System Boundary

  • Full life cycle (cradle-to-gate) greenhouse gas (GHG) emissions (as CO2e);
  • Aluminium Sector = All processes from mine (primary route) and end of life product collection (recycling route) to semis fabrication including ancillary processes, transport and electricity production;
  • Global coverage including informed estimates for non-reporting plants.

Primary Aluminium

The International Aluminium Institute (IAI) has published three life cycle inventory (LCI) reports of the global primary aluminium industry for the reporting years 2005, 2010 and 2015.

The 2015 LCI report was used for the 2015 numbers and is using GaBi-Software (v8, 2018). Please note, that the dataset for alumina refining reflects a change in modelling assumptions for the process.

For 2005 and 2010, the direct and electricity-related indirect emissions of reporting production were calculated, using GHG Protocol tools. These two datasets are used as reference to calculate the global average carbon footprint of one tonne of cast primary aluminium.

For the years with no LCI publication, data from the previous LCI report is used, updated with annually collected energy data for smelting (intensity and source) and refining (intensity and source) as well as perfluorocarbon (PFC) emissions data. These three datasets collectively constitute over 80% of total global aluminium sector emissions.

Process Emissions Recycled Aluminium

New scrap = 0.5 tonnes CO2e per tonne of recycled aluminium

Old scrap = 0.6 tonnes CO2e per tonne of recycled aluminium

Internal scrap = 0.3 tonnes CO2e per tonne of recycled aluminium

These emissions are process emissions and do not represent the carbon footprint of recycled aluminium.

Recycling processes emissions data are taken from the publications of European Aluminium (2015 data) and The Aluminum Association (US) (2010 data) and applied to the global recycling industry, with the same per tonne CO2e emissions assumed for all years.

Old scrap – refers to scrap resulting from collection systems after the final product has been used and scrapped (also referred to as post-consumer scrap).

New scrap – refers to scrap within the supply chain after semis production.

Internal scrap – refers to scrap within semis production and after the cast house. It typically has internal scrap loop processes, where common alloys are recycled backwards to their upstream supply.          

Pre-consumer scrap – refers to new and internal scrap.

Process Emissions Semis Production

Semis production processes* = 0.3 tonnes CO2e per tonne of semis

*without recycling of internal scrap

Average of European Aluminium and the US Aluminum Association published data, with the same per tonne CO2e emissions assumed for all years. This is a weighted average across all semi-fabrication processes, though there is variability between each (e.g. rolling, extrusion), shown in the European Aluminium and The Aluminum Association publications above.

Production Data

Historical primary production is based on IAI statistics. Primary aluminium is defined in the IAI production statistics as liquid aluminium tapped from electrolytic cells or pots during the electrolytic reduction of metallurgical alumina (aluminium oxide). It thus excludes alloying and scraps additions in cast metal production. While this data does not fully represent a primary ingot (i.e., excluding alloying elements and metal losses), it is a proxy for primary aluminium ingot production.

Semis production and recycling data published on Alucycle. For data on internal scrap please contact IAI.

DISCLAIMER

The IAI own the intellectual property rights to these datasets. Use of this data in any written or online form must credit the International Aluminium Institute as the rightful owner. The IAI reserves the right to revise the data based on improved modelling assumptions and updated external datasets. The IAI shall not have any liability, duty or obligation for or relating to the data contained herein, any errors, inaccuracies, omissions in the data, or any actions taken in reliance thereon.

© International Aluminium Institute