CHARACTERISTICS

Coal-fired electric power plants produce considerable amounts of solid by-products, ( in excess of 100 million tons per year in the U.S., ( primarily fly ash (80%) and bottom ash, of which less than 30 percent are recycled for productive purposes. These amounts will only increase with the rise in the number of power plants that use pollution control technologies.

Fly ash can be used in many cement and concrete applications as a substitute for portland cement. The manufacture of portland cement requires considerable amounts of energy, which generates GHG emissions, and emits CO₂ during the calcination process.

Currently, less than 25% of U.S. fly ash is utilized in any form, and less than 15% is being used as a portland cement substitute. Gypsum and other sludges generated from the flue gas desulfurization process can replace raw gypsum in industrial and agricultural processes. The energy costs and resulting emissions associated with the acquisition and use of raw gypsum can be avoided by recycling the desulfurization process byproducts.

SIZE:
The capability exists for significantly increasing the use of by-products from power plants.

FEATURES:
Use of by-products reduces the amount and cost of landfilling required. At the same time, it could be substituted for materials, that when processed, emit GHGs.

COST:
O&M costs of existing landfills are $2-4/ton, but the cost of developing new landfills is up to $30/ton

CURRENT USAGE:
Less than 25% of U.S. fly ash is utilized.

POTENTIAL USAGE:
The potential exists for most of the by-products from power plants to be utilized.

CLIMATE CHANGE IMPACT

EMISSION EFFECT:
    

CONDITIONS FOR EMISSIONS MITIGATION:

• Great potential for significant reductions in GHG emissions.

EMISSION ESTIMATE:
N/A. Varies from site to site.

COST-EFFECTIVENESS:
Can be very cost-effective, especially where landfill costs are high.

SECONDARY EFFECTS:
Additional benefit derived from eliminating need for landfill.

ISSUES ASSOCIATED WITH IMPLEMENTING ACTION

• Must have sufficient market for by-product produced that is within economic distance of the power plant.
• Tipping for by-product must be less than landfill costs.
• Quality of by-product must meet the market specifications.

RESOURCES

• The U.S. Department of Energy has posted the Climate Challenge Options Workbook online at http://www.eren.doe.gov/climatechallenge/.
• U.S. DOE FETC Coal Combustion Byproduct Utilization Research & Development Program, http://www.fetc.doe.gov/products/power/enviro/ccb/. This site also provides links to related activities of other organizations and U.S. state governments.

CONTACTS

American Coal Ash Association
Barry Stewart
Director of Technical Services
Alexandria, VA
Tel: (703) 317-2400
Fax: (703) 317-2409
ACAA-USA@acaa-usa.org
http://www.acaa-usa.org

U.S. Department of Energy
Scott Renninger, Project Manager, Power & Environmental Systems Division
Federal Energy Technology Center
Coal Combustion By-product (CCB) Utilization Research and Development Program
Tel: (304) 285-4790
Fax: (304) 285-4403
srenni@fetc.doe.gov
http://www.fetc.doe.gov