Specific Flow missing in characterization factors for global warming - not relevant or missing?

Question

Hi again,

I have some flows that are quite rare like higher Carbohydrate chains that are not listed in the impact methods -> ReCiPe Mid (H) -> global warming. Not relevant, or possibly missing?

Also: I didn't really get when I have to use elementary flows. When it's neither product or waste, I know, but whatever my output is, either I can use it or I have to dispose it, right? Then you need the Waste and Product categorization to be able to make that check for co-products/recycled streams but I still don't know when to use the green elementary flows... Also why are so many Flows not available as product or waste? E.g. Carbohydrate chains, or carbon monoxide just as product never as waste...

Thanks and best regards

Sam

Answer 1

You have to check the methodology that is always used in LCA. Elementary flows are exchanges between the biosphere (environment) and the technosphere (product system) and all impact assessments methods are based on the calculated inventory (LCI) of elementary flows times their corresponding characterization factors.

Technosphere flows are exchanges between the technosphere (product system) and the technosphere (product system). If wanted, they can be classified into product flows and waste flows as it is done in openLCA (material flow logic).

Comments

Ok so if I look at my whole plant as a black box: everything going into/leaving the box is elementary, everything within the box is a recycling (marked as waste) or product stream?

How are real waste streams like waste water out of the box declared? elementary or waste stream

How are real product streams like kerosene declared? product or elementary?


Also what I didn't get reading through the forum and manual: How do you simulate waste water/gas treatment?

- All Waste streams from the life cyclce as input in a newly created "waste water treatment" process and then waste water - treated as output? Does the program do its calculations then?

- There are also predefined waste treatment processes but there are tons of other flows that don't fit with my process. Should I just modify them rather than creating my own?