Method for producing biomonomers and precursors thereof

Abstract

Methods for producing biomonomers and precursors thereof. A carboxylation reaction is carried out between an aromatic hydrocarbon, such as a furoic acid compound, and a dicarboxylated basic salt. The reaction produces a carboxylated aromatic hydrocarbon and a decarboxylated basic salt. The carboxylated aromatic hydrocarbons can be isolated and used to produce biomonomers such as methyl furandicarboxylate and furandicarboxylic acid. The decarboxylated basic salt can be regenerated.

Description

[0001] Priority Claim

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 477,860, filed Dec. 30, 2022, the entire disclosure of which is incorporated herein by reference. Field of the Invention

[0003] The present invention generally relates to methods for producing aromatic carboxylic acid compounds including furandicarboxylic acid and methyl furandicarboxylate from biomass. Background of the Invention

[0004] Recently, methods have been developed for producing aromatic carboxylic acids and esters from sugars derived from biomass. These aromatic carboxylic acids and esters can be converted to dicarboxylic acid compounds, which in turn can be used to produce monomers such as methyl furandicarboxylate (FDME) and furandicarboxylic acid (FDCA). As is known, these monomers can be used to prepare polymers and plastics and, since they are at least partially derived from biomass, can be referred to as biobased monomers.

[0005] These methods are desirable because they provide production of biobased monomers rather than production of chemicals and monomers from fossil fuel sources. Additionally, the methods are desirable because they may consume carbon dioxide, which is considered a greenhouse gas.

[0006] These methods generally rely on the carboxylation reaction of furoic acid with carbon dioxide and an alkali base. While generally effective for their intended purpose, this reaction is difficult to optimize, and the thermal decarboxylation of the furoic acid compound to furan is a competing side reaction.

[0007] Accordingly, there has been a continuing desire and need to provide effective and efficient methods for producing biobased monomers from biomass-derived components and carbon dioxide. Summary of the Invention

[0008] The inventors have discovered an alternative furoic acid carboxylation reaction that occurs at lower temperatures to achieve high conversion and produces fewer by-products for downstream separation. Specifically, it has been found that the reaction of a hydrocarbon having an aromatic ring with an alkali salt of a dicarboxylic acid produces a carboxylated aromatic compound and a decarboxylated alkali salt. Additionally, the carboxylic acid transfer reaction of the present invention does not require an additional alkali base reagent.

[0009] Accordingly, in at least one aspect, the present invention can be characterized as providing a method for performing a carboxylic acid transfer reaction by the steps of: mixing an aromatic ring with an alkali salt of a dicarboxylic acid 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.

[0010] The aromatic ring may contain a counterion, and the basic base, the counterion, or both are selected from: lithium, sodium, potassium, rubidium, cesium, and mixtures thereof.

[0011] The dicarboxylic acid basic salt may be a 1,3-dicarboxylic acid basic salt.

[0012] The mixture may be heated to a temperature between 120 °C and 400 °C at a pressure of up to 6,895 kPa (1,000 psi).

[0013] The mixture may be a slurry, and the slurry may be formed in a hydrocarbon.

[0014] Carbon dioxide may be provided as bubbles flowing in a countercurrent manner.

[0015] The aromatic ring may be a furoic acid compound, and the dicarboxylic acid basic salt may be a malonic acid compound.

[0016] The method may further include regenerating the dicarboxylic acid basic salt from the decarboxylated basic salt.

[0017] The present invention generally may also be characterized as providing a method for producing a carboxylated aromatic compound, the method comprising: transferring an aromatic hydrocarbon and a dicarboxylic acid basic 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 basic salt.

[0018] The aromatic hydrocarbon may also contain a counterion, and the basic base, the counterion, or both are selected from: lithium, sodium, potassium, rubidium, cesium, and mixtures thereof.

[0019] The dicarboxylic acid basic salt may be a 1,3-dicarboxylic acid basic salt.

[0020] The aromatic hydrocarbon may be a furoic acid compound, and the dicarboxylic acid basic salt may be a malonic acid compound.

[0021] The mixture may be heated to a temperature between 120 °C and 400 °C at a pressure of up to 6,895 kPa (1,000 psi).

[0022] The mixture may be a slurry, and the slurry may be formed in a hydrocarbon. Carbon dioxide may be provided as bubbles flowing countercurrently to the slurry.

[0023] The method may further include separating the carboxylated aromatic compound from the hydrocarbon forming the slurry. The method may further include recycling the hydrocarbon forming the slurry.

[0024] The method may include regenerating the dicarboxylic acid basic salt from the decarboxylated basic salt.

[0025] Additional aspects, embodiments, and details of the present invention (all of which may be combined in any manner) are set forth in the following detailed description of the present invention. Detailed Description

[0026] As described above, the present invention provides a method for a carboxylic acid transfer reaction between a hydrocarbon having an aromatic ring and a dicarboxylic acid basic salt. Preferably, the hydrocarbon having an aromatic ring is a furoic acid compound produced from biomass. See, U.S. Patent No. 7,572,925 and U.S. Patent No. 8,772,515. As used herein, "biomass" includes, but is not limited to, lignin, plant parts, fruits, vegetables, plant processing waste, wood chips, husks, grains, grasses, corn, corn husks, waste, aquatic plants, hay, paper stock, paper products, recycled paper and paper products, and any cellulose, lignin, or combination thereof containing biological or bio-derived materials.

[0027] Generally, the method mixes an aromatic hydrocarbon and a dicarboxylic acid basic salt to form a mixture. In the presence of carbon dioxide gas, and possibly in a countercurrent slurry-bubble column reactor, the mixture is heated to a reaction temperature. The hydrocarbon having an aromatic ring and the dicarboxylic acid basic salt react and form a carboxylated aromatic compound and a decarboxylated basic salt. Then, the carboxylated aromatic compound can be converted into a biobased monomer such as FDCA or FDME in a subsequent chemical step. The decarboxylated basic salt can be regenerated and recycled in the method.

[0028] With these general principles in mind, one or more embodiments of the present invention will be described with the understanding that the following description is not intended to be limiting.

[0029] The method according to the present invention includes forming a mixture of an aromatic hydrocarbon and a dicarboxylic acid basic salt. The aromatic hydrocarbon is preferably a furoic acid compound. The furoate counterion and the base of the dicarboxylic acid basic salt can each independently be lithium, sodium, potassium, rubidium, cesium, and mixtures thereof. The dicarboxylic acid compound can be a 1,3-dicarboxylic acid compound, such as dipotassium malonate.

[0030] The dicarboxylic acid basic salt can be in the following molar ratio of dicarboxylic acid basic salt to aromatic hydrocarbon, and the molar ratio can be from 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.

[0031] The mixture can be formed in a hydrocarbon oil, such as a hydrocarbon material containing 5 to 30 carbon atoms per molecule and having alkane and / or aromatic functional groups to form a slurry. Generally, the hydrocarbon oil selected for the slurry has negligible solubility for the aromatic hydrocarbon and the dicarboxylic acid basic salt.

[0032] In addition, carbon dioxide is provided to the mixture. For example, carbon dioxide can be provided as bubbles into the slurry. The bubbles can flow in a direction opposite to the flow of the slurry.

[0033] The mixture is heated with carbon dioxide at a pressure of at most 6,895 kPa (1,000 psi), or at most 4,826 kPa (700 psig), or at most 4,137 kPa (600 psig) to a temperature of 120 °C to 400 °C, 150 °C to 360 °C, or 270 °C to 330 °C, and heated for a sufficient time to form a carboxylated aromatic compound and a decarboxylated basic salt via a carboxylation reaction between the reagents. The reaction time sufficient to produce the carboxylated aromatic compound is 1 second to 24 hours, 1 minute to 12 hours, 1 minute to 6 hours, or 1 minute to 1 hour. The process can be a continuous, semi-batch or batch reaction process.

[0034] The produced carboxylated aromatic compounds can include terephthalic acid, naphthalenedicarboxylic acid, thiophenedicarboxylic acid, pyridinedicarboxylic acid, carbazoledicarboxylic acid and dibenzothiophenedicarboxylic acid. In particular, the carboxylated aromatic compound can be a furandicarboxylate, and specifically, furan-2,4-dicarboxylate and / or furan-2,5-dicarboxylate.

[0035] The carboxylated aromatic compound can be recovered by separation from the slurry. The recovered carboxylated aromatic compound can be converted to FDME, FDCA or both. Specifically, the produced biobased monomers 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 their salts. These biobased monomers can be converted to polymers known in the art.

[0036] After the carboxylated aromatic compound has been separated, the decarboxylated basic salt can be regenerated and recycled.

[0037] Compared with existing reactions, the reaction of the present invention provides improved yields and does not require a carboxylation reaction promoter.

[0038] Experiment

[0039] One (1) molar equivalent of potassium furoate (K-furoate) is mixed with 1.0 molar equivalent of dipotassium malonate (K2-malonate). The mixture is heated to 250 °C for 5 hours in the presence of carbon dioxide. The conversion of potassium furoate is found to be 55% (molar), and the yield of K2-FDCA is found to be 33 wt%.

[0040] Specific implementation plan

[0041] Although the following is described in connection with specific embodiments, it should be understood that the description is intended to illustrate and not limit the scope of the foregoing description and the appended claims.

[0042] A first embodiment of the present invention is a method for carrying out a carboxylic acid transfer reaction, the method comprising: mixing an aromatic ring with a dicarboxylic acid base salt to form a mixture; and heating the mixture in the presence of carbon dioxide to form a carboxylated aromatic compound and a decarboxylated base salt. One embodiment of the present invention is one, any, or all of the first embodiment of this paragraph to the previous embodiments of this paragraph, wherein the aromatic ring further comprises a counterion, and wherein the base base, the counterion, or both are selected from lithium, sodium, potassium, rubidium, cesium, and mixtures thereof. One embodiment of the present invention is one, any, or all of the first embodiment of this paragraph to the previous embodiments of this paragraph, wherein the dicarboxylic acid base salt comprises a 1,3-dicarboxylic acid base salt. One embodiment of the present invention is one, any, or all of the first embodiment of this paragraph to the previous embodiments of this paragraph, wherein the mixture is heated to a temperature between 120 °C and 400 °C at a pressure of at most 6,895 kPa (1,000 psi). One embodiment of the present invention is one, any, or all of the first embodiment of this paragraph to the previous embodiments of this paragraph, wherein the mixture comprises a slurry. One embodiment of the present invention is one, any, or all of the first embodiment of this paragraph to the previous embodiments of this paragraph, wherein the slurry is formed in a hydrocarbon. One embodiment of the present invention is one, any, or all of the first embodiment of this paragraph to the previous embodiments of this paragraph, wherein the carbon dioxide is provided as countercurrent flowing bubbles. One embodiment of the present invention is one, any, or all of the first embodiment of this paragraph to the previous embodiments of this paragraph, wherein the aromatic ring comprises a furoic acid compound, and wherein the dicarboxylic acid base salt is a malonic acid compound. One embodiment of the present invention is one, any, or all of the first embodiment of this paragraph to the previous embodiments of this paragraph, further comprising regenerating the dicarboxylic acid base salt from the decarboxylated base salt.

[0043] A second embodiment of the present invention is a method for producing a carboxylated aromatic compound, the method comprising: conveying an aromatic hydrocarbon and a dicarboxylic acid basic salt to a vessel in a reaction zone to form a mixture; and conveying carbon dioxide to the vessel to contact the mixture; and heating the mixture to form a carboxylated aromatic compound and a decarboxylated basic salt. One embodiment of the present invention is one, any, or all of the second embodiment to the previous embodiments of this paragraph, wherein the aromatic hydrocarbon further comprises a counter ion, and wherein the basic base, the counter ion, or both are selected from lithium, sodium, potassium, rubidium, cesium, and mixtures thereof. One embodiment of the present invention is one, any, or all of the second embodiment to the previous embodiments of this paragraph, wherein the dicarboxylic acid basic salt comprises a 1,3-dicarboxylic acid basic salt. One embodiment of the present invention is one, any, or all of the second embodiment to the previous embodiments of this paragraph, wherein the aromatic hydrocarbon comprises a furoic acid compound, and wherein the dicarboxylic acid basic salt is a malonic acid compound. One embodiment of the present invention is one, any, or all of the second embodiment to the previous embodiments of this paragraph, wherein the mixture is heated to a temperature between 120 °C and 400 °C at a pressure of at most 6,895 kPa (1,000 psi). One embodiment of the present invention is one, any, or all of the second embodiment to the previous embodiments of this paragraph, wherein the mixture comprises a slurry. One embodiment of the present invention is one, any, or all of the second embodiment to the previous embodiments of this paragraph, wherein the slurry is formed in a hydrocarbon. One embodiment of the present invention is one, any, or all of the second embodiment to the previous embodiments of this paragraph, wherein the carbon dioxide is provided as bubbles flowing countercurrently to the slurry. One embodiment of the present invention is one, any, or all of the second embodiment to the previous embodiments of this paragraph, further comprising separating the carboxylated aromatic compound from the hydrocarbon forming the slurry. One embodiment of the present invention is one, any, or all of the second embodiment to the previous embodiments of this paragraph, further comprising recycling the hydrocarbon to form a slurry. One embodiment of the present invention is one, any, or all of the second embodiment to the previous embodiments of this paragraph, further comprising regenerating the dicarboxylic acid basic salt from the decarboxylated basic salt.

[0044] Although no further elaboration is provided, it is believed that those skilled in the art can make the most of the present invention by using the foregoing description and can easily determine the basic features of the present invention without departing from the essence and scope of the present invention to make various changes and modifications thereto and adapt it to various uses and conditions. Therefore, the foregoing preferred specific embodiments should be understood as merely illustrative and not in any way limiting the remainder of the disclosure, and are intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0045] In the foregoing, all temperatures are shown in degrees Celsius and all parts and percentages are by weight unless otherwise indicated.

[0046] Although at least one exemplary embodiment has been presented in the foregoing specific embodiments of the present invention, it should be understood that there are a large number of variations. It should also be understood that one exemplary embodiment or multiple exemplary embodiments are merely examples and are not intended to limit the scope, applicability, or construction of the present invention in any way. On the contrary, the foregoing specific embodiments will provide those skilled in the art with a convenient roadmap to implement the exemplary embodiments of the present invention, and it should be understood that various changes can be made to the functions and arrangements of the elements described in the exemplary embodiments without departing from the scope of the present invention as set forth in the appended claims and their legal equivalents.

Claims

1. A method for carrying out a carboxylic acid transfer reaction, the method comprising: Mixing an aromatic ring with a dicarboxylic acid base salt to form a mixture; And Heating the mixture in the presence of carbon dioxide to form a carboxylated aromatic compound and a decarboxylated base salt.

2. The method according to claim 1, wherein the aromatic ring further comprises a counterion, and wherein the dicarboxylic acid base, the counterion, or both are selected from: lithium, sodium, potassium, rubidium, cesium, and mixtures thereof.

3. The method according to claim 1, wherein the dicarboxylic acid base salt comprises a 1,3-dicarboxylic acid base salt.

4. The method according to claim 1, wherein the mixture is heated to a temperature between 120 °C and 400 °C at a pressure of at most 6,895 kPa (1,000 psi).

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

6. The method according to claim 5, wherein the slurry is formed in a hydrocarbon.

7. The method according to claim 6, the method further comprising: Separating the carboxylated aromatic compound from the hydrocarbon forming the slurry.

8. The method according to any one of claims 1 to 4, wherein the carbon dioxide is provided as countercurrent flowing bubbles.

9. The method according to any one of claims 1 to 4, wherein the aromatic ring comprises a furoic acid compound, and wherein the dicarboxylic acid base salt is a malonic acid compound.

10. The method according to any one of claims 1 to 4, the method further comprising: Regenerating the dicarboxylic acid base salt from the decarboxylated base salt.