Aluminum, a much more circular material than PVC and wood

Aluminum stands out as a more circular material than PVC or wood. This can be seen in the Circularity Report recently published by the Spanish Aluminum Association. According to this report, the circularity value of aluminum stands at 70%. This is twice that of wood and four times that of PVC.

This value has been extracted from various indicators obtained by various methods, such as the Material Reuse Score, the Material Circularity Indicator and the Circularity Index. The results of these indices thus provided a range in terms of the circularity of each material, these intervals being:

• Aluminum presents circularity values ​​between 65.9% for the ICM, 75.3% for the PRM, and 66.7% for the IC.
• In the case of plastic (PVC), the studied indicators are between 10.1% obtained for the CI, and 24.4% for the ICM.
• For wood, a value of 35.5% for the ICM and a value of 43.3% for the PRM have been obtained.

The purpose of the study is to analyze the circularity indices of these three materials (aluminum, PVC and wood), fundamental in sectors as heavy as construction, where efforts are directed to continue growing from non-emissivity, durability, and the use of materials whose continuity is assured beyond their useful life as building materials.

Thus, in the case of window profiles, the ICM value can reach 81% for aluminum. This is due to the extension of the useful life of aluminum windows compared to PVC and wood.

The circularity indicator is understood as a percentage, so the ideal would be 100%. The further we get from that figure, it means that the flow of materials is not circular, but purely linear. That is, with a disposable life cycle. “In the case of aluminum, the indicators could seem low considering the high recovery rate and the efficiency in recycling this material. What today keeps aluminum away from that 100% figure is the fact that the demand for this material is higher than the aluminum currently in circulation, which makes it necessary to put primary aluminum in the material flow ”, Jon pointed out. de Olabarria, Secretary General of the AEA.

In other words; recycled aluminum content is currently limited by the scrap availability of this material. The constant increase in demand for aluminum and the fact that, in some sectors, such as construction, the useful life of products is several decades, causes that currently recycled aluminum is not enough to meet the demand of this material. Therefore, the injection of primary aluminum in the supply chain is required.

Why have these three methodologies been applied?

The growing interest in the Circular Economy has opened the debate about the identification of the most appropriate metrics when determining the achievement of its objectives by products, organizations, countries or regions, although there is still no consensus in this regard.

That is why, when obtaining these average circularity indices, a review of three of the proposed methods has been carried out: those of the “Cradle to Cradle” certification, the one proposed by the Ellen MacArthur Foundation, and the calculation of the circularity indicator proposed by Professor Cullen. From the results obtained following each of the formulas (which are explained, developed and whose results are shown in the report), this mean value of circularity, which place aluminum as the most circular and sustainable material.

Where does the need for this study come from?

It is well known that the volume of raw materials extracted from nature has undergone a dramatic increase in recent decades. Added to this is the linear nature of the consumption model that accompanies this resource extraction, in which the flow of materials that return to the economic system after being recycled is very low. The clearest direct consequence is the serious environmental problems that this generates, and an increasing shortage of certain raw materials, which has led to a no less dramatic rise in prices.

Undoubtedly, the substantial increase in the efficiency of the processes has contributed to the solution; however, it has meant an improvement only in the short term. In some cases it has even led to a higher consumption of resources due to a rebound effect. “A paradigm shift in which economic activity and the use of resources do not follow the same pattern is therefore necessary and imperative,” says Armando Mateos, president of the AEA.