Polyester manufacturing method

Abstract

Polyester manufacturing method A method for producing a polyester, comprising: (a) providing a biomass-based composition comprising ethylene glycol and having a UV transmittance at 275 nm of less than 40% as measured according to ASTM method E2193-16; and (b) contacting the biomass-based composition with at least one reagent to form a polyester.

Description

[Technical Field]

[0001] Field The present invention relates to a method for producing polyester using a biomass-based composition comprising ethylene glycol. The present invention further relates to polyester obtained from the method for producing polyester, and to packaging articles or preforms formed from the polyester. [Background technology]

[0002] background Ethylene glycol is an organic polyol with the IUPAC name ethane-1,2-diol. Currently, ethylene glycol is most commonly produced from fossil fuels. A typical method for producing fossil-based ethylene glycol is to use ethylene produced from oil. Ethylene is oxidized in the presence of a catalyst to form ethylene oxide, which is then hydrolyzed to form ethylene glycol.

[0003] In view of changing environmental and economic conditions, it is desirable to use ethylene glycol obtained from renewable resources such as biomass, e.g., sugars. For example, WO2016001169A1 discloses a method for producing ethylene glycol from sugars, in which the sugars are pyrolyzed to form mixed C1-C3 oxygen-containing compounds (e.g., formaldehyde, glycolaldehyde, glyoxal, acetol, pyruvaldehyde), which are then hydrogenated in the presence of a catalyst to form a crude ethylene glycol product.

[0004] One of the major industrial uses of ethylene glycol is as a raw material for the production of polyesters. Polyesters are used in a wide range of applications, including the manufacture of packaging materials such as bottles, textiles, and electronic products. One particularly industrially important polyester is polyethylene terephthalate (PET). Many patent applications disclose methods for purifying biomass-based crude ethylene glycol products to produce high-purity ethylene glycol (>99% by weight ethylene glycol) suitable for the production of PET. For example, WO 2015 / 150520 and WO 2022 / 223867 disclose purification methods involving distillation to obtain high-purity ethylene glycol. CN 106866371A discloses multi-stage crystallization as a purification method for producing polyester-grade ethylene glycol with purities ranging from 98.5% to 99.9% from crude ethylene glycol products obtained, for example, from HTHP oxalic acid hydrogenation. Neither of these patent applications addresses issues related to impurities, nor does it measure the UV transmittance or APHA color of the purified ethylene glycol compositions. Since neither study involves the synthesis of actual PET, measurements of PET properties such as CIELAB color are performed.

[0005] Packaging articles are often required to meet strict technical specifications with respect to color properties. It is also expected in the art that ethylene glycol compositions used to manufacture packaging articles have specific technical properties in order to produce packaging articles that meet the required technical specifications. For example, it is widely accepted in the art that ethylene glycol compositions must have high UV transmittance to produce polyester packaging articles that meet the required technical specifications. This is seen, for example, in Zhang et al., “Identification of impurities affecting commercial ethylene glycol UV transmittance,” J Chromatogr A 904 (2000) 87-97. This paper addresses the issue of ethylene glycol's low UV transmittance, making it unsuitable as a raw material for polyester. The paper further identifies the presence of several major UV-absorbing impurities and suggests removing the impurities (although the method is not described) to obtain “polymer-grade” ethylene glycol. The introduction states, "The ethylene glycol used in polyester production must be of exceptionally high purity and must meet specific UV transmittance specifications. The UV transmittance of ethylene glycol is required to be at least 75%, 95%, and 100% at 220, 275, and 350 nm, respectively. Low UV transmittance at these wavelengths is believed to indicate the presence of undesirable impurities that will degrade the quality of the resulting polyester."

[0006] This assumption regarding UV transmittance is clearly inferred from the fact that manufacturers of polyester-grade monoethylene glycol specify minimum UV transmittances at 350 nm, 275 nm, and 220 nm in their product specifications. For example, LyondellBasell (Monoethylene Glycol, Polyester Grade U.S. Sales Specification, Material No. 5017), MEGlobal (Monoethylene Glycol, Polyester Grade Sales Specification, Designation Material 000101232907, Revised January 1, 2019, and Commercial Polyester Grade Sales Specification, Designation Material 000101205133, Revised January 1, 2019), and SABIC (Monoethylene Glycol, Bulk Technical Data, Revised January 1, 20220825) all specify minimum UV transmittances of 98% at 350 nm, 90–94% at 275 nm, and 70% at 220 nm.

[0007] Furthermore, many patent applications related to biobased polyester-grade ethylene glycol use UV transmittance at 350 nm, 275 nm, and 220 nm as the target to be achieved. See, for example, WO2015 / 028156, WO2018 / 089600, WO2018 / 089605, CN104418997A, and CN104418997A. For example, CN101525424A states that biobased ethylene glycol suitable for preparing PET must have a transmittance of 50% or more in the wavelength range of 190 to 350 nm. Furthermore, CN1580020A discloses the purification of crude ethylene glycol product, citing UV absorbance at 220 nm as an important characteristic of polyester-grade ethylene glycol. The crude ethylene glycol product is passed through a cationic resin to remove metal (iron) ions, and then purified through an aldehyde adsorption resin to produce polyester-grade ethylene glycol. However, there are still no examples of polyesters produced from the disclosed polyester-grade ethylene glycol, no measurements of the UV transmittance or APHA color of purified ethylene glycol compositions, no production of actual PET, and no measurement of the CIELAB color of such PET. A sequential setup for purifying ethylene glycol has been proposed to avoid metal ions interfering with the aldehyde adsorption resin.

[0008] [Patent Document 1] WO2015 / 150520 [Patent Document 2] WO2022 / 223867 [Patent Document 3] CN106866371A [Patent Document 4] WO2015 / 028156 [Patent Document 5] WO2018 / 089600 [Patent Document 6] WO2018 / 089605 [Patent Document 7] CN104418997A [Patent Document 8] CN101525424A [Patent Document 9] CN1580020A

[0009] [Non-Patent Document 1] Zhang et al., “Identification of impurities affecting commercial ethylene glycol UV transmittance”, J Chromatogr A 904 (2000) 87-97 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0010] It would be desirable to provide biomass-based compositions containing ethylene glycol that can be used to produce polyesters and packaging articles that meet the necessary or desired technical specifications for the polyesters and packaging articles. It would also be desirable to provide economical and commercially viable methods for producing such biomass-based compositions and polyesters. [Means for solving the problem]

[0011] overview According to one aspect of the present invention, there is provided a method for producing a polyester, the method comprising: (a) providing a biomass-based composition comprising ethylene glycol and having a UV transmittance at 275 nm of less than 40% as measured according to ASTM method E2193-16; and (b) contacting the biomass-based composition with at least one reagent to form a polyester.

[0012] In one embodiment, the biomass-based composition has a UV transmittance at 275 nm measured according to ASTM method E2193-16 of 35% or less, such as 30% or less, such as 20% or less.

[0013] In one embodiment, the biomass-based composition has a UV transmittance of 10% or greater at 275 nm as measured according to ASTM method E2193-16.

[0014] In one embodiment, the biomass-based composition comprises ethylene glycol in an amount of 97% by weight or greater, such as 99% by weight or greater, such as 99.25% by weight or greater, such as 99.5% by weight or greater, such as 99.75% by weight or greater, for example 99.9% by weight or greater, based on the weight of the biomass-based composition. The biomass-based composition has a natural upper limit of 100% by weight ethylene glycol.

[0015] In one embodiment, the biomass-based composition has a total aldehyde concentration of 50 ppm or less, such as 20 ppm or less, such as 18 ppm or less, such as 15 ppm or less, for example 10 ppm or less, based on the weight of the biomass-based composition.

[0016] In one embodiment, the biomass-based composition is characterized by an APHA color value of less than or equal to 5 mg / L PtCo as measured according to ASTM D1209-05.

[0017] In one embodiment, the purified biomass-based composition is characterized by a post-heat APHA color value of 20 mg / L PtCo or less, as measured according to ASTM D1209-05.

[0018] In one aspect, the biomass-based composition of step (a) is provided by: (I) subjecting the biomass-based composition to at least one distillation step to provide a distillation product, wherein the concentration of ethylene glycol in the distillation product is greater than in the biomass-based composition; and (II) subjecting the distillation product to at least one melt crystallization step to form crystals and a mother liquor, wherein the crystals provide a purified biomass-based composition, wherein the concentration of ethylene glycol in the purified biomass-based composition is greater than in the distillation product. That is, the purified biomass-based composition is the biomass-based composition in step (a).

[0019] In one embodiment, the biomass-based composition in step (a) is provided by: (I) providing a biomass-based composition comprising water in an amount of at least 0.1% by weight, based on the weight of the biomass-based composition; and (II) contacting the biomass-based composition with a solid acid catalyst and contacting the biomass-based composition with an aldehyde-removing resin to provide a purified biomass-based composition. That is, the purified biomass-based composition is the biomass-based composition of step (a).

[0020] In one embodiment, the biomass-based composition in step (a) is provided by: (I) providing a biomass-based composition comprising at least 0.1% by weight of water based on the weight of the biomass-based composition; (II) contacting the biomass-based composition with a solid acid catalyst and contacting the biomass-based composition with an aldehyde-removing resin to provide a first purified biomass-based composition; and (III) subjecting the first purified biomass-based composition from (II) to at least one distillation step to provide a distillation product, wherein the concentration of ethylene glycol in the distillation product is higher than in the first purified biomass-based composition, and the distillation product is the second purified biomass-based composition. That is, the second purified biomass-based composition is the biomass-based composition in step (a).

[0021] In one embodiment, the biomass-based composition in step (a) is provided by: (I) providing a biomass-based composition comprising at least 0.1% by weight of water based on the weight of the biomass-based composition; (II) contacting the biomass-based composition with a solid acid catalyst and an aldehyde-removing resin to provide a first purified biomass-based composition; (III) subjecting the first purified biomass-based composition from (II) to at least one distillation step to provide a distillation product, wherein the concentration of ethylene glycol in the distillation product is higher than in the first purified biomass-based composition, the distillation product being a second purified biomass-based composition; and (IV) subjecting the distillation product to at least one melt crystallization step to form crystals and a mother liquor, the crystals providing a third purified biomass-based composition, wherein the concentration of ethylene glycol in the third purified biomass-based composition is higher than in the distillation product. That is, the third purified biomass-based composition is the biomass-based composition of step (a).

[0022] In one aspect, the biomass-based composition in step (a) is provided by: (I) subjecting the biomass-based composition to at least one distillation step to provide a distillation product, wherein the concentration of ethylene glycol in the distillation product is greater than in the biomass-based composition, the distillation product being a first purified biomass-based composition; (II) subjecting the distillation product to at least one melt crystallization step to form crystals and a mother liquor, the crystals providing a second purified biomass-based composition, wherein the concentration of ethylene glycol in the second purified biomass-based composition is greater than in the distillation product, and optionally diluting the second purified biomass-based composition; and (I II) contacting the second purified biomass-based composition (e.g., the diluted second purified biomass-based composition) with a solid acid catalyst and contacting the second purified biomass-based composition (e.g., the diluted second purified biomass-based composition) with an aldehyde-removal resin to provide a third purified biomass-based composition, wherein the second purified biomass-based composition (e.g., the diluted second purified biomass-based composition) comprises water in an amount of at least 0.1% by weight, based on the weight of the second purified biomass-based composition (e.g., the diluted second purified biomass-based composition). That is, the third purified biomass-based composition is the biomass-based composition of step (a).

[0023] In some embodiments, the biomass-based composition is obtained by pyrolytic fragmentation of sugars followed by hydrogenation.

[0024] According to another aspect of the present invention, there is provided a biomass-based polyester obtained by the method for producing polyester according to the above aspect of the present invention.

[0025] In one embodiment, the polyester is characterized by one or more of the following CIELAB color space values ​​measured according to ASTM D6290-19: * is 65 or more, for example, 85 or more;a * is -4 to 4, e.g., -2 to 2; and b *is -4 to 4, for example -2 to 2.

[0026] According to another aspect of the present invention, there is provided a packaging article or preform formed from a polyester according to the above aspect of the present invention.

[0027] In any one of the above aspects of the invention, the polyester may comprise polyethylene terephthalate.

[0028] In one aspect of the present invention, there is provided a biomass-based composition comprising ethylene glycol, having a UV transmittance at 275 nm of less than 40% as measured according to ASTM method E2193-16 and an APHA color after heating of less than or equal to 20 mg / L PtCo as measured according to ASTM method 1209-05.

[0029] Features of any aspect of the invention may be combined with features or functions of any other aspect of the invention.

[0030] Detailed Description Polyester manufacturing method As discussed herein, in one aspect of the present invention, a method for producing a polyester is provided, the method including: (a) providing a biomass-based composition comprising ethylene glycol and having a UV transmittance at 275 nm of less than 40% as measured according to ASTM method E2193-16; and (b) contacting the biomass-based composition with at least one reagent to form a polyester.

[0031] UV transmittance is used as a simple measure of whether low levels of impurities in ethylene glycol adversely affect the color of the resulting PET. In other words, a higher transmittance indicates fewer impurities. Removing low levels of impurities from ethylene glycol results in a higher purity ethylene glycol. To date, it has been widely accepted in the art that ethylene glycol compositions require high UV transmittance to be suitable for the production of polyesters with acceptable polymer quality. This is particularly true in the context of bottle production, e.g., polyethylene terephthalate bottle production. Purifying biomass-based ethylene glycol to achieve high UV transmittance, even if possible, can be expensive and complex (see, e.g., WO2015 / 028156, WO2018 / 089600, and WO2018 / 089605). The inability to provide biomass-based ethylene glycol that meets UV transmittance specifications in an economical manner presents a significant obstacle to providing more sustainable feedstocks for polyester preparation. Applicant has surprisingly discovered that even if the biomass-based ethylene glycol does not meet UV transmittance specifications, satisfactory "bottle grade" polyester can be produced by using biomass-derived ethylene glycol with low UV transmittance.

[0032] Here, the ultraviolet transmittance at a wavelength of 275 nm is measured in accordance with ASTM method E2193-16 at a temperature of 20° C. to 25° C. under atmospheric pressure.

[0033] In one aspect, the biomass-based composition of step (a) is provided by: (I) subjecting the biomass-based composition to at least one distillation step to provide a distillation product, wherein the concentration of ethylene glycol in the distillation product is greater than in the biomass-based composition; and (II) subjecting the distillation product to at least one melt crystallization step to form crystals and a mother liquor, wherein the crystals provide a purified biomass-based composition, wherein the concentration of ethylene glycol in the purified biomass-based composition is greater than in the distillation product. The purified biomass-based composition may be the biomass-based composition of step (a).

[0034] Distillation has been used to purify fossil-based compositions containing ethylene glycol. While distillation can be used to adequately remove impurities from fossil-based compositions containing ethylene glycol, biomass-based compositions containing ethylene glycol have a different impurity profile, and impurities therein can be difficult to remove using distillation alone. The challenge of providing an economically feasible purification method for biomass-derived compositions containing ethylene glycol poses a significant obstacle to providing more sustainable feedstocks for the preparation of polyesters. The present inventors have determined that a combination of distillation and melt crystallization can be used to purify biomass-based compositions containing ethylene glycol to a desired level in an economically feasible manner. More specifically, they have found that distillation can be used to efficiently prepare a semi-pure composition (i.e., a distillation product), and melt crystallization can be used to purify the semi-pure composition to provide a highly pure composition enriched in ethylene glycol (i.e., a purified biomass-based composition). Significant energy savings can be achieved by combining the techniques of distillation and melt crystallization. This combination of techniques has been determined to be significantly more energy efficient than either technique used alone.

[0035] In one embodiment, the biomass-based composition in step (a) is provided by: (I) providing a biomass-based composition comprising water in an amount of at least 0.1% by weight, based on the weight of the biomass-based composition; and (II) contacting the biomass-based composition with a solid acid catalyst and contacting the biomass-based composition with an aldehyde-removing resin to provide a purified biomass-based composition. The purified biomass-based composition can be the biomass-based composition of step (a).

[0036] Biomass-based compositions containing ethylene glycol may contain small amounts of free aldehydes and acetals, and the presence of these components (e.g., on the ppm scale) can lead to discoloration of polyesters formed from the biomass-based compositions. This can be problematic when a final product (e.g., a bottle) with a specific color profile (e.g., reduced color, such as substantially colorless) is desired or required. The present inventors have found that treating a biomass-based composition containing ethylene glycol with an aldehyde-removal resin is not effective in itself. For example, they have found that a biomass-based composition containing ethylene glycol treated only with an aldehyde-removal resin can form a polyester with an undesirable color profile (e.g., yellow coloration). The present inventors have surprisingly found that contacting a biomass-based composition containing ethylene glycol with a solid acid catalyst and an aldehyde-removal resin can provide a biomass-based composition that can be used to form a polyester with a desirable color profile (e.g., reduced color, substantially colorless, etc.).

[0037] In one embodiment, the biomass-based composition in step (a) is provided by: (I) providing a biomass-based composition comprising at least 0.1% by weight of water, based on the weight of the biomass-based composition; (II) contacting the biomass-based composition with a solid acid catalyst and contacting the biomass-based composition with an aldehyde-removing resin to provide a first purified biomass-based composition; and (III) subjecting the first purified biomass-based composition from (II) to at least one distillation step to provide a distillation product, wherein the concentration of ethylene glycol in the distillation product is higher than in the first purified biomass-based composition, and the distillation product is a second purified biomass-based composition. The second purified biomass-based composition can be the biomass-based composition in step (a).

[0038] In one embodiment, the biomass-based composition in step (a) is provided by: (I) providing a biomass-based composition containing at least 0.1% by weight of water based on the weight of the biomass-based composition; (II) contacting the biomass-based composition with a solid acid catalyst and an aldehyde-removing resin to provide a first purified biomass-based composition; (III) subjecting the first purified biomass-based composition from (II) to at least one distillation step to provide a distillation product, wherein the concentration of ethylene glycol in the distillation product is greater than in the biomass-based composition, where the distillation product is a second purified biomass-based composition; and (IV) subjecting the distillation product to at least one melt crystallization step to form crystals and a mother liquor, where the crystals provide a third purified biomass-based composition, where the concentration of ethylene glycol in the third purified biomass-based composition is greater than in the distillation product. The third purified biomass-based composition can be the biomass-based composition of step (a).

[0039] In one aspect, the biomass-based composition in step (a) is provided by: (I) subjecting the biomass-based composition to at least one distillation step to provide a distillation product, wherein the concentration of ethylene glycol in the distillation product is greater than in the biomass-based composition, the distillation product being a first purified biomass-based composition; (II) subjecting the distillation product to at least one melt crystallization step to form crystals and a mother liquor, the crystals providing a second purified biomass-based composition, wherein the concentration of ethylene glycol in the second purified biomass-based composition is greater than in the distillation product, optionally diluting the second purified biomass-based composition; and (III) contacting the second purified biomass-based composition (e.g., the diluted second purified biomass-based composition). contacting the second purified biomass-based composition (e.g., the diluted second purified biomass-based composition) with a solid acid catalyst and contacting the second purified biomass-based composition (e.g., the diluted second purified biomass-based composition) with an aldehyde-removal resin to provide a third purified biomass-based composition, wherein the second purified biomass-based composition (e.g., the diluted second purified biomass-based composition) comprises water in an amount of at least 0.1 wt.%, based on the weight of the second purified biomass-based composition (e.g., the diluted second purified biomass-based composition). The third purified biomass-based composition can be the biomass-based composition of step (a).

[0040] Any of the purified biomass-based compositions (e.g., the first purified biomass-based composition, the second biomass-based composition, and the third purified biomass-based composition) can be characterized according to any of the characteristics of a biomass-based composition contacted with at least one reagent, as described herein.

[0041] purification Here, "purify" or "purified" or "purification" can be thought of as concentrating the ethylene glycol in a composition by removing other components from the composition. "Other components" can include impurities, i.e., components present in small concentrations.

[0042] Biomass-Based Compositions In one embodiment, the biomass-based composition has a total carbon content of greater than 0.5 parts per trillion (ppt) as measured by ASTM D6866-22. 14 It has a C content.

[0043] In one embodiment, the biomass-based composition is obtained by pyrolytic fragmentation of biomass followed by hydrogenation. Alternatively, the biomass-based composition can be obtained by hydrocracking of biomass. Hydrocracking is a chemical reaction similar to hydrolysis, in which hydrogen plays a role similar to water. Hydrocracking typically involves breaking the bonds of organic molecules and simultaneously adding hydrogen atoms to each of the resulting molecular fragments. In one embodiment, the biomass includes one or more of lignocellulose, lignin, sewage sludge, lipids, proteins, and carbohydrates.

[0044] Pyrolytic fragmentation (or pyrolysis) of biomass describes a method in which a biomass feedstock is subjected to thermal treatment to partially decompose its components and produce a pyrolysate. The pyrolytic fragmentation of glucose and the hydrogenation of the resulting pyrolysate are known, for example, from Schandel et al., ChemSusChem, 2020, 13, 688-692; US 9,926,247; and WO 2017 / 216311.

[0045] Biomass includes all types of biogenic material, that is, material resulting from the recent (i.e., last century) fixation of atmospheric CO2. This includes lignocellulose, lignin, sewage sludge, lipids, proteins, and carbohydrates.

[0046] The carbohydrate group includes polysaccharides, oligosaccharides, and saccharides. Polysaccharides include long polymers of sugars, such as cellulose, hemicellulose, and starch. Oligosaccharides include short polymers of sugars (4-10 monosaccharide units). Sugars include trisaccharides, disaccharides, and monosaccharides. Trisaccharides include maltotriose. Disaccharides include sucrose, maltose, lactose, and cellobiose. The monosaccharide group includes all monosaccharides in the triose, tetrose, pentose, and hexose groups. Preferred monosaccharides are pentoses and hexoses, and more preferred are glucose, fructose, mannose, galactose, xylose, and arabinose, or mixtures thereof. Glucose is the most preferred monosaccharide feedstock. A monosaccharide feedstock can contain up to 5% disaccharides and trisaccharides by weight relative to the monosaccharides and still be considered a monosaccharide feedstock.

[0047] In one embodiment, the biomass-based composition is obtained by pyrolytic fragmentation of carbohydrates followed by hydrogenation. In one embodiment, the biomass-based composition is obtained by pyrolytic fragmentation of polysaccharides, oligosaccharides, sugars, and mixtures thereof followed by hydrogenation. In one embodiment, the biomass-based composition is obtained by pyrolytic fragmentation of sugars followed by hydrogenation. In one embodiment, the biomass-based composition is obtained by pyrolytic fragmentation of polysaccharides, oligosaccharides, trisaccharides, disaccharides, monosaccharides, and mixtures thereof followed by hydrogenation. In one embodiment, the biomass-based composition is obtained by pyrolytic fragmentation of disaccharides, monosaccharides, and mixtures thereof followed by hydrogenation. In one embodiment, the biomass-based composition is obtained by pyrolytic fragmentation of at least disaccharides followed by hydrogenation. In one embodiment, the biomass-based composition is obtained by pyrolytic fragmentation of at least monosaccharides followed by hydrogenation.

[0048] Pyrolytic fragmentation refers to the application of heat (typically 300-700°C) to biomass feedstock for a period of time to convert it into pyrolysis products (or pyrolysis fragmentation products). Pyrolytic fragmentation does not include conditions or processes in which substantial combustion of the feedstock or gasification into permanent gases is achieved. Heat can be applied by combustion of a small amount of the feedstock through the introduction of oxygen or an oxidizing agent, or heat can be applied externally and transferred to the feedstock, for example, through contact with a hot surface, gas, liquid, or solid. Pyrolytic fragmentation can be carried out in a variety of reactors, including bubbling fluidized-bed reactors, circulating fluidized-bed reactors, ablative reactors, rotating cone reactors, and micropyrolysis reactors. Heat can be applied for long periods (slow pyrolysis, >5 minutes), medium periods (normal pyrolysis, 30-300 seconds), or short periods (fast pyrolysis, less than 30 seconds, typically around 0.5-2 seconds). The pyrolysis time and temperature affect the composition of the pyrolysis products.

[0049] Monosaccharide pyrolysis describes the conversion of a monosaccharide feedstock (i.e., a monosaccharide feedstock that is substantially free of lignocellulose, lignin, lipids, cellulose, hemicellulose, starch, protein, oligosaccharides, trisaccharides, and disaccharides) to pyrolysis products by pyrolysis. Monosaccharide pyrolysis is performed with a monosaccharide feedstock containing less than 15% water by weight, based on the weight of the monosaccharide feedstock, and is designated "dry monosaccharide pyrolysis." Monosaccharide pyrolysis performed with a monosaccharide feedstock containing more than 15% water by weight, based on the weight of the monosaccharide feedstock, is designated "wet sugar pyrolysis." The goal of wet monosaccharide pyrolysis is to convert an aqueous monosaccharide feedstock to glycolaldehyde (2-hydroxyacetaldehyde) along with the production of other light oxygenated compounds (pyruvaldehyde, acetol, formaldehyde, glyoxal), while minimizing the production of other products.

[0050] The monosaccharide feedstock for wet monosaccharide pyrolysis is an aqueous solution of monosaccharides containing more than 15% by weight of water, for example, more than 20%, more than 30%, more than 40%, more than 50%, more than 60%, more than 70%, or more than 80% by weight of water, based on the weight of the monosaccharide feedstock. An example of a monosaccharide feedstock for wet monosaccharide pyrolysis is a feedstock containing 64% by weight of glucose, 1% by weight of maltose (a disaccharide), and 35% by weight of water. Another example of a monosaccharide feedstock for wet monosaccharide pyrolysis is a feedstock containing 32% by weight of glucose, 31% by weight of fructose, 1.5% by weight of sucrose, and 35.5% by weight of water.

[0051] The monosaccharide feedstock for dry monosaccharide pyrolysis contains less than 15% water by weight, based on the weight of the monosaccharide feedstock. An example of a monosaccharide feedstock for dry monosaccharide pyrolysis is glucose monohydrate (91% monosaccharides, 9% water by weight).

[0052] After pyrolysis of the feedstock, the pyrolysis products formed are subjected to hydrogenation.

[0053] Hydrogenation refers to the chemical reaction of molecular hydrogen with another compound or element, optionally in the presence of a catalytic material and optionally in the presence of a solvent. In this method, glycolaldehyde may be formed from the pyrolysis fragmentation of biomass, such as the pyrolysis of sugars, and in this embodiment, hydrogenation of the pyrolysis products converts glycolaldehyde to ethylene glycol, optionally with the conversion of glyoxal to ethylene glycol, pyruvaldehyde and acetol to propylene glycol, and formaldehyde to methanol, while minimizing the formation of other products. The resulting composition is referred to as a biomass-based composition.

[0054] Suitable hydrogenation catalysts include an active material selected from the group consisting of ruthenium, rhenium, rhodium, iridium, palladium, platinum, copper, and nickel, or a mixture thereof, on a support. The support is usually made of an inert material. Suitable support materials are carbon, silica, alumina, titania, zirconia, or a mixture thereof.

[0055] In one embodiment, the pyrolysis product is subjected to gas-phase hydrogenation in the presence of hydrogen and a hydrogenation catalyst to obtain a biomass-based hydrogenated product. When the hydrogenation is gas-phase hydrogenation, the hydrogenation can be carried out at a temperature ranging from 200°C to 250°C and a hydrogen partial pressure ranging from 0.5 bar to 5 bar.

[0056] In one embodiment, the pyrolysis product is subjected to liquid-phase hydrogenation in the presence of hydrogen and a hydrogenation catalyst to obtain a biomass-based hydrogenated product. When the hydrogenation is liquid-phase hydrogenation, the hydrogenation can be carried out at a temperature ranging from 20°C to 200°C and a hydrogen partial pressure ranging from 60 bar to 140 bar. When the hydrogenation is liquid-phase hydrogenation, the hydrogen partial pressure is the partial pressure in the gas phase above or interposed in the hydrogenation fluid, and is proportional to the hydrogen concentration in the liquid phase.

[0057] In one embodiment, the hydrogenation is carried out in the presence of a solvent selected from the group consisting of water, methanol, ethanol, ethylene glycol and propylene glycol; and mixtures thereof.

[0058] Biomass-based hydrogenation products can be purified in a variety of ways. As mentioned above, there is much interest in producing biomass-based compositions containing "polymer-grade" or "polyester-grade" ethylene glycol. There have been many attempts to provide industrially applicable methods for purifying biomass-based compositions, all of which aim to reach technical specifications of at least 75%, 95%, and 100% UV transmittance at 220 nm, 275 nm, and 350 nm, respectively.

[0059] The present inventors have surprisingly found that an ethylene glycol composition (a biomass-based composition containing ethylene glycol) can be polymer-grade even if it does not meet industry standards for UV transmittance at 220 nm, 275 nm, and 350 nm. They have found that an APHA color of less than 5 mg / L PtCo before heating and less than 20 mg / L PtCo after heating are good indicators of whether an ethylene glycol composition is polymer-grade / suitable for producing colorless PET. An APHA color of 15 mg / L or less after heating is even more preferred.

[0060] Any purification method that results in a biomass-based composition containing ethylene glycol characterized by a post-heat APHA color value of less than 20 mg / L PtCo as measured according to ASTM D1209-05 and a UV transmittance at 275 nm of less than 40% as determined by ASTM method E2193-16 is therefore encompassed by the present invention.

[0061] According to one aspect of the present invention, there is provided a purified biomass-based composition characterized by an APHA color after heating of less than 20 mg / L PtCo as measured according to ASTM D1209-05 and a UV transmittance at 275 nm of less than 40% as determined by ASTM method E2193-16.

[0062] According to another aspect of the present invention, there is provided a purified biomass-based composition characterized by an APHA color after heating of less than 15 mg / L PtCo (measured according to ASTM D1209-05) and a UV transmittance at 275 nm of less than 40% (determined by ASTM method E2193-16).

[0063] Prior to hydrogenation, the pyrolysis product may also be subjected to operations such as condensation and / or separation.

[0064] Solid acid catalysts and aldehyde removal resins As described herein, in one aspect, a method for purifying a biomass-based composition includes contacting the biomass-based composition with a solid acid catalyst and contacting the biomass-based composition with an aldehyde-removing resin to provide a purified biomass-based composition. In this regard, the biomass-based composition can be contacted with the aldehyde-removing resin after the solid acid catalyst. Alternatively, the biomass-based composition can be contacted with the solid acid catalyst and the aldehyde-removing resin simultaneously (e.g., using a mixed bed comprising the solid acid catalyst and the aldehyde-removing resin).

[0065] In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removing resin comprises at least 0.1% by weight of water, based on the weight of the biomass-based composition. In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removing resin comprises at least 2% by weight of water, based on the weight of the biomass-based composition. In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removing resin comprises at least 5% by weight of water, based on the weight of the biomass-based composition. In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removing resin comprises at least 8% by weight of water, based on the weight of the biomass-based composition. In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removing resin comprises at least 10% by weight of water, based on the weight of the biomass-based composition. In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removing resin comprises at least 15% by weight of water, based on the weight of the biomass-based composition.

[0066] In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removing resin comprises 80% or less by weight of water, based on the weight of the biomass-based composition. In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removing resin comprises 70% or less by weight of water, based on the weight of the biomass-based composition. In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removing resin comprises 60% or less by weight of water, based on the weight of the biomass-based composition. In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removing resin comprises 50% or less by weight of water, based on the weight of the biomass-based composition. In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removing resin comprises 40% or less by weight of water, based on the weight of the biomass-based composition.

[0067] In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removal resin comprises water in an amount of 2% to 80% by weight, based on the weight of the biomass-based composition. In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removal resin comprises water in an amount of 5% to 70% by weight, based on the weight of the biomass-based composition. In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removal resin comprises water in an amount of 8% to 60% by weight, based on the weight of the biomass-based composition. In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removal resin comprises water in an amount of 10% to 50% by weight, based on the weight of the biomass-based composition. In one embodiment, the biomass-based composition contacted with the solid acid catalyst and the aldehyde-removal resin comprises water in an amount of 15% to 40% by weight, based on the weight of the biomass-based composition.

[0068] In one embodiment, the solid acid catalyst is provided in a first bed. The first bed may be provided in a column. In one embodiment, the aldehyde removal resin is provided in a second bed. The second bed may be provided in a column. In one embodiment, the second bed is downstream of the first bed. The column in which the first bed is provided may be different from the column in which the second bed is provided. The column in which the second bed is provided may be the same column in which the first bed is provided.

[0069] Here, "downstream" (and "upstream") refers to the flow direction of the biomass-based composition. For example, if operation Y on the biomass-based composition occurs after operation X on the biomass-based composition, then operation Y is downstream of operation X.

[0070] In one embodiment, the solid acid catalyst and the aldehyde-removing resin are provided in a common bed (mixed bed). The common bed may be provided in a column. Advantageously, it has been found that providing the solid acid catalyst and the aldehyde-removing resin in a common bed is particularly effective. Without being bound by any theory, it is believed that this arrangement facilitates the removal of aldehydes as they are produced and facilitates the continuous production of aldehydes.

[0071] In one embodiment, one or each of contacting the biomass-based composition with the solid acid catalyst and contacting the biomass-based composition with the aldehyde-removing resin is carried out at a temperature of 10° C. to 70° C. In one embodiment, one or each of contacting the biomass-based composition with the solid acid catalyst and contacting the biomass-based composition with the aldehyde-removing resin is carried out at a temperature of 35° C. to 65° C. In one embodiment, one or each of contacting the biomass-based composition with the solid acid catalyst and contacting the biomass-based composition with the aldehyde-removing resin is carried out at a temperature of 40° C. to 60° C. In one embodiment, one or each of contacting the biomass-based composition with the solid acid catalyst and contacting the biomass-based composition with the aldehyde-removing resin is carried out at a temperature of 45° C. to 55° C.

[0072] solid acid catalyst The solid acid catalyst has an acidic functional group. In one embodiment, the acidic functional group is a sulfonic acid functional group.

[0073] In one embodiment, the solid acid catalyst comprises an insoluble matrix (or support structure), which may be porous.

[0074] In one embodiment, the solid acid catalyst comprises a resin. In one embodiment, the solid acid catalyst comprises a cross-linked resin. Non-limiting examples of cross-linked resins or polymers include polystyrene cross-linked with divinylbenzene (styrene-divinylbenzene) and polyacrylic acid cross-linked with divinylbenzene (polyacrylic-divinylbenzene).

[0075] In one embodiment, the solid acid catalyst comprises Amberlyst 15, which is a strongly acidic, sulfonic acid functionalized styrene-divinylbenzene resin. In one embodiment, the solid acid catalyst comprises Amberlyst 131, which is a strongly acidic, sulfonic acid functionalized styrene-divinylbenzene resin. Those skilled in the art will recognize that many types of solid acid catalysts can be used.

[0076] In one embodiment, the solid acid catalyst is in particulate form. In one embodiment, the solid acid catalyst comprises a zeolite. Here, "solid" can also include semi-solids such as gels.

[0077] Aldehyde Removal Resin The aldehyde-scavenging resin at least partially removes aldehydes from the biomass-based composition.

[0078] In one embodiment, the aldehyde removal resin comprises one or more of: a primary amine functional group; a secondary amine functional group; a tertiary amine functional group; and a quaternary ammonium functional group, such as a quaternary ammonium bisulfite functional group.

[0079] In one embodiment, the aldehyde removal resin comprises an insoluble matrix (or supporting structure), which may be porous.

[0080] In one embodiment, the aldehyde-scavenging resin is a heterogeneous resin. In one embodiment, the aldehyde-scavenging resin is a solid or a gel.

[0081] In one embodiment, the aldehyde-scavenging resin comprises a cross-linked resin. Non-limiting examples of cross-linked resins or polymers include polystyrene cross-linked with divinylbenzene (styrene-divinylbenzene) and polyacrylic acid cross-linked with divinylbenzene (polyacrylic-divinylbenzene).

[0082] In one embodiment, the aldehyde scavenging resin comprises Purolite A110. In one embodiment, the aldehyde scavenging resin comprises Purolite A830. Purolite A110 is a weakly basic polystyrene-divinylbenzene resin with primary amine functionality. Purolite A830 is a weakly basic polyacrylic-divinylbenzene resin with primary amine functionality. Those skilled in the art will recognize that many types of aldehyde scavenging resins can be used.

[0083] In one embodiment, the aldehyde removal resin is in particulate form.

[0084] Further steps In some embodiments, the method of making the polyester comprises at least one additional step.

[0085] In one aspect, the method includes contacting the biomass-based composition with a solid acid catalyst, contacting the biomass-based composition with an aldehyde-removing resin, and then further contacting the biomass-based composition with the aldehyde-removing resin. This can be considered a "polishing" step that further aids in removing aldehydes from the biomass-based composition. For example, this "polishing" step can be performed after contacting the biomass-based composition with the solid acid catalyst and the aldehyde-removing resin via a common bed configuration or via separate beds.

[0086] In one embodiment, the method includes contacting the biomass-based composition with a solid acid catalyst and subjecting the biomass-based composition to at least one distillation step prior to contacting the biomass-based composition with the aldehyde-removing resin.

[0087] distillation As discussed herein, in one embodiment, a method for producing a polyester includes subjecting a biomass-based composition (e.g., a first purified biomass-based composition) to at least one distillation step to provide a distillation product, wherein the concentration of ethylene glycol in the distillation product is higher than in the biomass-based composition.

[0088] In one embodiment, the biomass-based composition that is subjected to at least one distillation step is aqueous.

[0089] Here, the "distillation product" can be a bottom fraction or a distillation fraction. Here, the "bottom fraction" (or "bottoms") can be recognized as a liquid fraction that collects at the bottom of a distillation column during distillation. Those skilled in the art will understand that the bottom fraction contains components that are less volatile than the components of the distillation fraction. Here, the "distillation fraction" can be considered as a fraction of vapor, liquid condensed from vapor, or a mixture of vapor and liquid that is removed from the distillation column at any point above the bottom of the distillation column during distillation. At least one fraction is recovered during distillation, but multiple fractions may be recovered from the distillation column simultaneously. Therefore, a "liquid side draw" is a distillation fraction that is not recovered from the top of the distillation column.

[0090] In one embodiment, the distilled product comprises ethylene glycol in an amount of 85% by weight or greater, such as 90% by weight or greater, such as 95% by weight or greater, based on the weight of the distilled product.

[0091] In one embodiment, the distilled product comprises ethylene glycol in an amount of 99% by weight or less, such as 98% by weight or less, such as 97% by weight or less, based on the weight of the distilled product.

[0092] In one embodiment, the at least one distillation step comprises a first distillation step comprising feeding the biomass-based composition (e.g., the first purified biomass-based composition) to a continuous distillation unit (continuous distillation apparatus) to provide a first bottoms fraction and at least one first distillation fraction, wherein one of the first bottoms fraction and the at least one first distillation fraction is an ethylene glycol-enriched fraction. The ethylene glycol-enriched fraction can be a distillation product.

[0093] In one embodiment, the at least one distillation step includes at least one further distillation step comprising feeding the ethylene glycol-enriched fraction from the preceding distillation step to a successive distillation unit to provide a further bottoms fraction and at least one further distillation fraction, wherein one of the further bottoms fraction and the at least one further distillation fraction is an ethylene glycol-enriched fraction, which may be a distillation product.

[0094] Here, "enriched" is relative to the composition from which the distillation was performed. For example, the ethylene glycol-enriched fraction from the third distillation step is enriched in ethylene glycol relative to the ethylene glycol-enriched fraction from the second distillation step.

[0095] In one embodiment, the ethylene glycol-rich fraction from the first distillation step is also enriched in propylene glycol, and the fractions are designated as ethylene glycol-enriched fraction and propylene glycol-enriched fraction.

[0096] In one embodiment, the at least one distillation step includes a second distillation step comprising feeding the ethylene glycol-enriched fraction from the first distillation step to a continuous distillation unit to provide a second bottoms fraction and at least one second distillation fraction, wherein one of the second bottoms fraction and the at least one second distillation fraction is an ethylene glycol-enriched fraction, which may be a distillation product.

[0097] In one embodiment, the at least one distillation step includes a second distillation step in which the ethylene glycol-enriched fraction and the propylene glycol-enriched fraction from the first distillation step are fed to a continuous distillation unit to provide a second bottoms fraction and at least one second distillation fraction, wherein one of the second bottoms fraction and the at least one second fraction is an ethylene glycol-enriched fraction, which may be a distillation product.

[0098] In one embodiment, the at least one distillation step includes a third distillation step comprising feeding the ethylene glycol-enriched fraction from the second distillation step to a continuous distillation unit to provide a third bottoms fraction and at least one third distillation fraction, wherein one of the third bottoms fraction and the at least one third fraction is an ethylene glycol-enriched fraction, which may be a distillation product.

[0099] In one embodiment, the at least one distillation step includes a fourth distillation step comprising feeding the ethylene glycol-enriched fraction from the third distillation step to a continuous distillation unit to provide a fourth bottoms fraction and at least one fourth distillation fraction, wherein one of the fourth bottoms fraction and the at least one fourth fraction is an ethylene glycol-enriched fraction, which may be a distillation product.

[0100] In one embodiment, at least 80% by weight, such as at least 85% by weight, for example at least 90% by weight, such as at least 92% by weight, for example at least 95% by weight, such as at least 97.5% by weight, for example at least 99% by weight, for example at least 99.5% by weight, of the non-ethylene glycol components (i.e., all components that are not ethylene glycol), based on the weight of the biomass-based composition, is removed from the biomass-based composition in at least one distillation step (in this example, the complete distillation step).

[0101] In this distillation, the splitting of the feed into the top (overhead) and bottom is controlled by the feed rate, reflux ratio, energy input to the reboiler, preheating of the feed, cooling medium input to the reflux and distillation condenser, column pressure and separating power, and vapor-liquid equilibrium of the components in the feed.

[0102] Components more volatile than ethylene glycol may be concentrated and removed as a distillate, with the concentrated ethylene glycol product being recovered as a bottoms fraction, or components less volatile than ethylene glycol may be concentrated and removed as a bottoms fraction, with the concentrated ethylene glycol product being recovered as a distillate.

[0103] It is within the knowledge of one skilled in the art of distillation to design a distillation step that provides an ethylene glycol enriched bottoms fraction or an ethylene glycol enriched distillation fraction.

[0104] Melt crystallization As described herein, in one embodiment, the method includes subjecting the distillation product to at least one melt crystallization step to form crystals and a mother liquor, such that the crystals provide a purified biomass-based composition, wherein the concentration of ethylene glycol in the purified biomass-based composition is higher than in the distillation product.

[0105] In one embodiment, the melt crystallization step comprises cooling the distillation product using a heat exchanger, the temperature of the heat exchanger being no higher than the freezing temperature of ethylene glycol.

[0106] In one embodiment, the temperature of the heat exchanger is -12.9°C or less. In one embodiment, the temperature of the heat exchanger is -15°C or less. In one embodiment, the temperature of the heat exchanger is -18°C or less. In one embodiment, the temperature of the heat exchanger is -20°C or less.

[0107] In one embodiment, the temperature of the heat exchanger is -40°C or higher. In one embodiment, the temperature of the heat exchanger is -35°C or higher. In one embodiment, the temperature of the heat exchanger is -30°C or higher. In one embodiment, the temperature of the heat exchanger is -25°C or higher.

[0108] In one embodiment, the distillation product is subjected to at least one melt crystallization step to form crystals and a mother liquor, the crystals being present in an amount of at least 50% by weight based on the weight of the crystals and the mother liquor. In one embodiment, the distillation product is subjected to at least one melt crystallization step to form crystals and a mother liquor, the crystals being present in an amount of 90% by weight or less based on the weight of the crystals and the mother liquor. In one embodiment, the distillation product is subjected to at least one melt crystallization step to form crystals and a mother liquor, the crystals being present in an amount of 60% to 70% by weight based on the weight of the crystals and the mother liquor.

[0109] In one embodiment, the or each melt crystallization step is a suspension melt crystallization step.

[0110] In one aspect, the or each melt crystallization step comprises heating the crystals to partially melt the crystals and form purified crystals and a residual liquid, wherein the concentration of ethylene glycol in the purified crystals is higher than in the crystals.

[0111] In one embodiment, the melt crystallization step comprises heating the crystals to partially melt the crystals and form purified crystals and a residual liquid, wherein 10% to 50% by weight of the crystals melt to form a residual liquid, based on the weight of the crystals.

[0112] In one embodiment, the at least one melt crystallization step comprises at least partially removing one or more from the distillation products: 1,2-pentanediol, 1,2-cyclopentanediol, 1,2-hexanediol, and 1,2-cyclohexanediol.

[0113] In one embodiment, the concentration of one or more of 1,2-pentanediol, 1,2-cyclopentanediol, 1,2-hexanediol, 1,2-cyclohexanediol is higher in the mother liquor than in the crystals.

[0114] In one embodiment, at least 80% by weight, e.g., at least 85% by weight, e.g., at least 90% by weight, of the non-ethylene glycol components (i.e., all components that are not ethylene glycol), based on the weight of the biomass-based composition, is removed from the biomass-based composition in the or each melt crystallization step.

[0115] Polyester manufacturing In one embodiment, the biomass-based composition contacted with the at least one reagent has a total aldehyde concentration of 50 ppm or less. In one embodiment, the biomass-based composition contacted with the at least one reagent has a total aldehyde concentration of 20 ppm or less. In one embodiment, the biomass-based composition contacted with the at least one reagent has a total aldehyde concentration of 18 ppm or less. In one embodiment, the biomass-based composition contacted with the at least one reagent has a total aldehyde concentration of 15 ppm or less. In one embodiment, the biomass-based composition contacted with the at least one reagent has a total aldehyde concentration of 10 ppm or less. "ppm" may be based on the mass of the biomass-based composition.

[0116] The biomass-based composition contacted with the at least one reagent can be a purified biomass-based composition, a second purified biomass-based composition, or a third biomass-based composition.

[0117] In one embodiment, the biomass-based composition contacted with the at least one reagent has a total aldehyde concentration of 1 ppm or greater. In one embodiment, the biomass-based composition contacted with the at least one reagent has a total aldehyde concentration of 2 ppm or greater. In one embodiment, the biomass-based composition contacted with the at least one reagent has a total aldehyde concentration of 5 ppm or greater. In one embodiment, the biomass-based composition contacted with the at least one reagent has a total aldehyde concentration of 10 ppm or greater. "ppm" may be based on the mass of the biomass-based composition.

[0118] In one embodiment, the biomass-based composition contacted with the at least one reagent is characterized by an APHA color value (measured according to ASTM D1209-05) of 10 mg / L PtCo or less. In one embodiment, the biomass-based composition contacted with the at least one reagent is characterized by an APHA color value (measured according to ASTM D1209-05) of 9 mg / L PtCo or less. In one embodiment, the biomass-based composition contacted with the at least one reagent is characterized by an APHA color value (measured according to ASTM D1209-05) of 8 mg / L PtCo or less. In one embodiment, the biomass-based composition contacted with the at least one reagent is characterized by an APHA color value (measured according to ASTM D1209-05) of 7 mg / L PtCo or less. In one embodiment, the biomass-based composition contacted with the at least one reagent is characterized by an APHA color value (measured according to ASTM D1209-05) of 6 mg / L PtCo or less. In one embodiment, the biomass-based composition contacted with the at least one reagent is characterized by an APHA color value (measured according to ASTM D1209-05) of less than or equal to 5 mg / L PtCo.

[0119] The American Public Health Association (APHA) color scale, also known as the Hazen scale or platinum-cobalt (PtCo) scale, is a color scale for liquid chemicals. This scale is used to assess the quality of chemicals and other substances and is a good measure of the level of impurities that affect the color of biomass-based compositions, including those containing ethylene glycol.

[0120] The terms "APHA color value" or "APHA color" are used interchangeably herein to refer to values ​​on the APHA color scale.

[0121] Here, the APHA color value is measured in accordance with ASTM D1209-05 at 20°C to 25°C (room temperature) and atmospheric pressure.

[0122] The APHA color value can also be used to evaluate the thermal stability of a liquid chemical by testing its "APHA color after heating." Here, this is done by performing a heating step in which the liquid chemical is heated to 200°C for an extended period of time. In this specification, a period of 2 to 4 hours is appropriate. After cooling to room temperature, the APHA color value is measured. The APHA color value can be used as an indicator of the thermal stability of a liquid. A high APHA color value may indicate that the substance decomposed or reacted during heating to form colored impurities.

[0123] Unless otherwise stated herein, APHA color refers to testing of the purified biomass-based composition without a heating step. If a heating step is performed, the reference is to "APHA color after heating."

[0124] The present inventors have surprisingly found that an ethylene glycol composition can be polymer grade even if it does not meet industry standards for UV transmittance at 220 nm, 275 nm, and 350 nm. They have found that an APHA color before heating of less than 5 mg / L PtCo and an APHA color after heating of less than 20 mg / L PtCo are good indicators of whether an ethylene glycol composition is polymer grade / suitable for producing colorless PET. An APHA color after heating of less than 15 mg / L is even more preferred.

[0125] Thus, thermal stability / APHA color after heating can be used as a measure of the suitability of a purified biomass-based composition containing ethylene glycol as an ethylene glycol reactant in the synthesis of PET. In embodiments according to the present invention, purified biomass-based compositions containing ethylene glycol that are considered suitable as a reactant in the synthesis of PET have an APHA color after heating of less than 20 mg / L PtCo. In embodiments, purified biomass-based compositions containing ethylene glycol that are considered suitable as a reactant in the synthesis of PET have an APHA color after heating of less than 15 mg / L PtCo.

[0126] In one embodiment, the biomass-based composition contacted with the at least one reagent is characterized by an APHA color value (measured according to ASTM D1209-05) of greater than 0 mg / L PtCo, which is considered a lower limit for any of the upper limits referenced herein.

[0127] In one embodiment, the purified biomass-based composition comprises ethylene glycol in an amount of 98% by weight or greater, based on the weight of the purified biomass-based composition. In one embodiment, the purified biomass-based composition comprises ethylene glycol in an amount of 99% by weight or greater, based on the weight of the purified biomass-based composition. In one embodiment, the purified biomass-based composition comprises ethylene glycol in an amount of 99.25% by weight or greater, based on the weight of the purified biomass-based composition. In one embodiment, the purified biomass-based composition comprises ethylene glycol in an amount of 99.5% by weight or greater, based on the weight of the purified biomass-based composition.

[0128] In one embodiment, the purified biomass-based composition comprises ethylene glycol in an amount of 99.95% by weight or less, based on the weight of the purified biomass-based composition. In one embodiment, the purified biomass-based composition comprises ethylene glycol in an amount of 99.9% by weight or less, based on the weight of the purified biomass-based composition. The purified biomass-based composition has an absolute upper limit of 100% by weight of ethylene glycol, based on the weight of the purified biomass-based composition.

[0129] In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 38% or less. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 35% or less. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 32% or less. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 30% or less. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 28% or less. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 25% or less. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 22% or less. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 20% or less.

[0130] In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E219) of 0% or greater. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E219) of 1% or greater. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 2% or greater. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 5% or greater. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 8% or greater. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 10% or greater. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 12% or greater. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of 15% or greater.

[0131] In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM Method E2193-16) of 0% to 40%. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM Method E2193-16) of 1% to 38%. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM Method E2193-16) of 2% to 38%. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM Method E2193-16) of 5% to 35%. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM Method E2193-16) of 10% to 35%. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of between 15% and 35%. In one embodiment, the biomass-based composition contacted with the at least one reagent has a UV transmittance at 275 nm (measured according to ASTM method E2193-16) of between 20% and 35%.

[0132] In one aspect of the invention, biomass-based compositions containing ethylene glycol that are believed to be suitable as a reactant in the synthesis of PET have an APHA color after heating of less than 20 mg / L PtCo. In one embodiment, biomass-based compositions containing ethylene glycol according to the present invention that are believed to be suitable as a reactant in the synthesis of PET have an APHA color after heating of less than 15 mg / L PtCo.

[0133] In one embodiment, contacting the purified biomass-based composition obtained by the method of purifying a biomass-based composition with at least one reagent comprises (I) reacting ethylene glycol with the at least one reagent to provide a monomer; and (II) polymerizing the monomer to provide a polyester. However, for the avoidance of doubt, the polyester may be polymerized by any method suitable to obtain the desired polyester properties.

[0134] In one embodiment, the at least one reagent comprises one or more of a diacid, a diester, and an acid anhydride.

[0135] In one embodiment, the diacid is a terephthalic acid compound, an isophthalic acid compound, or a mixture thereof.

[0136] In one embodiment, the diacids are renewably sourced, for example, they can be formed synthetically from biomass-derived starting materials such as furfural.

[0137] In one embodiment, the terephthalic acid compound is selected from the group consisting of terephthalic acid, dimethyl terephthalate, or a combination thereof.

[0138] In one embodiment, the isophthalic compound is selected from isophthalic acid, dimethyl isophthalate, or a combination thereof.

[0139] In one embodiment, the diacid is selected from naphthalene dicarboxylic acid, cyclohexane dicarboxylic acid, cyclohexane diacetic acid, succinic acid, glutaric acid, furandicarboxylic acid, adipic acid, azelaic acid, sebacic acid, and combinations thereof.

[0140] In one embodiment, the monomer comprises bis(2-hydroxyethyl) terephthalate.

[0141] The polyester can include polyethylene terephthalate. In one embodiment, contacting the purified biomass-based composition obtained by the method for purifying a biomass-based composition with at least one reagent includes: (I) reacting ethylene glycol with one or more of a diacid and a diester to provide a bis(2-hydroxyethyl) terephthalate monomer; and (II) polymerizing the monomer to provide a polyester including polyethylene terephthalate. In one embodiment, step (I) of the method for producing a polyester is performed at a temperature of 230°C to 260°C. In one embodiment, step (II) of the method for producing a polyester is performed at a temperature of 270°C to 300°C. In one embodiment, step (II) of the method for producing a polyester is performed in the presence of a catalyst. In one embodiment, the catalyst is a heterogeneous catalyst. In one embodiment, the catalyst is an antimony-containing catalyst, or a platinum-containing catalyst, or a titanium-containing catalyst, or an aluminum-containing catalyst, or a germanium-containing catalyst. In one embodiment, the catalyst is antimony(III) oxide. In one embodiment, step (II) of the method for producing a polyester is performed in the presence of a phosphorus compound added as a stabilizer.

[0142] If the ethylene glycol fraction of the diols in the polyester is greater than 90% and the terephthalic acid fraction of the diols in the polyester is greater than 90%, it is considered polyethylene terephthalate (PET).

[0143] In one embodiment, step (I) of reacting ethylene glycol with at least one reagent to provide a monomer can be carried out in the presence of a small amount of another diol, where a small amount is preferably less than 40 mole percent of the total molar amount of diols.

[0144] In one embodiment, the other diol is selected from the group comprising diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2-methyl-1,4-pentanediol, 3-methyl-2,4-pentanediol, trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,2-diethyl-1,3propanediol, 1,3-hexanediol, 1,4-di(hydroxyethoxy)benzene, 2,2-bis(4-hydroxycyclohexyl)propane, 2,4-dihydroxy-1,1,3,3-tetramethylcyclobutane, 2,2-bis(3-hydroxyethoxyphenyl)propane, 2,2-bis(4-hydroxypropoxyphenyl)propane, and cyclohexanedimethanol, or a mixture thereof.

[0145] Polymerization conditions can result in polymer grades with different molecular weights, which are traditionally described by their intrinsic viscosity (IV) values, as measured by ASTM D792.

[0146] In one embodiment, the polyester is further subjected to a solid-state polymerization (SSP) reaction in an inert or low-pressure atmosphere at a temperature of 180 to 230°C for a predetermined time to obtain a desired IV. In one embodiment, the IV of the polyester after SSP is at least 0.65 dL / g. In one embodiment, the IV of the polyester after SSP is at least 0.75 dL / g. In one embodiment, the IV of the polyester after SSP is at least 0.85 dL / g. In one embodiment, the IV of the polyester after SSP is at least 1.0 dL / g.

[0147] polyester According to another aspect of the present invention, there is provided a biomass-based polyester obtained by the method for producing a polyester according to an aspect of the present invention.

[0148] As used herein, biomass-based polyester is understood to be a polyester in which at least one component of the polyester is bio-based as described herein.

[0149] In one embodiment, the polyester compositions disclosed herein can include additives in addition to the polyester, including, but not limited to, colorants, ultraviolet (UV) stabilizers, antioxidants, fillers, gas barrier additives, plasticizers, nucleating agents, heat stabilizers, chain extenders, and combinations thereof.

[0150] The polyester compositions described herein can be blended with additives in a known manner. For example, additives can be introduced before, during, or after the polymerization step. Additives can also be blended with the polyester at a subsequent processing or conversion stage.

[0151] In one aspect, polyesters and articles thereof according to one or more embodiments can be recycled using conventional recycling methods, such as mechanical recycling and chemical recycling, under recycling operating conditions known to those skilled in the art. In one or more embodiments, packaging articles made from the polyesters disclosed herein are mechanically recycled in the form of chips or granules. Thus, the resulting chips and granules are typically 14 The resulting chips or granules can be reprocessed into the same or different polyester-based packaging materials using the processing and manufacturing techniques described herein. This reprocessing can occur simultaneously with, but is not limited to, chips and granules obtained by recycling PET or conventional polyester from conventional petrochemical sources (fossil fuel-derived or non-biobased sources).

[0152] In one embodiment, the polyester has an L of 65 or greater. *In one embodiment, the polyester is characterized by a CIELAB color space parameter value (measured according to ASTM method D6290-19) of 70 or greater. * In one embodiment, the polyester is characterized by a CIELAB color space parameter value (measured according to ASTM method D6290-19) of 75 or greater. * In one embodiment, the polyester is characterized by a CIELAB color space parameter value (measured according to ASTM method D6290-19) of 80 or greater. * In one embodiment, the polyester is characterized by a CIELAB color space parameter value (measured according to ASTM method D6290-19) of 85 or greater. * In one embodiment, the polyester is characterized by a CIELAB color space parameter value (measured according to ASTM method D6290-19) of 90 or greater. * are characterized by CIELAB color space parameter values ​​(measured according to ASTM method D6290-19) of

[0153] Here, the CIELAB color space parameter values ​​are measured in accordance with ASTM D6290-19 at 20° C. to 25° C. (room temperature) and atmospheric pressure.

[0154] In one embodiment, the polyester has an a of -4 to 4. * In one embodiment, the polyester is characterized by a CIELAB color space parameter value (measured according to ASTM method D6290-19) of -3 to 3. * In one embodiment, the polyester is characterized by a CIELAB color space parameter value (measured according to ASTM method D6290-19) of -2 to 2. * are characterized by CIELAB color space parameter values ​​(measured according to ASTM method D6290-19) of

[0155] In one embodiment, the polyester has a b of -4 to 4. *In one embodiment, the polyester is characterized by a CIELAB color space parameter value (measured according to ASTM method D6290-19) of b from -3 to 3. * In one embodiment, the polyester is characterized by a CIELAB color space parameter value (measured according to ASTM method D6290-19) of b from -2 to 2. * are characterized by CIELAB color space parameter values ​​(measured according to ASTM method D6290-19) of

[0156] The polyester may include polyethylene terephthalate.

[0157] Packaged articles or preforms According to another aspect of the present invention, there is provided a packaging article or preform formed from a polyester according to one aspect of the present invention.

[0158] The polyesters according to the present disclosure can be formulated for a number of polymeric articles and products, including, but not limited to, containers, flasks, bottles, vessels, caps, carpets, clothing, fabrics, strapping, rope, fiberfill, building materials, furniture, medical applications, films, sheets, laminates, protective packaging, electrical seals, solenoids, smart meters, photovoltaic components, solar cell junction boxes, automotive parts, wiper arms and gear housings, headlamp retainers, engine covers, connector housings, industrial fibers, 3D printing filaments, thermoformed articles, and the like.

[0159] As mentioned above, the polyester according to one or more embodiments can be used in films. In particular, the polyester film can be used in uniaxially oriented films, biaxially oriented films, multilayer films with other polymeric materials, blown films, and articles, or extrusion coatings. Blown articles can be extrusion blown, stretch blown, or injection blown.

[0160] In one or more embodiments, the polyester can be used to produce polyester fibers from melt spinning and / or drawing, which may include, but are not limited to, drawn textured yarns, partially oriented yarns, polyester staple fibers, fully oriented yarns, spin-drawn yarns, and polyester mesh.

[0161] Manufacturing processes include, but are not limited to, injection molding, stretch blow molding, lamination, extrusion, thermoforming, melt spinning, and 3D printing.

[0162] In one embodiment, the packaging article is a container. In one embodiment, the polyester container can be used to package, but is not limited to, food, cosmetics, soft drinks, water, alcoholic beverages, cosmetics, medicines, and edible oils.

[0163] In one embodiment, the packaging article is a bottle. The polyester may include polyethylene terephthalate.

[0164] Total aldehyde concentration The total aldehyde concentration can be determined by any suitable technique, as known to those of skill in the art. For example, in one embodiment, the total aldehyde concentration is measured using ASTM method E2313-20.

[0165] Ethylene glycol concentration The concentration of ethylene glycol can be determined by any suitable technique as known to those skilled in the art. In one embodiment, the concentration of ethylene glycol is measured using gas chromatography (GC) with flame ionization detection (FID), referred to herein as "GC-FID."

[0166] Any aspect of the present disclosure may be defined in relation to any other aspect of the present disclosure. For example, one aspect of the present disclosure may include any feature of any other aspect of the present disclosure. For example, the features of one aspect of the present disclosure may be as defined in relation to the features of any other aspect of the present disclosure. [Example]

[0167] example Example 1: GC analysis method In all cases, GC analysis was performed on an Agilent 7890A GC equipped with an FID and a PolyARC reactor (PolyARC from Activated Research Company, 7561 Corporate Way, Eden Prairie, MN 55344, USA). The PolyARC reactor converted all analytes to methane before quantification. Helium was used as the carrier and FID makeup gas. Air and H2 were supplied to the PolyARC electronic flow control module and FID. Samples were injected without pretreatment. The GC column effluent was sent directly to the inlet of the PolyARC reactor. The reactor effluent was directly connected to the FID. GC conditions were: inlet split: 15:1; inlet temperature: 230 °C; column: DB-624 (60 m × 0.32 mm × 1.8 μm); carrier gas (He): 2 ml / min; injection volume: 0.5 μL. FID conditions: Temperature 300°C; H2: 1.5 ml / min; Air: 350 ml / min; Makeup (He): 28 ml / min. PolyARC reactor conditions: Temperature 450°C; H2: 35 ml / min; Air: 2.5 ml / min. Oven starting temperature was 100°C. After injection, the temperature was increased to 125°C at 1.5°C / min and held for 5 minutes. The temperature was then increased to 260°C at 20°C / min and held for 10 minutes. Chromatograms were acquired and the desired analyses were performed. Quantitation was based on peak area unless otherwise specified.

[0168] Example 2 - Biomass-based composition As disclosed in Example 1 of WO2017 / 216311, a C1-C3 oxygenate mixture was obtained by pyrolytic fragmentation of an aqueous sugar (glucose) solution. As disclosed in Example 4 of US9926247, a hydrogenation product composition was obtained from the C1-C3 oxygenate mixture. The hydrogenation product composition thus obtained was concentrated to obtain an aqueous solution of ethylene glycol (a biomass-based composition containing ethylene glycol).

[0169] Example 3 - Distillation An aqueous solution of ethylene glycol provided by Example 2 was distilled to a concentration of 99.7 wt. % ethylene glycol based on the weight of the aqueous solution, as determined by GC-FID analysis (Example 1).

[0170] The distillation unit used in the experiment was a continuous distillation unit. The column was a packed column (50 mm diameter, 4 m length, Sulzer DX type) with a feed point at the middle of the column. The reboiler of the distillation unit was a wiped film heat exchanger. The bottom fraction was recovered as a liquid outlet from the wiped film heat exchanger. A water-cooled condenser was installed at the top of the column to completely condense the vapor from the column. The condensate was divided into two parts depending on the reflux ratio. The reflux fraction was returned to the top of the column as a liquid, and the remainder was recovered as a distillation fraction. The liquid side draw was recovered from a liquid side draw outlet installed 1 m below the top of the column.

[0171] Distillative purification was carried out as three successive vacuum distillations (low pressure distillations).

[0172] In the first distillation step, the aqueous ethylene glycol solution was distilled at a pressure of 200 mBar and a reflux ratio of 4, removing water and by-products more volatile than propylene glycol as distillate fractions. The bottom fraction was enriched in ethylene glycol.

[0173] In the second distillation step, the bottom fraction from the first distillation was distilled at a pressure of 200 mBar and a reflux ratio of 20. Propylene glycol and 1,2-butanediol were completely removed as distillate. The bottom fraction was enriched in ethylene glycol and was the distillation product of this distillation.

[0174] In the third distillation step, the bottom fraction from the second distillation was distilled at a pressure of 200 mBar and a reflux ratio of 24. The product of the distillation, i.e., a distillation fraction containing 99.7% by mass of ethylene glycol, was recovered through a liquid side draw. The composition of this product stream was "Distillation Product." The mass ratio of distillate to feed was 0.13, and the mass ratio of liquid side draw to feed was 0.6.

[0175] Example 4 - Melt Crystallization Melt crystallization was carried out in a cylindrical tank with a cooling jacket. The cooling jacket had an inlet and an outlet fluidly connected to a source of liquid cooling medium. The cylindrical tank had a valved outlet located in the center of the tank bottom. The inside of the tank bottom was lined with a mesh screen, which, in use, served to retain the crystals while the mother liquor was drained through the outlet. The drainage rate was controlled by applying a vacuum to the drain side.

[0176] For melt crystallization, a sample of the distillation product from Example 3 was transferred to a crystallization jar, and the distillation product was stirred at 50 rpm using an anchor stirrer. Stirring prevented the formation of crystalline clumps in the distillation product during crystallization. A liquid cooling medium was circulated through the cooling jacket. The temperature of the liquid cooling medium at the inlet of the cooling jacket was set to -22°C. This cooled the distillation product to a temperature of approximately -21°C to -22°C. Although the distillation product was cooled to this temperature, no crystal formation was observed.

[0177] To initiate crystallization, 5–10 g of dry ice was crushed to a particle size of 1–2 mm and poured into a crystallization jar under stirring. To disperse the dry ice particles in the liquid, the stirring anchor was rotated to 100 rpm for several minutes. The stirring anchor speed was then reduced to 50 rpm again. After a few more minutes, the distillation product became cloudy, indicating the initiation of crystal formation. A cooling medium at a temperature of −22°C was maintained circulating during crystallization, and the temperature of the crystal suspension rose to approximately −15°C. This resulted in the formation of crystals and a mother liquor containing the suspended crystals. The mother liquor was removed from the crystallization jar by applying a vacuum to the bottom valve of the crystallization jar. Approximately 30% by mass of the distillation product was removed from the crystallization jar as mother liquor (based on the mass of the distillation product).

[0178] The residue in the crystallization jar after vacuum filtration (vacuum filtration) was subjected to two sweating steps by adjusting the temperature of the cooling medium to −10° C. to partially melt the crystals so as to release the impurities trapped with them.

[0179] In the first sweating step, the crystals were partially melted to form a mixture of the crystals and the first solution (liquor). The first liquid was then removed by applying a vacuum to the bottom valve of the crystallization jar. The amount of liquid removed by vacuum filtration corresponded to approximately 30% by weight of the amount of material in the crystallization jar before sweating began.

[0180] In the second sweating step, the crystals remaining after the first sweating step were partially melted to form a mixture of crystals and a second solution (liquor). The second liquor was then removed by applying a vacuum to the bottom valve of the crystallization jar. The amount of liquid removed by vacuum filtration corresponded to approximately 30% by weight of the amount of material in the crystallization jar before the second sweating step began.

[0181] The crystals obtained in the second sweating step were melted and collected as a product, which is designated as "crystallized product."

[0182] Example 5 - Melt Recrystallization To obtain a further purified product, the crystallized product obtained in Example 4 was subjected to additional cycles of melt crystallization and sweating steps as described in Example 3. This further purified product is designated "recrystallized product."

[0183] Example 6 - Acid Catalyst and Resin Treatment The distillation product of Example 3 was subjected to processing steps, which included: (1) diluting the distillation product to form a diluted composition, the diluted composition having a water content of about 20% by weight, based on the weight of the diluted composition; (2) The diluted composition is passed through a column containing a mixed bed of a solid acid catalyst resin (Amberlyst 15) and an aldehyde removal resin (Purolite A110) at a temperature of 50°C; and (3) Water was removed from the diluted composition by evaporation in a rotary evaporator. Water was evaporated at 70 mBar pressure by immersing a rotating still pot in a heated oil bath at 150° C. Evaporation was stopped when the water content of the glycol product fraction in the still pot reached 2% by weight.

[0184] This product is designated the "acid catalyzed and resin treated" product.

[0185] Example 7 - Product analysis The distilled product of Example 3, the crystallized product of Example 4, the recrystallized product of Example 5, and the acid catalyst and resin-treated product of Example 6 were evaluated for parameters relevant to polyester (e.g., PET production), including the following measurements: diethylene glycol concentration (wt%); APHA color (mg / L PtCo); and APHA color (mg / L PtCo) after heating to 200° C. for 4 hours. Transmittance at 275 nm was also measured.

[0186] The standard method for determining diethylene glycol concentration is described in ASTM E2409-20a.

[0187] The standard method for measuring APHA color is described in ASTM Method D1209-05. APHA color measurements herein (per ASTM Method D1209-05) were performed using an instrumental method integrated into a Lovibond PFX-I series spectrophotometer. This method is designated Pt-Co D1209. APHA color was measured using a 100 mm glass cuvette to hold the sample. Measurements were performed at room temperature (20°C to 25°C) and atmospheric pressure. A standard curve covering the relevant color range was prepared in demineralized water using a commercially available Pt-Co standard solution, such as that available from Sigma-Aldrich (Pt-Co / Hazen / APHA Color Reference Standard, Sigma no. 134190 (ASTM Color 100)). The APHA value of a given sample was determined from the standard curve based on the sample's measured Pt-Co value. That is, a given sample was placed in the colorimeter and tested, and the Pt-Co value output from the colorimeter was compared with the standard curve to determine the APHA color value of the given sample.

[0188] The ethylene glycol samples were heat-treated prior to measurement by placing each sample in a glass container and flushing with nitrogen for 15 minutes to remove air. The glass container was sealed, ensuring a substantially oxygen-free environment. Each sample in the glass container was heated to 200°C for 4 hours. After cooling, the color of the heat-treated samples was measured using the APHA color method described above. The 4-hour heat treatment was intended to simulate discoloration during polyester synthesis.

[0189] Measurements of UV transmittance at 275 nm were performed using ASTM method E2193-16. UV transmittance was measured on a double-beam spectrophotometer using a 10 mm quartz cuvette for both the blank and product samples. The blank sample was demineralized water. Measurements were performed at a wavelength of 275 nm, at room temperature (20°C-25°C), and atmospheric pressure. Results are reported as transmittance, with 0% indicating no light and 100% indicating that the transmittance of the product sample is equal to that of the blank sample.

[0190] Table 1 shows the measurement results.

[0191] [Table 1]

[0192] The data in Table 1 show that the APHA color of the product was reduced by melt crystallization and further reduced by subsequent recrystallization. This applied to the product both before and after the 4-hour heat treatment. The acid-catalyzed and resin-treated product exhibited the lowest color values ​​of all the samples. The diethylene glycol content was not adversely affected by either treatment.

[0193] The ultraviolet transmittance of all four samples is less than 40%.

[0194] GC analysis of the distilled product of Example 3, the crystallized product of Example 4, and the recrystallized product of Example 5 qualitatively demonstrated that the areas of all impurity peaks were reduced by melt crystallization. Table 2 shows the peak areas of ethylene glycol and three impurities (designated as impurities 1, 2, and 3). Peaks 1-3 are identified by their retention times in the GC chromatogram. (The identities of the impurities were unknown.) Table 3 shows the peak areas of impurities 1-3 relative to the peak area of ​​ethylene glycol. In Table 4, the relative peak areas of the single peaks shown in Table 3 were recalculated as the residual impurity content relative to the residual impurity content of the distilled product.

[0195] [Table 2]

[0196] [Table 3]

[0197] [Table 4]

[0198] The data in Tables 2-4 show that the impurity content in the purified biomass-based composition is reduced by more than 50% by crystallization and by more than 80% by crystallization followed by recrystallization compared to the distillation-only product (distillation product). Thus, the crystallized and recrystallized products each have a higher concentration of ethylene glycol than the distillation product.

[0199] Example 8 - Polyester Production In each experiment, polyesters were produced using the distillation product from Example 3, the crystallization product from Example 4, the recrystallization product from Example 5, and the acid catalyst and resin-treated product from Example 6. Each experiment was conducted as a standard batch process. In each experiment, each product was contacted with terephthalic acid to produce a polyester containing polyethylene terephthalate (PET). Isophthalic acid (IPA) was added as a copolymerization compound at a ratio of 2% based on the total diacid compounds. This was carried out in two steps: (1) esterification reaction was carried out by contacting each product with terephthalic acid, during which bis(2-hydroxyethyl) terephthalate was produced and water and volatile by-products were removed; and (2) polymerization (polycondensation) of bis(2-hydroxyethyl) terephthalate was carried out in the presence of an antimony catalyst while continuously removing the released ethylene glycol.

[0200] Step (1) was carried out at atmospheric pressure at a temperature ranging from 150° C. to 260° C. Step (2) was carried out under vacuum (0.01 to 2 mbar) at a temperature ranging from 280° C. to 300° C.

[0201] Step (2) was carried out until a target level of polymerization was reached, as determined by measuring intrinsic viscosity, a standard method for measuring intrinsic viscosity being described in ASTM Method D4603-18.

[0202] The degree of polycondensation can also be indirectly and approximately determined by measuring the torque of the agitator shaft of the mixer in the polymerization reactor. This requires the construction of a standard curve showing the relationship between torque and intrinsic viscosity. This method was used to control the polycondensation time. When the torque of the agitator shaft reached the desired value, the polymerized melt was removed from the polymerization vessel and transferred to an ice-water cooling bath to terminate the reaction. The intrinsic viscosity values ​​shown in Table 4 are the actual measured values ​​of the polyester product obtained from the polycondensation. After cooling, the polymer was divided into pellets.

[0203] Example 9 - Analysis of Polyester Products The pellets of Example 8 were analyzed for intrinsic viscosity; COOH end groups (mmol / kg); and CIELAB color parameter L * , a * , and b * The standard method for measuring COOH end group concentration is described in ASTM D7409-15 (temperature 20°C to 25°C, atmospheric pressure).

[0204] The standard method for measuring CIELAB color parameters is described in ASTM Method D6290-19. The method herein (per ASTM Method D6290-19) was performed at a temperature of 20°C to 25°C and atmospheric pressure. PET pellets were spread into a disk (approximately 50 mm in diameter) in a uniform layer approximately 10 to 15 mm thick. The disk was placed in an automated colorimeter, and the CIELAB color coordinates were read on the display.

[0205] The main properties of the pellets are shown in Table 5 below.

[0206] [Table 5]

[0207] As described herein, L * , a * , and b * The parameter values ​​are CIELAB color components. *The value represents the perceived lightness, with black being 0 and white being 100. * value and b * The values ​​represent the four colors of human vision (red, green, blue, yellow). * Positive values ​​indicate yellow. Yellow is b * decreases as it approaches 0.

[0208] As can be seen from Table 5, the CIELAB color parameters of the polyester produced from the distillation product of Example 3 do not meet the requirements for bottle-grade PET. In contrast, despite the UV transmittance of the distillation product of Example 3, the crystallization product of Example 4, the recrystallization product of Example 5, and the acid-catalyzed and resin-treated product of Example 6 all being less than 40%, the polyesters produced from the ethylene glycol crystallization product of Example 4, the recrystallization product of Example 5, and the acid-catalyzed and resin-treated product of Example 6 all exhibit CIELAB color parameters that meet the requirements for bottle-grade PET. While UV transmittance significantly greater than 40% was previously considered a technical requirement for EG monomer to be usable in the production of bottle-grade PET, this has surprisingly been demonstrated to be unimportant for biomass-based compositions containing ethylene glycol. Instead, we have found that by providing a biomass-based composition containing ethylene glycol and contacting the biomass-based composition with at least one reagent to form a polyester, polyesters that meet the technical specifications for PET can be obtained, even if their UV transmittance at 275 nm, measured according to ASTM Method E2193-16, is less than 40%. This indicates application to purification involving melt crystallization or acid catalysis and resin treatment.

[0209] The various embodiments described herein are presented solely to aid in the understanding and teaching of the claimed features. These embodiments are provided only as a representative sample of embodiments and are not intended to be exhaustive and / or exclusive. The advantages, embodiments, examples, functions, features, structures, and / or other aspects described herein are not intended to be limitations on the scope of the invention as defined by the claims or limitations on the equivalents of the claims, and it should be understood that other embodiments may be utilized and changes may be made without departing from the scope of the claimed invention. Various embodiments of the present invention may suitably be composed of, consist of, or consist essentially of any suitable combination of the disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. Furthermore, the present disclosure may include other inventions not currently claimed but which may be claimed in the future.

Claims

1. 1. A method for producing a polyester, comprising: The method comprises: (a) providing a biomass-based composition comprising ethylene glycol, the biomass-based composition having a UV transmittance at 275 nm of less than 40% as measured according to ASTM method E2193-16; and (b) contacting the biomass-based composition with at least one reagent to form a polyester.

2. 2. The method of claim 1, wherein the biomass-based composition has a UV transmittance at 275 nm measured according to ASTM method E2193-16 of 35% or less, such as 30% or less, such as 20% or less.

3. 3. The method of claim 1 or 2, wherein the biomass-based composition has a UV transmittance at 275 nm of at least 5%, such as at least 10%, measured according to ASTM method E2193-16.

4. 4. The method of any one of claims 1 to 3, wherein the biomass-based composition comprises ethylene glycol in an amount of 97% by weight or more, such as 99% by weight or more, for example 99.25% by weight or more, such as 99.5% by weight or more, for example 99.75% by weight or more, for example 99.9% by weight or more, based on the weight of the biomass-based composition.

5. 5. The method of any one of claims 1 to 4, wherein the biomass-based composition has a total aldehyde concentration measured according to ASTM method E2313-20 of 50 ppm or less, such as 20 ppm or less, for example 18 ppm or less, such as 15 ppm or less, for example 10 ppm or less, based on the weight of the biomass-based composition.

6. The method of any one of claims 1 to 5, wherein the biomass-based composition has an APHA color of less than or equal to 5 mg / L PtCo, measured according to ASTM D1209-05.

7. 7. The method of any one of claims 1 to 6, wherein the biomass-based composition has an APHA color after heating of 20 mg / L PtCo or less, measured according to ASTM D1209-05.

8. 8. The method of any one of claims 1 to 7, wherein the biomass-based composition in step (a) is provided by: (I) subjecting the biomass-based composition to at least one distillation step to provide a distillation product, wherein the concentration of ethylene glycol in the distillation product is higher than in the biomass-based composition; and then (II) subjecting the distillation product to at least one melt crystallization step to form crystals and a mother liquor, wherein the crystals provide a purified biomass-based composition, wherein the concentration of ethylene glycol in the purified biomass-based composition is higher than in the distillation product, and wherein the purified biomass-based composition is the biomass-based composition of step (a).

9. 8. The method of any one of claims 1-7, wherein the biomass-based composition in step (a) is provided by: (I) providing a biomass-based composition comprising water in an amount of at least 0.1% by weight, based on the weight of the biomass-based composition; and (II) contacting the biomass-based composition with a solid acid catalyst and contacting the biomass-based composition with an aldehyde-removing resin to provide a purified biomass-based composition, wherein the purified biomass-based composition is the biomass-based composition of step (a).

10. 10. The method of claim 9, wherein the method comprises contacting the biomass-based composition with the solid acid catalyst and subjecting the biomass-based composition to at least one distillation step prior to contacting the biomass-based composition with the aldehyde-removing resin.

11. 8. The method of any one of claims 1-7, wherein the biomass-based composition in step (a) is provided by: (I) providing a biomass-based composition comprising at least 0.1% by weight of water, based on the weight of the biomass-based composition; (II) contacting the biomass-based composition of (I) with a solid acid catalyst and contacting the biomass-based composition with an aldehyde-removing resin to provide a first purified biomass-based composition; and (III) subjecting the first purified biomass-based composition from (II) to at least one distillation step to provide a distillation product, wherein the concentration of ethylene glycol in the distillation product is higher than in the first purified biomass-based composition, the distillation product is a second purified biomass-based composition, and the second purified biomass-based composition is the biomass-based composition of step (a).

12. 8. The method of claim 1, wherein the biomass-based composition in step (a) is provided by: (I) providing a biomass-based composition comprising at least 0.1% by weight of water, based on the weight of the biomass-based composition; (II) contacting the biomass-based composition of (I) with a solid acid catalyst and contacting the biomass-based composition with an aldehyde-removing resin to provide a first purified biomass-based composition; (III) subjecting the first purified biomass-based composition from (II) to at least one distillation step to provide a distillation product, wherein the concentration of ethylene glycol in the distillation product is higher than in the biomass-based composition, the distillation product being a second purified biomass-based composition; and (IV) subjecting the distillation product to at least one melt crystallization step to form crystals and a mother liquor, wherein the crystals provide a third purified biomass-based composition, wherein the concentration of ethylene glycol in the third purified biomass-based composition is higher than in the distillation product, the third purified biomass-based composition being the biomass-based composition of step (a).

13. The biomass-based composition in step (a) is provided by: (I) subjecting the biomass-based composition to at least one distillation step to provide a distillation product, wherein the concentration of ethylene glycol in the distillation product is greater than in the biomass-based composition, the distillation product being a first purified biomass-based composition; (II) subjecting the distillation product to at least one melt crystallization step to form crystals and a mother liquor, the crystals providing a second purified biomass-based composition, wherein the concentration of ethylene glycol in the second purified biomass-based composition is greater than in the distillation product, optionally diluting the second purified biomass-based composition; and and (III) contacting the second purified biomass-based composition (e.g., the diluted second purified biomass-based composition) with a solid acid catalyst and contacting the second purified biomass-based composition (e.g., the diluted second purified biomass-based composition) with an aldehyde-removal resin to provide a third purified biomass-based composition, wherein the second purified biomass-based composition (e.g., the diluted second purified biomass-based composition) comprises water in an amount of at least 0.1 wt. %, based on the weight of the second purified biomass-based composition, and the third purified biomass-based composition is the biomass-based composition of step (a).

14. 14. The method of any one of claims 1 to 13, wherein the biomass-based composition is obtained by pyrolytic fragmentation of sugars followed by hydrogenation.

15. A biomass-based polyester obtainable by the method according to any one of claims 1 to 14.

16. The polyester has one or more of the following CIELAB color space values ​​measured according to ASTM D6290-19: ＊ is 65 or more, for example 85 or more; ＊ is −4 to 4, for example, −2 to 2; and b ＊ 16. The polyester of claim 15, characterized by a .DELTA.I. of from -4 to 4, for example from -2 to 2.

17. A packaging article or preform formed from the polyester of claim 14 or 15.

18. The method, polyester, packaging article, or preform of any one of claims 1 to 15, wherein the polyester comprises polyethylene terephthalate.

19. A biomass-based composition comprising ethylene glycol, having a UV transmittance at 275 nm of less than 40% as measured according to ASTM method E2193-16 and an APHA color after heating of less than or equal to 20 mg / L PtCo as measured according to ASTM method D1209-05.

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