ABSTRACT
Coal began as layers of plant matter accumulated at the bottom of a body of water protected from biodegradation and oxidization, usually by mud or acidic water. The harder forms, such as anthracite coal, become metamorphic rock because of later exposure to elevated temperature and pressure Coal is composed primarily of carbon along with variable quantities of other elements, chiefly sulfur, hydrogen, oxygen, and nitrogen. The amount of coal used each year is projected to increase significantly through 2035 and beyond unfortunately, the higher-quality coal in places like China has been mined, so lower-quality, even dirtier coal is coming out of the ground. In China, coal is the inexpensive energy source needed to support a rapidly growing economy and it is wishful thinking to expect this to change any time soon. New and tougher Environmental Protection Agency regulations on coal pollutants such as acid rain-causing sulfur dioxide, mercury, and nitrogen oxide will have an impact.
