• Air emissions

 

Greenhouse gases

 

In 2002, Alcoa was the first company to sign a voluntary agreement with the Québec government to reduce greenhouse gas emissions (GHG). All of the objectives in this agreement were achieved. A second GHG reduction agreement was signed in 2008, covering the period up until 2012. Since then, Alcoa’s Québec smelters have been subject to the Quebec cap and trade system for greenhouse gas emission allowances. Our inventory of GHG emissions complies with the Regulation Respecting Mandatory Reporting of Certain Emissions of Contaminants into the Atmosphere, and is third-party audited on an annual basis.

 

Alcoa set its first company-wide GHG reduction target in 1998, with the objective of reducing GHG emissions by 25% below 1990 levels by 2010. This objective was reached in 2013. A new target was set to reduce the intensity of direct and indirect global emissions by 30% by 2020, from a 2005 baseline.

 

Click here to learn about Alcoa’s Climate Protection targets.

 
Other air emissions
 
All Alcoa Global Primary Products smelters are equipped with high-performance dry scrubbers to capture and treat fluoride and dust emissions from anode manufacturing and potrooms. Our facilities are also equipped with dust collectors (with leak detectors) to reduce emissions during the handling of raw materials and at various stages of the manufacturing process.

 

Regular inspections are conducted to ensure this equipment operates at peak performance. In the potrooms, the pot hoods are checked to ensure maximum emissions are directed toward the scrubbers. The quality of the anode cover (electrolytic bath and alumina) is also inspected, as it plays a key role in minimizing source emissions.

 

Emissions are measured at scrubber outlets on potroom roof vents and directly at some scrubbers. Environmental monitoring is also conducted outside the smelters.

Greenhouse gas emissions


Fluoride


Sulfur Dioxide (SO2)


Aromatic Polycyclic Hydrocarbons (PAH)


Particulates

 


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