Method for recovering polyethylene glycol terephthalate by using impurity concentration gradient

Abstract

A process for producing a first intermediate product comprising the steps of: a. Providing a feedstock comprising a first polyester; b. Contacting the first polyester with a further amount of a first organic compound in a volume segment V2, where i. At least one impurity is present in the volume segment V2, and ii. The volume segment V2 has a first region and a further region; c. Contacting the first polyester with a further organic compound, preferably in volume segment V3, to obtain a further initial mixture; d. Reducing the weight average molar mass of the first polyester, preferably in the volume segment V3, to obtain a first intermediate mixture comprising i. The first intermediate product, ii. A further organic compound; wherein the relative ratio of the number of particles per unit area of at least one impurity in the first region to the number of particles per unit area of at least one impurity in the other region is equal to or greater than 10, more preferably equal to or greater than 15, even more preferably equal to or greater than 20, further preferably equal to or greater than 25, even further preferably equal to or greater than 30.

Description

Field of the Invention

[0001] The present invention relates to a method for producing a first intermediate product from a first polyester, for example, a method for producing a polyethylene terephthalate (PET) oligomer from a PET flake. The present invention also relates to a first intermediate product obtained by the above method. The present invention also relates to a method for producing another intermediate product using the first intermediate product, for example, using a PET oligomer to produce a PET polymer. The present invention also relates to another intermediate product. The present invention also relates to a product comprising another intermediate product, for example, a PET yarn.

[0002] background

[0003] Polyethylene terephthalate (PET) is one of the most widely used and economically important thermoplastic polymers. PET is used, for example, in clothing fibers, food and beverage containers (such as bottles) and films.

[0004] Due to the widespread use of PET and its non-biodegradability, products containing PET have caused serious ecological problems. Therefore, methods for recycling PET are very important for reducing the amount of PET waste. One recycling method is to reduce PET to chemical components used to produce PET, and then polymerize the chemical components to obtain recycled PET. This is called chemical recycling. The disadvantages of the chemical recycling process include that the recycling process is usually very energy-saving, not environmentally friendly, and has low yields. In particular, if PET is depolymerized into monomers, a long depolymerization time is required and a large amount of degradation products that cannot be removed from the recycled PET are produced. It is also usually necessary to mix the chemically recycled PET with the original PET to obtain a recycled PET product of sufficiently high quality.

[0005] For example, chemical recycling of polyethylene terephthalate is described in Bartolome et al. (2012), Recent Developments in the Chemical Recycling of PET, Material Recycling–Trends and Perspectives. EP3778744A1 discloses a method for recycling PET, comprising mixing virgin PET liquid material with recycled PET (virgin PET liquid material is defined as the chemical components required to produce virgin PET, i.e. PET obtained without using a recycling method). CN109134244 A discloses a method for recycling PET, which uses ethylene glycol and methanol to depolymerize PET. CN108395373 A discloses a method for recycling PET, which uses ethylene glycol and propylene glycol.

[0006] Purpose

[0007] It is an object of the present invention to at least partially overcome at least one of the disadvantages encountered in the prior art.

[0008] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method can use a raw material having a greater impurity concentration. The raw material comprises a first polyester, and the first intermediate product is obtained from the first polyester.

[0009] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method requires less organic compound for depolymerizing the first polyester.The first intermediate product is obtained from the first polyester.

[0010] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method increases the service life of at least one filtering device used during filtering of the first intermediate product.

[0011] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method can remove more impurities during the production of the first intermediate product. The impurity source includes a raw material (for the method for producing the first intermediate product) containing impurities such as sand and polyvinyl chloride.

[0012] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method can remove more alkali during the production of the first intermediate product. The presence of alkali may be due to, for example, the raw material (used in the method for producing the first intermediate product) having been washed with alkali.

[0013] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method can more effectively remove a binder adhering to a raw material (a method for producing a first intermediate product).

[0014] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the transport rate of the raw material through the production plant is increased. Here, the raw material refers to the raw material of the method for producing the first intermediate product, and the production plant refers to the plant for producing the first intermediate product.

[0015] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method reduces the occurrence of blockages, for example, in a production plant for producing the first intermediate product.

[0016] Another object of the present invention is to provide a method for producing a first intermediate product which requires less energy.

[0017] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the method has an increased yield.

[0018] It is another object of the present invention to provide a method for producing a first intermediate product, wherein the method has a reduced carbon footprint.

[0019] Another object of the present invention is to provide a method for producing a first intermediate product, wherein the first intermediate product has an improved purity.

[0020] Another object of the present invention is to provide a first intermediate product that can be used in a process for producing another intermediate product.

[0021] Another object of the present invention is to provide a method for producing another intermediate product, wherein the method requires less energy.

[0022] It is another object of the present invention to provide a process for producing another intermediate product, wherein the process has a reduced carbon footprint.

[0023] Another object of the present invention is to provide a method for producing another intermediate product, wherein the method has an increased yield.

[0024] Another object of the present invention is to provide a process for producing another intermediate product, wherein the process has a reduced polymerization time.

[0025] Another object of the present invention is to provide a method for producing another intermediate product, wherein the another intermediate product has improved color quality.

[0026] Another object of the present invention is to provide a method for producing a further intermediate product, wherein the further intermediate product has an improved purity.

[0027] Another object of the present invention is to provide a method for producing another intermediate product, wherein the another intermediate product is obtained by using an increased amount of a first intermediate product. For example, the another intermediate product is a PET polymer obtained by polymerizing PET oligomers and PET monomers (first intermediate product), wherein the PET oligomers and PET monomers are obtained by depolymerization of PET products; and further, the PET polymer is obtained by adding less than 1% of original PET oligomers and esters that can be used to produce PET.

[0028] Another object of the present invention is to provide another intermediate product having improved color quality.

[0029] Another object of the present invention is to provide another intermediate product with improved purity.

[0030] Preferred embodiments of the present invention

[0031] Any embodiment of the present invention helps to at least partially achieve at least one of the above objectives.

[0032] The first embodiment of the present invention is a method for producing a first intermediate product, comprising the following steps:

[0033] a. providing a raw material comprising a first polyester;

[0034] b. contacting the first polyester with an additional amount of a first organic compound in volume segment V2, wherein

[0035] i. at least one impurity is present in volume segment V2, and

[0036] ii. The volume segment V2 has a first region and another region;

[0037] c. contacting the first polyester with another organic compound, preferably in volume segment V3, to obtain another initial mixture;

[0038] d. reducing the weight average molar mass of the first polyester, preferably in volume segment V3, to obtain a first intermediate mixture, wherein the first intermediate mixture comprises

[0039] i. The first intermediate product,

[0040] ii. another organic compound;

[0041] in,

[0042] The relative ratio of the number of particles per unit area of ​​at least one impurity in the first region to the number of particles per unit area of ​​at least one impurity in the other region is equal to or greater than 10, more preferably equal to or greater than 15, even more preferably equal to or greater than 20, further preferably equal to or greater than 25, even further preferably equal to or greater than 30.

[0043] In the first embodiment, an example of at least one impurity is an impurity present in the raw material. In one aspect of the first embodiment, at least one impurity is preferably conveyed from volume segment V1 to volume segment V2. In one aspect of the first embodiment, it is preferred that the first polyester is contacted with an additional amount of the first organic compound before contacting the first polyester with the other organic compound. In one aspect of the first embodiment, it is preferred that the first intermediate mixture further comprises the first organic compound. In one aspect of the first embodiment, it is preferred that the other organic compound is in liquid form. In one aspect of the first embodiment, it is preferred that the relative ratio of the number of particles per unit area of ​​the at least one impurity in the first region to the number of particles per unit area of ​​the at least one impurity in the other region is equal to or less than 1000, more preferably equal to or less than 500, even more preferably equal to or less than 250. In one aspect of the first embodiment, it is preferred that the conveying direction of the first polyester through the volume segment V2 is at least partially opposite to the direction of gravity, more preferably opposite to the direction of gravity. In one aspect of the first embodiment, it is preferred that the volume segment V2 is at least partially arranged vertically, more preferably arranged vertically. At least partially arranged vertically is preferably understood as the longest dimension (e.g., length) of the volume segment V2 is not parallel to the ground. For example, if the volume segment V2 is arranged vertically, the length of the volume segment V2 is perpendicular to the ground.

[0044] In a preferred embodiment of the method for producing the first intermediate product, the density of the first polyester in the raw material is 1.25 g / cm 3 Up to 1.55g / cm 3 In the range of 1.28 g / cm 3 Up to 1.50g / cm 3 and further preferably within the range of 1.31 g / cm 3 Up to 1.47g / cm 3 This preferred embodiment is the second embodiment of the present invention, which is preferably dependent on the first embodiment of the present invention.

[0045] In one aspect of the second embodiment, the first polyester is an example of a polyester having a density of 1.33 g / cm 3 Up to 1.39g / cm 3 Amorphous PET in the range of 1.455 g / cm 3 Single crystal PET.

[0046] In a preferred embodiment of the method for producing the first intermediate product, the first polyester is selected from polyethylene terephthalate, polybutylene terephthalate, polylactic acid, polytrimethylene terephthalate, polyethylene naphthalate, polycarbonate, polyester carbonate, polyarylate, polyester resin (preferably unsaturated polyester resin) and a combination of two or more thereof. This preferred embodiment is the third embodiment of the present invention, which is preferably dependent on any one of the first to second embodiments of the present invention.

[0047] In one aspect of the third embodiment, it is particularly preferred that the first polyester is polyethylene terephthalate.

[0048] In a preferred embodiment of the method for producing the first intermediate product, the raw material contains at least 65 wt-%, more preferably at least 85 wt-%, even more preferably at least 95 wt-%, and further preferably at least 99 wt-% of the first polyester based on the total mass of the raw material. This preferred embodiment is the fourth embodiment of the present invention, which is preferably dependent on any one of the first to third embodiments of the present invention.

[0049] In one aspect of the fourth embodiment, the first polyester is preferably polyethylene terephthalate. In another aspect of the fourth embodiment, the feedstock preferably contains less than 1 wt-%, more preferably less than 0.1 wt-%, and further preferably less than 0.01 wt-% of polyamide, based on the total mass of the feedstock.

[0050] In a preferred embodiment of the method for producing the first intermediate product, the bulk density of the raw material is between 0.10 g / cm 3 Up to 0.75g / cm 3 In the range of 0.15 g / cm 3 Up to 0.65g / cm 3 In the range of 0.18 g / cm 3 Up to 0.50g / cm 3 In the range of 0.20 g / cm 3 Up to 0.40g / cm 3 In the range of 0.22 g / cm 3 Up to 0.37g / cm 3 This preferred embodiment is the fifth embodiment of the present invention, which is preferably dependent on any one of the first to fourth embodiments of the present invention.

[0051] In a preferred embodiment of the method for producing the first intermediate product, the raw material further comprises at least one impurity. This preferred embodiment is the sixth embodiment of the present invention, which preferably depends on any one of the first to fifth embodiments of the present invention.

[0052] In a preferred embodiment of the method for producing the first intermediate product, at least one impurity in the raw material is in the range of 10 ppm wt to 10000 ppm wt, more preferably in the range of 20 ppm wt to 4000 ppm wt, even more preferably in the range of 30 ppm wt to 3000 ppm wt, and further preferably in the range of 40 ppm wt to 2500 ppm wt, wherein the mass is based on the total mass of the raw material. This preferred embodiment is the 7th embodiment of the present invention, which is preferably dependent on the 6th embodiment of the present invention.

[0053] In one aspect of the seventh embodiment, the ppm value of at least one impurity is preferably measured after the raw material has been subjected to a washing step. In another aspect of the seventh embodiment, the ppm value given for at least one impurity is preferably measured when the first polyester is provided in the form of a plurality of chips.

[0054] In a preferred embodiment of the method for producing the first intermediate product, the first polyester in the raw material is in the form of a plurality of fragments. This preferred embodiment is the eighth embodiment of the present invention, which preferably depends on any one of the first to seventh embodiments of the present invention.

[0055] In a preferred embodiment of the method for producing the first intermediate product, the form of the fragments is selected from flakes, wires, fibers, particles, fragments, sheets, films and combinations of two or more thereof. This preferred embodiment is the 9th embodiment of the present invention, which is preferably dependent on the 8th embodiment of the present invention.

[0056] In one aspect of the ninth embodiment, thin sheets are particularly preferred.

[0057] In a preferred embodiment of the method for producing the first intermediate product, based on the total mass of the plurality of fragments in the feedstock, at least 50 wt-%, more preferably at least 60 wt-%, even more preferably at least 70 wt-%, further preferably at least 80 wt-

[0058] %, even further preferably at least 85 wt-% of the fragments have at least one or all of the following characteristics:

[0059] a. The first dimension is in the range of 0.1 mm to 25.0 mm, more preferably in the range of 0.5 mm to 20.0 mm, even more preferably in the range of 1.0 mm to 15.0 mm, and further preferably in the range of 2.5 mm to 13 mm;

[0060] b. The thickness is in the range of 0.1 mm to 3.5 mm, more preferably in the range of 0.2 mm to 3.0 mm, and further preferably in the range of 0.3 mm to 2.7 mm.

[0061] This preferred embodiment is the 10th embodiment of the present invention, which is preferably dependent on any one of the 8th to 9th embodiments of the present invention.

[0062] Examples of the first dimension in the 10th embodiment are width and length. In one aspect of the 10th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b.

[0063] In a preferred embodiment of the method for producing the first intermediate product, based on the total mass of the plurality of fragments in the raw material, 30 wt-% or less, more preferably 27 wt-% or less, even more preferably 23 wt-% or less, and further preferably 20 wt-% or less of the fragments have a thickness equal to or greater than 1.0 mm. This preferred embodiment is the 11th embodiment of the present invention, which is preferably dependent on any one of the 8th to 10th embodiments of the present invention.

[0064] In an optional aspect of the 11th embodiment, the chips in the range of 1 wt-% to 30 wt-%, optionally in the range of 2 wt-% to 27 wt-%, optionally in the range of 5 wt-% to 23 wt-%, or optionally in the range of 7 wt-% to 20 wt-% have a thickness equal to or greater than 1.0 mm. In an aspect of the 11th embodiment, preferably, the wt-% range is applicable to chips having a thickness in the range of 1.0 mm to 4.0 mm, more preferably in the range of 1.0 mm to 3.5 mm, and further preferably in the range of 1.0 mm to 2.7 mm.

[0065] In a preferred embodiment of the method for producing a first intermediate product, the plurality of fragments are sorted at least in part according to physical characteristics. This preferred embodiment is the 12th embodiment of the present invention, which preferably depends on any one of the 8th to 11th embodiments of the present invention.

[0066] In one aspect of the twelfth embodiment, the fragments are preferably at least partially sorted based on at least one of the following properties: mass, thickness, color, optical sorting based on light absorption, electrical properties, aerodynamic properties, width, length, geometry (e.g., curvature), or a combination of two or more thereof. In one aspect of the twelfth embodiment, the sorting is preferably performed before contacting the feedstock with the first amount of the first organic compound (preferably in volume segment V1). In one aspect of the twelfth embodiment, the physical property is preferably not the density of the fragments.

[0067] In a preferred embodiment of the method for producing a first intermediate product, the plurality of fragments are at least partially sorted using at least one or all of the following:

[0068] a. sieve;

[0069] b. Gravity separator;

[0070] c. means suitable and arranged for sinking;

[0071] d. Centrifuge.

[0072] This preferred embodiment is the 13th embodiment of the present invention, which is preferably dependent on the 12th embodiment of the present invention.

[0073] In one aspect of the 13th embodiment, all possible combinations of features a. to d. are preferred aspects of this embodiment. These combinations are, for example, a; b; c; d; a+b; a+c; a+d; b+c; b+d; c+d; a+b+c; a+b+d; a+c+d; b+c+d; a+b+c+d. In one aspect of the 13th embodiment, it is preferred to use a device that does not utilize the density of the first polyester for at least partial sorting. In one aspect of the 13th embodiment, a gravity separator is particularly preferred. In this aspect, a gravity separator that does not require a fluid for at least partial sorting is more preferred. Suitable gravity separators can be obtained, for example, from Cimbria Heid GmbH (Austria).

[0074] In a preferred embodiment of the method for producing a first intermediate product, the first organic compound has at least one or all of the following characteristics:

[0075] a. comprising at least two hydroxyl groups, for example a diol having 2 hydroxyl groups, a triol having 3 hydroxyl groups;

[0076] b. The molar mass is at least 60 g / mol;

[0077] c. A boiling point of at least 192°C, more preferably at least 195°C.

[0078] This preferred embodiment is the 14th embodiment of the present invention, which is preferably dependent on any one of the 1st to 13th embodiments of the present invention.

[0079] Examples of the first organic compound include (mono)ethylene glycol, propylene glycol, and glycerol. In one aspect of the 14th embodiment, all possible combinations of features a. to c. are preferred aspects of this embodiment. These combinations are, for example, a; b; c; a+b; a+c; b+c; a+b+c. In one aspect of the 14th embodiment, it is particularly preferred that the first organic compound is (mono)ethylene glycol, more preferably monoethylene glycol. In one aspect of the 14th embodiment, it is particularly preferred that the first organic compound is not propylene glycol.

[0080] In a preferred embodiment of the method for producing a first intermediate product, the method further comprises a step of contacting the feedstock with a first amount of a first organic compound (preferably in volume segment V1) to obtain a first initial mixture, wherein the first amount is in liquid form. This preferred embodiment is the 15th embodiment of the present invention, which preferably depends on any one of the 1st to 14th embodiments of the present invention.

[0081] In one aspect of the fifteenth embodiment, it is preferred that the feedstock is contacted with the first amount of the first organic compound before contacting the first polyester with the additional amount of the first organic compound. In one aspect of the fifteenth embodiment, it is preferred that at least a portion of the first amount of the first organic compound is fed into the volume segment V1 before the feedstock is contacted with the first amount of the first organic compound. In this aspect, it is preferred that the temperature of at least a portion of the first amount of the first organic compound fed into the volume segment V1 is in the range of 100° C. to 160° C., more preferably in the range of 115° C. to 145° C. In one aspect of the fifteenth embodiment, it is preferred that the first polyester is fed into the volume segment V1 before the feedstock is contacted with the first amount of the first organic compound. In this aspect, it is preferred that the temperature of the first polyester fed into the volume segment V1 is in the range of 0° C. to 60° C., more preferably in the range of 10° C. to 40° C. In one aspect of the fifteenth embodiment, it is preferred that at least a portion of the first amount of the first organic compound and the feedstock are fed separately into the volume segment V1 before the feedstock is contacted with the first amount of the first organic compound. For example, the first amount portion and the feedstock are fed into the volume segment V1 using different inlets.

[0082] In a preferred embodiment of the method for producing the first intermediate product, the mass ratio of the raw material (more preferably the first polyester) to the first amount of the first organic compound in the preferred volume segment V1 is preferably in the range of 0.02 to 3, more preferably in the range of 0.04 to 2.8, even more preferably in the range of 0.06 to 2.6, further preferably in the range of 0.08 to 2.4, even further preferably in the range of 0.09 to 2.2. This preferred embodiment is the 16th embodiment of the present invention, which is preferably dependent on the 15th embodiment of the present invention.

[0083] In one aspect of the sixteenth embodiment, the mass ratio of the raw material (more preferably the first polyester) to the first organic compound in the volume segment V1 is preferably in the range of 0.02 to 1.3, more preferably in the range of 0.04 to 0.5, even more preferably in the range of 0.06 to 0.28, further preferably in the range of 0.08 to 0.22, even more preferably in the range of 0.09 to 0.16. In one aspect of the sixteenth embodiment, it is preferred that the temperature in the volume segment V1 is in the range of 55° C. to 80° C. In one aspect of the sixteenth embodiment, it is more preferred that the temperature in the volume segment V1 is below 79° C. In one aspect of the sixteenth embodiment, it is preferred that the temperature in the volume segment V1 is in the range of 65° C. to 77° C.

[0084] In a preferred embodiment of the method for producing a first intermediate product, the temperature of the first initial mixture in the volume section V1 is preferably in the range of 50° C. to 90° C., more preferably in the range of 55° C. to 85° C., even more preferably in the range of 55° C. to 80° C., further preferably in the range of 60° C. to 80° C., and even further preferably in the range of 65° C. to 77° C. This preferred embodiment is the 17th embodiment of the present invention, which preferably depends on any one of the 15th to 16th embodiments of the present invention.

[0085] In one aspect of the seventeenth embodiment, it is particularly preferred that the temperature of the first initial mixture is lower than the glass transition temperature of the first polyester. In one aspect of the seventeenth embodiment, it is preferred that the temperature of the first polyester in volume segment V1 differs from the temperature of the first organic compound in volume segment V1 by less than 4%, more preferably less than 2%, and further preferably less than 1%.

[0086] In a preferred embodiment of the method for producing the first intermediate product, the intrinsic viscosity of the first polyester in the volume segment V1 is in the range of 0.50 dL / g to 1.00 dL / g, more preferably in the range of 0.60 dL / g to 0.95 dL / g, even more preferably in the range of 0.70 dL / g to 0.90 dL / g, and further preferably in the range of 0.76 dL / g to 0.84 dL / g. This preferred embodiment is the 18th embodiment of the present invention, which is preferably dependent on any one of the 15th to 17th embodiments of the present invention.

[0087] In a preferred embodiment of the method for producing a first intermediate product, at least one or all of the following apply to the first polyester in volume section V1:

[0088] a. The intrinsic viscosity of the first polyester changes by less than 15%, more preferably less than 10%, even more preferably less than 7%, further preferably less than 5%, even further preferably less than 3%;

[0089] b. The weight average molar mass of the first polyester varies by less than 20%, more preferably less than 15%, even more preferably less than 10%, further preferably less than 7%, even further preferably less than 5%.

[0090] This preferred embodiment is the 19th embodiment of the present invention, which is preferably dependent on any one of the 15th to 18th embodiments of the present invention.

[0091] In one aspect of the 19th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b.

[0092] In a preferred embodiment of the method for producing the first intermediate product, at least one or all of the following apply:

[0093] a. before contacting with the first amount of the first organic compound, the weight average molar mass of the first polyester is in the range of 50 000Da to 73 000Da, more preferably in the range of 54 000Da to 68 000Da, and further preferably in the range of 57000Da to 65 000Da;

[0094] b. The weight average molar mass of the first polyester leaving volume segment V1 is in the range of 40 000 Da to 76 000 Da, more preferably in the range of 44 000 Da to 74 000 Da, even more preferably in the range of 48 000 Da to 72 000 Da, and further preferably in the range of 50 000 Da to 70 000 Da.

[0095] This preferred embodiment is the 20th embodiment of the present invention, which is preferably dependent on any one of the 15th to 19th embodiments of the present invention.

[0096] In one aspect of the 20th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b. In one aspect of the 20th embodiment, it is preferred that the weight average molar mass of the first polyester leaving the volume segment V1 is in the range of 51,000 Da to 55,000 Da.

[0097] In a preferred embodiment of the method for producing the first intermediate product, the relative ratio of the number of particles per unit area of ​​at least one impurity in the raw material to the number of particles per unit area of ​​at least one impurity at the outlet of the volume section V1 is equal to or greater than 15, more preferably equal to or greater than 20, even more preferably equal to or greater than 25, further preferably equal to or greater than 30, even further preferably equal to or greater than 35. This preferred embodiment is the 21st embodiment of the present invention, which is preferably dependent on any one of the 15th to 20th embodiments of the present invention.

[0098] In one aspect of the 21st embodiment, preferably, the relative ratio of the number of particles per unit area of ​​at least one impurity in the raw material to the number of particles per unit area of ​​at least one impurity at the outlet of volume segment V1 is equal to or less than 1000, more preferably equal to or less than 500, and even more preferably equal to or less than 250.

[0099] In a preferred embodiment of the method for producing the first intermediate product, the residence time of the first polyester in the volume section V1 is 5 minutes to 45 minutes, more preferably 8 minutes to 40 minutes, and further preferably 10 minutes to 30 minutes. This preferred embodiment is the 22nd embodiment of the present invention, which preferably depends on any one of the 15th to 21st embodiments of the present invention.

[0100] In a preferred embodiment of the method for producing the first intermediate product, the pressure in the volume section V1 is in the range of 75 kPa to 130 kPa, more preferably in the range of 90 kPa to 115 kPa, further preferably in the range of 95 kPa to 107 kPa, and even further preferably in the range of 98 kPa to 103 kPa. This preferred embodiment is the 23rd embodiment of the present invention, which preferably depends on any one of the 15th to 22nd embodiments of the present invention.

[0101] In one aspect of the 23rd embodiment, the pressure in the preferred volume segment V1 is atmospheric pressure.

[0102] In a preferred embodiment of the method for producing a first intermediate product, the method further comprises the step of stirring the first initial mixture preferably in volume section V1. This preferred embodiment is the 24th embodiment of the present invention, which preferably depends on any one of the 15th to 23rd embodiments of the present invention.

[0103] In one aspect of the 24th embodiment, the first initial mixture is preferably stirred using a mechanical device designed and arranged for stirring, a non-mechanical device designed and arranged for stirring, or a combination thereof. In this aspect, it is further preferred that the mechanical device, the non-mechanical device, or both are designed and arranged to suspend particles in a liquid, such as suspending multiple fragments of a raw material in a first organic compound. For example, the suspension of particles can be achieved by using a mechanical stirring device with a rotation speed per minute higher than a minimum value. In one aspect of the 24th embodiment, the first initial mixture is preferably stirred so that impurities can float on the surface of the first initial mixture. This can be achieved, for example, by using a stirring device with a rotation speed per minute lower than a maximum value.

[0104] In a preferred embodiment of the method for producing a first intermediate product, the method further comprises a step of at least partially removing at least one impurity from the first initial mixture in the preferred volume segment V1. This preferred embodiment is the 25th embodiment of the present invention, which preferably depends on any one of the 15th to 24th embodiments of the present invention.

[0105] In one aspect of the 25th embodiment, at least one impurity is preferably present in the feedstock. In one aspect of the 25th embodiment, at least one impurity is preferably at least partially removed using a floatable separation device. In another aspect of the 25th embodiment, at least one impurity is preferably at least partially removed using skimming, filtering, or a combination thereof.

[0106] In a preferred embodiment of the method for producing the first intermediate product, the method further comprises the step of transferring the first polyester preferably from volume section V1 to volume section V2. This preferred embodiment is the 26th embodiment of the present invention, which preferably depends on any one of the 1st to 25th embodiments of the present invention.

[0107] In one aspect of the 26th embodiment, the first polyester is preferably conveyed to the volume segment V2 after the feedstock has been contacted with the first amount of the first organic compound in the volume segment V1. In another aspect of the 26th embodiment, at least a portion of the first organic compound in the volume segment V1 is preferably conveyed to the volume segment V2 together with the first polyester. In another aspect of the 26th embodiment, at least a portion of the first organic compound in the volume segment V2 is preferably conveyed (e.g., flows) from the volume segment V2 to the volume segment V1. In one aspect of the 26th embodiment, the first polyester is preferably conveyed to the volume segment V2 before the first polyester is contacted with another organic compound.

[0108] In a preferred embodiment of the method for producing a first intermediate product, the volume section V2 is at least partially filled with a first organic compound, wherein

[0109] i. the level of the first organic compound in volume segment V1 is at a height H1 from the floor, and

[0110] ii. the level of the first organic compound in the volume segment V2 is at a height H2 from the floor,

[0111] and

[0112] Among them H1 <H2。

[0113] This preferred embodiment is the 27th embodiment of the present invention, which is preferably dependent on any one of the 15th to 26th embodiments of the present invention.

[0114] In one aspect of the 27th embodiment, it is preferred that at least a portion of the first organic compound in volume segment V2 is transferred from volume segment V1. In another aspect of the 27th embodiment, it is preferred that at least a portion of the first organic compound in volume segment V2 is added through at least one inlet of volume segment V2, such as another type of inlet and yet another type of inlet. In this aspect, it is preferred that at least 50 wt-%, more preferably at least 60 wt-%, and further preferably at least 70 wt-% of the first organic compound in volume segment V2 is due to the addition of the first organic compound through at least one inlet of volume segment V2. The wt-% is based on the total mass of the first organic compound in volume segment V2. "Another amount of the first organic compound" is an example of a portion of the first organic compound added through at least one inlet. In one aspect of the 27th embodiment, it is preferred that the first polyester is transferred from volume segment V1 to volume segment V2 via a siphon.

[0115] In a preferred embodiment of the method for producing the first intermediate product, the difference H2-H1 is at least 1 cm, more preferably at least 10 cm, further preferably at least 30 cm, and even further preferably at least 60 cm. This preferred embodiment is the 28th embodiment of the present invention, which is preferably dependent on the 27th embodiment of the present invention.

[0116] In an aspect of the 28th embodiment, the difference H2-H1 is preferably less than 250 cm, more preferably less than 180 cm, even more preferably less than 160 cm, and further preferably less than 140 cm.

[0117] In a preferred embodiment of the method for producing the first intermediate product, before entering the volume section V2, the first polyester is conveyed in a further direction, wherein the further direction is at least partially opposite to the direction of gravity. This preferred embodiment is the 29th embodiment of the present invention, which preferably depends on any one of the 26th to 28th embodiments of the present invention.

[0118] In one aspect of the 29th embodiment, it is preferred that at least a portion of the first organic compound is transported in a direction opposite to the further direction. For example, the first polyester and a portion of the first organic compound are transported in opposite directions.

[0119] In a preferred embodiment of the method for producing a first intermediate product, the angle between the further direction and the horizontal plane is in the range of 12° to 45°, more preferably in the range of 17° to 40°, even more preferably in the range of 20° to 35°, further preferably in the range of 24° to 32°. This preferred embodiment is the 30th embodiment of the present invention, which is preferably dependent on the 29th embodiment of the present invention.

[0120] In one aspect of the 30th embodiment, an example of a horizontal plane is a floor, such as a floor of a recycling plant. In one aspect of the 30th embodiment, the horizontal plane is preferably perpendicular to the direction of gravity.

[0121] In a preferred embodiment of the method for producing the first intermediate product, the method further comprises a step of increasing the temperature of the first polyester, preferably in volume section V2. This preferred embodiment is the 31st embodiment of the present invention, which preferably depends on any one of the 1st to 30th embodiments of the present invention.

[0122] In one aspect of the 31st embodiment, the temperature is preferably increased by contacting the first polyester with an additional amount of the first organic compound. In one aspect of the 31st embodiment, the temperature is preferably increased before the first polyester is contacted with the additional organic compound.

[0123] In a preferred embodiment of the method for producing the first intermediate product, the temperature in the volume section V2 is in the range of 50° C. to 220° C., more preferably in the range of 60° C. to 210° C., more preferably in the range of 65° C. to 205° C., and further preferably in the range of 68° C. to 200° C. This preferred embodiment is the 32nd embodiment of the present invention, which preferably depends on any one of the 1st to 31st embodiments of the present invention.

[0124] In one aspect of the thirty-second embodiment, the temperature in the preferred volume segment V2 is the temperature of the mixture comprising the first polyester and the first organic compound.

[0125] In preferred embodiments of the method for producing a first intermediate product, at least one or all of the following applies:

[0126] a. a relative ratio of the temperature of the first region to the temperature of the other region is in the range of 0.2 to 1.0, more preferably in the range of 0.3 to 0.9, and further preferably in the range of 0.4 to 0.8;

[0127] b. The relative ratio of the mass ratio of the first polyester to the first organic compound in the first region to the mass ratio of the first polyester to the first organic compound in another region is in the range of 0.01 to 0.90, more preferably in the range of 0.02 to 0.60, even more preferably in the range of 0.03 to 0.30, and further preferably in the range of 0.04 to 0.15.

[0128] This preferred embodiment is the 33rd embodiment of the present invention, which is preferably dependent on any one of the 1st to 32nd embodiments of the present invention.

[0129] In one aspect of the 33rd embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b.

[0130] In preferred embodiments of the method for producing a first intermediate product, at least one or all of the following applies:

[0131] a. The temperature of the first zone is in the range of 50°C to 220°C, preferably in the range of 50°C to 190°C, more preferably in the range of 60°C to 180°C, even more preferably in the range of 65°C to 170°C, further preferably in the range of 68°C to 160°C, and even further preferably in the range of 68°C to 150°C;

[0132] b. The temperature of the other zone is 120°C to 220°C, more preferably 130°C to 210°C, even more preferably 135°C to 205°C, and further preferably 138°C to 200°C.

[0133] This preferred embodiment is the 34th embodiment of the present invention, which is preferably dependent on any one of the 1st to 33rd embodiments of the present invention.

[0134] In one aspect of the 34th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b. In one aspect of the 34th embodiment, it is preferred that the temperature of the first zone increases from the first end of the first zone to the other end of the first zone. For example, the temperature increases from 70°C measured at the first end of the first zone to 145°C measured at the other end of the first zone. In this aspect, it is preferred that the first end of the first zone is located downstream of the other end of the first zone. For example, the first end of the first zone is located near the inlet of the volume segment V2, through which the first polyester enters the volume segment V2. In another aspect of the 34th embodiment, it is preferred that the temperature of the other zone increases from the first end of the other zone to the other end of the other zone. For example, the temperature increases from 140°C measured at the first end of the other zone to 200°C measured at the other end of the other zone. In this aspect, it is preferred that the first end of the other zone is located downstream of the other end of the other zone. For example, the other end of the other zone is located near the outlet of the volume segment V2, through which the first polyester leaves the volume segment V2. For example, moving from the inlet to the outlet of the volume segment V2, the ends of the regions are arranged in the following order: a first end of the first region, the other end of the first region, the first end of the other region, and the other end of the other region. In another aspect of the 34th embodiment, it is preferred that the other end of the first region forms the first end of the other region. In one aspect of the 34th embodiment, in feature a., it is particularly preferred that the temperature in the first region is in the range of 50°C to 190°C, more preferably in the range of 60°C to 180°C, even more preferably in the range of 65°C to 170°C, further preferably in the range of 68°C to 160°C, and even further preferably in the range of 68°C to 150°C. In one aspect of the 34th embodiment, in feature a., it is preferred that the temperature in the first region is in the range of 60°C to 210°C, more preferably in the range of 60°C to 200°C, further preferably in the range of 65°C to 197°C, and even further preferably in the range of 67°C to 196°C. In one aspect of the 34th embodiment, feature a., it is particularly preferred that the temperature in the first region is in the range of 50°C to 196°C, more preferably in the range of 55°C to 196°C, even more preferably in the range of 60°C to 196°C, further preferably in the range of 65°C to 196°C, and even more preferably in the range of 68°C to 196°C. In one aspect of the 34th embodiment, feature a., it is preferred that the temperature of the first region is lower than the boiling point of the first organic compound. In one aspect of the 34th embodiment, feature b., it is preferred that the temperature of the other region is in the range of 160°C to 220°C, more preferably in the range of 170°C to 210°C, even more preferably in the range of 180°C to 200°C, further preferably in the range of 185°C to 196°C, even more preferably in the range of 190°C to 196°C.In one aspect of the 34th embodiment, feature b., the temperature of the other region is preferably lower than the boiling point of the first organic compound.

[0135] In a preferred embodiment of the method for producing the first intermediate product, at least one or all of the following apply:

[0136] a. the mass ratio of the first polyester to the first organic compound in the first region is from 0.1 to 0.9, more preferably from 0.2 to 0.8, even more preferably from 0.3 to 0.6, and further preferably from 0.4 to 0.5;

[0137] b. The mass ratio of the first polyester to the first organic compound in the other region is in the range of 1 to 20, more preferably in the range of 2 to 16, even more preferably in the range of 3 to 12, and further preferably in the range of 5 to 10.

[0138] This preferred embodiment is the 35th embodiment of the present invention, which is preferably dependent on any one of the 1st to 34th embodiments of the present invention.

[0139] In one aspect of the 35th embodiment, all possible combinations of features a and b are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b.

[0140] In a preferred embodiment of the method for producing the first intermediate product, at least one or all of the following apply:

[0141] a. a first portion of the first organic compound in contact with the first polyester in an additional amount in the form of a gas, such as steam;

[0142] b. Another portion of the additional amount of the first organic compound contacted with the first polyester is in liquid form.

[0143] This preferred embodiment is the 36th embodiment of the present invention, which is preferably dependent on any one of the 1st to 35th embodiments of the present invention.

[0144] In the 36th embodiment, the first part and the further part are measured in wt-%, based on the total mass of the further amount of the first organic compound contacted with the first polyester. In one aspect of the 36th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b. In the 36th embodiment, "part" (e.g., first part, further part) should preferably be understood as including a value of 100 wt-%. For example, in one aspect of the 36th embodiment, where only feature a. applies, the first part will be 100 wt-%. In the 36th embodiment, the first part should preferably be understood as including the first organic compound that was initially in gaseous form but condensed before contacting with the first polyester. In one aspect of the 36th embodiment, feature a., it is preferred that the temperature of the first part of the further amount of the first organic compound is above the boiling point of the first organic compound. In one aspect of the 36th embodiment, feature a., it is preferred that the temperature of the first part of the further amount of the first organic compound is in the range of 200°C to 240°C, more preferably in the range of 210°C to 230°C. In one aspect of the 36th embodiment, feature b., preferably, the temperature of another portion of the additional amount of the first organic compound is below the boiling point of the first organic compound. In one aspect of the 36th embodiment, feature b., preferably, the temperature of another portion of the additional amount of the first organic compound is in the range of 180° C. to 196° C., more preferably in the range of 190° C. to 196° C.

[0145] In a preferred embodiment of the method for producing the first intermediate product, the first part accounts for 50 wt-% to 90 wt-%, more preferably 55 wt-% to 85 wt-%, even more preferably 60 wt-% to 80 wt-%, and further preferably 65 wt-% to 75 wt-% of the first organic compound of the additional amount. The wt-% is based on the total mass of the first organic compound of the additional amount. This preferred embodiment is the 37th embodiment of the present invention, which is preferably dependent on the 36th embodiment of the present invention.

[0146] In the 37th embodiment, the sum of the wt-% of the first part and the wt-% of the other part is 100 wt-%. For example, if the first part accounts for 55 wt-% of the other amount of the first organic compound, the other part accounts for the remaining 45 wt-% of the other amount of the first organic compound.

[0147] In a preferred embodiment of the method for producing a first intermediate product, the first polyester enters the volume section V2 via at least one inlet of a first type, wherein at least one or all of the following apply:

[0148] a. at least a portion (e.g. the first portion) of the further amount of the first organic compound, preferably in the form of a gas, enters the volume segment V2 through at least one inlet of another type, wherein the at least one inlet of another type is adapted and arranged such that the flow direction of the further amount of the first organic compound entering through the at least one inlet of another type through the volume segment V2 is at least partially along the transport direction of the first polyester through the volume segment V2;

[0149] b. at least a portion (e.g., another portion) of an additional amount of the first organic compound, preferably in liquid form, enters the volume segment V2 through at least one further type of inlet, wherein the at least one further type of inlet is adjusted and arranged so that the flow direction of the additional amount of the first organic compound entering through the at least one further type of inlet through the volume segment V2 is at least partially opposite to the transport direction of the first polyester through the volume segment V2.

[0150] This preferred embodiment is the 38th embodiment of the present invention, which is preferably dependent on any one of the 1st to 37th embodiments of the present invention.

[0151] In one aspect of the 38th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b. In one aspect of the 38th embodiment, it is preferred that the conveying direction of the first polyester through the volume segment V2 is parallel to the length of the volume segment V2. In one aspect of the 38th embodiment, it is preferred that the conveying direction of the first polyester through the volume segment V2 is at least partially opposite to the direction of gravity. In this aspect, it is more preferred that the conveying direction is opposite to the direction of gravity. In one aspect of the 38th embodiment, it is preferred that the portion in feature a. is a first portion of an additional amount of the first organic compound. In one aspect of the 38th embodiment, it is preferred that the portion in feature b. is another portion of an additional amount of the first organic compound.

[0152] In a preferred embodiment of the method for producing a first intermediate product, at least one or all of the following apply to volume segment V2:

[0153] a. The pressure is in the range of 80 kPa to 135 kPa, more preferably in the range of 95 kPa to 120 kPa, further preferably in the range of 100 kPa to 115 kPa, even further preferably in the range of 104 kPa to 109 kPa;

[0154] b. The overpressure range is 2 kPa to 12 kPa, more preferably 4 kPa to 8 kPa, and further preferably 5 kPa to 7 kPa.

[0155] This preferred embodiment is the 39th embodiment of the present invention, which is preferably dependent on any one of the 1st to 38th embodiments of the present invention.

[0156] In one aspect of the 39th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b.

[0157] In a preferred embodiment of the method for producing the first intermediate product, the residence time of the first polyester in the volume section V2 is in the range of 30 minutes to 270 minutes, more preferably in the range of 50 minutes to 250 minutes, and further preferably in the range of 80 minutes to 220 minutes. This preferred embodiment is the 40th embodiment of the present invention, which preferably depends on any one of the 1st to 39th embodiments of the present invention.

[0158] In a preferred embodiment of the method for producing a first intermediate product, the method further comprises the step of reducing at least one or all of the following, preferably in the volume segment V2:

[0159] a. the weight average molar mass of the first polyester;

[0160] b. The intrinsic viscosity of the first polyester.

[0161] This preferred embodiment is the 41st embodiment of the present invention, which is preferably dependent on any one of the 1st to 40th embodiments of the present invention.

[0162] In one aspect of the 41st embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b. In one aspect of the 41st embodiment, at least one or all of steps a. and b. in the 41st embodiment are preferably performed before contacting the first polyester with another organic compound.

[0163] In a preferred embodiment of the method for producing the first intermediate product, at least one or all of the following apply:

[0164] a. The weight-average molar mass of the first polyester is preferably reduced by at least 50% in the volume segment V2, more preferably at least 60%, even more preferably at least 70%, further preferably at least 75%, even further preferably at least 80%, particularly preferably at least 85%;

[0165] b. The intrinsic viscosity of the first polyester is preferably reduced by at least 40%, more preferably at least 50%, even more preferably at least 60%, further preferably at least 70%, further preferably at least 75% in volume segment V2.

[0166] This preferred embodiment is the 42nd embodiment of the present invention, which is preferably dependent on the 41st embodiment of the present invention.

[0167] In one aspect of the 42nd embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b. In one aspect of the 42nd embodiment, it is preferred that the intrinsic viscosity of the first polyester is reduced by 97% or less, more preferably 95% or less, even more preferably 93% or less, and further preferably 90% or less. In one aspect of the 42nd embodiment, it is preferred that the intrinsic viscosity of the first polyester is reduced by a value in the range of 70% to 80%. In one aspect of the 42nd embodiment, it is preferred that the weight average molar mass of the first polyester is reduced by 97% or less, more preferably 95% or less, and further preferably 93% or less. In one aspect of the 42nd embodiment, it is preferred to reduce the weight average molar mass of the first polyester by a value in the range of 85% to 93%.

[0168] In a preferred embodiment of the process for producing a first intermediate product, after completion of the reducing step, preferably in volume section V2, the first polyester has at least one or all of the following properties:

[0169] a. an intrinsic viscosity in the range of 0.08 dL / g to 0.45 dL / g, more preferably in the range of 0.10 dL / g to 0.35 dL / g, even more preferably in the range of 0.12 dL / g to 0.25 dL / g, and further preferably in the range of 0.12 dL / g to 0.20 dL / g;

[0170] b. The weight average molar mass is in the range of 3000 Da to 7500 Da, more preferably in the range of 3200 Da to 7300 Da, even more preferably in the range of 3800 Da to 7100 Da, and further preferably in the range of 4000 Da to 6900 Da.

[0171] This preferred embodiment is the 43rd embodiment of the present invention, which is preferably dependent on any one of the 41st to 42nd embodiments of the present invention.

[0172] In one aspect of the 43rd embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. Such combinations are, for example, a; b; a+b. In one aspect of the 43rd embodiment, preferred properties a. and b. are properties of the first polyester leaving volume segment V2. In one aspect of the 43rd embodiment, the preferred weight average molar mass is in the range of 4000 Da to 5000 Da.

[0173] In a preferred embodiment of the process for producing a first intermediate product, the first polyester is fed:

[0174] I. / When the first polyester has a value greater than or equal to Y IV,1 When the intrinsic viscosity is , the conveyor is transported in a first direction at least partially opposite to the direction of gravity, wherein Y IV,10.10 dL / g, more preferably 0.15 dL / g, even more preferably 0.20 dL / g, and further preferably 0.30 dL / g; and

[0175] II. / When the first polyester has less than or equal to Y IV,2 When the intrinsic viscosity is at least partially in the direction of gravity, the transport direction Y IV,2 It is 0.09 dL / g, more preferably 0.07 dL / g, and even more preferably 0.05 dL / g.

[0176] This preferred embodiment is the 44th embodiment of the present invention, and is preferably subordinate to any one of the 1st to 43rd embodiments of the present invention.

[0177] In the 44th embodiment, Y 1,IV >Y 2,IV In one aspect of the 44th embodiment, the term "delivery" is preferably understood to mean at least one or all of the following:

[0178] The first polyester is transported from the first volume segment to another volume segment (e.g., transported from volume segment V1 to volume segment V2, and transported from volume segment V2 to volume segment V3), and the first polyester is transported to pass through the volume segments (e.g., volume segment V1, volume segment V3). In one aspect of the 44th embodiment, it is preferred to first transport the first polyester to a first direction and then transport the first polyester to another direction. In one aspect of the 44th embodiment, it is preferred to transport the first polyester to the first direction after contacting the first polyester with a first amount of a first organic compound in volume segment V1. In one aspect of the 44th embodiment, when the intrinsic viscosity of the first polyester is at Y 2,IV To Y 1,IV In one aspect of the 44th embodiment, when the first polyester is transported in the first direction, at least a portion of the organic compound (preferably the first organic compound) is transported in the reverse direction of the first direction. In one aspect of the 44th embodiment, when the first polyester is transported in the other direction, at least a portion of the organic compound (preferably the other organic compound) is transported in the other direction. In one aspect of the 44th embodiment, Y IV,1 and Y IV,2 One of the following combinations of values ​​in features I. / and II. / : Y IV,1 is 0.10dL / g and Y IV,2 0.09dL / g; Y IV,1 0.15dL / g, Y IV,2 0.07dL / g; Y IV,1 0.20dL / g, Y IV,2 0.05dL / g; Y IV,10.30dL / g, Y IV,2 0.05dL / g; Y IV,1 0.10dL / g, Y IV,2 0.05 dL / g; or Y IV,1 0.30dL / g, Y IV,2 0.09 dL / g. In one aspect of the 44th embodiment, the transporting of the first polyester along the first direction preferably comprises at least one or all of the following: transporting from volume segment V1 to volume segment V2, transporting through volume segment V2, or both. In one aspect of the 44th embodiment, the transporting of the first polyester along another direction preferably comprises transporting through volume segment V3. In one aspect of the 44th embodiment, the first polyester is preferably in the form of a plurality of fragments.

[0179] In a preferred embodiment of the method for producing the first intermediate product, the method further comprises the step of conveying the first polyester to volume section V3. This preferred embodiment is the 45th embodiment of the present invention, which preferably depends on any one of the 1st to 44th embodiments of the present invention.

[0180] In one aspect of the 45th embodiment, the first polyester is preferably conveyed from volume segment V1 to volume segment V3, more preferably via volume segment V2. In other words, the first polyester can be conveyed from volume segment V1 to volume segment V3 without the first polyester passing through volume segment V2. However, it is more preferred that the first polyester is conveyed from volume segment V2 to volume segment V3.

[0181] In a preferred embodiment of the method for producing a first intermediate product, the other organic compound has at least one or all of the following characteristics:

[0182] a. comprising at least two hydroxyl groups, for example a diol having 2 hydroxyl groups, a triol having 3 hydroxyl groups;

[0183] b. The molar mass is at least 60 g / mol;

[0184] c. A boiling point of at least 192°C, more preferably at least 195°C.

[0185] This preferred embodiment is the 46th embodiment of the present invention, which is preferably dependent on any one of the 1st to 45th embodiments of the present invention.

[0186] Examples of the other organic compound include (mono)ethylene glycol, propylene glycol and glycerol. In one aspect of the 46th embodiment, all possible combinations of features a. to c. are preferred aspects of this embodiment. These combinations are, for example, a; b; c; a+b; a+c; b+c; a+b+c. In one aspect of the 46th embodiment, it is particularly preferred that the other organic compound is (mono)ethylene glycol, more preferably monoethylene glycol. In one aspect of the 46th embodiment, it is particularly preferred that the other organic compound is not propylene glycol.

[0187] In a preferred embodiment of the method for producing the first intermediate product, a further initial mixing (preferably in volume section V3) is stirred. This preferred embodiment is the 47th embodiment of the present invention, which preferably depends on any one of the 1st to 46th embodiments of the present invention.

[0188] In one aspect of the 47th embodiment, stirring is preferably performed using a mechanical device designed and arranged for stirring, a non-mechanical device designed and arranged for stirring, or a combination thereof.

[0189] In a preferred embodiment of the method for producing the first intermediate product, preferably at the inlet end of volume section V3, the mass ratio of the first polyester to the other organic compound in the other initial mixture is greater than 1.0. This preferred embodiment is the 48th embodiment of the present invention, which preferably depends on any one of the 1st to 47th embodiments of the present invention.

[0190] In one aspect of the 48th embodiment, the preferred inlet end is the location where the first polyester enters volume section V3.

[0191] In a preferred embodiment of the method for producing a first intermediate product, the temperature of the other initial mixture, preferably in volume section V3, is in the range of 180° C. to 220° C., more preferably in the range of 180° C. to 210° C. This preferred embodiment is the 49th embodiment of the present invention, which preferably depends on any one of the 1st to 48th embodiments of the present invention.

[0192] In a preferred embodiment of the method for producing the first intermediate product, the pressure in the volume section V3 is in the range of 75 kPa to 131 kPa, more preferably in the range of 90 kPa to 116 kPa, further preferably in the range of 95 kPa to 108 kPa, and even further preferably in the range of 98 kPa to 104 kPa. This preferred embodiment is the 50th embodiment of the present invention, which preferably depends on any one of the 45th to 49th embodiments of the present invention.

[0193] In one aspect of the 50th embodiment, preferably, the pressure in volume segment V3 is atmospheric pressure.

[0194] In a preferred embodiment of the method for producing the first intermediate product, the residence time of the other initial mixture in the volume section V3 is in the range of 100 minutes to 560 minutes, more preferably in the range of 140 minutes to 440 minutes, and further preferably in the range of 170 minutes to 380 minutes. This preferred embodiment is the 51st embodiment of the present invention, which preferably depends on any one of the 45th to 50th embodiments of the present invention.

[0195] In a preferred embodiment of the method for producing the first intermediate product, the first intermediate mixture contains at least 70wt-%, more preferably at least 80wt-%, even more preferably at least 85wt-%, further preferably at least 90wt-%, and further preferably at least 94wt-% of the first intermediate product. This preferred embodiment is the 52nd embodiment of the present invention, which preferably depends on any one of the 1st to 51st embodiments of the present invention.

[0196] In the 52nd embodiment, the wt-% is based on the total mass of the first intermediate mixture. In an optional aspect of the 52nd embodiment, the first intermediate mixture comprises a first intermediate product in a range of 70 wt-% to 99 wt-%, optionally in a range of 80 wt-% to 95 wt-%, and optionally in a range of 88 wt-% to 92 wt-%.

[0197] In a preferred embodiment of the method for producing the first intermediate product, at least 40 wt-%, more preferably at least 50 wt-%, even more preferably at least 60 wt-%, further preferably at least 65 wt-%, even further preferably at least 70 wt-% of the first intermediate product is in the form of an oligomer having 2 to 35 repeating units, more preferably 2 to 30 repeating units, even more preferably 2 to 25 repeating units, further preferably 2 to 20 repeating units. This preferred embodiment is the 53rd embodiment of the present invention, which preferably depends on any one of the 1st to 52nd embodiments of the present invention.

[0198] In a 53rd embodiment, the wt-% is based on the total mass of the first intermediate product in the first intermediate mixture. In one aspect of the 53rd embodiment, it is preferred that at least 40 wt-%, more preferably at least 50 wt-%, even more preferably at least 60 wt-%, further preferably at least 65 wt-%, and even further preferably at least 70 wt-% of the first intermediate product is in the form of an oligomer having a number of repeating units in at least one of the following ranges: 3 to 30, 4 to 30, 6 to 30, 8 to 30, 3 to 20, 4 to 20, 6 to 20. In one aspect of the 53rd embodiment, it is preferred that at least 70 wt-% of the oligomer has a number of repeating units in the range of 2 to 35, more preferably in the range of 2 to 30, even more preferably in the range of 2 to 25, and further preferably in the range of 2 to 20. Preferred oligomers include repeating units of ethylene terephthalate. In one aspect of the 53rd embodiment, preferably at least 40 wt-%, more preferably at least 50 wt-%, even more preferably at least 60 wt-%, further preferably at least 65 wt-%, even further preferably at least 70 wt-% of the first intermediate product is in the form of an oligomer, wherein the number of repeating units of the oligomer is in the range of 2 to 15, more preferably in the range of 2 to 12, and further preferably in the range of 2 to 10.

[0199] In a preferred embodiment of the method for producing the first intermediate product, at least one or all of the following apply:

[0200] a. The first intermediate product comprises 30 wt-% or less, more preferably 25 wt-% or less, even more preferably 20 wt-% or less, further preferably 15 wt-% or less, even further preferably 10 wt-% or less of the monomer;

[0201] b. The first intermediate product comprises at least 70 wt-%, more preferably at least 75 wt-%, even more preferably at least 80 wt-%, further preferably at least 85 wt-%, even further preferably at least 90 wt-% of oligomers.

[0202] This preferred embodiment is the 54th embodiment of the present invention, which preferably depends on any one of the 1st to 53rd embodiments of the present invention.

[0203] In the 54th embodiment, the wt-% is based on the total mass of the first intermediate product in the first intermediate mixture. In one aspect of the 54th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b. For example, the first intermediate product comprises 20 wt-% of monomer and 80 wt-% of oligomer. In the 54th embodiment, an example of a monomer is BHET. In the 54th embodiment, an example of an oligomer is a PET oligomer. In an optional aspect of the 54th embodiment, the first intermediate product comprises monomers in the range of 15 wt-% to 30 wt-%, and optionally comprises monomers in the range of 20 wt-% to 25 wt-%. In an optional aspect of the 54th embodiment, the first intermediate product comprises oligomers in the range of 70 wt-% to 85 wt-%, and optionally comprises oligomers in the range of 75 wt-% to 85 wt-%. In one aspect of the 54th embodiment, particularly preferred oligomers have 2 to 10 repeating units.

[0204] In a preferred embodiment of the method for producing the first intermediate product, at least one or all of the following apply:

[0205] a. The first intermediate product comprises at least 20 wt-%, more preferably at least 30 wt-%, even more preferably at least 40 wt-%, further preferably at least 50 wt-%, even further preferably at least 60 wt-% of monomer;

[0206] b. The first intermediate product comprises at least 20 wt-%, preferably at least 30 wt-%, more preferably at least 40 wt-%, and further preferably at least 50 wt-% of oligomers.

[0207] This preferred embodiment is an alternative embodiment of the 54th embodiment of the present invention, which preferably depends on any one of the 1st to 53rd embodiments of the present invention. In one aspect of the present invention, any one of the 55th to 106th embodiments of the present invention preferably depends on this alternative embodiment of the 54th embodiment of the present invention.

[0208] In an alternative 54th embodiment, the wt-% is based on the total mass of the first intermediate product in the first intermediate mixture. In an alternative 54th embodiment, an example of a monomer is BHET. In an alternative 54th embodiment, an example of an oligomer is a PET oligomer. In one aspect of the alternative 54th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b. In a preferred aspect of the alternative 54th embodiment, feature a., the first intermediate product contains monomers in the range of 20 wt-% to 60 wt-%, more preferably monomers in the range of 30 wt-% to 50 wt-%, and further preferably monomers in the range of 35 wt-% to 40 wt-%. In this regard, it is preferred that the remaining wt-% of the first intermediate product consists of oligomers. In an aspect of the alternative 54th embodiment, particularly preferred oligomers have 2 to 10 repeating units.

[0209] In a preferred embodiment of the method for preparing the first intermediate product, the first intermediate product has at least one or all of the following characteristics:

[0210] a. an intrinsic viscosity in the range of 0.010 dL / g to 0.120 dL / g, more preferably in the range of 0.030 dL / g to 0.090 dL / g, further preferably in the range of 0.040 dL / g to 0.070 dL / g, further preferably in the range of 0.045 dL / g to 0.065 dL / g;

[0211] b. The weight average molar mass is in the range of 350Da to 800Da, more preferably in the range of 450Da to 650Da, further preferably in the range of 500Da to 600Da.

[0212] This preferred embodiment is the 55th embodiment of the present invention, which preferably depends on any one of the 1st to 54th embodiments of the present invention.

[0213] In one aspect of the 55th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b.

[0214] In a preferred embodiment of the method for producing the first intermediate product, at least one or all of the following apply:

[0215] a. The first intermediate mixture comprises 20 wt-% or less, more preferably 15 wt-% or less, even more preferably 12 wt-% or less, further preferably 10 wt-% or less, even further preferably 8 wt-% or less of another organic compound;

[0216] b. The first intermediate mixture contains less than 15 wt-%, more preferably less than 10 wt-%, and further preferably less than 5 wt-% of a dicarboxylic acid, such as terephthalic acid.

[0217] This preferred embodiment is the 56th embodiment of the present invention, which preferably depends on any one of the 1st to 55th embodiments of the present invention.

[0218] In one aspect of the 56th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b. In the 56th embodiment, the wt-% is based on the total mass of the first intermediate mixture. In one aspect of the 56th embodiment, the other organic compound should preferably be understood as free, i.e., not chemically bound to the first intermediate product by a covalent bond. In an optional aspect of the 56th embodiment, the first intermediate mixture contains another organic compound in the range of 5 wt-% to 20 wt-%, optionally in the range of 7 wt-% to 15 wt-%, optionally in the range of 9 wt-% to 12 wt-%.

[0219] In a preferred embodiment of the method for producing a first intermediate product, the method further comprises the step of conveying the first intermediate mixture, preferably from volume section V3, to volume section V4. This preferred embodiment is the 57th embodiment of the present invention, which preferably depends on any one of the 1st to 56th embodiments of the present invention.

[0220] In one aspect of the 57th embodiment, preferably, the intrinsic viscosity of the first intermediate product increases by less than 5%, more preferably less than 3%, further preferably less than 1%, and even more preferably less than 0.1% in the volume section V4. In another aspect of the 57th embodiment, preferably, the intrinsic viscosity of the first intermediate product decreases by less than 5%, more preferably less than 3%, further preferably less than 1%, and even more preferably less than 0.1% in the volume section V4. In another aspect of the 57th embodiment, preferably, the intrinsic viscosity of the first intermediate product changes (neither increases nor decreases) by less than 5%, more preferably less than 3%, further preferably less than 1%, and even more preferably less than 0.1% in the volume section V4.

[0221] In a preferred embodiment of the method for producing a first intermediate product, the method further comprises the step of adding a first particulate material to the first intermediate mixture, preferably in volume segment V4. This preferred embodiment is the 58th embodiment of the present invention, which preferably depends on any one of the 1st to 57th embodiments of the present invention.

[0222] In one aspect of the 58th embodiment, preferably, the first particulate material is designed and arranged for adsorption. In another aspect of the 58th embodiment, preferably, the first particulate material is designed and arranged for decolorization. In another aspect of the 58th embodiment, preferably, the first particulate material is porous. In one aspect of the 58th embodiment, particularly preferably, the first particulate material is designed and arranged for filtration, more preferably microfiltration. Microfiltration is the filtration of particles in the range of 0.5 μm-10 μm. In one aspect of the 58th embodiment, preferably, the first particulate material is added after the weight average molar mass of the first polyester is reduced.

[0223] In a preferred embodiment of the method for producing the first intermediate product, the median pore size of the first granular material is in the range of 5.0 μm to 20.0 μm, preferably in the range of 10.0 μm to 20.0 μm, and further preferably in the range of 15.0 μm to 18.0 μm. This preferred embodiment is the 59th embodiment of the present invention, which is preferably dependent on the 58th embodiment of the present invention.

[0224] In a preferred embodiment of the method for preparing the first intermediate product, the first particulate material has a pore size distribution in which at least one mode is in the range of 8000nm to 20000nm, more preferably in the range of 10000nm to 18000nm, and further preferably in the range of 10000nm to 15000nm. This preferred embodiment is the 60th embodiment of the present invention, which preferably depends on any one of the 58th to 59th embodiments of the present invention.

[0225] In a preferred embodiment of the method for producing a first intermediate product, the first particulate material has a pore size distribution having at least two modes in the range of 8000 nm and 20000 nm, wherein

[0226] a. at least one mode in the range of 8000nm to 15000nm, preferably in the range of 10000nm to 15000nm;

[0227] b. At least one mode is in the range of >15000nm to 20000nm, preferably in the range of 16000nm to 18000nm.

[0228] This preferred embodiment is the 61st embodiment of the present invention, which preferably depends on any one of the 58th to 60th embodiments of the present invention.

[0229] In one aspect of the 61st embodiment, all possible combinations of features a. and b. are preferred aspects of the embodiment. These combinations are, for example, a; b; a+b. In one aspect of the 61st embodiment, preferably, the mode in feature a. is a secondary mode. In one aspect of the 61st embodiment, preferably, the mode in feature b. is a primary mode.

[0230] In a preferred embodiment of the method for producing a first intermediate product, the first particulate material has a pore size distribution, wherein at least one first mode is in the range of 9000nm to 15000nm, and at least one other mode is in the range of >15000nm to 20000nm, wherein the ratio of the first mode to the other mode is in the range of 0.30 to 1.00, preferably in the range of 0.40 to 0.90, and further preferably in the range of 0.45 to 0.85. This preferred embodiment is the 62nd embodiment of the present invention, which preferably depends on any one of the 58th to 61st embodiments of the present invention.

[0231] In a preferred embodiment of the method for producing a first intermediate product, the first particulate material has at least one or all of the following characteristics:

[0232] a. For pores with diameters between 9000nm and 20000nm, the cumulative pore volume is 0.6cm 3 / g to 1.9cm 3 / g range, preferably within 0.9cm 3 / g to 1.7cm 3 / g range, more preferably within 1.1cm 3 / g to 1.5cm 3 / g range;

[0233] b. For pores with diameters between 10000nm and 15000nm, the cumulative pore volume is 0.5cm 3 / g to 1.4cm 3 / g range, preferably within 0.6cm 3 / g to 1.2cm 3 / g range, more preferably 0.8cm 3 / g to 1.0cm 3 / g range;

[0234] c. And for pores with diameters in the range of >15000nm to 20000nm, the cumulative pore volume is 0.10cm 3 / g to 0.80cm 3 / g range, preferably within 0.20cm 3 / g to 0.60cm 3 / g, more preferably within 0.25cm 3 / g to 0.40cm 3 / g range.

[0235] This preferred embodiment is the 63rd embodiment of the present invention, which preferably depends on any one of the 58th to 62nd embodiments of the present invention.

[0236] In one aspect of the 63rd embodiment, all possible combinations of features a. to c. are preferred aspects of this embodiment. These combinations are, for example, a; b; c; a+b; a+c; b+c; a+b+c.

[0237] In a preferred embodiment of the method for producing a first intermediate product, the first particulate material has at least one or all of the following characteristics:

[0238] a. a permeability in the range of 0.7 Darcy to 10.0 Darcy, preferably in the range of 1.5 Darcy to 7.5 Darcy, more preferably in the range of 3.0 Darcy to 5.0 Darcy, and further preferably in the range of 3.5 Darcy to 4.5 Darcy;

[0239] b. The median particle size is in the range of 25 mm to 60 mm, preferably in the range of 35 mm to 55 mm, more preferably in the range of 40 mm to 50 mm, and further preferably in the range of 43 mm to 50 mm.

[0240] This preferred embodiment is the 64th embodiment of the present invention, which preferably depends on any one of the 58th to 63rd embodiments of the present invention.

[0241] In one aspect of the 64th embodiment, all possible combinations of features a and b are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b.

[0242] In a preferred embodiment of the method for producing the first intermediate product, the first particulate material is selected from activated carbon (e.g., activated carbon), activated clay, diatomaceous earth, perlite, bentonite, cellulose, and a combination of at least two thereof. This preferred embodiment is the 65th embodiment of the present invention, which preferably depends on any one of the 58th to 64th embodiments of the present invention.

[0243] In one aspect of the 65th embodiment, it is particularly preferred that the first particulate material is diatomaceous earth.

[0244] In a preferred embodiment of the method for preparing the first intermediate product, the mass ratio of the first particulate material to the first intermediate mixture in the volume segment V4 is 5.0×10 -4 Up to 2.5x10 -3 range, more preferably within 1.0x10 -3 Up to 2.0x10 -3 range, and more preferably within 1.2x10 -3 Up to 1.8x10 -3 This preferred embodiment is the 66th embodiment of the present invention, which preferably depends on any one of the 58th to 65th embodiments of the present invention.

[0245] In a preferred embodiment of the method for producing a first intermediate product, the temperature of the first intermediate mixture in volume segment V4 is in the range of 160° C. to 230° C., more preferably in the range of 170° C. to 220° C., even more preferably in the range of 180° C. to 215° C., further preferably in the range of 185° C. to 209° C., even further preferably in the range of 190° C. to 205° C. This preferred embodiment is the 67th embodiment of the present invention, which preferably depends on any one of the 57th to 66th embodiments of the present invention.

[0246] In a preferred embodiment of the method for producing a first intermediate product, the first intermediate mixture in volume segment V4 is stirred. This preferred embodiment is the 68th embodiment of the present invention, which preferably depends on any one of the 57th to 67th embodiments of the present invention.

[0247] In one aspect of the 68th embodiment, the first intermediate mixture is preferably agitated using a mechanical device designed and arranged for agitation.

[0248] In a preferred embodiment of the method for preparing the first intermediate product, the residence time of the first intermediate mixture in the volume section V4 is 10 hours or less, more preferably 7 hours or less, and further preferably 5 hours or less. This preferred embodiment is the 69th embodiment of the present invention, which preferably depends on any one of the 57th to 68th embodiments of the present invention.

[0249] In an optional aspect of the 69th embodiment, the residence time of the first intermediate mixture in the volume segment V4 is at least 0.1 hours, optionally at least 1 hour, optionally at least 3.5 hours.

[0250] In a preferred embodiment of the method for producing a first intermediate product, the method further comprises the step of conveying the first intermediate mixture to a filtering device, preferably conveying from volume section V4. This preferred embodiment is the 70th embodiment of the present invention, which preferably depends on any one of the 1st to 69th embodiments of the present invention.

[0251] In a preferred embodiment of the method for producing the first intermediate product, the filtering device is selected from a leaf filter, a sheet clarifier, a candle filter, a porous filter, a sintered filter, a wire mesh, a rotary drum filter, and a combination of two or more thereof. This preferred embodiment is the 71st embodiment of the present invention, which is preferably dependent on the 70th embodiment of the present invention.

[0252] In one aspect of the 71st embodiment, the preferred filtering device is a leaf filter, more preferably a vertical leaf filter.

[0253] In a preferred embodiment of the method for producing the first intermediate product, the pressure in the filtration device is in the range of 80 kPa to 1000 kPa, more preferably in the range of 140 kPa to 800 kPa, even more preferably in the range of 170 kPa to 610 kPa, and further preferably in the range of 200 kPa to 545 kPa. This preferred embodiment is the 72nd embodiment of the present invention, which preferably depends on any one of the 70th to 71st embodiments of the present invention.

[0254] In a preferred embodiment of the method for producing the first intermediate product, the temperature in the filtration device is in the range of 150° C. to 215° C., more preferably in the range of 160° C. to 205° C., even more preferably in the range of 165° C. to 200° C., and further preferably in the range of 170° C. to 195° C. This preferred embodiment is the 73rd embodiment of the present invention, which preferably depends on any one of the 70th to 72nd embodiments of the present invention.

[0255] In a preferred embodiment of the method for producing the first intermediate product, the method further comprises a step of pre-coating the filter device, preferably using the first granular material. This preferred embodiment is the 74th embodiment of the present invention, which preferably depends on any one of the 70th to 73rd embodiments of the present invention.

[0256] In one aspect of the 74th embodiment, a pre-coating step is preferably performed prior to at least partially removing at least one or all of: at least one impurity, the first particulate material.

[0257] In a preferred embodiment of the method for producing the first intermediate product, the method further comprises a step of at least partially removing at least one impurity from the first intermediate mixture, preferably using a filtering device. This preferred embodiment is the 75th embodiment of the present invention, which preferably depends on any one of the 1st to 74th embodiments of the present invention.

[0258] In one aspect of the 75th embodiment, the first particulate material is preferably at least partially removed from the first intermediate mixture, more preferably using a filtering device. For example, at least one impurity and the first particulate material are at least partially removed. In one aspect of the 75th embodiment, the particles (e.g., at least one impurity, the first particulate material) preferably removed have a particle size greater than 100 nm, more preferably greater than 150 nm, and further preferably greater than 200 nm. In one aspect of the 75th embodiment, preferably, the particles (e.g., at least one impurity, the first particulate material) removed have a particle size of 50 mm or less, more preferably 20 mm or less, even more preferably 10 mm or less, and further preferably 5 mm or less.

[0259] In a preferred embodiment of the method for producing a first intermediate product, the method further comprises the step of conveying the first intermediate mixture to volume section V5. This preferred embodiment is the 76th embodiment of the present invention, which preferably depends on any one of the 1st to 75th embodiments of the present invention.

[0260] In one aspect of the 76th embodiment, it is preferred that the first intermediate mixture is conveyed from volume segment V3 to volume segment V5. However, it is more preferred that the first intermediate mixture is conveyed from volume segment V3 to volume segment V5 via at least one or all of the following: volume segment V4, filtering device. In this aspect, it is particularly preferred that the first intermediate mixture is conveyed from the filtering device to volume segment V5.

[0261] In a preferred embodiment of the method for producing a first intermediate product, the method further comprises a step of adjusting, preferably in volume segment V5, the b value of the Hunter Lab color coordinates of the first intermediate mixture so that b≤0, more preferably b≤-1, and further preferably b≤-2. This preferred embodiment is the 77th embodiment of the present invention, which preferably depends on any one of the 1st to 76th embodiments of the present invention.

[0262] In one aspect of the 77th embodiment, the Hunter Lab color coordinates of the first intermediate mixture are preferably adjusted, preferably in volume segment V5, so that b is in the range of -10 to -3, more preferably in the range of -9 to -4, and further preferably in the range of -8 to -6.

[0263] In a preferred embodiment of the method for producing a first intermediate product, the method further comprises the step of adjusting, preferably in volume segment V5, the L value of the Hunter Lab color coordinates of the first intermediate mixture so that L ≥ 65, more preferably L ≥ 70, and further preferably L ≥ 75. This preferred embodiment is the 78th embodiment of the present invention, which preferably depends on any one of the 1st to 77th embodiments of the present invention.

[0264] In one aspect of the 78th embodiment, the Hunter Lab color coordinates of the first intermediate mixture are preferably adjusted, preferably in volume segment V5, so that L is in the range of 65 to 92, more preferably in the range of 70 to 86, and further preferably in the range of 75 to 82.

[0265] In a preferred embodiment of the method for producing a first intermediate product, the Hunter Lab color coordinates L, b or both are adjusted by adding at least one colorant to the first intermediate mixture, preferably in volume segment V5. This preferred embodiment is the 79th embodiment of the present invention, which preferably depends on any one of the 77th to 78th embodiments of the present invention.

[0266] Suitable colorants are well known to those skilled in the art and are commercially available from Avient Corporation (USA) and Clariant AG (Switzerland).

[0267] In a preferred embodiment of the method for producing a first intermediate product, the amount of the at least one colorant added to the first intermediate mixture is determined by at least one or all of the following:

[0268] a. adding less than 200ppm wt, more preferably less than 100ppm wt, even more preferably less than 50ppm wt, further preferably less than 20ppm wt, even further preferably less than 15ppm wt, and particularly preferably less than 10ppm wt of a red colorant;

[0269] b. adding less than 300ppm wt, more preferably less than 150ppm wt, even more preferably less than 70ppm wt, further preferably less than 30ppm wt, even further preferably less than 20ppm wt, and particularly preferably less than 15ppm wt of a blue colorant;

[0270] c. Adding a red colorant and a blue colorant, wherein the ratio of the red colorant to the blue colorant is in the range of 0.1 to 10.0, more preferably in the range of 0.1 to 6.0, even more preferably in the range of 0.1 to 3.0, further preferably in the range of 0.1 to 1.0, even further preferably in the range of 0.3 to 0.8, and particularly preferably in the range of 0.4 to 0.7.

[0271] This preferred embodiment is the 80th embodiment of the present invention, which is preferably dependent on the 79th embodiment of the present invention.

[0272] In the 80th embodiment, the ppm mass value is based on the total mass of the first intermediate mixture. In one aspect of the 80th embodiment, all possible combinations of features a. to c. are preferred aspects of this embodiment. These combinations are, for example, a; b; c; a+b; a+c; b+c; a+b+c. In one aspect of the 80th embodiment, feature a., optionally at least 1 ppm wt, optionally at least 2 ppm wt, optionally at least 3 ppm wt of red colorant is added. In one aspect of the 80th embodiment, feature b., optionally at least 0.8 ppm wt, optionally at least 1.8 ppm wt, optionally at least 2.7 ppm wt of blue colorant is added. In the 80th embodiment, in feature c., the ratio of red colorant to blue colorant is calculated by dividing the ppm wt of the added red colorant by the ppm wt of the added blue colorant. In a preferred aspect of the 80th embodiment, feature c., both the red colorant and the blue colorant are added before any colorant is added, and the L value of the first intermediate mixture is preferably in the range of 80 to 90, more preferably in the range of 82 to 88. In a preferred aspect of the 80th embodiment, feature c., both the red colorant and the blue colorant are added before any colorant is added, and the b value of the first intermediate mixture is preferably in the range of 0.8 to 2.0, more preferably in the range of 1 to 2.

[0273] In a preferred embodiment of the method for producing the first intermediate product, at least one colorant is selected from a dye, a toner, a pigment and a combination of at least two. This preferred embodiment is the 81st embodiment of the present invention, which preferably depends on any one of the 79th to 80th embodiments of the present invention.

[0274] In one aspect of the 81st embodiment, it is particularly preferred that at least one colorant is a pigment, a dye, or a combination thereof. In this regard, pigments are more preferred than dyes. In another aspect of the 81st embodiment, it is preferred that at least one colorant is not an acid dye. In another aspect of the 81st embodiment, it is preferred that at least one colorant is a pigment having a particle size of less than 20 microns, more preferably less than 10 microns, even more preferably less than 1 micron, and further preferably less than 0.5 microns.

[0275] In a preferred embodiment of the method for producing the first intermediate product, the intrinsic viscosity of the first intermediate product increases by less than 5%, more preferably less than 3%, further preferably less than 1%, even further preferably less than 0.1% in the volume section V4. In a preferred embodiment of the method for producing the first intermediate product, the intrinsic viscosity of the first intermediate product decreases by less than 5%, more preferably less than 3%, further preferably less than 1%, even further preferably less than 0.1% in the volume section V4. In a preferred embodiment of the method for producing the first intermediate product, the intrinsic viscosity of the first intermediate product changes (neither increases nor decreases) by less than 5%, more preferably less than 3%, further preferably less than 1%, even further preferably less than 0.1% in the volume section V4.

[0276] The 82nd embodiment of the present invention is a method for producing another intermediate product, comprising the following steps:

[0277] a. providing a first intermediate mixture comprising a first intermediate product, wherein the first intermediate product can be obtained by a method for producing a first intermediate product according to the present invention, preferably a method according to any one of Embodiments 1 to 81 of the present invention;

[0278] b. Increasing the weight average molar mass of the first intermediate product in the first intermediate mixture, preferably in volume segment V6, to obtain another intermediate mixture comprising another intermediate product.

[0279] In an optional aspect of the 82nd embodiment, the first intermediate mixture comprises at least one or all of the following: a first organic compound, another organic compound. The first organic compound and / or another organic compound in the other intermediate mixture may exist due to, for example, one of the following reasons: the first organic compound and / or another organic compound are transported from another volume segment (e.g., volume segment V5) to volume segment V6; the first organic compound and / or another organic compound are bound and released during the increase in weight-average molar mass. In another optional aspect of the 82nd embodiment, the other intermediate mixture comprises at least one or all of the following: a first organic compound, another organic compound. In one aspect of the 82nd embodiment, it is preferred that at least one or all of the following: a first organic compound, another organic compound are at least partially removed in volume segment V6. In another aspect of the 82nd embodiment, it is preferred that the other intermediate mixture comprises less than 1 wt-%, more preferably less than 0.1 wt-%, and further preferably less than 0.01 wt-% of at least one or all of the following: a first organic compound, another organic compound, based on the total mass of the other intermediate mixture. In one aspect of the 82nd embodiment, it is preferred to use less than 20 wt-%, more preferably less than 10 wt-%, even more preferably less than 5 wt-%, and further preferably less than 1 wt-% of the original product to obtain another intermediate product. The wt-% is based on the total mass of the first intermediate mixture. Here, the original product has the following characteristics: a.) It is a monomer, an oligomer, a polymer or a combination thereof, preferably a first polyester; b.) It is obtained by chemical synthesis, wherein the chemical synthesis does not include depolymerization and solvent decomposition. An example of the original product is a BHET monomer obtained by esterification of terephthalic acid with ethylene glycol.

[0280] In a preferred embodiment of the method for producing a further intermediate product, the first intermediate mixture is provided by conveying the first intermediate mixture to volume section V6. This preferred embodiment is the 83rd embodiment of the present invention, which preferably depends on the 82nd embodiment of the present invention.

[0281] In one aspect of the 83rd embodiment, it is preferred that the first intermediate mixture is conveyed from volume segment V3 to volume segment V6. However, it is more preferred that the first intermediate mixture is conveyed from volume segment V3 to volume segment V6 via at least one or all of the following: volume segment V4, filtering device, volume segment V5. In this aspect, it is particularly preferred that the first intermediate mixture is conveyed from volume segment V5 to volume segment V6.

[0282] In a preferred embodiment of the method for producing another intermediate product, at least one or all of the following substances are added to the first intermediate mixture:

[0283] a. an amount of catalyst in the range of 20 ppm to 600 ppm, more preferably in the range of 30 ppm to 500 ppm, and further preferably in the range of 40 ppm to 400 ppm;

[0284] b. An amount of stabilizer in the range of 1 ppm to 120 ppm, more preferably in the range of 5 ppm to 100 ppm, even more preferably in the range of 10 ppm to 80 ppm, further preferably in the range of 20 ppm to 60 ppm.

[0285] This preferred embodiment is the 84th embodiment of the present invention, which preferably depends on any one of the 82nd to 83rd embodiments of the present invention.

[0286] In the 84th embodiment, the ppm value is based on the total mass of the first intermediate mixture. In one aspect of the 84th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b. In one aspect of the 84th embodiment, the preferred catalyst is Sb2O3, tetrabutoxytitanium, PTO (K2TiO(C2H4)2*2H2O), or a combination of at least two thereof. In this respect, Sb2O3 is particularly preferred. In one aspect of the 84th embodiment, at least one or all of the following is preferably applied: adding a catalyst before the first intermediate mixture enters volume segment V6; adding the catalyst to the first intermediate mixture in volume segment V6, preferably before increasing the weight-average molar mass of the first intermediate product. In one aspect of the 84th embodiment, the preferred stabilizer is diphenylamine, 4-aminobenzoic acid, orthophosphoric acid, or a combination of at least two thereof. In one aspect of the 84th embodiment, at least one or all of the following is preferably applied: adding a stabilizer before the first intermediate mixture enters volume segment V6; preferably adding the stabilizer to the first intermediate mixture in volume segment V6 before increasing the weight-average molar mass of the first intermediate product.

[0287] In a preferred embodiment of the method for producing a further intermediate product, at least one or all of the following apply to volume segment V6:

[0288] a. a temperature in the range of 260°C to 295°C, more preferably in the range of 268°C to 289°C, and further preferably in the range of 272°C to 285°C;

[0289] b. The pressure is equal to or less than 3.7 kPa, more preferably equal to or less than 3.3 kPa, and further preferably equal to or less than 2.8 kPa.

[0290] This preferred embodiment is the 85th embodiment of the present invention, which preferably depends on any one of the 83rd to 84th embodiments of the present invention.

[0291] In one aspect of the 85th embodiment, all possible combinations of features a. and b. are preferred aspects of the embodiment. These combinations are, for example, a; b; a+b. In one aspect of the 85th embodiment, the preferred pressure is in the range of 0.01 kPa to 3.70 kPa, more preferably in the range of 0.05 kPa to 3.30 kPa, and further preferably in the range of 0.10 kPa to 2.80 kPa.

[0292] In a preferred embodiment of the method for producing another intermediate product, the residence time of the first intermediate mixture in volume segment V6 is less than 750 minutes, more preferably less than 500 minutes, even more preferably less than 350 minutes, and further preferably less than 200 minutes. This preferred embodiment is the 86th embodiment of the present invention, which preferably depends on any one of the 83rd to 85th embodiments of the present invention.

[0293] In one aspect of the 86th embodiment, it is preferred that the residence time of the first intermediate mixture in the volume segment V6 is 40 minutes or longer, more preferably 70 minutes or longer, and further preferably 150 minutes or longer.

[0294] In a preferred embodiment of the method for producing a further intermediate product, the further intermediate product, preferably the further intermediate product leaving the volume segment V6, has at least one or all of the following properties:

[0295] a. an intrinsic viscosity in the range of 0.15 dL / g to 0.45 dL / g, more preferably in the range of 0.18 dL / g to 0.40 dL / g, and further preferably in the range of 0.20 dL / g to 0.30 dL / g;

[0296] b. The weight average molar mass is in the range of 5000 Da to 30000 Da, more preferably in the range of 9000 Da to 24000 Da, even more preferably in the range of 12000 Da to 20000 Da, and further preferably in the range of 14000 Da to 16500 Da.

[0297] This preferred embodiment is the 87th embodiment of the present invention, which preferably depends on any one of the 82nd to 86th embodiments of the present invention.

[0298] In one aspect of the 87th embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b.

[0299] In a preferred embodiment of the method for producing another intermediate product, the method further comprises the step of conveying another intermediate mixture, preferably from volume segment V6 to volume segment V7. This preferred embodiment is the 88th embodiment of the present invention, which preferably depends on any one of the 82nd to 87th embodiments of the present invention.

[0300] In a preferred embodiment of the method for producing another intermediate product, the method further comprises a step of further increasing the weight average molar mass of another intermediate product in another intermediate mixture, preferably in volume segment V7. This preferred embodiment is the 89th embodiment of the present invention, which preferably depends on any one of the 82nd to 88th embodiments of the present invention.

[0301] In a preferred embodiment of the method for producing a further intermediate product, at least one or all of the following apply to volume segment V7:

[0302] a. a temperature in the range of 240°C to 310°C, more preferably in the range of 258°C to 298°C, and further preferably in the range of 264°C to 288°C;

[0303] b. The pressure is equal to or less than 0.4 kPa, more preferably equal to or less than 0.35 kPa, and further preferably equal to or less than 0.32 kPa.

[0304] This preferred embodiment is the 90th embodiment of the present invention, which preferably depends on any one of the 88th to 89th embodiments of the present invention.

[0305] In one aspect of the 90th embodiment, all possible combinations of features a. and b. are preferred aspects of the embodiment. These combinations are, for example, a; b; a+b. In one aspect of the 90th embodiment, the temperature given in the preferred embodiment is the temperature measured at the inlet of volume segment V7, more preferably the temperature measured at the inlet of another intermediate mixture into volume segment V7. In one aspect of the 90th embodiment, the preferred pressure is in the range of 0.001 kPa to 0.400 kPa, more preferably in the range of 0.005 kPa to 0.350 kPa.

[0306] In a preferred embodiment of the method for producing another intermediate product, the residence time of the other intermediate mixture in volume segment V7 is less than 300 minutes, more preferably less than 200 minutes, even more preferably less than 150 minutes, and further preferably less than 100 minutes. This preferred embodiment is the 91st embodiment of the present invention, which preferably depends on any one of the 88th to 90th embodiments of the present invention.

[0307] In an aspect of the 91st embodiment, preferably, the residence time of the another intermediate mixture in the volume segment V7 is 10 minutes or longer, more preferably 25 minutes or longer, and further preferably 40 minutes or longer.

[0308] In a preferred embodiment of the method for producing a further intermediate product, the further intermediate product, preferably the further intermediate product leaving the volume segment V7, has at least one or all of the following properties:

[0309] a. an intrinsic viscosity in the range of 0.50 dL / g to 0.80 dL / g, more preferably in the range of 0.57 dL / g to 0.75 dL / g, and further preferably in the range of 0.62 dL / g to 0.67 dL / g;

[0310] b. The weight average molar mass is in the range of 40000 Da to 60000 Da, more preferably in the range of 44000 Da to 54000 Da, and further preferably in the range of 46000 Da to 52000 Da.

[0311] This preferred embodiment is the 92nd embodiment of the present invention, which preferably depends on any one of the 82nd to 91st embodiments of the present invention, and more preferably is based on any one of the 88th to 91st embodiments of the present invention.

[0312] In one aspect of the 92nd embodiment, all possible combinations of features a. and b. are preferred aspects of this embodiment. These combinations are, for example, a; b; a+b.

[0313] In a preferred embodiment of the method for producing another intermediate product, the method further comprises a step of at least partially removing at least one organic compound, preferably in volume segment V6, volume segment V7 or both. This preferred embodiment is the 93rd embodiment of the present invention, which preferably depends on any one of the 82nd to 92nd embodiments of the present invention.

[0314] In one aspect of the 93rd embodiment, it is preferred that the at least one organic compound is at least one or all of the following: a first organic compound, another organic compound. In another aspect of the 93rd embodiment, it is preferred that the at least one organic compound is at least partially removed from at least one or all of the following: a first intermediate mixture and another intermediate mixture. In another aspect of the 93rd embodiment, it is preferred that the first organic compound is at least partially removed by flash distillation. In one aspect of the 93rd embodiment, it is preferred that the at least one organic compound is at least partially removed simultaneously with at least one or all of the following: increasing the weight average molar mass of the first intermediate product, and increasing the weight average molar mass of another intermediate product.

[0315] In a preferred embodiment of the method for producing another intermediate product, the other intermediate product is another polyester. This preferred embodiment is the 94th embodiment of the present invention, which preferably depends on any one of the 82nd to 93rd embodiments of the present invention.

[0316] In a preferred embodiment of the method for producing another intermediate product, the other polyester is selected from polyethylene terephthalate, polybutylene terephthalate, polylactide, polytrimethylene terephthalate, polyethylene naphthalate, polycarbonate, polyester carbonate, polyarylate, polyester resin (preferably unsaturated polyester resin) and a combination of two or more thereof. This preferred embodiment is the 95th embodiment of the present invention, which is preferably dependent on the 94th embodiment of the present invention.

[0317] In one aspect of the 95th embodiment, it is particularly preferred that the other polyester is polyethylene terephthalate.

[0318] In a preferred embodiment of the method for producing another intermediate product, the other intermediate product is in the form of a liquid (e.g., a melt or a molten polymer), a particle, or a combination thereof. This preferred embodiment is the 96th embodiment of the present invention, which preferably depends on any one of the 82nd to 95th embodiments of the present invention.

[0319] In one aspect of the 96th embodiment, the particles are generally referred to as chips. In one aspect of the 96th embodiment, the particles are preferably obtained by extruding and cooling a hot melt.

[0320] In a preferred embodiment of the method for producing another intermediate product, the other intermediate product undergoes at least one processing step to obtain a product. This preferred embodiment is the 97th embodiment of the present invention, which preferably depends on any one of the 82nd to 96th embodiments of the present invention.

[0321] In one aspect of the 97th embodiment, it is preferred that the further intermediate product undergoes at least one processing step downstream of volume section V6, more preferably downstream of volume section V7.

[0322] In a preferred embodiment of the method for producing another intermediate product, at least one processing step comprises at least one or all of the following: cooling, spinning, texturing, coloring (preferably by adding at least one colorant), melting, injection molding, blow molding, coating (preferably spin coating), cutting, extrusion, or a combination of at least two thereof. This preferred embodiment is the 98th embodiment of the present invention, which is preferably dependent on the 97th embodiment of the present invention.

[0323] The 99th embodiment of the present invention is a first intermediate product obtainable by the method for producing a first intermediate product according to the present invention, preferably the method according to any one of the 1st to 81st embodiments of the present invention.

[0324] The 100th embodiment of the present invention is another intermediate product obtainable by a method for producing another intermediate product according to the present invention, preferably a method according to any one of the 82nd to 98th embodiments of the present invention.

[0325] In one aspect of the 100th embodiment, the other intermediate product is preferably another polyester.

[0326] In a preferred embodiment of the further intermediate product, the further intermediate product has at least one or all of the following characteristics:

[0327] a. a weight average molar mass in the range of 40000Da to 100000Da, more preferably in the range of 44000Da to 80000Da, and further preferably in the range of 48000Da to 60000Da;

[0328] b. an intrinsic viscosity in the range of 0.50 dL / g to 0.80 dL / g, more preferably in the range of 0.57 dL / g to 0.75 dL / g, and further preferably in the range of 0.62 dL / g to 0.67 dL / g;

[0329] c. In Hunter Lab color coordinates, the L value is at least 48 and the b value is 6 or less.

[0330] This preferred embodiment is the 101st embodiment of the present invention, which is preferably dependent on the 100th embodiment of the present invention.

[0331] In one aspect of the 101st embodiment, all possible combinations of features a. to c. are preferred aspects of this embodiment. These combinations are, for example, a; b; c; a+b; a+c; b+c; a+b+c. In one aspect of the 101st embodiment, feature c., it is preferred that the other intermediate product has an L value in the range of 45 to 75 in Hunter Lab color coordinates, more preferably in the range of 50 to 70, and further preferably in the range of 55 to 65. In one aspect of the 101st embodiment, feature c., it is preferred that the other intermediate product has a b value in the range of 0 to 6 in Hunter Lab color coordinates, more preferably in the range of 1 to 5, and further preferably in the range of 2 to 4.

[0332] The 102nd embodiment of the present invention is a product comprising another intermediate product according to the present invention, preferably another intermediate product according to any one of the 100th to 101st embodiments of the present invention.

[0333] In a preferred embodiment of the product, the product is selected from yarn, textile, shaped article (e.g., bottle), molding material, film, sheet, granule, composite material, foam, fiber, lubricant, adhesive, thickener, suspending agent, flocculant, resin, plastic, coating, building material, absorbent material, medicine, material for controlled release of active substance, powder and a combination of at least two or more thereof. This preferred embodiment is the 103rd embodiment of the present invention, which is preferably dependent on the 102nd embodiment of the present invention.

[0334] In one aspect of the 103rd embodiment, it is particularly preferred that the product is a yarn, more preferably a yarn for textiles. Examples of yarns include fully stretched yarns, stretched textured yarns, and partially oriented yarns.

[0335] In a preferred embodiment of the product, the product has at least one or all of the following characteristics:

[0336] a. In the Hunter Lab color coordinates, the L value is at least 62, more preferably at least 68, and further preferably at least 73;

[0337] b. In the Hunter Lab color coordinates, the b value is at least 1, more preferably at least 2, and further preferably at least 3;

[0338] c. The tensile strength is 1.5 g / Denier or more, preferably 2.0 g / Denier or more, and further preferably 2.5 g / Denier or more;

[0339] d. a weight average molar mass in the range of 40,000 Da to 100,000 Da, more preferably in the range of 44,000 Da to 80,000 Da, further preferably in the range of 48,000 Da to 60,000 Da;

[0340] e. an intrinsic viscosity in the range of 0.50 dL / g to 0.80 dL / g, more preferably in the range of 0.57 dL / g to 0.75 dL / g, further preferably in the range of 0.62 dL / g to 0.67 dL / g;

[0341] f. The elongation is in the range of 5% to 175%, more preferably in the range of 10% to 150%, further preferably in the range of 20% to 125%.

[0342] This preferred embodiment is the 104th embodiment of the present invention, which preferably depends on any one of the 102nd to 103rd embodiments of the present invention.

[0343] In one aspect of the 104th embodiment, all possible combinations of features a. to f. are preferred aspects of the embodiment. These combinations are, for example, a; b; c; d; e; f; a+b; a+c; a+d; a+e; a+f; b+c; b+d; b+e; b+f; c+d; c+e; c+f; d+e; d+f; e+f; a+b+c; a+b+d; a+b+e; a+b+f; a+c+d; a+c+e; a+c+f; a+d+e; a+d+f; a+e+f; b+c+d; b+c+e; b+c+f; b+d+e; b+d+f; b+e+f; c+d+e; c+d+f; c+e+f; d+ e+f;a+b+c+d;a+b+c+e;a+b+c+f;a+b+d+e;a+b+d+f;a+b+e+f;a+c+d+e;a+c+d+f;a+c+e+f;a+d+e+f;b+c+d+e;b+c+d+ f; b+c+e+f; b+d+e+f; c+d+e+f; a+b+c+d+e; a+b+c+d+f; a+b+c+e+f; a+b+d+e+f; a+c+d+e+f; b+c+d+e+f; a+b+c+d+e+f. In one aspect of the 104th embodiment, feature a., if the product is a yarn, it is preferred that the product has an L value in the Hunter Lab chromaticity coordinates ranging from 62 to 95, more preferably, ranging from 68 to 90, and further preferably, ranging from 73 to 87. In one aspect of the 104th embodiment, feature b., if the product is a yarn, it is preferred that the product has a b in the Hunter Lab chromaticity coordinates ranging from 1 to 7, more preferably, ranging from 2 to 6, and further preferably, ranging from 3 to 5. In the 104th embodiment, tensile strength and elongation are measured according to standard ASTM D2256 / D2256M-21.

[0344] The 105th embodiment of the present invention is the use of the first intermediate product according to the present invention (preferably the first intermediate product according to the 99th embodiment of the present invention) for producing another intermediate product (preferably further polyester).

[0345] In one aspect of the 105th embodiment, preferably, another intermediate product produced is any one of the 100th to 101st embodiments of the present invention.

[0346] The 106th embodiment of the present invention is the use of another intermediate product according to the present invention (preferably according to any one of the 100th to 101st embodiments of the present invention) for producing a product, preferably a product produced according to any one of the 102nd to 104th embodiments of the present invention.

[0347] Detailed description of the invention

[0348] Throughout the document, the disclosure of a range should preferably be understood as including both endpoints of the range. In addition, the disclosure of each range in the document should preferably be understood as also disclosing a preferred sub-range in which one endpoint is excluded or both endpoints are excluded. For example, the disclosure of a range of 60°C to 75°C should be understood as disclosing a range including both endpoints of 60°C and 75°C. In addition, it should also be understood as disclosing a range including endpoint 60°C but not including endpoint 75°C, a range excluding endpoint 60°C but including endpoint 75°C, and a range excluding both endpoints of 60°C and 75°C.

[0349] Throughout the document, preferred embodiments and preferred aspects that disclose two or more features with preferred ranges or alternatives should be understood to include all possible combinations of these features. For example, an embodiment in which "wt-%a of feature A, more preferably wt-%b of feature A, and further preferably wt-%c of feature A has a length of x, more preferably wt-%c of feature A has a length of y, and further preferably wt-%c of feature A has a length of z" discloses all embodiments having the following combinations of features: a, x; a, y; a, z; b, x; b, y; b, z; c, x; c, y; c, z.

[0350] Some preferred embodiments and preferred aspects may include different combinations of features. If various combinations are listed, the combinations are separated by semicolons (";"). For example, the list "a; a+b; a+c+d" should be understood to disclose an embodiment including feature "a", an embodiment including features "a" and "b", and an embodiment including features "a", "c", and "d".

[0351] The following abbreviations are used in the description: polyethylene terephthalate (PET), polyvinyl chloride (PVC), ethylene glycol (EG), monoethylene glycol (MEG), bis(2-hydroxyethyl)terephthalate (BHET).

[0352] Volume Segment

[0353] A "volume segment" (e.g., V1, V2) is best understood to refer to a volume designed and arranged to receive a certain amount of solid, liquid, gas, or a combination thereof. Examples of a "volume segment" include a storage tank, a storage container, a reactor (e.g., a depolymerization reactor), a pipeline, a siphon, or a combination of two or more thereof. The numbering of the volume segments is best understood as a means of identifying the volume segments. For example, if a method for producing a first intermediate product is performed in volume segments V1 and V3, this does not mean that the method is also performed in volume segment V2.

[0354] In one aspect of the present invention, it is preferred that at least two volume segments at least partially intersect in space. For example, a first polyester is contacted with a first amount of a first organic compound in volume segment V1, while a reduction in the weight-average molar mass of the first polyester is carried out in volume segment V3. If volume segments V1 and V3 both refer to the same internal volume of the reactor, then volume segments V1 and V3 intersect in space. If two volume segments (e.g., a first volume segment and a further volume segment) intersect in space, the volume segments differ from each other in that the difference in at least one physical parameter (e.g., temperature) in the volume segments is at least 15%. For example, the average temperature of the first volume segment is 60°C, while the average temperature of the further volume segment is 120°C. If two volume segments (e.g., a first volume segment and a further volume segment) intersect in space, then, for example, the transfer of the first initial mixture from the first volume segment to the further volume segment should preferably be understood to mean that at least one physical parameter (e.g., temperature) in the volume segment changes by at least 15%.

[0355] In another more preferred aspect of the present invention, at least two, more preferably at least three, even more preferably at least four, and further preferably all volume segments spatially intersect less than 30%, more preferably less than 20%, and further preferably less than 10%. In this regard, preferably at least two volume segments are located in the same container, such as a reactor or a storage tank. However, in this regard, more preferably the volume segments are located in different containers, such as reactors or storage tanks.

[0356] In one aspect of the present invention, the first polyester is preferably conveyed from the volume segment V1 to the volume segment V2. In this aspect, it is preferred that at least one outlet for the first polyester to leave the volume segment V1 is arranged at a distance of less than 50 cm, more preferably less than 40 cm, and further preferably less than 35 cm from the bottom of the volume segment V1. In this aspect, it is preferred that at least one inlet (e.g., an inlet of the first type) for the first polyester to enter the volume segment V2 is arranged at a distance of less than 50 cm, more preferably less than 40 cm, and further preferably less than 30 cm from the bottom of the volume segment V2. The distance from the bottom of the volume segment to the inlet (or outlet) is measured from the bottom of the volume segment to the point of the inlet (or outlet) closest to the bottom.

[0357] In one aspect of the present invention, preferably at least one, more preferably at least two, even more preferably at least three, and further preferably all volume segments are fluidly connected. In another aspect of the present invention, preferably at least one or all of the following apply: volume segment V1 is fluidly connected to volume segment V2; volume segment V2 is fluidly connected to volume segment V3; volume segment V3 is fluidly connected to volume segment V4; volume segment V4 is fluidly connected to volume segment V5; volume segment V5 is fluidly connected to volume segment V6; volume segment V6 is fluidly connected to volume segment V7; volume segment V1 is fluidly connected to volume segment V3; volume segment V3 is fluidly connected to volume segment V5; volume segment V3 is fluidly connected to volume segment V7; volume segment V5 is fluidly connected to volume segment V7.

[0358] In one aspect of the present invention, preferably at least one, more preferably at least two, even more preferably at least three, and further preferably all volume segments are in fluid communication with at least one filter device. In one aspect of the present invention, preferably at least one or all of the following apply: volume segment V4 is in fluid communication with at least one filter device; volume segment V5 is in fluid communication with at least one filter device.

[0359] In one aspect of the present invention, it is preferred that the volume segment V2 has a first region and another region. In this aspect, it is preferred that the other region is located downstream of the first region. In this aspect, it is preferred that the mass ratio of the first polyester to the first organic compound in the first region is different from the mass ratio of the first polyester to the first organic compound in the other region. It is further preferred that the mass ratio of the first polyester to the first organic compound in the first region is less than the mass ratio of the first polyester to the first organic compound in the other region.

[0360] In one aspect of the present invention, it is preferred that the volume segment V2 has a first region and another region, wherein the first region and the another region are not adjacent to each other.

[0361] In another aspect of the present invention, the volume segment V2 preferably has a first region and a further region, wherein the first region and the first region are adjacent to each other. In this aspect, it is preferred that the first region and the further region are at least partially separated by a boundary. Preferred boundaries are physical boundaries and imaginary boundaries, or a combination thereof. Preferably, the imaginary boundary is defined as a location where a measurable physical property in the volume segment V2 changes rapidly. An example of a physical property is the mass ratio of the first polyester to the first organic compound in the volume segment V2. The rapid change is preferably defined as a change of at least 50%, more preferably at least 60%, and further preferably at least 70% in the value of the physical property within a distance of less than 50 cm, more preferably less than 30 cm, and further preferably less than 15 cm. For example, the imaginary boundary can be defined by the liquid level of the first organic compound in the volume segment V2. An example of a physical boundary between the first region and the further region is a sieve.

[0362] In one aspect of the invention, preferably, volume segment V1 is adjusted and arranged to be used for at least one or all of the following: removing at least one impurity from the surface of the first polyester (e.g., removing a label from a PET sheet), removing at least one impurity from the first initial mixture, and removing at least one impurity from the raw material (e.g., dust).

[0363] In one aspect of the invention, preferably the volume segment V2 is designed and arranged for at least one or all of the following: removing at least one impurity from a mixture comprising a first polyester and a first organic compound, at least partially depolymerizing the first polyester (preferably by solvolysis), and embrittlement of the first polyester. "Embellishing" is preferably understood as a process of making the first polyester more brittle. For example, if the first polyester is in the form of PET flakes, the force required to break the flakes into smaller fragments after embrittlement is less than the force required to break the PET flakes into smaller fragments before embrittlement.

[0364] In an aspect of the invention, preferably, volume V3 is designed and arranged for at least partially depolymerizing the first polyester, preferably using solvolysis.

[0365] In an aspect of the invention, it is preferred that volume section V4 is adapted and arranged for at least one or all of: mixing liquid with particulate material, and heating the liquid.

[0366] In one aspect of the present invention, it is preferred that the volume segment V5 is designed and arranged to be used for at least one or all of the following: storing liquid, maintaining the temperature of the liquid, heating the liquid, or a combination of at least two thereof.

[0367] In one aspect of the invention, preferably, volume segment V6 is designed and arranged to at least partially polymerize at least one or all of the following, more preferably by polycondensation: monomers and oligomers.

[0368] In one aspect of the invention, preferably, volume segment V7 is designed and arranged to at least partially polymerize at least one or all of the following substances, more preferably by polycondensation: monomers and oligomers.

[0369] In one aspect of the invention, preferably, A1.) the first polyester is contacted with a further amount of the first organic compound in a volume section V2, and A2.) the weight average molar mass of the first polyester is reduced in the volume section V2. In this respect, preferably, steps A1.) and A2.) are carried out at least partially simultaneously.

[0370] In one aspect of the present invention, preferably, B1.) the first polyester is contacted with another organic compound in volume section V3, and B2.) the weight average molar mass of the first polyester is reduced in volume section V3. In this aspect, preferably steps B1.) and B2.) are carried out at least partially simultaneously.

[0371] Fluid connections

[0372] The phrase "fluidic connection" should preferably be understood as meaning that if a first component (e.g. volume segment V1) and another component (e.g. volume segment V2) are in fluidic connection with each other, a fluid, a gas or a combination thereof can flow from the first component to the other component, or from the other component to the first component, or both. It should also preferably be understood that if components are "in fluidic connection" with each other, this does not mean that the components must be adjacent to each other. For example, a further component is arranged between the first component and the further component. The first component and the further component are "in fluidic connection" if, for example, a fluid can flow from the first component to the further component through the further component.

[0373] In one aspect of the present invention, if a first component is in fluid communication with another component, and the other component is in fluid communication with the further component, this should preferably be understood to mean that the first component and the further component are in fluid communication with each other.

[0374] In one aspect of the present invention, preferably, at least one or all of the following can be transported between two components in fluid communication with each other: a solid, a mixture of a solid and a fluid, a mixture of a solid and a gas, and a mixture of a solid, a liquid, and a gas. For example, a mixture comprising PET flakes and MEG can be transported between two volume segments in fluid communication with each other using an Archimedean screw, a siphon, or a combination thereof.

[0375] Mass ratio of the first polyester to the organic compound

[0376] The mass ratio of the first polyester to the organic compound (eg, the first organic compound, the further organic compound) is preferably understood as the mass ratio of the first polyester to the free organic compound.

[0377] raw material

[0378] In one aspect of the present invention, a "feedstock" comprising a first polyester is provided. In this aspect, the feedstock may optionally contain one or more other components, such as at least one impurity. In various aspects and preferred aspects of the present invention, the first polyester is contacted with an organic compound (e.g., a first organic compound, another organic compound). Such contact of the first polyester with the organic compound is preferably understood to include the following two situations: a.) before contacting with the organic compound, at least one other component of the feedstock is at least partially separated from the first polyester (i.e., the originally provided feedstock no longer exists or its composition has been changed), and it is the first polyester (wherein at least one other component is at least partially removed) that is contacted with the organic compound; b.) the feedstock is contacted with the organic compound without at least partially removing at least one other component. The above, after necessary modifications, preferably applies to the transportation of the first polyester.

[0379] For example, a first polyester is contacted with a first organic compound in volume segment V1. The first polyester is provided as part of a raw material that also contains impurities. The impurities are not removed before contact. That is, the contact of the first polyester with the first organic compound is equivalent to the contact of the raw material with the first organic compound. In volume segment V1, the impurities are partially removed, and the first polyester is transported to volume segment V2 together with some of the impurities that were not removed. Here, the first polyester and the transported impurities are no longer equivalent to the raw material that was originally provided.

[0380] Multiple fragments

[0381] "Product item" is preferably understood to mean an item comprising the first polyester. Examples of product items include: items that have been used at least once, preferably by a consumer (e.g., post-consumer waste); items that have been produced but never used (e.g., items that have been rejected due to not meeting quality requirements); items that are by-products of a production process (e.g., scraps). Examples of product items include bottles and thermoformed items. In a preferred aspect of the present invention, the product item is a bottle and a thermoformed item, more preferably a bottle.

[0382] In one aspect of the present invention, it is preferred that the first polyester in the raw material is in the form of a plurality of fragments. In this aspect, it is preferred that the plurality of fragments is obtained by processing the product article. Examples of processing the product article include shredding, grinding, or a combination thereof. For example, a PET bottle is provided, which is first shredded to obtain PET flakes, and the PET flakes are subsequently ground. In another example, a textile comprising PET is provided, and the textile is shredded to obtain textile fragments. In this aspect in which the raw material is in the form of a plurality of fragments, it is preferred that the product article is processed to obtain a plurality of fragments, wherein at least 50%, more preferably at least 60%, and further preferably at least 70% of the fragments have at least one physical dimension, and the difference between the physical dimension and the average value of at least one physical dimension is less than 50%, more preferably less than 40%, and further preferably less than 30%. An example of at least one physical dimension is the width, length, and thickness of the fragments. For example, at least 70% of the fragments have a width that is less than 40% of the difference from the average width of the plurality of fragments. In another aspect of the present invention, it is preferred that the product is processed before the raw material is contacted with the first amount of the first organic compound.

[0383] The "fragments" of the first polyester preferably have physical dimensions (e.g., length, width, thickness) that are all below the upper limit. Preferably, the upper limit is less than 5 cm, more preferably less than 4 cm, and further preferably less than 3 cm. An example of a plurality of "fragments" is PET flakes, which are well known to those skilled in the art of recycling technology.

[0384] The "first dimension" of a fragment is preferably understood to mean the width, length or both of the fragment. The "length" of a fragment is preferably understood to mean the largest dimension of the fragment. The "width" of a fragment is preferably understood to mean the second largest dimension of the fragment. The "thickness" of a fragment is preferably understood to mean the smallest dimension of the fragment.

[0385] In a preferred aspect of the invention, the geometry of the fragments is not limited. For example, the fragments may be flat, parabolic or irregularly shaped.

[0386] In one aspect of the invention, preferably the plurality of fragments comprises a plurality of first type fragments and a plurality of other type fragments. "First type fragments" are preferably understood as fragments having a maximum thickness of less than 1.0 mm. "Other type fragments" are preferably understood as fragments having a maximum thickness of 1.0 mm or more. Examples of "first type fragments" are fragments obtained by shredding the walls of a PET beverage container. Examples of "other type fragments" are fragments obtained by shredding the bottom of a PET beverage container.

[0387] In the preferred embodiments and description, if "fragments" are mentioned, then preferably fragments constituting a plurality of fragments are to be understood.

[0388] At least one impurity

[0389] In one aspect of the invention, it is preferred that the feedstock contains at least one impurity. In this regard, it is preferred that the feedstock contains less than 3.0 wt-%, more preferably less than 2.0 wt-%, even more preferably less than 1.0 wt-%, further preferably less than 0.5 wt-%, even further preferably less than 0.1 wt-% of at least one impurity based on the total mass of the feedstock.

[0390] Examples of "at least one impurity" include adhesives, paper, sand (e.g., in the form of dust), stones (e.g., gravel), wood, food scraps, at least one metal (e.g., Sb, Fe, Ti, Al), at least one polyolefin (e.g., high-density polyethylene, polyethylene, polypropylene), polystyrene, polyvinyl chloride, fuel (e.g., paraffin, gasoline, diesel), or a combination of two or more thereof. An example of at least one polyolefin impurity is a bottle cap.

[0391] In a preferred aspect of the present invention, wherein the first polyester in the raw material is provided in the form of a plurality of fragments, examples of the at least one impurity are one or all of the following: at least one impurity adhered to the outer surface of the fragments (e.g., labels adhered to the outer surface of PET flakes), at least one impurity mixed with the plurality of fragments (e.g., gravel mixed with PET flakes), or a combination thereof.

[0392] In one aspect of the invention, the raw material is preferably washed, preferably using at least one or all of: water, alkali wash. The preferred alkali wash comprises sodium hydroxide. In this regard, preferably, the raw material is washed before contacting the raw material with the first amount of the first organic compound. For example, according to the present invention, the raw material used in the method for producing the first intermediate product is washed before contacting with the first amount of the first organic compound.

[0393] Number of particles per unit area

[0394] In one aspect of the present invention, at least one or all of the following are preferably applied:

[0395] a. The number of particles per unit area of ​​at least one impurity in volume segment V1 is at least 100,000 particles / cm 2 , more preferably at least 1,000,000 particles / cm 2 , more preferably at least 3,000,000 particles / cm 2 ;

[0396] b. The number of particles per unit area of ​​at least one impurity in the first region of volume segment V2 is 3000 particles / cm 2 Up to 350,000 particles / cm 2 The particle size is preferably within the range of 30,000 particles / cm 2 Up to 250,000 particles / cm 2 The particle size is preferably within the range of 100,000 particles / cm 2 Up to 200,000 particles / cm 2 within the scope;

[0397] c. In another region of volume segment V2, at least one impurity has a particle count per unit area of ​​100 particles / cm 2 Up to 12000 particles / cm 2 In the range of 500 particles / cm 2 Up to 6000 particles / cm 2 In the range of 1000 particles / cm 2 Up to 2000 particles / cm 2 within the range.

[0398] In the above aspects, all possible combinations of features a. to c. are preferred. These combinations are, for example, a; b; c; a+b; a+c; b+c; a+b+c.

[0399] Entrance

[0400] "First type of inlet" is best understood as an inlet designed and arranged to allow the first polyester to enter the volume segment. For example: the volume segment is a reactor and the first type of inlet is an opening in the side of the reactor.

[0401] "Another type of inlet" is best understood to mean an inlet designed and arranged to allow an organic compound (e.g., a first organic compound) to enter the volume segment. A preferred another type of inlet is designed and arranged to allow the organic compound to enter the volume segment in the form of a gas (e.g., a steam). An example of another type of inlet is a gas nozzle, such as a high-pressure gas nozzle.

[0402] A further type of inlet is preferably understood to mean an inlet designed and arranged to allow an organic compound (e.g. a first organic compound) to enter the volume segment. A preferred further type of inlet is designed and arranged to allow an organic compound to enter the volume segment in the form of a liquid. An example of a further type of inlet is a nozzle, e.g. a nozzle designed and arranged to spray a liquid.

[0403] Molar mass

[0404] In one aspect of the present invention, preferably, the first polyester has a number average molar mass in the range of 12000 Da to 18500 Da, more preferably in the range of 12700 Da to 17700 Da, and further preferably in the range of 13200 Da to 17200 Da before contacting with the first amount of the first organic compound.

[0405] In one aspect of the present invention, preferably, the number average molar mass of the first polyester leaving the volume segment V1 is in the range of 10100 Da to 21800 Da, more preferably in the range of 10900 Da to 21100 Da, further preferably in the range of 11400 Da to 20600 Da.

[0406] In one aspect of the present invention, preferably, the number average molar mass of the first polyester present in volume segment V2 is in the range of 500 Da to 2500 Da, more preferably in the range of 700 Da to 2000 Da, further preferably in the range of 1000 Da to 1500 Da.

[0407] In one aspect of the present invention, preferably, the number average molar mass of the first intermediate product is in the range of 200 Da to 600 Da, more preferably in the range of 300 Da to 500 Da, further preferably in the range of 350 Da to 400 Da.

[0408] In one aspect of the present invention, preferably, the number average molar mass of the further intermediate product leaving volume segment V6 is in the range of 200 Da to 600 Da, more preferably in the range of 3000 Da to 6500 Da, and further preferably in the range of 3700 Da to 5500 Da.

[0409] In one aspect of the present invention, preferably, the number average molar mass of the further intermediate product leaving volume segment V7 is in the range of 6500Da to 10500Da, more preferably in the range of 7500Da to 10000Da, and further preferably in the range of 8000Da to 9500Da.

[0410] In one aspect of the present invention, it is preferred that the first polyester is in the form of a plurality of first type fragments and a plurality of another type fragments. In this aspect, it is preferred that at least one or all of the following apply:

[0411] A.) before contacting with the first amount of the first organic compound, the weight average molar mass of the plurality of first type fragments is in the range of 55000 Da to 72000 Da, more preferably in the range of 60000 Da to 68000 Da, and further preferably in the range of 62000 Da to 66000 Da;

[0412] B.) before contacting with the first amount of the first organic compound, the weight average molar mass of the plurality of another type of fragments is in the range of 50,000 Da to 70,000 Da, more preferably in the range of 55,000 Da to 64,000 Da, and further preferably in the range of 57,000 Da to 62,000 Da;

[0413] C.) the mass average molar mass of the plurality of first type fragments leaving the volume segment V1 is in the range of 47000 Da to 58000 Da, more preferably in the range of 49000 Da to 56500 Da, and further preferably in the range of 51000 Da to 54500 Da;

[0414] D.) the mass average molar mass of the plurality of fragments of the other type leaving the volume segment V1 is in the range of 44000 Da to 77000 Da, more preferably in the range of 48000 Da to 73000 Da, and further preferably in the range of 50000 Da to 71000 Da;

[0415] E.) the mass average molar mass of the plurality of first type fragments leaving the volume segment V2 is in the range of 3700 Da to 6000 Da, more preferably in the range of 4100 Da to 5300 Da;

[0416] F.) The mass average molar mass of the plurality of fragments of the other type leaving the volume segment V2 is in the range of 2300 Da to 7500 Da, more preferably in the range of 3200 Da to 7200 Da.

[0417] In the above aspects, all possible combinations of features A. to F. are preferred. These combinations are, for example, a; b; c; d; e; f; a+b; a+c; a+d; a+e; a+f; b+c; b+d; b+e; b+f; c+d; c+e; c+f; d+e; d+f; e+f; a+b+c; a+b+d; a+b+e; a+b+f; a+c+d; a+c+e; a+c+f; a+d+e; a+d+f; a+e+f; b+c+d; b+c+e; b+c+f; b+d+e; b+d+f; b+e+f; c+d+e; c+d+f; c+e+f; d+ e+f;a+b+c+d;a+b+c+e;a+b+c+f;a+b+d+e;a+b+d+f;a+b+e+f;a+c+d+e;a+c+d+f;a+c+e+f;a+d+e+f;b+c+d+e;b+c+d+ f; b+c+e+f; b+d+e+f; c+d+e+f; a+b+c+d+e; a+b+c+d+f; a+b+c+e+f; a+b+d+e+f; a+c+d+e+f; b+c+d+e+f; a+b+c+d+e+f.

[0418] Direction relative to gravity

[0419] If a direction (e.g., a first direction) is "at least partially opposite to the direction of gravity," it is best understood that if the direction is decomposed into three perpendicular components, the orientation of the component parallel to the direction of gravity is such that the component is opposite to the direction of gravity. If a direction (e.g., a first direction) is "at least partially along the direction of gravity," it is best understood that if the direction is decomposed into three perpendicular components, the orientation of the component parallel to the direction of gravity is such that the component is along the direction of gravity, i.e., points in the same direction as gravity.

[0420] Stirring in the volume segment

[0421] The stirring in the volume segment is preferably carried out using a mechanical device suitable for stirring, a non-mechanical device suitable for stirring, or a combination thereof. Examples of suitable mechanical devices include stirrers, such as vertical blade stirrers, turbines, impellers, and propellers. Examples of suitable non-mechanical devices include injecting at least one fluid (e.g., in the form of a gas, a liquid, or a combination thereof) into the volume segment (preferably under pressure) and ultrasound. For example, another organic compound is injected as a liquid into the volume segment V3 through a nozzle.

[0422] Organic compounds

[0423] Preferred "organic compounds" (e.g., the first organic compound, the other organic compound) are compounds suitable for reducing the molar mass (e.g., weight average molar mass, number average molar mass) of the first polyester, preferably by solvolysis. For example, if the first polyester is PET, the weight average molar mass of the first polyester can be reduced by a solvolysis process using (mono)ethylene glycol, alcohol or methanol. Preferred "organic compounds" (e.g., the first organic compound, the other organic compound) are selected from (mono)ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, polypropylene glycol, alcohol, methanol and a combination of at least two thereof, wherein (mono)ethylene glycol is more preferred, and monoethylene glycol is particularly preferred.

[0424] "Free" organic compound is preferably understood to mean an organic compound that is not chemically bound to, for example, the first polyester, the first intermediate product, the further intermediate product, by a covalent bond. "Free" organic compound is in contrast to "bound" organic compound, which is chemically bound to, for example, the first polyester, the first intermediate product, the further intermediate product, by a covalent bond. For example, during the solvolysis of PET using MEG, some MEG is chemically bound to PET oligomers. This bound MEG is not free MEG.

[0425] In one aspect of the present invention, it is preferred that the first organic compound and the further organic compound are the same organic compound. For example, it is preferred that the first organic compound and the further organic compound are both (mono)ethylene glycol.

[0426] Initial mixture

[0427] In one aspect of the invention, it is preferred that the first initial mixture comprises a first polyester and a first organic compound. In one aspect of the invention, it is preferred that a further initial mixture comprises a first polyester and another organic compound. In this aspect, it is further preferred that a further initial mixture also comprises a first organic compound. In one aspect of the invention, it is preferred that a further initial mixture comprises a first polyester and a first organic compound.

[0428] First granular material

[0429] First particulate materials suitable for use in the present invention are commercially available from, for example, Merck KGaA (Germany) and Donau Carbon GmbH (Germany).

[0430] The "mode" of a first particle material is a well-known measure of a statistical distribution. The mode of a first particle material will be referred to below in conjunction with Figure 8 Further description.

[0431] Further aspects and definitions

[0432] In one aspect of the invention, it is preferred that the feedstock contains less than 5 wt-%, more preferably less than 1 wt-%, and further preferably less than 0.1 wt-% of colorant. For example, the feedstock contains PET flakes obtained by crushing colorless bottles. In one aspect of the invention, it is preferred that the feedstock contains less than 5 wt-%, more preferably less than 1 wt-%, and further preferably less than 0.1 wt-% of colored fragments.

[0433] In one aspect of the present invention, it is preferred that the process of the present invention is operated continuously, semi-continuously or batchwise. Examples of these processes are "a process for producing a first intermediate product" and "a process for producing another intermediate product".

[0434] A preferred example of the "method for producing a first intermediate product" is a method in which the first intermediate product is produced by recycling the first polyester. A preferred example of the "method for producing another intermediate product" is a method in which the another intermediate product is produced by recycling the first polyester.

[0435] The process step of "contacting" the component (e.g., the first polyester) with the organic compound preferably includes at least one or all of the following: a process step of mixing the organic compound with the component (e.g., mixing the organic compound and the component in a volume section using a stirring device); a process step of keeping the organic compound and the component in contact with each other (e.g., the component and the organic compound form a mixture, the component is suspended in the organic compound, or the component is at least partially dissolved in the organic compound); a process step of passing the organic compound through the component (e.g., passing steam through a porous component, or the component is in the form of a plurality of fragments and passing steam between the fragments); or a combination of at least two or more thereof.

[0436] The process step of "reducing the weight-average molar mass of the first polyester" preferably includes at least one or all of the following: at least partially depolymerizing the first polyester (for example, by solvent decomposition); heating the first polyester; photodegrading the first polyester; shearing the first polyester; or a combination of at least two or more thereof.

[0437] In one aspect of the invention, it is particularly preferred to reduce the weight average molar mass of the first polyester by solvolysis. Examples of solvolysis include hydrolysis, glycolysis, alcoholysis and aminolysis. For example, if the first polyester is PET, water can be used to depolymerize PET into terephthalic acid and ethylene glycol (hydrolysis). For example, if the first polyester is PET, methanol can be used to depolymerize PET into dimethyl terephthalate and ethylene glycol (methanolysis). For example, if the first polyester is PET, (mono) ethylene glycol can be used to depolymerize PET into BHET and other PET glycolysis products (glycolysis). In this regard, glycolysis is particularly preferred.

[0438] The process step of "increasing the weight average molar mass of the intermediate product" (e.g., the first intermediate product or another intermediate product) preferably comprises at least one or all of the following: at least partially polymerizing the intermediate product; crosslinking the intermediate product; transesterification of the intermediate product; or a combination of at least two or more thereof. In one aspect of the present invention, it is particularly preferred to increase the weight average molar mass of the intermediate product by at least partially polymerizing the intermediate product. In this regard, polycondensation is preferred.

[0439] "Intrinsic viscosity" is preferably understood to mean the average intrinsic viscosity.

[0440] The "first direction" is preferably understood as a direction at least partially opposite to the direction of gravity. The "another direction" is preferably understood as a direction at least partially along the direction of gravity.

[0441] The "ambient pressure" in a volume segment is preferably understood to mean the pressure in the head space of the volume segment. The "overpressure" in a volume segment is preferably understood to mean the pressure difference relative to the ambient pressure (eg atmospheric pressure at the location of the volume segment).

[0442] A "repeat unit" is preferably understood as a part of a polymer, which is repeated to produce a polymer chain. For example, a polymer is formed by linking "repeat units" together. A "dimer" is preferably understood as a chain consisting of two "repeat units". A "trimer" is preferably understood as a chain consisting of three "repeat units". In one aspect of the invention, a preferred repeat unit has the form

[0443]

[0444] The "first intermediate product" is preferably understood to be a product obtained by reducing the weight-average molar mass of the first polyester. Examples of the "first intermediate product" are oligomers of the first polyester, monomers of the first polyester, or combinations thereof. In one aspect of the present invention, preferably the "first intermediate product" includes at least one or all of the following: monomers of the first polyester, oligomers of the first polyester, or both.

[0445] "Oligomer" is preferably understood to mean a chain of repeating units, wherein the number of repeating units does not exceed 50.

[0446] Test Method

[0447] The following test methods are used within the scope of the present invention. Unless otherwise stated, the measurements are carried out at an ambient temperature of 25° C., an ambient pressure of 100 kPa (0.986 atm) and a relative air humidity of 65%. Unless otherwise stated, the margin of error of the measurement method is ±5%.

[0448] In the following test methods, when reference is made to PET, it is understood that the particular test method is applicable to any polyester without adapting the test method.

[0449] Bulk density of raw materials

[0450] When the raw material contains multiple fragments, the bulk density of the raw material p BULK，FEED Calculated according to standard ASTM D1895-17 B. The bulk density of the feedstock is measured before the feedstock is contacted with the first amount of the first organic compound. The method is described using a PET flake feedstock as an example.

[0451] Bulk density of the first polyester in volume segments V1 and V2

[0452] If the first polyester is in the form of a plurality of flakes, the bulk density of the first polyester in the volume segment V1 and in the first region of the volume segment V2 is determined as follows: The method is explained using a PET flake as an example.

[0453] a. Assume that the packing density of the PET flakes leaving the volume segment V1 is the same as the packing density of the flakes in the volume segment V1 BULK,V1 Same. BULK,V1 The value of p is calculated by taking 10 samples of PET flakes at the outlet of volume segment V1 and using the same procedure as for calculating the bulk density of the raw material. BULK,V1 to be sure.

[0454] b. Due to the pressure in the first region of volume segment V2, the PET sheet will be compressed, resulting in a bulk density p in the first region. BULK,V2,Z1 Increase. The bulk density is calculated as follows:

[0455] p BULK,V2,Z1 =C FACTOR ×p BULK,V1 ,

[0456] Among them, C FACTOR is the compression factor.

[0457] c. Bulk density p of PET flakes in another region of volume segment V2 BULK,V2,Z2 By taking 10 samples of PET flakes at the outlet of volume segment V2 and calculating p using the same procedure as for the bulk density of the raw material BULK,V2,Z2 to be sure.

[0458] Compression coefficient C FACTOR Determine as follows:

[0459] a. Head pressure p at the bottom of volume segment V2 HEAD,V2 The calculation is as follows:

[0460] p HEAD,V2 =[H MEG,V2 ×(p PET -p MEG )+(H REACTOR,V2 –HMEG,V2 )×p BULK,V2,Z2 ]×a GRAV ,

[0461] Among them, H MEG,V2 is the height of the first organic compound (eg, MEG) in the volume segment V2 (measured from the bottom of the volume segment V2), H REACTOR,V2 is the height of volume segment V2, p PET is the density of PET (SI unit) (1380kg / m 3 ), p MEG is the density of MEG (SI unit) (1110kg / m 3 ), p BULK,V2,Z2 is the SI unit system, a GRAV is the acceleration due to gravity (9.81 m / s). HEAD,V2 The value is in N / m 2 As unit.

[0462] b. 500ml PET sheet (V PET,C-TEST,INITIAL ) was placed in a cylindrical container with a diameter of 50 mm. The PET flake samples were taken from the raw material without mixing with any organic compounds.

[0463] c. Use a cylindrical rod with a diameter of 12 mm to apply pressure to the PET sheet. The pressure applied by the rod is p ROD,TEST The calculation is as follows:

[0464] p ROD,TEST =p HEAD,V2 ×(A CONTAINER / A ROD ),

[0465] Among them, A CONTAINER is the diameter of the cylindrical container (1964mm 2 ), A ROD is the diameter of the rod (13mm 2 ).

[0466] d. The pressure p ROD,TEST The rod was then removed and the volume (V PET,C-TEST,AFTER ).

[0467] e. The above experiment was performed 10 times. Compression factor C FACTOR The calculation is as follows:

[0468] C FACTOR =V PET,C-TEST,INITIAL,AVG –V PET,C-TEST,AFTER,AVG ,

[0469] Among them, V PET,C-TEST,INITIAL,AVG(500 ml) is the average volume of the PET flake in 10 repeated experiments, measured before using the rod, and V PET,C-TEST,AFTER,AVG is the average volume of the PET flake in 10 replicates, measured after removing the rod.

[0470] Mass ratio of the first polyester to the organic compound

[0471] The mass ratio of the first polyester to the organic compound is determined as follows: This method is described by taking PET flakes as the first polyester, MEG as the first organic compound and another organic compound as an example.

[0472] The mass ratio of PET to MEG in volume segment V1 is determined as follows. The collective sample used to determine the mass ratio is as follows Fig. 9 By first measuring the first initial mixture M SAMPLE,TOTAL,V1 The mass ratio is determined by the mass of the collective sample. Then MEG is poured out from the collective sample, and the remaining PET flakes are placed in an oven at 250°C for 1 hour. After 1 hour, the PET flakes are taken out and weighed to obtain the PET flake M SAMPLE,PET,V1 Therefore, the collective sample M SAMPLE,MEG,V1 The MEG mass in

[0473] M SAMPLE,MEG,V1 =M SAMPLE,TOTAL,V1 -M SAMPLE,PET,V1 Given.

[0474] The mass ratio of PET to MEG in volume segment V1 is then calculated as follows:

[0475] R PET / MEG,SAMPLE,V1 =M SAMPLE,PET,V1 / M SAMPLE,MEG,V1 .

[0476] I. Mass ratio R of PET to MEG in the first region of volume segment V2 PET / MEG,V2,Z1 The calculation method is as follows:

[0477] a. Filling ratio V of the sheet F-RATIO,PET,V2 The calculation formula is as follows:

[0478] V F-RATIO,PET,V2,Z1 =p BULK,V2,Z1 / p PET ,

[0479] where p BULK,V2,Z1 is the packing density of the flakes in the first region of volume segment V2, calculated as described above, p PET is the density of PET (1380kg / m 3 ).

[0480] b. Filling ratio V of MEGF-RATIO,MEG,V2,Z1 The calculation method is as follows:

[0481] V F-RATIO,MEG,V2,Z1 =1–V F-RATIO,PET,V2,Z1 .

[0482] c. Then calculate the filling ratio R F-RATIOS,V2,Z1 The ratio is as follows

[0483] R F-RATIOS,V2,Z1 =V F-RATIO,PET,V2,Z1 / V F-RATIO,MEG,V2,Z1 .

[0484] d. Calculate the mass ratio R of PET to MEG in the first region of volume segment V2 using the following formula PET / MEG,V2,Z1 :

[0485] R PET / MEG,V2,Z1 =R F-RATIOS,V2,Z1 ×(p PET / p MEG ),

[0486] Among them, p MEG is the density of MEG (1113kg / m 3 ).

[0487] II. The mass ratio R of PET to MEG in another region of the volume segment V2 PET / MEG,V2,Z2 is calculated by taking 10 PET flake samples from volume segment V2. Each sample is 100 g. The PET flakes in the sample have MEG adhered to their surfaces. Sample R SAMPLE,PET / MEG The mass ratio is calculated as follows:

[0488] a. The mass of the sample is expressed as M SAMPLE,V2,Z2 This mass is the PET sheet M SAMPLE,PET,V2,Z2 The quality and adhesion to PET film M SAMPLE,MEG,V2,Z2 The sum of the masses of the MEGs on the .

[0489] b. Place the sample on a tray, then place the tray in an oven and bake at 250°C for at least 1 hour. Take out the sample every 20 minutes, weigh it with an analytical balance, and return it to the oven. Repeat this process until the mass measurement value changes by no more than 0.2% for three consecutive times. The average of the last three measurements is M. SAMPLE,PET,V2,Z2 The quality of MEG is determined by

[0490] M SAMPLE,MEG,V2,Z2 =M SAMPLE,V2,Z2 –M SAMPLE,PET,V2,Z2 Given.

[0491] c. Therefore, the mass ratio of PET to MEG in the sample is given by

[0492] RSAMPLE,PET / MEG,V2,Z2 =M SAMPLE,PET,V2,Z2 / M SAMPLE,MEG,V2,Z2 Given.

[0493] d. Mass ratio R PET / MEG,V2,Z2 Calculated by: R calculated for 10 samples SAMPLE,PET / MEG,V2,Z2 The average of the values.

[0494] Characteristics changes

[0495] The percent change in a physical property (e.g., intrinsic viscosity of the first polyester) is determined as follows:

[0496] χ=100×|P2–P1| / P1,

[0497] Where x is the percent change, P1 is the average of the property measured at the first location, and P2 is the average of the property measured at the second location. A change can be an increase or decrease. The physical property at the first location should be measured 10 times, with 5 minutes between each measurement. P1 is the average of the 10 measurements taken at the first location. Similarly, the physical property at the second location should be measured 10 times, with 5 minutes between each measurement. P2 is the average of the 10 measurements taken at the second location.

[0498] To determine the percent change in intrinsic viscosity and molar mass (eg, weight average molar mass, number average molar mass) of the first polyester in volume segment V1, P1 is measured at the inlet of the first polyester into volume segment V1, and P2 is measured at the outlet of the first polyester from volume segment V1.

[0499] To determine the percent change in intrinsic viscosity and molar mass (e.g., weight average molar mass, number average molar mass) of the first polyester in volume segment V2, P1 is measured at the inlet of the first polyester into volume segment V2, and P2 is measured at the outlet of the first polyester from volume segment V2.

[0500] Changes in physical properties should be calculated using values ​​expressed in the units used for that property in the description, for example, changes in temperature should be calculated using values ​​expressed in °C.

[0501] Relative proportions of characteristics

[0502] Unless otherwise stated, the relative proportion β of a physical property (e.g., the number of particles per unit area of ​​at least one impurity) is determined as follows:

[0503] β=P1 / P2,

[0504] Where P1 is the average of the property measured at the first location and P2 is the average of the property measured at the second location. In addition to the P1 value for the feedstock, the values ​​of P1 and P2 are calculated as described in the method for determining "property change".

[0505] In order to determine the relative ratio of the number of particles per unit area of ​​at least one impurity in the feedstock to the number of particles per unit area of ​​at least one impurity at the outlet of volume section V1, P1 is measured in the feedstock before it is conveyed to volume section V1, while P2 is measured at the outlet of the first polyester from volume section V1. For the feedstock, P1 is measured 10 times at 10 different positions in the feedstock, which are evenly distributed in the volume of the feedstock.

[0506] In order to determine the relative ratio of the temperature of a first region to the temperature of another region in volume V2, P1 is measured at the inlet of the first polyester into volume V2 and P2 is measured at the outlet of the first polyester from volume V2.

[0507] In order to determine the relative ratio of the number of particles per unit area of ​​at least one impurity in a first region in volume segment V2 to the number of particles per unit area of ​​at least one impurity in another region, P1 is measured at the entrance of the first polyester into volume segment V2, and P2 is measured at the outlet of the first polyester from volume segment V2.

[0508] The relative ratio β of the mass ratio of the first polyester to the first organic compound in the first region in the volume segment V2 to the mass ratio of the first polyester to the first organic compound in another region PET / MEG,V2,Z1 / Z2 The calculation is as follows:

[0509] β PET / MEG,V2,Z1 / Z2 =R PET / MEG,V2,Z1 / R PET / MEG,V2,Z2 ,

[0510] Among them, R PET / MEG,V2,Z1 and R PET / MEG,V2,Z2 Calculated as above.

[0511] Relative proportions should be calculated using values ​​expressed in the units used for the characteristic in the description, for example, relative proportions of temperature should be calculated using values ​​expressed in °C.

[0512] Density of the first polyester

[0513] The density of the first polyester is well known in the art and can be found, for example, in CA Harper, Modern Plastics Handbook: Handbook, McGraw-Hill Professional, New York, 2000 and https: / / en.wikipedia.org / wiki / Polyethylene_terephthalate.

[0514] Composition of raw materials

[0515] Raw Material C PVC The PVC content in the raw material is determined by selecting 10 samples containing PET flakes from the raw material. The samples should be evenly distributed in the volume of the raw material. Sample C SAMPLE,PVC The PVC content of the product is determined as follows:

[0516] i.) Weigh out 250g of sample. The sample weighed is of mass W A Place sample A on the tray.

[0517] ii.) Place the tray in an oven at 200°C for 2 hours.

[0518] iii.) Remove the tray from the oven and allow Sample A to cool to room temperature (25°C or lower).

[0519] iv.) Remove any burnt or blackened parts or pieces from Sample A - the removed parts or pieces form Sample B.

[0520] v.) Weigh sample B. The mass of sample B is W B .

[0521] vi.) PVC content of the sample C SAMPLE,PVC The calculation is as follows:

[0522] C SAMPLE,PVC =W B / W A ×10 6 ,

[0523] Among them, C SAMPLE,PVC It is the PVC content in ppm.

[0524] Weigh Sample A and Sample B using an analytical balance. Raw Material C PVC The PVC content in the sample is the C SAMPLE,PVC The average of the values.

[0525] Determine the raw material C by selecting 10 samples containing PET flakes from the raw material FThe sample locations should be evenly distributed in the volume of the raw material. Sample C SAMPLE,C The floatable impurities content is determined as follows:

[0526] i.) Pour 500 ml of distilled water into a plastic beaker.

[0527] ii.) Weigh out 250g of sample. The raw material weighed is of mass W C Sample C.

[0528] iii.) Transfer Sample C to a plastic beaker and stir the distilled water and Sample C for 10 minutes.

[0529] iv.) Allow the mixture of distilled water and Sample C to sit for 10 minutes.

[0530] v.) Remove any floating material from the surface of the distilled water and place the removed material in a petri dish. Measure the mass of the petri dish with the material removed, W D .

[0531] vi.) Place the dish in an oven and bake at 110°C for 1 hour.

[0532] vii.) Take the Petri dish out of the oven and place it in a desiccator to cool. Measure the mass of the Petri dish after cooling. E .

[0533] viii.) Floatability content C of the sample SAMPLE,F The calculation is as follows:

[0534] C SAMPLE,F =(W E –W D ) / W C ×10 6 .

[0535] Weigh Sample C and the Petri dish using an analytical balance. F The floatable impurities content in the sample is determined by the C SAMPLE,F The average of the values.

[0536] Determine the raw material C by selecting 10 samples containing PET flakes from the raw material S The solid impurity content in the raw material. The sample selection location should be evenly distributed in the volume of the raw material. Sample C SAMPLE,S The solid impurity content is determined as follows:

[0537] i.) Weigh out 250g of sample. The sample weighed is specimen F, and its mass is W. F .

[0538] ii.) Spread specimen F on the surface of a stainless steel tray and place it in the tray.

[0539] iii.) The following types of impurities were manually screened out from specimen F: labels, adhesive labels, caps and closures, colored debris (e.g., blue, green, red, yellow, and other colors), metals, stones, rubber, any other unidentified materials.

[0540] iv.) Provide a G of the petri dish.

[0541] v.) Put the impurities sorted out manually into a petri dish and weigh the petri dish. The mass of the petri dish containing impurities is W H .

[0542] ix.) Solid content C SAMPLE,S The calculation is as follows:

[0543] C SAMPLE,S =(W H –W G ) / W F ×10 6 .

[0544] Weigh sample F and the petri dish using an analytical balance. Raw material C S The solid impurity content in the sample is C SAMPLE,S The average of the values.

[0545] wt-% of PET in raw material (PET wt-％ ) is determined as follows:

[0546] PET wt-％ =100% – (C PVC –C F –C S ) / 10 6 .

[0547] Percentage associated with multiple fragments

[0548] In many preferred embodiments and aspects of the present invention, the feedstock includes a plurality of fragments. Many of these aspects and embodiments have the following features: "at least X wt-% of the fragments" or "X wt-% or less of the fragments" have certain geometric properties, such as a thickness greater than 1 mm. Geometric properties include the thickness, width and length of the fragments. Here X is a variable, which is calculated as follows

[0549] X=M ％ / M FRAGMENT,TOTAL ,

[0550] Among them, M ％ is the mass of the fragment with the specified properties, M FRAGMENT,TOTAL is the mass of a selected sample among multiple fragments.

[0551] To determine X, a sample of 10 pieces is selected from evenly distributed locations in the stock, each piece weighing 250 g. Thus M FRAGMENT,TOTAL The weight of the fragment is 2.5 kg. The geometrical properties (e.g., thickness) of each fragment are measured at 5 locations evenly distributed on the fragment. The geometrical properties are measured using a caliper. The maximum value of the measurement is defined as the value of the geometrical property of the fragment. For example, if the thickness of the fragments is measured to be 1.3 mm, 1.2 mm, 1.7 mm, 1.4 mm, and 1.2 mm, the thickness of the fragment is 1.7 mm.

[0552] Particle size of the first particulate material

[0553] The median particle size of the first particulate material is measured using the following particle analyzer and apparatus: Helos / BR+Rodos+Vibri / L. The particle analyzer and apparatus can be purchased from Sympatec GmbH (Germany).

[0554] temperature

[0555] The temperature was measured using a resistance thermometer commercially available from WIKA Alexander Wiegand SE & Co. KG (Germany).

[0556] The temperature of a first region in the volume segment V2 is measured at 10 different equidistant positions in the first region. The average of the 10 measurements determines the temperature of the first region. The temperature of another region in the volume segment V2 is measured at 10 different equidistant positions in the other region. The average of the 10 measurements determines the temperature of the other region.

[0557] Molar mass

[0558] Number average molar mass M n Defined as

[0559] Weight average molar mass M w Defined as

[0560] Among them, in the above two expressions, M i is the mass of polymer i with chain length L, N i is the number of polymers with chain length L.

[0561] The molar mass (e.g., weight average molar mass, number average molar mass) of the first polyester is measured using gel permeation chromatography (GPC). This method is suitable for determining number average molar mass and weight average molar mass. The method is performed as follows:

[0562] i.) A sample of the first polyester was mixed with an eluent to produce a solution having a first polyester concentration of 3.0 mg / ml. The eluent was 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) + 0.05 M potassium trifluoroacetate (KTFAc).

[0563] ii.) The solution was maintained at a temperature of 23°C for 12 hours.

[0564] iii.) Filter the solution using a polytetrafluoroethylene syringe filter with a nominal porosity of 1.0 μm.

[0565] iv.) 50 μL of the filtrate was injected into the detector using a PSS SECurity 1260 autosampler. The flow rate was 1.0 mL / min. The detector used was a PSS SECurity 1260RI detector. To evaluate the measurement results, the software PSS-WinGPC UniChrom Version 8.33 was used. The autosampler, detector and software can be purchased from PSS Polymer Standards Service GmbH (Germany). The column temperature was 25°C.

[0566] In order to evaluate the measurement results, the measurement results must be calibrated. The calibration method is as follows:

[0567] a.) A routine calibration is performed using a narrow distribution standard made of polymethyl methacrylate (PMMA), which reproduces the separation behavior of a gel permeation chromatography (GPC) column. The PMMA is measured using the same eluents and parameter values ​​as described in points i.) to iv.) above.

[0568] b.) Eight broad distribution standards of a first polyester (eg PET) are then measured.

[0569] c.) M according to the known first polyester standard w The value is used to determine the calibration of the first polyester standard using PMMA calibration. This calibration is performed using mathematical calculations. This provides the absolute molar mass for the first polyester sample. Based on the first polyester calibration curve, the molar mass distribution and molar mass mean value of the first polyester sample are calculated by the strip method. In addition, the calculation is performed using a computer.

[0570] The calibration curve used for the above calibration is shown in FIG6 . Fig. 6A The calibration curve for PMMA is shown, which corresponds to the following data:

[0571] Vp / mL Mp / Da Standard No. Increase deviation% 13.71 988000 PSS-ReadyCal-Kit mmkitr1-07, red -0.32 -2.14 14.31 608000 PSS-ReadyCal-Kit mmkitr1-07, white -0.31 3.37 15.15 340000 PSS-ReadyCal-Kit mmkitr1-07, green -0.29 3.34 16.05 202000 PSS-ReadyCal-Kit mmkitr1-07, red -0.29 -4.15 17.33 88500 PSS-ReadyCal-Kit mmkitr1-07, white -0.28 -5.10 18.42 41400 PSS-ReadyCal-Kit mmkitr1-07, green -0.29 -1.00 19.45 18700 PSS-ReadyCal-Kit mmkitr1-07, red -0.3 8.83 20.41 9680 PSS-ReadyCal-Kit mmkitr1-07, white -0.32 5.04 21.35 5050 PSS-ReadyCal-Kit mmkitr1-07, green -0.35 -2.59 22.35 2380 PSS-ReadyCal-Kit mmkitr1-07, red -0.38 -10.24 23.35 800 PSS-ReadyCal-Kit mmkitr1-07, white -0.42 6.28

[0572] Figure 6B A first polyester standard is shown being measured, wherein the first polyester is PET. Figure 6CThe calibration curve used to determine the molar mass of the first polyester is shown. Figure 6C The curve in corresponds to the following data:

[0573]

[0574]

[0575] for Fig. 6A and 6C The following calibration parameters were used for the fit:

[0576] Fig. 6A Figure 6C parameter value value substance PPMA PET Eluent HFIP+0.05KTFAc HFIP+0.05KTFAc Fitting Polynomial 3 Polynomial 3 R 1.000 1.000 Mark-Houwink K - 1.5834mL / g Mark-Houwink alpha - -0,02914

[0577] for Figures 6A to 6C The measurements shown in , used the following columns: PSS PFG, 7 μm, precolumn, 8 mm x 50 mm; and two PSS PFG, 7 μm, linear M, 8 mm x 300 mm. These columns can be purchased from PSS Polymer Standards Service GmbH (Germany).

[0578] The above method is also used to measure the molar mass (eg, weight average molar mass, number average molar mass) of the first intermediate product (eg, PET oligomer), another intermediate product (eg, recycled PET), and the product.

[0579] Composition of the first intermediate mixture

[0580] The amount of free MEG in the first intermediate mixture (comprising, for example, PET oligomers and free MEG) is determined as follows:

[0581] i.) Prepare periodic acid solution: Add 23 g of periodic acid into a 1000 ml volumetric flask. Dissolve the periodic acid in distilled water. The volumetric flask must be filled with distilled water so that 1000 ml of solution is obtained.

[0582] ii.) Preparation of 10% sulfuric acid: Add 25 ml of distilled water to a 100 ml volumetric flask. Add 10 g of 98% sulfuric acid to the volumetric flask. Cool the solution to 23°C. Then, fill the volumetric flask with distilled water to obtain 100 ml of solution.

[0583] iii.) Prepare 10% potassium iodide: Add 10 g of potassium iodide into a beaker. Add 90 ml of distilled water into the beaker and shake vigorously.

[0584] iv.) Standardization of 0.1N sodium arsenite solution: Add 125±0.1 mg potassium iodate to a 300 ml conical flask. Dissolve potassium iodate in 100 ml distilled water at 50°C. Add 4 g solid potassium iodide and 4 ml 10% sulfuric acid (prepared in step ii) to the flask. Place the solution in a sealed flask and protect from light for 5 minutes. Then add 12 g solid sodium bicarbonate and dilute with distilled water. Titrate the iodine formed with the arsenite solution, using starch as an indicator. Calculate the F factor:

[0585] F-factor = initial mass of KIO3 (mg) / 3.567 x consumed arsenic solution (ml).

[0586] v.) Preparation of starch indicator solution: Add 1 g starch powder into a 100 ml beaker, add 10 ml distilled water, and then add 100 ml boiling distilled water.

[0587] vi.) Take a sample of the first intermediate mixture, grind the sample finely, and determine the initial mass of the sample based on the expected ethylene glycol content.

[0588] Ethylene glycol content (%) Initial sample mass (mg) 1 9300 5 1860 10 930 15 620 20 465 30 311 40 233 50 186

[0589] vii.) Accurately weigh the sample and transfer it to a 300 ml conical flask and prepare a slurry with 100 ml of distilled water. Acidify the slurry with 3 drops of 10% sulfuric acid (prepared in step ii.) and then add 25 ml of periodic acid solution (prepared in step i.) using a burette. Loosely stopper the flask and let the flask stand at 23°C for 30 minutes. Shake occasionally. Then, add 10 g of solid sodium bicarbonate and 10% potassium iodide (prepared in step iii.) to the flask. Shake vigorously and immediately titrate with 0.1N sodium arsenite solution (prepared in step iv.) until it turns light yellow. Then, add 1 ml of starch indicator solution (prepared in step v.) and continue titrating until the blue color disappears completely. The endpoint of the titration is marked by the disappearance of the blue color. The color disappearance must last for 3 minutes.

[0590] viii.) A blank was determined as described in previous step vii.), i.e. 25 ml of periodic acid solution (prepared in step i.), i.e. except for the sample addition, all added chemicals were added as described in previous step vii.).

[0591] ix.) The percentage of free MEG is determined as follows:

[0592] %MEG content=[(BW–V)x F x 0.31] / E

[0593] Wherein, BW is the 0.1 N sodium arsenite solution consumed in the blank experiment (ml), V is the 0.1 N sodium arsenite solution consumed in the sample experiment (ml), F is the factor of the 0.1 N sodium arsenite solution, and E is the initial mass of the sample (in g).

[0594] Mass ratio of the first particulate material to the first intermediate mixture

[0595] The mass ratio R of the first particulate material to the first intermediate mixture PM / FIM The calculation formula is

[0596] R PM / FIM =M PM / M FIM ,

[0597] Among them, M PM is the mass of the first particle material, M FIM is the mass of the first intermediate mixture.

[0598] Intrinsic viscosity

[0599] The intrinsic viscosity IV of the first polyester is measured according to standard ASTM D4603:2018, but with the following changes: the flow time of the solution in the capillary viscometer is determined at 25° C. instead of 30° C. (as given in the standard).

[0600] The above method is also used to measure the intrinsic viscosity of the first intermediate product, the further intermediate product and the product.

[0601] Unless otherwise stated, the intrinsic viscosity of the first polyester in volume section V1 is measured at the outlet of the first polyester from volume section V1. Unless otherwise stated, the intrinsic viscosity of the first polyester in another region of volume section V2 is measured at the outlet of the first polyester from volume section V2. The intrinsic viscosity of the first intermediate product is measured at the outlet of the first intermediate product from volume section V3.

[0602] Number of particles per unit area of ​​at least one impurity

[0603] 10 pieces of the first polyester (e.g., 10 PET flakes) were selected. A scanning electron microscope (SEM) image was taken for each piece, with an image area of ​​100 mm x 100 mm (see Figure 7 ). Count the number of impurities in each image to obtain the number of particles per square centimeter in each image, N. i The subscript i here refers to the number of particles per square centimeter determined for the i-th fragment. In addition, the number of impurities is calculated on the surface of the fragment, not on the edge of the fragment. The number of particles per unit area P COUNT Determine as follows:

[0604]

[0605] Here, i = from 1 to 10. Therefore, the number of particles per unit area is determined by averaging the values ​​determined for the 10 images.

[0606] For the feedstock, a fragment for determining the number of particles per unit area of ​​the feedstock is selected prior to contacting the feedstock with a first amount of a first organic compound.

[0607] If the volume segment V2 has a first region and another region: At the entry of the fragments into the volume segment V2 (i.e. the first type of entry), select fragments for determining the number of particles per unit area in the first region. Select 10 fragments every 5 minutes until all 10 fragments are selected.

[0608] At the exit of the fragments leaving the volume segment V2, the fragments for determining the number of particles per unit area in another region are selected. Similar to the fragments entering the volume segment V2, 10 fragments are selected every 5 minutes until all 10 fragments are selected.

[0609] pressure

[0610] The pressure was measured using a pressure gauge commercially available from WIKA Alexander Wiegand SE & Co. KG (Germany).

[0611] Dwell time

[0612] Residence time T RES Determined by the following formula:

[0613] T RES =V REACTOR / F PRODUCT VOLUME RATE ,

[0614] Among them, V REACTOR is the volume of the volume space, such as the reactor volume, F PRODUCT VOLUME RATE is the volume rate of the mixture (eg, the first intermediate mixture, another intermediate mixture) leaving the volume segment.

[0615] Color coordinates

[0616] The color coordinates of, for example, the first intermediate mixture and the product (eg, yarn) are measured using an UltraScan VIS spectrophotometer commercially available from Hunter Lab (USA).

[0617] The color coordinates of a sample, such as a first intermediate mixture (eg, comprising PET oligomers and MEG) or a product, are measured when the temperature of the sample is in the range of 22°C to 25°C.

[0618] Properties of the First Granular Material

[0619] The properties of the first particulate material, such as total pore surface area, total pore volume, average pore size, median pore size, mode pore size and total pore volume, were measured using mercury (Hg) porosimetry. The mercury porosimetry analysis was performed according to ISO 15901-1 (2005). A packing volume of 460.82 mm 3 / g blank was calibrated with Thermo Fisher Scientific PASCAL 140 (low pressure up to 4 bar) and PASCAL 440 (high pressure up to 4000 bar) and SOLID software version 3.0.2 (both provided by Thermo Fisher Scientific, Inc.). During the measurement, the pressure was continuously increased or decreased and was automatically controlled by the instrument operating in PASCAL mode, with the invasion speed set to 3 and the extrusion speed set to 7. The evaluation was performed using the "cylinder and plate" model and the density of Hg was corrected according to the actual temperature. The surface tension value of Hg is 0.48 N / m and the contact angle is 140°. The sample size of the first granular material ranged from 0.28 g to 0.29 g.

[0620] The invention will now be illustrated by means of non-limiting examples and exemplary embodiments.In the examples and figures, the following abbreviations are used: polyethylene terephthalate (PET), monoethylene glycol (MEG), bis(2-hydroxyethyl)terephthalate (BHET).

[0621] Attached photos

[0622] List of Figures

[0623] The accompanying drawings are used to illustrate the present invention and should not be considered as limiting the present invention. In addition, the accompanying drawings are not drawn to scale.

[0624] Figures 1A to 1C : Schematic diagram of an apparatus and a method according to the invention for producing a first intermediate product and a further polyester.

[0625] Figure 2A and Figure 2B : Schematic diagram of the angle between another direction and the horizontal plane.

[0626] Figure 3 : Flowchart showing the exemplary steps of the method according to the present invention for producing a first intermediate product.

[0627] Figure 4 : Flowchart showing the exemplary steps of the method according to the present invention for producing another intermediate product.

[0628] Figure 5A and Figure 5B : The orientation of the direction relative to gravity.

[0629] FIG. 6A to FIG. 6C : Calibration diagram used in methods for measuring molar mass.

[0630] Figure 7 : Scanning electron microscope image of PET flakes, showing impurities on the surface of the PET flakes.

[0631] Figure 8 : A graph showing the pore size distribution of a first particulate material.

[0632] Fig. 9 : Description of the test method for determining the mass ratio of the starting material, more preferably the first polyester, to the first organic compound in volume segment V1. BRIEF DESCRIPTION OF THE DRAWINGS

[0633] In the description of the figures, reference is made to a raw material comprising PET flakes obtained by shredding PET plastic bottles. Additionally or alternatively, the raw material may comprise textile scraps and / or threads obtained by shredding textiles. Therefore, in the description of the figures, the term "PET flakes" should preferably be understood as a generic term for PET flakes obtained from shredding bottles and / or textile scraps and / or threads obtained from shredding textiles.

[0634] Figure 1 is a schematic diagram of an apparatus and method for producing a first intermediate product and another polyester (eg, PET) according to the present invention. More specifically, Figure 1 shows an apparatus and method for recycling used PET.

[0635] Figure 1A A cross section of a first part of the device as viewed from the side is shown. A raw material 101 comprising PET flakes (a first polyester in the form of a plurality of fragments) is provided. Residual impurities such as glue, polyvinyl chloride (PVC) labels, food preservatives and flavorings adhere to the surface of the PET flakes. The raw material may also contain other impurities, such as sand. The PET flakes are obtained by crushing PET plastic bottles for beverages. The raw material 101 is placed in a hopper 102. The raw material 101 is conveyed from the hopper 102 to a volume section V1 103. The conveying of the raw material 101 can be carried out using, for example, a conveying screw, gravity or a combination thereof. The volume section V1 103 can be, for example, a container, a tank or a reactor (e.g. a washing reactor).

[0636] Liquid MEG (a first amount of a first organic compound) is added to volume segment V1 103 through inlet 104 and mixed (contacted) with the PET flakes and impurities constituting the feedstock 101 to obtain a first initial mixture 105 comprising PET flakes and liquid MEG. The first initial mixture 105 is stirred (stirring means not shown) to improve the mixing of the PET flakes and MEG. The stirring is performed mechanically. MEG can remove impurities on the surface of the PET flakes. This is partly because MEG is a strong solvent whose ability to remove organic contaminants is enhanced at moderate temperatures. Stirring the first initial mixture 105 can also, at least in part, remove glue on the surface of the PET flakes by friction between the PET flakes.

[0637] At least a portion of the impurities (e.g., bottle cap fragments containing polyolefin) float on the surface 106 of the first initial mixture 105. These floating impurities can be removed by using, for example, skimming or filtering. The impurities are removed from the volume section V1 103 through the outlet 123. In contrast, the PET flakes in the first initial mixture 105 sink to the bottom 107 of the volume section V1 103.

[0638] PET flakes and part of the MEG in the first initial mixture 105 are conveyed to a volume section V2 108 partially filled with MEG. The conveying is carried out using a conveying screw 109 (Archimedes screw) and a siphon (not shown) in fluid communication with the conveying screw 109 and the volume section V2 108. Other conveying devices not shown may also be used, such as additional conveying screws or pumps. In addition, the volume section V2 108 is in fluid communication with the volume section V1 103. The volume section V2 108 may be, for example, a container, a tank or a reactor, such as a pre-glycolysis reactor. The conveying screw 109 is arranged so that the PET flakes conveyed to the volume section V2 108 are conveyed along a direction 110 (another direction) at least partially opposite to the direction of gravity 161.

[0639] The PET flakes enter the volume segment V2 108 through the first type of inlet 115. Figure 1A108. In the embodiment of the present invention, an inlet 115 of a first type is an opening in the volume segment V2 108. In addition, MEG (an additional amount of a first organic compound) is injected into the volume segment V2 108. A first part of the MEG is injected in the form of vapor through an inlet 116 of another type. The first part may include MEG in the form of vapor, but has been condensed before being injected into the volume segment V2 108. The inlet 116 of another type is a nozzle, which is suitable and arranged to inject the MEG vapor under pressure into the volume segment V2 108. Although only one inlet 116 of another type is shown, there may also be a plurality of inlets 116 of another type. Another part of the MEG is injected in the form of liquid through an inlet 117 of yet another type. The inlet 117 of yet another type is a nozzle, which is designed and arranged to spray liquid MEG into the volume segment V2 108. The PET flakes in the volume segment V2 108 are partially depolymerized (reduced in weight average molar mass) by glycolysis, thereby reducing the weight average molar mass of the PET flakes in the volume segment V2. Part of the PET flakes can be depolymerized into oligomers in volume section V2.

[0640] A screw conveyor (not shown) conveys the PET flakes (and PET oligomers, if present) in the volume section V2 108 in an upward conveying direction 118. MEG vapor entering the volume section V2 108 through another type of inlet 116 also flows in an upward direction, i.e., along the conveying direction 118. In contrast, liquid MEG entering the volume section V2 108 through yet another type of inlet 117 flows in a downward direction, i.e., opposite to the conveying direction 118.

[0641] The liquid MEG in volume section V2 108 includes liquid MEG delivered from volume section V1 103, liquid MEG injected through a further type of inlet 117, and any condensed MEG vapor (injected through another type of inlet 116). The liquid MEG does not completely fill volume section V2 108. Therefore, the surface (or level) of the liquid MEG forms a boundary 119 that divides volume section V2 108 into a first region 120 and a further region 121. The further region 121 is located downstream of the first region 120.

[0642] The first region 120 is filled with another initial mixture, which includes a mixture of PET flakes (and PET oligomers, if present) immersed in MEG. Another region 121 includes the PET flakes and any liquid MEG adhering to the surface of the PET flakes, as well as MEG vapor. Another region 121 may also include PET oligomers.

[0643] like Figure 1A As shown, the level 111 of MEG in volume segment V1 103 is lower than the level 113 of MEG in volume segment V2 108 . Figure 1AIt is also shown that the levels 111 and 113 of MEG are measured from the ground 114 (e.g. the floor of a recycling plant) to the surface of the liquid MEG in the volume sections V1 103 and V2 108. Due to the difference between the levels 111 and 113 of MEG, a portion of the liquid MEG in the volume section V2 108 flows back to the volume section V1 103 via the conveying screw 109. The floatable impurities that were not removed in the volume section V1 103, as well as the floatable impurities that were conveyed to the volume section V2 108 (together with the conveying of the PET flakes), can thus be conveyed back to the volume section V1 103. The PET flakes (and PET oligomers, if present) with MEG adhering to the surface leave the volume section V2 108 via the outlet 122.

[0644] Figure 1B A cross section of another portion of the device as seen from the side is shown. The PET flakes (and PET oligomers, if present) flowing out through the outlet 122 are transported to the volume section V3 124, which is a reactor (e.g., a glycolysis reactor). The volume section V3 124 is in fluid communication with the volume section V2 108. The PET flakes (and PET oligomers, if present) enter the volume section V3 124 via the inlet 125 and flow through the volume section V3 124 as shown by the arrow 136. The inlet 125 of the volume section V3 124 is also located below the outlet 122 of the volume section V2 108. In other words, when the PET flakes (and PET oligomers, if present) are transported from the volume section V2 108 to the volume section V3 124, the PET flakes (and PET oligomers, if present) are at least partially transported in the direction of gravity.

[0645] MEG (another organic compound) is fed into volume section V3 124 through inlet 143. The mixing of PET and MEG (fed into volume section V3) results in obtaining another initial mixture comprising PET flakes (and PET oligomers, if present) and MEG. When the other initial mixture flows through volume section V3 124, the MEG in the other initial mixture causes the partially depolymerized PET flakes (and PET oligomers, if present) to undergo further glycolysis (reducing the weight-average molar mass of the first polyester). A first intermediate mixture is thereby obtained. A delivery pipe 144 in fluid communication with outlet 126 is located within volume section V3 124. The first intermediate mixture leaves volume section V3 124 through delivery pipe 144 and outlet 126. The first intermediate mixture leaving outlet 126 of volume section V3 124 includes free MEG and a first intermediate product (including BHET and PET oligomers). An oligomer is a polymer having multiple repeating units (e.g., dimers, trimers, and oligomers having more than three repeating units). There may also be some PET flakes in the first intermediate mixture that have not been depolymerized into oligomers or BHET.

[0646] like Figure 1B As shown by the arrow in , after the first intermediate mixture leaves volume segment V3 124 through outlet 126, it is conveyed to volume segment V4 127, which is fluidically connected to volume segment V3 124. Volume segment V4 127 can be, for example, a container or a tank, such as a stirred tank. The first intermediate mixture enters volume segment V4 127 through inlet 128. In volume segment V4 127, the first intermediate mixture is mixed with diatomaceous earth (first particulate material). The first intermediate mixture in volume segment V4 127 is stirred to improve mixing of the first intermediate mixture and the diatomaceous earth.

[0647] like Figure 1B As shown by the arrow in , the first intermediate mixture containing diatomaceous earth leaves the volume section V4 127 through the outlet 129 and is transported to the vertical blade filter 130 (filtering device), which is in fluid communication with the volume section V4 127. The first intermediate mixture containing diatomaceous earth enters the vertical blade filter 130 through the inlet 131. The first intermediate mixture flows through the blade filter 130 and recirculates between the blade filter 130 and the volume section V4 127 (not shown), so that each filter sheet of the blade filter 130 is coated with diatomaceous earth. Initially, the filtrate (intermediate mixture) will be turbid. However, if each filter sheet has been fully coated, the filtrate will become clear. Once the filtrate becomes clear, the intermediate mixture can leave the vertical blade filter 130 through the outlet 132. The vertical blade filter 130 filters out the diatomaceous earth and other particulate materials (i.e., impurities) in the first intermediate mixture, as well as any PET flakes that have not yet been depolymerized into oligomers or BHET. The first intermediate mixture leaving the vertical blade filter 130 through the outlet 132 contains only trace amounts of impurities and diatomaceous earth.

[0648] like Figure 1B As shown by the arrow in , the first intermediate mixture flowing out of the vertical blade filter 130 is transported to the volume segment V5 133 connected to the vertical blade filter 130 fluid through the outlet 132. The first intermediate mixture enters the volume segment V5 133 through the inlet 134. The volume segment V5 133 can be, for example, a container or a tank, such as a distillation tank. The volume segment V5 133 is used to determine and correct the color of the first intermediate mixture. If necessary, at least one colorant is added to the first intermediate mixture in the volume segment V5 133. If at least one colorant is added to the first intermediate mixture, the first intermediate mixture is stirred to better mix the first intermediate mixture with the at least one colorant. The first intermediate mixture (which may contain at least one colorant) leaves the volume segment V5 133 through the outlet 135.

[0649] Figure 1CA cross section of another part of the device as seen from the side is shown. A first intermediate mixture, which may contain at least one colorant, is conveyed from outlet 135 to volume section V6 137, which is fluidically connected to volume section V5 133. The first intermediate mixture enters volume section V6 137 through inlet 138. Before entering volume section V6 137, a catalyst and a stabilizer may be added to the first intermediate mixture. The PET flakes in the raw material are obtained by crushing used PET bottles. During the production of PET for bottles, a catalyst is usually added. Therefore, the PET flakes of the raw material usually already contain a catalyst, and further catalyst may not need to be added during the recycling process. Volume section V6 137 is a prepolymerization reactor, which polymerizes the oligomers and BHET in the first intermediate mixture (increasing the weight average molar mass of the first intermediate product) to obtain a polymer (another intermediate product). Another intermediate mixture comprising a polymer (i.e., a PET polymer) and MEG is thereby obtained. In volume section V6137, up to 95% of excess MEG is evaporated under vacuum conditions. The excess MEG includes free MEG delivered into volume section V6 and bound MEG released by polymerization. Another intermediate mixture leaves volume section V6 137 through outlet 139 .

[0650] like Figure 1C As shown by the arrow in , another intermediate mixture leaving volume section V6 137 through outlet 139 is conveyed to volume section V7 140, which is fluidically connected to volume section V6 137. Another intermediate mixture enters volume section V7 140 through inlet 141. Volume section V7 140 is a polymerization reactor, such as a cage reactor, for further increasing the weight average molar mass of the polymer and any remaining oligomers in another intermediate mixture (through polymerization). In addition, any remaining MEG in another intermediate mixture is also evaporated under vacuum conditions in volume section V7 140. The remaining MEG includes free MEG conveyed to volume section V7 and bound MEG released by polymerization. Another intermediate mixture containing another intermediate product leaves volume section V7 140 through outlet 142. Another intermediate product (i.e., recycled PET) obtained after completing polymerization in volume section V7 140 is in the form of a hot melt. The hot melt can be used to produce yarn (product example) and particles commonly referred to as chips. Chips can be obtained by extruding and cooling the hot melt. A further intermediate product is therefore a further polyester.

[0651] Although not shown, the first intermediate mixture is pumped between volume sections V3, V4, V5, V6 and the vertical blade filter. This also applies to the other intermediate mixture, that is, the other intermediate mixture is pumped between volume sections V6 and V7.

[0652] (not shown in the figure): The further intermediate product can then be used to produce further products, such as yarn for textiles. For example, the further intermediate product in molten form is pumped through a spinning pack. The spinning pack is conceptually similar to a household shower head. The number of holes in the spinning pack determines the number of filaments in the yarn produced. The molten further intermediate product stream leaving the spinning pack is cooled and coalesced into a single yarn. The single yarn is then wound onto a bobbin. The further intermediate product can be obtained without using virgin PET. For example, virgin PET monomers and oligomers are not mixed with the first intermediate product before polymerization. For example, virgin PET polymer is also not mixed with the further intermediate product.

[0653] Back to Figure 1A and 1B :These figures show that when the intrinsic viscosity of PET flakes is greater than or equal to Y IV,1 When the intrinsic viscosity of the PET flakes is less than Y IV,2 When the value (here Y IV,1 and Y IV,2 represents a variable, where Y IV,1 >Y IV,2 ), the PET sheet is transported in another direction at least partially along the direction of gravity.

[0654] like Figure 1A As shown, after contacting MEG in volume segment V1 103, the PET flakes are transported to volume segment V2 108 along direction 110, which is at least partially opposite to the gravity direction 161. In volume segment V2 108, the PET flakes are transported along a transport direction 118, which is opposite to the gravity direction 161, i.e., the average transport direction of the PET flakes in volume segment V2 108 is upward. Figure 1A In the context of , the first direction may be defined as the direction from the bottom 107 of the volume segment V1 103 to the outlet 122 of the volume segment V2 108. However, the foregoing should not be considered as a general definition of the first direction. Conveying PET (e.g., in the form of flakes) along the first direction is generally understood as providing that the intrinsic viscosity of the PET flakes is greater than or equal to the value Y. IV,1 , the PET chips (eg in the form of flakes) are conveyed at least partially in the direction of gravity.

[0655] like Figure 1B As shown, when the PET flakes enter the volume segment V3 124 through the inlet 125, the PET flakes are transported in a direction 136, which is oriented along the gravity direction 161. Figure 1BIn the context of , direction 136 defines another direction. However, the foregoing should not be considered as a general definition of this other direction. The transport of PET (e.g., in the form of flakes) along this other direction should generally be understood as the transport of PET flakes (e.g., in the form of flakes) at least partially along the gravity direction, as long as the intrinsic viscosity of the PET flakes is less than or equal to the value Y. IV,2 However, once the PET is depolymerized, the PET oligomers and / or monomers can be transported against or along the direction of gravity.

[0656] FIG. 2 is a schematic diagram 200 showing how to measure the angle between the further direction 210 and the horizontal plane 214. The horizontal plane 214 is perpendicular to the gravity direction 261. The angle is measured as the minimum angle between the further direction 210 and the horizontal plane 214. Figure 2A and Figure 2B In these figures, angle 262 is defined as the angle between further direction 210 and horizontal plane 214, rather than angle 263.

[0657] Figure 3 is a flow chart illustrating steps for producing a first intermediate product according to an embodiment of a method 300 of the present invention. Figure 3 The optional steps in are indicated by dashed boxes. A description of the method steps is given below.

[0658] Steps: Description:

[0659] 301: Providing a raw material comprising a first polyester.

[0660] 302: Optionally, contacting the feedstock with a first amount of a first organic compound in volume segment V1 to obtain a first initial mixture, wherein the first amount is in liquid form.

[0661] 303: Optionally, the first polyester is conveyed from volume section V1 to volume section V2.

[0662] 304: contacting the first polyester with an additional amount of the first organic compound in volume segment V2, wherein at least one impurity is present in volume segment V2, and volume segment V2 has a first region and another region; and

[0663] The relative ratio of the number of particles per unit area of ​​at least one impurity in the first region to the number of particles per unit area of ​​at least one impurity in another region is equal to or greater than 10, more preferably equal to or greater than 15, even more preferably equal to or greater than 20, further preferably equal to or greater than 25, and even further preferably equal to or greater than 30.

[0664] 305: Optionally, reducing the weight average molar mass of the first polyester in volume segment V2.

[0665] 306: Optionally, the first polyester is conveyed from volume section V2 to volume section V3.

[0666] 307: In volume segment V3, the first polyester is contacted with another organic compound to obtain another initial mixture.

[0667] 308: Reducing the weight average molar mass of the first polyester in volume segment V3 to obtain a first intermediate mixture, wherein the first intermediate mixture comprises the first intermediate product and the another organic compound.

[0668] 309: Optionally, the first intermediate mixture is conveyed from volume segment V3 to volume segment V4.

[0669] 310: Optionally, adding a first particulate material to the first intermediate mixture in volume segment V4.

[0670] 311: Optionally, the first intermediate mixture is conveyed from volume segment V4 to a filtering device.

[0671] 312: Optionally, using a filtering device to at least partially remove the following substances from the first intermediate mixture: the first particulate material, at least one impurity.

[0672] 313: Optionally, the first intermediate mixture is conveyed from the filtration device to volume segment V5.

[0673] 314: Optionally, at least one colorant is added to the first intermediate mixture in volume segment V5.

[0674] exist Figure 3 In one aspect of the embodiment of , preferably, steps 304 and 305 are at least partially performed simultaneously. Figure 3 In one aspect of the embodiment of the present invention, preferably, steps 307 and 308 are performed at least partially simultaneously.

[0675] Figure 4 is a flow chart showing the steps of an embodiment of a method 400 according to the present invention for producing another intermediate product. Figure 4 The optional steps in are indicated by dashed boxes. A description of the method steps is given below.

[0676] Steps: Description:

[0677] 401: Provide a first intermediate mixture containing a first intermediate product. The first intermediate product and the first intermediate mixture are Figure 3 The first intermediate mixture is provided in the volume section V6 by conveying the first intermediate mixture from the filtering device to the volume section V6.

[0678] 402: Increasing the mass average molar mass of the first intermediate product in the first intermediate mixture in volume segment V6 to obtain another intermediate mixture containing another intermediate product. The other intermediate mixture further includes at least one or all of the following: a first organic compound, another organic compound.

[0679] 403: Optionally, the further intermediate mixture is conveyed to volume segment V7.

[0680] 404: Optionally, further increasing the mass average molar mass of another intermediate product in another intermediate mixture in volume segment V7.

[0681] 405: Optionally, at least partially remove at least one organic compound, such as the first organic compound or another organic compound, from another intermediate mixture. This step can be at least partially performed simultaneously with at least one or all of steps 402 and 404.

[0682] exist Figure 4 In one aspect of the embodiment of the present invention, it is preferred that step 405 is at least partially performed simultaneously with at least one or all of steps 402 and 405. In a preferred embodiment of the present invention, according to the present invention, the method for producing another intermediate product comprises steps 301 to 314 and steps 401 to 405. For example, Figure 3 The steps can be Figure 4 A combination of steps, where Figure 3 The steps are Figure 4 In such a combination, Figure 3 and Figure 4 The optional steps described in remain optional.

[0683] FIG. 5 shows how the orientation relative to the direction of gravity is defined. Figure 5A A direction 570 is shown that is at least partially opposite to the gravity direction 561. The direction 570 can be decomposed into three components. The direction 570 has a component 571 parallel to the gravity direction 561 and a component 572 perpendicular to the gravity direction (another component perpendicular to the gravity direction is not shown). The direction of the component 571 is opposite to the gravity direction.

[0684] Figure 5B A direction 570 is shown that is at least partially along the direction of gravity 561. Figure 5A Similarly, direction 570 has a component 571 parallel to the gravity direction 561 and a component 572 perpendicular to the gravity direction. Figure 5A on the contrary, Figure 5B The direction of component 571 in is along the direction of gravity.

[0685] Figure 7An SEM image of a PET flake is shown. Impurities on the surface of the PET flake can be identified as white particles. Figure 7 Three impurities 781a, 781b and 781c are marked. Figure 7 is an example of a SEM image used to determine the number of particles per unit area of ​​the at least one impurity.

[0686] Figure 8 The pore size distribution of the first particulate material is shown. Figure 8 It can be seen that the first particle material has modes at about 17100 nm, 15100 nm, 12300 nm, 10600 nm and 9300 nm. The modes are where the quantity dV / dlogD has a maximum value (either a local maximum or a global maximum). dV is the differential volume and dlogD is the differential of the logarithm of the pore size of the first particle material. The primary mode refers to the global maximum value of dV / dlogD. The secondary mode refers to the second largest maximum value of dV / dlogD. Figure 8 The cumulative pore size of the first particulate material is also shown.

[0687] Fig. 9 is a graphical representation of a test method for determining the mass ratio of the starting material (more preferably the first polyester) to the first organic compound in volume segment V1. Fig. 9 Shows Figure 1A An enlarged view of a cross section of volume segment V1 103 (for ease of illustration, Fig. 9 The size of the volume segment V1 103 in Figure 1A The size of the volume segment V1 in FIG. 1 is changed compared to the previous one).

[0688] The first initial mixture 105 in the volume segment V1 is divided into a plurality of height sections H, such as Fig. 9 As shown. The first height portion H1 is bounded by the bottom 107 of the volume segment V1 103 and the height A1, the second height portion H2 is bounded by the heights A1 and A2, and so on. The last height portion H6 is bounded by the height A5 and the surface 106 of the first initial mixture 105. Although Fig. 9 Six height sections H are shown, but the number of height sections is determined by the filling height of the first initial mixture 105 in the volume segment V1 103. The height of each height section should be 20 cm, except for the last height section ( Fig. 9 For example, if the filling height of the first initial mixture in the volume segment V1 is 150 cm, the first initial mixture is divided into 8 height segments, 7 of which have a height of 20 cm and the last has a height of 10 cm. The height of the first height segment H1 bounded by the bottom 107 is measured from the lowest point of the bottom 107.

[0689] Take 5 samples of the first initial mixture in each height section. The volume of each sample is 250 ml. Then all samples are combined to obtain a collective sample. Use the collective sample to determine the mass ratio.

[0690] If the volume segment V1 is stirred during normal operation of the PET recycling process, the samples should be taken while stirring the volume segment V1. In this case, the 5 samples taken in the height segment should be taken at the same position in the height segment, with a two-minute interval between the two subsequent samples. Fig. 9 , where the five samples in the height segment H1 are collected at the position B1, and the sampling interval is two minutes. The height segment position where the five samples are collected can be any position in the height segment.

[0691] If the stirring device is a physical stirring device (e.g. Fig. 9 164), which does not allow the collection of samples below a certain height, the lowest height A at which the sample can be collected without interfering with the stirring device min Replace the bottom 107 in the above procedure, that is, the first height segment is A min For the boundary. Fig. 9 A new height portion I is shown, which has been adjusted for the presence of the stirring device 164. Similar to the height portion H, the height of the height portion I is also 20 cm, except for the height portion I5 bordering the surface 106.

[0692] If the volume section V1 is not stirred during normal operation of the PET recycling process, the five samples collected in the height section should be collected at positions evenly distributed in the direction perpendicular to the height of the first initial mixture. Fig. 9 Shown as positions C1 to C5.

[0693] Example

[0694] The present invention is further described below by way of examples. The present invention is not limited to the examples. In the tables given in the examples, the magnitude of the technical effect is indicated by one or more "-" or "+". The scale from low to high is as follows: "---, -, -, +, ++, +++".

[0695] Basic Settings

[0696] Unless otherwise noted, the basic setup described below applies to all examples.

[0697] A raw material comprising PET flakes is provided. The PET flakes are obtained by processing (e.g., shredding) old PET bottles. The PET flakes are Figure 1AIn other words, the PET flakes are conveyed through the volume sections V1 and V2. In both the volume sections V1 and V2, the PET flakes come into contact with the MEG.

[0698] It should be noted that in the following examples, the existence of the volume segment V1 is not essential.

[0699] The volume segment V2 has a first region and a further region. The following parameters are used for the volume segment V2:

[0700] The first zone: the mass ratio of PET to MEG is in the range of 0.3 to 0.5, and the temperature is in the range of 60°C to 165°C.

[0701] In another zone, the mass ratio of PET to MEG is in the range of 5 to 20, and the temperature is in the range of 125°C to 200°C.

[0702] The overpressure in volume segment V2 ranges from 98 kPa to 103 kPa, and the residence time ranges from 110 minutes to 150 minutes.

[0703] like Figure 1B As shown, the PET flakes are then transported from volume section V2 to volume section V3 (glycolysis reactor). The PET flakes in volume section V3 are also in contact with MEG. In volume section V3, the glycolysis process uses the following parameters: temperature range of 195°C to 240°C, overpressure range of 0.7 kPa to 0.9 kPa, and residence time range of 250 minutes to 420 minutes.

[0704] In V3, depolymerization is carried out by glycolysis to obtain a first intermediate mixture comprising BHET, PET oligomers and free MEG. The first intermediate mixture comprises 85 wt-% to 93 wt-% of the first intermediate product (BHET and PET oligomers), and the remaining first intermediate mixture consists of free MEG and residual impurities (to be filtered out). The wt-% value is based on the total mass of the first intermediate mixture.

[0705] The first intermediate product is Figure 1B The steps (such as filtering) and Figure 1C The polymerization is carried out. Thus, recycled PET is obtained. The recycled PET is used to produce yarn.

[0706] Example 1

[0707] In various examples, the relative ratio of the number of particles per unit area of ​​the impurities in the first region to the number of particles per unit area of ​​the impurities in another region is different, as shown in Table 1 below.

[0708] Table 1

[0709]

[0710]

[0711] The technical effects described in Table 1 are as follows:

[0712] Maximum weight of impurities allowed in the feedstock: The maximum weight of impurities that may be present in the feedstock and still produce recycled PET of sufficiently high purity and guarantee a sufficiently high output and uptime of the recycling plant. It is desirable to increase this maximum amount. The wt-% values ​​in Table 1 are based on the total weight of the feedstock. The maximum weight of impurities is measured immediately before the feedstock is fed into volume segment V1.

[0713] MEG usage: The amount of MEG required in the recovery process. It is desirable to reduce the amount of MEG required in the recovery process.

[0714] Filter life: The number of hours a filter in a recycling plant can be used before it needs to be cleaned or replaced. It is, for example, a filter used to filter the first intermediate mixture comprising oligomers obtained from depolymerized PET flakes. It is desirable to increase this filter life.

[0715] Energy required: The energy required to perform the recovery process (such as filtering and distilling the used MEG). It is desirable to reduce the energy required to a greater extent.

[0716] Unless otherwise stated, the "basic settings" described above also apply to the examples below. In the tables given in the examples below, the size of the technical effect is indicated by one or more "-" or "+". The scales arranged from low to high are as follows: "------, -----, ----, ---, -, +, ++, +++, ++++, ++++++, ++++++". The value "Ref" represents the reference value, that is, the increase or decrease of the technical effect is relative to the "Ref" value. The value "0" means no change relative to the reference value. When the "Ref" value is used, the scales arranged from low to high are as follows: "------, -----, ----, ---, -, Ref, +, ++, +++, ++++, +++++, ++++++".

[0717] Example 2

[0718] Example 2 is the same as Example 1. Table 2 below shows another experiment in which the relative ratio of the number of impurities per unit area in the first region to the number of impurities per unit area in the other region is different. In Example 2, Example 2.1 is used as a reference. In other words, the technical effects shown in Table 2 are for Example 2.1.

[0719] Table 2

[0720]

[0721] The technical effects in Table 2 are the same as those in Table 1.

[0722] Example 3

[0723] Example 3 is similar to Example 1, except that the relative ratio of the number of particles per unit area of ​​at least one impurity in the raw material to the number of particles per unit area of ​​at least one impurity at the outlet of volume segment V1 is also changed. The changes are shown in Table 3. In addition, the relative ratio of the number of particles per unit area of ​​the impurity in the first region of volume segment V2 to the number of particles per unit area of ​​the impurity in another region is maintained in the range of 30 to 35.

[0724] Table 3

[0725]

[0726] The technical effects in Table 3 are the same as those in Table 1.

[0727] Reference Mark List

[0728] 100 Apparatus and method for producing another polyester

[0729] 101 Raw Materials

[0730] 102 Hopper

[0731] 103 Volume segment V1

[0732] 104 Entrance of volume segment V1

[0733] 105 First initial mixture

[0734] 106 The surface of the first initial mixture

[0735] 107 Bottom of volume segment V1

[0736] 108 Volume Segment V2

[0737] 109 conveying screw

[0738] 110 Another direction

[0739] 111 Horizontal plane H1 of the first organic compound

[0740] 112 Bottom of volume segment V2

[0741] 113 The first organic compound level H2

[0742] 114 Ground

[0743] 115 First type of inlet of volume segment V2

[0744] 116 Another type of inlet for volume segment V2

[0745] 117 Another type of inlet of volume segment V2

[0746] 118 Conveying direction

[0747] 119 Boundary

[0748] 120 First Area

[0749] 121 Another area

[0750] 122 Exit of volume segment V2

[0751] 123 Exit of volume segment V1

[0752] 124 Volume Segment V3

[0753] 125 Entrance of volume segment V3

[0754] 126 Exit of volume segment V3

[0755] 127 Volume Segment V4

[0756] 128 Entrance of volume segment V4

[0757] 129 Exit of volume segment V4

[0758] 130 Vertical Leaf Filter

[0759] 131 Vertical leaf filter inlet

[0760] 132 Vertical leaf filter outlet

[0761] 133 Volume segment V5

[0762] 134 Entrance of volume segment V5

[0763] 135 Volume segment V5 outlet

[0764] 136 Flow direction through volume segment V3

[0765] 137 Volume Segment V6

[0766] 138 Entrance of volume segment V6

[0767] 139 Volume segment V6 outlet

[0768] 140 Volume Segment V7

[0769] 141 Entrance of volume segment V7

[0770] 142 Exit of volume segment V7

[0771] 143 Entrance of volume segment V3

[0772] 144 Delivery pipe

[0773] 161 Gravity Direction

[0774] 200 The measured angle between a direction and the horizontal plane

[0775] 210 Another direction

[0776] 214 Horizontal plane

[0777] 261 Gravity Direction

[0778] 262 defines the angle of another direction relative to the horizontal plane

[0779] 263 Incorrect Angle

[0780] 500 Direction of orientation

[0781] 561 Gravity Direction

[0782] 570 Direction

[0783] 571 Component parallel to gravity

[0784] 572 Component perpendicular to gravity

[0785] 700 SEM image for determining the number of foreign particles per unit area

[0786] 781 Impurities

Claims

1. A method for producing a first intermediate product, comprising the following steps a. providing a raw material comprising a first polyester; b. in volume segment V2, contacting the first polyester with an additional amount of a first organic compound, wherein, i. at least one impurity is present in the volume segment V2, and ii. The volume segment V2 has a first region and another region; c. contacting the first polyester with another organic compound, preferably in volume segment V3, to obtain another initial mixture; d. reducing the weight average molar mass of the first polyester, preferably in the volume segment V3, to obtain a first intermediate mixture, wherein the first intermediate mixture comprises: i. The first intermediate product, ii. another organic compound; in, A relative ratio of the number of particles per unit area of ​​the at least one impurity in the first region to the number of particles per unit area of ​​the at least one impurity in the other region is equal to or greater than 10.

2. The method according to claim 1, further comprising the step of contacting the feedstock with a first amount of a first organic compound in volume segment V1 to obtain a first initial mixture, wherein the first amount is in liquid form.

3. A method according to any one of the preceding claims, wherein: The first polyester is selected from polyethylene terephthalate, polybutylene terephthalate, polylactic acid, polytrimethylene terephthalate, polyethylene naphthalate, polycarbonate, polyester carbonate, polyarylate, polyester resin and a combination of two or more thereof.

4. A method according to any one of the preceding claims, wherein: The feedstock further comprises the at least one impurity.

5. The method according to claim 4, wherein: The at least one impurity in the feedstock is in the range of 10 ppm wt to 10000 ppm wt, wherein the wt is based on the total mass of the feedstock.

6. The method according to any one of claims 4 to 5, wherein: The relative ratio of the number of particles per unit area of ​​the at least one impurity in the raw material to the number of particles per unit area of ​​the at least one impurity at the outlet of the volume segment V1 is equal to or greater than 15.

7. A method according to any one of the preceding claims, wherein: The first organic compound has at least one or all of the following characteristics: a. Containing at least two hydroxyl groups; b. The molar mass is at least 60 g / mol; c. The boiling point is at least 192°C.

8. A method according to any one of the preceding claims, wherein: The other organic compound has at least one or all of the following characteristics: a. Containing at least two hydroxyl groups; b. The molar mass is at least 60 g / mol; c. The boiling point is at least 192°C.

9. A method according to any one of the preceding claims, wherein: At least 40 wt-% of the first intermediate product is in the form of an oligomer having 2 to 35 repeating units.

10. A method for producing another intermediate product, comprising the steps of: a. providing a first intermediate mixture comprising a first intermediate product, wherein the first intermediate product can be obtained by the method according to any one of claims 1 to 9; b. Increasing the mass average molar mass of the first intermediate product in the first intermediate mixture, preferably in volume segment V6, to obtain a further intermediate mixture comprising a further intermediate product.

11. A first intermediate product obtained by the method according to any one of claims 1 to 9.

12. A further intermediate product obtainable by the process according to claim 10.

13. A product comprising another intermediate product according to claim 12.

14. Use of the first intermediate product according to claim 11 for producing another intermediate product.

15. Use of another intermediate product according to claim 12 for producing a product.

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