Figure A) Net-zero and carbon balance require the carbon amount in corresponding boxes in feedstock and destination be the same, and together set a limit in the demand. Only CO2 emissions related to embedded carbon are considered (i.e., carbons that go into chemical products of demand). Process emissions are outside the scope of the diagram and need to be dealt with separately by renewable energy, CCS, etc. B) Simplified carbon flows across lifecycle stages in the value chain.