Catalyst, preparation method and application in low carbon hydrocarbon hydrogenation to remove acetylene

Abstract

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

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of low-carbon hydrocarbon hydrogenation acetylene removal, and in particular to a catalyst, a preparation method and application thereof in low-carbon hydrocarbon hydrogenation acetylene removal. BACKGROUND

[0002] Low-carbon hydrocarbon (C2-C4) is an important organic chemical raw material, and its downstream products have a wide range of applications in the fields of plastics, films, fibers, rubber, resins, coatings and the like. The source of low-carbon hydrocarbon is mainly obtained by cracking of naphtha and dehydrogenation of light alkanes. However, the low-carbon hydrocarbon separated from the device often carries trace amounts of oxygen, sulfur, acetylene and CO impurities, which can cause problems such as catalyst poisoning and deactivation, reduced reaction rate or decreased product quality in downstream reactions. Ethylene is one of the most important basic raw materials in the petroleum chemical industry, and the ethylene obtained by cracking of petroleum usually contains 0.5-2.5% (mole fraction) of acetylene. The presence of acetylene can affect the process of ethylene polymerization and the performance of the product. If the concentration of acetylene is too high, there is also a risk of explosion. The carbon three fraction in the cracking gas is usually obtained in the ethylene production device by cracking of petroleum, and its composition usually contains 1-5% (mole fraction) of propyne (MA) and propadiene (PD). MAPD is a toxic substance that affects the application of downstream propylene, so high-purity propylene must first be obtained by removing MAPD. In addition, low-carbon fractions containing acetylenes and dienes can easily polymerize into gum at high temperatures, which can settle on the surface of the catalyst, causing the catalyst to quickly deactivate, and the catalyst has to be frequently activated and regenerated. Therefore, it is desirable for the hydrogenation catalyst to have high low-temperature activity, so that the catalyst has appropriate gum capacity, so that the polymer on the surface of the catalyst does not change in activity before being flushed, thereby prolonging the service life of the catalyst, which is very important in industrial production. SUMMARY

[0003] In order to solve the above problems in the prior art, the present application provides a catalyst, a preparation method and application thereof in low-carbon hydrocarbon hydrogenation acetylene removal. The catalyst is suitable for low-carbon olefin hydrogenation acetylene removal reaction by specific matching of the carrier and several metal active components.

[0004] In a first aspect, the present application provides a catalyst, comprising a carrier and an active component, the carrier being a metal composite oxide, the metal composite oxide containing metal element I, the metal element I including aluminum, copper and titanium; the active component containing metal element II, the metal element II being selected from at least one of Mn, Ni, Pd or Ag.

[0005] As a specific embodiment of the present application, the metal composite oxide is an Al2O3-CuO-TiO2 composite oxide.

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

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

[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 application, the metal composite oxide contains, in mass parts, 0.1 to 5 parts of CuO, 5 to 25 parts of TiO2, and 75 to 95 parts of Al2O3.

[0010] Preferably, the metal composite oxide contains, in mass parts, 0.3 to 3 parts of CuO, 9 to 20 parts of TiO2, and 77 to 90.7 parts of Al2O3; more preferably, the metal composite oxide contains, in mass parts, 1.5 to 3 parts of CuO, 12 to 18 parts of TiO2, and 79 to 86.5 parts of Al2O3.

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

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

[0013] In a second aspect, the present application provides a preparation method of the catalyst, comprising the following steps:

[0014] Step one: 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 precipitate product, and washing, drying I, and calcining I of the precipitate product to obtain a carrier;

[0015] Step two: mixing the carrier prepared in step one with a salt solution containing a metal element II, drying II, and calcining II to obtain the catalyst.

[0016] As a specific embodiment of the present application, the pH value of the mixed solution is adjusted to 8 to 10 in step one.

[0017] As a specific embodiment of the present application, the process of adjusting the pH value of the mixed solution to 8-10 in step one comprises: adjusting the pH value of the mixed solution to 5.5-7 by using an alkali solution for the first time, adjusting the pH value of the mixed solution to 8-10 by using an alkali solution for the second time after the first time of standing, and obtaining the precipitated product after the second time of standing.

[0018] Preferably, the first time of standing is under the condition of 50-90℃ for 15-20 min.

[0019] Preferably, the second time of standing is under the condition of 50-90℃ for 15-20 min.

[0020] Preferably, the alkali solution is an ammonium salt solution, and further preferably, the concentration of NH4 + The prepared composite oxide carrier in the present application is carried out under weak alkali condition, which can ensure the regular and ordered lattice structure of the composite oxide carrier and good active point position; the weak alkali used is easy to decompose and hydrolyze, and no anion impurity is left after drying and calcination, and the vacancy after decomposition provides 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 application, 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 condition in step two comprises: 40-60℃ for 8-12 h.

[0024] Preferably, the salt solution containing active component metal comprises oxalate, sulfate, nitrate and halide of the active metal; the type of the solution can be aqueous solution, or salt solution formed by using ethanol, benzene and the like as solvent.

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

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

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

[0028] As a specific embodiment of the present application, the conditions of drying I in step one include: temperature of 100-150°C, drying time of 4-12h.

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

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

[0031] As a specific embodiment of the present application, the conditions of drying II in step two include: temperature of 90-120°C, drying time of 2-8h;

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

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

[0034] In a fourth aspect, the present application provides a use of the catalyst provided in the first aspect or the catalyst provided in the third aspect in a C 2-4 fraction selective hydrogenation reaction, wherein the C 2-4 fraction contains impurities, and the impurities are C 3-4 alkynes and / or dienes.

[0035] In the present application, selective hydrogenation refers to that hydrogen selectively reacts with the impurities to generate C 2-4 alkenes.

[0036] As a specific embodiment of the present application, the C 2-4 fraction contains C 2-4 alkenes and C 2-4 alkanes.

[0037] As a specific embodiment of the present application, the C 2-4 alkenes have a mass content of 0-99.99 parts;

[0038] As a specific embodiment of the present application, the C 2-4 alkanes have a content of 0-19.99 parts;

[0039] As a specific embodiment of the present application, the C 3-4 alkynes have a content of 0.01-3 parts;

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

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

[0042] In a fifth aspect, the present application provides a C 2-4 The fraction is composed of 92-96 parts of propylene, 2.8-3.5 parts of propane, 1-5 parts of propyne and propadiene by mass fraction. 2-4 The impurities in the fraction are subjected to hydrogenation reaction, and the impurities include C 3-4 Alkynes and dienes.

[0043] As a specific embodiment of the present application, the reaction conditions include: using a fixed bed reactor, the reactor inlet temperature is 20-50℃, 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℃, the pressure is 0.5-0.7MPa, 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 application, the catalyst needs to be activated and passivated before application. Specifically, the catalyst activation treatment is carried out under hydrogen condition, 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 compound condition.

[0046] The preparation method of the composite oxide carrier provided by the present application can uniformly mix TiO2, Al2O3 and CuO, and the obtained carrier has uniformly dispersed TiO2, Al2O3 and CuO. It is found in the present application that Al2O3, CuO and TiO2 can form strong mutual interaction at high temperature. The strong mutual interaction can result in high thermal stability of the Al2O3-CuO-TiO2 carrier, overcoming the defect that elemental copper is unstable at high temperature; and after high-temperature calcination at 700-1000℃, TiO2 can still maintain the active phase of anatase, without being converted into rutile phase, thereby ensuring the activity of the catalyst; at the same time, Al2O3 can maintain the crystal phase of γ-Al2O3, thereby ensuring the crushing strength and pore structure of the catalyst, and meeting the requirements of industrial application.

[0047] The TiO2 uniformly dispersed in the composite oxide carrier prepared by the application can well adjust the acidity of the surface of the catalyst carrier, and has an electron induction effect on the active component, so that the adsorption capacity of the active metal to the alkyne in the reactant is enhanced, thus the low-temperature activity of the catalyst is improved, and the carrier calcined at high temperature has a stable skeleton structure and a pore structure mainly with large pore size, which can well accommodate the polymer such as green oil generated by the polymerization of the alkyne side reaction. Since the catalyst needs a relatively low reaction temperature, the alkyne side reaction can be effectively controlled, so the catalyst has enhanced capacity to accommodate the polymer and hydrogenation stability.

[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 application will be further described below in combination with specific examples, but does not constitute any limitation to the application.

[0050] Example 1

[0051] An aluminum sulfate deionized water solution with a concentration of 0.8 mol / L is prepared in 1L, a metatitanic acid dilute sulfuric acid solution with a concentration of 0.46 mol / L is prepared in 0.5L, a copper nitrate solution with a concentration of 0.39 mol / L is prepared in 0.1L, and a mixed alkali solution with pH=11-12 is prepared in 1L by mixing 0.22 mol / L of ammonium bicarbonate solution with 25% ammonia water.

[0052] At a temperature of 65℃, the above-mentioned aluminum sulfate deionized water solution is added with 0.1L of the copper nitrate solution and 0.5L of the metatitanic acid dilute sulfuric acid solution in parallel flow, and an appropriate amount of the mixed alkali solution is added to keep the pH value of the mixed solution system at 6.2, and the system is kept for 20 min; the mixed alkali is continuously added to make the pH=9.1, and the system is kept for 20 min, to obtain a precipitate, which is filtered to obtain a filter cake.

[0053] The filter cake is repeatedly washed with 20 times the volume of deionized water for 5 times, and the washed filter cake is dried at 110℃ for 6h and calcined at 860℃ for 5h to obtain an Al2O3-CuO-TiO2 composite oxide carrier.

[0054] Example 2

[0055] An aluminum sulfate deionized water solution with a concentration of 0.88 mol / L is prepared in 1L, a metatitanic acid dilute sulfuric acid solution with a concentration of 0.35 mol / L is prepared in 0.5L, a copper nitrate solution with a concentration of 0.2 mol / L is prepared in 0.13L, and a mixed alkali solution with pH=11-12 is prepared in 1L by mixing 0.22 mol / L of ammonium bicarbonate solution with 25% ammonia water.

[0056] At a temperature of 75°C, an aluminum sulfate deionized water solution is added with a copper nitrate solution, a metatitanic acid dilute sulfuric acid solution, and an appropriate amount of mixed alkali solution is added to keep the pH value of the mixed solution system at 6.8, and the system is kept for 15 min; the mixed alkali solution is continuously added to make the pH value 8.5, and the system is kept for 15 min to obtain a precipitate, which is filtered to obtain a filter cake.

[0057] The filter cake is repeatedly washed with 30 times the volume of deionized water for 7 times, and the washed filter cake is dried at 120°C for 6 h and calcined at 950°C for 4 h to obtain an Al2O3-CuO-TiO2 composite oxide carrier.

[0058] Example 3

[0059] The preparation method of the carrier is basically the same as that in Example 1, except that the concentrations of the solutions are different, specifically, 1L of 0.9 mol / L aluminum sulfate deionized water solution, 0.5L of 0.25 mol / L metatitanic acid dilute sulfuric acid solution, and 0.1L of 0.1 mol / L copper nitrate solution are prepared. An Al2O3-CuO-TiO2 composite oxide carrier is prepared. 3- CuO-TiO2 composite oxide carrier.

[0060] Example 4

[0061] The preparation method of the carrier is basically the same as that in Example 1, except that the concentrations of the solutions are different, specifically, 1L of 0.8 mol / L aluminum sulfate deionized water solution, 0.5L of 0.55 mol / L metatitanic acid dilute sulfuric acid solution, and 0.05L of 0.1 mol / L copper nitrate solution are prepared. An Al2O3-CuO-TiO2 composite oxide carrier is prepared.

[0062] Example 5

[0063] Preparation of the catalyst

[0064] 1L of 0.4 mol / L manganese oxalate deionized water solution and 1L of 0.7 mol / L nickel oxalate deionized water solution are prepared.

[0065] 60g of the Al2O3-CuO-TiO2 composite oxide carrier prepared in Examples 1-4 is weighed and put into 0.25L of 0.4 mol / L manganese oxalate deionized water solution, and the system is kept 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 prepare catalysts numbered 5-1, 5-2, 5-3, and 5-4, respectively.

[0066] Example 6

[0067] Take 51.6 g of the Al2O3-CuO-TiO2 composite oxide carrier prepared in the above Example 2. Put into 0.26 L of a manganese oxalate deionized aqueous solution with a concentration of 0.4 mol / L, stand still at 55°C for 12 h, dry at 110°C for 6 h, and then calcine at 500°C for 4 h in an air atmosphere to prepare a catalyst.

[0068] Example 7

[0069] Adjust the amount of the manganese oxalate deionized aqueous solution according to the preparation method of the above Example 6 to prepare catalysts with different Mn contents.

[0070] Example 8

[0071] Take 76.3 g of the Al2O3-CuO-TiO2 composite oxide carrier prepared in Example 2. Put into a mixed solution of 0.3 L of a manganese oxalate deionized aqueous solution with a concentration of 0.4 mol / L and 0.3 L of a nickel oxalate deionized aqueous solution with a concentration of 0.7 mol / L, stand still at 55°C for 12 h, dry at 110°C for 6 h, and then calcine at 500°C for 4 h in an air atmosphere to prepare a catalyst.

[0072] Example 9

[0073] Adjust the amounts of the manganese oxalate deionized aqueous solution and the nickel oxalate deionized aqueous solution according to the preparation method of the above Example 8, and use the Al2O3-CuO-TiO2 composite oxide carrier prepared in Example 2 to prepare catalysts with different Mn and Ni contents.

[0074] Example 10

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

[0076] Put 100 g of the Al2O3-CuO-TiO2 composite oxide carrier prepared in the above Example 2 into 82 mL of the palladium nitrate deionized aqueous solution with a Pd concentration of 0.01 mol / L. After standing still at 55°C for 12 h, dry at 110°C for 6 h, and then calcine at 500°C for 4 h in an air atmosphere to prepare a catalyst.

[0077] Example 11

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

[0079] Example 12

[0080] The Al2O3-CuO-TiO2 composite oxide support prepared in Example 2 above was 98.3 g in amount and was put into a mixed solution of 0.25 L of a palladium nitrate aqueous solution having a concentration of 0.01 mol / L and 0.18 L of a silver nitrate aqueous solution having a concentration of 0.05 mol / L. After being left to stand at 55°C for 12 h, the mixture was dried at 110°C for 6 h and then calcined at 500°C for 4 h in an air atmosphere to prepare a catalyst.

[0081] Example 13

[0082] The amounts of the palladium nitrate aqueous solution and the silver nitrate aqueous solution were adjusted according to the preparation method of Example 12 above to prepare catalysts having different Pd and Ag contents.

[0083] Comparative Example 1

[0084] An aluminum sulfate aqueous solution having a concentration of 0.8 mol / L was prepared in an amount of 1 L, a metatitanic acid dilute sulfuric acid solution having a concentration of 0.46 mol / L was prepared in an amount of 0.56 L, and an ammonium bicarbonate solution having a concentration of 0.22 mol / L was prepared and mixed with 25 wt% ammonia water to prepare a mixed alkali solution having a pH of 11 to 12 in an amount of 1 L. + An aluminum sulfate aqueous solution having a concentration of 0.8 mol / L was prepared in an amount of 1 L, a metatitanic acid dilute sulfuric acid solution having a concentration of 0.46 mol / L was prepared in an amount of 0.56 L, and an ammonium bicarbonate solution having a concentration of 0.22 mol / L was prepared and mixed with 25 wt% ammonia water to prepare a mixed alkali solution having a pH of 11 to 12 in an amount of 1 L.

[0085] The three solutions, i.e., the aluminum sulfate aqueous solution, the metatitanic acid dilute sulfuric acid solution, and the mixed alkali solution, were co-precipitated at a temperature of 65°C. The flow rate of the mixed alkali solution was controlled so that the pH of the precipitate was maintained in the range of 5.0 to 6.0 for 8 min, the flow rate of the mixed alkali solution was then increased so that the pH of the mixed solution was maintained in the range of 8.5 to 9.5 for 8 min, the flow rate of the mixed alkali solution was then decreased so that the pH of the mixed solution was maintained in the range of 5.0 to 6.0 for 8 min, and the flow rate of the mixed alkali solution was then increased so that the pH of the precipitate was maintained in the range of 8.5 to 9.5. This process was repeated until the solutions were completely added. The reaction solution was left to stand at 70°C for 30 min, and the precipitate was filtered and washed with deionized water in an amount of 5 times the volume of the precipitate for 30 min. This process was repeated four times. The precipitate was then dried at 110°C for 10 h and calcined at 950°C for 5 h in an air atmosphere to obtain an Al2O3-TiO2 composite.

[0086] An Al2O3-TiO2 composite oxide support was weighed in an amount of 60 g and put into 0.25 L of a manganese oxalate aqueous solution having a concentration of 0.4 mol / L. After being left to stand at 55°C for 12 h, the mixture was dried at 110°C for 6 h and then calcined at 500°C for 4 h in an air atmosphere to prepare a catalyst.

[0087] Comparative Example 2

[0088] An Al2O3-TiO2 composite oxide support 76.3 g prepared in the above-mentioned Comparative Example 1 was put into a mixed solution of 0.3 L of a manganese oxalate aqueous solution having a Mn concentration of 0.4 mol / L and 0.3 L of a nickel oxalate aqueous solution having a Ni concentration of 0.7 mol / L, and was 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 prepare a catalyst.

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

[0090] The specific surface area and pore volume of the support were measured using an ASAP 2020 adsorption instrument (N2adsorption-desorption method) of Micromeritics, USA. The support sample was degassed at 623 K for 4 h, and nitrogen was adsorbed at liquid nitrogen temperature. The sample data were processed using AMS software, and the specific surface area of the sample was obtained using the Brunauer-Emmet-Teller (BET) method. The average pore diameter was obtained from the nitrogen adsorption isotherm using the Barrett-Joyner-Halenda (BJH) method, and the pore volume was obtained from the P / Po single-point desorption curve.

[0091] Determination of the contents of Al2O3, TiO2, and CuO in the support: UV-2100 ultraviolet spectrophotometry was used to determine the components in the support. Each substance can absorb light of a specific wavelength. In the ultraviolet-visible light range, the extent of absorption of a specific wavelength by different metals is directly proportional to the concentration of the component in the sample. Quantitative analysis was performed by comparing the absorption with that of a standard sample of known concentration.

[0092] Table 1 Contents of oxides and pore structure parameters of the supports prepared in Examples 1 to 4 and Comparative Examples 1 and 2

[0093]

[0094]

[0095] The composition of the catalysts prepared in Examples 5 to 13 and Comparative Examples 1 and 2 is shown in Table 2.

[0096] The contents of Ni, Pd, Mn, and Ag in the catalyst were determined using an ICP atomic emission spectrometer. The test standard used was JYT015 General Rules for Inductively Coupled Plasma Atomic Emission Spectrometry. A full-spectrum direct-reading ICP spectrometer Optima 8300 of PerkinElmer (PE), USA, was used, which has a step grating, a solid-state detector, dual light paths in the ultraviolet and visible light regions, and dual solid-state detectors, and uses a flat plasma technology, thereby ensuring the lowest argon consumption of the instrument.

[0097] Table 2 Content of active component in catalyst prepared in Examples 5-13 and Comparative Examples 1-2

[0098] Carrier Mn, wt% Ni, wt% Pd, wt% Ag, wt% Example 5 Al2O3-CuO-TiO2 12 / / / Example 6 Al2O3-CuO-TiO2 15 / / / Example 7 Al2O3-CuO-TiO2 20 / / / Example 8 Al2O3-CuO-TiO2 10 15 / / Example 9 Al2O3-CuO-TiO2 5 20 / / Example 10 Al2O3-CuO-TiO2 / / 0.1 / Example 11 Al2O3-CuO-TiO2 / / 0.25 / Example 12 Al2O3-CuO-TiO2 / / 0.3 1 Example 13 Al2O3-CuO-TiO2 / / 0.15 1.5 Comparative Example 1 Al2O3-CuO 12 / / / Comparative Example 2 Al2O3-CuO 10 15 / /

[0099] Since the content of active component in catalysts numbered 5-1, 5-2, 5-3, 5-4 in Example 5 is the same, only the content of active component in catalyst numbered 5-2 is listed in Table 2.

[0100] The catalysts prepared in Examples 5-13 and Comparative Examples 1-2 were applied in the selective hydrogenation of carbon three fraction.

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

[0102] Table 3 Composition of raw material for selective hydrogenation of carbon three fraction

[0103]

[0104]

[0105] The hydrogenation process was carried out using a fixed bed small test evaluation device of TAKAWA Scientific Equipment Co., Ltd. with 50 mL catalyst loaded, for the selective hydrogenation of carbon three fraction. The reaction conditions were as follows: the reactor inlet temperature was 25℃, the reaction pressure was 0.5 MPa, the circulation ratio was 20:1, the hydrogen feed amount was 40 mL / h, and the impurity feed amount was 25 mL / h. The impurities were 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 are shown in Tables 4 and 5.

[0107] The chromatograph was used to test the content of each component during the experiment, and the calculation formulas of MAPD conversion rate and propylene selectivity were as follows.

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

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

[0110] Table 4 Selective hydrogenation results of carbon three fraction of catalyst prepared with different carriers

[0111]

[0112] As can be seen from the reaction results, the catalysts prepared with different carriers according to the present application all exhibit high conversion rate and selectivity in the selective hydrogenation of carbon three fraction, and the carrier in Example 2 is the best.

[0113] Table 5 Carbon trimmer selectivity hydrogenation results of catalysts prepared with different active components

[0114]

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

[0116] It should be noted that the above-described examples are only used to explain the present application and do not constitute any limitation to the present application. The present application is described by referring to typical examples, but it should be understood that the words used therein are descriptive and explanatory words, rather than limiting words. The present application can be modified as specified within the scope of the claims of the present application, and the present application can be revised without departing from the scope and spirit of the present application. Although the present application described therein relates to specific methods, materials and examples, it does not mean that the present application is limited to the specific examples disclosed therein, on the contrary, the present application can be extended to all other methods and applications having the same function.

Claims

1. A catalyst characterized in that, comprise a carrier and an active component; the carrier is an Al2O3-CuO-TiO2 composite oxide; the composite oxide contains, in mass fraction, 1.5-3 parts of CuO, 12-18 parts of TiO2, and 79-86.5 parts of Al2O3; the active component contains a metal element II selected from at least one of Mn, Ni, Pd, or Ag; the content of the active component is 0.1wt%-40wt% of the catalyst, calculated in terms of the amount of the oxide of the metal element II.

2. The catalyst according to claim 1, characterized in that, the metal element II is selected from Mn and / or Ni, and the content of the active component is 10wt%-25wt% of the catalyst, calculated in terms of the amount of the oxide of the metal element II; and / or, the metal element II is selected from Pd and / or Ag, and the content of the active component is 0.1wt%-1.7wt% of the catalyst, calculated in terms of the amount of the oxide of the metal element II.

3. The catalyst according to claim 2, characterized in that, the metal element II is selected from Mn and / or Ni, and the content of the active component is 15wt%-25wt% of the catalyst, calculated in terms of the amount of the oxide of the metal element II; and / or, the metal element II is selected from Pd and / or Ag, and the content of the active component is 0.8wt%-1.4wt% of the catalyst, calculated in terms of the amount of the oxide of the metal element II.

4. The catalyst according to any one of claims 1 to 3, characterized in that The specific surface area of the complex oxide is 30 to 155 m 2 / g; and / or, the pore volume of the composite oxide is 0.2-0.8mL / g.

5. The catalyst of claim 4, wherein The specific surface area of the composite oxide is 55 to 85 m 2 / g; and / or, the pore volume of the composite oxide is 0.3-0.4mL / g.

6. The catalyst of claim 5, wherein The specific surface area of the composite oxide is 59 to 82 m 2 / g.

7. A process for the preparation of the catalyst according to any one of claims 1 to 6, characterized in that, comprise the following steps: Step one: 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 precipitate, and washing and drying I, calcining I of the precipitate to obtain the carrier; Step two: mixing the carrier prepared in step one with a salt solution containing a metal element II, drying II, and calcining II to obtain the catalyst.

8. The method of claim 7, wherein the catalyst is prepared by a method comprising: The pH value of the mixed solution is adjusted to 8-10 in step one.

9. The method of claim 8, wherein the catalyst is prepared by a method comprising: The process of adjusting the pH value of the mixed solution to 8-10 in step one comprises: first adjusting the pH value of the mixed solution to 5.5-7 using an alkali solution, after the first standing, second adjusting the pH value of the mixed solution to 8-10 using an alkali solution, and after the second standing, obtaining the precipitate.

10. The method of claim 9, wherein the catalyst is prepared by the steps of: The first standing conditions comprise: a temperature of 50-90℃ and a time of 15-20min; and the second standing conditions comprise: a temperature of 50-90℃ and a time of 15-20min.

11. The process for the preparation of a catalyst according to any one of claims 7 to 10, characterized in that, The concentration of Al in the aluminum salt solution is 0.5-2.5mol / L, the concentration of Ti in the titanium salt solution is 0.2-1.2moL / L, and the concentration of Cu in the copper salt solution is 0.1-0.6moL / L.

12. The process for the preparation of a catalyst according to any one of claims 7 to 10, characterized in that, The mixing conditions in step two comprise: a temperature of 40-60℃ and a time of 8-12h.

13. The process for the preparation of a catalyst according to any one of claims 7 to 10, characterized in that, The drying I conditions in step one comprise: a temperature of 100-150℃ and a time of 4-12h; and / or, the calcining I conditions in step one comprise: a temperature of 500-1100℃, a time of 4-12h, and an atmosphere of air and / or inert gas; And / or, the conditions for drying II in step two include: temperature of 90-120℃, time of 2-8h; And / or, the conditions for calcining II in step two include: temperature of 300-800℃, time of 2-10h, and atmosphere of air and / or inert gas.

14. A catalyst prepared by the method of any one of claims 7-13.

15. Use of a catalyst according to any one of claims 1 to 6 or a catalyst according to claim 14 in the selective hydrogenation of a C 2-4 fraction, said C 2-4 fraction, said C 3-4 fraction, said C 16. The use according to claim 15, characterized in that, The C 2-4 The distillate contains C 2-4 Olefins and C 2-4 Alkanes; The C 2-4 The mass content of the olefin is 0-99.99 parts; and / or, the C 2-4 the mass content of alkane is 0-19.99 parts; and / or, the C 3-4 The mass content of the alkyne is 0.01-3 parts. And / or, the mass content of the diene is 0-5 parts.

17. Use according to claim 16, characterized in that, The C 2-4 The fraction consists of 92 to 96 parts by mass of propylene, 2.8 to 3.5 parts by mass of propane, and 1 to 5 parts by mass of propyne and propadiene.

18. A C 2-4 The process for the selective hydrogenation of a distillate fraction is characterized in that, C in the presence of a catalyst according to any one of claims 1 to 6 or a catalyst according to claim 14 2-4 The impurities in the fraction are subjected to a hydrogenation reaction, said impurities including C 3-4 Alkynes and dienes; the reaction conditions include: using a fixed bed reactor, a reactor inlet temperature of 20 to 50 °C, a pressure of 0.5 to 0.8 MPa, a circulation ratio of 10 to 30:1, and a molar ratio of hydrogen to impurities of 1 to 2.5:

1.

19. The C of claim 18, wherein the C is a C 2-4 The process for the selective hydrogenation of a distillate fraction is characterized in that, The reactor inlet temperature is 20-25℃, the pressure is 0.5-0.7MPa, 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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