Integrated chemical recycling facility with polyethylene terephthalate production

Abstract

A method and system for producing recycled polyethylene terephthalate (r-PET) is provided. The integration of a chemical recycling facility with a PET manufacturing facility reduces energy consumption and minimizes adverse environmental impacts while providing a valuable end product with up to 100% recycled content.

Description

[Background technology]

[0001]

[0001] Waste, especially non-biodegradable waste, can have a negative impact on the environment if disposed of in landfills after a single use. Therefore, from an environmental perspective, it is desirable to recycle as much waste as possible. However, there are still low-value waste streams that are nearly impossible or economically unfeasible to recycle using conventional recycling techniques. Furthermore, some recycling processes generate waste streams that are themselves economically unfeasible to recover or recycle, resulting in additional waste streams that must be disposed of or otherwise treated.

[0002]

[0002] More specifically, some chemical recycling processes used to break down waste plastics into simpler products suffer from many operational inefficiencies that do not allow for efficient recycling of various waste plastics. For example, these recycling processes may require high operating costs, especially in terms of energy consumption, which may offset the financial benefits of utilizing waste plastics as a raw material.

[0003]

[0003] Solvolysis can be used to break down plastics such as polyethylene terephthalate (PET) into its component monomers (e.g., ethylene glycol and dimethyl terephthalate). However, the processing steps and equipment required to purify these recycled content components (as well as the capital and operating costs required to provide suitable PET feedstock) may make it economically impossible to use r-EG and r-DMT in low-margin processes, and thus less desirable from a business perspective. However, recovery and reuse of these recycled components is highly desirable from an environmental and sustainability perspective, so there is a need for more efficient and cost-effective processes for chemical recycling of PET. Summary of the Invention [Means for solving the problem]

[0004]

[0004] In one aspect, the present technology relates to a method for producing recycled polyethylene terephthalate (r-PET) from mixed plastic waste, the method comprising the steps of: (a) treating the mixed plastic waste in a plastics processing facility to provide a primary polyethylene terephthalate (PET) waste plastic stream; (b) subjecting the primary PET waste plastic stream to methanolysis in a methanolysis facility to form recycled ethylene glycol (r-EG) and recycled dimethyl terephthalate (r-DMT); and (c) reacting at least a portion of the r-EG and / or r-DMT in a reaction zone of a PET production facility to form recycled polyethylene terephthalate (r-PET), wherein the plastics processing facility, methanolysis facility, and PET production facility are co-located.

[0005] In one aspect, the present technology relates to a method for producing recycled polyethylene terephthalate (r-PET), the method comprising the steps of: (a) depolymerizing waste plastics containing primarily polyethylene terephthalate (PET) in a methanolysis reactor to form one or more methanolysis streams containing methanol, recycled ethylene glycol (r-EG), and / or recycled dimethyl terephthalate (r-DMT); (b) isolating, in one or more distillation columns, r-EG, methanol, and r-DMT from at least a portion of the one or more methanolysis streams. (c) reacting r-EG and r-DMT in a reaction zone of the PET production facility to form a recycled PET polymer melt (r-PET polymer melt) having an inherent viscosity (IV) of at least 0.50 dL / g; (d) withdrawing a vapor phase stream from the reaction zone of the PET production facility comprising primarily EG, DMT, and / or methanol; and (e) separating in at least one of the distillation columns at least a portion of the vapor phase stream withdrawn from the PET production facility from the one or more methanolysis streams.

[0006]

[0006] In one aspect, the present technology relates to a method for producing recycled polyethylene terephthalate (r-PET), the method comprising the steps of: (a) reacting ethylene glycol (EG) and dimethyl terephthalate (DMT) in a reaction zone of a PET production facility, wherein the EG comprises recycled ethylene glycol (r-EG) and / or the DMT comprises recycled dimethyl terephthalate (r-DMT); (b) removing a gaseous stream from the reaction zone of the PET production facility; (c) contacting the gaseous stream with water to remove at least a portion of the EG and / or water azeotrope-forming compounds present in the gaseous stream, and (d) introducing at least a portion of the azeotrope-forming compounds removed from the gaseous stream into a distillation column of a methanolysis facility.

[0007]

[0007] In one aspect, the technology of the present invention relates to a method for producing recycled polyethylene terephthalate (r-PET), the method including the steps of: (a) depolymerizing waste plastics, primarily comprising polyethylene terephthalate (PET), in a methanolysis reactor of a methanolysis facility to form at least recycled ethylene glycol (r-EG) and recycled dimethyl terephthalate (r-DMT); (b) reacting the r-EG and / or r-DMT in a reaction zone of a PET production facility to form a recycled PET polymer melt (r-PET polymer melt) having an inherent viscosity (IV) of at least 0.65 dL / g; (c) pelletizing at least a portion of the r-PET polymer melt to form r-PET particles; and (d) crystallizing at least a portion of the r-PET particles to form crystalline r-PET particles.

[0008]

[0008] In one aspect, the present technology relates to a method for producing recycled polyethylene terephthalate (r-PET), the method comprising the steps of: (a) transesterifying recycled ethylene glycol (r-EG) and recycled dimethyl terephthalate (r-DMT) in an transesterification zone of a PET production facility to form recycled PET oligomers (r-PET oligomers); (b) polycondensing at least a portion of the r-PET oligomers to provide a recycled PET polymer melt (r-PET polymer melt) having an inherent viscosity (IV) of at least 0.65 dL / g; (c) pelletizing at least a portion of the r-PET polymer melt by underwater cutting to form recycled PET particles (r-PET particles); and (d) crystallizing the r-PET particles to form crystalline r-PET particles.

[0009]

[0009] In one aspect, the present technology relates to a recycled content polyethylene terephthalate (r-PET) resin comprising a diester component comprising at least 50 mole % of residues of dimethyl terephthalate (DMT), based on the total number of moles in the diester component, and a diol component comprising at least 50 mole % of residues of ethylene glycol (EG), based on the total number of moles in the diol component, wherein the r-PET comprises recycled content obtained from waste plastics, and the r-PET comprises less than 0.1 mole % of residues of each of the following components: 4-methyl formyl benzoate, dimethyl 1,4-cyclohexanedicarboxylate, dimethyl phthalate, methyl isopropyl terephthalate, methyl propyl terephthalate, and methyl isobutyl terephthalate.

[0010]

[0010] In one aspect, the present technology relates to a recycled content polyethylene terephthalate (r-PET) resin comprising a diester component comprising at least 50 mole % of residues of dimethyl terephthalate (DMT), based on the total number of moles in the diester component; and a diol component comprising at least 50 mole % of residues of ethylene glycol (EG), based on the total number of moles in the diol component, wherein the r-PET comprises recycled content obtained from waste plastics, and the r-PET comprises at least 0.1 mole % of residues of each of the following compounds: diisobutyl phthalate, methyl 4-ethyl benzoate, and methyl 4-vinyl benzoate.

[0011]

[0011] In one aspect, the present technology relates to a recycled content polyethylene terephthalate (r-PET) resin comprising a diester component comprising at least 50 mol % of dimethyl terephthalate (DMT) residues and 0.50 mol % or less of terephthalic acid residues, based on the total number of moles in the diester component; and a diol component comprising at least 50 mol % of ethylene glycol (EG) residues, based on the total number of moles in the diol component, wherein the r-PET comprises recycled content obtained from waste plastics and has an inherent viscosity (IV) in the range of 0.65 to 1.10 dL / g, and the r-PET comprises a plurality of spheroidal particles, the intrinsic viscosity (It.V.) of the surface of each pellet being less than 0.25 dL / g higher than the It.V. of the center of the particle.

[0012] In one aspect, the present technology relates to a recycled content polyethylene terephthalate (r-PET) resin comprising a diester component comprising at least 50 mole % of residues of dimethyl terephthalate (DMT) based on the total number of moles in the diester component; and a diol component comprising at least 50 mole % of residues of ethylene glycol (EG) based on the total number of moles in the diol component, the r-PET being made from recycled content (recycled polyethylene terephthalate) obtained from waste plastics. content and has an inherent viscosity (IV) of 0.65 to 0.85 dL / g, the r-PET comprises a plurality of particles, the intrinsic viscosity (It.V.) of the surface of at least a portion of the particles is less than 0.25 dL / g higher than the It.V. of the center of the particle, and at least one of the following (i) to (iii) is true: (i) the r-PET contains 100 ppm or less of cobalt (Co) and bromide (Br); (ii) the r-PET has a methyl end concentration of at least 5% and no more than 30%, based on the total number of moles of polyester; and (iii) the r-PET contains 0.1 mole % or less of residues of 4-carboxybenzaldehyde and 9-fluoreneone-2,6-dicarboxylic acid, based on the total number of moles of polyester. [Brief description of the drawings]

[0013] [Figure 1]

[0013] A block flow diagram illustrating the major steps of an integrated chemical recycling facility is shown, in particular the major steps of a plastics processing facility, a solvolysis facility, and a polyethylene terephthalate (PET) production facility. [Diagram 2]

[0014] A block flow diagram illustrating the main processes of an integrated chemical recycling facility, in particular the methanolysis unit and the PET production unit, is shown. [Diagram 3]

[0015] FIG. 1 shows a block flow diagram illustrating the main steps of an integrated chemical recycling facility, in particular one embodiment of a co-located methanolysis facility and a PET production facility. [Figure 4]

[0016] FIG. 1 shows a block flow diagram illustrating the major steps of an integrated chemical recycle facility, specifically illustrating one embodiment of a methanolysis unit and a PET production unit with a shared distillation zone. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014]

[0017] The inventors have discovered a method and system for efficient and energy-reduced chemical recycling of waste plastics by integrating plastic processing with solvolysis (methanolysis) and PET production. This allows for more efficient production and chemical recycling with product formation. Furthermore, this results in the production of high inherent viscosity (IV) crystalline PET formed from recycled EG (r-EG) and / or recycled dimethyl terephthalate (r-DMT) formed during solvolysis. This PET exhibits additional desirable properties both during processing and during the end use of the PET. The resulting PET can also have up to 100% recycled content.

[0015]

[0018] Referring initially to Figure 1, a process and system are provided for use in the chemical recycling of waste plastics, particularly waste plastics that contain polyethylene terephthalate (PET). The chemical recycling facility shown in Figure 1 generally includes a plastics processing facility or process, a solvolysis facility or process, and a PET manufacturing facility or process.

[0016]

[0019] Chemical recycling facilities are not mechanical recycling facilities. As used herein, the terms "mechanical recycling" and "physical recycling" refer to recycling processes that include melting waste plastics and forming the molten plastics into new intermediate products (e.g., pellets or sheets) and / or new final products (e.g., bottles). Generally, mechanical recycling does not substantially change the chemical structure of the plastics being recycled. Chemical recycling facilities described herein can be configured to receive and process waste streams from mechanical recycling facilities and / or waste streams that cannot normally be processed by mechanical recycling facilities.

[0017]

[0020] In some cases, at least two or all of the plastic processing facility, the solvolysis facility, and the PET manufacturing facility may be co-located. As used herein, the term "co-located" refers to the property that at least two objects are located on a common physical site and / or are located within 5 miles, 2 miles, 1 mile, 0.75 miles, 0.5 miles, or 0.25 miles of each other, measured as the straight line distance between two specified points. When two facilities are said to be "co-located," the distance may be measured between the geographic centers of the facilities.

[0018]

[0021] When two or more facilities are co-located, the facilities may be integrated in one or more ways. Examples of integration include, but are not limited to, heat integration, utility integration, wastewater integration, mass flow integration through conduits, integration of office space, cafeteria, plant management, IT department, maintenance department, and sharing of common equipment and parts such as seals, gaskets, etc. Specific embodiments of integration between plastic processing facilities, solvolysis facilities, and PET manufacturing facilities are discussed in detail herein.

[0019]

[0022] One or more, or all, of the plastic processing facility, the solvolysis facility, and the PET production facility may be commercial-scale facilities. For example, in some cases, the plastic processing facility may accept a mixed waste plastic feed stream at an average annual feed rate of at least 500, at least 1,000, at least 2,000, at least 5,000, at least 10,000, at least 50,000, or at least 100,000 pounds per hour, averaged over a one-year period. In some cases, the solvolysis facility and / or the PET production facility may produce one or more recycled-containing product streams at an average annual rate of at least 100, or at least 1,000, or at least 5,000, at least 10,000, at least 50,000, or at least 75,000 pounds per hour, averaged over a one-year period. In cases where more than one r-product stream is produced, these rates may apply to the combined rate of all r-products.

[0020]

[0023] One or more, or all, of the plastic processing facilities, the solvolysis facilities, and the PET manufacturing facilities can be operated continuously. For example, each process within each facility and / or between the facilities may be operated continuously and may not include batch or semi-batch operation. In some cases, at least a portion of one or more facilities may be operated in a batch or semi-batch mode, but the operation between the facilities may be entirely continuous.

[0021]

[0024] In operation, the chemical recycling facility shown in FIG. 1 can process a mixed waste plastic stream in a plastic processing facility to form a primary PET waste plastic. As used herein, the term "primarily" means at least 50% by weight. The primary PET waste plastic stream can then be sent to a solvolysis facility where it can be combined with a solvent before being subjected to a solvolysis reaction. Examples of suitable solvents can include, but are not limited to, (i) water (in which case solvolysis can be referred to as "hydrolysis"), (ii) alcohols (in which case solvolysis can be referred to as "alcohololysis"), such as methanol (in which case solvolysis can be referred to as "methanolysis") or ethanol (in which case solvolysis can be referred to as "ethanolysis"), (iii) glycols, such as ethylene glycol or diethylene glycol (in which case solvolysis can be referred to as "glycolysis"), or (iv) ammonia (in which case solvolysis can be referred to as "ammonolysis"). As shown in Figure 1, the products of solvolysis include recycle-containing glycols (r-glycols), recycle-containing terephthalyl (r-terephthalyl), a solvent, and one or more by-products. When the solvolysis facility is a methanolysis facility, the r-glycols include recycle-containing ethylene glycol (r-EG) and the r-terephthalyl includes recycle-containing dimethyl terephthalate (r-DMT).

[0022]

[0025] As shown in FIG. 1, at least a portion of the r-glycol and / or r-terephthalyl can be transported to a reaction zone of a PET manufacturing facility, where the r-glycol and r-terephthalyl can optionally react with one or more comonomers to form recycled PET oligomers (r-PET). The r-PET oligomers can be further reacted in a polymerization (or polycondensation) zone (not shown in FIG. 1) to form a recycled PET polymer melt (r-PET polymer melt). The resulting r-PET polymer melt can then be pelletized and crystallized to form recycled PET (r-PET). In some cases, the total recycled content of the r-PET can be at least 5%, at least 10%, at least 25%, at least 50%, at least 75%, at least 90%, or at least 95% and / or 95% or less, 90% or less, 75% or less, or 50% or less.

[0023]

[0026] Referring now to FIG. 2, an exemplary chemical recycling facility including a methanolysis facility is shown. As shown in FIG. 2, a mixed waste plastic stream can be introduced into a plastic processing facility. As used herein, the terms "mixed plastic waste" and "MPW" refer to a mixture of at least two types of waste plastics, including, but not limited to, the following types of plastics: polyethylene terephthalate (PET), one or more polyolefins (PO), and polyvinyl chloride (PVC). In some cases, the MPW can include at least 20% by weight, at least 25% by weight, at least 30% by weight, at least 35% by weight, at least 40% by weight, at least 45% by weight, at least 50% by weight, at least 55% by weight, at least 60% by weight, at least 65% by weight, at least 70% by weight, at least 75% by weight, at least 80% by weight, at least 85% by weight, at least 90% by weight, or at least 95% by weight of PET, based on the total weight of the stream. Alternatively, or in addition, the MPW contains 99.9% or less, 99% or less, 97% or less, 92% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, or 5% or less by weight of PET, based on the total weight of the stream.

[0024]

[0027] In addition to PET, MPW can include non-PET components such as other plastics (e.g., polyolefins, polyvinyl chloride, etc.), as well as non-plastic components such as glass, metal, dirt, sand, and cardboard. In some cases, the non-PET components can include other plastics in amounts ranging from 2-35%, 5-30%, or 10-25% by weight, based on the total weight of the stream. The amount of non-PET and non-PO plastics can be 2% by weight, at least 5% by weight, at least 10% by weight, at least 15% by weight, at least 20% by weight, at least 30% by weight, at least 40% by weight, at least 50% by weight, or 55% by weight, and / or 70% by weight or less, 60% by weight or less, 50% by weight or less, 40% by weight or less, 30% by weight or less, 20% by weight or less, 15% by weight or less, 10% by weight or less, 7% by weight or less, or 5% by weight or less, based on the total weight of the mixed waste plastics.

[0025]

[0028] In the plastic processing facility, the mixed waste plastics can be separated and / or sized to provide a stream of primary PET waste plastics. In some cases, sizing can include increasing the size of the plastic particles (e.g., by densification or agglomeration), while in other cases, sizing can include decreasing the size of the particles (e.g., crushing / granulation, shredding, chopping, or cutting). In some cases, the size of the PET waste plastics removed from the plastic processing facility can be in the form of particles having a D90 particle size of less than 1 inch, less than 3 / 4 inch, or less than 1 / 2 inch, or a D90 particle size range of 1 / 16 inch to 1 inch, 1 / 8 inch to 3 / 4 inch, 1 / 4 inch to 5 / 8 inch, or 3 / 8 inch to 1 / 2 inch.

[0026]

[0029] In some cases, plastic processing facilities may include a separation step to remove non-PET plastics and / or non-plastic components (e.g., glass, metal, cardboard and paper, as well as soil and sand) from the waste plastics. Such separation may be mechanical and may include utilizing a fluid such as air. In some cases, separation may include a float-sink process where different types of plastics are separated by density, usually using water or a pH-controlled liquid (e.g., a caustic solution). In some cases, separation may include the use of hydrocyclones.

[0027]

[0030] As a result, the primary PET waste plastic can contain at least 50% by weight, at least 55% by weight, at least 60% by weight, at least 65% by weight, at least 70% by weight, at least 75% by weight, at least 80% by weight, at least 85% by weight, at least 90% by weight, at least 95% by weight, at least 97% by weight, at least 99% by weight, at least 99.5% by weight, or at least 99.9% by weight PET, based on the total weight of plastic in the primary PET waste plastic stream. This stream may also contain polyvinyl chloride (PVC) in an amount of at least 0.05%, at least 0.1%, at least 0.5%, at least 1%, at least 2%, at least 3%, at least 5% and / or 10% or less, 8% or less, 6% or less, 5% or less, 3% or less, and polyolefins in an amount of PO of 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, 5% or less, 2% or less, 1% or less, 0.5% or less, based on the total weight of the primary PET waste plastic.

[0028]

[0031] In some cases, at least a portion of the non-PET (or PO) waste plastics can themselves be chemically recycled in the same or a different chemical recycling facility. Examples of chemical recycling processes that non-PET (or PO) waste plastics can undergo include, but are not limited to, pyrolysis, molecular modification, and combinations thereof.

[0029]

[0032] As shown in Figure 2, the PET waste plastic can then be introduced into a reaction zone of a methanolysis facility. In the reaction zone, the waste plastic can be contacted with a solvent (e.g., methanol) and at least partially depolymerized to form its component monomers (e.g., EG and DMT). The temperature of the methanolysis reaction can be at least 50°C, at least 55°C, at least 60°C, at least 65°C, at least 70°C, at least 75°C, at least 80°C, or at least 85°C and / or 350°C or less, 345°C or less, 340°C or less, 335°C or less, 330°C or less, 325°C or less, 320°C or less, 315°C or less, 310°C or less, 300 or less, or 295°C or less. The methanol used in the methanolysis reaction is not superheated. In some cases, the solvolysis process may be a low pressure solvolysis process, and the pressure in the solvolysis reactor (or reaction zone) may be within 5 psi, within 10 psi, within 15 psi, within 20 psi, within 25 psi, within 30 psi, within 35 psi, within 40 psi, within 45 psi, or within 50 psi of atmospheric pressure, or within 55 psi, within 75 psi, within 90 psi, within 100 psi, within 125 psi, within 150 psi, within 200 psi, or within 250 psi of atmospheric pressure.

[0030]

[0033] In some cases, the average residence time of the reaction medium in the methanolysis reaction zone can be at least 1 minute, at least 2 minutes, at least 5 minutes, at least 10 minutes, or at least 15 minutes, and / or 12 hours or less, 11 hours or less, 10 hours or less, 9 hours or less, 8 hours or less, 7 hours or less, 6 hours or less, 5 hours or less, or 4 hours or less. At least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% of the total weight of PET introduced into the methanolysis facility can be decomposed upon exiting the reaction zone. Additionally, any suitable type of reactor can be used, including, but not limited to, continuous stirred tank reactors (CSTRs), plug flow reactors, and combinations thereof.

[0031]

[0034] The resulting methanolysis reactor stream removed from the reaction zone can be introduced into a product separation zone, as shown in FIG. 2. In the product separation zone, one or more distillation columns can be used to separate the solvent (e.g., methanol), recycle-containing ethylene glycol (r-EG), and recycle-containing dimethyl terephthalate (r-DMT) from the methanolysis by-products, including, for example, a light organic by-product stream, a heavy organic by-product stream, and bottoms streams from one or more columns (e.g., a glycol bottoms stream and a DMT bottoms stream). These by-product streams can be further processed to remove valuable chemicals or can be chemically recycled in the same or another chemical recycle facility. If further recycled, one or more by-product streams can be subjected to pyrolysis and / or molecular reforming in the same or another chemical recycle facility.

[0032]

[0035] Referring again to FIG. 2, at least a portion of the r-EG and / or r-DMT (or both r-EG and r-DMT) removed from the methanolysis facility may be introduced into the reaction zone of the PET production facility. Although shown in FIG. 2 as being introduced separately into the PET reaction zone, the r-DMT and / or r-EG may be introduced into the reaction zone as a single stream. This may be done by combining the streams of r-DMT and r-EG removed from the methanolysis facility into a single stream before being introduced into the PET production facility, or by removing a single stream of r-DMT and r-EG from the methanolysis facility (embodiment not shown). The r-DMT and / or r-EG provided from the methanolysis facility to the PET facility may be in the liquid and / or gas phase.

[0033]

[0036] As shown in Figure 2, the r-DMT and / or r-EG from the methanolysis facility can optionally be combined with another stream of DMT and / or another stream of EG, respectively, which may or may not contain recycle material. In some cases, the DMT and / or EG combined with the r-DMT and / or r-EG can be virgin, while in other instances, it may include some recycle material from elsewhere in the same or a different chemical recycling facility. The DMT introduced into the reaction zone can include at least 10%, at least 25%, at least 50%, at least 75%, at least 90%, at least 95%, at least 99%, or 100% recycle content, and / or the EG introduced into the reaction zone can include at least 10%, at least 25%, at least 50%, at least 75%, at least 90%, at least 95%, at least 99%, or 100% recycle content.

[0034]

[0037] The reaction zone of a PET facility may include at least two major sections: a transesterification section and a polymerization (or polycondensation) section (not shown in FIG. 2). In the transesterification section, EG (or r-EG) and DMT (r-DMT) react in the presence of a transesterification catalyst and optionally one or more comonomers to form PET oligomers (r-PET oligomers). As used herein, the term "oligomer" refers to polymer species ranging from about 7 to about 50 chain lengths. As used herein, the term "monomer" refers to polymer species containing chain lengths less than about 3, and the term "polymer" refers to polymer species containing chain lengths greater than about 50.

[0035]

[0038] During transesterification, the catalyst present in the reaction medium may be in an amount of at least 1 ppm, at least 2 ppm, at least 4 ppm, at least 5 ppm, and / or no more than 300 ppm, no more than 250 ppm, no more than 200 ppm, no more than 150 ppm, or no more than 100 ppm by weight. Examples of suitable transesterification catalysts include, but are not limited to, titanium alkoxides, tin (II) or (IV) esters, alkali or alkaline earth metals (e.g., Li and Ca), manganese compounds, zinc compounds, magnesium acetate or magnesium benzoate, and combinations thereof. Phosphorus-containing compounds and some colorants may also be added to the transesterification zone.

[0036]

[0039] Optionally, one or more comonomers may be added to the reaction zone of the PET facility and reacted with DMT and EG to form a PET copolymer. As used herein, the term "PET copolymer" refers to PET that contains at least 2 mol % of the residues of at least one diester (or diacid) other than dimethyl terephthalate, and / or at least 2 mol % of at least one diol other than ethylene glycol.

[0037]

[0040] Examples of suitable diester (or diacid) comonomers include, but are not limited to, terephthalic acid, phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, cyclohexanedicarboxylic acid, cyclohexanediacetic acid, diphenyl-4,4'-dicarboxylic acid, dipheny-3,4'-dicarboxylic acid, 2,2,-dimethyl-1,3-propanediol, dicarboxylic acids, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid, alkyl esters thereof, and combinations thereof. Examples of suitable diol comonomers include, but are not limited to, ethylene glycol (EG), diethylene glycol, triethylene glycol, 1,4-cyclohexane-dimethanol, propane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, neopentyl glycol, 3-methylpentanediol-(2,4), 2-methylpentanediol-(1,4), 2,2,4-trimethylpentane-diol-(1,3), 2-ethylhexanediol-(1,3), 2,2-diethylpropane-diol-(1,3). , hexanediol-(1,3), 1,4-di-(hydroxyethoxy)-benzene, 2,2-bis-(4-hydroxycyclohexyl)-propane, 2,4-dihydroxy-1,1,3,3-tetramethyl-cyclobutane, 2,2,4,4 tetramethyl-cyclobutanediol, 2,2-bis-(3-hydroxyethoxyphenyl)-propane, 2,2-bis-(4-hydroxy-propoxyphenyl)-propane, isosorbide, hydroquinone, BDS-(2,2-(sulfonylbis)4,1-phenyleneoxy))bis(ethanol), and mixtures thereof.

[0038]

[0041] When present, the diester and / or diol comonomers can constitute up to 50 mol % of the diester or diol component, based on the total residues of that component. For example, when one or more diester modified comonomers are used (e.g., DMI), the PET resin can contain at least 5 mol %, at least 10 mol %, at least 25 mol %, at least 30 mol %, at least 35 mol %, at least 40 mol %, or at least 45 mol % and / or up to 50 mol %, up to 45 mol %, up to 40 mol %, up to 35 mol %, up to 30 mol %, up to 25 mol %, or up to 20 mol % of the residues of one or more diester (or diacid) comonomers, based on the total moles of diesters in the PET. Alternatively, or in addition, the PET resin may include at least 5 mol%, at least 10 mol%, at least 25 mol%, at least 30 mol%, at least 35 mol%, at least 40 mol%, or at least 45 mol% and / or up to 50 mol%, up to 45 mol%, up to 40 mol%, up to 35 mol%, up to 30 mol%, up to 25 mol%, or up to 20 mol% of one or more diol comonomers (e.g., NPG), based on the total moles of diol in the resin. In some cases, the comonomers may include recycled-containing comonomers (e.g., r-NPG, r-CHDM, r-DEG), while in other instances, the comonomers may include non-recycled materials or may themselves be virgin comonomers.

[0039]

[0042] In the reaction zone of a PET manufacturing facility, the transesterification step or reaction can be carried out at a temperature of at least 175, at least 180°C, at least 185°C, at least 190°C, at least 195°C, at least 200°C, at least 205°C, at least 210°C, at least 215°C, at least 220°C, at least 235°C, at least 245°C or at least 250°C and / or at or below 350°C, at or below 345°C, at or below 335°C, at or below 30°C, at or below 325°C, at or below 320°C, at or below 310°C, at or below 300°C, at or below 285°C, or at or below 275°C, and at a pressure of -5 to 35 psig, 5 to 35 psig, 10 to 25 psig, or 12 to 20 psig. The pressure of the transesterification reaction can be at least 0 psig, at least 5 psig, at least 10 psig, at least 25 psig, at least 50 psig, or at least 75 psig and / or no more than 100 psig, no more than 75 psig, no more than 50 psig, no more than 25 psig, no more than 20 psig, no more than 10 psig, or no more than 5 psig.

[0040]

[0043] The transesterification section includes stages (e.g., reactors or vessels) 1-5 in which the transesterification reaction of DMT and EG occurs to form PET monomers and oligomers. Any suitable reactor can be used to carry out the transesterification step, including, but not limited to, CSTRs, plug flow reactors, heat exchangers, horizontal reactors, vertical gravity-driven reactors, falling film reactors, and even reactive distillation columns, as well as combinations of two or more of the above.

[0041]

[0044] In some cases, the average chain length of the monomers and / or oligomers exiting the transesterification step may be less than about 25, about 1 to about 20, or 5 to 15. Additionally, in some cases, the conversion of DMT after transesterification may be at least 90%, at least 92%, at least 95%, at least 97%, or at least 99%. As used herein, the term "conversion" is used to describe the properties of the liquid phase of the stream subjected to transesterification, and the conversion of the esterified stream indicates the percentage of the original ester end groups that have been converted (i.e., transesterified) to other ester groups. Conversion can be quantified as the number of converted end groups (i.e., alcohol end groups) divided by the total number of end groups (i.e., alcohol + DMT end groups), expressed as a percentage. Although conversion is used herein, it should be understood that average chain length, which represents the average number of monomer units that a compound contains, may also be suitable for describing properties. In some cases, the average chain length of the monomers and / or oligomers exiting the transesterification step may be less than about 25, about 1 to about 20, or 5 to 15.

[0042]

[0045] After transesterification, the r-PET oligomers are then subjected to further polymerization or polycondensation in the polymerization section of the reaction zone. During polycondensation, the r-PET oligomers react to form a r-PET polymer melt. The polymerization (polycondensation) reaction can take place in one to three vessels or stages. During polymerization, the monomer and oligomer end groups react further, releasing EG, residual methanol, water, diethylene glycol (DEG), and other glycols (if present), which may allow for an increase in polymer weight. Steam removed from the polymerization (or polycondensation) section can be distilled to separate the desired components (e.g., EG and methanol), which can then be reused in various parts of the process, as described in more detail with respect to Figures 3 and 4.

[0043]

[0046] Typically, polycondensation can be carried out at temperatures ranging from 220°C to 350°C, or 240°C to 320°C, and at subatmospheric (i.e., vacuum) pressures. When polycondensation is carried out in a two-stage process, a prepolymerization (or prepolymer) reactor can convert the monomers and oligomers exiting the transesterification stage into an oligomer / polymer mixture having an average chain length ranging from 2 to 40, 5 to 35, or 10 to 30. A finisher reactor can then convert the oligomer / polymer mixture into a final polyester product (e.g., polymer melt) having the desired average chain length and IV. In some cases, the r-PET polymer melt can have a trimer concentration of 1 wt% or less, 0.5 wt% or less, or 0.1 wt% or less based on the total weight of the r-PET polymer melt. Further, the polycondensation reaction can be carried out in the presence of at least one polycondensation catalyst present in an amount of at least 0.1 ppm, at least 10 ppm, at least 25 ppm, at least 50 ppm, at least 100 ppm, or at least 250 ppm and / or no more than 500 ppm, no more than 350 ppm, no more than 250 ppm, no more than 100 ppm, based on the weight of the PET. Examples of polycondensation catalysts can include at least one catalytically active metal compound such as titanium, aluminum, antimony, germanium, cobalt, alkali metals, and alkaline earth metals, magnesium, calcium, and combinations thereof.

[0044]

[0047] Phosphorus stabilizers can be added during or after polymerization. The phosphorus stabilizer deactivates the catalyst, thereby stabilizing the polymer. Examples of phosphorus stabilizers include phosphate esters (MERPOL A®) or phosphoric acid. Other additives can also be introduced into the process at various times, including colorants (e.g., red and / or blue toners) or reheat (IR) accelerators such as black iron oxide, reduced antimony catalysts, carbon black, and titanium nitride. When present, the reheat (IR) accelerator can be present in an amount of at least 0.1 wt.%, at least 0.5 wt.%, at least 1 wt.%, or at least 1.5 wt.%, and / or 5 wt.% or less, 3 wt.% or less, 2 wt.% or less, 1 wt.% or less, or 0.5 wt.% or less, based on the total weight of the r-PET (or r-PET particles).

[0045]

[0048] The polymerization reaction can be carried out in any type of reactor, including but not limited to tubular reactors, tray reactors, plug flow reactors, falling film reactors, and even reactive distillation columns. In some cases, the polymerization process may include two sub-processes (prepolymerization and finishing) carried out in different reaction vessels. In other cases, the entire polymerization reaction may be carried out in one step.

[0046]

[0049] In some cases, the polymerization rate (polycondensation) can be adjusted to achieve a desired degree of polymerization or inherent viscosity. For example, the mass transfer rate of at least some or all of the polymerization step can be at least 1, at least 1.25, at least 1.5, at least 1.75, or at least 2 number average degrees of polymerization (DP) per minute (DP / min).

[0047]

[0050] The inherent viscosity (IV) of the r-PET polymer melt exiting the polymerization zone can be at least 0.50 dL / g, at least 0.52 dL / g, at least 0.55 dL / g, at least 0.57 dL / g, at least 0.60 dL / g, at least 0.62 dL / g, at least 0.65 dL / g, at least 0.67 dL / g, at least 0.68 dL / g, at least 0.69 dL / g, at least 0.70 dL / g, at least 0.71 dL / g, at least 0.72 dL / g, at least 0.73 dL / g, at least 0.74 dL / g, at least 0.75 dL / g, at least 0.76 dL / g, at least 0.77 dL / g, at least 0.78 dL / g, at least 0.79 dL / g, or at least 0.80 dL / g. Additionally or alternatively, the inherent viscosity (IV) of the r-PET polymer melt withdrawn from the reaction zone of the PET manufacturing facility may be 1.10 dL / g or less, 1.07 dL / g or less, 1.05 dL / g or less, 1.02 dL / g or less, 1.0 dL / g or less, 0.97 dL / g or less, 0.95 dL / g or less, 0.94 dL / g or less, 0.93 dL / g or less, 0.92 dL / g or less, 0.91 dL / g or less, 0.90 dL / g or less, 0.89 dL / g or less, 0.88 dL / g or less. The inherent viscosity (IV) is measured in 60 / 40 wt / wt phenol / tetrachloroethane at 25° C. unless otherwise specified.

[0048]

[0051] Referring again to FIG. 2, the r-PET polymer melt removed from the reaction zone can be pelletized and then crystallized to form recycled PET (r-PET) particles. As shown in FIG. 2, once the polyester polymer completes melt phase polymerization, it can be formed into particles that are solid at 25° C. and 1 atm. The r-PET particles can be any suitable shape, including, but not limited to, spheres, cubes, pellets, chips, pastilles, stars, and combinations thereof. In some cases, the number average weight of the particles is at least 0.10, at least 1.0, or at least 50 g per 100 particles. The volume of the particles is not particularly limited, but a bulk of the particles can be provided having a volume of at least 1, at least 3, or at least 5 cubic meters.

[0049]

[0052] The method of pelletizing the r-PET polymer melt is not limited. For example, in some cases, the molten PET can be led through a die and cut, or led through a die and then cut to form r-PET particles. A gear pump or a single or twin screw extruder can be used to provide the motive force for the melt to pass through the die, and once through the die, the polyester melt can be cut at the die head. In some cases, the die head can be in a liquid (such as water or other aqueous liquid) so that the particles come into contact with the liquid as soon as they are extruded through the die and cut. This method is commonly referred to as underwater cutting. In some cases, the r-PET particles are formed by subjecting the r-PET polymer melt to underwater cutting.

[0050]

[0053] After cutting, the r-PET particles can be optionally at least partially dried and then crystallized to form crystalline r-PET particles. Any suitable crystallization method can be used, and the particles can be thermally crystallized, for example, in a gas or liquid. The crystallization vessel can be mechanically agitated, a fluidized bed, a bed agitated by fluid movement, an unagitated vessel or pipe, or contacted with a crystallization liquid medium at a temperature above the glass transition temperature (Tg) of the polyester. In some cases, the crystallization can be latent heat crystallization, which can occur without the addition of external heat or energy. Instead, the heat of crystallization comes from the particles themselves.

[0051]

[0054] In some cases, the polymer may be fed to the crystallizer at a polymer temperature below its Tg or above its Tg. For example, the molten polymer from the melt phase polymerization reactor may be fed through a die plate, sheared in water, and then immediately fed to an underwater thermal crystallization reactor, where the polymer is crystallized in water. Alternatively, the molten polymer may be sheared and cooled below its Tg before being fed to an underwater thermal crystallization reactor. Alternatively, the molten polymer may be sheared in a conventional manner, cooled below its Tg, and optionally stored, and then crystallized. Optionally, the crystallized polyester spheroids may be in a solid state according to known methods.

[0052]

[0055] As used herein, "solid-state polymerization" refers to a process of increasing the polymer chain length by heating polyester in a state where oxygen and water are substantially absent. During solid-state polymerization, the polymer is in a solid form and not in a molten phase. In some cases, since the crystallized polyester spheroid is not solid, less than 10%, less than 5%, less than 2%, less than 1%, or less than 0.5% of the total inherent viscosity (IV) can be added to the final r-PET after polycondensation. Therefore, the difference in inherent viscosity (IV) between the r-PET polymer melt and the crystallized r-PET particles can be 0.25 dL / g or less, 0.20 dL / g or less, 0.15 dL / g or less, 0.10 dL / g or less, or 0.05 dL / g or less.

[0053]

[0056] In some cases, the crystalline r-PET may exhibit at least two melting peaks in the first heating scan of DSC. As used herein, "melting point" refers to the peak temperature of endotherm of a differential scanning calorimeter (DSC) that raises the temperature upward at a rate of 20 °C / min for a sample weighing about 10 mg. It is not necessary to perform DSC analysis on the particles, as long as the particles have the described form. The described tests need only be performed to clarify the properties of the polymer and to determine whether the polymer has the described properties.

[0054]

[0057] When the r-PET particles exhibit at least two melting peaks, the low peak melting point is considered to be Tm1a, as further described below, and is classified as a melting peak when the absolute value of the area under the heating curve of the first heating scan of DSC is at least 1 J / g. When two or more peaks appear in the heating curve from the first heating scan of DSC, the first peak is the low peak melting point Tm1a, the second peak is the high peak melting point Tm1b, and Tm1a < Tm1b. The low peak melting point of the polymer particles is in the range of 130 °C to 220 °C. Preferably, the low peak melting point of the polyester polymer has a peak temperature of at least 140 °C, or at least 150 °C, or at least 160 °C, or at least 170 °C, and does not exceed 210 °C, or 200 °C, or 195 °C.

[0055]

[0058] After crystallization, the r-PET particles can be contacted with a steam stream to remove acetaldehyde (AA) and other undesirable components. This stripping step can be carried out at a gas temperature of at least 25°C, at least 30°C, at least 35°C, or at least 40°C and / or no more than 60°C, no more than 55°C, no more than 50°C, or no more than 45°C, and a pressure within 5 psig, no more than 2 psig, or no more than 1 psig of atmospheric pressure. The average residence time of the r-PET particles in the stripping zone is 1 to 24 hours, depending on the temperature of the gas and the mass ratio of gas to particles. The residual AA content of the stripped r-PET particles can be no more than 20 ppm, no more than 15 ppm, no more than 10 ppm, no more than 5 ppm, no more than 2 ppm, no more than 1 ppm, or no more than 0.5 ppm AA. Suitable gases can include air, carbon dioxide, or inert gases such as nitrogen, which may or may not be dry. The gas may be passed co-currently or counter-currently with the particles, and the step may be carried out continuously or batchwise in a vessel.

[0056]

[0059] In some cases, the r-PET particles may be in the shape of spheroids. As used herein, a "spheroid" is a particle that is substantially imperfectly spherical or approximately spherical or globular in shape. It is distinct from slab-shaped, cylindrical, pastille-shaped, conical, rod-shaped, or angular irregularly shaped particles. Spheroids combine various properties. For example, a spheroid does not stand on either end of its long axis through its center, and preferably, but not necessarily, has a y / x ratio of less than 2 (y is the long axis and x is the short axis). Also, for one pellet thickness classification, if 10.0 g of particles are placed near one edge of a smooth horizontal steel plate and the plate is smoothly and gradually lifted at the edge to tilt the plate, when the plate first makes an angle of 13 degrees to the horizontal, the spheroid will roll off the plate and no more than 0.5 g of particles will remain on the plate. The spheroids may be spherical, elliptical, or ovoid, and may have tails.

[0057]

[0060] The spheroids can have a peak mode of circularity distribution of less than 1.4, or less than 1.3, or less than 1.2. The circularity of the spheroids can be determined by the perimeter 2 / (4π × area). "Perimeter" and "area" are defined in the context of a cross-sectional view of the spheroid.

[0058]

[0061] In some cases, the crystalline r-PET particles may include spheroids having the melting characteristics described below. For example, in some cases, the r-PET may have a melting point characterized by (a) at least two melting peaks, one of which has a peak temperature in the range of 140°C to 220°C as measured by a first heating scan of DSC, and is a low peak melting point with a melting endotherm area of ​​at least 1 J / g absolute value, or (b) one or more melting points having a heating curve that deviates from the baseline in the endotherm direction at a temperature of 200°C or less as measured by a first heating scan of DSC. Alternatively or additionally, the r-PET particles may have a low crystallinity in the range of at least 20% and a maximum crystallinity Tcmax defined by the following formula: Tcmax=50%-DE-OH where DE is the total mole % of all diester residues other than dimethyl terephthalate residues based on 100 mole % of diester residues in PET, and OH is the total mole % of hydroxyl functional compound residues other than ethylene glycol residues based on 100 mole % of hydroxyl functional compound residues in PET.

[0059]

[0062] In some cases, the r-PET particles may be crystallized to a crystallinity of at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, or at least 40%. Pellet crystallinity is determined using differential scanning calorimetry (DSC). The sample weight for this measurement is 10±1 mg, and the sample consists of either (1) a portion of a single pellet, or more preferably (2) a sample taken from several grams of cryogenically ground particles. An initial heating scan is performed. The sample is heated from about 25° C. to 290° C. at a rate of 20° C. / min, and the absolute value of the melting endotherm area(s) minus the crystallization exotherm area is determined. This area corresponds to the net heat of fusion, expressed in Joules. The heat of fusion of 100% crystalline PET is considered to be 119 Joules / gram, so the weight fraction crystallinity of the pellet is calculated as the net heat of fusion divided by 119. Unless otherwise stated, the initial melting point in each case is also determined using the same DSC scan. The % crystallinity is calculated from both the lower peak melting point (Tma1) and the upper peak melting point (Tmb1).

[0060]

[0063] As mentioned above, the r-PET particles formed as described herein may not be polymerized in the solid state. If not in the solid state, the r-PET particles may have a smaller surface-to-center molecular weight gradient from the surface to the center of the particle than is found in polyester particles in the solid state. In some cases, the polyester polymer particles have a surface and a center, and the intrinsic viscosity (It.V.) of the particle's surface may be less than 0.25 dL / g, less than 0.20 dL / g, less than 0.15 dL / g, less than 0.10 dL / g, or less than 0.05 dL / g higher than the It.V. of the particle's center.

[0061]

[0064] In this specification, the "surface of the pellet" is defined as the outer 8-12% by mass, and the "center" is defined as the inner 8-16% by mass around the center point of the particle. Although it may be difficult to accurately determine the center point of an irregularly shaped particle, the center point is the best approximation of the intersection of the most straight line that can be drawn through the particle between the edges or corners that are the furthest away from each other. To measure the It.V. of the surface and center, randomly sample 10 particles from the batch and gradually dissolve them according to the procedure described in the Examples, and the weighted average of all measurement cuts within the first 8-12% by mass of the pellet dissolved, which is the surface, is recorded as the It.V. surface, and the weighted average of all measurement cuts within the last 8-16% by mass of the center, which is the center, is recorded as the It.V. center, and the slope is the difference between the It.V. surface minus the It.V. center. There is no limit to the number of measurements made within each range, and only one measurement is possible. The GPC method described herein is used to measure the It.V. of each dissolved portion individually. In this way, the gradient from the surface of the particle to the center of the particle can be measured by taking only surface and center cuts, or as many cuts as desired across the entire particle, or by slicing the particle with a microtome and cutting out a portion of the surface and a portion of the center, which are then measured separately by the GPC method described herein.

[0062]

[0065] The intrinsic viscosity (It.V.) values ​​given herein are calculated from the inherent viscosity (IV) measured in 60 / 40 wt / wt phenol / tetrachloroethane at 25° C. The inherent viscosity is calculated from the measured solution viscosity. The following formulas describe such solution viscosity measurements and the subsequent calculation to IV and from IV to It.V. η inh =[ln(t s / t o )] / C Here, η inh = Inherent viscosity at 25°C for 60% phenol and 40% 1,1,2,2-tetrachloroethane with a polymer concentration of 0.50 g / 100 mL ln = natural logarithm t s= Flow time of the sample through the capillary t o = Flow time of the solvent blank through the capillary C = concentration of polymer (grams) per 100 mL of solvent (0.50%)

[0063]

[0066] Intrinsic viscosity is the limiting value at infinite dilution of the specific viscosity of a polymer. It is defined by the following formula: η int =lim(η sp / C)=lim ln(η r / C) C → 0 C → 0 Here, η int = intrinsic viscosity η r = relative viscosity = t s / t o η sp =Specific viscosity=η r-1

[0064]

[0067] Calibration of the instrument involves repeat testing of standard reference materials and then applying the appropriate mathematical equation to calculate an "acceptable" IV value. Calibration factor = Acceptable IV of reference material / average of replicate measurements Corrected IV = Calculated IV x Calibration Factor

[0065]

[0068] Intrinsic Viscosity (It.V. or η int ) can be estimated using the Billmeyer formula as follows: η int =0.5[e 0.5×補正IV -1] + (0.75 x correction IV)

[0066]

[0069] Recycle-containing PET formed as described herein can include a diester component that includes at least 50 mol%, at least 55 mol%, at least 60 mol%, at least 65 mol%, at least 70 mol%, at least 75 mol%, at least 80 mol%, at least 85 mol%, at least 90 mol%, at least 95 mol%, or at least 99 mol% of the residues of dimethyl terephthalate (DMT), based on the total number of moles in the diester component; and a diol component that includes at least 50 mol%, at least 55 mol%, at least 60 mol%, at least 65 mol%, at least 70 mol%, at least 75 mol%, at least 80 mol%, at least 85 mol%, at least 90 mol%, at least 95 mol%, or at least 99 mol% of the residues of ethylene glycol (EG), based on the total number of moles in the diol component.

[0067]

[0070] All compounds containing ester groups (or corresponding acid groups) present in r-PET include "diester components" and the mole % of all compounds containing ester groups in r-PET add up to 100. Residue of one or more compounds containing ester groups in r-PET refers to the portion of one or more compounds remaining on the oligomeric and / or polymeric chain after a condensation reaction with one or more compounds containing one or more hydroxyl groups. Residue of a diester component refers to the portion of a component remaining on the oligomeric and / or polymeric chain after the component has condensed with a compound containing one or more hydroxyl groups.

[0068]

[0071] All compounds containing one or more hydroxyl groups or derivatives thereof that become part of r-PET include the "diol component" and the mole % of all compounds containing hydroxyl groups in r-PET add up to 100. The residue of the compound(s) containing one or more hydroxyl groups that become part of r-PET is the portion of the compound(s) remaining in r-PET after the compound(s) have condensed with the compound(s) containing one or more diester groups and / or further polycondensed with polymer chains of various lengths. The residue of the diol component refers to the portion of the component that remains in r-PET. The mole percentages of hydroxyl and diester residues in r-PET can be determined by proton NMR.

[0069]

[0072] In some cases, r-PET may contain no more than 0.1 mol%, no more than 0.05 mol%, or no more than 0.01 mol% of residues of one or more (or each) of the following components: 4-methylformylbenzoate, dimethyl 1,4-cyclohexanedicarboxylate, dimethyl phthalate, methyl isopropyl terephthalate, methyl propyl terephthalate, and methyl isobutyl terephthalate. Such components may be found in virgin DMT and may be absent or substantially absent from the r-DMT used to make the r-PET described herein. In some cases, r-PET may contain no more than 0.5 mol%, no more than 0.1 mol%, or no more than 0.05 mol% of residues of methyl ethyl terephthalate, based on the total moles of diester components.

[0070]

[0073] Alternatively or in addition, r-PET may contain at least 0.1 mol%, at least 0.5 mol%, at least 0.75 mol%, or at least 1 mol% and / or no more than 2 mol%, no more than 1.5 mol%, or no more than 1 mol% of one or more (or each) of the following components: diisobutyl phthalate, methyl 4-ethyl benzoate, and methyl 4-vinyl benzoate. Such components are not found in virgin DMT, but may be present in the r-DMT used to form the r-PET described herein. Other components that may be present in such amounts include, for example, methyl 4-acetylbenzoate, methyl cyanobenzoate, nonylphenol, methyl stearate, methyl laurate, methyl 4-bromobenzoate, diethylene glycol methyl ether, methyl caprylate, 4-methylenecyclohexylmethanol, and dimethyl 9-oxo-9H-fluorene-2,6-dicarboxylate.

[0071]

[0074] In some cases, the r-PET may be a DMT-based PET and may contain little or no residues of terephthalic acid (TPA). For example, the crystalline r-PET (or r-PET particles) may contain 0.50 mol% or less, 0.25 mol% or less, 0.10 mol% or less, or 0.05 mol% or less of residues of terephthalic acid, based on the total moles of diester components. In some cases, the absence of TPA from the system may result in less in-situ formation of diethylene glycol (DEG), and the DEG content of the r-PET (or r-PET particles) may be 1.75 mol% or less, 1.5 mol% or less, 1.25, 1 mol% or less, 0.75 mol% or less, or 0.5 mol% or less, 0.45 mol% or less, or 0.40 mol% or less, based on the total moles of diol components. Additionally, or alternatively, the amount of DEG present in the crystalline r-PET (or r-PET particles) described herein can be at least 0.1 mol%, at least 0.2 mol%, at least 0.25 mol%, at least 0.30 mol%, or at least 0.35 mol%, based on the total moles of diol components.

[0072]

[0075] In some cases, r-PET may contain little or no residues of isophthalate, which may result from the addition of isophthalic acid (IPA) and / or dimethyl isophthalate (DMI) to the reaction zone. For example, crystalline r-PET (or r-PET particles) may contain 0.50 mol% or less, 0.25 mol% or less, 0.10 mol% or less, or 0.05 mol% or less of residues of isophthalate, based on the total moles of diester components. In other cases, isophthalate residues may be used as an acid comonomer and may fall within one or more of the ranges discussed herein.

[0073]

[0076] In some cases, r-PET may be free of other components typically associated with TPA-based PET. For example, in some cases, r-PET may contain 100 ppm or less, 75 ppm or less, 50 ppm or less, 25 ppm or less, or 10 ppm or less of cobalt (Co) and / or bromide (Br) typically present in the process of forming TPA. Additionally or alternatively, r-PET may contain 100 ppm or less, 75 ppm or less, 50 ppm or less, 25 ppm or less, or 10 ppm or less of one or more metals selected from manganese (Mn), zinc (Zn), and combinations thereof. In some cases, PET may contain 0.1 mole % or less, 0.05 mole % or less, or 0.01 mole % or less of residues of 4-carboxybenzaldehyde and 9-fluoreneone-2,6-dicarboxylic acid, based on the total moles of PET. These components are typical intermediates in the TPA-based PET process and are absent (or present in very small amounts) in DMT-based PET.

[0074]

[0077] Further, in some cases, r-PET formed from r-DMT described herein may contain at least 5%, at least 7%, at least 10%, at least 12%, at least 15%, or at least 20% and / or no more than 30%, no more than 27%, no more than 25%, no more than 17%, or no more than 15% methyl end groups based on the total number of end groups. PET containing TPA-based terephthalyl residues typically does not have methyl end groups within these ranges. In some cases, r-PET may have a carboxyl number of less than 15 meq / kg, less than 10 meq / kg, less than 7 meq / kg, less than 5 meq / kg, or less than 2 meq / kg.

[0075]

[0078] r-PET is less than 2, less than 1, or less than 0, or in the range of -2 to 2, -1.5 to 1.5, or -1 to 0. * Additionally or alternatively, the r-PET can have an L* color greater than 70, greater than 75, greater than 80, or greater than 85 and / or less than or equal to 95, less than or equal to 92, less than or equal to 90, or less than or equal to 87.

[0076]

[0079] As discussed herein, r-PET can include one or more comonomers that modify the diester and / or diol components of the resin. The one or more modifying monomers can include a modified diol, a modified diester (or acid), or both a modified diol and a diester (or acid). Examples of modifying monomers include, but are not limited to, 1,4-cyclohexanedimethanol (CHDM), neopentyl glycol (NPG), isophthalic acid (IPA), dimethyl isophthalate (DMI), and diethylene glycol (DEG). The one or more modifying monomers can include recycled materials. In some cases, the r-PET includes at least 1 mol%, at least 5 mol%, at least 10 mol%, at least 15 mol%, at least 20 mol%, at least 25 mol%, at least 30 mol%, at least 35 mol%, or at least 40 mol% and / or no more than 50 mol%, no more than 45 mol%, no more than 40 mol%, no more than 35 mol%, no more than 30 mol%, no more than 25 mol%, no more than 20 mol%, no more than 15 mol%, no more than 10 mol%, or no more than 5 mol% of at least one modifying monomer, based on the total moles of the diester component, the diol component, or both.

[0077]

[0080] r-PET can be used in a variety of end uses including sheets, films, trays, rods, tubes, lids, bottles (water bottles, hot fill bottles, soda bottles), and packaging as well as filaments and fibers. Additionally, r-PET can be used to form injection molded articles.

[0078]

[0081] As discussed herein, in some cases, the methanolysis facility and the PET production facility may be co-located. When co-located, one or more streams from one facility may be transported to and utilized in the other facility that consolidates the facilities. Such consolidation can reduce energy use and increase overall process efficiency while enabling the production of up to 100% recycled PET.

[0079]

[0082] Referring now to FIG. 3, a portion of a chemical recycling facility is shown that includes a co-located methanolysis facility and a PET manufacturing facility. In some cases, the chemical recycling facility may further include a co-located and integrated plastic processing facility as shown in FIGS. 1 and 2. When integrated, the facilities may share utilities such as furnaces, steam, condensate, heat transfer media (HTM), cooling tower water, chilled water, nitrogen, city water, wastewater treatment, flare systems, and catalyst systems. Additionally, facilities such as office facilities, warehouse facilities, etc. may be shared. Plastic processing and its associated components and streams may also be co-located and integrated with the methanolysis and / or PET facilities.

[0080]

[0083] Referring again to Figure 3, the r-DMT and / or r-EG from the methanolysis facility can be introduced into the transesterification zone of the PET production facility, optionally with DMT (or r-DMT) and / or EG (or r-EG) from another source (not shown). If the methanolysis and PET production facilities are co-located and in fluid communication with one another, the r-DMT and / or r-EG can be transported between the two facilities with little or no cooling or separation. For example, the temperature of the r-DMT can be maintained above a minimum temperature of at least 125°C, at least 130°C, at least 135°C, at least 140°C, at least 145°C, or at least 150°C as it is transported from the methanolysis facility to the PET production facility (e.g., from the outlet of the r-DMT vessel in the methanolysis facility to the inlet of the vessel in the PET production facility). Additionally, at least 85%, at least 90%, at least 95%, at least 97%, at least 99%, or 100% of the r-DMT removed from the methanolysis facility can be introduced into the PET facility. Similarly, the temperature of the r-EG can be maintained above a minimum temperature of at least 125° C., at least 130° C., at least 135° C., at least 140° C., at least 145° C., or at least 150° C. as it is transported from the methanolysis facility to the PET manufacturing facility. Additionally, at least 85%, at least 90%, at least 95%, at least 97%, at least 99%, or 100% of the r-EG removed from the methanolysis facility can be introduced into the PET facility.

[0081]

[0084] In some cases, the total travel path (or transportation path) of the r-EG and / or r-DMT (e.g., between the outlet of the methanolysis facility and the inlet of the PET facility) can be less than 5 miles, less than 3 miles, less than 2 miles, less than 1 mile, or less than 1500 feet, less than 1000 feet, or less than 500 feet, measured between the outlet of the methanolysis facility and the inlet of the PET facility. Alternatively, the total travel path can be at least 100 feet, at least 500 feet, at least 0.5 mile, at least 1 mile, or at least 2 miles, and / or 5 miles or less, 4 miles or less, 3 miles or less, 2 miles or less, 1.5 miles or less, or 1 mile or less.

[0082]

[0085] Further, there may be little or no intermediate storage of r-DMT and / or r-EG between the two facilities, for example, the intermediate storage (e.g., tank volume) of r-DMT and / or r-EG between the two facilities may be 5 days or less, 4 days or less, 3 days or less, 2 days or less, or 1 day or less.

[0083]

[0086] In other cases, the PET and methanolysis facilities may be located remotely from one another but integrated. For example, vapors from the methanolysis facility may be cooled and condensed, and the condensed vapors transported to the methanolysis facility. In such cases, intermediate storage between the two facilities may be sufficient for more than 5 days, at least 10 days, at least 15 days, at least 20 days, or more, and may be co-located with the methanolysis facility, the PET production facility, or may be located remotely from both.

[0084]

[0087] Referring again to FIG. 3, during the transesterification reaction carried out in the reaction zone of the PET production facility between DMT and EG, methanol is released as a by-product and may be recovered in the vapor phase from the transesterification step and introduced into the distillation zone. Additionally, additional methanol and vaporized EG (as well as other vaporized by-products and comonomers) from the polymerization zone may also be collected and sent to the distillation zone. In some cases, one or more streams removed from the reaction zone and introduced into the distillation zone may contain at least 0.5% by weight, at least 1% by weight, at least 2% by weight, or at least 5 and / or 10% by weight or less, 7% by weight or less, 5% by weight or less, 2% by weight or less, or 1% by weight or less of terephthalyl components, based on the total weight of the stream.

[0085]

[0088] In the distillation step or zone, one or more distillation columns can be used to separate DMT (r-DMT) or terephthalyl components (r-terephthalyl components), EG (r-EG), methanol (r-methanol), and other components such as water, low boiling components (e.g., components with a boiling point lower than methanol and / or EG), and high boiling components (e.g., components with a boiling point higher than EG). As shown in FIG. 3, at least a portion of the r-methanol recovered from the distillation zone of the PET production facility can be introduced into the reaction zone of the methanolysis facility. In some cases, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 99% of the methanol recovered from the PET production facility can be used in the reaction zone of the methanolysis facility. Additionally, as also shown in FIG. 3, all or a portion of the methanol recovered in the product separation zone of the methanolysis facility can be returned to the reaction zone for further use. As also shown in Figure 1, EG (r-EG) recovered in the distillation zone of the PET plant can be returned to the transesterification zone of the PET plant for use in the transesterification reaction. Additionally, one or more of the streams returned to the distillation zone can contain DMT (r-DMT), which can be separated and reintroduced into the reaction zone of the PET plant.

[0086]

[0089] Referring now to FIG. 4, another portion of a chemical recycling facility including an integrated methanolysis facility and a PET manufacturing facility is shown, particularly when the methanolysis facility and the PET manufacturing facility share a common distillation zone. As shown in FIG. 4, once the PET waste plastic is subjected to methanolysis in the reaction zone, the methanolysis reactor stream can be separated into a light organic stream and a heavy organic stream in a product separation zone. The heavy organic stream, which contains primarily DMT, can be further separated in a heavy organic separation zone, while the light organic stream, which contains primarily methanol and EG, can be separated in one or more distillation columns (also separating methanol and / or EG containing streams from the transesterification zone and polymerization zone of the PET manufacturing facility). These streams may also contain terephthalyl components. In some cases, the shared distillation column or columns may provide an EG-enriched stream, a methanol-enriched stream, or other by-product streams.

[0087]

[0090] When introduced into a shared distillation column, the stream from the methanolysis facility (e.g., the methanolysis reactor product stream) and the stream from the reaction zone of the PET production facility may be combined prior to entering the column, or each may be introduced separately. In some cases, one or both streams may be heated or cooled as necessary to maintain the temperature and / or concentration profile throughout the column, and the streams may be vapor, liquid, or mixed phase (vapor and liquid) streams when introduced into the column.

[0088]

[0091] In some cases, the shared column may be an EG separation column for removing EG (r-EG) from one or more incoming feed streams, and the vapor stream from the PET manufacturing facility may contain primarily EG. In some cases, the shared column may be a methanol separation column for removing methanol from one or more incoming feed streams, and the vapor stream removed from the PET manufacturing facility (or transesterification zone) may contain primarily methanol. In some cases, the shared column may be a spray column downstream of a methanolysis reactor, and the stream from the PET manufacturing facility may contain r-EG, r-methanol, and r-DMT (or r-terephthalyl components).

[0089]

[0092] In some cases, at least a portion of the vapor stream removed from the reaction zone (e.g., transesterification zone and / or polymerization zone) of the PET production facility can be decanted with water to provide an organic phase and an aqueous phase. Contact with water can serve to remove at least a portion of the EG azeotrope-forming compounds, which can also form azeotropes with EG and water. In some cases, the decanting step (if performed) can remove at least 50%, at least 60%, at least 70%, at least 75%, at least 80%, at least 90%, or at least 95% of the EG azeotrope-forming compounds from the vapor stream of the PET reaction zone introduced into the distillation zone and at least one distillation column therein. If solid stating is performed, the overhead stream from the solid stating zone can be introduced into the distillation zone and can optionally be decanted with water before introduction.

[0090]

[0093] In some cases, removing compounds that form EG (and / or water) azeotropes from the vapor stream of a PET facility (e.g., from the transesterification, polymerization, solid stating (if present), or crystallization zones) can reduce the energy usage of one or more distillation columns used to separate streams from the methanolysis and / or PET manufacturing facility.

[0091]

[0094] Additionally or alternatively, in some cases, at least a portion of the vapor streams from the PET reaction zone (or crystallization or solid stating, if present) can be introduced directly into one or more distillation columns of the shared distillation zone, which can increase energy efficiency. In other cases, at least a portion or all of these streams may be condensed prior to separation in the distillation zone.

[0092]

[0095] Additionally, in some cases, the reaction zone of the methanolysis facility and the transesterification zone of the PET facility can share a common catalyst source, as generally shown in Figure 4. This can occur, for example, when the same catalyst is used by both reaction zones. The catalyst can be of the same type and present in the same amounts as described herein. definition

[0093]

[0096] It should be understood that the following is not intended to be an exhaustive list of defined terms. Other definitions may be provided in the preceding description, for example, as accompanying the use of the defined term in context.

[0094]

[0097] As used herein, the terms "a," "an," and "the" mean one or more.

[0095]

[0098] As used herein, the term "and / or," when used in a list of two or more items, means that any one of the listed items can be used alone, or any combination of two or more of the listed items can be used. For example, if a composition is described as containing components A, B, and / or C, the composition can include A only; B only; C only; a combination of A and B; a combination of A and C, a combination of B and C; or a combination of A, B, and C.

[0096]

[0099] As used herein, the phrase "at least a portion" includes from at least a portion to the entire amount or period.

[0097]

[0100] As used herein, the term "chemical recycling" refers to waste plastic recycling processes that involve chemically converting waste plastic polymers into lower molecular weight polymers, oligomers, monomers, and / or non-polymer molecules (e.g., hydrogen, carbon monoxide, methane, ethane, propane, ethylene, and propylene) that are useful in their own right and / or as feedstocks to one or more additional chemical manufacturing processes.

[0098]

[0101] As used herein, the term "monomer" refers to a polymeric species containing a chain length of less than about three.

[0099]

[0102] As used herein, the term "oligomer" refers to a species of polymer containing chain lengths ranging from about 7 to about 50.

[0100]

[0103] As used herein, the term "polymer" refers to polymer species that contain a chain length greater than about 50.

[0101]

[0104] As used herein, the terms "polyethylene terephthalate" and "PET" include PET homopolymer, PET copolymer, and PETG.

[0102]

[0105] As used herein, the term "PET copolymer" refers to PET modified by up to 10 mol% with one or more added comonomers. For example, the term "PET copolymer" includes PET modified by up to 10 mol% isophthalic acid on a 100 mol% carboxylic acid basis. In another example, the term PET copolymer includes PET modified by up to 10 mol% 1,4-cyclohexanedimethanol (CHDM) on a 100 mol% diol basis.

[0103]

[0106] As used herein, the term "residue" refers to a moiety that is a resulting product of a chemical species in a particular reaction scheme or subsequent formulation or chemical product, regardless of whether the moiety is actually derived from the chemical species.

[0104]

[0107] As used herein, the term "co-located" refers to the property of at least two objects being located on a common physical site and / or within one mile of each other.

[0105]

[0108] As used herein, the terms "comprising," "comprises," and "comprise" are open-ended transitional terms used to transition from the subject matter listed before the term to one or more elements listed after the term, and the element or elements listed after the transitional term are not necessarily the only elements that make up the subject matter.

[0106]

[0109] As used herein, the term "commercial-scale facility" refers to a facility having an average annual feed rate of at least 500 pounds per hour averaged over a one-year period.

[0107]

[0110] As used herein, the term "D90" refers to a specified diameter where 90% of a distribution of particles have a diameter smaller than the specified diameter and 10% have a diameter larger than the specified diameter. To ensure a representative D90 value, the sample size of the particles should be at least 1 pound. To determine the D90 of particles in a continuous method, tests should be performed on at least five samples taken at equal intervals over at least 24 hours. Testing for D90 is done using high speed photography and computer algorithms to generate a particle size distribution. One suitable particle size analyzer for determining D90 values ​​is the Model CPA4-1 Computerized Particle Analyzer manufactured by WS Tyler, Mentor, Ohio.

[0108]

[0111] As used herein, "diameter" means the maximum chord length of a particle (ie, its largest dimension).

[0109]

[0112] As used herein, the term "directly derived" refers to having at least one physical component that originates from waste plastic.

[0110]

[0113] As used herein, the terms "having," "has," and "have" have the same open-ended meaning as "comprising," "comprises," and "comprise" provided above.

[0111]

[0114] As used herein, the term "heavy organic methanolysis by-products" refers to methanolysis by-products that have a higher boiling point than DMT.

[0112]

[0115] As used herein, the term "heavy organic solvolysis by-products" refers to solvolysis by-products that have a higher boiling point than the primary terephthalyl product of the solvolysis unit.

[0113]

[0116] As used herein, the terms "including," "include," and "included" have the same open-ended meaning as "comprising," "comprises," and "comprise" provided above.

[0114]

[0117] As used herein, the term "indirectly derived" refers to having an allocated recycled content that i) originates from waste plastics, but ii) is not based on having a physical component that originates from waste plastics.

[0115]

[0118] As used herein, the term "light organic methanolysis by-products" refers to methanolysis by-products that have a lower boiling point than DMT.

[0116]

[0119] As used herein, the term "light organic solvolysis by-products" refers to solvolysis by-products that have a lower boiling point than the primary terephthalyl product of the solvolysis unit.

[0117]

[0120] As used herein, the term "methanolysis by-product" refers to any compound removed from a methanolysis facility other than dimethyl terephthalate (DMT), ethylene glycol (EG), or methanol.

[0118]

[0121] As used herein, the terms "mixed plastic waste" and "MPW" refer to a mixture of at least two types of waste plastics, including, but not limited to, the following plastic types: polyethylene terephthalate (PET), one or more polyolefins (PO), and polyvinyl chloride (PVC).

[0119]

[0122] As used herein, the term "molecular reforming" refers to the conversion of carbon-containing feedstocks into synthesis gas (CO, CO2, and H2). Molecular reforming encompasses both steam reforming and partial oxidation (POX) gasification.

[0120]

[0123] As used herein, "PET" refers to a homopolymer of polyethylene terephthalate, or polyethylene terephthalate modified with modifiers, or containing residues or moieties other than ethylene glycol and terephthalic acid, such as residues or moieties of isophthalic acid, 1,4-cyclohexanedicarboxylic acid, diethylene glycol, TMCD (2,2,4,4-tetramethyl-1,3-cyclobutanediol), CHDM (cyclohexanedimethanol), propylene glycol, isosorbide, 1,4-butanediol, 1,3-propanediol, and / or NPG (neopentyl glycol). or a polyester having repeating terephthalate units (with or without repeating ethylene glycol based units) and one or more residues or moieties of TMCD (2,2,4,4-tetramethyl-1,3-cyclobutanediol), CHDM (cyclohexanedimethanol), propylene glycol, or NPG (neopentyl glycol), isosorbide, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-butanediol, 1,3-propanediol, and / or diethylene glycol, or combinations thereof.

[0121]

[0124] As used herein, the term "PET solvolysis" refers to a reaction in which a polyester terephthalate-containing plastic feed is chemically decomposed in the presence of a solvent to form a predominant terephthalyl product and / or a predominant glycol product.

[0122]

[0125] As used herein, "physical recycling" (also known as "mechanical recycling") refers to a waste plastic recycling process that involves melting waste plastic and forming the molten plastic into new intermediate products (e.g., particles or sheets) and / or new final products (e.g., bottles). Generally, physical recycling does not substantially change the chemical structure of the plastic, although some degradation may occur.

[0123]

[0126] As used herein, the term "predominantly" means greater than 50% by weight. For example, a predominantly propane stream, composition, feedstock or product is a stream, composition, feedstock or product that contains greater than 50% by weight propane.

[0124]

[0127] As used herein, the term "pyrolysis" refers to the thermal decomposition of one or more organic materials at elevated temperatures in an inert (i.e., substantially oxygen-free) atmosphere.

[0125]

[0128] As used herein, "recycle content" and "r-content" refer to a composition that is or contains directly and / or indirectly derived from waste plastics.

[0126]

[0129] As used herein, the term "remotely located" refers to a distance between two facilities, locations, or reactors that is at least 5, at least 10 miles, at least 50 miles, at least 100 miles, at least 500 miles, or at least 1000 miles.

[0127]

[0130] As used herein, "solid state polymerization" refers to a process in which polymer chain length is increased by heating a polyester in the substantial absence of oxygen and water. During solid state polymerization, the polymer is in solid form and is not in a molten phase.

[0128]

[0131] As used herein, the term "solvolysis" or "ester solvolysis" refers to a reaction in which an ester-containing feed is chemically decomposed in the presence of a solvent to form predominantly carboxyl and / or glycol products. Examples of solvolysis include hydrolysis, alcoholysis, and ammonolysis.

[0129]

[0132] As used herein, the term "solvolysis by-product" refers to any compound removed from a solvolysis unit that is not the primary carboxyl (terephthalyl) product of the solvolysis unit, the primary glycol product of the solvolysis unit, or the primary solvent fed to the solvolysis unit.

[0130]

[0133] As used herein, the term "terephthalyl" refers to a molecule that contains the following group:

[0131] [ka]

[0132]

[0134] As used herein, the term "primary terephthalyl" refers to the main or major terephthalyl product recovered from a solvolysis unit.

[0133]

[0135] As used herein, the term "glycol" refers to a moiety that contains two or more --OH functional groups per molecule.

[0134]

[0136] As used herein, the term "primary glycol" refers to the primary glycol product recovered from a solvolysis unit.

[0135]

[0137] As used herein, the terms "waste plastic" and "plastic waste" refer to post-consumer, scrap, and / or discarded plastic materials. Waste plastics supplied to chemical recycling facilities may be unprocessed or partially processed.

[0136] Supporting Description of Additional Claims - First Embodiment

[0137]

[0138] In a first embodiment of the present technology, there is provided a method for producing recycled content polyethylene terephthalate (r-PET) from mixed plastic waste, comprising the steps of: (a) treating the mixed plastic waste in a plastics processing facility to provide a primary polyethylene terephthalate (PET) waste plastic stream; (b) subjecting the primary PET waste plastic stream to methanolysis in a methanolysis facility to form recycled content ethylene glycol (r-EG) and recycled content dimethyl terephthalate (r-DMT); and (c) reacting at least a portion of the r-EG and / or r-DMT in a reaction zone of a PET production facility to form recycled content polyethylene terephthalate (r-PET), wherein the plastics processing facility, the methanolysis facility, and the PET production facility are co-located.

[0138]

[0139] The first embodiment described in the previous paragraph may also include one or more additional aspects / features listed in the following bulleted paragraphs. Each of the following additional features of the first embodiment may be an independent feature or may be combined with one or more other additional features to the extent consistent. Furthermore, the following bulleted paragraphs may be considered features of dependent claims with the level of dependency indicated by the degree of indentation in the bulleted list (i.e., a feature indented further than the feature listed above is considered to be dependent on the feature listed above).

[0139] Step (b) includes contacting the primary PET waste plastic with methanol at a temperature which may be at least 50°C, at least 55°C, at least 60°C, at least 65°C, at least 70°C, at least 75°C, at least 80°C, or at least 85°C and / or no greater than 350°C, no greater than 345°C, no greater than 340°C, no greater than 335°C, no greater than 330°C, no greater than 325°C, no greater than 320°C, no greater than 315°C, no greater than 310°C, no greater than 300, or no greater than 295°C. Methanol does not get superheated when it comes into contact with PET waste plastic. · The primary PET waste plastic stream contains at least 50 (75, 85, 90, 95) percent by weight PET, based on the total weight of the stream. Mixed plastic waste mainly contains PET and polyolefin (PO), and the PET waste plastic is removed from the PO waste plastic during processing. Further included is chemical recycling of at least a portion of the PO waste plastic. The treatment in step (a) comprises separating and / or sizing the mixed waste plastics. o Sizing involves increasing or decreasing the size of the mixed plastic waste. Sizing involves reducing the size of mixed plastic waste. Sizing involves increasing the size of the mixed plastic waste. Processing involves separating PET waste plastic from non-PET waste plastic. (iii) At least a part of the separation is carried out using a sink-float separator. The mixed plastic waste contains at least 2 (5, 10, 15) % by weight and / or no more than 20 (15, 10, 7, 5) % by weight of plastics other than PET and PO.

[0140] The pressure of the methanolysis reaction in step (b) is within 5 psi, within 10 psi, within 15 psi, within 20 psi, within 25 psi, within 30 psi, within 35 psi, within 40 psi, within 45 psi, or within 50 psi of atmospheric pressure. The pressure of the methanolysis reaction in step (b) is within 55 psi, within 75 psi, within 90 psi, within 100 psi, within 125 psi, within 150 psi, within 200 psi, or within 250 psi of atmospheric pressure. The temperature of the methanolysis reaction in step (b) is at least 50 (55, 60, 65, 70, 75, 80, 85) °C and / or not more than 350 (345, 340, 335, 330, 325, 320, 315, 310, 300, or 295) °C. The reaction includes transesterifying DMT and EG in a transesterification reactor to form recycled PET oligomers (r-PET oligomers), where the DMT includes r-DMT and / or the EG includes r-EG. The transesterification reaction is carried out at a temperature of at least 175°C, 180°C, 185°C, 190°C, 195°C, 200 (210, 215, 220)°C and / or up to 350 (345, 340, 335, 330, 325, or 320)°C. o The transesterification reaction is carried out at pressures within 1 psig, 2 psig, 5 psig, or 10 psig of atmospheric pressure. The transesterification reaction is carried out at a pressure of at least 0, 5, 10, 25, 50, or 75 psig and / or up to 100, 75, 50, 25, 20, 10, or 5 psig. The ratio of EG to DMT introduced into the transesterification reactor is at least 1.1 (1.2:1, 1.3:1, 1.4:1, or 1.5:1) and / or not more than 5:1 (4:1, 3.5:1, or 3:1). The conversion of DMT after transesterification is at least 85 (90, 95, 97, or 99)%. The transesterification reaction is carried out in the presence of a transesterification catalyst selected from the group consisting of titanium alkoxides, tin (II) or (IV) esters, alkali metals or alkaline earth metals (e.g., Li and Ca), manganese compounds, zinc compounds, magnesium acetate or magnesium benzoate, and combinations thereof. Further included is polymerizing the r-PET oligomers to provide a recycle-containing PET polymer melt (r-PET polymer melt) having an inherent viscosity (IV) of at least 0.65 dL / g. ■ The polymerization is carried out at a temperature of at least 240 (245, 250, 255, or 260)°C and / or up to 340 (335, 330, 325, 320, 315, 310, or 300)°C. ■ The polymerization is carried out at a pressure of atmospheric pressure or less, or less than 750 Pa, less than 500 Pa, less than 250 Pa, less than 100 Pa, less than 50 Pa, or less than 20 Pa. ■ The polymerization is carried out in the presence of a non-antimony catalyst.

[0141] · r-PET contains at least one IR absorber additive. IR absorber additives are selected from the group consisting of black iron oxide, graphite, reduced antimony catalyst, carbon black and titanium nitride. The IR absorber additive is present in an amount of at least 0.10 (0.5, 1, 1.5) wt% and / or no more than 5 (3, 2, 1, 0.5) wt%, based on the weight of the r-PET. The reaction includes polymerizing r-PET oligomers in a polycondensation zone to provide an r-PET polymer melt having an inherent viscosity (IV) of at least 0.60 (0.62, 0.65, 0.67, 0.70, 0.72, 0.75, 0.77, 0.80) dL / g and / or no greater than 1.05 (1.02, 1.0, 0.97, 0.95, 0.92, 0.90, 0.87, 0.85, 0.82) dL / g. The method further includes pelletizing at least a portion of the r-PET polymer melt to form r-PET particles, and crystallizing at least a portion of the particles to form crystalline r-PET particles. ■ Pelletization involves underwater cutting. ■Crystallization includes latent heat crystallization. ■ The method further includes stripping the r-PET particles to form stripped r-PET, said stripping removing residual acetaldehyde (AA). ■ r-PET particles are not solid-state polymerized. ■ The average particle size of the r-PET particles is at least 0.5 (0.6, 0.7, or 0.8) g / 50 particles and / or no more than 1 (0.90, 0.85, or 0.80) g / 50 particles. (iii) Prior to the crystallization, the method further includes drying the r-PET particles in a dryer and crystallizing the dried r-PET particles. ■ Crystallization occurs without external or additional heat. ■ The crystallization is carried out at a temperature of at least 125 (130, 135, 140, 145)°C and / or up to 225 (220, 215, 210, 205, or 200)°C. ■ The average residence time of the r-PET particles during crystallization is at least 30 minutes, 45 minutes or 1 hour, and / or not more than 15 hours, 12 hours, or 10 hours.

[0142] The reaction further includes one or more comonomers. The one or more comonomers are selected from the group consisting of isophthalic acid (IPA), dimethyl isophthalate (DMI), neopentyl glycol (NPG), 1,4-cyclohexanedimethanol (1,4-CHDM), diethylene glycol (DEG), and combinations thereof. Residues of comonomers are present in said r-PET in a total amount of at least 5 (10, 15, 20, 25, 30, 35) mol % and / or no more than 50 (45, 40, 35, 30, 25, 20, 15) mol %, based on the total moles of diester or diol components. At least a part of the reaction in step (c) is carried out in a reactive distillation column. At least a portion of the reaction in step (c) is carried out in a CSTR, a pipe reactor, a plug flow reactor, a reactive distillation column, a falling film reactor, a horizontal stirred reactor, a vertical gravity driven reactor, or a combination thereof. transporting at least a portion of the r-DMT and / or r-EG from the methanolysis facility to a PET production facility and introducing the r-DMT and / or r-EG to a transesterification reactor of the PET production facility. The r-DMT and / or r-EG are in a liquid phase during delivery and / or introduction. The r-DMT and / or r-EG are in the gas phase during delivery and / or introduction. Further included is transporting and introducing at least a portion of both r-DMT and r-EG. ■ r-DMT and r-EG are introduced separately into the transesterification reactor. ■ The r-DMT and r-EG are combined and the combined stream is introduced into the transesterification reactor.

[0143] During at least a portion of the forming step (c), a stream comprising recycle-containing methanol (r-methanol) is removed from a reaction zone of a PET production facility. The method further includes separating the r-methanol in at least one distillation column. ■ The method further includes transporting at least a portion of the r-methanol to a reaction zone of a methanolysis facility. The transport is in at least one pipe in fluid communication with a distillation column and a methanolysis reactor of the PET production facility. · The total migration path of r-methanol between the distillation column and the methanolysis reactor in the PET manufacturing facility is less than 2 (1.5, 1, 0.5, 0.25) miles. r-PET is formed at least in part from r-EG and r-DMT. At least 90 (92, 95, or 97)% of the DMT used to form r-PET in step (c) originates from the methanolysis facility. Transporting at least a portion of the r-DMT from the methanolysis facility to a PET production facility and introducing the r-DMT into a transesterification reactor of the PET production facility. During at least 90 (92, 95, 97, 99)% of the transport from the methanolysis plant to the transesterification reactor, the temperature of the r-DMT is above 135°C (140, 145°C). The temperature of the r-EG is above 135°C (140, 145°C) for at least 90 (92, 95, 97, 99)% of the transport from the methanolysis plant to the transesterification reactor. The total travel path of r-DMT and / or r-EG between the methanolysis facility and the transesterification reactor is at least 100 (500 feet, 0.5, 1, 2 miles) and / or no more than 5 (4, 3, 2, 1.5, 1) miles. The total storage capacity of r-DMT or r-EG between the methanolysis unit and the transesterification reactor is less than or equal to 5 (4, 3, 2, 1.5, 1) days.

[0144] The process is continuous. · The process is a commercial scale process and the PET facility has an average production rate of at least 1,000 lbs / hour of r-PET. r-PET has at least one of the following characteristics (i) to (v): (i) not more than 0.1 mole % of residues of each of the following components: 4-methyl formyl benzoate, dimethyl 1,4-cyclohexanedicarboxylate, dimethyl phthalate, methyl isopropyl terephthalate, methyl propyl terephthalate, and methyl isobutyl terephthalate; (ii) at least 0.1 mole % of residues of each of the following compounds: diisobutyl phthalate, methyl 4-ethyl benzoate, and methyl 4-vinyl benzoate; (iii) r-PET contains 100 ppm or less of cobalt (Co) and bromide (Br); (IV) the r-PET has a methyl end concentration of at least 5% and not more than 30%, based on the total end groups; and (v) the r-PET contains no more than 0.1 mole percent, based on the total moles of polyester, of residues of 4-carboxybenzaldehyde and 9-fluoreneone-2,6-dicarboxylic acid. The r-PET has an inherent viscosity in the range of 0.65-1.10 dL / g, and the r-PET comprises a plurality of spherical particles, the intrinsic viscosity (It.V.) of the surface of each particle being less than 0.25 dL / g higher than the It.V. of the center of the particle. r-PET is in the range of -2 to 2 (0, less than -1) * and r-PET has an L of at least 70 (75, 80, 85) and / or 95 (92, 90) or less. * It has color. · The acetaldehyde (AA) content of r-PET is less than 5 (2, 1, 0.5) ppm. ·r-PET has less than 0.001 ppm of Bisphenol A (BPA). r-PET has a diester component that includes at least 75 (80, 85, 90, 95, or 99) mole % of residues of DMT, based on the total number of moles in the diester component, and a diol component that includes at least 75 (80, 85, 90, 95, or 99) mole % of residues of EG, based on the total number of moles in the diol component. · r-PET is crystalline. · r-PET contains no more than 0.5 (0.1, 0.05) mole percent of residues of terephthalic acid based on the total moles of diester components. · forming at least one r-PET article from at least a portion of the r-PET particles. The r-PET article is selected from the group consisting of water bottles, hot fill bottles, carbonated beverage bottles, packaging materials, and fibers.

[0145] Supporting Description of Additional Claims - Second Embodiment

[0146]

[0140] In a second embodiment of the present technology, a method for producing recycled polyethylene terephthalate (r-PET) is provided, the method comprising the steps of: (a) depolymerizing waste plastics containing primarily polyethylene terephthalate (PET) in a methanolysis reactor to form one or more methanolysis streams comprising methanol, recycled ethylene glycol (r-EG), and / or recycled dimethyl terephthalate (r-DMT); (b) isolating, in one or more distillation columns, r-EG, methanol, and r-DMT from at least a portion of the one or more methanolysis streams; (c) reacting the r-EG and r-DMT in a reaction zone of the PET production facility to form a recycled PET polymer melt (r-PET polymer melt) having an inherent viscosity (IV) of at least 0.50 dL / g; (d) withdrawing a vapor phase stream from the reaction zone of the PET production facility comprising primarily EG, DMT, and / or methanol; and (e) separating in at least one of the distillation columns at least a portion of the vapor phase stream withdrawn from the PET production facility from one or more methanolysis streams.

[0147]

[0141] The second embodiment described in the previous paragraph may also include one or more additional aspects / features listed in the following bulleted paragraphs. Each of the following additional features of the second embodiment may be an independent feature or may be combined with one or more other additional features to the extent consistent. Furthermore, the following bulleted paragraphs may be considered features of dependent claims with the level of dependency indicated by the degree of indentation in the bulleted list (i.e., a feature indented further than the feature listed above is considered to be dependent on the feature listed above).

[0148] · Step (d) comprises withdrawing a gas phase stream comprising primarily EG from the reaction zone, the stream further comprising at least 0.5 (1, 2, 5) wt. % of a terephthalyl component, based on the total weight of the stream. Prior to the separation in step (e), the stream removed from the PET production facility is combined with the methanolysis reactor product stream, and then in the separation in step (e), the combined streams are separated. The separation in step (b) comprises separating r-EG in an EG separation column, and step (d) comprises removing a vapor stream comprising primarily EG from the polycondensation reactor of the PET reaction zone. The separating in step (b) comprises separating methanol in a methanol column, and step (d) comprises removing a vapor stream comprising primarily methanol from the transesterification reactor of the PET reaction zone. The removal of step (d) involves removing a stream containing EG, methanol, and DMT and separating it in a spray column downstream of the methanolysis reactor. The reaction of step (c) includes transesterifying r-EG and r-DMT to form PET oligomers and polymerizing at least a portion of the r-PET oligomers to form an r-PET polymer melt. The r-PET polymer melt has an inherent viscosity (IV) of at least 0.65 dL / g. The method further includes pelletizing at least a portion of the r-PET polymer melt via underwater cutting to provide recycled PET (r-PET) particles, and crystallizing the r-PET particles via latent heat crystallization to provide crystalline r-PET particles. ■ r-PET particles are not subjected to solid-state polymerization.

[0149] The separating step (b) comprises removing r-EG from one or more methanolysis streams. The separating in step (b) comprises removing r-DMT from one or more methanolysis streams. The separating in step (b) comprises removing methanol from one or more of the methanolysis streams. Prior to step (a), the method further includes treating the mixed waste plastics in a plastic processing facility to obtain primarily PET waste plastics, and in step (a), primarily depolymerizing PET. Processing includes sizing and / or separating the mixed waste plastics to provide primary PET waste plastics.

[0150] The process is continuous. · The process is a commercial scale process and the PET facility has an average production rate of at least 500 pounds / hour of r-PET. · The methanolysis facility and the PET manufacturing facility are located in the same place. The r-PET has an inherent viscosity in the range of 0.65-1.10 dL / g, and the r-PET comprises a plurality of spherical particles, the intrinsic viscosity (It.V.) of the surface of each particle being less than 0.25 dL / g higher than the It.V. of the center of the particle. · The acetaldehyde content of r-PET is 75 (50, 25, 10, 5) ppm or less. r-PET has a diester component that includes at least 75 (80, 85, 90, 95, or 99) mole % of residues of DMT, based on the total moles in the diester component, and a diol component that includes at least 75 (80, 85, 90, 95, or 99) mole % of residues of EG, based on the total moles in the diol component, and the r-PET includes no more than 0.5 (0.1, 0.05) mole % of residues of terephthalic acid, based on the total moles in the diester component.

[0151] Supporting Description of Additional Claims - Third Embodiment

[0152]

[0142] In a third embodiment of the present technology, a method for producing recycled polyethylene terephthalate (r-PET) is provided, the method comprising: (a) reacting ethylene glycol (EG) and dimethyl terephthalate (DMT) in a reaction zone of a PET production facility, wherein the EG comprises recycled ethylene glycol (r-EG) and / or the DMT comprises recycled dimethyl terephthalate (r-DMT); (b) removing a gaseous stream from the reaction zone of the PET production facility; (c) contacting the gaseous stream with water to remove at least a portion of the EG and / or water azeotrope-forming compounds present in the gaseous stream; and (d) introducing at least a portion of the azeotrope-forming compounds removed from the gaseous stream into a distillation column of a methanolysis facility.

[0153]

[0143] The third embodiment described in the previous paragraph may also include one or more additional aspects / features listed in the following bulleted paragraphs. Each of the following additional features of the third embodiment may be an independent feature or may be combined with one or more other additional features to the extent consistent. Furthermore, the following bulleted paragraphs may be considered features of dependent claims with the level of dependency indicated by the degree of indentation in the bulleted list (i.e., a feature indented further than the feature listed above is considered to be dependent on the feature listed above).

[0154] The EG reacted in step (a) comprises at least 75 (90, 95) wt % r-EG. The DMT reacted in step (a) comprises at least 75 (90, 95) wt. % r-DMT. The DMT and EG contain at least 99% by weight of r-DMT and r-EG, respectively. Further included is separating EG, DMT, and / or methanol from at least a portion of the vapor phase stream removed from the reaction zone of the PET production facility in a distillation column of the methanolysis facility. The contact removes at least 50 (75, 90, 95)% of the EG and / or water azeotrope in the vapor stream. The reaction zone includes a transesterification reactor and a polycondensation reactor, and the gas phase stream is taken from the transesterification reactor of the PET production facility. Further included is depolymerizing PET waste plastic in a methanolysis facility to provide recycled EG (r-EG) and recycled dimethyl terephthalate (r-DMT), and at least a portion of the r-EG and / or r-DMT from the methanolysis facility is used in the reaction of step (a). The process is continuous. · The process is a commercial scale process and the PET facility has an average production rate of at least 500 lbs / hour of r-PET. · The methanolysis facility and the PET manufacturing facility are located in the same place. r-PET has an inherent viscosity in the range of 0.65-1.10 dL / g, and r-PET comprises a plurality of spherical particles in which the intrinsic viscosity (It.V.) at the surface of each particle is less than 0.25 dL / g higher than the (It.V.) at the center of the particle. · The acetaldehyde content of r-PET is 75 (50, 25, 10, 5) ppm or less. r-PET has a diester component that includes at least 75 (80, 85, 90, 95, or 99) mole % of residues of DMT, based on the total moles in the diester component, and a diol component that includes at least 75 (80, 85, 90, 95, or 99) mole % of residues of EG, based on the total moles in the diol component, and the r-PET includes no more than 0.5 (0.1, 0.05) mole % of residues of terephthalic acid, based on the total moles in the diester component.

[0155] Claims not limited to the disclosed embodiments.

[0156]

[0144] The above-mentioned preferred embodiments of the present invention are used only as examples and should not be used in a limiting sense to interpret the scope of the present invention. Modifications to the above-mentioned exemplary embodiments can be easily made by those skilled in the art without departing from the spirit of the present invention.

[0157]

[0145] The inventors hereby express their intention to rely on the doctrine of equivalents to determine and assess a reasonably fair scope of the invention with respect to devices that do not materially depart from the literal scope of the invention as set forth in the following claims, but that are outside that scope.

Claims

1. 1. A method for producing recycled polyethylene terephthalate (r-PET) from mixed plastic waste, the method comprising: (a) treating mixed plastic waste at a plastics processing facility to provide a primarily polyethylene terephthalate (PET) waste plastic stream; (b) subjecting the primary PET waste plastic stream to methanolysis in a methanolysis facility to form recycled ethylene glycol (r-EG) and recycled dimethyl terephthalate (r-DMT); (c) reacting at least a portion of the r-EG and / or r-DMT in a reaction zone of a PET manufacturing facility to form recycled polyethylene terephthalate (r-PET); The method, wherein said plastics processing facility, said methanolysis facility, and said PET production facility are co-located.

2. 2. The method of claim 1, The process wherein the r-PET is formed from at least a portion of the r-EG and at least a portion of the r-DMT from the methanolysis facility, and at least 90% of the r-DMT and at least 90% of the r-EG reacted in step (c) originates from the methanolysis facility.

3. 2. The method of claim 1, and transporting at least a portion of the r-DMT from the methanolysis facility to the PET production facility and introducing the r-DMT into an ester exchange reactor within the PET production facility, wherein a temperature of the r-DMT is maintained above a minimum temperature of at least 135° C. during transport from the methanolysis facility to the ester exchange reactor.

4. 2. The method of claim 1, The process wherein the total storage capacity of r-DMT and / or r-EG between the methanolysis facility and the transesterification reactor is 5 days or less.

5. 2. The method of claim 1, The reacting in step (c) comprises transesterifying the r-EG and r-DMT to form a recycled PET oligomer (r-PET oligomer) and then polymerizing at least a portion of the r-PET oligomer in a polycondensation zone to provide a recycled PET polymer melt (r-PET polymer melt) having an inherent viscosity (IV) in the range of 0.60 to 1.05 dL / g.

6. 6. The method of claim 5, The method further comprises the steps of pelletizing at least a portion of the r-PET polymer melt to form r-PET particles and crystallizing at least a portion of the r-PET particles to form crystalline r-PET particles, wherein the pelletizing step comprises underwater cutting and the crystallizing step comprises latent heat crystallization.

7. 10. The method of claim 1 , The process wherein the reacting in step (c) comprises reacting one or more comonomers selected from the group consisting of isophthalic acid (IPA), dimethyl isophthalate (DMI), neopentyl glycol (NPG), 1,4-cyclohexanedimethanol (1,4-CHDM), diethylene glycol (DEG), and combinations thereof, with the r-DMT and r-EG, wherein residues of the comonomers are present in the r-PET in a total amount in the range of 5 to 45 mole %, based on the total moles of diester and / or diol components of the r-PET.

8. 1. A method for producing recycled polyethylene terephthalate (r-PET), the method comprising: (a) depolymerizing waste plastics containing primarily polyethylene terephthalate (PET) in a methanolysis reactor to form one or more methanolysis streams comprising methanol, recycled ethylene glycol (r-EG), and / or recycled dimethyl terephthalate (r-DMT); (b) separating at least a portion of at least one of r-EG, methanol, and r-DMT from at least a portion of said one or more methanolysis streams in one or more distillation columns; (c) reacting the r-EG and r-DMT in a reaction zone of a PET manufacturing facility to form a recycle-containing PET polymer melt (r-PET polymer melt) having an inherent viscosity (IV) of at least 0.50 dL / g; (d) withdrawing a vapor phase stream from the reaction zone of the PET production facility comprising primarily EG, DMT, and / or methanol; (e) separating at least a portion of said vapor phase stream removed from said PET facility from said one or more methanolysis streams in at least one of said distillation columns.

9. 9. The method of claim 8, The process further comprising combining said stream removed from said PET production facility with a methanolysis reactor product stream prior to said separation in step (e), and then separating said combined stream in said separation in step (e).

10. 9. The method of claim 8, wherein said separating in step (b) comprises separating r-EG in an EG separation column, and step (d) comprises removing a vapor stream comprising primarily EG from a polycondensation reactor of said PET reaction zone, and / or said separating in step (b) comprises separating methanol in a methanol column, and step (d) comprises removing a vapor stream comprising primarily methanol from a transesterification reactor of said PET reaction zone.

11. 9. The method of claim 8, The separating in step (c) comprises transesterifying at least a portion of the r-EG and r-DMT to form recycled PET oligomers (r-PET oligomers); and polymerizing at least a portion of the r-PET oligomers to form a recycled PET polymer melt (r-PET polymer melt), wherein the r-PET polymer melt has an inherent viscosity (IV) of at least 0.65 dL / g; and further comprising pelletizing at least a portion of the r-PET polymer melt by underwater cutting to provide recycled PET particles (r-PET particles); and crystallizing the r-PET particles by latent heat crystallization to provide crystalline r-PET particles.

12. 9. The method of claim 8, The method further comprises treating mixed waste plastics in a plastics processing facility prior to step (a) to provide primary PET scrap plastics, and depolymerizing said primary PET scrap plastics in step (a), said treating comprising sizing and / or separating the mixed waste plastics to provide said primary PET scrap plastics.

13. 1. A method for producing recycled polyethylene terephthalate (r-PET), the method comprising: (a) reacting ethylene glycol (EG) and / or dimethyl terephthalate (DMT) in a reaction zone of a PET production facility, wherein the EG comprises recycled ethylene glycol (r-EG) and / or the DMT comprises recycled dimethyl terephthalate (r-DMT); (b) withdrawing a gas phase stream from the reaction zone of the PET production facility; (c) contacting the vapor phase stream with water to remove at least a portion of the EG and / or water azeotrope forming compounds present in the vapor phase stream; (d) introducing at least a portion of said azeotrope-forming compounds removed from said vapor phase stream into a distillation column of a methanolysis unit.

14. 14. The method of claim 13, The process wherein said contacting removes at least 50% of said EG and / or water azeotrope forming compounds from said vapor phase stream.

15. 14. The method of claim 13, The method further comprises separating EG, DMT, and / or methanol from at least a portion of said vapor phase stream removed from said reaction zone of said PET production facility in a distillation column shared with said methanolysis facility.

16. 14. The method of claim 13, The method further comprises depolymerizing PET waste plastic in a methanolysis facility to provide recycled EG (r-EG) and recycled dimethyl terephthalate (r-DMT), wherein at least a portion of the r-EG and / or r-DMT from the methanolysis facility is used in the reaction of step (a).

17. 17. The method according to any one of claims 1 to 16, The r-PET is crystalline and at least one of the following (i) through (v) is true: (i) the r-PET contains less than 0.1 mol % of residues of each of the following components: 4-methyl formyl benzoate, dimethyl 1,4-cyclohexanedicarboxylate, dimethyl phthalate, methyl isopropyl terephthalate, methyl propyl terephthalate, and methyl isobutyl terephthalate; (ii) the r-PET contains at least 0.1 mol % of residues of each of the following compounds: diisobutyl phthalate, methyl 4-ethyl benzoate, and methyl 4-vinyl benzoate; (iii) the r-PET contains 100 ppm or less of cobalt (Co) and bromide (Br); (iv) the r-PET has a methyl end concentration of at least 5% and no more than 30%, based on the total end groups; and (v) the r-PET contains less than or equal to 0.1 mole percent, based on the total moles of polyester, of residues of 4-carboxybenzaldehyde and 9-fluoreneone-2,6-dicarboxylic acid.

18. 17. The method according to any one of claims 1 to 16, The r-PET has an inherent viscosity (IV) in the range of 0.65 to 1.10 dL / g and comprises a plurality of spherical particles, the intrinsic viscosity (It.V.) of the surface of each particle being less than 0.25 dL / g higher than the It.V. of the center of the particle.

19. 17. The method according to any one of claims 1 to 16, The process is a continuous process.

20. 17. The method according to any one of claims 1 to 16, The process is a commercial scale process and the PET manufacturing facility has an average production rate of at least 500 pounds per hour (lb / hr).

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