I am working on modelling timber. During the manufacturing process woodchips are produced as a byproduct /manufacturing waste which leaves the system in A3 module.
Should biogenic carbon and energy balancing as raw materials occur at the same stage?
Should the associated CO₂ emissions and energy be accounted for in Module A3—as direct emissions to air and as renewable energy input—or should they be included in Module D instead?
Based on the biogenic energy and carbon balancing guide from OCLCA, the biogenic carbon balancing field should be selected as ‘do nothing’ for waste treatment datapoints. However, since this biobased material is leaving the system boundary, it makes me uncertain about how biogenic carbon should be balanced across the whole lifecycle of the product.
Hello Adeleh, thank you for joining the forum and for raising this question.
When woodchips are produced as a byproduct during manufacturing and leave the system in Module A3, both biogenic carbon and energy content should be balanced in the life cycle stage where these materials exit the system—here, A3 (waste treatment).
-For biogenic carbon and energy as material, select “Balance in EoL” (End of Life) for the A1 raw material resource, allocating 100% to the module where the material leaves the system (A3 in your case) .
-In A3, for the waste treatment process (e.g., incineration or other treatment of woodchips), select “Balance in the same LCA stage” for both biogenic carbon and energy as material .
This ensures that the biogenic carbon and energy content are accounted for at the point where the material leaves the system boundary, not in Module D. Module D is only used for benefits and loads beyond the system boundary, and any transfer to Module D must be done manually if needed .
If you have a production loss % in A1, the biogenic carbon and energy content of the loss will automatically be balanced in A3.