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.

A Review of Biocarbon Substitutes in Electrodes and Refractories for the Metallurgical Industries

“…EAF Electric Arc Furnace, SAF Submerged Arc Furnace, CPC Calcined Petroleum Coke, ECA Electrically Calcined Anthracite, GCA Gas Calcined Anthracite, GCP Gas Calcined Petcoke, CTP Coal Tar Pitch, GCN Gas Calcined Needle coke a Estimate based on anode consumption rate of 450 kg per ton of Al [12,33], multiplied by 69 038 Mton primary Al in 2022 [34] The first step is aggregate preparation where raw petroleum cokes, pitch/petroleum needle cokes, or anthracites are calcined (thermally treated) to facilitate carbonization, volumetric stabilization, and partial graphitization [10]. The resulting calcine is then classified into desired size fractions, and oversized material can be milled to form part of a fine fraction.…”