Defining requirements of PET scrap for open loop recycling of post-industrial waste

Abstract: To reduce the environmental impact and minimize the exploitation of the depleting re-sources, the transition to a circular economy is vital. It proposes an economy of reduced ma-terial consumption and increased reuse and recycling of plastics and other materials. Only last year, 359 million tonnes of plastic were produced worldwide and only a third of the col-lected waste in Europe was recycled. Among the five largest produced commodity plastics, polyethylene terephthalate (PET) has the highest recycling rates. The recycled PET on the market is mostly post-consumer waste, mainly PET bottles. If bottle-to bottle recycling is to increase, other recycled PET grades need to enter the market. In the production of foamed plastics, waste is produced and accumulated. To decrease the environmental impact of the process it was investigated how to best recycle the waste. The requirements of recycled PET were defined by comparison of existing PET on the market, both virgin and recycled. The most important properties of recycled PET are the intrinsic viscosity and the melting tem-perature and to be processable they cannot differ considerably compared to virgin PET. Ad-ditionally, the quantity and type of contaminants present is important for its recyclability. It was concluded that the plastic scrap from the production has a high intrinsic viscosity and an acceptable melting temperature for reprocessing. However, the plastic waste contains an organic blowing agent and the effect of the compound to reprocessing is unknown and re-quires further investigation. An economic analysis was made to compare three alternatives of waste handling. It was concluded that the current case with circulation is the most eco-nomically beneficial option. Possible applications for the recycled waste was evaluated and several suitable applications were found. The sector with the highest potential was the build-ing and construction sector with applications of high value and good recyclability.