SOFTDEPET - Soft depolymerisation of polyester-based plastics

After the closure of Asian borders to the flow of plastic waste - especially based on polyester (PET) - from the rest of the world and given the constant increase in the use of plastic, the recycling of plastic waste is a major challenge.

However, current solutions (mechanical recycling) do not make it possible to recycle the new difficult PETs that have appeared (colored, opaque, trays) into food plastic. The solution will therefore come from chemical recycling, which allows you to return to the initial molecules that make up PET and therefore to remanufacture any type of new PET.

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Combine regional academic and industrial skills in order to offer a reliable solution for the chemical recycling of (complex) PET-based products, under mild conditions, complementary to mechanical recycling.

The method is intended to be rapidly applicable industrially and easily implemented. The originality of the process is that it can start from plastic waste to make “new” plastic ready to be used in food quality: bottles, trays, film...

Various sources of PET plastic waste (transparent or colored PET, trays, refusal of mechanical recycling) were depolymerised into PET monomers and then repolymerised into rPET.

The characterisations carried out by IMP INSA made it possible to show that the recycled PET obtained had a quality similar to virgin PET of petroleum-based origin.

The industrial partner: IVA, validated the technical quality of the monomer on a recipe of several kilograms of varnish.

To move the chemical recycling technology of polyester from the laboratory scale (hundred grams) to the pilot scale (a few kilograms) with the establishment of a reaction tool (investment in a 15L pilot allowing the increase to 5 kg of depolymerised PET) but also to optimise the process to make it more circular (reuse of the reaction medium several times).