2,5-furandicarboxylic acid particles, preparation method therefor, and use thereof

Abstract

2,5-furandicarboxylic acid particles, a preparation method therefor, and a use thereof, relating to the technical field of bio-based monomer preparation for polymerization reactions. The method uses 2,5-furandicarboxylic acid (FDCA) as a raw material, which is heated and dissolved in water at a high temperature, then cooled, filtered, and dried to obtain FDCA particles. The particles have high sphericity and good flowability, thereby facilitating material uniformity during polymerization and contributing to a reduction in polymerization reaction time. In addition, the usage amount of ethylene glycol equivalents can be reduced, which helps to lower the content of the impurity diethylene glycol.

Description

2,5-furan dicarboxylic acid particles, and methods of making and using the same TECHNICAL FIELD

[0001] The present invention belongs to the technical field of bio-based monomer preparation for polymerization reaction, and specifically relates to 2,5-furan dicarboxylic acid particles, and methods of making and using the same. BACKGROUND

[0002] 2,5-furan dicarboxylic acid (FDCA) can be produced from biomass feedstock. The typical preparation process is that the biomass containing six-carbon sugars is first converted into 5-hydroxymethylfurfural (5-HMF) through dehydration reaction, and then the 5-HMF is converted into FDCA through oxidation. FDCA is a high-performance polymer that can replace petroleum-based monomer terephthalic acid (PTA) to produce, such as polyethylene 2,5-furan dicarboxylate (PEF), which has attracted widespread attention. Compared with polyethylene terephthalate (PET), PEF has better oxygen and carbon dioxide barrier properties and lower carbon footprint. Because it comes from biomass, the application of PEF plastic can reduce the dependence on petroleum-based polymers.

[0003] Currently, the technology of preparing PTA from p-xylene (PX) oxidation and the technology of producing PET from PTA and ethylene glycol polymerization are very mature. The global production capacity of PTA has exceeded 950 million tons, and the production capacity of bottle-grade PET has exceeded 350 million tons. In the polymerization reaction process of producing PET, terephthalic acid is mixed with ethylene glycol and then added to the reaction system in the form of slurry. In this process, it is better to have good flowability of the terephthalic acid slurry in order to improve the uniformity of the reaction, and good powder flowability is also conducive to the handling of terephthalic acid powder in the aspects of transportation and storage. In industry, in order to obtain good slurry and reaction uniformity, a stoichiometric excess of ethylene glycol relative to terephthalic acid can be used for adjustment, but the excess ethylene glycol will increase impurities and energy consumption in the polycondensation reaction.

[0004] As a substitute for PTA, FDCA also needs to undergo a similar polymerization process. The slurry formed after mixing FDCA particles with ethylene glycol needs to have good fluidity, which is beneficial to the uniformity of the reaction and can shorten the polymerization reaction time. Patent document CN114929679A discloses a process for producing a carboxylic acid composition comprising 2,5-furan dicarboxylic acid, the heat treatment method of which is to dissolve a certain percentage of FDCA in the treatment solvent composition during heat treatment, while the remaining FDCA remains as a solid precipitate. The chemical equilibrium and exchange between the dissolved FDCA and the precipitated FDCA during heat treatment result in a particularly advantageous particle shape, increased particle strength and / or a beneficial particle size distribution of the FDCA. However, the chemical equilibrium and exchange between the dissolved FDCA and the precipitated FDCA are difficult to control, resulting in low yield of FDCA particles. Patent document CN116120264A discloses a method for regulating the particle size of 2,5-furan dicarboxylic acid crystals. By adjusting the type and content of the crystallization aid, combined with process parameters such as crystallization temperature, etc., FDCA crystals with a certain particle size range can be obtained. The average particle size d 50 of the FDCA crystals is 20-2000 μm. However, the use of adjusting agents in this method reduces the crystallization purity and the method is complex.

[0005] The fluidity of the slurry of FDCA is affected by the particle size distribution and average particle size of the FDCA particles. Generally speaking, the wider the particle size distribution range from large particles to small particles, the better the slurry characteristics of the particles. The average particle size is usually in the range of 50-150 μm. If the proportion of particles with a particle size of 250 μm (40 mesh) or more increases, the FDCA is prone to incomplete reaction when using the direct method for polymerization, resulting in problems such as prolonged reaction time and increased by-products. Similar to the direct polymerization method of PET, in order to achieve good slurry characteristics and reaction uniformity, a stoichiometric excess of ethylene glycol relative to FDCA can be used, but an excess of ethylene glycol can cause problems such as increased impurity diethylene glycol fragments, reduced polymerization degree, and deepened color. However, using an amount of ethylene glycol close to the stoichiometric amount of FDCA can cause the polymerization reaction system to be very viscous, the solid particles to be unevenly dispersed, and the power consumption required for stirring to increase.

[0006] Therefore, in order to improve the slurry characteristics during the polymerization process, there is an urgent need for a 2,5-furan dicarboxylic acid particle and a preparation method thereof to solve the above problems. SUMMARY

[0007] One of the purposes of the present application is to provide a 2,5-furan dicarboxylic acid particle to solve the problems of uneven distribution and poor dispersion of existing FDCA particles.

[0008] The second object of the present application is to provide a preparation method of 2,5-furan dicarboxylic acid particles.

[0009] The third object of the present application is to provide an application of 2,5-furan dicarboxylic acid particles in the synthesis of poly(2,5-furan dicarboxylic acid) glycol ester (FEF) to solve the problems of poor flowability and uniformity of the mixed slurry of FDCA and ethylene glycol in the existing FEF preparation process, resulting in low polymerization reaction efficiency and high content of impurity diethylene glycol.

[0010] The objects of the present application can be achieved by the following technical solutions:

[0011] In a first aspect, the 2,5-furan dicarboxylic acid particles have an average particle size of 50-200 μm, a loose bulk density of 0.7-1.0 g / mL, and a repose angle of 25-40°.

[0012] In a second aspect, a preparation method of 2,5-furan dicarboxylic acid particles includes the following steps:

[0013] The 2,5-furan dicarboxylic acid raw material is added to an autoclave, deionized water is added to the autoclave to obtain a mixed liquid, stirring and heating are started, the system temperature is raised from room temperature (25-30°C) to 100-150°C, and then the system is kept at a constant temperature for a certain period of time; after the constant temperature is kept, the system is cooled to room temperature; the collected material is filtered and washed to obtain wet 2,5-furan dicarboxylic acid, which is dried to obtain 2,5-furan dicarboxylic acid particles.

[0014] As a further aspect of the present application, the purity of the 2,5-furan dicarboxylic acid raw material is >95%.

[0015] As a further aspect of the present application, the pressure of the system in the autoclave is <1.5 MPa.

[0016] As a further aspect of the present application, the mass percentage of 2,5-furan dicarboxylic acid in the mixed liquid is 5%-20%.

[0017] As a further aspect of the present application, the stirring rate is 200-400 rpm.

[0018] As a further aspect of the present application, the heating time is 2-4 h.

[0019] As a further aspect of the present application, the holding time is 0.5-6 h.

[0020] As a further aspect of the present application, the cooling time is 2-10 h.

[0021] In a third aspect, the application provides a use of the 2,5-furan dicarboxylic acid particles prepared by the above-mentioned method for a polymerization reaction.

[0022] Compared with the prior art, the application has the following advantages:

[0023] 1. The application discloses 2,5-furan dicarboxylic acid, and a preparation method thereof is simple. The FDCA particles prepared by the preparation method have almost no edges and corners in micro-morphology, a smooth and round surface, high sphericity, good dispersity, high bulk density, an average particle size of 50-200 μm, a loose bulk density of 0.7-1.0 g / mL, and a repose angle of 25-40°.

[0024] 2. The application changes the appearance shape and particle size distribution of the FDCA solid particles, thereby significantly improving the flowability of the FDCA slurry, being beneficial to improving the uniformity of the polymerization material and shortening the polymerization time, reducing the use equivalent of ethylene glycol in the polymerization process of PEF, and being beneficial to reducing the content of impurities diethylene glycol. BRIEF DESCRIPTION OF DRAWINGS

[0025] The application will be further described below in combination with the drawings.

[0026] Fig. 1 is a micro-morphology diagram of the FDCA particles prepared in the embodiment 1 of the application.

[0027] Fig. 2 is a micro-morphology diagram of the FDCA raw material in the application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the application will be clearly and completely described below in combination with the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all the other embodiments obtained by those skilled in the art without any creative work fall within the protection scope of the application.

[0029] A preparation method of 2,5-furan dicarboxylic acid particles, comprising the following steps:

[0030] The 2,5-furan dicarboxylic acid with purity of 95% is added into an autoclave, deionized water is added into the autoclave to obtain a mixed solution, the mass percentage of 2,5-furan dicarboxylic acid in the mixed solution is 5%-20%, stirring and heating are started, the stirring rate is 200-400 rpm, the temperature of the system is raised from room temperature to 100-150 ℃, the temperature raising time is 2-4 h, then the system is kept for 0.5-6 h, the pressure of the system in the autoclave is less than 1.5 MPa during the reaction; after the keeping, the system is cooled to room temperature, the cooling time is 2-10 h; the material is collected by filtration, then elution is performed to obtain wet 2,5-furan dicarboxylic acid, and the 2,5-furan dicarboxylic acid particles are obtained after drying.

[0031] Example 1

[0032] A preparation method of 2,5-furan dicarboxylic acid particles, comprising the following steps:

[0033] 100 g of 2,5-furan dicarboxylic acid with purity of 99.5% is added into an autoclave, 400 g of deionized water is added into the autoclave to obtain a mixed solution, then the autoclave is closed, stirring and heating are started, the stirring rate is 300 rpm, the temperature of the system is raised from room temperature to 145 ℃, the temperature raising time is 2.5 h, then the system is kept for 6 h, the pressure of the system in the autoclave is 1 MPa during the reaction; after the keeping, the system is cooled to room temperature, the cooling time is 4 h; the material is collected by filtration, then a small amount of deionized water is used for elution to obtain wet 2,5-furan dicarboxylic acid, and the 2,5-furan dicarboxylic acid particles are obtained after drying.

[0034] Example 2

[0035] A preparation method of 2,5-furan dicarboxylic acid particles, the preparation method is the same as that in Example 1, except that 1900 g of deionized water is added into the autoclave, and the other components and parameters are unchanged.

[0036] Example 3

[0037] A preparation method of 2,5-furan dicarboxylic acid particles, the preparation method is the same as that in Example 1, except that 990 g of deionized water is added into the autoclave, and the other components and parameters are unchanged.

[0038] Example 4

[0039] A preparation method of 2,5-furan dicarboxylic acid particles, the preparation method is the same as that in Example 1, except that the keeping time after heating is 1.5 h, and the other components and parameters are unchanged.

[0040] Example 5

[0041] A preparation method of 2,5-furan dicarboxylic acid particles, which is the same as that of Example 1, except that the holding time after the temperature rising is 5.5 h, and the rest of the components and parameters remain unchanged.

[0042] Example 6

[0043] A preparation method of 2,5-furan dicarboxylic acid particles, which is the same as that of Example 1, except that the system temperature is raised from room temperature to 110°C, and the temperature rising time is 2 h, and the rest of the components and parameters remain unchanged.

[0044] Example 7

[0045] A preparation method of 2,5-furan dicarboxylic acid particles, which is the same as that of Example 1, except that the system temperature is raised from room temperature to 130°C, and the temperature rising time is 2 h, and the rest of the components and parameters remain unchanged.

[0046] Example 8

[0047] A preparation method of 2,5-furan dicarboxylic acid particles, which is the same as that of Example 1, except that the cooling time after the holding is 1.5 h, and the rest of the components and parameters remain unchanged.

[0048] Example 9

[0049] A preparation method of 2,5-furan dicarboxylic acid particles, which is the same as that of Example 1, except that the cooling time after the holding is 6 h, and the rest of the components and parameters remain unchanged.

[0050] Example 10

[0051] A preparation method of 2,5-furan dicarboxylic acid particles, which is the same as that of Example 1, except that the cooling time after the holding is 9 h, and the rest of the components and parameters remain unchanged.

[0052] The 2,5-furan dicarboxylic acid particles prepared in Examples 1-10 are characterized for performance:

[0053] (1) Microscopic morphology characterization: Figure 1 is a microscopic morphology diagram of the 2,5-furan dicarboxylic acid particles prepared in Example 1, and Figure 2 is a microscopic morphology diagram of the 2,5-furan dicarboxylic acid raw material; as can be seen from the comparison of Figure 1 and Figure 2, the appearance of the FDCA particles after the reaction is almost without edges and corners, the particle surface is smooth and round, the sphericity is high, and the flowability is good;

[0054] (2) Average particle size: calculated after screening by a standard sieve;

[0055] (3) Bulk density: the bulk density of the particles is determined by the test method specified in GB / T 16913-2008;

[0056] (4)Repose angle test: The test method specified in GB / T 16913-2008 was used to determine the repose angle of the particles;

[0057] The test results are shown in Table 1:

[0058] Table 1

[0059] As can be seen from Table 1, the mass fraction of FDCA in the mixed solution of FDCA and water, the heating temperature and holding time, and the cooling time are all factors affecting the average particle size, bulk density and repose angle of the FDCA particles. Optimizing the reaction conditions can obtain FDCA particles with good quality.

[0060] Example 11

[0061] A method for using 2,5-furan dicarboxylic acid particles, using the synthesis of polyethylene furanoate as a model example of a polymerization reaction, comprising the following steps:

[0062] The 2,5-furan dicarboxylic acid particles prepared in Example 1 (15.6 g, 0.1 mol) and ethylene glycol (6.8 g, 0.11 mol) were added to the slurry tank, mixed thoroughly, and then transferred to the esterification tank. The reaction was stopped after 2 h at 190°C and the water was discharged. To the dimethyl furandicarboxylate generated in the esterification step, 0.78 g of germanium oxide catalyst was added, and then melt polycondensation was carried out in a polycondensation kettle at a pressure of 70 pa and a temperature of 235°C for 3 h. The reaction was stopped, and a polymer PEF (polyethylene furanoate) was obtained.

[0063] Comparative Example 1

[0064] The 2,5-furan dicarboxylic acid particles prepared in Example 1 (15.6 g, 0.1 mol) and ethylene glycol (6.8 g, 0.11 mol) were added to the slurry tank, mixed thoroughly, and then transferred to the esterification tank. The reaction was stopped after 2 h at 190°C and the water was discharged. To the dimethyl furandicarboxylate generated in the esterification step, 0.78 g of germanium oxide catalyst was added, and then melt polycondensation was carried out in a polycondensation kettle at a pressure of 70 pa and a temperature of 235°C for 3 h. The reaction was stopped, and a polymer PEF (polyethylene furanoate) was obtained.

[0065] The PEF polyesters prepared in Example 11 and Comparative Example 1 were tested for performance:

[0066] Diethylene glycol content test: The diethylene glycol content was tested using the methanol ester exchange method in GB / T 14190-2017;

[0067] PEF polyester molecular weight test: the gel permeation chromatograph (GPC) was used to determine the polyester molecular weight; the test results are shown in Table 2;

[0068] Table 2

[0069] As can be seen from Table 2, under the same dosage parameter conditions, the FDCA particles with better quality obtained by optimizing the reaction conditions are beneficial to improve the uniformity of the material in the polymerization process of PEF, and also beneficial to shorten the polymerization reaction time, and more importantly, can reduce the equivalent of ethylene glycol, thereby being beneficial to reduce the content of impurity diethylene glycol.

[0070] It should be noted that in this document, the terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or inherent to such process, method, article or device.

[0071] Although the embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. 2,5-furan dicarboxylic acid particles, characterized in that, The average particle size is 50-200 μm, the loose bulk density is 0.7-1.0 g / mL, and the repose angle is 25-40°.

2. A process for the preparation of the 2,5-furan dicarboxylic acid particles of claim 1, characterized in that, The method comprises the following steps: The 2,5-furan dicarboxylic acid raw material is added into an autoclave, deionized water is added into the autoclave to obtain a mixed solution, stirring and heating are started, the temperature of the system is raised from room temperature to 100-150 ℃, and then the system is kept at the temperature for reaction; after the keeping at temperature, the system is cooled to room temperature; the material is collected by filtration, and then eluted to obtain wet 2,5-furan dicarboxylic acid, which is dried to obtain 2,5-furan dicarboxylic acid particles.

3. The method for preparing 2,5-furandicarboxylic acid particles according to claim 2, characterized in that: The purity of the 2,5-furan dicarboxylic acid raw material is greater than 95%.

4. The method for preparing 2,5-furandicarboxylic acid particles according to claim 2, characterized in that: The pressure of the system in the autoclave is less than 1.5 MPa.

5. The method for preparing 2,5-furandicarboxylic acid particles according to claim 2, characterized in that: The mass percentage of 2,5-furan dicarboxylic acid in the mixed solution is 5%-20%.

6. The method for preparing 2,5-furandicarboxylic acid particles according to claim 2, characterized in that: The stirring rate is 200-400 rpm.

7. The method of claim 2, wherein the 2,5-furan dicarboxylic acid particles are prepared by the process of claim 1, wherein the 2,5-furan dicarboxylic acid particles have a D90 of 100 μιη or less. The heating time is 2-4 h.

8. The method of claim 2, wherein the 2,5-furan dicarboxylic acid particles are prepared by the process of claim 1, wherein the 2,5-furan dicarboxylic acid particles have a D90 of 100 μιη or less. The keeping at temperature time is 0.5-6 h.

9. The method of claim 2, wherein the 2,5-furan dicarboxylic acid particles are prepared by the process of claim 1, wherein the 2,5-furan dicarboxylic acid particles have a D90 of 100 μιη or less. The cooling time is 2-10 h.

10. Application of the 2,5-furan dicarboxylic acid particles of claim 1 in a polymerization reaction.

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