Information about PENRM e PERM of the product regarding database EN15804 add-on to ecoinvent

Question

I'm working on database EN15804 add-on to ecoinvent in order to obtain an EPD.

How can I quantify the PERM and PENRM for EUR-flat pallet?

Only the following information are reported inside the flow:

• carbon content fossil: 3.11%
• carbon content non fossil:  47.2%
• heating value: 335 MJ

Considering that there is a quantity of fossil carbon in the pallet, how can I quantify the PENRM?

Answer 1

Hello, 

You can actually consider the heating value to be entirely PERM because wooden pallet is based on biomass which is a fair assumption. If you want to allocate the heating value between PERM/PENRM then you can follow the carbon content split. To do this, first you need to calculate the non-fossil and fossil carbon allocation factors based on the dry weight of the wooden pallet which is 20.8 kg (should be in the flow description)

• Fossil carbon = 20.8 × 0.0311 = 0.65 kg C
• Biogenic carbon = 20.8 × 0.472 = 9.82 kg C 
• Total C content = 0.65 + 9.82 = 10.47 kg C

So to calculate PERM/PENRM

• PERM = 335 x (9.82/10.47) = 314 MJ
• PENRM = 335 x (0.65/10.47) = 21 MJ

You should note that this sort of calculation is heavily based on assumptions of course and obtaining actually heating values based on the BOM of the wooden pallet in real life should be favored.