Incineration of biowaste using ecoinvent

Question

Hi, I am very new to conducting LCAs and I would very much appreciate your help! My study looks into biowaste management options (incineration, anaerobic codigestion), and I am using the latest Ecoinvent (v 3.5) dataset in openLCA 1.7. 

1. As I am looking purely at the incineration/burning process' impact categories only, is it correct to use Cut-off, and not APOS or consequential modelling?

2. When I click 'create product system' out of the dataset "treatment of biowaste, municipal incineration|biowaste|Cutoff, U", my impact categories do not seem right. For instance, under CML 2001 methods, the global warming impact (GWP 100a) is very slight for large amount of 1kg of biowaste. Am I doing it correctly or should there be other inputs that I missed out?

3. Referring to the same image above, the other bars that are not red indicate the GWP from other processes like quicklime production etc. If I want only the GWP from burning the biowaste, can I ignore these other bars (i.e. only use the red bar)?

Thank you very much! 

Answer 1

Hi Natalie!

1) The ecoinvent system models are described on the ecoinvent website https://www.ecoinvent.org/database/system-models-in-ecoinvent-3/system-models-in-ecoinvent-3.html; I would say you picked the right version.

2) You correctly calculated the impact of 1kg of "treatment of biowaste, municipal incineration ... ". The figure you provided lists the five processes with the highest contributions to your product system with regard to the selected impact category.

3) All bars in your figure indicate the contribution from a process (or several processes for 'other') to the selected impact category. If you sum them up you get the total impact. You can also see the latter in the impact analysis tab. If you would like to see the impact along the supply chain you should refer to the contribution tree.

I hope this helps.

Comments

Thank you for your reply!

I just wanted to clarify further: this is the result i obtained when i used Ecoinvent 3.4 LCIA methods. (it is the same when I checked the Ecoinvent LCIA database directly). However, when I use OpenLCA methods, I get a very different result (0.50.55655kg Co2eq/ kg) for the same CML 2001 categories. Is there a reason for this?