Method for recycling plastic products
AssigneeCarbios
InventorsCédric Boisart, Emmanuel Maille
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Abstract
The invention relates to a method for recycling at least one plastic product, the method comprising degrading at least one polymer of the plastic product to monomers using an enzyme and recovering the resulting monomers. The method of the invention may be used for degrading, simultaneously or sequentially, at least two different polymers of the plastic product, and/or for recycling at least two plastic products.
Claims23
A method for recycling at least one plastic product comprising at least partially semi-crystalline polyethylene terephthalate (PET) and at least one other additive, the method comprising:
- providing, without sorting, a mixture of plastic products coming from plastic waste collection and comprising said at least one plastic product;
- selecting a degrading enzyme suitable for degrading the at least partially semi-crystalline PET of the at least one plastic product;
- depolymerizing the at least partially semi-crystalline PET of the plastic product to monomers by contacting the at least one plastic product with the degrading enzyme;
- recovering the resulting monomers;
- and
- synthesizing polymers from the recovered monomers,
- wherein the depolymerizing step is conducted in a liquid medium whose pH is adjusted to be maintained at the optimal pH of the degrading enzyme during all of the depolymerizing step.
A method for producing terephthalic acid from a mixture of plastic products coming from plastic waste collection, wherein at least one plastic product comprises at least partially semi-crystalline polyethylene terephthalate (PET) and at least one or several other additives, wherein the method comprises the steps of:
- providing a mixture of plastic products coming from plastic waste collection and comprising said at least one plastic product;
- selecting a degrading enzyme suitable for degrading the semi-crystalline PET of the at least one plastic product;
- depolymerizing the semi-crystalline PET of the at least one plastic product to terephthalic acid by contacting the at least one plastic product with the degrading enzyme;
- and
- recovering the resulting terephthalic acid,
- wherein the depolymerizing step is conducted in a liquid medium whose pH is adjusted to be maintained at the optimal pH of the degrading enzyme during all of the depolymerizing step.
Dependencies are inferred from the claim text.