I'm hoping someone here may be able to help.
I'm trying to find out what value is used for energy density of coal in the 3.7 database. For instance, the "hard coal mine operation, GLO" process (https://v371.ecoquery.ecoinvent.org/Details/UPR/d7893887-4c1b-4ac7-ae38-e85ed73e2fe9/8b738ea0-f89e-4627-8679-433616064e82
) extracts 1.25 kg of "Coal, hard, unspecified, in ground" per 1kg of "hard coal" output.
According to this reference (https://ecoinvent.org/wp-content/uploads/2020/08/201007_hischier_weidema_implementation_of_lcia_methods.pdf
) the energy content of the "Coal, hard, unspecified, in ground" is 19.1 MJ/kg. According to this reference (https://ecoinvent.org/wp-content/uploads/2020/08/200712_frischknecht_jungbluth_overview_methodology_ecoinvent2.pdf
) the energy content of "Hard coal" is 28.9, which means that somehow 1.25*19.1 = 23.8 MJ of "Coal, hard, unspecified, in ground" coming into the process is turning into 28.9 MJ of "Hard coal" leaving the process, which clearly is not possible.
Can anyone please help us make sense of this?