What is Pure Coal?

Abstract

While the environmental issues related to controlling air pollution from coal combustion have been argued extensively, little attention has been given to the fact that there are some fundamental weaknesses in the way impurities in coal are analyzed and classified. Relatively minor changes in the classification of impurities in coal can open the way to much easier comparison of the environmental implications of utilizing coal from different regions. There are four important measurements of coal quality: heat content, sulfur, ash, and toxic trace elements. Heat content is a measure of the energy-per-unit-weight of coal and is conventionally expressed as the number of Btu per pound of coal. The tendency of coal investigators to deal with coal on a weight basis rather than on a Btu basis has led to serious misrepresentations of coal data. For example, if calculations are made in terms of Btu rather than tons we find that total energy consumption for the U.S. was overestimated by 27.8 trillion Btu between 1955 and 1971. Air and water pollution by sulfur, coal reserves in terms of sulfur content, a new comparison basis for sulfur content, and sulfur removal are discussed. Ash and trace elements are treated in similar detail.more » (MU)« less