EP4237371A1

EP4237371A1 - Device for producing a fluid by catalytic reaction, comprising a recuperator

Info

Publication number: EP4237371A1
Application number: EP21794183.0A
Authority: EP
Inventors: Luc Aixala; Vincent Faucheux; Florian D'AMBRA; Emmanuel Nicolas; Raphaël SILVA COSTA
Original assignee: Commissariat a lEnergie Atomique CEA; Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Current assignee: Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Priority date: 2020-10-28
Filing date: 2021-10-27
Publication date: 2023-09-06
Also published as: WO2022090345A1

Abstract

The present invention relates to a device for producing a fluid by catalytic reaction from a storage fluid, comprising a recuperator, and also the use of the device for producing the fluid, and a method for producing said fluid using a recuperator. The invention also relates to a method for producing the device.

Description

DEVICE FOR THE PREPARATION OF A FLUID BY REACTION

CATALYTIC INCLUDING RECOVERY

The present invention relates to a device for the preparation of a fluid by catalytic reaction from a storage fluid, comprising a recuperator, but also the use of said device for the preparation of said fluid, and a process for the preparation of said fluid using a recoverer. The invention also relates to a process for preparing said device.

The present invention also relates to new organic hydrogen-carrying liquids (LOHCs), as well as the corresponding LOHC/dehydrogenated LOHC pairs. The invention also relates to their uses for the transport and storage of hydrogen, and the hydrogen generation processes using them.

After more than a century of intensive use of fossil fuels as the predominant source of energy, these natural resources are being depleted and there is an increasing need to develop alternative energy sources to replace traditional sources. These must be inexpensive, safe, non-polluting and easy to implement.

For these reasons, stable organic fluids have been developed in particular capable of storing and releasing in a safe and efficient manner an energetic fluid, for example a fuel, by means of a catalytic reaction.

Containing the highest energy density per unit mass and producing only water when burned or oxidized in a hydrogen-oxygen fuel cell, hydrogen is considered one of the most efficient and efficient candidates. the most environmentally friendly as a future fuel. Hydrogen is a very energetic compound compared to conventional fossil fuels and burns in air at widely varying concentrations (including 5% to 75%).

The concept of using hydrogen as an important energy carrier was suggested as far back as the 1970s. However, hydrogen storage is one of the key points to access the attractive "energy era". 'hydrogen". Thus, a major challenge is to find suitable hydrogen carriers. For decades, scientists have been searching for suitable materials for hydrogen storage.

Recently, organic compounds, such as formic acid, methanol-water, formaldehyde-water mixtures, and carbohydrates, have been intensively investigated as potential hydrogen storage materials. Among them are organic liquid hydrogen carriers (LOHC), which can be dehydrogenated and hydrogenated by involving considerable amounts of hydrogen (typically more than 10% by mass of th storage) and could be used for ground transportation applications, are of particular interest.

However, the dehydrogenation reaction of LOHCs takes place at high temperature and is endothermic, which requires a significant external energy input (for example using part of the dihydrogen generated or the battery of a vehicle) and impairs the energy efficiency of the system.

The present invention makes it possible in particular to appreciably limit the energy necessary to release the fluid from its source, which increases the energy efficiency linked to said fluid, and when an on-board system is considered, the autonomy of the vehicle wearing.

In principle, hydrogen is attached to the hydrogen-poor organic liquid (dehydrogenated LOHC) through a hydrogenation reaction to produce a hydrogen-rich organic liquid (hydrogenated LOHC) which should be a stable liquid under ambient conditions and therefore transportable and storable. The hydrogen-rich organic liquid is then dehydrogenated in a second reaction to regenerate the hydrogen and the hydrogen-poor organic liquid. Advantageously, these LOHCs are therefore capable of being hydrogenated and dehydrogenated reversibly in the presence of a catalyst. In addition, thanks to their high volumetric density (50-100 g of hydrogen per liter of hydrogenated LOHC) and mass content (typically 5-10 mass % of hydrogen in the hydrogenated LOHC) and their stability in ambient conditions it It is possible to transport and store them in simple tanks, cisterns or pipelines. The most cited LOHCs are aromatic hydrocarbons and heteroaromatic compounds of the carbazole family. The aromatic hydrocarbons are most particularly benzene, toluene, naphthalene, biphenyl derivatives, benzyltoluenes including dibenzyltoluenes (DBT). They form, in their hydrogenated form, cyclic alkanes. These compounds have the advantage of having a wide temperature range for their implementation in liquid form, for example from −40° C. to more than 300° C. for the dibenzyltoluene/perhydrodibenzyltoluene pair. In addition, these aromatic compounds, as well as their cyclic alkanes, exhibit great stability. Finally, certain aromatic compounds such as toluene are produced worldwide on significant scales (25 Mt/year for toluene) allowing rapid development of this type of transport for hydrogen to be envisaged. Their hydrogenation is carried out at high pressure and moderate temperature (example of DBT: 40-80 bar, 180°C, -71 kJ/molH2) while dehydrogenation is carried out at atmospheric pressure and higher temperature (example of TBD: 1 bar, 300°C, 71 kJ/molH2). As regards the heteroaromatic compounds of the carbazole family, the most frequent compounds are N-ethylcarbazole (NEC) and the derivatives furans, pyrroles and indoles. In this case, the hydrogenation reaction leads to cyclic amines or cyclic ethers.

However, all of these compounds do not give complete satisfaction. Thus, the main high-performance catalysts used during the hydrogenation and dehydrogenation reactions of the LOHCs presented above are based on platinum, iridium, rhodium, ruthenium or palladium. However, these metals are not widely available on the planet and therefore very expensive. Some alternatives using nickel-based catalysts have been proposed, but their low activity (300 to 3000 times lower than ruthenium-based catalysts) is an obstacle to their use in an industrial context.

Furthermore, these compounds are mainly obtained from non-renewable fossil resources, which are depleting as mentioned above. Consequently, the hydrogen transported by these vectors cannot be considered as perfectly decarbonized.

The object of the invention is therefore to provide new hydrogenated organic liquids capable of generating, by catalytic dehydrogenation, hydrogen contents by mass and volume which are satisfactory or even higher than those generated by certain conventional LOHCs, including at least one of the compounds of the dehydrogenated LOHC/LOHC pair hydrogenated can be synthesized from a biosourced, renewable resource, such as wood lignin, for example.

Another object of the invention is to provide new hydrogenated organic liquids which can be dehydrogenated by reactions which can be at least partially catalyzed by more available metals, which makes it possible in particular to reduce the use of catalysts based on noble metals, and therefore savings.

Yet another object of the invention is to provide hydrogenated LOHCs whose dehydrogenated counterparts have the ability to hydrogenate catalytically and reversibly, as well as dehydrogenated LOHCs having the ability to hydrogenate catalytically and reversibly to these hydrogenated LOHCs.

Yet another object of the invention is to provide a process for the dehydrogenation of these new hydrogenated organic liquids which is efficient, with high conversion, and selective (to avoid any degradation of the LOHC) while using fewer catalysts based on noble metals. .

Thus, according to a first aspect, the invention relates to a device for the preparation of a second fluid by catalytic reaction from a first fluid, source of said second fluid, the device comprising at least one inlet (1) of the first fluid communicating with one or more first columns (2), which also communicate with at least one outlet (6) of the second fluid, and with one or more second columns (7), which also communicate with at least one outlet (10) of the first fluid discharged from the second fluid, the first column(s) (2) comprising a zone (4) for heating the first fluid, in contact with one or several external heating means, said zone (4) also being a heterogeneous catalysis zone (5) or followed by a heterogeneous catalysis zone (5), characterized in that the second column or columns (7) comprise a zone ( 8) comprising one or more heat exchangers (9) serving as a heat source for a zone (3) for heating the first fluid of the first column(s) (2), said zone (3) preceding or merging with said zone ( 4).

According to a particular embodiment, zones (3) and (4) coincide. In this case, this zone (3,4) of one or more columns (2) is a zone for heating the first fluid both by the first fluid discharged from the second fluid obtained at the end of step iii) , using one or more heat exchangers, and by one or more external heating means. For example, one or more elements of the heat exchanger(s) can also play the role of external heating means, in particular by Joule effect, by being connected to an electrical source.

According to a particular embodiment, zones (4) and (5) coincide. In this case, this zone (4.5) of one or more columns (2) comprises the catalyst as well as one or more external heating means.

According to a particular embodiment, zones (3), (4) and (5) coincide. In this case, this zone (3,4,5) of one or more columns (2) comprises the catalyst and is also a zone for heating the first fluid both by the first fluid discharged from the second fluid obtained at the from step iii), using one or more heat exchangers, and by one or more external heating means.

The external heating means or means are for example chosen from electrical resistors and heating means by combustion of dihydrogen.

According to a particular embodiment, the catalyst of heterogeneous catalysis zone (5) consists of or contains one or more catalysts based on copper, platinum, palladium, iridium, rhodium, or ruthenium.

According to a particular embodiment, the catalyst of heterogeneous catalysis zone (5) is a fixed-bed catalyst, or a catalyst deposited on the surface of said zone (5). Thus, according to this particular embodiment, the heterogeneous catalysis zone (5) consists of or comprises a fixed bed of catalyst, or said catalyst deposited on all or part of its surface(s).

According to a particular embodiment, the section of the first column(s) (2) has an area ranging from 0.5 mm ² to 10 cm ² .

According to another aspect, the invention relates to a process for manufacturing the device as defined herein, in which the heat exchanger(s) (9) are obtained by 3D printing.

Thus, the invention also relates to a method of manufacturing the device as defined above, comprising a step of manufacturing the heat exchanger(s) (9) by 3D printing. The elements of the device other than the heat exchanger(s) (9) can be manufactured by any technique well known to those skilled in the art.

According to a particular embodiment, the 3D printing is 3D printing by selective laser sintering (SLS), by selective laser melting (SLM), by electron beam melting (EBM), or by binder sputtering (BJ) .

According to another aspect, the invention relates to the use of a device as defined previously for preparing by catalytic reaction a second fluid from a first fluid, source of said second fluid.

This use can in particular take place on board a vehicle, in particular when the second fluid is dihydrogen. The device according to the invention is then said to be embedded.

This use can also be stationary. In this case, the first fluid discharged from the second fluid can in particular be recharged with dihydrogen according to techniques well known to those skilled in the art, for example using dihydrogen produced by electrolysis of water. This first fluid discharged from the second fluid can also be stored, once it has left the device of the invention, in an adiabatic storage means, before recharging.

According to another aspect, the invention relates to a method for preparing a second fluid from a first fluid, source of said second fluid, by at least one generally endothermic chemical reaction, comprising:

(i) a step of heating the first fluid from a temperature TA to a temperature TB;

(ii) a step of heating the first fluid from the temperature TB to a temperature Te, the heating being carried out using one or more external heating means;

(iii) a step of converting said first fluid by said chemical reaction, in contact with a heterogeneous catalyst, to obtain said second fluid as well as the first fluid discharged from the second fluid, at a temperature TD lower than the temperature Te; (iv) a step for recovering the second fluid obtained in step iii); the partial or complete heating of step i) being carried out with the first fluid discharged from the second fluid obtained at the end of step iii), as a heat source, using one or more heat exchangers.

According to a particular embodiment, the method according to the invention is a method in which step i) and step ii) are combined, so as to constitute a step of heating the first fluid from a temperature TA to a temperature Te, the heating being carried out with as heat source at the same time:

- the first fluid discharged from the second fluid obtained at Tissue from step iii), using one or more heat exchangers; and

- one or more external heating means.

According to a particular embodiment, the method according to the invention comprises:

(i) a step of heating the first fluid from a temperature TA to a temperature TB in a heating zone (3) of one or more columns (2) communicating with at least one inlet (1) of the first fluid;

(ii) a step of heating the first fluid from the temperature TB to a temperature Te in a heating zone (4) of the first column or columns (2), the heating being carried out using one or more means external heaters;

(iii) a step of converting said first fluid by said chemical reaction, in contact with a heterogeneous catalyst, in a zone (5) of heterogeneous catalysis, to obtain said second fluid as well as the first fluid discharged from the second fluid, at a temperature TD lower than temperature Te;

(iv) a step of recovering the second fluid obtained in step iii) via the outlet (10) of said second fluid, and the first fluid discharged from the second fluid via one or more second columns (7); the partial or complete heating of step i) being carried out with as heat source the first fluid discharged from the second fluid obtained at Tissue from step iii) in a zone (8) of the second column or columns (7), using one or more heat exchangers (9).

According to a particular embodiment, the method according to the invention is a method in which step i) and step ii) are combined, so as to constitute a step of heating the first fluid from a temperature TA to a temperature Te in a zone (3,4) of one or more columns (2) communicating with at least one inlet (1) of the first fluid, the heating being carried out with as heat source both: - the first fluid discharged from the second fluid obtained at the end of step iii), using one or more heat exchangers; and

- one or more external heating means.

According to a particular embodiment, the first fluid is a liquid or a gas, in particular a liquid, the second fluid is a gas and the first discharged fluid is a liquid, the second fluid preferably being dihydrogen.

According to a more particular embodiment, the first fluid is an organic hydrogen-carrying liquid (LOHC), and the second fluid being dihydrogen.

According to an even more particular embodiment, the first fluid is an organic hydrogen-bearing liquid chosen from dibenzyltoluene (DBT), AZ-ethylcarbazolc (NEC), l,2-dihydro-l,2-azaborine (AB), acid formic (FA), naphthalene (NAP), toluene (TOL), acetophenone perhydrogens.

According to another more particular embodiment, the first fluid is a gas, the second fluid is dihydrogen, and the first discharged fluid is a liquid. This is, for example, the case of 1-cyclohexylethanol (whose boiling point is 190°C), which dehydrogenates to acetophenone (boiling point 200°C), when the temperature TD is approximately 195°C.

According to a particular embodiment, the invention relates to a method in which the first fluid is an organic hydrogen-carrying liquid (LOHC) and the second fluid is dihydrogen, and in which said dihydrogen is obtained at a flow rate of 1 at 50000 g.min ^-1 , in particular from 1 to 50 g.min ^-1 or from 1000 to 50000 g. min ¹ , more particularly about 20 or about 20,000 g.min ¹ .

According to a particular embodiment, the invention relates to a method in which the first fluid is an organic liquid hydrogen carrier (LOHC) and the second fluid is dihydrogen, and in which the enthalpy of the chemical reaction of the stage iii) is greater than or equal to 10 kJ.mol ⁻¹ , in particular comprised from 10 to 120 kJ.mol ⁻¹ , more particularly approximately 60 kJ.mol ¹ .

According to a particular embodiment, the invention relates to a method in which the first fluid is an organic hydrogen-bearing liquid (LOHC) and the second fluid is dihydrogen, and in which the temperature TA is in particular the ambient temperature, the temperature TB is between 200 and 300°C, upper limit excluded, in particular around 284°C, the temperature Te is between 300 and 375°C, in particular around 350°C, the temperature TD is between from room temperature to 100°C, in particular about 69°C. According to a particular embodiment, the first fluid is a liquid or a gas, the second fluid is a gas and the first discharged fluid is a gas.

According to a more particular embodiment, the first fluid being in particular NH3, and the second fluid being dihydrogen, and the first fluid discharged from dinitrogen.

According to another more particular embodiment, the first fluid being in particular methanol, and the second fluid being dihydrogen, and the first fluid discharged carbon dioxide.

According to a particular embodiment, the first fluid is a gas, the second fluid is a liquid.

According to a particular embodiment, the catalyst consists of or contains one or more catalysts based on copper, platinum, palladium, iridium, rhodium, or ruthenium.

According to a particular embodiment, the catalyst is a fixed-bed catalyst, or a catalyst deposited on the surface of the zone where step iii takes place), for example the catalysis zone of one or more columns.

According to another aspect, the invention also relates to a device for implementing the method as defined above.

Thus, according to another aspect, the invention relates to an organic liquid hydrogen carrier (LOHC) of formula (I) below: where: n is 0, 1, 2, 3, 4 or 5; at least one of the carbons being optionally substituted with a R group, independently selected from linear or branched C 1 to C 4 alkyls and Y groups;

X and Y are independently a perhydrogenated aryl group or a perhydrogenated heteroaryl group, said group being optionally substituted by at least one R2 group, independently chosen from linear or branched C1 to C4 alkyl groups, in particular methyl, O-alkyl groups linear or branched C1 to C4, in particular O-methyl, the groups -NR _a Rb, with R _a and Rb independently chosen from linear or branched C1 to C4 alkyl groups, in particular the group -N(Me)2. According to one embodiment, the invention relates to an organic hydrogen-carrying liquid (LOHC) of the following formula (Ia): where: n is 0, 1, 2, 3 or 4;

R1 is H, a linear or branched C1-C4 alkyl group, or a Y group.

X and Y are independently a perhydrogenated aryl group or a perhydrogenated heteroaryl group, said group being optionally substituted by at least one R2 group, independently chosen from linear or branched C1 to C4 alkyl groups, in particular methyl, O-alkyl groups linear or branched C1 to C4, in particular O-methyl, the groups -NR _a Rb, with R _a and Rb independently chosen from linear or branched C1 to C4 alkyl groups, in particular the group -N(Me)2.

The compounds of formula (I) and (la) preferably have a volumetric density of hydrogen varying from 50 g/L to 70 g/L and/or a mass content of hydrogen varying from 6% to 6.5%.

The volumetric density is calculated for 1 liter of hydrogenated vector by the formula (1): zg\ mass H2 released by the hydrogenated LOHC (g)

Volumetric density H2 - = - - - — — 7—— — -; — 7-777 - (1) vL Total hydrogen LOHC volume (L)

The mass content of hydrogen is determined by formula (2): mass H2 released by the hydrogenated LOHC (a) mass content of H2 (%)=100 x −; —; — 7—7— —: - - — - (2) total mass of hydrogenated LOHC g)

According to a particular embodiment, X is a perhydrogenated aryl group, X being in particular a cyclohexyl group.

According to another particular embodiment, X is a perhydrogenated heteroaryl group, X being chosen in particular from the piperidinyl, piperazinyl, hexahydropyrimidinyl and hexahydropyridazinyl groups.

According to a particular embodiment, n is 0, 1 or 2.

According to a particular embodiment, Ri is H or methyl.

According to a particular embodiment, the invention relates to an organic hydrogen-bearing liquid in which: Ri is H; Where

Ri is a group Y; and or

X is a perhydrogenated aryl group or a perhydrogenated heteroaryl group, said group being substituted by at least one R2 group, independently chosen from linear or branched C1 to C4 alkyl groups, linear or branched C1 to C4 O-alkyl groups, -NR _a Rb groups, with R _a and Rb independently selected from linear or branched C1 to C4 alkyl groups; and/or n is 1, 2, 3 or 4.

According to a particular embodiment, the hydrogen-bearing organic liquid according to the invention is chosen from 1-cyclohexylethanol, cyclohexylmethanol, (4-methylcyclohexyl)methanol, dicyclohexylcarbinol, and 3-cyclohexylpropanol-l-ol.

According to a particular embodiment, the hydrogen-bearing organic liquid according to the invention is not 1-cyclohexylethanol.

According to another aspect, the invention also relates to the use of at least one compound of formula (I) below, as organic liquid hydrogen carrier (LOHC): x<k- ^OH

" (i), in which: n is 0, 1, 2, 3, 4 or 5; at least one of the carbons being optionally substituted with a R group, independently selected from linear or branched C 1 to C 4 alkyls and Y groups;

According to one embodiment, the invention also relates to the use of at least one compound of formula (la) below, as an organic liquid hydrogen carrier (LOHC): in which : n is 0, 1, 2, 3 or 4;

R1 is H, a linear or branched C1-C4 alkyl group, or a Y group.

All the embodiments mentioned above with regard to the compounds of formula (I) and (la) can also be applied here, alone or in combination.

According to a particular embodiment, the invention relates to the use of at least one compound of formula (I) or (Ia), as LOHC for the transport and storage of hydrogen.

According to another aspect, the invention also relates to a pair of a hydrogenated organic hydrogen-bearing liquid (LOHC) and a dehydrogenated LOHC, the hydrogenated LOHC being of the following formula (I), and the dehydrogenated LOHC being of formula (II): where: n is 0, 1, 2, 3, 4 or 5; at least one of the carbons being optionally substituted with a R group, independently selected from linear or branched C 1 to C 4 alkyls and Y groups; R1 is H, a linear or branched C1-C4 alkyl group, or a Y group,

X is the perhydrogen counterpart of the aryl or heteroaryl group X', optionally substituted by at least one R2 group, independently selected from linear or branched C1-C4 alkyl groups, linear or branched C1-C4 O-alkyl groups, -NR _a Rb groups, with R _a and Rb independently selected from linear or branched C1 to C4 alkyl groups;

Y is the perhydrogen counterpart of the aryl or heteroaryl group Y', optionally substituted by at least one R2 group, independently selected from linear or branched C1 to C4 alkyl groups, linear or branched C1 to C4 O-alkyl groups, groups - NRaRb, with R _a and Rb independently selected from linear or branched C1 to C4 alkyl groups;

A is -CH2- and n' is n, or A is -CH=CH- and n' is 1 or 2, at least one of the carbons of group A being optionally substituted by a group Ri, independently selected from linear alkyls or branched at C1 to C4 and the Y' groups;

X' is an aryl or heteroaryl group, said group being optionally substituted by at least one R2 group, independently chosen from linear or branched C1-C4 alkyl groups, linear or branched C1-C4 O-alkyl groups, -NR _a Rb, with R _a and Rb independently selected from linear or branched C1 to C4 alkyl groups;

Y' is an aryl or heteroaryl group, said group being optionally substituted by at least one R2 group, independently selected from linear or branched C1-C4 alkyl groups, linear or branched C1-C4 O-alkyl groups, -NR _a Rb, with R _a and Rb independently selected from linear or branched C1 to C4 alkyl groups.

According to one embodiment, the invention also relates to a couple of a hydrogenated organic hydrogen-bearing liquid (LOHC) and a dehydrogenated LOHC, the hydrogenated LOHC being of the following formula (Ia), and the dehydrogenated LOHC being of formula (IIa): x« ^OH

Ri (la), (IIa), wherein: n is 0, 1, 2, 3 or 4;

R1 is H, a linear or branched C1-C4 alkyl group, or a Y group,

Y is the perhydrogen counterpart of the aryl or heteroaryl group Y', optionally substituted by at least one R2 group, independently selected from linear or branched C1-C4 alkyl groups, linear or branched C1-C4 O-alkyl groups, -NR _a Rb groups, with R _a and Rb independently selected from linear or branched C1 to C4 alkyl groups; A is -CH2- and n' is n, or A is -CH=CH- and n' is 1 or 2,

R'i is Ri, when Ri is H or a linear or branched C1 to C4 alkyl group; or a group Y',

Thus, a compound of formula (II) or (IIa) with n'=l corresponds to a compound (I) or (Ia) with n=2, and a compound of formula (II) with n'=2 corresponds to a compound (I) or (Ia) with n=4.

The compounds of formula (I) and (Ia) and/or of formula (II) and (IIa) have in particular the advantage of being able to be, essentially, biosourced. For example, one of the routes to obtain these compounds may relate to the processing of lignin. This treatment can be by oxidation (J. Zakzesk and al., Chem. Rev. 2010, 110, 3552-3599), by thermolysis (J. Zakzesk and al., Chem. Rev. 2010, 110, 3552-3599, M. P. Pandey and al., Chem. Eng. Technol. 2011, 34, No. 1, 29-41) or by enzymatic synthesis (R. Rahmanpour and al., Current Opinion in Chemical Biology 2015, 29:10-17). They make it possible to obtain derivatives of the vanillin (benzaldehyde) and monolignols (cinnamaldehyde) type, which can for example be subsequently converted into acetophenone, benzaldehyde and cinnamaldehyde by chemical reaction of deoxygenation and dehydration.

Another possible way of synthesizing these compounds may relate to cinnamaldehyde. This product is a major component present in the essential oil of Cassia and/or cinnamon, bark and leaf (Dayan Tao and al., J. For. Res. 27, 707-717 (2016); IN Jardim and al. , J Pest Sci 91, 479-487 (2018), Y. Shih and al., Int. J. Mol. Sci. 2013, 14, 19186-19201). It is also possible to obtain this compound by enzymatic synthesis of L-phenylalanine, a proteinogenic amino acid (Bang et al., Microb Cell Fact (2016) 15:16, J.-Q. Kong RSC Adv., 2015, 5 , 62587-62603, SK Nair et al., Structure23, 2032-2042, November 3, 2015). The cinnamaldehyde thus obtained can for example be used to synthesize benzaldehyde (US4673766A, US4727058A). Cinnamic acid, resulting from the oxidation of cinnamaldehyde, can lead to acetophenone by enzymatic action of Mucor-type fungi (Zuohui Zhang et al., World J Microbiol Biotechnol (2011) 27:2133-2137).

The compounds of formula (I) or (Ia), hydrogenated, are capable of being dehydrogenated to produce, in addition to the corresponding compounds of formula (II) or (IIa), hydrogen.

The compounds of formula (II) or (IIa), dehydrogenated, are in turn capable of regenerating by catalytic hydrogenation the corresponding compounds of formula (I) or (Ia), according to the invention.

According to a particular embodiment, the pair according to the invention is chosen from the following pairs:

1-Cyclohexylethanol/Acetophenone;

Cyclohexylmethanol/Benzaldehyde;

4-Methylcyclohexanemethanol/(4-Methylphenyl)methanol;

Dicyclohexylcarbinol/Benzophenone;

Cyclohexanepropanol/Cinnamaldehyde.

According to a particular embodiment, the pair according to the invention is not the 1-Cyclohexylethanol/Acetophenone pair.

According to another aspect, the invention also relates to a process for generating hydrogen comprising at least one stage of catalytic dehydrogenation of an organic hydrogen-bearing liquid (LOHC) of formula (I) or (Ia) as defined above .

According to a particular embodiment, the at least one dehydrogenation step is carried out in the presence of one or more catalysts based on copper, platinum, palladium, iridium, rhodium, ruthenium, or nickel.

According to a particular embodiment, the at least one dehydrogenation step is carried out in a reactor, in particular in a reactor comprising the catalyst in a fixed bed.

According to a particular embodiment, the at least one dehydrogenation step is carried out in a reactor of the batch, semi-batch or continuous type.

In general, the compound (I) according to the invention is preheated to the reaction temperature, and in particular injected into a reactor. At the outlet of the reactor, the liquids produced are separated from the hydrogen by gas/liquid separation.

According to a particular embodiment, the at least one dehydrogenation step is carried out at a temperature comprised from 80 to 320° C., and/or at a pressure comprised from 0.8 to 2 bar. According to a particular embodiment, the process according to the present invention comprises a first stage of dehydrogenation in the presence of one or more catalysts based on Ni, Co, Cu, Ru, Rh, Mn, Ag, Pd, Ir, Zr, Mo, W, Cr, Fe, Mn, Re, and their mixtures, in particular Cu, then a second stage of dehydrogenation in the presence of one or more catalysts based on platinum, palladium, iridium, rhodium, ruthenium, nickel, or mixtures thereof.

These are successive steps, carried out in particular in the order indicated above.

According to a more particular embodiment, said first dehydrogenation step in the presence of one or more catalysts chosen from catalysts based on Ni, Co, Cu, Ru, Ag, Pd, Ir, Zr, Mo, W, Cr, Fe, Mn, Re, and their mixtures, in particular Cu, Co, Fe, Mn, Ni, Ag, and their mixtures, in particular Cu.

The said catalyst(s) are in particular those on oxides, in particular metal oxides, in particular of Ce, Al, Zn, Mg, Zr, Zn, V, Cr, Sn, Ti, Si, and mixtures thereof, more particularly ternary or quaternary oxides ; on ores such as hydrolactite or hydroxyapatite; on sulfur compounds; on boron nitride, in particular hexagonal (hBN); or on a carbon support, for example graphene (reduced or not) or activated carbon (C). Homogeneous catalysts clamps based on Ru, Rh, Ir, Fe, Mn can also be grafted onto metal oxides and serve as catalysts for the reaction.

According to a particular embodiment, the said catalyst or catalysts are on SiCl, Al2O3, MgO, ZrO2, ZnO, CeCl, TiCh, C, or hBN. According to a more particular embodiment, said first dehydrogenation step in the presence of one or more catalysts chosen from catalysts based on copper or nickel, for example catalysts Cu/ZnO/AhOs/MgC), Cu/CeO ₂ , Cu/ZrO ₂ , Cu/MgO, Ni/Al ₂ O ₃ , Cu/C, and Cu/hBN.

According to a more particular embodiment, said second dehydrogenation step in the presence of one or more catalysts chosen from catalysts based on platinum, palladium, ruthenium, or nickel.

The said catalyst(s) are in particular those on oxides, in particular metal oxides, in particular of Ce, Al, Zn, Mg, Zr, Zn, V, Cr, Sn, Ti, Si, and mixtures thereof, more particularly ternary or quaternary oxides ; on ores such as hydrolactite or hydroxyapatite; on sulfur compounds; on boron nitride, in particular hexagonal (hBN); or on a carbon support, for example graphene (reduced or not) or activated carbon (C).

According to a more particular embodiment, said second dehydrogenation step in the presence of one or more catalysts chosen from the catalysts Pt/Al ₂ O ₃ , Pd/Al ₂ O ₃ , Pt/C, Pt/CeO ₂ , Pt/MgO, Pt/ZrO ₂ , RU/A1 ₂ O ₃ , Pd/C, Ru/C, Pt/hBN , and Ni/Al ₂ O ₃ .

A possible purification between the two steps is possible.

According to a particular embodiment, the at least one dehydrogenation step is carried out in the presence of a base, in particular an alkali metal hydroxide, more particularly NaOH, LiOH or KOH.

In this case, the dehydrogenation is in particular carried out in a single step, in particular in the presence of one or more catalysts based on Ni, Co, Cu, Ru, Rh, Mn, Ag, Pd, Ir, Zr, Mo, W, Cr, Fe, and/or Re, in particular Cu, and one or more catalysts based on platinum, palladium, iridium, rhodium, or ruthenium.

According to another aspect, the invention also relates to a method for regenerating a compound of formula (I) or (Ia) from a compound of formula (II) or (IIa) as defined above, the process comprising a stage of catalytic hydrogenation of said compound of formula (II) or (IIa).

This step can be carried out: in the presence of a mixture of catalysts, comprising: o a catalyst chosen from catalysts based on Ni, Co, Cu, Ru, Ag, Pd, Pt, Au, Ni, and/or Mo, in particular supported on metal oxides such as SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , ZnO, CeO ₂ , FeOx and/or graphite; and clamp homogeneous catalysts based on Ru, Pd, Pt, Au, Ir, Fe, Rh, in particular grafted onto metal oxides; and o A catalyst based on Pt, Pd, Ni, Ru, Rh, Ir, in particular supported on metal oxides such as SiO ₂ , A1 ₂ O ₃ or on graphite; in the presence of a catalyst based on Pt or Ni-Cr.

Generally, said compound of formula (II) or (IIa) is preheated within a reactor, to a temperature which can vary from 100° C. to 260° C., then mixed with hydrogen at the reaction pressure and the The whole is injected into a fixed bed reactor, loaded with catalyst.

The hydrogen and the compound of formula (II) or (IIa) can also be fed directly separately into the reactor.

This reduction is exothermic, and is therefore favored by the use of isothermal reactors, limiting temperature inhomogeneities.

Furthermore, the energy released by the reaction in the form of heat can be advantageously used to preheat the reactants. At the outlet of the reactor, the liquids produced are separated from the unreacted hydrogen by a gas/liquid separation.

The processes can be operated in batch or semi-batch reactors or even continuously in “slurry”, “trickle bed”, fluidized bed or fixed bed type reactors.

In general, the hydrogenation reaction is carried out at a temperature varying from 100 to 300°C, preferably from 100 to 260°C.

The pressure can vary from 10 to 280 bar (or 1 to 28 MPa).

Of course, the pressure/temperature couple can be adjusted according to the nature of the dehydrogenated LOHC/hydrogenated LOHC couple. The choice of catalyst is generally made taking into account the nature of the dehydrogenated LOHC/hydrogenated LOHC pair considered.

According to another aspect, the invention relates to a method for transporting and/or storing hydrogen, characterized in that it uses at least one compound of formula (I) or (Ia) as defined above.

The compounds of formula (I) or (la) according to the invention can be used in particular in devices for converting electrochemical energy or by combustion or in hydrogenation processes as a renewable source of hydrogen or even as fuel.

According to another of its aspects, the present invention relates to the use, in particular in devices for converting electrochemical energy or by combustion, of at least one compound of formula (I) or (Ia) according to the invention.

All of the compounds considered according to the invention are organic liquids known and already used as solvents in fine chemicals. The infrastructures to transport them already exist.

Furthermore, these are compounds that are stable under normal temperature and pressure conditions, which means that they can be transported in standard containers or tanks that can be loaded onto boats, trains or trucks depending on the context.

The direct applications of a compound of formula (I) or (la) according to the invention are the transport and storage of hydrogen.

The compound of formula (I) or (Ia) can be transported and stored to the place of use of the hydrogen, then converted by dehydrogenation into a compound of formula (II) or (IIa) and into hydrogen.

The hydrogen produced can then be used as a reagent in an industrial process (hydrodesulfurization, hydrogenation of various compounds, recovery of CO2 in gaseous or liquid fuels, etc.). The hydrogen produced can also be used as a carbon-free energy carrier either by combustion or by supplying an electrochemical energy conversion device.

In addition, the liquid properties of these organic compounds make them good candidates for use as fuels for heat engines or electrochemical energy conversion devices.

They are compatible with conditioning in the tank of a vehicle where dehydrogenation can be carried out in order to produce hydrogen fueling the vehicle. Once dehydrogenated, the LOHC can be stored in order to be subsequently discharged in exchange for a hydrogenated LOHC in accordance with the invention.

The invention also relates to the following points.

1. Hydrogen-bearing organic liquid (LOHC) of formula (I) below:

_XH ^ ^OH

X and Y are independently a perhydrogenated aryl group or a perhydrogenated heteroaryl group, said group being optionally substituted by at least one R2 group, independently selected from linear or branched C1 to C4 alkyl groups, linear or branched O-alkyl groups C1 to C4, the groups -NR _has Rb, with R _a and Rb independently selected from linear or branched C1 to C4 alkyl groups.

2. Hydrogen-bearing organic liquid as defined above, in which:

X is a perhydrogenated aryl group, X being in particular a cyclohexyl group; Where

X is a perhydrogenated heteroaryl group, X being chosen in particular from piperidinyl, piperazinyl, hexahydropyrimidinyl and hexahydropyridazinyl groups.

3. Hydrogen-bearing organic liquid as defined above, in which: n is 0, 1 or 2; and or

Ri is H or methyl. 4. Hydrogen-bearing organic liquid as defined previously, which is chosen from 1-cyclohexylethanol, cyclohexylmethanol, (4-methylcyclohexyl)methanol, dicyclohexylcarbinol, and 3-cyclohexylpropanol-1-ol.

5. Use of at least one compound of formula (I) as defined above, as organic liquid hydrogen carrier (LOHC).

6. Couple of a hydrogenated organic hydrogen-carrying liquid (LOHC) and a dehydrogenated LOHC, the hydrogenated LOHC being of the following formula (I), and the dehydrogenated LOHC being of formula (II):

(I),

(II), wherein: n is 0, 1, 2, 3, 4 or 5; at least one of the carbons being optionally substituted with a R group, independently selected from linear or branched C 1 to C 4 alkyls and Y groups;

X is the perhydrogen counterpart of the aryl or heteroaryl group X', optionally substituted by at least one R2 group, independently selected from linear or branched C1-C4 alkyl groups, linear or branched C1-C4 O-alkyl groups, -NRaRb groups, with R _a and Rb independently chosen from linear or branched C 1 to C 4 alkyl groups;

Y is the perhydrogen counterpart of the aryl or heteroaryl group Y', optionally substituted by at least one R2 group, independently selected from linear or branched C1-C4 alkyl groups, linear or branched C1-C4 O-alkyl groups, -NR _a Rb groups, with R _a and Rb independently selected from linear or branched C1 to C4 alkyl groups;

A is -CH2- and n' is n, or A is -CH=CH- and n' is 1 or 2, at least one of the carbons of group A being optionally substituted by a group Ri, independently selected from linear alkyls or branched at C1 to C4 and the Y'groups; X' is an aryl or heteroaryl group, said group being optionally substituted by at least one R2 group, independently chosen from linear or branched C1-C4 alkyl groups, linear or branched C1-C4 O-alkyl groups, -NR _a Rb, with R _a and Rb independently selected from linear or branched C1 to C4 alkyl groups;

7. Process for generating hydrogen comprising at least one stage of catalytic dehydrogenation of an organic hydrogen-bearing liquid (LOHC) of formula (I) as defined previously.

8. Process as defined above, in which the at least one dehydrogenation step is carried out in the presence of one or more catalysts based on copper, platinum, palladium, iridium, rhodium, ruthenium, or nickel.

9. Process as defined previously, in which the at least one dehydrogenation stage is carried out in a reactor, in particular in a reactor comprising the catalyst in a fixed bed and/or in a reactor of the batch, semi-batch or continuous type.

10. Process as defined above, in which the at least one dehydrogenation step is carried out at a temperature of 80 to 320° C., and/or at a pressure of 0.8 to 2 bar.

11. Process as defined above, comprising a first stage of dehydrogenation in the presence of one or more catalysts based on Ni, Co, Cu, Ru, Ag, Pd, Ir, Zr, Mo, W, Cr, Fe, Mn , Re, and their mixtures, in particular Cu, Co, Fe, Mn, Ni, Ag, and their mixtures, in particular of copper, then a second stage of dehydrogenation in the presence of one or more catalysts based on platinum, palladium , iridium, rhodium, ruthenium, or nickel.

12. Process as defined above, in which the at least one dehydrogenation stage is carried out in the presence of a base, in particular an alkali metal hydroxide, more particularly NaOH, LiOH or KOH. Definitions

As used herein, the term "about" refers to an interval of values within ±10% of a specific value. For example, the expression "about 20" includes values of 20 ± 10%, i.e. values of 18 to 22.

Within the meaning of the present description, the percentages refer to percentages by mass with respect to the total mass of the formulation, unless otherwise indicated.

As understood here, value ranges in the form of "x-y" or "from x to y" or "between x and y" include the x and y bounds as well as the integers between these bounds. By way of example, "1-5", or "from 1 to 5" or "between 1 and 5" designates the integers 1, 2, 3, 4 and 5. Preferred embodiments include each integer taken individually in the range of values, as well as any sub-combination of these integers. By way of example, preferred values for "1-5" may include the integers 1, 2, 3, 4, 5, 1-2, 1-3, 1-4, 1-5, 2-3, 2 -4, 2-5, etc.

By "fluid" is meant in particular a liquid or a gas.

By “source of the second fluid”, is meant in particular a chemical compound being the starting product of the catalytic reaction producing the second fluid as well as the first fluid discharged from the second fluid.

By "column" is meant in particular any means allowing the circulation of the fluid or fluids concerned. This means is therefore suitable for the circulation of the fluid, for example when the fluid is a liquid or a gas. It may for example be a duct comprising cylindrical zones with various sections and/or diameters, and/or whose generatrices have various directions. By "an element A communicating with an element B", we mean in particular an element A linked to an element B by any means suitable for the circulation of the fluid, for example liquid or gas, between the element A and the element B.

By "catalysis zone" is meant in particular a zone in which is present the catalyst necessary for the catalytic reaction producing the second fluid as well as the first fluid discharged from the second fluid.

As used herein, the term "alkyl" denotes a straight or branched chain, in particular straight, alkyl group having the number of carbon atoms indicated before said term, in particular 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, etc. Thus, an expression such as "C1-C4 alkyl" designates an alkyl radical containing from 1 to 4 carbon atoms. The same is true for the term “alkane”. As used herein, the term "arene" means a mono- or bicyclic, substituted or unsubstituted aromatic hydrocarbon ring system having 6 to 10 carbon atoms in the ring. Examples include benzene and naphthalene. Preferred arenes include unsubstituted or substituted benzene and naphthalene. Included in the definition of "arene" are fused ring systems, including, for example, ring systems in which an aromatic ring is fused to a cycloalkyl ring. Examples of such fused ring systems include, for example, indan, indene and tetrahydronaphthalene.

As used herein, the term "heteroarene" means a ring aromatic system containing 5 to 10 carbon atoms in which one or more ring carbon atoms are replaced by at least one heteroatom such as -O-, -N - or -S-, in particular -N- and/or -O-. Examples of heteroarenes include pyrrole, furan, thiophene, pyrazole, imidazole, thiazole, isothiazole, isoxazole, oxazole, oxathiol, oxadiazole, triazole, oxatriazole, furazan, tetrazole, pyridine, pyrazine, pyrimidine, pyridazine, triazine, indole, isoindole, indazole, benzofuran, isobenzofuran, purine, quinazoline, quinoline, isoquinoline, benzoimidazole, benzothiazole, benzothiophene, thianaphthene, benzoxazole, benzisoxazole, cinnoline, phthalazine, naphthyridine and quinoxaline. Included within the definition of "heteroarene" are fused ring systems, including, for example, ring systems in which an aromatic ring is fused to a heterocycloalkyl ring. Examples of such fused ring systems include, for example, phthalamide, phthalic anhydride, indoline, isoindoline, tetrahydroisoquinoline, chromane, isochromane, chromene and isochromene.

FIGURES

Figure 1 shows an example of a device according to the invention.

In this example, the device comprising an inlet (1) of the first fluid communicating with the first column (2). This first column (2) includes:

- a zone (3) for heating the first fluid of the first column (2),

- a zone (4) for heating the first fluid, in contact with one or more external heating means,

- a zone (5) of heterogeneous catalysis.

The first column (2) communicates with the outlet (6) of the second fluid and the second column (7), here combined. The separation of the second fluid and the first fluid discharged from the second fluid, optional, is not shown in Figure 1. The second column (7) comprises a zone (8) comprising one or more heat exchangers (9), not shown here, serving as a heat source for the zone (3) for heating the first fluid of the first column (2).

The second column (7) communicates with the outlet (10) of the first fluid discharged from the second fluid, here merged with the outlet (6) of the second fluid, as mentioned previously.

EXAMPLES

Example 1 A system was considered operating with perhydrogenated DBT (di-benzyl toluene) as organic hydrogen-carrying liquid (LOHC), and a target tk flow rate of 20 g/min. The H2 mass loading rate is 6.2%, thus the flow rate of loaded LOHC required is 323 g/min.

The system related parameters are as follows:

The energy data relating to certain steps of the process of the invention are as follows:

The use of the device according to the invention therefore makes it possible to heat the LOHC without external energy input from 20° C. to 284° C., thus making it possible to save 2.2 kW of heat out of the 12.6 kW necessary to discharge the Eh of the LOHC, a substantial gain of 17%.

It should also be noted that by using molecules with higher Cp values and lower AH (this is particularly the case of biobased LOHCs), the energy gain is around 40%.

Example 2: hydrogenated LOHCs of the invention

As illustrated in the examples in the following table, the compounds according to the invention have in particular a mass hydrogen storage content of between 4 and 8% relative to their total weight. They are thus able to generate, by catalytic dehydrogenation, hydrogen contents by mass and by volume that are satisfactory or even higher than those generated by certain conventional LOHCs. Example 3: Two-step dehydrogenation of a compound of formula (I) according to the invention

The 2-step dehydrogenation is carried out as follows:

1-Cyclohexylethanol is first selectively converted to acetylcyclohexane through a Cu/ZnO/AhCL/MgO catalyst, then acetylcyclohexane is converted to acetophenone through a Pt/C catalyst.

Step 1: 1-Cyclohexylethanol Acetylcyclohexane

The reaction conditions are collated in the following table:

1-Cyclohexylethanol is selectively converted to Acetylcyclohexane.

Step 2: Acetylcyclohexane Acetophenone

The reaction conditions are collated in the following table:

The two-step approach makes it possible to ensure the selectivity of the reaction: blocking of the formation of impurities, in particular after 14 min of retention. For comparison, the one-step dehydrogenation of 1-Cylohexylethanol to Acetophenone: was also carried out, under the conditions indicated below:

Partial and total dehydrogenation can be obtained. Several impurities are present and only 4 could be identified by GCMS: ethylbenzene, ethylcyclohexane, 1,3-Dicyclohexylbutane and 1,3-Diphenylbutane are present. The one-step approach does not make it possible to ensure the selectivity of the reaction: there is formation of numerous impurities after 14 min of retention.

Example 4: Hydrogenation of Acetophenone to 1-Cyclohexylethanol

Total hydrogenation can be achieved under the above conditions.

Example 5: Presence of a base during dehydrogenation

Under the same conditions as Example 3, the addition of 1% mol of NaOH makes it possible to significantly increase the selectivity of the reaction as presented below:

The increase in the reaction time makes it possible to see a clear increase in the yield with a gain in selectivity still apparent (in 18 h, 30% conversion and 96% selectivity relative to GC areas).

Claims

1. Device for the preparation of a second fluid by catalytic reaction from a first fluid, source of said second fluid, the device comprising at least one inlet

(1) of the first fluid communicating with one or more first columns (2), which further communicate with at least one outlet (6) of the second fluid, and with one or more second columns (7), which further communicate with at least one at least one outlet (10) for the first fluid discharged from the second fluid, the first column(s)

(2) comprising a zone (4) for heating the first fluid, in contact with one or more external heating means, said zone (4) also being a heterogeneous catalysis zone (5) or followed by a zone (5 ) of heterogeneous catalysis, characterized in that the second column or columns (7) comprise a zone (8) comprising one or more heat exchangers (9) serving as a heat source for a zone (3) for heating the first fluid of the or the first columns (2), said zone

(3) preceding or merging with said zone (4).

2. Device according to claim 1, in which the catalyst of the heterogeneous catalysis zone (5) consists of or contains one or more catalysts based on copper, platinum, palladium, iridium, rhodium, or ruthenium.

3. A method of manufacturing the device according to any one of claims 1 to 2, wherein the heat exchanger(s) (9) are obtained by 3D printing, in particular by selective laser sintering (SLS), by selective laser melting (SLM) , electron beam melting (EBM), or binder spraying (BJ).

4. Use of a device according to any one of claims 1 to 2 for preparing by catalytic reaction a second fluid from a first fluid, source of said second fluid.

5. Process for preparing a second fluid from a first fluid, source of said second fluid, by at least one globally endothermic chemical reaction, comprising:

6. Method according to claim 5, in which the first fluid is a liquid or a gas, in particular a liquid, the second fluid is a gas and the discharged first fluid is a liquid, the second fluid preferably being dihydrogen, the first fluid being in particular an organic hydrogen-bearing liquid (LOHC), and the second fluid being dihydrogen, the first fluid being more particularly an organic hydrogen-bearing liquid chosen from dibenzyltoluene (DBT), A-cthylcarbazolc (NEC) , l,2-dihydro-l,2-azaborine (AB), formic acid (FA), naphthalene (NAP), toluene (TOL), acetophenone perhydro genes.

7. Process according to claim 6, in which the first fluid is an organic hydrogen-carrying liquid (LOHC) and the second fluid is dihydrogen, and in which:

- Said dihydrogen is obtained at a flow rate comprised from 1 to 50000 g.min ^-1 , in particular from 1 to 50 g.min ¹ or from 1000 to 50000 g.min ¹ , more particularly from about 20 or about 20000 g. min ¹ ; and or

- the enthalpy of the chemical reaction of step iii) is greater than or equal to 10 kJ.mol ^-1 , in particular between 10 and 120 kJ.mol ^-1 , more particularly approximately 60 kJ.mol ^-1 ; and or

- the temperature TA is in particular the ambient temperature, the temperature TB is between 200 and 300° C., upper limit excluded, in particular around 284° C., the temperature Te is between 300 and 375° C., in particular d 350°C, the temperature TD is from room temperature to 100°C, in particular from about 69°C.

8. Method according to claim 5, in which the first fluid is a liquid or a gas, the second fluid is a gas and the first fluid discharged is a gas, the first fluid being in particular NH3, and the second fluid being dihydrogen. , and the first fluid discharged from nitrogen, or the first fluid being in particular methanol, and the second fluid being dihydrogen, and the first fluid discharged from carbon dioxide.

9. Process according to any one of claims 5 to 8, in which the catalyst consists of or contains one or more catalysts based on copper, platinum, palladium, iridium, rhodium, or ruthenium.

10. Process according to any one of claims 5 to 9, in which the catalyst is a fixed-bed catalyst, or a catalyst deposited on the surface of the zone where step iii takes place), for example the catalysis zone one or more columns.