FR3020062A1 - METHOD FOR TRANSFORMING A LOAD COMPRISING A LIGNOCELLULOSIC BIOMASS USING A HOMOGENEOUS CATALYST COMPRISING A LANTHANIDE IN COMBINATION WITH A HETEROGENEOUS CATALYST - Google Patents

Abstract

The invention relates to a process for converting a filler selected from lignocellulosic biomass and carbohydrates, alone or as a mixture, into mono- or polyoxygenated compounds, in which the filler is brought into contact simultaneously with a catalytic system. comprising a combination of one or more homogeneous catalysts selected from metal salts wherein the metal M is a lanthanide selected from Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, and one or more heterogeneous catalysts, in the same reaction chamber, in the presence of at least one solvent, said solvent being water alone or in admixture with at least one other solvent, under a reducing atmosphere, and at a temperature between 50 ° C and 300 ° C, and at a pressure between 0.5 MPa and 20 MPa.

Description

PRIOR ART In recent years, there has been a great revival of interest in the incorporation of products of renewable origin into the fuel and chemical sectors, in addition to or in substitution for products of fossil origin. One possible route is the conversion of the cellulose contained in the lignocellulosic biomass into products or chemical intermediates, such as products containing from one to six hydroxyl functions, namely n-propanol, ethylene glycol, propylene glycol, glycerol, 1,2-butanediol or 1,2-hexanediol.

The term lignocellulosic biomass (LBC) or lignocellulose encompasses several constituents present in varying amounts depending on its origin: cellulose, hemicellulose and lignin. Hemicellulose and cellulose constitute the carbohydrate part of lignocellulose. They are polymers of sugars (pentoses and hexoses). Lignin is a macromolecule rich in phenolic motifs. By lignocellulosic biomass, we mean, for example, forest products and agricultural by-products such as straw, as well as certain crops with a high agricultural yield such as miscanthus or poplar.

The production of chemicals from lignocellulosic biomass can both reduce energy dependence on oil and preserve the environment by reducing greenhouse gas emissions without using resources for food uses.

The direct conversion of a feed selected from lignocellulosic biomass and carbohydrates, alone or in admixture into chemical products or intermediates, in particular mono- or polyoxygenated, is a particularly advantageous route. Direct transformation is the transformation into a step of said charge, optionally pretreated, to mono- or polyoxygenated products that can be upgraded. The valorization of lignocellulosic biomass or cellulose contained in biomass by the use of a combination of homogeneous and heterogeneous catalysts is widely described in the literature.

In particular, the use of a combination of homogeneous catalysts based on Bronsted acids and heterogeneous catalysts has often been described for the transformation of lignocellulosic biomass or cellulose.

The patent application WO2013 / 015990 describes a process for producing polyols and in particular alcohols, organic acids, aldehydes, monosaccharides, polysaccharides, phenolic compounds, carbohydrates, glycerol, proteins and depolymerized lignin as well as hydrocarbons by the hydrolysis and hydrogenation of microcrystalline celluloses, pulp and glucose, in the presence of a catalyst system comprising an unsupported compound based on tungsten or molybdenum, alone or as a mixture, and a supported compound based on Pt, Pd, Ru, Rh, Ni, Ir alone or in admixture on a solid support selected from carbon, Al 2 O 3, ZrO 2, SiO 2, MgO, Ce, ZrO 2, TiO 2, SiC, silica alumina, clays, zeolites taken alone or in mixture. The unsupported compounds based on tungsten or molybdenum, alone or as a mixture, are the Bronsted acids chosen from tungstic acid, molybdic acid, ammonium metatungstate, heteropolyanions of tungsten, molybdenum and tungstic acid. of molybdic acid, alone or in admixture. Said process allows the conversion of cellulose to ethylene glycol or propylene glycol with high yield and good selectivity. In the examples illustrating the invention, the unsupported catalysts are the following Bronsted acids: tungstic acid (WO3xH2O), phosphotungstic acid (H3PW12040) and ammonium metatungstate ((NH4) 6 (W12040) .xH2O ). The supported catalyst is Ni / Norit CA-1 or Pd / C, the metal contents being between 0.6 and 5% by weight. The majority products in these examples are ethylene glycol and propylene glycol. The cellulose conversion is carried out in water at a content of 1% wt cellulose / water at 245 ° C. under 60 bar of H2 (at room temperature). US2009 / 0326286 discloses the hydrolysis and hydrogenation of lignocellulosic biomasses to monosaccharides in the presence of a homogeneous catalyst and a heterogeneous catalyst. The homogeneous catalyst is described as a mineral or organic Bronsted acid preferably selected from H2SO4, H3PO4, H3PO3, H3PO2 and CH3COOH. The heterogeneous catalyst is based on activated charcoal or acidic alumina on which is deposited a transition metal chosen from ruthenium, nickel, platinum and palladium at contents of between 0.1% and 5.5% by weight. relative to the total mass of heterogeneous catalyst. The products formed and the associated yields are not specified. Sels et al. (Chem Commun 2010, 46, 3577-3579) study the transformation of cellulose into hexitols (sorbitol + mannitol) in the presence of a homogeneous catalyst and a heterogeneous catalyst. The homogeneous acidic catalysts used are Bronsted acids H2SO4 and H4SiW12040. The heterogeneous catalyst is 5% Ru / C weight. The conversion of the microcrystalline cellulose is respectively 50% and 80% with these two acids for a reaction in water at 190 ° C. and 50 bar of H2 for 24 hours (pH (250c) = 2). The associated yields of hexitols are 13% and 48%. The ground cellulose is solubilized more rapidly with a total conversion in 1 hour under the same operating conditions and an 87% hexitol yield. With a slightly different perspective, Zhang et al. (Chem., 2012, 48, 7052-7054) combine tungstic acid H2W04, insoluble in water at room temperature, and heterogeneous catalyst 5% w / w Ru for the conversion of cellulose to ethylene glycol in water at 245 ° C sow 60 bar H2. The peculiarity of this system is that the tungstic acid solubilizes hot and passes from the heterogeneous to the homogeneous during the rise in temperature to 245 ° C. The yield of ethylene glycol reaches 59% with total conversion of the cellulose to 30%. min. More recently, C. Liang (Green Chem., 2013, 15, 891-895) describes a combination of catalysts for the production of ethylene glycol from cellulose in water at 245 ° C. under 60 bar. Calcium hydroxide Ca (OH) 2 in combination with the heterogeneous CuCr catalyst makes it possible to increase the ethylene glycol yield of the reaction by 5% to 30%. The yield of propylene glycol remains stable around 30-35%. The US2011 / 0060148 patent application of BIOeCON International Holding describes a process for converting lignocellulosic biomass into polyols which makes it possible to obtain a high yield of polyols and to minimize the formation of by-products. In particular, the process comprises a step of hydrolysis of cellulose and lignocellulosic biomasses to glucose, a step of hydrogenation of glucose formed into sorbitol, a step of dehydration of the polyols obtained and a recovery step, said steps being carried out in a hydrated metal salt used as a solvent in a ratio of hydrated metal salt / lignocellulosic biomass of between 1 and 50, which corresponds to a lignocellulosic biomass / metal salt ratio of between 0.02 and 1. The hydrolysis of the cellulose is carried out in a hydrated metal salt, used as a solvent, chosen from zinc, calcium and lithium halides, alone or as a mixture and in particular in the ZnCl 2 .4H 2 O used as a solvent. The hydrolysis step is also carried out in the presence of an inorganic acid, preferably hydrochloric acid (HCl). The hydrogenation of glucose is also carried out in said hydrated metal salt, used as a solvent, in the presence of an inorganic acid, preferably hydrochloric acid (HCl) and a heterogeneous catalyst chosen from conventional hydrogenation catalysts. sugars such as Ru / C catalysts, Raney nickel, Raney copper, and carbon or alumina supported nickel and preferably in the presence of Ru / C, without precision of the mass content of metals. The examples illustrate the use as a solvent of the hydrated inorganic salt ZnCl 2 .4H 2 O in a weight ratio ZnCl 2 .4H 2 O / cellulose of 12/1. The maximum conversion of the cellulose thus obtained after 1h30 is 100%. Finally, in 2009, R. Raines (JACS, 2009, 131, 1979-1985) described the transformation of sugars, cellulose and lignocellulose into 2,5-dimethylfuran in two stages. The first step is carried out in an ionic liquid medium based on dimethylacetamide-LiCl / [EMIM] Cl ([EMIM] [CI] = 1-ethyl-3-methylimidazolium chloride) at 140 ° C. for 2 h and is catalyzed by a mixture of the metal salt of chromium trichloride (CrCl3) and hydrochloric acid (HCl) both at 10 mol% relative to the cellulose. At the end of this first step, a step of purification by steric exclusion chromatography is carried out and makes it possible to eliminate the chloride ions of the medium so as to avoid the poisoning of the catalyst used in the second step. The second step can thus take place and involves the transformation of the purified solution in the presence of a copper-based catalyst deposited on Ru / C under hydrogen, in 1-butanol at 220 ° C. for 10 hours to form 2, 5-dimethylfuran. The two-step process thus described makes it possible to obtain a high selectivity for 2,5-dimethylfuran but also leads to the production of a significant quantity of humins.

It is not described in the process literature that allows a direct transformation of a charge selected from lignocellulosic biomass and carbohydrates, singly or in mixture, into mono or polyoxygenated recoverable products by contacting said feedstock. simultaneously, within the same reaction medium with a combination of at least one homogeneous catalyst chosen from metal salts in which the metal M is chosen from among the lanthanides, with the exception of the element La, and one or more heterogeneous catalysts of the type described in the present invention.

The work of the applicant has made it possible to demonstrate that, surprisingly, the contacting of a filler chosen from lignocellulosic biomass and carbohydrates, alone or as a mixture, simultaneously, with at least one homogeneous catalyst chosen from the metal salts in which the metal M is chosen from lanthanides with the exception of the element La, and one or more heterogeneous catalysts, in the same reaction chamber operating under specific operating conditions allowed to obtain mono-valued products directly. or polyoxygenated and reduce the content of non-recoverable products, such as humins.

SUMMARY OF THE INVENTION An object of the present invention is therefore to provide a process for converting a filler selected from lignocellulosic biomass and carbohydrates, alone or as a mixture, into mono- or polyoxygenated compounds, wherein said filler is contacted simultaneously with a combination of one or more homogeneous catalyst (s) and one or more heterogeneous catalysts, in the same reaction chamber, in the presence of at least one solvent, said solvent being water alone or in admixture with at least one other solvent, under a reducing atmosphere, and at a temperature of between 50 ° C and 300 ° C, and at a pressure of between 0.5 MPa and 20 MPa, wherein said homogeneous catalyst (s) being (are) selected from hydrated or non-hydrated metal salts having the general formula M, T, Xn · n 'H 2 O, wherein the metal M is a lanthanide selected from Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb e t Lu, m is an integer between 1 and 10, n is an integer between 1 and 10 and n 'is a number between 0 and 20 and X is at least one anion selected from halides, nitrates, carboxylates, halocarboxylates, acetylacetonates, hydroxides, alcoholates, phenolates, substituted or unsubstituted, sulphates, alkyl sulphates, phosphates, alkyl phosphates, halosulfonates, alkyl sulphonates, perhaloalkyl sulphonates, bis (perhaloalkylsulphonyl) amides, arenesulfonates, substituted or unsubstituted by halogen or haloalkyl groups, said anions X being identical or different in the case where n is greater than 1, said heterogeneous catalyst (s) comprising at least one metal chosen from metals of groups 6 to 11 and metals of group 14 of the Periodic Table and a support selected from among the oxides of the elements selected from aluminum, titanium, silicon, zirconium, cerium and niobium, alone or in admixture, and mixed oxides chosen from zinc, copper and cobalt aluminates, said oxides possibly doped with at least one metal compound selected from among tungsten, tin, molybdenum and antimony, taken alone or as a mixture, crystallized aluminosilicates or not, aluminophosphates and amorphous or crystallized carbon compounds.

In the present invention, reference is made to the new notation of the Periodic Table of Elements: Handbook of Chemistry and Physics, 76th Edition, 1995-1996.

In the present invention, the term "homogeneous catalyst" means a catalyst that is soluble in the operating conditions of the reaction. By heterogeneous catalyst is meant a catalyst that is not soluble in the reaction operating conditions. An advantage of the present invention is to allow the direct production of mono- or polyoxygenated recoverable products while limiting the formation of non-recoverable products such as soluble and insoluble humins, ie products of high molecular weight resulting from unwanted condensation of sugars and their derivatives.

In the case where the treated filler is a solid filler, that is to say preferably chosen from lignocellulosic biomass or cellulose, another advantage of the present invention is that it allows both the increase of the maximum conversion and acceleration of the kinetics of conversion of lignocellulosic biomass or of cellulose by the simultaneous use in the same reaction chamber operating under a reducing atmosphere, of the combination of at least one homogeneous catalyst and one or more heterogeneous catalyst (s) as claimed.

DETAILED DESCRIPTION OF THE INVENTION The feedstock The feedstock treated in the process according to the invention is a feedstock chosen from lignocellulosic biomass and carbohydrates, alone or as a mixture, the carbohydrates being preferably chosen from polysaccharides, oligosaccharides and monosaccharides, alone or in admixture. By polysaccharides we mean one or more compounds containing at least 10 subunits of covalently linked monosaccharides. Preferred polysaccharides used as filler in the present invention are selected from starch, inulin, cellulose and hemicellulose alone or in admixture. By oligosaccharides we mean one or more compounds containing from two to ten subunits of covalently linked monosaccharides. By oligosaccharide, is meant more particularly, on the one hand a carbohydrate having the formula (C6H1005) n or C6nHion + 205n +, where n is an integer greater than 1, obtained by partial hydrolysis of the starch, the inulin, lignocellulosic biomass, cellulose and hemicellulose, and on the other hand a so-called mixed carbohydrate having the composition (C6H1005) m (C5H804) n, (C6, Hion, ± 205m + 1) (C5nH8n + 204n + 1) where m and n are integers greater than or equal to 1.

The oligosaccharides are preferably chosen from oligomers of pentoses and / or hexoses with a degree of polymerization lower than that of cellulose and hemicellulose (2-30). They can be obtained by partial hydrolysis of starch, inulin, lignocellulosic biomass, cellulose or hemicellulose. Oligosaccharides are generally soluble in water.

The preferred oligosaccharides used as filler in the present invention are chosen from sucrose, lactose, maltose, isomaltose, inulobiosis, melibiose, gentiobiose, trehalose, cellobiose, cellotriose, cellotetraose and oligosaccharides. from the hydrolysis of the polysaccharides named in the previous paragraph. By monosaccharides is meant simple sugars (hexoses, pentoses) which can be produced by complete or partial depolymerization of the polysaccharides. Preferred monosaccharides used as filler in the present invention are selected from glucose, galactose, mannose, fructose, altrose. Lignocellulosic biomass consists essentially of three natural constituents present in varying amounts according to its origin: cellulose, hemicellulose and lignin.

Cellulose (C6H1005) accounts for most (40-60%) of the composition of lignocellulosic biomass. Cellulose is a linear homopolymer composed of numerous units of D-Anhydroglucopyranose (AGU) linked together by [3- (1-4) glycosidic linkages. The repetition pattern is the cellobiose dimer.

Cellulose is insoluble in water at ambient temperature and pressure. The cellulose used may be crystalline or amorphous. Hemicellulose is the second carbohydrate in quantity after cellulose and constitutes 20 to 40% by weight of lignocellulosic biomass. Unlike cellulose, this polymer consists mainly of pentose monomers (5-atom rings) and hexoses (6-atom rings). Hemicellulose is an amorphous heteropolymer with a lower degree of polymerization than cellulose (30-100). Lignin is an amorphous macromolecule present in lignocellulosic compounds in variable proportions depending on the origin of the material (straw 15%, wood: 20-26%). Its function is mechanical strengthening, hydrophobization and plant support. This macromolecule rich in phenolic units can be described as resulting from the combination of three monomer units of propyl-methoxy-phenol type. Its molar mass varies from 5000 g / mol to 10000 g / mol for hardwoods and reaches 20000 g / mol for softwoods. The lignocellulosic raw material may advantageously consist of wood or vegetable waste. Other non-limiting examples of lignocellulosic biomass material are farm residues such as, for example, straw, grasses, stems, cores, or shells, logging residues such as thinning products , bark, sawdust, chips, or falls, logging products, dedicated crops (short rotation coppice), residues from the agri-food industry such as residues from the cotton industry , bamboo, sisal, banana, maize, panicum virgatum, alfalfa, coconut, or bagasse, household organic waste, waste wood processing facilities and woods used construction, pulp, paper, recycled or not.

The lignocellulosic biomass can advantageously be used in its raw form, that is to say in its entirety of these three constituents cellulose, hemicellulose and lignin. The raw biomass is generally in the form of fibrous residues or powder. It can also advantageously be milled or shredded to allow its transport.

The lignocellulosic biomass feed may advantageously also be used in its pretreated form, that is to say in a form containing at least one cellulosic part after extraction of lignin and / or hemicellulose. The biomass is preferably pretreated to increase the reactivity and accessibility of the cellulose within the biomass prior to processing. These pretreatments are of a mechanical, thermochemical, thermomechanical and / or biochemical nature and cause the decystallinization of the cellulose, a decrease in the degree of polymerization of the cellulose, the solubilization of the hemicellulose and / or lignin and / or cellulose or partial hydrolysis of hemicellulose and / or cellulose following the treatment. Pretreatment prepares the lignocellulosic biomass by separating the carbohydrate portion of the lignin and adjusting the size of the biomass particles to be treated. The size of the biomass particles after pretreatment is generally less than 5 mm, preferably less than 500 microns.

The catalysts According to the invention, said feedstock is contacted in the process according to the invention, simultaneously with one of one or more homogeneous catalyst (s) and one or more heterogeneous catalyst (s). (s) as claimed, in the same reaction chamber, in the presence of at least one solvent, said solvent being water alone or in admixture with at least one other solvent, under a reducing atmosphere, and at a temperature between 50 ° C and 300 ° C, and at a pressure of between 0.5 MPa and 20 MPa. An essential criterion of the present invention lies in bringing said charge into contact under the operating conditions as claimed simultaneously with a combination of one or more homogeneous catalyst (s) and one or more catalyst (s). s) heterogeneous (s) as claimed, within the same reaction chamber. Indeed, the reactions involved in the process for transforming said feedstock are not successive reactions because of the use and simultaneous operation of a combination of one or more homogeneous catalyst (s) such as claimed and one or more heterogeneous catalysts, in the same reaction chamber. The conversion of the feedstock induced by the homogeneous catalyst (s) and the transformation of the products thus dissolved by the heterogeneous catalyst (s) is therefore concomitant and complementary. It is thus possible to take advantage of this compatibility between the homogeneous and heterogeneous catalysts to overcome any intermediate work of treatment or purification, synonymous with additional process costs and significant losses of material associated with this step. Preferably, said method according to the invention does not operate in two successive steps. According to the invention, the at least one homogeneous catalyst (s) is (are) chosen from hydrated or non-hydrated metal salts having the general formula M, Xn.n'H 2 O wherein the metal M is a lanthanide chosen from Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, m is an integer between 1 and 10, n is an integer between 1 and n 'is a number between 0 and 20 and X is at least one anion selected from halides, nitrates, carboxylates, halocarboxylates, acetylacetonates, alcoholates, phenolates, substituted or unsubstituted, sulphates, alkyl sulphates, phosphates, alkyl phosphates, halosulfonates, alkylsulphonates, perhaloalkylsulphonates, bis (perhaloalkylsulphonyl) amides, arenesulphonates, substituted or unsubstituted by halogen or haloalkyl groups, said anions X being identical or different in the case where n is greater than 1. In the where several homogeneous catalysts chosen from hydrated metal salts or not of general formula M, Xn.n'H20, M, X, m, n and n 'having the aforementioned meanings, are used in the process according to the invention, said Homogeneous catalysts may be the same or different. In a preferred embodiment, a single homogeneous catalyst chosen from hydrated or non-hydrated metal salts of general formula M, Xn.n'H 2 O, M, X, m, n and n 'having the above-mentioned meanings, is used in the process according to the invention.

Said metal M of said homogeneous catalyst (s) chosen from the metal salts, hydrated or not, chosen from among the lanthanides, is preferably chosen from the following metals: Ce, Pr, Nd, Pm, Sm, Gd , Eu, Er, Tm, Yb.

Preferably, said metal M is selected from the following metals: Ce, Pr, Nd, Sm, Eu, Gd, Er, Yb. Very preferably, said metal M is selected from metals: Ce and Er. According to the invention, in the composition of the metal salt, the metal M selected from the lanthanides mentioned is associated with one or more anions X, which may be identical or different. Preferably, the anion X is at least one anion selected from halides, alkylsulfonates, perhaloalkylsulfonates, bis (perhaloalkylsulfonyl) amides. Preferably, the halide is fluoride, chloride, bromide and iodide.

Preferably, the alkylsulfonate is mesylate and tosylate. Preferably, the perhaloalkylsulfonate is triflate. Preferably, the bis (perhaloalkylsulfonyl) amide is bis (triflimide).

Very preferably, the anion X is a chloride. Said said homogeneous catalyst (s) very preferably are advantageously selected from cerium chloride heptahydrate CeC13.7H20 and erbium chloride heptahydrate ErC13.6H20, alone or in mixture In the case where a single homogeneous catalyst selected from the hydrated or non-hydrated metal salts of the general formula M, Xn.n'H 2 O, M, X, m, n and n 'having the abovementioned meanings, is used, the most preferred homogeneous catalyst is cerium chloride heptahydrate CeC13.7H20. In a preferred embodiment, at least one second homogeneous catalyst of a different type than the homogeneous catalyst or catalysts chosen from hydrated or non-hydrated metal salts having the general formula M, Xn.n'H 2 O may optionally be added simultaneously in said same reaction chamber in which the method according to the invention is implemented. Preferably, said second (s) homogeneous catalyst (s) is (are) chosen from organic or inorganic Bronsted acids. In this case, said charge is brought into contact, simultaneously, in said same reaction chamber, with a combination of one or more homogeneous catalyst (s) chosen from hydrated or non-hydrated metal salts, having the formula general M, Xn.n'H20 wherein M, m, n, n 'and X have the abovementioned meaning, of one or more second homogeneous catalyst (s) chosen (s) from organic acids or inorganic Bronsted and one or more heterogeneous catalyst (s) according to the invention. In the case where several homogeneous catalysts chosen from organic or inorganic Bronsted acids are used in the process according to the invention, said catalysts may be identical or different. In a very preferred embodiment, said filler is brought into contact, simultaneously, in said same reaction chamber, with a combination of a homogeneous catalyst chosen from hydrated or non-hydrated metal salts having the general formula M, Xn.n. Wherein M, m, n, n 'and X have the abovementioned meaning, of a second homogeneous catalyst selected from organic or inorganic Bronsted acids and a heterogeneous catalyst according to the invention.

Preferably, the inorganic Bronsted acids are chosen from the following inorganic acids: HF, HCl, HBr, HI, H 2 SO 3, H 2 SO 4, H 3 PO 2, H 3 PO 4, HNO 2, HNO 3, H 2 O 4, H 4 SiO 2 OO 4 O, H 3 PW 1 O 4 O 40, (NH 4) 6 (W 12 O 40) xH2O, (NH4) 6Mo7O24.xH2O, H3B03, HCIO4, HBF4, HSbF5, HPF6, H2FO3P, CISO3H, FSO3H, HN (SO2F) 2 and HI03. Preferably, the inorganic Bronsted acids are chosen from the following inorganic acids: HCl, H2SO4, H3PO4, H2W03, (N1-14) 6 (W12040) .xH2O, (N H4) 6Mo7O24.xH2O A second very preferred homogeneous catalyst is hydrochloric acid (HCI). Preferably, the organic Bronsted acids are chosen from organic acids of general formulas R-COOH, RSO2H, RSO3H, (RSO2) NH, (RO) 2 PO2H, ROH where R is a hydrogen or a carbon chain composed of alkyl groups or aryls, substituted or not by heteroatoms. Preferably, the organic Bronsted acids are chosen from the following organic acids: formic acid, acetic acid, trifluoroacetic acid, lactic acid, levulinic acid, methanesulphonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, bis (trifluoromethanesulfonyl) amine, benzoic acid, para-toluenesulfonic acid, 4-biphenylsulfonic acid, diphenylphosphate, and 1,11-binaphthyl-2,2'-dihydrogen phosphate . A second most preferred homogeneous catalyst is methanesulfonic acid.

According to the invention, said heterogeneous catalyst or catalysts comprise at least one metal chosen from metals of groups 6 to 11 and metals of group 14 of the periodic table and a support chosen from oxides of elements chosen from aluminum, titanium, silicon, zirconium, cerium and niobium, alone or as a mixture, and the mixed oxides chosen from zinc, copper and cobalt aluminates, said oxides possibly being doped or not by at least one compound metal chosen from tungsten, tin, molybdenum and antimony, taken alone or as a mixture, crystallized aluminosilicates or not, aluminophosphates and amorphous or crystallized carbon compounds.

In the case where several heterogeneous catalysts are used in the process according to the invention, said catalysts may be identical or different.

Said metal chosen from the metals of groups 6 to 11 and the metals of group 14 of the periodic classification of the heterogeneous catalyst or catalysts according to the invention are preferably chosen from the following metals: Cr, Mo, W, Mn, Tc, Re , Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, and Hg, on the one hand, and among: Ge, Sn and Pb on the other hand, taken alone or mixed.

Preferably, said metal is chosen from metals Mo, W, Re, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, on the one hand and Sn, on the other hand, taken alone and as a mixture . Very preferably, said metal is selected from metals Ru, Ir, Ni, Pd, Pt, on the one hand and Sn, on the other hand, taken alone and in admixture. Even more preferably, said metal is selected from metals Ni, Pt, on the one hand and Sn, on the other hand, taken alone and mixed. According to a preferred embodiment, the following metal mixtures are preferred: NiSn, RePt, FePt, SnPt, CuPt, IrPt, CoPt, RhPt, OsPt, RuRe, PdRe, RuSn and RuPt and even more preferably, the mixtures of following metals: NiSn, RePt, RuRe and RuPt. According to a very preferred embodiment, said metal is platinum. In the case where the metal M of said one or more heterogeneous catalysts is chosen from the following noble metals: Ru, Os, Rh, Pd, Pt, Ag, Au, the content of noble metal on said heterogeneous catalyst or catalysts is advantageously between 0.degree. , 1% and 10% by weight and preferably between 0.1% and 5% by weight relative to the total mass of said heterogeneous catalyst (s).

In the case where the metal M of said one or more heterogeneous catalysts is chosen from non-noble metals, the content of non-noble metal on said heterogeneous catalyst (s) is advantageously between 0.1% and 40% by weight and preferably between 0% and 40% by weight. , 1% and 30% by weight relative to the total mass of said one or more heterogeneous catalysts.

The metal (s) of the heterogeneous catalyst (s) according to the invention are advantageously deposited on a support.

According to the invention, said heterogeneous catalyst or catalysts comprise a support chosen from oxides of the elements chosen from alumina, titanium, silica, zirconium, cerium, niobium, alone or as a mixture, and mixed oxides. chosen from zinc, copper and cobalt aluminates, said oxides possibly being doped with at least one metal compound chosen from among tungsten, tin, molybdenum and antimony, taken alone or as a mixture, aluminosilicates crystallized or not, aluminophosphates and amorphous or crystallized carbon compounds. Preferably, the crystallized aluminosilicates or not are selected from zeolites and mesostructured solids. Preferably, the amorphous or crystallized carbon compounds are chosen from active carbons, carbon blacks, carbon nanotubes, mesostructured carbons and carbon fibers. In the case where said support is chosen from doped oxides, elements selected from aluminum, titanium, silicon, zirconium, cerium, niobium, alone or as a mixture, a metallic element preferably selected from the group consisting of tungsten, tin, antimony and molybdenum, alone or in mixture, is advantageously added to said support. Preferably, the content of metal element chosen from tungsten, tin, antimony and molybdenum alone or as a mixture is advantageously between 0.1% and 30% by weight and preferably between 1 and 20% by weight. relative to the total mass of said support. Said support is preferably hydrothermally stable, ie stable under conditions combining water and temperature. Thus, the support may undergo a treatment step to improve its stability in the hydrothermal conditions of the reaction. For example, surface passivation, carbon film deposition, oxide deposition may be mentioned.

The deposition of the metal (s) chosen from groups 6 to 11 and the metals of group 14 of the periodic table on said support of the heterogeneous catalyst (s) according to the invention generally involves a precursor of the metal (s). For example, it may be metal organic complexes, metal salts such as metal chlorides, metal nitrates, metal carbonates. The introduction of the metal or metals may advantageously be carried out by any technique known to those skilled in the art such as ion exchange, dry impregnation, excess impregnation, vapor deposition, etc. The introduction of metal can be carried out before or after the shaping of the support The step of introducing the metal or metals can advantageously be followed by a heat treatment step. The heat treatment is advantageously carried out between 300 ° C. and 700 ° C. under an oxygen or air atmosphere. Lw: pe heat treatment can be followed by a temperature reduction treatment. The reducing heat treatment is advantageously carried out at a temperature of between 200 ° C. and 600 ° C. under a stream or atmosphere of hydrogen. Preferably, said one or more heterogeneous catalysts also undergo an in situ reduction step, that is to say in the reactor where the reaction takes place, before the introduction of the reaction charge. Said reduction step may also advantageously be carried out ex-situ. The heterogeneous catalyst (s) used in the present invention may be in the form of powder, extrudates, beads or pellets. The shaping can be carried out before or after the introduction of the metal.

The heterogeneous catalyst (s) used in the present invention are characterized by techniques known to those skilled in the art. For example, in order to characterize the metallic phase, transmission microscopy is mentioned.

Transformation Process According to the invention, the process for transforming the feed selected from lignocellulosic biomass and carbohydrates, alone or as a mixture, is carried out in a reaction vessel in the presence of at least one solvent, said the solvent being water alone or mixed with at least one other solvent, under a reducing atmosphere, and at a temperature of between 50 ° C. and 300 ° C., and at a pressure of between 0.5 MPa and 20 MPa. The process is therefore carried out in a reaction vessel comprising at least one solvent and wherein said feedstock is placed in the presence of the catalytic system according to the invention. According to the invention, the process according to the invention operates in the presence of at least one solvent, said solvent being water alone or mixed with at least one other solvent. According to a preferred embodiment, the process according to the invention operates in the presence of water in a mixture with at least one alcohol or at least one organic solvent, under sub- or supercritical conditions. The alcohols are advantageously chosen from methanol, ethanol and propanols. The organic solvents may advantageously be chosen from tetrahydrofuran and ethyl acetate. In the case where said method according to the invention operates in the presence of water in admixture with at least one other solvent, the solvent mixture comprises a mass content of water greater than 5% by weight and preferably greater than 30% and very preferably greater than 50% relative to the total mass of said mixture. According to another embodiment, the process according to the invention operates only in the presence of water. Preferably, the process according to the invention operates in the presence of at least one solvent with the exception of the solvents chosen from ionic liquids. According to the invention, the process for converting said filler is carried out under a reducing atmosphere, preferably under a hydrogen atmosphere. Hydrogen can be used pure or as a mixture.

Preferably, said method according to the invention operates at a temperature between 50 ° C and 250 ° C and preferably between 80 ° C and 250 ° C, and at a pressure between 2 MPa and 10 MPa.

Generally the method can be operated according to different embodiments. Thus, the process can advantageously be carried out batchwise or continuously, for example in a fixed bed. It can be carried out in a closed reaction chamber or in a semi-open reactor.

Said homogeneous catalysts are advantageously introduced into the reaction chamber in an amount corresponding to a homogeneous charge / catalyst mass ratio of between 1.5 and 1000, preferably between 5 and 1000, and preferably between 10 and 500. The heterogeneous catalyst (s) are introduced into the reaction chamber in an amount corresponding to a heterogeneous charge / catalyst mass ratio (s) of between 1 and 1000, preferably between 1 and 500, preferably between 1 and 100, preferably between 1 and 50 and more preferably between 1 and 25. The heterogeneous catalyst (s) introduced into the reactor can undergo a reducing heat treatment step beforehand. the introduction of the reaction charge. The reducing heat treatment is preferably carried out at a temperature between 150 ° C and 600 ° C under a stream or hydrogen atmosphere. The feedstock is introduced into the process in an amount corresponding to a mass ratio solvent / feed of between 1 and 1000, preferably between 1 and 500 and more preferably between 5 and 100. If a process is selected continuous, the hourly mass velocity (mass load flow / mass of heterogeneous catalyst (s)) is between 0.01 and 5 h -1, preferably between 0.02 and 2 h -1.

The products obtained and their mode of analysis The products of the reaction of the transformation process according to the invention are mono- or polyoxygenated compounds. Said mono- or polyoxygenated compounds are soluble in water.

Said mono- or polyoxygenated compounds are advantageously constituted by monosaccharides and their derivatives, oligosaccharides, and also soluble polymers advantageously formed by successive combinations of the monosaccharide derivatives.

By monosaccharide is meant a carbohydrate composition C, H2.0, where n is greater than 2, obtained by total hydrolysis of cellulose, or hemicellulose, or starch. Monosaccharides are simple sugars that are produced by complete depolymerization of cellulose and / or hemicellulose, such as, in particular, glucose, galactose, mannose, xylose, fructose, etc.

Derivatives of monosaccharides and oligosaccharides denote products which can be obtained for example by dehydration, isomerization, reduction or oxidation: sugar sugars, alcohols and polyols: in particular cellobitol, sorbitol, anhydrosorbitol, hexanetetrol , hexanetriols, hexanediols, xylitol, pentanetetrols, pentanetriols, pentanediols, erythritol, butanetriols, butanediols, glycerol, 1,3-propanediol, propylene glycol, ethylene glycol, hexanols , pentanols, butanols, propanols, ethanol ... - monocetones, polyketones: hydroxyacetone, 2,5-hexanedione ... - carboxylic acids and their esters, lactones: the acid formic acid, alkyl formates, acetic acid, alkyl acetates, hexanoic acid, alkyl hexanoates, levulinic acid, alkyl levulinates, lactic acid, lactates and the like. alkyls, glutaric acid , alkyl glutarates, 3-hydroxypropanoic acid, 3-hydroxybutyrolactone, rbutyrolactone, γ-valerolactone - cyclic ethers: for example tetrahydrofuran (THF), 3-methyltetrahydrofuran (Me-THF) and its isomers of position, 2,4-dimethyltetrahydrofuran and its positional isomers, tetrahydropyran-2-methanol and its positional isomers. furans: furan-2,5-dicarboxylic acid, 5- (hydroxymethyl) furfural acid, furfural ...

Soluble polymers are all products resulting from the condensation between monosaccharides, oligosaccharides and / or monosaccharide derivatives. At the end of the reaction, the reaction medium is removed and centrifuged. The reaction liquid is then analyzed by high pressure liquid chromatography (HPLC) using refractometry to determine the conversion product content of the aqueous solution. The amount of water-soluble reaction products (monosaccharides and derivatives, oligosaccharides, soluble polymers) is determined by TOC (Total Organic Carbon) analysis, which consists of measuring carbon in solution. The amount of monosaccharides and their derivatives is determined by HPLC analyzes. EXAMPLES In the examples below, the tungsten zirconia catalyst (ZrO 2 -WOx) is commercially available from MEL Chemicals and contains 10.3% tungsten by weight. The simple oxide supports ZrO2, TiO2 and CeO2 and the mixed oxide support ZrO2-CeO2 are commercial.

The supports S1 (CeO2-WOx) and S2 (ZrO2-CeO2-WOx) are prepared by dry impregnation of a solution of ammonium metatungstate (NE14) 4H2W12040 followed by calcination in dry air at 550 ° C. for 3 hours. . The mass content of tungsten measured by X-ray fluorescence is 8.3% by weight relative to the weight of the support for S1 and 8.5% by weight relative to the weight of the support for S2.

The cerium chloride heptahydrate CeC13.7H20 constituting the homogeneous catalyst is commercial and used without purification.

EXAMPLE 1 Preparation of heterogeneous catalysts C1, C2, C3, C4, C5, C6 and C7 comprising 0.5% by weight Pt on a support containing an oxide, doped or not, or a mixed oxide, doped or not. An aqueous solution of hexachloroplatinic acid H 2 PtCl 6 .xH 2 O at 1.9% by weight (25 ml, 0.475 g) is added at ambient temperature to the oxide support (24 g) previously desorbed under vacuum (1 h, 100 ° C.). The mixture is stirred for one hour and then evaporated. The solid obtained is then dried in an oven at 110 ° C. for 24 hours. The solid is calcined under a dry nitrogen flow rate at a temperature of 150 ° C. for 1 hour, then at 250 ° C. for 1 hour, then at 350 ° C. for 3 hours and finally at 420 ° C. for 4 hours. It is then reduced under hydrogen flow at 500 ° C for two hours. The heterogeneous catalysts obtained contain 0.5% by weight of platinum relative to the total weight of said catalysts. The formulations of the catalysts prepared are summarized in Table 1.

Table 1: Formulation of C1 to C7 heterogeneous catalysts NOM Composition Cl 0.5% Pt / Zr02 C2 0.5% Pt / Zr02-W0x C3 0.5% Pt / Ce02 C4 0.5% Pt / Ce02-W0x C5 0.5% Pt / TiO2 C6 0.5% Pt / Ce02-ZrO2 C7 0.5% Pt / Ce02 EXAMPLE 2 Transformation of the Cellulose Using the Catalysts C1, C2, C3 C4 C5 C6 and C7 in Combination with the Homogeneous Catalyst Example 2 relates to the conversion of cellulose from a combination of a heterogeneous catalyst Cl to C7 described in Example 1 and a homogeneous catalyst consisting of a metal salt CeC13.7H20 for the production of mono- and polyoxygenated products.

In a 100mL autoclave, 50mL of water, 1.3g of SigmaCelle cellulose, 26mg of CeC13.7H2O and 0.55g of heterogeneous catalyst are introduced under a nitrogen atmosphere. The metal salt is soluble in water at T = 25 ° C and atmospheric P = P. The homogeneous catalyst CeC13.7H20 is introduced into the reaction chamber in an amount corresponding to a mass ratio filler / CeC13.7H20 = 50. The heterogeneous catalysts are introduced into the reaction chamber in an amount corresponding to one heterogeneous charge / catalyst mass ratio = 2.5.

The feedstock is introduced into the autoclave in an amount corresponding to a mass ratio of solvent / feedstock = 38. The autoclave is heated to 230.degree. C. and a pressure of 5 MPa of hydrogen is introduced. After 12h reaction, the reaction medium is removed and centrifuged. Samples are also taken during the test and analyzed by high pressure liquid chromatography (HPLC) using refractometry to determine the content of conversion products of the aqueous solution. The results obtained are listed in Table 2 Table 2: Solubilization of cellulose and formation of humins Catalysts Nature Conversion at 12h (%) Formation of humines Without catalyst Without catalyst 50 Humines Cl + CeC13.7H20 5 ° oPt / ZrO2 65 Pas of humins 0. + CeC13.7H2O C2 + CeC13.7H20 0.5 ° oPt / Zr02-WO x + CeC13.7H20 55 No humins C3 + CeC13.7H20 0. + 87 No humins 0.5% Pt / CeO2 CeC13 .7H20 C4 + CeC13.7H20 0.5 ° oPt / Ce02-W03 + CeC13.7H20 65 No humins C5 + CeC13.7H20 5 ° oPt / TiO2 75 No humins 0. + CeC13.7H20 C6 + CeC13.7H20 0.5 ° oPt / Ce02-Zr02 + CeC13.7H20 85 No humins 07 + CeC13.7H20 0.5 ° / oPt / Ce02- 63 No humines ZrO2-W0x + CeC13.7H20 The use of a combination of a catalyst homogeneous CeC13.7H20 and a heterogeneous catalyst C1 to C7 makes it possible to increase the conversion of the feed from 50% to 55% for the catalyst C2, from 50% to 63% and 65% for the catalysts C7, C4 and Cl and from 50% to 75% and 85% and 87% for catalysts C5, C6 and C3. The simultaneous use of a homogeneous catalyst chosen from metal salts in which the metal M is chosen from lanthanides and a heterogeneous catalyst, in the same reaction chamber also makes it possible to reduce the content of non-recoverable products, such as humins. unlike the test carried out in the absence of heterogeneous catalyst. Example 3 Transformation of the Cellulose Using the Catalyst C3 in Combination with the Homogeneous CeC13.7H O Catalyst Under Variable Operating Conditions Example 3 relates to the conversion of cellulose from a combination of a heterogeneous catalyst C3 0.5% Pt / CeO2 described in Example 1 and a homogeneous catalyst consisting of a metal salt CeC13.7H20 for the production of mono- and polyoxygenated products. In a 100mL autoclave, 50mL of water, 1.3g of SigmaCelle cellulose, 26mg of CeC13.7H20 and 0.55g of heterogeneous catalyst C3 are introduced under a nitrogen atmosphere. The metal salt is soluble in water at T = 25 ° This atmospheric P = P.

The homogeneous catalyst CeC13.7H20 is introduced into the reaction chamber in an amount corresponding to a mass ratio filler / CeC13.7H20 = 50. The heterogeneous catalysts are introduced into the reaction chamber in an amount corresponding to one heterogeneous charge / catalyst mass ratio = 2.5.

The feedstock is introduced into the autoclave in an amount corresponding to a mass ratio solvent / feed = 38. The autoclave is heated to a temperature T between 190 ° C and 250 ° C and a pressure P varying between 2 MPa and 1 MPa of hydrogen is introduced. After 6 hours of reaction, the reaction medium is removed and centrifuged. Samples are also taken during the test and analyzed by high pressure liquid chromatography (HPLC) using refractometry to determine the content of conversion products of the aqueous solution.

The results obtained are listed in Table 3. Table 3: Cellulose conversion and formation of humins Temperature Pressure Conversion at 6h Conversion at 12h Formation (° C) (bar) (%) (%) of humines 190 50 18 30 No humines 210 50 40 67 No humines 230 50 88 91 No humines 240 50 89 85 No humines 250 50 82 77 No humines 230 80 82 88 No humines The increase in temperature heating from 190 to 210 and 230 ° C makes it possible to increase the conversion of cellulose from 30% after 12 hours to 67% and 91%, respectively, after 12 hours, in the presence of the homogeneous catalyst CeC13.7H20 and the heterogeneous catalyst C1 . This increase is not accompanied by the formation of humins. The use of more severe operating conditions at 240 ° C. and 250 ° C. with a hydroelectric pressure of 50 bar, or at 230 ° C. with 80 bar of hydrogen also makes it possible to overcome the formation of humins, while maintaining high cellulose conversion values. Example 4 Transformation of the Cellulose Using the Catalyst C3 in Combination with the Homogeneous Catalyst ErCl3.6H 0

Example 4 relates to the conversion of cellulose from a combination of a heterogeneous catalyst C3 0.5 ° / oPt / CeO2 described in Example 1 and a homogeneous catalyst consisting of a metal salt ErC13.6H20 for the production of mono- and polyoxygenated products. In a 100mL autoclave, 50mL of water, 1.3g of SigmaCell® cellulose, 26mg of ErC13.6H20 and 0.55g of heterogeneous catalyst C3 are introduced under a nitrogen atmosphere.

The metal salt is soluble in water at T = 25 ° This atmospheric P = P. The homogeneous ErC13.6H20 catalyst is introduced into the reaction chamber in an amount corresponding to a mass ratio filler / ErC13.6H20 = 50. The heterogeneous catalysts are introduced into the reaction vessel in an amount corresponding to one. heterogeneous charge / catalyst mass ratio = 2.5. The feedstock is introduced into the autoclave in an amount corresponding to a mass ratio solvent / feed = 38.

The autoclave is heated to 230 ° C. and a pressure of 5 MPa of hydrogen is introduced. After 12h reaction, the reaction medium is removed and centrifuged. Samples are also taken during the test and analyzed by high pressure liquid chromatography (HPLC) using refractometry to determine the content of conversion products of the aqueous solution.

The results obtained are given in Table 4. Table 4: Cellulose conversion and formation of humins Catalysts Conversion at 12 hrs Formation of humins (0/0) ErC13.6H20 50 Humids 0.5 ° / oPt / Ce02 (C3) 80 Pas of humines + ErC13.6H20 The simultaneous use of a homogeneous catalyst chosen from metal salts in which the metal M is chosen from lanthanides and a heterogeneous catalyst, in the same reaction chamber makes it possible to significantly reduce the content of non-recoverable products, such as humins compared to the test carried out in the absence of heterogeneous catalyst. Example 5 Transformation of Glucose Using Catalyst C3 in Combination with Homogeneous Catalyst Example 5 relates to the conversion of cellulose from a combination of a heterogeneous C3 catalyst described in Example 1 and a homogeneous catalyst consisting of a CeC13.7H20 metal salt for the production of mono- and polyoxygenated products. In a 100mL autoclave, 50mL of water, 1.3g of SigmaCelle cellulose, 26mg of CeC13.7H20 and 0.55g of heterogeneous catalyst C3 are introduced under a nitrogen atmosphere. The metal salt is soluble in water at T = 25 ° This atmospheric P = P. The homogeneous catalyst CeC13.7H20 is introduced into the reaction chamber in an amount corresponding to a mass ratio filler / CeC13.7H20 = 50. The heterogeneous catalysts are introduced into the reaction chamber in an amount corresponding to one heterogeneous charge / catalyst mass ratio = 2.5.

The feedstock is introduced into the autoclave in an amount corresponding to a mass ratio of solvent / feedstock = 38. The autoclave is heated to 230.degree. C. and a pressure of 5 MPa of hydrogen is introduced. After 12h reaction, the reaction medium is removed and centrifuged. Samples are also taken during the test and analyzed by high pressure liquid chromatography (HPLC) using refractometry to determine the content of conversion products of the aqueous solution. The results obtained are listed in Table 5.30 Table 5: Conversion of glucose and formation of humins Catalysts Conversion at 12h Formation of humins (0/0) CeC13.7H20 50 Humids 0.5% Pt / Ce02 (C3) 80 No humines + CeC13.7H20 The simultaneous use of a homogeneous catalyst chosen from metal salts in which the metal M is chosen from lanthanides and a heterogeneous catalyst, in the same reaction chamber containing a saccharide type filler makes it possible to reduce significant content of non-recoverable products, such as humins compared to the test carried out in the absence of heterogeneous catalyst.

EXAMPLE 6 Preparation of the C8 Heterogeneous Catalyst Comprising 10% by Weight Ni on a CeO 2 Support An aqueous solution of nickel nitrate hexahydrate Ni (NO 3) 2.6H 2 O at 15% by weight (50 mL, 7.4 g) is added at ambient temperature to Cerium oxide support CeO 2 (14 g) previously desorbed under vacuum (1 h, 100 ° C.). The mixture is stirred for one hour and then evaporated. The solid obtained is then dried in an oven at 110 ° C. for 24 hours. The solid is calcined under a dry nitrogen flow rate at a temperature of 150 ° C. for 1 hour, then at 250 ° C. for 1 hour, then at 350 ° C. for 3 hours and finally at 420 ° C. for 4 hours. It is then reduced under hydrogen flow at 500 ° C for two hours.

The heterogeneous catalysts obtained contain 10% by weight of nickel relative to the total mass of said catalysts. The formulation of the prepared catalyst is summarized in Table 6.

Table 6: Formulation of the C8 heterogeneous catalyst. Catalyst C8 Composition 10% Ni / CeO2 Example 7: Transformation of the Cellulose Using Catalyst C8 in Combination with CeCI3.7H O Homogeneous Catalyst Example 7 relates to the conversion of cellulose from a combination of a heterogeneous catalyst C8 described in Example 6 and a homogeneous catalyst consisting of a metal salt CeC13.7H20 for the production of mono- and polyoxygenated products. In a 100mL autoclave, 50mL of water, 1.3g of SigmaCelle cellulose, 26mg of CeC13.7H20 and 0.55g of heterogeneous C8 catalyst are introduced under a nitrogen atmosphere.

The metal salt is soluble in water at T = 25 ° This atmospheric P = P. The homogeneous catalyst CeC13.7H20 is introduced into the reaction chamber in an amount corresponding to a mass ratio filler / CeC13.7H20 = 50. The heterogeneous catalysts are introduced into the reaction chamber in an amount corresponding to one heterogeneous charge / catalyst mass ratio = 2.5. The feedstock is introduced into the autoclave in an amount corresponding to a mass ratio solvent / feed = 38.

The autoclave is heated to 230 ° C. and a pressure of 5 MPa of hydrogen is introduced. After 12h reaction, the reaction medium is removed and centrifuged. Samples are also taken during the test and analyzed by high pressure liquid chromatography (HPLC) using refractometry to determine the content of conversion products of the aqueous solution.

The results obtained are given in Table 7. Table 7: Cellulose conversion and humin formation Nature Conversion at 12 o'clock Formation of humins (o / o) CeC13.7H20 50 Humids 10 ° / oNi / CeO2 (C8) + 75 No humins CeC13.7H20 The simultaneous use of a homogeneous catalyst selected from metal salts in which the metal M is chosen from lanthanides with the exception of the element La, and a heterogeneous catalyst containing nickel , in the same reaction chamber containing a charge of polysaccharide type significantly reduces the content of non-recoverable products, such as humins unlike the test performed in the absence of heterogeneous catalyst.

Claims (15)

REVENDICATIONS1. A process for converting a filler selected from lignocellulosic biomass and carbohydrates, alone or in admixture, to mono- or polyoxygenated compounds, wherein said filler is contacted simultaneously with a combination of one or more catalysts (s) homogenous (s) and one or more heterogeneous catalysts, in the same reaction chamber, in the presence of at least one solvent, said solvent being water alone or in admixture with at least one other solvent, under reducing atmosphere, and at a temperature between 50 ° C and 300 ° C, and at a pressure between 0.5 MPa and 20 MPa, wherein - said homogeneous catalyst (s) being selected of the metal salts, hydrated or not, having the general formula M, Xn.n'H 2 O wherein the metal M is a lanthanide selected from Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er , Tm, Yb and Lu, m is an integer between 1 and 10, n is an integer between 1 and 10 and n 'is a number between 0 and 20 and X is at least one anion selected from halides, nitrates, carboxylates, halocarboxylates, acetylacetonates, hydroxides, alkoxides, phenolates, substituted or no, sulphates, alkyl sulphates, phosphates, alkyl phosphates, halosulfonates, alkylsulphonates, perhaloalkylsulphonates, bis (perhaloalkylsulphonyl) amides, arenesulphonates, substituted or unsubstituted by halogen or haloalkyl groups, said anions X being identical or different in the case where n is greater than 1, - said at least one heterogeneous catalyst (s) comprising at least one metal chosen from metals of groups 6 to 11 and metals of group 14 of the periodic table and a support selected from the oxides of the elements chosen from among aluminum, titanium, silicon, zirconium, cerium and niobium, alone or as a mixture, and the mixed oxides chosen from zinc, copper and cobalt aluminates, said oxides possibly being doped with or not by at least one metal compound chosen from tungsten, tin, molybdenum and antimony, taken alone or in combination with mixture, crystallized aluminosilicates or not, aluminophosphates and amorphous or crystallized carbon compounds. 2. Method according to claim 1 wherein the metal M or said homogeneous catalyst (s) chosen (s) among the metal salts hydrated or not, is selected from the following metals: Ce, Pr, Nd, Pm, Sm, Gd, Eu, Er, Tm, Yb. 3. Method according to one of claims 1 or 2 wherein the metal M or said homogeneous catalyst (s) selected (s) among the metal salts hydrated or not, is selected from the following metals: Ce, Pr , Nd, Sm, Eu, Gd, Er, Yb. 4. Method according to one of claims 1 to 3 wherein the anion X of the first catalyst is at least one anion selected from halides, alkylsulfonates, perhaloalkylsulfonate, bis (perhaloalkylsulfonyl) amides. 5. Method according to one of claims 1 to 4 wherein at least a second homogeneous catalyst selected (s) among the organic or inorganic Bronsted acids is added simultaneously in said same reaction chamber. The process according to claim 5 wherein the inorganic Bronsted acids are selected from the following inorganic acids: HF, HCl, HBr, HI, H2SO3, H2SO4, H3PO2, H3PO4, HNO2, HNO3, H2W04, H4SiW12O40, H3PW12040, (NH4) ) (W12O40) .xH2O, (NH4) 6Mo7O24.xH2O, H3B03, HCIO4, HBF4, HSbF5, HPF6, H2FO3P, CISO3H, FSO3H, HN (SO2F) 2 and HI03. 7. The method of claim 6 wherein the second homogeneous catalyst is hydrochloric acid (HCI). 25 8. Method according to one of claims 1 to 5 wherein the organic Bronsted acids are selected from organic acids of general formulas R-COOH, RSO2H, RSO3H, (RSO2) NH, (R0) 2PO21-1, ROH where R is a hydrogen or a carbon chain composed of alkyl or aryl groups, substituted or not by heteroatoms. 9. Method according to one of claims 1 to 8 wherein the metal of the heterogeneous catalyst or catalysts is selected from metals Mo, W, Re, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, d one part and Sn, on the other hand, taken alone and mixed. 10. Method according to one of claims 1 to 9 wherein the homogeneous catalysts are introduced into the reaction chamber in an amount corresponding to a mass ratio filler / catalyst (s) homogeneous (s) between 1.5 and 1000. 11. Method according to one of claims 1 to 10 wherein, in the case where said method operates in the presence of water in a mixture with at least one other solvent, the solvent mixture comprises a mass content of water greater than 5%. weight and preferably greater than 30% and very preferably greater than 50% relative to the total mass of said mixture. 12. Method according to one of claims 1 to 10 wherein said process operates only in the presence of water. 13. Method according to one of claims 1 to 12 wherein the process operates in the presence of at least one solvent with the exception of the solvents selected from ionic liquids. 14. Method according to one of the preceding claims wherein the reducing atmosphere is an atmosphere of hydrogen, pure or in mixture. 15. Method according to one of the preceding claims operating at a temperature between 80 ° C and 250 ° C, and a contiguous pressure between 2 MPa and 10 MPa.25