Method and system for hydrogenating unsaturated hydrocarbon compounds

Abstract

The invention relates to a method for the metal-catalysed hydrogenation of organic compounds at least having C-C double bonds and / or C-C triple bonds by means of unsupported, in-situ-generated catalyst particles. Furthermore, the present invention relates to the use of the method for reacting natural vegetable oils into synthetic fuels or synthesis building blocks of chemical reactions, and to a system consisting of unsupported, in-situ-generated metal catalyst particles and a liquid medium.

Description

[0001] Technical University of Dortmund

[0002] Process and system for the hydrogenation of unsaturated hydrocarbon compounds

[0003] The invention relates to a process for the metal-catalyzed hydrogenation of organic compounds containing at least one carbon-carbon double bond and / or one or more carbon-carbon triple bonds using unsupported, in-situ generated catalyst particles. Furthermore, the present invention relates to the use of the process for converting natural vegetable oils into synthetic fuels or synthesis building blocks for chemical reactions, as well as to a system comprising unsupported, in-situ generated metallic catalyst particles and a liquid medium.

[0004] The environmental sustainability of chemical transformations results, on the one hand, from the efficiency of the actual transformation in terms of conversion, yield, and selectivity, and, on the other hand, from the environmental impact of the raw materials used. While the chemical transformation is more or less predetermined by the kinetics and thermodynamics of the reaction, the use of renewable raw material components as starting materials still offers great potential for improving the environmental or carbon footprint of the manufacturing process in question. Unfortunately, not all available natural raw material sources can be utilized in industrial production, as the chemical heterogeneity of natural raw materials precludes efficient use in targeted chemical syntheses or specific applications.In this respect, it would be desirable to have chemical conversion processes available that could highly efficiently reduce the variance in the molecular structure of natural raw materials. This applies particularly to polyunsaturated hydrocarbon compounds obtained from renewable resources, which, with a more homogeneous chemical composition, could easily replace less sustainable "synthetic" starting materials in existing processes. Efficient hydrogenation processes would be helpful for this purpose, which specifically generate monounsaturated compounds from the polyunsaturated compounds without modifying any other functional groups present in the hydrocarbons.

[0005] One method for hydrogenating unsaturated organic compounds is to react them with hydrogen over a metallic catalyst. A wide variety of processes are known from the literature, which are used for hydrogenating reactions of organic molecules under different reaction conditions and with a wide variety of metals and metal structures.

[0006] The patent literature also contains a wide variety of processes for the hydrogenation of organic compounds.

[0007] For example, DE 4109246 A1 describes a process for producing monounsaturated fatty acids or their derivatives such as sunflower oil using palladium salts in the presence of activators such as carbonic acid esters.

[0008] Furthermore, GB 228 899 0 A describes a process for producing a metal catalyst composition comprising the steps of: i) mixing a composition of finely divided particulate catalytic metal in an oleophilic medium with a solvent that dissolves the oleophilic medium, thereby producing a dispersion of metal in a solution of the medium and the solvent; ii) mixing particulate support material into the dispersion such that the metal impregnates the support material; and iii) separating the metal-impregnated support material from the solution, the separated material constituting the metal catalyst composition. EP 2735390 B1 discloses a carbon-free suspension of gold or metal nanoparticles from the platinum group, as well as an apparatus and a process for their production.For example, organic molecules, especially biologically active compounds, linked to the nanoparticles, as well as inorganic carriers, electrodes or optical components coated with the nanoparticles are produced.

[0009] Despite the already known processes for the catalyzed reaction of organic compounds with hydrogen, there is still a need for solutions that can hydrogenate particularly inhomogeneous organic compounds very selectively, simply and with high conversions and yields.

[0010] The object of the present invention is therefore to provide a process that hydrogenates unsaturated organic compounds very selectively and in high yields. Furthermore, the object of the present invention is to provide a system with which unsaturated organic compounds can be converted very selectively and with high conversion rates.

[0011] The object is achieved for the method by the features of claim 1, for the system according to the invention by the features of claim 11 and for the use according to the invention by the features of claim 16. Preferred embodiments of the method and the use are specified in the subclaims.

[0012] According to the invention, there is therefore provided a process for the metal-catalyzed hydrogenation of organic compounds having at least one CC double bond or at least one CC triple bond or mixtures thereof, by means of unsupported, in-situ generated catalyst particles, the process comprising the steps of: a) contacting a liquid comprising the organic compounds with a metallic target, wherein the target comprises one or more metals selected from the group consisting of Pd, Pt, Ni, Rh, Co, Cu, Ru, Au, Ag, Fe, Ir; b) removing catalyst particles from a surface of the metallic target by emitting laser energy through the liquid onto the surface of the metallic target, thereby obtaining unsupported, in-situ generated catalyst particles; c) adding hydrogen to the liquid, wherein the addition of hydrogen to the liquid takes place before, after and / or during process step b);and d) at least partially hydrogenating the organic compounds.;

[0013] Surprisingly, it has been shown that liquid, unsaturated organic compounds can be reacted with hydrogen very selectively and with high conversions and yields using in-situ produced metal catalysts. The unsupported catalysts generated by laser ablation exhibit very high stability and very good hydrogenation activity and selectivity in the inventive environment. The reaction can be carried out efficiently with a variety of different metals and with a variety of chemically different starting materials from the claimed class. The process is particularly suitable for the hydrogenation of mixtures of substances, such as those found in natural starting materials. Despite the inhomogeneous starting materials, the hydrogenation leads to chemically very homogeneous products, which indicates a very specific selectivity of the catalyst.In this respect, the process opens up new, natural raw material sources for reactions that require homogeneous reactant compositions. The catalyst can be provided within the reaction without major logistical effort, and base metals in particular can be used, which contributes to a reduction in overall process costs. Batch and continuous processes are possible, and the process is easily scaled up to higher throughputs. The latter enables a functional and cost-effective approach for many reactants in the chemical industry. A key advantage is the simple in-situ provision of a highly functional catalyst. Heterogeneous hydrogenations are usually carried out in the fluid phase using supported catalysts.These are produced through complex, multi-step synthesis processes, such as wet impregnation, in which catalyst precursors are prepared and adsorbed onto catalyst supports. The supported catalysts are then dried or subjected to further physical steps. The focus in the production of supported metal catalysts is primarily on producing easily dispersible, small metal particles in order to maximize the catalyst surface-to-volume ratio. However, it is not easy to control the particle size and size distribution during impregnation, and catalysts produced using conventional methods often exhibit poor reproducibility, lack selectivity, and insufficient service life.An alternative method for obtaining supported catalysts with well-defined metal particles is to immobilize preformed nanoparticles on supports, for example, in the form of adsorbed nanoparticles on colloidal supports. The major advantage of colloidally adsorbed nanoparticles is that the particle size, size distribution, and crystal structure of these nanoparticles can be well controlled. However, the catalysts are chemically altered by immobilization on the supports, resulting in different catalytic behavior. Without being bound by theory, the advantageous chemical properties of the unsupported catalyst particles generated in situ according to the invention arise in particular from the fact that thermal and chemical disequilibrium states induced by laser ablation are retained on the catalyst particles and can be utilized during hydrogenation.Compared to supported or further chemically or physically processed catalysts, the chemical behavior during hydrogenation is significantly different. The catalytic potential of the catalysts during hydrogenation also differs from that of chemically complexed or chemically stabilized catalysts. These catalysts, which are subjected to further processing steps or reactions after ablation, do not achieve the selectivity and efficiency of the unmodified catalysts usable according to the invention in the selected reactant class. This is most likely due to the fact that the absorption of the additional substances renders part of the surface of the catalyst particles inaccessible for reactions. This process can be used, in particular, to obtain biofuels with uniform chemical properties from unrefined vegetable oils or defined synthetic building blocks for chemical reactions.Another advantage of the catalyst system used is that the ablated metal catalysts can be easily separated from the hydrogenated organic compounds after the reaction.

[0014] The process according to the invention is a process for the metal-catalyzed hydrogenation of organic compounds having at least one carbon-carbon double bond or at least one carbon-carbon triple bond, or mixtures thereof. Metal-catalyzed hydrogenation of organic compounds is understood to mean a chemical reaction in which an unsaturated, hydrocarbon-containing organic compound is reacted with hydrogen, the organic compound having a smaller number of carbon-carbon double or triple bonds after the reaction. The unsaturated compound can have unsaturated carbon-carbon bonds that are isolated, conjugated, or incorporated into an aromatic system. An organic compound can consist purely of carbon and hydrogen or can also have further heteroatom-based functional groups. The organic compound can preferably have a carbon number of greater than or equal to 5 and less than or equal to 50.These are preferably organic compounds that are liquid at room temperature and standard pressure. They can contain one or more double or triple bonds per molecule. The organic compounds used can preferably have a statistical distribution of different numbers of double or triple bonds per molecule, so that the number average unsaturation per molecule can be a non-whole number. The hydrogenation reaction takes place with the addition of hydrogen, with the actual reaction of the organic compounds with the hydrogen taking place on the surface of one of the metal catalyst particles. The hydrogenation takes place using unsupported, in-situ generated catalyst particles. The selective addition of hydrogen to the n-electrons of the organic compound takes place using metallic catalyst particles.Catalyst particles are more or less spherically shaped particles containing more than one metal atom. The particles are formed at the phase boundary between the target surface and the reaction solution and exhibit physical and chemical properties that are determined by their formation in the reaction environment. The use of catalyst particles that have already left the reaction environment in the form of the reactants to be converted, or that are additionally or subsequently added from outside to the reaction environment of the reactants, is not in accordance with the invention. In particular, the catalyst particles are not absorbed onto other substances, particles, or supports. Therefore, the catalyst particles used can consist solely of the catalyst metal, without any further additives or support materials.Furthermore, the catalyst particle preferably does not have any stabilizing chemical complexing agents or surface-active substances, such as surfactants, on its surface that are not involved in the hydrogenation reaction. Exceptions to this are cases in which the organic substances to be reacted, in addition to the unsaturated bond, themselves have properties that lead to deposition on the surface of the catalyst particle for a prolonged period without catalytic conversion. The in-situ produced catalyst particles are preferably particles with a number-average size in the nm range. For example, the particles can have an average diameter in the range of greater than or equal to 1 nm and less than or equal to 500 nm. The catalyst particles are thus produced by ablating them from a target, wherein the target is in contact with the reactants usable according to the invention.It is also possible to add additional components to the ablation environment, such as additional solvents or the reaction gas hydrogen, but no other particles or carrier materials. The ablated particles then do not leave this chemical environment; however, it is possible for the particles to be dispersed or transferred to another reactor for the actual reaction in contact with the reactant according to the invention, optionally containing additional solvents.

[0015] The method comprises step a) contacting a liquid comprising the organic compounds with a metallic target, wherein the target comprises one or more metals selected from the group consisting of Pd, Pt, Ni, Rh, Co, Cu, Ru, Au, Ag, Fe, and Ir. The in-situ production of the catalyst particles requires that the organic compounds are contacted with a target in the form of a liquid. For this purpose, the organic compounds can, for example, contact the surface of a metal body, for example in the form of a metal piece, metal cuboid, or metal sheet. For this purpose, the organic compounds can flow around the entire metallic target or wet it only from one surface side. The organic compounds can be used as such if they are liquid under the selected ablation / reaction conditions. In these cases, the liquid can consist of the organic compounds.However, it is also possible for the solid or liquid organic compounds intended for hydrogenation to be dissolved in an inert solvent and then contacted in liquefied form with the metallic target. Liquid organic compounds are preferably selected under reaction conditions, whereby the liquid can then consist purely of the organic compounds to be reacted. Alternatively, the reaction conditions can be chosen so that the organic compounds are fluid. This selection can avoid the need to separate an additional solvent from the hydrogenated products. The liquid can contact the target in a stationary manner or be moved along the target. The medium in the reaction space can also be stirred or agitated, for example, by mechanical means. The target consists of one or more metals from the list given above. The metals are not present as salts, but in metallic form.Alloys of at least two different metals from the given list can also form the metallic carrier. Metals from the group of non-noble metals can preferably be used. Inert solvents suitable for hydrogenation can be, for example, carbonates such as dimethyl carbonate, in particular cyclic carbonates such as propylene carbonate and ethylene carbonate; alcohols such as methanol, ethanol, in particular polyhydric alcohols such as ethanediol (glycol), 1,2-propanediol, 1,3-propanediol, glycerol, hexafluoroacetone; ethers such as diethylene glycol, diethylene glycol dimethyl ether, oligo- and polyethylene glycol; esters such as ethyl acetate, in particular polyhydric esters such as triglycerides; and ketones such as acetone.

[0016] The process comprises step b), the removal of catalyst particles from a surface of the metallic target by emitting laser energy through the liquid onto the surface of the metallic target, resulting in unsupported, in-situ generated catalyst particles. The actually active catalysts are generated in the form of catalyst particles, which are knocked out of the surface of the metallic target by the laser energy. To generate the particles, energy in the form of continuous or pulsed laser beams is emitted through the liquid containing the organic compounds onto the target. Both the laser beam and the target can be moved. However, it is also possible for only one point on the surface of the target to be exposed to a laser beam.The metallic particles ejected from the target temporarily exhibit both specific thermal and electronic properties. Without being bound by theory, it is also assumed that the selection of unsaturated organic compounds, in particular, influences the stability of the non-equilibrium states formed on the catalyst particle surface, which accordingly also influences the hydrogenation properties of the catalyst particles. The active catalyst particles are thus generated within the liquid being reacted and are thus generated in situ. Due to the choice of a metallic target and the fact that no suitable supports for the catalyst particles are present in the liquid, the catalyst particles are unsupported due to the lack of a deposition option.In principle, different laser sources can be used to release the catalyst particles from the metallic target. For example, green, UV, or IR lasers are possible. For efficient generation of the catalyst particles, the fluence should preferably be greater than or equal to 0.05 J / cm. 2 and less than or equal to 20 J / cm 2 The applied laser energy is determined in a known manner from the wavelength, the irradiation duration, and the irradiated area.

[0017] The process comprises step c) of adding hydrogen to the liquid, wherein the hydrogen is added to the liquid before, after, and / or during process step b). To hydrogenate the unsaturated organic compounds, gaseous hydrogen is passed into the organic liquid. The hydrogen can be added to the liquid before, during, or after the removal of the actually active catalyst particles. Preferably, the hydrogen is introduced before and / or during the removal of the catalyst particles. In this embodiment, the physical and / or chemical imbalances on the catalyst particle surface can be efficiently utilized. The hydrogen can be introduced continuously, intermittently, or discontinuously.For the hydrogenation of organic compounds, hydrogen mole fractions in the gas phase of greater than or equal to 25% to less than or equal to 100% have proven efficient. Likewise, hydrogen concentrations of greater than or equal to 1 mmol / mol hydrogen per unsaturated carbon–carbon bond to be converted in the compound have proven efficient.

[0018] The process comprises step d), the at least partial hydrogenation of the organic compounds. During the process, the unsaturated organic compounds are at least partially converted on the catalyst particles with the addition of hydrogen into organic compounds with a smaller number of double or triple bonds. This reduces the average number of double or triple bonds in the organic compounds. Preferably, the process can result in an average of one double bond remaining per molecule of organic compound. Thus, hydrogenation does not necessarily result in complete conversion of the double or triple bonds. However, this step is particularly suitable for equalizing the number of unsaturated carbon-carbon bonds in the organic compounds.This means, for example, that before hydrogenation, a mixture of organic compounds has a varying number of double bonds, for example, one, two, or three double bonds, and after hydrogenation, the organic compounds have essentially only one double bond per molecule. Preferably, the temperature of the liquid during hydrogenation can be greater than or equal to 5°C and less than or equal to 50°C. The analytical determination of the number of unsaturated bonds in an organic compound can be carried out by methods known to those skilled in the art.

[0019] In a preferred embodiment of the process, the organic compounds can comprise at least one further functional group in addition to the CC double bond or CC triple bond, wherein the functional group has a heteroatom selected from the group consisting of O, N, S, halides or combinations of these elements. It has been shown that the in-situ generated catalyst particles very selectively catalyze the hydrogenation of unsaturated CC bonds and do not react any other functional groups present in the organic compound, comprising heteroatoms from the above-mentioned list, or do so to a negligible extent. Thus, the process according to the invention can be carried out on a large number of organic compounds. The organic compounds can have one or more identical or different functional groups. These can preferably be oxygen-based functional groups.These are implemented in the process only to a very limited extent or not at all. For example, the organic compounds can comprise further functional groups from the further specified substance classes: Halides: -X (where X is F, Cl, Br, I), Alcohols: -OH, Phenols: Ar-OH (Ar with at least one aromatic ring), Ethers: RO-R', where R and R' are an alkyl or aromatic radical, Epoxides, Amines: -NH2, -NHR, or -NR2, Amides: -CONH2, -CONHR, or -CONR2, Nitriles: -C=N, Aldehydes: -CHO, Ketones: R-CO-R' where R and R' are an alkyl or aromatic radical, Carboxylic acids: -COOH, Esters: R-COO-R' where R and R' are an alkyl or aromatic radical, Acid chlorides: -COC1, Carboxylic anhydrides: -CO-O-CO-, Thiols: -SH, Thioethers (sulfides): RS-R', Disulfides: RS- S-R', isocyanates: -N=C=O, isothiocyanates: -N=C=S, nitro: -NO2, azides: -N3, alkoxides: R- O(-), acetals and ketals: RC(OR')2, isocyanates: -N=C=O, oximes: RC=NOH.The compounds can be present as such or in the form of salts. Suitable salts can, for example, be selected from the group consisting of salts containing P, Si, alkali, alkaline earth, or generally metal atoms.

[0020] Within a preferred aspect of the process, the organic compounds can have on average at least two CC double bonds and / or on average at least one CC triple bond per molecule. The process described here is particularly suitable for effecting the selective hydrogenation of organic compounds having multiple double or triple bonds. In these cases, the unsaturated CC bonds are preferably not completely hydrogenated, but rather the number of unsaturated compounds is reduced to an average of one monounsaturated compound per molecule, with preferably at least 75 mol%, preferably at least 85 mol%, more preferably at least 95 mol%, and furthermore preferably at least 98 mol% of the organic compounds carrying a double bond.This group of reactants can be derived particularly from natural raw material sources that exhibit a statistical distribution of functional groups and unsaturated carbon–carbon bonds. The process allows the chemical properties of this group of substances to be highly homogenized, making it suitable as a chemically defined reactant class for further chemical transformations.

[0021] In a preferred embodiment, the liquid can consist of greater than or equal to 75 wt.% organic compounds. Very efficient reactions can be achieved in cases where the liquid has a very high proportion of organic compounds. Preferably, the proportion of organic compounds in the liquid can be greater than or equal to 85 wt.%, furthermore greater than or equal to 95 wt. Furthermore, the liquid can preferably consist entirely of organic compounds without any additives.

[0022] In a preferred embodiment of the process, the organic compounds can be selected from the group consisting of unsaturated triacylglycerides, unsaturated fatty acids, unsaturated fatty acid alkyl esters, or mixtures of at least two members from this group. In particular, the group of fatty acids or their derivatives can be hydrogenated very selectively using the process according to the invention. Hardly any by-products are formed, and the other functional groups remain unchanged. Without being bound by theory, the oxygen groups in these compounds in particular appear to contribute to stabilizing the catalyst system, resulting in high conversions and high selectivities over long periods. It has also been shown that this reactant group can be chemically homogenized to a particularly high degree using the process, so that the hydrogenated products have, on average, only one double bond per molecule.The group of organic compounds used can preferably have an average C number of greater than or equal to 5 and less than or equal to 50, and more preferably greater than or equal to 7 and less than or equal to 20. Furthermore, the average number of double bonds can preferably be greater than or equal to 1.1 and less than or equal to 3.5, further preferably greater than or equal to 1.5 and less than or equal to 2.5. Suitable sources for the organic compounds are, for example, unrefined oils, for example sunflower oil, soybean oil, linseed oil, olive oil, cottonseed oil, jatropha oil, coconut oil, tung oil, palm oil, rapeseed oil, their alkyl esters or mixtures of at least two oils from this list. Thus, single or multiple esters, in particular methyl esters, ethyl esters, isopropyl esters, 2-ethylhexyl esters, triglycerides, free acids and alcohols of unsaturated hydrocarbon compounds, cyclic compounds, such as, for example,1,4-cyclohexadiene, 1,5-cyclooctadiene, 1,3,5,7-cyclooctatetraene, 1,5,9-cyclododecatriene, norbonadiene, dicyclopentadiene, and non-cyclic and cyclic mono-, sesqui-, and diterpenes, polyunsaturated oils and fats and their derivatives, in particular mono-, di-, tri-, tetra- and pentaesters of oleates, palmitoleates, gadoleates and erucates, linoleates, linolenates, as well as their free acids, alcohols and amines.

[0023] Within a preferred characteristic of the process, the liquid can have a viscosity, determined according to DIN 51562-1 at a temperature of 20°C, of ​​greater than or equal to 1 mPas and less than or equal to 500 mPas. Of the group of organic compounds that can be used according to the invention, those that exhibit a viscosity in the above-specified range have proven particularly suitable. This can be particularly advantageous in cases where the liquid consists of organic compounds. Without being bound by theory, this viscosity range appears suitable for achieving favorable detachment from the target surface and rapid distribution of the catalyst particles in the liquid, which leads to rapid and homogeneous hydrogenation of the organic compounds used.

[0024] In a preferred embodiment of the process, the liquid can have a thermal conductivity, determined according to ASTM D7896, of greater than or equal to 0.05 W / (m*K) and less than or equal to 5.0 W / (m*K). In combination with unsupported, in-situ generated catalyst particles, liquids can be used that have the thermal conductivities specified above. This can reduce the thermal load on the target and maintain the thermal imbalances on the catalyst surface for a sufficiently long time to enable efficient hydrogenation. This can increase yields and improve the service life of the catalyst particles.

[0025] In a preferred embodiment of the process, the liquid can be moved along the target in process step b) and / or process step d), wherein the movement speed of the liquid along the target is greater than or equal to 0.1 mm / s and less than or equal to 1000 mm / s. For rapid and complete hydrogenations, even of complex organic compounds, it can be advantageous for the liquid to be moved within the hydrogenation reaction. To achieve homogeneous hydrogenations, the above-specified liquid speeds along the target have proven particularly suitable. Particularly preferably, the movement speed can also be greater than or equal to 1 mm / s and less than or equal to 250 mm / s.

[0026] According to a preferred aspect of the process, the metal of the target can be selected from the group consisting of Ni, Co, Cu, Ag, Fe, or mixtures of at least two metals from this group. Efficient hydrogenations according to the specified process can be carried out not only with expensive precious metal catalysts. A major advantage of the process according to the invention is that high conversions with very good selectivity can be achieved with comparatively inexpensive catalysts from the above-mentioned group. Another advantage of this group is that the reacted catalysts can be separated relatively easily from the liquid and converted back into a target. Furthermore, the group can preferably also contain more expensive targets and include, for example, Pd, Pt, Ni, Rh, Co, Ru, Au, Ag, Fe, Ir. Compared to known reactions, this group also delivers efficient reactions and improved recoverability.

[0027] Within a preferred aspect of the method, the fluence of the laser energy emitted in step b) may be greater than or equal to 0.01 J / cm 2 and less than or equal to 100 J / cm 2 This energy range appears to be highly suitable for providing catalyst particles that are very suitable for hydrogenation, particularly for converting inhomogeneous organic compounds with multiple double bonds into more homogeneous products. Lower fluences can be disadvantageous, as this can reduce the achievable conversions too much. Higher fluences, on the other hand, can be disadvantageous, as in these cases the selectivity of the reaction is unnecessarily impaired. Preferably, the fluence can be greater than or equal to 0.05 J / cm 2 and less than or equal to 50 J / cm 2 , more preferably greater than or equal to 0.5 J / cm 2 and less than or equal to 10 J / cm 2 and more preferably greater than or equal to 0.75 J / cm2 and less than or equal to 2.5 J7 cm 2 be.

[0028] For ablation, for example, a pulsed laser with a wavelength of 532 nm and a pulse length of 18 ps can be used. The pulse duration can be less than 100 ns, for example, and a frequency in the range of 1 Hz to 10 kHz can be used. Average power levels in the range of 0.5 W and above are sufficient for rapid ablation. In general, different lasers can be used for ablation, with a wavelength in the range of 500 nm to 1100 nm being preferred. The laser beam can be focused onto the target using a lens, whereby the working distance (laser - target) can be in the range of 100 to 500 mm. The laser beam can be focused onto the target using a lens, whereby the focal length of a suitable focusing lens can be in the range of 100 to 300 mm.

[0029] The hydrogenation reaction can be carried out at a temperature in a range above the melting point of the substrate and / or solvent to be hydrogenated, preferably in a range between 0°C and 350°C. In particular, the reaction should preferably be carried out in a range between 20°C and 120°C, particularly preferably in a range around 50°C. The absolute pressure during the hydrogenation can range from 1 bar to 300 bar, preferably from 1 bar to 100 bar, particularly preferably from 10 bar to 60 bar.

[0030] The hydrogen used for the hydrogenation, which is supplied, for example, as a component of a gas mixture, can be present in this gas mixture in a proportion of at least 5 mol%, preferably in a proportion of >50 mol%.

[0031] The reaction time of the hydrogenation reaction can be up to 10 hours, but preferably the reaction time is within a range of up to 15 minutes, and particularly preferably the reaction time is within a range of up to 3 minutes. Furthermore, the proportion of catalyst particles can be within a range of up to 1% (w / w), preferably up to 0.01% (w / w), particularly preferably up to 0.002% (w / w).

[0032] Furthermore, the invention relates to a system of unsupported, in-situ generated metallic catalyst particles in a liquid medium, wherein the metal of the unsupported, in-situ generated catalyst particles is selected from the group consisting of Pd, Pt, Ni, Rh, Co, Cu, Ru, Au, Ag, Fe, Ir or mixtures of at least two metals from this list; the unsupported, in-situ generated catalyst particles have a number-averaged mean size, determined by means of transmission electron microscopy, of greater than or equal to 0.5 nm and less than or equal to 20 nm; the liquid medium comprises unsaturated organic compounds in a proportion of greater than or equal to 10 wt.%.

[0033] Surprisingly, it has been shown that unsupported catalyst particles dissolved in situ from a target by laser ablation in a liquid medium containing unsaturated organic compounds are catalytically very active and stable over a long period of time. Surprisingly, it was also found that the system of ablated nanoparticles exhibits high catalytic activity in the group of reactants usable according to the invention, without the particles having to be saturated with hydrogen or preformed before contact with the reactant. Thus, in situ preparation in a purely aqueous or polar solvent results in no or only very low hydrogenation activity upon addition of hydrogenable reactants without prior conditioning of the catalyst. The latter is necessary for other hydrogenation catalysts or reactants to achieve comparable catalytic activity.A wide variety of reactions, such as hydrogenations, can be carried out in the system according to the invention. Deposition of the catalyst particles onto a support or some other form of stabilization is rather disadvantageous for a wide variety of metal-catalyzed processes. This is most likely due to the fact that catalyst particles formed by ablation lose their electronic disequilibrium properties and thus some of their catalytic properties through further treatment steps. For further advantages of the system according to the invention, explicit reference is made to the advantages discussed in the process according to the invention. The organic compounds of the system can preferably be unrefined vegetable oils or their derivatives. The organic compounds can preferably have, on average, more than one double or triple bond in the molecule.The concentration of catalyst particles in the liquid medium can, for example, be greater than or equal to 200 ppb and less than or equal to 350 ppm.

[0034] Also within the meaning of the invention are unsupported catalyst particles, wherein the unsupported catalyst particles are obtainable by the process according to the invention.

[0035] Preferably, the liquid medium can consist of greater than or equal to 75 wt. % of at least partially unsaturated organic hydrocarbons or hydrocarbons with one or more functional groups containing one or more of the heteroatoms O, N, S, or halide. Furthermore, the liquid medium can preferably consist of the organic compounds.

[0036] Within a preferred characteristic of the system, the unsupported, in-situ generated catalyst particles can have a bimodal size distribution, with the bimodal size distribution having a maximum in the size distribution between greater than or equal to 1 nm and less than or equal to 4 nm and a further maximum between greater than or equal to 5 nm and less than or equal to 10 nm. For efficient conversion of the organic compounds, ablation of the target with the formation of a bimodal size distribution has proven particularly suitable. Efficient catalytic conversions can be carried out, which are characterized by high conversions and high selectivity. In particular, these catalyst particles allow efficient hydrogenations to be carried out in the presence of hydrogen. The size distribution reflects the number distribution of the particles, whereby the sizes can be determined, for example, using TEM.This catalyst particle size range can also advantageously be used in the process according to the invention.

[0037] In a preferred embodiment of the system, the liquid medium can be free of substances selected from the group consisting of water, surfactants, complexing agents, organic salts, or mixtures thereof. The system according to the invention can exhibit improved catalytic properties, particularly in cases where the catalyst particles are generated in situ, are not further chemically stabilized, and are unsupported. In these cases, the thermal and electrical disequilibrium states on the surface of the particles appear to be maintained longer and are available for catalytic conversions. The medium is free of the members of this above-mentioned group in cases where the concentration of these substances is below 0.5 wt. %, preferably below 0.1 wt. %. The amount of water in the liquid medium can be determined, for example, using Karl Fischer.Complexing agents are low-molecular-weight compounds that form stable electrostatic interactions with the catalyst particles and absorb onto the particles, whereby the bond remains intact even after the actual reactants of the catalytic conversion have entered. Individual members of the surfactant group, such as anionic, cationic, or amphoteric surfactants, are known to those skilled in the art.

[0038] In a preferred characteristic of the system, the liquid medium can comprise greater than or equal to 50 wt. % partially unsaturated organic hydrocarbons having at least one heteroatom selected from the group consisting of O, N, S, and halides. Particularly efficient and long-term stable catalyst particles can be provided in a liquid medium with a high proportion of unsaturated hydrocarbons containing additional heteroatoms. The particles retain their catalytic efficiency over a long period of time and can catalyze a wide variety of reactions very selectively. The compounds can be present as such or in the form of salts. Suitable salts can include, for example, P, Si, alkali, and alkaline earth metals in a salt form.

[0039] In a preferred embodiment of the system, hydrogen can be dissolved in the liquid medium at a concentration of greater than or equal to 0.001 mol / l and less than or equal to 10 mol / l. For efficient catalytic conversions in the form of hydrogenations of unsaturated organic compounds, the system can preferably contain hydrogen at the concentration specified above. These concentrations allow for rapid and selective conversions of the organic compounds.

[0040] In a preferred embodiment of the system, the concentration of the metal catalyst particles in the liquid medium can be greater than or equal to 100 ppb and less than or equal to 500 ppm. More preferably, the concentration can be greater than or equal to 1 ppm and less than or equal to 100 ppm. These small amounts of catalyst are suitable for the efficient conversion of the usable reactants. The stated amounts are the average over the entire conversion. This takes into account the fact that different amounts of catalyst metal can be present in the liquid within the catalytic conversions.

[0041] Furthermore, the invention relates to the use of the process according to the invention for converting natural vegetable oils, vegetable oil derivatives, or mixtures thereof into synthetic fuels or synthesis building blocks for chemical reactions. The process according to the invention and the system according to the invention are particularly suitable for providing chemically precisely defined reactants. These defined reactants are obtainable via the process according to the invention from chemically inhomogeneous, natural raw materials, which, due to their natural origin, exhibit a greater variance in composition. These variances in composition prevent use in larger quantities, since the different structures result in unacceptable properties of the products produced with these natural reactants.The process and system thus constitute a processing step in which the reactant properties are homogenized to such an extent that the converted natural reactants are suitable for use as defined synthesis building blocks in large-scale chemical processes. After passing through the process, these can be used, for example, as synthesis components in PU production or for the synthesis of polyesters. Furthermore, the process and system are suitable for refining natural vegetable oils, for example, through a hydrogenation step, so that the converted natural oils can be used as green fuels for use in combustion engines.

[0042] Furthermore, a method may be preferred, wherein the method is a method for hydrogenating a substrate, wherein the substrate comprises at least one unsaturated hydrocarbon compound and is carried out by means of the steps: a) providing a suspension at least comprising the substrate and colloidal catalyst particles produced by laser ablation, b) mixing the suspension with supply of hydrogen gas or a gas mixture containing at least partially hydrogen; c) terminating the supply of the hydrogen gas or the gas mixture containing at least partially hydrogen gas; d) removing the hydrogenated hydrocarbon compounds with or without the catalyst particles from a reaction chamber, wherein the colloidal catalyst particles are produced in-situ by laser ablation directly in the fluid substrate before the start of the hydrogenation and are present in dispersed form in the suspension.The hydrogenation can be carried out selectively, achieving complete or partial hydrogenation of the double bonds present in the substrate. The substrate can comprise hydrocarbon compounds and their derivatives that have at least one unsaturated CC bond, with the unsaturated CC bond preferably being conjugated or conjugable to at least two unsaturated CC bonds. The hydrocarbon compounds of the substrate can comprise olefins, alkynes, and aromatics, with the olefins and alkynes being cyclic or branched, open-chain, or linear.The compounds of the substrate may comprise one or more functional groups selected from the following classes of substances: halides, alcohols, phenols, ethers, epoxides, amines, amides, nitriles, aldehydes, ketones, carboxylic acids, carboxylic acid esters, acid chlorides, carboxylic acid anhydrides, thiols, thioethers, disulfides, isocyanates, isothiocyanates, nitrites, azides, alkoxides, nitrates, acetals, ketals, isocyanates, oximes, whereby the functional group of the substrate that gives the substance class its name arises unchanged from the hydrogenation of the substrate. The catalyst particles produced may contain at least one element from transition groups six to eleven of the periodic table, particularly preferably rhodium and / or palladium and / or nickel and / or platinum and / or iridium and / or ruthenium and / or iron.The substrate can be provided together with an inert solvent, wherein the inert solvent comprises water and / or saturated hydrocarbon compounds, which in particular include alkanes, cycloalkanes, alcohols, cyclic alcohols, polyols, carbonates, and cyclic carbonates. The saturated hydrocarbons of the inert solvent can carry at least one or more functional groups selected from the following substance classes: halides, alcohols, phenols, ethers, epoxides, amines, amides, nitriles, aldehydes, ketones, carboxylic acids, carboxylic acid esters, acid chlorides, carboxylic acid anhydrides, thiols, thioethers, disulfides, isocyanates, isothiocyanates, nitrites, azides, alkoxides, nitrates, acetals, ketals, isocyanates, and oximes, wherein the hydrogenation of the substrate occurs without altering the functional groups of the solvent.The substrate can be solid-like or viscous and can be mixed with the inert solvent in a ratio ranging from 99:1 (w / w) to 1:99 (w / w). The process of preparing the suspension, reaction, and separation can be carried out continuously or discontinuously, particularly in a continuously flowing reaction chamber. The hydrogenation reaction can be carried out at a temperature in a range above the melting point of the substrate and / or solvent, preferably above the melting point of the substrate and / or solvent up to a temperature of 350°C, preferably in a range between 0°C and 350°C, particularly preferably in a range between 20°C and 120°C, particularly preferably around 50°C, and / or the hydrogenation can be carried out at a hydrogen partial pressure of 1 bar to 300 bar, preferably 1 bar to 180 bar, particularly preferably 10 bar to 60 bar.The hydrogen can be supplied as a component of a gas mixture in which it is present in a proportion of at least 5 mol%, preferably in a proportion of >50 mol%. The reaction time can be in a range of up to 10 hours, preferably in a range of up to 3 hours, particularly preferably in a range of up to 15 minutes, very particularly preferably in a range of up to 3 minutes, and / or the proportion of catalyst particles in the suspension can be in a range of up to 10% (w / w), preferably in a range of up to 0.01% (w / w), particularly preferably in a range of up to 0.002% (w / w).The catalyst particles can be separated by a process based on density difference, in particular centrifugation, cyclone separation, or sedimentation, or by processes based on particle size difference, in particular filtration or osmosis, or by interaction processes in an electric or magnetic field, preferably electrophoresis and particularly preferably free-flow electrophoresis. Furthermore, the catalyst particles can be used for the hydrogenation of substrates used in the chemical industry, in particular in the food, polymer, elastomer, cosmetic, surfactant, coating, adhesive, paint, lubricant, chemical, oleo, and / or pharmaceutical industries.

[0043] The invention is explained using the following experimental variants and examples.

[0044] Variant 1 : Particles in reactant in batch operation

[0045] The particles are produced by pulsed laser ablation under ambient conditions in a continuously flowing reactant. The reactant, containing catalyst particles, is fed into the reaction chamber. The reaction chamber is heated to reaction conditions while being thoroughly mixed, followed by three consecutive evacuations and purging with inert gas. The evacuated reaction chamber is pressurized with hydrogen. The reaction proceeds with constant mixing and temperature control. The reaction takes place under constant pressure, and the consumed hydrogen is continuously replenished. The reaction progress is determined by the hydrogen consumed in the reaction. When the desired reaction progress is reached, the reaction solution is cooled, the hydrogen is removed, and the reactor is purged with inert gas. The product is removed from the reaction chamber.The catalyst-containing product is transferred to a sedimentation tank and, after a suitable residence time, removed without catalyst. The catalyst can be removed as the lower phase and, after processing, returned to the process.

[0046] Variant 2: Particles in reactant continuously

[0047] The particles are produced by pulsed laser ablation under ambient conditions in a continuously flowing reactant. The reactant, coated with catalyst particles, is heated and fed into the already evacuated reaction chamber. The reaction chamber is brought to reaction pressure by mixing with hydrogen. The reaction proceeds with constant mixing and temperature control. The reaction takes place under constant pressure, and consumed hydrogen is continuously replenished. Once the desired reaction progress is reached / the predetermined average residence time has elapsed, the hydrogen is removed, and the product is removed from the reaction chamber. The catalyst-containing product is transferred to a suitable separation operation, such as a sedimentation tank, and after a suitable residence time, is removed without the catalyst. The catalyst can be removed as the lower phase and returned to the process after processing.

[0048] Example 1: To prepare the catalyst particle-containing suspension, soy methyl ester is continuously pumped through a suitable ablation cell containing a Pd target. A pulsed laser scans the target with a pulse duration of 40 ns, a frequency of 5 kHz, a power of 27 W, a pulse energy of 5.4 mJ, a wavelength of 1064 nm, a working distance of 310 mm, and a lens focal length of 254 mm, with the soy methyl ester remaining in the cell for 15 s. A sample of the suspension thus prepared is analyzed for its metal content using ICP-OES and shows a mass fraction of 11 ppm. 100 mL of the suspension thus prepared is then transferred to a pressure-resistant glass reactor equipped with a gas inlet stirrer. The reactor is sealed, purged twice with argon as an inert gas, and then vacuumized.The reactor is heated to a temperature of 50°C using a magnetically stirred oil bath and rotated at 3400 rpm. 1 stirred. To start the hydrogenation, the hydrogen supply is started and the pressure in the reactor is kept constant at 10 bar using a mass flow controller. The amount of hydrogen consumed is recorded, and the hydrogen supply is interrupted after a previously calculated 128 mmol of hydrogen has been consumed (substrate-specific amount of hydrogen = amount of C18:2 + 2*amount of C18:3). The stirrer is then switched off, the remaining hydrogen atmosphere is first released, and then purged with nitrogen. The reactor is cooled in air to ambient temperature. The reactor is then opened, the reaction mixture is removed, and analyzed by GC-FID and ICP-OES. The composition of the substrate before and after hydrogenation can be found in the following table.

[0049] Example 1 : See above The ester groups show no chemical changes during the hydrogenation step. This results in a very selective hydrogenation of the compounds. ICP-OES measurements show a constant mass content of 11 ppm Pd.

[0050] Example 2: As in Example 1, except that the unsaturated substrate and acetone were present in a mass ratio of 1:1. The reaction took place at 20°C and 10 bar. The reaction time was 3 hours.

[0051] A clear trend toward the generation of monounsaturated compounds can be observed, while the proportion of nonunsaturated compounds remains almost constant. Thus, products with only one double bond are formed very specifically.

[0052] Example 3: As in Example 1, except that the unsaturated substrate is present with acetonitrile in a mass ratio of 1:1. The reaction proceeded at 20°C. Reaction time: 3 hours.

[0053] A clear trend toward the generation of monounsaturated compounds can be observed, while the proportion of nonunsaturated compounds remains almost constant. Thus, products with only one double bond are formed very specifically.

[0054] Example 4: As in Example 1, except that the unsaturated substrate and toluene were present in a mass ratio of 1:4. The reaction took place at 20°C and 10 bar. The reaction time was 3 hours.

[0055] Example 5: As in Example 1, except that the unsaturated substrate and hexanamide were present in a mass ratio of 135:1. The reaction proceeded at 20°C and 10 bar. Reaction time: 3 h.

[0056] Example 6: As in Example 1, except that the unsaturated substrate is present with 1-hexanol in a mass ratio of 1.5:1. The reaction proceeded at 20°C and 10 bar. Reaction time: 3 h.

[0057] Example 7: As in Example 1, except that the unsaturated substrate is present with hexanal in a mass ratio of 9:1. The reaction proceeded at 20°C and 10 bar. Reaction time: 3 h. Example 8: As in Example 1, except that the unsaturated substrate and cyclohexane were present in a mass ratio of 1:1. The reaction proceeded at 20°C and 10 bar. Reaction time: 3 h.

[0058] Examples 1-8 demonstrate the activity and selectivity of the catalytic system, both with respect to the hydrogenation of CC double bonds compared to other tunable functional groups and the selectivity towards monounsaturated hydrocarbons.

[0059] The reaction is therefore very selective for hydrogenation, with other functional groups either not being converted at all or only to a very small extent. Furthermore, the reaction predominantly forms monounsaturated compounds. Example 9: As in Example 1, but the unsaturated substrate is linseed oil, which is filled with propylene carbonate after ablation, with propylene carbonate present in a mass ratio of 4:1. The reaction took place at 80°C and 10 bar. Example 10: As in Example 9, except that the unsaturated substrate is soy methyl ester and is present with propylene carbonate in a ratio of 4:1, the reaction taking place at 50°C and 10 bar. Example 11: As Example 9, where the unsaturated substrate is soy biodiesel and is present with propylene carbonate in a ratio of 4:1, the reaction taking place at 50°C and 10 bar.

[0060] Example 12: As in Example 9, except that the unsaturated substrate is linseed methyl ester and is present with propylene carbonate in a mass ratio of 4:1, the reaction taking place at 80°C and 10 bar.

[0061] Example 13: As in Example 9, except that the unsaturated substrate is sunflower oil and is present with propylene carbonate in a mass ratio of 4:1, the reaction taking place at 50°C and 10 bar.

[0062] Example 14: As in Example 9, except that the unsaturated substrate is sunflower methyl ester and is present with propylene carbonate in a mass ratio of 4:1, the reaction taking place at 50°C and 10 bar.

[0063] Example 15: As Example 9, where the unsaturated substrate is rapeseed oil and is present with propylene carbonate in a mass ratio of 4:1, the reaction proceeded at 50°C and 10 bar.

[0064] Example 16: As in Example 9, except that the unsaturated substrate is rapeseed methyl ester and is present with propylene carbonate in a mass ratio of 4:1, the reaction taking place at 50°C and 10 bar.

[0065] Example 17: As Example 9, where the unsaturated substrate is tung oil and is present with propylene carbonate in a mass ratio of 4:1, the reaction proceeded at 50°C and 10 bar. Example 18: As in Example 9, except that the unsaturated substrate is tungsten methyl ester and is present with propylene carbonate in a mass ratio of 4:1, the reaction taking place at 50°C and 10 bar.

[0066] Example 19: As Example 9, where the unsaturated substrate is hemp oil and is present with propylene carbonate in a ratio of 4:1, the reaction taking place at 50°C and 10 bar. Example 20: As in Example 9, except that the metal is Pd. A sample of the suspension thus prepared is analyzed for its metal content using ICP-OES and shows a mass fraction of 19 ppm. This 30 mL suspension is made up to 100 mL with soy methyl ester. The reaction proceeds at 50°C and 10 bar. The reaction time is 3 h.

[0067] Examples 9-20 demonstrate the activity of the catalytic system when using different substrates. Unsaturated methyl esters, triglycerides, and fatty acids can be hydrogenated. Both with and without the addition of a solvent after ablation, the catalysis shows high activity and high conversion of the polyunsaturated compounds.

[0068] Example 21: As in Example 9, except that the palladium particles were ablated into the solvent propylene carbonate and the unsaturated reactant was added before the catalyst particles were contacted with hydrogen. Reaction time: 116 hours. Reaction temperature: 80°C.

[0069] Example 21 shows a significantly reduced hydrogenation activity in cases where the particles are first prepared in situ in a solvent and contacted with the unsaturated reactant without preforming with hydrogen. In this process, almost no hydrogenation conversion occurs.

[0070] Example 22: As in Example 21, except that the particles are contacted with hydrogen for 15 minutes before contacting the unsaturated reactant. Reaction time: 2 hours.

[0071] The comparison between Examples 21, 22, and 20 shows that the particles produced in a stabilizing (polar) solvent such as propylene carbonate must be contacted with hydrogen before being mixed with the unsaturated reactant. If this is not done, the catalyst exhibits virtually no catalytic activity in the hydrogenation. In comparison, the particles produced according to the invention (e.g., Example 20), i.e., the particles produced directly in the reactant and only subsequently contacted with hydrogen, exhibit very high catalytic activity. This indicates that the reactants usable according to the invention influence the catalytic properties of the ablated particles toward improved hydrogenation performance or improved catalytic activity.

[0072] Example 23: As in Example 1, except that the metal is Fe. A sample of the suspension thus prepared is analyzed for its metal content using ICP-OES and shows a mass fraction of 38 ppm. This 70 mL suspension is made up to 100 mL with soy methyl ester. The reaction proceeds at 80°C and 10 bar. The reaction time is 3 h.

[0073] Example 23 demonstrates a relatively high catalytic activity and selectivity for iron compared to other known effective hydrogenation catalysts. It is expected that by optimizing the reaction parameters, especially pressure, temperature, and reaction vessel, higher catalytic activity can be achieved with this relatively inexpensive metal.

[0074] Example 24: As in Example 1, the supplied gas was a 1:1 mixture of argon and hydrogen. The reaction took place at 20°C and 10 bar. The reaction time was 3 hours.

[0075] Example 24 demonstrates the activity and selectivity of the catalytic system when the gas mixture is diluted. Efficient hydrogenations can also be carried out with gas mixtures containing hydrogen.

[0076] Example 25: As in Example 1, the conditions in catalyst production by pulsed laser ablation change to: A pulsed laser scans the target with a pulse duration of 1 ns, a frequency of 1 kHz, a power of 0.5 W, a fluence of 1.8 J / cm 2 , a spot diameter on the target of 0.1 mm, a wavelength of 1064 nm, and a lens focal length of 50 mm, with a soy methyl ester flow rate through the ablation process of 0.06 ml / s. The residence time in the ablation cell was 8.33 s. A sample of the resulting suspension was analyzed for its metal content using ICP-OES and showed a mass fraction of 19 ppm. This 16 mL suspension was made up to 100 mL with soy methyl ester.

[0077] The 100 mL of the resulting suspension are then transferred to a pressure-resistant glass reactor equipped with a gas-introducing stirrer. The reactor is sealed and purged twice with argon as an inert gas, and then vacuumed. The reactor is heated to 50°C using a magnetically stirred oil bath and agitated at 3400 rpm. 1Stirred. To start the hydrogenation, the hydrogen supply is started, and the pressure in the reactor is kept constant at 10 bar using a mass flow controller. The amount of hydrogen consumed is recorded, and the hydrogen supply is interrupted after the previously calculated 128 mmol of hydrogen consumed (substrate-specific amount of hydrogen = amount of C18:2 + 2*amount of C18:3). Reaction time: 140 min. The stirrer is then switched off, the remaining hydrogen atmosphere is first released, and then purged with nitrogen. The reactor is cooled in air to ambient temperature. The reactor is then opened, the reaction mixture is removed, and analyzed by GC-FID and ICP-OES.

[0078] The composition of the substrate before and after hydrogenation can be seen in the following table.

[0079] Example 26: As in Example 24, except that the unsaturated substrate is rapeseed oil. The ablation is carried out at a flow rate of 0.01 ml / s. The residence time in the ablation cell is 50 s. A sample of the suspension thus prepared is analyzed for its metal content using ICP-OES and shows a mass fraction of 96 ppm. This suspension, which is 115 mL, is made up to 2200 mL with rapeseed oil. The metal content in this mixture is 5 ppm. The 2200 mL of the suspension thus prepared is then transferred to a pressure-resistant stainless steel reactor with a viewing window and a gas-introducing stirrer. The reactor is sealed and purged twice with argon as an inert gas, and then vacuumized. The reactor is heated to a temperature of 120°C using a double-jacketed tempering oil and stirred at 2200 rpm. 1Stirred. To start the hydrogenation, the hydrogen supply is started, and the pressure in the reactor is kept constant at 8 bar using a mass flow controller. The amount of hydrogen consumed is recorded, and the hydrogen supply is discontinued after the previously calculated 79 mmol of hydrogen consumed (substrate-specific hydrogen amount = amount of C18:2 + 2*amount of C18:3). Reaction time: 77 min. The stirrer is then switched off, the remaining hydrogen atmosphere is first released, and then purged with nitrogen. The reactor is actively cooled to ambient temperature. The reactor is then opened, the reaction mixture is removed, and analyzed by GC-FID and ICP-OES. The composition of the substrate before and after hydrogenation can be found in the following table.

[0080] Example 27: As in Example 1, the conditions in catalyst production by pulsed laser ablation change to: A pulsed laser scans the target with a pulse duration of 1 ns, a frequency of 1 kHz, a power of 0.5 W, a fluence of 1.8 J / cm 2 , a spot diameter on the target of 0.1 mm, a wavelength of 1064 nm, and a lens focal length of 50 mm, with a butynol flow rate through the ablation of 0.02 ml / s. Residence time in the ablation cell was 25 s. A sample of the suspension thus prepared was analyzed for its metal content using ICP-OES and showed a mass fraction of 134 ppm. This suspension, which contains 9.4 mL, was made up to 50 mL with butynol. The metal content of the mixture was 25.2 ppm.

[0081] The 50 mL of the resulting suspension are then transferred to a pressure-resistant stainless steel reactor equipped with a gas-introducing stirrer. The reactor is sealed and purged twice with argon as an inert gas, and then vacuumed. The reactor is heated to 20°C using an electric heating jacket and circulated at 1500 rpm. 1 Stirred. To start the hydrogenation, the hydrogen supply is started, and the pressure in the reactor is kept constant at 50 bar using a mass flow controller. The amount of hydrogen consumed is recorded, and the supply is stopped after a previously calculated 637 mol. Reaction time: 203 min. The stirrer is then turned off, the remaining hydrogen atmosphere is first released, and then purged with nitrogen. The reactor is cooled to ambient temperature in air. The reactor is then opened, the reaction mixture is removed, and analyzed by GC-FID and ICP-OES.

[0082] The composition of the substrate before and after hydrogenation can be seen in the following table.

[0083] Using the process according to the invention and the systems according to the invention, even triple CC conditions can be converted very efficiently into compounds with only one CC double bond. These reactions are highly selective and, for example, leave OH groups untouched during hydrogenation reactions.

[0084] Figures 1 and 2 show transmission electron microscope images of a system according to the invention. Figure 1 shows, at a relatively high magnification, in-situ ablated Pd particles in a reactant SME (according to Example 1) that can be used according to the invention. Figure 2 shows an enlarged section, with the ablated particles visible as dark shadows.

Claims

Patent claims 1. A process for the metal-catalyzed hydrogenation of organic compounds having at least one CC double bond or at least one CC triple bond or mixtures thereof, by means of unsupported, in-situ generated catalyst particles, the process comprising the steps of: a) contacting a liquid comprising the organic compounds with a metallic target, wherein the target comprises one or more metals selected from the group consisting of Pd, Pt, Ni, Rh, Co, Cu, Ru, Au, Ag, Fe, Ir; b) removing catalyst particles from a surface of the metallic target by emitting laser energy through the liquid onto the surface of the metallic target, thereby obtaining unsupported, in-situ generated catalyst particles; c) adding hydrogen to the liquid, wherein the addition of hydrogen to the liquid takes place before, after and / or during process step b);and d) at least partially hydrogenating the organic compounds.; 2. The process according to claim 1, wherein the organic compounds comprise, in addition to the CC double bond or CC triple bond, at least one further functional group, wherein the functional group has a heteroatom selected from the group consisting of O, N, S, halides or combinations of these elements.

3. Process according to one of the preceding claims, wherein the organic compounds have on average at least two CC double bonds and / or on average at least one CC triple bond per molecule.

4. A process according to any one of the preceding claims, wherein the organic compounds are selected from the group consisting of unsaturated triacylglycerides, unsaturated saturated fatty acids, unsaturated fatty acid alkyl esters or mixtures of at least two members from this group.

5. Method according to one of the preceding claims, wherein the liquid has a viscosity, determined according to DIN 51562-1 at a temperature of 20°C, of ​​greater than or equal to 1 mPas and less than or equal to 500 mPas.

6. A method according to any one of the preceding claims, wherein the liquid has a thermal conductivity, determined according to ASTM D7896, of greater than or equal to 0.05 W / (m*K) and less than or equal to 5.0 W / (m*K).

7. Method according to one of the preceding claims, wherein the liquid is moved along the target in method step b) and / or method step d), the movement speed of the liquid along the target being greater than or equal to 0.1 mm / s and less than or equal to 1000 mm / s.

8. The method according to any one of the preceding claims, wherein the metal of the target is selected from the group consisting of Ni, Co, Cu, Ag, Fe or mixtures of at least two metals from this group.

9. Method according to one of the preceding claims, wherein the fluence of the laser energy emitted in method step b) is greater than or equal to 0.01 J / cm 2 and less than or equal to 100 J / cm 2 is.

10. A system of unsupported, in-situ generated metallic catalyst particles in a liquid medium, characterized in that - the metal of the unsupported, in-situ generated catalyst particles is selected from the group consisting of Pd, Pt, Ni, Rh, Co, Cu, Ru, Au, Ag, Fe, Ir or mixtures of at least two metals from this list; - the unsupported, in-situ generated catalyst particles have a number-average mean size, determined by transmission electron microscopy, of greater than or equal to 0.5 nm and less than or equal to 20 nm; - the liquid medium contains unsaturated organic compounds in a proportion of greater than or equal to 10% by weight.

11. The system according to claim 10, wherein the unsupported, in-situ generated catalyst particles have a bimodal size distribution, wherein the bimodal size distribution has a maximum in the size distribution between greater than or equal to 1 nm and less than or equal to 4 nm and a further maximum between greater than or equal to 5 nm and less than or equal to 10 nm.

12. System according to one of claims 10 or 11, wherein the liquid medium is free of substances selected from the group consisting of water, surfactants, complexing agents, organic salts or mixtures thereof.

13. System according to one of claims 10 to 12, wherein the liquid medium comprises greater than or equal to 50% by weight of partially unsaturated organic hydrocarbons having at least one heteroatom selected from the group consisting of O, N, S, halides.

14. System according to one of claims 10 to 13, wherein hydrogen is dissolved in the liquid medium in a concentration of greater than or equal to 0.001 mol / l and less than or equal to 10 mol / l.

15. Use of a process according to any one of claims 1 to 9 for converting natural vegetable oils, vegetable oil derivatives or mixtures thereof into synthetic fuels or synthesis building blocks of chemical reactions.

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