We solved the optimization model with four different levels of carbon prices ($45, $105, $450, $920 per tonne of CO 2 eq) imposed to the system. The optimal pathways under prices of $45, $105, and $450 per tonne of CO 2 eq are presented in Figured 5 (b), (c), and (d), while the result under the carbon price of $920 per tonne of CO 2 eq is provided in the supporting information (SI). In the scenario with carbon price of $45 per tonne of CO 2 eq, we observe that the production pathway for benzene will shift from initially catalytic reforming of naphtha to pyrolysis of corn stover. This change can decrease the carbon footprint of N66 and polystyrene production, resulting in 16.3% reduction of total GHG emissions in the system. It is interesting to observe that N66 is prioritized, but this makes sense because the polymer has a much higher carbon footprint than the rest of the plastics.