WO2020260172A1

WO2020260172A1 - Process for the conversion of a furfural compound using a heterogeneous sulfide catalyst

Info

Publication number: WO2020260172A1
Application number: PCT/EP2020/067254
Authority: WO
Inventors: Marc Jacquin; Etienne Girard
Original assignee: IFP Energies Nouvelles
Priority date: 2019-06-28
Filing date: 2020-06-19
Publication date: 2020-12-30
Also published as: FR3097861A1; FR3097861B1

Abstract

The invention relates to a process for converting furfural compounds to a reduced compound using a heterogeneous sulfide catalyst.

Description

PROCESS FOR CONVERTING A COMPOUND OF FURFURALDEHYDE TYPE USING A HETEROGENIC SULPHIDE CATALYST

Technical field of the invention

The present invention relates to a process for converting furfuraldehyde-type compounds to a reduced compound via a heterogeneous catalyst in sulfur form.

Prior art

In recent years, there has been a sharp revival of interest in the incorporation of products of renewable origin in addition to or in substitution for products of fossil origin in the fuel and chemical sectors. The production of bio-based alkylfurans or hydroxyalkylfurans or furans is thus the subject of intense research and development efforts.

5-hydroxymethylfurfural or even 5-chloromethylfurfural or even 5-hydroxymethylfurfural, or even 2,5-diformylfuran are compounds derived from biomass resulting from the dehydration of sugar (C6) which can be upgraded in many fields as precursors of active ingredients in pharmacy, agrochemistry or specialty chemicals.

Furfural is another compound derived from biomass resulting from the dehydration of sugar (C5), compounds that can be obtained by dehydration of sugars (C5) which can be upgraded in many basic intermediates for industry, such as for example furfuryl alcohol, 2-methylfuran, furan.

In particular, 2,5-dimethylfuran and 2-methylfuran are among the alkylfurans arousing great interest. 2,5-Dimethylfuran is of great industrial interest because it can be converted directly into 2,5-furanedicarboxylic acid (FDCA) via an oxidation process or in 2 stages into terephthalic acid (TA) via a first reaction of Diels-Alder with ethylene giving paraxylene as described in application WO2018 / 015112 followed by an oxidation reaction well known to those skilled in the art to produce terephthalic acid. The molecules of FDCA and TA can be used to produce plasticizers, but also polymers of the family of polyesters or polyamides. Surprisingly, the Applicant has demonstrated that the bringing into contact of a heterogeneous sulfurized catalyst comprising at least one metallic element from group VI B and / or one metallic element from group VI 11 B deposited on a solid support with compounds furans allows the selective conversion of furan compounds by hydrogenation and hydrogenolysis reactions to hydroxyalkylfurans, alkylfurans or furans, without hydrogenating the furan ring.

An advantage of the use of sulphide catalysts in the process according to the invention is that said catalysts have a lower manufacturing cost compared to catalysts based on noble metals with activity and selectivity at least equivalent or better.

Another advantage of using sulfur catalysts in the process according to the invention is that said catalysts are resistant to the presence of impurities such as sulfur compounds.

Another advantage of using sulfurized catalysts in the process according to the invention is that said catalysts can be regenerated, which contributes to reducing the cost of the process, particularly on an industrial scale.

Definitions and Abbreviations

It is specified that, throughout this description, the expressions "included between ... and ...""including between ... and ..." must be understood as including the limits cited. In the following, groups of chemical elements are given according to CAS Classification (CRC Handbook of Chemistry and Physics, CRC press publisher, editor DR Lide, 81 ^th Edition, 2000-2001). For example, group VI 11 B according to the CAS classification corresponds to the metals of columns 8, 9 and 10 according to the new IUPAC classification.

The term “heterogeneous catalyst” means a catalyst which is insoluble in the reaction medium. FDCA is understood to mean 2,5-furanedicarboxylic acid.

By 5-HMF is meant 5-hydroxymethylfurfural.

The term 2,5-DMF is understood to mean 2,5-dimethylfuran. In the present invention, the terms metal or metals, and elements of groups VI B or VIIIB are used in an equivalent manner.

The term% by weight denotes a percentage by weight.

The term halogen (denoted X) denotes an iodine atom (I), a bromine atom (Br), a chlorine atom (Cl) and a fluorine atom (F).

In the sense of the present invention, the various embodiments presented can be used alone or in combination with each other, without limitation of combination.

OBJECT OF THE INVENTION The present invention relates to a process for the conversion, preferably hydrogenation, of a feed comprising a furan compound of formula (I) by bringing said feed into contact with a heterogeneous sulfurized catalyst comprising at least one metallic element of group VIB and / or an element of group VIIIB deposited on a porous solid support in oxide form or on an amorphous or crystalline carbon support, and hydrogen, said furan compound of formula (I) being represented by formula next general

in which

R _! is chosen from an aldehyde function -C (0) H, a carboxylic acid function -COOH, an ester function -COOR ₃ , a hydroxymethyl function -CH ₂ OH, a methyl halide function, a hydrogen, or an ether function -CH ₂ OR ₄ , R ₃ and R ₄ representing a linear or branched alkyl group of 1 to 6 carbons,

R ₂ is chosen from an aldehyde function -C (0) H, a carboxylic acid function -COOH, an ester function -COOR ₃ , a hydroxymethyl function -CH ₂ OH, a methyl halide function, or an ether function -CH ₂ OR ₄ , R ₃ and R ₄ representing a linear or branched alkyl group of 1 to 6 carbons. An advantage of the process according to the invention is that the sulfurized catalysts exhibit an activity and a selectivity at least equivalent or better with a lower manufacturing cost compared to the catalysts based on noble metals.

Another advantage of the process according to the invention is that the sulfur catalysts are resistant to the presence of impurities such as sulfur compounds.

Another advantage of the process according to the invention is that the sulfur catalysts can be regenerated, which contributes to reducing the cost of the process, particularly on an industrial scale.

Preferably, the process is carried out at a temperature of between 100 and 300 ° C, and at a total pressure of between 0.5 and 6.0 MPa. Preferably, the catalyst is introduced in a charge / catalyst (s) mass ratio of between 0.1 and 1000.

Preferably, the compound of formula (I) is mixed with at least one sulfur compound.

Preferably, the sulfur compound is present in a mass ratio relative to the compound of formula (I) of between 0.1 and 1000. Preferably, the process is carried out in a solvent chosen from aromatic, furan and thiophenic solvents. or benzene, alone or as a mixture.

Preferably, the element or elements of group VIIIB are chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum and the element or elements of group VI B are chosen from chromium, molybdenum and tungsten. Preferably, the elements of groups VI B and VIIIB are chosen according to the following combinations NiMo, CoMo, FeMo, NiW, NiMoW and NiCoMo.

Preferably, the porous solid support in oxide form is chosen from aluminas, silicas, silica-alumina or even titanium or magnesium oxides used alone or as a mixture with alumina or silica. -alumina. Preferably, the amorphous or crystallized carbonaceous solid support is chosen from active charcoals, carbon blacks, carbon nanotubes, mesostructured carbons and carbon fibers. Preferably, the catalyst has a pore volume of the support is generally between 0.4 and 5.0 cm ³ / g.

Preferably, the catalyst has a specific surface area of the support which is generally between 40 and 1500 m ² / g. Preferably, the catalyst has an overall degree of sulfurization greater than or equal to 50%.

Preferably, the process comprises the preparation of the heterogeneous sulfurized catalyst comprising the following steps:

i) at least one step of bringing at least said support into contact with at least one solution containing at least one precursor of at least said metal from group VIIIB or a precursor of at least said metal from group VIB,

ii) at least one drying step to obtain at least said metal from group VIIIB and at least said metal from group VIB in oxide form, then,

iii) at least one sulfurization step so that the metals of said active phase are in sulfurized form. Preferably, the preparation process further comprises a calcination step carried out after step ii) at a temperature between 200 ° C and 600 ° C.

Detailed description of the invention

Process implementation

The present invention relates to a process for the conversion, preferably hydrogenation, of a feed comprising a furan compound of formula (I) by bringing said feed into contact with a heterogeneous sulphide catalyst comprising at least one metal element from group VIB. and / or a metallic element of group VIIIB, hydrogen, and a furan compound of formula (I)

in which R _! is chosen from an aldehyde function -C (0) H, a carboxylic acid function -COOH, an ester function -COOR ₃ , a hydroxymethyl function -CH ₂ OH, a methyl halide function, a hydrogen, or an ether function -CH ₂ OR ₄ , R ₃ and R ₄ representing a linear or branched alkyl group of 1 to 6 carbons, R ₂ is chosen from an aldehyde function -C (0) H, a carboxylic acid function -COOH, an ester function -COOR ₃ , a hydroxymethyl function -CH ₂ OH, a methyl halide function, or an ether function -CH ₂ OR ₄ , R ₃ and R ₄ representing a linear or branched alkyl group of 1 to 6 carbons.

Advantageously, the process is carried out at a temperature between 100 and 300 ° C, preferably between 120 and 240 ° C, preferably between 140 and 220 ° C and very preferably between 160 and 200 ° C.

Advantageously, the process is carried out at a total pressure of between 0.5 and 6.0 MPa, preferably between 1.0 and 5.0 MPa, preferably between 2.0 and 4.0 MPa, of preferably between 2.5 and 3.5 MPa and more preferably 3.0 MPa.

The method according to the invention can advantageously be carried out batchwise or continuously. The reaction time can advantageously vary with the reaction conditions and therefore the rate of conversion of the feed.

In particular, the process according to the invention can be carried out in one or more reactors in series of the fixed bed type or of the bubbling bed type. The process can also be carried out in a Grignard reactor, closed or semi-continuous.

The compound of formula (I) can be introduced into the reaction zone alone or in the presence of a solvent.

In a preferred embodiment, the process comprises a prior step of in situ or ex situ sulfurization. Preferably said step is carried out in situ. Said sulphurization step consists in sulphurizing the metal oxides of the catalyst to give sulphides.

The catalyst according to the invention is advantageously introduced in a charge / catalyst (s) mass ratio of between 0.1 and 1000, preferably between 0.2 and 500, of preferably between 0.3 and 100, preferably between 0.05 and 50 and more preferably between 1 and 25.

Charge

The feed converted in the process according to the present invention comprises at least one furan compound of formula (I)

in which

R ₂ is chosen from an aldehyde function -C (0) H, a carboxylic acid function -COOH, an ester function -COOR ₃ , a hydroxymethyl function -CH ₂ OH, a methyl halide function, or an ether function -CH ₂ OR ₄ , R ₃ and R ₄ representing a linear or branched alkyl group of 1 to 6 carbons.

Advantageously, the group ^ is chosen from a hydrogen (H), an aldehyde function -C (0) H, a carboxylic acid function -COOH, a hydroxymethyl function - CH ₂ OH, a methyl halide function -CH ₂ X. preferably, ^ is chosen from H, - CH ₂ OH, -CH ₂ CI, and very preferably is chosen from H, and -CH ₂ OH. Advantageously, the R ₂ group is chosen from an aldehyde function -C (0) H, a carboxylic acid function -COOH, a hydroxymethyl function -CH ₂ OH, a methyl halide function -CH ₂ X. Preferably, R ₂ is chosen from -C (0) H, -CH ₂ OH, -CH ₂ CI, and very preferably R ² is a -C (0) H group.

Advantageously, the groups R ₃ and R ₄ are chosen from alkyls, linear or branched, comprising between 1 and 4 carbon atoms, preferably between 1 and 3 carbon atoms. carbon, preferably from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl and hexyl groups.

In a preferred embodiment, the compound of formula (I) is obtained from biomass and in particular from the dehydration of sugars with 6 or 5 carbon atoms. Preferably, the compound of formula (I) results from the dehydration of sugar chosen from fructose, glucose, and xylose. Preferably, in this embodiment, the R ₂ group is an aldehyde -C (O) H function.

In a particular embodiment, the filler is a mixture of compounds of formula (I). In a particular embodiment, the compound of formula (I) as defined above is mixed with at least one sulfur compound. In particular, when the compound of formula (I) is obtained by the transformation of biomass, said sulfur compound may be an impurity or a solvent resulting from one of the upstream preparation steps of said compound of formula (I). In particular, said sulfur compound is chosen from the family of thiophenic compounds, preferably from thiophene, 2-methylthiophene, 3-methylthiophene and 2,5-dimethylthiphene, and very preferably thiophene. In particular, said sulfur compound can be DMSO or sulfolane.

In particular, said sulfur compound is present in a mass ratio relative to the compound of formula (I) of between 0.1 and 1000, preferably between 0.5 and 500 and very preferably between 1 and 250.

Generally, the presence of a sulfur compound with the compound of formula (I) is detrimental for the conversion of the latter because the sulfur compound at least partially poisons the catalysts based on noble metals. An advantage of the present invention is that when the compound of formula (I) and mixed with a sulfur-containing compound, the use of heterogeneous sulfur-containing catalysts comprising at least one metal from group VI B and one metal from group VI 11 B in a process according to the invention has proved surprisingly robust to the presence of said sulfur-containing compound and exhibits good activity and selectivity for the conversion of the compound of formula (I). Solvents

In a preferred embodiment of the invention, the process according to the invention is carried out in the presence of a solvent, the furan compound of formula (I) is then introduced into said process in solution in said solvent in a solvent mass ratio / furan compound of formula (I) between 1 and 1000, preferably between 2 and 500 and more preferably between 5 and 250.

Said solvent can advantageously be chosen from aromatic furan, thiophenic or benzene solvents, alone or as a mixture. Advantageously, said solvents make it possible to solubilize the furan compound of formula (I). The furan solvents are preferably chosen from furan, 2-methylfuran or 2,5-dimethylfuran, alone or as a mixture. Advantageously, said furan solvent is a recycling of the product (s) obtained by the process according to the invention with the feed.

The thiophenic solvents are preferably chosen from thiophene or alkylthiophenes (substituted in position 2 or 3 for methylthiophenes and substituted in positions 2 and 5 for dimethylthiophenes), alone or as a mixture.

The benzene solvents are preferably chosen from solvents comprising one or more benzene rings, preferably from benzene, toluene, xylenes, any other alkylbenzene, and naphthalene and its derivatives. The benzene solvent can also be chosen from phenol or alkyl phenols, such as, for example, cresols or anisole.

Said solvent can also be chosen from polar solvents, preferably from dimethylsulfoxide (DMSO) or sulfolane.

Catalysts

The catalysts used in the process according to the invention are heterogeneous sulfurized catalysts comprising at least one metallic element of group VI B and / or one metallic element of group VI 11 B deposited on a porous solid support in oxide form or a support. amorphous or crystallized carbon.

For the purposes of the present invention, the term “sulfurized catalysts” is understood to mean a catalyst in which the metal elements of groups VI B and VI 11 B are in sulfurized forms. The sulphide form is obtained by a sulphurization step described below allowing the metal oxides to be converted into sulphides.

An advantage of the use of sulfurized catalysts in the process according to the invention is that said catalysts have a lower manufacturing cost compared to catalysts based on noble metals with an activity and a selectivity at least equivalent or better.

Another advantage of using sulfur-containing catalysts in the process according to the invention is that said catalysts are resistant to the presence of impurities such as sulfur compounds (i.e. thiophene or DMSO).

The elements of group VIB denote chromium (Cr), molybdenum (Mo), tungsten (W). Preferably, the metal element (s) from group VIB are chosen from chromium, molybdenum and tungsten. Preferably, the element or elements of group VIB are chosen from molybdenum and tungsten.

The metallic elements of group VIIIB denotes iron (Fe), cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), and hassium (Hs). Preferably, the metallic element (s) of group VIIIB are chosen from iron (Fe), cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir) and platinum (Pt). Preferably, the metallic element or elements of group VIIIB are chosen from iron (Fe), cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium (Pd) and platinum (Pt). Very preferably, the metal element (s) of group VIIIB are chosen from iron (Fe), cobalt (Co) and nickel (Ni).

Preferably, the metal elements of groups VIB and VIIIB are chosen according to the following combinations NiMo, CoMo, FeMo, NiW, NiMoW and NiCoMo, and preferably from NiMo and CoMo.

The metallic elements, also called metals, of group VIB and VIIIB are deposited on a support and form the active phase of the catalyst. Said support can be formed of at least one porous solid in oxide form, preferably chosen from aluminas, silicas, silica-alumina or else titanium or magnesium oxides used alone or as a mixture. with alumina or silica-alumina. Preferably, the support is chosen from silicas, transition aluminas and silica-alumina. Very preferably, the support consists essentially of a transition alumina or of silica. A support essentially consisting of a transition alumina comprises at least 51% by weight, preferably at least 60% by weight, very preferably at least 80% by weight, or even at least 90% by weight of said transition alumina.

By transition alumina is meant for example an alpha phase alumina, a delta phase alumina, a gamma phase alumina.

A support essentially consisting of silica comprises at least 51% by weight, preferably at least 60% by weight, very preferably at least 80% by weight, or even at least 90% by weight of silica. Even more preferably, said support consists only of a transition alumina or only of silica. According to one variant, the amorphous or crystallized carbon-containing supports are chosen from activated charcoals, carbon blacks, carbon nanotubes, mesostructured carbons and carbon fibers.

The specific surface area is determined in the present invention by the B.E.T method according to the ASTM D3663 standard, as described in the book Rouquerol F .; Rouquerol J .; Singh K. "Adsorption by Powders & Porous Solids: Principle, methodology and applications",

Academie Press, 1999, for example by means of an Autopore III ™ model apparatus of the brand Microméritics ™.

The specific surface of the support is advantageously between 40 and 1500 m ² / g, and preferably between 60 and 1400 m ² / g. The specific surface of the porous support in oxide form is advantageously between 40 and 350 m ² / g, preferably between 60 and 300 m ² / g.

According to one variant, the specific surface of the amorphous or crystallized carbon support is advantageously between 200 m ² / g and 1500 m ² / g, preferably between 400 m ² / g and 1450 m ² / g, and preferably between 600 m ² / g ² / g and 1400 m ² / g. The pore volume of the support is advantageously between 0.4 and 5.0 cm ³ / g, and preferably between 0.5 and 4.0 cm ³ / g. The total pore volume is measured by mercury porosimetry according to standard ASTM D4284 with a wetting angle of 140 °, as described in the same book. The pore volume of the porous support in oxide form is advantageously between 0.4 and 1.4 cm ³ / g, preferably between 0.5 and 1.3 cm ³ / g.

According to one variant, the pore volume of the amorphous or crystallized carbon support is generally between 0.4 and 5.0 cm ³ / g, preferably between 0.5 and 4.0 cm ³ / g and preferably between 0, 6 and 3.5 cm ³ / g. Said porous or carbonaceous supports are advantageously in the form of beads, extrudates, pellets, or irregular and non-spherical agglomerates, the specific shape of which may result from a crushing step. Very advantageously, said support is in the form of balls or extrudates.

Advantageously, the catalyst used in the process according to the invention has an overall sulfurization rate greater than or equal to 50%, preferably greater than or equal to 55%, preferably greater than or equal to 60%, preferably greater than or equal at 65%, preferably greater than or equal to 70 and very preferably greater than or equal to 75%.

Advantageously, the catalyst used in the process according to the invention further comprises phosphorus on the active phase. Process for preparing the catalyst

Another object of the invention relates to a process for preparing a catalyst used in the process according to the invention comprising:

i) at least one step of bringing at least one support into contact with at least one solution containing at least one precursor of at least one metal from group VI 11 B and / or one precursor of at least one metal from group VI B,

ii) at least one drying step to obtain at least said metal from group VIIIB and / or at least one metal from group VI B in oxide form, then,

iii) at least one sulfurization step so that the metals of said active phase are in sulfurized form. According to one variant, the process for preparing the catalyst further comprises a calcination step at a temperature between 200 ° C and 600 ° C is carried out after step ii).

The catalyst according to the invention can be prepared by means of any technique known to those skilled in the art allowing the support and the metals from groups VI B and VI II B to be brought into contact during step i) and in particular by impregnation. elements of groups VI 11 B and VI B on the selected support. This impregnation can for example be carried out according to the method known to those skilled in the art under the terminology of dry impregnation, in which just the quantity of elements desired in the form of precursors soluble in the chosen solvent, for example of demineralized water, so as to fill the porosity of the support as exactly as possible.

According to one variant, salts of metals from groups VIB and VIIIB which can be used in the preparation process according to the invention are, for example, cobalt nitrate, nickel nitrate, iron nitrate, ammonium heptamolybdate or metatungstate. ammonium. Any other salt known to those skilled in the art exhibiting sufficient solubility and which can be decomposed during the activation treatment can also be used.

According to another variant, the catalyst is prepared by depositing said components of metals from group VIB, and / or from group VIIIB and optionally phosphorus on said support, by one or more steps i) of co-impregnations, that is to say to say that said components of metals from group VIB, group VIIIB and optionally phosphorus are introduced simultaneously into said support. The co-impregnation step (s) is (are) preferably carried out by dry impregnation or by impregnation in excess of solution. When this first mode comprises the implementation of several co-impregnation steps, each co-impregnation step is preferably followed by an intermediate drying step generally at a temperature below 200 ° C, advantageously between 50 and 180. ° C, preferably between 60 and 150 ° C, very preferably between 75 and 140 ° C.

According to a preferred embodiment of co-impregnation, the impregnation solution is preferably an aqueous solution. Preferably, the aqueous impregnation solution when it contains cobalt, molybdenum and phosphorus is prepared under pH conditions favoring the formation of heteropolyanions in solution. For example, the pH of such an aqueous solution is between 1 and 5. According to another variant, the catalyst precursor is prepared by carrying out successive deposits and in any order of a component of a metal from group VIB, a component of a metal from group VIIIB and optionally phosphorus on said support for the implementation of step i). The deposits can be made by dry impregnation, by excess impregnation or else by deposition-precipitation according to methods well known to those skilled in the art. In this second embodiment, the deposition of the components of the metals of groups VIB and VIIIB and optionally of phosphorus can be carried out by several impregnations with an intermediate drying step between two successive impregnations generally at a temperature below 200 ° C, advantageously included between 50 and 180 ° C, preferably between 60 and 150 ° C, very preferably between 75 and 140 ° C.

Whatever the method of depositing the metals and the optional phosphorus used, the solvent which goes into the composition of the impregnation solutions is chosen so as to dissolve the metal precursors of the active phase, such as water or a organic solvent (for example an alcohol).

By way of example, among the sources of molybdenum, use may be made of oxides and hydroxides, molybdic acids and their salts, in particular ammonium salts such as ammonium molybdate, ammonium heptamolybdate, phosphomolybdic acid (H ₃ PMO ₁₂ 04O), and their salts, and optionally silicomolybdic acid (H ₄ SiMo ₁₂ 0 ₄ o) and its salts. The sources of molybdenum can also be any heteropolycompound such as Keggin, Lacunar Keggin, substituted Keggin, Dawson, Anderson, Strandberg, for example. Molybdenum trioxide and heteropolycompounds of Keggin, lacunar Keggin, substituted Keggin and Strandberg type are preferably used.

The tungsten precursors which can be used are also well known to those skilled in the art. For example, among the sources of tungsten, it is possible to use oxides and hydroxides, tungstic acids and their salts, in particular ammonium salts such as ammonium tungstate, ammonium metatungstate, phosphotungstic acid and theirs. salts, and optionally silicotungstic acid (H ₄ SiW ₂ O ₄₀ ) and its salts. The sources of tungsten can also be any heteropolycompound such as Keggin, Lacunar Keggin, substituted Keggin, Dawson, for example. Oxides and ammonium salts, such as ammonium metatungstate or heteropolyanions of the Keggin, lacunar Keggin or substituted Keggin type, are preferably used. The cobalt precursors which can be used are advantageously chosen from oxides, hydroxides, hydroxycarbonates, carbonates and nitrates, for example. Cobalt nitrate, cobalt hydroxide and cobalt carbonate are preferably used.

The nickel precursors which can be used are advantageously chosen from oxides, hydroxides, hydroxycarbonates, carbonates, acetates and nitrates, for example. Nickel nitrate, nickel hydroxide and nickel hydroxycarbonate are preferably used.

The iron precursors which can be used are advantageously chosen from oxides, hydroxides, carbonates, acetates and nitrates, for example. Preferably, iron nitrate and iron acetate are used.

The phosphorus can also be advantageously introduced alone or as a mixture with at least one of the metals of group VIB and VIIIB. The phosphorus is preferably introduced as a mixture with the precursors of the metals of group VIB and of group VIII, in whole or in part on the shaped alumina support, by dry impregnation of said alumina support using of a solution containing the precursors of metals and the precursor of phosphorus. The preferred source of phosphorus is orthophosphoric acid H ₃ P0 ₄ , but its salts and esters such as ammonium phosphates or their mixtures are also suitable. Phosphorus can also be introduced at the same time as the group VIB element (s) in the form, for example, of Keggin, lacunar Keggin, substituted Keggin or Strandberg-type heteropolyanions.

The content of elements from group VIIIB in the catalyst according to the invention is preferably between 1.0 and 20% by weight of oxides of elements from group VIIIB, preferably between 2.0 and 16% by weight of oxides of 'elements of group VIIIB and more preferably between 3.0 and 15% by weight of oxides of elements of group VIIIB. Preferably, the metallic element of group VIIIB is iron, cobalt or nickel or a mixture of these two elements, and more preferably, the metallic element of group VIIIB consists only of cobalt or nickel.

The content of elements of group VIB is preferably between 1, 5 and 60% by weight of oxides of elements of group VIB, more preferably between 3.0 and 50% by weight of oxides of elements of group VIB . Preferably the metallic element of group VIB is molybdenum or tungsten or a mixture of these two elements, and more preferably the metallic element of group VI B consists only of molybdenum or tungsten.

According to one variant, the catalyst also contains phosphorus, the phosphorus content being between 0.3 and 10.0% by weight expressed as P ₂ 0 ₅ relative to the total weight of the catalyst.

Stage ii) of drying is carried out at a temperature below 200 ° C, advantageously between 50 and 180 ° C, preferably between 60 and 150 ° C, very preferably between 75 and 140 ° C. Step ii) is advantageously carried out in a crossed bed using air or any other hot gas. Preferably, when the drying is carried out in a crossed bed, the gas used is either air or an inert gas such as argon or nitrogen. Very preferably, the drying is carried out in a crossed bed in the presence of air.

Preferably, this drying step ii) lasts between 30 minutes and 4 hours, and preferably between 1 hour and 3 hours.

According to one variant, the dried catalyst can be subjected to a subsequent calcination step, for example in air, at a temperature greater than or equal to 200 ° C. The calcination is generally carried out at a temperature less than or equal to 600 ° C, and preferably between 200 ° C and 600 ° C, and particularly preferably between 250 ° C and 500 ° C. The calcination time is generally between 0.5 hour and 16 hours, preferably between 1 hour and 5 hours. It is generally carried out in air. Calcination makes it possible to transform the precursors of metals of group VI B and VIII into oxides.

Sulfurization stage iii) makes it possible to obtain the catalyst in sulfurized form by the temperature treatment in contact with a decomposable organic sulfur compound which generates H ₂ S or directly in contact with a gas stream of H ₂ S diluted in H ₂ . Preferably, sulfurization step iii) is carried out in a sulforreducing medium, that is to say in the presence of H ₂ S and hydrogen, in order to convert the metal oxides into sulphides such as, for example, MoS ₂ and Co ₉ S ₈ . Sulfurization is carried out by injecting onto the catalyst a stream containing H ₂ S and hydrogen, or else a sulfur compound capable of decomposing into H ₂ S in the presence of the catalyst and hydrogen. Polysulfides such as dimethyldisulfide (DMDS) are precursors of H ₂ S commonly used to sulfide catalysts. The temperature is adjusted so that the H ₂ S reacts with metal oxides to form metal sulphides. Said sulfurization can be carried out in situ or ex situ (inside or outside the reactor) of the reactor of the process according to the invention at temperatures between 200 and 600 ° C, and more preferably between 300 ° C and 500 ° C. . To be active, metals must be sulfurized. The sulfur content in the sulfurized catalyst is measured by elemental analysis according to ASTM D5373. A metal is considered to be sulfurized when the overall sulfurization rate defined by the molar ratio between the sulfur (S) present on the catalyst and said metal is at least equal to 50% of the theoretical molar ratio corresponding to the total sulfurization of the (s) metal (s) considered. The overall sulfurization rate is defined by the following equation:

(S / metal) _catalyst - 0.6 X (S / metal) theoretical in which:

(S / metal) _catalyst molar ratio between sulfur (S) and metal present on the catalyst

(S / metal) _theoretical molar ratio between sulfur and metal corresponding to the total sulphurization of the metal to sulphide.

This theoretical molar ratio varies according to the metal considered:

(S / Fe) theoretical ^- 1

(S / Co) theoretical ^- 8/9

(S / Ni) theoretical ^- 2/3 (S / Mo) theoretical ^- 2/1

(S / W) theoretical ^- 2/1

When the catalyst comprises several metals, the molar ratio between the S present on the catalyst and all the metals must also be at least equal to 50% of the theoretical molar ratio corresponding to the total sulphurization of each metal to sulphide, the calculation being carried out in proportion to the relative mole fractions of each metal. For example, for a catalyst comprising molybdenum and nickel with a respective molar fraction of 0.7 and 0.3, the minimum molar ratio (S / Mo + Ni) is given by the relation:

(S / MO + N i) cata | _y seur = 0.6 X {(0.7 X 2) + (0.3 X (2/3)} Preferably, the overall degree of metal sulfurization is greater than or equal to 50%, preferably greater than or equal at 55%, preferably greater than or equal to 60%, preferably greater than or equal to 65%, preferably greater than or equal to 70 and very preferably greater than or equal to 75%.

Sulfurization is carried out on the metals in the form of an oxide without carrying out a preliminary stage of reduction of the metals. This is because the sulfurization of reduced metals is more difficult than the sulfurization of metals in the form of oxides.

Another object according to the invention relates to a method comprising

A step for preparing the heterogeneous sulfurized catalyst comprising at least one metallic element from group VIB and / or one metallic element from group VIIIB deposited on a carbonaceous or porous solid support in oxide form as described above, and

A step of converting a feed comprising a furan compound of formula (I) as described above by bringing said feed into contact with the catalyst prepared in the previous step, and hydrogen.

Examples Example 1 - Preparation of an oxide catalyst A (comparative)

The support for catalyst A is a transition alumina with a specific surface area of 140 m ² / g and a pore volume of 1.0 cm ³ / g. Catalyst A is prepared by dry impregnation of the support with an aqueous solution of ammonium heptamolybdate and cobalt nitrate, the volume of the solution containing the metal precursors being strictly equal to the pore volume of the support mass. The concentration of the metal precursors in aqueous solution is adjusted so as to obtain the desired weight percentage of molybdenum, cobalt on the final catalyst. After dry impregnation on the support, the catalyst is left to mature for 1 hour 30 minutes in a chamber saturated with water, dried in air in an oven at 90 ° C. for 12 hours then calcined in air at 450 ° C. for 2 hours. Catalyst A obtained after calcination has a content of 10.3% by weight of molybdenum (MoO ₃ equivalent) and 2.8% by weight of cobalt (CoO equivalent).

Example 2 - Preparation of a reduced catalyst B (comparative)

3 grams of catalyst A are reduced beforehand at 200 ° C under hydrogen for 2 hours with a hydrogen flow rate of 1 L / h / g. Catalyst B is thus obtained.

Example 3 - Preparation of a sulfurized catalyst C (according to the invention)

3 grams of catalyst A are pretreated at 350 ° C for 2 hours with a feed containing 4% by weight of sulfur in the form of DMDS (dimethyldisulphide) in heptane with a feed rate of 1 L / h / g to ensure sulphurization oxide phases, and finally, reduced under hydrogen for 2 hours at 200 ° C with a hydrogen flow rate of 1 L / h / g. Catalyst C is thus obtained. The overall sulfurization rate of the catalyst measured is 61%.

Example 4 - Preparation of catalyst D

The support for catalyst D is a transition alumina with a specific surface area of 70 m ² / g and a pore volume of 1.0 cm ³ / g. The support is dry impregnated with an aqueous solution of ammonium heptamolybdate and nickel nitrate, the volume of the solution containing the metal precursors being strictly equal to the pore volume of the support mass. The concentration of metal precursors in aqueous solution is adjusted so as to obtain the desired weight percentage of molybdenum, nickel on the final catalyst. The dry impregnated support is then left to mature for 1 hour 30 minutes in a chamber saturated with water, dried in air in an oven at 90 ° C. for 12 hours and then calcined in air at 450 ° C. for 2 hours. After calcination, the impregnated support has a content of 6.0% by weight of molybdenum (equivalent Mo0 ₃ ) and 10.2% by weight of nickel (equivalent NiO). 3 grams of the impregnated and then calcined support are then treated beforehand at 350 ° C for 2 hours with a feed containing 4% by weight of sulfur in the form of DM DS (dimethyldisulphide) in heptane with a feed rate of 1 L / h / g to ensure the sulfurization of the oxide phases, and finally, reduced under hydrogen for 2 hours at 200 ° C with a hydrogen flow rate of 1 L / h / g. Catalyst D is thus obtained. The overall sulfurization rate of the catalyst measured is 65%. Example 5 - Preparation of catalyst E

The support for catalyst E is a transition alumina with a specific surface area of 265 m ² / g and a pore volume of 0.8 cm ³ / g. The support is dry impregnated with an aqueous solution of ammonium metatungstate and nickel nitrate, the volume of the solution containing the precursors of the metals being strictly equal to the pore volume of the support mass. The concentration of the metal precursors in aqueous solution is adjusted so as to obtain the desired weight percentage of tungsten, nickel on the final catalyst. The dry impregnated support is then left to mature for 1 hour 30 minutes in a chamber saturated with water, dried in air in an oven at 90 ° C. for 12 hours and then calcined in air at 450 ° C. for 2 hours. After calcination, the impregnated support has a content of 16.4% by weight of tungsten (equivalent W0 ₃ ) and 1.6% by weight of nickel (equivalent NiO). 3 grams of the impregnated and then calcined support are then treated beforehand at 350 ° C for 2 hours with a feed containing 4% by weight of sulfur in the form of DM DS (dimethyldisulphide) in heptane with a feed rate of 1 L / h / g to ensure the sulfurization of the oxide phases, and finally, reduced under hydrogen for 2 hours at 200 ° C with a hydrogen flow rate of 1 L / h / g. Catalyst E is thus obtained. The overall sulfurization rate of the catalyst measured is 57%.

The support for catalyst F is a transition alumina with a specific surface area of 85 m ² / g and a pore volume of 0.8 cm ³ / g. The support is dry impregnated with an aqueous solution of molybdenum oxide, cobalt hydroxide and phosphoric acid, the volume of the solution being strictly equal to the pore volume of the mass of support. The concentration of the precursors in aqueous solution is adjusted so as to obtain the desired weight percentage of cobalt, molybdenum and phosphorus on the final catalyst. The dry-impregnated support is then left to mature for 1 hour 30 minutes in a chamber saturated with water, dried in air in an oven at 120 ° C. for 12 hours. After drying, the impregnated support has a content of 5.9% by weight of molybdenum (equivalent Mo0 ₃ ), 1.3% by weight of cobalt (equivalent CoO) and 0.7% by weight of phosphorus (equivalent P ₂ 0 ₅ ). 3 grams of the impregnated and then dried support are then treated beforehand at 350 ° C. for 2 hours with a feed containing 4% by weight of sulfur in the form of DM DS (dimethyldisulphide) in heptane with a feed rate of 1 L / h / g to ensure the sulfurization of the oxide phases, and finally, reduced under hydrogen for 2 hours at 200 ° C with a hydrogen flow rate of 1 L / h / g. Catalyst F is thus obtained. The overall sulfurization rate of the catalyst measured is 75%. Example 7 - Preparation of catalyst G

The support for catalyst G is a silica with a specific surface area of 220 m ² / g and a pore volume of 1.1 cm ³ / g. The support is dry impregnated with an aqueous solution of molybdenum oxide, cobalt hydroxide and phosphoric acid, the volume of the solution being strictly equal to the pore volume of the mass of support. The concentration of the precursors in aqueous solution is adjusted so as to obtain the desired weight percentage of cobalt, molybdenum and phosphorus on the final catalyst. The dry-impregnated support is then left to mature for 1 hour 30 minutes in a chamber saturated with water, dried in air in an oven at 120 ° C. for 12 hours and then calcined in air at 450 ° C. for 2 hours. After calcination, the impregnated support has a content of 10.1% by weight of molybdenum (equivalent MO0 ₃ ), 1.8% by weight of cobalt (equivalent CoO) and 1.1% by weight of phosphorus (equivalent P ₂ 0 ₅ ). 3 grams of the impregnated and then calcined support are then treated beforehand at 350 ° C for 2 hours with a feed containing 4% by weight of sulfur in the form of DM DS (dimethyldisulphide) in heptane with a feed rate of 1 L / h / g to ensure the sulfurization of the oxide phases, and finally, reduced under hydrogen for 2 hours at 200 ° C with a hydrogen flow rate of 1 L / h / g. Catalyst G is thus obtained. The overall sulfurization rate of the catalyst measured is 66%.

The support for catalyst H is an activated carbon with a specific surface area of 1380 m ² / g and a pore volume of 3.3 cm ³ / g. The support is dry impregnated with an aqueous solution of molybdenum oxide, nickel hydroxycarbonate and phosphoric acid, the volume of the solution being strictly equal to the pore volume of the support mass. The concentration of the precursors in aqueous solution is adjusted so as to obtain the desired weight percentage of nickel, molybdenum and phosphorus on the final catalyst. The dry impregnated support is then left to mature for 1 hour 30 minutes in an enclosure saturated with water, dried in air in an oven at 120 ° C. for 12 hours and then calcined in air at 450 ° C. for 2 hours. After calcination, the impregnated support has a content of 46.1% by weight of molybdenum (M0O3 equivalent), 9.6% by weight of nickel (NiO equivalent) and 13.0% by weight of phosphorus (P ₂ 0 ₅ equivalent). 3 grams of the impregnated and then calcined support are then treated beforehand at 350 ° C for 2 hours with a feed containing 4% by weight of sulfur in the form of DM DS (dimethyldisulphide) in heptane with a feed rate of 1 L / h / g to ensure the sulfurization of the oxide phases, and finally, reduced under hydrogen for 2 hours at 200 ° C with a hydrogen flow rate of 1 L / h / g. Catalyst H is thus obtained. The overall sulfurization rate of the catalyst measured is 63%.

The support for catalyst I is a titanium oxide with a specific surface area of 133 m ² / g and a pore volume of 0.50 cm ³ / g. The support is dry impregnated with an aqueous solution of molybdenum oxide, nickel hydroxycarbonate and phosphoric acid, the volume of the solution being strictly equal to the pore volume of the support mass. The concentration of the precursors in aqueous solution is adjusted so as to obtain the desired weight percentage of nickel, molybdenum and phosphorus on the final catalyst. The dry impregnated support is then left to mature for 1 hour 30 minutes in a chamber saturated with water and dried in air in an oven at 120 ° C. for 12 hours. After calcination, the impregnated support has a content of 16.0% by weight of molybdenum (equivalent of Mo0 ₃ ), 3.4% by weight of nickel (equivalent of NiO) and 3.8% by weight of phosphorus (equivalent P ₂ 0 ₅ ). 3 grams of the impregnated and then calcined support are then treated beforehand at 350 ° C for 2 hours with a feed containing 4% by weight of sulfur in the form of DM DS (dimethyldisulphide) in heptane with a feed rate of 1 L / h / g to ensure the sulfurization of the oxide phases, and finally, reduced under hydrogen for 2 hours at 200 ° C with a hydrogen flow rate of 1 L / h / g. Catalyst I is thus obtained. The overall sulfurization rate of the catalyst measured is 72%.

The support for catalyst J is a transition alumina with a specific surface area of 265 m ² / g and a pore volume of 0.8 cm ³ / g. The support is dry impregnated with an aqueous solution of phosphomolybdic acid, the volume of the solution being strictly equal to the pore volume of the mass of support. The concentration of the precursors in aqueous solution is adjusted so as to obtain the desired weight percentage of molybdenum and phosphorus on the final catalyst. The dry impregnated support is then left to mature for 1 hour 30 minutes in a chamber saturated with water and dried in air in an oven at 120 ° C. for 12 hours. After drying, the impregnated support has a content of 13.6% by weight of molybdenum (equivalent MO0 ₃ ), and 0.6% by weight of phosphorus (equivalent P ₂ 0 ₅ ). 3 grams of the impregnated and then calcined support are then treated beforehand at 350 ° C for 2 hours with a feed containing 4% by weight of sulfur in the form of DM DS (dimethyldisulphide) in heptane with a feed rate of 1 L / h / g to ensure the sulfurization of the oxide phases, and finally, reduced under hydrogen for 2 hours at 200 ° C with a hydrogen flow rate of 1 L / h / g. Catalyst J is thus obtained. The overall sulfurization rate of the catalyst measured is 77%.

Example 11 - Evaluation of the Catalytic Performance of Catalysts A to J in a Process for Converting 5-HMF to DMF A feed containing 1.25% by weight of 5-hydromethylfurfural in 250 mL of thiophene is used for the evaluation of the catalytic performance of different catalysts. The 5-HMF conversion reaction is carried out in a Grignard reactor under a total pressure of 3.0 MPa, at 180 ° C., for 130 min, with stirring at 1000 revolutions per minute and in the presence of 3.0 grams of catalyst. Samples are taken at different time intervals and are analyzed by gas chromatography to observe the disappearance of reagents and the formation of products, and to deduce their respective concentrations.

The catalytic performances of catalysts A, B, C, D, E, F, G, H, I and J are evaluated in terms of conversion of 5-HMF and in carbon yield to 2,5-dimethylfuran in liquid phase after 130 minutes reaction, taking into account the percentage of carbon in 5-HMF and in 2,5-dimethylfuran.

The carbon yield of 2,5-dimethylfuran in the liquid phase after reaction for 130 minutes is obtained by the following equation:

in which :

- _Carbon yield: _carbon yield of 2,5-dimethylfuran in liquid phase after 130 min

-% _carbon, 2 _, 5- _{dimethylfuran} : mass percentage of carbon in 2,5-dimethylfuran

-% car _b one _, 5-HMF: percentage by mass of carbon in 5-HMF. The results obtained with catalysts A to J are shown in Table 1 below.

Table 1: Catalytic performances of catalysts A to J for the conversion of 5-HMF to 2,5-dimethylfuran.

The conversion of 5-HMF and the carbon yield to 2-5 dimethylfuran are given after 130 minutes of reaction.

The conversion of 5-HMF remains low with oxide catalysts (oxide catalyst) or reduced catalysts (catalyst B) and is not accompanied by formation of 2,5-dimethylfuran.

The sulfurized catalysts C, D, E, F, G, H, I and J make it possible to obtain sufficient catalytic activities for the conversion reaction of 5-HMF under the conditions of process and allow the formation of 2,5-dimethylfuran. Catalyst D has the best carbon yield of 2,5-dimethylfuran.

Claims

1 Process for converting a feed comprising a furan compound of formula (I) by bringing said feed into contact with a heterogeneous sulfurized catalyst comprising at least one metallic element from group VI B and / or one metallic element from group VIIIB deposited on a porous solid support in oxide form or on an amorphous or crystalline carbon-based support, and on hydrogen, said furan compound of formula (I) being represented by the following general formula:

in which

Ri is chosen from an aldehyde function -C (0) H, a carboxylic acid function -

COOH, an ester function -COOR ₃ , a hydroxymethyl function -CH ₂ OH, a methyl halide function, a hydrogen, or an ether function -CH ₂ OR ₄ , R ₃ and R ₄ representing a linear or branched alkyl group of 1 with 6 carbons,

R ₂ is chosen from an aldehyde function --C (0) H, a carboxylic acid function - COOH, an ester function --COOR ₃ , a hydroxymethyl function --CH ₂ OH, a methyl halide function, or an ether function --CH ₂ OR ₄ , R ₃ and R ₄ representing a linear or branched alkyl group of 1 to 6 carbons.

2. Method according to claim 1 carried out at a temperature between 100 and 300 ° C, and at a total pressure between 0.5 and 6.0 MPa.

3. Method according to any one of the preceding claims, in which the catalyst is introduced in a charge / catalyst (s) mass ratio of between 1 and 1000.

4. Method according to any one of the preceding claims, in which the compound of formula (I) is mixed with at least one sulfur compound.

5. The method of claim 4 wherein the sulfur compound is present in a mass ratio relative to the compound of formula (I) of between 0.1 and 1000.

6. Method according to any one of the preceding claims carried out in a solvent chosen from aromatic, furan, thiophenic or benzene solvents, alone or as a mixture.

7. Method according to any one of the preceding claims wherein the element or elements of group VIIIB are chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum and the element or elements of group VIB are chosen from chromium, molybdenum and tungsten.

8. A method according to any preceding claim wherein the elements of groups VIB and VIIIB are chosen from the following combinations NiMo, CoMo, FeMo, NiW, NiMoW and NiCoMo.

9. Process according to any one of the preceding claims, in which the porous solid support in oxide form chosen from aluminas, silicas, silica-alumina or even titanium or magnesium oxides used alone or mixed with alumina or silica-alumina.

10. Method according to one of claims 1 to 8 wherein the solid support is chosen from amorphous or crystalline carbon compounds are chosen from activated carbons, carbon blacks, carbon nanotubes, mesostructured carbons and fibers of carbon.

11. Process according to any one of the preceding claims, in which the catalyst has a pore volume of the support which is generally between 0.4 and 5.0 cm ³ / g.

12. Process according to any one of the preceding claims, in which the catalyst has a specific surface area of the support which is generally between 40 and 1500 m ² / g.

13. Process according to any one of the preceding claims, in which the catalyst has an overall sulfurization rate greater than or equal to 50%.

14. Process according to any one of the preceding claims, comprising the preparation of the heterogeneous sulfurized catalyst comprising the following steps: i) at least one step of bringing at least one support into contact with at least one solution containing at least one precursor of at least one metal from group VI 11 B and / or one precursor of at least one metal from group VI B,

ii) at least one drying step to obtain at least said metal from group VIIIB and / or at least said metal from group VIB in oxide form, then,

iii) at least one sulfurization step so that the metals of said active phase are in sulfurized form.

15. The method of claim 14 wherein a calcination step at a temperature between 200 ° C and 600 ° C is implemented after step ii).