Negative Land use impact values in EF 3.1 single process calculations

Question

Hi,

I'm using the PEF 3.1 database and I'm calculating the impacts of organic chemical processes as they are in the database without any modifications. I'm using the Environmental Footprint 3.1 impact assessment method.

For certain chemicals (so far from the dataset of 'CEPE, The European Council of the Paint, Printing Ink, and Artists' Colours Industry'), the impact value for land use gives very high negative values, which is unreasonable for a chemical production.

For example, 'Pigment red 254, Production mix, at plant, Technology mix - GLO' gives -52.21 pt for the production of 1 kg of pigment.

When I look at the flows of the process, it seems that some of the flows related to the land use calculation are in the wrong direction. However, I'm not sure if the error is in the process flows or in the characterization factors of the LCIA method.

Are you aware of this problem? Can I fix this problem on my side for the whole PEF database or will this be fixed in the next release of the database?

Best regards,

Attila

Answer 1

Although some land use elementary flows would be logically expected on the output side (for example transformation to…), database and data set provider model usually all land use on the input side by convention, but not all do it.

Impact directions are introduced to openLCA to correct results when the same elementary flows appear as inputs and as outputs in a database.

Which openLCA version are you using? Please always use the newest one (currently v2.4.1) because in an older version (I think it was v2.0.3), there was a bug with the sign of the impact directions for characterization factor tables that had positive and negative values, as it is the case in land use for example.