Missing flow properties, that can't be added as flow as I have product and waste products as output

Question

I am using ecoinvent and am trying to build a Fischer Tropsch process. I therefore created different processes like electrolyzer, washer, reverse Water-Gas shift and Fischer Tropsch reactor with the different flows as Input/Outputs. I have multiple problems that might be solved easily as I am not very experienced with OpenLCA.

1.) Let's say there is a Purge Flow as waste stream after the FT reactor. Some containments like CO or carbohydrate chains are not available as flow properties, so I can't just build the flows like they are in real life.

2.) I tried adding them as seperate output flow which technically they are not, but the program doesn't care, as long as the amount of CO eg is the sum of the content of all flows.. Problem: Also as flows some C20+ chains don't exist and most of them not as a product or waste stream but as elementary flow. I am only interested in CO2eq and most of them are not relevant for this impact category, but still... any solution?

3.) What if I have Product and Waste streams as output, both including CO? I can't add it as property of a flow and also not as waste. Also can't just sum everything up, because one waste stream is a recycled one, another is a "real" waste stream.

Help is much appreciated.

Answer 1

Interesting post, LCA (as supported by openLCA) has typically quite simple flows that are not hierarchical; also, it is not common to have two processes be connected with more than one flow. This can be a bit tweaked, we have, for example, released a model of a municipal waste incineration plant where the different properties and contents of the flows are contained in parameters. The model is available on our openLCA Nexus website (for a fee). A "plain" answer here probably will not fully solve your questions. We could provide direct support, contact us if you are interested. Thank you!

Comments

I am doing this as part of my master thesis and a paid consulting service might not be covered by the department, but thank you :D

Anyway, about problem 1:
Should I download an additional database, is there one that has more carbonchains? Or more Basic Elements in general, I have CO leaving my process e.g. I know it has to be treated and filtered out, is that the reason why there is no elementary flow of CO?