Designing roadmaps for transitioning to value chains with net-zero emissions: Case of the chemical industry

The global economy must restrict net greenhouse gas emissions to the environment to zero by 2050. However, in the absence of rigorous methods, the precise path to net-zero remains ambiguous, despite the overabundance of candidate solutions. Our formulation builds on the existing net-zero roadmapping literature by including technologies at various readiness levels within the life-cycle network superstructure. A case study for chemicals and plastics value chains demonstrates the framework. We model the current global plastics and chemicals industry and the promising low carbon solutions, based on electrification, biomass, carbon capture and circularization. Our framework allows the evolution of background emissions and maturities of technological solutions. We solve a multi-objective optimization problem at discrete time steps to roadmap for projected chemicals production till 2050. Our results show that net-zero value chains are only possible with a combination of energy efficiency and material recycling. Lower TRL technologies enable this transition, but only on upfront investments into their development. Our framework incorporates the realistic limitations of adopting emerging technologies with low TRL values into the decision-making process. The product specific insights gained may be used to guide future strategies.