Method for synthesizing amines and co-producing aldehydes through amine and alcohol alkylation

Abstract

The invention discloses a method for synthesizing amines and co-producing aldehydes by alkylating amines and alcohols, which is characterized by comprising the following steps of: adding an amine compound as shown in a formula I or II and an alcohol compound as shown in a formula III or IV into a reactor filled with a supported catalyst, and reacting, and generating an amine compound as shown in a formula V or VI and an aldehyde compound as shown in a formula VII or VIII. According to the invention, the proportion of amines and aldehydes in the product is regulated and controlled, and the generation of other byproducts is inhibited, so that the amines and aldehydes are co-produced while the amines and the aldehydes are produced. # imgabs0 #

Description

Technical Field

[0001] The invention relates to a method for synthesizing amines by alkylation of amines and alcohols and co-producing aldehydes and ketones. Background Art

[0002] Amines are a class of nitrogen-containing organic compounds, which are derivatives of ammonia. When hydrogen atoms are replaced by organic groups, primary amines, secondary amines, tertiary amines and quaternary ammonium salts are formed. They are widely used in medicine, dyes, plastics and catalysts. The production methods of amines include reductive amination, nitro compound reduction, Haber synthesis, amination reaction (including alkylation), catalytic hydrogenation, Grignard reagent method and Beckmann rearrangement reaction.

[0003] Among them, alkylation is a commonly used method for converting low-level amines into high-level amines. The traditional alkylation scheme uses chloroalkanes as alkylating agents, which has the significant advantage of high conversion efficiency. However, chloroalkanes themselves are of high value and additional acid-binding agents need to be added during subsequent treatment. Compared with other alkylating agents, alcohols as alkylating agents are relatively cheap, and the theoretical by-product is only water, which is in line with the economic and green principles.

[0004] Patent CN202210034548 reports a method for preparing tertiary amines using secondary amines as raw materials. The method uses a proton-type ionic liquid catalyst to catalyze the amination reaction of aldehydes and ketones with secondary amines under acidic conditions. The reaction requires strong acid and strong base. The equipment requirements are high and continuous production operation cannot be achieved.

[0005] Patent CN114105784A reports a method for preparing N,N-diisopropylethylamine by alkylation reaction of ethanol and diisopropylamine using catalyst Mo-Ni-Cu / Al2O3 at appropriate pressure and temperature. However, in addition to producing N,N-diisopropylethylamine, this method also produces byproducts such as diethylamine, isopropanol and triethylamine. Moreover, in fact, due to the presence of dehydrogenation reaction in the process of alcoholamine alkylation reaction, aldehydes and ketones are intermediate products of the reaction, and it is very difficult to completely inhibit the generation of aldehydes and ketones and side reactions. Our research results show that the presence of amine compounds can promote the polymerization of aldehydes and ketones, and the aldehydes and ketones are difficult to avoid as byproducts. At present, these byproducts, including aldehydes and ketones, are usually treated as waste.

[0006] Therefore, in summary, a continuous production route solution for synthesizing amines by alkylation of amines and alcohols and co-producing aldehydes and ketones is proposed, which can obtain higher added value. Summary of the invention

[0007] In view of the fact that aldehydes and ketones are difficult to avoid as by-products in the reaction process of synthesizing amines by alkylation of amines and alcohols, and many aldehydes and ketones are usually obtained by dehydrogenation of alcohol compounds, and have higher added value than alcohols, the present invention proposes a method for synthesizing amines by alkylation of amines and alcohols and co-producing aldehydes, which solves the problem of suppressing other by-products and co-producing aldehydes and ketones in the traditional route.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] A method for synthesizing amines and co-producing aldehydes by alkylation of amines and alcohols, comprising the following steps: adding an amine compound represented by formula I or II and an alcohol compound represented by formula III or IV to a reactor filled with a supported catalyst for reaction to generate an amine compound represented by formula V or VI and an aldehyde compound represented by formula VII or VIII; the supported catalyst comprises a carrier and an active component, the carrier is one or more of silicon oxide, aluminum oxide, and iron oxide, the active component is composed of a main metal and an auxiliary metal, the main metal is selected from Pt, Co, Pd, Ru or Ni, and the auxiliary metal is selected from Sn, Fe, Mn, Ag, Cu or Mo; or the main metal is Cu and the auxiliary metal is Ag;

[0010] The reaction formula is as follows:

[0011]

[0012] R1-R5 are each independently selected from C1-C4 alkyl groups.

[0013] Preferably, the molar ratio of the amine compound represented by Formula I or II to the alcohol compound represented by Formula III or IV is 1:2-4, more preferably 1:3.

[0014] Preferably, the reactor is a batch reactor or a tube-type fixed bed, and more preferably, a continuous reaction is carried out in a tube-type fixed bed. Further preferably, the mixture of the amine compound represented by formula I or II and the alcohol compound represented by formula III or IV is gasified and then passed into a tube-type fixed bed for reaction.

[0015] It is further preferred that the reaction temperature in the tubular fixed bed is 100-150°C and the fixed bed reaction volume space velocity is 0.4-1h -1 , the pressure inside the fixed bed reaction tube is 0.1-0.5Mpa.

[0016] Preferably, in the supported catalyst, the mass ratio of the main metal to the auxiliary metal in the active component is 1-5:1, and the total loading amount of the active component (based on the mass of the catalyst) is 2%-30%, more preferably 10-30%.

[0017] In the present invention, the supported catalyst can be prepared by the following steps:

[0018] S1: Impregnation of the catalyst: Dissolve the soluble metal compounds corresponding to the main metal and the auxiliary metal in deionized water to prepare an impregnation solution, and use an equal volume impregnation method to prepare a catalyst precursor;

[0019] S2: Catalyst calcination: placing the catalyst precursor in a muffle furnace for programmed temperature calcination to obtain a calcined product;

[0020] S3: Catalyst reduction: The calcined product is subjected to reduction treatment to finally obtain a supported catalyst.

[0021] The soluble metal compound in S1 is one or more of nitrate, sulfate, acetate, and chloride. Preferably, the soluble metal salt is selected from nickel nitrate hexahydrate, copper nitrate trihydrate, tin tetrachloride, palladium chloride, chloroplatinic acid hexahydrate, ruthenium trichloride, silver nitrate, manganese chloride, cobalt nitrate hexahydrate, iron nitrate nonahydrate, and the like.

[0022] In S2, the conditions for programmed temperature calcination are: heating to 450-650°C at a rate of 1-20°C / min, keeping the temperature for reaction for 2-3 hours, stopping heating and cooling to room temperature.

[0023] In S3, the reduction treatment conditions are: in an atmosphere with a H2 flow rate of 30-60 mL / min, the temperature is raised to 450-650°C at a rate of 1-20°C / min, the reduction is carried out at this temperature for 2-3 hours, and then cooled to room temperature, and then filled with 0.1-0.5 MPa nitrogen for aging for 5-7 hours.

[0024] The reaction mixture obtained by reacting the amine compound represented by formula I or II and the alcohol compound represented by formula III or IV of the present invention can be separated by distillation to obtain the amine compound represented by formula V or VI and the aldehyde compound represented by formula VII or VIII, respectively.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) Compared with the waste of aldehyde substances produced in the existing supported metal-catalyzed alkylation of amines and alcohols to synthesize amines, the present invention adjusts the catalyst and the type of alcohol amine to achieve the regulation of the ratio of amines and aldehydes in the product, inhibits the formation of other by-products, and achieves the co-production of aldehyde substances while producing amines.

[0027] (2) Compared with the existing intermittent reactor-type amine synthesis equipment, the present invention adopts a continuous tube-type fixed bed equipment, which has the advantages of smaller liquid holdup and simpler operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flow chart of the reaction device used in the embodiment of the present invention.

[0029] Figure 2-Figure 4 These are the GC analysis results of the products obtained in Examples 1-3 respectively. DETAILED DESCRIPTION

[0030] In order to better understand the technical solution of the present invention, the technical solution provided by the present invention is described in detail below in conjunction with specific embodiments, but the scope of protection claimed in the present invention is not limited to the scope described in the embodiments.

[0031] The reaction device used in the embodiment of the present invention is as follows Figure 1 shown.

[0032] The supported catalyst used in the embodiment of the present invention is prepared by the following method: a certain amount of active metal precursors (nickel nitrate hexahydrate, copper nitrate trihydrate, tin tetrachloride, palladium chloride, chloroplatinic acid hexahydrate, ruthenium trichloride, silver nitrate, manganese chloride, cobalt nitrate hexahydrate, two of iron nitrate nonahydrate) are weighed and dissolved in deionized water to form a solution a with a total concentration of two metal elements of 0.05 g / mL, a certain amount of 20-40 mesh carrier (Al2O3, SiO2) is added to the solution a, impregnated at normal pressure for 24 hours, and then rotated. The catalyst was dried and evaporated in an evaporator, and then placed in a muffle furnace and heated to 450°C at a rate of 10°C / min for 240 min. After being taken out of the muffle furnace, it was allowed to cool at room temperature and placed in a tube furnace and heated to 450°C at a rate of 10°C / min in a pure hydrogen atmosphere with a gas flow rate of 30 ml / min for 180 min. After that, the heating program was turned off and naturally cooled to room temperature to finally obtain supported catalysts NiSn / SiO2 (Ni loading 25wt%, Sn loading 5wt%), NiC u / SiO2 (Ni loading 25wt%, Cu loading 5wt%), NiCu / Al2O3 (Ni loading 25wt%, Cu loading 5wt%), CoMo / Al2O3 (Co loading 25wt%, Mo loading 5wt%), PtSn / Al2O3 (Pt loading 5wt%, Sn loading 5wt%), PdMo / Al2O3 (Pd loading 5wt%, Mo loading 5wt%), RuAg / Al2O3 (Ru loading 5wt%, Ag loading 5wt%), RuSn / Al2O3 (Ru loading 5wt%, Sn loading 5wt%), CuAg / Al2O3 (Cu loading 10wt%, Ag loading 5wt%), CoMn / Al2O3 (Co loading 5wt%, Mn loading 5wt%), CoFe / Al2O3 (Co loading 5wt%, Fe loading 5wt%), wherein loading amount = metal element mass / (metal element mass+carrier)×100%.

[0033] Nickel nitrate hexahydrate, copper nitrate trihydrate, tin tetrachloride, palladium chloride, chloroplatinic acid hexahydrate, ruthenium trichloride, silver nitrate, manganese chloride, cobalt nitrate hexahydrate, and iron nitrate nonahydrate used in the examples of the present invention were all purchased from Sinopharm Group.

[0034] The sources of the carrier used in the embodiment of the present invention are: Al2O3 was purchased from Zibo Yinghe Chemical Co., Ltd., and SiO2 was purchased from Qingdao Borite Silicon Energy Technology Co., Ltd.

[0035] Examples 1-3

[0036] Catalyst regulation: Three catalysts, NiSn / SiO2, NiCu / SiO2 and NiCu / Al2O3, were prepared to catalyze the reaction of ethanol and diisopropylamine.

[0037] Embodiment 1:

[0038] (1) 10 g of NiSn / SiO2 (Ni loading 25 wt%, Sn loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was raised to 100°C and maintained.

[0039] (2) Ethanol and diisopropylamine were mixed in a molar ratio of 1:3 to obtain a raw material solution, and the reaction raw material solution was pumped at a speed of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0040] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0041] Embodiment 2:

[0042] (1) 10 g of NiCu / SiO2 (Ni loading 25 wt%, Cu loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was raised to 100°C and maintained.

[0043] (2) Ethanol and diisopropylamine were mixed in a molar ratio of 1:3 to obtain a raw material solution, and the reaction raw material solution was pumped at a speed of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0044] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0045] Embodiment 3:

[0046] (1) 10 g of NiCu / Al2O3 (Ni loading 25 wt%, Cu loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was raised to 100°C and maintained.

[0047] (2) Ethanol and diisopropylamine were mixed in a molar ratio of 1:3 to obtain a raw material solution, and the reaction raw material solution was pumped at a speed of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0048] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0049] The GC test results are shown in Table 1:

[0050] Table 1

[0051]

[0052] Embodiment 4-9

[0053] Alcohol regulation: Dimethylamine undergoes alkylation reaction with ethanol, propanol, butanol, and butanediol. Diisopropylamine undergoes alkylation reaction with propanol and n-butanol.

[0054] Embodiment 4:

[0055] (1) 10 g of CoMo / Al2O3 (Co loading 25 wt%, Mo loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was programmed to 120°C and maintained.

[0056] (2) Dimethylamine and ethanol were mixed in a molar ratio of 3:1 to obtain a raw material solution, and the reaction raw material solution was pumped at a rate of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0057] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0058] Embodiment 5:

[0059] (1) 10 g of PtSn / Al2O3 (Pt loading 5 wt%, Sn loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was raised to 120°C and maintained.

[0060] (2) Dimethylamine and propanol were mixed in a molar ratio of 3:1 to obtain a raw material solution, and the reaction raw material solution was pumped at a speed of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0061] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0062] Embodiment 6:

[0063] (1) 10 g of PdMo / Al2O3 (Pt loading 5 wt%, Mo loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was raised to 120°C and maintained.

[0064] (2) Dimethylamine and butanol were mixed in a molar ratio of 3:1 to obtain a raw material solution, and the reaction raw material solution was pumped at a speed of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0065] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0066] Embodiment 7:

[0067] (1) 10 g of RuAg / Al2O3 (Ru loading 5 wt%, Ag loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was raised to 120°C and maintained.

[0068] (2) Dimethylamine and butanediol were mixed in a molar ratio of 3:1 to obtain a raw material solution, and the reaction raw material solution was pumped at a speed of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0069] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0070] Embodiment 8:

[0071] (1) 10 g of PtSn / Al2O3 (Pt loading 5 wt%, Sn loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was raised to 120°C and maintained.

[0072] (2) Diisopropylamine and propanol were mixed in a molar ratio of 3:1 to obtain a raw material solution, and the reaction raw material solution was pumped at a speed of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0073] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0074] Embodiment 9:

[0075] (1) 10 g of NiCu / Al2O3 (Ni loading 25 wt%, Cu loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was raised to 120°C and maintained.

[0076] (2) Diisopropylamine and n-butanol were mixed in a molar ratio of 3:1 to obtain a raw material solution, and the reaction raw material solution was pumped at a rate of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0077] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0078] The GC test results are shown in Table 2:

[0079] Table 2

[0080]

[0081]

[0082] Examples 10-14

[0083] Amine regulation: Ethanol undergoes alkylation reaction with dimethylamine, piperidine, di-n-butylamine, di-n-propylamine, and diethylamine.

[0084] Embodiment 10:

[0085] (1) 10 g of RuSn / Al2O3 (Ru loading 5 wt%, Sn loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was programmed to 120°C and maintained.

[0086] (2) Ethanol and dimethylamine were mixed in a molar ratio of 3:1 to obtain a raw material solution, and the reaction raw material solution was pumped at a rate of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0087] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0088] Embodiment 11:

[0089] (1) 10 g of CuAg / Al2O3 (Cu loading 10 wt%, Ag loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was raised to 120°C and maintained.

[0090] (2) Ethanol and piperidine were mixed in a molar ratio of 3:1 to obtain a raw material solution, and the reaction raw material solution was pumped at a rate of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0091] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0092] Embodiment 12:

[0093] (1) 10 g of PtSn / Al2O3 (Pt loading 5 wt%, Sn loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was raised to 120°C and maintained.

[0094] (2) Ethanol and di-n-butylamine were mixed in a molar ratio of 3:1 to obtain a raw material solution, and the reaction raw material solution was pumped at a rate of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0095] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0096] Embodiment 13:

[0097] (1) 10 g of CoMn / Al2O3 (Pt loading 5 wt%, Sn loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was raised to 120°C and maintained.

[0098] (2) Ethanol and di-n-propylamine were mixed in a molar ratio of 3:1 to obtain a raw material solution, and the reaction raw material solution was pumped at a speed of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0099] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0100] Embodiment 14:

[0101] (1) 10 g of CoFe / Al2O3 (Pt loading 5 wt%, Sn loading 5 wt%) catalyst was uniformly added into the reaction bed, and the temperature was programmed to 120°C and maintained.

[0102] (2) Ethanol and diethylamine were mixed in a molar ratio of 3:1 to obtain a raw material solution, and the reaction raw material solution was pumped at a speed of 0.4 h. -1 The volume space velocity is pumped into the bed for reaction, and the pressure in the bed is maintained at 0.2MPa.

[0103] (3) After the reaction reaches equilibrium, take the liquid after the reaction for GC detection.

[0104] The GC test results are shown in Table 3:

[0105] Table 3

[0106]

[0107]

Claims

1. A method for synthesizing amines by alkylation of amines and alcohols and co-producing aldehydes, characterized in that: The method comprises the following steps: adding an amine compound represented by formula I or II and an alcohol compound represented by formula III or IV to a reactor filled with a supported catalyst for reaction to generate an amine compound represented by formula V or VI and an aldehyde compound represented by formula VII or VIII; the supported catalyst comprises a carrier and an active component, the carrier is one or more of silicon oxide, aluminum oxide, and iron oxide, the active component is composed of a main metal and an auxiliary metal, the main metal is selected from Pt, Co, Pd, Ru or Ni, and the auxiliary metal is selected from Sn, Fe, Mn, Ag, Cu or Mo; or the main metal is Cu and the auxiliary metal is Ag; The reaction formula is as follows: R1-R5 are each independently selected from C1-C4 alkyl groups.

2. The method according to claim 1, characterized in that: The molar ratio of the amine compound represented by formula I or II to the alcohol compound represented by formula III or IV is 1:2-4.

3. The method according to claim 1, characterized in that: The reactor is a batch reactor or a tube-in-tube fixed bed.

4. The method according to claim 1, characterized in that: The reactor is a tube-in-tube fixed bed, and the mixture of the amine compound represented by Formula I or II and the alcohol compound represented by Formula III or IV is gasified and then introduced into the tube-in-tube fixed bed for reaction.

5. The method according to claim 4, characterized in that: The reaction temperature in the tube-type fixed bed is 100-150°C, and the fixed bed reaction volume space velocity is 0.4-1h -1 , the pressure inside the fixed bed reaction tube is 0.1-0.5Mpa.

6. The method according to claim 1, characterized in that: In the supported catalyst, the mass ratio of the main metal to the auxiliary metal in the active component is 1-5:1, and the total loading amount of the active component is 2%-30%.

7. The method according to claim 6, characterized in that: The total loading of the active ingredients is 10-30%.

8. The method according to claim 1, 6 or 7, characterized in that: The supported catalyst is prepared by the following steps: S1: Impregnation of the catalyst: Dissolve the soluble metal compounds corresponding to the main metal and the auxiliary metal in deionized water to prepare an impregnation solution, and use an equal volume impregnation method to prepare a catalyst precursor; S2: Catalyst calcination: placing the catalyst precursor in a muffle furnace for programmed temperature calcination to obtain a calcined product; S3: Catalyst reduction: The calcined product is subjected to reduction treatment to finally obtain a supported catalyst.

9. The method according to claim 8, characterized in that: In S2, the conditions for programmed temperature calcination are: heating to 450-650°C at a rate of 1-20°C / min, keeping the temperature for reaction for 2-3 hours, stopping heating and cooling to room temperature.

10. The method according to claim 8, characterized in that: In S3, the reduction treatment conditions are: in an atmosphere with a H2 flow rate of 30-60mL / min, the temperature is raised to 450-650°C at a rate of 1-20°C / min, the reduction is carried out at this temperature for 2-3h, and then cooled to room temperature, and then filled with 0.1-0.5MPa nitrogen for aging for 5-7h.

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