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US-12624013-B2 - Purification of 2,5-furandicarboxylic acid, dimethyl ester and other esterified products

US12624013B2US 12624013 B2US12624013 B2US 12624013B2US-12624013-B2

Abstract

Methods are disclosed for the purification of crude compositions comprising 2,5-furandicarboxylic acid, dimethyl ester (FDME) or other diester derivatives (e.g., dialkyl ester derivatives) of 2,5-furandicarboxylic acid (FDCA), by crystallization. In this regard, certain solvents, and classes of solvents, have been discovered to promote the selective crystallization of FDME over impurities often generated in its production by FDCA esterification and other upstream processing steps. Importantly, certain impurities that are selectively removed include those that would otherwise be detrimental to the color and/or color stability of the purified composition. Other improvements in crystallization reside in the use of techniques such as liquid-liquid extraction and pre-treatment of the crystallization solution by contact with a solid medium.

Inventors

  • Iman Beheshti Tabar
  • Kenneth F. Stensrud
  • William Christopher Hoffman

Assignees

  • ARCHER DANIELS MIDLAND COMPANY

Dates

Publication Date
20260512
Application Date
20210729

Claims (15)

  1. 1 . A process for purifying a crude composition comprising 2,5-furandicarboxylic acid, dimethyl ester (FDME), the process comprising: forming a biphasic solution of the crude composition in a solvent comprising an organic phase and a separate aqueous phase, separating the organic phase from the aqueous phase, and crystallizing, from the organic phase, a purified composition having an increased content of FDME relative to the crude composition, wherein the steps of forming a biphasic solution and separating the organic phase from the aqueous phase are steps of a continuous liquid-liquid extraction, wherein one or more impurities in the crude composition are selectively solubilized in the aqueous phase, relative to FDME in the crude composition, and wherein FDME is selectively solubilized in the organic phase, relative to one or more impurities in the crude composition.
  2. 2 . The process of claim 1 , wherein the crude composition comprises FDME in an amount from 75 wt-% to 95 wt-%.
  3. 3 . The process of claim 1 , wherein the solution of the crude composition is formed at an elevated temperature from 25° C. to the normal boiling point of the compound in the solution having the lowest boiling point.
  4. 4 . The process of claim 3 , wherein the steps of dissolving and crystallizing are carried out at a temperature of less than 100° C.
  5. 5 . The process of claim 1 , wherein the step of crystallizing comprises cooling the solution of the crude composition.
  6. 6 . The process of claim 1 , wherein the steps of forming a biphasic solution and separating the organic phase from the aqueous phase are steps of a multi-stage liquid-liquid extraction, wherein the process further comprises: extracting the aqueous phase in one or more extracting stages by contact with one or more respective, additional extraction quantities of the organic phase to extract one or more respective, additional portions of FDME from the aqueous phase; and combining the one or more additional extraction quantities of the organic phase, comprising the one or more respective, additional portions of FDME, with the organic phase, prior to crystallizing, from a combined organic phase, the purified composition.
  7. 7 . The process of claim 1 , wherein the aqueous phase comprises a greater proportion, relative to FDME, than the organic phase, of partially esterified 2,5-furandicarboxylic acid, monomethyl ester (FDMME) and/or non-esterified 2,5-furan dicarboxylic acid (FDCA), and wherein the process further comprises: utilizing FDMME and/or FDCA, present in the aqueous phase, in an esterification reactor to convert at least a portion of the FDMME and/or FDCA to FDME.
  8. 8 . The process of claim 7 , wherein the step of utilizing FDMME and/or FDCA comprises recovering at least a portion of the FDMME and/or FDCA, present in the aqueous phase, as a solid precipitate.
  9. 9 . A process for purifying a crude composition comprising 2,5-furandicarboxylic acid, dimethyl ester (FDME), the process comprising: dissolving the crude composition in a solvent to form a solution of the crude composition, contacting the solution of the crude composition with a solid treatment medium comprising diatomaceous earth and/or activated carbon to provide a treated solution, and crystallizing, from the treated solution of the crude composition, a purified composition having an increased content of FDME relative to the crude composition.
  10. 10 . The process of claim 9 , further comprising recovering the purified composition and performing a second stage of purification comprising: dissolving the purified composition in a second-stage solvent to form a second-stage solution of the purified composition, contacting the second-stage solution of the purified composition with a solid treatment medium to provide a second-stage treated solution, having a lighter color relative to the second-stage solution, and crystallizing, from the second-stage treated solution, a second-stage purified composition having an increased content of FDME relative to both the purified composition and the crude composition.
  11. 11 . The process of claim 9 , wherein the crude composition comprises FDME in an amount from 75 wt-% to 95 wt-%.
  12. 12 . The process of claim 9 , wherein the solution of the crude composition is formed at an elevated temperature from 25° C. to the normal boiling point of the compound in the solution having the lowest boiling point.
  13. 13 . The process of claim 12 , wherein the steps of dissolving and crystallizing are carried out at a temperature of less than 100° C.
  14. 14 . The process of claim 9 , wherein the step of crystallizing comprises cooling the solution of the crude composition.
  15. 15 . The process of claim 9 , wherein the solution of the crude composition is formed at an elevated temperature from 25° C. to 100° C.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a national stage entry of International Application No. PCT/US21/043728, filed Jul. 29, 2021, which itself claims priority to U.S. Provisional Patent Application No. 63/064,872, filed Aug. 12, 2020, the contents of each are incorporated herein by reference. FIELD OF THE INVENTION The present invention relates to methods for the purification of biobased monomers, and particularly esterified monomers such as 2,5-furandicarboxylic acid, dimethyl ester (FDME), which are useful in producing biobased polymers such as poly(alkylene terephthalate) polymers. BACKGROUND OF THE INVENTION The depletion of fossil fuels has created major incentives for seeking alternative sources to petroleum-based carbon for the synthesis of so-called “platform” molecules that can serve as the building blocks for commercially significant products. Biomass is currently viewed as a potential replacement from which many such high value chemicals can be derived, but the development of sustainable technologies for the production of such chemicals from renewable resources remains a significant challenge. The biobased monomers, 2,5-furandicarboxylic acid (FDCA) and its methyl ester derivative, 2,5-furandicarboxylic acid, dimethyl ester (FDME) are recognized as important starting materials in the production of poly(alkylene furandicarboxylate) polymers that can substitute for their known, mass-produced petroleum derived analogs, namely poly(alkylene terephthalate) polymers, such as polyethylene terephthalate (PET). A prominent example of a biobased poly(alkylene furandicarboxylate) polymer is poly(ethylene furandicarboxylate), or PEF, obtained by reaction of FDCA or FDME with ethylene glycol. This biobased plastic exhibits superior properties in a number of respects, relative to its petroleum-derived analog, PET, particularly in the area of packaging. For example, blends of PEF and PET can provide improved barrier properties with respect to CO2 and O2, prolonging shelf life over pure PET and providing an acceptable container for products such as beer that are susceptible to oxidative degradation. Other packaging applications of PEF include films used to manufacture pouches, wrappers, and heat shrink materials having high mechanical strength and recyclability. In general, both FDCA and FDME are useful platform molecules in the production of polyamides, polyurethanes, and polyesters having diverse applications as plastics, fibers, coatings, adhesives, personal care products, and lubricants. A significant consideration with respect to polymers that are made from these monomers is their color and color stability, i.e., resistance to color degradation over time, particularly resulting from exposure to a combination of heat and oxygen (e.g., air). Color, or more appropriately the absence of color, is important for applications such food packaging and particularly beverage bottle manufacturing, in which a lack of transparency or possibly yellowness in the plastic are readily perceived and often equated to an inferior product. To this end, it has been recognized that the use of the esterified monomer, FDME, affords advantages over FDCA in terms of resulting in better color of the final poly(alkylene furan dicarboxylate) polymer, as well as a greater ease in handling and processing. Color improvement through esterification may at least partly result from improved stability of esterified product, in terms of preventing aldol condensation reactions that might otherwise occur. Known processes for converting FDCA to its dialkyl ester derivative (e.g., its dimethyl ester derivative, FDME) by reaction with an appropriate alcohol (e.g., methanol) are disclosed, for example in WO 2017/019431, and such methods include post-reaction crystallization steps to increase FDME purity. A reactive distillation process for the esterification of FDCA is disclosed in US 2019/0031634, whereby distillation is combined with the esterification reaction in an effort to provide an FDME product with increased purity. On the other hand, U.S. Pat. No. 9,169,229 describes a series of steps to obtain a purified FDME (termed “DMFD”) and other esterified derivatives, and such steps include physical separation (e.g., distillation to drive off excess alcohol) and solid-liquid separation, with optional drying or crystallization. Disclosed compositions are purported to have improved color and a reduced concentration of impurities, including not more than 0.8 wt-% of 5-formyl-2-furancarboxylic acid methyl ester (termed “methyl 5-formylfuran-2-carboxylate”). Improvements in the quality of FDME and other diester derivatives of FDCA are key to the overall effort in establishing poly(alkylene furandicarboxylate) polymers as commercially viable alternatives to their petroleum-based counterparts. Despite the efforts to date, however, obtaining such diester derivatives with sufficient purity remains a considerable challenge, especially in