Method for carrying out hydrogen transfer reaction by using microreactor device

Abstract

The invention discloses a method for carrying out hydrogen transfer reaction by utilizing a microreactor device. The microreactor device comprises a liquid pipeline system, a gas pipeline system, a microreactor and a cooling and product collecting system, the top of the microreactor is respectively communicated with a liquid pipeline system and a gas pipeline system, and the bottom of the microreactor is connected with a cooling and product collecting system; the method comprises the following steps: filling a Pt / Al2O3 catalyst in a reaction tube of the microreactor; the method comprises the following steps: introducing inert gas to discharge air in a micro-reactor, continuously pumping a raw material solution formed by mixing an alcohol compound shown in a formula I and an amine compound shown in a formula II into the micro-reactor for reaction, enabling a reaction solution to flow out of the micro-reactor, and then enabling the reaction solution to enter a cooling and product collecting system for collection, so as to obtain a product shown in a formula III. According to the invention, the hydrogen transfer reaction is carried out by using the microreactor, so that higher product yield is obtained. # imgabs0 #

Description

Technical Field

[0001] The invention relates to a method for carrying out hydrogen transfer reaction by utilizing a microreactor device. Background Art

[0002] Hydrogen transfer reaction, also known as hydrogen borrowing reaction, refers to the use of hydrogen donors as hydrogen sources, under the catalysis of metals and transition metals, to dehydrogenate relatively inert organic molecules to form metal hydrides, while activating organic molecules as active substrates and participating in subsequent coupling reactions; the metal hydrides formed by dehydrogenation then undergo reduction reactions with active intermediates generated during the reaction to synthesize the target product. Compared with ordinary hydrogenation reactions, this reaction uses non-high-pressure hydrogen as a hydrogen donor and is carried out at normal pressure. It has the advantages of low reaction temperature, mild reaction conditions, low equipment requirements, and low reaction risk. It has broad application prospects in the production of fine chemical industries such as medicine. In organic synthesis, hydrogen transfer reactions can be used to construct carbon-carbon bonds or carbon-hydrogen bonds. For example, hydrogen transfer reactions can be used to hydrogenate olefins and convert olefins into saturated hydrocarbons. In addition, hydrogen transfer reactions can also be used to synthesize alcohols and ether compounds. In the petroleum industry, catalytic cracking is an important refining process, through which heavy hydrocarbons can be decomposed into light hydrocarbons. In this process, hydrogen transfer reactions participate in the cracking process of hydrocarbons to generate new olefins and hydrocarbons.

[0003] Hydrogen transfer reactions are divided into homogeneous reactions and heterogeneous reactions. In homogeneous hydrogen transfer reactions, patent CN117603047A proposes a method for preparing bio-based polyols. The reaction is carried out in a traditional microreactor. The existing microchannel reactor is relatively expensive, the microchannel structure cannot be adjusted after it is determined, and its catalyst cannot be recovered and cyclically reacts. In heterogeneous hydrogen transfer reactions, patent CN116239471A proposes a method for preparing polysubstituted 1,3-butadiene compounds, providing a highly efficient and diversified synthesis method of polysubstituted 1,3-butadiene compounds with convenient and easy-to-obtain substrates and economical reaction atoms. However, the reaction is carried out in a high-pressure reactor, and the product yield is low due to the small heat exchange area, the difficult control of the reaction temperature, and the inconsistent residence time. Patent CN116003352A provides a method for selectively reducing unsaturated compounds using hydrogen transfer. The method of the present invention has mild reaction conditions, no high-pressure hydrogen danger, and is environmentally friendly. However, the reaction is carried out in a fixed bed, which will have problems such as poor heat transfer performance, difficulty in replacing catalysts, and easy clogging.

[0004] At present, the research on hydrogen transfer reaction mainly focuses on improving the reaction efficiency, selectivity and purity of the product. It is usually carried out in a reactor, and fixed bed reactor and fluidized bed reactor technology are also used to improve the selectivity and yield of the reaction. This requires certain requirements for catalyst molding, uniform particles and mechanical strength. It is widely used in petrochemical systems and has obvious advantages in large-scale production. Hydrogen transfer reaction has many applications in fine chemicals. For example, in drug synthesis, hydrogen transfer reaction can be used to introduce specific saturated groups to improve the pharmacological properties of compounds. In the spice industry, hydrogenation reactions are used to produce stable compounds with specific aroma characteristics. The recovery and recycling of catalysts are of great significance to reducing production costs and improving economic benefits. For example, the application of dendritic catalysts in asymmetric hydrogen transfer reactions can make the catalysts easy to separate and recycle after the reaction through specific designs, so as to achieve multiple recycling. Hydrogen transfer reactions are usually performed on a small scale. Many catalysts are modified based on powder catalysts for slurry bed (kettle) reactions. The molding process is relatively complicated. At the same time, the molding process will damage the pore structure of the catalyst. It is impossible to simply transplant it from a slurry bed reactor to a continuous reactor such as a fixed bed or fluidized bed. It cannot meet the requirements of fixed bed or fluidized bed catalysts, and the catalyst is easily lost to subsequent materials.

[0005] Patent CN116236992A invented a high-efficiency microchannel reactor. The disclosed microreactor can rotate and stretch the material contact surface by about 90° within a certain Re number range, further increase the contact area, further reduce the mass transfer distance, and improve the mixing effect. Patent CN116966853A is a microchannel reaction process system and process method, which simplifies the components of the reaction materials entering the microchannel reactor, can better play the mass transfer and heat transfer advantages of the microchannel reactor, reduce the phenomenon of violent local reactions due to uneven components in the microreactor, reduce the occurrence of side reactions, and is more conducive to ensuring production safety and improving product yield. Patent CN117123162A invented a sleeve-type microchannel reactor, which includes a supporting base, a driving mechanism, a reactor body and a driving platform, which solves the problem of the prior art that the flow between the media is reacted to achieve an ideal temperature state. However, the reactor has a complex structure, and it is more difficult to have a reactor, causing problems such as blockage. Patent CN117861564A proposes a method for synergistic catalysis in series with homogeneous and multiphase reactors, which connects a multiphase tubular fixed bed reactor and a homogeneous kettle reactor or a bubble tower reactor in series, and utilizes the advantages of multiphase catalytic gas-solid reaction to solve the problems of catalyst recovery in the homogeneous system and catalyst metal loss in the flash evaporation process of the homogeneous reaction; however, this reactor has problems such as difficulty in replacing the catalyst and the catalyst cannot be recovered.

[0006] In summary, the current microchannel reactor has certain problems, such as easy blockage during use, frequent replacement of the reactor greatly increases the reaction cost, etc. Therefore, the present invention provides a microreactor with a sieve plate added to the reactor and a controllable pore for filling porous materials, which is applied to hydrogen transfer reaction. Summary of the invention

[0007] In view of the existing technical problems, the purpose of the present invention is to provide a method for hydrogen transfer reaction using a microreactor device, which is used to solve the problems in the prior art that homogeneous reaction catalysts cannot be recycled, fixed beds or fluidized beds have high requirements on catalyst structure molding, uniform particle size and mechanical strength, traditional microchannel reactors have high cost, catalyst loading is difficult, easy to clog, and have high production costs.

[0008] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0009] A method for performing a hydrogen transfer reaction using a microreactor device, wherein the microreactor device comprises a liquid pipeline system, a gas pipeline system, a microreactor, and a cooling and product collection system; the top of the microreactor is connected to the liquid pipeline system and the gas pipeline system respectively, and the bottom of the microreactor is connected to the cooling and product collection system; wherein:

[0010] The microreactor is a packed microreactor tube, which includes a tube body, and a replaceable catalyst is filled inside the tube body; filter screens for intercepting catalysts of different sizes are respectively arranged at the upper and lower ends of the tube body, and the filter screens at both ends are respectively connected to the material inlet and outlet joints through fixings to stabilize the catalyst; a blade ring and a sealing ring are sequentially arranged between the fixing and the tube body from top to bottom;

[0011] The method comprises: filling a Pt / Al2O3 catalyst in a reaction tube of a microreactor; firstly introducing an inert gas to exhaust the air in the microreactor and maintaining the pressure in the filled microreactor at 0.1-0.5MPa, and then continuously pumping a raw material liquid mixed with the alcohol compound of formula I and the amine compound of formula II into the microreactor for reaction, setting the reaction temperature to 175-200°C and the raw material liquid space velocity to 0.1h -1 -0.4h -1 After the reaction liquid flows out of the microreactor, it enters the cooling and product collection system for collection to obtain the product shown in formula III;

[0012]

[0013] Wherein R1 is selected from C1-C6 alkyl, substituted alkyl or benzyl, the number of carbon atoms in the substituted alkyl is 1-6, and the substituent is C1-C4 alkoxy;

[0014] R2 is selected from phenyl or substituted phenyl, and the substituents on the substituted phenyl are one or more, and each substituent is independently selected from C1-C6 alkyl or halogen.

[0015] Furthermore, the particle size of the catalyst ranges from 0.1 to 1000 microns, and the hole size of the filter screen plate is adjustable to stabilize the catalyst and prevent the loss of the catalyst. It is suitable for catalysts that are difficult to shape, have low mechanical strength, and have uneven particle sizes.

[0016] Furthermore, the inner diameter of the tube body is 0.1-10 mm. Furthermore, the inner diameter of the tube body can be one of 0.25 mm, 0.32 mm, 0.53 mm, 2.1 mm, 3.0 mm or 4.6 mm.

[0017] Furthermore, the fixing member is a connecting screw.

[0018] Furthermore, the liquid pipeline system includes a raw material tank and a feed pump, the raw material tank and the feed pump are connected through a liquid pipeline, and the feed pump is connected to the top of the microreactor through the liquid pipeline.

[0019] Furthermore, the gas pipeline system includes a gas cylinder and a gas flow meter, the gas cylinder and the gas flow meter are connected through a gas pipeline, and the gas flow meter is connected to the top of the microreactor through the gas pipeline.

[0020] The Pt / Al2O3 catalyst described in the present invention can be a commercially available product.

[0021] Furthermore, the volume ratio of the alcohol compound to the amine compound in the raw material liquid is 1:1-3.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) Compared with fixed bed and other tubular reactors, which require the redesign and molding of powdered catalysts, the microreactor of the present invention can be compatible with catalysts with uneven particle size distribution through the sieve plate, can react without molding, and has a smaller liquid (gas) holding capacity.

[0024] (2) The present invention can reduce the problems of large liquid holdup, long-term contact between raw materials and catalysts, and long residence time leading to increased side reactions and reduced selectivity in autoclave reactors.

[0025] (3) Compared with the traditional microchannel reactor, the microreactor of the present invention is simple to load the catalyst, is not easy to be blocked, and has low production cost.

[0026] (4) The microreactor of the present invention can control materials through the pore structure to increase the mixing effect of materials in the hydrogen transfer reaction. At the same time, the sieve plate can improve the mass transfer efficiency of the reactor. The hydrogen transfer reaction is carried out using the microreactor to obtain a higher product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the packed micro-reaction tube of the present invention Figure 1 ;

[0028] Figure 2 Schematic diagram of the packed micro-reaction tube of the present invention Figure 2 ;

[0029] Figure 3 It is an enlarged schematic diagram of the connection screws and filter discs in the micro-reaction tube structure;

[0030] Figure 4 Schematic diagram of the microreactor device of the present invention.

[0031] The reference numerals are as follows:

[0032] 1-liquid pipeline system; 2-gas pipeline system; 3-microreactor; 4-cooling and product collection system; 11-raw material tank; 12-feed pump; 21-gas cylinder; 22-gas flow meter; 31-tube body; 32-porous filler; 33-filter sieve plate; 34-material inlet and outlet joint; 35-fixing part; 36-blade ring; 37-sealing ring.

[0033] Figure 5 is a gas chromatogram of the product of Example 1.

[0034] Figure 6 It is the gas chromatogram of the product of Comparative Example 1-1.

[0035] Figure 7 It is the gas chromatogram of the product of Comparative Example 1-2.

[0036] Figure 8 is a gas chromatogram of the product of Example 2.

[0037] Fig. 9 It is the gas chromatogram of the product of Comparative Example 2-1.

[0038] Fig.10 It is the gas chromatogram of the product of Comparative Example 2-2.

[0039] Fig.11 is a gas chromatogram of the product of Example 3.

[0040] Fig.12 It is the gas chromatogram of the product of Comparative Example 3-1.

[0041] Fig.13 It is the gas chromatogram of the product of Comparative Example 3-2.

[0042] Fig.14 Graph showing the particle size distribution of the fresh Pt / Al2O3 catalyst used in the examples and comparative examples.

[0043] Fig.15 This is the particle size distribution diagram of the Pt / Al2O3 catalyst after molding treatment.

[0044] Fig.16 This is the particle size distribution diagram of the Pt / Al2O3 catalyst after long-term use and pulverization after molding treatment. DETAILED DESCRIPTION

[0045] The technical solution of the present invention is further described below with specific embodiments, but the protection scope of the present invention is not limited thereto:

[0046] refer to Figures 1 to 4 The microreactor device used in the embodiment of the present invention comprises a liquid pipeline system 1, a gas pipeline system 2, a microreactor 3 and a cooling and product collection system 4; the top of the microreactor 3 is connected to the liquid pipeline system 1 and the gas pipeline system 2 respectively, and the bottom of the microreactor 3 is connected to the cooling and product collection system 4; wherein:

[0047] The microreactor 3 is a packed microreactor tube, which includes a tube body 31, and the interior of the tube body 31 is filled with a replaceable catalyst 32; the upper and lower ends of the tube body 31 are respectively provided with filter screen plates 33 for intercepting catalysts of different sizes, and the filter screen plates 33 at both ends are respectively connected to the material inlet and outlet joints 34 through fixing members 35 to stabilize the catalyst; a blade ring 36 and a sealing ring 37 are sequentially provided between the fixing member 35 and the tube body 31 from top to bottom;

[0048] The fixing member 35 is a connecting screw;

[0049] The liquid pipeline system 1 includes a raw material tank 11 and a feed pump 12, wherein the raw material tank 11 and the feed pump 12 are connected via a liquid pipeline, and the feed pump 12 is connected to the top of the microreactor 3 via the liquid pipeline;

[0050] The gas pipeline system 2 includes a gas cylinder 21 and a gas flow meter 22 . The gas cylinder 21 and the gas flow meter 22 are connected via a gas pipeline, and the gas flow meter 22 is connected to the top of the microreactor 3 via the gas pipeline 2 .

[0051] Embodiment 1:

[0052] The microreactor device is used to react ethylene glycol mono-n-propyl ether with 2,6-diethylaniline to synthesize the intermediate (Z)-N-(2,6-diethylphenyl)-2-propoxyethane-1-imine.

[0053] A mixture of ethylene glycol mono-n-propyl ether and 2,6-diethylaniline (V 乙二醇单正丙醚 :V 2,6二乙基苯胺 =1:3) as the reaction raw material, and load 150 mesh Pt / Al2O3 catalyst (Shanghai Aladdin Biochemical Technology Co., Ltd.) into the tube body 31. The length of the tube body 31 is 28 cm, the inner diameter is 2.1 mm, and the pore size of the filter screen 33 is 10 μm. First, open the pressure reducing valve in the gas pipeline system 2, open the nitrogen valve, and control the flow meter to continuously and stably pass the flow rate of 1m 3 / min of nitrogen, the air is basically exhausted after 3 seconds, then the pressure reducing valve is closed to form a closed space, and the flow rate is adjusted by the flow meter to 5m 3 / min of nitrogen, and when the pressure gauge shows 0.4Mpa, turn off the flow meter and the nitrogen valve. The raw material liquid is continuously pumped into the microreactor through the feed pump for preheating and mixing, and then enters the reaction zone for continuous reaction. Set the feed material space velocity to 2h -1 , pressure 1.0MPa, reaction temperature set to 200℃, after three hours of reaction, the reaction liquid was taken from the collection tank for gas chromatography analysis. The selectivity of the target product was calculated to be 94.35%, and the conversion rate was 94%.

[0054] Comparative Example 1-1:

[0055] The reaction of ethylene glycol mono-n-propyl ether and 2,6-diethylaniline to synthesize the intermediate (Z)-N-(2,6-diethylphenyl)-2-propoxyethane-1-imine was carried out in a tank reactor.

[0056] A mixture of ethylene glycol mono-n-propyl ether and 2,6-diethylaniline (V 乙二醇单正丙醚 :V 2,6二乙基苯胺 =1:3) as the reaction raw material, a 150 mesh Pt / Al2O3 catalyst was loaded into a kettle reactor (316L), the nitrogen valve was opened, and a continuous and stable flow rate of 1m 3 / min of nitrogen, the air is basically exhausted after 3 seconds, then the pressure reducing valve is closed to form a closed space, and the flow rate is adjusted by the flow meter to 5m 3 / min of nitrogen, and when the pressure gauge shows 1.0Mpa, turn off the flow meter and the nitrogen valve. (Shanghai Aladdin Biochemical Technology Co., Ltd.), the liquid holdup is 75%, and the reaction temperature is set to 200°C. After ten hours, the reaction liquid is collected in a collection tank and analyzed by gas chromatography. The selectivity of the target product is 84.35% and the conversion rate is 81%.

[0057] Comparative Example 1-2:

[0058] The fixed bed apparatus was used to react ethylene glycol mono-n-propyl ether with 2,6-diethylaniline to synthesize the intermediate (Z)-N-(2,6-diethylphenyl)-2-propoxyethane-1-imine.

[0059] The Pt / Al2O3 catalyst was shaped by tableting and then sieved into 20-40 mesh. The shaped catalyst was filled into the reaction tube to form a packed bed. First, the pressure reducing valve in the gas pipeline system was opened, and the nitrogen valve was opened. The flow rate was continuously and stably controlled by the flow meter to be 2m 3 / min of nitrogen, the air is basically exhausted after 6 seconds, then the pressure reducing valve is closed to form a closed space, and the flow rate is adjusted by the flow meter to 5m 3 / min of nitrogen, and when the pressure gauge shows 0.5Mpa, turn off the flow meter and the nitrogen valve. The liquid holdup is 70%. Raise the temperature to stabilize the catalyst bed and vaporization chamber to 200℃, start the liquid pump to pump the mixed liquid (V 乙二醇单正丙醚 :V 2,6二乙基苯胺 =1:3) was introduced into the reaction system, and the reaction was continued for ten hours and samples were taken. After analysis and calculation, the selectivity of the target product was 85.35%, and the conversion rate was 87%. A long-term reaction was carried out, and powderization was found after 15 hours.

[0060] Embodiment 2:

[0061] The microreactor device is used to carry out the reaction of synthesizing N-benzylaniline from aniline and benzyl alcohol.

[0062] A mixture of aniline and benzyl alcohol (V 苯胺 :V 苯甲醇 =1:1) as the reaction raw material, and load 150 mesh Pt / Al2O3 catalyst (Shanghai Aladdin Biochemical Technology Co., Ltd.) into the tube body 31. The length of the tube body is 28 cm, the inner diameter is 2.1 mm, and the pore size of the filter screen is 10 μm. First, open the pressure reducing valve in the gas pipeline system 2, open the nitrogen valve, and control the flow meter to continuously and stably pass the flow rate of 1m 3 / min of nitrogen, the air is basically exhausted after 3 seconds, then the pressure reducing valve is closed to form a closed space, and the flow rate is adjusted by the flow meter to 5m3 / min of nitrogen, and when the pressure gauge shows 0.4Mpa, turn off the flow meter and the nitrogen valve. The raw material liquid is continuously pumped into the microreactor through the feed pump for preheating and mixing, and then enters the reaction zone for continuous reaction. Set the feed material space velocity to 2h -1 , pressure 1.0MPa, reaction temperature set to 200℃, after three hours, the reaction liquid was taken from the collection tank for gas chromatography analysis. The selectivity of the target product was 95.24% and the conversion rate was 91%.

[0063] Comparative Example 2-1:

[0064] A tank reactor was used to synthesize N-benzylaniline from aniline and benzyl alcohol.

[0065] A mixture of aniline and benzyl alcohol (V 苯胺 :V 苯甲醇 =1:1) as the reaction raw material, a 150 mesh Pt / Al2O3 catalyst (powdered catalyst purchased from Aladdin) was loaded into the autoclave reactor, the nitrogen valve was opened, and the flow rate of the nitrogen gas was continuously and stably controlled by the flow meter to be 1m 3 / min of nitrogen, the air is basically exhausted after 3 seconds, then the pressure reducing valve is closed to form a closed space, and the flow rate is adjusted by the flow meter to 5m 3 / min of nitrogen, and when the pressure gauge shows 0.1Mpa, turn off the flow meter and the nitrogen valve. The liquid holdup is 75%, and the reaction temperature is set to 200℃. After ten hours, the reaction liquid is collected in a collection tank and analyzed by gas chromatography. The selectivity of the target product is 75.24% and the conversion rate is 82%.

[0067] Comparative Example 2-2:

[0068] A fixed bed apparatus is used to react aniline with benzyl alcohol to synthesize N-benzylaniline.

[0069] The Pt / Al2O3 catalyst was shaped by tableting and then sieved into 20-40 mesh. The shaped catalyst was filled into the reaction tube to form a packed bed. First, the pressure reducing valve in the gas pipeline system was opened, and the nitrogen valve was opened. The flow rate was continuously and stably controlled by the flow meter to be 1.5m 3 / min of nitrogen, the air is basically exhausted after 6 seconds, then the pressure reducing valve is closed to form a closed space, and the flow rate is adjusted by the flow meter to 6m 3 / min of nitrogen, and when the pressure gauge shows 0.5Mpa, turn off the flow meter and the nitrogen valve. The liquid holdup is 70%. Raise the temperature to stabilize the catalyst bed and vaporization chamber to 200°C, start the liquid pump to pump the mixed liquid (V 苯胺 :V 苯甲醇=1:1) into the reaction system, and the reaction continued for ten hours before sampling. Figure 6 The target product selectivity was 85.43% and the conversion rate was 87%. The product was subjected to a long-term reaction and powderization was found after 15 hours.

[0070] Embodiment 3:

[0071] The microreactor device is used to react methylethylaniline with 1-methoxypropanol to synthesize 2-ethyl-N-(2-methoxy-1-methylethyl)-6-methylaniline.

[0072] A mixture of 2-methyl-6-ethylaniline and 1-methoxy-2-propanol (V 甲乙基苯胺 :V 1-甲氧基丙醇 =2:1) ​​as the reaction raw material, a 150 mesh Pt / Al2O3 catalyst (powdered catalyst purchased from Aladdin) is loaded into the tube body 31. The length of this microreactor is 28 cm, the inner diameter is 2.1 mm, and the pore size of the filter screen is 10 μm. First, the pressure reducing valve in the gas pipeline system 2 is opened, and the nitrogen valve is opened. The flow rate of the continuous and stable inlet is 1m 3 / min of nitrogen, the air is basically exhausted after 3 seconds, then the pressure reducing valve is closed to form a closed space, and the flow rate is adjusted by the flow meter to 5m 3 / min of nitrogen, and when the pressure gauge shows 0.4Mpa, turn off the flow meter and the nitrogen valve. The raw material liquid is continuously pumped into the microreactor through the feed pump for preheating and mixing, and then enters the reaction zone for continuous reaction. Set the feed material space velocity to 2h -1 , pressure 1.0MPa, reaction temperature set to 200℃, after three hours, the reaction liquid was taken from the collection tank for gas chromatography analysis. The selectivity of the target product was calculated to be 93.32% and the conversion rate was 93%.

[0073] Comparative Example 3-1:

[0074] A tank reactor was used to react methylethylaniline with 1-methoxypropanol to synthesize 2-ethyl-N-(2-methoxy-1-methylethyl)-6-methylaniline.

[0075] A mixture of methylethylaniline and 1-methoxypropanol (V 甲乙基苯胺 :V 1-甲氧基丙醇 =2:1) ​​as the reaction raw material, a 150 mesh Pt / Al2O3 catalyst (powdered catalyst purchased from Aladdin) was loaded into the autoclave reactor, the nitrogen valve was opened, and the flow rate of the nitrogen gas was continuously and stably controlled by the flow meter at 1m 3 / min of nitrogen, the air is basically exhausted after 3 seconds, then the pressure reducing valve is closed to form a closed space, and the flow rate is adjusted by the flow meter to 5m 3 / min of nitrogen, and when the pressure gauge shows 0.4Mpa, turn off the flow meter and the nitrogen valve. The liquid holdup is 75%, and the reaction temperature is set to 200℃. After ten hours, the reaction liquid is collected in a collection tank and analyzed by gas chromatography. The selectivity of the target product is 80.32% and the conversion rate is 84%.

[0076] Comparative Example 3-2:

[0077] The invention relates to a fixed bed device for the reaction of methylethylaniline and 1-methoxypropanol to synthesize 2-ethyl-N-(2-methoxy-1-methylethyl)-6-methylaniline.

[0078] The Pt / Al2O3 catalyst is formed by tabletting and then sieved into 20-40 mesh. The formed catalyst is filled into the reaction tube to form a packed bed. First, the pressure reducing valve in the gas pipeline system is opened, and the nitrogen valve is opened. The nitrogen valve is opened and the continuous and stable flow rate is controlled by the flow meter to be 1.5m 3 / min of nitrogen, the air is basically exhausted after 5 seconds, then the pressure reducing valve is closed to form a closed space, and the flow rate is adjusted by the flow meter to 1.5m 3 / min of nitrogen, and when the pressure gauge shows 0.5Mpa, turn off the flow meter and the nitrogen valve. The liquid holdup is 70%. Raise the temperature to stabilize the catalyst bed and vaporization chamber to 200°C, start the liquid pump to transfer the mixed liquid (V 甲乙基苯胺 :V 1-甲氧基丙醇 =2:1) ​​was introduced into the reaction system, and the reaction was continued for ten hours and samples were taken. The selectivity of the target product was 83.32% and the conversion rate was 77% after analysis and calculation. A long-term reaction was carried out and powdering was found after 15 hours.

Claims

1. A method for hydrogen transfer reaction using a microreactor device, characterized in that: The microreactor device comprises a liquid pipeline system, a gas pipeline system, a microreactor, and a cooling and product collection system; the top of the microreactor is connected to the liquid pipeline system and the gas pipeline system respectively, and the bottom of the microreactor is connected to the cooling and product collection system; wherein: The microreactor is a packed microreactor tube, which includes a tube body, and a replaceable catalyst is filled inside the tube body; filter screens for intercepting catalysts of different sizes are respectively arranged at the upper and lower ends of the tube body, and the filter screens at both ends are respectively connected to the material inlet and outlet joints through fixings to stabilize the catalyst; a blade ring and a sealing ring are sequentially arranged between the fixing and the tube body from top to bottom; The method comprises: filling a Pt / Al2O3 catalyst in a reaction tube of a microreactor; firstly introducing an inert gas to exhaust the air in the microreactor and maintaining the pressure in the filled microreactor at 0.1-0.5MPa, and then continuously pumping a raw material liquid mixed with the alcohol compound of formula I and the amine compound of formula II into the microreactor for reaction, setting the reaction temperature to 175-200°C and the raw material liquid space velocity to 0.1h -1 -0.4h -1 After the reaction liquid flows out of the microreactor, it enters the cooling and product collection system for collection to obtain the product shown in formula III; Wherein R1 is selected from C1-C6 alkyl, substituted alkyl or benzyl, the number of carbon atoms in the substituted alkyl is 1-6, and the substituent is C1-C4 alkoxy; R2 is selected from phenyl or substituted phenyl, and the substituents on the substituted phenyl are one or more, and each substituent is independently selected from C1-C6 alkyl or halogen.

2. The method according to claim 1, characterized in that: The particle size of the catalyst ranges from 0.1 to 1000 microns, and the hole size of the filter screen is adjustable to stabilize the catalyst.

3. The method according to claim 1, characterized in that: The inner diameter of the tube is 0.1-10 mm.

4. The method according to claim 1, characterized in that: The fixing member is a connecting screw.

5. The method according to claim 1, characterized in that: The liquid pipeline system includes a raw material tank and a feed pump, the raw material tank and the feed pump are connected through a liquid pipeline, and the feed pump is connected to the top of the microreactor through the liquid pipeline.

6. The method according to claim 1, characterized in that: The gas pipeline system comprises a gas cylinder and a gas flow meter, the gas cylinder and the gas flow meter are connected through a gas pipeline, and the gas flow meter is connected to the top of the microreactor through the gas pipeline.

7. The method according to any one of claims 1 to 6, characterized in that: The volume ratio of the alcohol compound to the amine compound in the raw material liquid is 1:1-3.

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