Thank you for your answer-back,
I meant that I have found one study, which is the "Eco-profil" from CEFIC for the methly methacrylate production, and it says that it emits 3.47 kg CO2 eq for 1 kg of methyl methacrylate production. Knowing that even EcoInvent has based its database on that particular paper, so we have the same system boundaries, goal and scope.
However, when I plot on OpenLCA, I have the double. I am trying to understand what the problem is from, knowing that I simply have modeled one input "methyl methacrylate production" for 1 kg and I obtain at the end almost the double of the value, which is the equivalent of 7.0 kg CO2 eq.
My problem is : how is it possible to have different values knowing that the EcoInvent database has based its calculation on that paper citing that for 1 kg of methyl methacrylate we obtain 3.47 kg of CO2 eq and when I model with the same database, I obtain 7.0 kg CO2 eq, just with one input which is "methyl methacrylate production" for 1 kg (so the same functional unit).
What possible factors can influence my calculation ?