Den 2019-03-20 kl. 16.14 skrev Stefano Merciai:

Last thing, there are  values that are important when building a database, such as combustion coefficients (emissions produced in the activity act123 when burning fuel123). Are these properties of products?

In the wiki, we have about the observation (datapoint):

Number: Floating point numbers xsd:float. (...) Note also that ecoSpold2 has the option of providing a @mathematicalRelation that defines a mathematical formula which can also contain variables and which will fill the value of the @amount if @isCalculatedAmount is TRUE. This is a very explicit and recommendable option for providing provenance information. In ecoSpold2 the formula are defined by a sub-set of the OpenFormula standard. Other RDF-related formula standards are described on the Wikipedia-page for MathML.

The @mathematicalRelation allows exactly to e.g. express an emission as an input number multiplied by a fixed combustione coefficient.

Re. the distinction between CO2 emissions and CO2 as a product, one option can be to use different names (such as "carbon dioxide, purified" or ""carbon dioxide, under pressure" for the product).