Case Studies

These case studies illustrate how Alcoa is acting upon its commitment to sustainable development throughout the world. We are pleased with this progress, but look forward to achieving even more.

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United States - 2009

Alcoa-Led Industry Initiative Reduces PVC Use, Hydrogen Chloride Emissions

 

After spearheading an initiative to encourage the North American aluminum beverage can industry to use coatings free of polyvinyl chloride (PVC), Alcoa saw its Tennessee Operations achieve a 90% reduction in hydrogen chloride (HCl) emissions and avoid both a US$5.5 million capital investment for pollution control equipment and more than US$280,000 annually in operational and waste disposal costs.

In 1990, Alcoa initiated a research and development effort to convert can sheet coatings from PVC-based to PVC-free. Beginning in 2000, the company encouraged other beverage can sheet manufacturers to implement this change.

Concurrently, the company was evaluating the installation of pollution-control equipment that would reduce HCl emissions at its Tennessee Operations—one of the world’s leading producers of beverage can sheet—to comply with upcoming federal requirements that would cap such emissions at 1.5 pounds per ton of aluminum produced.

In the can sheet production process, HCl emissions occur when inks and coatings from used beverage containers are removed in delacquering furnaces prior to these cans being melted and reused. Historically, the main cause of such emissions was the PVC in the coatings.

After recognizing the positive impact PVC-free coatings could have on HCl emissions, Alcoa negotiated a one-year extension to comply with the new HCL emission limits and intensified its efforts to convert the industry to these coatings. As the number of cans with PVC-free coatings increased in the recycled beverage can stream, the company saw its HCl emissions decline. By 2004, Tennessee Operations was emitting 1.4 pounds of HCl per ton of aluminum produced—below the 1.5 pounds-per-ton federal limit and significantly down from the more than 2.5 pounds-per-ton emitted in 2002.

By 2008, approximately 90% of the North American beverage can sheet market was converted to PVC-free coatings. A retesting of Tennessee Operations’ delacquering furnaces in late 2008 showed that HCl emissions had been reduced to approximately 0.19 pounds per ton, the same emissions level the location could have achieved by using pollution-control equipment and a more than 90% reduction from the 2002 emission levels.

By converting the industry to PVC-free coatings instead of installing equipment, Alcoa avoided a US$5.5 million capital expenditure. In addition, the equipment would have required US$250,000 annually for operating expenses and produced 400 tons of potentially hazardous waste that would have resulted in US$32,000 in annual landfill costs.