Why does the comparison of different EoL scenarios in a project not work?

Question

So I created a product system for the life cycle of a wood plastic composite and I am using the EF and ELCD database.

I used parameters in the waste collection process to model the amounts of the WPC waste going to recycling, incineration or landfill. The inputs are the amount of WPC waste x the incineration/landfill/recycling rate (which are global parameters).

I then created a project to see how the different EoL scenarios (recycling, incineration, landfill) impact the results. The scenarios I want to compare are incineration only, landfill only, recycling only.

However I do not get results for 2 out of 3 scenarios that way.

Does anyone have any idea why?

I did run calculations of the product system setting the incineration/recycling/landfill rate to 100% and for climate change I get results of 1,76 kg CO2 eq (incineration only), -0,04 kg CO2 eq (landfill only) and 69,27 kg CO2 eq (recycling only). I don't get how the results for incineration only are so low and the results for landfilling are negative. I am using the ILCD 2011 midpoint + impact category btw.

Answer 1

Hm, the ELCD database should not be used with EF together since both use different flow nomenclatures, and are meant for different LCIA methods. EF must only be used for studies following the EF method, and the EF method does not allow to use other databases. If you combine it, you might get unexpected results.

Comments

yeah, i did get results. i used only the ELCD database in the end and used the opposite direction approach for modelling the EoL. I ended up creating different product systems for each scenario rather than creating a project with different variants for each EoL scenario. For some reason the project option never delivered accurate results for the different scenarios.