PROCESS FOR THE PREPARATION OF SECONDARY AND / OR TERTIARY AMINES IN THE PRESENCE OF A MANGANESE-DOPED COPPER CATALYST

Abstract

The present invention relates to a process for the preparation of secondary and / or tertiary amines comprising an amination step, said amination step being carried out by reacting a primary or secondary alcohol and / or a ketone with ammonia or a primary or secondary amine, in the gas phase and in the presence of a catalyst; said catalyst comprising copper and doped with manganese, the amount of manganese being between 1% and 10% by weight, relative to the total weight of the catalyst.

Description

Title of the invention: PROCESS FOR THE PREPARATION OF SECONDARY AND / OR TERTIARY AMINES IN THE PRESENCE OF A MANGANESE-DOPED COPPER CATALYST

[0001] The present invention relates to a process for the synthesis of secondary and / or tertiary amines by gas-phase reaction of a primary or secondary alcohol and / or a ketone with ammonia or a primary or secondary amine, in the presence of a catalyst comprising copper as a catalytically active metal, doped with manganese.

[0002] The present invention also relates to the use of such a catalyst for the synthesis of secondary and / or tertiary amines.

[0003] Amines, and in particular alkylamines, are organic compounds with very diverse industrial applications. These compounds are used in particular as neutralizing agents, corrosion inhibitors, polymerization and / or crosslinking catalysts, and especially as synthesis intermediates in pharmacy, agrochemistry, electronics and detergents. Examples of such compounds include:

[0005] - diisopropylamine (DIPA), a secondary amine, which is the main precursor of synthesis of N-ethyldiisopropylamine (Hünig base), used as an acid scavenger in the synthesis of pharmaceutical or agrochemical active ingredients. DIPA also provides access to diisopropylaminosilane (DIPAS) and other volatile aminosilane derivatives, precursors of choice for the controlled deposition of silicon oxide or silicon nitride films in the manufacture of semiconductor devices;

[0006] - N-ethylmethylamine (EMA) which is involved in the manufacture of molecules pharmaceutical active ingredients intended for the treatment of degenerative diseases of the nervous system as well as in the synthesis of metal salts, such as for example tetrakis(ethylmethylamino)-hafnium or -zirconium, volatile precursors of choice for the production of metal film deposits by CVD (Chemical Vapor Deposition) or ALD (Atomic Layer Deposition) in the manufacture of semiconductors; and

[0007] - N,N-dimethylethylamine (DMEA) and N,N-dimethylisopropylamine (DMIPA) which are tertiary amines used as catalysts for the polymerization of polyurethane resins for the manufacture of foundry molds using the so-called “cold box” process.

[0008] The preparation of secondary and / or tertiary amines by amination of alcohols and / or ketones with ammonia or primary or secondary amines in the presence of hydrogen and a hydrogenation / dehydrogenation catalyst is widely known (Amines, Aliphatic, § 3.1 and 3.2, Ullmann's Encyclopedia of Industrial Chemistry, 2015, Wiley Online Library). Depending on the nature of the raw materials and / or the type of catalyst, the preparation takes place in the liquid phase or in the gas phase.

[0009] As an example of synthesis, mention may be made of diisopropylamine (DIPA) which is conventionally obtained as a by-product in the processes for manufacturing mono-isopropylamine (MIPA) by catalytic amination of acetone and / or isopropanol with ammonia.

[0010] Starting from acetone, the synthesis is carried out according to the reaction scheme below:

[0011] [Chem.l]

[0012] From isopropanol, the reactions are analogous after prior in situ dehydrogenation of isopropanol to acetone:

[0013] [Chem.2] ,CH-> [catâî G + H He O

[0014] This synthesis is most often carried out continuously via gas phase or liquid phase processes which lead to the majority or almost exclusive production of MIPA, the main global application of which remains glyphosate salt.

[0015] To selectively obtain DIPA, it can be directly produced from MIPA and acetone as starting reagents; or the continuous disproportionation of MIPA is generally carried out at high temperature through a fixed bed of a catalyst or a zeolite, according to the following scheme:

[0016] [Chem.3] [cataf 2MIPA DIPA *

[0017] We therefore see that the most selective syntheses of DIPA and amines are secondary amines in general, consist of carrying out the amination of acetone (aldehyde or ketone more generally) or isopropanol (alcohol more generally) with primary amines (MIPA in the case of DIPA) or of carrying out the disproportionation of the latter. These two techniques therefore require the prior production of primary amines as main products, followed by a transformation into secondary amines.

[0018] There is therefore a need for a process for the synthesis of secondary and / or tertiary amines as main products (and no longer as by-products), in particular from ketone and / or alcohol and ammonia for the synthesis of secondary amines.

[0019] There is a need for a process for synthesizing secondary and / or tertiary amines that is easy to implement and industrially viable.

[0020] Furthermore, in cases where ketones (especially acetone) are less expensive than the corresponding alcohols (especially isopropanol), it is preferred to start with ketones as raw materials.

[0021] However, the reductive amination of ketones with ammonia or a primary or secondary amine is a much more exothermic process than that of the reductive amination of alcohols. When the amination reaction of a ketone is carried out continuously through a fixed catalytic bed, this strong exothermicity generates a significant increase in temperature at the heart of the catalyst grains causing the formation of secondary reactions and therefore a loss of selectivity; or it requires operating with a lower volume flow rate of ketone per unit volume of catalyst (WH or LHSV), and therefore with a loss of productivity compared to the same process operated from alcohol. This higher temperature can also have a negative impact on aging and therefore the lifetime of the catalyst.

[0022] Thus, a high temperature and / or a significant excess of nitrogenous reagent may be responsible for the formation of undesirable amine impurities. Among the impurities formed, we can note those resulting from secondary transamination or disproportionation reactions which give rise to the formation of undesirable amines.

[0023] For example and in a non-exhaustive manner, in the case of DIPA, the degradation of acetone into acetaldehyde leads in particular to the formation of monoethylamine (MEA) and N-ethylisopropylamine (EIPA) according to the following scheme:

[0024] [Chem. 4] H-^C _CH, + nh3 + h2 + CH^ [cata] HnO

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031] HSC H3C “CH3 CH -j- CH 4- H, He I O HH2 and / or [Chem. 5] H 3C H □ CCH •: CH, * "C" 4 H 2 I He NH, O ch3 ch3 h2c ...ch HH "CHj EiPA CH- CH3 C. ..CH WH "CH3 EIPA Furthermore, parasitic self-condensation of acetone leads to the formation of methyl isobutyl ketone (MIBK) which by reductive amination with ammonia and with monoisopropylamine leads respectively to the secondary formation of 1,3-dimethylbutylamine (1,3-DMBA) and N-(1,3-dimethylbutyl)isopropylamine (DMBIPA). Similarly, in the case of the use of dimethylamine (DMA) for the manufacture of tertiary amines of the dimethylalkylamine type such as DMEA, DMIPA or DMPA, DMA can be partially disproportionated into trimethylamine (TMA) and monomethylamine (MMA), according to the following reaction: [Chem. 6] CH, 2 NH H3C CH, I 3 + N HjC CH3 TMA MMA can also react with alcohol or ketone to form secondary amines that are difficult to separate from the desired amines. In the case of the use of MMA for the manufacture of secondary amines of the alkylmethylamine type such as N-ethylmethylamine (EMA) or N-isopropylmethylamine, MMA can be partially disproportionated into dimethylamine (DMA) and ammonia, according to the reaction:

[0032] [Chem.7] H,C [cata.l \ 2 HX—NH2 NH + NHL H3C

[0033] In the case of the manufacture of EMA from ethanol, the by-produced DMA can then react with ethanol to form DMEA with a boiling point very close to that of EMA (36.5 vs 32.6 °C) thus making the purification of EMA very complex to achieve the required specifications, particularly for electronic applications. Ammonia can also react with ethanol to lead to the by-production of mono-, di- and / or tri-ethylamines.

[0034] It can therefore be seen that current amination reactions give rise to the formation of numerous amine impurities. These impurities make it particularly difficult to obtain secondary and / or tertiary amines of satisfactory purity, or even of high purity.

[0035] There is therefore also a need for a process for the synthesis of secondary and / or tertiary amines which is selective for the desired secondary or tertiary amines, and in particular which limits or prevents the formation of amine impurities.

[0036] The objective of the present invention is to provide a simple and industrially viable process for the synthesis of secondary and / or tertiary amines.

[0037] The present invention also aims to provide a process for synthesizing secondary and / or tertiary amines in the gas phase which is easy to implement.

[0038] Another object of the present invention is to provide a selective process for the synthesis of secondary or tertiary amines, preferably secondary amines.

[0039] The objective of the present invention is to provide an amination catalyst which makes it possible to obtain satisfactory, even high, selectivity for secondary or tertiary amines.

[0040] The objective of the present invention is to provide an amination catalyst limiting, or even avoiding, transamination or disproportionation reactions of amines and thus the formation of amine impurities.

[0041] The present invention meets all or part of the above objectives.

[0042] The present inventor has discovered a new process for preparing amines using a catalyst making it possible to obtain satisfactory or even high or improved conversion and / or selectivity into secondary and / or tertiary amines. The new catalyst limits or even avoids the formation of amine impurities, in particular those formed by transamination or disproportionation of amines. The reaction thus catalyzed is improved and easy to carry out. The secondary and / or tertiary amines formed according to the invention can be purified more easily.

[0043] The present inventor has also surprisingly discovered a highly selective process for the synthesis of secondary amines, in particular when the catalyst according to the invention is used and the co-produced primary and / or tertiary amines are recycled at the amination stage. Such a process makes it possible in particular to achieve a selectivity for secondary amines greater than 90%.

[0044] In particular, the process according to the invention allows the selective synthesis of secondary amines directly from alcohol and / or ketone and ammonia.

[0045] Thus, the present invention relates to a process for the preparation of secondary and / or tertiary amines comprising an amination step, said amination step being carried out by reaction of a primary or secondary alcohol and / or a ketone with ammonia or a primary or secondary amine, in the gas phase and in the presence of a catalyst and hydrogen;

[0046] said catalyst comprising copper doped (or promoted) by manganese, and the quantity of manganese being between 1% and 10% by weight, relative to the total weight of the catalyst.

[0047] The present invention also relates to the use of a catalyst comprising copper doped with manganese, the manganese being present in an amount of between 1% and 10% by weight relative to the total weight of the catalyst, for the preparation of secondary and / or tertiary amines. Definitions

[0048] According to the present invention, the term "catalyst" means the catalytic composition comprising the active metals and the dopants (in particular copper and manganese, whatever their form, oxidized or not) as well as the support and any additives. The weight percentages mentioned below correspond to the catalyst before pre-activation or possible activation.

[0049] It is understood that in the catalyst according to the invention, copper is the active metal and that manganese is a dopant. The term "dopant" (also called "promoter") means a chemical substance or a composition of chemical substances capable of modifying, in particular improving, the catalytic activity of a catalyst. For example, the term "dopant" means a chemical substance or a composition of chemical substances making it possible to improve the conversion and / or the selectivity of the catalyzed reaction compared to the catalyst without dopant.

[0050] The term "nitrogen reagent" means ammonia, primary or secondary amines used as reagents in the amination reaction as according to the invention.

[0051] “Selectivity” means SA or the selectivity of amine (A) produced relative to the converted reactants calculated according to the following equation:

[0052] SA = 100 xx (number of moles of desired amine formed / number of moles of reactant converted),

[0053] with Zamine being the stoichiometric coefficient of the amine and Zreactant being the stoichiometric coefficient of the reactant. Preferably, the reactant used in the above calculation is the limiting reactant.

[0054] In particular, the process according to the invention makes it possible to obtain a selectivity for secondary amines greater than or equal to 50%, for example between 50% and 90%, preferably between 70% and 90%.

[0055] In particular, the process according to the invention makes it possible to obtain a selectivity for tertiary amines of between 90% and 100%, preferably between 90% and 99%.

[0056] The term "amine impurity" is understood to mean in particular any unwanted primary, secondary or tertiary amine obtained following a parasitic transamination or disproportionation reaction or following self-condensation of the ketone. In particular, the aim is to limit, or even avoid, the formation of these impurities. Catalyst according to the invention

[0057] The catalyst according to the invention comprises copper doped with manganese, the quantity of manganese being between 1% and 10% by weight, relative to the total weight of the catalyst.

[0058] Preferably, the amount of copper in the catalyst is less than or equal to 60% by weight, relative to the total weight of the catalyst. In particular, the amount of copper is between 15% and 60% by weight, relative to the total weight of the catalyst. The amount of copper is in particular between 20% and 60% by weight, preferably between 35% and 50% by weight, more preferably between 40% and 50% by weight, for example between 44% and 48% by weight, relative to the total weight of the catalyst. The copper may be present in the form of copper oxide(s), preferably in CuO form.

[0059] Preferably, the amount of manganese is between 4% and 10% by weight, more preferably between 4% and 8% by weight, relative to the total weight of the catalyst. The manganese may be present in the form of oxide(s), preferably in the form of manganese dioxide (MnO2) or Mn3O4.

[0060] The catalyst may also comprise a support chosen from the group consisting of: alumina (A12O3), silica (SiO2), titanium dioxide, zirconia, as well as mixtures of two or more of them, preferably alumina and / or silica.

[0061] In particular, the catalyst comprises: - between 20% and 60% by weight, preferably between 35% and 50%, for example between 40% and 50% by weight of copper, relative to the total weight of the catalyst; - between 1% and 10% by weight, preferably between 4% and 10%, for example between 4% and 8% by weight of manganese, relative to the total weight of the catalyst; and - alumina.

[0062] Preferably, said catalyst comprises copper in CuO form and manganese in MnO2 and / or Mn3O4 form. Copper and manganese are in particular present in the form of oxide(s) before activation of the catalyst. Preferably, said catalyst consists essentially of, or is even composed of, copper in oxidized form, manganese in oxidized form, a support such as alumina or silica and possible additives.

[0063] More particularly, the catalyst comprises: - between 25% and 75% by weight, preferably between 40% and 65% by weight of copper oxide (expressed as CuO), relative to the total weight of the catalyst; and - between 1% and 20% by weight, preferably between 5% and 15% by weight of manganese oxides (expressed as MnO2), relative to the total weight of the catalyst.

[0064] Preferably, the catalyst does not comprise any other active metal than copper (i.e. whether in elemental form or in the form of an organic or inorganic compound, for example a metal oxide). Preferably, the catalyst does not comprise any other dopant than manganese (i.e. whether in elemental form or in the form of an organic or inorganic compound, for example a metal oxide). In particular, said catalyst does not comprise chromium and / or nickel.

[0065] According to another embodiment, other metal compounds may be included in the catalyst. As non-limiting examples of such compounds, mention may be made of molybdenum, tungsten, chromium, vanadium and magnesium. They may be in oxidized form, for example in the form of MoO2, WO2, Cr2O3, V2O5 and MgO.

[0066] The catalyst may also comprise other additives such as stabilizers and / or shaping aids such as graphite, which are common in the field of catalysts. Generally, these compounds are included in an amount of between 1% and 15% by weight, relative to the total weight of the catalyst.

[0067] The catalyst is preferably used in the form of pellets with a diameter of between 3 and 6 mm and a length of between 3 and 6 mm.

[0068] For example, we can cite the HySat® 200 tab 4.8X4.8 catalyst from Clariant®. Process according to the invention

[0069] The process according to the invention makes it possible in particular to form secondary and / or tertiary alkylamines. Preferably, the amine formed is of the following general formula (A):

[0070] [Chem. 8]

[0071] Ri represents a linear, branched or cyclic alkyl radical, comprising from 1 to 10 carbon atoms, preferably from 1 to 7 carbon atoms and more preferably from 1 to 4 carbon atoms, optionally substituted (preferably by an aryl radical such as a phenyl);

[0072] R2 is chosen from the hydrogen atom and a linear, branched or cyclic alkyl radical, comprising from 1 to 10 carbon atoms, preferably from 1 to 7 carbon atoms and more preferably from 1 to 4 carbon atoms, optionally substituted (preferably by an aryl radical such as a phenyl);

[0073] or else

[0074] R1 and R2 form together and with the nitrogen atom which carries them, a cyclic radical, saturated or partially or totally unsaturated, optionally substituted and which may comprise one or more heteroatoms chosen from oxygen and nitrogen; said cycle may comprise a number of vertices between 3 and 9, preferably 5 or 6 vertices;

[0075] R3 represents a linear, branched or cyclic hydrocarbon chain, aromatic or not, comprising from 1 to 10 carbon atoms, preferably from 1 to 7 carbon atoms and more preferably from 1 to 4 carbon atoms and optionally substituted (preferably by an aryl radical such as a phenyl);

[0076] R4 is chosen from the hydrogen atom and a linear, branched or cyclic hydrocarbon chain, aromatic or not, comprising from 1 to 10 carbon atoms, preferably from 1 to 7 carbon atoms and more preferably from 1 to 4 carbon atoms and optionally substituted (preferably by an aryl radical such as a phenyl);

[0077] or else

[0078] R3 and R4 form together and with the carbon atom which carries them, a cyclic radical, saturated or partially unsaturated, optionally substituted and which may comprise one or more heteroatoms chosen from oxygen and nitrogen; said cycle comprising a number of vertices between 3 and 9, preferably 5 or 6 vertices.

[0079] R1 and / or R2 when they are represented by an alkyl radical as defined above may be substituted by one or more aryl group(s) containing between 6 and 10 carbon atoms, preferably a phenyl.

[0080] R3 and / or R4 when represented by an alkyl radical as defined above may be substituted by one or more aryl group(s) containing between 6 and 10 carbon atoms, preferably a phenyl.

[0081] R3 and R4 when they form together and with the carbon atom which carries them, a cyclic radical, saturated or partially unsaturated, can be substituted by one or more alkyl group(s) comprising between 1 and 10 carbon atoms, preferably by one or more methyl group(s).

[0082] In particular, Ri represents a linear or branched alkyl radical, comprising from 1 to 10 carbon atoms, preferably from 1 to 7 carbon atoms and more preferably from 1 to 4 carbon atoms;

[0083] R2 is chosen from the hydrogen atom and a linear or branched alkyl radical, comprising from 1 to 10 carbon atoms, preferably from 1 to 7 carbon atoms and more preferably from 1 to 4 carbon atoms;

[0084] R3 represents a linear or branched alkyl radical, comprising from 1 to 10 carbon atoms, preferably from 1 to 7 carbon atoms and more preferably from 1 to 4 carbon atoms; and

[0085] R4 is chosen from the hydrogen atom and a linear or branched alkyl radical, comprising from 1 to 10 carbon atoms, preferably from 1 to 7 carbon atoms and more preferably from 1 to 4 carbon atoms.

[0086] Preferably R2 and / or R4 is a hydrogen atom.

[0087] In particular, the amine formed is chosen from the group consisting of:

[0088] diisopropylamine (DIPA), di-n-propylamine (DPA), N-ethylmethylamine (EMA), N-isopropylmethylamine, N-ethylpropylamine, N-ethylisopropylamine, N-ethylbutylamine, N-methylcyclohexylamine, N-ethylcyclohexylamine, N-ethylbenzylamine, N,N-dimethylethylamine (DMEA), N,N-dimethylisopropylamine (DMIPA), (N,N-dimethylpropylamine (DMPA), N,N-dimethylbutylamine, N,N-diethylmethylamine (DEMA), triethylamine (TEA) and di-sec-butylamine (DB2A).

[0089] More particularly, the amine formed is chosen from the group consisting of DIPA, DMEA, DMIPA and EMA; even more preferably DIPA and EMA.

[0090] Said amination step may in particular correspond to one or more of the following reactions: - the reaction of ammonia with a primary or secondary alcohol and / or a ketone to form primary, secondary and tertiary amines, preferably predominantly a secondary amine;

[0091]

[0092] - the reaction of a primary amine with a primary or secondary alcohol and / or a ketone to form secondary and tertiary amines, preferably predominantly a secondary amine; or - the reaction of a secondary amine with a primary or secondary alcohol and / or a ketone to form a tertiary amine. In particular, within the scope of the present invention, it is desired to form secondary and / or tertiary amines, preferably secondary amines. In particular, an alcohol of formula (I) and / or a ketone of formula (II) is used with ammonia or an amine of formula (III): HO—C—H '2

[0093]

[0094]

[0095]

[0096] in which Rb R2, R3 and R4 are as defined above, with R4 different from the hydrogen atom for the ketone of formula (II). Among the alcohols of formula (I), the following may be mentioned: ethanol, n-propanol, iso-propanol, n-butanol, isobutanol, 2-butanol, n-pentanol, n-hexanol, methyl isobutyl carbinol, n-heptanol, 2-ethylhexanol, n-octanol, diisobutylcarbinol, cyclohexanol, benzyl alcohol, 2-phenylethanol and 3,3,5-trimethylcyclohexanol. Among the ketones of formula (II) the following may be mentioned: acetone, methyl ethyl ketone (MEK), methyl propyl ketone, methyl isopropyl ketone, diethyl ketone, methyl isobutyl ketone (MIBK), diisobutyl ketone, cyclobutanone, cyclopentanone, cyclohexanone, acetophenone, isophorone and 3,3,5-trimethylcyclohexanone.

[0097] It is understood that, under the operating conditions of the amination step, the alcohols dehydrate to form ketones before reacting with the hydrogen and the nitrogen reagent.

[0098] Besides ammonia, preferred amine reagents of formula (III) are: methylamine, dimethylamine, ethylamine, diethylamine, n-propylamine, di-n-propylamine, isopropylamine, diisopropylamine, n-butylamine, di-n-butylamine, iso-butylamine, 2-butylamine, pyrrolidine, piperidine, morpholine, cyclohexylamine, benzylamine and 2-phenylethylamine.

[0099] Examples of secondary or tertiary amines which can thus be preferably prepared according to the process of the invention are:

[0100] - diisopropylamine (DIPA) from acetone and / or isopropanol and ammonia,

[0101] - di-n-propylamine (DPA) from propanol and ammonia,

[0102] - di-sec-butylamine from methyl ethyl ketone and / or 2-butanol with ammonia,

[0103] - N-ethylmethylamine (EMA) from ethanol and monomethylamine (MMA),

[0104] - N-isopropylmethylamine from acetone and / or isopropanol and (MMA),

[0105] - N-ethylpropylamine from n-propanol and monoethylamine or from ethanol and n-propylamine,

[0106] - N-ethylisopropylamine from ethanol and isopropylamine or from acetone and / or isopropanol and monoethylamine,

[0107] - N-ethylbutylamine from n-butanol and monoethylamine or from of ethanol and n-butylamine,

[0108] - N-methylcyclohexylamine from cyclohexanol and / or cyclohexanone and MMA,

[0109] - N-ethylcyclohexylamine from cyclohexanol and / or cyclohexanone and mo noethylamine or from ethanol and cyclohexylamine,

[0110] - N-ethylbenzylamine from benzyl alcohol and monoethylamine or from from ethanol and benzylamine,

[0111] - N,N-dimethylethylamine (DMEA) from ethanol and dimethylamine (DMA),

[0112] - N,N-dimethylisopropylamine (DMIPA) from acetone and / or isopropanol and of DMA,

[0113] - N,N-dimethylpropylamine (DMPA) from n-propanol and DMA,

[0114] - N,N-dimethylbutylamine from n-butanol and DMA,

[0115] - N,N-diethylmethylamine (DEMA) from ethanol and DMA.

[0116] The amination step according to the invention makes it possible to form secondary and / or tertiary amines (and water) in the gas phase and in the presence of hydrogen. Said process can be carried out batchwise or continuously, preferably continuously.

[0117] By "gas phase" or "gaseous phase" is meant in particular that the reactants (alcohol and / or ketone and nitrogenous reactant) are in the gaseous state, at the temperature and pressure conditions of said amination step. The gas phase feed of the reactor can be ensured by a prior passage of the reactants which are liquid through an evaporator (for example heated by steam or by any other known means). The temperature of the evaporator is set so as to ensure the passage of the reactants from the liquid state to the gaseous state under the pressure conditions used. The gases formed can then be entrained towards the inlet of the reactor, for example with the flow of hydrogen and, where appropriate, ammonia.

[0118] The catalytic reaction can be carried out under hydrogen pressure (H2), preferably in excess. Preferably the molar ratio of hydrogen to alcohol and / or ketone is between 0.5 and 20 mol / mol, preferably between 1 and 15 mol / mol and more preferably between 2 and 10 mol / mol.

[0119] Preferably, the amination reaction is carried out through one or more fixed bed(s) of catalyst as according to the invention. The fixed bed(s) may comprise one or more layer(s) of catalyst according to the invention. In the case of the implementation of a catalytic bed comprising several layers of catalysts, the metal concentration (for example in Cu and / or in Mn) may increase from the inlet to the outlet of the reactor, the number of layers being able to vary according to the length of the catalytic bed.

[0120] The amination reaction can be carried out within one (or more) tubular or multitubular reactor(s), in series or in parallel.

[0121] The amination reaction can be carried out under an absolute pressure in the reactor less than or equal to 30 bars, preferably between 1 and 20 bars and more preferably between 2 and 10 bars.

[0122] The amination reaction can be carried out at a temperature between 120°C and 220°C, preferably between 140°C and 200°C and more preferably between 150°C and 190°C.

[0123] The temperature of the reactor can be maintained by means of a heat transfer fluid which can be heated by steam, electrically or by any other known means and which can be cooled by means of a water and / or ethylene glycol refrigeration circuit or any other known refrigeration fluid. The heat transfer fluid can in particular comprise a mixture of molten nitrate salts (KNO3, NaNO3, LiNO 3)-

[0124] The amination reaction can be carried out with a molar ratio of alcohol and / or ketone to nitrogenous reagent of between 0.1 and 20 mol / mol, preferably between 0.5 and 10 mol / mol and more preferably between 1 and 5 mol / mol.

[0125] The mass flow rate of alcohol and / or ketone per unit volume of catalytic bed (MVH) may be between 0.05 and 1.0 kg / Lh, preferably between 0.10 and 0.80 kg / Lh and more preferably between 0.15 and 0.60 kg / Lh

[0126] The preparation process according to the invention may also comprise the following steps:

[0127] i) amination step as defined above; said step making it possible to obtain an outgoing stream G comprising a secondary and / or tertiary amine and water;

[0128] ii) at least one step of separating the flow G, so as to obtain:

[0129] - a flow comprising water, and

[0130] - a stream comprising the secondary amine and / or the tertiary amine;

[0131] iii) optionally, a step of separating the stream comprising both a secondary amine and a tertiary amine, so as to obtain:

[0132] - a stream comprising the secondary amine; and

[0133] - a stream comprising the tertiary amine; and

[0134] iv) optionally, recycling the stream comprising the tertiary amine, to step i).

[0135] The secondary and / or tertiary amines can then be recovered and optionally purified.

[0136] More particularly, said method may comprise the following steps:

[0137] a) amination step as defined above; said step making it possible to obtain an outgoing stream G in the gaseous state comprising a secondary and / or tertiary amine, water and unreacted hydrogen;

[0138] b) condensation and separation of said flow G, so as to obtain:

[0139] - a liquid stream G' comprising a secondary and / or tertiary amine and water, and

[0140] - a gaseous flow G” of hydrogen;

[0141] c) optionally, recycling of the flow G” to step a);

[0142] d) separation of the flow G', so as to obtain:

[0143] - a flow K comprising water, and

[0144] - a stream L comprising the secondary amine and / or the tertiary amine;

[0145] e) optionally, separation of the stream L when the latter comprises both a secondary amine and a tertiary amine, so as to obtain:

[0146] - a stream M comprising the secondary amine; and

[0147] - a stream N comprising the tertiary amine; and

[0148] f) optionally, recycling of the flow N, in step a).

[0149] Steps b) and d) may or may not be simultaneous.

[0150] The gas stream G” may include traces of secondary and / or tertiary amines and possibly primary amines.

[0151] When ammonia is used as a reactant and does not react completely, it may be found in the G” stream as well as in trace amounts in G'. In this case, further separation of the G' and / or G' ' streams may be performed to recover ammonia and recycle it to step a).

[0152] Furthermore, when ammonia is used as a reactant, the corresponding primary amine can also be formed as a by-product. This primary amine is found successively in streams G, G' and L (and possibly in G” in trace amounts). It can be separated from stream L at the end of separation step e) so as to obtain a stream P comprising it. Said stream P can be recycled to the amination step a).

[0153] The separation steps b), d) and e) can be carried out by any known means (for example by distillation or decantation) and preferably by distillation.

[0154] The secondary and / or tertiary amines produced can then be purified if necessary. In particular, fractional distillation is used by means of a series of distillation columns operating continuously.

[0155] More particularly, said method may comprise the following steps:

[0156] a) amination step as defined above; said step making it possible to obtain an outgoing stream G in the gaseous state comprising a secondary and / or tertiary amine, water and optionally the unreacted reagents as well as the alcohol resulting from the hydrogenation reaction of the ketone into alcohol;

[0157] b) condensation and separation of said flow G, so as to obtain:

[0158] - a liquid G' stream comprising a secondary and / or tertiary amine, water and possibly the unreacted reagents as well as the alcohol resulting from the hydrogenation reaction of the ketone to alcohol, and

[0159] - a gaseous hydrogen flow G” comprising traces of secondary amine and / or tertiary, and possibly traces of unreacted reagents as well as traces of the alcohol resulting from the hydrogenation reaction of the ketone to alcohol;

[0160] c) optionally, recycling of the flow G” to step a);

[0161] d) separation of the flow G', so as to obtain:

[0162] - a K stream comprising water and possibly the reactants not having reacted in this way that the alcohol resulting from the hydrogenation reaction of the ketone into alcohol, and

[0163] - a stream L comprising the secondary amine and / or the tertiary amine;

[0164] e) optionally, separation of the stream L when the latter comprises both a secondary amine and a tertiary amine, so as to obtain:

[0165] - a stream M comprising the secondary amine; and

[0166] - a stream N comprising the tertiary amine; and

[0167] f) optionally, recycling of the flow N, in step a).

[0168] It is also possible to separate the K stream in order to obtain a O stream comprising water and a T stream comprising alcohol. The alcohol thus recovered can be recycled to step a). Possible activation of the catalyst

[0169] The catalyst may be activated prior to step a). Indeed, catalysts are generally loaded into the reactor in oxidized or pre-reduced form (i.e. the metals, such as Cu and Mn, are wholly or partly in the form of oxides). In this case, the catalyst is preferably pre-activated. Activation is carried out by reduction, preferably in the reactor in which the amination step will be carried out (in situ activation). Activation of the catalyst is carried out by conventional methods, well known to those skilled in the art. It makes it possible to obtain the active metal species for hydrogenation or dehydrogenation by reduction of the corresponding oxidized forms. The copper thus passes from the Cu11 state (in CuO) to the Cu° state via the following reaction: CuO + H2 Cu + H2O

[0170] Thus, the activation of the catalyst can be carried out under a flow of hydrogen (H2) at a temperature between 150°C and 400°C, for example between 200°C and 400°C, preferably between 250°C and 350°C. Use according to the invention

[0171] The present invention also relates to the use of a catalyst as defined above, for a process for the preparation of secondary and / or tertiary amines as defined above, and in particular for the amination step as described above. EXAMPLES

[0172] Abbreviations and definitions:

[0173] ACE: acetone

[0174] ISO: isopropanol

[0175] EtOH: ethanol

[0176] MIPA: monoisopropylamine

[0177] DIPA: diisopropylamine

[0178] EMA: N-ethylmethylamine

[0179] DEMA: N,N-diethylmethylamine

[0180] DMEA: N,N-dimethylethylamine

[0181] DMIPA: N,N-dimethylisopropylamine

[0182] RM: molar ratio

[0183] MVH: hourly mass flow rate of feed per catalyst volume (unit: kg / Lh)

[0184] SA = selectivity in amine (A) produced compared to the converted reactants

[0185] The selectivities are calculated on the basis of the mass compositions of the raw mixtures leaving the reaction zone; compositions determined by gas phase chromatographic analyses.

[0186] TTdma = DMA transformation rate implemented = DMA conversion

[0187] NL: NormoLitre corresponds to a volume of IL under normal conditions of pressure (1.013 bar) and temperature (273 K).

[0188] Example No. 1: Synthesis of diisopropylamine (PIPA) - Secondary amine

[0189] The tests are carried out in a vertical tubular reactor containing a catalytic bed with a volume of 7 L and a length of 2.8 m. The reactor is immersed in a bath of molten nitrate salts (KNO3, NaNO3, LiNO3) electrically heated and cooled using water circulation through a cooling pin. A temperature probe inserted and able to slide in a sheath passing through the entire catalytic bed makes it possible to measure the reaction temperature.

[0190] Nickel catalyst (comparative):

[0191] The three-layer catalytic bed comprises a nickel-based catalyst in cylindrical pellets (4.8x4.8 mm) of the following weight composition before activation:

[0192] - lower layer (reactor inlet) ~ 0.33 L:

[0193] 5.3% Ni (as Ni and NiO) on A12O3 and 2.5-5% graphite,

[0194] - intermediate layer ~ 0.33 L:

[0195] 20% Ni (as Ni and NiO) on A12O3 and 2.5-5% graphite,

[0196] - upper layer (reactor outlet) ~ 0.33 L: 43% Ni (in Ni and NiO form) on A12O3, and 10% graphite. Copper catalyst Cl (according to the invention):

[0197] The single-layer catalytic bed comprises cylindrical pellets (4.8x4.8 mm) of a manganese-doped copper-based catalyst on an alumina (A12O3) support; the copper and manganese being in oxidized form before activation.

[0198] The weight concentration of copper in the catalyst is 46% (corresponding to 57.6% expressed as CuO) and the weight concentration of manganese is 6% (corresponding to 9.5% expressed as MnO2) before activation.

[0199] Activation of nickel catalyst and Cl catalyst:

[0200] In the tubular reactor previously heated to 240 °C and at atmospheric pressure, a flow of hydrogen and nitrogen is introduced with volume flow rates per unit volume of catalytic bed (WH) of 50 NL / Lh of H2 and 500 NL / Lh of N2 respectively. As soon as the zone of highest exotherm, monitored by the multipoint temperature probe, has crossed the entire catalytic bed (after approximately 8 hours), the introduction of nitrogen is stopped and the injection of hydrogen is continued for 12 hours by increasing the temperature of the reactor to 280 °C in the case of the copper catalyst and to 350 °C in the case of the nickel catalyst and with a WH of H2 of 100 NL / Lh

[0201] Amination step:

[0202] The reactor is then fed from bottom to top with a mixture of fresh acetone, recycled isopropanol, ammonia and hydrogen previously evaporated and preheated through a steam exchanger. The reactor pressure is maintained at 4 bars absolute and the temperature at 150 °C.

[0203] The table below indicates the results obtained as a function of the nature of the catalytic bed, the proportion of recycled isopropanol, the MVH and the NH3 and H2 RMs:

[0204] [Tables 1] Catalyst Running time ih; Motatre flow h- MVH RM RM ProdiictMtÉBiPA ACE tso 'réeyçê iM&tSOÎ / SiHS H3 / ÀCt4SQ DE PA BPÂ fats Ni 1.03 21 21 Q.55 $.5 4 61.1)7 38.26 041 9.985 1378 .25 14 0.35 3.5 4 52.97 46>61 042 9418 2?3 75 21 333 9.5 4 62.57 : 9467 149 33 .4 'C'35 1 5 2554 72 71 04S3 Ma Ci) {£1} 1662 5s 2 55 1147 8^75 5,læ eepe with Mr 14 7: £48 11 22.35 7?f5B 9.954 1921 44 - 9.13 2 55 9.35 3^25 0; 983 1345 14 7 0.13 2 B .5 l-liE 89.74 9.983

[0205] The Cl catalyst makes it possible to obtain a much higher selectivity for diisopropylamine than the nickel catalyst and without secondary formation of EIPA, which is difficult to separate from DIPA by distillation. It is possible to directly achieve a DIPA selectivity close to 90% without recycling MIPA.

[0206] Example No. 2: Synthesis of dimethylisopropylamine (DMIPA) - Tertiary amine

[0207] These tests were carried out in a thermoregulated vertical tubular reactor containing a catalytic bed comprising catalyst C1 or a catalyst C2 with a volume of IL and a length of 80 cm.

[0208] Copper catalyst Cl (according to the invention): as described in example 1 Copper catalyst C2 (comparative):

[0209] The catalytic bed is made of cylindrical pellets (6x5 mm) with a weight composition before activation: 76% CuO, 3% MgO, 1.5% Cr2O3, on silica (SiO2).

[0210] Amination step:

[0211] After prior activation of the catalysts by reduction with H2 at 250-350 °C, the reactor is fed from bottom to top with a mixture of fresh acetone and / or fresh and / or recycled isopropanol, DMA and hydrogen previously evaporated and preheated through an electrically heated exchanger. The synthesis is carried out with a large molar excess of acetone and / or isopropanol relative to the DMA, under a pressure of 8 bars and at a temperature of 185 °C.

[0212] The table below indicates the results obtained as a function of the nature of the catalytic bed and the respective molar flow rates in ACE+ISO and DMA, knowing that in all cases, the conversion of DMA is greater than 99%:

[0213] [Tables2] Duration of DetamoiaS» imd / h; MVH MVH RM RM Sâert*tésm{S) Calasse tir marche ih] ACE ISO {ACE*:sO: ÎDMA; iACMSOyWi ffiftSCEW; TMA Me4PA BMiPA Me-BiPA CSaCtiiQJ 2 jb, 6 0.5=3 8117 36 7.6 4521 3.33 303 ihors 257 1.86 4.64 K? Wî 3.3 38 4.45' 3.31 saæ 5® 2.7 6.6 8.=53 years 30 1.38 1.84 9486 80S Casa tu {Cil dopé aset Mis 136 4.64- SW 30 131 1.71 95.« 8.83 337 1.S6 4.64 8.387 8®3 35 36 1.38 152 84>S 332

[0214] With catalyst C2, the selectivity to DMIPA over DMA is 8 to 9% lower than that obtained with catalyst C1. This may be due to a greater disproportionation of DMA into TMA and MMA; MMA then reacting with acetone to form methylisopropylamine (Me-IPA) and methyldiisopropylamine (Me-DIPA).

[0215] Example No. 3: Synthesis of ethylmethylamine (EMA - secondary amine) and / or diethylmethylamine (DEMA - tertiary amine) from ethanol and MMA, with or without recycling of DEMA

[0216] These tests were carried out in the same apparatus as that of example no. 2 with the previously reduced catalyst Cl.

[0217] The synthesis is carried out with a molar excess of ethanol relative to MMA, in the presence of hydrogen, under a pressure of 8 bars and at a temperature of 175°C and where appropriate with recycling of DEMA.

[0218] The table below shows the results obtained as a function of the EtOH / MMA molar ratio and the possible recycling of DEMA:

[0219] [Tables3] Catalyst Run time thj MVH phiHj MVH {MMA] SM EtOH / MMA RM H2 / ROB Productivity EMA Etes MMA DEMA recycled EMA SEMA 139 4.5 35 - 9.257 8.133 8.4 75.45 19.62 5.120 CataCu JC1] 453 4.5 35 - aae? 8.693 15 14.2 73.12 1S,® 5.180 dSiSSVSÇMfi 512 45 2.3 189 8.287' 5883 1.6 14.2 85.35 10.41 8.18? 7=8 45 3.0 1.85 6.287 0593 15 14.2 92.73 3.57 8.097

[0220] The results at 512h and 760h of operation correspond to tests carried out with recycling of the DEMA recovered at the end of the reaction by distillation and reintroduced into the reactor.

[0221] It can be seen that depending on the flow rate of recycled tertiary amine (DEMA), the selectivity of secondary amine (EMA) with respect to MMA can become greater than 90%.

[0222] Example No. 4: Synthesis of the secondary amine ethylpropylamine (EPA) from ethanol and MEA

[0223] These tests were carried out in the same apparatus as that of example no. 2 with the previously reduced catalyst Cl.

[0224] A continuous feed of 6 mol / h of ethanol and 2 mol / h of monoethylamine (MEA) is provided, at a temperature of 170°C, in the presence of H2 (RM H2 / EtOH = 4), under a pressure of 4 bars.

[0225] The conversion of the MEA at the reactor outlet is 81% and the EPA is obtained with a selectivity of 92% compared to the converted MEA.

[0226] Example No. 5: Synthesis of the secondary amine di-n-propylamine (PPA) from n-propanol and ammonia, with recycling of n-PA (n-propylamine) and TP A (tripropylamine)

[0227] These tests were carried out in the same apparatus as that of example no. 2 with the previously reduced catalyst Cl.

[0228] With a continuous feed of 8 mol / h of n-propanol (MVH = 0.48 Kg / Lh) and 24 mol / h of ammonia (RM PrOH / NH3 = 0.33), at a temperature of 165°C, in the presence of H2 (RM H2 / PrOH = 4), under a pressure of 4 bars, and a recycle of 196 g / h of n-PA and 90 g / h of TPA, the DPA is obtained with a selectivity of 92.5% for a conversion of n-propanol of 79.0%.

[0229] Example No. 6: Synthesis of the tertiary amine dimethylpropylamine (DMPA) from n-propanol and DMA

[0230] These tests were carried out in the same apparatus as that of example no. 2 with the previously reduced catalyst Cl, under an absolute pressure of 8 bars and at a reaction temperature TR of 185 or 190 °C.

[0231] The table below indicates the results obtained depending on the nature of the catalytic bed and the reaction conditions used:

[0232] [Tables4] Cataiyæur Flow PrOH MVH-PrOH; MVH RM RM Tr Ssfectwftés,;;;® {%} PrOH / OMA H2 / M3H TMA SMPA Me-OPA 4.1 OC,08S 24 47 ISO 89.4s 9837 $3$ CaîaCu(Cli 8.0 C.1C3 2.5 51 185 9935 98.24 Isa 3V=£ SA o 2.6 5.1 190 99.73 au 98.81 .•> .5 A 8.0 ¢88 aw U 5.4 185 SS, 83 A27 38.68

[0233] With catalyst Cl, very high DMPA selectivities are obtained, greater than 98% with a DMA conversion rate greater than 99% (TT), with very few amine impurities.

[0234] Example No. 7: Synthesis of the tertiary amine dimethylethylamine (DMEA) from ethanol and DMA - Alternating syntheses

[0235] These tests were carried out in the same apparatus as that of example No. 1 but with a catalytic bed of catalyst Cl with a volume of 3.2 L and a length of 2.8 m and under the following reaction conditions:

[0236] - Average molar flow rate of REN grade ethanol containing 4.3% water: 28.8 mol / h, corresponding to an average MVH in ethanol of 0.435 kg / Lcata.h

[0237] - Average molar flow rate of DMA: 6.6 mol / h, corresponding to an average MVH in DMA of 0.135 kg / Lcata.h and at an average EtOH / DMA molar ratio of 3

[0238] - Average molar ratio H2 / EtOH = 8

[0239] - Reaction carried out under an absolute pressure of 8 bars

[0240] The implementation of the catalytic bed is carried out alternately in DMEA production and in DMIPA production in order to evaluate the stability of the catalyst after different production campaigns.

[0241] The table below indicates the corresponding selectivities with respect to DMA, only the selectivities for DMEA production campaigns are calculated below.

[0242] [Tables5] Walking time fh; TR Selected^ TM A BMtA SEMA 73 190 99.95 0.64 98.21 0.83 Campaign 1 260 180 99.97 8.75 98.08 0.84 332 190 99.97 0.62 98.12 0.86 Use of lit tataiytitj in DMIPA synthesis from acetone and DMA during nt.B88h 32.50 190 99.96 0.78 97.67 .1.00 3314 185 99.97 0.54 98.08 0.81 Campaign 2 1361 175 99.96 0.69 97.97 0.76 1403 165 97.79 0.87 97.60 0.78 uæ* SO 99.94 0.94 97.83 1M Ut iii satin ndj lit eataiytip je in DMIPA synthesis from acetone and DMA for 5b0 h Then: Regeneration of the cataiytisue bed via an oxidation operation followed by a reduction step to Fhy erogene 2185 ISO 99.97 0.84 97.73 1.07 Campaign 3 2259 ISO. 99.95 0.83 97.89 0.94 * implementation at'&hanoî fecycié a>n ten c œ 1 0.7 K of water

[0243] These results demonstrate the stability of the catalyst's performance over time, despite intermediate DMIPA operation campaigns using acetone (a much more exothermic reaction). This catalyst can therefore be advantageously used in a multipurpose production unit allowing the manufacture of amines of different natures in successive campaigns.

[0244] Furthermore, it can be seen that, if necessary, the catalyst can be easily regenerated by an oxidation step followed by a new reduction with hydrogen without loss of its performance.

Claims

Claims

1. A process for the preparation of secondary and / or tertiary amines comprising an amination step, said amination step being carried out by reacting a primary or secondary alcohol and / or a ketone with ammonia or a primary or secondary amine, in the gas phase and in the presence of a catalyst and hydrogen; said catalyst comprising copper doped with manganese, the amount of manganese being between 1% and 10% by weight, relative to the total weight of the catalyst, and the amount of copper being between 20% and 60% by weight, relative to the total weight of the catalyst.

2. A preparation process according to claim 1, wherein the amount of copper in the catalyst is between 35% and 50% by weight, relative to the total weight of the catalyst.

3. Preparation process according to any one of the preceding claims, in which the amount of manganese is between 4% and 10% by weight, preferably between 4% and 8% by weight, relative to the total weight of the catalyst.

4. A preparation process according to any one of the preceding claims, wherein the catalyst comprises a support selected from the group consisting of: alumina (A12O3), silica (SiO2), titanium dioxide, zirconia, as well as mixtures of two or more of them, preferably alumina and / or silica.

5. Preparation process according to any one of the preceding claims, in which the amine formed is of the following general formula (A): [Chem. 8] ​​Ri 14 N—C—H R2 R, J (A) in which: Ri represents a linear, branched or cyclic alkyl radical, comprising from 1 to 10 carbon atoms, preferably from 1 to 7 carbon atoms

6. and more preferably from 1 to 4 carbon atoms optionally substituted; R2 is chosen from the hydrogen atom and a linear, branched or cyclic alkyl radical, comprising from 1 to 10 carbon atoms, preferably from 1 to 7 carbon atoms and more preferably from 1 to 4 carbon atoms, optionally substituted; or else R1 and R2 together form, with the nitrogen atom which carries them, a cyclic radical, saturated or partially or totally unsaturated, optionally substituted and which may comprise one or more heteroatoms chosen from oxygen and nitrogen; said cycle may comprise a number of vertices between 3 and 9, preferably 5 or 6 vertices. R3 represents a linear, branched or cyclic hydrocarbon chain, aromatic or not, comprising from 1 to 10 carbon atoms, preferably from 1 to 7 carbon atoms and more preferably from 1 to 4 carbon atoms and optionally substituted; R4 is chosen from the hydrogen atom and a linear, branched or cyclic hydrocarbon chain, aromatic or not, comprising from 1 to 10 carbon atoms, preferably from 1 to 7 carbon atoms and more preferably from 1 to 4 carbon atoms and optionally substituted; or else R3 and R4 form together and with the carbon atom which carries them, a cyclic radical, saturated or partially unsaturated, optionally substituted and which may comprise one or more heteroatoms chosen from oxygen and nitrogen; said cycle comprising a number of vertices between 3 and 9, preferably 5 or 6 vertices. A preparation process according to any one of the preceding claims, wherein the amine formed is selected from the group consisting of: diisopropylamine (DIPA), di-n-propylamine (DPA), N-ethylmethylamine (EMA), N-isopropylmethylamine, N-ethylpropylamine, N-ethylisopropylamine, N-ethylbutylamine, N-methylcyclohexylamine, N-ethylcyclohexylamine, N-ethylbenzylamine, N,N-dimethylethylamine (DMEA), N,N-dimethylisopropylamine (DMIPA), N,N-dimethylpropylamine (DMPA), N,N-dimethylbutylamine, N,N-diethylmethylamine (DEMA), triethylamine (TEA) and di-sec-butylamine (DB2A).

7. Preparation process according to any one of the preceding claims, in which the amine formed is chosen from the group consisting of DIPA, DMEA, DMIPA and EMA; even more preferably DIPA and EMA.

8. Preparation process according to any one of the preceding claims, in which the catalyst is previously activated by reduction, preferably under a flow of hydrogen (H2), at a temperature between 150°C and 400°C.

9. Preparation process according to any one of the preceding claims, comprising the following steps: i) amination step as defined in any one of claims 1 to 8; said step making it possible to obtain an outgoing stream G comprising a secondary and / or tertiary amine and water; ii) at least one step of separating the stream G, so as to obtain: - a stream comprising water, and - a stream comprising the secondary amine and / or the tertiary amine; iii) optionally, a step of separating the stream comprising both a secondary amine and a tertiary amine, so as to obtain: - a stream comprising the secondary amine; and - a stream comprising the tertiary amine; and iv) optionally, recycling the stream comprising the tertiary amine, to step i).

10. Preparation process according to claim 9, comprising the following steps: a) amination step as defined in any one of claims 1 to 8; said step making it possible to obtain an outgoing stream G in the gaseous state comprising a secondary and / or tertiary amine, water and unreacted hydrogen; b) condensation and separation of said stream G, so as to obtain: - a liquid stream G' comprising a secondary and / or tertiary amine and water, and - a gaseous stream G” of hydrogen; c) optionally, recycling of stream G” to step a); d) separation of stream G', so as to obtain: - a stream K comprising water, and - a stream L comprising the secondary amine and / or the tertiary amine; e) optionally, separation of stream L when the latter comprises at the both a secondary amine and a tertiary amine, so as to obtain: - a stream M comprising the secondary amine; and - a stream N comprising the tertiary amine; and f) optionally, recycling of stream N, to step a).

11. A method according to claim 10 wherein, when the reactant is ammonia, stream G also comprises a primary amine as a by-product, said primary amine then being found in streams G' and L and being separated in a stream P at the end of separation step e), said stream P possibly being recycled to step a).

12. Use of a catalyst comprising copper doped with manganese, the manganese being present in an amount of between 1% and 10% by weight relative to the total weight of the catalyst and the amount of copper being between 20% and 60% by weight, relative to the total weight of the catalyst, for the preparation of secondary and / or tertiary amines.