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In recent times, multilayer plastic packaging has been in high demand, as it provides better preservation and a prolonged shelf life for various packaging commodities. How-ever, its complicated structure poses a challenge to the existing recycling system and often ends up in a landfill or is incinerated. Unlike the current management system of MLP, the selective dissolution process represents a paradigm shift, as it enables the re-cycling of MLP with high material recovery and at a reasonable cost. Besides the bene-fits it offers, it is important to assess the environmental footprint of this process to ensure sustainability. Therefore, this study conducts a comparative life cycle assessment be-tween the selective dissolution process and the existing end-of-life management tech-niques (landfilling, incineration) to evaluate whether itbenefits to the existing practices. This study defines 1000 kg post-consumer plastic waste as a functional unit. It assumes 50% single-layer PE is mixed with 50% two-layer MLP (76% PE & 24% PET). This study assesses environmental impact in nine impact categories (fine particulate matter formation, freshwater ecotoxicity, marine ecotoxicity, global warming, human carcino-genic toxicity, human non-carcinogenic toxicity, terrestrial acidification, fossil resource scarcity and water consumption) using the ReCiPe Midpoint (E) impact assessment method. The outcome of this study finds the landfilling of plastic to be the least favora-ble, and the selective dissolution process to be the most favorable in terms of environ-mental sustainability among the alternatives. For example, the freshwater ecotoxicity impact of landfilling is 58.96 kg 1,4-DCB, while for selective dissolution the impact is -64.62 kg 1,4-DCB. Incineration of plastic waste with energy recovery is environmental-ly friendly in all impact assessment categories, except for the global warming impact. The global warming impact of incineration is 297.22 kg CO2 eq. A hotspot analysis of the selective dissolution process identifies that the steam energy required for the reboiler in the distillation column (78%-98%), pretreatment of multilayer film (9%-12%), and the solvent consumed (3%-6%) are the significant contributors to the total impact. Finally, a sensitivity analysis of the selective dissolution process has been performed, varying four key input parameters-5% lower reboiler duty, 95% solvent recovery, natural gas heating, and a 70:30 PE: PET ratio. This analysis shows that switching to natural gas for heating reduces the effect by around 70%-80% for every impact category. |
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