Technology

Rewind^® PET is a PET monomer recycling solution that allows producing high quality clear and food grade PET for packaging from currently undervalued waste PET. It is the result of the partnership between JEPLAN, IFPEN, and Axens as a licensor & engineering company. The Rewind^® PET preferred feedstocks are currently poorly valorized colored and opaque PET bottles and trays. Moreover, Rewind^® PET is unlocking the recycling of PET films, multi layers trays and fibers (clothes, carpets, …) into virgin food grade PET.^[1]
The Process is employing the AIES Co., Ltd. Glycolysis Technology^[2] acquired and developed by PET Rebirth^[3] that is made of seven different stages:
The BHET monomer is produced by depolymerising PET in MEG as a solvent at 220°C to form a pre-decomposition product in which PET is broken down into oligomers.

1. MEG and Sodium Methylate catalyst are added to this product and the mix is heated at 200°C for 2 hours to completely decompose PET into BHET.
2. The product of this reaction is then filtered with activated carbon to remove the colorants coming from the caps and the labels.
3. Through an ion-exchange resin, impurities and the metal catalyst are removed.
4. The BHET-containing MEG solution is cooled to about 20°C and gently stirred so that BHET crystals slowly grow into a pure monomer.
5. The mix is pressed to remove the BHET crystals that formed and MEG is removed to be reused in the process.
6. In the molecular distillation stage BHET cakes are heated to evaporate the remaining MEG and to increase the concentration of the BHET solids; BHET is then liquefied and treated in a vacuum to remove remaining impurities.

The picture shows the Process Step Diagram illustrating a preferred distillation step (combination of components of distiller) in US20040182782A1^[3], wherein reference numerals denote:

1. a first evaporator
2. a condenser
3. a melt solution transport pump
4. a second evaporator
5. a condenser
6. a melt solution transport pump
7. a condensate reservoir
8. a molecular still
9. an internal condenser
10. heating means
11. a product output port
12. a distillation pot residue output port
13. a cooling medium circulating tank
14. a heating medium tank

References

1. Rewind^® PET Commercial Bulletin, AXENS
2. BIS-B-HYDROXYETHYL TEREPHTHALATE, US 7,030,264 B1, Priority: 2000/07/31, Grant: 2006/04/1
3. Processes for the purification of bis(2-hydroxyethyl)terephthalate, US20040182782A1, Filed: 2003/05/30, Grant: 2007/05.01, Expired - Fee Related