Peer Reviewed: Developing Clean Coal Technology - ACS Publications

fuels in the future—and leave the environment intact. CARL O. BAUER. U.S. DEPARTMENT OF ENERGY. NATIONAL ENERGY TECHNOLOGY LABORATORY...
0 downloads 0 Views 425KB Size
Developing

Clean Coal Technology

Advances Advances may may extend extend the the efficiency efficiency and and economy economy of of fossil fossil fuels fuels in in the the future—and future—and leave leave the the environment environment intact. intact.

CARL O. BAUER U . S . D E PA RT M E N T O F E N E R G Y N AT I O N A L E N E R G Y T E C H N O LO G Y L A B O R AT O RY

or the foreseeable future, the United States must rely upon its abundant and reliable coal resources to meet growing electricity demand, maintain competitive energy rates, and sustain economic growth. Coal is the nation’s most plentiful and lowest-cost fuel for secure and reliable electric power generation, currently providing more than half of the electricity generated in the United States. In terms of energy value (measured as British thermal units, Btus), coal constitutes approximately 95% of total U.S. domestic fossil energy reserves (coal, oil, and natural gas) and has the energy equivalent of about 1 trillion barrels of crude oil,

PHOTODISC AND U.S. DEPT. OF ENERGY

F

©2003 American Chemical Society

which is comparable to all the world’s known oil reserves (1). However, for coal to remain a mainstay of electric power generation, both existing and new plants must be able to comply with increasingly stringent environmental standards (2). The U.S. Department of Energy’s (DOE’s) coal technology research programs, which are managed by the National Energy Technology Laboratory (NETL), support development and commercialization of advanced, low-cost combustion, gasification, and environmental control technologies for both the existing fleet of coal-based power plants and new-generation systems (3). These efforts, developed in part-

JANUARY 1, 2003 / ENVIRONMENTAL SCIENCE & TECHNOLOGY ■ 27 A

nership with industry, help constitute the DOE’s road map to clean power plants for the future, which, along with associated research and development projects, will ultimately lead to coal-fired power plants with near-zero emissions. This article reviews the significant DOE programs responsible for advancing clean coal technologies, provides time frames for deployment of some of the key technologies, and characterizes potential public benefits. These activities directly support a secure, reliable domestic power generation system and the recommendations President Bush made in the May 2001 National Energy Policy concerning the environmental performance of coal-based power systems (4).

Facing the problem The National Energy Policy Development Group recommends that the President direct the DOE to continue to develop advanced coal technology by investing $2 billion over 10 years to fund research, support a permanent extension of existing research and development tax credits, and explore regulatory approaches that encourage environmental technologies. Continued operation of old coal-fired plants may require installing environmental control retrofits or repowering technologies aimed at cost-effectively and efficiently reducing emissions of sulfur dioxide (SO2), oxides of nitrogen (NOx), fine particulate matter (PM), mercury, and other hazardous air pollutants. New coalfired capacity faces even greater challenges, particularly with the implementation of utility restructuring (5). New capacity additions will likely have to achieve near-zero pollutant emissions to maintain or improve ambient air quality, and face increasing regulations for obtaining permits to dispose of solid wastes (6). Moreover, concerns over global climate change have also placed a premium on increasing plant efficiency. Arguably, the environmental issue of greatest concern to the electric-power industry is the control of mercury. In a December 2000 regulatory determination, the U.S. EPA concluded that further control of mercury in coal- and oil-fired power plants was necessary (7). EPA is required to issue final control regulations by December 15, 2004, with compliance required within a projected three years after regulations go into effect. Coal can remain one of the United States’ greatest energy strengths if new, clean technologies are installed to reduce environmental impact and help keep this form of energy affordable. Clean coal technologies are a suite of advanced energy conversion and pollution control technologies developed over the past 20 years that are more efficient and environmentally superior to current technologies. New combustion processes, such as fluidized bed combustion and low-NOx burners remove pollutants or prevent them from forming. Advanced scrubbers clean pollutants, such as SO2, from flue gas before it exits a plant’s smokestack. Gasification converts coal into fuel forms that can be efficiently cleaned before being burned. For example, a coal-derived medium-Btu gas is a fuel form with environmental characteristics similar to clean-burning natural gas and is also a source of chemicals that can be used to coproduce a myriad of hydrocarbon-based products. 28 A ■ ENVIRONMENTAL SCIENCE & TECHNOLOGY / JANUARY 1, 2003

DOE programs and their deployment prospects Over the past 30 years, DOE and the energy industry have funded a combination of high-risk basic and applied research programs to foster innovative clean coal concepts and full-scale demonstration programs. Although many NETL programs have contributed to improved technology performance, DOE’s original Clean Coal Technology (CCT) Program was one of the most ambitious government–industry initiatives (8). Six of DOE’s CCT projects have received awards from Power magazine. Following the success of the CCT Program, Congress enacted a $95 million budget in fiscal year 2001 (FY2001) to fund the Power Plant Improvement Initiative (PPII) (9) and appropriated $150 million in funding for FY2002 to begin a Clean Coal Power Initiative (CCPI) to demonstrate clean coal technologies at a scale sufficient to speed their commercial sale (10). Today, NETL’s Office of Coal and Environmental Systems (OCES) manages the overall coal research programs, including the new clean coal initiatives (11). The work is largely allocated into technology lines corresponding to programs in combustion, gasification, environmental control (encompassing both combustion and gasification), and carbon sequestration that compose the Vision 21 Energy Plant of the Future. Each program strives to eliminate technical barriers to the clean use of coal. CCT was first. The CCT Program, funded from 1986 to 1993 and continuing today to complete the remaining projects, represents an investment of over $5.2 billion in demonstrating advanced coal-based technology at commercial scale, as mentioned previously. Industry and state governments provided an unprecedented 66% of the funding. Of the 38 active CCT projects selected in five separate solicitations, 29 projects, valued at $3.5 billion, address electric power generation applications—18 environmental control projects and 11 advanced power projects. The other nine projects involve coal processing for clean fuels and industrial applications. Seventeen of the environmental control projects have been completed. Three of the electric power generation projects are complete, four are in operation, and four are either in design or construction. The power generation projects are oriented toward combustion, gasification, or environmental control. Program results from the DOE Clean Coal Compendium will be fully disseminated to the public by 2007, when all of the projects are scheduled to be completed (12). Power Plant Improvement Initiative. PPII, a congressionally directed effort that serves as the precursor to President Bush’s Clean Coal Power Initiative, is targeted at advanced clean coal technologies. In January 2001, DOE issued a solicitation offering $95 million in federal matching funds for projects that demonstrate ways operators can boost the electricity produced by their power plants or help plants meet more stringent environmental standards (13). In October of that year, Energy Secretary Spencer Abraham announced more than $110 million (including an approximately 50% cost share by DOE) in new projects (14). PPII-proposed technologies must be mature enough to be commercialized within the next few years, and the cost-shared demonstrations

must be large enough to show that the technology is viable for commercial use. Clean Coal Power Initiative. President Bush initiated CCPI as a follow-up program to CCT that will further improve, expand, and demonstrate the use of clean coal technologies. This program will invest as much as $2 billion over 10 years. In FY2002, DOE has conducted the initial competition, offering federal matching funds of $300–400 million for a limited number of joint government–industry projects to

demonstrate new coal-fired power generation technology. These cost-shared partnerships should accelerate the commercialization of technologies and are aimed at enhancing the United States’ energy security, economic growth, and environmental progress.

OCES programs and technologies As a result of DOE’s clean coal programs, various advanced technologies are being made available to industrial, commercial, and utility markets. Figure 1

FIGURE 1

Overview of central power generation for clean-coal technologies Between 1990 and 2015, three planned stages will move coal power generation toward meeting zero emissions and stricter environmental standards. PFBC denotes pressurized fluidized-bed combustion.

Ozone NOx control Mercury control PM2.5 data and control

Existing plants

Coal combustion residue database Repowering database

Clean- coal technology

Low-emission boiler systems Advanced turbine system Next-generation turbine systems Nextgeneration plants

Second-generation PFBC Fuel-flexible gasification Indirectly fired cycle

Turbine fuel cell hybrids Gas separation and cleanup components Fuel flexibility database

Vision 21 plants

Product flexibility database Early-entry coproduction plant Vision 21 systems

1990

1995

2000

Year

2005

2010

2015

JANUARY 1, 2003 / ENVIRONMENTAL SCIENCE & TECHNOLOGY ■ 29 A

gives an overview of technology development and commercialization from 1990 to 2015 (15). Some advanced environmental control technologies, such as low-NOx burners and flue gas desulfurization systems for conventional pulverized coal plants, have been commercialized and widely applied; whereas other technologies, such as integrated gasification combined cycle (IGCC) systems, have only recently been demonstrated and have yet to gain wide acceptance in the United States. Low-emission, high-efficiency combustion systems. The Combustion Technologies Program’s objective is to develop, demonstrate, and commercially deploy advanced coal-fired combustion systems in the United States and abroad. These power plants offer significant improvements in performance and generate electricity at lower costs than the current fleet of power plants. The program has focused on three types of combustion systems: fluidized bed combustion (FBC), low-emissions boiler system (LEBS), and indirectly fired cycles (IFC). Key program goals include demonstrating pressurized FBC with more than 50% high heating value (HHV) efficiency, better environmental performance, and lower costs than other combustion systems by 2010; developing a 42% HHV-efficient LEBS for repowering or retrofitting existing plants with lower costs and emissions than existing pulverized coal technology by 2005; and producing a 47% HHV-efficient IFC–gas turbine combined cycle and advanced pulverized coal boiler with lower costs and emissions than than those of existing pulverized coal plants by 2010.

To date, the development and commercialization of FBCs is the most significant aspect of DOE’s combustion-related clean coal programs. A CCT program demonstration of atmospheric circulating fluidizedbed combustion (ACFB) in Colorado in 1992 provided the operating experience and data needed to commercialize this technology for utility-scale systems (16). The JEA (formerly Jacksonville Electric Authority) 300-MW ACFB plant, located in Jacksonville, Fla., is the largest ACFB in the world and Power Plant magazine’s most recent award winner. Currently, an estimated 9.5 gigawatts (GW) of commercial ACFB capacity is installed worldwide. ACFB is unique because it offers better fuel flexibility, higher carbon conversion, and in-furnace sulfur control. Pressurized fluidized-bed combustion (PFBC) technology is entering the market after work performed at the Ohio Power Co.’s Tidd plant (17). The CCT demonstration project and the associated development work resulted in several commercial sales, including a 360Megawatt electric (MWe) unit in Japan. The work with the Tidd plant has also provided a foundation for developing a second-generation system. Figure 2 shows a schematic of a fluidized-bed combustion combined cycle (FBCC) plant. In this secondgeneration PFBC system, coal is devolatized in a pressurized carbonizer to produce a low-Btu gas and a char. The char is then burned in the PFBC unit. Both the low-Btu and PFBC gases are cleaned by hot-gas filtration, and the carbonizer syngas is burned in a topping combustor to heat the PFBC flue gas. This hot flue

FIGURE 2

Second-generation pressurized fluidized-bed combustion (PFBC) The pressurized carbonizer to devolatize coal produces low-BTU gas and char. Integrating new technologies could make efficiency exceed 50% and result in near-zero NOx, SO2, and particulate emissions.

Coal

Pressurized carbonizer

Pressurized Fluidized-bed heat exchanger circulating SO2 sorbents fluidized-bed combustor Char

Hightemperature filters

Steam Spent SO2 sorbent

Syngas

Oxygen depleted air

Generator

High-pressure air

Steam turbine

Hightemperature filters

Topping combustor

Heat recovery steam generator

Air Generator

Air compressor

30 A ■ ENVIRONMENTAL SCIENCE & TECHNOLOGY / JANUARY 1, 2003

Gas Clean-gas turbine turbine exhaust Gas turbine

Stack

gas drives a gas turbine to generate power. The flue gas leaving the gas turbine then generates steam in a heat recovery steam generator, which is used to generate additional power. With the integration of newer buildingblock technologies—hot gas cleanup, advanced gasifier technology, and advanced turbine systems—efficiencies for PFBC systems are expected to eventually exceed 50% and have near-zero NOx, SO2, and particulate emissions. Market entry is projected for 2008. New approaches to flexible power generation. Gasification-based technologies are preferred for future energy plants based on existing commercial applications for power generation and fuel and chemical production. These systems are very attractive because of their high thermal efficiency and cost-effective removal of pollutants. The Gasification Program has four goals. First, it will develop revolutionary technologies (e.g., membranes) that will separate oxygen from air for the gasification process and separate hydrogen from carbon dioxide. The latter strategy will produce hydrogen for fuel and may capture carbon dioxide for disposal. Second, the program hopes to improve gasifier designs to be more durable and capable of handling various carbon-based feedstocks. Third, it will develop advanced gas cleaning technologies that can capture virtually all the ash particles, sulfur, nitrogen, alkali, chlorine, and hazardous air pollutants. Finally, the program will seek ways to minimize solid wastes and use them as commercial products. Four IGCC CCT demonstration projects, repre-

senting various gasifier types and cleanup systems, are evaluating systems in commercial service. The first two plants, Tampa Electric Co.’s 250-MWe Polk Power plant in Polk County, Fla. (18) and PSI Energy’s 262MWe retrofit of the Wabash River Generating Station in Vigo County, Ind. (19) have achieved the lowest levels of criteria pollutant air emissions (NOx, SOx, CO, PM10) of any coal-fired power plants in the world. The third IGCC project, Piñion Pine Plant in Storey County, Nev., experienced operational difficulties and funding was terminated. The fourth, the Kentucky Pioneer Energy IGCC Demonstration Project in Clark County, Ky., which is currently in the design phase with construction start-up scheduled for 2003, will demonstrate and assess the reliability, availability, and maintainability of a utility-scale IGCC system of 400 MWe. This plant will use a blend of a high-sulfur bituminous coal and municipal solid waste in an oxygen-blown, slagging gasifier. As a result of the Polk Power Plant demonstration, IGCC can be considered commercially and environmentally suitable for electric power generation using a wide variety of feedstocks. Sulfur capture is greater than 98%, while NOx emissions are 90% less than those from a conventional pulverized coal-fired power plant. Depicted in Figure 3, the Wabash River Coal Gasification Repowering Project transformed a 1950s vintage pulverized coal-fired plant from a nominally 33% efficient, 90-MWe unit into a nominally 40% ef-

FIGURE 3

The Wabash River Coal Gasification Repowering Project A 1950s vintage pulverized coal-fired plant was repowered according to the flow diagram to become a 40% efficient, 262-MWe (net) unit. High-pressure steam

Fuel gas preheat

Fuel gas Fuel gas

Feed water

Char

Slag quench water First stage

Steam

Oxygen from separation plant

Gas turbine Heat recovery steam generator

Generator

Hot exhaust gas

Flue gas to stack

Steam

Destec entrained-glow gasifier

Coal slurry

Combustor

Air

Second stage

Fuel gas

Sulfur removal Hot and ceramic recovery candle filter Liquid sulfur byproduct Particulate removal

Feed water

Slag water slurry Slag byproduct

Generator Steam turbine

JANUARY 1, 2003 / ENVIRONMENTAL SCIENCE & TECHNOLOGY ■ 31 A

U.S. DEPT. OF ENERGY

ficient, 262-MWe (net) unit. Cinergy, PSI’s parent company, dispatches power from the project with a demonstrated heat rate of 8910 Btu per kilowatt hour (kWH) HHV. This plant is second only to the company’s hydroelectric facilities on the basis of environmental emissions and efficiency. IGCC is already realizing commercial sales, and an estimated 5 GWe of installed capacity is expected in the United States during this decade. Crosscutting approaches to minimize air, water, and solid emissions. Focusing on advanced, low-cost environmental control technologies will allow the existing fleet of coal-based power plants to meet current and future environmental requirements. The DOE environmental program also provides high-quality scientific information on present and emerging environmental issues for use in regulatory and policy decision making. It includes research related to controlling mercury, NOx, PM, and acid gas emis-

The Wabash River Coal Gasification Repowering Project in Indiana demonstrates integrated gasification combined cycle in a power plant. IGCC combines modern gasification with gas turbine and steam power generation technology.

sions; focuses on reusing coal combustion and gasification byproducts and solid residues; and addresses the potential impact of power generation on water quality and availability in the United States. The CCT Program has provided a portfolio of NOx and SO2 control technologies applicable to all boiler types. These NOx technologies enable utilities to costeffectively comply with the first wave of NOx control requirements that address acid rain and, further, allow the utility industry to respond to emerging standards on ozone. Technologies include low-NOx burners and reburning systems that modify the combustion process to limit NOx formation, selective catalytic and noncatalytic reduction technologies that reduce already formed NOx, and artificial intelligence-based control systems to optimize the operational and environmental performance of boilers. Various SO2 control technologies are also available for new and old boilers. Two advanced wet flue gas desulfurization projects redefined designs for lime/ limestone-based scrubbers, nearly halving capital and 32 A ■ ENVIRONMENTAL SCIENCE & TECHNOLOGY / JANUARY 1, 2003

operating costs while producing useful byproducts and mitigating declines in plant efficiency (20). The CCT Program also initiated comprehensive cooperation between the DOE, EPA, and industry for the evaluation of air toxics emissions from a cross section of coal-fired plants (21). In particular, efforts have focused on mercury control. The results helped to further the technology, with follow-up efforts to be implemented through DOE’s environmental research and development program. NETL’s current mercury control program includes full-scale testing of two advanced technologies, sorbent injection and enhanced wet scrubbing. Sorbent injection entrains activated carbon into the flue gas to directly adsorb mercury with subsequent capture by the particulate control device. Enhanced wet scrubbing incorporates additives to help oxidize elemental mercury, which increases solubility and improves capture by the scrubber. NETL is also sponsoring the laboratory- and pilot-scale efforts to better understand the emission and control of mercury from coal-based power systems (22). These technologies need to be available by 2007 to meet proposed EPA regulations. Sensible approaches to carbon management. The carbon sequestration program is developing environmentally acceptable technologies to capture and store carbon and thereby stabilize atmospheric CO2 levels. Research activities are structured around the following basic pathways to long-term carbon sequestration: capture and storage; geologic, ocean, and terrestrial sequestration; advanced CO2 conversion and reuse; and modeling and analysis. Program goals include developing technology options for greenhouse gas management that are safe and environmentally acceptable; directly capturing CO2 at a competitive cost (less than a 25% increase in the cost of energy services); indirectly trapping CO2 at less than $10 per ton of carbon; reducing carbon intensity (amount of carbon per unit of energy produced) by 18% by 2012; and providing a portfolio of commercially ready technologies for an assessment scheduled for 2012 as part of a global climate change initiative. Currently, the most likely options for CO2 capture and sequestration include chemical and physical absorption and adsorption, low-temperature distillation, gas separation membranes, and mineralization/ biomineralization. Enhanced oil recovery (EOR) represents the best near-term option to sequester carbon at low net cost due to the revenues from recovered oil/gas. Another attractive option is to inject CO2 into unmineable coal seams. Tests have shown that CO2 is roughly twice as adsorbing on coal as methane, giving CO2 injected into unmineable coal seams the potential to efficiently displace methane and remain sequestered in the bed. (Coincidentally, these coal seams are often located near electricity-generation facilities that are large point sources of CO2 gas, which then requires only limited transport.) CO2 recovery of methane has been demonstrated in limited field tests, but much more work is necessary to understand and optimize the process. Similar to the byproduct value gained from EOR, the recov-

subprogram focuses on developing a technology base for materials and includes the Advanced Research and Technology Development Materials Program at Oak Ridge National Laboratory, the Advanced Metallurgical Research Program at Albany, Ore., and materials-related activities within the Office of Science and Technology at NETL. This program funds exploratory research designed to develop new materials, such as alloys and ceramics, which have the potential to improve the performance or reduce the cost of existing fossil fuel technologies. U.S. DEPT. OF ENERGY

ered methane provides a value-added revenue stream to the carbon sequestration process, creating a lownet-cost option. Integrating coal bed methane with a coal-fired electricity generation system may be an option for additional power generation with low emissions (23). Other potential sequestration sinks include depleted oil and gas wells, aquifers, forests, and other agricultural plots (24). Vision 21 incorporates industrial ecology. Vision 21 is DOE’s initiative for developing the technology needed for ultraclean 21st century energy plants. The goal is to effectively remove environmental concerns associated with using fossil fuels for producing electricity and transportation fuels at competitive costs. Collaborating with industry and academia, NETL has developed a 15-year plan that stresses innovation and revolutionary improvements in critical technologies, such as gasification, gas separation and purification, and fuel cells. Vision 21 integrates multiple advanced technologies and emphasizes market flexibility, multiple feedstocks and products, and industrial ecology. Projects are under way in these and other key technology areas (25). Many of the Vision 21 activities complement and extend activities to achieve second-generation PFBC and IGCC plants. Vision 21 addresses gas cleanup, air (N2, O2) and syngas (H2, CO2) separations, and extends the development effort to increase efficiency and cost-effective measures for particulate and sulfur/alkali control. Vision 21 activities include developing novel membranes for hydrogen separation, oxide-dispersion strengthened heat exchanger tubing, a PFCB partial gasification module, a rocket engine design adapted for turbine power, fuel-flexible gasification–combustion technology for production of hydrogen, various modeling and simulation packages for power systems, and a hybrid power module gas turbine with fuel cell power module. To accelerate market entry of Vision 21 systems, the implementation strategy includes having “early-entry” spinoff technologies, which become commercial products over the span of the program because they represent significant breakthroughs in cost and performance, such as the air separation membrane for low-cost oxygen production (26). Using fossil energy resources responsibly. The key goal for all of the subprograms is to apply novel research that links to Vision 21. The Advanced Research Program is a bridge between basic research and development and deployment of innovative systems. These systems are capable of improving the efficient and environmentally responsible use of fossil energy resources. The major subprograms are Coal Utilization Science (CUS) and Materials and Advanced Metallurgical Research. The CUS subprogram supports research that develops technologies for clean, efficient power generation from coal and other fossil fuels. It emphasizes producing fundamental information on the underlying processes and mechanisms that inhibit experimental research and theoretical investigations. Novel processes that address environmental issues and power generation are included in its purview. The Materials and Advanced Metallurgical Research

The gasifier structure is on the left side of the Piñon Pine construction site in Nevada. The raw coal storage dome on the right is 250 meters in diameter and holds a 20-day supply of coal. Funding for the profect was terminated after construction was completed because of start-up issues.

Other DOE subprograms that support clean coal include Bioprocessing of Coal, University Coal Research, Historically Black Colleges and Universities and Other Minority Institutions, Small Business Innovation Research/Small Business Technology Transfer, and Computational Energy Services.

Benefits to the public The investment in both advanced power system technology for new generating capacity and the environmental retrofit of existing power plants will result in a significant reduction in fuel and environmental compliance costs for U.S. utilities. Reducing the utility industry’s capital requirements and operating and fuel costs allows companies to provide more competitive pricing for consumers. Potential savings to utilities total $2.4 billion per year for NOx control by 2005, $2.1 billion per year for SO2 control by 2008, and $2–4 billion per year for mercury control by 2008. Technologies being developed to meet projected mercury emission standards have potential savings of $4.2 billion per year by 2008, and will reduce the cost of conventional compliance with environmental regulations for SO2, NOx, and mercury emissions by 50–90%. Estimates show that these environmental retrofit technologies will result in almost $200 billion JANUARY 1, 2003 / ENVIRONMENTAL SCIENCE & TECHNOLOGY ■ 33 A

U.S. DEPT. OF ENERGY

in cumulative savings over the forecast period. Macroeconomic impacts of both the advanced power systems and the environmental retrofit technologies between 2005 and 2025 are estimated to include a cumulative increase in real gross domestic product of nearly $550 billion and an additional average increase of almost 100,000 jobs each year (3). The National Research Council has reported other estimated benefits of coal research and development programs (27).

The Texaco gasifier and the radiant gas syngas cooler are inside the largest structure at the Tampa Electric Integrated Gasification Combined Cycle Project site in Florida.

Acknowledgments Support and assistance provided by the NETL OCES and Science Applications International Corporation staff in the preparation of this manuscript are gratefully appreciated. Carl O. Bauer is the associate laboratory director at the U.S. DOE’s NETL OCES ([email protected]).

References (1) Energy Information Administration: Annual Energy Review 2000; Energy Information Administration (U.S. Dept. of Energy), DOE/EIA-0384(00), 2000; www.eia.doe.gov/ emeu/aer/contents.html (2) EPA Office of Compliance Sector Notebook Project. Profile of the Fossil Fuel Electric Power Generation Industry; U.S. Environmental Protection Agency, Office of Enforcement and Compliance Assurance, Office of Compliance, EPA/310-R-97-007, September, 1997; www.epa.gov/ compliance/resources/publications/assistance/sectors/ notebooks/fossil.html (3) Coal and Power Systems—Strategic Plan and Multi-Year Program Plans, Office of Fossil Energy, U.S. Department of Energy, January 1999; www.fossil.energy.gov/coal_ power/programplans/99/99coalpwr_strategy.pdf. (4) Report of the National Energy Policy Development Group, May 2001; www.fe.doe.gov/general/energypolicy/ nationalenergypolicy.pdf. (5) Air Quality and Electricity Restructuring: A Framework for Aligning Economic and Environmental Interests under Electricity Restructuring; Center for Clean Air Policy:

34 A ■ ENVIRONMENTAL SCIENCE & TECHNOLOGY / JANUARY 1, 2003

Washington, DC, March 1997. (6) EPA Report to Congress: Wastes from Combustion of Fossil Fuels, Volume 2—Methods, Findings and Recommendations; U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response, EPA-530-R-010, U.S. EPA: Washington, DC, March 1999. (7) Regulatory Finding on the Emissions of Hazardous Air Pollutants from Electric Utility Steam Generating Units; U.S. Environmental Protection Agency, 6560-50-P, U.S. EPA: Washington, DC, December 2000. (8) Clean Coal Technologies—Research, Development, and Demonstration Program Plan; U.S. Department of Energy, DOE/FE-0284, (available from NTIS as DE94004382), 1993. (9) Implementing the U.S. Department of Energy’s Power Plant Improvement and Clean Coal Power Initiatives; www.lanl.gov/projects/cctc/PPII/PPII.pdf. (11) NETL’s Office of Coal and Environmental Systems Webpage; www.netl.doe.gov/coalpower/index.html (12) DOE Clean Coal Technology Compendium; www.lanl.gov/ projects/cctc/resources/library/bibliography/bibliogra phy_d.html (13) DOE Techline, Power Industry Signals Strong Support for Clean Coal Technology; www.netl.doe.gov/publications/ press/2001/tl_ppii_proposals.shtml. (14) DOE Techline, Abraham Announces Projects to Bolster Electricity Supply with New Technologies for Nation’s Coal Fired Power Plants; www.netl.doe.gov/publications/ press/2001/tl_ppii_sel.shtml. (15) DOE’s FY 2000 Strategic and Multiyear Program Plan for Central Power Systems; www.fe.doe.gov/coal_power/ programplans/00/index.shtml. (16) Comprehensive Report to Congress—Clean Coal Technology Program; Nucla CFB Demonstration Project, U.S. Department of Energy, Office of Fossil Energy, DOE/FE-0106, July 1988; www.lanl.gov/projects/cctc/resources/pdfs/ nucla/000000D7.pdf (17) Tidd PFBC Demonstration Project—DOE Project Fact Sheet; www.lanl.gov/projects/cctc/factsheets/tidd/tidd demo.html (18) Clean Coal Technology—Tampa Electric Integrated Gasification Combined-Cycle Project—An Update; DOE Topical Report Number 19, July 2000; www.lanl.gov/projects/cctc/ topicalreports/documents/topical19.pdf. (19) Clean Coal Technology—The Wabash River Coal Gasification Repowering Project—An Update; DOE Topical Report Number 20, September 2000; www.lanl.gov/ projects/cctc/topicalreports/documents/topical20.pdf. (20) Advanced Technologies for the Control of Sulfur Dioxide Emissions from Coal-Fired Boilers, Clean Coal Technology Topical Report #12, June 1999; www.lanl.gov/projects/ cctc/topicalreports/documents/topical12.pdf (21) Miller, S., et al., A Comprehensive Assessment of Toxic Emissions from Coal-Fired Power Plants: Phase I Results; from The U.S. Department of Energy Study, Final report prepared for Pittsburgh Energy Technology Center, Morgantown Energy Technology Center, September 1996; www.netl.doe.gov/coalpower/environment/mercury/pubs/ toxicreport.pdf. (22) Curbing Mercury Emissions, www.fe.doe.gov/coal_power/ existingplants/mercurycontrol_fs.shtml. (23) CO2 Capture and Storage in Geologic Formations—A white paper prepared for the National Climate Change Technology Initiative; U.S. Department of Energy, Office of Fossil Energy, NCCTI Energy Technologies Group, CO2 Capture and Storage Working Group, January 2002; www.netl.doe.gov/coalpower/sequestration/pubs/CS-NC CTIwhitepaper.pdf. (24) Carbon Sequestration Technology Roadmap—Pathways to Sustainable Use of Fossil Energy; U.S. Department of Energy, Office of Fossil Energy, National Energy Technology Laboratory, January 2002; www.netl.doe.gov/coal power/sequestration/pubs/CS_roadmap_0115.pdf. (25) Vision 21 Technology Roadmap, National Energy Technology Laboratory; www.netl.doe.gov/coalpower/ vision21/pubs/v21rdmp.pdf. (26) DOE Office of Fossil Energy, Clean Coal Technology Webpage; www.fe.doe.gov/coal_power/cct/cct_benefits.shtml. (27) Energy Research at DOE;Was It Worth It? Energy Efficiency and Fossil Energy Research 1978 to 2000, National Research Council, National Academy Press: Washington, DC, 2001.