Catalyst, preparation method and application of catalyst in alkyne removal through hydrogenation of low-carbon hydrocarbon

Abstract

The invention provides a catalyst, a preparation method and application of the catalyst in alkyne removal through low-carbon hydrocarbon hydrogenation. The invention provides a catalyst. The catalyst comprises a carrier and an active component, the carrier is a metal composite oxide, the metal composite oxide contains a metal element I, and the metal element I comprises aluminum, copper and titanium; the active component contains a metal element II, and the metal element II is selected from at least one of Mn, Ni, Pd or Ag. The catalyst provided by the invention has the advantages of good activity, high selectivity, good stability and industrial application value when being used for removing alkyne through low-carbon hydrocarbon hydrogenation.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogenation and acetylene removal of light hydrocarbons, and in particular to a catalyst, a preparation method and application in hydrogenation and acetylene removal of light hydrocarbons. Background Art

[0002] Low-carbon hydrocarbons (C2-C4) are important organic chemical raw materials, and their downstream products are widely used in the fields of plastics, films, fibers, rubbers, resins, coatings, etc. The sources of low-carbon hydrocarbons are mainly obtained by naphtha cracking and light alkane dehydrogenation routes. However, the low-carbon hydrocarbons separated from the device often carry trace amounts of impurities such as oxygen, sulfur, alkynes and CO, which can lead to problems such as catalyst poisoning and deactivation, reduced reaction rate or reduced product quality in downstream reactions. Ethylene is one of the most important basic raw materials in the petrochemical industry. Ethylene obtained by petroleum cracking usually contains 0.5-2.5% (molar fraction) of acetylene. The presence of acetylene can affect the process of ethylene polymerization and the performance of the product. If the acetylene concentration is too high, there is also a risk of explosion. The carbon three fraction in the cracked gas is usually obtained in the petroleum cracking ethylene production unit, and its composition usually contains 1-5% (molar fraction) of propyne (MA) and propadiene (PD). Among them, MAPD is a toxic substance that affects the downstream application of propylene, so to obtain high-purity propylene, MAPD must be removed first. In addition, low carbon fractions containing alkynes and dienes are easily polymerized into colloids at high temperatures and precipitate on the catalyst surface, which quickly deactivates the catalyst and causes the catalyst to be frequently activated and regenerated. Therefore, it is hoped that the hydrogenation catalyst has a higher low-temperature activity and maintains an appropriate colloid capacity so that the activity of the polymer on the catalyst surface remains unchanged before being washed, thereby extending the service life of the catalyst, which is very important in industrial production. Summary of the invention

[0003] In order to solve the above problems in the prior art, the present invention provides a catalyst, a preparation method and an application in hydrogenation and acetylene removal of low-carbon hydrocarbons. The catalyst is suitable for hydrogenation and acetylene removal of low-carbon olefins through a specific combination of a carrier and several metal active components.

[0004] In the first aspect, the present invention proposes a catalyst comprising a carrier and an active component, wherein the carrier is a metal composite oxide, the metal composite oxide contains metal element I, and the metal element I includes aluminum, copper and titanium; the active component contains metal element II, and the metal element II is selected from at least one of Mn, Ni, Pd or Ag.

[0005] As a specific embodiment of the present invention, the metal composite oxide is Al 2 O 3 -CuO-TiO 2 Composite oxides.

[0006] As a specific embodiment of the present invention, the content of the active component calculated based on the amount of the oxide of the metal element II is 0.1 wt% to 40 wt% of the catalyst.

[0007] Preferably, the metal element II is selected from Mn and / or Ni, and the content of the active component is 10 wt% to 25 wt% of the catalyst, more preferably 15 wt% to 25 wt%, calculated as the amount of the oxide of the metal element II.

[0008] Preferably, the metal element II is selected from Pd and / or Ag, and the content of the active component is 0.1wt% to 1.7wt% of the catalyst, calculated as the amount of the oxide of the metal element II; more preferably, 0.8wt% to 1.4wt%.

[0009] As a specific embodiment of the present invention, the metal composite oxide contains, by mass: 0.1 to 5 parts of CuO, 5 to 25 parts of TiO 2 , 75~95 parts Al 2 O 3 .

[0010] Preferably, the metal composite oxide contains, by mass: 0.3 to 3 parts of CuO, 9 to 20 parts of TiO 2 , 77~90.7 parts Al 2 O 3 More preferably, the metal composite oxide contains, by mass, 1.5 to 3 parts of CuO, 12 to 18 parts of TiO 2 , 79~86.5 parts Al 2 O 3 .

[0011] As a specific embodiment of the present invention, the specific surface area of ​​the metal composite oxide is 30 to 155 m 2 / g, preferably 55 to 85m 2 / g, more preferably 59 to 82 m 2 / g.

[0012] As a specific embodiment of the present invention, the pore volume of the metal composite oxide is 0.2 to 0.8 mL / g, preferably 0.3 to 0.4 mL / g.

[0013] In a second aspect, the present invention provides a method for preparing a catalyst, comprising the following steps:

[0014] Step 1: providing a mixed solution containing an aluminum salt solution, a copper salt solution and a titanium salt solution; adjusting the pH value of the mixed solution to obtain a precipitated product, washing, drying and calcining the precipitated product to obtain a carrier;

[0015] Step 2: Mix the carrier prepared in step 1 with a salt solution containing metal element II, and obtain a catalyst after drying II and calcining II.

[0016] As a specific implementation of the present invention, in step 1, the pH value of the mixed solution is adjusted to 8-10.

[0017] As a specific embodiment of the present invention, the process of adjusting the pH value of the mixed solution to 8-10 in step 1 includes: using an alkaline solution to adjust the pH value of the mixed solution to 5.5-7 for the first time, after the first standing, using an alkaline solution to adjust the pH value of the mixed solution to 8-10 for the second time, and after the second standing, obtaining a precipitated product.

[0018] Preferably, the conditions for the first standing still include: a temperature of 50 to 90° C. and a time of 15 to 20 minutes.

[0019] Preferably, the conditions for the second standing still include: a temperature of 50 to 90° C. and a time of 15 to 20 minutes.

[0020] Preferably, the alkaline solution is an ammonium salt solution, and further preferably, the ammonium salt solution contains NH 4 + The concentration is 0.1-0.3 mol / L. The composite oxide carrier prepared by the present invention is carried out under weak alkaline conditions, which can ensure that the lattice structure of the composite oxide carrier is regular and orderly, and ensure good active sites; the weak base used is easy to decompose and hydrolyze, and no anionic impurities remain after drying and roasting, and the vacancies after decomposition provide a rich pore structure for the composite oxide carrier.

[0021] Preferably, the ammonium salt is selected from one or more of ammonium bicarbonate, ammonium carbonate, and other organic ammonium salts.

[0022] As a specific embodiment of the present invention, the concentration of Al in the aluminum salt solution is 0.5-2.5 mol / L, the concentration of Ti in the titanium salt solution is 0.2-1.2 mol / L, and the concentration of Cu in the copper salt solution is 0.1-0.6 mol / L.

[0023] Preferably, the mixing conditions in step 2 include: temperature of 40 to 60° C. and time of 8 to 12 hours.

[0024] Preferably, the salt solution containing active component metals includes oxalates, sulfates, nitrates and halides containing active metals; the type of solution can be an aqueous solution or a salt solution formed with ethanol, benzene or the like as a solvent.

[0025] Preferably, the aluminum salt is selected from one or more of aluminum sulfate, aluminum chloride, aluminum nitrate and other organic aluminum salts.

[0026] Preferably, the copper salt is selected from one or more soluble copper salts such as copper chloride, copper sulfate, copper nitrate, etc.

[0027] Preferably, the titanium salt is selected from one or more of soluble acid solutions of metatitanic acid, titanium tetrachloride, tetraethyl titanate, and the like.

[0028] As a specific embodiment of the present invention, the conditions for drying I in step 1 include: a temperature of 100 to 150° C. and a drying time of 4 to 12 hours.

[0029] As a specific embodiment of the present invention, the conditions of calcination I in step 1 include: temperature of 500-1100° C., calcination time of 4-12 hours, atmosphere of air and / or inert gas. Specifically, the inert gas is nitrogen.

[0030] As a specific embodiment of the present invention, the precipitate washing process includes: washing the precipitate product with deionized water until it becomes neutral.

[0031] As a specific embodiment of the present invention, the conditions for drying II in step 2 include: a temperature of 90 to 120° C. and a drying time of 2 to 8 h;

[0032] As a specific embodiment of the present invention, the conditions of calcination II in step 2 include: temperature of 300-800° C., calcination time of 2-10 hours, atmosphere of air and / or inert gas. Specifically, the inert gas is nitrogen.

[0033] In a third aspect, the present invention provides a catalyst prepared by the preparation method provided in the second aspect.

[0034] In a fourth aspect, the present invention provides a method of using the catalyst provided in the first aspect of the present invention or the catalyst provided in the third aspect of the present invention in C 2-4 Application in the selective hydrogenation of fractions, C 2-4 The fraction contains impurities, which are C 3-4 Alkynes and / or dienes.

[0035] In the present invention, selective hydrogenation refers to the selective hydrogenation reaction of hydrogen with impurities to generate C 2-4 Olefins.

[0036] As a specific embodiment of the present invention, C 2-4 The fractions contained C 2-4 Olefins and C 2-4 Alkane.

[0037] As a specific embodiment of the present invention, C 2-4 The mass content of olefins is 0 to 99.99 parts;

[0038] As a specific embodiment of the present invention, C 2-4The content of alkanes is 0 to 19.99 parts;

[0039] As a specific embodiment of the present invention, C 3-4 The content of alkyne is 0.01 to 3 parts;

[0040] As a specific embodiment of the present invention, the content of the diene is 0 to 5 parts.

[0041] As a specific embodiment of the present invention, C 2-4 The fraction consists of 92-96 parts by mass of propylene, 2.8-3.5 parts by mass of propane, 1-5 parts by mass of propyne and propadiene.

[0042] In a fifth aspect, the present invention provides a C 2-4 A method for selective hydrogenation of a fraction, in the presence of the catalyst provided by the first aspect of the present invention or the catalyst provided by the third aspect of the present invention, C 2-4 The impurities in the fraction undergo hydrogenation reaction, including C 3-4 Alkynes and dienes.

[0043] As a specific embodiment of the present invention, the reaction conditions include: using a fixed bed reactor, the reactor inlet temperature is 20-50°C, the pressure is 0.5-0.8MPa, the circulation ratio is 10-30:1, and the molar ratio of hydrogen to alkyne is 1-2.5:1.

[0044] Preferably, the reactor inlet temperature is 20-25° C., the pressure is 0.5-0.7 MPa, the circulation ratio is 15-25:1, and the molar ratio of hydrogen to alkyne is 1.3-2.1:1.

[0045] As a specific embodiment of the present invention, the catalyst needs to be activated and passivated before use. Specifically, the catalyst activation treatment is carried out under hydrogen conditions, and the reaction tube is gradually heated to the reduction temperature, maintained for 10 hours, and then cooled to room temperature; the catalyst passivation treatment is carried out under hydrogen / inert gas and organic nitrogen-containing compounds.

[0046] The preparation method of the composite oxide carrier provided by the present invention can make TiO 2 、Al 2 O 3 and CuO are uniformly mixed, and the resulting carrier contains TiO 2 、Al 2 O 3 and CuO are uniformly dispersed. In this application, it is found that Al 2 O 3 , CuO, TiO 2 There will be a strong interaction between the three. This strong interaction will lead to Al 2 O 3-CuO-TiO 2 The carrier has high thermal stability, which overcomes the defect that copper is unstable at high temperature; and when calcined at 700-1000℃, TiO 2 It can still maintain the active phase of anatase without transforming into rutile phase, thus ensuring the activity of the catalyst. 2 O 3 Can maintain γ-Al 2 O 3 The crystal phase ensures the crushing strength and pore structure of the catalyst to meet the needs of industrial applications.

[0047] The TiO2 uniformly dispersed in the composite oxide carrier prepared by the present invention 2 The acidity of the catalyst carrier surface can be well adjusted, and the electron induction effect on the active components can be exerted, so that the active metal can enhance the adsorption capacity of alkynes in the reactants, thereby improving the low-temperature activity of the catalyst. At the same time, the high-temperature calcined carrier has a stable skeleton structure and a pore structure dominated by large pores, which can well accommodate polymers such as green oil generated by the side reaction polymerization of alkynes. Since the catalyst requires a low reaction temperature, the side reaction of alkynes can be effectively controlled, so the catalyst's gel capacity and hydrogenation stability are enhanced.

[0048] The catalyst prepared based on the composite oxide carrier has good activity, high selectivity and good stability and has industrial application value. DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with specific embodiments, but they do not constitute any limitation to the present invention.

[0050] Example 1

[0051] 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.

[0052] 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.

[0053] The filter cake was washed repeatedly 5 times with 20 times the volume of deionized water, dried at 110°C for 6 h, and calcined at 860°C for 5 h to obtain Al2 O 3 -CuO-TiO 2 Composite oxide support.

[0054] Example 2

[0055] 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.

[0056] 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.

[0057] 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 Al 2 O 3 -CuO-TiO 2 Composite oxide support.

[0058] Example 3

[0059] 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. 2 O 3- CuO-TiO 2 Composite oxide support.

[0060] Example 4

[0061] 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. 2 O 3 -CuO-TiO 2 Composite oxide support.

[0062] Example 5

[0063] Catalyst preparation

[0064] Prepare 1 L of deionized water solution of manganese oxalate with a Mn concentration of 0.4 mol / L, and prepare 1 L of deionized water solution of nickel oxalate with a Ni concentration of 0.7 mol / L.

[0065] Weigh the Al prepared in Example 1-4 2 O 3 -CuO-TiO 2 60 g of the composite oxide carrier was put into 0.25 L of a deionized manganese oxalate solution with a Mn concentration of 0.4 mol / L, left to stand at 55°C for 12 h, dried at 110°C for 6 h, and then calcined at 500°C for 4 h in an air atmosphere to obtain catalysts numbered 5-1, 5-2, 5-3, and 5-4, respectively.

[0066] Example 6

[0067] Weigh the Al prepared in Example 2 above 2 O 3 -CuO-TiO 2 51.6 g of the composite oxide carrier was put into a deionized manganese oxalate solution with a concentration of 0.26LMn and 0.4 mol / L, left to stand at 55°C for 12 h, dried at 110°C for 6 h, and then calcined at 500°C for 4 h in air atmosphere to obtain a catalyst.

[0068] Example 7

[0069] According to the preparation method of Example 6 above, the amount of deionized manganese oxalate solution was adjusted to prepare catalysts with different Mn contents.

[0070] Example 8

[0071] Weigh the Al prepared in Example 2 2 O 3 -CuO-TiO 2 76.3 g of the composite oxide carrier was put into a mixed solution of 0.3 L of a deionized aqueous solution of manganese oxalate with a Mn concentration of 0.4 mol / L and 0.3 L of a deionized aqueous solution of nickel oxalate with a Ni concentration of 0.7 mol / L, left to stand at 55°C for 12 h, dried at 110°C for 6 h, and then calcined at 500°C for 4 h in an air atmosphere to obtain a catalyst.

[0072] Example 9

[0073] According to the preparation method of Example 8, the amount of manganese oxalate deionized aqueous solution and nickel oxalate deionized aqueous solution was adjusted, and the Al prepared in Example 2 was used. 2 O3 -CuO-TiO 2 Catalysts with different Mn and Ni contents were prepared using composite oxide supports.

[0074] Example 10

[0075] Prepare 0.5 L of deionized aqueous palladium nitrate solution with a Pd concentration of 0.01 mol / L, and prepare 0.5 L of deionized aqueous silver nitrate solution with a Ag concentration of 0.05 mol / L.

[0076] The Al prepared in Example 2 above 2 O 3 -CuO-TiO 2 100 g of the composite oxide support was put into 82 mL of a deionized aqueous solution of palladium nitrate with a Pd concentration of 0.01 mol / L, left to stand at 55°C for 12 h, dried at 110°C for 6 h, and then calcined at 500°C for 4 h in air atmosphere to obtain a catalyst.

[0077] Embodiment 11

[0078] According to the preparation method of Example 10, the amount of deionized aqueous palladium nitrate solution with a Pd concentration of 0.01 mol / L was adjusted to prepare catalysts with different Pd contents.

[0079] Example 12

[0080] The Al prepared in Example 2 above 2 O 3 -CuO-TiO 2 98.3 g of the composite oxide support was added to a mixed solution of the above-mentioned 0.25L palladium nitrate deionized aqueous solution with a 0.01 mol / L LPd concentration and 0.18L silver nitrate deionized aqueous solution with a 0.05 mol / L Ag concentration. After standing at 55°C for 12 hours, it was dried at 110°C for 6 hours and then calcined at 500°C for 4 hours in an air atmosphere to obtain a catalyst.

[0081] Example 13

[0082] According to the preparation method of Example 12 above, the amounts of deionized aqueous palladium nitrate solution and deionized aqueous silver nitrate solution were adjusted to prepare catalysts with different Pd and Ag contents.

[0083] Comparative Example 1

[0084] Prepare 1L of aluminum sulfate deionized water solution with an Al concentration of 0.8mol / L, 0.56L of titanic acid dilute sulfuric acid solution with a Ti concentration of 0.46mol / L, and NH 4 +An ammonium bicarbonate solution with a concentration of 0.22 mol / L is mixed with 25 wt % ammonia water to prepare 1 L of a mixed alkaline solution with a pH of 11-12.

[0085] At a temperature of 65°C, 1L of aluminum sulfate deionized water solution, 0.5L of titanic 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 precipitate was washed with deionized water 5 times the volume of the precipitate for 30 minutes, filtered again, and washed again. This process was repeated four times, and finally the precipitate was dried at 110°C for 10 hours and calcined at 950°C for 5 hours. The calcination atmosphere was air to obtain Al 2 O 3 -TiO 2 Complex.

[0086] Weigh Al 2 O 3 -TiO 2 60 g of the composite oxide carrier was put into a 0.25LMn deionized manganese oxalate solution with a concentration of 0.4 mol / L, allowed to stand at 55°C for 12 h, dried at 110°C for 6 h, and then calcined at 500°C for 4 h in air to obtain a catalyst.

[0087] Comparative Example 2

[0088] The Al prepared in Comparative Example 1 2 O 3 -TiO 2 76.3 g of the composite oxide carrier was put into a mixed solution of 0.3 L of a deionized aqueous solution of manganese oxalate with a Mn concentration of 0.4 mol / L and 0.3 L of a deionized aqueous solution of nickel oxalate with a Ni concentration of 0.7 mol / L, allowed to stand at 55 ° C for 12 h, dried at 110 ° C for 6 h, and then calcined at 500 ° C for 4 h in an air atmosphere to obtain a catalyst.

[0089] The composition and pore structure parameters of the carriers prepared in Examples 1-4 and Comparative Examples 1-2 are shown in Table 1.

[0090] The specific surface area and pore volume of the carrier were measured using the ASAP 2020 adsorption instrument (N 2The carrier sample was degassed at 623K for 4h before testing, 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 size based on the nitrogen adsorption isotherm curve, and the P / Po single-point desorption curve was used to obtain the pore volume.

[0091] Al in carrier 2 O 3 、TiO 2 Determination of CuO content: UV-2100 ultraviolet spectrophotometer is used to determine the components in the carrier. Each substance can absorb light of a specific wavelength. In the range of ultraviolet and visible light, the degree of absorption of different metals for a specific wavelength is proportional to the concentration of the component in the sample. Quantitative analysis is performed based on the comparison of absorption with standard samples of known concentration.

[0092] Table 1 Contents of various oxides and pore structure parameters in the carriers prepared in Examples 1-4 and Comparative Examples 1-2

[0093]

[0094]

[0095] The compositions of the catalysts prepared in Examples 5-13 and Comparative Examples 1-2 are shown in Table 2.

[0096] The Ni, Pd, Mn and Ag contents in the catalyst were determined by ICP atomic emission spectrometer, and the test standard was: JYT015 General Rules for Inductively Coupled Plasma Atomic Emission Spectrometry. The instrument used the Optima8300 full-spectrum direct-reading ICP spectrometer from PerkinElmer (PE) of the United States, with a stepped grating, a solid-state detector, dual-path dual solid-state detectors in the ultraviolet and visible regions, and flat-plate plasma technology, ensuring the instrument had the lowest argon consumption.

[0097] Table 2 Content of active components in the catalysts prepared in Examples 5-13 and Comparative Examples 1-2

[0098] Carrier Mn, wt% Ni,wt% Pd, wt% Ag,wt% Example 5 <![CDATA[Al 2 OR 3 -CuO-TiO 2 ]]> 12 / / / Example 6 <![CDATA[Al 2 OR 3 -CuO-TiO 2 ]]> 15 / / / Example 7 <![CDATA[Al 2 OR 3 -CuO-TiO 2 ]]> 20 / / / Example 8 <![CDATA[Al 2 OR 3 -CuO-TiO 2 ]]> 10 15 / / Example 9 <![CDATA[Al 2 OR 3 -CuO-TiO 2 ]]> 5 20 / / Example 10 <![CDATA[Al 2 OR 3 -CuO-TiO 2 ]]> / / 0.1 / Embodiment 11 <![CDATA[Al 2 OR 3 -CuO-TiO 2 ]]> / / 0.25 / Example 12 <![CDATA[Al 2 OR 3 -CuO-TiO 2 ]]> / / 0.3 1 Example 13 <![CDATA[Al 2 OR 3 -CuO-TiO 2 ]]> / / 0.15 1.5 Comparative Example 1 <![CDATA[Al 2 O 3 -CuO]]> 12 / / / Comparative Example 2 <![CDATA[Al 2 O 3 -CuO]]> 10 15 / /

[0099] Since the contents of active components in the catalysts No. 5-1, 5-2, 5-3, and 5-4 in Example 5 are the same, only the content of active components in the catalyst No. 5-2 is listed in Table 2.

[0100] The catalysts prepared in Examples 5-13 and Comparative Examples 1-2 were used in the selective hydrogenation reaction of C3 fractions.

[0101] The composition of the raw materials used in the hydrogenation reaction process is shown in Table 3.

[0102] Table 3 Composition of raw materials for selective hydrogenation of C3 fraction

[0103]

[0104]

[0105] The hydrogenation process uses a fixed bed pilot evaluation device from Tuochuan Scientific Research Equipment Co., Ltd., loaded with 50 mL of catalyst, and performs a selective hydrogenation reaction of the C3 fraction. Reaction conditions: reactor inlet temperature of 25°C, reaction pressure of 0.5 MPa, circulation ratio of 20:1, hydrogen feed rate of 40 mL / h, and impurity feed rate of 25 mL / h. The impurities are propyne and propadiene.

[0106] The catalysts prepared in Examples 5-13 and Comparative Examples 1-2 were evaluated under the same conditions, and the selective hydrogenation results were shown in Tables 4 and 5.

[0107] During the experiment, a chromatograph was used to test the content of each component. The calculation formulas for MAPD conversion and propylene selectivity are as follows.

[0108] MAPD conversion rate = (MAPD in feedstock - MAPD in product) ÷ (MAPD in feedstock)

[0109] Propylene selectivity = (propylene in product - propylene in feed) ÷ (MAPD in feed - MAPD in product)

[0110] Table 4 Selective hydrogenation results of C3 fractions prepared with catalysts on different supports

[0111]

[0112] It can be seen from the reaction results that the catalysts prepared using different supports provided by the present invention all exhibited high conversion rates and selectivities in the selective hydrogenation of C3 fractions, and the support in Example 2 had the best effect.

[0113] Table 5 Results of selective hydrogenation of C3 fractions using catalysts prepared with different active components

[0114]

[0115] It can be seen from the test results that, by using the catalyst prepared in the present invention, the conversion rate of MAPD can reach more than 99%, and the selectivity of propylene can reach more than 90%.

[0116] 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 catalyst, characterized in that including a carrier and an active ingredient; The carrier is a metal composite oxide, and the metal composite oxide contains metal element I, and the metal element I includes aluminum, copper and titanium; The active component contains a metal element II, and the metal element II is selected from at least one of Mn, Ni, Pd and Ag.

2. The catalyst according to claim 1, characterized in that The metal composite oxide is Al2O3-CuO-TiO2 composite oxide; and / or, Calculated as the amount of the oxide of metal element II, the content of the active component is 0.1wt% to 40wt% of the catalyst; preferably, metal element II is selected from Mn and / or Ni, and calculated as the amount of the oxide of metal element II, the content of the active component is 10wt% to 25wt% of the catalyst, more preferably 15wt% to 25wt%; preferably, metal element II is selected from Pd and / or Ag, and calculated as the amount of the oxide of metal element II, the content of the active component is 0.1wt% to 1.7wt% of the catalyst; more preferably 0.8wt% to 1.4wt%.

3. The catalyst according to claim 2, characterized in that The metal composite oxide contains, by mass, 0.1 to 5 parts of CuO, 5 to 25 parts of TiO2, and 75 to 95 parts of Al2O3; preferably, the metal composite oxide contains, by mass, 0.3 to 3 parts of CuO, 9 to 20 parts of TiO 2、 77 to 90.7 parts of Al2O3; more preferably, the metal composite oxide contains, by mass, 1.5 to 3 parts of CuO, 12 to 18 parts of TiO2, and 79 to 86.5 parts of Al2O3.

4. The catalyst according to any one of claims 1 to 3, characterized in that The specific surface area of ​​the metal composite oxide is 30 to 155 m 2 / g, preferably 55 to 85m 2 / g, more preferably 59 to 82 m 2 / g; And / or, the pore volume of the metal composite oxide is 0.2 to 0.8 mL / g, preferably 0.3 to 0.4 mL / g.

5. A method for preparing a catalyst, characterized in that: The steps include: Step 1: providing a mixed solution containing an aluminum salt solution, a copper salt solution and a titanium salt solution, adjusting the pH value of the mixed solution to obtain a precipitated product, and washing, drying and calcining the precipitated product to obtain a carrier; Step 2: Mix the carrier prepared in step 1 with a salt solution containing metal element II, and obtain a catalyst after drying II and calcining II.

6. The method for preparing the catalyst according to claim 5, characterized in that: In step 1, the pH value of the mixed solution is adjusted to 8-10; Preferably, the process of adjusting the pH value of the mixed solution to 8-10 in step 1 comprises: using an alkaline solution to adjust the pH value of the mixed solution to 5.5-7 for the first time, after the first standing, using an alkaline solution to adjust the pH value of the mixed solution to 8-10 for the second time, and after the second standing, obtaining a precipitated product; Preferably, the conditions for the first standing still include: a temperature of 50 to 90° C. and a time of 15 to 20 min; the conditions for the second standing still include: a temperature of 50 to 90° C. and a time of 15 to 20 min.

7. The method for preparing the catalyst according to claim 5 or 6, characterized in that: The concentration of Al in the aluminum salt solution is 0.5-2.5 mol / L, the concentration of Ti in the titanium salt solution is 0.2-1.2 mol / L, and the concentration of Cu in the copper salt solution is 0.1-0.6 mol / L.

8. The method for preparing the catalyst according to any one of claims 5 to 7, characterized in that: The mixing conditions in step 2 include: temperature of 40 to 60° C. and time of 8 to 12 hours.

9. The method for preparing a catalyst according to any one of claims 5 to 8, characterized in that: The conditions for drying I in step 1 include: a temperature of 100 to 150° C. and a time of 4 to 12 hours; And / or, the conditions for calcining I in step 1 include: a temperature of 500 to 1100° C., a time of 4 to 12 hours, and an atmosphere of air and / or an inert gas; And / or, the conditions of drying II in step 2 include: temperature of 90 to 120° C. and time of 2 to 8 h; And / or, the conditions of calcination II in step 2 include: temperature of 300-800° C., time of 2-10 hours, atmosphere of air and / or inert gas.

10. A catalyst prepared by the preparation method according to any one of claims 5 to 9.

11. The catalyst according to any one of claims 1 to 4 or the catalyst according to claim 10 in C 2-4 Application of the selective hydrogenation reaction of distillates, the C 2-4 The fraction contains impurities, which are C 3-4 Alkynes and / or dienes.

12. The use according to claim 11, characterized in that: The C 2-4 The fractions contained C 2-4 Olefins and C 2-4 Alkanes; The C 2-4 The mass content of olefins is 0 to 99.99 parts; and / or, the C 2-4 The mass content of alkanes is 0 to 19.99 parts; and / or, the C 3-4 The mass content of alkyne is 0.01 to 3 parts; And / or, the mass content of the diene is 0 to 5 parts.

13. The use according to claim 12, characterized in that: The C 2-4 The fraction consists of 92-96 parts by mass of propylene, 2.8-3.5 parts by mass of propane, and 1-5 parts by mass of propyne and propadiene.

14. A C 2-4 A method for selective hydrogenation of distillates, characterized in that In the presence of the catalyst according to any one of claims 1 to 4 or the catalyst according to claim 10, C 2-4 The impurities in the fraction undergo hydrogenation reaction, and the impurities include C 3-4 Alkynes and dienes; reaction conditions include: using a fixed bed reactor, the reactor inlet temperature is 20 to 50°C, the pressure is 0.5 to 0.8 MPa, the circulation ratio is 10 to 30:1, and the molar ratio of hydrogen to impurities is 1 to 2.5:1; Preferably, the reactor inlet temperature is 20-25° C., the pressure is 0.5-0.7 MPa, the circulation ratio is 15-25:1, and the molar ratio of hydrogen to impurities is 1.3-2.1:1.

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