Click on the following links to view the graphs and related notes
Greehhouse gas emissions
Polycyclic Aromatic Hydrocarbon (PAH)
Sulfur Dioxide (SO2)
Anode effects: Exceptional performance at Deschambault
More detailed notes accompany graphs, at right.
In 1998, Alcoa Inc. established a Climate Change Strategy Team to develop its position on climate change. It set a goal to reduce direct greenhouse gas emissions by 25% below 1990 levels by 2010. After achieving that goal in 2003, Alcoa established a new long-term target in 2009. It would reduce 2005 levels of total carbon dioxide (CO2) intensity, for both direct and indirect emissions, by 20% by 2020 and 35% by 2030. Click here to view Alcoa’s climate protection engagement.
In June 2002, Alcoa Canada Global Primary Products became the first company to sign a voluntary agreement with the Government of Québec to reduce greenhouse gas emissions (GHG). All the targets set in this agreement were reached. A GHG reduction agreement was signed in December 2008 up until 2012. Since then, we are 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 yearly.
At the end of 2013, our total direct GHG emissions had decreased by nearly 37% compared to 2001 (reference year for the first voluntary GHG emissions reduction agreement). Part of this reduction was attained with the gradual curtailment of the Söderberg plant (C in 2008, A and B in August and September 2013). Other part of the reduction was reached by improving practices to control anodic effects in the electrolysis process to reduce perfluorocarbon (PFC) emissions.
Performance in this area is closely monitored across the organization. Our total PFC emissions have decreased by 85% compared to the base year of 2001. Although, compared to 2012 our PFC emissions from prebake plants were higher in 2013, due to operating issues at the Bécancour Smelter and raw material quality issues at the Baie-Comeau Smelter, our overall efforts and the closure of the Söderberg potlines accounted for a reduction of our regional GHG emissions in 2013: 7% on an absolute basis and 4% in terms of intensity, compared to 2012.
In addition, indirect emissions produced from the generation of power used in our operations in 2013 were just over 17 000 t CO2e, less than 1% of our total emissions, as smelters are mainly supplied with hydroelectricity.
Other air emissions
We rigorously control our production of air emissions through the use of modern treatment equipment and a highly effective monitoring system that assures we are in full compliance with all regulations. We also share best practices to ensure that all Alcoa facilities minimize their potential impact on the environment.
All Alcoa Canada Global Primary Products smelters are equipped with high-performance dry scrubbers to capture and treat fluoride and dust emissions in the anode manufacturing and electrolysis sectors. Our facilities are also equipped with numerous dust collectors (with leak detectors) to reduce dust emissions during the handling of raw materials and at various stages of the manufacturing process.
Regular inspections are conducted to assure that these equipments is in peak working order. In electrolysis operations, the pot hoods are checked to ensure maximum emissions are directed toward the scrubbers. The integrity of the bath cover is also inspected, as it plays a key role in minimizing emissions at the source.
Emissions are measured at the outlet of the scrubbers as well as at the roof vents outside the pot rooms. Environmental monitoring also takes place at several local sampling stations.
In 2008, Alcoa signed an environmental performance agreement with the Government of Québec as part of its project to modernize the Baie-Comeau Smelter.