Approximately one third of man-made carbon dioxide emissions come from fossil fuels used for generating electricity. Although AWL is a low-tech method to sequester carbon dioxide, it requires very large amounts of sea water, thus limiting AWL facilities to within about 10 kilometers of the coastline. About 12 percent of carbon dioxide emissions from U.S. electricity production occur at power plants within 10 kilometers of the coastline.

AWL also requires huge amounts of limestone fines: about 2,190,000 tons of limestone are needed each year to sequester 20 percent of the carbon dioxide from a 500 MW coal-fired plant. Studies show that the majority of those U.S. coastal power generating facilities are within economical transport distance of limestone resources, that sufficient waste limestone fines are being produced, and that transportation systems and material-handling capabilities currently exist to meet the huge demand for limestone fines that could be used by AWL, should it ever be implemented.

The best news is that Accelerated Weathering of Limestone presents opportunities for the crushed stone industry, electrical utilities, and research scientists to work together to help keep the Earth a cool place to live.

The author will be presenting a paper on AWL at the SME Annual Meeting in Denver, Colo., on Feb. 25, 2008 (www.smenet.org).