FR3053336A1 - PROCESS FOR PREPARING DICARBOXYLIC 2,5-FURANE ACID (FDCA) FROM PENTOSED DERIVATIVES - Google Patents

Abstract

The invention relates to a process for the preparation of 2,5-furan dicarboxylic acid (FDCA) from furfuryl alcohol comprising: i) the preparation of 2,5-bis (hydroxymethyl) furan (BHMF) by hydroxymethylation of the furfuryl alcohol with formaldehyde in aqueous solution in the presence of a microporous zeolite in the form of nanocrystals; ii) the oxidation of the BHMF obtained in step i) in water in the presence of a weak base and a supported catalyst comprising platinum and bismuth.

Description

Holder (s): NATIONAL CENTER OF

SCIENTIFIC RESEARCH, CLAUDE BERNARD LYON UNIVERSITY 1.

Extension request (s)

Agent (s): LAVOIX.

PROCESS FOR THE PREPARATION OF 2,5-FURANE DICARBOXYLIC ACID (FDCA) FROM PENTOSE DERIVATIVES.

FR 3,053,336 - A1 f5 /) The invention relates to a process for the preparation of 2,5-furan dicarboxylic acid (FDCA) from furfuryl alcohol comprising:

i) the preparation of 2,5-bis (hydroxymethyl) furan (BHMF) by hydroxymethylation of furfuryl alcohol with formaldehyde in aqueous solution in the presence of a microporous zeolite in the form of nanocrystals;

ii) the oxidation of the BHMF obtained in step i) in water in the presence of a weak base and of a supported catalyst comprising platinum and bismuth.

Process for the preparation of 2,5-furan dicarboxylic acid (FDCA) from pentose derivatives

The present invention relates to a two-step process for the preparation of 2,5-furan dicarboxylic acid (FDCA) from pentose derivatives, and in particular from furfuryl alcohol.

The FDCA is an important compound for the chemical industry, especially for the polymer industry. Indeed, the FDCA can constitute a basic monomer for the preparation of polyamides or polyesters.

FDCA is in particular a basic monomer for the preparation of polyethylene furandicarboxylate (PEF). However, PEF is described as being a bio-sourced polymer which can replace polyethylene terephthalate (PET) (Energy Environ. Sci., 2012, 5, 6407-6422) obtained from terephthalic acid obtained from fossil resources.

The usual route for obtaining FDCA is based on the oxidation of 5hydroxymethylfurfural (5-HMF), itself resulting from the dehydration of hexoses. However, the lack of availability of 5-HMF constitutes a technological obstacle for this production route of FDCA from hexoses. Indeed, if the catalytic oxidation of 5-HMF to FDCA by molecular oxygen can be quantitative, the formation of 5HMF by dehydration of hexoses is a step that is not very selective because of the high reactivity of 5-HMF. In addition, hexoses are already widely valued and thus, the production of 5-HMF from C6 sugar derivatives remains limited and its price high.

Alternative production routes to FDCA are known and in particular use an abundant renewable resource such as furfural, obtained by acid hydrolysis of the hemicellulosic fraction of plant waste rich in pentoses. WO 2013/096998 describes a production route through the oxidation of furfural to the salt of 2-furoic acid and requiring the use of homogeneous catalysts and the co-production of three compounds: furan, and acids 2, 5- and 2,4-furan dicarboxylic.

lovel et al. (Chem. Heterocy. Comp. 34 (19981-12) and J. Mol. Catal. 57 (1989) 91 103) describe the production of FDCA through the hydroxymethylation of furfural. However, they also describe the difficulty of stopping the reaction to the expected 5-HMF because of successive hydroxymethylation reactions leading to polymers of 5HMF.

FR 1995/2741343 describes the preparation of 2,5-bis (hydroxymethyl) furan (BHMF) from furfuryl alcohol in the presence of microporous acid zeolites coupled with extraction by organic solvent of the reaction product. However, the stability over time of the BHMF formed in the reaction medium is not shown and the formation of dimer and of trimer by successive and rapid transformation of BHMF is possible. Indeed, furfuryl alcohol is known to be very reactive because of its hydroxy-methyl functional electron donor groups, and the reaction, once BHMF is obtained, is difficult to stop with the primary hydroxyalkylation product.

There is therefore a particular interest in providing an alternative process for preparing FDCA from pentosic derivatives, requiring neither the use of 5-HMF nor the use of organic extraction solvent and making it possible to overcome all or part of the state of the art problems.

Thus, an objective of the present invention is to provide a process for the preparation of FDCA from pentosic derivatives, and preferably from furfuryl alcohol.

Another objective of the present invention is to provide a process for preparing the FDCA which does not require the use of organic solvent.

Another objective of the present invention is to provide a process for preparing the FDCA making it possible to obtain good yields, in particular quantitative yields.

Still other objectives will emerge in the light of the description of the invention which follows.

The above objectives are fulfilled by the invention which relates to a process for the preparation of 2,5-furan dicarboxylic acid (FDCA) from pentose derivatives and in particular from furfuryl alcohol. In particular, the process according to the invention makes it possible to prepare FDCA by synthesizing 2,5-bis (hydroxymethyl) furan (BHMF) by hydroxymethylation of furfuryl alcohol and then oxidizing it to FDCA.

In the context of the invention and unless otherwise indicated, the expression "between xxx and yyy" must be understood to include the terminals xxx and yyy.

According to the invention, the process for preparing 2,5-furan dicarboxylic acid (FDCA) from furfuryl alcohol comprises the following steps:

i) the preparation of 2,5-bis (hydroxymethyl) furan (BHMF) by hydroxymethylation of furfuryl alcohol with formaldehyde in aqueous solution in the presence of a microporous zeolite in the form of nanocrystals;

ii) the oxidation of the BHMF obtained in step i) in water in the presence of a weak base and of a supported catalyst comprising platinum and bismuth.

Step i)

The reaction described in step i) of the process according to the invention is represented in the following diagram (I):

OH HO OH

(i)

According to the invention, the hydroxymethylation reaction of furfuryl alcohol to BHMF takes place in the presence of a microporous zeolite in the form of nanocrystals. The use of such an acid catalyst makes it possible to carry out the hydroxymethylation reaction of furfuryl alcohol into BHMF selectively and to allow stabilization of BHMF in the reaction medium.

Preferably according to the invention, a zeolite is said to be microporous when its pore size is less than 18 Å. The pore size of the zeolite is measured by nitrogen adsorption.

Preferably, the microporous zeolite used in step i) is a microporous zeolite with medium pores.

Zeolites are crystalline materials composed of tetrahedra of SiO ₄ and [AIO ₄ ] with an open three-dimensional structure. The negative charge of the tetrahedra [AIO ₄ ] is compensated by a cation or a proton in the case of zeolites in protonic form. According to Wilson et al. (Heterogeneous catalysts for clean technology, K. Wilson and AF Lee, 2013) and Guisnet et al. (Zeolites for cleaner technologies, M. Guisnet and JP Gilson, Catalytic Science series n ° 3); the size of the pores of the zeolites can be defined according to the number of tetrahedrons delimiting the opening of its pores. Thus, in a preferred manner, a zeolite is said to have medium pores when the opening of its pores is delimited by 10 tetrahedrons TO ₄ with T being Si or Al.

According to the invention, the zeolite of step i) is in the form of nanocrystals. In a preferred manner according to the invention, the average size of these nanocrystals is between 10 and 1000 nm, preferably between 10 and 500 nm, preferably between 10 and 200 nm. The size of these nanocrystals is measured by electron microscopy.

Preferably, the average size of the nanocrystals corresponds to an average dimension, for example the dimension of a diagonal.

Preferably according to the invention, the zeolite used in step i) is a ZSM-5 zeolite, preferably an HZSM-5 zeolite in proton form. A zeolite in protonic form is a zeolite for which the compensating cations are constituted by H ⁺ protons, thus giving it its acid character.

The zeolite used in step i) of the invention is synthesized by any method known to those skilled in the art. In particular the work of Z.Qin et al. and Van Grieken et al. describe this synthesis (Z.Qin, LLakiss, LTosheva, J-P.Gilson, A.Vicente,

C. Fernandez, V. Valtchev Adv. Funct. Mater. 24 (2014) 257-264 and R. Van Grieken, J.L. Sotelo, J.M. Menéndez, J.A. Melero, Micro. Meso. Mast. 39 (2000) 135-147).

Advantageously, the zeolite described above in the form of nanocrystals overcomes the drawbacks mentioned above and encountered in the state of the art. Even more advantageously, and without being linked to any theory, the zeolite in the form of nanocrystals makes it possible to avoid the dimerization, trimerization or polymerization reactions of the BHMF synthesized during step i) and thus to limit the degradation of the product. of reaction. This is obtained through the use of a zeolite with medium pores which makes it possible to generate a significant steric constraint and to limit the successive reactions which involve the formation of bulky intermediates, associated with nanocrystals which generate a large, responsible external surface. increased activity while promoting the formation of the primary hydroxyalkylation product, BHMH.

In a preferred manner according to the invention, the zeolite / furfuryl alcohol mass ratio used in step i) is between 0.01 and 10, preferably between 0.1 and 5.

Preferably according to the invention, the formaldehyde / furfuryl alcohol molar ratio used in step i) is between 1 and 300, preferably between 50 and 150.

In a preferred manner according to the invention, the reaction temperature of step i) is between 10 and 70 ° C, preferably between 30 and 65 ° C, preferably the temperature of step i) is equal at 40 ° C.

Step i) of the process makes it possible not to degrade, or polymerize, the BHMF once formed. Thus, in a preferred manner according to the invention, step i) can be carried out without adding extraction solvent.

Surprisingly according to the invention, step i) of the process makes it possible to obtain a molar yield of BHMF greater than 40 mol%, preferably greater than 50 mol%, for example greater than or equal to 60 mol% without adding extraction solvent. Even more surprisingly according to the invention, step i) of the process makes it possible to obtain BHMF in a stable manner without subsequent degradation by dimerization, trimerization or polymerization reaction.

Step ii)

The reaction described in step ii) of the process according to the invention is represented in the following diagram (II):

HO OH HOOC COOH

(II)

Step ii) of the process according to the invention is carried out in the presence of a weak base. By "weak base" is meant the bases whose pKb is greater than 1.4, preferably between 3 and 10, for example between 3 and 8 at 25 ° C in dilute solution. Preferably according to the invention, the weak base can be chosen from carbonates and hydrogen carbonates of alkali metals, in particular sodium and potassium, alone or as a mixture. Preferably the base is sodium carbonate.

The use of a weak base advantageously makes it possible to limit the side reactions, in particular of decomposition of BHMF, which can occur in strongly alkaline media (strong base). The use of a weak base also advantageously makes it possible to obtain the FDCA in the form of a salt which avoids its adsorption on the surface of the catalyst and therefore the poisoning of the catalyst, while maintaining a pH favorable to the reaction.

The oxidation of the BHMF of step ii) according to the invention can be carried out in any manner known to those skilled in the art and in particular under air or oxygen pressure, preferably under air pressure. Preferably, the air or oxygen pressure used is such that the O ₂ / BHMF molar ratio is greater than 2. The pressure can in particular be from 20 to 60 bar of air, preferably from 30 to 50 air bar, for example 40 air bar. The partial oxygen pressure can be from 4 to 12 bar, preferably from 6 to 10 bar, for example from 8 bar.

Preferably according to the invention, step ii) of the process is carried out at a temperature of 70 to 150 ° C, preferably from 80 to 120 ° C, for example at 100 ° C.

The catalyst of step ii) of the invention is a supported catalyst comprising platinum and bismuth. The catalyst of the invention is hereinafter called PtBi / support.

Advantageously, the presence of bismuth protects the platinum against over-oxidation. Thus and advantageously, the catalyst of the invention can be reused several times without the need to subject it to a regeneration treatment, unlike the monometallic catalyst. This can in particular make it possible to increase the efficiency of an industrial installation.

The catalyst support can be chosen from all the supports known to a person skilled in the art and more particularly from supports stable in water and preferably in basic medium. The support is preferably chosen from activated carbon, carbons, metallic oxides or lanthanides stable in aqueous media, in particular basic aqueous media, for example zirconium, titanium, cerium oxides, or their mixture. Preferably, the support is activated carbon.

The PtBi / support catalyst of step ii) according to the invention can be prepared by any method known to a person skilled in the art.

Preferably, the PtBi / support catalyst is prepared in two stages, a first stage of preparation of a supported platinum and a second stage of addition of bismuth, such methods have, for example, been described by T. Mallat, A Baiker (Chem. Rev. 2004, 104, 3037) and WO2014 / 122319.

Preferably, the first step is carried out by impregnation in the liquid phase of the support with an aqueous solution of platinum, in particular an aqueous solution of H ₂ PtCI ₆ , followed by a reduction by a formaldehyde solution in basic medium. The final PtBi / support catalyst from step ii) of the invention is prepared from the supported platinum obtained in the first step:

- or in situ, in the reaction medium comprising the platinum supported by the oxidation process of BHMF, by adding an aqueous solution of a soluble bismuth salt, in particular bismuth nitrate Bi (NO ₃ ) ₃ .5H ₂ O ;

- Either ex situ by addition to the platinum supported with an aqueous solution of a soluble bismuth salt comprising a reducing agent, for example glucose, in particular bismuth oxynitrate (BiONO ₃ ).

In these two cases, the PtBi / support catalyst is obtained by surface redox reaction between the supported platinum and the bismuth salt in aqueous solution.

Preferably, the amount of platinum in the catalyst of step ii) is between 1% and 10%, preferably between 3% and 6% by weight relative to the total weight of the supported catalyst.

Preferably, in the catalyst of step ii) of the invention, the Bi / Pt molar ratio is between 0.05 and 2.5, preferably between 0.1 and 0.3, for example between 0.15 and 0.3. Advantageously, these ranges of Bi / Pt molar ratio make it possible to obtain a quantitative or almost quantitative molar yield, in particular greater than or equal to 80%, or even greater than or equal to 85%.

Step ii) of the present invention is preferably carried out with a weak base / BHMF molar ratio greater than or equal to 1, preferably between 2 and 6, for example between 2 and 4.

Step ii) of the process of the present invention is preferably carried out with a BHMF / Pt molar ratio of between 50 and 400, preferably between 100 and 200. Advantageously, the presence of bismuth in the catalyst of l he invention, which makes it possible to protect platinum from over-oxidation, and in particular in the ratios specified above, also makes it possible to limit the amount of platinum to be used in the process of the invention. The process of the invention is thus more economical and more environmental compared to the processes of the prior art.

Step ii) of the process of the invention is preferably carried out in water. It should therefore be understood that the reaction medium does not include an organic solvent.

In a particularly preferred manner, in step ii) of the process of the invention, the weak base is calcium or potassium carbonate and the molar ratio Bi / Pt is between 0.05 and 2.5, preferably it is 0.1 to 0.3, for example 0.15 to 0.3.

The two-step process according to the invention advantageously makes it possible to surprisingly obtain a total molar yield of FDCA greater than 40 mol%, preferably greater than 50 mol%, for example greater than or equal to 60 mol% (88% by mass ) starting with furfuryl alcohol. The method according to the invention has the advantage of bypassing the use of the intermediary 5-HMF to gain access to the FDCA.

Optionally, a filtration step, to recover the zeolite, can be implemented between step i) and step ii).

The present invention will now be described with the aid of nonlimiting examples.

Example 1 (comparative): Hydroxymethylation of furfuryl alcohol in the presence of Amberlyst 70

The hydroxymethylation of furfuryl alcohol (FF alcohol) by formaldehyde in aqueous solution was carried out in the presence of a sulfonated acid resin, Amberlyst 70 (A70). A70 is a heterogeneous macroporous catalyst (pore size: 220A °), thermally stable (up to 190 ° C) and which preserves a significant exchange capacity (2.55 mmolH7g cata).

The procedure applied is as follows:

250 mg of catalyst are introduced into a 25 ml two-necked flask equipped with a water cooler, a septum and a magnetic bar. 10 mL of formaldehyde in aqueous solution (37% by weight stabilized with 10% methanol) are added. The suspension is heated using an oil bath at 65 ° C. After 30 min, furfuryl alcohol (100 mM) is added, then the magnetic stirring is put in place (600 rpm, zero reaction time). The formaldehyde / furfuryl alcohol molar ratio is 101. Samples are taken periodically (0.2 mL).

The samples are analyzed by HPLC chromatography with two RID (Refractive Index Detector) and PDA (diode array detector) detectors (ICECoragel 107H column, eluent 10 mM H ₂ SO ₄ ).

The conversion of furfuryl alcohol (% mol) and the yield of BHMF (% mol) obtained are grouped in Table 1.

The conversion is calculated as follows:

Conv (% mol) = 100 * (Initial alcohol concentration FF - Instant concentration in alcohol FF) / (Initial alcohol concentration FF)

The yield is calculated as follows:

Yield (% mol) = 100 * (BHMF concentration at time t) / (Initial FF alcohol concentration)

Duration reaction (min) 0 10 20 40 60 90 120 180 240 Conversion of FF alcohol (mol%) 0 35 51 71 83 94 100 100 100 Yield in BHMF (mol%) 0 15 20 24 23 18 13 7 3 Table 1: Conversion of furfuryl alcohol (% mo ) and return in BH MF (% mol)

presence of Amberlyst 70.

The results show that the acidic resin A70 fully converts furfuryl alcohol in 2 hours. The maximum molar yield of 25% in BHMF is observed after 30 min, then the BHMF gradually disappears from the reaction medium, explained by successive condensation reactions.

Example 2 Hydroxymethylation of Furfuryl Alcohol in the Presence of Nano-HZMS-5

The hydroxymethylation of furfuryl alcohol (FF alcohol) by formaldehyde in aqueous solution was carried out in the presence of a microporous HZSM-5 zeolite in the form of nanocrystals (nano-HZMS-5). The average diameter of the HZMS-5 nanocrystals is less than 200 nm.

The procedure used is the same as in Example 1.

The conversion of furfuryl alcohol (% mol) and the yield of BHMF (% mol) obtained are grouped in Table 2.

Duration reaction (min) 0 5 10 20 40 60 90 120 180 240 Conversion of FF alcohol (mol%) 0 41 52 63 76 87 91 94 100 100 Yield in BHMF (mol%) 0 32 40 46 49 51 51 51 49 46 Table 2: Conversion of furfuryl alcohol (% mol) el BHMF yield (% mol)

presence of HZSM-5, 65 ° C.

In the presence of nanocrystalline HZSM-5, the total conversion of furfuryl alcohol is observed after 180 min. A higher yield of BHMF is obtained, 50%, after 60 min of reaction. During the reaction, a very slight drop in the BHMF concentration is observed. We deduce that the microporous structure of HZSM-5, zeolite with medium pores, in the form of nanocrystallites, makes it possible to limit the condensation reactions responsible for the degradation of BHMF.

Example 3 Hydroxymethylation of Furfuryl Alcohol in the Presence of Nanocrystallites

HZMS-5, influence of temperature.

The same protocol of Example 2 is repeated by changing the temperature of the reaction, first at 25 ° C and then at 40 ° C. The results are collated in Tables 3 and 4.

Duration reaction (min) 0 10 45 90 120 275 360 480 1740 2880 Conversion of FF alcohol (mol%) 0 12 13 16 17 28 31 35 64 82 Yield in BHMF (mol%) 0 2 5 9 10 19 22 65 49 60

Table 3: Conversion of furfuryl alcohol (% mol) and yield of BHMF (% mol) presence of HZSM-5, 25 ° C.

Duration reaction (min) 0 5 10 20 40 60 90 120 180 240 Conversion of FF alcohol (mol%) 0 21 26 37 57 66 75 82 90 95 Yield in BHMF (mol%) 0 19 23 32 43 49 55 56 61 60 Table 4: Conversion of furfurvliaue alcohol (% mol) el BHMF yield (% mol)

presence of HZSM-5, 40 ° C.

At 25 ° C the reaction is slow, a yield of 60% is obtained after 48 hours of reaction with a conversion of 82%. On the other hand, at 40 ° C. a yield of 60% is reached after 4 hours of reaction with a total conversion of the furfuryl alcohol. No significant degradation of the BHMF formed at longer reaction times is observed.

Example 4 Oxidation of BHMF to FDCA in the Presence of a PtBi / C Catalyst

The oxidation of BHMF was carried out in the presence of a PtBi / activated carbon catalyst. Stage ii) of the process of the invention is carried out in a batch reactor under pressure in a 300 ml autoclave equipped with a gas-stirring mobile with magnetic drive. Heating is provided by a heating collar connected to a PID regulator (proportional integral derivative). A sampling valve makes it possible to take a sample from the reaction medium via a dip tube, which makes it possible to follow the evolution of the reaction over time. The samples are analyzed by HPLC chromatography with two RID (Refractive Index Detector) and PDA (diode array detector) detectors (ICE-Coragel 107H column, eluent 10 mM H ₂ SO ₄ ).

The reactor is loaded with 150 mL of a 100 mM aqueous solution of BHMF, a mass of catalyst corresponding to a BHMF / Pt molar ratio of 100 and 2 equivalents of weak base in the form of Na ₂ CO ₃ . Air is introduced at a pressure of 40 bar, the reactor is heated to 100 ° C.

The platinum / bismuth molar ratio of the catalyst used is equal to 0.2.

The results of conversion of BHMF and of yield into FDCA are collated in Table 5, as well as the yields of the two main intermediates, namely 5-hydroxymethyl-2-furan carboxylic acid (HMFCA) and 5-formyl-2 acid -furan carboxylic FFCA.

Duration reaction (h) 0 0.5 1 2 3 4 5 6.5 8 10 12 Conversion of BHMF (mol%) 0 92 100 100 100 100 100 100 100 100 100 Yield in HMFCA (mol%) 0 9 6 3 2 1 0 0 0 0 0 Yield in FFCA (mol%) 0 36 30 20 14 10 8 5 4 2 1 Yield in FDCA (mol%) 0 29 48 63 70 73 77 80 82 85 86

Table 5: Oxidation of BHMF in FDCA in the presence of a PtBi / C catalyst and a weak base in water

The oxidation of BHMF is rapid. A total conversion is obtained after 1 hour of reaction. An 80% FDCA yield is obtained after 6.5 hours of reaction. The yield in FDCA reaches 86% after 12 hours. These results clearly show that the oxidation of BHMF to FDCA in a single step is possible and gives an almost quantitative yield in 10 hours of reaction.

Claims (10)

1. Process for the preparation of 2,5-furan dicarboxylic acid (FDCA) from furfuryl alcohol comprising: i) the preparation of 2,5-bis (hydroxymethyl) furan (BHMF) by hydroxymethylation of furfuryl alcohol with formaldehyde in aqueous solution in the presence of a microporous zeolite in the form of nanocrystals; ii) the oxidation of the BHMF obtained in step i) in water in the presence of a weak base and of a supported catalyst comprising platinum and bismuth. 2. The method of claim 1, wherein the microporous zeolite used in step 1 is a microporous zeolite with medium pores. 3. Method according to any one of claims 1 or 2, wherein the size of the nanocrystals of the zeolite used in step i) is between 10 and 1000nm, preferably between 10 and 500nm, preferably between 10 and 200nm . 4. Method according to any one of claims 1 to 3, in which the zeolite used in step i) is a ZSM-5 zeolite in proton form. 5. Method according to any one of claims 1 to 4, wherein the temperature of step i) is between 10 and 70 ° C, preferably between 30 and 65 ° C, preferably the temperature of step i) ed equal to 40 ° C. 6. Method according to any one of claims 1 to 5, wherein the amount of platinum in the catalyst of step ii) is between 1% and 10%, preferably between 3% and 6% by weight relative to the weight of supported catalyst. 7. Method according to any one of claims 1 to 6, wherein the Pt / Bi molar ratio of the catalyst of step ii) is between 0.05 and 2.5, preferably between 0.1 and 0 , 3, preferably between 0.15 and 0.3. 8. Method according to any one of claims 1 to 7, in which the weak base used in step ii) is chosen from bases whose pKb is greater than 1.4, preferably between 3 and 10, for example between 3 and 8, and preferably among the carbonates and hydrogen carbonates of alkali metals, in particular sodium and potassium, alone or as a mixture, for example sodium carbonate. 9. Method according to any one of claims 1 to 8, in which step ii) is carried out under pressure so as to have an O ₂ / BHMF molar ratio greater than 2, and at a temperature ranging from 70 to 150 ° C, preferably 80 to 120 ° C, for example 100 ° C. 10. Method according to any one of claims 1 to 9, in which in step ii), the weak base / BHMF molar ratio is greater than or equal to 1, preferably between 2 and 6, for example between 2 and 4 and the BHMF / Pt molar ratio is between 50 and 400, preferably between 100 and 200.