Impact of rolling processes in the production of aluminum packaging assessed through LCA

Abstract

PurposeThe environmental impact of aluminum cans and aluminum food packaging has been extensively studied in the last years; most of the researchers focused their attention on the whole lifecycle: from the aluminum extraction to the end-of-life management, while there are no dedicated studies devoted to the detailed analysis of the rolling phase. The aim of this paper is to present an LCA analysis focused on the fabrication of the thin plates to be used for can and tray production; the work has been carried out by studying the “Laminazione Sottile” plant with a cradle-to-gate approach, considering as functional unit thin plates of two different alloys.Materials and methodsInventory data were collected from the “Laminazione Sottile S.p.A.” plant, and off-plant emissions from external goods and fuels were accounted for based on existent LCA databases. Gabi has been used as software to model the process and calculate the impacts, while the CML method has been used. Most of the data have been directly measured in the plant during 1 year of work.Results and discussionThe results showed that the most impactful phase is the extraction of aluminum or the use of primary aluminum. Focusing the attention on the manufacturing process, the foundry is the most impacting stage, and the high energy required to melt the aluminum leads to most of the emissions. Moreover, this contribution is probably underestimated in this work because the impacts related to the manufacturing of the facilities used (furnaces and so on) are not considered. Another interesting finding is that both the supply chain and the general consumption have a non-negligible impact, highlighting the necessity to optimize these two aspects by implementing new policies for purchasing and work organization.ConclusionsThe study highlighted that the production of primary aluminum is the most impacting step, followed by the foundry and the hot rolling. Production of thin aluminum plates by rolling requires a lot of energy, so the carbon footprint of these processes is quite high. The chemicals used in the rolling steps play also a role in the general impact of the whole process. The company continuously promotes improvements of the process to reduce the footprint and puts a lot of money and effort to introduce new sensors and technologies to monitor the consumptions and improve the processes.