Process for recycling polyethylene terephthalate using selected temperature range for oligomer processing

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 organic compound in a volume section V3, to obtain a further initial mixture;
• c. 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;
• d. adding first particulated material to the first intermediate mixture in a volume section V4;
• e. transporting the first intermediate mixture to a filtering means;
• f. at least partially removing at least one impurity from the first intermediate mixture using the filtering means;
• wherein
• a temperature of the first intermediate mixture in the volume section V4 is in the range of 170° C. to 220° C., and wherein at least 40 wt-% of the first intermediate product is in the form of oligomers that have in the range of 2 to 35 repeating units, and wherein the first particulated material is diatomaceous earth,
• with the intrinsic viscosity, the wt-% of the first intermediate product in the form of oligomers, and the temperature in the volume section V4 determined according to the methods described herein.