Environmental laws and modern technologies have greatly reduced the impact on the environment from the production and consumption of coal.
What Are Some Environmental Concerns In Coal Mining?
Without proper care, mining can have a negative impact on ecosystems and water quality and alter landscapes and scenic views. Debris that chokes mountain streams can result from surface mining like mountaintop removal, and acidic water can drain from abandoned underground mines.
Today restoring the land damaged by surface mining is an important part of the mining process. Because mining activities often come into contact with water resources, coal producers must also go to great efforts to prevent damage to ground and surface waters.
Did You Know?
Fly ash and bottom ash are residues created when coal is burned. In the past, fly ash was released into the air through the smokestack, but by law much of it now must be captured prior to release. In the United States, fly ash is generally stored at coal power plants or placed in landfills. Nearly half is recycled for use in cement production or as a raw material for other products including road construction materials.
What Emissions and Byproducts Are Produced from Burning Coal?
The combustion of coal produces several types of emissions that adversely affect the environment. The five principal emissions associated with coal consumption in the energy sector are:
- Sulfur dioxide (SO2), which has been linked to acid rain and increased incidence of respiratory illnesses
- Nitrogen oxides (NOx), which have been linked to the formation of acid rain and photochemical smog and to depletion of the Earth’s ozone layer
- Particulates, which have been linked to the formation of acid rain and increased incidence of respiratory illnesses
- Carbon dioxide (CO2), which is the primary greenhouse gas emission from energy use.
- Mercury, which has been linked with both neurological and developmental damage in humans and other animals. Mercury concentrations in the air usually are low and of little direct concern. However, when mercury enters water — either directly or through deposition from the air — biological processes transform it into methylmercury, a highly toxic chemical that accumulates in fish and the animals (including humans) that eat fish.
How Are the Environmental Effects of Coal Use Diminished?
Reducing the Impacts of Coal Use
The Clean Air Act and the Clean Water Act require industries to reduce pollutants released into the air and the water.
Industry has found several ways to reduce sulfur, nitrogen oxides (NOx), and other impurities from coal. They have found more effective ways of cleaning coal after it is mined, and coal consumers have shifted towards greater use of low sulfur coal.
Power plants use flue gas desulfurization equipment, also known as "scrubbers," to clean sulfur from the smoke before it leaves their smokestacks. In addition, industry and government have cooperated to develop technologies that can remove impurities from coal or that make coal more energy-efficient so less needs to be burned.
Equipment intended mainly to reduce SO2 (such as scrubbers), NOx (such as catalytic converters), and particulate matter (such as electrostatic precipitators and baghouses) is also able to reduce mercury emissions from some types of coal. Scientists are also working on new ways to reduce mercury emissions from coal-burning power plants.
Research is underway to address emissions of carbon dioxide from coal combustion. Carbon capture separates CO2 from emissions sources and recovers it in a concentrated stream. The CO2 can then be sequestered, which puts CO2 into storage, possibly underground, in such a way that it will remain there permanently.
Reuse and recycling can also diminish coal’s environmental impact. Land that was previously used for coal mining can be reclaimed for uses like airports, landfills, and golf courses. Waste products can also be captured by scrubbers to produce synthetic gypsum for wallboard.
Source: National Mining Association