Introduction
Coal is a very cheap and abundant provision of energ. In fact, it is the most abundant fuel in the United States; U.S. has the highest coal reserve in the world, with up to 25% of the known world coal present in America and being mined in 26 out of the U.S. 50 states (fe.doe.gov, 2013). However, this abundant energy is seldom used because it is a very dirty energy. According to Hong & Slatick (1994), up to 204.3 pounds of carbon dioxide per million Btu is emitted when coal having 78% carbon content is completely burned to attain a ...