A propane dehydrogenation catalyst and a method for preparing the same

Abstract

The application provides a propane dehydrogenation catalyst and a preparation method thereof, and relates to the technical field of petroleum chemical catalysts.The raw material of the propane dehydrogenation catalyst comprises a carrier, an active component and an active component; the carrier is a spherical silicon-aluminum composite carrier prepared from SUZ-4-AlPO4-11 composite molecular sieves as raw materials; the active component is Pt; and the active component comprises Pt nanoparticles, an active component and a surfactant. The specific carrier, the active component and the active component Pt interact with each other, and the propane dehydrogenation catalyst prepared under the specific preparation method has significantly improved propane conversion, propane selectivity and propane yield.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of petrochemical catalyst technology, in particular to a propane dehydrogenation catalyst and a preparation method thereof. BACKGROUND

[0002] Propylene, as one of the basic raw materials in chemical industry, can be used to produce a series of downstream chemicals such as high molecular polymers and olefin oxides. Due to the rapid growth of downstream products in recent years, the demand for propylene is increasing. The current four main sources of propylene are catalytic cracking unit, ethylene cracking unit, propane dehydrogenation unit and methanol-to-olefins unit of coal chemical industry. Among them, propane dehydrogenation unit and methanol-to-olefins unit of coal chemical industry are new routes for producing propylene in recent years. With the increase of shale gas production in the United States, the by-product ethane has gradually become the main raw material of the steam cracking unit. The main product of ethane cracking is ethylene, and the amount of propylene by-product of the unit is greatly reduced, and the supply of propylene is becoming increasingly tight. While the price of propane is declining, making propane-to-propylene more and more concerned by people.

[0003] At present, the propane dehydrogenation technology is represented by the Oleflex process of UOP Company and the Catofin process of Lummus Company. The core of propane dehydrogenation process technology is high-efficiency and stable catalyst. Cr-based propane dehydrogenation catalyst, although has high dehydrogenation activity and selectivity, but the environmental problems caused by Cr catalyst are not consistent with the current environmental protection concept, and it is gradually eliminated. The current research focus is still Pt-based propane dehydrogenation catalyst, which mainly uses noble metal Pt as active component, molecular sieve as carrier, and reduces the content of noble metal Pt by adding / changing additives or changing the properties of the carrier to improve the overall dehydrogenation efficiency of the catalyst.

[0004] The reaction performance of propane dehydrogenation Pt-based catalyst mainly depends on its surface structure, i.e. electronic properties and geometric characteristics, both of which have significant influence on the adsorption strength and adsorption configuration of adsorbate.

[0005] At present, the stability strategy of catalyst mainly includes the chemical stability and physical confinement of the carrier. Molecular sieve is a kind of porous material with high thermal stability and large specific surface area, which is an ideal confined object for high-temperature catalytic reaction (High-temperature propane dehydrogenation with molecular sieve encapsulated PtZn catalyst, Zhang Bofeng, Doctoral Dissertation of Tianjin University). The high-strength microporous structure can fix the metal to ensure its high dispersion and inhibit the sintering and agglomeration of the metal under high-temperature calcination and reaction conditions. Molecular sieve has ion exchange performance, uniform molecular size channel, acid catalytic activity, and good thermal stability and hydrothermal stability, and can be made into catalyst with high activity and selectivity for many reactions, that is, molecular sieve catalyst. The application of molecular sieve catalyst in the synthesis field can greatly improve the production efficiency, reduce the consumption of raw materials, reduce the equipment investment cost, improve the yield and quality of products, and the waste molecular sieve catalyst is environmentally friendly and will not pollute the environment.

[0006] As disclosed in Chinese Patent Application CN 114849770 A, a catalyst for propane oxidative dehydrogenation and a preparation method thereof are provided, wherein the catalyst is an amorphous boron-silicon molecular sieve material containing meso-microporous composite channels with micropore diameters of 0.6-2.0 nm and mesopore diameters of 2.0-10.0 nm. The preparation method of the amorphous boron-silicon molecular sieve material includes the following steps: dissolving a silicon source, a boron source and an organic template agent in a solvent according to a certain molar ratio to obtain a gel, and then drying and calcining the gel to obtain the catalyst. However, the average selectivity of propylene is only 68.4%-79.6%, and the average conversion rate of propane is 11.8%-24.4%.

[0007] At present, the main problems limiting the performance of propane dehydrogenation catalyst are the occurrence of side reactions at high temperature, the deactivation of the catalyst caused by carbon deposition, and the low selectivity of propylene. Therefore, it is of great significance to develop a propane dehydrogenation catalyst with molecular sieve as the carrier, which has high stability, high catalytic efficiency and high yield. SUMMARY

[0008] The present application provides a propane dehydrogenation catalyst and a preparation method thereof, which has high stability, high propylene selectivity and yield, etc. by optimizing the carrier, activator and preparation method.

[0009] To achieve the above-mentioned purposes, the technical solutions adopted by the present application are as follows:

[0010] In a first aspect, the present application provides a propane dehydrogenation catalyst, the raw materials of which include a carrier, an active component and an activator. The carrier is a spherical silicon-aluminum composite carrier prepared from SUZ-4-AlPO4-11 composite molecular sieve. The active component is Pt. The activator includes Pt nanoparticles, an activator component and a surfactant.

[0011] Preferably, the preparation method of the carrier comprises the following steps:

[0012] S1: mixing the first aluminum source, the first silicon source, the first alkali source, the first template agent and water, aging, calcining to obtain SUZ-4 molecular sieve;

[0013] S2: mixing the second template agent, the second aluminum source, the phosphorus source and water, aging, crystallizing to obtain AlPO4-11 molecular sieve;

[0014] S3: mixing the SUZ-4 molecular sieve and the AlPO4-11 molecular sieve at a mass ratio of 1:5-10, mixing with an ammonium salt solution, drying, calcining to obtain the SUZ-4-AlPO4-11 composite molecular sieve;

[0015] S4: adding the SUZ-4-AlPO4-11 composite molecular sieve, a shaping aid and a peptizing agent to prepare a shaping slurry;

[0016] S5: dropping the shaping slurry into a water column shaping column to form spherical composite gel particles, washing with water, drying and calcining to obtain the spherical silicon-aluminum composite carrier.

[0017] Preferably, in step S1, the first aluminum source is alumina.

[0018] Preferably, in step S1, the first silicon source is selected from silica sol; further preferably, in step S1, the first silicon source is domestic silica sol S-1430.

[0019] Preferably, in step S1, the first alkali source is sodium hydroxide or potassium hydroxide; further preferably, in step S1, the first alkali source is potassium hydroxide.

[0020] Preferably, in step S1, the first template agent is tetrapropylammonium bromide.

[0021] Preferably, the raw material usage amount is SiO2 moles: Al2O3 moles: KOH moles: water mass = 16-35: 0.8-1.2: 5-12: 500-1200, in terms of Al2O3 of the first aluminum source, SiO2 of the first silicon source and KOH of the first alkali source.

[0022] Further preferably, the raw material usage amount is SiO2 moles: Al2O3 moles: KOH moles: water mass = 22-28: 0.8-1.0: 6-10: 600-1000.

[0023] More preferably, the raw material usage amount is SiO2 moles: Al2O3 moles: KOH moles: water mass = 28: 1.0: 8: 800.

[0024] Preferably, in step S1, the molar ratio of the first silicon source to the first template agent is 2-10:1; further preferably, in step S1, the molar ratio of the first silicon source to the first template agent is 3-8:1. More preferably, in step S1, the molar ratio of the first silicon source to the first template agent is 5.5:1.

[0025] Preferably, in step S1, the aging temperature is 40-60℃, and the aging time is 0.5-2h; further preferably, in step S1, the aging temperature is 50℃, and the aging time is 1h.

[0026] Preferably, in step S1, the calcination temperature is 450-550℃, and the calcination time is 1-3h; further preferably, in step S1, the calcination temperature is 500℃, and the calcination time is 2h.

[0027] Preferably, in step S2, the second template agent is tetraethylammonium hydroxide;

[0028] Preferably, in step S2, the second aluminum source is aluminum oxide;

[0029] Preferably, in step S2, the phosphorus source is phosphorus pentoxide;

[0030] Preferably, in step S2, the amounts of the second aluminum source, the phosphorus source, and water are Al2O3 moles:P2O5 moles:water mass = 1:0.8-1.2:35-48;

[0031] Further preferably, in step S2, the amounts of the second aluminum source, the phosphorus source, and water are Al2O3 moles:P2O5 moles:water mass = 1:1:42.

[0032] Preferably, in step S2, the amounts of the second template agent and the second aluminum source are in a molar ratio of 2-2.5:1 of the second template agent to Al2O3;

[0033] Further preferably, in step S2, the amounts of the second template agent and the second aluminum source are in a molar ratio of 2:1 of the second template agent to Al2O3.

[0034] Preferably, in step S2, the aging temperature is 70-100℃, and the aging time is 6-10h; further preferably, in step S2, the aging temperature is 75℃, and the aging time is 8h.

[0035] Preferably, in step S2, the crystallization temperature is 160-180℃, and the crystallization time is 12-18h; further preferably, in step S2, the crystallization temperature is 170℃, and the crystallization time is 16h.

[0036] Preferably, in step S3, the ammonium salt solution is an ammonium chloride solution with a concentration of 1-2 mol / L.

[0037] Preferably, in step S3, the calcination temperature is 600-750°C and the time is 5-12h; further preferably, in step S3, the calcination temperature is 700°C and the time is 6h.

[0038] Preferably, in step S3, the specific surface area of the SUZ-4-AlPO4-11 composite molecular sieve is 100-300m 2 ·g -1 ;

[0039] Preferably, in step S4, the forming aid is a soluble alginate salt.

[0040] Further preferably, the soluble alginate salt is at least one selected from sodium alginate, potassium alginate, magnesium alginate, and magnesium alginate.

[0041] Preferably, in step S4, the peptizing agent is at least one selected from nitric acid, citric acid, and acetic acid.

[0042] Preferably, in step S4, the molar ratio of the SUZ-4-AlPO4-11 composite molecular sieve, the forming aid, and the peptizing agent is 1:0.008-0.012:0.015-0.025.

[0043] Preferably, in step S4, the mass of the SUZ-4-AlPO4-11 composite molecular sieve is 30%-35% of the mass of water.

[0044] Preferably, in step S5, the calcination temperature is 500-700°C and the time is 5-10h; further preferably, in step S5, the calcination temperature is 600°C and the time is 6h.

[0045] Preferably, the strength of the spherical silicon-aluminum composite carrier obtained in step S5 is 70-80N.

[0046] Preferably, the mass of the active component is 3‰-8‰ of the mass of the propane dehydrogenation catalyst.

[0047] Preferably, the active component is at least one selected from sodium, potassium, magnesium, tin, lanthanum, cerium, gallium, iron, and cobalt; further preferably, the active component is sodium, potassium, tin, and gallium.

[0048] Preferably, the mass of the active component is 3‰-30‰ of the mass of the propane dehydrogenation catalyst.

[0049] Preferably, the molar ratio of sodium, potassium, tin and gallium is 1-3:2-5:2-5:0.1-0.5; further preferably, the molar ratio of sodium, potassium, tin and gallium is 2:3:3:0.2.

[0050] Preferably, the surfactant is fatty alcohol sulfate and tetradecyl dimethyl betaine.

[0051] Preferably, the molar ratio of fatty alcohol sulfate and tetradecyl dimethyl betaine is 3-6:1-2; further preferably, the molar ratio of fatty alcohol sulfate and tetradecyl dimethyl betaine is 3:2.

[0052] Preferably, the mass of the surfactant is 0.5%-2% of the mass of the Pt nanoparticles. Further preferably, the mass of the surfactant is 1% of the mass of the Pt nanoparticles.

[0053] Preferably, the molar ratio of the Pt nanoparticles and the co-active component is 3-6:1; further preferably, the molar ratio of the Pt nanoparticles and the co-active component is 4:1.

[0054] Preferably, the co-active component is a solution comprising Pt nanoparticles, a co-active component and a surfactant;

[0055] Preferably, in the solution, the concentration of Pt nanoparticles is 0.01g / mL-0.10g / mL.

[0056] In a second aspect, the present application provides a preparation method of the above-mentioned propane dehydrogenation catalyst, comprising the following steps:

[0057] Step 1: mixing chloroplatinic acid, tin chloride and gallium chloride with water to obtain a mixed solution 1;

[0058] Step 2: mixing sodium hydroxide, potassium hydroxide with water to obtain a mixed solution 2;

[0059] Step 3: mixing the mixed solution 1, the mixed solution 2, Pt nanoparticles and a surfactant, impregnating on a spherical silicon-aluminum composite carrier, drying, calcining to obtain a propane dehydrogenation catalyst.

[0060] Preferably, in step 3, the temperature of the drying is 100-150℃, and the time is 4-6h;

[0061] Preferably, in step 3, the temperature of the calcining is 400-600℃, and the time is 2-5h.

[0062] Compared with the prior art, the present application has the following beneficial effects:

[0063] 1、The present application is prepared by preparing a composite molecular sieve, SUZ-4 and AlPO4-11 molecular sieve are compounded to prepare a spherical silicon-aluminum composite carrier, on the one hand, through the synergistic effect of multi-dimensional pores and one-dimensional pores, the reaction molecule transmission path can be optimized, the mass transfer resistance is reduced, and the catalytic efficiency is improved; on the other hand, through the gradient distribution of acid sites, multi-step reaction cascade catalysis (such as adsorption-dehydrogenation-isomerization) can be realized, and the generation of side reactions is reduced; in addition, the composite structure obtained can prolong the service life of the catalyst in high-temperature catalysis and reduce the regeneration frequency.

[0064] 2、The present application is prepared by optimizing the active component, and the dispersing effect of the active agent is significantly improved by combining fatty alcohol sulfate and tetradecyl dimethyl betaine as a surface active dispersing agent, thereby improving the catalytic efficiency of the prepared catalyst.

[0065] 3、The specific carrier, active component and active component Pt of the present application interact, and the propane dehydrogenation catalyst prepared under the specific preparation method has significantly improved propylene conversion rate, propylene selectivity and propylene yield. DETAILED DESCRIPTION

[0066] In order to make the technical means, creative features, purposes and effects realized by the present application easy to understand, the following specific embodiments are further illustrated, but the following embodiments are only preferred embodiments of the present application, not all. Based on the embodiments in the embodiments, other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application. It is worth noting that the raw materials used in the present application are all ordinary commercially available products, and their sources are not specifically limited. The technologies and scientific terms used in the embodiments have the meanings generally understood by those skilled in the art to which the present application belongs.

[0067] Pt nanoparticles are purchased from Guangzhou Hongwu Material Technology Co., Ltd., and the particle size is 20 nm.

[0068] Example 1

[0069] A kind of propane dehydrogenation catalyst, raw material includes carrier, active component Pt and active component;

[0070] (1) the carrier is a spherical silicon-aluminum composite carrier prepared from SUZ-4-AlPO4-11 composite molecular sieve as raw material, and the preparation method is as follows:

[0071] S1: alumina, silica sol S-1430, potassium hydroxide, tetrapropylammonium bromide and water are mixed, aged at 50 DEG C for 1 h, calcined at 500 DEG C for 2 h, and SUZ-4 molecular sieve is obtained;

[0072] The amount of raw materials is SiO2: Al2O3: KOH: water = 28: 1.0: 8: 800 (mole of SiO2: mole of Al2O3: mole of KOH: mass of water);

[0073] The molar ratio of alumina to tetrapropylammonium bromide is 5.5:1;

[0074] S2: tetraethylammonium hydroxide, alumina, phosphorus pentoxide and water are mixed, aged at 75°C for 8h, and crystallized at 170°C for 16h to obtain AlPO4-11 molecular sieve;

[0075] The amount of Al2O3: P2O5: water = 1:1:42 (mole of Al2O3: mole of P2O5: mass of water); the molar ratio of tetraethylammonium hydroxide to Al2O3 is 2:1;

[0076] S3: SUZ-4 molecular sieve is mixed with AlPO4-11 molecular sieve at a mass ratio of 1:8, mixed with 1.5 mol / L ammonium chloride solution for 3 times, washed to neutral, dried, and calcined at 700°C for 6h to obtain SUZ-4-AlPO4-11 composite molecular sieve; the specific surface area of the SUZ-4-AlPO4-11 composite molecular sieve is 300m 2 ·g -1 ;

[0077] S4: SUZ-4-AlPO4-11 composite molecular sieve is added with water, sodium alginate and citric acid to prepare a molding slurry; the molar ratio of SUZ-4-AlPO4-11 composite molecular sieve, sodium alginate and citric acid is 1:0.01:0.02;

[0078] The mass of the SUZ-4-AlPO4-11 composite molecular sieve is 32% of the mass of water;

[0079] S5: the molding slurry is dropped into a water column molding column to form spherical composite gel particles, which are washed with water, dried, calcined at 600°C for 6h in a nitrogen atmosphere to obtain a spherical silicon-aluminum composite carrier with a strength of 80N.

[0080] (2) The active component is Pt, and the mass of the active component accounts for 5‰ of the mass of the propane dehydrogenation catalyst.

[0081] (3) The active component is composed of a Pt nanoparticle solution, an active component and a surfactant;

[0082] The concentration of the Pt nanoparticle is 0.05g / mL;

[0083] The active component is sodium, potassium, tin and gallium; the molar ratio of the sodium, potassium, tin and gallium is 2:3:3:0.2; the total mass of the active component accounts for 15‰ of the mass of the propane dehydrogenation catalyst.

[0084] The molar ratio of the Pt nanoparticles and the co-activating component is 4:1;

[0085] The surfactant is fatty alcohol sulfate and tetradecyl dimethyl betaine (molar ratio is 3:2), and the total mass of the surfactant is 1% of the mass of the Pt nanoparticles;

[0086] The preparation method of the propane dehydrogenation catalyst comprises the following steps:

[0087] Step 1: mixing chloroplatinic acid, tin chloride and gallium chloride with water to obtain a mixed solution 1;

[0088] Step 2: mixing sodium hydroxide, potassium hydroxide with water to obtain a mixed solution 2;

[0089] Step 3: mixing the mixed solution 1, the mixed solution 2, Pt nanoparticles and a surfactant, impregnating on a spherical silicon-aluminum composite carrier, drying at 120℃ for 5h, and calcining at 500℃ for 3h to obtain a propane dehydrogenation catalyst.

[0090] Example 2

[0091] A propane dehydrogenation catalyst, raw materials comprising a carrier, an active component Pt and a co-activating component;

[0092] (1) The carrier is a spherical silicon-aluminum composite carrier prepared by using SUZ-4-AlPO4-11 composite molecular sieve as raw materials, and the preparation method is as follows:

[0093] S1: mixing alumina, silicon sol S-1430, potassium hydroxide, tetrapropylammonium bromide and water, aging at 60℃ for 0.5h, and calcining at 550℃ for 1h to obtain SUZ-4 molecular sieve;

[0094] The amount of raw materials is SiO2mole: Al2O3mole: KOH mole: water mass = 16: 0.8: 5: 500;

[0095] The molar ratio of alumina to tetrapropylammonium bromide is 2:1;

[0096] S2: mixing tetraethylammonium hydroxide, alumina, phosphorus pentoxide and water, aging at 100℃ for 6h, and crystallizing at 160℃ for 18h to obtain AlPO4-11 molecular sieve;

[0097] Al2O3mole: P2O5mole: water mass = 1: 0.8: 35; the molar ratio of tetraethylammonium hydroxide to Al2O3 is 2.5:1;

[0098] S3: SUZ-4 molecular sieve is mixed with AlPO4-11 molecular sieve at a mass ratio of 1:5, mixed with an ammonium chloride solution with a concentration of 1 mol / L for 3 times, washed to neutral, dried, and calcined at 750°C for 5h to obtain SUZ-4-AlPO4-11 composite molecular sieve; the specific surface area of the SUZ-4-AlPO4-11 composite molecular sieve is 100m 2 ·g -1 ;

[0099] S4: SUZ-4-AlPO4-11 composite molecular sieve is added with water, potassium alginate and nitric acid to prepare a molding slurry; the molar ratio of SUZ-4-AlPO4-11 composite molecular sieve, sodium alginate and citric acid is 1:0.008:0.015;

[0100] The mass of the SUZ-4-AlPO4-11 composite molecular sieve is 30% of the mass of water;

[0101] S5: The molding slurry is dropped into a water column molding column to form spherical composite gel particles, which are washed with water, dried, calcined at 500°C for 10h in a nitrogen atmosphere to obtain a spherical silicon-aluminum composite carrier with a strength of 70N;

[0102] (2) The active component is Pt, and the mass of the active component accounts for 3 ‰ of the mass of the propane dehydrogenation catalyst.

[0103] (3) The active component is composed of a Pt nanoparticle solution, an active component and a surfactant;

[0104] The concentration of the Pt nanoparticle is 0.01g / mL;

[0105] The active component is sodium, potassium, tin and gallium; the molar ratio of the sodium, potassium, tin and gallium is 1:2:2:0.1; the total mass of the active component accounts for 5 ‰ of the mass of the propane dehydrogenation catalyst;

[0106] The molar ratio of the Pt nanoparticle and the active component is 3:1;

[0107] The surfactant is a fatty alcohol sulfate and a tetradecyl dimethyl betaine (molar ratio of 3:1), and the total mass of the surfactant is 0.5% of the mass of the Pt nanoparticle;

[0108] The preparation method of the propane dehydrogenation catalyst comprises the following steps:

[0109] Step 1: chloroplatinic acid, tin chloride and gallium chloride are mixed with water to obtain a mixed solution 1;

[0110] Step 2: sodium hydroxide and potassium hydroxide are mixed with water to obtain a mixed solution 2;

[0111] Step 3: mixing the mixed solution 1, the mixed solution 2, the Pt nanoparticles and the surfactant, impregnating on the spherical silicon-aluminum composite carrier, drying at 100℃ for 6h, and calcining at 600℃ for 2h to obtain the propane dehydrogenation catalyst.

[0112] Example 3

[0113] A propane dehydrogenation catalyst, the raw material comprising a carrier, an active component Pt and an active component;

[0114] (1) the carrier is a spherical silicon-aluminum composite carrier prepared by using SUZ-4-AlPO4-11 composite molecular sieve as raw material, and the preparation method is as follows:

[0115] S1: mixing alumina, silicon sol S-1430, potassium hydroxide, tetrapropylammonium bromide and water, aging at 40℃ for 2h, and calcining at 450℃ for 3h to obtain SUZ-4 molecular sieve;

[0116] The amount of the raw material is SiO2mole:Al2O3mole:KOH mole:water mass=35:1.2:12:1200;

[0117] The molar ratio of alumina to tetrapropylammonium bromide is 10:1;

[0118] S2: mixing tetraethylammonium hydroxide, alumina, phosphorus pentoxide and water, aging at 75℃ for 8h, and crystallizing at 170℃ for 16h to obtain AlPO4-11 molecular sieve;

[0119] Al2O3mole:P2O5mole:water mass=1:1.2:48; the molar ratio of tetraethylammonium hydroxide to Al2O3 is 2.2:1;

[0120] S3: mixing the SUZ-4 molecular sieve and the AlPO4-11 molecular sieve according to a mass ratio of 1:10, mixing with an ammonium chloride solution with a concentration of 2mol / L for 3 times, washing to neutral, drying, and calcining at 600℃ for 12h to obtain the SUZ-4-AlPO4-11 composite molecular sieve; the specific surface area of the SUZ-4-AlPO4-11 composite molecular sieve is 200m 2 ·g -1 ;

[0121] S4: preparing a molding slurry by adding the SUZ-4-AlPO4-11 composite molecular sieve, sodium alginate and citric acid; the molar ratio of the SUZ-4-AlPO4-11 composite molecular sieve, sodium alginate and citric acid is 1:0.012:0.025;

[0122] The mass of the SUZ-4-AlPO4-11 composite molecular sieve is 35% of the mass of water;

[0123] S5: drop the shaped slurry into the water column shaping column to form spherical composite gel particles, wash with water, dry, and calcine at 700℃ for 5h in nitrogen atmosphere to obtain spherical silicon-aluminum composite carrier with a strength of 75N.

[0124] (2) The active component is Pt, and the mass of the active component accounts for 8‰ of the mass of the propane dehydrogenation catalyst.

[0125] (3) The active component is composed of a Pt nanoparticle, an auxiliary active component, and a surfactant solution;

[0126] The concentration of the Pt nanoparticle is 2g / mL;

[0127] The auxiliary active component is sodium, potassium, tin, and gallium; the molar ratio of the sodium, potassium, tin, and gallium is 3:5:5:0.5; and the total mass of the auxiliary active component accounts for 30‰ of the mass of the propane dehydrogenation catalyst.

[0128] The molar ratio of the Pt nanoparticle and the auxiliary active component is 6:1;

[0129] The surfactant is a fatty alcohol sulfate and a tetradecyl dimethyl betaine (molar ratio of 6:1), and the total mass of the surfactant accounts for 2% of the mass of the Pt nanoparticle;

[0130] The preparation method of the propane dehydrogenation catalyst comprises the following steps:

[0131] Step 1: mixing chloroplatinic acid, tin chloride, and gallium chloride with water to obtain a mixed solution 1;

[0132] Step 2: mixing sodium hydroxide and potassium hydroxide with water to obtain a mixed solution 2;

[0133] Step 3: mixing the mixed solution 1, the mixed solution 2, the Pt nanoparticle, and the surfactant, impregnating on the spherical silicon-aluminum composite carrier, drying at 150℃ for 4h, and calcining at 400℃ for 5h to obtain the propane dehydrogenation catalyst.

[0134] Comparative Example 1

[0135] A propane dehydrogenation catalyst, the raw material of which comprises a carrier, an active component Pt, and an auxiliary active component;

[0136] (1) The carrier is a spherical silicon-aluminum composite carrier prepared by using ZSM-5 / AlPO4-5 double-structure molecular sieve disclosed in Chinese patent application CN1524617A as raw material, and the preparation method is as follows:

[0137] S1: ZSM-5 / AlPO4-5 double-structure molecular sieve is prepared by using the preparation method of Example 1 of Chinese patent application CN1524617A; the specific surface area of the SUZ-4-AlPO4-11 composite molecular sieve is 50m 2 ·g-1 ;

[0138] S2: ZSM-5 / AlPO4-5 bimorphous molecular sieve is added into water, sodium alginate and citric acid to prepare a molding slurry; the molar ratio of ZSM-5 / AlPO4-5 bimorphous molecular sieve, sodium alginate and citric acid is 1:0.01:0.02;

[0139] The mass of the ZSM-5 / AlPO4-5 bimorphous molecular sieve is 32% of the mass of water;

[0140] S3: The molding slurry is dropped into a water column molding column to form spherical composite gel particles, which are washed with water, dried, and calcined at 600°C for 6h in a nitrogen atmosphere to obtain a spherical silicon-aluminum composite carrier with a strength of 50N.

[0141] The rest is the same as example 1.

[0142] Comparative example 2

[0143] A propane dehydrogenation catalyst, compared with example 1, the co-active component and the surfactant in the co-active component are different:

[0144] consisting of a carrier, an active component Pt and a co-active component;

[0145] (1) The carrier is the same as example 1.

[0146] (2) The active component is the same as example 1.

[0147] (3) The co-active component consists of a solution of Pt nanoparticles, a co-active component (sodium, potassium, tin and manganese) and a surfactant;

[0148] The concentration of Pt nanoparticles is 0.05g / mL;

[0149] The co-active component is sodium, potassium, tin and manganese; the molar ratio of the sodium, potassium, tin and manganese is 2:3:3:0.2; the total mass of the co-active component accounts for 15‰ of the mass of the propane dehydrogenation catalyst;

[0150] The molar ratio of Pt nanoparticles and the co-active component is 4:1;

[0151] The surfactant is sorbitan monostearate and tetradecyl dimethyl betaine (molar ratio 3:2), and the total mass of the surfactant is 1% of the mass of Pt nanoparticles;

[0152] The preparation method of the propane dehydrogenation catalyst comprises the following steps:

[0153] Step 1: Mix chloroplatinic acid, tin chloride and manganese chloride with water to obtain a mixed solution 1;

[0154] Step 2: mixing sodium hydroxide, potassium hydroxide and water to obtain mixed solution 2;

[0155] Step 3: mixing mixed solution 1, mixed solution 2, Pt nanoparticles and surfactant, impregnating on the spherical silicon-aluminum composite carrier, drying at 120℃ for 5h, calcining at 500℃ for 3h to obtain a propane dehydrogenation catalyst.

[0156] Comparative Example 3

[0157] A propane dehydrogenation catalyst, the raw material comprising a carrier, active component Pt and active component (compared with Example 1, the molar ratio of the raw material is different);

[0158] (1) The carrier is a spherical silicon-aluminum composite carrier prepared from SUZ-4-AlPO4-11 composite molecular sieve as raw material, and the preparation method is as follows:

[0159] S1: mixing alumina, silica sol S-1430, potassium hydroxide, tetrapropylammonium bromide and water, aging at 50℃ for 1h, calcining at 500℃ for 2h to obtain SUZ-4 molecular sieve;

[0160] The amount of the raw material is SiO2mole: Al2O3mole: KOH mole: water mass = 40: 1.5: 15: 450;

[0161] The molar ratio of alumina to tetrapropylammonium bromide is 1:1;

[0162] S2: mixing tetraethylammonium hydroxide, alumina, phosphorus pentoxide and water, aging at 75℃ for 8h, crystallizing at 170℃ for 16h to obtain AlPO4-11 molecular sieve;

[0163] Al2O3mole: P2O5mole: water mass = 1: 1.5: 50; The molar ratio of tetraethylammonium hydroxide to Al2O3 is 1:1;

[0164] S3: mixing SUZ-4 molecular sieve and AlPO4-11 molecular sieve according to a mass ratio of 1:15, mixing with 1.5mol / L of ammonium chloride solution for 3 times, washing to neutral, drying, and calcining at 700℃ for 6h to obtain SUZ-4-AlPO4-11 composite molecular sieve; The specific surface area of the SUZ-4-AlPO4-11 composite molecular sieve is 80m 2 ·g -1 ;

[0165] S4: adding SUZ-4-AlPO4-11 composite molecular sieve, sodium alginate and citric acid to water to prepare a molding slurry; The molar ratio of SUZ-4-AlPO4-11 composite molecular sieve, sodium alginate and citric acid is 1:0.015:0.030;

[0166] The mass of the SUZ-4-AlPO4-11 composite molecular sieve is 40% of the mass of water;

[0167] S5: drop the molding slurry into a water column molding column to form spherical composite gel particles, wash with water, dry, and calcine at 600 DEG C in a nitrogen atmosphere for 6h to obtain a spherical silicon-aluminum composite carrier with a strength of 55N.

[0168] (2) the active component is Pt, and the mass of the active component accounts for 10 ‰ of the mass of the propane dehydrogenation catalyst.

[0169] (3) the active component is composed of a Pt nanoparticle, an auxiliary active component, and a surfactant;

[0170] The concentration of the Pt nanoparticle is 0.05 g / mL;

[0171] The auxiliary active component is sodium, potassium, tin, and gallium; the molar ratio of the sodium, potassium, tin, and gallium is 4:1:1:1; and the total mass of the auxiliary active component accounts for 35 ‰ of the mass of the propane dehydrogenation catalyst.

[0172] The molar ratio of the Pt nanoparticle and the auxiliary active component is 1:1;

[0173] The surfactant is a fatty alcohol sulfate and a tetradecyl dimethyl betaine (molar ratio 1:1), and the total mass of the surfactant is 3% of the mass of the Pt nanoparticle;

[0174] The preparation method of the propane dehydrogenation catalyst comprises the following steps:

[0175] Step 1: mix chloroplatinic acid, tin chloride, and gallium chloride with water to obtain a mixed solution 1;

[0176] Step 2: mix sodium hydroxide and potassium hydroxide with water to obtain a mixed solution 2;

[0177] Step 3: mix the mixed solution 1, the mixed solution 2, the Pt nanoparticle, and the surfactant, impregnate on the spherical silicon-aluminum composite carrier, dry at 120 DEG C for 5h, and calcine at 500 DEG C for 3h to obtain the propane dehydrogenation catalyst.

[0178] Test example

[0179] The catalysts prepared in Examples 1-3 and Comparative Examples 1-3 are subjected to a propane oxidative dehydrogenation reaction, 5g of the catalyst is loaded in a fixed bed reactor before the reaction, the reaction temperature is 610 DEG C, the reaction pressure is normal pressure, the reaction gas composition is: propane / hydrogen = 1:1 (V / V); the space velocity is 1500h -1The reaction gas was introduced into the reactor loaded with the catalyst for 1h and 30h, respectively, the products were introduced into the gas chromatograph, and the product analysis was performed by using the GC 7900 gas chromatograph. The test results are shown in Table 1.

[0180] Table 1. Catalyst performance

[0181]

[0182] As shown in Table 1, the catalyst prepared according to the specific components and the ratio of the present application has significantly improved propylene conversion, propylene selectivity and propylene yield.

[0183] Finally, it should be noted that the above content is only used to illustrate the technical solutions of the present application, and is not a limitation on the protection scope of the present application. Simple modifications or equivalent replacements of the technical solutions of the present application made by those skilled in the art do not deviate from the essence and scope of the technical solutions of the present application.

Claims

1. A propane dehydrogenation catalyst characterized in that, The raw material comprises a carrier, an active component and an auxiliary active component; the carrier is a spherical silicon-aluminum composite carrier prepared from SUZ-4-AlPO4-11 composite molecular sieve as raw material; The preparation method of the carrier comprises the following steps: S1: a first aluminum source, a first silicon source, a first alkali source, a first template agent and water are mixed, aged, and calcined to obtain SUZ-4 molecular sieve; the first aluminum source, the first silicon source and the first alkali source are in a molar ratio of SiO2:Al2O3:KOH = 16-35:0.8-1.2:5-12; the first silicon source and the first template agent are in a molar ratio of 2-10:1; S2: a second template agent, a second aluminum source, a phosphorus source and water are mixed, aged, and crystallized to obtain AlPO4-11 molecular sieve; the second aluminum source, the phosphorus source and water are in a molar ratio of Al2O3:P2O5:water = 1:0.8-1.2:35-48; the second template agent and the second aluminum source are in a molar ratio of 2-2.5:1; S3: the SUZ-4 molecular sieve and the AlPO4-11 molecular sieve are mixed in a mass ratio of 1:5-10, and then mixed with an ammonium salt solution, dried and calcined to obtain SUZ-4-AlPO4-11 composite molecular sieve; S4: the SUZ-4-AlPO4-11 composite molecular sieve is added into water, a molding aid and a peptizing agent to prepare a molding slurry; S5: the molding slurry is dropped into a water column molding column to form spherical composite gel particles, which are washed with water, dried and calcined to obtain a spherical silicon-aluminum composite carrier; The active component is Pt; the auxiliary active component comprises Pt nanoparticles, an auxiliary active ingredient and a surfactant; The mass of the active component accounts for 3‰-8‰ of the mass of the propane dehydrogenation catalyst; the mass of the auxiliary active ingredient accounts for 3‰-30‰ of the mass of the propane dehydrogenation catalyst; the auxiliary active ingredient is sodium, potassium, tin and gallium; the molar ratio of the sodium, potassium, tin and gallium is 1-3:2-5:2-5:0.1-0.5; the surfactant is fatty alcohol sulfate and tetradecyl dimethyl betaine; the molar ratio of the fatty alcohol sulfate and the tetradecyl dimethyl betaine is 3-6:1-2; the mass of the surfactant is 0.5%-2% of the mass of the Pt nanoparticles; the molar ratio of the Pt nanoparticles and the auxiliary active ingredient is 3-6:1; The preparation method of the propane dehydrogenation catalyst comprises the following steps: Step 1: chloroplatinic acid, tin chloride and gallium chloride are mixed with water to obtain a mixed solution 1; Step 2: sodium hydroxide and potassium hydroxide are mixed with water to obtain a mixed solution 2; Step 3: the mixed solution 1, the mixed solution 2, Pt nanoparticles and a surfactant are mixed, impregnated on the spherical silicon-aluminum composite carrier, dried and calcined to obtain the propane dehydrogenation catalyst.

2. The propane dehydrogenation catalyst of claim 1, wherein, In step S1, the first aluminum source is alumina; the first silicon source is silica sol; the first alkali source is potassium hydroxide; and the first template agent is tetrapropylammonium bromide. The aging temperature is 40-60℃, and the time is 0.5-2h; The calcination temperature is 450-550℃, and the time is 1-3h.

3. The propane dehydrogenation catalyst of claim 1, wherein, In step S2, the second template agent is tetraethylammonium hydroxide; the second aluminum source is aluminum oxide; and the phosphorus source is phosphorus pentoxide; The aging temperature is 70-100℃, and the time is 6-10h; The crystallization temperature is 160-180℃, and the time is 12-18h.

4. The propane dehydrogenation catalyst of claim 1, wherein, In step S3, the ammonium salt solution is an ammonium chloride solution with a concentration of 1-2mol / L; and the calcination temperature is 600-750℃, and the time is 5-12h.

5. The propane dehydrogenation catalyst of claim 1, wherein, In step S4, the molding aid is soluble alginate; and the peptizing agent is selected from at least one of nitric acid, citric acid and acetic acid; in step S5, the calcination temperature is 500-700℃, and the time is 5-10h; and the strength of the spherical silicon-aluminum composite carrier obtained in step S5 is 70-80N.

6. A process for the preparation of the propane dehydrogenation catalyst according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: Step 1: mixing chloroplatinic acid, tin chloride and gallium chloride with water to obtain a mixed solution 1; Step 2: mixing sodium hydroxide, potassium hydroxide with water to obtain a mixed solution 2; Step 3: mixing the mixed solution 1, the mixed solution 2, Pt nanoparticles and a surfactant, impregnating on the spherical silicon-aluminum composite carrier, drying and calcining to obtain a propane dehydrogenation catalyst.

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