 ^oC), harsh environments (strongly reducing or oxidizing conditions, particulates, etc.) The micro-gas-sensor development has focused on common fossil fuel exhaust species (e.g., O₂, CO₂, H₂, CO, NO, NO₂, SO₂, etc.) Many of these types of prototype sensors are progressing to the point where long term or large scale testing is necessary to assess their commercial viability. Much of the effort has been expended on how to best package and protect the micro-sensors from harsh environments while allowing the sensor to be exposed to the gas stream in a quasi in situ approach. Therefore, grant applications are sought to develop a standard, engineered testing package, with an integrated protective housing, for applying micro-sensors in high temperature harsh environments. Interested applicants should focus on one type of fossil fuel power system, including coal-fired boiler systems and coal gasification systems, so that the design meets the specifications and requirements of that system, which may include temperature ranges and fluctuations between 300 and 1000 ^oC, pressures up to 350 psig, and high concentrations of particulates. Packaging designs must consider proper selection of high temperature materials, appropriate size, ease of installation through standard process ports or couplings, ease in accessing or replacing the micro- sensors, adequate gas conditioning and particulate removal, high temperature electronics, provision for power input, provision for signal output, and provision for temperature and pressure control.

Descriptions of the coal-based power systems can be found at www.netl.doe.gov and descriptions of a select number of ongoing micro-sensor projects that could be potential candidates for testing are also listed on National Energy Technology Laboratory’s (NETL) website.

References:

Subtopic a: Continuous Measurements of Mass Concentration and Chemical Composition of Primary PM 2.5 Emitted from Coal-Fired Utility Boilers

1. Evaluation of Particulate Matter Continuous Emission Monitoring Systems, Final Report, U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, September 2000. (Report No. EPA-454/R-00-040a) (Full text available at: http://www.epa.gov/ttn/emc/cem.html. Scroll down to document title under heading, “File Description”)

2. TEOM Series 7000 Source Particulate Monitor, Product Description, Rupprecht & Patashnik Co. Inc., East Greenbush, NY, 2004. (See: http://www.rpco.com/products/cemprod/cem7000/)

3. Arnold, J. L. and Clapsaddle, C., “Beta Gauge Particulate Monitoring,” poster presentation summary, PM2.5 and Electric Power Generation: Recent Findings and Implications, Pittsburgh, PA, April 9-10, 2000. (Summary available at: http://www.netl.doe.gov/publications/proceedings/02/PM25/Posters/Clapsaddle_s.pdf)

Subtopic b: Water Usage in Electric Power Production

4. Energy-Water Interface, U.S. DOE National Energy Technology Laboratory, http://www.netl.doe.gov/coal/E&WR/water/index.html (To see how this program fits into NETL; start at the NETL home page, http://www.netl.doe.gov. On the left menu select “Technologies”. Under “Coal and Environmental Systems,” select “Environmental & Water Resources,” and then “Energy-Water Interface” on the right. These instructions should bring the viewer to the same Web location, and give a broader perspective of this subtopic.)

5. Estimated Use of Water in the United States in 2000, United States Geological Service (USGS), May 2004. (USGS Circular 1268) (http://water.usgs.gov/pubs/circ/2004/circ1268/

Subtopic c: High Volume Utilization of Coal Combustion By-Products

6. Pflughoeft-Hassett, D. F., and Renninger, S., “Review of Barriers to the Increased Utilization of CCBs by Government and Commercial Sectors,” presented at the American Coal Ash Association (ACAA) 13th International Symposium on the Management and Use of Coal Combustion Products (CCPs), Orlando, FL, January 10-14, 1999. (Full text available on ACAA Web site at: http://www.acaa-usa.org/PDF/13Symp_p79_Barriers.pdf)

7. Moretti, C. J., “An Evaluation of Disposal and Utilization Options for Advanced Coal Utilization Wastes,” American Power Conference, Chicago, IL, April 9-11, 1996. (Available in PDF at: http://www.netl.doe.gov/cctc/resources/library/bibliography/misc/bibm_cwbu.html. Scroll half way down page to citation, “C. J. Moretti…”.)

8. Choudhry, V. and Hadley, S., “Utilization of Lightweight Materials Made from Coal Gasification Slag,” Advanced Coal-Fired Power Systems '96 Review Meeting, Morgantown, WV, July 16-18, 1996. (Available in PDF at: http://www.netl.doe.gov/cctc/resources/library/bibliography/misc/bibm_cwbu.html. Citation is two thirds of the way down page.)

9. Hassett, D. J., “Current Practices and Issues for Placement of Coal Combustion By-Products in Mine Settings,” presented at the Western Region Ash Group 2nd Annual Coal Combustion Products (CCPs) Forum: CCP Utilization in Mining Applications, Scottsdale, AZ, August 17, 1999. (Full text of paper available via: http://www.undeerc.org/carrc/firstsearch/abstract.asp?abstractid=180)

Subtopic d: Engineering Needs for Micro Sensors in Coal-Based Power Systems

10. The 2002 NETL Sensor and Control Program Portfolio Review and Roadmapping Workshop, [Pittsburgh, PA, October 13-14-2002]: Workshop Proceedings. (Full text available at: http://www.netl.doe.gov/publications/reports/2002/ISCS%20Workshop%20Proceedings.pdf)

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