ecoinvent Forum Archive

The carbon emissions for the treatment of used copper cable is higher than primary production. The code for treatment of used copper cable has a carbon dioxide emissions to air of almost 5 kg CO2 per kg copper recovered. The documentation does not indicate where the emissions are coming from, or why recycling of copper wire results in larger emissions that primary production. Any help on why this is the case is helpful.

Ecoinvent code for copper with wire is: "Copper {GLO}| treatment of used cable | Alloc Def, U"

Dear rjf,

Thank you for your thread. APOS system model is functioning as it should be. It aggregates activities that produce this mft (used cable in your case) into one activity that is producing copper (and has the name of the treatment activity) and the latter one bears allocated impacts from all activities that produce the mft. You can have a look in the APOS dedicated page here: https://www.ecoinvent.org/database/system-models-in-ecoinvent-3/apos-system-model/allocation-at-the-point-of-substitution.html

Best regards,

Avraam Symeonidis,

Data analyst, ecoinvent association

 Dear Avraam,

Thank you for the response. I'm not too worried about the APOS system model running correctly. Moreso, the ecoinvent code for copper wire includes the use of crude oil, which is likely leading to the release of the CO2 emissions from fossil fuel coded into the wire LCI. My questions for this are more so:

a) why is crude oil being used here

b) where are these values being taken from, i.e., what are the references?

The reason for concern is that according to this code, wire recycling yields greater CO2 emissions than primary production, which is not supported in the literature and does not make physical sense since less energy is required to process secondary copper vs. copper ore. So understanding how the carbon emissions are determined is essential to having confidence in this process definition. The carbon emissions may make sense due to crude oil and waste plastic combustion, but information to figure out what is going on is not provided.

Thank you.

Dear rjf,

First of all, the dataset "treatment of used cable" is not using any crude oil in its undefined form. The reason you see the crude oil in the APOS linked version of the dataset, is because of the APOS system model methodology, which I have explained to you in brief in my previous reply. On top of that I have provided the webpage we explain in detail what is happening when linking is applied in APOS system model. As a user, it is your responsibility to choose the system model that matches best your case. This means that when you assess results, you inherently accept the underlined assumptions employed in the system model - here APOS. I hope everything is clearer now, otherwise please feel free to text us at support@ecoinvent.org.

Best regards,

Avraam Symeonidis,

Data analyst, ecoinvent Association