Physical Allocation

Question

Answer 1

I am not sure I understand, when you select allocation, it is performed "automatically" by the software, you do not need additional formulas? If you want to express several products in energy e.g. and some are in mass you can add a flow property (in the product flow) so that the software can do the conversion. That is it normally.

Comments

I understand allocation is performed automatically. The formula is for output. I have already added units to the flow property. However, When I use the unit as MJ in the output (process) it does not calculate the allocation properly. Can you please point out why the allocation is only calculated correctly when output has a ton as a unit?

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Hm I think it would be good if you showed more details of your model. "I have already added units to the flow property" - again, I do not understand, my point was that you need to add a flow property 'energy' to product flows that are only mass-based. Thank you.

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Sorry for the confusion. I meant I added 'energy' to product flow. Still, the calculation is wrong. For mass, it is 52:48 and for energy, it is 87:13.
I also did the conversion, 1 kg = 22.72 MJ for biogas. and 1Kg = 2.42 MJ for digester sludge ( Lower heating value). I set 'energy' as a reference to product flow.

Next when I have output of digester sludge amout= 1.85E8 MJ and biogas 2.52E8 MJ, the allocation is calculated as 87:13 that is different when I change the unit in output to ton.
Digester sludge = 1.85E8 t and biogas = 2.52E8 t gives 42:58 as allocation.

Sorry I don't see an option to add snips to explain you better.

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just edit your initial quesiton (via the pen icon) and add screenshot pictures.

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Please have a look at the snips now.

The first two snips shows the addition of energy as flow properties.

The third snip shows the automatic allocation calculation for unit MJ.

Why do I have different allocation for same value when the units are changed.
and last snip shows automatic allocation calculation for unit ton.