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Topics - dmutz

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1
Hello,

for human toxicity potential and ecotoxicity potential I want to use USEtox model.
In some projects I am currently using ecoinvent v3.1 database. But in other projects ecoinvent v2.2.

Now, I noticed strong deviations in CF by using both databases (separately), that the characterisation factors for same materials with (more or less) the same emission type, e.g. water/river or water/surface, respectively.

Is this described fact just an error within the database or does ecoinvent v2.2 really account USEtox indicators with other CF than in v3.1?

An example (for ecotoxicity CF for USEtox w/o LT):
  • 1,4-Butanediol:
    • no CF (v2.2) - emission into water, river
    • 7,31 CTUe (v3.1) - emission into water, surface water
  • Cadmium, ion:
    • no CF (v2.2) - emission into water, river
    • 9 712 CTUe (v3.1) - emission into water, surface water
  • Mercury:
    • 22 090 (v2.2) - emission into water, river
    • 22 090 CTUe (v3.1) - emission into water, surface water

In this example: Mercury does have the same CF, but Cadmium has not. Why?

2
General / Different Impact Result for same process ?!
« on: December 10, 2013, 15:27 »
Hello,

in my current LCA study, I am modelling wastewater treatment technologies. thus, the model has its characteristics more like a MFA-model than a typical LCA-model considering the distinct life cycle stages such as production-phase / use-phase etc.
in the attachment I put one example.

now the problem:
by dividing the impact result from the excel-file (export LCIA raw data) by the specific material flow, there are different results coming up.

as an example, I put here the electricity:

dividing the GWP-impact from electricity used [kg CO2-eq] by the amount of electricity used [kWh] there are some deviations, which should not be the case...

in following processes electricity has an impact of 643,6 g CO2-eq/kWh:
  • T10 (electricity used in T02: Vermischung Volumenströme)
  • T11 (electricity used in T05: P-Entfernung)
  • T90 (electricity produced in T90)

in the next processes, there are others quotients calculated from the results of the excel-file:
  • T12 (electricity used for Subnet: Schlammbehandlung): 530,2 g CO2/kWh
  • T13 (electricity used for Ozonation): 504,0 g CO2/kWh

First, there were different quotients for all processes. So, I thought by setting the allocation manually in each single process, I could fix the problem. But still, the specific impact-factor of electricity (probably 643,6 gCO2-eq/kWh) is not unique in all processes.
in the other attachments, there is an example how a process and the allocation is done (here: ozonation).

Can anyone help?

3
Hello,

I noticed following problem while modelling an own energy mix with ecoinvent v3.0 data: there are some large deviations in LCIA results comparing to the same energy mix by using econinvent v2.2 data in LCA NXT. I used ReCiPe Hierarchist w/o LT for the comparison.

Following deviations in results seem pretty unrealistic only due to updates in the database (just an exerpt):
Windpower (onshore)
  • freshwater ecotoxicity
         
    • v2.2 "electricity, at wind power plant 800kW [RER]": 1,1*10^(-4) kg 1,4-DCB/MWh
    • v3.0 "electricity production, wind, 1-3MW turbine, onshore [DE]": 0,6 kg/MWh
  • climate change
         
    • v2.2 "electricity, at wind power plant 800kW [RER]": 0,17 kg CO2-eq/MWh
    • v3.0 "electricity production, wind, 1-3MW turbine, onshore [DE]": 22 kg CO2-eq/MWh
Lignite
  • freshwater ecotoxicity
         
    • v2.2 "electricity, lignite, at power plant [DE]": 0,17 kg-DCB/MWh
    • v3.0 "electricity production, lignite [DE]": 40,9 kg DCB/MWh
  • climate change (comparable results between new and old database!)
         
    • v2.2 "electricity, lignite, at power plant [DE]": 1,24 kg CO2/kWh
    • v3.0 "electricity production, lignite [DE]": 1,25 kg CO2/kWh

By analyzing the results, I noticed that ReCiPe (H) w/o LT, take also category factors into account for long term emissions. Is that an error in the LCIA programming within the software? By comapring LCIA data, ecoinvent v3.0 includes long-term emissions (and they have large impacts, which lead to the higher Impacts in most categories) and ecoinvent v2.2 does not include those long-term emissions. But both energy-mixes were calculated at the same time (in Umberto NXT LCA with ReCiPe (H) w/o LT)

If it is an error in the LCIA programming, it seems old ecoinvent v2.2 has no long-term emissions in their dataset (if they had, there would/should be still comparable results)?

Thank you in advance for answering!
Regards, D. Mutz

4
General / input monitor in Umberto NXT available?
« on: May 22, 2013, 11:09 »
Hello,

in Umberto 5.6 there was an "input monitor" available, so you could set the input flow for different scenarios simulaneously. Is there a similar function given in Umberto NXT LCA or should the input flow set manually for each scenario now?

Kind regards

5
General / iterative calculation with dynamic modeling?
« on: May 22, 2013, 10:59 »
Hello,

in Umberto 5.6 I used the function of "dynamic modeling" for an iterative material flow calculation within the model. If haven't found a similar function in Umberto NXT yet. Is it still possible to do some iterative calculations?

Regards

6
General / Export of a model into a transition (or process)
« on: April 30, 2013, 17:15 »
Hello,

in Umberto 5.6 it was possible to export a whole subnet or a whole calculated net into a spreadsheet, which you could import into a single transition and use this transition as a new one through export this transition.

I couldn't find a similar function in Umberto NXT LCA yet. Is there any possibility to create such a transition from exporting a spread sheet of a calculated net?

Kind regards!

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