Plastics represent a serious waste-handling problem, with only 10% of the plastic waste (PW) generated world-wide being recycled. The remainder follows a linear economy model, involving disposal or incineration. Thermochemical recycling provides an opportunity to close the material cycle, and this work shows how this can be achieved using the existing petrochemical infrastructure. The transformation of a generic petrochemical cluster based on virgin fossil feedstocks into a cluster that is based on PW has the following proposed sequence: (1) the feedstock is partially replaced (45% on carbon basis) by PW; (2) the feedstock is totally replaced by PW; (3) the process undergoes electrification; and (4) oxy-combustion and carbon capture and storage are introduced to achieve 100% carbon recovery in the form of monomers or permanent storage. An alternative transformation pathway that includes the introduction of biomass is also considered.