An acetylene selective hydrogenation catalyst, its preparation method and application

Abstract

The present application provides a kind of acetylene selective hydrogenation catalyst and its preparation method and application, the catalyst can be converted into ethylene by the selective hydrogenation of acetylene in carbon dioxide fraction.The catalyst comprises main active component, auxiliary active component and carrier, by regulating the type, quantity and density of carrier oxygen-containing group, the distribution of metal active component is controlled, the metal utilization is improved while the green oil generation is reduced to obtain better ethylene selectivity.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of catalysts, and particularly relates to a selective hydrogenation catalyst for acetylene, a preparation method and application thereof, and especially to a selective hydrogenation catalyst for acetylene in a sequential separation process of cracking gas and application thereof. BACKGROUND

[0002] Petroleum chemical industry plays a huge role in the national economy and social development. With the continuous improvement of market demand, the number and capacity of ethylene plants gradually increase. Ethylene is a basic raw material for organic chemical industry, which is mainly used for producing synthetic materials such as polyethylene, ethylene oxide and styrene-butadiene rubber. Since the carbon dioxide fraction produced by the cracking device contains acetylene, trace amounts of acetylene have an impact on the subsequent polymerization reaction, continuous production and product quality. Therefore, selective hydrogenation is usually used to remove most of the acetylene, and the requirements for carbon dioxide hydrogenation catalysts are also increasing. The catalyst plays an important role in producing qualified ethylene products and improving ethylene yield, and the research and improvement of the catalyst mainly proceed from three aspects of carrier, main active component and auxiliary active component. At present, the research on the types of main active component and auxiliary active component and their crystal structure is relatively perfect, and the types of carrier and the method of surface modification still need to be developed.

[0003] Chinese patent CN102240565A discloses a carbon dioxide selective hydrogenation catalyst and a preparation method thereof. The catalyst comprises an inert matrix, an alumina coating and an active metal. Alumina slurry is sprayed on the inert matrix such as silicon carbide ring, the shell thickness of the eggshell type catalyst is controlled by controlling the weight ratio of alumina dry powder to the inert matrix, and the active component Pd and the auxiliary active component are loaded on the carrier after drying and calcination. The catalyst has a selectivity of about 40% under the conditions of inlet acetylene concentration of 0.5 mol%, hydrogen / acetylene ratio of 1.6 and space velocity of 10000 h -1

[0004] Chinese patent CN104096573A discloses a carbon dioxide selective hydrogenation catalyst with high anti-coking property and application thereof. The catalyst uses alumina with a bimodal pore structure distribution as a carrier, and uses Pd and Ni as active components, which are loaded into the small pores and large pores of the carrier respectively. The active metal Ni is loaded by using a microemulsion method, and the particle size is controlled to make it enter the large pores, so that the degree of catalyst surface coking is greatly reduced.

[0005] Chinese patent CN106925272A discloses a carbon dioxide selective hydrogenation catalyst. The catalyst uses a carbon material containing B and O doping as a carrier, which changes the chemical activity of the surface of the carrier, enhances the interaction between the carrier and the metal particles, and is beneficial to the dispersion of the active component Pd particles. Compared with the Al2O3 carrier, the catalyst prepared by using the carrier has a low green oil generation amount and can be stably operated for a long period. ​

[0006] In the prior art, the carbon dioxide selective hydrogenation catalyst has poor controllability of activity selectivity and thickness of active metal on the carrier, large green oil generation, and is difficult to meet the requirements of high metal utilization, high performance and long service life. The performance of the carbon dioxide selective hydrogenation catalyst prepared by controlling the types and amounts of oxygen-containing groups on the surface of the carrier is improved. SUMMARY

[0007] To solve the problems in the prior art, the application provides a novel carbon dioxide fraction selective hydrogenation catalyst. The catalyst is used for selective hydrogenation of carbon dioxide fraction, and converts acetylene into ethylene.

[0008] One of the purposes of the application is to provide an acetylene selective hydrogenation catalyst, which comprises 100 parts of a carrier, 0.01-0.1 parts of a main active component, and 0.01-0.15 parts of an auxiliary active component. The carrier surface contains 18-150 mmol / g of oxygen-containing groups. The main active component is Pd, and the auxiliary active component is at least one of Ga, Fe, Ni, As, Bi, Pb, Sn, Mn and Ag. The auxiliary active component can be a commonly used metal auxiliary active component in the art. In addition to the above listed metal elements, other commonly used active metal elements such as rare earth metals, alkali metals and alkaline earth metals can also be used.

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

[0010] The catalyst comprises 10000 parts of a carrier, 0.02-0.05 parts of a main active component, and 0.1-0.1 parts of an auxiliary active component.

[0011] The carrier contains alumina and a carbon-containing component. Preferably, the carbon-containing component accounts for 0.1-20 wt% of the total weight of the carrier.

[0012] According to the application, the acetylene selective hydrogenation catalyst comprises:

[0013] The carrier contains abundant oxygen-containing groups, which are at least one of hydroxyl groups, carboxyl groups and lactone groups. Preferably, the content of the hydroxyl groups is 3-60 mmol / g, preferably 12-50 mmol / g; the content of the carboxyl groups is 3-50 mmol / g, preferably 10-40 mmol / g; and / or the content of the lactone groups is 3-40 mmol / g, preferably 3-20 mmol / g.

[0014] The density of the surface oxygen-containing groups is 0.6-8 mmol / m 2 , preferably 0.8-5 mmol / m 2 .

[0015] The specific surface area of the carrier is 5-260m 2 / g, the water absorption is 40-120%, the carrier strength is 50-80N / pc, the bulk density is 0.6-0.9g / ml, and the pore volume is 0.4-1.2ml / g.

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

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

[0018] The metal compound of the main active component is selected from at least one of soluble compounds of palladium, preferably at least one of palladium chloride, palladium nitrate, palladium acetate, and palladium sulfate;

[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 Ga, Fe, Ni, As, Bi, Pb, Sn, Mn, and Ag;

[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 acetylene selective hydrogenation catalyst:

[0022] The loading mode of the main active component and the auxiliary active component can use any existing method in the art to load the active component onto the carrier, for example, the loading mode includes using a spraying method and / or an impregnation method to load the active component precursor compound onto the carrier;

[0023] The drying condition is 60-150℃ for 2-12h, preferably 70-140℃ for 4-10h;

[0024] The calcination condition is 200-1500℃ for 2-12h, preferably 300-1300℃ for 4-10h.

[0025] According to the present application, the carrier is obtained by the following preparation method: mixing an aluminum source, a shaping agent, a pore-expanding agent, and functional carbon, adding a binder, kneading, shaping, drying, and then performing surface treatment to obtain the carrier.

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

[0027] The aluminum source is selected from at least one of boehmite, pseudoboehmite, gamma-alumina, alpha-alumina, theta-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 reaming 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 binder is selected from a solution of at least one acid selected from nitric acid, sulfuric acid, hydrochloric acid, oxalic acid, acetic acid, citric acid, and ascorbic acid, and a solvent in the solution is selected from at least one of water, ethanol, ethylene glycol, and ethylenediamine;

[0032] The functional carbon is used in an amount of 1-40 parts by mass relative to 100 parts of the aluminum source, wherein the aluminum source is calculated based on Al2O3 contained therein;

[0033] The forming agent is used in an amount of 1-15 parts by mass relative to 100 parts of the aluminum source, wherein the aluminum source is calculated based on Al2O3 contained therein;

[0034] The reaming agent is used in an amount of 1-15 parts by mass relative to 100 parts of the aluminum source, wherein the aluminum source is calculated based on Al2O3 contained therein.

[0035] According to the present application, in the preparation method of the carrier:

[0036] The forming process of the carrier can adopt at least one of any existing forming technology in the art, such as fluidized granulation, agglomeration granulation, extrusion granulation, or spray granulation;

[0037] The granulated material is subjected to drying treatment before surface treatment, and the drying treatment can adopt the drying equipment and drying conditions commonly used in the prior art, for example, the drying conditions are 60-160°C for 4-12h, and preferably 80-140°C for 6-10h;

[0038] The surface treatment is selected from at least one of heat treatment, crystallization, oxidation, alkalization, and irradiation, and the crystal structure, surface isoelectric point, and local Al-O charge density of the carrier are changed by surface treatment, introduction of carbon species, and the like in the preparation process to increase the types and amounts of oxygen-containing groups of the carrier, and wherein:

[0039] The conditions of the heat treatment are that the atmosphere of the heat treatment comprises a first atmosphere selected from at least one of carbon dioxide, water vapor, acetylene, ethylene, and methane, and a second atmosphere 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 temperature of the heat treatment is 300-1200℃, the time of the heat treatment is 1-24h, and the pressure is 0.1-3MPa;

[0040] The conditions of the crystallization are that the temperature is 120-250℃, the time is 4-18h, and the pressure is 0.2-15MPa, and the solvent used in the crystallization is selected from at least one of water, ethanol, ethylene glycol, and ethylenediamine;

[0041] The conditions of the oxidation are that the temperature is 30-80℃, the time is 0.2-10h, and the oxidant solution used in the oxidation is selected from at least one of nitric acid, sulfuric acid, ammonium persulfate, hydrogen peroxide, and potassium permanganate, and the concentration of the oxidant solution is 0.1-10mol / L;

[0042] The conditions of the alkalization are that the temperature is 30-110℃, the time is 0.2-10h, and the alkaline solution used in the 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, and the concentration of the alkaline solution is 0.1-10mol / L;

[0043] The conditions of the irradiation are that the radiation source is selected from gamma rays and / or microwaves, preferably, the gamma ray irradiation dose rate is 1-90kGy / min, and the time is 0.2-24h; and / or, the power of the microwaves is 50-1000W, and the time is 0.5-60min.

[0044] In the present application, the alumina carrier and its preparation can refer to patent ZL202311028071.8, and the related contents disclosed in the foregoing document are introduced into the present application as reference.

[0045] The third object of the present application is to provide an application of the above-mentioned acetylene selective hydrogenation catalyst or the acetylene selective hydrogenation catalyst obtained by the above-mentioned preparation method in a carbon dioxide fraction selective hydrogenation reaction, and the "carbon dioxide fraction selective hydrogenation" refers to a process of converting acetylene into ethylene by selective hydrogenation.

[0046] According to the present application, in the hydrogenation reaction, the molar ratio of H2 to the alkyne in the carbon dioxide fraction raw material is (1.2-2):1, and preferably (1.3-1.6):1; the conditions of the hydrogenation reaction include that the reactor inlet temperature is 25-85℃, the reactor pressure is 0.5-3.2MPa, and the reaction space velocity is 2000-12000h-1 .

[0047] The present application adopts the alumina carrier rich in oxygen-containing groups on the surface to prepare the acetylene selective hydrogenation reaction catalyst, which can better interact with the noble metal palladium compared with the alumina commonly used in the prior art, the dispersion of the noble metal is improved by regulating the types and quantities of the oxygen-containing groups on the carrier, the utilization rate of the metal active component is improved, the catalyst prepared can provide more acetylene adsorption and hydrogen dissociation sites, thereby improving the acetylene conversion rate and selectivity while reducing the green oil generation amount, and prolonging the service life of the catalyst. DETAILED DESCRIPTION

[0048] The present application will be described in detail 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 the person skilled in the art according to the content of the present application still fall within the protection scope of the present application.

[0049] The raw materials used in the examples and comparative examples, if not particularly limited, are disclosed in the prior art, for example, can be directly purchased or prepared according to the preparation method disclosed in the prior art.

[0050] Example 1

[0051] 1. Preparation of shaped carrier

[0052] Take 100g pseudo-boehmite (specific surface area 195.6m 2 / g, pore volume 0.69ml / g, bulk density 0.23g / ml), 3g starch, 3 polyethylene glycol cellulose, 7g graphene, and put them into a kneader to mix uniformly. Take 3g concentrated sulfuric acid, add 110ml deionized water to prepare a mixed solution. Add the prepared solution into the kneader, extrude and cut into particles after kneading, to obtain 2-4mm particle size cylindrical particles. After crystallization in water at 1MPa, 250℃ for 10h, heat treatment with carbon dioxide and air (volume ratio 0.5:1) at 1100℃, 0.4MPa for 3h, then immerse in 30℃, 1.5mol / L potassium permanganate for 3h, and finally dry at 100℃ for 10h, to obtain the alumina carrier S1.

[0053] 2. Preparation of selective hydrogenation catalyst

[0054] Take 0.03 g of silver nitrate and 0.07 g of gallium nitrate into 8 mL of palladium nitrate solution (Pd content is 5 mg / mL), dilute to 63.2 mL with deionized water, and spray onto 100 g of alumina carrier S1. The sprayed sample is placed in an oven at 130°C for 8h and then calcined at 500°C for 10h to obtain catalyst C1, which has a Pd loading of 0.04 wt%, an Ag loading of 0.02 wt%, and a Ga loading of 0.02 wt%.

[0055] Example 2

[0056] 1. Preparation of shaped carrier

[0057] Take 100 g of pseudoboehmite in Example 1, 4 g of sesbania powder, 3 g of polyacrylamide, and 8 g of glassy carbon, and mix them evenly in a kneader. Take 2 g of concentrated nitric acid and 1 g of citric acid, add them to 120 g of deionized water, and mix them evenly 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. Crystallize in water at 150°C and 0.5 MPa for 5h, dry at 130°C for 6h, soak in a 40°C, 1.5 mol / L potassium citrate solution for 3h, dry at 100°C for 10h, and then irradiate with γ rays at 3 kGy / min for 5h to obtain the alumina carrier S2.

[0058] 2. Preparation of selective hydrogenation catalyst

[0059] Take 0.29 g of gallium nitrate and add it to 8 mL of palladium nitrate solution (Pd content is 5 mg / mL), dilute to 52.1 mL with deionized water, and spray onto 100 g of alumina carrier S2. The sprayed sample is placed in an oven at 130°C for 8h and then calcined at 500°C for 10h to obtain catalyst C2, which has a Pd loading of 0.04 wt% and a Ga loading of 0.08 wt%.

[0060] Example 3

[0061] 1. Preparation of shaped carrier

[0062] Take 100 g of pseudoboehmite in Example 1, 2 g of carboxyethyl cellulose, and 3 g of starch, and mix them evenly in a kneader. Take 3 g of oxalic acid and add it 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. Dry at 100°C for 10h, then heat treat with ethylene and nitrogen (volume ratio of 0.8:1) at 1000°C and 1 MPa for 5h, soak in a 60°C, 2 mol / L sodium carbonate solution for 3h, and finally irradiate with a 200w microwave for 30min to obtain the alumina carrier S3.

[0063] 2. Preparation of selective hydrogenation catalyst

[0064] Take 0.07 g of gallium nitrate and 0.19 g of bismuth nitrate into 8 mL of palladium nitrate solution (Pd content is 5 mg / mL), dilute to 46.2 mL with deionized water, and spray onto 100 g of alumina carrier S3. The sprayed sample is placed in an oven and dried at 130°C for 8 h and then calcined at 500°C for 10 h to obtain catalyst C3, which has a Pd loading of 0.04 wt%, a Ga loading of 0.02 wt%, and a Bi loading of 0.08 wt%.

[0065] Example 4

[0066] 1. Preparation of shaped carrier

[0067] Take 100 g of pseudoboehmite in Example 1, 6 g of carboxymethyl cellulose, 2 g of polyvinyl alcohol, and 5 g of activated carbon, and mix them uniformly in a kneader. Then take 4 g of acetic acid and add it to 120 g of deionized water to prepare a mixed solution. Add the prepared solution to the kneader, and after kneading, extrude and shape it to obtain cylindrical particles with a particle size of 2-4 mm. After drying at 110°C for 5 h, treat it with 1150°C, 1 MPa of carbon dioxide and argon (volume ratio of 0.1:1) for 5 h, soak it in a 50°C, 2 mol / L ascorbic acid solution for 2 h, and finally irradiate it with 1.5 kGy / min of γ rays for 2 h to obtain alumina carrier S4.

[0068] 2. Preparation of selective hydrogenation catalyst

[0069] Take 0.29 g of iron nitrate and 0.06 g of silver nitrate into 8 mL of palladium nitrate solution (Pd content is 5 mg / mL), dilute to 54.9 mL with deionized water, and spray onto 100 g of alumina carrier S4. The sprayed sample is placed in an oven and dried at 130°C for 8 h and then calcined at 500°C for 10 h to obtain catalyst C4, which has a Pd loading of 0.04 wt%, an Fe loading of 0.04 wt%, and an Ag loading of 0.04 wt%.

[0070] Example 5

[0071] 1. Preparation of shaped carrier

[0072] Take 100 g of pseudoboehmite in Example 1, 3 g of sesbania powder, 3 g of methyl cellulose, and 6 g of white carbon black, and mix them uniformly in a kneader. Then take 2 g of concentrated nitric acid and add it to 115 g of deionized water to prepare a mixed solution. Add the prepared solution to the kneader, and after kneading, extrude and shape it to obtain cylindrical particles with a particle size of 2-4 mm. After crystallization in 130°C, 1 MPa of ethanol for 6 h, drying at 130°C for 6 h, soaking in a 40°C, 2 mol / L ammonium persulfate solution for 3 h, and finally irradiating with 300 w microwaves for 20 min, obtain alumina carrier S5.

[0073] 2. Preparation of selective hydrogenation catalyst

[0074] 0.15 g of iron nitrate and 0.07 g of gallium nitrate were weighed into 8 mL of palladium nitrate solution (Pd content 5 mg / mL) and diluted to 48.7 mL with deionized water, and sprayed onto 100 g of the alumina carrier S5. The sprayed sample was dried in an oven at 130°C for 8 h and then calcined at 500°C for 10 h to obtain catalyst C5, which had a Pd loading of 0.04 wt%, an Fe loading of 0.02 wt%, and a Ga loading of 0.02 wt%.

[0075] Example 6

[0076] 1. Preparation of shaped carrier

[0077] The carrier was prepared as in Example 1.

[0078] 2. Preparation of selective hydrogenation catalyst

[0079] 0.08 g of iron nitrate and 0.1 g of bismuth nitrate were weighed into 9 mL of palladium nitrate solution (Pd content 5 mg / mL) and diluted to 48.7 mL with deionized water, and sprayed onto 100 g of the alumina carrier S1. The sprayed sample was dried in an oven at 130°C for 8 h and then calcined at 500°C for 10 h to obtain catalyst C6, which had a Pd loading of 0.045 wt%, an Fe loading of 0.01 wt%, and a Bi loading of 0.04 wt%.

[0080] Comparative Example 1

[0081] The catalyst was prepared using S1 as the carrier, except that no promoter component was added and the Pd loading was 0.05 wt%, to obtain catalyst D1.

[0082] Comparative Example 2

[0083] The carrier was prepared as in Example 1, except that no graphene was added during the shaping process, and the other treatment methods were unchanged, to obtain carrier S6. The catalyst was prepared as in Example 1 to obtain catalyst D2.

[0084] Comparative Example 3

[0085] The carrier was prepared as in Example 1, except that after the pellet drying, calcination was performed in a muffle furnace at 1200°C for 5 h, to obtain carrier S7. The catalyst was prepared as in Example 1 to obtain catalyst D3.

[0086] Comparative Example 4

[0087] A commercially available carrier with a specific surface area of 70.4 m 2The finished alumina with bulk density of 0.65 g / ml, strength of 43.7 Nm and water absorption of 52.6% was used as carrier S8, and the catalyst was prepared according to the method of Example 1 to obtain catalyst D4.

[0088] Comparative Example 5

[0089] The commercially available carrier S8 was used to prepare the catalyst according to the method of Comparative Example 1 to obtain catalyst D5.

[0090] The test instruments and test conditions used in the examples and comparative examples are as follows:

[0091] The specific surface area was measured by nitrogen physical adsorption BET method;

[0092] The bulk density was calculated by measuring the mass of 100 mL of the alumina carrier, and the average value was obtained after measuring each sample for 3 times;

[0093] The strength was measured by a general particle strength measuring instrument, and the average value of the measurement results of 20 carriers was taken;

[0094] The water absorption was obtained by taking 20 g of the alumina carrier, soaking in water for 10 minutes, then taking out and draining the surface moisture, and measuring the weight gain.

[0095] The properties and quantity of the oxygen-containing groups in the carrier were determined by Boehm chemical method.

[0096] The dispersity was determined by chemical adsorption method.

[0097] Table 1. Physical property measurement results of the alumina carriers in the examples and comparative examples

[0098]

[0099] The carrier oxygen-containing group analysis of the examples and comparative examples was determined. Three 0.6 g carriers were weighed and soaked in 40 ml of 0.05 mol / L NaHCO3, Na2CO3 and NaOH solution for 24 h. 10 ml of the soaked 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 data of the carrier. The results are shown in Table 2.

[0100] Table 2. Measurement results of the oxygen-containing groups of the alumina carriers in the examples and comparative examples

[0101]

[0102] From Table 2, it can be seen that the content and density of oxygen-containing groups on the surface of the alumina 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 carrier.

[0103] Test Example

[0104] 10 ml of the catalysts in the above examples and comparative examples were respectively added into an adiabatic fixed bed reactor, and evaluation was carried out under the following conditions, and the evaluation results are shown in Table 3.

[0105] Among them, the component content of the carbon dioxide fraction raw material and the material after selective hydrogenation using each catalyst was detected by gas chromatography, and the ethylene selectivity and conversion rate were calculated according to the following formula.

[0106] Ethylene selectivity = (Ethylene out - Ethylene in ) / (Acetylene in - Acetylene out )* 100%

[0107] Ethylene conversion rate = (Acetylene out - Acetylene in ) / Acetylene in * 100%

[0108] The evaluation conditions were as follows: the carbon dioxide fraction raw material was fed into the selective hydrogenation reactor from top to bottom, the reactor inlet temperature was 50°C, the pressure was 1.0 MPa, the raw material composition (molar fraction) of the reactor was as follows: ethane 7.02%, ethylene 91.94%, acetylene 0.43%, hydrogen 0.61%, the reaction space velocity was 8000 hr -1 .

[0109] Table 3. Evaluation results of the catalytic performance of the catalysts

[0110]

[0111] The content of the alkynyl and olefin components in the hydrogenation product in Table 3 is the weight percentage content after normalization calculation excluding the hydrogen content. From the results in Table 3, it can be seen that the metal active component in Examples 1-6 has higher dispersity on the carrier compared with Comparative Examples 1-5, which indicates that the oxygen-containing groups on the surface of the carrier can improve the uniformity of metal loading; in addition, the results of selective hydrogenation of the above carbon dioxide fraction show that the catalysts prepared in Examples 1-6 of the present application exhibit more excellent catalytic performance, have better selectivity, and the catalytic utilization rate of metal atoms is higher.

Claims

1. An acetylene selective hydrogenation catalyst comprising: 100 parts of a carrier, 0.01-0.1 parts of a main active component, and 0.01-0.15 parts of an auxiliary active component, wherein the carrier contains 18-150 mmol / g of oxygen-containing groups on the surface, the main active component is Pd, and the auxiliary active component is at least one of Ga, Fe, Ni, As, Bi, Pb, Sn, Mn, and Ag; the carrier is prepared by surface treatment and introduction of functional carbon to increase the number of oxygen-containing groups on the surface of the carrier, the surface treatment is at least one of heat treatment, crystallization, oxidation, alkalization, and irradiation, and the functional carbon is at least one of coke, activated carbon, carbon black, white carbon black, glassy carbon, charcoal, bamboo charcoal, coconut shell charcoal, graphene, graphyne, and diamond.

2. The acetylene selective hydrogenation catalyst according to claim 1, wherein the catalyst comprises 100 parts of a carrier, 0.02-0.05 parts of a main active component, and 0.01-0.1 parts of an auxiliary active component; and / or the carrier contains alumina and a carbon-containing component.

3. The acetylene selective hydrogenation catalyst according to claim 2, wherein the carbon-containing component accounts for 0.1-20 wt% of the total weight of the carrier.

4. The acetylene selective hydrogenation catalyst according to claim 1, wherein the oxygen-containing groups are at least one of hydroxyl groups, carboxyl groups, and lactone groups; and / or 5. The acetylene selective hydrogenation catalyst according to claim 4, wherein the content of the hydroxyl groups is 3-60 mmol / g, the content of the carboxyl groups is 3-50 mmol / g, and / or the content of the lactone groups is 3-40 mmol / g; and / or 6. A preparation method of the acetylene selective hydrogenation catalyst according to claim 1, comprising the following steps: mixing a metal compound containing the main active component and a solution of a metal compound containing the auxiliary active component with the carrier, shaping, drying, and calcining to obtain the acetylene selective hydrogenation catalyst.

7. The preparation method according to claim 6, wherein the metal compound of the main active component is at least one of soluble compounds of palladium; and / or the metal compound of the auxiliary active component is at least one of chlorides, nitrates, acetates, sulfates, and metal organic compounds of Ga, Fe, Ni, As, Bi, Pb, Sn, Mn, and Ag; and / or the solvent in the solution is at least one of water, hydrochloric acid, nitric acid, acetic acid, and alcohols; and / or the drying condition is 60-150℃ for 2-12 h; and / or the calcining condition is 200-1500℃ for 2-12 h.

8. The preparation method according to claim 7, wherein the metal compound of the main active component is at least one of palladium chloride, palladium nitrate, palladium acetate, and palladium sulfate; and / or the drying condition is 70-140℃ for 4-10 h; and / or the calcining condition is 300-1300℃ for 4-10 h. the density of the surface oxygen-containing groups is 0.6 to 8 mmol / m 2 ; and / or, The specific surface area of the carrier is 5-260 m 2 The specific surface area of the carrier is 5-260 m The specific surface area of the carrier is 5-260 m ​ ​ The density of the surface oxygen-containing groups is 0.8-5 mmol / m 2 .

6. A process for the preparation of the selective acetylene hydrogenation catalyst according to any one of claims 1 to 5, comprising: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 9. The preparation method according to claim 6, characterized in that, The carrier is prepared by the following method: mixing an aluminum source, a forming agent, a reaming agent and a functional carbon, adding a binder, kneading and forming, drying, and then performing surface treatment to obtain the carrier.

10. The method of claim 9, wherein, In the preparation method of the carrier: The aluminum source is at least one selected from boehmite, pseudoboehmite, gamma-alumina, alpha-alumina, theta-alumina, and aluminum hydroxide; and / or, The forming agent is at least one selected from polyethylene glycol cellulose, methyl cellulose, carboxymethyl cellulose, sodium hydroxymethyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, cyanoethyl cellulose, hydroxypropyl cellulose, and starch; and / or, The reaming agent is at least one selected from sesbania gum, polyvinyl alcohol, polyethylene glycol, polyacrylamide, and polypropylene glycol; and / or, The functional carbon is at least one selected from coke, activated carbon, carbon black, white carbon black, glassy carbon, charcoal, bamboo charcoal, coconut shell charcoal, graphene, graphyne, and diamond; and / or, The binder is a solution of at least one acid selected from nitric acid, sulfuric acid, hydrochloric acid, oxalic acid, acetic acid, citric acid, and ascorbic acid, and the solvent in the solution is at least one selected from water, ethanol, ethylene glycol, and ethylenediamine; and / or, 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 Al2O3 contained therein; and / or, 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 Al2O3 contained therein; and / or, The amount of the reaming agent is 1-15 parts by mass relative to 100 parts of the aluminum source, wherein the aluminum source is calculated based on Al2O3 contained therein.

11. The preparation method according to claim 9, characterized in that, In the preparation method of the carrier: The drying condition is 60-160°C for 4-12 h; and / or, The surface treatment is at least one selected from heat treatment, crystallization, oxidation, alkalization, and irradiation.

12. The method of claim 11, wherein, In the preparation method of the carrier: The drying condition is 80-140°C for 6-10 h.

13. The preparation method according to claim 11, wherein The heat treatment condition is that the atmosphere for heat treatment includes 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°C, the heat treatment time is 1-24 h, and the pressure is 0.1-3 MPa; and / or, The crystallization condition is a temperature of 120-250°C, a time of 4-18 h, and a pressure of 0.2-15 MPa, and the solvent used for crystallization is at least one selected from water, ethanol, ethylene glycol, and ethylenediamine; and / or, The oxidation condition is a temperature of 30-80°C, a time of 0.2-10 h, and the oxidant solution used for oxidation is a solution of at least one selected from nitric acid, sulfuric acid, ammonium persulfate, hydrogen peroxide, potassium permanganate, and ascorbic acid, and the concentration of the oxidant solution is 0.1-10 mol / 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 the following: 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 0.1-10mol / L; and / or, The irradiation conditions are: the radiation source is selected from γ-rays and / or microwaves.

14. The preparation method according to claim 13, characterized in that, the γ-ray irradiation dose rate is 1-90kGy / min, and the time is 0.2-24h; and / or, the microwave power is 50-1000W, and the time is 0.5-60min.

15. Use of the acetylene selective hydrogenation catalyst according to any one of claims 1-5 or obtained by the preparation method according to any one of claims 6-14 in a carbon dioxide fraction selective hydrogenation reaction.

16. The use according to claim 15, characterized in that, in the hydrogenation reaction, the molar ratio of H2 to acetylene in the carbon dioxide fraction raw material is (1.2-2):1; and / or, The conditions of the hydrogenation reaction include a reactor inlet temperature of 25 to 85°C, a reactor pressure of 0.5 to 3.2 MPa, and a reaction space velocity of 2000 to 12000 h -1 .

17. The use according to claim 16, characterized in that, in the hydrogenation reaction, the molar ratio of H2 to acetylene in the carbon dioxide fraction raw material is (1.3-1.6):1.

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