Clean Coal

Clean coal was an umbrella term for any methods that have been developed to reduce the environmental impact of coal-based electricity, which accounts for nearly half of the United States’ electricity supply. These efforts include chemically washing minerals and impurities from the coal, gasification (see also IGCC), treating the flue gases with steam to remove sulfur dioxide, carbon capture and storage technologies to capture the carbon dioxide from the flue gas and coal de-watering technologies to improve the energy quality and thus the efficiency of burning coal for energy. These methods and the technology used are referred to as clean coal technologies. Figures from the Environmental Protection Agency show that these technologies have made today’s coal-based generating fleet 77 percent cleaner on the basis of regulated emissions per unit of energy produced.

While the term clean coal is today commonly used for carbon capture technologies, the earliest use of the term can be traced back to U.S. Senate Bill 911 in April, 1987:

"The term clean coal technology means any technology...deployed at a new or existing facility which will achieve significant reductions in air emissions of sulfur dioxide or oxides of nitrogen associated with the utilization of coal in the generation of electricity."

The term also appeared in a speech to mine workers in 1918, when clean coal referred meant coal that was "free of dirt and impurities".

It was in the late 1980s and early 1990s that the U.S. Department of Energy (DOE) conducted a joint program with the industry and State agencies to demonstrate these technologies large enough for commercial use. The program, called the Clean Coal Technology & Clean Coal Power Initiative, has had a number of successes that have reduced emissions and waste from coal-based electricity generation. Moreover, the Program has met regulatory challenges by incorporating nitrogen oxide (NOx) control technologies “into a portfolio of cost-effective regulatory compliance options for the full range of boiler types.” This portfolio has positioned the U.S. as a top exporter of clean coal technologies such as those used for NOx. The DOE continues its programs and initiatives through regional sequestration partnerships, a carbon sequestration leadership forum and the Carbon Sequestration Core Program, a CCS research and development program.

According to a report by the assistant secretary for fossil energy at the U.S. Department of Energy, clean coal technology has paid measurable dividends. Technological innovation introduced through the CCT Program now provides consumers cost-effective, clean, coal-based energy.

Sulfur dioxide (SO₂) and nitrogen dioxide (NO₂) control technologies emerging from clean coal technology have moved into the utility and industrial marketplace and now provide cost-effective regulatory compliance. A new generation of advanced coal-based power systems has been placed in commercial service that represents a quantum leap forward in terms of efficiency and environmental performance. These advanced power systems projects will provide a springboard for widespread, global deployment. This in turn will contribute greatly to reductions in greenhouse gas emissions.

The government and industry officials continue to use the term "clean coal" to describe technologies designed to enhance both the efficiency and the environmental acceptability of coal extraction, preparation, and use. However, today, the term "clean coal technology" is usually used in reference to carbon capture and storage, an advanced process that eliminates carbon dioxide emissions from coal-based plants and permanently sequesters them.

In the early 20th century, prior to World War II, clean coal (also called "smokeless coal") referred to anthracite and high-grade bituminous coal, used for cooking and home heating.