Towards GHG Emissions Neutrality of Aluminium Slug Production: An Industrial Study

Abstract

The aluminium industry is one of the largest emitters of greenhouse gases (GHG) and accounts for approximately 1 % of global GHG emissions. A large portion of emissions are indirect emissions, due to the large GHG footprint of consumed electricity, while direct energy and process-related emissions are also significant. The aluminium is widely used in packaging, transportation, the building sector and for various other purposes. This study focuses on aluminium slugs, which are semi products made from aluminium alloys and are used as tubes and containers in the pharmaceutical, food and cosmetic industries. Since the aluminium industry is among the largest GHG emitters, a Life Cycle Assessment (LCA) was performed to evaluate the environmental impact of aluminium slug production. Environmental impact assessment was performed using OpenLCA software, the Ecoinvent 3.1 database and self-collected plant data. The study includes the environmental impact of anode production, electrolysis and slug production. The functional unit for the study is 1 t of aluminium slug at the company exit gate. Besides GHG emissions and the related GHG footprint associated with slug production, acidification potential and photochemical oxidation potential are further assessed. Various opportunities for GHG emission reduction are further investigated in accordance with the longer-term company strategy. If more aluminium scrap were used and carbon capture performed, the GHG footprint could be reduced by 65 % compared to the base case.