Spherical copper bismuth catalyst and preparation method thereof

Abstract

The invention discloses a spherical copper bismuth catalyst and a preparation method thereof. The sphericity degree of the catalyst is not less than 0.90, the powder fluidity of the catalyst requires that the angle of repose is less than 35 degrees, the tap density is 1.45-2.05 g / cm < 3 >, and the particle size distribution condition of the catalyst is as follows: the catalyst with the particle diameter of 10-30 microns accounts for 90-100% of the total catalyst in percentage by mass. The catalyst particles are high in sphericity degree and good in fluidity, and have the characteristics of low abrasion level and good long-period operation stability in the operation process of a slurry bed.

Description

TECHNICAL FIELD

[0001] The present application relates to a spherical copper bismuth catalyst and a preparation method thereof, in particular to a high-sphericity, high-fluidity and low-abrasion copper bismuth catalyst suitable for slurry bed process of synthesizing 1,4-butyne diol from formaldehyde acetylene and a preparation method thereof. BACKGROUND

[0002] In recent years, the market demand for degradable materials and their monomers in China has grown rapidly. 1,4-Butanediol (BDO) is a polymerization monomer for synthesizing degradable plastics such as polytetramethylene glycol ether (PTMEG), polybutylene terephthalate (PBT), polybutylene succinate (PBS) and polyurethane (PU). The main process for industrial production of BDO is the preparation of 1,4-butyne diol (BYD) by formaldehyde acetylene (Reppe method), and the hydrogenation of BYD to obtain BDO. In the 1970s, an improved Reppe method process was developed in the field, which uses slurry bed or suspension bed technology, and the reaction is carried out under normal pressure or low pressure. The core of the improved Reppe method for synthesizing BYD is the Cu-Bi catalyst, and existing industrial production practice shows that the sphericity of the catalyst is poor, the abrasion resistance is poor, and the service life is short, about 2 months, which seriously affects the continuous operation of the industrial device. Therefore, the preparation technology of basic copper bismuth carbonate particles with reasonable particle size distribution and high abrasion resistance is the key to the improved Reppe method for synthesizing 1,4-butyne diol.

[0003] US4110249 discloses a carrier-free copper bismuth microspherical catalyst, and the particle size of the catalyst is only 5-12 μm, which is relatively small; US4584418 discloses a carrier-free copper bismuth microspherical catalyst containing silicon, which enhances the strength of the catalyst, but the particle shape is irregular, which aggravates the degree of collision and abrasion between particles during the reaction; CN1118342A discloses a carrier-free copper oxide / bismuth oxide catalyst, which is not resistant to wear and the metal components are easily lost.

[0004] US3920759 discloses a copper bismuth supported catalyst with magnesium silicate as the carrier, and such catalysts have the following disadvantages: the carrier magnesium silicate is unstable and will dissolve in the reaction system, resulting in short service life. CN102125856A discloses a copper bismuth supported catalyst with kaolin as the carrier, and such catalysts have the following disadvantages: the amount of the catalyst is large, the content of copper oxide is high, and the catalyst is prone to agglomeration, which cannot fully exert the catalytic effect of each active center, resulting in waste of copper resources.

[0005] CN103170342A discloses a kind of synthesis 1,4-butynediol nano CuO-Bi2O3 catalyst, which will be appropriate amount of surfactant and sodium hydroxide solution is added into copper bismuth acidic aqueous solution respectively, pyrolysis is prepared at a certain temperature nano catalyst, the particle size of the prepared catalyst is 10~80nm, the catalyst has higher reactivity, but due to the small particle size of the catalyst, it is used in slurry bed or suspension bed, the particle is small, difficult to filter, and the active center of nano CuO-Bi2O3 is exposed, easy to deactivate.

[0006] US4536491 discloses a kind of spherical malachite catalyst, under the condition of 55℃, pH=6.0~7.0, using parallel flow feeding mode, alkali metal carbonate and silicic acid, Cu(NO3)2, Bi(NO3)3 mixed solution is uniformly mixed, condensation into spherical CuCO3·Cu(OH)2, then parallel flow feeding remaining silicic acid, Cu(NO3)2, Bi(NO3)3 mixed solution is carried out secondary precipitation, finally forming regular spherical malachite crystal CuCO3·Cu(OH)2(average particle size: 10~17 μm). Although the preparation of the catalyst is easy to operate under laboratory conditions and has high activity, but in large-scale industrial production, the catalyst has low activity, the spherical crystal cannot be continuously produced, and there are problems such as easy polymerization or desorption of silicic acid.

[0007] In summary, the bulk copper bismuth catalyst in the prior art has higher activity than the supported catalyst, but the strength is low, and there are problems such as irregular shape of catalyst particles, poor flowability, quick breakage and fine pulverization due to collision and friction in the slurry bed reaction process, resulting in filter cloth blockage and shutdown. SUMMARY

[0008] In view of the deficiencies of the prior art, the present application provides a kind of spherical copper bismuth catalyst and its preparation method, the spherical degree of the catalyst particle is high, the flowability is good, in the slurry bed operation process, it has the characteristics of low abrasion level, long period operation stability.

[0009] The first aspect of the present application provides a kind of spherical copper bismuth catalyst, the spherical degree of the catalyst is not less than 0.90, the flowability of catalyst powder requires that the angle of repose is less than 35 degrees, the tap density is 1.45 g / cm 3 ~2.05 g / cm 3 The particle size distribution of the catalyst is as follows: the catalyst with particle diameter of 10~30 μm accounts for 90%~100% of the total catalyst.

[0010] Further, the specific surface area of the spherical copper bismuth catalyst is 0.5~40 m 2 / g, preferably 1~20 m 2 / g, more preferably 3~15 m 2 / g, and the pore volume is 0.01 cm 3 / g~0.50 cm 3 / g, preferably 0.015 cm 3 / g~0.20 cm 3 / g, more preferably 0.02 cm 3 / g~0.10 cm 3 / g.

[0011] Further, the content of copper oxide in the spherical copper bismuth catalyst is 90 wt%~99.9 wt%, and the content of bismuth oxide is 0.1 wt%~10 wt%, preferably the content of copper oxide is 92.5 wt%~97.5 wt%, and the content of bismuth oxide is 2.5 wt%~7.5 wt%, more preferably the content of copper oxide is 94.5 wt%~96.5 wt%, and the content of bismuth oxide is 3.5 wt%~5.5 wt%, based on the weight of the spherical copper bismuth catalyst.

[0012] Further, the sphericity of the spherical copper bismuth catalyst is preferably 0.92~1.0, more preferably 0.95~1.0.

[0013] Further, the spherical copper bismuth catalyst powder flowability requires that the angle of repose is preferably 20~34 degrees, more preferably 20~30 degrees.

[0014] Further, the tap density of the spherical copper bismuth catalyst is preferably 1.65 g / cm 3 ~1.95 g / cm 3 , more preferably 1.70 g / cm 3 ~1.90 g / cm 3 .

[0015] Further, the particle size distribution of the spherical copper bismuth catalyst is that the catalyst with a particle diameter of 10~30 μm accounts for 95%~100% of the total catalyst in terms of mass fraction, more preferably the catalyst with a particle diameter of 10~30 μm accounts for 97%~100% of the total catalyst.

[0016] The second aspect of the present application provides a preparation method of the above-mentioned spherical copper bismuth catalyst, comprising the following steps:

[0017] (1) preparing a copper salt solution, adjusting the pH value, dissolving a bismuth salt in the copper salt solution, denoted as A solution; preparing an alkali metal salt solution, denoted as B solution;

[0018] (2) heating part of the B solution in a reaction kettle, adding the A solution to the B solution under stirring, stopping adding the A solution and continuing stirring when the pH value of the mixed solution is 6.5~7.5, aging to obtain a growth substrate material C, washing, filtering and drying;

[0019] (3) Put the treated growth substrate material C obtained in step (2) into a reactor, add water, stir and heat, and add the remaining A solution and the remaining B solution into the reactor in parallel flow, control the pH value of the system to be 6.8-7.2, and when the particle size of the precipitate reaches 18-25 μm, stop the reaction, and age under stirring to obtain a precipitate; 50

[0020] (4) Wash, filter and dry the precipitate to obtain a spherical copper-bismuth catalyst.

[0021] Further, in step (1), the copper salt is selected from one or more of copper nitrate, copper sulfate or copper chloride, preferably at least one of copper nitrate and copper sulfate, and more preferably copper nitrate. The bismuth salt is selected from one or more of bismuth nitrate, bismuth sulfate or bismuth chloride, preferably at least one of bismuth nitrate and bismuth sulfate, and more preferably bismuth nitrate.

[0022] Further, in step (1), the molar concentration of the copper salt solution is 0.01-5 mol / L, preferably 0.1-4 mol / L, and more preferably 0.3-3.5 mol / L. The molar concentration of the bismuth salt in the A solution is 0.03%-3% of the molar concentration of the copper salt, preferably 0.1%-2%, and more preferably 0.5%-1.8%.

[0023] Further, in step (1), the pH value of the copper salt solution is adjusted to 0.01-1.2, preferably 0.05-0.50. The pH value can be adjusted by using at least one of nitric acid solution, hydrochloric acid solution, sulfuric acid solution, acetic acid solution, etc., and preferably nitric acid solution.

[0024] Further, in step (1), the alkali metal salt is selected from one or more of potassium carbonate, potassium bicarbonate, sodium carbonate and sodium bicarbonate.

[0025] Further, in step (1), the molar concentration of the B solution is 0.01-5 mol / L, preferably 0.1-3.5 mol / L, and more preferably 0.3-3 mol / L.

[0026] Further, in step (2), the reactor can be a conventional reactor in the art, such as a reactor with or without baffles, and preferably a reactor without baffles.

[0027] Further, in step (2), the temperature of the reactor is controlled to be 30-60°C, preferably 35-50°C, and more preferably 40-45°C.

[0028] Further, in step (2), the A solution is preferably preheated before use, and the temperature thereof is controlled to be 30-60°C.

[0029] ​Further, in step (2), the pH value of the mixture solution is preferably 6.8-7.2, more preferably 6.9-7.1, and the addition of the A solution is stopped.

[0030] Further, in step (2), the addition of the A solution is stopped and the stirring is continued for 1-10 min. The aging is static aging. The aging time is 0.5-8 h, preferably 1-5 h, and more preferably 1.5-3 h.

[0031] Further, in step (2), the feeding speed of the A solution is determined according to the reactor and the volume of the B solution in the reactor, and the reaction time is controlled to be 5-50 min, preferably 10-30 min, and more preferably 13-20 min.

[0032] Further, in step (2), the washing and filtering can be performed by conventional methods in the art. The drying temperature is less than 120°C, and preferably 60-100°C. The drying time is 2-10 h.

[0033] Further, in step (2), the particle size distribution of the growth substrate material C is as follows: the proportion of particles with a diameter of 3-10 μm is 85%-100% by mass, and preferably the proportion of particles with a diameter of 3-10 μm is 90%-100% by mass. The sphericity of the growth substrate material C particles is 0.9-1.00.

[0034] Further, in step (3), the water is deionized water. The mass of the added growth substrate material C is ml, and the mass of the added water is m2. The ratio of ml to m2 is 0.01-0.25, preferably 0.05-0.2, and more preferably 0.08-0.16.

[0035] Further, in step (3), the stirring is performed and the temperature is heated to 30-70°C, and preferably 35-55°C.

[0036] Further, in step (3), the remaining A solution and the remaining B solution are added to the reactor in parallel flow. By adjusting the flow rates of the A solution and the B solution, the pH value of the system is controlled to be preferably 6.9-7.1, and more preferably 6.95-7.05. Further, it is preferred that the growth rate of the particles in the system is monitored by a laser particle size analyzer, and the growth rate of the particle diameter is controlled to be not more than 0.5 μm / h, and preferably not more than 0.3 μm / h.

[0037] Further, in step (3), it is preferred that the reaction is stopped when the particle diameter D 50 is 18-23 μm, and more preferably 19-21 μm.

[0038] Further, in step (3), the temperature of the aging is 30-80°C, preferably 45-65°C; the aging time is 90-360 min, preferably 120-300 min.

[0039] Further, in step (4), the washing and filtering can be performed by conventional methods in the art. The drying temperature is less than 120°C, preferably 60-100°C, and the drying time is 2-10 h.

[0040] The third aspect of the present application provides a use of the spherical copper-bismuth catalyst in the preparation of 1,4-butynediol by the acetylation of formaldehyde.

[0041] Further, in the use, the reaction raw material is a mixed gas of formaldehyde aqueous solution and acetylene, wherein the mass fraction of the formaldehyde aqueous solution is 30%-45%, and the mixed gas of acetylene is a mixed gas of acetylene and nitrogen, and the volume content of acetylene in the mixed gas is 20%-80%.

[0042] Further, in the use, the mass of the catalyst used is 5%-20% of the mass of the formaldehyde aqueous solution.

[0043] Further, the use is performed in a slurry bed reactor.

[0044] Further, the reaction temperature is 85-95°C, and the reaction time is 5-15 h.

[0045] Further, the catalyst is activated before the reaction, the activation temperature is 60-75°C, and the activation time is 1-8 h.

[0046] Compared with the prior art, the present application has the following advantages:

[0047] 1. The copper-bismuth catalyst of the present application has high sphericity and good flowability, so that the catalyst has strong wear resistance and is not easy to break into small particles in the slurry bed reaction process, and the service life of the catalyst can be significantly prolonged.

[0048] 2. The catalyst provided by the present application is prepared by a two-step growth method, which is simple, reproducible and suitable for large-scale production.

[0049] 3. The catalyst of the present application has good activity and selectivity in the reaction of preparing 1,4-butynediol by the acetylation of formaldehyde. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 SEM image of the spherical copper-bismuth catalyst product D01 in Example 1;

[0051] Figure 2 SEM image of the copper-bismuth catalyst product E01 in Comparative Example 1. DETAILED DESCRIPTION

[0052] The application is further described below by examples, but the application is not limited by the examples.

[0053] In the application, the SEM instrument used is ZEISS Gemini SEM 300 of Germany.

[0054] In the application, the particle size of the spherical copper bismuth catalyst particles is analyzed by a laser particle size analyzer of Dandong Bettersize.

[0055] In the application, the method for measuring the sphericity refers to the industry standard “Method for Determining Sphericity of Nickel-based High-temperature Alloy Powder by Scanning Electron Microscope”.

[0056] In the application, the angle of repose is measured according to the method for determining the angle of repose in GB / 16913-2008 Dust Physical Property Test Method 4.5 on a JL-A3 powder property tester.

[0057] In the application, the tap density is measured according to GB / T5162-2006 / ISO3953:1993 on a JZ-10B double-cylinder tap density tester.

[0058] In the application, the specific surface area and pore volume are obtained by low-temperature N2 physical adsorption and desorption testing on an ASAP 2420 automatic gas adsorption instrument produced by Micromeritics.

[0059] In the application, the method for testing the wear resistance of the prepared catalyst particles is as follows: the sample is subjected to 25000 times of ultrasonic oscillation, and the particle size distribution before and after ultrasonic crushing is measured to determine the wear resistance.

[0060] Example 1

[0061] (1) Copper nitrate trihydrate is used as the copper source, and a 1.0 mol / L copper nitrate aqueous solution is prepared by using deionized water, and the pH value of the solution is adjusted to 0.1 by using nitric acid, a certain amount of bismuth nitrate pentahydrate is dissolved in the copper salt solution, and the molar concentration of bismuth salt in the copper bismuth mixed solution is 1.5% of the molar concentration of copper salt, which is marked as A solution; a 1.2 mol / L sodium carbonate solution is prepared as a precipitant, which is marked as B solution;

[0062] (2) Take 2.0 L of B solution in the reaction kettle, heat to 45°C, while preheating A solution to 40°C, under stirring conditions, add A solution to B solution, after 15 min, the pH value of the mixed solution is 6.8, stop adding A solution and continue stirring for 5 min, then stop stirring, stand for 3 h, get the growth substrate material C01, wash, filter and dry at 80°C for 5 h, then cool to room temperature. The particle size distribution is: the proportion of particles with a diameter of 3-10 μm is 89% by mass fraction, and the particle sphericity is 0.85;

[0063] (3) Take 75 g of C01 of step (2) into the reaction kettle, add 800 g of deionized water, stir and heat to 50°C, then add A solution and B solution in a stream, and control the pH value of the mixed solution to be 7.0 and the reaction temperature to be 50°C. During the reaction, the particle size and distribution of the particles in the system are measured by a laser particle size analyzer, the particle size growth rate is controlled to be about 0.5 μm / h, and when the particle size D 50 is 19.5 μm, the reaction is stopped, and the final precipitate is obtained by aging at 60°C for 240 min;

[0064] (4) The precipitate is washed, filtered and dried at 80°C for 5 h to obtain spherical copper bismuth catalyst product D01. The content of copper oxide is 95.002 wt%, the content of bismuth oxide is 4.768 wt%, and the balance is impurities, based on the weight of the catalyst. The scanning electron microscope results show that D01 is a regular spherical structure, as shown in the accompanying Figure 1 .

[0065] Example 2

[0066] (1) Take 75 g of C01 of step (2) into the reaction kettle, add 800 g of deionized water, stir and heat to 50°C, then add A solution and B solution in a stream, and control the pH value of the mixed solution to be 7.0 and the reaction temperature to be 50°C. During the reaction, the particle size and distribution of the particles in the system are measured by a laser particle size analyzer, the particle size growth rate is controlled to be about 0.5 μm / h, and when the particle size D

[0067] (2) Take 2.5 L of B solution in the reaction kettle, heat to 40°C, while preheating A solution to 38°C, under stirring conditions, add A solution to B solution, after 13.5 min, the pH value of the mixed solution is 6.95, stop adding A solution and continue stirring for 5 min, then stop stirring, stand for 3 h, get the growth substrate material C02, wash, filter and dry at 80°C for 5 h, then cool to room temperature. The particle size distribution is: the proportion of particles with a diameter of 3-10 μm is 87% by mass fraction, and the particle sphericity is 0.88;

[0068] (3) Take 100 g of C02 of step (3) into a reactor, add 800 g of deionized water, stir and heat to 46°C, then add A solution and B solution in a flow reaction, and control the pH value of the mixed liquid to be 7.0 and the reaction temperature to be 46°C. During the reaction, the particle size and distribution of the particles in the system are measured by a laser particle size analyzer, the particle size growth rate is controlled to be about 0.3 μm / h, and when D 50 is 19.5 μm, the reaction is stopped, and the final precipitate is obtained by aging at 55°C for 240 min;

[0069] (4) The precipitate is washed, filtered, and dried at 80°C for 5 h to obtain spherical copper bismuth catalyst product D02. The content of copper oxide is 94.712 wt%, the content of bismuth oxide is 5.138 wt%, and the balance is impurities, based on the weight of the catalyst.

[0070] Example 3

[0071] (1) Copper sulfate is used as a copper source to prepare a 1.0 mol / L copper sulfate aqueous solution. Sulfuric acid is used to adjust the pH value of the solution to 0.5. A certain amount of bismuth sulfate is dissolved in the copper salt solution, and the bismuth salt molar concentration in the copper bismuth mixed solution is 1.6% of the copper salt molar concentration, which is marked as A solution. A 1.5 mol / L sodium bicarbonate solution is prepared as a precipitant, which is marked as B solution;

[0072] (2) Take 2.5 L of B solution into a reactor and heat to 45°C. Meanwhile, preheat A solution to 40°C. Under stirring, add A solution to B solution. After 18 min, the pH value of the mixed liquid is 6.95. Stop adding A solution and continue stirring for 5 min, then stop stirring. After 3 h of aging, the growing substrate material C03 is obtained. The growing substrate material C03 is washed, filtered, and dried at 90°C for 5 h, then cooled to room temperature. The particle size distribution is as follows: the proportion of particles with a diameter of 3-10 μm is 90% by mass fraction, and the particle sphericity is 0.82.

[0073] (3) Take 100 g of C03 of step (2) into a reactor, add 800 g of deionized water, stir and heat to 55°C, then add A solution and B solution in a flow reaction, and control the pH value of the mixed liquid to be 7.0 and the reaction temperature to be 55°C. During the reaction, the particle size and distribution of the particles in the system are measured by a laser particle size analyzer, the particle size growth rate is controlled to be about 0.2 μm / h, and when D 50 is 20 μm, the reaction is stopped, and the final precipitate is obtained by aging at 65°C for 180 min;

[0074] (4) The precipitate is washed, filtered, and dried at 90°C for 5h to obtain spherical copper bismuth catalyst product D03. The content of copper oxide is 94.495wt%, the content of bismuth oxide is 4.848wt%, and the balance is impurities, based on the weight of the catalyst.

[0075] Example 4

[0076] (1) Copper sulfate is used as the copper source, and a 0.8mol / L copper sulfate aqueous solution is prepared using deionized water. The pH value of the solution is adjusted to 0.1 using sulfuric acid. A certain amount of bismuth sulfate is dissolved in the copper salt solution, and the molar concentration of bismuth salt in the copper bismuth mixed solution is 1.5% of the molar concentration of copper salt, which is marked as A solution. A 1.5mol / L sodium bicarbonate solution is prepared as a precipitant, which is marked as B solution;

[0077] (2) 2.0L of B solution is taken in a reaction kettle and heated to 45°C. A is preheated to 40°C, and A solution is added to B solution under stirring. After 15min, the pH value of the mixed solution is 6.95, and the addition of A solution is stopped. After 5min of continuous stirring, the stirring is stopped, and the precipitate C04 is obtained after aging for 3h. The precipitate C04 is washed, filtered, and dried at 80°C for 5h, and then cooled to room temperature. The particle size distribution is as follows: the proportion of particles with a diameter of 3-10μm is 89% by mass fraction, and the particle sphericity is 0.90;

[0078] (3) 100g of C04 from step (2) is weighed and placed in a reaction kettle. 800g of deionized water is added, and the mixture is stirred and heated to 50°C. A solution and B solution are added in a flow, and the pH value of the mixed solution is controlled at 7.05, and the reaction temperature is controlled at 50°C. During the reaction, the particle size and distribution of the particles in the system are measured using a laser particle size analyzer, and the particle size growth rate is controlled at about 0.5μm / h. When the particle size D 50 is 19.5μm, the reaction is stopped, and the final precipitate is obtained after aging at 55°C for 240min.

[0079] (4) The precipitate is washed, filtered, and dried at 80°C for 5h to obtain spherical copper bismuth catalyst product D04. The content of copper oxide is 95.204wt%, the content of bismuth oxide is 4.679wt%, and the balance is impurities, based on the weight of the catalyst.

[0080] Example 5

[0081] (1) with copper chloride as copper source, 1.5 mol / L copper chloride aqueous solution was prepared by using deionized water, and the solution pH value was adjusted to 0.1 by using hydrochloric acid, a certain amount of bismuth chloride was dissolved in the copper salt solution, and the molar concentration of bismuth salt in the copper-bismuth mixed solution was 1.6% of the molar concentration of copper salt, which was marked as A solution; 2.5 mol / L sodium bicarbonate solution was prepared as a precipitant, which was marked as B solution;

[0082] (2) 2.5 L of B solution was taken in a reaction kettle and heated to 45℃, while A was preheated to 40℃, A solution was added to B solution under stirring, 20 min later the pH value of the mixed solution was 7.0, the addition of A solution was stopped and stirring was continued for 5 min, then the stirring was stopped, and the material C05 was obtained by aging for 3 h, and then the material C05 was washed, filtered, and dried at 80℃ for 5 h, and then cooled to room temperature. The particle size distribution was as follows: the proportion of particles with a diameter of 5-10 μm was 91% by mass fraction, and the particle sphericity was 0.92;

[0083] (3) 100 g of C05 of step (2) was weighed and placed in a reaction kettle, 800 g of deionized water was added, and after stirring and heating to 45℃, A solution and B solution were added in parallel, and the pH value of the mixed solution was controlled at 7.0 and the reaction temperature was 45℃. During the reaction, the particle size and distribution of the particles in the system were measured by using a laser particle size analyzer, and the particle size growth rate was controlled at about 0.3 μm / h, and when the particle size D 50 was 22 μm, the reaction was stopped, and the final precipitate was obtained by aging at 60℃ for 240 min;

[0084] (4) The precipitate was washed, filtered, and dried at 80℃ for 5 h to obtain spherical copper-bismuth catalyst product D05, the content of copper oxide was 95.048 wt%, the content of bismuth oxide was 5.042 wt%, and the balance was impurities.

[0085] Comparative Example 1

[0086] (1) with copper chloride as copper source, 1.5 mol / L copper chloride aqueous solution was prepared by using deionized water, and the solution pH value was adjusted to 0.1 by using hydrochloric acid, a certain amount of bismuth chloride was dissolved in the copper salt solution, and the molar concentration of bismuth salt in the copper-bismuth mixed solution was 1.6% of the molar concentration of copper salt, which was marked as A solution; 2.5 mol / L sodium bicarbonate solution was prepared as a precipitant, which was marked as B solution, and A and B solutions were kept at 50℃.

[0087] (2) In a reaction kettle, 600 g of deionized water was added, stirred and heated to 50°C, then A solution and B solution were added in parallel flow to react, and the pH value of the mixed liquid was controlled at 7.0 and the reaction temperature was 50°C. During the reaction, the particle size and distribution of the particles in the system were measured by a laser particle size analyzer, and the reaction was stopped when D 50 was 19.5 μm, and the final precipitate was obtained by aging at 60°C for 240 min.

[0088] (3) The precipitate was washed, filtered, and dried at 80°C for 5 hours to obtain copper bismuth catalyst product E01, and the scanning electron microscope results showed that it was an irregular polytwin-like spherical structure, as shown in the accompanying Figure 2 .

[0089] Comparative Example 2

[0090] Steps (1), (2) and (4) were the same as in Example 1, step (3) was operated according to the following method, and finally copper bismuth catalyst product E02 was obtained.

[0091] Step (3): 75 g of C01 of step (2) was weighed into a reaction kettle, 800 g of deionized water was added, stirred and heated to 50°C, then A solution and B solution were added in parallel flow to react, and the pH value of the mixed liquid was controlled at 7.0 and the reaction temperature was 50°C. During the reaction, the particle size and distribution of the particles in the system were measured by a laser particle size analyzer, and the particle size growth rate was controlled at about 2 μm / h, and the reaction was stopped when D 50 was 19.5 μm, and the final copper bismuth catalyst product E02 was obtained by aging at 60°C for 240 min.

[0092] Table 1: Properties of catalyst particles obtained in each example

[0093]

[0094] Test Example

[0095] Each 100 g of catalyst sample obtained in Examples 1-5 and Comparative Examples 1-2 was mixed with 1000 g of formaldehyde aqueous solution, the mass percentage of formaldehyde solution was 35%, and a mixture gas of acetylene with a volume fraction of 40% and nitrogen was introduced, the temperature was raised to 75°C and maintained for 6 h, the catalyst was activated, the temperature was raised to 90°C, a mixture gas of acetylene with a volume fraction of 60% and nitrogen was introduced, and the reaction was carried out for 10 h. The sample was analyzed, and the evaluation results of each example are shown in Table 2.

[0096] Table 2: Evaluation results of catalyst obtained in each example

[0097] Catalyst number Formaldehyde conversion, % 1,4-Butynediol selectivity, % D01 97.5 97.6 D02 97.9 97.1 D03 97.6 97.3 D04 98.1 97.5 D05 96.5 97.0 E01 96.4 95.2 E02 95.3 96.5

[0098] The above describes specific embodiments of the present application in detail, but the present application is not limited thereto. Within the technical concept of the present application, the technical features of the present application can be combined in any other suitable manner, and these simple modifications and combinations should also be considered as the disclosed range of the present application, and all fall within the protection scope of the present application.

Claims

1. A spherical copper-bismuth catalyst, characterized in that, The catalyst has a sphericity of not less than 0.90, the catalyst powder has a repose angle of less than 35 degrees, and a tap density of 1.45 g / cm³. 3 ~2.05g / cm 3 The particle size distribution of the catalyst is as follows: by mass fraction, catalyst particles with a diameter of 10 to 30 μm account for 90% to 100% of the total catalyst.

2. The spherical copper-bismuth catalyst according to claim 1, characterized in that, The specific surface area of ​​the spherical copper-bismuth catalyst is 0.5–40 m². 2 / g, preferably 1-20m 2 / g, more preferably 3-15m 2 / g, pore volume is 0.01cm 3 / g~0.50cm 3 / g, preferably 0.015cm 3 / g~0.20cm 3 / g, more preferably 0.02cm 3 / g~0.10cm 3 / g.

3. The spherical copper-bismuth catalyst according to claim 1, characterized in that, The spherical copper-bismuth catalyst, by weight, contains 90 wt% to 99.9 wt% copper oxide and 0.1 wt% to 10 wt% bismuth oxide, preferably 92.5 wt% to 97.5 wt% copper oxide and 2.5 wt% to 7.5 wt% bismuth oxide, more preferably 94.5 wt% to 96.5 wt% copper oxide and 3.5 wt% to 5.5 wt% bismuth oxide.

4. The spherical copper-bismuth catalyst according to claim 1, characterized in that, The sphericity of the spherical copper-bismuth catalyst is 0.92–1.0, more preferably 0.95–1.0; and / or, The spherical copper-bismuth catalyst powder is required to have a repose angle of 20–34 degrees, more preferably 20–30 degrees; and / or, The tap density of the spherical copper-bismuth catalyst is 1.65 g / cm³. 3 ~1.95g / cm 3 More preferably 1.70 g / cm³ 3 ~1.90g / cm 3 .

5. The spherical copper-bismuth catalyst according to claim 1, characterized in that, The particle size distribution of the spherical copper-bismuth catalyst is as follows: by mass fraction, catalyst particles with a diameter of 10–30 μm account for 95%–100% of the total catalyst; more preferably, catalyst particles with a diameter of 10–30 μm account for 97%–100% of the total catalyst.

6. A method for preparing a spherical copper-bismuth catalyst according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Prepare a copper salt solution, adjust the pH value, dissolve the bismuth salt in the copper salt solution, and denote it as solution A; Prepare an alkali metal salt solution, denoted as solution B; (2) Place part of solution B in a reaction vessel and heat it. While stirring, add solution A to solution B. When the pH of the mixture is 6.5 to 7.5, stop adding solution A and continue stirring. Aging is carried out to obtain growth substrate material C. Wash, filter and dry. (3) Place the treated growth substrate material C obtained in step (2) into a reaction vessel, add water, stir and heat, and add the remaining A solution and the remaining B solution to the reaction vessel in a parallel flow. Control the pH of the system to 6.8-7.2, and wait for D to form. 50 The reaction was stopped when the particle size was 18–25 μm, and the mixture was aged with stirring to obtain a precipitate. (4) The precipitate was washed, filtered and dried to obtain spherical copper bismuth catalyst.

7. The method according to claim 6, characterized in that, In step (1), the copper salt is selected from one or more of copper nitrate, copper sulfate, or copper chloride, preferably at least one of copper nitrate and copper sulfate, and more preferably copper nitrate; the bismuth salt is selected from one or more of bismuth nitrate, bismuth sulfate, or bismuth chloride, preferably at least one of bismuth nitrate and bismuth sulfate, and more preferably bismuth nitrate; and / or, The alkali metal salt is selected from one or more of potassium carbonate, potassium bicarbonate, sodium carbonate, and sodium bicarbonate.

8. The method according to claim 6 or 7, characterized in that, In step (1), the molar concentration of the copper salt solution is 0.01–5 mol / L, preferably 0.1–4 mol / L, more preferably 0.3–3.5 mol / L; the molar concentration of bismuth salt in solution A is 0.03%–3% of the molar concentration of copper salt, preferably 0.1%–2%, more preferably 0.5%–1.8%; and / or, The molar concentration of solution B is 0.01–5 mol / L, preferably 0.1–3.5 mol / L, and more preferably 0.3–3 mol / L.

9. The method according to claim 6, characterized in that, In step (1), the pH value of the copper salt solution is adjusted to 0.01 to 1.2, preferably 0.05 to 0.

50.

10. The method according to claim 6, characterized in that, In step (2), the temperature of the reactor is controlled at 30-60°C, preferably 35-50°C, and more preferably 40-45°C.

11. The method according to claim 6, characterized in that, In step (2), when the pH value of the mixed solution is 6.8 to 7.2, more preferably 6.9 to 7.1, the addition of solution A is stopped.

12. The method according to claim 6, characterized in that, In step (2), stop adding solution A and continue stirring for 1 to 10 minutes; the aging is static aging, and the aging time is 0.5 to 8 hours, preferably 1 to 5 hours, and more preferably 1.5 to 3 hours.

13. The method according to claim 6, characterized in that, In step (2), the reaction time is controlled to be 5 to 50 min, preferably 10 to 30 min, and more preferably 13 to 20 min.

14. The method according to claim 6, characterized in that, In step (2), the particle size distribution of the growth substrate material C is as follows: by mass fraction, the proportion of particles with a diameter of 3 to 10 μm is 85% to 100%, preferably 90% to 100%; the sphericity of the particles of the growth substrate material C is 0.9 to 1.

00.

15. The method according to claim 6, characterized in that, The mass of the added growth substrate material C is m1, and the mass of the added water is m2. The ratio of m1 to m2 is 0.01 to 0.25, preferably 0.05 to 0.20, and more preferably 0.08 to 0.

16.

16. The method according to claim 6, characterized in that, In step (3), the mixture is stirred and heated to 30-70°C, preferably 35-55°C.

17. The method according to claim 6, characterized in that, In step (3), the remaining solution A and the remaining solution B are added to the reactor in parallel flow. By adjusting the flow rates of solution A and solution B, the pH value of the system is preferably controlled to be 6.9 to 7.1, more preferably 6.95 to 7.

05. Preferably, the particle growth rate in the system is monitored by a laser particle size analyzer, and the particle diameter growth rate is controlled to be no more than 0.5 μm / h, and preferably no more than 0.3 μm / h.

18. The method according to claim 6 or 17, characterized in that, In step (3), D is to be 50 The reaction is stopped when the particle size is 18–23 μm, more preferably 19–21 μm.

19. The method according to claim 6, characterized in that, In step (3), the aging temperature is 30-80℃, preferably 45-65℃; the aging time is 90-360min, preferably 120-300min.

20. The method according to claim 6, characterized in that, In step (4), the drying temperature is below 120°C, preferably 60-100°C, and the drying time is 2-10 hours.

21. The use of a spherical copper-bismuth catalyst according to any one of claims 1-5 or a spherical copper-bismuth catalyst prepared according to any one of claims 6-20 in the acetylenelation of formaldehyde to prepare 1,4-butynediol.

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