Quantifying the Carbon Footprint of the Alouette Primary Aluminum Smelter

Abstract

The Alouette primary aluminum smelter is the largest in the Americas, with an annual production of ~ 630,000 t of aluminum. In this collaborative study, a detailed product carbon footprint analysis was undertaken by Rain Carbon using a large body of primary emissions data to provide a complete cradle-to-gate analysis of the smelter’s emissions. The total carbon footprint of the smelter in 2019 was 3914 kg CO2e/t of aluminum for scope 1, 2, and 3 emissions, and 1835 kg CO2e for scope 1 and 2 emissions. The modeling results were compared to those for global average and Canadian average smelters, using reference datasets developed by the International Aluminium Institute (IAI) and GaBi Professional Database. Alouette’s carbon footprint is ~ 76% lower than a world average smelter and ~ 25% lower than a Canadian average smelter. For the scope 3 emissions, the primary contributors to the lower carbon footprint are lower emissions from the alumina supply and the calcined petroleum coke supply. Today, Alouette produces among the lowest carbon aluminum in the world, and this is set to decrease further following a switch from fuel oil to natural gas in the anode baking furnaces, and a switch to LNG at the alumina supplier refinery.