Fifty-six percent of the coal ash produced during 2016 was recycled – establishing a new record and marking the second consecutive year that more than half of the coal ash produced in the United States was beneficially used rather than disposed.
“The trend for coal ash beneficial use continues to be very positive,” said Thomas H. Adams, executive director of the American Coal Ash Association (ACAA) – an organization that advances the environmentally responsible and technically sound use of coal ash as an alternative to disposal. “For the third straight year, we have seen significant improvement in the beneficial use rate. We look forward to continuing to grow these practices that conserve natural resources, make products that are more durable, and dramatically reduce the need for landfills.”
According to ACAA’s just-released “Production and Use Survey,” 60.2 million tons of coal combustion products were beneficially used in 2016 out of 107.4 million tons that were produced. Although the rate of ash utilization increased from 52 percent to 56 percent, the total volume of material utilized stayed about the same as production declined. Coal ash production volume declined 7 percent from 2015 levels as coal’s share of the electricity generation mix shrank in response to environmental regulations and competition from other energy sources. Coal ash utilization volume remained approximately level with the prior year.
“Coal ash” is a generic term that encompasses several Coal Combustion Products (CCP) that can be beneficially used in a wide variety of applications. Highlights of CCP production and use in 2016 include:
- Use of coal fly ash in concrete declined 8 percent to 14.4 million tons. While down from 2015’s record utilization of 15.7 million tons, utilization remained well above the 13.1 million tons performance in 2014. The dip in 2016 utilization is attributed to some regional seasonal shortages of supply that resulted from power plant shutdowns and changing generating profiles. Demand for fly ash remained strong across all concrete markets and utilization likely would have been higher if some logistical disruptions had not occurred. Fly ash improves concrete durability and significantly reduces greenhouse gas emissions associated with concrete production.
- Utilization of a key “non-ash” coal combustion product also declined. Synthetic gypsum is a byproduct of flue gas desulphurization units, also known as “scrubbers,” located at coal-fueled power plants. Use of synthetic gypsum in panel products (i.e. wallboard) decreased 19 percent to 9.9 million tons in 2016. The decrease is largely attributed to normal fluctuations in gypsum markets. During 2016, gypsum imports increased by 15 percent versus 2015, whereas exports decreased by 27 percent – thereby creating greater competition from natural gypsum.
- Synthetic gypsum use in agricultural applications – in which the gypsum improves soil conditions and prevents harmful runoff of fertilizers – also declined from 1.6 million tons to 772,000 tons.
- Production of boiler slag remained level at 2.2 million tons. Approximately 1.3 million tons of boiler slag was utilized in the production of blasting grit and roofing granules.
- For the first time, no utilities reported production of cenospheres – a very valuable form of ash mainly harvested from wet disposal impoundments. Production of this material dropped precipitously the year prior as impoundments began to close in response to EPA’s Final Rule for coal ash disposal.
“As America’s electricity grid changes, the coal ash beneficial use industry is evolving as well,” said Adams. “As we work diligently to utilize the 44 percent of coal combustion products that are still disposed annually, our industry is also taking significant strides in developing strategies for improving the quality and availability of these materials.”
Adams explained that increasing beneficial use requires ash marketers to ensure that products are consistent and available when customers need them – requiring large investments in technology and logistics. Additionally, the coal ash beneficial use industry is actively developing and deploying technologies and strategies for reclaiming coal ash materials that were previously disposed.
