ABSTRACT
Acid deposition, popularly known as acid rain, has long been suspected of damaging lakes, streams, forests, and soils; decreasing visibility; corroding monuments and tombstones; and, potentially threatening human health in North America and Europe. Sulfur dioxide, the most important of the two gaseous acid pollutants, is created when the sulfur in coal is released during combustion and reacts with oxygen in the air. The amount of sulfur dioxide created depends on the amount of sulfur in the coal. In an attempt to mitigate the effects of acid rain several proposals have appeared before the US Congress. Reduction in sulfur dioxide emissions, particularly from utility and industrial coal-fired boilers, is the primary target for combatting acid rain. Consumption of subbituminous coals will entail higher heat rates, higher handling costs, and capacity derates. Together, these economic and technical considerations tend to make the use of subbituminous coals in bituminous boilers a very site-specific issue that does not provide clear economic advantages.
