Identification of oxygen carriers for chemical recycling of plastic waste using chemical looping technologies

• Chemical recycling of plastics by CLC or CLG process is investigated. • Three Fe-based oxygen carriers (ilmenite, Fe20 and Mn66FeTi7) were evaluated. • Screening in batch fluidized bed at different temperatures with different plastics. • Ilmenite showed adequate for the CLG process to produce a syngas. • Mn66FeTi7 for CLC with plastics with high-ash content, otherwise Fe20. Chemical recycling of plastic waste is a promising technological alternative for the creation of a circular economy in plastics, enabling them to be used as raw material for the production of new plastics. Chemical looping (CL) technologies can facilitate the chemical recycling of plastics under different configurations. Chemical Looping Combustion (CLC) allows combustion with inherent CO 2 capture. In CLC, plastic waste can be burned to obtain a highly concentrated CO 2 stream from which new plastics can be produced. The transformations involved in chemical looping gasification (CLG) produce a synthesis gas from which monomers can be created for the production of new plastics. The key to optimal operation in all CL processes is determining the most suitable oxygen-carrying material for each application. In this work, three highly reactive Fe-based materials (ilmenite, Fe20 and Mn66FeTi7) were tested as oxygen carriers in a batch fluidized bed reactor. The plastic waste was gasified inside the reactor and the gaseous products react with the oxygen carrier. Ilmenite was proposed as an oxygen carrier for CLG. Mn66FeTi7 was recommended for CLC of plastics with high-ash content and Fe20 showed the highest reactivity to plastic devolatilization products.