Catalyst for synthesizing morpholine by diethylene glycol method as well as preparation method and application of catalyst

Abstract

The invention discloses a catalyst for synthesizing morpholine by a diethylene glycol method as well as a preparation method and application of the catalyst, and belongs to the technical field of catalyst preparation. The catalyst comprises a carrier and an active component loaded on the carrier, the carrier is carbon nano tube / gamma-Al2O3 / montmorillonite and is prepared by taking pseudo-boehmite, montmorillonite and carbon nano tube as raw materials through solvothermal reaction and calcination; the active components comprise Cu, Ni, Mg and La. According to the invention, the carbon nanotube / gamma-Al2O3 and montmorillonite are taken as basic raw materials to prepare the catalyst carrier loaded active component, so that the loading capacity and the connection strength of the carrier to the active component can be improved, and the catalyst with high catalytic activity and high yield to morpholine is further obtained. Through detection, when the catalyst is used for synthesizing morpholine through a diethylene glycol method, the yield of morpholine can reach 92.8%.

Description

Technical Field

[0001] The invention belongs to the technical field of catalyst preparation, and particularly relates to a catalyst for synthesizing morpholine by a diethylene glycol method and a preparation method and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Morpholine is an indispensable product in chemical production and an intermediate in the manufacture of many fine chemical products. Due to its chemical properties, morpholine has become one of the fine petrochemical products with important commercial uses. The diethylene glycol process is the most commonly used method for industrial production of morpholine. However, so far, the catalyst of this process still has shortcomings in terms of activity, stability and selectivity.

[0004] The key to the development of morpholine catalysts still depends on the activity and selectivity of the catalyst. The current carriers of morpholine catalysts mostly use nanoparticles such as γ-Al2O3, MgO or ZnO or inorganic nanomaterials formed by composite formation. The preparation of inorganic nanomaterials is mostly prepared by physical blending methods. This preparation method has low connection strength between the components of inorganic nanomaterials, and the connection relationship between inorganic nanomaterials and active components (metal ions) is physical adsorption (i.e., interacting with metal ions through van der Waals forces), which causes the problem of low active sites and low adsorption strength of the carrier, thereby affecting the activity of the catalyst.

[0005] Patent application number 202111017584.X discloses a graphene oxide

[0006] / Fe3O4 / γ-Al2O3@montmorillonite is used as a carrier, and the active components Cu, Ni, Zn and Mg are loaded on the carrier. The catalyst for continuous synthesis of morpholine by diethylene glycol vapor phase method increases the loading amount and connection strength of the carrier for the active components, has high catalytic activity, and has a high yield of morpholine. However, its morpholine yield is still not ideal and does not reach 90%. Summary of the invention

[0007] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a catalyst for synthesizing morpholine by a diethylene glycol method, and a preparation method and application thereof. The catalyst provided by the present invention uses carbon nanotubes / γ-Al2O3@montmorillonite as a carrier, which effectively improves the carrier's loading capacity and connection strength for active components, has high catalytic activity, and the morpholine yield can reach 92.8%.

[0008] In order to achieve the above object, the technical solution of the present invention is:

[0009] The first aspect of the present invention provides a catalyst for synthesizing morpholine by a diethylene glycol method, comprising a carrier and an active component supported on the carrier; the carrier is carbon nanotubes / γ-Al2O3@montmorillonite, and the active component comprises Cu, Ni, Mg and La.

[0010] In some embodiments of the present invention, the components of the catalyst for synthesizing morpholine by the diethylene glycol method are: by weight percentage, carbon nanotube / γ-Al2O3@montmorillonite material 50%-70%, Cu 12%-30%, Ni 10%-18%, Mg1%-5%, and La 0.7%-1.5%.

[0011] In some embodiments of the present invention, the carbon nanotube / γ-Al2O3@montmorillonite is prepared by using pseudo-boehmite, montmorillonite and carbon nanotubes as raw materials through solvent thermal reaction and calcination.

[0012] The second aspect of the present invention provides a method for preparing a catalyst for synthesizing morpholine by a diethylene glycol method, comprising the following steps:

[0013] Dissolving pseudo-boehmite, montmorillonite, carbon nanotubes and a rare earth stabilizer in a dispersant, and performing a solvent thermal reaction to obtain a first intermediate;

[0014] Drying, shaping, and calcining the first intermediate to obtain a second intermediate;

[0015] The second intermediate is sequentially immersed in solutions containing a magnesium source, a lanthanum source, a copper source and a nickel source, dried, and calcined to obtain a catalyst for synthesizing morpholine by a diethylene glycol method.

[0016] In some embodiments of the present invention, the rare earth stabilizer includes a rare earth composite stabilizer (XT-1 type).

[0017] In some embodiments of the present invention, the dispersant is an alcohol aqueous solution with a volume ratio of (2-4):1, preferably an ethanol aqueous solution, and more preferably an ethanol aqueous solution with a volume ratio of 3:1.

[0018] In some embodiments of the present invention, the mass ratio of the pseudo-boehmite, montmorillonite, carbon nanotubes, rare earth stabilizer and dispersant is (1-1.5):(1-1.5):(0.1-0.2):(0.005-0.01):(8-15).

[0019] In some embodiments of the present invention, the solvent thermal reaction is: reacting at 70-100° C. for 1.5-3 h.

[0020] In some embodiments of the present invention, the forming is: adding a peptizing agent to the dried first intermediate;

[0021] The peptizing agent includes aluminum nitrate, and preferably, the peptizing agent is a 99wt% aluminum nitrate nonahydrate solution;

[0022] The amount of the peptizing agent added is 2-4% of the mass of the first intermediate after drying.

[0023] In some embodiments of the present invention, the calcination is: heating to 400-600° C. at a heating rate of 3-7° C. / min and keeping the temperature for 4-5 h.

[0024] In some embodiments of the present invention, the magnesium source is selected from one of magnesium nitrate, magnesium chloride and magnesium sulfate;

[0025] The lanthanum source is selected from one of lanthanum nitrate, lanthanum chloride and lanthanum sulfate;

[0026] The copper source is selected from one of copper nitrate, copper chloride and copper sulfate;

[0027] The nickel source is selected from one of nickel nitrate, nickel chloride and nickel sulfate.

[0028] In some embodiments of the present invention, the second intermediate is sequentially immersed in a solution containing a magnesium source, a lanthanum source, a copper source and a nickel source, and dried and calcined as follows:

[0029] The second intermediate is immersed in the first mixed solution containing the magnesium source and the lanthanum source, stirred, dried after saturation, heated to 700-900°C at a heating rate of 3-7°C / min, and kept warm for 3-5h to obtain a third intermediate;

[0030] The third intermediate is immersed in a second mixed solution containing a copper source and a nickel source, stirred, dried after saturation, heated to 300-500° C. at a heating rate of 3-7° C. / min, and kept warm for 3-5 hours to obtain a catalyst for synthesizing morpholine by a diethylene glycol method.

[0031] In some embodiments of the present invention, the concentration of the magnesium source in the first mixed solution is 0.05-0.15 g / mL, and the concentration of the lanthanum source is 0.01-0.05 g / mL; the dosage ratio of the second intermediate to the first mixed solution is 2:0.5-1.5, preferably 2:1;

[0032] The concentration of the copper source in the second mixed solution is 0.4-0.8 g / mL, and the concentration of the nickel source is 0.2-0.6 g / mL; the dosage ratio of the third intermediate to the second mixed solution is 2:0.5-1.5, preferably 2:1.

[0033] The third aspect of the present invention provides a use of the catalyst for synthesizing morpholine by diethylene glycol method or the catalyst for synthesizing morpholine by diethylene glycol method obtained by the preparation method in the preparation of morpholine.

[0034] A fourth aspect of the present invention provides a method for synthesizing morpholine by a diethylene glycol method, comprising the following steps:

[0035] In the presence of a catalyst, diethylene glycol reacts with liquid ammonia to obtain morpholine;

[0036] The catalyst is the catalyst for synthesizing morpholine by diethylene glycol method or the catalyst for synthesizing morpholine by diethylene glycol method prepared by the preparation method; the catalyst for synthesizing morpholine by diethylene glycol method is firstly reduced and activated before participating in the reaction.

[0037] In some embodiments of the present invention, diethylene glycol reacts with liquid ammonia in a mixed atmosphere of nitrogen and hydrogen; the reaction is carried out in a fixed bed reactor; the molar ratio of diethylene glycol, liquid ammonia and hydrogen-nitrogen mixed gas is 1:15:(10-30); the reaction temperature is 210-230°C; the reaction pressure is 1.6-1.8 MPa; the diethylene glycol liquid space velocity is 0.1-0.15 h -1 .

[0038] In some embodiments of the present invention, the reduction activation is: the catalyst for synthesizing morpholine by the diethylene glycol method is kept at nitrogen and 190-210°C for 1-2 hours, and then kept at hydrogen and 250-350°C for 4-6 hours to complete the reduction activation.

[0039] The beneficial effects of the present invention are:

[0040] The invention provides a catalyst using carbon nanotubes / γ-Al2O3@montmorillonite as a carrier to load active components, which is used for catalyzing diethylene glycol to synthesize morpholine, effectively improving the loading amount of the carrier for the active components and the connection strength, having high catalytic activity, and the morpholine yield can reach 92.8%.

[0041] The catalyst of the present invention has high connection strength between the active component of the catalyst and the carrier, high stability, and can avoid the occurrence of γ-A l2 The phenomenon of O3 agglomeration; the addition of active component additive La improves the catalyst activity; carbon nanotubes provide sufficient space and attachment points for the loading of active components of the catalyst, so that the carrier in the catalyst has more adsorption sites for active sites and a large adsorption capacity; saturated impregnation can make all active components evenly loaded on the carrier, and the saturated impregnation method will not have the problem of solution waste.

[0042] When the catalyst of the invention is used to catalyze the production of morpholine from diethylene glycol, the morpholine yield is high and the catalytic effect is good, and the amount of ammonia in the reactant can be reduced, thereby saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0044] Figure 1 is a front view of the agitator used in the embodiment of the present invention;

[0045] Figure 2 It is a left side view of the agitator used in the embodiment of the present invention;

[0046] Figure 3 Schematic diagram of the blade structure of the agitator used in the embodiment of the present invention.

[0047] Among them, 1 is a horizontal mixing barrel, 2 is a rocker, 3 is a support frame, and 4 is a blade. DETAILED DESCRIPTION

[0048] A first typical embodiment of the present invention provides a catalyst for synthesizing morpholine by a diethylene glycol method, comprising a carrier and an active component loaded on the carrier; the carrier is carbon nanotubes / γ-Al2O3@montmorillonite, and the active component comprises Cu, Ni, Mg and La.

[0049] In some examples of this embodiment, the components of the catalyst for synthesizing morpholine by the diethylene glycol method are: by weight percentage, carbon nanotube / γ-Al2O3@montmorillonite material 50%-70%, Cu 12%-30%, Ni 10%-18%, Mg1%-5%, La 0.7%-1.5%.

[0050] In some examples of this implementation mode, the carbon nanotube / γ-Al2O3@montmorillonite is prepared by using pseudo-boehmite, montmorillonite and carbon nanotubes as raw materials through solvent thermal reaction and calcination.

[0051] The present application adopts γ-Al2O3 and montmorillonite as the basic matrix materials to prepare a composite material, which can improve the stability of the carrier and the active components and the adsorption sites for the active components. On the one hand, γ-Al2O3 can play the role of supporting montmorillonite, improving the adsorption sites of the carrier while improving the bonding strength between γ-Al2O3 and montmorillonite; on the other hand, montmorillonite can increase the adsorption effect on metal ions, and montmorillonite can also regulate the acidity of γ-Al2O3, which is beneficial to the catalytic effect of the carrier.

[0052] Then carbon nanotubes are added to γ-Al2O3 and montmorillonite. Carbon nanotubes can absorb more active components due to their structural characteristics, and it is relatively simple to obtain a catalyst with more uniform element doping, and the active components are evenly distributed on the carrier, and the nanoparticle size is uniform. Pseudo-boehmite can also use montmorillonite and carbon nanotubes as templates to improve the uniform dispersion of pseudo-boehmite, avoid the agglomeration of pseudo-boehmite, and at the same time improve the adsorption of active components, thereby improving the catalytic activity of the catalyst, reducing the amount of ammonia in the reactants, and saving costs.

[0053] A second typical embodiment of the present invention provides a method for preparing a catalyst for synthesizing morpholine by a diethylene glycol method, comprising the following steps:

[0054] Dissolving pseudo-boehmite, montmorillonite, carbon nanotubes and a rare earth stabilizer in a dispersant, and performing a solvent thermal reaction to obtain a first intermediate;

[0055] Drying, shaping, and calcining the first intermediate to obtain a second intermediate;

[0056] The second intermediate is sequentially immersed in solutions containing a magnesium source, a lanthanum source, a copper source and a nickel source, dried, and calcined to obtain a catalyst for synthesizing morpholine by a diethylene glycol method.

[0057] Due to the defects of the five-membered ring, the carbon nanotubes have enhanced reaction activity. Under the conditions of high temperature and the presence of other substances, the carbon nanotubes are easy to open at the end face to form a tube, which is very easy to be infiltrated by metals and form metal-based composite materials with metals, avoiding the collapse of the interlayer structure of γ-Al2O3 during the subsequent drying and calcination process, ensuring the structure of pseudo-boehmite, ensuring the high specific surface area of ​​pseudo-boehmite, and further ensuring the wide distribution of the action sites. Rare earth stabilizers have unique coupling functions and compatibilization properties, and can form ion coordination with organic and inorganic ligands, so that the components are closely combined. The uniform mixing of the components forms a catalyst carrier with high load and high connection strength.

[0058] In some examples of this embodiment, the rare earth stabilizer includes a rare earth composite stabilizer (XT-1 type).

[0059] In some examples of this embodiment, the dispersant is an alcohol aqueous solution with a volume ratio of (2-4):1, preferably an ethanol aqueous solution, and more preferably an ethanol aqueous solution with a volume ratio of 3:1.

[0060] In some examples of this embodiment, the mass ratio of the pseudo-boehmite, montmorillonite, carbon nanotubes, rare earth stabilizer and dispersant is (1-1.5):(1-1.5):(0.1-0.2):(0.005-0.01):(8-15).

[0061] In some examples of this embodiment, the solvothermal reaction is: reacting at 70-100° C. for 1.5-3 h.

[0062] In some examples of this embodiment, the first intermediate is dried under vacuum conditions. For example, it is dried in a vacuum drying oven, and the operating parameters of the vacuum drying are a vacuum degree of 0.9×10 5 Pa, heating to 110°C, heating rate of 100°C / h, drying for 3h-4h. This process parameter is convenient for forming a carrier with high particle strength and no cracks, and is also convenient for the evaporation of water molecules in the carrier.

[0063] In some examples of this embodiment, the forming is: adding a peptizing agent to the dried first intermediate;

[0064] The peptizing agent includes aluminum nitrate, and preferably, the peptizing agent is a 99wt% aluminum nitrate nonahydrate solution;

[0065] The amount of the peptizing agent added is 2-4% of the mass of the first intermediate after drying.

[0066] In some examples of this embodiment, the calcination is: heating to 400-600° C. at a heating rate of 3-7° C. / min, and keeping the temperature for 4-5 hours.

[0067] In some examples of this embodiment, the magnesium source is selected from one of magnesium nitrate, magnesium chloride, and magnesium sulfate;

[0068] The lanthanum source is selected from one of lanthanum nitrate, lanthanum chloride and lanthanum sulfate;

[0069] The copper source is selected from one of copper nitrate, copper chloride and copper sulfate;

[0070] The nickel source is selected from one of nickel nitrate, nickel chloride and nickel sulfate.

[0071] In some examples of this embodiment, the second intermediate is sequentially immersed in a solution containing a magnesium source, a lanthanum source, a copper source and a nickel source, dried, and calcined as follows:

[0072] The second intermediate is immersed in the first mixed solution containing the magnesium source and the lanthanum source, stirred, dried after saturation, heated to 700-900°C at a heating rate of 3-7°C / min, and kept warm for 3-5h to obtain a third intermediate;

[0073] The third intermediate is immersed in a second mixed solution containing a copper source and a nickel source, stirred, dried after saturation, heated to 300-500° C. at a heating rate of 3-7° C. / min, and kept warm for 3-5 hours to obtain a catalyst for synthesizing morpholine by a diethylene glycol method.

[0074] In some examples of this embodiment, the concentration of the magnesium source in the first mixed solution is 0.05-0.15 g / mL, and the concentration of the lanthanum source is 0.01-0.05 g / mL; the dosage ratio of the second intermediate to the first mixed solution is 2:0.5-1.5, preferably 2:1;

[0075] The concentration of the copper source in the second mixed solution is 0.4-0.8 g / mL, and the concentration of the nickel source is 0.2-0.6 g / mL; the dosage ratio of the third intermediate to the second mixed solution is 2:0.5-1.5, preferably 2:1.

[0076] In some examples of this embodiment, the second intermediate is sequentially immersed in a solution containing a magnesium source, a lanthanum source, a copper source, and a nickel source, and the stirring process is performed in a stirrer. The structure of the stirrer is as follows: Figure 1 , Figure 2 and Figure 3 shown.

[0077] Figure 1 is a front view of the stirrer, Figure 2 is a left side view of the agitator, Figure 3 The figure is a blade structure diagram of the agitator. The agitator includes a horizontal mixing drum 1, a rocker 2 and a support frame 3. A rocker 2 is fixedly connected to one bottom surface of the horizontal mixing drum 1, and the rotation of the rocker 2 drives the horizontal mixing drum 1 to rotate. The support frame 3 is arranged on the lower side of the horizontal mixing drum 1, and is used to support the horizontal mixing drum 1, and the support frame 3 is slidably connected to the horizontal mixing drum 1 to avoid the influence of the support frame 3 on the rotation of the horizontal mixing drum 1. The other bottom surface of the horizontal mixing drum 1 is threadedly connected or opened to the barrel wall of the horizontal mixing drum 1, which is a feed and discharge port. The agitator is also provided with a blade 4. The blade 4 is arranged inside the horizontal mixing drum 1, and is connected to the inner bottom surface of the horizontal mixing drum 1 by a nut. When the horizontal mixing drum 1 rotates, the blade 4 does not rotate with the horizontal mixing drum 1. The shape of the blade 4 is consistent with the shape of the inner wall of the horizontal mixing drum 1. The purpose of setting the blade 4 is to prevent the catalyst carrier from sticking to the inside of the horizontal mixing drum 1 and to prevent the catalyst carriers from sticking to each other.

[0078] It should be noted that when the horizontal mixing barrel 1 is cylindrical, the shape of the blade 4 is a right angle, and the angle inside the blade is consistent with the angle between the side wall and the inner bottom surface of the horizontal mixing barrel 1.

[0079] In some examples of this embodiment, the second intermediate impregnated with the first mixed solution is dried at 100-150° C. for about 10-15 hours;

[0080] The third intermediate impregnated with the second mixed solution is dried at 100-150° C. for about 10-15 hours.

[0081] A third typical embodiment of the present invention provides a use of the catalyst for synthesizing morpholine by diethylene glycol method or the catalyst for synthesizing morpholine by diethylene glycol method obtained by the preparation method in the preparation of morpholine.

[0082] A fourth typical embodiment of the present invention provides a method for synthesizing morpholine by a diethylene glycol method, comprising the following steps:

[0083] In the presence of a catalyst, diethylene glycol reacts with liquid ammonia to obtain morpholine;

[0084] The catalyst is the catalyst for synthesizing morpholine by diethylene glycol method or the catalyst for synthesizing morpholine by diethylene glycol method prepared by the preparation method; the catalyst for synthesizing morpholine by diethylene glycol method is firstly reduced and activated before participating in the reaction.

[0085] In some examples of this embodiment, diethylene glycol reacts with liquid ammonia in a mixed atmosphere of nitrogen and hydrogen; the reaction is carried out in a fixed bed reactor; the molar ratio of diethylene glycol, liquid ammonia and hydrogen-nitrogen mixed gas is 1:15:(10-30); the reaction temperature is 210-230°C; the reaction pressure is 1.6-1.8 MPa; the diethylene glycol liquid space velocity is 0.1-0.15 h -1 .

[0086] In some examples of this embodiment, the reduction activation is: the catalyst for synthesizing morpholine by the diethylene glycol method is kept at nitrogen and 190-210° C. for 1-2 hours, and then kept at hydrogen and 250-350° C. for 4-6 hours to complete the reduction activation.

[0087] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0088] The following examples adopt Figure 1 , 2, 3 are used for stirring. The stirrer comprises a horizontal stirring barrel 1, a rocker 2, a support frame 3 and a blade 4. Specifically, the upper bottom radius of the horizontal stirring barrel 1 is 5 cm, the lower bottom radius is 10 cm, the support frame 3 is connected to the horizontal stirring barrel 1 by threads, and the horizontal stirring barrel 1 at the connection is provided with a groove with a thickness of 0.5 cm and a width of 1 cm. The angle between the side wall and the lower bottom surface of the horizontal stirrer 1 is 30°. The rocker 2 is arranged outside the horizontal stirring barrel 1, and it is tightly connected to the lower bottom surface of the horizontal stirring barrel 1 and cannot be disassembled. The blade 4 is arranged inside the horizontal stirring barrel 1, and it is connected to the lower bottom surface inside the horizontal stirring barrel 1 by a nut. When the horizontal stirring barrel 1 rotates, the blade 4 does not rotate therewith. The blade 4 is composed of a surface and b surface, the b surface is connected to the horizontal stirring barrel 1, the angle between the a surface and the b surface is 30°, the a surface is 17 cm long, the b surface is 9.5 cm long, and the a and b surfaces are 0.3 cm thick.

[0089] Depend on Figure 1 and Figure 2 It can be seen that the support frame 3 includes three parts, a bottom plate, a high support plate (10 cm high, 1 cm thick, 8 cm wide) and a low support plate (5 cm high, 1 cm thick, 18 cm wide), and the three parts are integrated. The high support plate contacts the side wall of the horizontal mixing barrel 1 in an arc with a radius of 3.5 cm, and the low support plate contacts the side wall of the horizontal mixing barrel 1 in an arc with a radius of 10.5 cm. The material of the stirrer is 316L stainless steel.

[0090] Example 1

[0091] A catalyst for synthesizing morpholine by diethylene glycol method, the preparation method is as follows:

[0092] (1) Preparation of carrier

[0093] Carbon nanotubes, pseudo-boehmite, montmorillonite and rare earth stabilizer (rare earth composite stabilizer (XT-1 type)) were dissolved in a dispersant, added into a mechanochemical reactor, and stirred at 85° C. for 2 hours to obtain a first intermediate.

[0094] The mass ratio of pseudo-boehmite, montmorillonite, rare earth stabilizer, dispersant and carbon nanotubes is 1:1:0.005:8:0.1; the dispersant is an ethanol aqueous solution, and the volume ratio of ethanol to water in the ethanol aqueous solution is 3:1;

[0095] The first intermediate was placed in a vacuum drying oven for drying. The operating parameters of the vacuum drying oven were as follows: the vacuum degree was 0.9×10 5Pa, heat to 110°C, heating rate is 100°C / h, dry for 3h; add 99% aluminum nitrate nonahydrate solution to form, the amount of aluminum nitrate nonahydrate solution added accounts for 3% of the mass of the first intermediate after drying; then put it into a muffle furnace for calcination, the calcination temperature is 400°C, the heating rate is 5°C / h, the insulation time is 4h, and the second intermediate is obtained.

[0096] The molding process is: adding aluminum nitrate nonahydrate solution, drying, and extruding the dried powder with a tablet press to obtain a carbon nanotube / γ-Al2O3@montmorillonite carrier.

[0097] (2) Preparation of Catalyst

[0098] Prepare 50mL of the first mixed solution, the content of magnesium nitrate and lanthanum nitrate is 0.1g / mL and 0.03g / mL respectively, spray the first mixed solution onto the second intermediate (the mass ratio of the first mixed solution to the second intermediate is 1:2), and shake it continuously to make it evenly impregnated. Then dry the impregnated catalyst at 120℃ for 12h, and then calcine it at high temperature, heat it to 800℃ at a rate of 5℃ / min and keep it for 4h to obtain the third intermediate. Prepare 50mL of the second mixed solution, the content of copper nitrate and nickel nitrate is 0.6g / mL and 0.4g / mL respectively, spray the second mixed solution onto the third intermediate (the mass ratio of the second mixed solution to the third intermediate is 1:2), and shake it continuously to make it evenly impregnated. Then dry the impregnated catalyst at 120℃ for 12h, and then calcine it at high temperature, heat it to 400℃ at a rate of 5℃ / min and keep it for 4h to obtain a catalyst for synthesizing morpholine by diethylene glycol method.

[0099] Example 2

[0100] A catalyst for synthesizing morpholine by diethylene glycol method, the preparation method of which is different from that of Example 1 in that: during the preparation process, the mass ratio of pseudo-boehmite, montmorillonite, rare earth stabilizer, dispersant, and carbon nanotube is 1.2:1.3:0.008:10:0.15. The remaining steps are consistent with those of Example 1.

[0101] Example 3

[0102] A catalyst for synthesizing morpholine by a diethylene glycol method, the preparation method of which is different from that of Example 1 in that during the preparation process, the mass ratio of pseudo-boehmite, montmorillonite, rare earth stabilizer, dispersant, and carbon nanotube is 1.5:1.5:0.01:15:0.2. The remaining steps are consistent with those of Example 1.

[0103] Example 4

[0104] A catalyst for synthesizing morpholine by diethylene glycol method, the preparation method of which is different from that of Example 1 in that: adding the catalyst to a mechanochemical reactor, stirring and reacting at 70°C for 1.5 hours to obtain a first intermediate; vacuum drying for 4 hours; calcining in a muffle furnace, the calcination temperature is 400°C, the heating rate is 5°C / h, and the insulation time is 5 hours. The remaining steps are consistent with those of Example 1.

[0105] Example 5

[0106] A catalyst for synthesizing morpholine by diethylene glycol method, the preparation method of which is different from that of Example 1 in that: adding the catalyst to a mechanochemical reactor, stirring and reacting at 100° C. for 3 hours to obtain a first intermediate; vacuum drying for 5 hours; calcining in a muffle furnace, the calcination temperature is 400° C., the heating rate is 5° C. / h, and the insulation time is 6 hours. The remaining steps are consistent with those of Example 1.

[0107] Example 6

[0108] A method for synthesizing morpholine by a diethylene glycol method comprises the following steps:

[0109] Take the catalyst prepared in Example 1 and place it in the constant temperature zone of the reaction column, fill the upper and lower parts with fillers, and then purge the fixed bed reactor with nitrogen to reduce the catalyst. First, keep it at 200°C for one hour under a nitrogen atmosphere, and then keep it for five hours under a hydrogen atmosphere. After the reduction activation is completed, the temperature is lowered to the reaction temperature to carry out the diethylene glycol gas phase method for synthesizing morpholine. After the temperature drops to the reaction temperature of 230°C, the pressure of the mixed gas of nitrogen and hydrogen is adjusted to 1.6MPa, and then diethylene glycol and liquid ammonia are introduced. The liquid air velocity of diethylene glycol is 0.15h -1 The molar ratio of diethylene glycol, liquid ammonia and hydrogen and nitrogen mixed gas is 1:15:10.

[0110] Example 7

[0111] A method for synthesizing morpholine by a diethylene glycol method comprises the following steps:

[0112] The catalyst of Example 1 was placed in the constant temperature zone of the reaction column, and the fillers were filled up and down. After nitrogen was purged into the fixed bed reactor, the catalyst was reduced. It was first kept at 200°C for one hour under a nitrogen atmosphere, and then kept for five hours under a hydrogen atmosphere. After the reduction activation was completed, the temperature was lowered to the reaction temperature to carry out the diethylene glycol gas phase method for synthesizing morpholine. After the temperature was lowered to the reaction temperature of 210°C, the pressure of the mixed gas of nitrogen and hydrogen was adjusted to 1.7MPa, and then diethylene glycol and liquid ammonia were introduced. The liquid air velocity of diethylene glycol was 0.1h -1 The molar ratio of diethylene glycol, liquid ammonia and hydrogen and nitrogen mixed gas is 1:15:20.

[0113] Example 8

[0114] A method for synthesizing morpholine by a diethylene glycol method comprises the following steps:

[0115] The catalyst of Example 1 was placed in the constant temperature zone of the reaction column, and the fillers were filled up and down. After nitrogen was purged into the fixed bed reactor, the catalyst was reduced. It was first kept at 200°C for one hour under a nitrogen atmosphere, and then kept for five hours under a hydrogen atmosphere. After the reduction activation was completed, the temperature was lowered to the reaction temperature to carry out the diethylene glycol gas phase method for synthesizing morpholine. After the temperature was lowered to the reaction temperature of 220°C, the pressure of the mixed gas of nitrogen and hydrogen was adjusted to 1.8MPa, and then diethylene glycol and liquid ammonia were introduced. The liquid air velocity of diethylene glycol was 0.13h -1 The molar ratio of diethylene glycol, liquid ammonia and hydrogen-nitrogen mixture is 1:15:30.

[0116] The test results of the method for synthesizing morpholine by the diethylene glycol method of Examples 6 to 8 are shown in Table 1.

[0117] Table 1 Experimental results of Examples 6, 7, and 8

[0118]

[0119]

[0120] Comparative Example 1

[0121] The difference between this comparative example and Example 1 is that the carrier is γ-Al2O3, and Cu, Ni, Mg, and La are active components, wherein γ-Al2O3 accounts for 65.3%, Cu is 17%, Ni is 15%, Mg is 2%, and La is 0.7%, and no homemade agitator is used during saturated impregnation.

[0122] Comparative Example 2

[0123] The difference between this comparative example and Example 1 is that the mass ratio of pseudo-boehmite, montmorillonite, rare earth stabilizer, dispersant and carbon nanotubes in carbon nanotubes / γ-Al2O3@montmorillonite is 0.8:0.8:0.005:8:0.08.

[0124] Comparative Example 3

[0125] The difference between this comparative example and Example 1 is that the mass ratio of pseudo-boehmite, montmorillonite, rare earth stabilizer, dispersant and carbon nanotubes in carbon nanotubes / γ-Al2O3@montmorillonite is 1.6:1.6:0.01:8:0.3.

[0126] Comparative Example 4

[0127] The difference between this comparative example and Example 1 is that no carbon nanotubes are used in the carrier preparation process and no homemade stirrer is used during saturation impregnation.

[0128] Comparative Example 5

[0129] The difference between this comparative example and Example 1 is that no carbon nanotubes are used in the preparation process of the carrier. The mass ratio of pseudo-boehmite, montmorillonite, rare earth stabilizer and dispersant is 1:1:0.005:8.

[0130] Catalyst performance evaluation

[0131] The catalysts prepared in Examples 1 to 5 and Comparative Examples 1 to 5 were used to prepare morpholine using the method of Example 6. The test results are shown in Table 2.

[0132] Table 2 Test results of Examples 1-5 and Comparative Examples

[0133] sample Conversion rate of diethylene glycol (%) Morpholine yield (%) Example 1 99.9 92.8 Example 2 99.7 91.6 Example 3 99.4 89.9 Example 4 99.5 91.0 Example 5 99.8 92.3 Comparative Example 1 97.6 82.4 Comparative Example 2 98.2 85.7 Comparative Example 3 98.5 86.2 Comparative Example 4 97.5 81.9 Comparative Example 5 98.8 90.6

[0134] It can be seen from the experimental results in Table 2 that the experimental data of the embodiment group are all higher than the experimental results of the comparative example group, and the diethylene glycol conversion rate and morpholine yield results are both higher. Compared with comparative example 1, the embodiment group uses the catalyst carrier of the present application and the homemade agitator compared with the conventional γ-Al2O3 and saturated impregnation method, and the technical effect obtained is the best. Compared with comparative examples 2 to 5, the embodiment group uses the components of the present application and the catalyst carrier within the limited range, and its effect is the best.

[0135] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A catalyst for synthesizing morpholine by diethylene glycol method, characterized in that: The invention comprises a carrier and active components loaded on the carrier; the carrier is carbon nanotube / γ-Al2O3@montmorillonite, and the active components comprise Cu, Ni, Mg and La.

2. The catalyst for synthesizing morpholine by diethylene glycol method as claimed in claim 1, characterized in that: The components of the catalyst for synthesizing morpholine by diethylene glycol method are as follows: by weight percentage, carbon nanotube / γ-Al2O3@montmorillonite material 50%-70%, Cu 12%-30%, Ni 10%-18%, Mg 1%-5%, La 0.7%-1.5%; Preferably, the carbon nanotube / γ-Al2O3@montmorillonite is prepared from pseudo-boehmite, montmorillonite and carbon nanotubes as raw materials through solvent thermal reaction and calcination.

3. A method for preparing a catalyst for synthesizing morpholine by diethylene glycol method according to claim 1 or 2, characterized in that: The following steps are involved: Dissolving pseudo-boehmite, montmorillonite, carbon nanotubes and a rare earth stabilizer in a dispersant, and performing a solvent thermal reaction to obtain a first intermediate; Drying, shaping, and calcining the first intermediate to obtain a second intermediate; The second intermediate is sequentially immersed in solutions containing a magnesium source, a lanthanum source, a copper source and a nickel source, dried, and calcined to obtain a catalyst for synthesizing morpholine by a diethylene glycol method.

4. The preparation method according to claim 3, characterized in that: The dispersant is an alcohol aqueous solution with a volume ratio of (2-4):1, preferably an ethanol aqueous solution, and more preferably an ethanol aqueous solution with a volume ratio of 3:1; Preferably, the mass ratio of the pseudo-boehmite, montmorillonite, carbon nanotubes, rare earth stabilizer and dispersant is (1-1.5):(1-1.5):(0.1-0.2):(0.005-0.01):(8-15); Preferably, the solvent thermal reaction is: reacting at 70-100° C. for 1.5-3 h.

5. The preparation method according to claim 3, characterized in that: The forming step comprises: adding a peptizing agent to the dried first intermediate; The peptizing agent includes aluminum nitrate, and preferably, the peptizing agent is a 99wt% aluminum nitrate nonahydrate solution; The amount of the peptizing agent added is 2-4% of the mass of the first intermediate after drying; Preferably, the calcination is: heating to 400-600°C at a heating rate of 3-7°C / min and keeping the temperature for 4-5h.

6. The preparation method according to claim 3, characterized in that: The magnesium source is selected from one of magnesium nitrate, magnesium chloride and magnesium sulfate; The lanthanum source is selected from one of lanthanum nitrate, lanthanum chloride and lanthanum sulfate; The copper source is selected from one of copper nitrate, copper chloride and copper sulfate; The nickel source is selected from one of nickel nitrate, nickel chloride and nickel sulfate.

7. The preparation method according to claim 3, characterized in that: The second intermediate is sequentially immersed in a solution containing a magnesium source, a lanthanum source, a copper source and a nickel source, and dried and calcined as follows: The second intermediate is immersed in the first mixed solution containing the magnesium source and the lanthanum source, stirred, dried after saturation, heated to 700-900°C at a heating rate of 3-7°C / min, and kept warm for 3-5h to obtain a third intermediate; The third intermediate is immersed in a second mixed solution containing a copper source and a nickel source, stirred, dried after saturation, heated to 300-500° C. at a heating rate of 3-7° C. / min, and kept warm for 3-5 hours to obtain a catalyst for synthesizing morpholine by a diethylene glycol method.

8. The preparation method according to claim 7, characterized in that: The concentration of the magnesium source in the first mixed solution is 0.05-0.15 g / mL, and the concentration of the lanthanum source is 0.01-0.05 g / mL; the dosage ratio of the second intermediate to the first mixed solution is 2:0.5-1.5, preferably 2:1; The concentration of the copper source in the second mixed solution is 0.4-0.8 g / mL, and the concentration of the nickel source is 0.2-0.6 g / mL; the dosage ratio of the third intermediate to the second mixed solution is 2:0.5-1.5, preferably 2:

1.

9. Use of the catalyst for synthesizing morpholine by diethylene glycol method according to claim 1 or 2 or the catalyst for synthesizing morpholine by diethylene glycol method obtained by the preparation method according to any one of claims 3 to 8 in the preparation of morpholine.

10. A method for synthesizing morpholine by diethylene glycol method, characterized in that: The following steps are involved: In the presence of a catalyst, diethylene glycol reacts with liquid ammonia to obtain morpholine; The catalyst is the catalyst for synthesizing morpholine by diethylene glycol method according to claim 1 or 2, or the catalyst for synthesizing morpholine by diethylene glycol method obtained by the preparation method according to any one of claims 3 to 8; the catalyst for synthesizing morpholine by diethylene glycol method is firstly reduced and activated before participating in the reaction; Preferably, diethylene glycol reacts with liquid ammonia in a mixed atmosphere of nitrogen and hydrogen; the reaction is carried out in a fixed bed reactor; the molar ratio of diethylene glycol, liquid ammonia and hydrogen-nitrogen mixed gas is 1:15:(10-30); the reaction temperature is 210-230°C; the reaction pressure is 1.6-1.8 MPa; the diethylene glycol liquid space velocity is 0.1-0.15 h -1 ; Preferably, the reduction activation is: the catalyst for synthesizing morpholine by the diethylene glycol method is kept at nitrogen at 190-210° C. for 1-2 hours, and then kept at hydrogen at 250-350° C. for 4-6 hours to complete the reduction activation.

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