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Prepared Witness Testimony The House Committee on Energy and Commerce
Future Options for Generation of Electricity from Coal.
Subcommittee on Energy and Air Quality
Dr. Roe-Han Yoon
Many power companies opted to meet the requirements of the 1990 Clean Air Act Amendment by switching to low-sulfur coals, and Central Appalachia has been the major source of compliance coals. Recently, the coal companies operating in this region have been experiencing difficulties due to high operating costs and low prices of coal. The price of coal had been declining between 1980 and 2000. During the same period, the productivity of underground coal mining operations increased 3.6 times. Thus, the industry combated the difficult market condition by increasing productivity. However, further increases in productivity are becoming difficult due to adverse geological conditions, stringent environmental regulations, and shortages of trained workforce. It is, therefore, necessary to develop advanced technologies for increasing mining productivity and improving the efficiency of separating coal from waste materials. The coal industry has been producing large amounts of waste at mine sites, creating public concerns and contributing to increased production costs. These problems can be minimized by developing advanced mining and processing technologies. In this testimony, examples are given to show that advanced technologies developed through research can be used to transform environmental liabilities, such as fine coal impoundment, to a valuable resource. Developing advanced mining and processing technologies will be the key to assuring a steady supply of low-cost fuels in an environmentally acceptable manner for the U.S. power industry. THE COAL INDUSTRY IN CENTRAL APPALACHIA The 1990 Clean Air Act Amendment called for the reduction of sulfur dioxide (SO2) emissions in coal-burning power plants. Of the various options the industry had, the following three were considered most viable, namely, i) fuel switching, ii) purchasing emission allowances, and iii) installation of scrubbers. Most of the coal-burning power plants chose the first two, with about 25% choosing scrubbers. There are two major sources of low-sulfur coals in the U.S., i.e., western subbituminous coal and central Appalachian bituminous coal. In 2002, the coal industry produced 550 million tons of western subbituminous coal and 248 million tons of bituminous coal from central Appalachia. In 1997, the Energy Information Administration (EIA) estimated that central Appalachia has approximately 17.6 billion tons of recoverable coal reserves, which is defined as the coal that can be recovered "economically with the application of extraction technology available currently or in the foreseeable future." According to this definition, the EIA estimate includes coal that can be minable in the future using more advanced technologies. On the other hand, the John T. Boyd Company has recently estimated the recoverable reserves in Central Appalachia to be about 7.1 billion tons (Bate, 2003), while the major coal companies operating in the region reported 5.2 billion tons of reserves. Noting that much of the reported coal reserves included the coal seams that are more difficult to mine, the John T. Boyd Company "guesstimated" that only 10-15% of the estimated 7.1 billion tons may actually be economically recoverable at today's coal prices. If the price of coal increases in the future, however, the economically recoverable reserve base in central Appalachia should increase. On the other hand, coal prices have actually been declining in real dollars between 1980 and 2000. The U.S. coal companies combated this problem by increasing productivity. During the same 20-year period, underground coal mining productivity increased 3.5 times from 1.2 to 4.2 tons per man hour. This remarkable achievement was made possible through technology development, particularly the longwall mining method. This technology was introduced to the U.S. coal industry in 1960s. In 1987, the mining industry made a complete transition from using medium voltage (1000 V) to high voltage (2400-4160 V) equipment, which allowed for the development of much larger equipment. This and other innovations such as self-advancing roof-support systems allowed companies to mine coal seams at wider face widths and deeper web cutting depths, resulting in substantial increase in productivity. However, the large reserve blocks that are conducive to present-day longwall mining technology are becoming depleted, and companies must now mine thinner coal seams. Furthermore, they have to deal with various regulatory hurdles and lack of trained workforce. All of these factors have contributed to increased costs of producing coal from central Appalachia. The combination of high production costs and low coal prices caused financial difficulties for the coal companies operating in central Appalachia, and a large number of them have filed bankruptcy proceedings since 2000. Most of the coal mined in central Appalachia is cleaned of its impurities such as ash-forming minerals and inorganic sulfur before combustion. Typically, more than 50% of the run-of-mine (ROM) coal is separated from waste at coal cleaning (or preparation) plants. In general, the larger the amount of waste generated, the higher the operating costs, which are eventually passed on to utility companies. According to the 2003 Energy Outlook, fuel costs accounted for 76% of the operating costs for electricity generation in 2000. For this reason, utility companies are striving to reduce their fuel costs. Developing advanced mining and coal cleaning technologies would help coal companies provide low-cost compliance coals to utilities for power generation. ADVANCED MINING AND PROCESSING TECHNOLOGIES The U.S. is the largest mining country of the western world. In 2001, the U.S. produced a total of $58 billion of raw materials, which consisted of $39 billion from minerals and $19 billion from coal. The mineral processing industries increased the value of the minerals to $374 billion, while coal was used to produce 52% of the nation's electricity and uranium 20%. The dollar value of the electricity produced from the two mining products was estimated to be $177 billion in 2001. Thus, the U.S. mining industry contributed a total of $551 billion to the nation's economy, which accounted for 5.4% of its GDP. According to the 2002 Mineral Commodity Summary, major industries further increased the value of the processed mineral materials (not including coal and uranium) to $1.72 trillion, which accounted for 17% of the GDP. Despite the large contributions made by the U.S. mining industry, the research and development expenditure in mining and processing research is miniscule when compared to that being spent for coal utilization. The lack of interest in these areas of research stems from the perception that the technologies used in the mining industry are mature and there is little room for further improvement. This is far from the truth. The longwall mining method, for example, was originally developed in Europe in the 17th century (Lucas and Haycocks, 1973). The technology continually advanced during the last 20 years, and has been the main reason that the U.S. coal industry has been able to increase its productivity. I would hope that development of advanced mining and processing technologies would become an integral part of the FutureGen project so that the coal industry can be a steady and reliable supplier of low-cost fuel for power generation. It is my understanding that the FutureGen project is to address environmental issues in coal utilization. It is important to recognize that environmental problems also exist at mine sites. On October 11, 2000, near Inez, Kentucky, a 72-acre coal waste impoundment accidentally released 250 million gallons of slurry into nearby underground mines, creeks, rivers, and schoolyards. This incident caused Congress to appropriate $2 million for the National Research Council (NRC) to conduct a paper study to identify causes of the incident and suggest possible ways of preventing future incidents. According to the report published as a result of the NRC study, there are 713 impoundments, mostly in Appalachia, and the coal industry is still discarding 70-90 million tons of fine coal annually. A recent study suggested that the fine coal discarded in the various impoundments in the U.S. may amount to 2.5 billion tons. This is a significant amount in view of the depleting coal reserves in Central Appalachia. It is unfortunate that the U.S. mining industry is forced to discard significant portions of the coal after mining it from deep underground at high costs. There are two main reasons for discarding fine coal to impoundments. First, the separation of coal from ash-forming minerals is difficult when particle sizes are smaller that approximately 45 microns. Second, the fine coal retains large amounts of water due to the large surface area, which makes it difficult to handle and increases shipping costs. Virginia Tech has been developing technologies that may be used to address these problems. Two years ago, I had the privilege of testifying in front of this Committee. I talked about a coal company in Southwest Virginia that was using an advanced separation technology, known as Microcel, to recover fine coal from an impoundment. The median particle size of the coal recovered was about 20 microns, which was the reason that it had been discarded in the first place. Exhibit 1 shows the impoundment when it was filled with fine coal waste, and Exhibit 2 shows the same pond that is nearly empty as a result of the remining operation. This is an example of turning an environmental liability into "gold" using an advanced separation technology. The pond recovery project in Southwest Virginia was made possible because the company had an old thermal drier that could be used to dewater the coal cleaned by the advanced solid-solid separation technology. Many other companies do not have the luxury of using thermal driers, which are costly to install and operate. In order to address this problem, we have also been developing advanced dewatering technologies, which include dewatering chemicals and a hyperbaric centrifuge. The former, which is designed to improve the filtration processes that are currently used in industry, is close to commercialization, while the latter is being tested at bench-scale. The dewatering technology has recently been tested on a very fine coal recovered from a large impoundment in southern West Virginia. The coal sample taken from the impoundment was cleaned first to 5% ash using the Microcel technology. The product was then dewatered to 16-18% moisture using the novel dewatering aids. Based on pilot-scale test work conducted by Virginia Tech as part of a project sponsored by the U.S. Department of Energy, Beard Technologies is planning to build a 200- ton per hour recovery plant. CONCLUSION There is a need to develop advanced mining and separation technologies that can be used to reduce the cost of producing solid fuels (coal) in an environmentally acceptable manner for the U.S. power industry. They can also be used to cleanup waste coal impoundments, thereby minimizing public concerns for the environmental problems created at mine sites. REFERENCES SITED Lucas, J.R. and Haycocks, C, eds., "Underground Mining Systems and Equipment," Sec. 12 in SME Mining Engineering Handbook, A.B. Cummins and I.A. Givens, eds., Society of Mining Engineers, AIME, New York, pp. 485-489, 1973. Bate, R. L., "Quantifying the Reserve Dilemma in the Central Appalachian Mining Region," American Coal Council, May 2003. Exhibit 1: Middlefork fine coal impoundment before remining.
Exhibit 2: Middlefork impoundment now after remining. The operation is still ongoing.
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