Extrusions and Embodied Carbon
As these EPDs show, the predominant determination of CO2e for an aluminum extrusion is the feedstock – i.e. – the aluminum billet that is the raw material for the extrusion process:
- For extrusions that require the least intensive processing, i.e., standard extrusions in mill finish, the CO2e contribution to the module A1-A3 total from the extrusion process is less than 25%.
- For the product form that has most intensive processing – painted extrusion that is thermally enhanced -- the contribution from the extrusion/paint/thermal process is less than 33% of the A1-A3 total.
Note that these assessments are based on the average billet composition documented in the new Life Cycle Assessment (LCA) – a 47% prime, 53% recycled mix with the prime assumed to be the North American average as reported by the Aluminum Association.
Achieving significant reductions in the embodied carbon is most practically achieved by adjusting the billet mix – either increasing the recycled content and/or shifting the prime content towards prime produced from less carbon-intense energy sources.