COMPOSITE OXIDE, PREPARATION METHOD FOR COMPOSITE OXIDE, HYDROGENATION CATALYST AND USE THEREOF

Abstract

A composite oxide contains 60-95 wt % of aluminum oxide and 5-40 wt % of titanium dioxide. The specific surface area of the composite oxide determined by means of BET method is expressed as X m.sup.2/g. The average pore diameter of the composite oxide determined by means of nitrogen adsorption isothermal curve method is expressed as Y nm. The ratio of X to Y is 5-30. By means of the determination of X-ray diffraction method, titanium dioxide in an anatase crystalline phase in the composite oxide accounts for 95-100 wt % of the total titanium dioxide. X is in the range of 50-200, preferably X is in the range of 60-180, more preferably in the range of 80-150, and Y is in the range of 5-25 nm. A hydrogenation catalyst that contains the composite oxide shows a high vinyl acetylene conversion rate and a high 1,3-butadiene selectivity.

Claims

1. A composite oxide, comprising 60 to 95 wt % of aluminum oxide and 5 to 40 wt % of titanium dioxide, wherein the composite oxide has a specific surface area expressed as X m2/g as measured by a BET method and an average pore diameter expressed as Y nm as measured by a nitrogen adsorption isotherm method, with a ratio of X to Y being in a range of from 5 to 30, wherein in the composite oxide, titanium dioxide in an anatase crystal phase accounts for 95 wt % to 100 wt % of the total titanium dioxide, as measured by X-ray diffraction method, and wherein X is in a range of from 50 to 200, preferably from 60 to 180, and more preferably from 80 to 150, and Y is in a range of from 5 to 25 nm.

2. The composite oxide according to claim 1, wherein the composite oxide has a pore volume expressed as Z mL/g, wherein Z is in a range of from 0.3 to 0.5, and wherein a ratio of X to Z is from 220 to 400, and preferably from 250 to 350.

3. The composite oxide according to claim 1, having at least one of the following features: X is from 90 to 150; Y is from 9 to 20, and preferably from 12 to 16; at least 85% of pores have a pore diameter in a range of 10 to 20 nm; Z is from 0.3 to 0.4; and/or the composite oxide comprises 5 wt % to 21 wt % of titanium dioxide; and the composite oxide has a coral thicket-like 3D layered structure.

4. A method for preparing a composite oxide, comprises the following steps: I, dissolving a soluble aluminum source in water to form an aluminum source solution, dissolving a titanium source in an acid solution to form a titanium source solution, and mixing an ammonium salt and an alkali liquid to form a mixed alkali solution; II, (a) adding the titanium source solution and the mixed alkali solution to the aluminum source solution, and maintaining a resulting mixed solution at a first pH value for a first period of time; (b) adding an additional amount of the mixed alkali solution to the mixed solution, and maintaining a resulting mixed solution at a second pH value for a second period of time; (c) adding an additional amount of the titanium source solution to the mixed solution, and maintaining a resulting mixed solution at a third pH value for a third period of time; III, after step II(c), raising the temperature of the mixed solution and maintaining that temperature for a fourth period of time to obtain a precipitate; and IV, drying and calcining the precipitate to obtain a composite oxide comprising alumina and titanium dioxide, with washing and filtering being preferably conducted prior to the drying.

5. The method according to claim 4, wherein in step II, the first pH value is less than 5, and preferably 3 to 4, the second pH value is greater than 8.5, and preferably 9 to 10, and the third pH value is greater than 7 and less than 9, and preferably 7.5 to 8.5.

6. The method according to claim 4, wherein each of the first, second and third periods of time is from 5 to 20 minutes, and preferably from 10 to 15 minutes; and/or the fourth period of time is from 20 to 60 minutes.

7. The method according to claim 4, wherein in step II, an operating temperature is 25 C. to 60 C.; and/or in step III, the temperature is raised to 80 C. to 150 C.; and/or in step IV, a drying temperature is 110 C. to 130 C., and/or a calcining temperature is 800 C. to 1000 C.

8. (canceled)

9. A hydrogenation catalyst, comprising the composite oxide of claim 1 and an active component, preferably the active component is nickel, and preferably the catalyst has a nickel content of 8 to 25 wt %, and more preferably 12 to 20 wt %.

10. A process for selective hydrogenation of alkynes, comprising subjecting a distillate oil to selective hydrogenation of alkynes in the presence of the hydrogenation catalyst of claim 9 to increase the production of butadiene, wherein the distillate oil comprises a C4 distillate oil, preferably a high-alkyne tail gas co-produced in a butadiene extraction unit; preferably, in the process of selective hydrogenation of alkynes, a reaction temperature is 20 C. to 40 C., a molar ratio of hydrogen to alkynes is 1:1 to 2.5:1, a pressure is 0.5 MPa to 0.8 MPa, and a circulation ratio is 10:1 to 30:1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] FIG. 1 shows a coral thicket-like 3D microscopic morphology of the alumina-titanium dioxide composite oxide prepared in Example 1.

[0060] FIG. 2 shows an XRD pattern of the alumina-titanium dioxide composite oxide prepared in Example 1.

EXAMPLES

[0061] In order to make the invention easy to be understood, the invention will be described in detail below in conjunction with examples. These examples are only for illustrative purposes and do not limit the scope of application of the invention.

[0062] Unless otherwise indicated, the raw materials or components used in the invention can be commercially obtained or prepared by a conventional method.

[0063] An ASAP 2020 model adsorption instrument (N.sub.2 adsorption and desorption method) available from the Mike Instrument Company, USA was used to determine the specific surface area and pore structure of the composite oxide. Prior to measuring, a sample of the composite oxide was degassed at 623K for 4 hours, and nitrogen was adsorbed at liquid nitrogen temperature. AMSM software was used to process the sample data, and the Brunauer-Emmet-Teller (BET) method was used to obtain the specific surface area of the sample. The Barrett-Joyner-Halenda (BJH) method was used to obtain the average pore diameter based on the nitrogen adsorption isotherm curve, and the P/Po single-point desorption curve was used to obtain the pore volume.

[0064] A QUANTA 200 model scanning electron microscope available from the FEI Company was used to observe the morphology of the composite oxide.

[0065] The crystal phase structure of the composite oxide was characterized by using an EMPYREAN X-ray diffractometer available from PANalytical B.V., the Netherlands. Cu K is used as the radiation source, X-ray tube voltage is 40 kV, light tube current is 40 mA, slit width is 10 mm, scanning range is 5-90, and scanning speed is 0.013/s.

Example 1

[0066] 328.02 g of Al.sub.2(SO.sub.4).sub.3 was dissolved in deionized water to prepare 1000 mL of aluminum sulfate solution. 21.14 g of TiO(OH).sub.2 was dissolved in 16 mL of 98 wt % sulfuric acid, and deionized water was added thereto to prepare 500 mL of metatitanic acid solution in dilute sulfuric acid. 18 g of NH.sub.4HCO.sub.3 was dissolved in 600 mL of deionized water to prepare an ammonium bicarbonate solution, then 250 mL of 27 wt % ammonia water was added thereto, and the resulting mixed solution was stirred to mix uniformly and then complemented with deionized water to prepare 1000 mL of mixed alkali solution.

[0067] Under normal pressure and at a temperature of 55 C., 230 mL of the metatitanic acid solution in dilute sulfuric acid and 360 mL of the mixed alkali solution were co-current added into 1000 mL of the prepared aluminum sulfate solution with strong stirring, and the pH value of the resulting mixed solution was maintained at 3 to 4 for 15 min. Then, additional 320 mL of the mixed alkali solution was added to bring the pH value to 9 to 10, and the reaction mixture was maintained at that pH value for 15 min. Then, the remaining metatitanic acid solution in dilute sulfuric acid was added thereto to bring the pH value to 7.5 to 8.5, and the reaction mixture was maintained at that pH value for 6 to 10 minutes. Then, the temperature was raised to 92 C. and maintained for 20 minutes, and the reaction mixture was then filtered. The filter cake was repeatedly washed with 20 times volume of deionized water 5 times, and the washed filter cake was dried at 110 C. for 6 hours and calcined at 850 C. for 5 hours. 114.3 g of composite oxide with a TiO.sub.2 content of 15.0 wt % was obtained.

[0068] It can be seen from the SEM in FIG. 1 that the composite oxide exhibits a surface micromorphology of coral thicket-like 3D layered structure. FIG. 2 shows the XRD pattern of the alumina-titanium dioxide composite oxide prepared in Example 1. For titanium dioxide, only characteristic diffraction peak of anatase appears at 20=25.4 and no diffraction peaks of other crystal phases appear at other positions, indicating that all TiO.sub.2 component in the composite oxide is present as the anatase crystal phase. In other words, the titanium dioxide in the anatase crystal phase accounts for 100 wt % of the total titanium dioxide.

Example 2

[0069] 256.04 g of Al.sub.2(SO.sub.4).sub.3 was dissolved in deionized water to prepare 1000 mL of aluminum sulfate solution. 32.15 g of Ti(SO.sub.4).sub.2 was dissolved in deionized water, and 5 mL of concentrated sulfuric acid (98%) was added thereto, to prepare 500 mL of titanium sulfate solution in dilute sulfuric acid. 18 g of NH.sub.4HCO.sub.3 was dissolved in 600 mL of deionized water to prepare an ammonium bicarbonate solution, then 250 mL of 27 wt % ammonia water was added thereto, and the resulting mixed solution was stirred to mix uniformly and then complemented with deionized water to prepare a 1000 mL mixed alkali solution.

[0070] Under normal pressure and at a temperature of 60 C., 280 mL of the titanium sulfate solution in dilute sulfuric acid and 320 mL of the mixed alkali solution were co-current added into 1000 mL of the aluminum sulfate solution with strong stirring, and the pH value of the resulting mixed solution was maintained at 3 to 4 for 15 min. Then, additional 240 mL of the mixed alkali solution was added to bring the pH value to 9 to 10, and the reaction mixture was maintained at that pH value for 15 min. Then, the remaining titanium sulfate solution in dilute sulfuric acid was added thereto to bring the pH value to 7.5 to 8.5. The temperature was raised to 85 C. and maintained for 40 minutes, and the reaction mixture was then filtered. The filter cake was repeatedly washed with 20 times volume of deionized water 5 times, and the washed filter cake was dried at 110 C. for 6 hours and calcined at 950 C. for 5 hours. 86.8 g of alumina-titanium dioxide composite oxide with a TiO.sub.2 content of 12.3% was obtained.

Example 3

[0071] The procedure for preparing titanium dioxide-alumina composite oxide as described in Example 1 was repeated, except that 379.79 g of Al(NO.sub.3).sub.3 was dissolved in deionized water to prepare 1000 mL of aluminum nitrate solution and that 25.99 g of Ti(OCH.sub.2CH.sub.3).sub.4 was dissolved in absolute ethanol to prepare 500 mL of tetraethyl titanate solution in ethanol. Finally, alumina-titanium dioxide composite oxide with a TiO.sub.2 content of 9.1% was obtained.

Example 4

[0072] The procedure for preparing titanium dioxide-alumina composite oxide as described in Example 1 was repeated, except that 396.92 g of Al(NO.sub.3).sub.3 was dissolved in deionized water to prepare 1000 mL of aluminum nitrate solution and that 6.13 g of TiO(OH).sub.2 was dissolved in sulfuric acid and deionized water was added thereto to prepare 500 mL of metatitanic acid solution in dilute sulfuric acid. Finally, alumina-titanium dioxide composite oxide with a TiO.sub.2 content of 5.0% was obtained.

Example 5

[0073] The procedure for preparing titanium dioxide-alumina composite oxide as described in Example 1 was repeated, except that 396.92 g of Al(NO.sub.3).sub.3 was dissolved in deionized water to prepare 1000 mL of aluminum nitrate solution, that 6.13 g of TiO(OH).sub.2 was dissolved in sulfuric acid and deionized water was added thereto to prepare 500 mL of metatitanic acid solution in dilute sulfuric acid, and that the temperature for calcining the filter cake was 800 C. Finally, alumina-titanium dioxide composite oxide with a TiO.sub.2 content of 5.0% was obtained.

Example 6

[0074] The procedure for preparing titanium dioxide-alumina composite oxide as described in Example 1 was repeated, except that 374.13 g of AlCl.sub.3.Math.6H.sub.2O was dissolved in deionized water to prepare 1000 mL of aluminum chloride solution and that 59.99 g of Ti(OCH.sub.2CH.sub.3).sub.4 was dissolved in absolute ethanol to prepare 500 mL of tetraethyl titanate solution in ethanol. Finally, alumina-titanium dioxide composite oxide with a TiO.sub.2 content of 21.0% was obtained.

[0075] Scanning electron microscopy and XRD test results showed that the composite oxides prepared in Examples 2-6 were similar to that of Example 1, exhibiting a surface micromorphology of coral thicket-like 3D layered structure, and that all TiO.sub.2 component in the composite oxides was present as the anatase crystal phase.

Comparative Example 1

[0076] 268.46 g of Al.sub.2(SO.sub.4).sub.3 was dissolved in deionized water to prepare 1000 mL of aluminum sulfate solution. 24.5 g of TiO(OH).sub.2 was dissolved in sulfuric acid, and deionized water was added thereto to prepare 1000 mL of metatitanic acid solution in dilute sulfuric acid. 18 g of NH.sub.4HCO.sub.3 was dissolved in 600 mL of deionized water to prepare an ammonium bicarbonate solution, then 250 mL of 24-28 wt % ammonia water was added thereto, and the resulting mixed solution was stirred to mix uniformly and then complemented with deionized water to prepare 1000 mL of mixed alkali solution.

[0077] Under the conditions of normal pressure and a temperature of 70-75 C., the above three solutions, i.e., the aluminum sulfate solution in deionized water, the metatitanic acid solution in dilute sulfuric acid and the mixed alkali solution, were co-current combined to conduct co-precipitation. The flow rate of the mixed alkali solution was controlled so as to keep the pH value of the precipitating reactants within a range of 5.0 to 6.0 for 8 minutes, then the flow rate of the mixed alkali solution was increased so as to keep the pH value of the combined solution within a range of 8.5 to 9.5 for 8 minutes, then the flow rate of the mixed alkali solution was reduced so as to keep the pH value of the combined solution within a range of 5.0 to 6.0 for 8 minutes, and then the flow rate of the mixed alkali solution was increased so as to keep the pH value of the precipitating reactants within a range of 8.5 to 9.5. The operations were so repeated until the dropwise addition of the solutions A1 and B1 were completed. The reaction liquid was left to stand for 30 minutes at 70 C. and then filtered, and the filter cake was washed with 15 times volume of deionized water for 30 minutes, filtered again, and washed again. This process was repeated four times, and finally the filter cake was dried at 100-120 C. for 8-12 hours and calcined at 950 C. for 5 hours to afford a titanium dioxide-alumina composite. The structure and performance results of the composite are shown in Table 1.

Comparative Example 2

[0078] 401.88 g of analytically pure AlCl.sub.3.Math.6H.sub.2O was dissolved in 1000 ml of deionized water to prepare solution A1; 43.25 g of chemically pure Ti(OCH.sub.2CH.sub.3).sub.4 was dissolved in 500 ml of benzene (having a benzene content of 99.8 wt %) to prepare solution B1; 18 g of analytically pure NH.sub.4HCO.sub.3 was dissolved in 600 ml of deionized water, 250 ml of 24-28 wt % ammonia water was added thereto, and the resulting mixed solution was stirred to mix uniformly and then complemented with deionized water to prepare 1000 mL of solution C.sub.1.

[0079] Under the conditions of normal pressure and a temperature of 70-75 C., the three solutions, A1, B1 and C1, were co-current combined to conduct co-precipitation. The flow rate of the solution C1 was controlled so as to keep the pH value of the precipitating reactants within a range of 5.0 to 6.0 for 8 minutes, then the flow rate of the solution C1 was increased so as to keep the pH value of the combined solution within a range of 8.5 to 9.5 for 8 minutes, then the flow rate of the solution C1 was reduced so as to keep the pH value of the combined solution within a range of 5.0 to 6.0 for 8 minutes, and then the flow rate of the solution C1 was increased so as to keep the pH value of the precipitating reactants within a range of 8.5 to 9.5. The operations were so repeated until the dropwise addition of the solutions A1 and B1 were completed. The reaction liquid was left to stand for 30 minutes at 70 C. and then filtered, and the filter cake was washed with 15 times volume of deionized water for 30 minutes, filtered again, and washed again. This process was repeated four times, and finally the filter cake was dried at 100-120 C. for 8-12 hours and calcined at 550 C. for 5 hours to afford 42.7 g of a titanium dioxide-alumina composite. The structure and performance results of the composite are shown in Table 1.

Comparative Example 3

[0080] The procedure for preparing titanium dioxide-alumina composite oxide as described in Comparative Example 2 was repeated, except that the calcining temperature after drying was 950 C.

[0081] Scanning electron microscopy and XRD test results showed that the composite oxides prepared in Comparative Examples 1-3 did not have a coral thicket-like 3D layered structure, and the TiO.sub.2 crystal phase therein is mainly rutile crystal phase.

[0082] For the carriers prepared above, the N.sub.2 adsorption-desorption method was used to determine the specific surface area and pore structure of the composite oxides.

TABLE-US-00001 TABLE 1 Analytical data of titanium dioxide-alumina composites BET specific Pore Average surface volume pore TiO.sub.2 area X Z diameter Y content (m.sup.2/g) (mL/g) (nm) X/Y X/Z Example 1 15.0 wt % 110 0.39 15.6 7.05 282 Example 2 12.3 wt % 112 0.38 15.4 7.27 295 Example 3 9.1 wt % 120 0.38 15.7 7.64 316 Example 4 5.0 wt % 130 0.39 15.8 8.23 333 Example 5 5.0 wt % 153 0.48 13.6 11.25 319 Example 6 21.0 wt % 105 0.38 14.8 7.09 276 Comp. 20.0 wt % 55 0.31 15.0 3.67 177 Example 1 Comp. 15.14 wt % 286 0.54 7.5 38.1 530 Example 2 Comp. 15.14 wt % 64 0.32 14.9 4.30 200 Example 3

TABLE-US-00002 TABLE 2 Pore distribution of titanium dioxide-alumina composite support Proportion of pores with a pore diameter in a range of 10 to 20 nm accounting for all pores, on volume basis Example 1 86% Example 2 88% Example 3 89% Example 4 90% Example 5 85% Example 6 85% Comp. 78% Example 1 Comp. 34% Example 2 Comp. 82% Example 3

Catalyst Preparation

Example 7

[0083] 156 g of the composite oxide prepared in Example 1 was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 24.72 g Ni/100 mL for 1 h. After filtering, the filer cake was dried at 110 C. for 6 h and then calcined at 600 C. for 4 h to afford Ni/Al.sub.2O.sub.3TiO.sub.2 catalyst A having a Ni content of 13.6800.

Example 8

[0084] 180 g of the composite oxide prepared in Example 1 was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 20.0 g Ni/100 mL for 0.5 h. After filtering, the filer cake was dried at 110 C. for 5 h and then calcined at 550 C. for 5 h. Next, 100 g of the above-prepared calcined catalyst precursor was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 12.24 g Ni/100 mL for 0.5 h. After filtering, the filer cake was dried at 110 C. for 4 h and then calcined at 550 C. for 6 h to afford Ni/Al.sub.2O.sub.3TiO.sub.2 catalyst B having a Ni content of 19.82%.

Example 9

[0085] 156 g of the composite oxide prepared in Example 6 was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 13.56 g Ni/100 mL for 1 h. After filtering, the filer cake was dried at 110 C. for 6 h and then calcined at 600 C. for 4 h to afford Ni/Al.sub.2O.sub.3TiO.sub.2 catalyst C having a Ni content of 8%.

Example 10

[0086] 180 g of the composite oxide prepared in Example 4 was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 20.0 g Ni/100 mL for 0.5 h. After filtering, the filer cake was dried at 110 C. for 5 h and then calcined at 550 C. for 5 h. Next, 100 g of the above-prepared calcined catalyst precursor was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 20 g Ni/100 mL for 0.5 h. After filtering, the filer cake was dried at 110 C. for 4 h and then calcined at 550 C. for 6 h to afford Ni/Al.sub.2O.sub.3TiO.sub.2 catalyst D having a Ni content of 25%.

Example 11

[0087] 180 g of the composite oxide prepared in Example 2 was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 20.0 g Ni/100 mL for 0.5 h. After filtering, the filer cake was dried at 110 C. for 5 h and then calcined at 550 C. for 5 h. Next, 100 g of the above-prepared calcined catalyst precursor was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 12.24 g Ni/100 mL for 0.5 h. After filtering, the filer cake was dried at 110 C. for 4 h and then calcined at 550 C. for 6 h to afford Ni/Al.sub.2O.sub.3TiO.sub.2 catalyst E having a Ni content of 19.82%.

Example 12

[0088] 180 g of the composite oxide prepared in Example 3 was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 20.0 g Ni/100 mL for 0.5 h. After filtering, the filer cake was dried at 110 C. for 5 h and then calcined at 550 C. for 5 h. Next, 100 g of the above-prepared calcined catalyst precursor was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 12.24 g Ni/100 mL for 0.5 h. After filtering, the filer cake was dried at 110 C. for 4 h and then calcined at 550 C. for 6 h to afford Ni/Al.sub.2O.sub.3TiO.sub.2 catalyst F having a Ni content of 19.82%.

Example 13

[0089] 156 g of the composite oxide prepared in Example 5 was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 24.72 g Ni/100 mL for 1 h. After filtering, the filer cake was dried at 110 C. for 6 h and then calcined at 600 C. for 4 h to afford Ni/Al.sub.2O.sub.3TiO.sub.2 catalyst G having a Ni content of 13.68%.

Example 14

[0090] 100 g of the composite oxide prepared in Example 1 was immersed into 85 mL of aqueous solution of palladium chloride having a palladium content of 0.32 g/100 mL. After 1.5 hours, the impregnated composite carrier was filtered out, reduced with 120 mL of aqueous solution of hydrazine hydrate with a concentration of 10 wt % at room temperature for 1 hour, rinsed repeatedly with deionized water until the chloride ions were washed off. After draining, the solids were dried at 120 C. for 6 hours and then calcined at 480 C. for 4 hours to afford Pd/Al.sub.2O.sub.3TiO.sub.2 catalyst H having a Pd content of 0.3%.

Comparative Example 4

[0091] 156 g of the composite oxide prepared in Comparative Example 1 was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 24.72 g Ni/100 mL for 1 h. After filtering, the filer cake was dried at 110 C. for 6 h and then calcined at 600 C. for 4 h to afford Ni/Al.sub.2O.sub.3TiO.sub.2 catalyst I having a Ni content of 13.68%.

Comparative Example 5

[0092] 156 g of the composite oxide prepared in Comparative Example 2 was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 24.72 g Ni/100 mL for 1 h. After filtering, the filer cake was dried at 110 C. for 6 h and then calcined at 600 C. for 4 h to afford Ni/Al.sub.2O.sub.3TiO.sub.2 catalyst J having a Ni content of 13.68%.

Comparative Example 6

[0093] 156 g of the composite oxide prepared in Comparative Example 3 was impregnated with 100 mL of aqueous solution of nickel nitrate having a concentration of 24.72 g Ni/100 mL for 1 h. After filtering, the filer cake was dried at 110 C. for 6 h and then calcined at 600 C. for 4 h to afford Ni/Al.sub.2O.sub.3TiO.sub.2 catalyst K having a Ni content of 13.68%.

Example 15

[0094] This example demonstrated the application of catalysts in the selective hydrogenation of butadiene extraction tail gas.

[0095] The catalysts used in this example were the catalysts A-K.

[0096] The raw material used in this example was butadiene extraction tail gas from a certain plant. The composition is shown in Table 3.

TABLE-US-00003 TABLE 3 Composition of the butadiene extraction tail gas from a certain plant No. Composition Wt % 1 Isobutane 2.658 2 n-butane 5.652 3 trans-2-butene 5.994 4 n-butene 24.635 5 Isobutylene 31.445 6 cis-2-butene 2.986 7 1,3-butadiene 3.162 8 1,2-butadiene 0 9 Vinyl acetylene (VA) 20.563 10 Ethyl acetylene (EA) 2.344

[0097] In this example, a fixed-bed small-scale evaluation device from Tuochuan Scientific Research Equipment Co., Ltd. was used, and 50 mL of the catalyst was loaded to perform the selective hydrogenation of the butadiene extraction tail gas.

[0098] Reaction conditions include reaction pressure of 0.5 to 0.7 MPa, hydrogen amount of 1.92 L/h, reactor inlet temperature of 25 C., circulation ratio of 20:1, and raw material feeding amount of 25 mL/h.

[0099] Catalysts A to K were evaluated under the same conditions, and the results of hydrogenation to remove alkynes are shown in Table 4.

TABLE-US-00004 TABLE 4 Selective hydrogenation results of butadiene extraction tail gas 1,3- Butadiene Vinyl Conversion Selectivity to (product) acetylene 1-Butyne of vinyl 1,3-butandiene** Catalyst % (product) (product) acetylene (%) A 10.529 3.964 0.804 80.72 44.38 B 9.536 3.35 0.737 83.71 37.50 E 9.583 3.849 0.759 81.28 38.42 F 9.820 3.971 0.762 80.69 40.13 G 10.271 3.355 0.727 83.68 41.32 H 10.508 3.105 0.687 84.90 42.08 C 10.519 4.458 0.845 78.32 45.68 D 9.055 4.065 0.811 80.23 35.72 I 8.498 8.425 1.171 66.32 43.96 J 4.615 0.757 0.512 96.32 7.34 K 8.522 8.155 1.463 60.34 43.20 **Selectivity to 1,3-butadiene = (1,3-butadiene in the product 1,3-butadiene in the raw material)/(vinyl acetylene in the raw material vinyl acetylene in the product)

[0100] It can be seen from the above table that the catalysts provided by the invention exhibit a high conversion of vinyl acetylene and a high selectivity to 1,3-butadiene. Because the vinyl acetylene in the hydrogenated product can be controlled to a lower level, the hydrogenated product can be directly returned to the extraction system to increase butadiene production.

Example 16

[0101] A long-term stability experiment was conducted by using the catalyst A prepared in Example 7 under the same conditions as in Example 15. The stability evaluation experimental data for 1000 hours are shown in Table 5.

TABLE-US-00005 TABLE 5 Conversion Run Selectivity to of vinyl time 1,3-butadiene acetylene (h) (%) (%) 96 44.38 80.72 192 43.65 82.74 288 42.97 81.62 384 42.12 81.53 480 43.38 81.08 576 44.85 80.45 672 44.38 80.49 768 43.57 81.27 864 44.81 80.72 960 42.76 81.67 1056 42.59 81.76

[0102] It can be seen from Table 5 that the catalyst provided by the invention exhibits a high stability in the selective hydrogenation of butadiene tail gas with a high alkyne content as a feedstock. The hydrogenation catalyst of the invention not only has a high selectivity to 1,3-butadiene (%) and a high vinyl acetylene conversion (%), but also can maintain the selectivity and the conversion at a high level for a long time, so that it is suitable for long-term operation.

[0103] It should be noted that the above-described embodiments are only used to explain, but do not constitute any limitation on, the invention. The invention has been described with reference to exemplary embodiments, but it should be understood that the words used therein are descriptive and explanatory rather than restrictive. The invention may be modified as specified within the scope of the claims of the invention and may be modified without departing from the scope and spirit of the invention. Although the invention described herein relates to specific methods, materials and embodiments, it is not intended that the invention be limited to these specific examples disclosed herein, but rather the invention extends to all other methods and applications having the same functions.