A catalyst for preparing gamma-butyrolactone by dehydrogenating 1,4-butanediol, a preparation method and applications thereof

Abstract

The application provides a catalyst for preparing gamma-butyrolactone by dehydrogenating 1,4-butanediol, a preparation method and application, and the catalyst comprises 20-35 wt% of copper oxide, 5-15 wt% of indium oxide, 5-10 wt% of molybdenum oxide, 0.5-2 wt% of lithium oxide and 50%-65 wt% of silicon oxide. The preparation method comprises the following steps: firstly, mixing a silica sol with a soluble salt solution of copper, indium and molybdenum, adding ammonia water to form a complex solution, and then heating and evaporating ammonia; filtering, washing, drying and calcining the slurry after evaporation of ammonia to obtain a main catalyst powder; uniformly mixing a lithium hydroxide aqueous solution with the main powder, adding a molding aid and then performing wet pressing; and aging the pressed tablets at low temperature to obtain a catalyst product. The catalyst of the application shows high activity, high selectivity and high stability in the process of preparing gamma-butyrolactone by dehydrogenating 1,4-butanediol, and can especially solve the problems of high content of by-products tetrahydrofuran and n-butanol caused by high hydrogenation activity of a Cr-free catalyst, and can also greatly reduce the content of high-boiling substances in the product.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of alcohol catalytic dehydrogenation, in particular to a catalyst for preparing gamma-butyrolactone by dehydrogenation of 1,4-butanediol, a preparation method and application thereof. BACKGROUND

[0002] Gamma-butyrolactone, also known as 1,4-butyrolactone, is an important organic chemical product, which is widely used in petroleum chemical industry, dyes, medicines, pesticides and fine chemical industry. Abroad, gamma-butyrolactone is mainly used as a solvent and to produce pyrrolidone series products. In recent years, due to the increasing demand for high value-added products such as pyrrolidone, N-methyl pyrrolidone, vinyl pyrrolidone and alpha-acetyl butyrolactone, the demand for gamma-butyrolactone is also increasing, and its synthesis process and catalyst become the main research object. There are two main synthesis processes of gamma-butyrolactone, namely malonic anhydride hydrogenation method and 1,4-butanediol dehydrogenation method, and the 1,4-butanediol dehydrogenation method is the main process route in industry.

[0003] There are many patents and literatures reported about the catalyst for preparing gamma-butyrolactone by dehydrogenation of 1,4-butanediol.

[0004] Japanese patent JP0525151 reported a catalyst for preparing gamma-butyrolactone by gas phase dehydrogenation of 1,4-butanediol, which was composed of Cu, Cr, Na or K. Under the conditions of 230℃, space velocity 3.0h -1 , conversion rate 87.28%, and selectivity 98.75%.

[0005] US5110954B2 reported that Cu / Cr2O3 catalyst in slurry bed, reaction temperature 195℃, reaction time 220min, 1,4-butanediol conversion rate 99.51%, and gamma-butyrolactone selectivity 97.92%.

[0006] European patent EP523,774A introduced Cu-Cr-Ba or Cu-Cr-Mn-Ba catalyst, in which alkali metal Na or K was added as an additive. The catalyst composition was Cu: 33.5%, Cr: 28.6%, Mn: 4.0%, Na: 2.2%, under the conditions of temperature 230℃, pressure 0.4MPa, hydrogen / alcohol ratio 4, space velocity 3.0h -1 , conversion rate 96.1%, and selectivity 95.1%.

[0007] Chinese patent CN103769110A introduces a Cr-free catalyst, which mainly consists of Cu-Zn-Ti, wherein the CuO content is 30-55%, the ZnO content is 30-55%, and the TiO2 content is 5-15%. The catalyst is prepared by co-precipitation reaction, using sodium carbonate as the precipitant, at a precipitation temperature of 70-90°C and a pH of 7-9. The prepared catalyst is used in the reaction at a reaction temperature of 230-250°C, a liquid hourly space velocity of 1.2-1.5 h -1 , a hydro-alcohol ratio of 3-10:1, and a pressure of 0-0.3 MPa, with a reaction conversion rate of above 98% and a γ-butyrolactone selectivity of above 98.8%.

[0008] The catalysts mentioned in the above patent all contain Cr element, which is not friendly to the environment. At present, some Cr-free catalysts in China have high generation amounts of tetrahydrofuran, n-butanol and heavy components due to excessive dehydration and hydrogenation, thereby reducing the selectivity of γ-butyrolactone. SUMMARY

[0009] The present application aims to provide a catalyst for preparing γ-butyrolactone by dehydrogenation of 1,4-butanediol, which has excellent activity, selectivity and stability in the reaction of preparing γ-butyrolactone by dehydrogenation of 1,4-butanediol.

[0010] Another object of the present application is to provide a preparation method of the catalyst.

[0011] Still another object of the present application is to provide the application of the catalyst.

[0012] To achieve the above objects, the technical solution adopted by the present application is as follows:

[0013] A catalyst for preparing γ-butyrolactone by dehydrogenation of 1,4-butanediol, which comprises the following components based on the total weight of the catalyst:

[0014] 20-35 wt% of copper oxide, preferably 25-30 wt%;

[0015] 5-15 wt% of indium oxide, preferably 8-12 wt%;

[0016] 5-10 wt% of molybdenum oxide, preferably 6-8 wt%;

[0017] 0.5-2 wt% of lithium oxide, preferably 1.0-1.5 wt%;

[0018] 50%-65 wt% of silicon oxide, preferably 55%-60 wt%.

[0019] In another aspect, a preparation method of the aforementioned catalyst for preparing γ-butyrolactone by dehydrogenation of 1,4-butanediol comprises the following steps:

[0020] (1) mixing a mixed salt solution containing copper salt, indium salt and molybdenum salt with silica sol into a reaction kettle, adding ammonia water dropwise in the process of continuous stirring, stopping adding ammonia water when the mixture becomes clear again from turbidity, to obtain a complex solution;

[0021] (2) heating and evaporating ammonia of the complex solution in the reaction kettle until the pH of the liquid in the reaction kettle approaches neutral, and stopping heating;

[0022] (3) filtering, washing, drying and calcining the slurry in the reaction kettle to obtain a main catalyst powder;

[0023] (4) adding lithium hydroxide solution and a molding aid to the main catalyst powder and mixing uniformly to perform wet pressing and molding;

[0024] (5) aging the molded catalyst tablet at low temperature, and then calcining to obtain a finished catalyst product.

[0025] In some specific embodiments, the copper salt in step (1) is selected from one or more of copper nitrate, copper chloride and copper sulfate; and / or

[0026] the indium salt is indium nitrate; and / or

[0027] the molybdenum salt is one or both of ammonium molybdate and ammonium heptamolybdate; and / or

[0028] the silica sol is an acidic silica sol;

[0029] Preferably, the concentration of the mixed salt solution containing copper salt, indium salt and molybdenum salt in step (1) is 0.5-2 mol / L, based on the total molar amount of copper, indium and molybdenum, preferably 1.0-1.5 mol / L; and / or

[0030] the particle size of the silica sol is 10-40 nm, preferably 20-30 nm.

[0031] In some specific embodiments, the temperature of the reaction kettle in step (1) is controlled at 50-65°C, preferably 55-60°C.

[0032] In some specific embodiments, the end point pH value in step (2) is between 6 and 8, preferably 6.5-7.5; and / or

[0033] The temperature of ammonia evaporation is greater than 80°C, preferably 85-90°C.

[0034] In some specific embodiments, the calcination temperature in step (3) is 400-550°C, preferably 450-500°C; and the calcination time is 2-8h, preferably 4-6h.

[0035] In some specific embodiments, the concentration of the lithium hydroxide solution in step (4) is 4wt%-16wt%, preferably 8wt%-12wt%.

[0036] Preferably, the lithium hydroxide solution is added to the main catalyst powder in the form of a spray.

[0037] In some specific embodiments, the forming aid in step (4) is graphite.

[0038] Preferably, the particle size distribution of the graphite is 20 mesh-200 mesh, preferably 50 mesh-150 mesh; and / or

[0039] The amount of graphite added is 1%-5% of the mass of the main catalyst powder, preferably 2%-3%; and / or

[0040] The catalyst specification formed by the wet tabletting forming is any one of 3mm*3mm cylinder, 4mm*4mm cylinder or 5mm*5mm cylinder, preferably 4mm*4mm cylinder.

[0041] In some specific embodiments, the aging temperature in step (5) is 40-70℃, preferably 50-60℃; the aging time is more than 6h, preferably 6.5-8h, and / or

[0042] The calcination temperature is 400-550℃, preferably 450-500℃; the calcination time is 2-8h, preferably 4-6h.

[0043] In still another aspect, the use of the aforementioned catalyst for preparing gamma-butyrolactone by dehydrogenation of 1,4-butanediol or the catalyst prepared by the aforementioned method for preparing gamma-butyrolactone by dehydrogenation of 1,4-butanediol in catalyzing the dehydrogenation of 1,4-butanediol to prepare gamma-butyrolactone, preferably, the dehydrogenation reaction is a fixed bed continuous reaction, the reaction pressure is 0.1-0.5MPa, the reaction temperature is 220-240℃, the H2 / ketone molar ratio is 10-20:1, and the liquid hourly space velocity is 0.2-0.5h -1 .

[0044] Compared with the prior art, the technical scheme of the present application has the beneficial effects that:

[0045] The catalyst for preparing gamma-butyrolactone by dehydrogenation of 1,4-butanediol of the present application has a simple catalyst composition, and the main raw material is a bulk chemical; the dispersion degree of the active component of the catalyst is high, so that the catalyst has very high dehydrogenation activity; in addition, the special design of the catalyst components makes the dehydration and hydrogenation activity weak, and the generation amount of by-products tetrahydrofuran, n-butanol and heavy components is low, so that the catalyst has good selectivity; among them, the conversion rate of the catalyst is more than 98%, and the selectivity is greater than 98%.

[0046] The preparation method of the catalyst makes the catalyst have high mechanical strength and wear resistance, ensures long service life of the catalyst; meanwhile, the forming process makes the catalyst have developed pores, good mass and heat transfer performance; and the process is simple, safe and environmentally friendly, and has no special toxic and harmful substances. DETAILED DESCRIPTION

[0047] In order to better understand the technical solutions of the present application, the following examples will further illustrate the method provided by the present application, but the present application is not limited to the listed examples, and any other known changes within the scope of the claims of the present application should also be included.

[0048] A catalyst for preparing gamma-butyrolactone by dehydrogenating 1,4-butanediol, the catalyst comprises the following components based on the weight of the finished catalyst:

[0049] Copper oxide 20-35wt%, such as 20wt%, 21wt%, 22wt%, 23wt%, 25wt%, 28wt%, 30wt%, 31wt%, 2wt%, 33wt%, 34wt%, etc.;

[0050] Indium oxide 5-15wt%, such as 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 9.5wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, etc.;

[0051] Molybdenum oxide 5-10wt%, such as 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 9.5wt%, 10wt%, etc.;

[0052] Lithium oxide 0.5-2wt%, such as 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, etc.;

[0053] Silicon oxide 50%-65wt%, such as 50wt%, 51wt%, 52wt%, 53wt%, 54wt%, 55wt%, 56wt%, 57wt%, 58wt%, 59wt%, 60wt%, 61wt%, 62wt%, 63wt%, 64wt%, 65wt%, etc.

[0054] In a preferred embodiment, the catalyst comprises the following components: copper oxide 25-30wt%, indium oxide 8-12wt%, molybdenum oxide 6-8wt%, lithium oxide 1.0-1.5wt%, and silicon oxide 55%-60wt%.

[0055] In the formula, the copper oxide is the active component, the silicon oxide is the main carrier, the indium oxide is the auxiliary carrier, the molybdenum oxide is another auxiliary carrier, and the lithium oxide is the alkaline additive.

[0056] The application exemplarily provides a preparation method of a catalyst for preparing gamma-butyrolactone by dehydrogenation of 1,4-butanediol, which comprises the following steps:

[0057] (1) a mixed salt solution of copper salt, indium salt and molybdenum salt is mixed with silica sol and added into a reaction kettle, ammonia water is added dropwise under continuous stirring, the addition of ammonia water is stopped when the mixed solution becomes clear again from turbidity, and a complex solution is obtained;

[0058] (2) the reaction kettle is heated to evaporate ammonia until the pH of the liquid in the reaction kettle approaches neutrality, and the heating is stopped;

[0059] (3) the slurry in the reaction kettle is filtered, washed, dried and calcined to obtain a main catalyst powder;

[0060] (4) a certain amount of lithium hydroxide solution and a molding aid are added into the main catalyst powder, and mixed uniformly to be wet-pressed and molded;

[0061] (5) the molded catalyst tablets are aged at low temperature, and secondarily calcined to obtain the final product.

[0062] In step (1), first mix the soluble salts of copper, indium, and molybdenum together, dissolve in water, then mix with a certain amount of silica sol, pour into a reaction kettle and stir uniformly; when the liquid temperature in the reaction kettle reaches 50-65℃, for example 50℃, 51℃, 52℃, 53℃, 54℃, 55℃, 56℃, 57℃, 58℃, 59℃, 60℃, 61℃, 62℃, 63℃, 64℃, 65℃, etc., preferably 55-60℃, start adding ammonia water until the liquid in the kettle becomes a complex solution. The concentration of the mixed salt solution containing copper salt, indium salt, and molybdenum salt is 0.5-2 mol / L, for example 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.7 mol / L, 1.8 mol / L, 1.9 mol / L, 2 mol / L, etc., preferably 1.0-1.5 mol / L; the particle size of the silica sol is 10-40 nm, for example 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, etc., preferably 20-30 nm; the concentration of ammonia water is not particularly limited, preferably 10%-15% is optimal, too high concentration of ammonia water will prolong the ammonia evaporation time; too low concentration will increase the amount of wastewater.

[0063] In step (1), each metal salt is a soluble salt, preferably the copper salt is selected from one or more of copper nitrate, copper chloride, and copper sulfate; the indium salt is for example indium nitrate; the molybdenum salt is for example one or both of ammonium molybdate or ammonium heptamolybdate; the silica sol is an acidic silica sol, for example KHAS acidic silica sol produced by Linyi Kohan Silicon.

[0064] In step (2), heating to evaporate ammonia means heating to evaporate ammonia water, the ammonia evaporation temperature is usually greater than 80℃, usually it is appropriate to control at 85-90℃, for example 86℃, 87℃, 88℃, 89℃, 90℃, etc., a lower temperature will make the ammonia evaporation time too long, and a too high temperature will cause a large amount of water to vaporize, which is easy to cause the slurry to solidify in the reaction kettle.

[0065] In step (2), the ammonia evaporation end point pH value is controlled between 6-8, for example 6.2, 6.3, 6.5, 6.8, 7.0, 7.1, 7.3, 7.5, 7.8, etc., preferably 6.5-7.5.

[0066] In step (3), filtration, washing, drying, calcination and the like are all conventional operations. Among them, the washing function is to wash the soluble salt ions in the filter cake, and the standard is that the conductivity of the washing water is ≤200 us / cm; the drying is conventional drying, and the drying temperature can be 90-150°C, such as 95°C, 100°C, 110°C, 120°C, 130°C and the like, and the drying time can be usually 6h or more, such as 6h, 7h, 8h and the like; the calcination temperature is 400-550°C, such as 410°C, 430°C, 450°C, 480°C, 500°C, 510°C, 530°C, 540°C and the like, preferably 450-500°C; and the calcination time is 2-8h, such as 3h, 4h, 5h, 6h, 7h and the like, preferably 4-6h.

[0067] In step (4), the concentration of the lithium hydroxide solution is 4wt%-16wt%, such as 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt% and the like, preferably 8wt%-12wt%; the lithium hydroxide solution is preferably added to the main powder in the form of spraying, which facilitates uniform mixing, and a three-dimensional mixer or the like can also be used for mixing to ensure uniform mixing.

[0068] The reason why the lithium hydroxide solution is selected as the basic auxiliary medium is that, compared with sodium and potassium ions, lithium ions are least likely to migrate at low temperatures, which can effectively avoid the auxiliary from clustering on the surface of the catalyst.

[0069] Since lithium ions will also migrate to the surface of the catalyst with water during high-temperature drying, they cannot be added during the ammonia evaporation reaction, but can only be added during the mixing of the powder.

[0070] In step (4), the forming auxiliary is graphite powder, and the particle size distribution is 20-200 mesh, such as 40 mesh, 50 mesh, 70 mesh, 90 mesh, 100 mesh, 130 mesh, 150 mesh, 180 mesh and the like, preferably 50-150 mesh, and the addition amount is 1%-5% of the mass of the main powder, such as 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% and the like, preferably 2%-3%. The graphite powder mainly plays a lubricating role during the forming process.

[0071] In step (4), the mixing method is not particularly limited, and after uniform mixing, wet tabletting forming can be performed. The wet tabletting forming process can refer to the prior art, and in the present application, the specifications of the tablets are 3mm*3mm cylindrical, 4mm*4mm cylindrical or 5mm*5mm cylindrical, preferably 4mm*4mm cylindrical.

[0072] In step (5), the catalyst tablet formed by wet compression is aged at low temperature, the aging temperature is 40-70℃, for example, 40℃, 41℃, 42℃, 43℃, 45℃, 48℃, 50℃, 53℃, 55℃, 57℃, 59℃, 60℃, 62℃, 65℃, 68℃, 70℃, etc., preferably 50-60℃; the aging time is 6h and above, for example, 7h, 8h, 9h, 10h, 11h, 12h, 15h, 20h, 24h, etc.; after aging, secondary calcination is carried out, the calcination temperature is 400-550℃, for example, 410℃, 420℃, 430℃, 440℃, 450℃, 460℃, 470℃, 480℃, 490℃, 500℃, 510℃, 520℃, 530℃, 540℃, etc., preferably 450-500℃; the calcination time is 2-8h, for example, 3h, 4h, 5h, 6h, 7h, etc., preferably 4-6h.

[0073] The role of aging is, on the one hand, to slowly evaporate the moisture in the tablet, and on the other hand, the process of the basic adjuvant interacting with the active component and the carrier, ultimately making the basic adjuvant uniformly dispersed in the catalyst, and forming a strong binding force.

[0074] The present application also relates to the application of the prepared catalyst in the catalysis of 1,4-butanediol dehydrogenation to prepare gamma-butyrolactone, and the person skilled in the art knows that the dehydrogenation catalyst usually needs to be reduced and activated before use.

[0075] Exemplarily, the method for reducing and activating the catalyst of the present application comprises: keeping the nitrogen gas with a volume space velocity of 800-1000h -1 passed into the reactor, preferably first increasing the temperature of the reactor to 150-160℃, keeping the temperature for 1-2h to remove the physical water adsorbed by the catalyst, then passing in hydrogen gas, so that the hydrogen content in the mixed gas of hydrogen and nitrogen is within 5v%, such as 4v%, 3v%, 2v%, etc., pre-reducing the catalyst for at least 2h, such as 2.5h or 3h, then gradually increasing the proportion of hydrogen in the mixed gas of hydrogen and nitrogen, for example, gradually increasing the H2 content to 10v%, 15v%, 30v%, 50%, 100%, controlling the hot spot temperature of the catalyst bed in the process to be not more than 220℃, and finally reducing at a pure hydrogen atmosphere at 210-220℃ for 3-6h, such as 4 or 5h, to obtain the activated catalyst.

[0076] In the application, the reduced catalyst is used in the catalysis of 1,4-butanediol dehydrogenation to prepare gamma-butyrolactone, the dehydrogenation reaction is continuously carried out in a fixed bed, the reaction pressure is 0.1-0.5 MPa, for example, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, etc., the reaction temperature is 220-240 DEG C, for example, 225 DEG C, 230 DEG C, 235 DEG C, etc., the H2 / ketone molar ratio is 10-20:1, for example, 11, 13, 15, 17, 18, 19, etc., the liquid hourly space velocity is 0.2-0.5 h -1 , for example, 0.25 h -1 , 0.3 h -1 , 0.35 h -1 , 0.4 h -1 , etc.

[0077] The method of the application is described in detail below in combination with more specific examples, but is not limited to the examples.

[0078] In the following examples, the raw materials and hydrogenated liquids are analyzed by Agilent 7890A gas chromatograph. The detector is a hydrogen flame detector, and the chromatographic column is DB-5MS (30 m*0.25 mm*0.25 μm). The chromatographic operating conditions are as follows: the carrier is nitrogen, the split ratio is 50:1, the injection port temperature is 260 DEG C, the detector temperature is 260 DEG C, and the injection amount is 0.2 μL. The chromatographic temperature program is as follows: initial 50 DEG C→hold for 3 min→8 DEG C / min to 120 DEG C→hold for 12 min→20 DEG C / min to 250 DEG C→hold for 25 min→cooling.

[0079] The catalyst side pressure strength tester is model KC-3 digital particle strength tester, and the manufacturer is Jiangyan Analysis Instrument Factory in Taizhou.

[0080] The chemical raw materials and reagents used in the following examples are all of analytical purity, and the amount calculation does not include crystal water; the type of Cu salt has no effect on the experimental results, and nitrate is taken as an example in the examples; the type of molybdenum salt has no effect on the experimental results, and ammonium molybdate is taken as an example in the examples. The silicon sol is KHAS acidic silicon sol (particle size 10-40 nm) produced by Linyi Kohan Silicon. Other raw materials not specifically mentioned are conventional products purchased on the market. The preparation amount of a single batch of catalyst is 100 g; the amount of graphite added is small and not included in the weight of the catalyst; the specification of the catalyst is taken as 4 mm*4 mm as an example.

[0081] Example 1

[0082] A catalyst was prepared according to a catalyst composition of 20% CuO-15% In2O3-10% MoO3-2% Li2O-53% SiO2. 47.2 g of copper nitrate, 32.5 g of indium nitrate, and 13.6 g of ammonium molybdate were weighed and prepared into an aqueous solution with a concentration of 0.5 mol / L, and mixed with 132.5 g of silica sol (particle size 10 nm) with a SiO2content of 40% to be added into a reaction kettle. Ammonia water was added dropwise under stirring at a temperature of 50°C until the solution was twice clarified. The addition of ammonia water was stopped, and heating was started to 85°C to evaporate ammonia. When the pH reached 6.0, heating was stopped, and a mixed slurry was obtained. The slurry was filtered, washed, and dried at 120°C for 6 h, and then calcined at 400°C for 8 h to obtain a main powder. 20 g of LiOH solution with a concentration of 16% was sprayed onto the main powder and mixed uniformly, 1 g of graphite was further added and mixed uniformly, and then tabletting was performed to obtain a 4 mm*4 mm shaped tablet. The tablet was aged at 40°C for 8 h, and twice calcined at a temperature of 450°C for 6 h to obtain a final catalyst product A.

[0083] Catalyst activation: catalyst A was loaded into a fixed-bed hydrogenation reactor, and the catalyst loading amount was 50 ml. First, the volume speed of nitrogen was kept at 800 h-1, and the temperature was raised to 160°C for 2 h to remove the physical water adsorbed by the catalyst. Then, a mixture of 2% H2 and nitrogen was introduced for 2 h for pre-reduction, and then the hydrogen content was gradually increased to 5%, 10%, 20%, 50%, and 100% while the hot spot temperature of the catalyst bed was controlled to be less than 220°C. Finally, the temperature was raised to 220°C, and reduction was performed in a pure hydrogen atmosphere for 4 h. -1

[0084] Example 2

[0085] A catalyst was prepared according to a catalyst composition of 25% CuO-12% In2O3-8% MoO3-1.5% Li2O-53.5% SiO2. 59 g of copper nitrate, 26 g of indium nitrate, and 10.9 g of ammonium molybdate were weighed and prepared into an aqueous solution with a concentration of 1 mol / L, and mixed with 133.8 g of silica sol (particle size 20 nm) with a SiO2content of 40% to be added into a reaction kettle. Ammonia water was added dropwise under stirring at a temperature of 55°C until the solution was twice clarified. The addition of ammonia water was stopped, and heating was started to 90°C to evaporate ammonia. When the pH reached 6.5, heating was stopped, and a mixed slurry was obtained. The slurry was filtered, washed, and dried at 120°C for 6 h, and then calcined at 450°C for 6 h to obtain a main powder. 20 g of LiOH solution with a concentration of 12% was sprayed onto the main powder and mixed uniformly, 2 g of graphite was further added and mixed uniformly, and then tabletting was performed to obtain a 4 mm*4 mm shaped tablet. The tablet was aged at 50°C for 8 h, and then calcined at 400°C for 8 h to obtain a final catalyst product B.

[0086] The activation conditions were the same as in Example 1. ​

[0087] Example 3

[0088] A catalyst was prepared according to the catalyst composition of 30% CuO-8% In2O3-6% MoO3-1% Li2O-55% SiO2. 70.8 g of copper nitrate, 17.3 g of indium nitrate, and 8.2 g of ammonium molybdate were weighed and prepared into a 1.5 mol / L aqueous solution, which was mixed with 137.5 g of a silica sol (particle size 30 nm) with a SiO2content of 40% and added to a reaction kettle. Ammonia water was added dropwise under stirring at a temperature of 60°C until the solution was twice clarified. The addition of ammonia water was stopped, and heating was started to 85°C to evaporate ammonia. When the pH reached 7.0, heating was stopped, and a mixed slurry was obtained. The slurry was filtered, washed, and dried at 120°C for 6 h, and then calcined at 500°C for 4 h to obtain a main powder. 20 g of a LiOH solution with a concentration of 8% was sprayed onto the main powder and mixed uniformly, 3 g of graphite was further added and mixed uniformly, and then tableting was performed to obtain a 4 mm*4 mm shaped tablet. The tablet was aged at 60°C for 8 h, and then calcined at 500°C for 4 h to obtain a final catalyst product C.

[0089] The activation conditions were the same as in Example 1.

[0090] Example 4

[0091] A catalyst was prepared according to the catalyst composition of 35% CuO-5% In2O3-5% MoO3-0.5% Li2O-54.5% SiO2. 82.5 g of copper nitrate, 10.8 g of indium nitrate, and 6.8 g of ammonium molybdate were weighed and prepared into a 2 mol / L aqueous solution, which was mixed with 136.3 g of a silica sol (particle size 40 nm) with a SiO2content of 40% and added to a reaction kettle. Ammonia water was added dropwise under stirring at a temperature of 65°C until the solution was twice clarified. The addition of ammonia water was stopped, and heating was started to 90°C to evaporate ammonia. When the pH reached 7.5, heating was stopped, and a mixed slurry was obtained. The slurry was filtered, washed, and dried at 120°C for 6 h, and then calcined at 550°C for 2 h to obtain a main powder. 20 g of a LiOH solution with a concentration of 4% was sprayed onto the main powder and mixed uniformly, 4 g of graphite was further added and mixed uniformly, and then tableting was performed to obtain a 4 mm*4 mm shaped tablet. The tablet was aged at 70°C for 8 h, and then calcined at 500°C for 4 h to obtain a final catalyst product D.

[0092] The activation conditions were the same as in Example 1.

[0093] Example 5

[0094] A catalyst was prepared according to a catalyst composition of 20% CuO-10% In2O3-9% MoO3-1% Li2O-60% SiO2. 47.2 g of copper nitrate, 21.7 g of indium nitrate, and 12.3 g of ammonium molybdate were weighed and prepared into an aqueous solution with a concentration of 1.5 mol / L, and mixed with 150 g of a silica sol (particle size 20 nm) with a SiO2content of 40% to be added into a reaction kettle, and ammonia water was added dropwise under stirring at a temperature of 55°C until the solution was twice clarified, the addition of ammonia water was stopped, and heating was started to 88°C to evaporate ammonia. When the pH reached 8.0, heating was stopped, and a mixed slurry was obtained. The slurry was filtered, washed, and dried at 120°C for 6 h, and then calcined at 520°C for 4 h to obtain a main powder. 20 g of a LiOH solution with a concentration of 8% was sprayed onto the main powder and mixed uniformly, 5 g of graphite was further added and mixed uniformly, and a tablet was prepared, to obtain a 4 mm*4 mm shaped tablet. The tablet was aged at 60°C for 8 h, and calcined at 550°C for 2 h to obtain a final catalyst product E.

[0095] The activation conditions were the same as in Example 1.

[0096] Example 6

[0097] A catalyst was prepared according to a catalyst composition of 20% CuO-9% In2O3-5% MoO3-1% Li2O-65% SiO2. 47.2 g of copper nitrate, 19.5 g of indium nitrate, and 6.8 g of ammonium molybdate were weighed and prepared into an aqueous solution with a concentration of 1.5 mol / L, and mixed with 162.5 g of a silica sol (particle size 20 nm) with a SiO2content of 40% to be added into a reaction kettle, and ammonia water was added dropwise under stirring at a temperature of 60°C until the solution was twice clarified, the addition of ammonia water was stopped, and heating was started to 88°C to evaporate ammonia. When the pH reached 7.0, heating was stopped, and a mixed slurry was obtained. The slurry was filtered, washed, and dried at 120°C for 6 h, and then calcined at 520°C for 4 h to obtain a main powder. 20 g of a LiOH solution with a concentration of 8% was sprayed onto the main powder and mixed uniformly, 2 g of graphite was further added and mixed uniformly, and a tablet was prepared, to obtain a 4 mm*4 mm shaped tablet. The tablet was aged at 60°C for 8 h, and calcined at 500°C for 4 h to obtain a final catalyst product F.

[0098] The activation conditions were the same as in Example 1.

[0099] Example 7

[0100] A catalyst was prepared according to the catalyst composition of 30% CuO-10% In2O3-8% MoO3-1% Li2O-50% SiO2. 70.8 g of copper nitrate, 21.7 g of indium nitrate, and 10.9 g of ammonium molybdate were weighed and prepared into an aqueous solution with a concentration of 1.5 mol / L, and mixed with 125 g of a silica sol (particle size 20 nm) containing 40% SiO2to be added into a reaction kettle. Ammonia water was added dropwise under stirring at a temperature of 60°C until the solution was clarified twice, and then the addition of ammonia water was stopped and the temperature was raised to 88°C to evaporate ammonia. When the pH reached 7.0, the heating was stopped, and a mixed slurry was obtained. The slurry was filtered, washed, and dried at 120°C for 6 h, and then calcined at 520°C for 4 h to obtain a main powder. 20 g of LiOH solution with a concentration of 8% was sprayed onto the main powder and mixed uniformly, 3 g of graphite was further added and mixed uniformly, and then a tablet was prepared. The tablet was aged at 60°C for 8 h and calcined at 500°C for 4 h to obtain a final catalyst product G.

[0101] The activation conditions were the same as in Example 1.

[0102] Comparative Example 1

[0103] A catalyst H (Cu: 33.5%, Cr: 28.6%, Mn: 4.0%, Na: 2.2%) was prepared according to the formula and preparation method introduced in Example 1 of the patent EP523,774.

[0104] The activation conditions were the same as in Example 1.

[0105] Comparative Example 2

[0106] A catalyst I (CuO: 45%, ZnO: 45%, TiO2: 10%; precipitation temperature 72°C, precipitation pH 8.0, aging temperature 92°C, aging pH 9.0, aging time 10 h) was prepared according to the formula and preparation method introduced in Example 1 of the patent CN103769110.

[0107] The activation conditions were the same as in Example 1.

[0108] Comparative Example 3

[0109] On the basis of Example 1, indium oxide was not added in the composition, and the same proportion of silicon dioxide was used instead, i.e., a catalyst was prepared according to the catalyst composition of 20% CuO-10% MoO3-2% Li2O-68% SiO2, and other conditions were the same as in Example 1 to obtain a catalyst J.

[0110] The activation conditions were the same as in Example 1.

[0111] Comparative Example 4

[0112] On the basis of Example 1, the catalyst was prepared according to the catalyst composition of 20% CuO-15% In2O3-2% Li2O-63% SiO2, without adding molybdenum oxide, and replacing the same proportion of silica, and the other conditions were the same as in Example 1 to obtain catalyst K.

[0113] The activation conditions were the same as in Example 1.

[0114] Comparative Example 5

[0115] On the basis of Example 1, the catalyst was prepared according to the catalyst composition of 20% CuO-15% In2O3-10% MoO3-55% SiO2, without adding lithium oxide, and replacing the same proportion of silica, and the other conditions were the same as in Example 1 to obtain catalyst L.

[0116] The activation conditions were the same as in Example 1.

[0117] Comparative Example 6

[0118] On the basis of Example 1, the catalyst was prepared according to the catalyst composition of 20% CuO-2% Li2O-78% SiO2, without adding indium oxide and molybdenum oxide, and replacing the same proportion of silica, and the other conditions were the same as in Example 1 to obtain catalyst M.

[0119] The activation conditions were the same as in Example 1.

[0120] Comparative Example 7

[0121] On the basis of Example 1, the catalyst was prepared according to the catalyst composition of 20% CuO-80% SiO2, without adding indium oxide, molybdenum oxide and lithium oxide, and replacing the same proportion of silica, and the other conditions were the same as in Example 1 to obtain catalyst N.

[0122] Performance test

[0123] Catalyst evaluation: The catalysts A-I prepared in the examples and comparative examples were used for the reaction of dehydrogenation of 1,4-butanediol to prepare γ-butyrolactone.

[0124] The hydrogenation conditions were as follows: 50 ml of catalyst was loaded into a reaction tube with an inner diameter of 32 mm, the reaction temperature was 225°C, the reaction pressure (gauge pressure) was 0.3 MPa, the hydrogen / alcohol molar ratio was 15:1, the liquid hourly space velocity was 0.3 h -1 Under these conditions, the reaction of dehydrogenation of 1,4-butanediol to prepare γ-butyrolactone was carried out to obtain a reaction liquid, which was analyzed and the results were calculated to obtain the reaction results as shown in Table 1.

[0125] Table 1 Catalyst evaluation results

[0126]

[0127]

[0128] Note: The conversion rate of BDO (1,4-butanediol) in the table = (1 - the number of moles of BDO remaining in the reaction solution / the number of moles of BDO contained in the raw material) * 100%; the selectivity of a certain product = the number of moles of the product generated / the number of moles of BDO converted * 100%.

[0129] The strength of the catalyst before and after the reaction was detected and the appearance was observed, and the following Table 2 data was obtained.

[0130] Table 2 Catalyst strength and state before and after reaction

[0131]

[0132]

[0133] *N / grain is the unit of catalyst strength, that is, the force exerted when 1 grain of catalyst is broken.

[0134] *The degree of carbon deposition is determined by the color of the catalyst surface, the darker the color, the heavier the carbon deposition; the lighter the color, the lighter the carbon deposition. The classification is as follows: 1-light, 2-moderate, 3-moderate, 4-moderate, 5-heavy.

[0135] From the above Tables 1 and 2, it can be seen that:

[0136] I. Compared with the catalyst containing Cr, the catalyst of the present application has higher activity and selectivity, and the increase in heavy components is smaller and the amount of carbon deposition is less after long-term operation, and the stability is better.

[0137] II. Compared with the catalyst without Cr, the catalyst of the present application has less dehydration and hydrogenolysis by-products under the condition of equivalent activity, and the selectivity is better; after long-term operation, the selectivity advantage of the catalyst of the present application is more obvious, the amount of carbon deposition is less, and the stability is better.

[0138] III. Without the addition of indium, the stability of the catalyst is poor, and the performance decreases significantly after 240h of operation.

[0139] IV. Without the addition of molybdenum, the catalyst has more hydrogenation side reactions, resulting in an increase in the amount of THF and NBL by-products and a decrease in selectivity.

[0140] V. Without the addition of basic additives, the catalyst has increased polymerization side reactions, resulting in an increase in heavy components, a decrease in selectivity, and a significant increase in carbon deposition, which blocks the pores and wraps the catalyst surface, making the catalyst hard after reaction.

[0141] Six, without adding indium and molybdenum, the stability of the catalyst is poor, and the performance is greatly reduced after running for 240h; at the same time, the hydrogenation side reaction of the catalyst is more, which leads to the increase of the amount of THF and NBL by-products, and the selectivity is poor.

[0142] Seven, without adding indium, molybdenum and lithium, the performance of the catalyst is greatly reduced, the stability becomes very poor, the light components and heavy components are increased, and the selectivity is greatly reduced. The increase of heavy components will cover the surface of the catalyst and block the pore, which leads to the faster decline of the performance of the catalyst, and more carbon deposition, so that the disassembled catalyst is hardened due to too much carbon deposition.

[0143] It can be seen from the above examples that the catalyst prepared by the method of the application has good activity and selectivity, and high use intensity and low carbon deposition amount for preparing gamma-butyrolactone by dehydrogenation of 1,4-butanediol, which ensures the stability of the catalyst.

Claims

1. A catalyst for preparing γ-butyrolactone from 1,4-butanediol, characterized in that, The catalyst comprises the following components based on the total weight of the catalyst: Copper oxide 20-35wt%; Indium oxide 5-15wt%; Molybdenum oxide 5-10wt%; Lithium oxide 0.5-2wt%; Silicon oxide 50%-65wt%.

2. The catalyst for producing γ-butyrolactone from 1,4-butanediol by dehydrogenation according to claim 1, characterized by, The catalyst comprises the following components based on the total weight of the catalyst: Copper oxide 25-30wt%; Indium oxide 8-12wt%; Molybdenum oxide 6-8wt%; Lithium oxide 1.0-1.5wt%; Silicon oxide 55%-60wt%.

3. A process for the preparation of a catalyst for the production of gamma-butyrolactone from 1,4-butanediol dehydrogenation according to claim 1 or 2, characterized in that, The method comprises the following steps: (1) A mixed salt solution comprising copper salt, indium salt and molybdenum salt is mixed with silica sol and added to a reaction kettle, ammonia water is added dropwise during continuous stirring, and the addition of ammonia water is stopped when the mixture becomes clear again from turbidity, to obtain a complex solution; (2) The complex solution in the reaction kettle is heated to evaporate ammonia until the liquid in the reaction kettle approaches neutral pH, and heating is stopped; (3) The slurry in the reaction kettle is filtered, washed, dried and calcined to obtain a catalyst main powder; (4) Lithium hydroxide solution and a forming aid are added to the catalyst main powder and mixed uniformly for wet pressing and forming; (5) The formed catalyst tablet is aged at low temperature and then calcined to obtain a finished catalyst product.

4. The production method according to claim 3, characterized by, The copper salt in step (1) is selected from one or more of copper nitrate, copper chloride and copper sulfate; and / or The indium salt is indium nitrate; and / or The molybdenum salt is one or both of ammonium molybdate or ammonium heptamolybdate; and / or The silica sol is an acidic silica sol.

5. The production method according to claim 4, characterized by, The concentration of the mixed salt solution comprising copper salt, indium salt and molybdenum salt in step (1) is 0.5-2mol / L, based on the total molar amount of copper, indium and molybdenum; and / or The particle size of the silica sol is 10-40nm.

6. The preparation method according to claim 5, characterized in that, The concentration of the mixed salt solution comprising copper salt, indium salt and molybdenum salt in step (1) is 1.0-1.5mol / L, based on the total molar amount of copper, indium and molybdenum, and / or The particle size of the silica sol is 20-30nm.

7. The preparation method according to claim 3, characterized in that, The temperature of the reaction kettle in step (1) is controlled at 50-65℃.

8. The preparation method according to claim 7, characterized in that, The temperature of the reaction kettle in step (1) is controlled at 55-60℃.

9. The method of any one of claims 3-8, wherein, The end point pH value in step (2) is between 6-8; and / or The ammonia evaporation temperature is greater than 80℃.

10. The method of claim 9, wherein, The end point pH value in step (2) is 6.5-7.5; and / or The ammonia evaporation temperature is 85℃-90℃.

11. The method of any one of claims 3-8, wherein, The calcination temperature in step (3) is 400-550℃; and the calcination time is 2-8h.

12. The method of claim 11, wherein, The calcination temperature in step (3) is 450-500℃; and the calcination time is 4-6h.

13. The method of any one of claims 3-8, wherein, The concentration of the lithium hydroxide solution in step (4) is 4wt%-16wt%.

14. The method of claim 13, wherein, The concentration of the lithium hydroxide solution in step (4) is 8wt%-12wt%.

15. The preparation method according to claim 13, characterized in that, The lithium hydroxide solution is added to the catalyst main powder in the form of a spray.

16. The method of claim 13, wherein, The forming aid in step (4) is graphite.

17. The preparation method according to claim 16, characterized in that, The particle size distribution of the graphite is 20 mesh-200 mesh; and / or The amount of graphite added is 1%-5% of the mass of the catalyst main powder; and / or The catalyst formed by wet pressing and forming is any one of a 3mm*3mm cylinder, a 4mm*4mm cylinder or a 5mm*5mm cylinder.

18. The method of claim 17, wherein, The particle size distribution of the graphite is 50-150 mesh; and / or The added amount of the graphite is 2-3% of the mass of the main catalyst powder; and / or The catalyst size formed by the wet method of tabletting is 4mm*4mm cylinder.

19. The method of making according to any one of claims 3-8, wherein, The aging temperature in step (5) is 40-70℃, the aging time is more than 6h, and / or The calcination temperature is 400-550℃, and the calcination time is 2-8h.

20. The method of claim 19, wherein, The aging temperature in step (5) is 50-60℃, the aging time is 6.5-8h, and / or The calcination temperature is 450-500℃, and the calcination time is 4-6h.

21. Use of the catalyst for preparing γ-butyrolactone by dehydrogenation of 1,4-butanediol according to claim 1 or 2 or the catalyst for preparing γ-butyrolactone by dehydrogenation of 1,4-butanediol prepared by the method according to any one of claims 3-20 in catalyzing the preparation of γ-butyrolactone by dehydrogenation of 1,4-butanediol.

22. The use according to claim 21, characterized in that, The dehydrogenation reaction is a fixed bed continuous reaction, the reaction pressure is 0.1-0.5 MPa, the reaction temperature is 220-240℃, the H2 / alcohol molar ratio is 10-20:1, and the liquid hourly space velocity is 0.2-0.5 h -1 .

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