Refined Coal发表评论(0)编辑词条

Refined coal
Refined coal is the product of a coal upgrading technology that removes moisture and certain pollutants from lower-rank coals such as sub-bituminous and lignite (brown) coals. It is one form of several pre-combustion treatments and processes for coal that alter coal's characteristics before it is burned. The goals of pre-combustion coal technologies are to increase efficiency and reduce emissions when the coal is burned. Depending on the situation, pre-combustion technology can be used in place of or as a supplement to post-combustion technologies to control emissions from coal-fueled boilers.

The best known producer of refined coal is a company based in Denver, Colorado called Evergreen Energy Inc.The company is publicly traded and is listed on the NYSE Arca exchange. According to the company's web site and its Form 10-K on file with the U.S. Securities and Exchange Commission, it was founded in 1984 with the goal of commercializing a coal upgrading technology first developed in a Stanford University laboratory by Edward Koppelman. Taking the K from Koppelman's name, Evergreen, known formerly as KFx Inc., branded its refined coal product as "K-Fuel."

Much of the coal in the western United States is known as "lower-rank" coal that falls under the categories of "sub-bituminous" and "lignite" coals. These coals have high moisture levels and can be 20 to 30 percent water. This relatively high moisture content when compared to "higher rank" coals like bituminous and anthracite coals make lower-rank coals less efficient. The average heat content of sub-bituminous coal consumed in the United States is approximately 8,500 British thermal units (Btu) per pound. The K-Fuel(R) process uses heat and pressure to remove approximately 30 percent of the moisture from raw, low-rank coal and raises its thermal content to approximately 11,000 Btu per pound. In addition to raising the coal's heat value, a significant amount, up to 70 percent, of the elemental mercury in the coal is removed and, because of its higher efficiency, lower chloride and nitrogen oxides emissions are achieved on a per kilowatt hour generated basis.

The advantages of the refined coal process are more efficient transportation and the ability of utilities to switch to a fuel made of 100 percent refined coal or a blend of raw and refined coals in order to achieve lower emissions and greater efficiency.