lion) and related studies ($0.8 million). The AR&TD program on bioprocessing of coal would continue at its present level ($1.9 million), with emphasis on involvement with small and emerging companies.
Current physical coal cleaning techniques cannot reduce the sulfur content of coal to the levels needed to comply with most environmental regulations. Although the inorganic sulfur component of coal can be removed with other mineral matter, the organic sulfur is chemically bonded to the coal and is not amenable to physical separation. Biological and chemical methods for sulfur removal so far have not been promising for commercial-scale application. Because coal is an abundant and relatively low-cost fuel, the added cost of advanced preparation technology, combined with the cost of coal that is lost with separation process wastes, makes it extremely difficult for advanced cleaning methods to be economically competitive for applications involving direct coal use. The most promising applications for advanced beneficiation methods lie in the production of premium fuels that replace oil or gas (e.g., coal-liquid mixtures, discussed below). However, current and projected prices for oil and gas make it unlikely that significant markets for coal-based alternative fuels will emerge before the mid-term period. In the near-term, however, coal preparation might prove a desirable technique for selective treatment of coal to meet possible future hazardous air pollutant regulations by reducing trace element concentrations prior to combustion.
The utility industry is interested in promoting technical and economic improvements in coal beneficiation methods as an indirect means of reducing fuel-related costs. Lower-sulfur fuels provide better cost-benefit solutions for older boilers than scrubbers. Burning upgraded coal reduces the cost of maintaining boiler systems and increases combustion efficiency. SOx reduction in the flue gas reduces scrubber costs where flue gas desulfurization (FGD) is needed. Achieving maximum energy recovery requires improved liberation, improved separation efficiency, total cleaning, and process control. Size reduction and thermal drying account for about 75 percent of the capital costs and 50 percent of the operating costs for processing coal. The challenge for coal cleaning is to deliver coal at a price that is economically competitive with other sources of coal of comparable quality. Thus, the markets for cleaned coals are highly dependent on site-specific factors.
There is an emerging global market for this segment of the U.S. coal industry, particularly in India, Poland, and China, which have large reserves of relatively low quality coal. Improved U.S. coal preparation technology would make the United States more competitive in the international coal technology market. Improving the technology, in some cases, requires more development. For example, commercial preparation is not currently economically optimized. There is a need for testing and verifying new technologies, performing unit operations