How can I model reclycling flows?

Question

I am having trouble modelling a product system with many recycling flows, meaning that output flows from one process are directed to previous processes of the same product system as input flows.

That is often the case of defective pieces and products that are redirected to the same product system in order to be recycled and reintroduced.  

I've noticed that if I link this flows to their process of origin through the "Provider" feature, I get (notably) incorrect results when I run the LCIA. If I decide to don't link them, then I get proper results, but ones that do not represent the ruturn flows I'm trying to model.

Does anyone have a solution to this problem?

Answer 1

Not sure if I fully understand the problem but I think you are creating loops in your supply chain (?). Of course, this has to be avoided. Maybe you can apply system expansion. Possibly, the answer on this question about end-of-life modelling helps too: https://ask.openlca.org/1761/how-does-waste-treatment-end-life-eol-modelling-work-openlca.