Method for removing alkyne from C5 alkyne-containing raw material through selective hydrogenation

Abstract

The invention discloses a method for removing alkyne from a C5 alkyne-containing raw material through selective hydrogenation, which comprises the following steps: mixing the C5 alkyne-containing raw material with an optional diluting solvent, and carrying out hydrogenation reaction with hydrogen in the presence of a catalyst, wherein the catalyst comprises an Al2O3-CuO-TiO2 composite oxide carrier, a main active component Ni and an optional auxiliary active component, the main active component Ni and the optional auxiliary active component are loaded on the Al2O3-CuO-TiO2 composite oxide carrier, and the auxiliary active component is selected from at least one of Ag and Ru. According to the method disclosed by the invention, the C5 alkyne selective hydrogenation reaction is carried out by using the specific catalyst, so that the conversion rate and saturated alkyne can be improved, and the loss rate of isoprene can be reduced, thereby achieving the purposes of canceling primary extraction and reducing the energy consumption and material consumption of a device.

Description

Technical Field

[0001] The invention relates to a method for selectively hydrogenating and removing alkynes from a C5-containing alkyne raw material. Background Art

[0002] When petroleum is cracked to produce ethylene, a large amount of C5 fraction is produced as a by-product, which contains 15% to 25% isoprene by mass. Isoprene is the main raw material for synthetic rubber. In order to prevent catalyst poisoning during isoprene polymerization, the mass fraction of alkynes in polymerization-grade isoprene products is required to be no more than 5.0×10 -5 . Currently, the industry generally uses the extractive distillation method to remove alkynes from the C5 fraction to produce polymerization-grade isoprene. However, this method has many problems. Taking my country's cracking C5 fraction separation device as an example, dimethylformamide is used as the solvent and a two-stage extractive distillation method is used to separate and produce polymerization-grade isoprene products. The second extraction unit has the disadvantages of high energy consumption, large solvent loss, difficult operation and serious environmental pollution.

[0003] If the selective hydrogenation technology is used before the first extraction system to reduce the mass fraction of alkynes in the material to 2.5×10 -5 Next, in the first extraction unit, reactive distillation technology is used to remove cyclopentadiene to a mass fraction of 1×10 -6 Therefore, the second extraction unit can be eliminated, thereby greatly reducing energy consumption and material consumption.

[0004] In the prior art, a commonly used noble metal selective hydrogenation catalyst is a noble metal selective hydrogenation catalyst prepared by loading a noble metal active component such as a palladium-based catalyst active component on an alumina carrier. The noble metal selective hydrogenation catalyst has high hydrogenation activity and good selectivity, but the cost is increasing day by day, and the ability to resist impurities and stability are not satisfactory. Since the boiling point of small molecular sulfur such as carbon disulfide is close to that of carbon five, the carbon five fraction generally contains 10 to 20 ppm of low-carbon sulfur, which easily affects the stability of the palladium-based catalyst. Non-noble metal catalysts such as nickel-based and copper-based catalysts, although their selectivity and activity are not as good as those of noble metal catalysts, are low in cost, have good impurity resistance and good stability. Therefore, the development of a non-noble metal catalyst with low cost, high activity, good selectivity, strong impurity resistance and high stability has great scientific research value and industrial application value.

[0005] In summary, it is necessary to develop a catalyst for the selective hydrogenation and removal of alkynes from C5 alkynes, which has high low-temperature reaction activity, good selectivity, simple process, mild reaction conditions, low production cost, and long-term stable operation. Summary of the invention

[0006] In view of this, in order to overcome at least one of the above problems existing in the prior art, the present invention provides a method for selectively hydrogenating and removing alkynes from a C5-containing alkyne feedstock.

[0007] The objectives of the present invention are achieved through the following technical solutions.

[0008] In a first aspect, the present invention provides a method for selectively hydrogenating and removing alkynes from a C5-containing alkyne feedstock, wherein the method comprises the following steps: mixing the C5-containing alkyne feedstock and an optional diluent solvent, and conducting a hydrogenation reaction with hydrogen in the presence of a catalyst;

[0009] The catalyst comprises an Al2O3-CuO-TiO2 composite oxide carrier and a main active component Ni and an optional auxiliary active component supported thereon, wherein the auxiliary active component is selected from at least one of Ag and Ru.

[0010] In the present invention, a non-precious metal C5-alkyne selective hydrogenation catalyst is obtained by combining a specific carrier, a main active component and an auxiliary active component. The catalyst not only has high low-temperature reaction activity and selectivity, but also can saturate the alkynes and reduce the loss rate of isoprene when used for the selective hydrogenation of C5-alkyne raw materials to remove alkynes, thereby achieving the purpose of eliminating the single extraction and reducing the energy and material consumption of the device.

[0011] According to the method provided by the present invention, based on 100 parts by weight of the composite oxide support, the content of CuO is 0.1 to 5 parts, the content of TiO2 is 5 to 25 parts, and the content of Al2O3 is 70 to 94.9 parts.

[0012] In some embodiments, based on 100 parts by weight of the composite oxide support, the content of CuO is 0.3 to 3 parts, the content of TiO2 is 9 to 20 parts, and the content of Al2O3 is 77 to 90.7 parts.

[0013] According to the method provided by the present invention, based on the total weight of the catalyst as 100 parts by weight, the content of the main active component Ni is 5 to 25 parts in terms of NiO, preferably 10 to 20 parts; the content of the auxiliary active component is 0 to 5 parts in terms of oxide, preferably 0.5 to 3 parts; the content of the composite oxide is 70 to 95 parts, preferably 79.5 to 87 parts.

[0014] According to the catalytic method provided by the present invention, based on the total weight of the catalyst as 100 parts by weight, the sum of the contents of the main active component Ni calculated as NiO and the auxiliary active components calculated as oxides is 12 to 21 parts, preferably 13 to 21.5 parts.

[0015] According to the catalytic method provided by the present invention, the main active component Ni and the auxiliary active component can exist in the form of atoms or compounds independently of each other. Such compounds can be compounds of the main active component Ni and the auxiliary active component commonly used in nickel-based catalysts for selective hydrogenation. In some embodiments, the main active component Ni and the auxiliary active component exist in the form of oxides independently of each other, such as NiO, Ag2O, RuO2.

[0016] According to the method provided by the present invention, the specific surface area of ​​the composite oxide carrier is 30 to 155 m 2 / g, preferably 55 to 85m 2 / g.

[0017] According to the method provided by the present invention, the pore volume of the composite oxide carrier is 0.2 to 0.8 mL / g, preferably 0.3 to 0.4 mL / g.

[0018] According to the method provided by the present invention, the C5-alkyne raw material comprises 30-80 wt% of isoprene, 0.01-1 wt% of isopentenyne, and 0.005-0.1 wt% of 2-butyne.

[0019] Optionally, the C5-alkyne feedstock further comprises a balance of monoolefins and / or alkanes.

[0020] According to the method provided by the present invention, the dilution solvent is independently selected from n-heptane, isooctane, and cyclohexane, preferably selected from n-heptane and isooctane.

[0021] According to the method provided by the present invention, it is characterized in that the conditions of the hydrogenation reaction in step S330 include: the reaction temperature is 20-70°C, the reaction pressure is 0.1-1.5MPa, the feed volume space velocity is 0.5-15h -1 The molar ratio of the sum of alkynes and isoprene in the C5-containing alkyne raw material to hydrogen is 1:(1.0-3.0), and the volume ratio of the C5-containing alkyne raw material to the dilution solvent is 1:(0-20).

[0022] In some embodiments, the carbon pentaacetylenic hydrocarbon feedstock comprises monoolefins and / or alkanes. In this case, no diluent solvent may be used.

[0023] In a second aspect, the present invention provides a method for preparing the above-mentioned catalyst, wherein the preparation method comprises the following steps:

[0024] S110, impregnating the Al2O3-CuO-TiO2 composite oxide support with a nickel salt solution to obtain an impregnated composite oxide support, and drying and calcining the impregnated composite oxide support to obtain a catalyst precursor;

[0025] Optionally, S120, the catalyst precursor is impregnated with a salt solution of an auxiliary active component to obtain an impregnated catalyst precursor, and the impregnated catalyst precursor is dried and calcined to obtain a catalyst.

[0026] According to the preparation method provided by the present invention, the time of the immersion treatment in steps S110 and S120 is independently 1 to 8 hours, preferably 1 to 4 hours.

[0027] According to the preparation method provided by the present invention, the conditions for the drying treatment in steps S110 and S120 independently include: a drying temperature of 90 to 120° C.; and / or a drying time of 2 to 8 hours.

[0028] According to the preparation method provided by the present invention, the conditions for the calcination treatment in steps S110 and S120 independently include: a calcination temperature of 300 to 800° C.; and / or a calcination time of 2 to 10 hours.

[0029] According to the preparation method provided by the present invention, examples of the nickel salt include, but are not limited to, nickel sulfate, nitrate, soluble carboxylate, hypophosphite and halide. In some embodiments, the nickel salt is nickel sulfate, nickel nitrate, nickel chloride or nickel acetate.

[0030] According to the preparation method provided by the present invention, the present invention has no particular restrictions on the type of nickel salt solution, which can be an aqueous solution or an organic nickel salt solution formed by ethanol, benzene, etc. as a solvent, preferably an aqueous solution of an inorganic nickel salt. Compared with an organic nickel salt solution, an aqueous solution of an inorganic nickel salt has low cost and is green and environmentally friendly.

[0031] According to the preparation method provided by the present invention, the concentration of the nickel salt solution is 1.0-3.0 mol / L, calculated as NiO.

[0032] According to the preparation method provided by the present invention, the salt of the co-active component can be a salt of the co-active component commonly used in the field of catalysts for selective hydrogenation, examples of which include but are not limited to: nitrates, soluble carboxylates and soluble halides of the co-active component, preferably nitrates, hydrochlorides, oxalates or acetates.

[0033] According to the preparation method provided by the present invention, the present invention has no particular restrictions on the type of salt solution of the auxiliary active component, which can be an aqueous solution, or an organic salt solution formed by ethanol, benzene, etc. as a solvent, preferably an inorganic salt solution of the auxiliary active component. Compared with the organic salt solution, the inorganic salt solution has low cost and is green and environmentally friendly. For example, the salt of the auxiliary active component can be silver nitrate or ruthenium nitrate.

[0034] According to the preparation method provided by the present invention, the concentration of the salt solution of the co-active component is 0.01-0.3 mol / L in terms of the metal oxide.

[0035] According to the preparation method provided by the present invention, the preparation method of the composite oxide support comprises:

[0036] S210, adding a copper salt solution, a titanium salt solution and an alkaline solution to an aluminum salt solution in parallel at a temperature of 50 to 90° C., and after staying at a pH value of 5.5 to 7.0 for 15 to 20 minutes, continuing to add an alkaline solution until the pH value reaches 8 to 10, and staying for 15 to 20 minutes to obtain a precipitate;

[0037] S220, washing, drying and calcining the precipitate to obtain a composite oxide support.

[0038] According to the preparation method provided by the present invention, in step S210, by adjusting the pH value, several solutions can be fully mixed. Further, by continuing to add alkaline solution to a pH value of 8 to 10, the precipitation can be more thorough and the utilization rate of the metal can be improved; at the same time, the pore structure can be optimized to obtain a moderate pore volume and specific surface area.

[0039] According to the preparation method provided by the present invention, the aluminum salt is selected from aluminum sulfate, aluminum chloride, aluminum nitrate and organic aluminum salt, and / or the concentration of the aluminum salt solution is 0.5-2.5 mol / L.

[0040] According to the preparation method provided by the present invention, the titanium salt solution is selected from the acid solution of a soluble titanium salt of metatitanic acid, titanium tetrachloride, and tetraethyl titanate, such as a sulfuric acid solution; and / or the concentration of the titanium salt solution is 0.2 to 1.2 mol / L.

[0041] According to the preparation method provided by the present invention, the copper salt is a soluble copper salt, preferably selected from copper chloride, copper sulfate and copper nitrate; and / or the concentration of the copper salt solution is 0.1 to 0.6 mol / L.

[0042] According to the preparation method provided by the present invention, the alkaline solution comprises an ammonium salt solution and an alkaline solution. The ammonium salt is selected from ammonium bicarbonate, ammonium carbonate and an organic ammonium salt; and / or the concentration of the ammonium salt in the alkaline solution is 0.1 to 0.3 mol / L.

[0043] Similarly, the alkali solution is selected from ammonia water, sodium hydroxide, potassium hydroxide and organic base, and / or the concentration of the alkali solution is 0.2-0.4 mol / L.

[0044] According to the preparation method provided by the present invention, the precipitate washing process in step S220 includes washing with deionized water until no acid ions are detected.

[0045] According to the preparation method provided by the present invention, the drying conditions in step S220 include: a drying temperature of 100 to 150° C. and a drying time of 4 to 12 hours.

[0046] According to the preparation method provided by the present invention, the calcination conditions in step S220 include: a calcination temperature of 500 to 1100° C. and a calcination time of 4 to 12 hours.

[0047] According to the preparation method provided by the present invention, the preparation method of the titanium salt solution comprises: dissolving a soluble titanium salt such as metatitanic acid, titanium tetrachloride, and tetraethyl titanate in a sulfuric acid solution to form a titanium salt solution.

[0048] According to the preparation method provided by the present invention, the preparation method further comprises activating the catalyst obtained in step S120.

[0049] In some embodiments, the preparation method further comprises:

[0050] S310, using hydrogen to activate the catalyst obtained in step S120.

[0051] Preferably, the conditions for the activation treatment in step S310 include: an activation temperature of 300 to 600° C., an activation pressure of 0 to 3.0 MPa, a flow rate of hydrogen relative to the catalyst of 1 to 15 mL / min·g, and an activation time of 6 to 18 h.

[0052] The present invention has the following advantages:

[0053] (1) In the method of the present invention, a specific catalyst is used for the selective hydrogenation reaction of C5 alkynes, which can improve the conversion rate, saturate alkynes and reduce the loss rate of isoprene, thereby achieving the purpose of eliminating the first extraction and reducing the energy consumption and material consumption of the device.

[0054] (2) The Al2O3-CuO-TiO2 composite oxide used in the present invention has titanium oxide and aluminum oxide uniformly mixed and enriched on the surface of the composite oxide, and CuO is uniformly dispersed on the composite oxide skeleton structure. The inventors were surprised to find that a strong interaction is formed between Al2O3, CuO and TiO2 at high temperatures, so the composite oxide has high thermal stability, which overcomes the defect that copper alone is unstable at high temperatures. Furthermore, TiO2 can still maintain the active phase of anatase when calcined at a high temperature of 700 to 1000°C, ensuring the activity of the catalyst. In addition, it is believed that Al2O3 can maintain the crystal phase of γ-Al2O3, ensure the crushing strength and pore structure of the catalyst, and meet the needs of industrial applications.

[0055] (3) The catalyst used in the method of the present invention has high low-temperature reaction activity and selectivity, and its preparation process is simple, the reaction conditions are mild, the production cost is low, and it can operate stably for a long time in production, and has industrial application value. In addition, the catalyst used in the method of the present invention has a large "green oil" capacity, stable hydrogenation activity, and can be used for a long period of time. DETAILED DESCRIPTION

[0056] The present invention will be further described below in conjunction with specific embodiments, but they do not constitute any limitation to the present invention.

[0057] Example 1

[0058] Preparation of vector

[0059] Prepare 1 L of 0.8 mol / L aluminum sulfate deionized water solution, 0.5 L of 0.46 mol / L metatitanic acid dilute sulfuric acid solution, 0.1 L of 0.39 mol / L copper nitrate solution, mix 0.22 mol / L ammonium bicarbonate solution with 25% ammonia water to prepare 1 L of mixed alkaline solution with a pH of 11-12.

[0060] At a temperature of 65°C, 0.1L of copper nitrate solution and 0.5L of dilute sulfuric acid solution of titanic acid were added to the above-mentioned deionized aluminum sulfate solution in parallel, and an appropriate amount of mixed alkali solution was added to keep the pH value of the mixed solution system at 6.2, and the mixture was kept for 20 minutes; the mixed alkali was continued to be added to make the pH = 9.1, and the mixture was kept for 20 minutes to obtain a precipitate, which was filtered to obtain a filter cake.

[0061] The filter cake was repeatedly washed 5 times with 20 times the volume of deionized water, and the washed filter cake was dried at 110°C for 6 hours and calcined at 860°C for 5 hours to obtain Al2O3-CuO-TiO2 composite oxide support A.

[0062] Example 2

[0063] Prepare 1 L of 0.88 mol / L aluminum sulfate deionized water solution, 0.5 L of 0.35 mol / L metatitanic acid dilute sulfuric acid solution, 0.13 L of 0.2 mol / L copper nitrate solution, mix 0.22 mol / L ammonium bicarbonate solution with 25% ammonia water to prepare 1 L of mixed alkaline solution with a pH of 11-12.

[0064] At a temperature of 75°C, copper nitrate solution and dilute sulfuric acid solution of metatitanic acid were added to the deionized aluminum sulfate solution in parallel, and an appropriate amount of mixed alkali solution was added to keep the pH value of the mixed solution system at 6.8, and the mixture was kept for 15 minutes; the mixed alkali solution was continued to be added to make the pH value = 8.5, and the mixture was kept for 15 minutes to obtain a precipitate, which was filtered to obtain a filter cake.

[0065] The filter cake was washed repeatedly 7 times with 30 times the volume of deionized water, dried at 120°C for 6 h, and calcined at 950°C for 4 h to obtain Al2O3-CuO-TiO2 composite oxide support B.

[0066] Example 3

[0067] The steps are basically the same as those in the preparation method of the carrier in Example 1, except that the concentrations of the solutions are different. Specifically, 1 L of a 0.9 mol / L aluminum sulfate deionized water solution, 0.5 L of a 0.25 mol / L metatitanic acid dilute sulfuric acid solution, and 0.1 L of a 0.1 mol / L copper nitrate solution are prepared. The Al2O3-CuO-TiO2 composite oxide carrier C is obtained.

[0068] Example 4

[0069] The steps are basically the same as those in the preparation method of the carrier in Example 1, except that the concentrations of the solutions are different. Specifically, 1 L of a 0.8 mol / L aluminum sulfate deionized water solution, 0.5 L of a 0.55 mol / L metatitanic acid dilute sulfuric acid solution, and 0.05 L of a 0.1 mol / L copper nitrate solution are prepared. The Al2O3-CuO-TiO2 composite oxide carrier D is obtained.

[0070] Example 5

[0071] The steps are basically the same as those in the preparation method of the carrier in Example 1, except that the concentrations of the solutions are different. Specifically, 1 L of a 0.9 mol / L aluminum sulfate deionized water solution, 0.4 L of a 0.2 mol / L metatitanic acid dilute sulfuric acid solution, and 0.4 L of a 0.2 mol / L copper nitrate solution are prepared. Al2O3-CuO-TiO2 composite oxide carrier E is obtained.

[0072] Example 6

[0073] The steps are basically the same as those in the preparation method of the carrier in Example 1, except that the concentrations of the solutions are different. Specifically, 1 L of a 0.8 mol / L aluminum sulfate deionized water solution, 0.5 L of a 0.75 mol / L metatitanic acid dilute sulfuric acid solution, and 0.015 L of a 0.1 mol / L copper nitrate solution are prepared. The Al2O3-CuO-TiO2 composite oxide carrier F is obtained.

[0074] Comparative Example 1

[0075] 1. Preparation of Vector

[0076] 1 L of deionized aluminum sulfate solution with a concentration of 0.8 mol / L was prepared, 0.56 L of dilute sulfuric acid solution of titanic acid with a concentration of 0.46 mol / L was prepared, and 0.22 mol / L ammonium bicarbonate solution was mixed with 25% ammonia water to prepare a mixed alkaline solution with a pH of 11-12.

[0077] Under normal pressure and temperature of 65°C, three solutions of aluminum sulfate deionized water solution, metatitanic acid dilute sulfuric acid solution and mixed alkali solution were co-precipitated in parallel. The flow rate of the mixed alkali solution was controlled to keep the pH value of the precipitate in the range of 5.0-6.0 for 8 minutes, and then the flow rate of the mixed alkali solution was increased to keep the pH value of the mixed solution in the range of 8.5-9.5 for 8 minutes, and then the flow rate of the mixed alkali solution was reduced to keep the pH value of the mixed solution in the range of 5.0-6.0 for 8 minutes, and then the flow rate of the mixed alkali solution was increased to keep the pH value of the precipitate in the range of 8.5-9.5, and this process was repeated until all the solutions were added. The reaction solution was allowed to stand at 70°C for 30 minutes, filtered, and the filter cake was washed with deionized water 15 times the volume of the filter cake for 30 minutes, filtered again, and washed again. This process was repeated four times, and finally the filter cake was dried at 110°C for 10 hours and calcined at 950°C for 5 hours to obtain titanium oxide-aluminum oxide composite G.

[0078] Comparative Example 2

[0079] 97g of γ-Al2O3 produced by Yantai Henghui Company was impregnated in 0.1L of 0.38mol / L copper nitrate solution for 4h, dried at 110℃ for 8h, and calcined at 550℃ for 5h. Al2O3 with a CuO content of 3% was obtained. 3- CuO composite oxide support H.

[0080] Comparative Example 3

[0081] γ-Al2O3 produced by Yantai Henghui Company was used as a carrier, which is denoted as carrier I.

[0082] Vector characterization

[0083] 1. Specific surface area and pore volume

[0084] The specific surface area and pore volume of the carrier were determined using the ASAP 2020 adsorption instrument (N2 adsorption-desorption method) from Mack Instruments, USA. Specifically, the carrier sample was degassed at 623K for 4 hours before the test, nitrogen was adsorbed at liquid nitrogen temperature, the sample data was processed using AMSM software, and the specific surface area of ​​the sample was obtained using the Brunauer-Emmet-Teller (BET) method. The average pore size was obtained based on the nitrogen adsorption isotherm curve using the Barrett-Joyner-Halenda (BJH) method, and the pore volume was obtained using the P / Po single-point desorption curve. The results are shown in Table 1.

[0085] 2. Determination of carrier components

[0086] UV-2100 ultraviolet spectrophotometer was used to measure the components in the carrier. The results are shown in Table 1.

[0087] Table 1 Carrier parameters of Examples 1 to 6 and Comparative Examples 1 to 3

[0088]

[0089]

[0090] Example 7

[0091] A method for preparing Ni / Al2O3-CuO-TiO2 catalyst.

[0092] Take 100 g of the Al2O3-CuO-TiO2 composite oxide carrier A prepared in Example 1, put it into 0.2 L of 1.0 mol / L nickel nitrate solution, soak it for 2 h, dry it at 110°C for 6 h, and then calcine it at 500°C for 4 h to obtain catalyst A1 with a NiO content of 10.6 parts by weight.

[0093] Example 8

[0094] The catalyst was prepared according to the preparation method of the Ni / Al2O3-CuO-TiO2 catalyst in Example 7, with the only difference being that the Al2O3-CuO-TiO2 composite oxide carriers B, C, and D prepared above were taken respectively, and the concentration of the nickel nitrate solution was changed to prepare catalysts B1, C1, and D1 with different Ni contents.

[0095] Example 9

[0096] A method for preparing a Ni-Ag / Al2O3-CuO-TiO2 catalyst.

[0097] Take 100 g of the Al2O3-CuO-TiO2 composite oxide carrier A prepared in Example 1, put it into 0.2 L of 1.0 mol / L nickel nitrate solution, soak it for 1.5 h, dry it at 110°C for 6 h, and then calcine it at 550°C for 6 h to obtain a catalyst precursor with a NiO content of 10.6 parts by weight.

[0098] 100 g of the above catalyst precursor was put into 0.2 L of 0.18 mol / L silver nitrate aqueous solution, immersed for 1 h, dried at 110°C for 6 h, and then calcined at 600°C for 6 h to obtain catalyst A2, whose composition was: 3 parts by weight of Ag2O, 10 parts by weight of NiO and 87 parts by weight of the composite oxide carrier.

[0099] Example 10

[0100] The catalyst was prepared according to the preparation method of the Ni-Ag / Al2O3-CuO-TiO2 catalyst in Example 9, with the only difference being that the Al2O3-CuO-TiO2 composite oxide carriers B, C, and D prepared above were taken respectively, and the concentrations of the nickel nitrate solution and the silver nitrate aqueous solution were changed to prepare catalysts B2, C2, and D2 with different Ni and Ag contents.

[0101] Embodiment 11

[0102] A method for preparing a Ni-Ru / Al2O3-CuO-TiO2 catalyst.

[0103] Take 100 g of the Al2O3-CuO-TiO2 composite oxide carrier D prepared in Example 4, put it into 0.4 L of 1.0 mol / L nickel nitrate solution, soak it for 3 h, dry it at 110°C for 6 h, and then calcine it at 500°C for 4 h to obtain a catalyst precursor with a NiO content of 20.8 parts by weight.

[0104] 100 g of the above catalyst precursor was put into 0.2 L of 0.025 mol / L ruthenium nitrate aqueous solution, immersed for 1 h, dried at 110°C for 6 h, and then calcined at 500°C for 4 h to obtain catalyst D3, whose composition was: Ru content of 0.5 parts by weight, NiO content of 20 parts by weight and composite oxide carrier content of 79.5 parts by weight.

[0105] Example 12

[0106] The catalyst was prepared according to the preparation method of the Ni-Ru / Al2O3-CuO-TiO2 catalyst in Example 11, with the only difference being that the Al2O3-CuO-TiO2 composite oxide carriers A, B, and C prepared above were taken, the concentrations of the nickel nitrate solution and the ruthenium nitrate aqueous solution were changed, and catalysts A3, B3, and C3 with different Ni and Ru contents were prepared.

[0107] Example 13

[0108] A method for preparing a Ni-Ag / Al2O3-CuO-TiO2 catalyst.

[0109] Take 100 g of the Al2O3-CuO-TiO2 composite oxide carrier A prepared in Example 1, put it into 0.2 L of 1.0 mol / L nickel nitrate solution, soak it for 150 min, dry it at 110°C for 6 h, and then calcine it at 500°C for 4 h to obtain a catalyst precursor with a NiO content of 10.6 parts by weight.

[0110] 100 g of the above catalyst precursor was taken, and the concentration of the silver nitrate aqueous solution was changed to prepare catalysts A4, A5, and A6 with the same carrier, the same Ni content, and different Ag contents.

[0111] Comparative Example 4

[0112] Take 100 g of the Al2O3-TiO2 composite oxide carrier G prepared in Comparative Example 1, put it into 0.2 L of 1.0 mol / L nickel nitrate solution, soak it for 1 hour, dry it at 110°C for 6 hours, and then calcine it at 550°C for 6 hours to obtain a catalyst precursor with a NiO content of 10.6 parts by weight.

[0113] 100 g of the above catalyst was taken as a precursor and put into 0.2 L of 0.18 mol / L silver nitrate aqueous solution, immersed for 1 h, dried at 110° C. for 6 h, and then calcined at 600° C. for 6 h to obtain catalyst G1, whose composition was: Ag content of 0.5 parts by weight, NiO content of 10 parts by weight and composite oxide carrier content of 89.5 parts by weight.

[0114] Comparative Example 5

[0115] Take 100 g of the Al2O3-TiO2 composite oxide carrier G prepared in Comparative Example 1, put it into 0.2 L of 1.0 mol / L nickel nitrate solution, soak it for 1 hour, dry it at 110°C for 6 hours, and then calcine it at 550°C for 6 hours to obtain a catalyst precursor with a NiO content of 10.6 parts by weight.

[0116] Take 100 g of the above catalyst as a precursor and put it into 0.2 L of a 0.15 mol / L ruthenium nitrate aqueous solution, soak it for 1 hour, dry it at 110°C for 6 hours, and then calcine it at 500°C for 4 hours to obtain catalyst G2, whose composition is: Ru content is 0.5 parts by weight, NiO content is 10 parts by weight and composite oxide carrier content is 89.5 parts by weight.

[0117] Comparative Example 6

[0118] Take 100 g of the Al2O3-CuO composite oxide support H prepared in Comparative Example 2, put it into 0.2 L of 1.0 mol / L nickel nitrate solution, soak it for 150 min, dry it at 110°C for 6 h, and then calcine it at 500°C for 4 h to obtain a catalyst precursor with a NiO content of 10.6 parts by weight.

[0119] 100 g of the above catalyst was taken as a precursor and put into 0.2 L of 0.18 mol / L silver nitrate aqueous solution, immersed for 1 h, dried at 110°C for 6 h, and then calcined at 600°C for 6 h to obtain catalyst H1, whose composition was: Ag content of 3 parts by weight, NiO content of 10 parts by weight and composite oxide carrier content of 89.5 parts by weight.

[0120] Comparative Example 7

[0121] Take 100 g of the Al2O3-CuO composite oxide support H prepared in Comparative Example 2, put it into 0.2 L of 1.0 mol / L nickel nitrate solution, soak it for 150 min, dry it at 110°C for 6 h, and then calcine it at 500°C for 4 h to obtain a catalyst precursor with a NiO content of 10.6 parts by weight.

[0122] Take 100 g of the above catalyst as a precursor and put it into 0.2 L of a 0.15 mol / L ruthenium nitrate aqueous solution, soak it for 1 hour, dry it at 110°C for 6 hours, and then calcine it at 500°C for 4 hours to obtain a catalyst H2, whose composition is: 0.5 parts by weight of Ru, 10 parts by weight of NiO and 89.5 parts by weight of the composite oxide carrier.

[0123] Comparative Example 8

[0124] Take 100 g of the γ-Al2O3 carrier of Comparative Example 3, put it into 0.2 L of 1.0 mol / L nickel nitrate solution, soak it for 150 min, dry it at 110°C for 6 h, and then calcine it at 500°C for 4 h to obtain a catalyst precursor with a NiO content of 10.6 parts by weight.

[0125] Take 100 g of the above catalyst as a precursor and put it into 0.2 L of 0.18 mol / L silver nitrate aqueous solution, soak it for 1 hour, dry it at 110°C for 6 hours, and then calcine it at 600°C for 6 hours to obtain catalyst I1, whose composition is: Ag content is 3 parts, NiO content is 10 parts and composite oxide carrier content is 89.5 parts.

[0126] Comparative Example 9

[0127] Take 100 g of the γ-Al2O3 carrier of Comparative Example 3, put it into 0.2 L of 1.0 mol / L nickel nitrate solution, soak it for 150 min, dry it at 110°C for 6 h, and then calcine it at 500°C for 4 h to obtain a catalyst precursor with a NiO content of 10.6 parts by weight.

[0128] Take 100 g of the above catalyst as a precursor and put it into 0.2 L of a 0.15 mol / L ruthenium nitrate aqueous solution, soak it for 1 hour, dry it at 110°C for 6 hours, and then calcine it at 500°C for 4 hours to obtain catalyst I2, whose composition is: Ru content is 0.5 parts by weight, NiO content is 10 parts by weight and composite oxide carrier content is 89.5 parts by weight.

[0129] According to specific examples 7 to 13 and comparative examples 4 to 9, the contents of the various components of the catalyst are shown in Table 2.

[0130] Table 2 Composition of each catalyst

[0131]

[0132] Embodiment 14

[0133] This example is used to illustrate the method for selectively hydrogenating and removing alkynes from a C5-containing alkyne feedstock.

[0134] The reaction conditions for selective hydrogenation to remove alkynes were as follows: a trickle bed hydrogenation reactor with a catalyst loading volume of 100 mL was used, the catalyst loading volume was 100 mL, the reaction pressure was 0.6 Pa, the reaction temperature was 30 ° C, the molar ratio of hydrogen to total alkynes in the hydrogenation feed was 1.8:1, and the feed volume space velocity (the volume ratio of the liquid feed volume to the catalyst loading volume per hour) was 2.2 h -1 .

[0135] The hydrogenation feedstock is the top material of the pre-deweighting tower in a petrochemical cracking carbon five fraction separation device (before the first extraction system), and the mass fraction of each component is: isoprene 41.3wt%, isopentenyne 0.18wt%, 2-butyne 0.028wt%, and the remainder is monoolefins and alkanes.

[0136] The activity of the catalyst is represented by the mass fraction of the alkyne remaining after the reaction; the reaction selectivity is represented by the loss rate of isoprene, and the calculation formula is as follows. The results are shown in Table 3.

[0137] Isoprene loss rate = (mass fraction of isoprene in the raw material - mass fraction of isoprene in the product) / mass fraction of isoprene in the raw material × 100%.

[0138] Table 3 Selective hydrogenation results

[0139]

[0140]

[0141] As can be seen from Table 3, the selective hydrogenation reaction of C5 alkynes using the catalyst provided by the present invention can improve the conversion rate, saturate alkynes and reduce the loss rate of isoprene, thereby achieving the purpose of eliminating one extraction and reducing the energy and material consumption of the device. Combined with Table 1 and Table 2, it is believed that the Al2O3-CuO-TiO2 composite oxide used in the present invention, titanium oxide and aluminum oxide are uniformly mixed and enriched on the surface of the composite oxide, and CuO is uniformly dispersed on the composite oxide skeleton structure. At high temperatures, Al2O3, CuO, and TiO2 form a strong interaction, so the thermal stability of the composite oxide is high, which overcomes the defect that copper is unstable at high temperatures. Further, the high temperature roasting of TiO2 at 700 to 1000 ° C can still maintain the active phase of rutile, ensuring the activity of the catalyst.

[0142] Any numerical value mentioned in the present invention, if there is only an interval of two units between any minimum value and any maximum value, includes all values ​​from the minimum value to the maximum value each time increasing by one unit. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, time, etc. is declared to be 50-90, in this specification it means that 51-89, 52-88... and 69-71 and 70-71 are specifically listed. For non-integer values, 0.1, 0.01, 0.001 or 0.0001 can be appropriately considered as a unit. These are just some specially specified examples. In this application, in a similar manner, all possible combinations of numerical values ​​between the listed minimum and maximum values ​​are considered to have been disclosed.

[0143] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A method for selectively hydrogenating and removing alkynes from a C5-containing alkyne feedstock, wherein: The method comprises the following steps: mixing a C5-containing alkyne raw material and an optional diluent solvent, and performing a hydrogenation reaction with hydrogen in the presence of a catalyst; The catalyst comprises an Al2O3-CuO-TiO2 composite oxide carrier and a main active component Ni and an optional auxiliary active component supported thereon, wherein the auxiliary active component is selected from at least one of Ag and Ru.

2. The method according to claim 1, characterized in that Based on 100 parts by weight of the composite oxide support, the content of CuO is 0.1 to 5 parts, the content of TiO2 is 5 to 25 parts, and the content of Al2O3 is 70 to 94.9 parts.

3. The method according to claim 1, characterized in that Based on 100 parts by weight of the composite oxide support, the content of CuO is 0.3 to 3 parts, the content of TiO2 is 9 to 20 parts, and the content of Al2O3 is 77 to 90.7 parts.

4. The method according to any one of claims 1 to 3, characterized in that Based on 100 parts by weight of the total weight of the catalyst, the content of the main active component Ni is 5 to 25 parts in terms of NiO; the content of the auxiliary active component is 0 to 5 parts in terms of oxide; and the content of the composite oxide is 70 to 95 parts.

5. The method according to claim 4, characterized in that Based on 100 parts by weight of the total weight of the catalyst, the content of the main active component Ni is 10 to 20 parts in terms of NiO; and / or the content of the auxiliary active component is 0.5 to 3 parts in terms of oxide; and / or the content of the composite oxide is 79.5 to 87 parts.

6. The method according to any one of claims 1 to 5, characterized in that Based on 100 parts by weight of the total weight of the catalyst, the sum of the contents of the main active component Ni calculated as NiO and the auxiliary active component calculated as oxide is 12 to 21 parts, preferably 13 to 21.5 parts.

7. The method according to any one of claims 1 to 6, characterized in that The specific surface area of ​​the composite oxide carrier is 30 to 155 m 2 / g, preferably 55 to 85m 2 / g; And / or, the pore volume of the composite oxide support is 0.2 to 0.8 mL / g, preferably 0.3 to 0.4 mL / g.

8. The method according to any one of claims 1 to 7, characterized in that The dilution solvent is selected from n-heptane, isooctane and cyclohexane, preferably selected from n-heptane and isooctane.

9. The method according to any one of claims 1 to 8, characterized in that The C5-alkyne raw material comprises 30-80 wt% of isoprene, 0.01-1 wt% of isopentenyne, and 0.005-0.1 wt% of 2-butyne; Optionally, the C5-alkyne feedstock further comprises a balance of monoolefins and / or alkanes.

10. The method according to any one of claims 1 to 9, characterized in that The conditions of the hydrogenation reaction include: reaction temperature of 20-70°C, reaction pressure of 0.1-1.5 MPa, feed volume space velocity of 0.5-15 h -1 The molar ratio of alkyne to hydrogen in the C5-containing alkyne raw material is 1:(1.0-3.0).

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