Closing plastic loop with CCUS: Life cycle assessment of a novel strategy for plastic sustainable transition and negative emissions

The global plastic sector urgently needs a circular economy and decarbonization since excessive plastic use is aggravating plastic pollution and climate change. In this regard, a novel strategy was proposed to close both the plastic loop and carbon loop using carbon capture, utilization, and storage (CCUS), which involves recycling waste plastic into adsorbents for CO2 capture and converting the captured CO2 back into new plastic. This plasticCO2-plastic route applied in polyurethane was assessed through life cycle assessment and a new indicator, carbon closure efficiency (CCE), was proposed to quantify the extent to which a carbon loop is closed. Results indicate a negative emission of -9.57 kg CO2 eq/kg polyurethane. However, CCUS amplifies other impacts, including primary energy demand, water use, etc. Chemical feedstocks and adsorbent preparation are crucial factors for most environmental impacts. CCUS-based strategy far surpasses chemical recycling in CCE score, highlighting its effectiveness in closing the carbon loop.