CN104437489B - Ferrum-based Fischer-Tropsch synthesis catalyst and preparation and application thereof - Google Patents

Abstract

The invention relates to a ferrum-based Fischer-Tropsch synthesis catalyst and preparation and application thereof. The catalyst contains an aluminum oxide carrier and an active metal component ferrum, wherein the carrier has a bimodal pore structure, characterized by a mercury intrusion method, the carrier has the pore volume of 0.6-1.4 ml/g and the specific surface area of 80-400 m＜2＞/g, the volume of pores with the diameter of 5-20 nm accounts for 30-60% the total pore volume, and the volume of pores with the diameter of 100-300 nm accounts for 15-45% the total pore volume. Compared with the prior art, the catalyst provided by the invention has better Fischer-Tropsch synthesis performance.

Description

A kind of iron-based Fischer-Tropsch synthesis catalyst and its preparation and application

technical field

The invention relates to a Fischer-Tropsch synthesis catalyst and its preparation and application, more specifically to an iron-based Fischer-Tropsch synthesis catalyst and its preparation and application.

Background technique

In 1923, Fischer and Tropsch discovered a method for the synthesis of hydrocarbon products from a mixture of CO and _H2 (FT synthesis). In recent years, with the increasing shortage of petroleum resources, rising crude oil prices, increasingly stringent fuel requirements, and increasing proven reserves of coal and natural gas, the research in this field of FT synthesis is very active, and many companies are working on FT synthesis Conducted research and development. A good catalyst for FT synthesis should have adsorption activity for CO and _H2 , have a hydrogenation effect on the adsorbed CO, contribute to chain growth, and promote hydrogenation mildly, while at the same time, it should not be too strong hydrogenation, excessive water-gas shift, and the formation of non- Activated carbide, etc. The first step in FT synthesis is the chemisorption of CO and _H2 . From the viewpoint of structural chemistry, transition elements with 3d and 4f bonds and energy levels are mostly used as active components of FT synthesis catalysts. Among them, there are many studies on Ni, Fe, Co, and Ru. Except that Ni is mainly used for methanation due to its strong hydrogenation activity, which makes the chain growth rate too high, and is not suitable as an active component for the synthesis of high-molecular wax catalysts, the other three metal catalysts can be used for FT synthesis. However, Co and Fe catalysts are of commercial application value. Because of Co’s high FT synthesis activity, mild reaction conditions, less water-gas shift reaction, stable performance, and longer life, people have carried out more research and application on Co catalysts. Extensive research. For Co catalysts used in FT, unsupported oxides were used in the early stage, such as pure cobalt oxides, cobalt-chromium oxides, and cobalt-zinc oxides; later it was found that adding thorium oxide and magnesium oxide could increase the activity of the catalyst; Currently, carrier-supported Co catalysts are the mainstream of research and industrial applications. For Co catalysts for FT synthesis, researchers selected a variety of additives to modify them in order to improve their catalytic performance.

Disclosed in CN89109859 and CN93106465 is a kind of catalyst preparation method and use method, and this catalyst comprises the cobalt of the catalytic activity amount that is loaded on the alumina carrier and is selected from platinum, iridium, rhodium, and the first that is also sensitive to loading amount Two metals. Metal oxide promoters may be added.

CN01810769.9 and CN01810773 disclose a method for preparing and using a catalyst. The catalyst includes a catalytically active amount of cobalt, and its content is 5gCo/100g-70gCo/100g carrier. Pd and Pt can also be added as a catalyst with enhanced Co reduction. Ability dopant.

Contents of the invention

The technical problem to be solved by the present invention is to provide a Fischer-Tropsch synthesis catalyst with modified properties and a preparation method and application of the catalyst based on the prior art.

The inventors have found that when a carrier with a bimodal pore structure is used to prepare a FT synthesis catalyst, the FT synthesis reaction performance of the catalyst, such as the selectivity of C ₅ ⁺ is significantly improved.

The content involved in the present invention includes:

1. An iron-based Fischer-Tropsch synthesis catalyst, containing alumina carrier and active metal component iron, wherein, the carrier has a bimodal pore structure, characterized by mercury porosimetry, and the pore volume of the carrier is 0.6-1.4 milliliters /g, the specific surface area is 80-400 ^m2 /g, the pore volume of pores with a diameter of 5-20nm accounts for 30-60% of the total pore volume, and the pore volume of pores with a diameter of 100-300nm accounts for 15-45% of the total pore volume %.

2. according to the described catalyst of 1, it is characterized in that, the pore volume of described carrier is 0.7-1.3 milliliter/gram, and specific surface area is 100-300 meter / gram, and diameter is that the pore volume of ^5-20nm hole accounts for total hole The volume of pores with a diameter of 100-300nm accounts for 20-40% of the total pore volume.

3. The catalyst according to 1, characterized in that, based on the catalyst, the content of the active metal component iron in terms of oxides is 5-70% by weight.

4. The catalyst according to 3, characterized in that, based on the catalyst, the content of the active metal component iron in terms of oxide is 10-50% by weight.

5. The catalyst according to 4, characterized in that, based on the catalyst, the content of the active metal component iron in terms of oxides is 12-30% by weight.

6. The catalyst according to 1, characterized in that, the catalyst contains one or more first selected from Cu, Mo, Ta, W, Zr, Ti, REO, Re, Mn, V or K Auxiliary components, based on the catalyst, the content of the first auxiliary component in terms of oxides is 10% by weight or less.

7. The catalyst according to 6, characterized in that, the first promoter metal component is selected from one or more of Ti, Zr, W or Mn, taking the catalyst as a benchmark, and the second metal component in terms of oxides The content of an auxiliary component is 6% by weight or less.

8. The catalyst according to 1 or 6, characterized in that, the catalyst contains one or more second additive components selected from Ru, Rh, Pd, Os, Ir, Pt, Ag or Au , based on the catalyst, the content of the second additive component in terms of elements is less than 0.5% by weight.

9. The catalyst according to 8, characterized in that, the second additive component is selected from one or more of Ru, Pt or Pd, based on the catalyst, the second additive group in terms of elements The content of the component is 0.3% by weight or less.

10. according to the preparation method of catalyzer described in 1, comprise preparation support and on this support active metal component iron, wherein, the preparation of described support comprises the hydrated aluminum oxide PA that contains pseudo-boehmite and PB and a A modified PC containing pseudo-boehmite alumina hydrate is mixed, shaped, dried and calcined, wherein the weight mixing ratio of PA, PB and PC is 20-60:20-50:5-50, The κ value of PC is 0 to less than or equal to 0.9, said κ=DI ₂ /DI ₁ , DI ₁ is the acid peptization index of alumina hydrate before PC modification, and DI ₂ is the acid peptization index of PC.

11. The method according to 10, wherein the weight mixing ratio of the PA, PB and PC is 30-50:35-50:10-30; the k value of the PC is 0 to less than or equal to 0.6.

12. The method according to 10 or 11, wherein the pore volume of the hydrated alumina PA containing pseudoboehmite is 0.75-1 ml/g, and the specific surface area is 200-450 ^m2 /g, The most possible pore diameter is 3-10nm; the pore volume of the hydrated alumina PB containing pseudoboehmite is 0.9-1.4 ml/g, the specific surface is 100-350 ^m2 /g, and the most likely pore diameter is greater than 10 to less than or equal to 30nm.

13. The method according to 12, characterized in that the pore volume of the hydrated alumina PA containing pseudoboehmite is 0.80-0.95 ml/g, and the specific surface is 200-400 ^m2 /g, the most possible The pore diameter is 5-10nm; the pore volume of the hydrated alumina PB containing pseudoboehmite is 0.95-1.3 ml/g, the specific surface area is 120-300 ^m2 /g, and the most possible pore diameter is greater than 10 to Less than or equal to 25nm.

14. The method according to any one of 10 or 11, characterized in that the PC is 80-300 mesh particles.

15. The method according to 14, wherein the PC is 100-200 mesh particles.

16. The method according to 10, characterized in that the drying conditions include: the temperature is 40-350°C, and the time is 1-24 hours, and the roasting conditions include: the temperature is greater than 500 to less than or equal to 1200°C , the time is 1-8 hours.

17. The method according to 16, characterized in that the drying conditions include: the temperature is 100-200°C, and the time is 2-12 hours, and the roasting conditions include: the temperature is greater than 800 to less than or equal to 1000°C , The roasting time is 2-6 hours.

18. The method according to 10, characterized in that one of the methods of modifying the hydrated alumina containing pseudo-boehmite to PC is to form and dry the hydrated alumina containing pseudo-boehmite, Then all or part of it is ground and sieved, and the drying conditions include: the temperature is 40-350 ° C, and the time is 1-24 hours; the second method is to roast the molded product obtained in the first method, and the roasting temperature is greater than 350 to less than or equal to 1400 °C, the roasting time is 1-8 hours, and then all or part of it is ground and sieved; the third method is to flash dry the hydrated alumina containing pseudo-boehmite, and the flash-dry temperature is greater than 150 to less than or equal to 1400°C, and the flash-drying time is 0.05-1 hour; the fourth method is obtained by mixing one or more of the modified products obtained by the first method, the second method and the third method.

19. The method according to 18, characterized in that the drying conditions in the first method include: the temperature is 100-200°C, and the time is 2-12 hours; the calcination temperature in the second method is 500-1200°C , the calcination time is 0.1-6 hours; the flash-drying temperature in method 3 is 200-1000° C., and the flash-drying time is 0.1-0.5 hours.

20. The method according to 18, characterized in that the PC is 80-300 mesh particles in the modified product of alumina hydrate containing pseudoboehmite.

21. The method according to 20, characterized in that the PC is a 100-200 mesh particle in a modified product of alumina hydrate containing pseudoboehmite.

22. The method according to 10, characterized in that, the method of loading the active metal component iron on the carrier is an impregnation method, which is based on the oxide and is based on the catalyst, and the impregnation makes the catalyst active The content of the metal component is 5-70% by weight.

23. method according to claim 22, is characterized in that, described active metal component is cobalt, is based on oxide meter and with catalyzer, and described impregnation makes the content of active metal component in the described catalyst be 10-50% by weight.

24. The method according to 23, characterized in that the impregnation is such that the content of the active metal component in the catalyst is 12-30% by weight, calculated as oxide and based on that of the catalyst.

25. The method according to 10, characterized in that the method includes introducing one or more of the first selected from Cu, Mo, Ta, W, Zr, Ti, REO, Re, Mn, V or K A step of an auxiliary metal component, calculated as an oxide and based on the catalyst, the introduction amount of the auxiliary metal component is not more than 10% by weight.

26. The method according to 25, characterized in that, the first promoter metal component is selected from one or more of Ti, Zr, W or Mn, in terms of oxides and based on the catalyst , the introduced amount of the first auxiliary metal component is not more than 6% by weight.

27. The catalyst according to claim 10 or 25, characterized in that, the method includes introducing one or more second assistants selected from Ru, Rh, Pd, Os, Ir, Pt, Ag or Au In the step of adding an additive metal component, in terms of elements and based on the catalyst, the introduction amount of the second additive metal component is not more than 0.5% by weight.

28. The catalyst according to claim 27, characterized in that, the second promoter metal component is selected from one or more of Ru, Pt or Pd, in terms of elements and based on the catalyst, The introduction amount of the second auxiliary metal component is not more than 0.3% by weight.

29. A Fischer-Tropsch synthesis method, comprising contacting a mixture of carbon monoxide and hydrogen with a catalyst under Fischer-Tropsch synthesis reaction conditions, characterized in that the catalyst is the one described in any one of claims 1-9. catalyst.

According to the catalyst provided by the present invention, depending on different requirements, the carrier can be made into various easy-to-handle shapes, such as spherical, honeycomb, bird's nest, tablet or strip (clover, butterfly, cylindrical, etc.). Molding can be carried out by conventional methods, for example, one method or a combination of several methods in ball rolling, sheeting and extrusion molding. When molding, such as extrusion molding, in order to ensure that the molding is carried out smoothly, water, extrusion aids and/or adhesives, with or without pore-expanding agents, can be added to the mixture, and then extrusion molding, followed by Dry and roast. The type and amount of the extrusion aid and the peptizing agent are well known to those skilled in the art, for example, the common extrusion aid can be selected from one of squash powder, methyl cellulose, starch, polyvinyl alcohol, polyethanol or several, the peptizer can be inorganic acid and/or organic acid, and the pore-enlarging agent can be one or more of starch, synthetic cellulose, polymeric alcohol and surfactant. Wherein the synthetic cellulose is preferably one or more in hydroxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxycellulose fatty alcohol polyvinyl ether, and the polymeric alcohol is preferably polyethylene glycol, polypropylene alcohol, One or more of polyvinyl alcohol, the surfactant is preferably one of fatty alcohol polyvinyl ether, fatty alcohol amide and its derivatives, acrylic alcohol copolymer and maleic acid copolymer with a molecular weight of 200-10000 or several.

In the present invention, the acid peptization index DI refers to the hydrated alumina containing pseudoboehmite and the modified alumina hydrate containing pseudoboehmite after adding nitric acid at a certain acid-aluminum ratio, in a certain reaction Percentage of hydrated alumina containing pseudoboehmite peptized within the time, calculated as Al ₂ O ₃ , DI=(1-W ₂ /W ₁ )×100%, W ₁ and W ₂ are respectively Hydrated alumina of diaspore before and after reaction with _acid by weight in terms of _Al2O3 .

The determination of DI includes: (1) Determination of the ignited base (also called dry base) content of hydrated alumina containing pseudo-boehmite (the ignited base content refers to roasting quantitative pseudo-boehmite at 600°C for 4 hours , the ratio of the weight after burning to the weight before burning, expressed as a percentage), is counted as a; (2) Use an analytical balance to weigh W ₀ grams of hydrated alumina containing pseudo-boehmite, and the amount of W ₀ meets the requirement of Al ₂ O The W ₁ of ₃ is 6 grams (W ₁ /a=W ₀ ), weigh W gram of deionized water, W=40.0-W ₀ , and mix the weighed hydrated alumina containing pseudo-boehmite and Add deionized water into the beaker and mix; (3) use a 20mL pipette to pipette 20mL of dilute nitric acid solution with a concentration of 0.74N, add the acid solution into the beaker of step (2), and react for 8 minutes under stirring; (3) Centrifuge the reacted slurry in a centrifuge, put the precipitate into a weighed crucible, then dry it at 125°C for 4 hours, bake it in a muffle furnace at 850°C for 3 hours, and weigh The weight of the burnt sample is W ₂ grams; (5) is calculated according to the formula DI=(1-W ₂ /W ₁ )×100%.

Under the premise that the final carrier is sufficient to meet the requirements of the present invention, the present invention has no special requirements for the hydrated alumina PA and PB containing pseudo-boehmite, which can be pseudo-boehmite prepared by any prior art, or It may be a mixture of pseudo-boehmite and other hydrated alumina, and the other hydrated alumina is selected from one or more of monohydrate alumina, trihydrate alumina and amorphous hydrate alumina.

In a specific embodiment, the hydrated alumina PA containing pseudoboehmite preferably has a pore volume of 0.75-1 ml/g, a specific surface of 200-450 ^m2 /g, and a most likely pore diameter of 3-10 nm , further preferably the pore volume is 0.80-0.95 ml/g, the specific surface is 200-400 ^m2 /g, and the most possible pore diameter is 5-10nm; the preferred pore volume of the hydrated alumina PB containing pseudo-boehmite is 0.9-1.4 ml/g, the specific surface is 100-350 ^m2 /g, the most probable pore diameter is greater than 10 to less than or equal to 30 nm, more preferably the pore volume is 0.95-1.3 ml/g, and the specific surface is 120-300 ^m2 /g, the most probable pore diameter is greater than 10 to less than or equal to 25nm.

In the present invention, the pore volume, specific surface area and most accessible pore diameter of the hydrated alumina containing pseudo-boehmite are determined by BET Nitrogen adsorption was characterized.

In a further preferred embodiment, as characterized by X-ray diffraction, the pseudo-boehmite content in the pseudo-boehmite-containing alumina hydrates PA and PB is not less than 50%, more preferably not less than 60%.

The inventors of the present invention surprisingly found that the modified product PC is obtained by heat-treating alumina hydrate containing pseudo-boehmite. Compared with the original hydrated alumina containing pseudo-boehmite, the peptization of the modified product PC The index changes, and after molding this modification with PA and PB, drying and calcination, the obtained support has a clear bimodal pore distribution. Especially after the 80-300 mesh particles, preferably 100-200 mesh particles are mixed with PA and PB, dried and calcined, the pore distribution of each unimodal in the obtained bimodal carrier is particularly concentrated. Here, the 80-300 mesh particles, preferably 100-200 mesh particles mean that the modified product has been sieved (including the step of crushing or grinding if necessary), and the sieved material (undersize) meets the 80-300 mesh Particles, preferably 100-200 mesh particles, account for a percentage (by weight) of not less than 60% of the total, more preferably not less than 70%. The hydrated alumina containing pseudo-boehmite here can be pseudo-boehmite prepared by any prior art, or a mixture of pseudo-boehmite and other hydrated aluminas, and the other hydrated aluminas One or more selected from alumina monohydrate, alumina trihydrate and amorphous hydrated alumina. In a preferred embodiment, the PC is a modified product of PA and/or PB.

In the present invention, the weight mixing ratio of PA, PB and PC refers to the ratio of the parts by weight of PA, PB and PC in the mixture of PA, PB and PC per hundred parts. Among them, PA:PB:PC is preferably 20-60:20-50:5-50, more preferably 30-50:35-50:10-30.

Among the present invention, described PC can obtain conveniently by following method:

Hereinafter, a method for obtaining PC will be described using the aforementioned PA and PB as starting materials.

⑴Based on drying to obtain PC, including the tailings produced by drying during the preparation of conventional alumina carriers by forming hydrated alumina PA and/or PB containing pseudoboehmite according to conventional methods, for example: in extrusion molding , the tailings (customarily called dry waste) produced by the drying and shaping process of the strip-shaped moldings, the tailings are ground and sieved to obtain PC.

(2) Obtained on the basis of roasting, including the tailings (customarily called roasting waste) produced by roasting during the preparation of conventional alumina carriers from hydrated alumina PA and/or PB containing pseudoboehmite according to conventional methods, For example, in rolling ball molding, the tailings produced by the spherical particles during the roasting process are ground and sieved to obtain PC; or directly obtained by flashing PA and/or PB. And/or when PB is flash-dried, the flash-dry time is preferably 0.05-1 hour, more preferably 0.1-0.5 hour.

(3) Obtained based on the mixture of two or more of the modified PCs obtained by the aforementioned method. When using the mixing method to obtain C, there is no limit to the mixing ratio of the modified PC obtained by the aforementioned methods.

According to the catalyst provided by the present invention, the content of the active metal component iron wherein is the conventional content of Fischer-Tropsch synthesis catalysts, for example, in terms of oxides and based on the catalyst, the content of the active metal component is 5 to 70% by weight %, preferably 10 to 50% by weight, more preferably 12 to 30% by weight.

On the premise that it is sufficient to load the active metal component on the support, the present invention has no special limitation on the method for loading the active metal component on the support. For example, the support may be contacted with a solution containing an effective amount of a compound containing an active metal component under conditions sufficient to deposit an effective amount of the active metal component on the support, such as by impregnating , co-precipitation and other methods, preferably the impregnation method, followed by drying, roasting or no roasting. The drying method is a conventional method, for example, the method of heating and drying. When the drying method is heating and drying, the operating conditions of the drying include: the temperature is 80-350°C, preferably 100-300°C, and the time is 1 to 24 hours, preferably 2 to 12 hours. When the catalyst needs to be calcined, the calcining temperature is for the purpose of converting the compound containing the active metal component into its oxide, the preferred calcining temperature is 200-700°C, and the calcining time is 1-6 hours , the more preferred temperature is preferably 250-500°C, and the calcination time is 2-4 hours.

The compound containing the active metal component is preferably selected from one or more of their soluble compounds, such as one or more of water-soluble salts and complexes containing the active metal component.

Prior art studies have shown that one or more additives selected from Cu, Mo, Ta, W, Zr, Ti, REO, Re, Mn, V or K are introduced separately or jointly into the Fischer-Tropsch synthesis catalyst Metal components; or a group of additional additive components introduced by one or more selected from Ru, Rh, Pd, Os, Ir, Pt, Ag or Au are beneficial to improve catalyst performance.

According to the catalyst provided by the present invention, the catalyst contains one or more promoter metal components selected from Cu, Mo, Ta, W, Zr, Ti, REO, Re, Mn, V or K, preferably containing One or more selected from Ti, Zr, W or Mn, calculated as oxides and based on the catalyst, the content of the auxiliary metal component is not more than 10% by weight, preferably not more than 6% by weight %.

When the catalyst contains one or two selected from components such as Cu, Mo, Ta, W, Zr, Ti, REO, Re, Mn, V or K, its introduction method can be to contain the The compound of the auxiliary agent and the compound containing the active metal component are formulated into a mixed solution and then contacted with the carrier; it is also possible that the compound containing the auxiliary agent is separately prepared in a solution and then contacted with the carrier, and then dried and calcined. When the auxiliary agent and the active metal group are respectively introduced into the carrier, it is preferable to first contact the carrier with a solution containing the auxiliary agent compound, and then contact with the solution of the compound containing the active metal component after drying and roasting, for example, by ionizing Methods such as exchange, impregnation, co-precipitation, etc., preferably the impregnation method. The calcination temperature is 200-700°C, preferably 250-500°C, and the calcination time is 2-8 hours, preferably 3-6 hours.

According to the catalyst provided by the present invention, the catalyst also contains one or more additional additive components selected from Ru, Rh, Pd, Os, Ir, Pt, Ag or Au, preferably containing selected from Ru One or more of , Pt or Pd, calculated as elements and based on the catalyst, the content of the auxiliary metal component is no more than 0.3% by weight, preferably no more than 0.15% by weight.

When containing one or more additive components selected from Ru, Rh, Pd, Os, Ir, Pt, Ag or Au in the catalyst, its introduction method can be that the compound containing the additive is mixed with Compounds containing active metal components with or without other additive components (e.g., containing additive components selected from Cu, Mo, Ta, W, Zr, Ti, REO, Re, Mn, V or K The compound) is formulated into a mixed solution and then contacted with the carrier; it is also possible that the compound containing the auxiliary agent is formulated into a solution separately and then contacted with the carrier, and then dried and calcined. When the auxiliary agent and the active metal group are respectively introduced into the carrier, it is preferable to contact the carrier with a solution containing the auxiliary agent compound at first, and after drying and roasting, it is mixed with the solution of the compound containing the active metal component (with or without Compounds of other auxiliary components) contact, for example, by ion exchange, impregnation, co-precipitation and other methods, preferably impregnation. The calcination temperature is 200-700°C, preferably 250-500°C, and the calcination time is 2-8 hours, preferably 3-6 hours.

According to the catalyst provided by the present invention, the active metal needs to be reduced and activated in the presence of hydrogen before being used in the Fischer-Tropsch synthesis reaction. The reduction condition is: the reduction temperature is 100°C to 800°C, preferably 200°C to 600°C, more preferably 300°C to 450°C; the reduction time is 0.5-72 hours, preferably 1-24 hours, more preferably 2-8 hours, and the reduction can be carried out in pure hydrogen or a mixture of hydrogen and inert gas For example, in a mixture of hydrogen, nitrogen and/or argon, the hydrogen pressure is 0.1-4MPa, preferably 0.1-2MPa.

According to the Fischer-Tropsch synthesis method provided by the present invention, the conditions for the contact reaction of the mixture of carbon monoxide and hydrogen with the catalyst: the preferred temperature is 160-280°C, more preferably 190-250°C, and the pressure is preferably 1-8MPa, More preferably 1-5MPa, the molar ratio of hydrogen to carbon monoxide is 0.4-2.5, preferably 1.5-2.5, more preferably 1.8-2.2, and the hourly space velocity of the gas is 200 hours ^-1 to 20000 hours ^-1 , preferably 500 hours ^-1 ~ 12000 hours ^-1 .

The Fischer-Tropsch synthesis catalyst provided by the invention adopts bimodal porous alumina as a carrier, so that the performance of the catalyst is improved. For example, in the case of the catalyst having the same active metal component content and preparation conditions, compared with the reference agent, the CO conversion activity of the catalyst provided by the present invention is increased by nearly 6%, and the methane selectivity is reduced by nearly 2%.

detailed description

The following examples will further illustrate the present invention, but should not therefore be interpreted as limiting the present invention.

The pseudo-boehmite used in the following examples includes:

PA-1: Dry rubber powder produced by Changling Catalyst Branch (pore volume is 0.9 ml/g, specific surface is 280 ^m2 /g, and the most probable pore diameter is 8.5nm. The dry basis is 73%, of which the pseudo-thin water The content of gibbsite is 68%, the content of gibbsite is 5% by weight, and the balance is amorphous alumina (DI value 34.6).

PA-2: Dry rubber powder produced by Zibo Qimao Catalyst Co., Ltd. (the pore volume is 0.9 ml/g, the specific surface is 290 ^m2 /g, the most probable pore diameter is 8.3nm. The dry basis is 73%, of which the pseudo-thin water The content of gibbsite is 68%, the content of gibbsite is 5% by weight, and the balance is amorphous alumina (DI value 33.2).

PB-1: Dry rubber powder produced by Changling Catalyst Branch (pore volume is 1.2 ml/g, specific surface is 280 ^m2 /g, and the most probable pore diameter is 15.8nm. Dry basis is 73%, of which pseudo-thin water The content of gibbsite is 68%, the content of gibbsite is 5% by weight, and the balance is amorphous alumina (DI value 15.8).

PB-2: Dry rubber powder produced by Yantai Henghui Chemical Co., Ltd. (pore volume is 1.1 ml/g, specific surface is 260 ^m2 /g, and the diameter of most pores is 12nm. Dry basis is 71%, of which pseudo-thin water The content of gibbsite is 67%, the content of gibbsite is 5% by weight, and the balance is amorphous alumina (DI value 17.2).

Examples 1-10 illustrate the PC and its preparation method of the present invention.

Example 1

Weigh 1000 grams of PA-1, then add 1000 milliliters of an aqueous solution containing 10 milliliters of nitric acid (product of Tianjin Chemical Reagent No. Dry the wet strips at 120°C for 4 hours to obtain dry strips, shape the dry strips, sieve, grind and sieve the dry strip materials (generally called industrial dry strip waste) with a length of less than 2mm, and take 100-200 Mesh sieving to obtain the modified PC-A1 of PA-1. See Table 1 for the k value of PC-A1.

Example 2

Weigh 1000 grams of PA-1, then add 1000 milliliters of an aqueous solution containing 10 milliliters of nitric acid (product of Tianjin Chemical Reagent No. The wet strips were dried at 120°C for 4 hours, and roasted at 800°C for 4 hours to obtain the carrier. The carrier strips were shaped and sieved, and the carrier strip materials (generally called industrial carrier waste) with a length of less than 2mm were ground, sieved, and collected. Among them, sieve with 100-200 meshes to obtain the modified product PC-A2 of PA-1. See Table 1 for the k value of PC-A2.

Example 3

Weigh 1000g of PA-2, and flash dry at 400°C for 6 minutes to obtain PC-A3, a modified product of PA-2. See Table 1 for the k value of PC-A3.

Example 4

Each 200 grams of PC-A1 obtained in Example 1 and PC-A3 obtained in Example 3 were evenly mixed to obtain the modified PC-A4 of PA-1 and PA-2. See Table 1 for the k value of PC-A4.

Example 5

Weigh 1000 grams of PB-1, then add 1440 milliliters of aqueous solution containing 10 milliliters of nitric acid (product of Tianjin Chemical Reagent No. The wet strips were dried at 120°C for 4 hours, and roasted at 1200°C for 4 hours to obtain the carrier. The carrier strips were shaped and sieved, and the carrier strip materials (generally called industrial carrier waste) with a length of less than 2mm were ground, sieved, and collected. Among them, 100-200 mesh sieve to obtain the modified product PC-B1 of PB-1. See Table 1 for the k value of PC-B1.

Example 6

Weigh 1000 g of PB-2 and flash dry at 650°C for 10 minutes to obtain PC-B2, a modified product of PB-2. See Table 1 for the k value of PC-B2.

Example 7

Weigh 1000 grams of PB-2, then add 1440 milliliters of aqueous solution containing 10 milliliters of nitric acid (product of Tianjin Chemical Reagent No. Dry the wet strips at 120°C for 4 hours to obtain dry strips, shape the dry strips, sieve, grind and sieve the dry strip materials (generally called industrial dry strip waste) with a length of less than 2mm, and take 100-200 Mesh sieving to obtain the modified product PC-B3 of PB-2. See Table 1 for the k value of PC-B3.

Example 8

Each 200 grams of PC-B1 obtained in Example 5 and PC-B2 obtained in Example 6 were evenly mixed to obtain the modified product PC-B4 of PB-1 and PB-2. See Table 1 for the k value of PC-B4.

Example 9

100 grams of PC-A1 obtained in Example 1 and 150 grams of PC-B3 obtained in Example 7 were evenly mixed to obtain PC-B5, a modified product of PA-1 and PB-2. See Table 1 for the k value of PC-B5.

Example 10

Each 150 grams of PC-A3 obtained in Example 3 and PC-B1 obtained in Example 5 were uniformly mixed to obtain the modified product PC-B6 of PA-2 and PB-1. See Table 1 for the k value of PC-B6.

Table 1

Example raw material DI k 1 PC-A1 10.0 0.29 2 PC-A2 0.9 0.02 3 PC-A3 3.6 0.11 4 PC-A4 6.7 0.20 5 PC-B1 0 0 6 PC-B2 2.1 0.12 7 PC-B3 5.3 0.31 8 PC-B4 1.0 0.06 9 PC-B5 7.0 0.29 10 PC-B6 1.6 0.07

Examples 11-18 illustrate the bimodal pore supports provided by the present invention and methods for their preparation. Comparative Examples 1-5 illustrate conventional catalyst supports and methods for their preparation.

Example 11

Take by weighing each 400 grams of PA-1 and PB-1, after mixing evenly with 200 grams of raw material PC-A2 obtained in Example 2, add 1300 milliliters of aqueous solution containing 10 milliliters of nitric acid (product of Tianjin Chemical Reagent No. On the screw extruder, it is extruded into a butterfly-shaped strip with an outer diameter of φ1.4mm. The wet strip was dried at 120° C. for 4 hours to obtain a molded product, which was calcined at 900° C. for 3 hours to obtain a carrier Z1. The properties of carrier Z1 are listed in Table 2.

Example 12

Take by weighing 300 grams of PA-2, 200 grams of PB-2, after mixing evenly with the 500 grams of raw material PC-B2 that embodiment 6 makes, add the aqueous solution 1300 milliliters containing 10 milliliters of nitric acid Tianjin Chemical Reagent No. On the screw extruder, it is extruded into a butterfly-shaped strip with an outer diameter of φ1.4mm. The wet strip was dried at 120° C. for 4 hours to obtain a molded product, which was calcined at 900° C. for 3 hours to obtain a carrier Z2. The properties of carrier Z2 are listed in Table 2.

Example 13

Take by weighing 500 grams of PA-2, 300 grams of PB-2, after mixing evenly with the 200 grams of raw material PC-B4 that embodiment 8 makes, add the aqueous solution 1300 milliliters containing 10 milliliters of nitric acid Tianjin Chemical Reagent No. On the screw extruder, it is extruded into a butterfly-shaped strip with an outer diameter of φ1.4mm. The wet strip was dried at 120° C. for 4 hours to obtain a shaped product, which was calcined at 950° C. for 3 hours to obtain a carrier Z3. The properties of carrier Z3 are listed in Table 2.

Comparative example 1

Weigh 500 grams of PA-2 and 500 grams of PB-2, mix them evenly, add 10 milliliters of aqueous solution containing 10 milliliters of nitric acid (product of Tianjin Chemical Reagent No. strip. The wet strip was dried at 120°C for 4 hours to obtain a molded product, which was calcined at 900°C for 3 hours to obtain a carrier DZ1. The properties of vector DZ1 are listed in Table 2.

Comparative example 2

Weigh 400 grams of PA-1, 600 grams of PB-1, mix evenly, add 10 milliliters of aqueous solution containing 10 milliliters of nitric acid (product of Tianjin Chemical Reagent No. strip. The wet strip was dried at 120°C for 4 hours to obtain a molded product, which was calcined at 950°C for 3 hours to obtain the carrier DZ2. The properties of vector DZ2 are listed in Table 2.

Example 14

Take by weighing 250 grams of PA-1, 500 grams of PB-1, after mixing evenly with 250 grams of raw material PC-B5 that embodiment 9 makes, add the aqueous solution 1300 milliliters that contains nitric acid (Tianjin chemical reagent No. 3 factory product) 10 milliliters, in On the twin-screw extruder, it is extruded into a butterfly-shaped strip with an outer diameter of φ1.4mm. The wet strip was dried at 120° C. for 4 hours to obtain a molded product, which was calcined at 1000° C. for 3 hours to obtain a carrier Z4. The properties of carrier Z4 are listed in Table 2.

Example 15

Take by weighing 350 grams of PA-2, 350 grams of PB-2, after mixing evenly with the 300 grams of raw material PC-B6 that embodiment 10 makes, add the aqueous solution 1440 milliliters containing 10 milliliters of nitric acid Tianjin Chemical Reagent No. On the screw extruder, it is extruded into a butterfly-shaped strip with an outer diameter of φ1.4mm. The wet strip was dried at 120° C. for 4 hours to obtain a shaped product, which was calcined at 1000° C. for 3 hours to obtain a carrier Z5. The properties of vector Z5 are listed in Table 2.

Example 16

Take by weighing 200 grams of PA-1, 600 grams of PB-1, after mixing evenly with the 200 grams of raw material PC-B1 that embodiment 5 makes, add the aqueous solution 1440 milliliters containing 10 milliliters of nitric acid Tianjin Chemical Reagent No. On the screw extruder, it is extruded into a butterfly-shaped strip with an outer diameter of φ1.4mm. The wet strip was dried at 120°C for 4 hours to obtain a molded product, which was calcined at 850°C for 3 hours to obtain a carrier Z6. The properties of carrier Z6 are listed in Table 2.

Example 17

Take by weighing 200 grams of PA-1, 600 grams of PB-1, after mixing evenly with the 200 grams of raw material PC-A4 that embodiment 4 makes, add the aqueous solution 1440 milliliters that contains 10 milliliters of nitric acid (Tianjin Chemical Reagent No. On the screw extruder, it is extruded into a butterfly-shaped strip with an outer diameter of φ1.4mm. The wet strip was dried at 120°C for 4 hours to obtain a molded product, which was calcined at 850°C for 3 hours to obtain a carrier Z7. The properties of vector Z76 are listed in Table 2.

Example 18

Take by weighing 200 grams of PA-1, 600 grams of PB-1, after mixing evenly with the 200 grams of raw material PC-A2 that embodiment 2 makes, add the aqueous solution 1440 milliliters that contains 10 milliliters of nitric acid (Tianjin Chemical Reagent No. On the screw extruder, it is extruded into a butterfly-shaped strip with an outer diameter of φ1.4mm. The wet strip was dried at 120° C. for 4 hours to obtain a molded product, which was calcined at 850° C. for 3 hours to obtain a carrier Z8. The properties of carrier Z8 are listed in Table 2.

Comparative example 3

According to the method provided in Example 7 of the patent CN1782031A, the butterfly bar with an outer diameter of φ1.4mm is extruded on a plunger extruder. The wet strip was dried at 120°C for 4 hours to obtain a molded product, which was calcined at 900°C for 3 hours to obtain the carrier DZ3. The properties of vector DZ3 are listed in Table 2.

Comparative example 4

According to the method provided in Example 1 of the patent CN1120971A, the butterfly bar with an outer diameter of φ1.4mm is extruded on a plunger extruder. The wet strip was dried at 120°C for 4 hours to obtain a molded product, which was calcined at 1000°C for 3 hours to obtain the carrier DZ3. The properties of vector DZ3 are listed in Table 2.

Comparative example 5

Weigh 200 grams of PA-1, 800 grams of PB-2, add 1300 milliliters of an aqueous solution containing 10 milliliters of nitric acid (product of Tianjin Chemical Reagent No. The wet strip was dried at 120°C for 4 hours to obtain a molded product, which was calcined at 1000°C for 3 hours to obtain the carrier DZ5. The properties of vector DZ5 are listed in Table 2.

Table 2

From the results in Table 2, it can be seen that compared with the conventional method, the alumina support prepared by the method provided by the present invention has an obvious bimodal pore structure.

Examples 19-26

The Fischer-Tropsch synthesis catalyst prepared by the alumina shaped carrier provided by the present invention is illustrated.

Carriers Z1, Z2, Z3, Z4, Z5, Z6, Z7 and Z8 in the examples were saturated with a mixed solution containing ferric nitrate, copper nitrate and potassium nitrate, followed by drying and roasting to obtain catalysts C1, C2, C3, C4, C5, C6, C7 and C8. Wherein, the drying temperature is 120°C, the drying time is 6 hours, the calcination temperature is 400°C, and the calcination time is 3 hours. The amounts of iron nitrate, copper nitrate and potassium nitrate are such that the content of Fe in the final catalyst is 12.0% by weight, the content of Cu is 0.2% by weight, and the content of K ₂ O is 0.1% by weight.

Comparative example 6-10

The DZ1, DZ2, DZ3, DZ4 and DZ5 carriers were impregnated with a mixed solution containing iron nitrate, copper nitrate and potassium nitrate, then dried and calcined to obtain catalysts DC1, DC2, DC3, DC4 and DC5 respectively. Wherein, the drying temperature is 120°C, the drying time is 6 hours, the calcination temperature is 400°C, and the calcination time is 3 hours. The amounts of iron nitrate, copper nitrate and potassium nitrate are such that the content of Fe in the final catalyst is 12.0% by weight, the content of Cu is 0.2% by weight, and the content of K ₂ O is 0.1% by weight.

Examples 27-34

The application and effect of the catalyst provided by the present invention are illustrated.

The Fischer-Tropsch synthesis reaction performance of catalysts C1, C2, C3, C4, C5, C6, C7 and C8 were evaluated in a fixed-bed reactor.

Raw material gas composition: H ₂ /CO/N ₂ =64%/32%/4% (volume percentage). Catalyst reduction reaction conditions: the pressure is normal pressure, the temperature rise rate is 5°C/min, the hydrogen space velocity is 600h ^-1 , the reduction temperature is 400°C, and the reduction time is 5 hours.

Reaction conditions: pressure 2.5MPa, temperature 200°C, synthesis gas (raw material gas) space velocity 2000h ^-1 . After the reaction was carried out for 24 hours, a gas sample was taken for chromatographic analysis, wherein the conversion rate of carbon dioxide and methane selectivity are listed in Table 3.

Comparative example 11-15

To illustrate the performance of the comparative catalysts, the catalysts DC1, DC2, DC3, DC4, and DC5 were respectively evaluated in the same manner as in Examples 27-34. Wherein, the conversion ratio of carbon dioxide and methane selectivity are listed in Table 3.

table 3

As can be seen from Table 3, the bimodal porous alumina provided by the present invention is used as a catalyst carrier, and then prepared into a Fischer-Tropsch synthesis catalyst, which has better Fischer-Tropsch synthesis performance under other conditions being the same, that is, more High CO conversion and C5+ hydrocarbon selectivity, lower methane selectivity and CO2 selectivity.

Claims (28)

1. a kind of iron-base fischer-tropsch synthesis catalyst, containing alumina support and active metal component ferrum, wherein, the carrier has Structure of double peak holes, is characterized with mercury injection method, and the pore volume of the carrier is 0.6-1.4 ml/g, and specific surface area is 80-400 rice²/ Gram, the pore volume in a diameter of 5-20nm holes accounts for the 30-60% of total pore volume, and the pore volume in a diameter of 100-300nm holes accounts for total pore volume 15-45%.

2. catalyst according to claim 1, it is characterised in that the pore volume of the carrier is 0.7-1.3 ml/g, than Surface area is 100-300 rice²/ gram, the pore volume in a diameter of 5-20nm holes accounts for the 35-50% of total pore volume, a diameter of 100-300nm The pore volume in hole accounts for the 20-40% of total pore volume.

3. the catalyst according to claim 1, it is characterised in that on the basis of catalyst, the activity gold in terms of oxide The content of category component of iron is 5-70 weight %.

4. catalyst according to claim 3, it is characterised in that on the basis of catalyst, the activity gold in terms of oxide The content of category component of iron is 10-50 weight %.

5. catalyst according to claim 4, it is characterised in that on the basis of catalyst, the activity gold in terms of oxide The content of category component of iron is 12-30 weight %.

6. catalyst according to claim 1, it is characterised in that in the catalyst containing selected from Cu, Mo, Ta, W, Zr, The first adjuvant component of one or more in Ti, REO, Re, Mn, V or K, on the basis of catalyst, first in terms of oxide The content of adjuvant component is below 10 weight %.

7. catalyst according to claim 6, it is characterised in that the first promoter metal component be selected from Ti, Zr, W or One or more in Mn, on the basis of catalyst, the content of the first adjuvant component counted with oxide is as below 6 weight %.

8. the catalyst according to claim 1 or 6, it is characterised in that in the catalyst containing selected from Ru, Rh, Pd, The second adjuvant component of one or more in Os, Ir, Pt, Ag or Au, the second auxiliary agent group on the basis of catalyst, in terms of element The content divided is below 0.5 weight %.

9. catalyst according to claim 8, it is characterised in that second adjuvant component is in Ru, Pt or Pd One or more, on the basis of catalyst, the content of the second adjuvant component in terms of element is below 0.3 weight %.

10. the preparation method of catalyst according to claim 1, including preparing carrier and supported active metals on this carrier Component of iron, wherein, the preparation of the carrier is included the hydrated alumina PA and PB containing boehmite with a kind of containing plan The modifier PC mixing of the hydrated alumina of boehmite, molding, drying roasting, it is wherein, described containing boehmite The pore volume of hydrated alumina PA is 0.75-1 ml/g, and specific surface is 200-450 rice²/ gram, most probable bore dia 3-10nm；Institute The pore volume for stating the hydrated alumina PB containing boehmite is 0.9-1.4 ml/g, and specific surface is 100-350 rice²/ gram, most Can several bore dias more than 10 to less than or equal to 30nm, the Mixing ratio by weight of described PA, PB and PC is 20-60：20-50：5-50, PC κ values be the κ=DI 0 to less than or equal to 0.9₂/DI₁, DI₁For the sour peptization index of PC hydrated aluminas before modified, DI₂ For the sour peptization index of the PC.

11. methods according to claim 10, it is characterised in that the Mixing ratio by weight of described PA, PB and PC is 30-50： 35-50：10-30；The κ values of the PC are 0 to less than or equal to 0.6.

12. methods according to claim 10 or 11, it is characterised in that the hydrated alumina containing boehmite The pore volume of PA is 0.80-0.95 ml/g, and specific surface is 200-400 rice²/ gram, most probable bore dia 5-10nm；It is described containing The pore volume of the hydrated alumina PB of boehmite is 0.95-1.3 ml/g, and specific surface is 120-300 rice²/ gram, most probable Bore dia is more than 10 to less than or equal to 25nm.

13. methods according to claim 10 or 11 any one, it is characterised in that granules of the PC for 80-300 mesh Thing.

14. methods according to claim 13, it is characterised in that particulate matters of the PC for 100-200 mesh.

15. methods according to claim 10, it is characterised in that the condition of the drying includes：Temperature is 40-350 DEG C, Time is 1-24 hours, and the condition of the roasting includes：Temperature is that the time is that 1-8 is little more than 500 to less than or equal to 1200 DEG C When.

16. methods according to claim 15, it is characterised in that the condition of the drying includes：Temperature is 100-200 DEG C, the time is 2-12 hours, and the condition of the roasting includes：Temperature is that to less than or equal to 1000 DEG C, roasting time is more than 800 2-6 hours.

17. methods according to claim 10, it is characterised in that the hydrated alumina containing boehmite is modified as One of method of PC is, by the hydrated alumina molding containing boehmite, drying, to enter its all or part afterwards Row grinding, screening, the condition of the drying include：Temperature is 40-350 DEG C, and the time is 1-24 hours；The two of method are by method One of the article shaped roasting that obtains, sintering temperature is that roasting time is 1-8 hours, afterwards more than 350 to less than or equal to 1400 DEG C Its all or part is ground, is sieved；The three of method are that the hydrated alumina containing boehmite is dodged dry, dodge dry temperature Degree is that flash-off time is 0.05-1 hours more than 150 to less than or equal to 1400 DEG C；The four of method be by one of method, method it Two and method three modifiers for obtaining in several be mixed to get.

18. methods according to claim 17, it is characterised in that the condition of the drying in one of methods described includes：Temperature Spend for 100-200 DEG C, the time is 2-12 hours；The dry temperature of sudden strain of a muscle in the three of method is 200-1000 DEG C, and flash-off time is 0.1- 0.5 hour.

19. methods according to claim 17, it is characterised in that the PC is the hydrated alumina containing boehmite Modifier in 80-300 mesh particulate matter.

20. methods according to claim 19, it is characterised in that the PC is the hydrated alumina containing boehmite Modifier in 100-200 mesh particulate matter.

21. methods according to claim 10, it is characterised in that the side in supported on carriers active metal component ferrum Method is infusion process, is counted by oxide and on the basis of catalyst, and described dipping makes active metal component in the catalyst Content is 5-70 weight %.

22. methods according to claim 21, it is characterised in that counted by oxide and on the basis of catalyst, it is described It is 10-50 weight % that dipping makes the content of active metal component in the catalyst.

23. methods according to claim 22, it is characterised in that counted by oxide and on the basis of catalyst, it is described Dipping make active metal component in the catalyst content be 12-30 weight %.

24. methods according to claim 10, it is characterised in that methods described include introduce selected from Cu, Mo, Ta, W, The step of one or more in Zr, Ti, REO, Re, Mn, V or K the first promoter metal component, urge in terms of oxide and with described On the basis of agent, the introduction volume of the promoter metal component is less than 10 weight %.

25. methods according to claim 24, it is characterised in that the first promoter metal component be selected from Ti, Zr, W or One or more in Mn, are counted by oxide and on the basis of the catalyst, the introduction volume of the first promoter metal component Less than 6 weight %.

26. methods according to claim 10 or 24, it is characterised in that methods described include introduce selected from Ru, Rh, The step of one or more in Pd, Os, Ir, Pt, Ag or Au the second promoter metal component, in terms of element and with the catalyst On the basis of, the introduction volume of the second promoter metal component is less than 0.5 weight %.

27. methods according to claim 26, it is characterised in that the second promoter metal component is selected from Ru, Pt or Pd In one or more, counted by element and on the basis of the catalyst, the introduction volume of the second promoter metal component does not surpass Cross 0.3 weight %.

A kind of 28. Fischer-Tropsch synthesis methods, be included under the conditions of Fischer-Tropsch synthesis by the mixture of carbon monoxide and hydrogen with urge Agent haptoreaction, it is characterised in that the catalyst is the catalyst described in aforementioned any one of claim 1-9.