Process for recycling polyethylene terephthalate using gaseous and/or liquid mono-ethylene glycol

A method for producing a first intermediate product, comprising the steps of

• a. providing a feedstock that comprises a first polyester;
• b. contacting the first polyester with a further amount of a first organic compound in a volume section V2;
• c. reducing an intrinsic viscosity of the first polyester in the volume section V2, wherein, after the reductions step has been completed, the first polyester has an intrinsic viscosity in the range of 0.10 dL/g to 0.45 dL/g;
• d. transporting the first polyester to a volume section V3;
• e. contacting the first polyester with a further organic compound in a volume section V3 to obtain a further initial mixture;
• f. reducing a weight average molar mass of the first polyester in the volume section V3 to obtain a first intermediate mixture, wherein the first intermediate mixture comprises
• i. a first intermediate product that has an intrinsic viscosity in the range of 0.010 dL/g to 0.120 dL/g,
• ii. the further organic compound;
• wherein
• a first fraction of the further amount of the first organic compound contacted with the first polyester is in the form of a gas and a further fraction of the further amount of the first organic compound contacted with the first polyester is in the form of a liquid,
• wherein the first fraction makes up in the range of 50 wt-% to 90 wt-% of the further amount of the first organic compound, with the wt-% is based on the total weight of the further amount of the first organic compound,
• the first polyester enters the volume section V2 via at least one inlet of a first kind, and the first fraction enters the volume section V2 via at least one inlet of a further kind, wherein the at least one inlet of the further kind is adapted and arranged such that a flow direction of the first fraction, which enters through the at least one inlet of the further kind, through the volume section V2 is at least partially along a transport direction of the first polyester through the volume section V2,
• the further fraction of the further amount of the first organic compound enters the volume section V2 via at least one inlet of an even-further kind, wherein the at least one inlet of the even-further kind is adapted and arranged such that a flow direction of the further amount of first organic compound, which enters through the at least one inlet of the even-further kind, through the volume section V2 is at least partially opposite the transport direction of the first polyester through the volume section V2, and
• the volume section V2 comprises a first zone and a further zone, wherein a temperature in the first zone is in the range of 50° C. to 190° C.,
• with the intrinsic viscosity and the temperature determined according to the methods described herein.