Composite catalyst for synthesizing 1, 4-butynediol and preparation method thereof

Abstract

The invention provides a preparation method of a composite catalyst for synthesizing 1, 4-butynediol, which comprises the following steps: preparing a solution A containing copper and cerium ions and a solution B containing copper, bismuth and magnesium ions, and adjusting the pH value; preparing a solution C containing a carbon dioxide storage material and sodium carboxymethyl cellulose, and adjusting the pH value; preheating the solution A, the solution B and the solution C, adding the preheated solution A, the preheated solution B and the preheated solution C into a liquid storage tank, and synchronously conveying the solution A and the solution C into a supergravity reactor for reaction to form slurry D; synchronously conveying the solution B and the solution C into a supergravity reactor, mixing the solution B and the solution C with the slurry D, and reacting to form slurry E; transferring the slurry E into a stirring kettle for continuous reaction or carrying out hydrothermal reaction in a high-pressure reaction kettle; and finally, aging, filtering, washing and drying the reacted slurry E in a constant-temperature drying box to obtain the powder catalyst. According to the invention, the carbon dioxide storage and collection material and the sodium carboxymethyl cellulose are used, and the supergravity reactor is combined, so that the prepared catalyst is good in crystallinity, more uniform in dispersion and excellent in activity and wear resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of 1,4-butanediol synthesis, and specifically relates to a composite catalyst for synthesizing 1,4-butynediol and a preparation method thereof. Background Art

[0002] Carbon dioxide capture is one of the key technologies for reducing greenhouse gas emissions and coping with climate change, and will play an important role in future energy transformation and industrial emission reduction. Patent CN201410578343.6 provides a method for rapidly preparing a carbon dioxide storage material (CO2SM) by capturing carbon dioxide. CO2SM is an alkyl carbonate and can be used as a precipitating agent and a structure-directing agent for the preparation of carbonates. This not only realizes the reduction of carbon dioxide emissions, but also realizes the recycling of carbon dioxide, thereby realizing circular economy.

[0003] 1,4-Butynediol (BYD) is an important organic chemical intermediate and can be derived into various organic products such as butadiene, butanediol, and tetrahydrofuran, and is widely used in industries, agriculture, and pharmaceuticals. Among them, products such as 1,4-butanediol (BDO) and tetrahydrofuran (THF) can be further used to manufacture engineering plastics, elastic fibers, pesticides, etc. In recent years, the demand for BYD and BDO in China has been increasing continuously with the development of their downstream industrial chains. At present, 1,4-butynediol is mainly produced industrially by the Reppe method, that is, formaldehyde and acetylene are used as reaction raw materials, and a polymerization reaction occurs under the action of a copper-based catalyst to generate 1,4-butynediol. China has rich coal resources, and the technology for preparing acetylene by the calcium carbide method is mature and the cost is low, which has great advantages in the Reppe method process production.

[0004] The key element of the Reppe method process is the catalyst. At present, traditional catalysts generally have problems such as poor stability, short lifespan, and easy carbon deposition deactivation. In industrial production, the catalyst needs to be frequently replaced. As a consumable used in large quantities, the catalyst increases the cost of the production line. Therefore, carrying out the research and development of high-efficiency catalysts and forming advanced catalyst preparation technologies in China have great practical significance for promoting the efficient application of the Reppe method process in China and improving the economic benefits of enterprises.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] In order to solve the above technical problems, the present invention provides a preparation method of a composite catalyst for synthesizing 1,4-butynediol. This method first uses a carbon dioxide storage material and sodium carboxymethylcellulose as a precipitation system, and combines the application of a rotating packed bed reactor, and the obtained catalyst has good crystallinity, uniform dispersion, excellent activity and abrasion resistance.

[0007] The basic concept of the technical solution of the present invention is as follows: A preparation method of a composite catalyst for synthesizing 1,4 - butynediol, comprising the following steps: (1) Prepare a solution A from the active metal salts of copper and cerium, and a solution B from the active metal salts of copper, bismuth and magnesium. Add acid to solutions A and B to adjust the pH of the solutions; dissolve a precipitant and an active agent in deionized water to form a solution C, and add alkali to solution C to adjust the pH. Among them, the precipitant is a carbon dioxide storage material, and the active agent is sodium carboxymethyl cellulose; (2) Preheat solutions A, B and C respectively and then add them to a storage tank. Then synchronously and uniformly convey solutions A and C into a rotating packed bed reactor for mixing reaction to form a slurry D; then synchronously and uniformly convey solution B and solution C into the rotating packed bed reactor to fully mix with slurry D, and finally form a slurry E after the reaction ends; (3) Perform either of the following treatments a) or b) on the slurry E after the reaction ends: a) Transfer the slurry E to a stirring kettle for continuous reaction; b) Transfer the slurry E to a high - pressure reaction kettle for hydrothermal reaction: (4) Age the slurry E that has completed the reaction in step (3) in a constant - temperature drying oven; (5) Filter, wash and dry the aged slurry E to obtain a powder catalyst.

[0008] As a mode, the active metal salts of copper, cerium, bismuth and magnesium are selected from one or several combinations of nitrates, sulfates or acetates.

[0009] As a mode, the pH of solution A and solution B is 1.0 - 3.0; the pH of solution C is 8.5 - 10.5.

[0010] As a mode, the preheating temperature in step (2) is 50 - 90 °C; preferably, the rotating packed bed reactor is used as the super - gravity reactor, and the selected packing is mesh packing.

[0011] Preferably, the rotation speed of the super - gravity reactor is 900 - 2200 rpm, and the reaction time is 0.5 - 2.0 h.

[0012] As a mode, in step (3), the temperature of the hydrothermal reaction of the slurry E in the high - pressure reaction kettle is 50 - 110 °C, and the reaction time is 1 - 12 h.

[0013] As a mode, in step (4), the aging time is 2 - 48 h, and the aging temperature is 20 - 40 °C.

[0014] As a mode, in the active metal salts of copper, cerium, bismuth and magnesium, the molar ratio of copper, cerium, bismuth and magnesium is 6-20:1-3:1:1.

[0015] The present invention further provides a composite catalyst for synthesizing 1,4-butyne diol, which is obtained according to the preparation method described above.

[0016] As a mode, more than 80% of the particle size of the catalyst is between 20-30 μm.

[0017] The present invention has the following advantages compared with the prior art: 1. The present invention combines the carbon dioxide capture technology disclosed in the expired patent CN201410578343.6 to prepare carbon dioxide storage materials, and then uses them for the preparation of the catalyst for synthesizing 1,4-butyne diol, which not only reduces carbon dioxide emissions, but also realizes a circular economy model of carbon dioxide.

[0018] 2. The present invention uses a carbon dioxide storage material and sodium carboxymethyl cellulose in synergy as a precipitant, and puts a specific raw material formula into a rotating packed bed reactor for preparation. The obtained spherical particles of the catalyst for 1,4-butyne diol are more uniformly dispersed, have a high crystallinity and strong wear resistance, solve the problems such as the decrease in particle size and fragmentation due to wear during the use of the catalyst, extend the service life of the catalyst, and the activity of the catalyst is stronger.

[0019] 3. The preparation method of the composite catalyst for synthesizing 1,4-butyne diol provided by the present invention adopts the rotating packed bed technology, the process is simple, and it is suitable for large-scale production. The rotating packed bed technology has the characteristics of fast reaction speed, small equipment volume, low energy consumption and convenient maintenance, providing a new idea for large-scale industrial production.

[0020] 4. The preparation method of the composite catalyst for synthesizing 1,4-butyne diol provided by the present invention has the advantages of short mixing time and uniform mixing. The rotating packed bed reactor increases the interfacial contact area, speeds up the phase interface renewal speed, improves the interphase mass transfer rate, and strengthens the micro-mixing process, and the obtained catalyst has excellent performance. Description of the Drawings

[0021] The drawings are used to provide a further understanding of the technical solutions of the present invention, and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solutions of the present invention, and do not constitute a limitation to the technical solutions of the present invention.

[0022] Figure 1 It is the SEM image of the catalyst prepared in Example 1 of the present invention.

[0023] Figure 2 It is the SEM image of the catalyst prepared in Comparative Example 3 of the present invention.

[0024] Figure 3 It is a device diagram for evaluating the performance of the catalyst adopted by the present invention.

[0025] Markings in the figure: 1. Nitrogen cylinder; 2. Acetylene cylinder; 31. First mass flowmeter; 32. Second mass flowmeter; 33. Third mass flowmeter; 4. Condenser; 5. Peristaltic pump; 6. Beaker; 7. Oil bath; 8. Online pH detector; 9. Four-necked flask. Specific embodiments

[0026] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0027] The reagents and equipment used in the present invention are all known products or obtained by purchasing commercially available products.

[0028] As an example, for the carbon dioxide storage material (CO2SM) used in the preparation of the catalyst, it is obtained according to the preparation method disclosed in the expired patent CN201410578343.6 (entitled: A rapid synthesis method of a carbon dioxide storage material). The specific preparation process is as follows: at 35°C, 20 g of ethylenediamine is dissolved in 80 g of polyethylene glycol, and 3 g of water is added to eliminate foaming during the process. A gas stream containing 12% (vol.) CO2 gas is passed into the solution at a gas flow rate of 400 ml / min for 3 h continuously, washed with absolute ethanol, filtered, and vacuum dried at 60°C for 2 h to obtain CO2SM powder. Prepare the required amount of carbon dioxide storage material (CO2SM) according to this method.

[0029] In the following cases, the rotating packed bed with high gravity is used as the high-gravity reactor, and the packing is mesh packing.

[0030] The preparation method of the catalyst of the present invention is specifically illustrated by the following examples.

[0031] Example 1 (1) Prepare Solution A: Weigh 432.00 g of Cu(NO3)2﹒3H2O and 42.90 g of Ce(NO3)3· 6H2O and put them into deionized water. After dissolution, make up the volume to 2000 mL. Prepare Solution B: Weigh 432.00 g of Cu(NO3)2﹒3H2O, 50.00 g of Bi(NO3)3﹒5H2O and 26.00 g of Mg(NO3)2﹒6H2O and put them into deionized water. After dissolution, make up the volume to 2000 mL.

[0032] Prepare Solution C: Weigh 200 g of carbon dioxide storage material and 5 g of sodium carboxymethylcellulose and make up a 2000 mL solution.

[0033] Adjust the pH of Solution A to 2.0, the pH of Solution B to 1.0, and the pH of Solution C to 8.5.

[0034] (2) Preheat Solution A, Solution B and precipitant Solution C to 90°C respectively in a constant temperature water bath, and then add them into the storage tank; adjust the feeding rate of Solution A to 3 mL / min and the feeding rate of precipitant Solution C to 9 mL / min, and transport them into the high gravity reactor. The feeding time is 30 min. The two liquids are efficiently mixed under the action of a high-speed rotating packing, and slurry D is formed after 10 min of reaction; Adjust the feeding rate of mixed salt Solution B to 4 mL / min and the feeding rate of precipitant Solution C to 9 mL / min, and transport them into the high gravity reactor. The feeding time is 60 min. The two liquids and slurry D are efficiently mixed under the action of a high-speed rotating packing, and slurry E is formed after 0.5 h of reaction; among them, the rotation speed of the high gravity reactor is 1000 rpm.

[0035] (3) Transfer slurry E to a high-pressure reaction kettle for hydrothermal reaction. The temperature of the hydrothermal reaction is 90°C and the time of the hydrothermal reaction is 3 h. After the hydrothermal reaction is completed, turn off the heating and cool naturally to room temperature; (4) Age slurry E obtained from step (3) in a constant temperature drying oven for 12 h, and the aging temperature is 35°C.

[0036] (5) After aging, filter, and then wash the filter cake with deionized water several times. Dry the washed filter cake at 110°C for 24 h.

[0037] The obtained catalyst sample is numbered as Catalyst 1.

[0038] Example 2 (1) Prepare Solution A: Weigh 376.00 g of Cu(NO3)2﹒3H2O and 42.90 g of Ce(NO3)3·6H2O and put them into deionized water. After dissolution, make up the volume to 2000 mL. Prepare Solution B: Weigh 376.00 g of Cu(NO3)2﹒3H2O, 50.00 g of Bi(NO3)3﹒5H2O and 26.00 g of Mg(NO3)2﹒6H2O and put them into deionized water. After dissolution, make up the volume to 2000 mL.

[0039] Prepare Solution C: Weigh 200 g of carbon dioxide storage material and 5 g of sodium carboxymethylcellulose and make up a 2000 mL solution.

[0040] Adjust the pH of Solution A to 3.0, the pH of Solution B to 1.5, and the pH of Solution C to 9.5.

[0041] (2) Preheat Solution A, Solution B and precipitant Solution C to 80 °C respectively in a constant temperature water bath, and then add them into the storage tank; adjust the feeding rate of Solution A to 2 mL / min and the feeding rate of precipitant Solution C to 7 mL / min, and transfer them into the high gravity reactor. The feeding time is 30 min. The two liquids are efficiently mixed under the action of a high-speed rotating packing, and slurry D is formed after reacting for 10 min; Adjust the feeding rate of mixed salt Solution B to 5 mL / min and the feeding rate of precipitant Solution C to 10 mL / min, and transfer them into the high gravity reactor. The feeding time is 60 min. The two liquids and slurry D are efficiently mixed under the action of a high-speed rotating packing, and slurry E is formed after reacting for 0.5 h; among them, the rotation speed of the high gravity reactor is 1500 rpm.

[0042] (3) Transfer slurry E to a stirring reaction kettle and continue the reaction. The stirring speed is 500 rpm, the reaction temperature is 90 °C, and the reaction time is 3 h; (4) Age slurry E, which has completed the reaction in step (3), in a constant temperature drying oven for 12 h, and the aging temperature is 35 °C.

[0043] (5) After aging, filter, and then wash the filter cake with deionized water multiple times. Dry the washed filter cake at 110 °C for 24 h.

[0044] The obtained catalyst sample is numbered as Catalyst 2.

[0045] Example 3 (1) Prepare Solution A: Weigh 432.00 g of Cu(NO3)2﹒3H2O and 43.40 g of Ce(NO3)3·6H2O and put them into deionized water. After dissolution, make up the volume to 2000 mL. Prepare Solution B: Weigh 432.00 g of Cu(NO3)2﹒3H2O, 50.00 g of Bi(NO3)3﹒5H2O and 26.00 g of Mg(NO3)2﹒6H2O and put them into deionized water. After dissolution, make up the volume to 2000 mL.

[0046] Prepare Solution C: Weigh 200 g of carbon dioxide storage material and 5 g of sodium carboxymethylcellulose and make up a 2000 mL solution.

[0047] Adjust the pH of Solution A to 1.5, the pH of Solution B to 1.0, and the pH of Solution C to 8.3.

[0048] (2) Preheat Solution A, Solution B and precipitant Solution C to 90°C respectively in a constant temperature water bath, and then add them into the storage tank; adjust the feeding rate of Solution A to 3 mL / min and the feeding rate of precipitant Solution C to 8 mL / min, and transfer them into the high gravity reactor. The feeding time is 20 min. The two liquids are efficiently mixed under the action of a high-speed rotating packing, and slurry D is formed after reacting for 10 min; Adjust the feeding rate of mixed salt Solution B to 4 mL / min and the feeding rate of precipitant Solution C to 9 mL / min, and transfer them into the high gravity reactor. The feeding time is 60 min. The two liquids and slurry D are efficiently mixed under the action of a high-speed rotating packing, and slurry E is formed after reacting for 0.5 h; Among them, the rotation speed of the high gravity reactor is 1800 rpm.

[0049] (3) Transfer slurry E to a high-pressure autoclave for hydrothermal reaction. The temperature of the hydrothermal reaction is 70°C and the time of the hydrothermal reaction is 2 h. After the hydrothermal reaction is completed, turn off the heating and let it cool naturally to room temperature; (4) Age slurry E obtained from step (3) in a constant temperature drying oven for 24 h, and the aging temperature is 50°C.

[0050] (5) After aging, filter, and then wash the filter cake with deionized water multiple times. Dry the washed filter cake at 110°C for 24 h.

[0051] The obtained catalyst sample is numbered as Catalyst 3.

[0052] Example 4 (1) Prepare Solution A: Weigh 576.00 g of Cu(NO3)2﹒3H2O and 86.80 g of Ce(NO3)3·6H2O and put them into deionized water. After dissolution, make up the volume to 2000 mL. Prepare Solution B: Weigh 576.00 g of Cu(NO3)2﹒3H2O, 75.00 g of Bi(NO3)3﹒5H2O and 39.00 g of Mg(NO3)2﹒6H2O and put them into deionized water. After dissolution, make up the volume to 2000 mL.

[0053] Prepare Solution C: Weigh 200 g of carbon dioxide storage material and 5 g of sodium carboxymethyl cellulose and prepare a 2000 mL solution.

[0054] Adjust the pH of Solution A to 2.0, the pH of Solution B to 2.0, and the pH of Solution C to 8.3.

[0055] (2) Preheat Solution A, Solution B and precipitant Solution C to 80°C in a constant temperature water bath respectively, and then add them into the storage tank; adjust the feeding rate of Solution A to 3 mL / min and the feeding rate of precipitant Solution C to 9 mL / min, and transfer them into the high gravity reactor. The feeding time is 30 min. The two liquids are efficiently mixed under the action of a high-speed rotating packing, and slurry D is formed after 10 min of reaction; Adjust the feeding rate of mixed salt Solution B to 4 mL / min and the feeding rate of precipitant Solution C to 9 mL / min, and transfer them into the high gravity reactor. The feeding time is 60 min. The two liquids and slurry D are efficiently mixed under the action of a high-speed rotating packing, and slurry E is formed after 2 h of reaction; among them, the rotation speed of the high gravity reactor is 1000 rpm.

[0056] (3) Transfer slurry E to a high-pressure autoclave for hydrothermal reaction. The temperature of the hydrothermal reaction is 70°C and the time is 6 h. After the hydrothermal reaction is completed, turn off the heating and cool naturally to room temperature; (4) Age slurry E obtained from step (3) in a constant temperature drying oven for 12 h, and the aging temperature is 35°C.

[0057] (5) After aging, filter, and then wash the filter cake with deionized water multiple times. Dry the washed filter cake at 110°C for 24 h. The obtained catalyst sample is numbered as Catalyst 4.

[0058] Comparative Example 1 The difference from Example 1 is that in step (1), the method for preparing mixed salt Solution C is: weigh 160 g of sodium bicarbonate and prepare a 2000 mL solution. The others are the same as in Example 1.

[0059] The finally prepared catalyst sample is numbered as Catalyst 5.

[0060] Comparative Example 2 The difference from Example 1 is that the method for preparing Solution A in step (1) is as follows: Weigh 432.00 g of Cu(NO3)2·3H2O and put it into water containing 5 g of nitric acid. After it is dissolved, make up the volume to 2000 mL; the method for preparing Solution B is: Weigh 432.00 g of Cu(NO3)2·3H2O and 50.00 g of Bi(NO3)3·5H2O and put them into water containing 5 g of nitric acid. After it is dissolved, make up the volume to 2000 mL.

[0061] The serial number of the finally prepared catalyst sample is Catalyst 6.

[0062] Comparative Example 3 The difference from Example 1 is that the method for preparing Solution C in step (1) is: Weigh 160 g of sodium bicarbonate and make it into 2000 mL of solution. In step (2), adjust the feeding rate of Solution A to 3 mL / min, and the feeding rate of precipitant solution C to 9 mL / min, and transport them into the stirred tank reactor. The feeding time is 30 min. After the feeding is over, react for 10 min to form slurry D; Adjust the feeding rate of mixed salt solution B to 4 mL / min, and the feeding rate of precipitant solution C to 9 mL / min, and transport them into the stirred tank reactor. The feeding time is 60 min. The two liquids and slurry D are mixed in the stirred tank reactor and react for 30 min to form slurry E; among them, the stirring speed of the stirred tank reactor is 500 rpm, and the reaction temperature is 60°C.

[0063] The serial number of the finally prepared catalyst sample is Catalyst 7.

[0064] Physical property analysis method of the catalyst SEM image detection of the catalyst: Use a Hitachi S-4800 scanning electron microscope to observe the morphology of the catalyst sample.

[0065] Measurement method: First, perform gold spraying treatment on the catalyst sample, evenly cover the conductive adhesive on the sample holder, and then select different areas for observation and imaging. Specifically, take the catalyst prepared in Example 3 as an example, the SEM image is as Figure 1 shown, and the morphologies of the catalysts in other examples are similar to Figure 1 it. However, for the catalyst prepared in Comparative Example 3, agglomeration problems occur between the catalyst particles. The SEM image is as Figure 2 shown, and it is not as dispersed as the catalyst particles shown in Figure 1 it.

[0066] The particle size of the catalyst is measured by a wet laser particle size analyzer.

[0067] Wear resistance test of catalyst: The catalyst was placed in a high-speed stirring autoclave and stirred at 1000 rpm for 24 h and 48 h respectively, and the particle size of the catalyst was measured. The results are shown in Table 1.

[0068] Table 1 Activity evaluation of catalyst The activity evaluation device of the catalyst (an existing evaluation method) is as Figure 3 shown. The reaction main body of the alkynylation catalytic reaction evaluation device is a four-neck flask 9. One port of the four-neck flask 9 is connected to an acetylene cylinder 2 and a nitrogen cylinder 1. In addition, on the pipelines connecting the four-neck flask 9 with the nitrogen cylinder 1 and the acetylene cylinder 2, there are a first mass flowmeter 31 and a second mass flowmeter 32 respectively. One port of the four-neck flask 9 is equipped with a condenser 4, and a third mass flowmeter 33 is provided on the pipeline where the condenser 4 is connected to the outside. The third port of the four-neck flask 9 is connected to a beaker 6 containing a mixed solution of sodium hydroxide and sodium carbonate for adjusting the pH of the reaction solution, and a peristaltic pump 5 is provided on the connected pipeline. One port of the four-neck flask 9 is provided with an on-line pH detector 8 capable of detecting the pH of the reaction system in real time.

[0069] Before acetylene (flow rate 33 ml / min) is introduced into the four-neck flask 9, it needs to be purified by dilute alkali, dilute acid and distilled water. During the reaction process, a constant-temperature oil bath and magnetic stirring are adopted, and the tail gas during the reaction process is discharged from the condenser through a sodium sulfite tail gas absorption solution. 1 g of catalyst and 20 mL of formaldehyde (mass fraction 37%) aqueous solution are added to the four-neck flask 9. First, N2 (flow rate 30 mL / min) is introduced to displace the air in the four-neck flask 9 for 30 min. The temperature of the reaction system is raised to 90 °C, stirring is started (500 rpm), acetylene is introduced and nitrogen is turned off to start the reaction, and the reaction time is 5 h. After the reaction, the temperature of the reaction system is lowered to room temperature, and acetylene gas is continuously introduced during the cooling process. Then, the catalyst is separated from the reaction solution. The catalyst is washed alternately with deionized water and ethanol and stored and recovered in a vacuum drying oven.

[0070] Product analysis method: (1) Formaldehyde analysis: The analysis method of formaldehyde follows the National Environmental Protection Standard HJ601-2011 of the People's Republic of China, and the unreacted residual formaldehyde in the product solution is determined by acetylacetone spectrophotometry.

[0071] (2) 1,4-Butynediol analysis: The content of 1,4-butynediol in the reaction solution is determined by gas chromatography. The gas chromatography model is 7890A, the chromatographic column model is DB-5, and the temperature of the FID detector (i.e., hydrogen flame ionization detector) is 300 °C, and the vaporization chamber temperature is 250 °C.

[0072] The test results of the formaldehyde conversion rate and BYD selectivity of each catalyst are shown in Table 2.

[0073] Table 2 Although the embodiments disclosed in the present invention are as above, the above content is only an embodiment adopted for the convenience of understanding the present invention and is not intended to limit the present invention. Any person skilled in the art within the scope of the present invention can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed by the present invention. However, the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. Preparation method of composite catalyst for synthesizing 1,4-butynediol, characterized in that, It includes the following steps: (1) Prepare solution A by dissolving the active metal salts of copper and cerium, and prepare solution B by dissolving the active metal salts of copper, bismuth and magnesium. Add acid to solutions A and B to adjust the pH of the solutions. Dissolve the precipitant and the surfactant in deionized water to form solution C, and add base to solution C to adjust the pH of the solution. Among them, the precipitant is a carbon dioxide storage material, and the surfactant is sodium carboxymethyl cellulose; (2) Preheat solutions A, B and C respectively and then add them to the storage tank. Then synchronously and uniformly transport solutions A and C into the rotating packed bed reactor for mixing reaction to form slurry D. Then synchronously and uniformly transport solution B and solution C into the rotating packed bed reactor to fully mix with slurry D. After the reaction ends, finally form slurry E; (3) Perform either of the following treatments a) or b) on the slurry E after the reaction ends: a) Transfer slurry E to a stirring kettle for continuous reaction; b) Transfer slurry E to an autoclave for hydrothermal reaction: (4) Age the slurry E that has completed the reaction in step (3) in a constant temperature drying oven; (5) Filter, wash and dry the aged slurry E to obtain a powder catalyst.

2. The preparation method of the composite catalyst for synthesizing 1,4-butyne diol according to claim 1, characterized in that, The active metal salts of copper, cerium, bismuth and magnesium are selected from one or several combinations of nitrates, sulfates or acetates.

3. The preparation method of the composite catalyst for synthesizing 1,4-butyne diol according to claim 1, characterized in that, The pH of solution A and solution B is 1.0 - 3.0; the pH of solution C is 8.5 - 10.

5.

4. The preparation method of the composite catalyst for synthesizing 1,4-butyne diol according to claim 1, characterized in that, The preheating temperature in step (2) is 50 - 90°C; preferably, the rotating packed bed reactor is used, and the selected packing is mesh packing; Preferably, the rotation speed of the rotating packed bed reactor is 900 - 2200 rpm, and the reaction time is 0.5 - 2.0 h.

5. The preparation method of the composite catalyst for synthesizing 1,4-butynediol according to claim 1, characterized in that, In step (3), the temperature of the hydrothermal reaction of slurry E in the autoclave is 50 - 110°C, and the reaction time is 1 - 12 h.

6. The preparation method of the composite catalyst for synthesizing 1,4-butyne diol according to claim 1, characterized in that, In step (4), the aging time is 2 - 48 h, and the aging temperature is 20 - 40°C.

7. The preparation method of the composite catalyst for synthesizing 1,4 - butynediol according to claim 1, characterized in that, Among the active metal salts of copper, cerium, bismuth and magnesium, the molar ratio of copper, cerium, bismuth and magnesium is 6 - 20:1 - 3:1:

1.

8. Composite catalyst for synthesizing 1,4-butyne diol, characterized in that, Obtained by the preparation method according to any one of claims 1 - 7.

9. The composite catalyst for synthesizing 1,4-butynediol according to claim 8, wherein, More than 80% of the particle size of the catalyst is between 20 - 30 μm.

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