Shape-selective isomerization catalyst based on twelve-membered ring aluminum silicate molecular sieve, preparation method of shape-selective isomerization catalyst and long-chain alkane isomerization method

Abstract

The invention discloses a shape-selective isomerization catalyst based on a twelve-membered ring aluminum silicate molecular sieve, a preparation method and a long-chain alkane isomerization method. The catalyst comprises the twelve-membered ring aluminum silicate molecular sieve, a noble metal active component and a metal oxide auxiliary active component. The twelve-membered ring aluminum silicate molecule is selected from at least one of ZSM-12, NU-13, CZH-5, TPZ-12, VS-12 and Theta-3; the noble metal active component is selected from at least one of Pt and Pd; and the metal oxide auxiliary agent is WO3. Compared with the catalyst prepared in the prior art, the catalyst prepared by the method provided by the invention has higher activity and isomer yield in the isomerization reaction of long-chain n-alkanes.

Description

Technical Field

[0001] The present application relates to a shape-selective isomerization catalyst based on dodecasil aluminosilicate zeolite, a preparation method thereof, and a method for isomerization of long-chain alkanes, belonging to the technical field of petrochemical industry. Background Art

[0002] Bifunctional solid catalysts are widely used in the alkane hydroisomerization process, which consists of a hydrogenation-dehydrogenation component and an acidic support. Among them, the hydrogenation-dehydrogenation component is mainly Group VIII metals such as Pt, Pd, Rh, Ir, and Ni, etc.; the acidic support can be divided into the following three categories: 1. Amorphous single metal oxides or composite oxides, such as Al2O3 treated with halides, SiO2 / Al2O3, superacid ZrO2 / SO4 2- 、WO3 / ZrO2, etc.; 2. Zeolite series of silicon-aluminum, such as Y, Beta, ZSM-5, etc.; 3. Zeolite series of aluminum phosphate, such as SAPO-5, SAPO-11, SAPO-31, and SAPO-41, etc. Compared with amorphous oxides and superacids, zeolites show excellent performance in terms of shape-selective selectivity, stability, anti-poisoning, and anti-coking ability. Therefore, isomerization catalysts with zeolites as carriers are widely used. Patent documents such as US5882505, US20040138051A1, US20050077209A1, CN1792451, CN1788844A, CN101245260A, etc. have all described in detail the preparation methods of alkane hydroisomerization catalysts with zeolites as carriers.

[0003] ZSM-12, NU-13, CZH-5, TPZ-12, VS-12, Theta-3 zeolites are a class of synthetic aluminosilicate microporous zeolites belonging to the MTW topological structure, with a one-dimensional dodecasil ring pore structure, and the pore mouth size is about It can be synthesized using different templating agents. Due to the characteristics of its one-dimensional pores and moderate acidity, the supported catalyst with it as the carrier shows excellent performance in the hydroisomerization reaction of long-chain alkanes.

[0004] According to the reaction mechanism of normal paraffins on bifunctional catalysts, the conversion of normal paraffins on the catalyst surface mainly undergoes three chemical reaction steps and two diffusion steps. The chemical reaction steps include alkane dehydrogenation reaction and olefin hydrogenation reaction on metal centers and isomerization / cracking reaction on acidic centers. The diffusion steps include the diffusion of normal olefins from metal centers to acidic centers and the diffusion of isomer olefins from acidic centers to metal centers. From the perspective of chemical reaction steps, the isomerization performance of bifunctional catalysts is affected by factors such as the metallicity (electronic properties, loading amount, dispersion degree, etc.), acidity (acid type, acid amount, acid strength, etc.), and pore structure of the catalyst. In the alkane isomerization reaction, the metallicity of the catalyst can not only ensure the progress of alkane dehydrogenation reaction and olefin hydrogenation reaction, improve the reaction activity and isomer selectivity of the catalyst, but also inhibit the formation of coke and improve the stability of the catalyst. When the metallicity is insufficient to balance the acidity, the isomerization carbocations on acidic centers are prone to further isomerization or even cracking reactions, resulting in lower isomer selectivity of the catalyst. For a long time, people often increase the number of metal active sites by increasing the metal loading amount and improving the dispersion degree to maintain its balance with acidic sites, while little attention has been paid to improving the intrinsic activity of metal sites. Summary of the Invention

[0005] The purpose of the present invention is to provide a shape-selective isomerization catalyst based on dodecasil aluminosilicate molecular sieve and its preparation method.

[0006] The present invention also relates to the application of the above catalyst in the isomerization reaction of long-chain normal paraffins.

[0007] Specifically, the present invention provides a shape-selective isomerization catalyst based on dodecasil aluminosilicate molecular sieve, which improves the hydrogenation / dehydrogenation performance of noble metals by means of metal oxide promoter WO3, thereby obtaining excellent hydroisomerization performance.

[0008] According to one aspect of the present application, there is provided a shape-selective isomerization catalyst based on dodecasil aluminosilicate molecular sieve, the shape-selective isomerization catalyst comprising a dodecasil aluminosilicate molecular sieve, a noble metal active component, a co-active component, and a binder;

[0009] The dodecasil aluminosilicate molecular sieve is mixed with the binder to form a support, and the noble metal active component and the co-active component are loaded on the support;

[0010] The noble metal active component is selected from at least one of Pt and Pd;

[0011] The co-active component is WO3;

[0012] The binder is alumina;

[0013] The twelve-membered ring aluminosilicate molecular sieve is selected from at least one of ZSM-12, NU-13, CZH-5, TPZ-12, VS-12, and Theta-3.

[0014] Optionally, the acid amount of the twelve-membered ring aluminosilicate molecular sieve is 0.4 to 1.0 mmol(NH3) / g.

[0015] Optionally, the acid amount of the twelve-membered ring aluminosilicate molecular sieve is independently selected from any value of 0.4 mmol(NH3) / g, 0.5 mmol(NH3) / g, 0.6 mmol(NH3) / g, 0.7 mmol(NH3) / g, 0.8 mmol(NH3) / g, 0.9 mmol(NH3) / g, 1.0 mmol(NH3) / g or the range value between any two of the above.

[0016] Optionally, in the shape-selective isomerization catalyst, the content of the noble metal active component is 0.05 wt.% to 0.2 wt.%.

[0017] Optionally, in the shape-selective isomerization catalyst, the content of the noble metal active component is independently selected from any value of 0.05 wt.%, 0.08 wt.%, 0.1 wt.%, 0.12 wt.%, 0.15 wt.%, 0.18 wt.%, 0.2 wt.% or the range value between any two of the above.

[0018] Optionally, in the shape-selective isomerization catalyst, the content of WO3 is 0.1 wt.% to 10 wt.%.

[0019] Optionally, in the shape-selective isomerization catalyst, the content of WO3 is independently selected from any value of 0.1 wt.%, 0.5 wt.%, 1 wt.%, 2 wt.%, 3 wt.%, 4 wt.%, 5 wt.%, 6 wt.%, 7 wt.%, 8 wt.%, 9 wt.%, 10 wt.% or the range value between any two of the above.

[0020] Optionally, in the shape-selective isomerization catalyst, the content of WO3 is 0.5 wt.% to 5 wt.%.

[0021] Optionally, in the shape-selective isomerization catalyst, the content of alumina is 20 wt.% to 66 wt.%.

[0022] Optionally, in the shape-selective isomerization catalyst, the content of alumina is independently selected from any value of 20 wt.%, 25 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, 66 wt.% or the range value between any two of the above.

[0023] Optionally, in the shape-selective isomerization catalyst, the content of the twelve-membered ring aluminosilicate molecular sieve is 29 wt.% to 79.5 wt.%.

[0024] Optionally, in the shape-selective isomerization catalyst, the content of the twelve-membered ring aluminosilicate molecular sieve independently selects any value from 29 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, 65 wt.%, 70 wt.%, 75 wt.%, 79.5 wt.% or the range value between any two of the above.

[0025] According to another aspect of the present application, a preparation method of the above-mentioned shape-selective isomerization catalyst is provided, and the preparation method includes the following steps:

[0026] (1) Drying I and roasting I the twelve-membered ring aluminosilicate molecular sieve containing a template agent to obtain a twelve-membered ring aluminosilicate molecular sieve from which the template agent is removed;

[0027] (2) Kneading, shaping, drying II, and roasting II the mixture of the twelve-membered ring aluminosilicate molecular sieve from which the template agent is removed, a binder, and an acid solution to obtain a carrier;

[0028] (3) Loading a promoter precursor on the carrier by electrostatic adsorption I, drying III, and roasting III to obtain a carrier loaded with the promoter;

[0029] (4) Loading a noble metal active component precursor on the carrier loaded with the promoter in step (3) by electrostatic adsorption II, drying IV, roasting IV, and reducing to obtain the shape-selective isomerization catalyst.

[0030] Optionally, in step (1), in the twelve-membered ring aluminosilicate molecular sieve containing a template agent, the template agent is an MTW-type structure molecular sieve.

[0031] Optionally, in the MTW-type structure molecular sieve, the organic ammonium in the pore channels selects at least one from tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium hydroxide, methyltriethylammonium hydroxide, and methyltriethylammonium bromide.

[0032] Optionally, in step (2), the weight ratio of the twelve-membered ring aluminosilicate molecular sieve from which the template agent is removed to the binder is 1:2 to 5:1.

[0033] Optionally, in step (2), the weight ratio of the twelve-membered ring aluminosilicate molecular sieve from which the template agent is removed to the binder independently selects any value from 1:2, 1:1, 2:1, 3:1, 4:1, 5:1 or the range value between any two of the above.

[0034] Optionally, the acid solution is selected from at least one of hydrochloric acid, nitric acid, sulfuric acid, citric acid, acetic acid, and phosphoric acid.

[0035] Optionally, the temperatures of the first roasting and the second roasting are independently selected from 350 to 600 °C.

[0036] Optionally, the times of the first roasting and the second roasting are independently selected from 4 to 24 h.

[0037] Optionally, in the step (3), the promoter precursor is selected from at least one of ammonium paratungstate, ammonium tungstate, and ammonium metatungstate.

[0038] Optionally, in the first electrostatic adsorption, the pH value of the first electrostatic adsorption mixed solution is 7 to 9.

[0039] Optionally, in the first electrostatic adsorption, the pH value regulator is selected from at least one of hydrochloric acid, nitric acid, oxalic acid, sulfuric acid, ammonia water, liquid ammonia, methylamine, and ethylamine.

[0040] Optionally, the temperature of the third roasting is 330 to 740 °C, and the time of the third roasting is 0.5 to 24 h.

[0041] Optionally, the temperature of the third roasting is 350 to 650 °C, and the time of the third roasting is 4 to 24 h.

[0042] Optionally, the temperature of the third roasting is 400 to 600 °C, and the time of the third roasting is 0.5 to 24 h.

[0043] Optionally, the noble metal active component precursor is selected from at least one of platinum nitrate, tetraammineplatinum dichloride, diamineplatinum dichloride, dinitrodiammineplatinum, palladium chloride, tetraamminepalladium dichloride, diaminepalladium dichloride, and dinitrodiamminepalladium.

[0044] Optionally, in the second electrostatic adsorption, the pH value of the second electrostatic adsorption mixed solution is 10 to 13.

[0045] Optionally, in the first electrostatic adsorption, the pH value regulator is selected from at least one of hydrochloric acid, nitric acid, oxalic acid, sulfuric acid, ammonia water, liquid ammonia, methylamine, and ethylamine.

[0046] Optionally, the temperatures of the first drying, the second drying, the third drying, and the fourth drying are independently selected from 50 to 200 °C.

[0047] Optionally, the times of the first drying, the second drying, the third drying, and the fourth drying are independently selected from 0.5 to 24 h.

[0048] Optionally, the temperature of the fourth calcination is 350 to 650 °C, and the time of the fourth calcination is 0.5 to 24 h.

[0049] Optionally, the atmospheres of the first calcination, the second calcination, the third calcination, and the fourth calcination are oxygen-containing atmospheres, and the oxygen content in the oxygen-containing atmosphere is 10 to 100%.

[0050] Optionally, the oxygen-containing atmosphere is selected from pure oxygen, oxygen-nitrogen mixture, or oxygen-argon mixture.

[0051] Optionally, the atmosphere for reduction is a hydrogen atmosphere.

[0052] Optionally, the gas flow rate of the hydrogen atmosphere is 2 to 200 mL / min / g 催化剂 。

[0053] Optionally, the temperature for reduction is 200 to 400 °C, and the time for reduction is 2 to 8 h.

[0054] Optionally, the temperature for reduction is 250 to 350 °C, and the time for reduction is 4 to 8 h.

[0055] According to another aspect of the present application, a method for isomerization of long-chain alkanes is provided, and the method includes: using a shape-selective isomerization catalyst in the isomerization reaction of long-chain alkanes;

[0056] The shape-selective isomerization catalyst is selected from the shape-selective isomerization catalysts described above;

[0057] The long-chain alkanes are selected from C8-C50 long-chain alkanes.

[0058] Optionally, the conditions for the isomerization reaction of long-chain alkanes are as follows:

[0059] The reaction temperature is 200 to 400 °C, the reaction pressure is 0.1 to 10 MPa, the feed volume space velocity is 0.5 to 5 h -1 , and the hydrogen-oil ratio (mol / mol) is 5 to 50.

[0060] Optionally, the reaction temperature is 280 to 350 °C.

[0061] The catalyst provided by the present invention can be widely applied to the processing processes of petroleum fractions, biomass, and Fischer-Tropsch synthesis products, such as isomerization for pour point reduction, isomerization dewaxing, and other processes.

[0062] The above catalyst preparation method provided by the present invention: First, mix, mold, and calcine the dodecacyclic aluminosilicate molecular sieve with a binder to form a support, then use the electrostatic adsorption method to load the promoter on the dodecacyclic aluminosilicate molecular sieve, and then use the electrostatic adsorption method to load the noble metal active component after calcination. After calcination and reduction, the target catalyst is obtained, including the following steps:

[0063] (1) Dry and calcine the twelve - membered ring aluminosilicate molecular sieve containing the template agent to remove the template agent.

[0064] (2) Mix the twelve - membered ring aluminosilicate molecular sieve after removing the template agent in step (1) with an alumina binder in a certain proportion and mix evenly. Then add an acid solution for kneading and forming, and then obtain the carrier after drying and calcining.

[0065] (3) Load the promoter precursor on the carrier obtained in step (2) by electrostatic adsorption, dry and then calcine in an oxygen - containing atmosphere to obtain the carrier loaded with metal oxide promoters.

[0066] (4) Further load the noble metal precursor on the carrier loaded with metal oxide promoters obtained in step (3) by electrostatic adsorption, dry and then calcine in an oxygen - containing atmosphere, and reduce in hydrogen at 200 - 400 °C for 2 - 8 h to prepare the shape - selective isomerization catalyst.

[0067] In the method provided by the present invention, the electrostatic adsorption method in steps (3) and (4) is to soak the carrier in a solution containing the precursor of the loaded substance, adjust the charged property of the carrier surface, and selectively adsorb positively or negatively charged loaded substance ions.

[0068] The beneficial effects that this application can produce include:

[0069] 1) The noble metal content in the shape - selective isomerization catalyst provided by this application is 0.05 wt.% - 0.2 wt.%, which is greatly reduced compared with the noble metal loading of about 0.5 wt.% in traditional hydroisomerization catalysts.

[0070] 2) The prepared shape - selective isomerization catalyst provided by this application has higher activity, isomer selectivity and isomer yield in the alkane isomerization reaction. Detailed implementation mode

[0071] The following describes this application in detail with reference to the examples, but this application is not limited to these examples.

[0072] Unless otherwise specified, the raw materials in the examples of this application are all purchased through commercial channels.

[0073] Conversion rate (Conv) = C 所有产物 / (C 所有产物 +C 剩余正十二烷 )×100%

[0074] Selectivity (S) = C 异十二烷 / C 所有产物 ×100%

[0075] Yield (Y) = Conv × S × 100%

[0076] Comparative Example 1

[0077] Take 120 g of as - received ZSM - 12 molecular sieve powder containing tetraethylammonium hydroxide template (content is 10 wt% of the weight of the molecular sieve), calcine it in an air atmosphere at 550 °C for 18 h to obtain about 100 g of ZSM - 12 molecular sieve with the template completely removed, and the acid amount is 0.8 mmol(NH3) / g. Take 100 g of the ZSM - 12 molecular sieve with the template removed, take 30 g of pseudoboehmite (hydrate of alumina) and mix it evenly, add 50 g of 5 wt% HNO3 solution, knead, form it with an extrusion machine, dry it naturally, then dry it at 120 °C for 4 h and calcine it at 550 °C for 12 h to prepare the carrier. Immerse 50 g of the above - mentioned carrier with 25 mL of H2PtCl6 solution containing 0.01 g / mL of Pt, dry it naturally and dry it at 120 °C for 4 h, calcine it at 500 °C for 4 h, and then use hydrogen with a flow rate of 60 mL / min / g 催化剂 to reduce it at 400 °C for 4 h to prepare a 0.5 wt% Pt / ZSM - 12 catalyst. The catalytic reaction evaluation results are shown in Table 1.

[0078] Comparative Example 2

[0079] Take 120 g of as - received TPZ - 12 molecular sieve powder containing tetrabutylammonium hydroxide template (content is 12 wt% of the weight of the molecular sieve), calcine it in an air atmosphere at 550 °C for 18 h to obtain about 100 g of TPZ - 12 molecular sieve with the template completely removed, and the acid amount is 0.5 mmol(NH3) / g. Take 100 g of the TPZ - 12 molecular sieve with the template removed, take 30 g of pseudoboehmite (hydrate of alumina) and mix it evenly, add 50 g of 5 wt% HNO3 solution, knead, form it with an extrusion machine, dry it naturally, then dry it at 120 °C for 4 h and calcine it at 550 °C for 12 h to prepare the carrier. Immerse 50 g of the above - mentioned carrier with 25 mL of H2PtCl6 solution containing 0.01 g / mL of Pt, dry it naturally and dry it at 120 °C for 4 h, calcine it at 500 °C for 4 h, and then use hydrogen with a flow rate of 60 mL / min / g 催化剂 to reduce it at 400 °C for 4 h to prepare a 0.5 wt% Pt / TPZ - 12 catalyst. The catalytic reaction evaluation results are shown in Table 1.

[0080] Comparative Example 3

[0081] Take 120 g of as - prepared ZSM - 12 molecular sieve powder containing tetraethylammonium hydroxide template (content is 10 wt% of the weight of the molecular sieve), calcine it in air atmosphere at 550 °C for 18 h to obtain about 100 g of ZSM - 12 molecular sieve with the template completely removed, and the acid amount is 0.8 mmol(NH₃) / g. Take 100 g of the ZSM - 12 molecular sieve with the template removed, take 30 g of pseudoboehmite (hydrate of alumina), mix them evenly, add 50 g of 5 wt% HNO₃ solution, knead, form it with an extrusion machine, air - dry naturally, then dry it at 120 °C for 4 h and calcine it at 550 °C for 12 h to prepare the support. Impregnate 50 g of the above - mentioned support with 25 mL of (NH₃)₂PtCl₂ solution containing 0.01 g / mL of Pt, air - dry naturally and dry it at 120 °C for 4 h, calcine it at 500 °C for 4 h, and then use hydrogen with a flow rate of 80 mL / min / g 催化剂 to reduce it at 400 °C for 4 h to prepare 0.5 wt% Pt / ZSM - 12 catalyst. The evaluation results of the catalytic reaction are shown in Table 1.

[0082] Comparative Example 4

[0083] Take 120 g of as - prepared TPZ - 12 molecular sieve powder containing tetrabutylammonium hydroxide template (content is 12 wt% of the weight of the molecular sieve), calcine it in air atmosphere at 550 °C for 18 h to obtain about 100 g of TPZ - 12 molecular sieve with the template completely removed, and the acid amount is 0.5 mmol(NH₃) / g. Take 100 g of the TPZ - 12 molecular sieve with the template removed, take 30 g of pseudoboehmite (hydrate of alumina), mix them evenly, add 50 g of 5 wt% HNO₃ solution, knead, form it with an extrusion machine, air - dry naturally, then dry it at 120 °C for 4 h and calcine it at 550 °C for 12 h to prepare the support. Impregnate 50 g of the above - mentioned support with 25 mL of (NH₃)₂PdCl₂ solution containing 0.01 g / mL of Pd, air - dry naturally and dry it at 120 °C for 4 h, calcine it at 500 °C for 4 h, and then use hydrogen with a flow rate of 80 mL / min / g 催化剂 to reduce it at 400 °C for 4 h to prepare 0.5 wt% Pd / TPZ - 12 catalyst. The evaluation results of the catalytic reaction are shown in Table 1.

[0084] Comparative Example 5

[0085] Take 120 g of as - prepared ZSM - 12 molecular sieve powder containing tetraethylammonium hydroxide template (content is 10 wt% of the weight of the molecular sieve), calcine it in air atmosphere at 550 °C for 18 h to obtain about 100 g of ZSM - 12 molecular sieve with the template completely removed, and the acid amount is 0.8 mmol(NH₃) / g. Impregnate 50 g of the above - mentioned molecular sieve support with 25 mL of H₂PtCl₆ solution containing 0.01 g / mL of Pt, air - dry naturally and dry it at 120 °C for 4 h, calcine it at 500 °C for 4 h, and then use hydrogen with a flow rate of 60 mL / min / g催化剂 The hydrogen gas was reduced at 400 °C for 4 h to prepare a 0.5 wt% Pt / ZSM-12 catalyst. The catalytic reaction evaluation results are shown in Table 1.

[0086] Comparative Example 6

[0087] 120 g of as-synthesized ZSM-12 zeolite powder containing tetraethylammonium hydroxide template (content: 10 wt% of the zeolite weight) was calcined in air at 550 °C for 18 h to obtain approximately 100 g of ZSM-12 zeolite with the template completely removed, and the acid amount was 0.8 mmol(NH3) / g. 50 g of the above support was impregnated with 25 mL of (NH3)2PdCl2 solution containing 0.01 g / mL of Pd, air-dried naturally, dried at 120 °C for 4 h, calcined at 500 °C for 4 h, and then reduced with hydrogen gas at a flow rate of 80 mL / min / g 催化剂 at 400 °C for 4 h to prepare a 0.5 wt% Pd / ZSM-12 catalyst. The catalytic reaction evaluation results are shown in Table 1.

[0088] Example 1

[0089] Step 1: 120 g of as-synthesized ZSM-12 zeolite powder containing tetraethylammonium hydroxide template (content: 10 wt% of the zeolite weight) was calcined in air at 550 °C for 18 h to obtain approximately 100 g of ZSM-12 zeolite with the template completely removed, and the acid amount was 0.8 mmol(NH3) / g; Step 2: 100 g of the template-removed ZSM-12 zeolite was mixed with 30 g of pseudo-boehmite (hydrate of alumina) evenly, 50 g of 5 wt% HNO3 solution was added, kneaded, formed by an extrusion machine, air-dried naturally, then dried at 120 °C for 4 h and calcined at 550 °C for 12 h to obtain the support; Step 3: Ammonium metatungstate was dissolved in deionized water and diluted to an ammonium metatungstate solution with a concentration of 0.005 g / mL of W. 200 mL of this solution was measured, and 50 g of the support prepared in Step 2 was soaked in it. The pH value was adjusted to 8.8 with ammonia water. After soaking for 6 h, it was filtered and washed 4 times with deionized water until the eluate was neutral. The obtained solid was air-dried naturally and dried at 120 °C for 4 h, and then calcined at 450 °C for 4 h for standby; Step 4: (NH3)4PtCl2 was dissolved in ammonia water and diluted to a concentration of 0.0005 g / mL of Pt. 200 ml of this (NH3)4PtCl2 ammonia water solution was measured, and 50 g of the support loaded with tungsten oxide promoter obtained in Step 3 was soaked in it. The pH value was further adjusted to 12.1 with ammonia water. After soaking for 4 h, it was filtered and washed 4 times with deionized water until the eluate was neutral. The obtained solid was air-dried naturally and dried at 120 °C for 4 h, and then calcined at 400 °C for 4 h, and then reduced with hydrogen gas at a flow rate of 60 mL / min / g 催化剂Hydrogen gas was used to reduce it at 350 °C for 4 h to prepare a 0.2 wt% Pt-2 wt% WO3 / Al2O3-ZSM-12 catalyst. The catalytic reaction evaluation results are shown in Table 1.

[0090] Example 2

[0091] Step 1: Take 120 g of the original TPZ-12 molecular sieve powder containing tetrabutylammonium hydroxide template agent (with a content of 12 wt% of the molecular sieve weight), and calcine it in an air atmosphere at 550 °C for 18 h to obtain about 100 g of TPZ-12 molecular sieve with the template agent completely removed, and the acid amount is 0.5 mmol(NH3) / g. Step 2: Take 100 g of the TPZ-12 molecular sieve with the template agent removed, mix it evenly with 50 g of pseudo-boehmite (hydrate of alumina), add 70 g of 5 wt% HNO3 solution, knead, form it with an extrusion machine, air dry it naturally, then dry it at 120 °C for 4 h and calcine it at 550 °C for 12 h to obtain the carrier; Step 3: Dissolve ammonium metatungstate in deionized water and dilute it to an ammonium metatungstate solution with a concentration of containing 0.01 g / mL of W. Measure 200 mL of this solution, take 50 g of the carrier prepared in Step 2 and soak it in it, adjust the pH value to 8.5 with ammonia water, after soaking for 6 h, filter and wash it 4 times with deionized water until the eluate is neutral. The obtained solid is air dried and dried at 120 °C for 4 h, and calcined at 450 °C for 4 h for standby; Step 4: Dissolve (NH3)2PtCl2 in ammonia water and dilute it to a concentration of containing 0.00025 g / mL of Pt. Measure 200 ml of this (NH3)2PtCl2 ammonia water solution, soak 50 g of the carrier loaded with tungsten oxide promoter obtained in Step 3 in it, further adjust its pH value to 12.5 with ammonia water, soak for 4 h, filter and wash it 4 times with deionized water until the eluate is neutral. The obtained solid is air dried and dried at 120 °C for 4 h, and calcined at 450 °C for 4 h, and then with a flow rate of 60 mL / min / g 催化剂 of hydrogen gas was used to reduce it at 400 °C for 4 h to prepare a 0.1 wt% Pt-4 wt% WO3 / Al2O3-TPZ-12 catalyst. The catalytic reaction evaluation results are shown in Table 1.

[0092] Example 3

[0093] Step 1: Take 120 g of as-synthesized ZSM-12 zeolite powder containing tetraethylammonium hydroxide template (content is 10 wt% of the weight of the zeolite), and calcine it in air atmosphere at 550 °C for 18 h to obtain about 100 g of ZSM-12 zeolite with the template completely removed, and the acid amount is 0.8 mmol(NH3) / g; Step 2: Take 100 g of the ZSM-12 zeolite with the template removed, mix it evenly with 100 g of pseudo-boehmite (hydrate of alumina), add 90 g of 5 wt% HNO3 solution, knead, extrude it into shape with an extrusion machine, dry it naturally, then dry it at 120 °C for 4 h and calcine it at 550 °C for 12 h to obtain the carrier; Step 3: Dissolve ammonium metatungstate in deionized water and dilute it to an ammonium metatungstate solution with a concentration of 0.0075 g / mL of W. Measure 200 mL of this solution, take 50 g of the carrier prepared in Step 2 and soak it in it. Adjust the pH value to 8.0 with ammonia water. After soaking for 6 h, filter and wash it 4 times with deionized water until the eluate is neutral. The obtained solid is dried naturally and dried at 120 °C for 4 h, and calcined at 450 °C for 4 h for standby; Step 4: Dissolve (NH3)4PdCl2 in ammonia water and dilute it to a concentration of 0.00025 g / mL of Pt. Measure 200 ml of this (NH3)4PdCl2 ammonia water solution, soak 50 g of the carrier loaded with tungsten oxide promoter obtained in Step 3 in it, further adjust its pH value to 11.5 with ammonia water, soak for 4 h, filter and wash it 4 times with deionized water until the eluate is neutral. The obtained solid is dried naturally and dried at 120 °C for 4 h, and calcined at 420 °C for 4 h, and then reduced at 380 °C for 4 h with hydrogen with a flow rate of 60 mL / min / g 催化剂 to obtain a 0.1 wt% Pd-3 wt% WO3 / Al2O3-ZSM-12 catalyst. The catalytic reaction evaluation results are shown in Table 1.

[0094] Catalyst performance evaluation of Example 4

[0095] The catalyst evaluation was carried out in a stainless steel tube fixed-bed reactor. Take 10 mL of the catalysts prepared in Comparative Examples 1-6 and Examples 1-3 and load them into the reactor. Heat up to the reaction temperature in a hydrogen atmosphere, feed the raw material oil n-dodecane for reaction, and analyze the products by gas chromatography. Reaction conditions: reaction temperature 280 - 350 °C, 3 MPa, n-dodecane feed volume space velocity 1.0 h -1 , and the hydrogen-oil ratio (mol / mol) is 15. The specific results are shown in Table 1.

[0096] Table 1. Catalyst evaluation results in comparative examples and examples

[0097]

[0098]

[0099] As can be seen from Table 1, compared with the catalysts prepared by the conventional methods in Comparative Examples 1 to 6, the catalysts prepared by the present method in Examples 1 to 3 can obtain higher activity and higher isomer selectivity in the hydroisomerization reaction of long-chain alkanes, and the isomer yield is greatly improved.

[0100] The above are only several embodiments of the present application, and do not impose any form of limitation on the present application. Although the present application is disclosed above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art, without departing from the scope of the technical solution of the present application, making some changes or modifications using the technical content disclosed above is equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

Claims

1. A shape-selective isomerization catalyst based on dodecasil aluminosilicate zeolite, characterized in that, The shape-selective isomerization catalyst includes a twelve-membered ring aluminosilicate molecular sieve, a noble metal active component, a co-active component, and a binder; The twelve-membered ring aluminosilicate molecular sieve is mixed with the binder to form a support, and the noble metal active component and the co-active component are loaded on the support; The noble metal active component is selected from at least one of Pt and Pd; The co-active component is WO3; The binder is alumina; The twelve-membered ring aluminosilicate molecular sieve is selected from at least one of ZSM-12, NU-13, CZH-5, TPZ-12, VS-12, and Theta-3.

2. The shape-selective isomerization catalyst according to claim 1, characterized in that, The acid amount of the twelve-membered ring aluminosilicate molecular sieve is 0.4 - 1.0 mmol(NH3) / g; Preferably, in the shape-selective isomerization catalyst, the content of the noble metal active component is 0.05 wt.% - 0.2 wt.%; Preferably, in the shape-selective isomerization catalyst, the content of WO3 is 0.1 wt.% - 10 wt.%; Preferably, in the shape-selective isomerization catalyst, the content of WO3 is 0.5 wt.% - 5 wt.%; Preferably, in the shape-selective isomerization catalyst, the content of alumina is 20 wt.% - 66 wt.%; Preferably, in the shape-selective isomerization catalyst, the content of the twelve-membered ring aluminosilicate molecular sieve is 29 wt.% - 79.5 wt.%.

3. A method for preparing the shape-selective isomerization catalyst according to any one of claims 1 to 2, characterized in that, The preparation method includes the following steps: (1) The twelve-membered ring aluminosilicate molecular sieve containing a template agent is dried I and calcined I to obtain a twelve-membered ring aluminosilicate molecular sieve with the template agent removed; (2) A mixture of the binder, the twelve-membered ring aluminosilicate molecular sieve with the template agent removed, and an acid solution is kneaded, formed, dried II, and calcined II to obtain a support; (3) The co-active component precursor is loaded on the support by electrostatic adsorption I, dried III, and calcined III to obtain a support loaded with the co-active component; (4) The noble metal active component precursor is loaded on the support loaded with the co-active component in step (3) by electrostatic adsorption II, dried IV, calcined IV, and reduced to obtain the shape-selective isomerization catalyst.

4. The preparation method according to claim 3, characterized in that, In step (1), in the twelve-membered ring aluminosilicate molecular sieve containing a template agent, the template agent is an MTW-type structure molecular sieve; Preferably, in the MTW-type structure molecular sieve, the organic ammonium in the pore channels is selected from at least one of tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium hydroxide, methyltriethylammonium hydroxide, and methyltriethylammonium bromide.

5. The preparation method according to claim 3, characterized in that, In step (2), the weight ratio of the twelve-membered ring aluminosilicate molecular sieve with the template agent removed to the binder is 1:2 - 5:1; Preferably, the acid solution is selected from at least one of hydrochloric acid, nitric acid, sulfuric acid, citric acid, acetic acid, and phosphoric acid; Preferably, the temperatures of calcination I and calcination II are independently selected from 350 - 600 °C; Preferably, the times of calcination I and calcination II are independently selected from 4 - 24 h.

6. The preparation method according to claim 3, characterized in that, In step (3), the co-active component precursor is selected from at least one of ammonium paratungstate, ammonium tungstate, and ammonium metatungstate; Preferably, in the electrostatic adsorption I, the pH value of the electrostatic adsorption I mixed solution is 7-9; Preferably, in the electrostatic adsorption I, the pH value regulator is selected from at least one of hydrochloric acid, nitric acid, oxalic acid, sulfuric acid, ammonia water, liquid ammonia, methylamine, and ethylamine; Preferably, the temperature of the calcination III is 330-740 °C, and the time of the calcination III is 0.5-24 h.

7. The preparation method according to claim 3, characterized in that, The noble metal active component precursor is selected from at least one of platinum nitrate, tetraammineplatinum dichloride, diamineplatinum dichloride, dinitrodiammineplatinum, palladium chloride, tetraamminepalladium dichloride, diaminepalladium dichloride, and dinitrodiamminepalladium; Preferably, in the electrostatic adsorption II, the pH value of the electrostatic adsorption II mixed solution is 10-13; Preferably, in the electrostatic adsorption I, the pH value regulator is selected from at least one of hydrochloric acid, nitric acid, oxalic acid, sulfuric acid, ammonia water, liquid ammonia, methylamine, and ethylamine; Preferably, the temperatures of the drying I, drying II, drying III, and drying IV are independently selected from 50-200 °C; Preferably, the times of the drying I, drying II, drying III, and drying IV are independently selected from 0.5-24 h; Preferably, the temperature of the calcination IV is 350-650 °C, and the time of the calcination IV is 0.5-24 h; Preferably, the atmospheres of the calcination I, calcination II, calcination III, and calcination IV are oxygen-containing atmospheres, and the oxygen content in the oxygen-containing atmosphere is 10-100%; Preferably, the atmosphere of the reduction is a hydrogen atmosphere; Preferably, the gas flow rate of the hydrogen atmosphere is 2 to 200 mL / min / g 催化剂 ; Preferably, the temperature of the reduction is 200-400 °C, and the time of the reduction is 2-8 h.

8. A method for isomerization of long-chain alkanes, characterized in that, The method includes: using the shape-selective isomerization catalyst in the long-chain alkane isomerization reaction; The shape-selective isomerization catalyst is selected from the shape-selective isomerization catalysts described in any one of claims 1 to 2; The long-chain alkane is selected from C8-C50 long-chain alkanes.

9. The method according to claim 8, characterized in that, The conditions of the long-chain alkane isomerization reaction are: The reaction temperature is 200 to 400 °C, the reaction pressure is 0.1 to 10 MPa, and the feed volume space velocity is 0.5 to 5 h -1 , and the hydrogen-oil ratio (mol / mol) is 5 to 50.

10. The method according to claim 9, characterized in that, The reaction temperature is 280-350 °C.

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