Preparation method and application of BYD low-pressure hydrogenation catalyst

Abstract

The present application belongs to the technical field of hydrogenation catalysts, and specifically provides a preparation method and application of a BYD low-pressure hydrogenation catalyst, comprising the following steps: S01. taking mixed microspheres, calcining them, and cooling them to obtain a dense corundum carrier; S02. taking the dense corundum carrier, placing it in an acid etching solution for ultrasonic treatment, then filtering out the solid portion and washing it with water until it is neutral to obtain an acid etching carrier; S03. taking nickel nitrate and bismuth nitrate, dispersing them in water and adjusting the pH, then adding the acid etching carrier, dispersing them, then filtering out the solid portion, drying them, calcining them, reducing them, and cooling them; the mixed microspheres are obtained by spray granulation of a mixed micropowder of corundum particles and metal oxides. Using the BYD low-pressure hydrogenation catalyst of the present application for hydrogenation catalytic reactions, the conversion rate of the raw material BYD can reach 96.4%, the selectivity of BED in the catalytic product is ≥89.3%, and the catalyst has excellent anti-hydration performance.

Description

Technical Field

[0001] The present application belongs to the technical field of hydrogenation catalysts, and in particular relates to a preparation method and application of a BYD low-pressure hydrogenation catalyst. Background Art

[0002] 1,4-Butynediol (BYD), an important organic chemical intermediate, is widely used in pesticides, pharmaceuticals, plastics, fibers, and electroplating. Through selective catalytic hydrogenation, BYD can be converted into 1,4-butenediol (BED). BED, a key intermediate, plays an irreplaceable role in the synthesis of vitamin B6 and the production of the broad-spectrum insecticide endosulfan.

[0003] The selective synthesis of BED from BYD typically requires a hydrothermal process. The BYD feedstock reacts with H₂ in the presence of a hydrogenation catalyst. During this process, the carbon-carbon triple bonds in the BYD molecule are catalytically hydrogenated and converted into carbon-carbon double bonds, yielding the target product, BED. The introduction of a hydrogenation catalyst is crucial in this synthesis reaction, significantly reducing the activation energy and improving reaction rate and selectivity. Commonly used hydrogenation catalyst supports include zirconium oxide, titanium oxide, and carbon nanotubes. However, these catalyst supports are limited in large-scale industrial applications due to their high raw material costs and complex processing. In contrast, alumina is widely available, relatively inexpensive, and possesses a high specific surface area, making it an ideal catalyst support material. However, its use as a hydrogenation catalyst presents challenges, particularly in hydrothermal environments, where it can hydrate, leading to pore blockage and desorption of catalytically active sites, compromising catalyst performance.

[0004] Patent application document with application publication number CN120019873A discloses an aldehyde hydrogenation catalyst and a preparation method thereof. In the application, an aluminum precursor, a zinc precursor, and a precipitant solution are treated to obtain a mixture. The mixture is then mixed with a hydrophobic modifier, heated and stirred, and the resulting solid phase is separated and then calcined to obtain a catalyst. Due to the introduction of hydrophobic silicon in the hydrophobic modifier, the hydrophobic properties of the catalyst surface are improved, and the hydration loss of the carrier aluminum oxide is reduced.

[0005] The aforementioned application documents state that while the introduction of hydrophobic groups onto the support reduces the overall hydrophilicity of the support and thus enhances its hydration resistance, this reduction in support hydrophilicity inevitably reduces the reaction rate of the hydrophilic BYD raw material in water during the hydrothermal process, which is detrimental to the catalyst's high catalytic efficiency. Furthermore, the pH requirements of the process affect the loading of active centers on the support, leading to a reduction in the catalyst's catalytic activity. Therefore, it is necessary to find a BYD low-pressure hydrogenation catalyst that can enhance the support's hydration resistance while also improving the catalyst's catalytic performance. Summary of the Invention

[0006] In response to the above problems, in order to further improve the hydration resistance of the alumina carrier and at the same time improve the catalytic effect of the catalyst, the present application provides a preparation method and application of the BYD low-pressure hydrogenation catalyst.

[0007] This application first provides a preparation method of BYD low-pressure hydrogenation catalyst, comprising the following steps:

[0008] S01 take mixed microspheres, calcined, and cooled to obtain a dense corundum carrier; the mixed microspheres are obtained by spray granulation of corundum particles and metal oxide powders;

[0009] S02. Take a dense corundum carrier, place it in an acid etching solution for ultrasonic treatment, filter the solid part and wash it with water until it is neutral to obtain an acid etching carrier;

[0010] S03 take nickel nitrate and bismuth nitrate, add water and disperse after adjusting the pH, then add the acid-etched carrier, disperse, then filter, the filter collection after drying and heat burning, and then after reduction and cooling to obtain;

[0011] In step S01, the preparation step of the metal oxide mixed micropowder includes: mixing calcium oxide, magnesium oxide, iron oxide and copper oxide, ball milling and sieving;

[0012] The mass ratio of calcium oxide, magnesium oxide, iron oxide and copper oxide is (2.5-3.2): (5.7-8.5): (2.2-2.7):

[0013] (1.7-1.9);

[0014] The average particle size of the corundum particles is 0.5-1 mm;

[0015] The mass ratio of the corundum particles to the metal oxide mixed micropowder is (50-60): (1-2).

[0016] By employing this technical solution, after spray granulation, metal oxides adhere to the surface of the corundum particles. Subsequent calcination results in a dense alloy phase. This alloy phase contains high-lattice density structures such as magnesia-alumina spinel (MgAl2O4) and calcium-iron garnet (Ca3Fe2(SiO4)3). During the catalytic reaction, this effectively inhibits the hydrothermal environment from corroding the alumina component of the carrier, thereby suppressing hydration and pore plugging, allowing the catalyst to maintain stability for a longer period. Further treatment of the carrier with an acid etchant can improve surface roughness and promote the loading of active catalytic metal ions.

[0017] Furthermore, in step S01, the roasting process includes a first stage heating and a second stage heating, specifically:

[0018] Stage 1 heating: heating to 650-720°C at a heating rate of 2-3°C / min, then keeping warm for 40-60 minutes;

[0019] Second stage heating: heat to 1300-1475℃ at a heating rate of 4.5-5℃ / min, and then keep warm for 3-4h.

[0020] By adopting the above technical solution, programmed heating can give the alloy phase more sufficient time to form and promote the aluminum oxide on the surface of the corundum particles to participate in the formation of the alloy phase; in the second stage heating process, components such as copper oxide are melted to form a low-melting-point dispersed phase, and an alloy is obtained after subsequent cooling to form a protective structure; programmed heating can also improve the carrier stress concentration problem and shrinkage problem caused by excessively rapid heating.

[0021] Furthermore, in step S02, the steps of preparing the etching solution include the following:

[0022] Take glacial acetic acid, mix it with 85wt% phosphoric acid and tartaric acid, dilute it with water, then add dimethylpyridiniumamine and adjust the pH to 3-4 to obtain the product;

[0023] The ratio of glacial acetic acid, 85 wt% phosphoric acid, tartaric acid and dimethylpyridinamine is (3-4) ml:0.5 ml:(0.2-0.3) g:(0.5-0.6) g.

[0024] By adopting the above technical solution, the etching solution is a combination of polybasic mixed acid and dimethylpyridinium amine, which can play two roles: on the one hand, the mixed acid component can modify the alloy phase and the exposed alumina surface, increase the roughness of the carrier surface to improve the catalytic metal ion Ni 2+ 、Bi 3+ The loading activity; at the same time, the dimethylpyridinium amine in the acid etching solution can react with the Cu in the alloy phase 2+ Selectively adsorbed and retained on the surface of the alloy phase, and further adsorbed Ni through the amino nitrogen atom and pyridine ring structure on its molecule 2+ ions, improve Ni 2+ Ion loading on the carrier. During the subsequent calcination process, dimethylpyridylamine decomposes due to heat, while the active catalytic metal ions remain on the surface of the carrier and can play a catalytic role after reduction treatment.

[0025] Furthermore, in step S02, the ultrasonic treatment is: treating at an ultrasonic frequency of 10-15 kHz for 10-30 minutes.

[0026] Furthermore, in step S03, the mass ratio of nickel nitrate, bismuth nitrate and acid etching carrier is (0.6-0.7): (0.3-0.4): (10-15).

[0027] In step S03, the calcination is as follows: setting the heating temperature to 450-475° C. and maintaining it for 2-3 hours.

[0028] Furthermore, in step S01, the preparation step of the adhesive includes the following steps:

[0029] Take sodium silicate, add water to disperse, then add carboxymethyl cellulose and gum arabic, adjust the pH to 8.5-9, and you have it.

[0030] The ratio of sodium silicate, water, carboxymethyl cellulose and gum arabic is (10-12) g: (20-30) ml.

[0031] :(5-8)g:(2-3)g.

[0032] By adopting the above technical solution, the sodium silicate in the binder can construct a silicate network in the mixed microspheres and participate in the formation of an alloy phase during the roasting process, thereby promoting the densification process of the carrier; in addition, the small amount of gum arabic added to the binder decomposes during the roasting process, leaving micropores, which can increase the attachment points of active catalytic metal ions and further improve the loading rate of active catalytic metal ions.

[0033] Furthermore, in step S01, the spray granulation is as follows: controlling the air inlet temperature to 185-220° C., the air outlet temperature to 75-85° C., and the atomization pressure to 0.3-0.5 MPa.

[0034] As a general inventive concept, the present invention also provides the use of the BYD low-pressure hydrogenation catalyst prepared by the above-mentioned preparation method in hydrogenation catalysts.

[0035] Compared with the prior art, this application has the following beneficial effects:

[0036] 1. This application constructs a high lattice density alloy dispersed phase structure on the surface of the corundum particles through spray granulation and calcination treatment, and improves the hydration resistance of the catalyst carrier through the alloy dispersed structure; during the catalytic reaction, it can effectively inhibit the erosion of the hydrothermal environment on the carrier aluminum oxide component, thereby inhibiting the hydration and pore blocking behavior of the aluminum oxide, so that the catalyst can be stable for a longer time.

[0037] 2. This application uses an acid etching solution to treat a dense corundum carrier. The acid etching solution is a combination of a polybasic mixed acid and dimethylpyridinium amine, which can play two roles. On the one hand, the mixed acid component can modify the alloy phase and the exposed alumina surface, increase the roughness of the carrier surface to improve the catalytic metal ion Ni 2+ 、Bi 3+ The loading activity; at the same time, the dimethylpyridinium amine in the acid etching solution can react with the Cu in the alloy phase 2+Selectively adsorbed and retained on the surface of the alloy phase, and further adsorbed Ni through the amino nitrogen atom and pyridine ring structure on its molecule 2+ ions, improve Ni 2+ Ion loading on the carrier. During the subsequent calcination process, dimethylpyridylamine decomposes due to heat, while the active catalytic metal ions remain on the surface of the carrier and can play a catalytic role after reduction treatment.

[0038] 3. When the BYD low-pressure hydrogenation catalyst of the present application is used for hydrogenation catalytic reaction, the conversion rate of the raw material BYD can reach 96.4%, the selectivity of BED in the catalytic product is ≥89.3%, and the catalyst has excellent anti-hydration performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is the powder XRD diffraction pattern of the mixed microsphere ball-milled fine material prepared in Example 2 of this application.

[0040] Figure 2 These are the catalytic activity test results of the catalysts in Examples 1-4 and Comparative Examples 1-2 of the present application.

[0041] Figure 3 These are the test results of the catalyst cycle performance of Example 2 of the present application and Comparative Examples 1-2. DETAILED DESCRIPTION

[0042] The technical solution of the present invention is explained in detail below with reference to several representative embodiments of the present invention.

[0043] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods. Unless otherwise specified, the materials, reagents, etc. used in the following examples are all commercially available.

[0044] Description of the raw materials used in the examples and comparative examples of the present invention:

[0045] Calcium oxide, average particle size 20-30 microns;

[0046] Magnesium oxide, average particle size 10-15 microns;

[0047] Iron oxide, average particle size 0.2-0.5 microns;

[0048] Copper oxide, average particle size 50-70 microns;

[0049] Corundum particles, average particle size 0.5-1 mm, Al2O3wt% ≥ 98.5;

[0050] Glacial acetic acid, analytical grade.

[0051] Preparation Example 1

[0052] Take 25g of calcium oxide, 57g of magnesium oxide, 22g of iron oxide and 17g of copper oxide, mix them, use a high-speed disperser to disperse them for 5 minutes, then place the mixed material in a small ball mill, control the ball-to-material ratio to 1:5, the ball mill speed to 200rpm, continue processing for 30 minutes, and then pass through a 300-mesh sieve to obtain metal oxide mixed powder.

[0053] 10 g of sodium silicate was added to 20 ml of deionized water, followed by the addition of 5 g of carboxymethyl cellulose and 2 g of gum arabic, and the pH was adjusted to 8.5 to obtain a binder.

[0054] 250 g of corundum particles and 5 g of metal oxide mixed powder were mixed and placed in a spray granulator. The binder was sprayed with a spray gun. The inlet air temperature was controlled at 185 ° C, the outlet air temperature was 75 ° C, and the atomization pressure was 0.3 MPa. The granulated product was then dried at a constant temperature of 50 ° C for 10 minutes to obtain mixed microspheres.

[0055] Take 20g of mixed microspheres and place them in a tubular furnace. First, increase the system temperature to 650℃ at a heating rate of 2℃ / min, then keep it warm for 40min, then increase the system temperature to 1300℃ at a heating rate of 4.5℃ / min, then keep it warm for 3h, and then stop heating. After the product cools in the furnace, a dense corundum carrier is obtained.

[0056] Preparation Example 2

[0057] Take 30g of calcium oxide, 72g of magnesium oxide, 25g of iron oxide and 18g of copper oxide, mix them, use a high-speed disperser to disperse them for 8 minutes, then place the mixed material in a small ball mill, control the ball-to-material ratio to 1:5, the ball mill speed to 250rpm, continue processing for 35 minutes, and then pass through a 300-mesh sieve to obtain metal oxide mixed powder.

[0058] 12 g of sodium silicate was added to 25 ml of deionized water, followed by the addition of 6 g of carboxymethyl cellulose and 2.2 g of gum arabic, and the pH was adjusted to 8.5 to obtain a binder.

[0059] 275 g of corundum particles and 8 g of metal oxide mixed powder were mixed and placed in a spray granulator. The binder was sprayed with a spray gun. The inlet air temperature was controlled at 200 ° C, the outlet air temperature was 80 ° C, and the atomization pressure was 0.4 MPa. The granulated product was then dried at a constant temperature of 50 ° C for 15 minutes to obtain mixed microspheres.

[0060] Take 25g of mixed microspheres and place them in a tubular furnace. First, increase the system temperature to 680℃ at a heating rate of 2.3℃ / min, then keep it warm for 50min, then increase the system temperature to 1425℃ at a heating rate of 4.8℃ / min, then keep it warm for 4h, and then stop heating. After the product is cooled in the furnace, a dense corundum carrier is obtained.

[0061] Preparation Example 3

[0062] Take 32g of calcium oxide, 85g of magnesium oxide, 27g of iron oxide and 19g of copper oxide, mix them, use a high-speed disperser to disperse them for 10 minutes, then place the mixed material in a small ball mill, control the ball-to-material ratio to 1:5, the ball mill speed to 300rpm, continue to process for 40 minutes, and then pass through a 300-mesh sieve to obtain metal oxide mixed powder.

[0063] 12 g of sodium silicate was added to 30 ml of deionized water, followed by the addition of 8 g of carboxymethyl cellulose and 3 g of gum arabic, and the pH was adjusted to 9 to obtain a binder.

[0064] 300 g of corundum particles and 10 g of metal oxide mixed powder were mixed and placed in a spray granulator. The binder was sprayed with a spray gun. The inlet air temperature was controlled at 220 ° C, the outlet air temperature was 85 ° C, and the atomization pressure was 0.5 MPa. The granulated product was then dried at a constant temperature of 50 ° C for 30 minutes to obtain mixed microspheres.

[0065] Take 30g of mixed microspheres and place them in a tubular furnace. First, increase the system temperature to 720℃ at a heating rate of 3℃ / min, then keep it warm for 60min, then increase the system temperature to 1475℃ at a heating rate of 5℃ / min, then keep it warm for 4h, and then stop heating. After the product is cooled in the furnace, a dense corundum carrier is obtained.

[0066] Example 1

[0067] Take 50 ml of deionized water, slowly add 3 ml of glacial acetic acid, then add 0.5 ml of 85% phosphoric acid and 0.2 g of tartaric acid, stir to mix, then add 0.5 g of dimethylpyridinamine, adjust the pH of the system to 3, and set aside.

[0068] 10 g of dense corundum carrier was added to 200 ml of acid etching solution, and ultrasonically treated at 10 kHz for 10 min. The solid part was then filtered and washed with water until neutral to obtain an acid etching carrier.

[0069] Take 0.6g nickel nitrate and 0.3g bismuth nitrate, add 100ml deionized water to disperse, adjust the pH to 5, then add 10g acid-etched carrier to the system, ultrasonicate at 20kHz for 30min, then filter out the solid part, evaporate the water in an oven at 50℃, then transfer to a tubular furnace, set the heating temperature to 450℃, continue for 2h, and then reduce in a 5% H2 / N2 atmosphere at a temperature of 350℃. The product is cooled in the furnace to obtain BYD low-pressure hydrogenation catalyst.

[0070] In this embodiment, the dense corundum carrier is prepared by Preparation Example 1.

[0071] Example 2

[0072] Take 50 ml of deionized water, slowly add 3.5 ml of glacial acetic acid, then add 0.5 ml of 85% phosphoric acid and 0.2 g of tartaric acid, stir to mix, then add 0.6 g of dimethylpyridinamine, adjust the pH of the system to 3.2, and set aside.

[0073] 12 g of dense corundum carrier was added to 220 ml of acid etching solution, and ultrasonically treated at 12 kHz for 20 min. The solid part was then filtered and washed with water until neutral to obtain an acid etching carrier.

[0074] Take 0.6g nickel nitrate and 0.4g bismuth nitrate, add 100ml deionized water to disperse, adjust the pH to 5.5, then add 12g acid-etched carrier to the system, ultrasonicate at 22kHz for 45min, then filter out the solid part, evaporate the water in an oven at 55℃, then transfer to a tubular furnace, set the heating temperature to 450℃, continue for 3h, and then reduce in a 5% H2 / N2 atmosphere at a temperature of 350℃. The product is cooled in the furnace to obtain BYD low-pressure hydrogenation catalyst.

[0075] In this embodiment, the dense corundum carrier is prepared by Preparation Example 2.

[0076] Example 3

[0077] Take 50 ml of deionized water, slowly add 4 ml of glacial acetic acid, then add 0.5 ml of 85% phosphoric acid and 0.3 g of tartaric acid, stir to mix, then add 0.6 g of dimethylpyridinamine, adjust the pH of the system to 4, and set aside.

[0078] 15 g of dense corundum carrier was added to 250 ml of acid etching solution, and ultrasonically treated at 15 kHz for 30 min. The solid part was then filtered and washed with water until neutral to obtain an acid etching carrier.

[0079] Take 0.7g nickel nitrate and 0.4g bismuth nitrate, add 150ml deionized water to disperse, adjust the pH to 6, then add 15g acid-etched carrier to the system, ultrasonicate at 22kHz for 50min, then filter out the solid part, evaporate the water in an oven at 55℃, then transfer to a tubular furnace, set the heating temperature to 475℃, continue for 3h, and then reduce in a 5% H2 / N2 atmosphere at a temperature of 350℃. The product is cooled in the furnace to obtain BYD low-pressure hydrogenation catalyst.

[0080] In this embodiment, the dense corundum carrier is prepared by Preparation Example 3.

[0081] Example 4

[0082] The only difference between this embodiment and embodiment 1 is that the dense corundum carrier is prepared by Preparation Example 2.

[0083] The remaining steps are the same as those in Example 1.

[0084] Comparative Example 1

[0085] The difference between this comparative example and Example 1 is that an equal amount of silicon dioxide powder is used instead of the metal oxide mixed powder, and the metal oxide mixed powder is mixed with the corundum particles for spray granulation.

[0086] Silicon dioxide powder (industrial grade), average particle size 20 microns.

[0087] The remaining steps are the same as those in Example 1.

[0088] Comparative Example 2

[0089] The difference between this comparative example and Example 1 is that the steps for preparing the etching solution are as follows:

[0090] Take 50 ml of deionized water, slowly add 3 ml of glacial acetic acid, then add 0.5 ml of 85% phosphoric acid and 0.2 g of tartaric acid, stir and mix, then add 0.5 g of polymaleic anhydride, adjust the pH of the system to 3, and obtain the product.

[0091] The remaining steps are the same as those in Example 1.

[0092] Performance testing

[0093] 1. XRD test

[0094] Take the mixed microspheres of Preparation Example 2, place them in a small ball mill, control the ball-to-material ratio to 1:5, and the ball mill speed to 200 rpm. Process for 10 minutes, then pass the product through a 250 mesh sieve to obtain fine material for XRD test. The test results are as follows: Figure 1 shown.

[0095] Analyze Preparation Example 2 and combine Figure 1 It can be seen that after the metal oxide mixed powder and corundum particles are calcined, a variety of aluminum-doped alloy phases are detected in the obtained XRD spectrum, indicating that each component has been effectively doped; from the diffraction peak results, there is a part of alloy phases with high lattice density [such as MgAl2O4, Ca3Fe2(SiO4)3, etc.] and a mixed peak of α-Al2O3 at the position of 2θ=35.1°. These high lattice density alloy phases are generated and mixed on the surface of the corundum particles, which can effectively improve the density of the catalyst support surface, reduce the erosion of the hydrothermal catalytic environment on the support, and improve the anti-hydration performance of the catalyst support; In addition, the Al formed in the alloy phase 2.5 (Ca 1.2 Fe 0.5 )(SiO4) 2.85 、CuFe2O4、Ca 0.3 Cu 0.7The multi-alloy components such as Fe2O4 are dispersed and doped on the surface of the corundum particles, which can jointly improve the surface hardness of the carrier and inhibit the desorption behavior of the active center of the catalyst.

[0096] 2. Catalytic activity test

[0097] 30 ml of BYD raw material was added to a 200 ml reactor and stirred to dissolve. 1 g of BYD low-pressure hydrogenation catalyst prepared in Examples 1-4 and Comparative Examples 1-2 was then added, respectively. Nitrogen was introduced to displace the air in the reactor. The reactor temperature was then controlled at 105°C, the reaction pressure at 0.5 MPa, and the magnetic stirring speed at 250 rpm. The reaction was continued for 2.5 hours. The concentrations of BYD and BED before and after catalysis were measured using a GC-MS chromatograph-mass spectrometer (Saturn 2100) with 1,3-propylene glycol as the internal standard. According to the formula:

[0098] W1=(C0-C1) / C0×100%;

[0099] W2=C2 / (C0-C1)×100%;

[0100] Calculate the BYD conversion rate W1 and the BED selectivity W2.

[0101] in,

[0102] C0: initial BYD concentration;

[0103] C1: final concentration of BYD;

[0104] C2: Final concentration of BED.

[0105] The test results are as follows Figure 2 shown.

[0106] Analyze Examples 1-4 and Comparative Examples 1-2 and combine Figure 2It can be seen that when the hydrogenation catalyst of the embodiment scheme is used for the catalytic synthesis reaction, the conversion rate of BYD can reach more than 96.3%, and the selectivity of the catalyst for BED is higher than 89.3%, and the catalytic activity is significantly improved compared with the comparative example scheme. Comparative Example 1 uses silica instead of the metal oxide mixed powder. Under the calcination temperature conditions, although a mullite (3Al2O3·2SiO2) reinforcement phase may be formed, the hydrothermal catalytic environment exacerbates the pore blocking behavior of the catalyst support and is not effectively suppressed. The active catalytic metal ions attached to the surface of the catalyst will still lose their catalytic activity due to entrapment, and the hydration behavior of the support will also cause the active catalytic metal ions attached to the surface of the support to desorb. The combined effect leads to a decrease in the catalytic activity of the catalyst. In Comparative Example 2, due to the lack of dimethylpyridylamine in the acid etching solution component to increase the loading of active catalytic metal ions, the loading effect of active catalytic metal ions on the catalyst surface is poor, and both the BYD raw material conversion rate and the BED selectivity are reduced. Among all the test groups, the catalytic activity of the hydrogenation catalyst of Example 2 is the best.

[0107] 3. Cycle performance test

[0108] The cyclic performance of a catalyst can, to some extent, reflect the support's resistance to hydration in a hydrothermal environment. If the support undergoes increased hydration during hydrothermal treatment, the catalyst's conversion rate to the feedstock will decrease within the same reaction time due to pore plugging. Therefore, the smaller the decrease in feedstock conversion after cyclic testing, the stronger the support's resistance to hydration.

[0109] After the catalytic activity tests of Example 2 and Comparative Examples 1-2, the BYD hydrogenation catalyst was separated from the system, dried, and re-tested for catalytic activity. The cycle was repeated 5 times, and the BYD conversion rate after each test was recorded. The test results are shown in FIG. Figure 3 shown.

[0110] Analyze Example 2 and Comparative Examples 1-2 and combine Figure 3It can be seen that the conversion rate change trend of BYD of the hydrogenation catalysts of Example 2 and Comparative Example 2 is relatively stable; among them, after 5 cycle tests, the conversion rate of BYD of the hydrogenation catalyst of Example 2 can still be maintained at 91.54%, with a decrease of less than 6.5%, and the cycle performance of the catalyst is relatively superior; while the conversion rate change data of BYD of the hydrogenation catalyst of Comparative Example 1 shows a gradient decrease, and the change trend is different from that of the other two groups; and in the third cycle, the BYD conversion rate of Comparative Example 1 drops sharply, which is related to the deactivation of the active catalytic metal ions on the surface of the catalyst; it can be explained that, with the progress of the hydrothermal catalytic reaction, the hydration behavior of the aluminum oxide on the surface of the catalyst support of Comparative Example 1 intensifies, and the hydration product AlOOH can block the pore structure of the surface of the support, so that the active catalytic metal ions attached to the surface of the support are isolated from the reaction raw materials and become ineffective, and as the hydration of the catalyst support continues, some of the active catalytic metal ions attached to the catalyst surface are desorbed from the catalyst, which ultimately leads to a decrease in the overall cycle performance of the catalyst.

[0111] Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a 1,4-butynediol (BYD) low-pressure hydrogenation catalyst, characterized in that: The steps include: S01. Take mixed microspheres, calcine them, and cool them to obtain a dense corundum carrier; the mixed microspheres are obtained by spraying granulation with a binder from a mixed micropowder of corundum particles and metal oxides; the preparation steps of the mixed micropowder of metal oxides include: mixing calcium oxide, magnesium oxide, iron oxide and copper oxide, ball milling and sieving; the mass ratio of calcium oxide, magnesium oxide, iron oxide and copper oxide is (2.5-3.2): (5.7-8.5): (2.2-2.7): (1.7-1.9); the average particle size of the corundum particles is 0.5-1 mm; the corundum particles The mass ratio of the particles to the metal oxide mixed powder is (50-60): (1-2); the preparation steps of the binder include the following steps: taking sodium silicate, adding water to disperse, then adding carboxymethyl cellulose and gum arabic, and adjusting the pH to 8.5-9 to obtain; the roasting treatment includes a first heating stage and a second heating stage, specifically, the first heating stage: heating to 650-720°C at a heating rate of 2-3°C / min, and then keeping warm for 40-60 minutes; the second heating stage: heating to 1300-1475°C at a heating rate of 4.5-5°C / min, and then keeping warm for 3-4 hours; S02. A dense corundum carrier is placed in an acid etching solution for ultrasonic treatment. After filtering, the solid portion is washed with water until neutral to obtain an acid etching carrier. The acid etching solution is prepared by mixing glacial acetic acid with 85 wt % phosphoric acid and tartaric acid, diluting with water, and then adding dimethylpyridinium to adjust the pH to 3-4. The ratio of the glacial acetic acid, 85 wt % phosphoric acid, tartaric acid, and dimethylpyridinium to obtain the carrier is (3-4) ml:0.5 ml:(0.2-0.3) g:(0.5-0.6) g. S03. Take nickel nitrate and bismuth nitrate, add water to disperse and adjust the pH, then add an acid-etched carrier, disperse, and then filter. The filtrate is dried and calcined, and then reduced and cooled.

2. The preparation method of the BYD low-pressure hydrogenation catalyst according to claim 1, characterized in that: In the step S01, the ratio of sodium silicate, water, carboxymethyl cellulose and gum arabic is (10-12) g: (20-30) ml: (5-8) g: (2-3) g.

3. The preparation method of BYD low-pressure hydrogenation catalyst according to claim 1, characterized in that: In step S01, the spray granulation is as follows: the air inlet temperature is controlled at 185-220° C., the air outlet temperature is controlled at 75-85° C., and the atomization pressure is controlled at 0.3-0.5 MPa.

4. The preparation method of BYD low-pressure hydrogenation catalyst according to claim 1, characterized in that In step S02, the ultrasonic treatment is performed at an ultrasonic frequency of 10-15 kHz for 10-30 minutes.

5. The preparation method of BYD low-pressure hydrogenation catalyst according to claim 1, characterized in that: In the step S03, the mass ratio of nickel nitrate, bismuth nitrate and acid etching carrier is (0.6-0.7): (0.3-0.4): (10-15).

6. The preparation method of BYD low-pressure hydrogenation catalyst according to claim 1, characterized in that: In step S03, the calcination is as follows: setting the heating temperature to 450-475° C. and maintaining it for 2-3 hours.

7. Use of the BYD low-pressure hydrogenation catalyst prepared by the preparation method according to any one of claims 1 to 6 in hydrogenation catalysts.

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