Techno-economic and life cycle assessment of CO2 storage using amorphous carbon derived from end-of-life Polyethylene Terephthalate

Abstract

Plastics have become an integral part of our daily life. The advantages and benefits of plastic applications are counterbalanced by its drawbacks. Governments across the world are struggling to repurpose or value used plastic products. To minimize greenhouse gas emissions into the atmosphere, this study aims to recover carbon from waste Polyethylene Terephthalate (PET) based plastics into value-added products. The study also aims to model and simulate the feasibility of converting End of Life PET(EOL-PET) to porous carbon for CO₂ capture. Pyrolysis is regarded as one of the most effective methods for turning long-chain hydrocarbons into low-molecular-weight compounds. EOL-PET can be converted to value-added products like pyrolysis oil and porous carbon. In this study, non-recyclable PET plastics are pyrolyzed into gaseous, liquid, and solid/ash products. EOL-PET is carbonized, and the carbonized PET is heated with KOH (activating agent) in the presence of N₂. The KOH method improves the textural properties of the porous carbon and the CO₂ uptake and increases the efficiency of adsorption. Simulated the complete process of the conversion of Waste PET into porous carbon and that porous carbon used as an adsorbent for CO₂ storage using Aspen Plus. Performed the detailed techno-economic feasibility using Aspen Plus, obtained the pay-back period for derived porous carbon from waste PET and CO₂ storage is 2.5 years. Performed the detailed environmental feasibility analysis using OpenLCA, it resulted that the Global warming potential of porous carbon is higher than Carbon derived from various sources like woody biomass, Activated Carbon (AC) from olive waste cakes, and granulated AC.