Process for producing an aldehyde by hydroformylation in the presence of porous catalytic capsules

Abstract

Hydroformylation process by reaction between at least one alkene and a gaseous mixture comprising at least carbon monoxide and dihydrogen in the presence of porous catalytic capsules dispersed in at least one organic liquid phase L1. Said porous catalytic capsules, formed from a Pickering emulsion, consist of a liquid core comprising at least one liquid phase L2 comprising at least said hydroformylation catalyst and a porous crust formed by solid particles crosslinked by a crosslinking agent.

Description

Title of the invention: Process for producing an aldehyde by hydroformylation in the presence of porous catalytic capsules technical field

[0001] The present invention relates to the field of manufacturing aldehydes, large reaction intermediates for the manufacture in particular of alcohols, esters, acids, amines in the field of solvents and plasticizers from an alkene and a gaseous mixture comprising carbon monoxide and dihydrogen in the presence of a catalyst in the form of porous catalytic capsules. State of the art

[0002] The hydroformylation of olefinic compounds is a reaction of great importance industrially. Most processes use catalysts which are dissolved in an organic phase consisting of reactants, products and possibly an excess of ligands, so that difficulties are encountered in separating and recovering the catalyst, especially when it is a noble metal such as rhodium.

[0003] Various solutions have been proposed for solubilizing the catalyst in perfluoroalkanes, in ionic liquids or in water, consisting essentially of using either fluorinated phosphines or ionic phosphines or water-soluble phosphines.

[0004] Horvath et al. (Science, 1994, 266, 72-75) describe the hydroformylation of a C10 olefin in toluene solution, catalyzed by a rhodium complex dissolved in C6FnCF3 and in the presence of P{CH2CH2(CF2)5CF3}3. In this process, the catalyst is easily recyclable because it is located in the perfluorinated phase, while the aldehyde is located in the toluene phase, which is immiscible with the former.

[0005] EP patent 0 776 880 describes the implementation of the hydroformylation reaction with a catalyst, in particular one based on cobalt or rhodium, in a liquid non-aqueous ionic solvent at the reaction temperature. Since the reaction products are only slightly soluble or insoluble in the ionic solvent, recycling the catalyst is facilitated.

[0006] The use of a two-phase water-organic phase system is described in French patent FR 2,314,910. This is the only two-phase system used on an industrial scale. It consists of carrying out the hydroformylation reaction in the presence of an aqueous solution containing a rhodium complex, which is rendered water-soluble by the presence of a water-soluble sulfonated phosphine ligand, such as the sodium salt of triphenylphosphine trisulfonate, commonly known as TPPTS. In this way, the organic phase containing the aldehydes is easily separated from the aqueous phase containing the catalyst. This technique has been the subject of a considerable number of work which has been discussed in the literature (Angewandte Chemie. International Edition English, 1993, 32, 1524-1544). Despite the great industrial interest of this technique for the hydroformylation of propylene, this two-phase system suffers from the lack of solubility of long olefins in water, which leads to relatively low reaction rates making any industrial application inconceivable for olefins with a solubility of less than 100 mg / L (Industrial & Engineering Chemistry Research, 1996, 35, 3927-3933).

[0007] Several studies have also aimed to increase the solubility of long olefins in aqueous solution so that they can be incorporated into an aqueous two-phase process. One solution proposed by Hablot et al. is to use a co-solvent such as acetonitrile, methanol, ethanol, acetone, etc. (Chemical Engineering Science, 1992, 47, 2689-2694). Another solution is the addition of a surfactant to the reaction medium containing the catalytic system, such as cetyltrimethylammonium bromide (Journal of Molecular Catalysis A: Chemical, 2002, 189, 195-202). In these processes, the introduction of a co-solvent or a surfactant complicates the industrial process for recycling the catalyst.

[0008] An alternative approach is to increase the exchange surface area between the organic phase containing the alkene to be reacted and the aqueous phase containing the catalyst by creating an emulsion. For example, Pogrzeba et al. (Industrial & Engineering Chemistry Research, 2017, 56, 9934-9941) propose stabilizing an emulsion using surfactants. The problem with this solution lies in the difficulty of breaking the emulsion to separate the phases and recover the catalyst. Zhao et al. (Journal of Catalysis, 2016, 334, 52-59) propose replacing the surfactants with hydrophobic silica nanoparticles, which stabilize the emulsion in the form of a Pickering emulsion.This technique makes it easier to separate the phases to recover the catalyst but does not allow for a continuous process, i.e. with a continuous supply of the alkene via the oil phase which is the continuous phase and the continuous extraction of the aldehyde in this same phase (Chang et al., Green Chemistry, 2021, 23, 2575-2594). Indeed, the hydroformylation reaction is carried out under pressure generally between 1 and 5 MPa (Applied Catalysis A: General, 2001, 221, 219-225) and it is known to those skilled in the art that at this pressure and with continuous phase circulation, a Pickering emulsion is destabilized (Chang et al., Green Chemistry, 2021, 23, 2575-2594; Zhang et al., JACS, 2019, 141, 5220-5230).

[0009] To maintain the exchange surface area between the oil and water phases under the process implementation conditions, Zhang X. et al. (New J Chem, 2019, 43, 14134) propose encapsulating the aqueous phase in porous capsules with an average diameter of approximately 100 nm, but the particularly small size of said capsules The capsules make it very difficult to separate them using techniques known to those skilled in the art to recover the catalyst. Object of the invention

[0010] The applicant has developed a process for manufacturing aldehydes by reacting an alkene with a gaseous mixture of carbon monoxide and dihydrogen in the presence of porous liquid-core capsules containing a catalyst for aldehyde synthesis. The alkene, contained in an organic liquid phase called the continuous phase, reacts with the carbon monoxide and dihydrogen in the liquid core of the capsules, which consists of a liquid phase comprising a transition metal compound selected from groups 8, 9, and 10 of the periodic table of elements. The aldehydes formed by the reaction are extracted from the continuous phase.

[0011] The present invention therefore offers the advantage of facilitating the separation of the continuous phase from the encapsulated metal compounds. This advantage is particularly important in the context of supply constraints on certain critical metals, such as cobalt, and due to the high cost of certain metals, such as rhodium.

[0012] Liquid-core capsules containing the metal compound are prepared from a Pickering emulsion, which has the advantage of allowing the capsule size to be adjusted to facilitate separation using techniques well-known to those skilled in the art, such as filtration, which is not suitable for very small capsule sizes. This method of preparing liquid-core capsules also has the advantage of using a sol-gel process, which allows control of the porous capsule shell properties (thickness and porosity) adapted to the implementation of the process, in particular to optimize the transfer of reagents and products through the porous shell.

[0013] The present invention also has the advantage of developing a large exchange surface area between the liquid phase containing the alkene to be reacted and the liquid phase containing the catalyst, without the use of surfactants that do not allow the separation of the catalyst and that can have an environmental impact. This large exchange surface area between the two liquid phases strongly promotes the reaction, even with olefins that are only slightly soluble in the aqueous phase, such as olefins with a long carbon chain whose water solubility is less than 100 mg / L. Furthermore, the liquid-core capsules have the advantage of acting as microreactors, thus promoting the reaction kinetics.

[0014] The use of liquid-core capsules according to the invention also eliminates the need for vigorous agitation, which is traditionally required to transfer a molecule between two liquid phases, thus reducing the energy demand of the process. They allow for an emulsion that remains stable after its creation. It is no longer necessary to supply energy to keep the two liquid phases in contact.

[0015] Finally, the process according to the present invention has the advantage of being able to be implemented continuously with continuous addition of alkene to the continuous phase and / or continuous withdrawal of the continuous phase to separate the reaction products. Such continuous implementation allows for productivity gains.

[0016] The present invention therefore has the advantage of implementing a process for manufacturing aldehyde from reagents that are very little soluble in water and of being able to easily recover the catalyst.

[0017] The present invention relates to a process for producing an aldehyde by hydroformylation between at least one alkene and a gaseous mixture comprising at least carbon monoxide and dihydrogen in the presence of a catalyst comprising at least the following steps:

[0018] 1) porous catalytic capsules dispersed in at least one phase are prepared organic L1 according to the following steps:

[0019] a. a mixture is emulsified comprising at least one liquid phase L2, immiscible in the organic phase L1, comprising at least one hydroformylation catalyst based on metal compounds selected from groups 8, 9 and 10 of the periodic table of elements, an organic phase L1 and solid particles in order to form a Pickering emulsion comprising droplets of said liquid phase L2 stabilized by the solid particles in the organic phase L1;

[0020] 1b. an agent is added to the Pickering emulsion obtained in step a) crosslinking to form porous catalytic capsules suspended in the organic phase L1; said porous catalytic capsules comprising a liquid core comprising at least said liquid phase L2 comprising at least said hydroformylation catalyst and a porous shell formed by the crosslinked solid particles;

[0021] 2) the hydroformylation reaction is carried out by adding at least one alkene and one gaseous mixture comprising at least carbon monoxide and dihydrogen in the organic phase Ll comprising at least said porous catalytic capsules to form at least one aldehyde;

[0022] 3) said aldehyde formed in step (2) is recovered in said organic phase LL

[0023] Advantageously, said alkene is a C2 to C18 alkene.

[0024] Preferably, said alkene is a C4 Cl8 alkene.

[0025] Advantageously, the metal compounds are chosen from cobalt or rhodium compounds.

[0026] Advantageously, said liquid phase L2 comprises at least water.

[0027] Advantageously, said liquid phase L2 comprises at least water with added acid or base.

[0028] Advantageously, said liquid phase L2 comprises at least one ionic liquid.

[0029] Advantageously, porous catalytic capsules have an average diameter in numbers ranging from 1 pm to 1000 pm.

[0030] Advantageously, the solid particles added in step a) are silica particles.

[0031] Advantageously, the crosslinking agent added in step 1b) is chosen from at least one silica precursor compound of the silicate or orthosilicate or silicic or orthosilicic or alkoxysilane type.

[0032] Advantageously, the mass ratio between the crosslinking agent and the solid particles is between 1 and 10.

[0033] Advantageously, the organic phase L1 comprises at least one or more saturated hydrocarbons selected from linear or cyclic alkanes, and / or one or more unsaturated hydrocarbons selected from olefins or aromatic compounds, alcohols and aldehydes.

[0034] Advantageously, the organic phase L1 comprises at least one or more organic compounds comprising between 3 and 20 atoms.

[0035] Advantageously, the organic phase L1 is constituted by said alkene.

[0036] Advantageously, the volume ratio between the liquid phase L2 and the organic liquid phase L1 is between 2:1 and 1:10. Detailed description of the invention

[0037] 1. Definitions

[0038] Emulsion:

[0039] An emulsion is a heterogeneous medium formed by the dispersion of one liquid (dispersed phase) in another liquid (continuous phase). Emulsions are generally stabilized by surfactants due to their amphiphilic properties.

[0040] Pickering emulsion:

[0041] Emulsions can also be stabilized with particles; this is called a Pickering emulsion.

[0042] Pickering emulsions are indeed liquid / liquid dispersions stabilized by nanoparticles or aggregates of solid nanoparticles that accumulate at the interface between the two immiscible liquids (generally water and oil) and prevent the coalescence of the dispersed droplets (see, for example, the publication Pickering, SU (1907). J. Chem. Soc. Trans. 91, 2001-2021). In fact, the particles used to make Pickering emulsions are capable of irreversibly adsorbing at the interface between the two liquids, causing stabilization The emulsion is much more effective than surfactant adsorption (see, for example, Aveyard, R., Binks, BP, and Clint, JH (2003); Adv. Colloid Interface Sci. 100, 503-546). The direction of the emulsion (water-in-oil or oil-in-water) is determined by the preferential wettability of the particles towards one or the other phase. In fact, the liquid with the highest wetting power towards the particles will constitute the continuous phase of the emulsion, and the one with the lowest wetting power will constitute the dispersed phase (see, for example, Binks, B., and Lumsdon, S. (2000). Langmuir 16, 8622-8631).

[0043] Pickering emulsions have the advantage of promoting the transfer of mass between the two liquid phases. Indeed, to ensure the transfer of a molecule between two liquid phases, it is necessary to create a large exchange surface between the two liquids.

[0044] Liquid-core capsules:

[0045] Pickering emulsions can also be strengthened, for example against a pressure drop, by encapsulating the emulsion. These are then referred to as liquid-core capsules.

[0046] This consolidation is achieved through encapsulation of the Pickering emulsion. However, unlike conventional encapsulations, where the envelope is airtight and the encapsulated substance is released only under certain conditions (a phenomenon called controlled release), here the envelope is porous in order to facilitate mass transfer between the continuous phase and the dispersed phase.

[0047] This can be done via the sol-gel process. An alkoxysilane (generally TEOS) solubilized in the continuous phase and water from the dispersed phase react at the interface of the emulsion droplets to form a silica shell. These capsules constitute porous inorganic microreactors that allow for continuous reactions, improved pressure resistance, and easier catalyst recovery. The reactants are introduced into the continuous phase and pass through the porous wall to come into contact with the catalyst. The products formed, being chosen for their lower soluble content in the dispersed phase, pass through the wall to migrate into the continuous phase. Thanks to the continuous extraction of products from the dispersed phase where the reaction takes place, an increase in activity and selectivity can be observed.

[0048] An “emulsifier” is a compound or substance that acts as a stabilizer for emulsions, preventing liquids from separating.

[0049] A "hydrophobic" molecule or part of a molecule is a molecule that is repelled by a mass of water and other polar substances.

[0050] A "hydrophilic" molecule or part of a molecule is a molecule that tends to interact with or be dissolved by water and other polar substances.

[0051] “Amphiphile” is a term describing a chemical compound comprising both hydrophilic and hydrophobic properties.

[0052] Particle and droplet sizes:

[0053] Particle size: The solid particles according to the invention can be of various shapes and sizes, for example from a few nanometers to a few microns, or even tens of microns, in the form of substantially spherical or non-spherical beads (FB de Carvalho-Guimarães, K Leal Correa, T Pereira de Souza, JR Rodriguez Amado, RM Ribeiro-Costa and JO Carréra Silva-Junior (2022) A Review of Pickering Emulsions: Perspectives and Applications, Pharmaceuticals, 15, 1413. https: / / doi.org / 10.3390 / phl5111413). The shape can be substantially spherical, or in the form of a rod, ellipsoid, needle, spindle, nanofibril, nanocage, plate, nanotube, nanocube, etc. (Li W, Jiao B, Li S, Faisal S, Shi A, Fu W, Chen Y and Wang Q (2022) Recent Advances on Pickering Emulsions Stabilized by Diverse Edible Particles: Stability Mechanism and Applications. Front. Nutr. 9:864943. doi: 10.3389 / fnut.2022.864943).The size can vary enormously, from a few nanometers to a few tens of microns. The size obviously depends on the morphology of the particles involved. It is generally determined by scanning and transmission electron microscopy analyses. It is easy to define for spherical particles (diameter), and more difficult for particles whose shape deviates from sphericity (plates, rods, ellipsoids, needles, etc.). In these cases, two characteristic sizes are usually specified: the smallest and the longest. Another difficulty is related to the spontaneous formation of aggregates between elementary particles. A distinction is then made between the size of the elementary particles and the size of the aggregates. For example, the commercial silica Aerosil R972 is a mixture of elementary particles between 5 nm and 50 nm with aggregates of average size on the order of 250 nm.

[0054] Droplet size: Droplet size means the largest dimension of the droplets measured by optical microscopy (in particular by Olympus BX51 with analysIS software for image analysis).

[0055] Characterization of the porous structure of the envelope:

[0056] The porous structure of the envelope can be analyzed by nitrogen porosimetry (Micromeritics ASAP 2420) to determine, in particular, the BET surface area and the pore volume. The size distribution of the mesopores can be obtained by applying the B JH method in the case of a type IV isotherm.

[0057] Characterization of crust thickness:

[0058] The thickness of the crust can be obtained by observation in scanning electron microscopy and image analysis of the images obtained (SEM, ZEISS Supra 40 device). 1. Detailed description

[0059] The present invention relates to a process for producing an aldehyde by hydroformylation between at least one alkene and a gaseous mixture comprising at least carbon monoxide and dihydrogen in the presence of a catalyst comprising at least the following steps:

[0060] 1) porous catalytic capsules dispersed in at least one phase are prepared organic L1 according to the following steps:

[0061] a. a mixture is emulsified comprising at least one liquid phase L2, immiscible in the organic phase L1, comprising at least one hydroformylation catalyst based on metal compounds selected from groups 8, 9 and 10, an organic phase L1 and solid particles in order to form a Pickering emulsion comprising droplets of said liquid phase L2 stabilized by the solid particles in the organic phase L1;

[0062] 1b. an agent is added to the Pickering emulsion obtained in step a) crosslinking to form porous catalytic capsules suspended in the organic phase L1; said porous catalytic capsules comprising a liquid core comprising at least said liquid phase L2 comprising at least said hydroformylation catalyst and a porous shell formed by the crosslinked solid particles;

[0063] 2) the hydroformylation reaction is carried out by adding at least one alkene and one gaseous mixture comprising at least carbon monoxide and dihydrogen in the organic phase Ll comprising at least said porous catalytic capsules to form at least one aldehyde;

[0064] 3) said aldehyde formed in step (2) is recovered in said organic phase LL

[0065] Step 1) porous catalytic capsules dispersed in an organic LL phase are prepared

[0066] The porous catalytic capsules are prepared by going through an intermediate step of forming a so-called Pickering emulsion (step 1a). Instead of using the droplets of solution L2 containing the catalyst surrounded by solid particles as is, the invention creates an envelope from these solid particles arranged around the droplets. Thus encapsulated, the droplets are more stable, easier to recycle and implement, and can also withstand higher pressure. The porous catalytic capsules formed from a Pickering emulsion therefore make it possible to confine the hydroformylation catalyst within the liquid core (called the dispersed phase). The porous envelope of the capsules will serve for the exchange of reactants and products. These capsules formed from a Pickering emulsion have a large contact surface between the alkene and the capsules. including the hydroformylation catalyst and allows the use of alkenes that are poorly soluble in water.

[0067] The manufacture of porous catalytic capsules comprises at least the following steps:

[0068] a. a mixture is emulsified comprising at least one liquid phase L2 immiscible in the organic phase L1 comprising at least one hydroformylation catalyst based on metal compounds selected from groups 8, 9 and 10 according to the periodic table of elements, an organic phase L1 and solid particles in order to form a Pickering emulsion comprising droplets of said liquid phase L2 stabilized by the solid particles in the organic phase L1;

[0069] 1b. an agent is added to the Pickering emulsion obtained in step a) crosslinking to form porous catalytic capsules suspended in the organic phase L1; said porous catalytic capsules comprising at least a liquid core comprising at least said liquid phase L2 comprising at least said hydroformylation catalyst and a porous shell formed by said crosslinked solid particles;

[0070] Step a) preparation of the Pickering emulsion.

[0071] In the present invention, an immiscible liquid phase L2 in an organic phase L1 comprising at least one hydroformylation catalyst based on metal compounds selected from groups 8, 9, and 10 according to the periodic table of elements, an organic phase L1, and solid particles are brought into contact. When all these species are brought into contact, a biphasic mixture comprising an organic phase L1 and a liquid phase L2 is formed. The biphasic mixture is emulsified to form a Pickering emulsion L2 in L1, i.e., droplets of L2, comprising said hydroformylation catalyst, stabilized by the solid particles in the organic phase L1

[0072] Liquid phase L2 immiscible in L1

[0073] The liquid phase L2 is a solvent that is not miscible in the organic phase L1 and comprises at least one hydroformylation catalyst based on compounds of metals from groups 8, 9 and 10 according to the periodic table of elements.

[0074] Advantageously, this solvent is selected from fluorinated solvents, ionic liquids, amines, or water. These solvents can be used alone or in mixtures. Advantageously, this solvent is selected from ionic liquids and water, and preferably water.

[0075] In an embodiment where the chosen solvent is water, the liquid phase L2, which is immiscible in the organic phase L1 constituting the dispersed phase, comprises at least water in which is dissolved at least one compound of a transition metal chosen from groups 8, 9 and 10 according to the periodic table of Elements. Advantageously, the aqueous phase can be water with the addition of an organic acid or base (e.g., triethylammonium hydroxide (TEAOH), triethylamine, acetic acid, formic acid, etc.) or an inorganic acid or base (ammonia, sodium hydroxide, nitric acid, hydrochloric acid, etc.) to vary the pH of this aqueous phase. Advantageously, the pH is between 6 and 11, and preferably between 6 and 9.

[0076] In another embodiment where the chosen solvent is an ionic liquid, the liquid phase L2 which constitutes the dispersed phase comprises at least one ionic liquid in which is dissolved at least one compound of a transition metal from groups 8, 9 and 10 according to the periodic table of elements.

[0077] An ionic liquid medium comprises at least one organic cation Q+ and one anion A.

[0078] Advantageously, the organic cation Q+ is a quaternary ammonium and / or a quaternary phosphonium and / or a trialkylsulfonium, and the anion A is an anion forming with the cation Q+ a liquid salt below 150°C.

[0079] Advantageously, Fanion A is selected from the tetrafluoroborate, tetraalkylborate, hexafluorophosphate, hexafluoroantimonate, alkylsulfonate, in particular methylsulfonate, perfluoroalkylsulfonate, in particular trifluoromethylsulfonate, fluorosulfonate, sulfate, phosphate, perfluoroacetate, in particular trifluoroacetate, perfluorosulfonamide, in particular bis-trifluoromethanesulfonyl (CF3SO2)2N fluorosulfonamide amide, perfluorosulfomethide, in particular tris-trifluoromethanesulfonyl (CF3SO2)3C methylide and carboranes.

[0080] Preferably, Fanion A is an anion forming with the cation Q+ a liquid salt below 150°C and advantageously below 90°C, and preferably at most 50°C.

[0081] The Q+ cation is in particular selected from the following compounds:

[0082] [Chem.l]

[0083] for which R1, R2, R3, R4, R5 and R6 are identical or different, linked or not to each other, represent hydrogen or hydrocarbyl groups having from 1 to 12 carbon atoms, in particular alkyl groups, saturated or unsaturated, cycloalkyl or aromatic, aryl or aralkyl, comprising from 1 to 12 carbon atoms.

[0084] By way of examples of Q+A ionic liquids according to the invention, we may mention N-butylpyridinium hexafluorophosphate, N-ethylpyridinium tetrafluoroborate, butyl-3-methyl-1-imidazolium hexafluoroantimonate, butyl-3-methyl-1-imidazolium hexafluorophosphate, butyl-3-methyl-1-imidazolium trifluoromethylsulfonate, pyridinium fluorosulfonate, trimethylphenylammonium hexafluorophosphate, bis-trifluoromethylsulfonylamide of butyl-3-methyl-1-imidazolium, bis-trifluoromethylsulfonylamide of triethylsulfonium, bis-trifluoromethylsulfonylamide of tributylhexylammonium, butyl-3-methyl-1-imidazolium trifluoroacetate, bis-trifluoromethylsulfonylamide of butyl-3-dimethyl-1,2-imidazolium. These salts can be used alone or in mixtures.

[0085] According to a particular embodiment of the invention, the ionic liquid is mixed with water.

[0086] In another embodiment where the chosen solvent is a fluorinated solvent, the liquid phase L2 which constitutes the dispersed phase comprises at least one fluorinated solvent in which is dissolved at least one compound of a transition metal from groups 8, 9 and 10.

[0087] The fluorinated solvent used comprises at least one or more partially or totally fluorinated linear, cyclic, or branched hydrocarbons that may bear heteroatoms and functional groups such as ethers, tertiary amines, carboxylic acids, phosphonic acids, and sulfonic acids. Preferably, the solvent is perfluorinated. The fluorinated hydrocarbon(s) preferably have between 3 and 20 carbon atoms, and more preferably between 5 and 16 carbon atoms. Non-limiting examples include perfluoro(methylcyclohexane), perfluorooctanoic acid, and perfluorooctanesulfonic acid. These solvents may be used alone or in mixtures.

[0088] According to a particular embodiment of the invention, the fluorinated solvent is mixed with water.

[0089] In another embodiment where the chosen solvent is an amine solvent, the phase liquid L2 which constitutes the dispersed phase comprises at least one amine solvent in which is dissolved at least one compound of a transition metal from groups 8, 9 and 10.

[0090] The amine solvent used comprises primary, secondary, and tertiary amines. Preferably, the solvent is a tertiary amine. The amine solvent has the formula NR1R2R3, in which the radicals RI, R2, and R3 are identical or different and are selected from a hydrogen atom, an alkyl group, or an aralkyl group having from 1 to 20 carbon atoms (in C1-C20) cyclic or non-cyclic, containing or not a heteroatom, bearing or not functional groups such as alcohols, amines, ethers, carboxylic acids, phosphonic acids and sulfonic acids. Advantageously, RI, R2 and R3 are chosen from an alkyl group having 1 to 10 carbon atoms (in Cl-ClO) containing or not a heteroatom, bearing or not functional groups, a cycloalkyl group having 3 to 10 carbon atoms (in C3-C10) containing or not a heteroatom, bearing or not functional groups, and a substituted or unsubstituted aryl group having 4 to 15 carbon atoms (in C4-C15) containing or not a heteroatom, bearing or not functional groups. Examples, but not limited to, triethanolamine, 2-(dimethylamino)-ethanol, 3-(dimethylamino)-1,2-propanediol, and N,N,N',N'-tetramethyl-1,3-propanediamine can be cited. These solvents can be used alone or in mixtures.

[0091] According to a particular embodiment of the invention, the amine solvent is mixed with water.

[0092] The transition metal compounds usable according to the invention are generally all transition metal compounds from groups 8, 9, and 10, and in particular those known to those skilled in the art for hydroformyling olefins. A metal compound is understood to be a metal salt or a metal complex, whether or not associated with at least one ligand. The metal is preferably chosen from cobalt, rhodium, iridium, ruthenium, palladium, and platinum, and advantageously from cobalt or rhodium.The metal compound is preferably chosen from HRh(CO)(PR3)3, HRh(CO)2(PR3), HRh(CO)[P(OR)3]3, Rh(acac)(CO)2, (acac meaning acetylacetonate), Rh6(CO)i6, [Rh(norbomadiene)(PPh3)2]+[PF6], [Rh(CO)3(PPh3)2]+[BPh4], RhCl(CO)(PEt3)2, [RhCl(cyclooctadiene)]2, [Rh(CO)3(PR3)2]+[BPh4], [Rh(CO)3(PR3)2]+[PF6], HCo(CO)4, Ru3(CO)12, [RuH(CO)(acetonitrile)2(PPh3)3]+[BF4], PtCl2(cyclooctadiene), [lr(CO)3(PPh3)]+[PF6], [HPt(PEt3)3]+[PF6], Rh2O3, Pd(NO3)2 and Rh(NO3)3. R is chosen from an alkyl or aralkyl group having from 1 to 15 carbon atoms (in Cl-Cl5), cyclic or non-cyclic, containing or not a heteroatom. Advantageously, R is chosen from an alkyl group having between 1 and 10 carbon atoms (in C1-C10), containing or not a heteroatom, a cycloalkyl group having from 3 to 10 carbon atoms (in C3-C10), containing or not a heteroatom, and a substituted or unsubstituted aryl group having from 4 to 15 carbon atoms (in C4-C15), containing or not a heteroatom.

[0093] Preferably, the metal compound comprises organic ligands bearing a phosphorus atom (phosphorus ligand), a nitrogen atom (nitrogen ligand), an arsenic atom (e.g., arsines), or an antimony atom (e.g., stibines). They may be mono- or bidentate. These ligands may also be attached to the heteroatom and / or the chain carbon-based, at least one other functional group such as an amine, ammonium, alcohol, carboxylic acid, or sulfonate. Examples include the sodium salt of triphenylphosphine monosulfonate and the sodium salt of triphenylphosphine trisulfonate.

[0094] The concentration of the metal compound, expressed in metal atoms, in the dispersed phase is advantageously between 0.1 mmole per liter of phase L2 and 500 mmoles per liter, preferably between 1 and 200 mmoles per liter, and even between 1 and 100 mmoles per liter, or even 1 to 50 mmoles per liter.

[0095] According to one embodiment of the invention, the metal compound comprises a ligand whose quantity is chosen so that the molar ratio of the quantity of ligand divided by the quantity of metal is between 1 and 100, and preferably between 1 and 20.

[0096] Organic phase L1

[0097] The organic phase L1 can be any liquid immiscible with phase L2. A person skilled in the art may preferentially choose an organic compound or a mixture of organic compounds with a high partition coefficient for the aldehyde formed.

[0098] In one or more particular embodiments of the invention, the organic phase L1 comprises at least one or more saturated hydrocarbons selected from linear or cyclic alkanes, and / or one or more unsaturated hydrocarbons selected from olefins or aromatic compounds, alcohols and aldehydes.

[0099] Advantageously, said organic compound or compounds comprise between 3 and 20 carbon atoms, preferably between 5 and 16 carbon atoms.

[0100] Without being exhaustive, the organic phase L1 comprises one or more organic compounds selected from pentane, hexane, heptane, octane, decane, dodecane, hexadecane, cyclohexane, methylcyclohexane, toluene, paraxylene, metaxylene, orthoxylene, ethylbenzene.

[0101] In one or more particular embodiments of the invention, the organic phase L1 is composed of one of the alkene-type reactants of the hydroformylation reaction.

[0102] In one or more particular embodiments of the invention, the organic phase L1 is composed of one of the aldehyde-type products of the hydroformylation reaction.

[0103] In one or more particular embodiments of the invention, the organic compounds of phase L1 are chosen to facilitate their separation from the product of the hydroformylation reaction. In a particular embodiment of the invention, they have a boiling point far removed from that of the product of the hydroformylation reaction.

[0104] The volume ratio between the liquid phase L2 and the organic phase L1 is preferably between 2:1 and 1:10, in particular between 1:1 and 1:5.

[0105] Solid particles

[0106] The solid particles according to the invention can be of various shapes and sizes, for example from a few nanometers to a few microns, or even tens of microns, in the form of substantially spherical or non-spherical beads (FB de Carvalho-Guimarães, K Leal Correa, T Pereira de Souza, JR Rodriguez Amado, RM Ribeiro-Costa and JO Carréra Silva-Junior (2022) A Review of Pickering Emulsions: Perspectives and Applications, Pharmaceuticals, 15, 1413. https: / / doi.org / 10.3390 / phl5111413). The shape can be substantially spherical, or in the form of a rod, ellipsoid, needle, spindle, nanofibril, nanocage, plate, nanotube, nanocube, etc. (Li W, Jiao B, Li S, Faisal S, Shi A, Fu W, Chen Y and Wang Q (2022) Recent Advances on Pickering Emulsions Stabilized by Diverse Edible Particles: Stability Mechanism and Applications. Front. Nutr. 9:864943. doi: 10.3389 / fnut.2022.864943).

[0107] Advantageously, they are modified to change their surface properties (in particular to modify their wettability). They can be of a single type, or be used in a mixture of several types of particles (in terms of size, shape and wettability).

[0108] Optionally, at least one surfactant is added to the particles. This surfactant (or each of them if a mixture of surfactants is used) may be anionic, cationic, nonionic, or amphoteric.

[0109] Advantageously, the solid particles are selected from: metal hydroxide or oxide particles such as AlOOH, Al2O3, TiO2, Fe3O4, Ce2O3 or SiO2, preferably at least partially functionalized with hydrophobic hydrocarbon groups; clay particles, preferably at least partially modified with organic or amphiphilic molecules; organic particles such as carbon nanotubes, graphene oxide particles, synthetic polymer particles such as polyethylene glycol (PEG), polystyrene (PS), polylactic acid (PLA), polycaprolactone (PCL), or latex particles; particles of a material of natural origin, preferably selected from hydroxyapatite, chitosan, cyclodextrin, dextran, particles in the form of cellulose nanocrystals or nanofibers; particles of biological material, particularly food-grade, preferably selected from starch,Zein, soy protein, bacteria and yeasts.

[0110] These particles are advantageously silica particles having an affinity for each of the two phases. Given the hydrophobic nature of the organic liquid phase, the silica particles, naturally hydrophilic due to the In the presence of silanol groups, they are preferentially functionalized by hydrophobic hydrocarbon groups.

[0111] In a particular embodiment of the invention, the solid particles are nanometric, with an average size between 1 nm and 500 nm, preferably between 5 nm and 300 nm.

[0112] Advantageously, the solid particle content is between 0.1% wt to 10% wt, in particular between 0.5% wt to 5% wt, and preferably between 0.5% wt and 3% wt of solid particles relative to the weight of the mixture obtained at the end of step 1a).

[0113] Emulsification

[0114] Emulsification transforms the biphasic mixture into dispersed droplets of phase L2 within the organic phase L1, forming a Pickering emulsion. Advantageously, the largest dimension of the droplets is between 1 pm and 1000 pm, preferably between 1 pm and 140 pm, preferably between 2 pm and 100 pm, and even more preferably between 10 pm and 50 pm. The droplet size is measured by optical microscopy (in particular, using an Olympus BX51 with AnalySIS software for image analysis).

[0115] Emulsification is carried out by any type of system that supplies energy to generate the emulsion known to those skilled in the art. While not exhaustive, examples include rotor-stator type tools, propeller agitators, static mixers, colloid mills, membrane systems, ultrasonic stirring, and microfluidic systems. The principle of these mixers is described, for example, in the Techniques de l'Ingénieur dossier J2153V1: Emulsification Processes - Equipment Techniques, by M. Poux and JP Canselier, June 10, 2004. A microfluidic system is described, for example, in the Techniques de l'Ingénieur dossier J8010V1: Microfluidics and Formulation - Emulsions and Complex Colloidal Systems, by V. Nardello-Rataj and JF Ontiveros, May 10, 2019.

[0116] In a particular embodiment of the invention, emulsification is carried out using a rotor-stator system of the type of the system marketed under the name Ultra-Turrax.

[0117] Advantageously, the ratio between the largest dimension of the dispersed droplets and the largest dimension of the amphiphilic solid particles is preferably at least 100. (The largest dimension is understood to be the diameter when the particles are substantially spherical). They are located at the interface of the water / oil emulsion droplets.

[0118] The solid particles are at the interface between the two phases.

[0119] Step 1b) Crosslinking of the porous capsule envelope

[0120] A crosslinking agent is added to the Pickering emulsion obtained in step a) in order to form porous catalytic capsules in suspension in the organic phase L1; said porous catalytic capsules comprising a liquid core comprising at least said liquid phase L2 comprising at least said hydroformylation catalyst and a porous shell formed by the crosslinked solid particles.

[0121] The solid material of the capsule shell is formed by said particles which stabilize the Pickering emulsion (step 1a) and which are crosslinked by the addition of a crosslinking agent. This crosslinking agent allows the solid particles to bind together.

[0122] The porous envelope consists of two elements:

[0123] - on the one hand, the solid particles used in the preparation of the emulsion of Pickering. The solid particles are described above in the description of the Pickering emulsion.

[0124] - on the other hand, a so-called crosslinking agent, which forms a porous envelope allowing the particles to bind together.

[0125] Crosslinking agent:

[0126] Advantageously, the crosslinking agent is selected from at least one silica precursor compound of the silicate, orthosilicate, silicic, orthosilicic, or alkoxysilane type, in particular selected from at least tetramethyl orthosilicate, tetraethyl orthosilicate, tetrabutyl orthosilicate, trimethoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, and triethoxysilane. This type of crosslinking agent is indeed capable of crosslinking by hydrolysis and thus serves as a base material for forming a solid shell.

[0127] Advantageously, the manufacture of the capsule shell by hydrolysis of the precursor is carried out at a temperature between 20°C and 60°C, for a heating time of between 2 h and 24 h. Initially, the alkoxysilane hydrolyzes, releasing the corresponding alcohol. Then, in a second step, the hydrolyzed alkoxysilane condenses, releasing water to form a Si-O-Si bond. (Zhang, X.; Hou, Y.; Ettelaie, R.; Guan, R.; Zhang, M.; Zhang, Y.; Yang, H. J. Am. Chem. Soc. 2019, 141 (13), 5220-5230).

[0128] Advantageously, the mass ratio between the crosslinking agent and the solid particles is between 1 and 10, in particular between 1 and 6.

[0129] The crosslinking agent can be introduced into the aqueous dispersed phase before the formation of the Pickering emulsion or be introduced a posteriori into the continuous phase.

[0130] A base or an organic acid (e.g. tetraethylammonium hydroxide (TEAOH), triethylamine, acetic acid, formic acid...) or inorganic acid (ammonia, sodium hydroxide, nitric acid, hydrochloric acid...) may be added to the aqueous dispersed phase in order to modify its pH to promote crosslinking and / or vary the porous architecture of the capsules. In this case, the acid or base is introduced simultaneously with the catalyst; a pH between 6 and 11 is advantageously targeted, preferably between 6 and 9.

[0131] A person skilled in the art will be able to choose the appropriate reactor for this operation. Generally, crosslinking is carried out in a rotary evaporator-type reactor or a double-jacketed glass reactor equipped with a four-bladed agitator or other type of impeller ensuring the mixing of the reaction medium.

[0132] Advantageously, the liquid-core capsules have an average number diameter of between 1 pm and 1000 pm, preferably between 2 pm and 100 pm, which allows them to be easily separated from the reaction system.

[0133] The preparation process according to the invention may also include a step of washing the capsules in particular with a solvent that is not miscible with the encapsulated catalytic composition, in particular non-aqueous, and preferably based on hydrocarbon(s).

[0134] The average size of the capsules is measured by optical microscopy (Olympus BX51 with analysIS software for image analysis) or by scanning electron microscopy (SEM, ZEISS Supra 40 instrument).

[0135] Said capsules advantageously have a pore volume (measured by nitrogen physisorption at P / P0 max) between 0.2 ml / g and 0.8 ml / g and a BET surface (measured by nitrogen physisorption) between 60 m2 / g and 350 m2 / g.

[0136] Step 2) Hydroformylation reaction

[0137] The hydroformylation reaction is carried out by adding at least one alkene and a gaseous mixture comprising at least carbon monoxide and dihydrogen to a mixture comprising the organic phase L1 and said porous catalytic capsules to form at least one aldehyde.

[0138] With the embodiment according to the invention, the medium is three-phase gas / liquid / solid. The gaseous phase consists of the gaseous mixture comprising carbon monoxide and dihydrogen. The liquid phase consists of the mixture of the alkene and the organic phase L1, and the solid phase consists of the porous catalytic capsules containing the liquid phase L2.

[0139] A person skilled in the art may use different implementations of this reaction. The process can be implemented in a closed, semi-open, or continuous system, with one or more reaction stages in steel reactors capable of withstanding the pressures and temperatures applied, as well as corrosion. Each reactor is equipped with a device for efficiently removing the heat released by the reaction and regulating the temperature to the desired level. In addition, it is useful to ensure a good contact between the liquid phase and the synthesis gas by forced circulation of the reaction mixture inside the reactor.

[0140] These liquid-core capsules can be brought into contact with the reagent(s), for example in free suspension or in a fixed bed with upstream or downstream co-current in a reactor.

[0141] The reactants (alkene and gaseous mixture) react upon contact with the hydroformylation catalyst contained in the porous capsules and form reaction products which diffuse out of the capsules.

[0142] Alcène:

[0143] The alkenes, or olefins, capable of being hydroformylated are selected from the group consisting of monoolefins, diolefins, in particular conjugated diolefins, and olefinic compounds comprising one or more heteroatoms, notably in unsaturated groups such as ketone and carboxylic acid functions. Advantageously, the alkenes according to the invention are C2 to C18 alkenes, preferably C4 to C8, and preferably C5 to C8.

[0144] Examples include the hydroformylation of pentenes to hexanal and methylpentanal, of hexenes to isoheptanals, of isooctenes to isononanals and of C18 olefinic C10 cuts to C19 C11 aldehydes.

[0145] The temperature at which the hydroformylation takes place is advantageously between 30°C and 250°C, advantageously the temperature is less than 150°C, preferably between 50°C and 120°C.

[0146] Advantageously, the ratio of the partial pressures of dihydrogen and carbon monoxide used in the reaction medium for hydroformylation may be from 10:1 to 1:10, preferably from 2:1 to 1:1, and preferably equal to 1:1, but any other ratio may be used depending on the implementation of the process. The pressure may be from 1 MPa to 35 MPa, advantageously from 1 MPa to 10 MPa, and preferably from 2 MPa to 5 MPa.

[0147] The duration of the reaction depends on the operating conditions and the reactivity of the catalyst. It will be adjusted by a person skilled in the art to obtain the desired aldehyde yield in a minimum time.

[0148] According to a particular embodiment of the invention, the alkene is continuously introduced into the organic phase LL

[0149] Step 3) Recovery of the aldehyde in the organic phase L1

[0150] Advantageously, the step of recovering the aldehyde formed in the organic phase L1 takes place in two steps:

[0151] -Step 3a) Separation of the porous catalytic capsules from said organic phase LL

[0152] Said organic phase L1 is separated from the porous catalytic capsules by liquid / solid separation techniques known to those skilled in the art such as filtration, decantation, or centrifugation.

[0153] -Step 3b) Separation of the aldehyde in the organic phase L1;

[0154] At the end of the hydroformylation reaction, the organic phase L1 comprises at least the aforementioned organic compounds, the unreacted alkene, the aldehyde formed, the side reaction products, and gaseous species solubilized in the liquid. The aldehyde is separated by any method known to those skilled in the art, and preferably by distillation (Technique de l'ingénieur, 2016, J5750 V2).

[0155] According to a particular embodiment of the invention, the aldehyde is separated from the organic phase L1 as it is formed by distillation from a withdrawal of the L1 phase which is returned to the reactor after partial or total evaporation of the aldehyde in this withdrawal. Examples

[0156] Example 1 (Comparative): Preparation of the rhodium-based catalytic solution SI

[0157] In a laboratory slänk, 19.5 mg of Rh(acac)(CO)2 complex and 213 mg of trisodium tri(sulfophenyl)phosphine salt are weighed out. After inertizing the slänk with argon, 30 mL of water previously deaerated with argon is added for 30 minutes. Under an inert atmosphere, the solution is stirred with a magnetic stir bar for at least 30 minutes. It turns yellow-orange.

[0158] Example 2 (According to the invention): Preparation of porous catalytic capsules Cl - Preparation of the rhodium-based catalytic solution S2 containing trimethoxysilane as a crosslinking agent:

[0159] A rhodium S2-based catalytic solution is prepared by weighing 19.5 mg of Rh(acac)(CO)2 complex and 213 mg of trisodium tri(sulfophenyl)phosphine salt. After inertizing the schlenk with argon, 30 mL of an aqueous NaOH solution at pH 8.5, previously deaerated with argon for 30 minutes, is added. Under an inert atmosphere, the solution is stirred with a magnetic stir bar for at least 30 minutes. It turns yellow-orange. - Preparation of the Pickering emulsion containing the catalyst

[0160] In a beaker, 1 g of Aerosil R972 silica is weighed and 60 mL of n-Heptane is added. The silica is dispersed in the organic phase using an ultra-turrax (dispersion module IKA S25 N - 18 G) at 10000 rpm for 30 seconds.

[0161] 29.5 g of the rhodium-based catalytic solution S2 are added to the suspension of silica in n-Heptane under agitation using an ultra-turrax at 20000 rpm for 1 min 30. The agitation is prolonged for 1 min 30. - Preparation of Cl capsules

[0162] The Pickering emulsion containing the catalyst is transferred into a 2 L flask with 450 mL of n-Heptane. 3.59 g of trimethoxysilane (CAS 2487-90-3) are added and the mixture is heated and stirred in a rotary evaporator at 50°C for 5 hours.

[0163] The Cl capsule suspension is recovered and the heptane supernatant is discarded (460 mL). The Cl capsule suspension is then washed twice with 50 mL of n-Heptane (addition of solvent, stirring, decantation, and discarding of the supernatant).

[0164] A fraction of the Cl capsules thus prepared is dried for 16 hours at 80°C for their characterization. They exhibit a BET surface area of ​​142 m2 / g and a total pore volume (volume at P / P0 max) of 0.275 mL / g (results obtained by nitrogen physisorption on ASAP 2420 after pretreatment under secondary vacuum for 6 hours at 110°C).

[0165] Example 3 (according to the invention): Preparation of porous catalytic capsules C2 - Preparation of the rhodium-based catalytic solution containing sodium silicate as a crosslinking agent:

[0166] A rhodium-based catalytic solution is prepared by weighing 6 mg of Rh(acac)(CO)2 complex and 71 mg of trisodium tri(sulfophenyl)phosphine salt. After inertizing the schlenk with argon, 10 g of an aqueous sodium silicate solution with a SiO2 / Na2O molar ratio of 3.2 to 3.4 wt% SiO2, previously deaerated with argon for 30 minutes, is added. Under an inert atmosphere, the solution is stirred with a magnetic stir bar for at least 30 minutes. It turns yellow-orange. - Preparation of the Pickering emulsion containing the catalyst and the crosslinking agent

[0167] In a beaker, 0.22 g of Aerosil R972 silica is weighed and 20 mL of n-Heptane is added. The silica is dispersed in the organic phase using an ultra-turrax (dispersion module IKA S25 N - 18 G) at 10000 rpm for 30 seconds.

[0168] 10 g of the rhodium-based catalytic solution containing sodium silicate S3 are added to the silica suspension in n-Heptane under stirring using an ultra-turrax at 20000 rpm in 30 s. The stirring is prolonged for 1 min. - Preparation of C2 capsules:

[0169] The Pickering emulsion containing the catalyst and sodium silicate is transferred with 150 mL of n-Heptane into a 250 mL double-jacketed reactor equipped with a four-bladed stirrer. With the mixture stirred at 180 rpm, 180 mg of glacial acetic acid are added to the reactor, and the mixture is heated to 25 °C and stirred for 2 h.

[0170] The C2 capsule suspension is recovered and the heptane supernatant is discarded (150 mL). The C2 capsule suspension is then washed with 2 x 20 mL of n-Heptane (addition of solvent, stirring, decantation and discarding of the supernatant).

[0171] A fraction of the C2 capsules thus prepared is dried for 16 hours at 80°C for their characterization. They exhibit a BET surface area of ​​80 m2 / g and a total pore volume (volume at P / PO max) of 0.386 mL / g (results obtained by nitrogen physisorption on ASAP 2420 after pretreatment under secondary vacuum for 6 hours at 110°C).

[0172] Example 4 (Comparative): Biphasic hydroformylation test with SI catalytic solution with pentene-1

[0173] The hydroformylation reaction is carried out in a 100 mL stainless steel autoclave equipped with a double jacket allowing temperature control and magnetic stirring. In this autoclave, which has been previously purged of air and moisture and placed under a syngas atmosphere of dihydrogen-carbon monoxide (1:1 molar ratio), 30 mL of heptane, previously degassed by argon bubbling, 30 mL of the SI catalytic solution prepared in Example 1, and 10 mL of pentene-1 (6.41 g) are introduced. The pressure in the autoclave with the dihydrogen-carbon monoxide mixture is brought to 1 MPa, and the temperature is set to 80°C with stirring at 700 rpm. When the temperature reaches 78°C, the pressure is adjusted to 2 MPa. We continue stirring while maintaining the temperature at 80°C and the pressure at 2 MPa by adding the same gas mixture for 24 hours.

[0174] After this time, the autoclave is cooled to 10°C and then gently degassed. The recipe contained in the reactor is decanted and the organic phase is analyzed by gas chromatography after the addition of decane as an internal standard.

[0175] It is found to contain: - 3.6 g of pentene-1 - 0.24 g of other pentenes - 0.01 g of pentane - 3.61 g of hexanals

[0176] Example 5 (According to the invention): Hydroformylation test with porous catalytic capsules Cl with pentene-1

[0177] The hydroformylation reaction is carried out in a 100 mL stainless steel autoclave equipped with a double jacket allowing temperature control and magnetic stirring. When the autoclave is opened, 50 mL of the mixture prepared in Example 2, containing 30 mL of Cl capsules and 20 mL of heptane, is introduced. Once the autoclave is closed, it is placed under a syngas atmosphere of dihydrogen-carbon monoxide (1:1 molar ratio). Then, 10 mL of pentene-1 (6.41 g) is introduced. The pressure in the autoclave with the dihydrogen-carbon monoxide mixture is brought to 1 MPa, and the temperature is set to 80°C with stirring at 700 rpm. When the temperature reaches 78°C, the pressure is adjusted to 2 MPa. We continue stirring while maintaining the temperature at 80°C and the pressure at 2 MPa by adding the same gas mixture for 24h.

[0178] After this time, the autoclave is cooled to 10°C and then gently degassed. The recipe contained in the reactor is decanted and the organic phase is analyzed by gas chromatography after the addition of decane as an internal standard.

[0179] It is found to contain: - 0.20 g of pentene-1 - 2.27 g of other pentenes - 0.02 g of pentane - 4.40 g of hexanals

[0180] The results of examples 4 and 5 are summarized in Table 1. These results show that the use of porous catalytic capsules allows for better conversion of pentene-1 into hexanals.

[0181] [Tab 1] Hydroformylation of pentene-1 with the catalytic solution (comparative example 4) Hydroformylation of pentene-1 with porous catalytic capsules C1 (example 5 according to the invention) Pentane-1 recovered 3.6 g 0.20 g Transformation rate of pentene-1 44% 97% Hexanals formed 3.61 g 4.40 g Molar yield of hexanals relative to pentene-1 committed 40% 48%

[0182] The molar yield of hexanals with respect to committed pentene-1 is defined as the number of moles of hexanals formed divided by the number of moles of pentene-1 committed.

[0183] Example 6 (Comparative): Biphasic hydroformylation test with the SI catalytic solution with octene-1

[0184] The hydroformylation reaction is carried out in a 100 mL stainless steel autoclave equipped with a double jacket allowing temperature control and magnetic stirring. In this autoclave, which has been previously purged of air and moisture and placed under a syngas atmosphere of dihydrogen-carbon monoxide (1:1 molar ratio), 20 mL of heptane is introduced. Degassed by argon bubbling, 10 mL of octene-1 (7.15 g) and 30 mL of SI catalytic solution prepared in Example 1 are added. The pressure is brought to 1.5 MPa in the autoclave with the dihydrogen-carbon monoxide mixture, and the temperature is set to 100°C with agitation at 700 rpm. When the temperature reaches 98°C, the pressure is adjusted to 4 MPa. Agitation is continued, maintaining the temperature at 100°C and the pressure at 4 MPa by adding the same gas mixture for 69 hours.

[0185] After this time, the autoclave is cooled to 10°C and then gently degassed. The recipe contained in the reactor is decanted and the organic phase is analyzed by gas chromatography after the addition of decane as an internal standard.

[0186] It is found to contain: - 0.59 g of octene-1 - 1.34 g of other octenes - 0.06 g of octane - 4.42 g of nonanals

[0187] Example 7 (According to the invention): Hydroformylation test with porous catalytic capsules Cl with octene-1

[0188] The hydroformylation reaction is carried out in a 100 mL stainless steel autoclave equipped with a double jacket allowing temperature control and magnetic stirring. When the autoclave is opened, 50 mL of the mixture prepared in Example 2, containing 30 mL of prepared Cl-capsules and 20 mL of heptane, is introduced. Once the autoclave is closed, it is placed under a syngas atmosphere of dihydrogen-carbon monoxide (1:1 molar ratio). Then, 10 mL of octene-1 (7.15 g) is introduced. The pressure in the autoclave with the dihydrogen-carbon monoxide mixture is brought to 1.5 MPa, and the temperature is set to 100°C with stirring at 700 rpm. When the temperature reaches 98°C, the pressure is adjusted to 4 MPa. We continue stirring while maintaining the temperature at 100°C and the pressure at 4 MPa by adding the same gas mixture for 69 hours.

[0189] After this time, the autoclave is cooled to 10°C and then gently degassed. The recipe contained in the reactor is decanted and the organic phase is analyzed by gas chromatography after the addition of decane as an internal standard.

[0190] It is found to contain: - 0.05 g of octene-1 - 0.05 g of other octenes - 0.06 g of octane - 7.74 g of nonanals

[0191] The results of examples 6 and 7 are summarized in Table 2. These results show that the use of porous catalytic capsules allows for better conversion of octene-1 into nonanals.

[0192] [Tab 2] Hydroformylation of octene-1 with the catalytic solution (comparative example 6) Hydroformylation of octene-1 with porous catalytic capsules Cl (example 7 according to the invention) Octene-1 recovered 0.59 g 0.05 g Octene-1 transformation rate 92% 99% Nonanals formed 4.42 g 7.74 g Molar yield of nonanals relative to octene-1 committed 49% 85%

[0193] The molar yield of nonanals with respect to committed octen-1 is defined as the number of moles of nonanals formed divided by the number of moles of committed octen-1.

Claims

Demands

1. A process for producing an aldehyde by hydroformylation between at least one alkene and a gaseous mixture comprising at least carbon monoxide and dihydrogen in the presence of a catalyst comprising at least the following steps: 1) porous catalytic capsules dispersed in at least one organic phase L1 are prepared according to the following steps: a. a mixture comprising at least one liquid phase L2, immiscible in the organic phase L1, comprising at least one hydroformylation catalyst based on compounds of metals selected from groups 8, 9 and 10 of the periodic table of elements, an organic phase L1 and solid particles is emulsified to form a Pickering emulsion comprising droplets of said liquid phase L2 stabilized by the solid particles in the organic phase L1; 1b.1) a crosslinking agent is added to the Pickering emulsion obtained in step 1a) in order to form porous catalytic capsules in suspension in the organic phase L1; said porous catalytic capsules comprising a liquid core comprising at least said liquid phase L2 comprising at least said hydroformylation catalyst and a porous shell formed by the crosslinked solid particles; 2) the hydroformylation reaction is carried out by adding at least one alkene and a gaseous mixture comprising at least carbon monoxide and dihydrogen to the organic phase L1 comprising at least said porous catalytic capsules to form at least one aldehyde; 3) said aldehyde formed in step (2) is recovered in said organic phase L1.

2. A process according to claim 1, wherein said alkene is a C2 Cl8 alkene.

3. A process according to claim 1, wherein said alkene is a C4 to Cl8 alkene.

4. A method according to any one of the preceding claims, wherein the metal compounds are selected from cobalt or rhodium compounds.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15. A method according to any one of the preceding claims, wherein said liquid phase L2 comprises at least water. A process according to any one of the preceding claims, wherein said liquid phase L2 comprises at least water with added acid or base. A method according to any one of the preceding claims, wherein said liquid phase L2 comprises at least one ionic liquid. A method according to any one of the preceding claims, wherein the porous catalytic capsules have a number-average diameter of between 1 µm and 1000 µm. A method according to any one of the preceding claims, wherein the solid particles added in step a) are silica particles. A process according to any one of the preceding claims, wherein the crosslinking agent added in step 1b) is selected from at least one silica precursor compound of the silicate or orthosilicate or silicic or orthosilicic or alkoxysilane type. A method according to any one of the preceding claims, wherein the mass ratio between the crosslinking agent and the solid particles is between 1 and 10. A process according to any one of the preceding claims, wherein the organic phase L1 comprises at least one or more saturated hydrocarbons selected from linear or cyclic alkanes, and / or one or more unsaturated hydrocarbons selected from olefins or aromatic compounds, alcohols, and aldehydes. A process according to any one of the preceding claims, wherein the organic phase L1 comprises at least one or more organic compounds having between 3 and 20 carbon atoms. A process according to any one of the preceding claims, wherein the organic phase L1 consists of said alkene. A process according to any one of the preceding claims, wherein the volume ratio between the liquid phase L2 and the organic liquid phase L1 is between 2:1 and 1:10.