A selection of hydrogenation catalysts, methods for their preparation and use

Abstract

The present invention provides a selective hydrogenation catalyst, its preparation method and application, which can selectively hydrogenate acetylenes in C4 fraction into butadiene. The catalyst comprises a main active component, an optional active auxiliary component and a carrier. By regulating the type, quantity and density of oxygen-containing groups of the carrier, the distribution of the metal active component is controlled, the metal utilization is improved and better butadiene selectivity is obtained.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of catalysts, and particularly relates to a selective hydrogenation catalyst, a preparation method and application thereof. BACKGROUND

[0002] In recent years, with the increase and expansion of ethylene plants, the production of ethylene has been increasing year by year, and the amount of by-product carbon four has also been rapidly increasing. At present, the by-product carbon four of most ethylene plants is mainly utilized through the processes of extracting butadiene, etherizing MTBE and separating 1-butene and 2-butene, but there are also problems of butadiene tail gas containing acetylene and incomplete utilization of part of the carbon four raffinate. Among them, the acetylene tail gas of carbon four with low utilization rate accounts for about 2wt% of the carbon four production capacity, which often needs to be diluted and discharged to the flare, resulting in a large amount of greenhouse gas emissions, resource waste and safety problems. Through selective hydrogenation, the acetylene in the acetylene tail gas of carbon four can be hydrogenated to generate butadiene or butene for utilization, therefore, the selective hydrogenation catalyst plays a key role in the full utilization of carbon four resources.

[0003] Chinese patent CN111054388A discloses a carbon four selective hydrogenation catalyst and a preparation method thereof. The catalyst uses a powder obtained by crushing a mixture of magnesium-aluminum spinel and pseudo-boehmite as a carrier, Ni-Ag as an active component, and adopts an impregnation method to load the active component, and after loading, a pore-expanding agent and other forming aids are added to form an extruded strip. The addition of magnesium-aluminum spinel reduces the isomerization activity of 1-butene while ensuring the conversion rate of butadiene.

[0004] Chinese patent CN110813288A discloses a preparation method and application of a carbon four acetylene selective hydrogenation catalyst. The patent uses a co-precipitation method to prepare a precursor, then adds a binder and a pore-forming agent to extrude a ZrO2 / CdO / Bi2O3 composite carrier, and adopts an equal-volume impregnation method to load the active components Re-Pd-La. The catalyst reduces the loss of olefins while improving the selectivity of butadiene, the conversion rate of acetylenes and the resistance to poisoning.

[0005] Chinese patent CN114308059A discloses a carbon four selective hydrogenation catalyst. The catalyst uses alumina with a bimodal pore distribution structure as a carrier, with a small pore size of 10-45 nm and a large pore size of 80-500 nm. The main active component Pd is loaded by two methods of microemulsion and solution. The active component loaded by the microemulsion method is mainly distributed in the large pores. Long-term evaluation shows that the catalyst has excellent anti-coking ability.

[0006] The existing technical solution has the problems of low uniformity of active metal distribution of the carbon four selective hydrogenation catalyst, poor thickness controllability, and difficulty in achieving high metal utilization, high performance, and long service life. By controlling the types and amounts of oxygen-containing groups on the surface of the carrier, the performance of the carbon four selective hydrogenation catalyst prepared using the carrier is correspondingly improved. SUMMARY

[0007] To solve the problems in the prior art, the present application provides a novel carbon four fraction selective hydrogenation catalyst. The catalyst is used for the selective hydrogenation of carbon four fraction, and converts acetylenes into butadiene by selective hydrogenation.

[0008] One of the objects of the present application is to provide a selective hydrogenation catalyst, which comprises an alumina-containing carrier and a main active component supported on the alumina-containing carrier, the main active component being selected from at least one of Group VIII elements, and the alumina-containing carrier having a surface oxygen-containing group density of 0.3-6 mmol / m 2 The alumina-containing carrier contains other inorganic compounds in addition to alumina.

[0009] According to the present application, the selective hydrogenation catalyst comprises:

[0010] The main active component is selected from at least one of Pd and Ni;

[0011] The weight of the main active component is 0.1-25%, preferably 0.2-20%, based on 100% of the weight of the alumina-containing carrier;

[0012] The catalyst optionally contains a co-active component, which can be a metal co-active component commonly used in the art. Preferably, the co-active component is at least one of Au, Zn, Pb, Sn, Ag, Cu, alkali metals, and alkaline earth metals. In addition to the above-listed metal elements, other commonly used active metal elements, such as rare earth elements, can also be used. The weight of the co-active component is 0-10%, preferably 0.01-5%, based on 100% of the weight of the carrier;

[0013] The alumina-containing carrier can be used alone or in combination with other inorganic compounds. For example, the alumina-containing carrier contains 0-30% of other inorganic compounds, based on 100% of the weight of the alumina-containing carrier. The other inorganic compounds are selected from at least one of titanium dioxide, silicon oxide, magnesium oxide, barium oxide, calcium oxide, and hydrotalcite.

[0014] According to the present application, the alumina-containing carrier contains abundant oxygen-containing groups. Preferably, the surface oxygen-containing group density of the alumina-containing carrier is 0.5-6 mmol / m 2The surface oxygen-containing group can be at least one of hydroxyl, carboxyl, lactone group, wherein the content of the hydroxyl is 3-60 mmol / g, the content of the carboxyl is 3-50 mmol / g, and the content of the lactone group is 3-40 mmol / g.

[0015] The specific surface area of the alumina-containing carrier is 20-250 m 2 / g, the water absorption is 40-120%, the carrier strength is 60-170 N / pea, the bulk density is 0.45-0.95 g / ml, and the pore volume is 0.40-1.6 ml / g.

[0016] The second object of the present application is to provide a preparation method of the selective hydrogenation catalyst, which comprises mixing a metal compound containing a main active component, and a solution of a metal compound optionally added with an auxiliary active component, and an alumina-containing carrier, drying and calcining to obtain the selective hydrogenation catalyst.

[0017] According to the present application, in the preparation method of the selective hydrogenation catalyst,

[0018] The metal compound of the main active component is selected from at least one of chlorides, nitrates, acetates, sulfates, metal organic compounds of Group VIII elements, and preferably at least one of chlorides, nitrates, acetates, sulfates, and metal compounds of Pd and Ni;

[0019] The metal compound of the auxiliary active component is selected from at least one of chlorides, nitrates, acetates, sulfates, and metal organic compounds of Au, Zn, Pb, Sn, Ag, Cu, alkali metals, and alkaline earth metals;

[0020] The solvent in the solution is selected from at least one of water, hydrochloric acid, nitric acid, acetic acid, and alcohols.

[0021] According to the present application, in the preparation method of the selective hydrogenation catalyst,

[0022] The metal compound solution can be loaded on the carrier by spraying and / or dipping;

[0023] The drying condition is 60-180℃ for 6-15h, and preferably 80-160℃ for 8-12h;

[0024] The calcining condition is 250-650℃ for 4-12h, and preferably 300-600℃ for 6-10h.

[0025] According to the present application, the alumina-containing carrier is prepared by mixing an aluminum source, a forming agent, a pore-expanding agent, a functional carbon, and optionally other inorganic compounds, adding a binder, kneading and forming, drying, calcining, and then performing surface treatment.

[0026] According to the present application, in the preparation method of the alumina-containing carrier:

[0027] The aluminum source is selected from at least one of boehmite, pseudoboehmite, γ-alumina, α-alumina, θ-alumina, and aluminum hydroxide;

[0028] The forming agent is selected from at least one of polyethylene glycol cellulose, methyl cellulose, carboxymethyl cellulose, sodium hydroxymethyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, cyanoethyl cellulose, hydroxypropyl cellulose, and starch;

[0029] The pore-expanding agent is selected from at least one of sesbania gum, polyvinyl alcohol, polyethylene glycol, polyacrylamide, and polypropylene glycol;

[0030] The functional carbon is selected from at least one of coke, activated carbon, carbon black, white carbon black, glassy carbon, charcoal, bamboo charcoal, coconut shell charcoal, graphene, graphyne, and diamond;

[0031] The other inorganic compound is selected from at least one of titanium dioxide, silicon oxide, magnesium oxide, barium oxide, calcium oxide, and hydrotalcite;

[0032] The binder is a solution containing at least one acid selected from nitric acid, sulfuric acid, hydrochloric acid, oxalic acid, acetic acid, and ascorbic acid, and the solvent in the solution is selected from at least one of water, ethanol, ethylene glycol, and ethylenediamine;

[0033] The amount of the functional carbon is 1-40 parts by mass relative to 100 parts of the aluminum source, wherein the aluminum source is calculated based on the contained Al2O3;

[0034] The amount of the forming agent is 1-15 parts by mass relative to 100 parts of the aluminum source, wherein the aluminum source is calculated based on the contained Al2O3;

[0035] The amount of the pore-expanding agent is 1-15 parts by mass relative to 100 parts of the aluminum source, wherein the aluminum source is calculated based on the contained Al2O3;

[0036] The amount of the other inorganic compound is 0-30 parts by mass relative to 100 parts of the aluminum source, wherein the aluminum source is calculated based on the contained Al2O3.

[0037] According to the present application, in the preparation method of the alumina-containing carrier:

[0038] The kneaded and shaped material is dried before surface treatment, and the drying treatment can use the drying equipment and drying conditions commonly used in the prior art, for example, the drying treatment conditions are 40-140 DEG C for 1-12 h, preferably 60-120 DEG C for 2-8 h;

[0039] The surface treatment is at least one selected from heat treatment, crystallization, oxidation, alkalization and irradiation, wherein,

[0040] The heat treatment conditions are that the heat treatment atmosphere comprises a first atmosphere and a second atmosphere, the first atmosphere is at least one selected from carbon dioxide, water vapor, acetylene, ethylene and methane, the second atmosphere is at least one selected from air, nitrogen, argon and helium, the volume ratio of the first atmosphere to the second atmosphere is (0.05-1) : 1, the heat treatment temperature is 300-1200 DEG C, the heat treatment time is 1-24 h, and the pressure is 0.1-3 MPa;

[0041] The crystallization conditions are that the temperature is 120-250 DEG C, the time is 4-18 h, and the pressure is 0.2-15 MPa, and the solvent used for crystallization is at least one selected from water, ethanol, ethylene glycol and ethylenediamine;

[0042] The oxidation conditions are that the temperature is 30-80 DEG C, the time is 0.2-10 h, and the oxidant solution used for oxidation is at least one selected from nitric acid, sulfuric acid, ammonium persulfate, hydrogen peroxide and potassium permanganate, and the concentration of the oxidant solution is 0.1-10 mol / L;

[0043] The alkalization conditions are that the temperature is 30-110 DEG C, the time is 0.2-10 h, and the alkaline solution used for alkalization is at least one selected from sodium hydroxide, sodium bicarbonate, sodium carbonate, sodium acetate, sodium oxalate, sodium citrate, potassium hydroxide, potassium bicarbonate, potassium carbonate, potassium acetate and potassium citrate, and the concentration of the alkaline solution is 0.1-10 mol / L;

[0044] The irradiation conditions are that the radiation source is selected from gamma rays and / or microwaves, preferably, the gamma ray irradiation dose rate is 2-90 kGy / min, and the time is 0.2-24 h; the power of the microwaves is 50-1000 W, and the time is 0.5-60 min.

[0045] In the present application, the alumina and the preparation can refer to patent ZL202311028071.8, and the related contents disclosed in the foregoing document are introduced into the present application as reference. In the preparation process of the alumina-containing carrier, heat treatment, crystallization, oxidation, irradiation treatment or introduction of carbon species and other means are adopted to change the crystal structure, surface isoelectric point and local Al-O charge density of the carrier, so as to improve the types and quantities of oxygen-containing groups in the carrier.

[0046] The third object of the present application is to provide an application of the selective hydrogenation catalyst or the selective hydrogenation catalyst prepared by the above method in the selective hydrogenation reaction of carbon four fraction. The "selective hydrogenation of carbon four fraction" refers to a process of converting acetylenes into butadiene by selective hydrogenation.

[0047] According to the present application, the carbon four fraction is high acetylene tail gas produced by a butadiene unit, the content of 1,3-butadiene in the carbon four fraction is 3-60 wt%, the content of vinyl acetylene is 0.5-30 wt%, and the content of ethyl acetylene is 0.1-10 wt%; in the selective hydrogenation reaction, the molar ratio of unsaturated hydrocarbons in the carbon four fraction to H2 is 1:(0.5-1), preferably 1:(0.8-1), wherein the unsaturated hydrocarbons in the carbon four fraction are counted by the total molar amount of unsaturated acetylenes and dienes contained therein, including 1,3-butadiene, vinyl acetylene, ethyl acetylene, etc.

[0048] The conditions of the selective hydrogenation reaction include: the reactor inlet temperature is 35-45℃, the reactor pressure is 0.6-3 MPa, and the liquid feed space velocity based on the carbon four fraction raw material is 30-50 h -1 .

[0049] The present application provides a selective hydrogenation catalyst for carbon four fraction, which comprises an alumina-containing carrier, a main active component, and an optional auxiliary active component. The alumina-containing carrier contains abundant oxygen-containing groups, and the density of oxygen-containing groups on the surface of the carrier is 0.3-6 mmol / m 2 g. The alumina-containing carrier contains other inorganic compounds in addition to alumina. By regulating the types and amounts of oxygen-containing groups on the carrier, the present application can manufacture anchor points, expose more active sites, reduce the agglomeration phenomenon in the calcination process, improve the dispersion of the catalyst, and make the distribution of the active component more uniform, thereby improving the performance of the catalyst. The catalyst provided by the present application can selectively hydrogenate acetylenes in the carbon four fraction into butadiene, and by regulating the types, amounts, and densities of oxygen-containing groups on the carrier, the distribution of metal active components can be controlled, the metal utilization rate can be improved, and better butadiene selectivity can be obtained. DETAILED DESCRIPTION

[0050] The present application will be specifically described below in combination with specific examples. It is necessary to point out here that the following examples are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Some non-essential improvements and adjustments of the present application made by those skilled in the art based on the content of the present application still fall within the protection scope of the present application.

[0051] The raw materials used in the examples and comparative examples, if not specifically defined, are all disclosed in the prior art, for example, can be directly purchased or prepared according to the preparation method disclosed in the prior art.

[0052] Example 1

[0053] 1. Preparation of shaped carrier

[0054] Take 100 g of pseudo-boehmite (specific surface area 246.3 m 2 / g, pore volume 0.89 ml / g, bulk density 0.26 g / ml), 25 g of α-Al2O3 powder, 5.4 g of hydroxypropyl methyl cellulose, 6 g of starch, and 12 g of coconut shell ash, and put them into a kneader to mix uniformly. Take 1.0 g of concentrated nitric acid and 0.5 g of citric acid, add them to 100 ml of deionized water to prepare a mixed solution. Add the prepared solution to the kneader, extrude and shape after kneading, and cut into particles to obtain cylindrical particles with a particle size of 2-4 mm. The particles are dried at 80°C for 8 h, crystallized at 160°C for 5 h, soaked in 1.5 mol / L potassium permanganate for 3 h, and then dried at 80°C for 8 h to obtain an alumina-containing carrier S1.

[0055] 2. Preparation of selective hydrogenation catalyst

[0056] Take 0.09 g of zinc nitrate and add it to 1.6 mL of palladium nitrate solution (Pd content 25 mg / mL), dilute with deionized water to 12.0 mL, and spray it onto 20 g of the alumina-containing carrier S1. The sprayed sample is dried in an oven at 120°C for 10 h and then calcined at 550°C for 8 h to obtain a catalyst C1 with a Pd loading of 0.2 wt% and a Zn loading of 0.1 wt%.

[0057] Example 2

[0058] 1. Preparation of shaped carrier

[0059] Take 100 g of pseudo-boehmite, 20 g of γ-Al2O3, 6 g of polyvinyl alcohol, and 10 g of white carbon black in Example 1, and put them into a kneader to mix uniformly. Take 2.2 g of concentrated nitric acid and 8 g of carboxymethyl cellulose, and add them to 130 g of deionized water to mix uniformly to prepare a mixed solution. Add the prepared solution to the kneader, extrude and shape after kneading, and cut into particles to obtain cylindrical particles with a particle size of 2-4 mm. The particles are dried at 120°C for 8 h, heat-treated at 400°C, 0.6 MPa of acetylene and nitrogen (volume ratio 0.06:1) for 5 h, and finally irradiated with a 60 W microwave for 10 min to obtain an alumina-containing carrier S2.

[0060] 2. Preparation of selective hydrogenation catalyst

[0061] Take 12 g of nickel nitrate and 0.32 g of silver nitrate, dilute to 13.2 mL with deionized water, and spray onto 20 g of the alumina-containing carrier S2. The sprayed sample is dried in an oven at 120°C for 10 h and then calcined at 550°C for 8 h to obtain catalyst C2, which has a Ni loading of 12 wt% and an Ag loading of 1 wt%.

[0062] Example 3

[0063] 1. Preparation of shaped carrier

[0064] Take 100 g of pseudoboehmite, 15 g of alumina trihydrate, 4 g of sesbania powder, 6 g of polyethylene glycol cellulose, and 5 g of charcoal in the kneader and mix uniformly. Then take 1 g of concentrated sulfuric acid and 0.5 g of ascorbic acid and add them to 115 g of deionized water to prepare a mixed solution. Add the prepared solution to the kneader, extrude and shape after kneading, and cut into particles to obtain cylindrical particles with a particle size of 2-4 mm. After drying the particles at 100°C for 6 h, immerse them in a 1 mol / L potassium hydroxide solution for 2 h, dry them according to the above conditions, and then immerse them in a 2 mol / L hydrogen peroxide solution for 2 h. After drying at 80°C for 8 h, the alumina-containing carrier S3 is obtained.

[0065] 2. Preparation of selective hydrogenation catalyst

[0066] Take 0.05 g of lead nitrate and add it to 1.6 mL of palladium nitrate solution (Pd content: 25 mg / mL), dilute to 14.5 mL with deionized water, and spray onto 20 g of the alumina-containing carrier S3. The sprayed sample is dried in an oven at 120°C for 8 h and then calcined at 550°C for 8 h to obtain catalyst C3, which has a Pd loading of 0.20 wt% and a Pb loading of 0.15 wt%.

[0067] Example 4

[0068] Take 100 g of pseudoboehmite, 6 g of starch, 4 g of sesbania powder, 4 g of polyvinyl alcohol, and 7 g of graphdiyne in the kneader and mix uniformly. Then take 1 g of acetic acid and 1 g of concentrated nitric acid and add them to 105 g of deionized water to prepare a mixed solution. Add the prepared solution to the kneader, extrude and shape after kneading, and cut into particles to obtain cylindrical particles with a particle size of 2-4 mm. After drying the particles at 80°C for 6 h, crystallize them at 200°C and 3 MPa for 15 h, and then irradiate them with γ rays at a dose rate of 3 kGy / min for 10 h to obtain the alumina-containing carrier S4.

[0069] 2. Preparation of selective hydrogenation catalyst

[0070] Take 0.19 g of copper nitrate and add to 1.6 mL of palladium nitrate solution (Pd content 25 mg / mL), dilute to 13.7 mL with deionized water, and spray onto 20 g of carrier S4 containing alumina. The sprayed sample is dried in an oven at 120°C for 9 h and then calcined at 550°C for 8 h to obtain catalyst C4, which has a Pd loading of 0.20 wt% and a Cu loading of 0.25 wt%.

[0071] Example 5

[0072] Take 100 g of pseudoboehmite, 20 g of TiO2, 3 g of ethyl cellulose, 5 g of starch, 6 g of polypropylene glycol, and 9 g of activated carbon in a kneader and mix well. Take 3 g of citric acid and add to 130 g of deionized water to prepare a mixed solution. Add the prepared solution to the kneader, and after kneading, extrude and cut into 2-4 mm cylindrical particles. Dry at 100°C for 5 h, and then treat at 300°C under 3 MPa of carbon dioxide and nitrogen (volume ratio 0.3:1) for 2 h. Then immerse in a 1.5 mol / L ammonium persulfate solution for 3 h, and then dry at 80°C for 8 h to obtain carrier S5 containing alumina.

[0073] 2. Preparation of selective hydrogenation catalyst

[0074] Take 3 mL of aqua regia solution containing gold (Au content 10 mg / mL) and 1.6 mL of palladium nitrate solution (Pd content 25 mg / mL), dilute to 12.6 mL with deionized water, and spray onto 20 g of carrier S5 containing alumina. The sprayed sample is dried in an oven at 120°C for 12 h and then calcined at 550°C for 8 h to obtain catalyst C5, which has a Pd loading of 0.20 wt% and an Au loading of 0.15 wt%.

[0075] Comparative Example 1

[0076] Prepare the carrier according to the method of Example 1, except that no coconut shell ash is added during the molding process, to obtain carrier S6. Prepare the catalyst according to the method of Example 1 to obtain catalyst D1.

[0077] Comparative Example 2

[0078] Prepare the carrier according to the method of Example 1, except that no crystallization and oxidation operations are performed after drying the carrier. Place the dried carrier in a muffle furnace and calcine at 1200°C for 5 h to obtain carrier S7. Prepare the catalyst according to the method of Example 1 to obtain catalyst D2.

[0079] Comparative Example 3

[0080] Take commercially available activated carbon with a specific surface area of 90.5 m 2The finished alumina with a bulk density of 0.61 g / ml, a strength of 52.4 N / pellet, and a water absorption of 69.8% was used as carrier S8. The catalyst was prepared according to the method of Example 1 to obtain catalyst D3.

[0081] Comparative Example 4

[0082] The commercially available carrier S8 was immersed in 3.0 mol / L potassium permanganate for 4 h, dried at 120°C for 8 h, and then treated with a 300 W microwave for 40 min to obtain carrier S9. The catalyst was prepared according to the method of Example 1 to obtain catalyst D4.

[0083] Test Example 1 Carrier Characterization

[0084] The specific surface area was measured by nitrogen physical adsorption BET method;

[0085] The bulk density was calculated by measuring the mass of 100 mL of the carrier containing alumina, and the average value was obtained after measuring each sample 3 times;

[0086] The strength was measured by a general particle strength measuring instrument, and the average value of 20 carriers was taken;

[0087] The water absorption was measured by taking 20 g of the carrier containing alumina, immersing it in water for 10 minutes, then taking it out and draining the surface moisture, and measuring the weight gain.

[0088] The properties and quantity of oxygen-containing groups in the carrier were determined by Boehm chemical method.

[0089] Table 1. Physical property measurement results of the alumina-containing carriers of the examples and comparative examples

[0090]

[0091] The carrier oxygen-containing group analysis of the examples and comparative examples was determined. Three 0.6 g portions of the carrier were immersed in 40 ml of 0.05 mol / L NaHCO3, Na2CO3 and NaOH solution, respectively, for 24 h. 10 ml of the immersed solution was titrated with 0.05 mol / L hydrochloric acid. Each sample was titrated three times, and the arithmetic mean value was taken. The quantity of each type of oxygen-containing group in the carrier was calculated according to the consumption of alkali, and the oxygen-containing group density was obtained in combination with the specific surface area data of the carrier. The results are shown in Table 2.

[0092] Table 2. Measurement results of the oxygen-containing groups of the alumina-containing carriers of the examples and comparative examples

[0093]

[0094] As shown in Table 2, the content and density of oxygen-containing groups on the surface of the alumina-containing carrier prepared by the method of the present application are obviously higher. Meanwhile, by adjusting the raw material ratio, preparation process parameters and conditions, the method of the present application can realize the regulation of the number and distribution of oxygen-containing groups on the surface of the alumina-containing carrier.

[0095] Evaluation of the catalytic performance of the catalyst of Test Example 2

[0096] The catalysts in Examples 1-5 and Comparative Examples 1-4 above were each taken 20 ml and added into an adiabatic fixed bed reactor, and evaluated under the following conditions, and the evaluation results are shown in Table 3.

[0097] Among them, the composition content of the carbon four fraction raw material and the material after selective hydrogenation using each catalyst was detected by gas chromatography, and the butadiene selectivity was calculated according to the following formula.

[0098] Butadiene selectivity = (butadiene out -butadiene in ) / (vinyl acetylene in -vinyl acetylene out )*100%

[0099] The evaluation conditions were: the carbon four fraction raw material was fed into the selective hydrogenation reactor from top to bottom, the reactor inlet temperature was 40°C, the pressure was 2.0 MPa, the molar ratio of hydrogen to alkyne content in the mixture stream at the inlet was 0.87:1, the vinyl acetylene content at the inlet of the reactor was 2.71 wt%, and the liquid hourly space velocity (LHSV) calculated based on the carbon four fraction raw material feed amount was 40 h -1 .

[0100] Table 3 Composition of carbon four fraction

[0101]

[0102] Table 4 Evaluation results of catalysts

[0103]

[0104] The content of alkyne and olefin components in the hydrogenation product in Table 4 is the weight percent content after normalization calculation excluding the hydrogen content. The results of using the above catalysts for selective hydrogenation of carbon four fraction show that the catalysts in the present application have better selectivity and higher catalytic utilization rate of metal atoms.

Claims

1. A selective hydrogenation catalyst, comprising an alumina-containing support and a main active component supported on the alumina-containing support, wherein the main active component is selected from at least one element of Group VIII, and the density of oxygen-containing groups on the surface of the alumina-containing support is 0.3~6 mmol / m³. 2 The alumina-containing carrier contains other inorganic compounds in addition to alumina; the alumina-containing carrier is prepared by surface treatment and introduction of functional carbon to increase the number of oxygen-containing groups in the carrier. The surface treatment is selected from at least one of heat treatment, crystallization, oxidation, alkalization and irradiation. The functional carbon is selected from at least one of coke, activated carbon, carbon black, white carbon black, glassy carbon, charcoal, bamboo charcoal, coconut shell carbon, graphene, graphyne, and diamond.

2. The selective hydrogenation catalyst according to claim 1, characterized in that, The main active component is selected from at least one of Pd and Ni; and / or, Based on the alumina-containing carrier comprising 100% by weight, the main active component comprises 0.1% to 25% by weight; and / or, The catalyst optionally contains a co-activating component; and / or, Based on the weight of the alumina-containing carrier being 100%, the alumina-containing carrier contains 0-30% other inorganic compounds in addition to alumina, and the other inorganic compounds are selected from at least one of titanium dioxide, silicon dioxide, magnesium oxide, barium oxide, calcium oxide, and hydrotalcite.

3. The selective hydrogenation catalyst according to claim 2, characterized in that, Based on the alumina-containing carrier comprising 100% by weight, the main active component comprises 0.2% to 20% by weight; and / or, The co-active component is at least one of Au, Zn, Pb, Sn, Ag, Cu, alkali metal, and alkaline earth metal; and / or, based on the weight of the carrier as 100%, the weight of the co-active component is 0-10%.

4. The selective hydrogenation catalyst according to claim 3, characterized in that, Based on the carrier weight as 100%, the weight of the active ingredient is 0.01~5%.

5. The selective hydrogenation catalyst according to claim 1, characterized in that, The density of oxygen-containing groups on the surface of the alumina-containing carrier is 0.5~6 mmol / m³. 2 ; and / or, The specific surface area of ​​the alumina-containing carrier is 20~250 m². 2 / g, water absorption rate of 40~120%, carrier strength of 60~170N / particle, bulk density of 0.45~0.95 g / ml, and pore volume of 0.40~1.6 ml / g.

6. A method for preparing the selective hydrogenation catalyst according to any one of claims 1 to 5, comprising: A solution of a metal compound containing the main active component and a metal compound with optional auxiliary active components is mixed with an alumina-containing support, dried, and calcined to obtain the selective hydrogenation catalyst.

7. The preparation method according to claim 6, characterized in that, The metal compound of the main active component is selected from at least one of the chlorides, nitrates, acetates, sulfates, and organometallic compounds of Group VIII elements; and / or, The metal compound of the co-activating component is selected from at least one of Au, Zn, Pb, Sn, Ag, Cu, chlorides, nitrates, acetates, sulfates, and organometallic compounds of alkali metals and alkaline earth metals; and / or, The solvent in the solution is selected from at least one of water, hydrochloric acid, nitric acid, acetic acid, and alcohols; and / or, The drying conditions are: drying at 60~180℃ for 6~15 hours; and / or, The calcination conditions are: calcination at 250~650℃ for 4~12 hours.

8. The preparation method according to claim 6, characterized in that, The metal compound of the main active component is selected from at least one of the following: chlorides, nitrates, acetates, sulfates, and organometallic compounds of Pd and Ni; and / or, The drying conditions are: drying at 80~160℃ for 8~12 hours; and / or, The calcination conditions are: calcination at 300~600℃ for 6~10 hours.

9. The preparation method according to claim 6, characterized in that, The alumina-containing carrier is obtained by the following preparation method: mixing components including aluminum source, forming agent, pore expander, functional carbon, and other optional inorganic compounds, adding binder to knead and shape, and then performing surface treatment to obtain the alumina-containing carrier.

10. The preparation method according to claim 9, characterized in that, In the preparation method of the alumina-containing carrier: The aluminum source is selected from at least one of boehmite, pseudoboehmite, γ-alumina, α-alumina, θ-alumina, and aluminum hydroxide; and / or, The molding agent is selected from at least one of polyethylene glycol cellulose, methylcellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, hydroxypropyl methylcellulose, ethylcellulose, hydroxyethyl cellulose, cyanoethyl cellulose, hydroxypropyl cellulose, and starch; and / or, The pore-expanding agent is selected from at least one of guar gum powder, polyvinyl alcohol, polyethylene glycol, polyacrylamide, and polypropylene glycol; and / or, The functional carbon is selected from at least one of coke, activated carbon, carbon black, silica, glassy carbon, charcoal, bamboo charcoal, coconut shell carbon, graphene, graphylene, and diamond; and / or, The other inorganic compounds are selected from at least one of titanium dioxide, silicon dioxide, magnesium oxide, barium oxide, calcium oxide, and hydrotalcite; and / or, The adhesive is a solution containing at least one acid selected from nitric acid, sulfuric acid, hydrochloric acid, oxalic acid, acetic acid, and ascorbic acid, wherein the solvent in the solution is selected from at least one of water, ethanol, ethylene glycol, and ethylenediamine; and / or, The amount of functional carbon used is 1 to 40 parts by weight relative to 100 parts of aluminum source, wherein the aluminum source is calculated based on the Al2O3 content; and / or, The amount of the molding agent is 1 to 15 parts by weight relative to 100 parts of aluminum source, wherein the aluminum source is calculated based on its Al2O3 content; and / or, The amount of the pore-expanding agent is 1 to 15 parts by weight relative to 100 parts of aluminum source, wherein the aluminum source is calculated based on its Al2O3 content; and / or, The amount of the other inorganic compounds is 0 to 30 parts by mass relative to 100 parts of aluminum source, wherein the aluminum source is calculated based on the Al2O3 contained therein.

11. The preparation method according to claim 9, characterized in that, The heat treatment conditions are as follows: the heat treatment atmosphere includes a first atmosphere and a second atmosphere, wherein the first atmosphere is selected from at least one of carbon dioxide, water vapor, acetylene, ethylene, and methane, and the second atmosphere is selected from at least one of air, nitrogen, argon, and helium; the volume ratio of the first atmosphere to the second atmosphere is (0.05~1):1; the heat treatment temperature is 300~1200℃; the heat treatment time is 1~24h; and the pressure is 0.1~3MPa; and / or, The crystallization conditions are: temperature 120~250℃, time 4~18h, pressure 0.2~15MPa, and the solvent used for crystallization is selected from at least one of water, ethanol, ethylene glycol, and ethylenediamine; and / or, The oxidation conditions are: temperature 30~80℃, time 0.2~10h; the oxidant solution used for oxidation is selected from at least one of nitric acid, sulfuric acid, ammonium persulfate, hydrogen peroxide, potassium permanganate, and ascorbic acid; the concentration of the oxidant solution is 0.1~10mol / L; and / or, The alkalization conditions are: temperature 30~110℃, time 0.2~10h, and the alkaline solution used for alkalization is selected from at least one of sodium hydroxide, sodium bicarbonate, sodium carbonate, sodium acetate, sodium oxalate, sodium citrate, potassium hydroxide, potassium bicarbonate, potassium carbonate, potassium acetate, and potassium citrate, with a solution concentration of 0.1~10 mol / L; and / or, The irradiation conditions are as follows: the radiation source is selected from gamma rays and / or microwaves.

12. The preparation method according to claim 11, characterized in that, The gamma ray irradiation dose rate is 2~90 kGy / min, and the time is 0.2~24h; and / or, the microwave power is 50~1000W, and the time is 0.5~60min.

13. The use of a selective hydrogenation catalyst according to any one of claims 1 to 5 or a selective hydrogenation catalyst obtained by the preparation method according to any one of claims 6 to 12 in the selective hydrogenation reaction of C4 fraction.

14. The application according to claim 13, characterized in that, The C4 fraction contains 3-60 wt% 1,3-butadiene, 0.5-30 wt% vinylacetylene, and 0.1-10 wt% ethylacetylene; and / or, In the selective hydrogenation reaction, the molar ratio of unsaturated hydrocarbons to H2 in the C4 fraction is 1:(0.5~1), wherein the unsaturated hydrocarbons in the C4 fraction are calculated based on the total molar amount of unsaturated alkynes and dienes contained therein; and / or, The conditions for selecting the hydrogenation reaction include: reactor inlet temperature of 35-45°C, reactor pressure of 0.6-3 MPa, and liquid feed space velocity of 30-50 h⁻¹ based on C4 fraction feedstock. -1 .

15. The application according to claim 14, characterized in that, In the selective hydrogenation reaction, the molar ratio of unsaturated hydrocarbons to H2 in the C4 fraction is 1:(0.8~1), wherein the unsaturated hydrocarbons in the C4 fraction are calculated based on the total molar amount of unsaturated alkynes and dienes contained therein.

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