Production process of biomonomers and their precursors

Abstract

A process for producing biomonomers and precursors for their production. A carboxylation reaction is carried out between an aromatic hydrocarbon, such as furoate, and a dicarboxylated alkali salt. This reaction produces a carboxylated aromatic hydrocarbon and a decarboxylated alkali salt. The carboxylated aromatic hydrocarbon can be separated and used to produce biomonomers such as furandicarboxylate methyl ester and furandicarboxylic acid. The decarboxylated alkali salt can be regenerated.

Description

[Technical Field]

[0001] (Priority statement) This application claims priority to U.S. Provisional Patent Application No. 63 / 477,860, filed December 30, 2022, which is incorporated herein by reference in its entirety.

[0002] FIELD OF THE INVENTION The present invention relates generally to a process for producing aromatic carboxylic acid compounds, including furandicarboxylic acid and furandicarboxylate methyl ester, from biomass. [Background technology]

[0003] Recently, processes have been developed for producing aromatic carboxylic acids and esters from sugars produced from biomass. These aromatic carboxylic acids and esters can be converted to dicarboxylates, which can then be utilized to produce monomers such as furan dicarboxylate methyl ester (FDME) and furan dicarboxylic acid (FDCA). As is known, these monomers are useful for making polymers and plastics and are sometimes referred to as biomonomers because they are derived at least in part from biomass.

[0004] These processes are desirable because they provide for the production of biomonomers, as opposed to producing chemicals and monomers from fossil fuel sources. Additionally, the processes are desirable because they can consume carbon dioxide, which is considered a greenhouse gas.

[0005] These processes typically rely on the furoate carboxylation reaction with carbon dioxide and an alkali base. While generally effective for their intended purposes, such reactions are difficult to optimize, and thermal furoate decarboxylation to furan is a competing side reaction.

[0006] Therefore, there is a continuing desire and need to provide an effective and efficient process for producing biomonomers from biomass-derived components and carbon dioxide. Summary of the Invention

[0007] The present inventors have discovered an alternative furoate carboxylation reaction that can occur at lower temperatures to high conversions and produces fewer by-products for downstream separation. Specifically, they discovered that the reaction of aromatic hydrocarbons with alkali salt dicarboxylates produces carboxylated aromatic compounds and decarboxylated alkali salts. Furthermore, this carboxylate transfer reaction does not require the use of an additional alkali base reagent.

[0008] Thus, the present invention, in at least one aspect, can be characterized as providing a process for conducting a carboxylate transfer reaction by combining an aromatic ring with a dicarboxylate alkali salt to form a mixture and heating the mixture in the presence of carbon dioxide to form a carboxylated aromatic compound and a decarboxylated alkali salt.

[0009] The aromatic ring may include a counterion, and the alkali base, the counterion, or both may be selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, and mixtures thereof.

[0010] The dicarboxylate alkali salt may be a 1,3-dicarboxylate alkali salt.

[0011] The mixture may be heated to a temperature between 120°C and 400°C at a pressure up to 6,895 kPa (1,000 psi).

[0012] The mixture may be a slurry, and the slurry may be formed in a hydrocarbon.

[0013] The carbon dioxide may be provided as bubbles flowing countercurrently.

[0014] The aromatic ring may be a furoate and the dicarboxylate alkali salt may be a malonate.

[0015] The process may also include regenerating the dicarboxylate alkali salt from the decarboxylated alkali salt.

[0016] The invention may also be generally characterized as providing a process for producing a carboxylated aromatic compound by transferring an aromatic hydrocarbon and a dicarboxylate alkali salt to a reaction zone vessel to form a mixture, transferring carbon dioxide to the vessel to contact the mixture, and heating the mixture to form the carboxylated aromatic compound and a decarboxylated alkali salt.

[0017] The aromatic hydrocarbon may further comprise a counterion, and the alkali base, the counterion, or both may be selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, and mixtures thereof.

[0018] The dicarboxylate alkali salt may be a 1,3-dicarboxylate alkali salt.

[0019] The aromatic hydrocarbon may be a furoate and the dicarboxylate alkali salt may be a malonate.

[0020] The mixture may be heated to a temperature between 120°C and 400°C at a pressure up to 6,895 kPa (1,000 psi).

[0021] The mixture may be a slurry, which may be formed in a hydrocarbon, and the carbon dioxide may be provided as bubbles flowing countercurrently to the slurry.

[0022] The process may also include separating the carboxylated aromatic compounds from the hydrocarbons that form the slurry.The process may also include recycling the hydrocarbons that form the slurry.

[0023] The process may include regenerating the dicarboxylate alkali salt from the decarboxylated alkali salt.

[0024] Further aspects, embodiments and details of the invention, all of which may be combined in any manner, are set out in the detailed description of the invention below. DETAILED DESCRIPTION OF THE INVENTION

[0025] As described above, the present invention provides a process for carrying out a carboxylate transfer reaction between a hydrocarbon having an aromatic ring and an alkali dicarboxylate salt. Preferably, the hydrocarbon having an aromatic ring is a furoate produced from biomass. See U.S. Patent Nos. 7,572,925 and 8,772,515. As used herein, "biomass" includes, but is not limited to, lignin, plant parts, fruits, vegetables, plant processing waste, wood chips, rice husks, grains, grass, corn, corn husks, weeds, aquatic plants, hay, paper, paper products, recycled paper and paper products, and any combination thereof containing cellulose, lignin, or biological material or material of biological origin.

[0026] Generally, the process involves combining an aromatic hydrocarbon with an alkali dicarboxylate salt to form a mixture. This mixture is heated to a reaction temperature in the presence of carbon dioxide gas, optionally in a countercurrent slurry bubble column reactor. The hydrocarbon containing an aromatic ring reacts with the alkali dicarboxylate salt to form a carboxylated aromatic compound and a decarboxylated alkali salt. The carboxylated aromatic compound can then be converted into a biomonomer, such as FDCA or FDME, in a subsequent chemical step. The decarboxylated alkali salt can be regenerated and recycled in the process.

[0027] With these general principles in mind, one or more embodiments of the invention are described below with the understanding that the description is not intended to be limiting.

[0028] The method according to the present invention includes forming a mixture of an aromatic hydrocarbon and an alkali dicarboxylate salt. The aromatic hydrocarbon is preferably furoate. The furoate counterion and the alkali of the alkali dicarboxylate salt may each independently be lithium, sodium, potassium, rubidium, cesium, or mixtures thereof. The dicarboxylate may be a 1,3 dicarboxylate, such as dipotassium malonate.

[0029] The dicarboxylate alkali salt can have a molar ratio of dicarboxylate alkali salt to aromatic hydrocarbon of 1:1 to 2:1, 1:0.1 to 1:1, 1:0.1 to 1:0.5, or 0.1:1 to 1:1.

[0030] The mixture may be formed in a hydrocarbon oil, such as a hydrocarbon material containing 5 to 30 carbon atoms per molecule and having paraffinic and / or aromatic functionality, to form a slurry. Generally, the hydrocarbon oil selected for the slurry has negligible solubility for the aromatic hydrocarbon and the alkali dicarboxylate salt.

[0031] Additionally, carbon dioxide may be provided to the mixture. For example, the carbon dioxide may be provided as gas bubbles in the slurry. The gas bubbles may flow countercurrently to the flow of the slurry.

[0032] With carbon dioxide, the mixture is heated to a temperature of 120°C to 400°C, 150°C to 360°C, or 270°C to 330°C at a pressure from atmospheric up to 6,895 kPa (1,000 psi), or 4,826 kPa (700 psig), or 4,137 kPa (600 psig), and with sufficient heat for a time sufficient to form a carboxylated aromatic compound and a decarboxylated alkali salt via a carboxylation reaction between the reagents. The reaction time is sufficient to produce the carboxylated aromatic compound and is from 1 second to 24 hours, from 1 minute to 12 hours, from 1 minute to 6 hours, or from 1 minute to 1 hour. The process can be a continuous, semi-batch, or batch reaction process.

[0033] The carboxylated aromatic compounds produced may include terephthalic acid, naphthalic acid, thiophenedicarboxylic acid, pyridinedicarboxylic acid, carbazoledicarboxylic acid, and dibenzothiophenedicarboxylic acid. In particular, the carboxylated aromatic compounds may be furandicarboxylates, specifically furan-2,4-dicarboxylate and / or furan-2,5-dicarboxylate.

[0034] The carboxylated aromatic compounds can be recovered by separation from the slurry. The recovered carboxylated aromatic compounds can be converted to FDME, FDCA, or both. In particular, the biomonomers produced can include one or more of furan-2,5-dicarboxylic acid, furan-2,4-dicarboxylic acid, dimethyl furan-2,5-dicarboxylate, dimethyl furan-2,4-dicarboxylate, and salts thereof. These biomonomers can be converted to polymers as known in the art.

[0035] After separation of the carboxylated aromatic compounds, the decarboxylated alkali salt can be regenerated and recycled.

[0036] Compared to existing reactions, the present reaction provides improved yields and does not require carboxylation reaction promoters.

[0037] experiment One molar equivalent of K-furoate was mixed with 1.0 molar equivalent of K2-malonate. The mixture was heated to 250°C in the presence of carbon dioxide for 5 hours. The K-furoate conversion was found to be 55% (mol), and the K2-FDCA yield was found to be 33% by weight.

[0038] Specific Embodiments While the following will be described in conjunction with specific embodiments, it will be understood that this description is illustrative, but not intended to limit the scope of the preceding description and appended claims.

[0039] A first embodiment of the present invention is a process for conducting a carboxylate transfer reaction, comprising: combining an aromatic ring with a dicarboxylate alkali salt to form a mixture; and heating the mixture in the presence of carbon dioxide to form a carboxylated aromatic compound and a decarboxylated alkali salt. An embodiment of the present invention is any one, any, or all of the preceding through first embodiments of this paragraph, wherein the aromatic ring further comprises a counterion, and the alkali base, counterion, or both are selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, and mixtures thereof. An embodiment of the present invention is any one, any, or all of the preceding through first embodiments of this paragraph, wherein the dicarboxylate alkali salt comprises a 1,3-dicarboxylate alkali salt. An embodiment of the present invention is any one, any, or all of the preceding through first embodiments of this paragraph, wherein the mixture is heated to a temperature of 120°C to 400°C at a pressure of up to 6,895 kPa (1,000 psi). An embodiment of the present invention is one, any, or all of the preceding embodiments through the first embodiment of this paragraph, wherein the mixture comprises a slurry. An embodiment of the present invention is one, any, or all of the preceding embodiments through the first embodiment of this paragraph, wherein the slurry is formed in a hydrocarbon. An embodiment of the present invention is one, any, or all of the preceding embodiments through the first embodiment of this paragraph, wherein the carbon dioxide is provided as bubbles flowing countercurrently. An embodiment of the present invention is one, any, or all of the preceding embodiments through the first embodiment of this paragraph, wherein the aromatic ring comprises a furoate and the dicarboxylate alkali salt is a malonate. An embodiment of the present invention is one, any, or all of the preceding embodiments through the first embodiment of this paragraph, further comprising regenerating the dicarboxylate alkali salt from the decarboxylated alkali salt.

[0040] A second embodiment of the present invention is a process for producing a carboxylated aromatic compound, comprising: transferring an aromatic hydrocarbon and a dicarboxylate alkali salt to a vessel in a reaction zone to form a mixture; transferring carbon dioxide to the vessel to contact the mixture; and heating the mixture to form a carboxylated aromatic compound and a decarboxylated alkali salt. An embodiment of the present invention is any one, any, or all of the preceding through second embodiments of this paragraph, wherein the aromatic hydrocarbon further comprises a counterion, and the alkali base, counterion, or both are selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, and mixtures thereof. An embodiment of the present invention is any one, any, or all of the preceding through second embodiments of this paragraph, wherein the dicarboxylate alkali salt comprises a 1,3-dicarboxylate alkali salt. An embodiment of the present invention is any one, any, or all of the preceding through second embodiments of this paragraph, wherein the aromatic hydrocarbon comprises a furoate and the dicarboxylate alkali salt is a malonate. An embodiment of the invention is one, any, or all of the preceding through second embodiments of this paragraph, wherein the mixture is heated to a temperature of 120°C to 400°C at a pressure of up to 6,895 kPa (1,000 psi). An embodiment of the invention is one, any, or all of the preceding through second embodiments of this paragraph, wherein the mixture comprises a slurry. An embodiment of the invention is one, any, or all of the preceding through second embodiments of this paragraph, wherein the slurry is formed in a hydrocarbon. An embodiment of the invention is one, any, or all of the preceding through second embodiments of this paragraph, wherein carbon dioxide is provided as bubbles flowing countercurrently to the slurry. An embodiment of the invention is one, any, or all of the preceding through second embodiments of this paragraph, further comprising separating the carboxylated aromatic compounds from the hydrocarbons forming the slurry.An embodiment of the invention is one, any, or all of the preceding through second embodiments of this paragraph, further comprising recycling the hydrocarbons that form the slurry.An embodiment of the invention is one, any, or all of the preceding through second embodiments of this paragraph, further comprising regenerating the dicarboxylate alkali salt from the decarboxylated alkali salt.

[0041] Without further elaboration, it is believed that, using the preceding description, one skilled in the art can utilize the present invention to its fullest extent and easily ascertain the essential characteristics of the present invention, and can make various changes and modifications to the present invention to adapt it to various uses and conditions, without departing from the spirit and scope of the present invention. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way, and are intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0042] Above, all temperatures are set forth in degrees Celsius and all parts and percentages are by weight unless otherwise indicated.

[0043] While at least one exemplary embodiment has been presented in the foregoing detailed description of the present invention, it should be understood that numerous variations exist. It should also be understood that the exemplary embodiment(s) are merely examples and are in no way intended to limit the scope, applicability, or configuration of the present invention. Rather, the foregoing detailed description provides those skilled in the art with a convenient guide for implementing exemplary embodiments of the present invention, and it should be understood that various changes can be made in the functions and arrangement of elements described in the exemplary embodiment without departing from the scope of the present invention as set forth in the appended claims and their legal equivalents.

Claims

1. 1. A process for conducting a carboxylate transfer reaction, comprising: combining an aromatic ring with a dicarboxylate alkali salt to form a mixture; heating the mixture in the presence of carbon dioxide to form a carboxylated aromatic compound and a decarboxylated alkali salt.

2. 2. The process of claim 1, wherein the aromatic ring further comprises a counterion, and the dicarboxylate alkali base, the counterion, or both, is selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, and mixtures thereof.

3. 2. The process of claim 1, wherein the dicarboxylate alkali salt comprises a 1,3-dicarboxylate alkali salt.

4. 10. The process of claim 1, wherein the mixture is heated to a temperature of 120°C to 400°C at a pressure of up to 6,895 kPa (1,000 psi).

5. The process of any one of claims 1 to 4, wherein the mixture comprises a slurry.

6. The process of claim 5 wherein the slurry is formed in a hydrocarbon.

7. 7. The process of claim 6, further comprising separating the carboxylated aromatic compounds from the hydrocarbons forming the slurry.

8. 5. The process of any one of claims 1 to 4, wherein the carbon dioxide is provided as bubbles flowing countercurrently.

9. 5. The process of any one of claims 1 to 4, wherein the aromatic ring comprises a furoate and the dicarboxylate alkali salt is a malonate.

10. 5. The process of any one of claims 1 to 4, further comprising regenerating the dicarboxylate alkali salt from the decarboxylated alkali salt.

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