The volume of coal fly ash used in concrete production increased to 13.1 million tons in 2014, for the first time exceeding the 12.6 million ton utilization mark set in 2008, a trade group said Dec. 15.
Increases in the use of synthetic gypsum produced by power plant emissions control equipment also helped to push the recycling rate for all types of coal combustion products to a record 48%, said American Coal Ash Association (ACAA) Executive Director Thomas Adams.
“After a half decade of stalled growth in the utilization of coal combustion products, 2014 finally began to show signs of recovery,” Adams said.
ACAA is an organization that advances the environmentally responsible and technically sound use of coal ash as an alternative to disposal. “We are excited to once again focus on growing a practice that conserves energy and natural resources, reduces greenhouse gas emissions, and safely keeps ash out of landfills and disposal ponds,” Adams said.
Coal ash avoided ‘hazardous waste’ label by EPA
The volume of coal ash utilization stalled between 2009 and 2013 as the U.S. Environmental Protection Agency (EPA) pursued a protracted rulemaking process that posed the threat of a “hazardous waste” designation for coal ash that is disposed.
Ash producers, specifiers and users restricted coal ash use in light of the regulatory uncertainty and publicity surrounding EPA’s activities. In 2014, EPA began signaling that the “hazardous waste” designation proposal was off the table and in December 2014 finalized coal ash disposal regulations under the non-hazardous section of federal law.
According to ACAA’s just-released “Production and Use Survey,” 62.4 million tons of coal combustion products were beneficially used in 2014 – up from 51.4 million tons in 2013 and above the 2008 peak of 60.6 million tons. A total of 129.7 million tons of coal combustion products were produced in 2014 – up from 114.7 million tons the prior year.
The volume of coal fly ash and bottom ash produced in 2014 actually declined from the prior year, reflecting a reduced amount of coal consumed by electric utilities in response to environmental regulations and energy market conditions. Fly ash production declined nearly 3 million tons to 50.4 million tons. Bottom ash production declined nearly 2 million tons to 12.5 million tons.
Overall fly ash utilization in 2014 was about even with the prior year at 23.2 million tons, but the use shifted toward concrete applications. Use in concrete and for cement production increased 1.9 million tons, while use in mining, oil field services, and other applications declined.
While ash production declined, the production and use of another “non-ash” coal combustion product increased substantially. Synthetic gypsum is a byproduct of flue gas desulphurization units, also known as “scrubbers,” located at coal-fueled power plants. As more power plants install and operate this type of emissions control equipment, the volume of synthetic gypsum is growing rapidly.
Synthetic gypsum production in 2014 increased 9.7 million tons to 34.1 million tons. Use of synthetic gypsum increased 4.8 million tons to 16.8 million tons, driven by increased utilization in wallboard manufacturing and agricultural applications in which the gypsum improves soil conditions and prevents harmful runoff of fertilizers.
“Although 2014’s results show a significant improvement, it’s important to remember that the United States is still disposing of more than half of the coal combustion products that could be put to good use,” said Adams. “Additionally, the coal ash beneficial use industry is taking significant strides in developing strategies and technologies for reclaiming coal ash materials that were previously disposed.”
Adams referred to a 2015 ACAA-commissioned study by the American Road and Transportation Builders Association that found there will be ample supplies of coal combustion products for beneficial use in the future. The report concluded: “Coal will continue to account for a significant percentage of U.S. electric generation during the next two decades.
As a result, CCP production is expected to remain steady, increasing by 5% through 2033. The future of CCP utilization is equally bright. Growing demand in construction markets is expected to increase CCP utilization by over 48%. Forecast models project that CCP utilization rises to 63% of production by 2033. Even under alternative scenarios of accelerated coal-fueled electric generating unit retirements, CCP production is still expected to exceed overall demand.”