Good morning,
I have a doubt about a model I am working on. In the model I have to insert as input "3´,5´-dimethoxy-4´-hydroxyacetophenone" used as chemical in a industrial process. I found this substance only in the elementary flow as "emission". Is it correct to insert it as input in the model? Thank you in advance.
Dear User,
Could you please provide more context to your setup? What version of ecoinvent are you using and which application do you use for modelling? Because I was not able to reproduce the situation. In the current version of ecoinvent this flow is neither an intermediate exchange nor an elementary exchange i.e. does not exist. Are you perhaps using other data sources than ecoinvent? Generally, it is not correct to use an emission as an input to a model. Elementary exchanges are designed to contribute directly to the overall LCIA results and the role of the intermediate exchanges is to include the production of this particular product and all of the elementary exchanges in the background system attached to the production of that intermediate exchange.
Best regards,
Johannes Müller, Junior Data Analyst, ecoinvent Association
Dear Johanees,
sorry for my delay, I read only now your answer. Thank you so much for your information provided. I am using Ecoinvent 3.5 and OpenLCA software. My question was related to the fact that often, when I am building my model and I am searchng the data, It happens that I don't find any data of the substance I am looking for as input flow (for example a flow from technosphere or flow from ecosphere) but instead I find the substance or a proxy data as emission flow. I bring you another example. I need to insert as input for a chemical process the gallic acid (3,4,5-trihydroxybenzoic acid). There are no data that represent this chemical as input flow but instead there is this chemical as emission flow named as "3,4,5-Trihydroxybenzoic acid".
So it doesn't make sense to use it as input because it is an emission flow, right? In this case if don't find anything usually how should I proceed to consider it?
Another question also: I checked the impact factors of the flow "3,4,5-Trihydroxybenzoic acid" and it is only considered in the Usetox 2 Impact Assessment method (with impact factor=0). Does it means that if I use CML for example as Impact assessment method, this flow has no impacts in my calculation also if I put it in the outputs as emission flow?
thank you very much for you support.
Dear User,
Yes, you are right. It is incorrect to add an emission flow as an input to a dataset. With an input you want to add the burdens associated with the production of this product to your system. In the case when a product can not be found, you could look for a proxy to substitute the burdens of the original product with or consider the missing input in the calculation of uncertainty.
However, we do not have "3,4,5-Trihydroxybenzoic acid" as a flow in ecoinvent, neither intermediate nor as elementary flow. If an impact assessment method does not contain an entry for the considered flow, it is also not included in the calculation and thus does not have any impact on the result of that impact assessment method.
Best regards,
Johannes Müller, Junior Data Analyst, ecoinvent association
Dear Johannes,
thank you for your kind answer. How coud I know if a flow is from Ecoinvent Database? The flow "3,4,5-Trihydroxybenzoic acid" is in the folder "Elementary flow --> Emission to air --> lower stratosphere+upper troposhere": maybe is from OpenLCA software? Are all the flow from ecoinvent contained in folders named with an alphabet letter? For example: A: Agricuture, Forestry and fishing. Thank you for your support.
Dear User,
These are very software specific questions. For an answer please contact the support of OpenLCA (Greendelta).
Best regards,
Johannes Müller, Junior Data Analyst, ecoinvent association