ecoinvent Forum Archive

Hello,

I'm relatively new to LCA and ecoinvent so it could be that I put this question wrong.

Anyhow, I'm interested in the LCIA from waste treatment operations. Take for example the dataset:

"treatment of aluminium scrap, new, at refiner"Reference product: aluminium, cast alloy [kg]Location: RERSystem model: Allocation, cut-off by classification

If I look at the LCIA information - do I get the environmental impact of this dataset alone, i.e. the impact from the process from "aluminium scrap, post-consumer, prepared for melting" to "aluminium, cast alloy"? And if I want to find the environmental impact from the sorting process, then I have to look at the LCIA from that dataset? Have I understood it corect?

One of the reasons why I am asking is because I have thought that the LCIA represents the cumulative effects, i.e. account for all the upstreams processes as well. I know that a "zero burden" aproach is used for waste in ecoinvent but I'm wondering if the LCIA of the dataset described above - "treatment of aluminium scrap" also accounts for upstream processes such as sorting and collection of the aluminium waste?

Regards, Jacob

Dear Jacob,

This thing you claim to know about ecoinvent adopting a "zero burden" approach is simply not correct.

When you use a dataset you get also the upstream impacts up the point of your dataset. If for instance this dataset is using electricity from hard coal then you get burdened with the amount of hard coal necessary to produce the electricity for your dataset. 

What processes are included in the upstream of your dataset is something you should look for.

Best regards,

Avraam Symeonidis,

Data analyst, ecoinvent

Aha, thank you! What I was reffering to was something i read here: https://www.ecoinvent.org/database/system-models-in-ecoinvent-3/cut-off-system-model/allocation-cut-off-by-classification.html -> that "recycable materials are available burden-free to recycling processes" (in the cut-off system model). 

So the recycable material is burden-free but the datasets account for the upstream impacts of ancillary materials (in the cut-off system model)? 

One last question:If I look at the LCIA from the dataset "treatment of aluminium, new, at refiner", ref product: "aluminium, cast alloy", System model: "Cut-off by classification".Then, as I have understood it, the LCIA account for the upstream burdens of ancillary materials/energy used in the process (such as electricity and oil) but the LCIA does not include impacts from previous treatment of the recycable material, such as collection, sorting and baling? Is that correct?

Dear Jacob,

When you use an LCIA of a dataset you get also the upstream LCIA impacts up the point of your dataset. If for instance this dataset is producing a waste then you get burdened with the amount of waste treated. 

Best regards,

Avraam Symeonidis,

Data analyst, ecoinvent

Ok, but I still don't really understand what it means that upstream impacts are included. For example - as I wrote above. In the dataset treatment of aluminium scrap it is stated that the activity starts with sorted aluminium and ends with cast aluminium. But does this mean that the LCIA of this dataset also include the activities that are necessary before aluminium can be recycled (i.e. collection and sorting), even if it is not mentioned in the description of the dataset and even if there is another dataset for the activities collection and sorting.

 https://v35.ecoquery.ecoinvent.org/Details/LCIA/c17f635d-acd7-410c-ac3d-48312e31574e/290c1f85-4cc4-4fa1-b0c8-2cb7f4276dce

Regards, Jacob

Dear Jaboc, 

The dataset "treatment of aluminium scrap, new, at refiner" represents the treatment of "aluminium scrap, new", which is a recyclable material. The activity produces "aluminium oxide" and "aluminium, cast alloy" as valuable products. 

In the cut-off system model, "aluminium scrap, new" is moved to the input side, with a change in sign (i.e from negative to positive). Read about this here Why is the reference product of the treatment activities negative? and see this is the unit process activity. When looking at the unit process, if you click on the exchange for  "aluminium scrap, new", you will see that the exchange comes from the RER market. The market is constituted by transport and the burden free activity "aluminium scrap, new, Recycled Content cut-off". This exchange therefore only carries the burden of transport. 

The "treatment of aluminium scrap, new, at refiner" includes different inputs, for example electricity. The impacts carried by the exchange for electricity are from cradle to gate, i.e. from raw material extraction till electricity provided to the grid.

If instead you look at, for example, "treatment of aluminium scrap, post-consumer, prepared for recycling, at refiner" in the cut-off system model, the dataset treats "aluminium scrap, post-consumer, prepared for melting". This product comes from the market which in turn is fed by the activity "treatment of aluminium scrap, post-consumer, by collecting, sorting, cleaning, pressing". This activity treats "aluminium scrap, post-consumer", whose market is constituted by transport and "aluminium scrap, post-consumer, Recycled Content cut-off". The Recycled content exchange is burden free. The exchange "aluminium scrap, post-consumer, prepared for melting" carries the impacts of the transport as well as of the collection, sorting etc.

Collecting, sorting, cleaning and pressing are therefore only considered for post-consumer scrap. This is not included for new scrap, as this scrap occurs during the production of semi-finished or final goods.

I hope this clarifies it. 

Best regards, 

Lucia Valsasina, Junior Project Manager, ecoinvent

Thank you so much! Now it makes sense!

Best regards, Jacob