Ni / SBA-15 catalyst for preparing butane through C4 hydrocarbon hydrogenation as well as preparation method and application of Ni / SBA-15 catalyst

Abstract

The invention relates to the technical field of hydrogenation catalysis, in particular to a Ni / SBA-15 catalyst for preparing butane through C4 hydrocarbon hydrogenation as well as a preparation method and application of the Ni / SBA-15 catalyst for preparing butane through C4 hydrocarbon hydrogenation, and the Ni / SBA-15 catalyst for preparing butane through C4 hydrocarbon hydrogenation is prepared according to the following steps: dissolving a required amount of nickel salt in water to obtain a nickel salt solution; adding a required amount of strip-shaped SBA-15 molecular sieve into the nickel salt solution, and uniformly mixing to obtain a reaction mixture; and sequentially carrying out ultrasonic treatment, standing, drying, roasting and reduction treatment on the reaction mixture to obtain the Ni / SBA-15 catalyst for preparing butane through C4 hydrocarbon hydrogenation. The Ni / SBA-15 catalyst for butane preparation through C4 hydrocarbon hydrogenation has the characteristics of large specific surface area and concentrated pore size distribution, has excellent catalytic performance in butane preparation through alkyne-rich C4 hydrocarbon selective hydrogenation, and has the beneficial effects of low cost and environmental protection.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogenation catalysis, and is a Ni / SBA-15 catalyst for hydrogenating C4 hydrocarbons to butane, and a preparation method and application thereof. Background Art

[0002] my country is rich in C4 resources, but the chemical utilization rate is low. In addition, C4 hydrocarbons contain a small amount of dienes and alkynes, which will lead to unsafe venting. Dienes and alkynes are prone to polymerization during chemical utilization, causing catalyst poisoning. The use of a large amount of butene and butane will reduce their value after dilution. Catalytic hydrogenation technology can be used to hydrogenate alkyne-containing materials into high-value-added chemical raw materials. The hydrogenation of dienes and alkynes is mainly hydrogenation to butane and butane. For butane fractions containing a small amount of dienes and alkynes, the dienes and alkynes are selectively hydrogenated to butane, which can improve the purity of butane. Research on the selective hydrogenation of C4 hydrocarbons to butane has great application significance.

[0003] The key to the selective hydrogenation of C4 highly unsaturated hydrocarbons is to control the hydrogenation of reactants and inhibit the side reactions of carbon deposition and cracking into smaller molecules, otherwise the process selectivity will deteriorate and the yield of the target product will decrease. In order to obtain the target product butane, a selective and targeted hydrogenation catalyst should be used, so the development of efficient catalysts has become the core of selective hydrogenation technology.

[0004] Supported catalysts are the main catalyst type for the selective hydrogenation of carbon tetraacetylenes. 2 O 3 、SiO 2 、TiO 2 and molecular sieves, etc., which can effectively improve the selective hydrogenation activity, selectivity and stability, but still cannot meet the requirements of corporate products. In recent years, SBA-15 molecular sieve has been widely used in the field of catalysis due to its special hexagonal pore structure, large specific surface area and pore volume, and good stability. Its unique two-dimensional pores play a key role in the adsorption process of reaction molecules. The particle morphology and pore structure of SBA-15 molecular sieve have a great influence on the catalytic performance of the catalyst. By controlling the synthesis conditions, the two-dimensional length, morphology and particle size of the hexagonal SBA-15 molecular sieve can be controlled to improve the selectivity in the hydrogenation reaction of C4 hydrocarbons, which is of great significance for its application in the selective hydrogenation catalyst of C4 hydrocarbons. Summary of the invention

[0005] The present invention provides a Ni / SBA-15 catalyst for preparing butane by hydrogenating C4 hydrocarbons and a preparation method thereof, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problems of poor selectivity and low conversion rate in the existing selective hydrogenation of C4 highly unsaturated hydrocarbons to prepare butane.

[0006] One of the technical solutions of the present invention is achieved by the following measures: A Ni / SBA-15 catalyst for hydrogenating C4 hydrocarbons to butane is prepared according to the following steps:

[0007] Step 1, dissolving a required amount of nickel salt in water to obtain a nickel salt solution;

[0008] Step 2, adding a required amount of long strip SBA-15 molecular sieve to the nickel salt solution, mixing evenly, to obtain a reaction mixture;

[0009] Step 3, subjecting the reaction mixture to ultrasonic treatment, standing treatment, drying, calcination and reduction treatment in sequence to obtain a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane;

[0010] The aspect ratio of the long strip SBA-15 molecular sieve is 10 to 17.

[0011] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions:

[0012] The nickel salt is Ni(NO 3 ) 2 6H 2 O; the mass ratio of nickel salt to long strip SBA-15 molecular sieve is 0.060:1.0 to 0.090:1.0.

[0013] The reaction mixture is subjected to ultrasonic treatment, standing, drying, calcination and reduction treatment in sequence to obtain a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane, comprising:

[0014] The reaction mixture is ultrasonicated for 20 to 45 minutes, and then allowed to stand at room temperature for 10 to 14 hours. After drying at 75 to 85°C, it is placed in a muffle furnace, and the temperature is increased to 540 to 560°C at a heating rate of 2°C / min. The reaction mixture is then calcined at a constant temperature for 5.5 to 6.5 hours to obtain solid particles. The solid particles are reduced in a hydrogen atmosphere to obtain a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane.

[0015] The above-mentioned long strip SBA-15 molecular sieve is prepared according to the following method:

[0016] In the first step, a required amount of P123 (polyethylene oxide-polypropylene oxide-polyethylene oxide), concentrated hydrochloric acid and water are mixed and stirred until P123 is completely dissolved to obtain a first mixed solution;

[0017] The second step is to add a required amount of silicon source ethyl orthosilicate to the first mixed solution, and stir to obtain a second mixed solution;

[0018] The third step is to perform hydrothermal crystallization on the second mixed solution to obtain a molecular sieve containing a template;

[0019] In the fourth step, the molecular sieve containing the template is calcined at high temperature to obtain a long strip of SBA-15 molecular sieve.

[0020] In the first step, the stirring temperature is 47°C to 55°C.

[0021] In the first step above, the molar ratio of silicon source tetraethyl orthosilicate, P123, concentrated hydrochloric acid and water is 1:(0.015 to 0.019):(5.8 to 6.2):(135 to 140).

[0022] In the above second step, the stirring temperature is 47° C. to 55° C., the stirring speed is 500 r / min to 1000 r / min, and the stirring time is 20 h to 25 h.

[0023] In the third step, the temperature of the hydrothermal crystallization is 110° C. to 125° C., and the time is 20 h to 25 h.

[0024] In the fourth step, the operation of calcination at high temperature is as follows: placing the molecular sieve containing the template in a muffle furnace, heating the temperature to 500° C. to 600° C. at a heating rate of 2° C. / min, and then calcining at a constant temperature for 5.5 h to 6.5 h.

[0025] The above-mentioned long strip SBA-15 molecular sieve has a length of 800nm ​​to 1300nm, a diameter of 60nm to 120nm, a pore size of 9nm to 10nm, and a pore volume of 1.3cm 3 / g to 1.5cm 3 / g, with a specific surface area of ​​400m 2 / g to 500m 2 / g.

[0026] The third technical solution of the present invention is achieved by the following measures: A method for preparing a Ni / SBA-15 catalyst for hydrogenating C4 hydrocarbons to butane is carried out according to the following steps:

[0027] Step 1, dissolving a required amount of nickel salt in water to obtain a nickel salt solution;

[0028] Step 2, adding a required amount of long strip SBA-15 molecular sieve to the nickel salt solution, mixing evenly, to obtain a reaction mixture;

[0029] Step 3, subjecting the reaction mixture to ultrasonic treatment, standing treatment, drying, calcination and reduction treatment in sequence to obtain a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane;

[0030] The aspect ratio of the long strip SBA-15 molecular sieve is 10 to 17.

[0031] The third technical solution of the present invention is achieved through the following measures: an application of a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane in the selective hydrogenation of acetylene-rich C4 hydrocarbons to butane.

[0032] The following is a further optimization and / or improvement of the third technical solution of the above invention:

[0033] The reaction conditions for the selective hydrogenation of the above-mentioned alkyne-rich carbon four to butane are:

[0034] The reaction temperature is 38°C to 42°C, the reaction pressure is 0.8MPa to 1.2MPa, and the volumetric space velocity is 14h -1 Until 22h -1 , the hydrogen / hydrocarbon ratio is 140 to 180 (v / v).

[0035] The raw materials for selective hydrogenation of alkyne-rich carbon four to butane are composed of the following molar percentages: the total amount of dienes and alkynes is 2% to 20%, and the rest is butane.

[0036] The invention provides a Ni / SBA-15 catalyst for hydrogenating C4 hydrocarbons to butane, which has the characteristics of large specific surface area and concentrated pore size distribution. The catalyst has excellent catalytic performance in the selective hydrogenation reaction of acetylene-rich C4 hydrocarbons, high conversion rate, good selectivity, low cost, and green environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Attached Figure 1 The SEM images of the SBA-15 molecular sieves of Examples 14 and 15 of the present invention and Comparative Examples 4 and 5 are shown.

[0038] Attached Figure 2 N is the N of the Ni / SBA-15 catalysts of Examples 14 and 15 of the present invention and Comparative Examples 4 and 5. 2 -Adsorption-desorption isotherms (a, b) and pore size distribution curves (c, d). DETAILED DESCRIPTION

[0039] The present invention is not limited by the following embodiments, and the specific implementation method can be determined according to the technical scheme of the present invention and the actual situation. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all known and commonly used chemical reagents and chemicals in the prior art; unless otherwise specified, the percentages in the present invention are all mass percentages; the normal temperature and room temperature in the present invention generally refer to the temperature of 15°C to 25°C, and are generally defined as 25°C.

[0040] The present invention will be further described below in conjunction with embodiments:

[0041] Example 1: The Ni / SBA-15 catalyst for hydrogenating C4 hydrocarbons to butane is prepared according to the following steps:

[0042] Step 1, dissolving a required amount of nickel salt in water to obtain a nickel salt solution;

[0043] Step 2, adding a required amount of long strip SBA-15 molecular sieve to the nickel salt solution, mixing evenly, to obtain a reaction mixture;

[0044] Step 3, subjecting the reaction mixture to ultrasonic treatment, standing treatment, drying, calcination and reduction treatment in sequence to obtain a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane;

[0045] The aspect ratio of the long strip SBA-15 molecular sieve is 10 to 17.

[0046] Example 2: As an optimization of the above example, the nickel salt is Ni(NO 3 ) 2 6H 2 O; the mass ratio of nickel salt to long strip SBA-15 molecular sieve is 0.060:1.0 to 0.090:1.0.

[0047] Example 3: As an optimization of the above example, the reaction mixture is subjected to ultrasonic treatment, standing, drying, calcination, and reduction treatment in sequence to obtain a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane, comprising:

[0048] The reaction mixture is ultrasonicated for 20 to 45 minutes, and then allowed to stand at room temperature for 10 to 14 hours. After drying at 75 to 85°C, it is placed in a muffle furnace, and the temperature is increased to 540 to 560°C at a heating rate of 2°C / min. The reaction mixture is then calcined at a constant temperature for 5.5 to 6.5 hours to obtain solid particles. The solid particles are reduced in a hydrogen atmosphere to obtain a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane.

[0049] Example 4: As an optimization of the above example, a long strip of SBA-15 molecular sieve was prepared according to the following method:

[0050] In the first step, a required amount of P123 (polyethylene oxide-polypropylene oxide-polyethylene oxide), concentrated hydrochloric acid and water are mixed and stirred until P123 is completely dissolved to obtain a first mixed solution;

[0051] The second step is to add a required amount of silicon source ethyl orthosilicate to the first mixed solution, and stir to obtain a second mixed solution;

[0052] The third step is to perform hydrothermal crystallization on the second mixed solution to obtain a molecular sieve containing a template;

[0053] In the fourth step, the molecular sieve containing the template is calcined at high temperature to obtain a long strip of SBA-15 molecular sieve.

[0054] Example 5: As an optimization of the above example, in the first step, the stirring temperature is 47° C. to 55° C. Specifically, the optimized condition is: the stirring temperature is 48° C. to 52° C.

[0055] Example 6: As an optimization of the above example, in the first step, the molar ratio of silicon source tetraethyl orthosilicate, P123, concentrated hydrochloric acid and water is 1: (0.015 to 0.019): (5.8 to 6.2): ​​(135 to 140).

[0056] Example 7: As an optimization of the above example, in the second step, the stirring temperature is 47°C to 55°C, the stirring speed is 500r / min to 1000r / min, and the stirring time is 20h to 25h. Specifically, the optimized conditions are: the stirring temperature is 48°C to 52°C, and the stirring speed is 550r / min to 650r / min.

[0057] Example 8: As an optimization of the above example, in the third step, the temperature of the hydrothermal crystallization is 110°C to 125°C, and the time is 20h to 25h.

[0058] Example 9: As an optimization of the above example, in the fourth step, the operation of calcination at high temperature is: placing the molecular sieve containing the template in a muffle furnace, heating the temperature to 500°C to 600°C at a heating rate of 2°C / min, and then calcining at a constant temperature for 5.5h to 6.5h.

[0059] Example 10: As an optimization of the above example, the length of the long SBA-15 molecular sieve is 800nm ​​to 1300nm, the diameter is 60nm to 120nm, the pore size is 9nm to 10nm, and the pore volume is 1.3cm 3 / g to 1.5cm 3 / g, with a specific surface area of ​​400m 2 / g to 500m 2 Specifically, under the optimized conditions, when the stirring temperature is 48°C to 52°C and the stirring speed is 550r / min to 650r / min in the second step, the morphology of the prepared long strip SBA-15 molecular sieve is: length 850nm to 1050nm, diameter 60nm to 90nm, and aspect ratio 10 to 17.

[0060] Example 11: Application of the Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane in the selective hydrogenation of acetylene-rich C4 hydrocarbons to butane.

[0061] Example 12: As an optimization of the above example, the reaction conditions for selective hydrogenation of acetylene-rich carbon four to butane are:

[0062] The reaction temperature is 38°C to 42°C, the reaction pressure is 0.8MPa to 1.2MPa, and the volumetric space velocity is 14h-1 Until 22h -1 , the hydrogen / hydrocarbon ratio is 140 to 180 (v / v).

[0063] Example 13: As an optimization of the above example, the raw material for selective hydrogenation of acetylene-rich carbon tetrahydrofuran to butane is composed of the following molar percentages: the total amount of dienes and alkynes is 2% to 20%, and the rest is butane.

[0064] Example 14: The preparation process of the Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane is as follows:

[0065] ① Preparation of long strip SBA-15 molecular sieve:

[0066] S1-1, take 4.00 g of P123, 20.73 mL of concentrated hydrochloric acid and 87.92 mL of deionized water and place them in a beaker, and stir them continuously for 1 h in a 50°C water bath until P123 is completely dissolved to obtain a first mixed solution;

[0067] S1-2, add 8.452 g of ethyl orthosilicate dropwise to the first mixed solution, heat in a water bath at 50° C. and stir for 24 h at a stirring rate of 900 r / min to obtain a second mixed solution;

[0068] S1-3, transferring the second mixed solution into a polytetrafluoroethylene kettle and placing it in an oven for crystallization at a temperature of 120° C. for a crystallization time of 24 h to obtain a third mixed solution;

[0069] S1-4, washing the third mixed solution with ethanol and deionized water in turn, and drying at 80° C. for 6 h to obtain a long strip of SBA-15 molecular sieve containing a template;

[0070] S1-5, placing the long strip SBA-15 molecular sieve containing the template in a muffle furnace and calcining it under programmed temperature to obtain a long strip SBA-15 molecular sieve, wherein the programmed temperature increase rate is 2°C / min, the calcination temperature is 550°C, and the constant temperature calcination time is 6h.

[0071] The morphology of the long strip SBA-15 molecular sieve obtained in this example is: length of 1100nm to 1300nm, diameter of 80nm to 120nm, pore size of 9.42nm, pore volume of 1.4cm 3 / g, specific surface area is 430.62m 2 / g, and the aspect ratio is 10 to 17.

[0072] ② Preparation of Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane: Ni / SBA-15 catalyst was prepared by equal volume impregnation method.

[0073] S2-1, 0.080 g Ni(NO3 ) 2 6H 2 O, add 3.5 mL of deionized water to obtain a nickel salt solution;

[0074] S2-3, adding the nickel salt solution dropwise to 1.0 g of a long strip of SBA-15 molecular sieve, and then subjecting the long strip of SBA-15 molecular sieve containing the nickel salt to calcination at a programmed temperature in a muffle furnace at a rate of 2°C / min, a calcination temperature of 550°C, and a calcination time of 6 hours after ultrasonic treatment for 30 minutes, standing for 12 hours, and drying at 80°C for 6 hours to obtain solid particles;

[0075] S2-3, the solid particles are tableted and sieved, and then reduced in a hydrogen atmosphere to obtain a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane, wherein the mesh size of the sieve is 30 to 40 meshes, the reduction temperature is 450°C, and the reduction time is 8 hours.

[0076] Example 15: The preparation process of the Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane is as follows:

[0077] ① Preparation of long strip SBA-15 molecular sieve:

[0078] S1-1, take 4.20 g of P123, 21.40 mL of concentrated hydrochloric acid and 85.42 mL of deionized water and place them in a beaker, and stir them continuously for 1 h in a 50°C water bath until P123 is completely dissolved to obtain a first mixed solution;

[0079] S1-2, add 9.00 g of tetraethyl orthosilicate dropwise to the first mixed solution, heat in a water bath at 50° C. and stir for 24 h at a stirring rate of 600 r / min to obtain a second mixed solution;

[0080] S1-3, transferring the second mixed solution into a polytetrafluoroethylene kettle and placing it in an oven for crystallization at a temperature of 120° C. for a crystallization time of 24 h to obtain a third mixed solution;

[0081] S1-4, washing the third mixed solution with ethanol and deionized water in turn, and drying at 80° C. for 6 h to obtain a long strip of SBA-15 molecular sieve containing a template;

[0082] S1-5, placing the long strip SBA-15 molecular sieve containing the template in a muffle furnace and calcining it under programmed temperature to obtain a long strip SBA-15 molecular sieve, wherein the programmed temperature increase rate is 2°C / min, the calcination temperature is 560°C, and the constant temperature calcination time is 5.5h.

[0083] The morphology of the long strip SBA-15 molecular sieve obtained in this example is: length 850nm to 1050nm, diameter 60nm to 90nm, pore size 9.65nm, pore volume 1.42cm 3 / g, specific surface area is 465.31m 2 / g, and the aspect ratio is 10 to 17.

[0084] ② Preparation of Ni / SBA-15 catalyst: Ni / SBA-15 catalyst was prepared by equal volume impregnation method.

[0085] S2-1, 0.080 g Ni(NO 3 ) 2 6H 2 O, add 3.5 mL of deionized water to obtain a nickel salt solution;

[0086] S2-2, adding the nickel salt solution dropwise to 1.0 g of a long strip of SBA-15 molecular sieve, and then subjecting the long strip of SBA-15 molecular sieve containing the nickel salt to calcination at a programmed temperature in a muffle furnace at a rate of 2°C / min, a calcination temperature of 550°C, and a calcination time of 6 hours after ultrasonic treatment for 30 minutes, standing for 12 hours, and drying at 80°C for 6 hours to obtain solid particles;

[0087] S2-3, the solid particles are tableted and sieved, and then reduced in a hydrogen atmosphere to obtain a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane, wherein the mesh size of the sieve is 30 to 40 meshes, the reduction temperature is 450°C, and the reduction time is 8 hours.

[0088] Comparative Example 1: The difference from Example 14 is that in step S1-1, the first mixed solution is obtained by the following steps: 4.00 g of P123, 6.97 mL of concentrated hydrochloric acid, 131.02 mL of deionized water, 26.52 mL of anhydrous ethanol and 0.708 g of hexadecyltrimethylammonium bromide are continuously stirred in a water bath at 40° C. until P123 is completely dissolved to obtain the first mixed solution. The remaining steps are the same.

[0089] The SBA-15 molecular sieve obtained in this comparative example is spherical, with a diameter of 2.5 μm to 3.5 μm, a pore size of 1.98 nm, and a pore volume of 0.68 cm 3 / g, specific surface area is 760.54m 2 The spherical SBA-15 molecular sieve was further prepared according to the steps of Example 14 to obtain a Ni / SBA-15 catalyst.

[0090] Comparative Example 2: The difference from Example 14 is that in steps S1-1 and S1-2, the water bath temperature is 30° C. The remaining steps are the same.

[0091] The SBA-15 molecular sieve obtained in this comparative example is short columnar, with a length of 700nm to 1100nm, a diameter of 350nm to 450nm, a pore size of 7.74nm, and a pore volume of 1.0cm 3 / g, specific surface area is 432.78m 2 / g, and the aspect ratio is 1.5 to 3. The short columnar SBA-15 molecular sieve is further prepared according to the steps of Example 14 to obtain a Ni / SBA-15 catalyst.

[0092] Comparative Example 3: The difference from Example 14 is that in steps S1-1 and S1-2, the water bath temperature is 40° C. The remaining steps are the same.

[0093] The SBA-15 molecular sieve obtained in this example is in the shape of short strips, with a length of 500 nm to 650 nm, a diameter of 100 nm to 150 nm, a pore size of 7.77 nm, and a pore volume of 1.63 cm 3 / g, specific surface area is 568.12m 2 / g, and the aspect ratio is 3 to 5. The short strip SBA-15 molecular sieve is further prepared according to the steps of Example 14 to obtain a Ni / SBA-15 catalyst.

[0094] Comparative Example 4: The difference from Example 14 is that in step S1-2, the stirring rate is 300 r / min. The remaining steps are the same.

[0095] The SBA-15 molecular sieve obtained in this comparative example is in the shape of long strips, with a length of 650nm to 900nm, a diameter of 50nm to 65nm, a pore size of 9.82nm, and a pore volume of 1.47cm 3 / g, specific surface area is 511.44m 2 / g, and the aspect ratio is 10 to 17. The Ni / SBA-15 catalyst is further prepared from the long strip SBA-15 molecular sieve according to the steps of Example 14.

[0096] Comparative Example 5: The difference from Example 14 is that in step S1-2, the stirring rate is 0 r / min. The remaining steps are the same.

[0097] The SBA-15 molecular sieve obtained in this comparative example is in the shape of long strips, with a length of 500 nm to 700 nm, a diameter of 40 nm to 50 nm, a pore size of 9.97 nm, and a pore volume of 1.53 cm 3 / g, specific surface area is 534.67m 2 / g, and the aspect ratio is 10 to 17. The Ni / SBA-15 catalyst is further prepared from the long strip SBA-15 molecular sieve according to the steps of Example 14.

[0098] Application and performance evaluation of catalysts in selective hydrogenation of acetylene-rich carbon four to methane:

[0099] The Ni / SBA-15 catalyst prepared in Examples 14 and 15 and Comparative Examples 1 to 5 was applied to the selective hydrogenation reaction of acetylene-rich carbon four, and the target product was butane.

[0100] The raw material composition is as follows: diene + alkyne content is 2.80% and butane content is 97.20wt.%.

[0101] The reaction conditions are: reaction temperature 40°C, reaction pressure 1.0 MPa, volume space velocity 18 h -1 , hydrogen / hydrocarbon ratio is 160 (v / v), and Ni loading is 1.5 wt.% (calculated as Ni).

[0102] The diene + alkyne conversion and butane selectivity of the nickel-based catalysts prepared in Examples 14 and 15 and Comparative Examples 1 to 5 are shown in Table 1.

[0103] Table 1

[0104] serial number Diolefin + alkyne conversion rate / % Butane selectivity / % Embodiment 14 97.92％ 100％ Embodiment 15 99.99％ 100％ Comparative Example 1 67.83％ 100％ Comparative Example 2 55.32％ 73％ Comparative Example 3 64.58％ 21.63％ Comparative Example 4 98.21％ 94.50％ Comparative Example 5 95.62％ 90.03％

[0105] As can be seen from Table 1, in the application of selective hydrogenation of alkyne-rich carbon tetrachloride to butane prepared by the Ni / SBA-15 catalysts prepared in Example 14 and Comparative Examples 1, 2 and 3, the conversion rate and butane selectivity of the Ni / SBA-15 catalysts prepared in Example 14 and Example 15 are much higher than those of the Ni / SBA-15 catalysts prepared in Comparative Examples 1 to 3. This is because the long-range two-dimensional pores of the long strip-shaped SBA-15 molecular sieve allow the reactants and products to stay in the pores for a long time, and are easily adsorbed by the active components to undergo primary and secondary hydrogenation reactions, so that the intermediate product butene can have enough time to be hydrogenated again to butane.

[0106] From the comparison between Examples 14 and 15 and Comparative Examples 4 and 5, it can be seen that by changing the shear force during the preparation of the second mixed solution, SBA-15 molecular sieves of different sizes can be obtained, and the size of the long strip SBA-15 molecular sieve particles can be adjusted. Figure 1 As shown in the figure (SL-9 is Example 14, SL-6 is Example 15, SL-3 is Comparative Example 4, and SL-0 is Comparative Example 5). The image shows that all materials are in the form of long strips, with obvious orderly stripes on the surface of the material and small fragments attached. After measurement, the average length of the particles is 1200nm (Example 14), 950nm (Example 15), 800nm ​​(Comparative Example 4), and 580nm (Comparative Example 5).

[0107] Figure 2N is the N of the SBA-15 molecular sieve and Ni / SBA-15 catalyst of Examples 14, 15 and Comparative Examples 4 and 5. 2 Adsorption-desorption isotherms and pore size distribution curves (in the figure, SL-9 is Example 14, SL-6 is Example 15, SL-3 is Comparative Example 4, and SL-0 is Comparative Example 5). Figure 2 As can be seen in a and c, SBA-15 molecular sieves of different sizes all present typical type IV isotherms with H1 type hysteresis loops, indicating that the synthesized mesoporous materials have high order and uniform pore size distribution. 2 The adsorption-desorption isotherms and the corresponding pore size distribution diagrams can also be obtained, which also show typical type IV isotherms and H1 type hysteresis loops, and the mesoporous materials have high order and uniform pore size distribution.

[0108] The detailed structural characteristics of the SBA-15 molecular sieves and the Ni / SBA-15 catalysts loaded with Ni in Examples 14 and 15 and Comparative Examples 4 and 5 are shown in Table 2 (where S BET is the multi-point BET specific surface area; S Micro is the specific surface area in the t-plot method; S Meso V is the external specific surface area according to t-plot method; Total is the total pore volume at a single point; D HK D is the most probable pore size of the micropores by HK method; BJH is the most probable mesopore diameter according to the BJH method). As shown in Table 2, all materials have a mesopore diameter of 400 m 2 / g to 600m 2 / g high specific surface area and 9nm to 10nm mesopore diameter. As the particle size of SBA-15 molecular sieve decreases, the pore size tends to increase overall. After the active metal components are loaded, the specific surface area, pore volume and pore size of the catalyst will decrease, because the active components cover part of the pores and specific surface area.

[0109] As can be seen from Table 1, the conversion rates of dienes and alkynes are: Example 15> Example 14> Comparative Example 4> Comparative Example 5. After the addition of tetraethyl orthosilicate, the silicon source will hydrolyze and aggregate, and will gradually form micelles with the template agent P123. At this time, the dynamic shear force of stirring will accelerate the hydrolysis rate of tetraethyl orthosilicate and strengthen the solubilization effect of the micelles. As the shear force increases, the micelles gradually increase, so that the size of the molecular sieve particles finally obtained increases. As the catalyst particles decrease, the selectivity for butane decreases during the hydrogenation reaction, and butenes that are not fully hydrogenated begin to appear in the product, indicating that the size of the catalyst particles will affect the activity and selectivity of the carbon four hydrocarbon hydrogenation reaction process. Generally speaking, the larger the particle size, the higher the selectivity for butane, but the appropriate size can obtain the highest conversion rate of dienes + alkynes. The cumulative amount of polymers of the catalysts in Examples 14, 15 and Comparative Examples 4 and 5 after 8 hours of reaction is <0.001%. With the purpose of converting dienes + alkynes in C4 hydrocarbons into butane as much as possible, the Ni / SBA-15 catalyst prepared in Example 15 has good comprehensive performance in hydrogenating C4 hydrocarbons to butane in terms of hydrogenation activity, selectivity and stability.

[0110] Table 2

[0111]

[0112]

[0113] The present invention compares the catalyst support materials for selective hydrogenation of alkyne-rich carbon tetrahydrofuran to butane:

[0114] Select Al 2 O 3 , pseudo-boehmite, silica gel, ZSM-5, SBA-15 molecular sieve as carriers to prepare nickel-based catalysts for hydrogenation reaction (reaction conditions: reaction temperature 40 ° C, reaction pressure 1.0 MPa, volume space velocity 18h -1 , hydrogen / hydrocarbon ratio of 160 (v / v), Ni loading of 1.5 wt.% (calculated as Ni)), the catalysts were respectively recorded as Ni / Al, Ni / PB, Ni / Si, Ni / Z, and Ni / S (Example 14).

[0115] Table 3 shows the calculated conversion rate of dienes + alkynes and butane selectivity after hydrogenation reaction of Ni-based catalysts on different supports. It can be seen that the content of dienes + alkynes in the reaction products of Ni / Al, Ni / PB and Ni / Z is high and the conversion rate is low; although the conversion rate of Ni / Si is relatively high, the selectivity for the target product butane is poor, and within the reaction time (8 hours), the content of "green oil" (low-order olefin polymers produced during the reaction process) in the side reaction products of Ni / Si catalyst is the highest, and the stability is poor. The support type and morphology have a great influence on the selective hydrogenation performance of alkyne-rich carbon four. Comprehensively balancing activity, selectivity and stability, Ni / S (SBA-15 molecular sieve) is the most suitable catalyst for the selective hydrogenation of alkyne-rich carbon four.

[0116] Table 3

[0117] serial number Diolefin + alkyne conversion rate / % Butane selectivity / % Ni / S 97.92％ 100％ Ni / Z 5.40％ 0 Ni / Si 42.09％ 0 Ni / PB 4.35％ 0 Ni / Al 4.17％ 0

[0118] In summary, the present invention provides a Ni / SBA-15 catalyst for hydrogenating C4 hydrocarbons to butane, which is prepared from an elongated SBA-15 molecular sieve and a nickel salt, and the elongated SBA-15 molecular sieve has the characteristics of large specific surface area and concentrated pore size distribution. The Ni / SBA-15 catalyst of the present invention can convert dienes + alkynes in C4 hydrocarbons into butane as much as possible in the selective hydrogenation reaction of alkyne-rich C4 hydrocarbons, has excellent comprehensive catalytic performance, low cost, and is green and environmentally friendly.

[0119] The above technical features respectively constitute various embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A Ni / SBA-15 catalyst for hydrogenating C4 hydrocarbons to butane, characterized in that Prepared according to the following steps: Step 1, dissolving a required amount of nickel salt in water to obtain a nickel salt solution; Step 2, adding a required amount of long strip SBA-15 molecular sieve to the nickel salt solution, mixing evenly, to obtain a reaction mixture; Step 3, subjecting the reaction mixture to ultrasonic treatment, standing treatment, drying, calcination and reduction treatment in sequence to obtain a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane; The aspect ratio of the long strip SBA-15 molecular sieve is 10 to 17.

2. The Ni / SBA-15 catalyst for preparing butane by hydrogenation of C4 hydrocarbons according to claim 1, characterized in that The nickel salt is Ni(NO3)2·6H2O; the mass ratio of the nickel salt to the long strip SBA-15 molecular sieve is 0.060:1.0 to 0.090:1.

0.

3. The Ni / SBA-15 catalyst for preparing butane by hydrogenation of C4 hydrocarbons according to claim 1 or 2, characterized in that The reaction mixture is subjected to ultrasonic treatment, standing, drying, calcination and reduction treatment in sequence to obtain a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane, comprising: The reaction mixture is ultrasonicated for 20 to 45 minutes, and then allowed to stand at room temperature for 10 to 14 hours. After drying at 75 to 85°C, it is placed in a muffle furnace, and the temperature is increased to 540 to 560°C at a heating rate of 2°C / min. The reaction mixture is then calcined at a constant temperature for 5.5 to 6.5 hours to obtain solid particles. The solid particles are reduced in a hydrogen atmosphere to obtain a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane.

4. The Ni / SBA-15 catalyst for hydrogenating C4 hydrocarbons to butane according to any one of claims 1 to 3, characterized in that The length of the long SBA-15 molecular sieve is 800nm ​​to 1300nm, the diameter is 60nm to 120nm, the pore size is 9nm to 10nm, and the pore volume is 1.3cm 3 / g to 1.5cm 3 / g, specific surface area is 400m 2 / g to 500m 2 / g.

5. The Ni / SBA-15 catalyst for hydrogenating C4 hydrocarbons to butane according to any one of claims 1 to 4, characterized in that Long strip SBA-15 molecular sieve is prepared by the following method: In the first step, a required amount of P123, concentrated hydrochloric acid and water are mixed and stirred until P123 is completely dissolved to obtain a first mixed solution; The second step is to add a required amount of silicon source ethyl orthosilicate to the first mixed solution, and stir to obtain a second mixed solution; The third step is to perform hydrothermal crystallization on the second mixed solution to obtain a molecular sieve containing a template; In the fourth step, the molecular sieve containing the template is calcined at high temperature to obtain a long strip of SBA-15 molecular sieve.

6. The Ni / SBA-15 catalyst for preparing butane by hydrogenation of C4 hydrocarbons according to claim 5, characterized in that In the first step, the stirring temperature is 47°C to 55°C; or / and; the molar ratio of silicon source tetraethyl orthosilicate, P123, concentrated hydrochloric acid and water is 1:0.015 to 0.019:5.8 to 6.2:135 to 140; or / and; in the second step, the stirring temperature is 47°C to 55°C, the stirring speed is 500r / min to 1000r / min, and the stirring time is 20h to 25h.

7. The Ni / SBA-15 catalyst for preparing butane by hydrogenation of C4 hydrocarbons according to claim 5 or 6, characterized in that In the third step, the hydrothermal crystallization temperature is 110°C to 125°C, and the time is 20h to 25h; or / and; in the fourth step, the operation of calcination at high temperature is: placing the molecular sieve containing the template in a muffle furnace, heating the temperature to 500°C to 600°C at a heating rate of 2°C / min, and then calcining at a constant temperature for 5.5h to 6.5h.

8. A method for preparing the Ni / SBA-15 catalyst for hydrogenating C4 hydrocarbons to butane according to any one of claims 2 to 7, characterized in that Follow these steps: Step 1, dissolving a required amount of nickel salt in water to obtain a nickel salt solution; Step 2, adding a required amount of long strip SBA-15 molecular sieve to the nickel salt solution, mixing evenly, to obtain a reaction mixture; Step 3, subjecting the reaction mixture to ultrasonic treatment, standing treatment, drying, calcination and reduction treatment in sequence to obtain a Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane; The aspect ratio of the long strip SBA-15 molecular sieve is 10 to 17.

9. Use of the Ni / SBA-15 catalyst for hydrogenation of C4 hydrocarbons to butane according to any one of claims 1 to 7 in selective hydrogenation of acetylene-rich C4 hydrocarbons to butane.

10. The use of the Ni / SBA-15 catalyst according to claim 9 in selective hydrogenation of acetylene-rich carbon four to butane, characterized in that The reaction conditions for selective hydrogenation of acetylene-rich carbon four to butane are: reaction temperature of 38°C to 42°C, reaction pressure of 0.8MPa to 1.2MPa, and volume space velocity of 14h -1 Until 22h -1 , the hydrogen / hydrocarbon ratio is 140 to 180; or / and; the raw material for selective hydrogenation of alkyne-rich carbon four to butane is composed of the total amount of dienes and alkynes of 2% to 20% and the rest of butane in terms of molar percentage.

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