Problem with system modelling (waste)

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Iside30
Posts: 3
Joined: 02 Apr 2015 09:08
Location: Italy

Problem with system modelling (waste)

Post by Iside30 » 02 Apr 2015 09:23

Hello everyone.
I am a new user of openLCA and I need help with the modelling of my analysis. I am also a beginner of LCA, and I'm learning to use the tool.
I don't understand how to outline the system that I have to study, especially how to separate flows and processes.
In my attempt I indicated as reference flow 1 ton of product, while production process I created a process where I indicated all inputs and outputs. And the problem is here... How do I do now to join the second part of the system, namely the use of the product? And then how I insert the part of recycling of the used product (waste)? (the system becomes a closed recycling)
Below you can see a rough outline of my system, I apologize for its simplicity but I write from a phone and I haven't with me the file of my flowchart.
I hope you can help me. Thanks to anyone who answer me.
Have a nice day,
Eli

Image

aciroth
Posts: 750
Joined: 09 May 2010 23:28

Re: Problem with system modelling (waste)

Post by aciroth » 07 Apr 2015 08:31

Hi,
first I hope you are fine with the edit of your headline (I added "(waste)" to make it more clear) - waste modeling in openLCA at present needs to be done as in ecoinvent, the process which is taking the waste ("waste" in your picture) needs to be modeled as provider of a waste treatment service to the process that is producing the waste ("use"). Then the waste process has in your example two products, produced waste that goes into process production and waste treatment service that goes into use. And you need to apply allocation in this case.
Hope this helps?
Andreas
p.s. We also offer trainings if you are interested: http://www.openlca.org/training

Iside30
Posts: 3
Joined: 02 Apr 2015 09:08
Location: Italy

Re: Problem with system modelling (waste)

Post by Iside30 » 11 Apr 2015 09:23

Hi Andreas,
thanks for your advices, but I don't completely understand how to risolve my problem..
I created all the processes of my system with respective input/output (of course, most of outputs of previous step correspond to inputs of the next), and I can connect steps between them in the model graph (also manually). But when I start the calculation everything is considered separate while I need a single system to be analyzed.
Where am I doing wrong?
Best wishes,
Eli

ps: thanks for recommending me the openLCA course, it's my intention to attend it but not in the short term, perhaps after graduation. I'll keep it seriously anyway.

aciroth
Posts: 750
Joined: 09 May 2010 23:28

Re: Problem with system modelling (waste)

Post by aciroth » 11 Apr 2015 15:01

If you model as I recommended and if you then have a system which has the product that is outcome of the 'use' process as reference product (tab 'general information' of the product system), then it will work. In the picture below, it is 'construction of a dung slab' from ecoinvent.
Hth,
Andreas
2015-04-11 15_00_54-openLCA 1.4.1.png
2015-04-11 15_00_54-openLCA 1.4.1.png (14.79 KiB) Viewed 3795 times

Iside30
Posts: 3
Joined: 02 Apr 2015 09:08
Location: Italy

Re: Problem with system modelling (waste)

Post by Iside30 » 11 Apr 2015 18:06

Hi Andreas,
just to be precise, here is the model graph:
Image
The product is a recycled inert aggregate, and the cycle starts from raw material extraction, its use in building work, demolition and waste which is then reintroduced into the system instead of raw material. And I have to compare this with the "worse cycle" that ends with landfill (the model graph up there).
If you say that allocation is the only way, I'll try to figure out how to do it... although it's not very clear.
Thanks,
Eli

ps: I'm sorry, my English is not the best and maybe I have misunderstanded your last message... but why dung slab? Explain if possible, please :)

judlj
Posts: 4
Joined: 28 Apr 2011 12:08

Re: Problem with system modelling (waste)

Post by judlj » 20 Jun 2016 14:00

Dear Eli, Andreas,

I'm also interested in modeling a closed loop recycling in openLCA. There is an example in the beer bottle tutorial provided by GreenDelta in which closed loop recycling is illustrated and it could help you somehow: http://www.openlca.org/documentation/in ... eer_Bottle

However, in the that example I struggle to understand the logic of allocation (50:50) between a waste flow which is recycled in a closed loop and a "reference" product (both essentially represent the same). Moreover, it is not said in the documentation if one should select physical allocation as the allocation rule when running the analysis (as this of course affects the results). It would be great if Andreas could explain this issues a bit more!

It seems that what Andreas is suggesting here somehow reflects the logic in the beer bottle example, but is not entirely clear to me either. Could you, Andreas, please open it up?
According to that logic the flowchart looks like this:
Capture.PNG
Capture.PNG (30.52 KiB) Viewed 2589 times
What is the FU for which impacts are calculated? There is no product flow which would be leaving the system boundary.

It would be great to get some more examples and guidance. Has any of the openLCA users a good example of their own on how they modeled waste management and especially recycling in the program?

All the best,
Jáchym

P.S. Eli, are you sure you want to connect all the flows between the steps 2 and 3? You need one main product flow which leaves the process 2 and is an input of the process 3. The other outputs would be byproducts and need an allocation. But you wouldn't connect them to the step 3.

smnipa
Posts: 15
Joined: 30 Apr 2017 03:55

Re: Problem with system modelling (waste)

Post by smnipa » 03 May 2017 04:01

Hi Andrew,

I am using Open LCA for my thesis work. Could you please give us some example of recycling scenario modelling and system expansion modelling in OpenLCA, It would be a great help for us for understanding this.

Regards,
Smnipa

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