Recycling of Plastics as a Strategy to Reduce Life Cycle GHG Emission, Microplastics and Resource Depletion

Abstract

Plastic waste is the most challenging type of waste because its generation rate (consumption rate) is high, and the current recycling rate is low. The increase in the production and disposal of plastics has led to significant environmental problems including greenhouse gas (GHG) emissions, microplastic pollution, and resource depletion. The study aimed at quantifying the potential environmental effects reduction achieved by recycling the most widely consumed polymers. One approach to establishing a circular economy for plastics is recycling. Plastic recycling as a strategy to reduce life cycle GHG emissions, microplastic emissions, and resource depletion was investigated. Life cycle assessment methodology was employed, considering cradle-to-gate as a system boundary. The results showed that recycling can significantly reduce life cycle GHG emissions and resource depletion. Replacing the virgin material with recycled material reduces the emission to −67 MtCO2e. Recycling could have saved 56.8 million microplastic emissions per year. However, mechanical recycling, which is commercialised nowadays, contributed to an increase in microplastics as much as 2.4 × 109 million particles per year. Recycling will also save about 50 million tonnes of resources from depletion worldwide by recycling around 20 Mt plastics. However, microplastic emissions reduction in the present scenario of mechanical recycling is not possible unless other mechanisms to capture the emitted microplastics are introduced or other recycling methods, such as chemical recycling, are employed.