High-activity catalyst for producing alcohol through bond breaking of tetrahydrofuran as well as preparation method and application of high-activity catalyst

Abstract

The invention provides a high-activity catalyst for producing alcohol through bond breaking of tetrahydrofuran as well as a preparation method and application of the high-activity catalyst, and relates to the field of catalysts for tetrahydrofuran. The preparation method of the high-activity catalyst for generating alcohol through bond breaking of tetrahydrofuran comprises the following steps: preparing a precursor solution, and carrying out composite molding; the application of the high-activity catalyst for producing alcohol through bond breaking of tetrahydrofuran comprises the following steps: catalyst activation, tetrahydrofuran vaporization, continuous hydrogenation reaction and refining. According to the high-activity catalyst for producing alcohol through tetrahydrofuran bond breaking as well as the preparation method and application thereof, the reaction activity can be improved, the required reaction temperature and reaction pressure are reduced, the reaction efficiency is improved, the reaction conversion rate and selectivity are improved, and the product yield is improved; the stability of the catalyst in the tetrahydrofuran hydrogenation process is effectively improved, the catalytic activity can be kept in the long-time reaction process, and the inactivation and replacement frequency of the catalyst is reduced.

Description

Technical Field

[0001] The present invention relates to the field of catalysts for tetrahydrofuran, in particular to a high-activity catalyst for tetrahydrofuran bond cleavage to generate alcohol, a preparation method and application thereof. Background Art

[0002] Tetrahydrofuran (THF) is a colorless, water-miscible organic liquid with a characteristic ethereal odor. It is an important organic solvent and chemical raw material, widely used in the synthesis of polymer materials, pharmaceutical intermediates, coatings, and adhesives. However, the World Health Organization's International Agency for Research on Cancer (IARC) has classified THF as a Class 2B carcinogen, meaning it may be carcinogenic to humans. While the evidence for its carcinogenicity is insufficient, it warrants significant attention. People with long-term contact or exposure to THF should undergo regular health checks to identify and address potential health issues.

[0003] However, the industrial-scale synthesis of existing chemicals (such as 1,4-butanediol) produces a significant amount of tetrahydrofuran as a byproduct. However, separating and purifying this byproduct from 1,4-butanediol is difficult, cumbersome, and uneconomical. Research has shown that hydrogenation of tetrahydrofuran, targeting its properties and subsequently converting it to the corresponding alcohol, can overcome the challenges associated with its separation and purification.

[0004] However, the use of existing hydrogenation catalysts in the process of tetrahydrofuran bond cleavage to produce alcohols has limitations in actual industrial-scale application, specifically manifested in the following deficiencies: (1) low reaction activity and low reaction efficiency; (2) low reaction conversion rate and low yield; (3) low catalyst selectivity, many side reactions, and poor product purity; (4) high reaction temperature and high reaction energy consumption; (5) long reaction time; and (6) weak catalyst stability and easy oxidation.

[0005] At the same time, in order to improve the reaction effect of tetrahydrofuran breaking bonds to produce alcohol, existing hydrogenation catalysts need to be carried out under high temperature and high pressure conditions. The oxygen atoms in the catalyst will react with the active sites on the catalyst surface, thereby generating carbon deposits that block the catalyst pores, reducing the contact between tetrahydrofuran and the catalyst active sites. The catalytic effect of the catalyst is severely degraded, and it is impossible to maintain ideal long-term catalytic performance. Summary of the Invention

[0006] In order to solve the technical problems existing in the prior art, the present invention provides a high-activity catalyst for the bond cleavage of tetrahydrofuran to generate alcohol, a preparation method and an application thereof. The catalyst can improve the reaction activity, reduce the required reaction temperature and reaction pressure, improve the reaction efficiency, improve the reaction conversion rate and selectivity, and improve the product yield based on the reaction characteristics of tetrahydrofuran. At the same time, the catalyst can effectively improve the stability of the catalyst in the tetrahydrofuran hydrogenation process, maintain the catalytic activity during a long reaction process, and reduce the deactivation and replacement frequency of the catalyst.

[0007] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows: A method for preparing a high-activity catalyst for tetrahydrofuran bond cleavage to generate alcohol comprises the following steps: preparing a precursor solution, and composite molding; The precursor solution is prepared by adding magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, and palladium nitrate dihydrate into deionized water and dispersing them uniformly, then adding MOF-303(Al) and hexadecyltrimethylammonium bromide and dispersing them uniformly to obtain a premixed solution; heating the premixed solution to 60-65° C., keeping the temperature and stirring, and then dripping the urea solution into the premixed solution; after the urea solution is added dropwise, stirring is continued to obtain a precursor solution; The composite molding comprises placing the precursor solution in a sealed environment, subjecting the precursor solution to a hydrothermal reaction at 110-120° C., separating and obtaining a solid, and washing and drying the solid to obtain a high-activity catalyst for tetrahydrofuran bond cleavage to generate alcohol.

[0008] Preferably, in the preparation of the precursor solution, the stirring speed when the urea solution is added dropwise is 400-450 rpm, and the dropping rate of the urea solution is 0.1-0.2 mL / min; The mass concentration of urea solution is 15-18wt%; The stirring time after the urea solution is added dropwise is 2-3 hours.

[0009] Preferably, in the preparation of the precursor solution, the weight ratio of magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, palladium nitrate dihydrate, deionized water, MOF-303 (Al), and hexadecyltrimethylammonium bromide is 25.5-26.5:12.7-13.3:1.02-1.07:0.17-0.19:100-105:3.1-3.3:1.5-1.6; The molar amount of urea in the dropwise added urea solution is 3.2-3.5 times the total molar amount of magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate and palladium nitrate dihydrate.

[0010] Preferably, during the composite molding, the rate of heating to 110-120°C is 2-3°C / min; The hydrothermal reaction time at 110-120°C is 14-18h.

[0011] A high-activity catalyst for tetrahydrofuran bond cleavage to generate alcohol, prepared by the above method.

[0012] An application of the aforementioned high-activity catalyst for the cleavage of tetrahydrofuran to generate alcohols comprises the following steps: catalyst activation, tetrahydrofuran vaporization, continuous hydrogenation reaction, and refining; The tetrahydrofuran is vaporized, and the tetrahydrofuran raw material with a purity greater than 99.0 wt% is continuously vaporized to obtain vaporized material; In the continuous hydrogenation reaction, after the first hydrogen stream is mixed with the vaporized material, it is continuously fed from the top of the hydrogenation device filled with the activated catalyst; at the same time, a second hydrogen stream is continuously added from the bottom of the hydrogenation device; the hydrogenation reaction temperature is controlled at 170-180°C and the reaction pressure is 3-5MPa, and a crude butanol product is obtained through hydrogenation reaction; The crude butanol product is refined to obtain a butanol product.

[0013] Preferably, in the continuous hydrogenation reaction, the residence time of the material in the hydrogenation device is 0.5-1h; The mass space velocity of the catalyst is 779-1580h -1 .

[0014] Preferably, in the continuous hydrogenation reaction, the total flow rate of the first hydrogen flow and the second hydrogen flow is 1500-2000 Nm³ / h, and the volume ratio of the first hydrogen flow to the second hydrogen flow is 8.5-9:1; The molar ratio of hydrogen entering the hydrogenation unit to tetrahydrofuran in the vaporized material per unit time is 200-220:1.

[0015] Furthermore, in the refining, the crude butanol product is continuously fed into a light-removing tower, the absolute pressure of the light-removing tower is controlled to be 4-5 KPa, the top temperature is 130-135° C., and the bottom temperature is 160-165° C., and after removing the light components, a light-removing product is obtained; and the light-removing product is continuously fed into a heavy-removing tower, the absolute pressure of the heavy-removing tower is controlled to be 1-2 KPa, the top temperature is 150-153° C., and the bottom temperature is 168-170° C., and after removing the heavy components, a butanol product is obtained.

[0016] Furthermore, the catalyst activation is performed by heat treating the high-activity catalyst for tetrahydrofuran bond cleavage to generate alcohol at 270-280° C. in an air atmosphere, cooling the temperature, and then activating the catalyst at 200-220° C. in a hydrogen atmosphere to obtain an activated catalyst.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) In the preparation of the catalyst of the present application, in view of the characteristics of the hydrogenation reaction of tetrahydrofuran, a specific magnesium salt, an aluminum salt, a copper salt, a palladium salt, MOF-303(Al) and a template agent are used in combination through a co-precipitation method to form a composite layered structure with high crystallinity, thereby preparing a hydrotalcite composite catalyst with a multi-level microporous structure; the catalyst has high active site density, high active potential contact area and high efficient transmission path, and in view of the characteristics of the hydrogenation reaction of tetrahydrofuran, the non-noble metal active component, the noble metal active component and the MOF active component are used in combination to synergistically catalyze the continuous vaporization hydrogenation process of tetrahydrofuran, thereby reducing the problem of reducing the catalytic activity due to the accumulation of carbon during the reaction, inhibiting the generation of by-products, improving the catalytic activity of the catalyst, reducing the reaction temperature and reaction pressure required for the hydrogenation of tetrahydrofuran, improving the reaction efficiency, improving the reaction conversion rate and selectivity, improving the product yield, effectively improving the stability of the catalyst in the hydrogenation process of tetrahydrofuran, maintaining the catalytic activity during a long reaction process, and reducing the frequency of catalyst deactivation and replacement.

[0018] (2) In the process of using the catalyst of the present application for the generation of alcohol by breaking the bond of tetrahydrofuran, the required hydrogenation reaction temperature is 170-180 DEG C, the optimal hydrogenation reaction pressure is 3-3.5 MPa, the material contact reaction time (i.e. residence time) is 0.5-1 h; at the same time, under the conditions of a total hydrogen flow of 1500-2000 Nm³ / h, a hydrogen to tetrahydrofuran molar ratio of 200-220:1, and a catalyst mass space velocity of 779-1580 h -1 , good long-term continuous catalytic performance can be achieved; the conversion rate of tetrahydrofuran can reach 98.7-99.5%, the content of the final product butanol is 99.2-99.7 wt%, and the yield is 97.5-99.0%.

[0019] (3) In the process of using the catalyst of the present application for the generation of alcohol by breaking the bond of tetrahydrofuran, the catalytic conditions are mild and the reaction efficiency is high, the required hydrogenation reaction temperature is 170-180 DEG C, which is significantly lower than the 220-250 DEG C required by existing hydrogenation catalysts, thereby greatly reducing the production energy consumption and production cost.

[0020] (4) In the process of using the catalyst of the present application for the generation of alcohol by breaking the bond of tetrahydrofuran, the mass of butanol produced per ton of catalyst is 1687-1894 tons, and the catalyst can maintain good catalytic performance in long-term continuous catalysis, the catalyst replacement time is more than 12 months, and the quality of the product prepared in long-term continuous production is stable.

[0021] (5) The high-activity catalyst for the breaking of tetrahydrofuran bonds to generate alcohol, the preparation method and the application thereof have the advantages that the process is simple, the production process is easy to control, the long-term continuous production stability is good, the scale production is facilitated, the existing by-product tetrahydrofuran in the production of products (such as 1,4-butanediol) can be converted into the corresponding alcohol, and a series of problems caused by the separation and purification of the by-product tetrahydrofuran in industrial production can be effectively overcome. DETAILED DESCRIPTION

[0022] In order to have a clearer understanding of the technical features, objectives and effects of the present application, the specific embodiments of the present application will be described in detail. It should be pointed out that the following detailed description is exemplary and is intended to provide further description of the present application. Unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0023] It should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, "first", "second", and the like are used to distinguish similar objects, and are not intended to describe a particular order or sequence, and it should also be understood that when the terms "comprise" and / or "include" are used in the present description, the presence of a feature, step, operation, device, component and / or combination thereof is indicated.

[0024] The present application provides a preparation method of a high-activity catalyst for the breaking of tetrahydrofuran bonds to generate alcohol, comprising the following steps: preparing a precursor solution, and composite molding.

[0025] In the preparation of the precursor solution, magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, and palladium nitrate dihydrate are added to deionized water, stirred for 10-20 min, then MOF-303(Al) and cetyltrimethylammonium bromide CTAB are added, ultrasonic dispersion is performed for 20-30 min, a premix solution is obtained; the premix solution is stirred and heated to 60-65 DEG C, and then heated; under the condition of 400-450 rpm stirring, a urea solution with a mass concentration of 15-18 wt% is added dropwise to the premix solution at a dropwise rate of 0.1-0.2 mL / min; after the dropwise addition of the urea solution is completed, the stirring is continued for 2-3 h, and the precursor solution is obtained.

[0026] In the preparation of the precursor solution, the weight ratio of magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, palladium nitrate dihydrate, deionized water, MOF-303(Al), and cetyltrimethylammonium bromide CTAB is 25.5-26.5:12.7-13.3:1.02-1.07:0.17-0.19:100-105:3.1-3.3:1.5-1.6.

[0027] In the preparation of the precursor solution, urea solution is added dropwise to the premixed solution, and the molar amount of urea in the added urea solution is controlled to be 3.2-3.5 times the total molar amount of magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, and palladium nitrate dihydrate.

[0028] The composite molding comprises placing a precursor solution in a high-pressure reactor, sealing the high-pressure reactor, controlling the heating rate to be 2-3°C / min, heating to 110-120°C, maintaining the temperature for a hydrothermal reaction for 14-18 hours, cooling to room temperature, and centrifuging at 9000-10000 rpm to obtain a solid; the solid is washed with dilute hydrochloric acid (concentration 0.01-0.02 mol / L) and deionized water, and then placed in a vacuum drying oven and dried at 80-85°C to a constant weight in a vacuum environment of 0.08-0.09 MPa to obtain a highly active catalyst for tetrahydrofuran bond cleavage to generate alcohol.

[0029] The embodiment of the present invention also provides a high-activity catalyst for tetrahydrofuran bond cleavage to generate alcohol, which is prepared by the above method.

[0030] The embodiment of the present invention also provides the use of the aforementioned high-activity catalyst for cleaving the bonds of tetrahydrofuran to generate alcohol, which comprises the following steps: catalyst activation, tetrahydrofuran vaporization, continuous hydrogenation reaction, and refining.

[0031] The catalyst activation comprises the following steps: placing a high-activity catalyst for tetrahydrofuran bond cleavage to generate alcohol in a calciner, heating the catalyst to 270-280° C. in an air atmosphere, maintaining the temperature for 1-2 hours, and then naturally cooling the temperature to room temperature; completely replacing the air in the calciner with hydrogen, heating the catalyst to 200-220° C. in a hydrogen atmosphere, maintaining the temperature for 2-3 hours, and then introducing nitrogen to protect the catalyst to prevent oxidation caused by contact with air, thereby obtaining an activated catalyst for standby use.

[0032] The tetrahydrofuran is vaporized by pumping a tetrahydrofuran raw material with a purity greater than 99.0 wt % into a vaporizer, controlling the vaporizer temperature at 210-220° C., and continuously vaporizing the tetrahydrofuran to continuously obtain vaporized material (ie, vaporized tetrahydrofuran).

[0033] In the tetrahydrofuran vaporization, the tetrahydrofuran raw material used is a crude purified product of tetrahydrofuran produced as a by-product in the production process of 1,4-butanediol.

[0034] In the continuous hydrogenation reaction, after continuously mixing a first hydrogen flow with the vaporized material, the first hydrogen flow continuously carries the vaporized material from the top of the hydrogenation device filled with the aforementioned activated catalyst into the hydrogenation device; simultaneously, a second hydrogen flow is continuously added from the bottom of the hydrogenation device; the hydrogenation reaction temperature is controlled to be 170-180° C. (preferably 172-178° C.), the reaction pressure is controlled to be 3-5 MPa (preferably 3.3-3.5 MPa), and the residence time of hydrogen and tetrahydrofuran (vaporized material) in the hydrogenation device is 0.5-1 hour; and a crude butanol product after hydrogenation is continuously discharged from the bottom of the hydrogenation reactor.

[0035] In the continuous hydrogenation reaction, the total flow rate of the first hydrogen flow and the second hydrogen flow is 1500-2000 Nm³ / h (preferably 1800-2000 Nm³ / h), and the volume ratio of the first hydrogen flow to the second hydrogen flow is 8.5-9:1.

[0036] In the continuous hydrogenation reaction, the molar ratio of hydrogen entering the hydrogenation device to tetrahydrofuran in the vaporized material per unit time is 200-220:1.

[0037] In the continuous hydrogenation reaction, the catalyst used is loaded in the middle of the fixed bed of the hydrogenation unit, and the mass space velocity of the catalyst is controlled to be 779-1580h -1 (Preferably 1170-1205h -1 ), the remaining filling is white porcelain balls.

[0038] In the refining, the crude butanol product obtained by the continuous hydrogenation reaction is continuously fed into a light-removal tower, the pressure of the light-removal tower is controlled at 4-5 kPa (absolute pressure), the temperature at the top of the tower is 130-135° C., and the temperature at the bottom of the tower is 160-165° C., the light components are removed, and a light-removal product is obtained (the butanol content in the light-removal product is not less than 99 wt %); the light-removal product is continuously fed into a heavy-removal tower, the pressure of the heavy-removal tower is controlled at 1-2 kPa (absolute pressure), the temperature at the top of the tower is 150-153° C., and the temperature at the bottom of the tower is 168-170° C., and the heavy components are removed to obtain a butanol product.

[0039] The present invention will be further described below with reference to some specific embodiments.

[0040] Example 1 This embodiment provides a method for preparing a highly active catalyst for cleaving bonds in tetrahydrofuran to generate alcohols, the specific steps being: 1. Prepare precursor solution Magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, and palladium nitrate dihydrate were added to deionized water and stirred for 10 minutes. Then, MOF-303 (Al) and hexadecyltrimethylammonium bromide (CTAB) were added and ultrasonically dispersed for 20 minutes to obtain a premixed solution. The premixed solution was stirred and heated to 60°C and kept warm. Then, a 15wt% urea solution was added dropwise to the premixed solution at a dropping rate of 0.1mL / min under stirring at 400rpm. After the addition of the urea solution was completed, stirring was continued for 2 hours to obtain a precursor solution.

[0041] The weight ratio of magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, palladium nitrate dihydrate, deionized water, MOF-303 (Al), and hexadecyltrimethylammonium bromide (CTAB) is 25.5:12.7:1.02:0.17:100:3.1:1.5.

[0042] The urea solution was added dropwise to the premixed solution, and the molar amount of urea in the added urea solution was controlled to be 3.2 times the total molar amount of magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, and palladium nitrate dihydrate.

[0043] 2. Composite molding The precursor solution was placed in a high-pressure reactor, which was sealed and heated to 110°C at a rate of 2°C / min. The reactor was kept hydrothermally reacted for 14 hours, then cooled to room temperature and centrifuged at 9000 rpm to obtain a solid. The solid was washed with dilute hydrochloric acid (concentration 0.01 mol / L) and deionized water, placed in a vacuum drying oven, and dried at 80°C to constant weight in a vacuum environment of 0.08 MPa to obtain a highly active catalyst for the cleavage of tetrahydrofuran to generate alcohol.

[0044] This embodiment also provides a high-activity catalyst for tetrahydrofuran bond cleavage to generate alcohol, which is prepared by the aforementioned method.

[0045] Example 2 This embodiment provides a method for preparing a highly active catalyst for cleaving bonds in tetrahydrofuran to generate alcohols, the specific steps being: 1. Prepare precursor solution Magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, and palladium nitrate dihydrate were added to deionized water and stirred for 20 minutes. Then, MOF-303 (Al) and hexadecyltrimethylammonium bromide (CTAB) were added and ultrasonically dispersed for 30 minutes to obtain a premixed solution. The premixed solution was stirred and heated to 65°C and kept warm. Then, a urea solution with a mass concentration of 18 wt% was added dropwise to the premixed solution at a dropping rate of 0.2 mL / min under stirring conditions of 450 rpm. After the addition of the urea solution was completed, stirring was continued for 3 hours to obtain a precursor solution.

[0046] Among them, the weight ratio of magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, palladium nitrate dihydrate, deionized water, MOF-303 (Al), and cetyltrimethylammonium bromide (CTAB) is 26.5:13.3:1.07:0.19:105:3.3:1.6.

[0047] The urea solution was added dropwise to the premixed solution, and the molar amount of urea in the added urea solution was controlled to be 3.5 times the total molar amount of magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, and palladium nitrate dihydrate.

[0048] 2. Composite molding The precursor solution was placed in a high-pressure reactor, which was sealed and heated to 120°C at a controlled heating rate of 3°C / min. The reactor was subjected to a hydrothermal reaction for 18 hours, then cooled to room temperature and centrifuged at 10,000 rpm to obtain a solid. The solid was washed with dilute hydrochloric acid (concentration 0.01 mol / L) and deionized water, placed in a vacuum drying oven, and dried at 85°C to constant weight in a vacuum environment of 0.09 MPa to obtain a highly active catalyst for the cleavage of tetrahydrofuran to generate alcohol.

[0049] This embodiment also provides a high-activity catalyst for tetrahydrofuran bond cleavage to generate alcohol, which is prepared by the aforementioned method.

[0050] Example 3 This embodiment provides a method for preparing a highly active catalyst for cleaving bonds in tetrahydrofuran to generate alcohols, the specific steps being: 1. Prepare precursor solution Magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, and palladium nitrate dihydrate were added to deionized water and stirred for 15 minutes. Then, MOF-303 (Al) and hexadecyltrimethylammonium bromide (CTAB) were added and ultrasonically dispersed for 25 minutes to obtain a premixed solution. The premixed solution was stirred and heated to 62°C and kept warm. Then, a urea solution with a mass concentration of 16 wt% was added dropwise to the premixed solution at a dropping rate of 0.15 mL / min under stirring conditions of 420 rpm. After the addition of the urea solution was completed, stirring was continued for 2.5 hours to obtain a precursor solution.

[0051] The weight ratio of magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, palladium nitrate dihydrate, deionized water, MOF-303 (Al), and cetyltrimethylammonium bromide (CTAB) is 26:13.1:1.05:0.18:103:3.2:1.55.

[0052] The urea solution was added dropwise to the premixed solution, and the molar amount of urea in the added urea solution was controlled to be 3.3 times the total molar amount of magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, and palladium nitrate dihydrate.

[0053] 2. Composite molding The precursor solution was placed in a high-pressure reactor, which was sealed and heated to 115°C at a rate of 2.6°C / min. The reactor was kept hydrothermally reacted for 16 hours, then cooled to room temperature and centrifuged at 10,000 rpm to obtain a solid. The solid was washed with dilute hydrochloric acid (concentration 0.01 mol / L) and deionized water, placed in a vacuum drying oven, and dried at 82°C to constant weight in a vacuum environment of 0.09 MPa to obtain a highly active catalyst for the cleavage of tetrahydrofuran to generate alcohol.

[0054] This embodiment also provides a high-activity catalyst for tetrahydrofuran bond cleavage to generate alcohol, which is prepared by the aforementioned method.

[0055] Example 4 This embodiment provides the use of the highly active catalyst for cleaving bonds in tetrahydrofuran to generate alcohols according to embodiment 1, and the specific steps are as follows: 1. Catalyst activation A highly active catalyst for tetrahydrofuran bond cleavage to generate alcohol is placed in a calciner, heated to 275°C in an air atmosphere, heat-treated for 1.5 hours, and then naturally cooled to room temperature; the air in the calciner is completely replaced by hydrogen, heated to 210°C in a hydrogen atmosphere, and activated for 2.5 hours, followed by nitrogen protection to prevent oxidation of the catalyst from contact with air, thereby obtaining an activated catalyst for standby use.

[0056] 2. Tetrahydrofuran vaporization A tetrahydrofuran raw material with a purity of 99.2 wt% was pumped into a vaporizer, and the temperature of the vaporizer was controlled at 215° C. The tetrahydrofuran was continuously vaporized to continuously obtain vaporized material (i.e., vaporized tetrahydrofuran).

[0057] The tetrahydrofuran raw material used in this embodiment is a crude purified product of tetrahydrofuran produced as a by-product in the production of 1,4-butanediol.

[0058] 3. Continuous hydrogenation reaction After continuously mixing the first hydrogen flow with the vaporized material, the first hydrogen flow continuously carries the vaporized material from the top of the hydrogenation unit filled with the aforementioned activated catalyst into the hydrogenation unit; simultaneously, a second hydrogen flow is continuously added from the bottom of the hydrogenation unit; the hydrogenation reaction temperature is controlled at 175°C and the reaction pressure is 3.5 MPa), the residence time of hydrogen and tetrahydrofuran (vaporized material) in the hydrogenation unit is 1 hour; and a hydrogenated crude butanol product (butanol content 98.0 wt%) is continuously discharged from the bottom of the hydrogenation reactor.

[0059] The total flow rate of the first hydrogen flow and the second hydrogen flow is 1800 Nm³ / h, and the volume ratio of the first hydrogen flow to the second hydrogen flow is 9:1.

[0060] In the continuous hydrogenation reaction, the molar ratio of hydrogen entering the hydrogenation unit to tetrahydrofuran in the vaporized material per unit time is 210:1.

[0061] In the continuous hydrogenation reaction, the catalyst used is loaded in the middle of the fixed bed of the hydrogenation unit, and the mass space velocity of the catalyst is controlled to be 1170h -1 , the remaining filling is white porcelain balls.

[0062] 4. Refining The crude butanol product obtained by the continuous hydrogenation reaction is continuously fed into a light-removal tower, and the pressure of the light-removal tower is controlled to be 5 kPa (absolute pressure), the temperature at the top of the tower is 130° C., and the temperature at the bottom of the tower is 160° C. to remove light components and obtain a light-removal product (the butanol content in the light-removal product is not less than 99 wt %); the light-removal product is continuously fed into a heavy-removal tower, and the pressure of the heavy-removal tower is controlled to be 2 kPa (absolute pressure), the temperature at the top of the tower is 150° C., and the temperature at the bottom of the tower is 170° C. to remove heavy components and obtain a butanol product.

[0063] The butanol content of the butanol product finally obtained in this example was 99.2 wt % and the yield was 97.5%; the tetrahydrofuran conversion rate was 98.7%.

[0064] Example 5 This embodiment provides the use of the highly active catalyst for cleaving bonds in tetrahydrofuran to generate alcohols according to embodiment 2, and the specific steps are as follows: 1. Catalyst activation A highly active catalyst for tetrahydrofuran bond cleavage to generate alcohol is placed in a calcination furnace, heated to 280°C in an air atmosphere, heat-treated for 1.7 hours, and then naturally cooled to room temperature; the air in the calcination furnace is completely replaced with hydrogen, heated to 220°C in a hydrogen atmosphere, and activated for 2.5 hours, and then nitrogen is introduced to protect the catalyst to prevent oxidation caused by contact with air, thereby obtaining an activated catalyst for standby use.

[0065] 2. Tetrahydrofuran vaporization A tetrahydrofuran raw material with a purity of 99.2 wt% was pumped into a vaporizer, and the temperature of the vaporizer was controlled at 220° C. The tetrahydrofuran was continuously vaporized to continuously obtain vaporized material (i.e., vaporized tetrahydrofuran).

[0066] The tetrahydrofuran raw material used in this embodiment is a crude purified product of tetrahydrofuran produced as a by-product in the production of 1,4-butanediol.

[0067] 3. Continuous hydrogenation reaction After continuously mixing the first hydrogen flow with the vaporized material, the first hydrogen flow continuously carries the vaporized material from the top of the hydrogenation unit filled with the aforementioned activated catalyst into the hydrogenation unit; simultaneously, a second hydrogen flow is continuously added from the bottom of the hydrogenation unit; the hydrogenation reaction temperature is controlled to 178° C., the reaction pressure is controlled to 3.3 MPa, and the residence time of hydrogen and tetrahydrofuran (vaporized material) in the hydrogenation unit is 0.75 h; and a hydrogenated crude butanol product (butanol content 98.5 wt%) is continuously discharged from the bottom of the hydrogenation reactor.

[0068] The total flow rate of the first hydrogen flow and the second hydrogen flow is 1900 Nm³ / h, and the volume ratio of the first hydrogen flow to the second hydrogen flow is 8.7:1.

[0069] In the continuous hydrogenation reaction, the molar ratio of hydrogen entering the hydrogenation unit to tetrahydrofuran in the vaporized material per unit time is 220:1.

[0070] In the continuous hydrogenation reaction, the catalyst used is loaded in the middle of the fixed bed of the hydrogenation unit, and the mass space velocity of the catalyst is controlled to be 1192h -1 , the remaining filling is white porcelain balls.

[0071] 4. Refining The crude butanol product obtained by the continuous hydrogenation reaction is continuously fed into a light-removal tower, and the pressure of the light-removal tower is controlled to be 5 kPa (absolute pressure), the temperature at the top of the tower is 130° C., and the temperature at the bottom of the tower is 160° C. to remove light components and obtain a light-removal product (the butanol content in the light-removal product is not less than 99 wt %); the light-removal product is continuously fed into a heavy-removal tower, and the pressure of the heavy-removal tower is controlled to be 2 kPa (absolute pressure), the temperature at the top of the tower is 150° C., and the temperature at the bottom of the tower is 170° C. to remove heavy components and obtain a butanol product.

[0072] The butanol content of the butanol product finally obtained in this example was 99.5 wt %, and the yield was 98.2%; the tetrahydrofuran conversion rate was 99.0%.

[0073] Example 6 This embodiment provides the use of the highly active catalyst for cleaving bonds in tetrahydrofuran to generate alcohols according to embodiment 3, and the specific steps are as follows: 1. Catalyst activation A highly active catalyst for the cleavage of tetrahydrofuran to generate alcohol is placed in a calcination furnace, heated to 270°C in an air atmosphere, kept warm for 1 hour, and then naturally cooled to room temperature; the air in the calcination furnace is completely replaced with hydrogen, the temperature is raised to 200°C in a hydrogen atmosphere, kept warm for 2 hours, and then nitrogen is introduced to protect the catalyst to prevent oxidation caused by contact with air, thereby obtaining an activated catalyst for standby use.

[0074] 2. Tetrahydrofuran vaporization A tetrahydrofuran raw material with a purity of 99.2 wt% was pumped into a vaporizer, and the temperature of the vaporizer was controlled at 210° C. The tetrahydrofuran was continuously vaporized to continuously obtain vaporized material (i.e., vaporized tetrahydrofuran).

[0075] The tetrahydrofuran raw material used in this embodiment is a crude purified product of tetrahydrofuran produced as a by-product in the production of 1,4-butanediol.

[0076] 3. Continuous hydrogenation reaction After continuously mixing the first hydrogen flow with the vaporized material, the first hydrogen flow continuously carries the vaporized material from the top of the hydrogenation unit filled with the aforementioned activated catalyst into the hydrogenation unit; simultaneously, a second hydrogen flow is continuously added from the bottom of the hydrogenation unit; the hydrogenation reaction temperature is controlled to 172° C., the reaction pressure is 3.2 MPa, and the residence time of hydrogen and tetrahydrofuran (vaporized material) in the hydrogenation unit is 0.5 h; and a hydrogenated crude butanol product (butanol content 99.0 wt%) is continuously discharged from the bottom of the hydrogenation reactor.

[0077] The total flow rate of the first hydrogen flow and the second hydrogen flow is 2000 Nm³ / h, and the volume ratio of the first hydrogen flow to the second hydrogen flow is 8.5:1.

[0078] In the continuous hydrogenation reaction, the molar ratio of hydrogen entering the hydrogenation unit to tetrahydrofuran in the vaporized material per unit time is 200:1.

[0079] In the continuous hydrogenation reaction, the catalyst used is loaded in the middle of the fixed bed of the hydrogenation unit, and the mass space velocity of the catalyst is controlled to be 1205h -1 , the remaining filling is white porcelain balls.

[0080] 4. Refining The crude butanol product obtained by the continuous hydrogenation reaction is continuously fed into a light-removal tower, and the pressure of the light-removal tower is controlled to be 5 kPa (absolute pressure), the temperature at the top of the tower is 130° C., and the temperature at the bottom of the tower is 160° C. to remove light components and obtain a light-removal product (the butanol content in the light-removal product is not less than 99 wt %); the light-removal product is continuously fed into a heavy-removal tower, and the pressure of the heavy-removal tower is controlled to be 2 kPa (absolute pressure), the temperature at the top of the tower is 150° C., and the temperature at the bottom of the tower is 170° C. to remove heavy components and obtain a butanol product.

[0081] The butanol content of the butanol product finally obtained in this example was 99.7 wt %, and the yield was 99.0%; the tetrahydrofuran conversion rate was 99.5%.

[0082] The application effect indicators of the catalysts in Examples 4-6 are summarized in the following table:

[0083] Long-term continuous catalytic reactions were conducted using the methods described in Examples 4-6 for the highly active catalysts for the cleavage of tetrahydrofuran bonds to produce alcohols. The continuous catalytic time for each catalyst was recorded until the tetrahydrofuran conversion dropped to 95.5% or the butanol yield dropped to 95% during the continuous hydrogenation reaction. The mass of butanol produced per unit mass of catalyst during the aforementioned continuous catalytic time was calculated. The results are shown in the following table:

[0084] Comparative Example 1 The catalyst of Comparative Example 1 is a catalyst prepared by the preparation method of Example 3, except that the addition of copper nitrate hexahydrate and MOF-303 (Al) is omitted in the preparation of the precursor solution; at the same time, the application method of the catalyst adopts the technical scheme of Example 6, and in the continuous hydrogenation reaction, in order to adapt to the performance of the comparative example catalyst, the hydrogenation temperature is adjusted to 180°C, the reaction pressure is adjusted to 4.2 MPa, the residence time of hydrogen and tetrahydrofuran (vaporized material) in the hydrogenation device is adjusted to 0.75h, and the total hydrogen flow rate is adjusted to 1650Nm³ / h.

[0085] The butanol content of the butanol product finally obtained in Comparative Example 1 was 99.1 wt % and the yield was 97.2%. The tetrahydrofuran conversion rate was 98.5%. At the same time, the continuous catalytic time of the catalyst was 337 days, and the mass of butanol produced per ton of catalyst was 1595 tons.

[0086] It can be seen that in the preparation of the catalyst of the present invention, with respect to the characteristics of the tetrahydrofuran hydrogenation reaction, a high-crystallinity composite layered structure is formed by co-precipitation method by using specific magnesium salts, aluminum salts in combination with copper salts, palladium salts, MOF-303 (Al) and templates, and a multi-level micro-mesoporous structure is prepared. The hydrotalcite composite catalyst has a high active site density, a high active potential contact area and an efficient transmission path. With respect to the characteristics of the tetrahydrofuran hydrogenation reaction, the non-precious metal active component, the precious metal active component and the MOF active component are combined to synergistically catalyze the continuous vaporization hydrogenation process of tetrahydrofuran, reduce the problem of reduced catalytic activity due to reaction carbon deposition during the reaction, inhibit the formation of by-products, and can improve the catalytic activity of the catalyst, reduce the reaction temperature and reaction pressure required for tetrahydrofuran hydrogenation, improve reaction efficiency, improve reaction conversion rate and selectivity, and improve product yield. At the same time, it can effectively improve the stability of the catalyst in the tetrahydrofuran hydrogenation process, maintain catalytic activity during a long reaction process, and reduce the deactivation and replacement frequency of the catalyst.

[0087] Unless otherwise specified, all percentages used in the present invention are by mass.

[0088] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a highly active catalyst for the cleavage of tetrahydrofuran to generate alcohols, characterized in that: The method comprises the following steps: preparing a precursor solution and composite molding; The precursor solution is prepared by adding magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, and palladium nitrate dihydrate into deionized water and dispersing them uniformly, then adding MOF-303(Al) and hexadecyltrimethylammonium bromide and dispersing them uniformly to obtain a premixed solution; heating the premixed solution to 60-65° C., keeping the temperature and stirring, and then dripping the urea solution into the premixed solution; after the urea solution is added dropwise, stirring is continued to obtain a precursor solution; The composite molding comprises placing the precursor solution in a sealed environment, subjecting the precursor solution to a hydrothermal reaction at 110-120° C., separating and obtaining a solid, and washing and drying the solid to obtain a high-activity catalyst for tetrahydrofuran bond cleavage to generate alcohol.

2. The method for preparing a highly active catalyst for the cleavage of tetrahydrofuran to generate alcohols according to claim 1, wherein In the preparation of the precursor solution, the stirring speed when the urea solution is added dropwise is 400-450 rpm, and the dropping rate of the urea solution is 0.1-0.2 mL / min; The mass concentration of urea solution is 15-18wt%; The stirring time after the urea solution is added dropwise is 2-3 hours.

3. The preparation method of the highly active catalyst for the cleavage of tetrahydrofuran to generate alcohol according to claim 1, wherein In the precursor solution, the weight ratio of magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate, palladium nitrate dihydrate, deionized water, MOF-303 (Al), and hexadecyltrimethylammonium bromide is 25.5-26.5:12.7-13.3:1.02-1.07:0.17-0.19:100-105:3.1-3.3:1.5-1.6; The molar amount of urea in the dropwise added urea solution is 3.2-3.5 times the total molar amount of magnesium nitrate hexahydrate, aluminum nitrate nonahydrate, copper nitrate hexahydrate and palladium nitrate dihydrate.

4. The method for preparing a highly active catalyst for the cleavage of tetrahydrofuran to generate alcohols according to claim 1, wherein During the composite molding, the temperature is raised to 110-120°C at a rate of 2-3°C / min; The hydrothermal reaction time at 110-120℃ is 14-18h.

5. A highly active catalyst for the cleavage of tetrahydrofuran to generate alcohols, prepared by the method according to any one of claims 1 to 4.

6. Use of a highly active catalyst for cleaving bonds in tetrahydrofuran to generate alcohols according to claim 5, characterized in that: The process comprises the following steps: catalyst activation, tetrahydrofuran vaporization, continuous hydrogenation reaction, and refining; The tetrahydrofuran is vaporized, and the tetrahydrofuran raw material with a purity greater than 99.0 wt% is continuously vaporized to obtain vaporized material; In the continuous hydrogenation reaction, after the first hydrogen stream is mixed with the vaporized material, it is continuously fed from the top of the hydrogenation device filled with the activated catalyst; at the same time, a second hydrogen stream is continuously added from the bottom of the hydrogenation device; the hydrogenation reaction temperature is controlled at 170-180°C and the reaction pressure is 3-5MPa, and a crude butanol product is obtained through hydrogenation reaction; The crude butanol product is refined to obtain a butanol product.

7. The use of a highly active catalyst for the cleavage of tetrahydrofuran to generate alcohols according to claim 6, wherein In the continuous hydrogenation reaction, the residence time of the material in the hydrogenation device is 0.5-1h; The mass space velocity of the catalyst is 779-1580h -1 .

8. The use of a highly active catalyst for the cleavage of tetrahydrofuran to generate alcohols according to claim 6, wherein In the continuous hydrogenation reaction, the total flow rate of the first hydrogen flow and the second hydrogen flow is 1500-2000 Nm³ / h, and the volume ratio of the first hydrogen flow to the second hydrogen flow is 8.5-9:1; The molar ratio of hydrogen entering the hydrogenation unit to tetrahydrofuran in the vaporized material per unit time is 200-220:

1.

9. The use of a highly active catalyst for the cleavage of tetrahydrofuran to generate alcohols according to claim 6, wherein In the refining, the crude butanol product is continuously fed into a light-removing tower, the absolute pressure of the light-removing tower is controlled to be 4-5 KPa, the top temperature is controlled to be 130-135° C., and the bottom temperature is controlled to be 160-165° C., and after removing the light components, a light-removing product is obtained; and the light-removing product is continuously fed into a heavy-removing tower, the absolute pressure of the heavy-removing tower is controlled to be 1-2 KPa, the top temperature is controlled to be 150-153° C., and the bottom temperature is controlled to be 168-170° C., and after removing the heavy components, a butanol product is obtained.

10. The use of a highly active catalyst for the cleavage of tetrahydrofuran to generate alcohols according to claim 6, characterized in that: The catalyst activation process is to heat-treat a high-activity catalyst for tetrahydrofuran bond cleavage to generate alcohol at 270-280° C. in an air atmosphere, cool it down, and then activate it at 200-220° C. in a hydrogen atmosphere to obtain an activated catalyst.

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