Hollow microsphere catalyst as well as preparation method and application thereof

Abstract

The invention discloses a hollow microsphere catalyst and a preparation method and application thereof, the catalyst comprises a carrier and an active component, the carrier contains an aluminum oxide and a titanium nitride, the active component is a composition with the following general formula: Fe100CoaMbOx, M is selected from at least one of alkali metals, a is 3-30, b is 0.7-15, and x is 1-10. X is the total number of oxygen atoms required for meeting the valence of each element in the catalyst. The catalyst is of a hollow structure and has the advantages of being good in heat dissipation effect, high in CO conversion rate and high in olefin selectivity when applied to direct preparation of olefin from synthesis gas.

Description

Technical Field

[0001] The present invention belongs to the field of hollow microsphere catalysts, and particularly relates to a hollow microsphere catalyst, a preparation method thereof and an application thereof. Background Art

[0002] The Fischer-Tropsch synthesis process for catalytic synthesis of organic hydrocarbons from syngas is an important route for indirect coal liquefaction. Commonly used Fischer-Tropsch catalysts include iron-based catalysts and cobalt-based catalysts. Iron-based catalysts are generally prepared by precipitation method (precipitation catalyst), sintering method (sintering catalyst) and oxide mixing method (molten iron catalyst). According to different preparation methods and heavy process conditions used, iron-based catalysts can be used to produce both low-carbon light hydrocarbons and high-carbon chain saturated hydrocarbons; cobalt-based catalysts are mostly supported type, and the impregnation method is mostly used in the preparation method. The main active element cobalt is dispersed on the surface of the carrier and is mostly used for the production of saturated heavy hydrocarbons. For example, Patent CN110252358A and Patent CN106582890B respectively introduce a supported cobalt-based catalyst prepared by the impregnation method for the production of heavy hydrocarbons. For cobalt catalysts, the active phase is generally considered to be the metallic elemental phase reduced by hydrogen. During the Fischer-Tropsch synthesis process, it is necessary to pay attention to controlling the reaction conditions not to exceed 280 °C to avoid deactivation of the catalyst caused by the carbonization of cobalt.

[0003] Whether it is iron-based catalytic Fischer-Tropsch synthesis or cobalt-based catalytic Fischer-Tropsch synthesis, there is a problem that due to the Fischer-Tropsch synthesis, especially high-temperature Fischer-Tropsch is a strong exothermic process, heat removal is difficult, temperature runaway is easy, and the catalyst is prone to deactivation. Summary of the Invention

[0004] In order to overcome the problems existing in the prior art, the present invention provides a hollow microsphere catalyst, a preparation method thereof and an application thereof. The catalyst comprises a carrier and an active component. The carrier comprises alumina and titanium nitride. The active component comprises a composition with the following general formula: Fe 100 Co a M b O x , wherein M is selected from at least one of alkali metals; the catalyst is a hollow structure, and the catalyst has the advantages of good heat dissipation effect, high CO conversion rate and high olefin selectivity when applied to the direct synthesis of olefins from syngas.

[0005] One of the purposes of the present invention is to provide a hollow microsphere catalyst, which comprises a carrier and an active component. The carrier comprises alumina and titanium nitride. The active component comprises a composition with the following general formula: Fe 100 Co a M b O x, wherein M is selected from at least one of alkali metals, a = 3 - 30, b = 0.7 - 15, and x is the total number of oxygen atoms required to satisfy the valences of the various elements in the catalyst.

[0006] Preferably, the catalyst is a mixture of a carrier and an active component.

[0007] In a preferred embodiment, the alkali metal is selected from at least one of sodium, potassium, and rubidium.

[0008] In a preferred embodiment, a = 5 - 20, such as 5, 8, 10, 12, 15, 18, or 20; and / or, b = 1 - 10, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0009] In a preferred embodiment, in the monolithic catalyst, the molar ratio of aluminum element in the alumina to titanium element in the titanium nitride is 100:(2 - 20), such as 100:2, 100:4, 100:6, 100:8, 100:10, 100:12, 100:14, 100:16, 100:18, or 100:20.

[0010] In a further preferred embodiment, on the surface of the catalyst (characterized by elemental analysis of the catalyst surface), the molar ratio of aluminum element in the alumina to titanium element in the titanium nitride is 100:(22 - 40), such as 100:22, 100:25, 100:28, 100:30, 100:32, 100:35, 100:38, or 100:40.

[0011] In a preferred embodiment, based on 100 wt% of the total weight of the catalyst, the carrier accounts for 20 - 80 wt%, and the active component accounts for 20 - 80 wt%.

[0012] For example, based on 100 wt% of the total weight of the catalyst, the carrier accounts for 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, or 80 wt%, and the active component accounts for 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, or 80 wt%.

[0013] In a further preferred embodiment, based on 100 wt% of the total weight of the catalyst, the carrier accounts for 40 - 60 wt%, and the active component accounts for 40 - 60 wt%.

[0014] In a preferred embodiment, the interior of the catalyst is hollow, preferably the wall thickness is 1 / 4 - 3 / 4 of the radius of the catalyst microsphere particles, preferably 1 / 3 - 2 / 3.

[0015] In a further preferred embodiment, the average particle size of the catalyst is 30 to 200 μm, preferably 50 to 130 μm.

[0016] A second object of the present invention is to provide a method for preparing a hollow microsphere catalyst, preferably for preparing the hollow microsphere catalyst described in the first object of the present invention. Among them, the preparation method includes: (1) separately preparing an aqueous solution of a soluble iron salt, an aqueous solution of a soluble cobalt salt, and an aqueous solution of an alkali metal compound; (2) mixing the aqueous solution of the soluble iron salt with a precipitant and filtering to obtain a precipitate; (3) mixing and slurrying the aqueous solution of the soluble cobalt salt with an alumina sol, titanium nitride powder, and the precipitate, and adjusting the pH to obtain slurry I; (4) adding the aqueous solution of the alkali metal compound to slurry I and continuing to slurry to obtain slurry II; (5) spray-drying and calcining slurry II to obtain the hollow microsphere catalyst.

[0017] In a preferred embodiment, the titanium nitride is selected from titanium nitride powders with a size of 5 to 100 nm, preferably 10 to 50 nm.

[0018] In a preferred embodiment, the alkali metal compound is selected from at least one of alkali metal nitrate compounds, hydrochloric acid compounds, sulfuric acid compounds, and hydroxides. Preferably, the alkali metal is selected from at least one of sodium, potassium, and rubidium; and / or, the soluble iron salt is selected from at least one of iron nitrate, iron chloride, and iron sulfate; and / or, the soluble cobalt salt is selected from at least one of cobalt nitrate, cobalt chloride, and cobalt sulfate.

[0019] In a preferred embodiment, the molar ratio of iron element in the soluble iron salt to cobalt element in the soluble cobalt salt is 100:(3 - 30), preferably 100:(5 - 20), such as 100:5, 100:8, 100:10, 100:12, 100:15, 100:18, or 100:20.

[0020] In a further preferred embodiment, the molar ratio of iron element in the soluble iron salt to alkali metal element in the alkali metal compound is 100:(0.7 - 15), preferably 100:(1 - 10), such as 100:1, 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9, or 100:10.

[0021] In a preferred embodiment, the molar ratio of aluminum element in the alumina sol to titanium element in the titanium nitride is 100:(2 - 20).

[0022] In a preferred embodiment, based on the total weight of the oxide corresponding to the soluble iron salt, the oxide corresponding to the soluble cobalt salt, the oxide corresponding to the alkali metal compound, and alumina in the alumina sol and titanium nitride powder being 100 wt%, wherein: the total amount of alumina in the alumina sol and titanium nitride powder is 20 - 80 wt%, preferably 40 - 60 wt%; the total amount of the oxide corresponding to the soluble iron salt, the oxide corresponding to the soluble cobalt salt, and the oxide corresponding to the alkali metal compound is 20 - 80 wt%, preferably 40 - 60 wt%. Among them, the amount of the soluble iron salt is based on the weight of its oxide, the amount of the soluble cobalt salt is based on the weight of its oxide, the amount of the alkali metal compound is based on the weight of its oxide, and the weight of the alumina sol is based on the weight of alumina therein.

[0023] In a preferred embodiment, the precipitant is selected from basic precipitants, preferably at least one of ammonia water, potassium carbonate, and sodium hydroxide.

[0024] Among them, the amount of the precipitant is such that it can ensure complete precipitation of iron ions.

[0025] In a preferred embodiment, in step (3), the pH is adjusted to 1 - 5, such as 1, 2, 3, 4, or 5.

[0026] In a preferred embodiment, in step (4), the solid content in the slurry II is 10 - 50 wt%, preferably 15 - 45 wt%, such as 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, or 45 wt%.

[0027] In a preferred embodiment, the spray drying is carried out in the presence of a hot air medium, and the hot air medium is a mixture of air and an inert gas. Preferably, the volume ratio of the air to the inert gas is 1:(2 - 10), preferably 1:(3 - 8), such as 1:3, 1:4, 1:5, 1:6, 1:7, or 1:8.

[0028] In a further preferred embodiment, the spray drying is carried out in a spray dryer, and the inlet temperature of the spray dryer is 300 - 400 °C, and the outlet temperature is 150 - 250 °C.

[0029] For example, the inlet temperature of the spray dryer is 300 °C, 320 °C, 340 °C, 360 °C, 380 °C, or 400 °C, and the outlet temperature is 150 °C, 160 °C, 180 °C, 200 °C, 220 °C, 240 °C, or 250 °C.

[0030] In a preferred embodiment, the calcination includes primary calcination and secondary calcination. The primary calcination is carried out in an air atmosphere, and the secondary calcination is carried out in a protective atmosphere. The protective atmosphere is selected from at least one of nitrogen and inert gases, preferably nitrogen and / or helium.

[0031] In a further preferred embodiment, the conditions for the primary calcination include: a temperature of 350 to 500 °C and a time of 0.5 to 5 h; and / or, the conditions for the secondary calcination include: a temperature of 550 to 750 °C and a time of 0.5 to 5 h.

[0032] For example, the conditions for the primary calcination include: a temperature of 350 °C, 360 °C, 380 °C, 400 °C, 420 °C, 440 °C, 460 °C, 480 °C or 500 °C and a time of 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h or 5 h; and / or, the conditions for the secondary calcination include: a temperature of 550 °C, 560 °C, 580 °C, 600 °C, 620 °C, 640 °C, 660 °C, 680 °C, 700 °C, 720 °C, 740 °C or 750 °C and a time of 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h or 5 h.

[0033] A third object of the present invention is to provide a catalyst obtained by using the preparation method described in the second object of the present invention.

[0034] A fourth object of the present invention is to provide the use of the catalyst described in the first object of the present invention or the catalyst obtained by using the preparation method described in the second object of the present invention in the reaction of synthesizing syngas to produce light olefins.

[0035] Wherein, the syngas is a mixture of CO and hydrogen. Preferably, the volume ratio of CO to H2 is 1:(2.5 to 4.5), such as 1:2.5, 1:3, 1:3.5, 1:4 or 1:4.5.

[0036] In the ranges disclosed in the present invention, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein. In the following text, in principle, the various technical solutions can be combined with each other to obtain new technical solutions, and this should also be regarded as specifically disclosed herein.

[0037] Compared with the prior art, the present invention has the following beneficial effects: The catalyst has a hollow structure, and when applied to the direct synthesis of olefins from syngas, the catalyst has the advantages of good heat dissipation effect, high CO conversion rate, and high olefin selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The SEM diagram of the catalyst obtained in Example 1 is shown. DETAILED DESCRIPTION OF THE INVENTION

[0039] The present invention will be specifically described below in conjunction with specific embodiments. It is necessary to point out here that the following embodiments are only used for further illustration of the present invention and cannot be understood as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention still fall within the protection scope of the present invention.

[0040] In addition, it should be noted that the various specific technical features described in the following detailed embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0041] In addition, any combination can be made between various different embodiments of the present invention as long as it does not violate the idea of the present invention. The technical solutions formed thereby belong to a part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0042] If there is no special limitation on the raw materials used in the examples and comparative examples, they are all disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0043]

Example 1

[0044] Dissolve 1 mol of Fe(NO3)3·9H2O in water to prepare a 0.5 mol / L Fe element solution; after co-currently flowing it with a 10% ammonia water solution containing 3.5 mol of NH3 and filtering, obtain fresh Fe(OH)3 precipitate; dissolve 0.1 mol of Co(NO3)2·6H2O in water to prepare a 35 wt% Co element solution; take a 35 wt% aluminum sol containing 79.6 g of Al2O3 and 9.7 g of 20 nm nano TiN powder, mix them with the Co solution and the Fe(OH)3 precipitate, and beat them in a water bath at 80 °C, while adjusting the pH value of the slurry to 5 with 25 wt% ammonia water; dissolve 0.05 mol of NaOH in water to prepare a 30 wt% Na element solution, add it to the above slurry, continue to beat it in a water bath at 80 °C for 0.5 h, and at the same time adjust the solid content of the slurry to 35 wt%; spray-dry the slurry to form a shape, the inlet temperature of the spray machine is 320 °C, the outlet temperature is 190 °C, and the hot air medium is a mixed gas of air: nitrogen = 1:5; then carry out roasting, first roast in an air atmosphere at 400 °C for 1 h, and then roast in a nitrogen atmosphere at 600 °C for 1 h to obtain a catalyst, and its composition is: 50 wt% Fe 100 Co 10 Na5O x +50 wt% Al 100 O 150 Ti 10 N 10 ; The SEM photo of the catalyst is as shown in the figure. After XPS detection, the molar ratio of Al to Ti on the surface of the prepared catalyst is 100:30. In the whole catalyst, the molar ratio of aluminum element in the aluminum oxide to titanium element in the titanium nitride of the catalyst is 100:10. The obtained catalyst is of a hollow structure, and the average wall thickness is 3 / 8 of the average radius of the catalyst microsphere particles.

[0045] The catalyst is reduced by the in-situ reduction method. After the reduction is completed, directly switch the process conditions to the synthesis reaction conditions in the reactor used for reduction to start the reaction;

[0046] Reactor specifications: Millimeter fluidized bed reactor;

[0047] Catalyst loading: 50 grams;

[0048] The reduction conditions are: temperature 450 °C

[0049] Pressure 1.0 MPa

[0050] Catalyst load (actual reaction volume space velocity) 1000 h-1 -1

[0051] Reducing gas H2

[0052] Reduction time: 12 hours

[0053] The synthesis reaction conditions are as follows: reaction temperature 370°C

[0054] Reaction pressure 1.0 MPa

[0055] Catalyst loading (actual reaction volume space velocity) 1100 h⁻¹ -1

[0056] Raw material ratio (mol): H₂ / CO = 3 / 1

[0057] The initial activity calibration of the catalyst was carried out at 100 h of the synthesis reaction. The catalyst can maintain stable operation for 2000 h in a long cycle without any abnormalities found.

[0058]

Example 2

[0059] Dissolve 1 mol of Fe(NO₃)₃·9H₂O in water to prepare a 0.5 mol / L Fe element solution; after co-currently flowing it with a 10% ammonia water solution containing 3.5 mol NH₃ and filtering, a fresh Fe(OH)₃ precipitate is obtained; dissolve 0.05 mol of Co(NO₃)₂·6H₂O in water to prepare a 35 wt% Co element solution; take a 35 wt% aluminum sol containing 106.4 g of Al₂O₃ and 21.3 g of 30 nm nano-sized TiN powder, mix them with the Co solution and the Fe(OH)₃ precipitate, and beat the pulp in a 90°C water bath. At the same time, adjust the pH value of the pulp to 5 with 15 wt% ammonia water; dissolve 0.1 mol of KOH in water to prepare a 30 wt% Na element solution, add it to the above pulp, continue to beat the pulp in an 80°C water bath for 0.5 h, and at the same time adjust the solid content of the pulp to 35 wt%; spray-dry the pulp to form a shape. The inlet temperature of the spray dryer is 320°C, the outlet temperature is 190°C, and the hot air medium is a mixture of air: nitrogen = 1:3; then carry out roasting, first roast in an air atmosphere at 500°C for 1 h, and then roast in a nitrogen atmosphere at 550°C for 5 h to obtain a catalyst, and its composition is: 40 wt% Fe 100 Co₅K 10 O x + 60 wt% Al 100 O 150 Ti 20 N 20 ; Through XPS detection, the molar ratio of surface Al to Ti of the prepared catalyst is 100:39. The obtained catalyst is a hollow structure, and the average wall thickness is 1 / 2 of the average radius of the catalyst microsphere particles.

[0060] The catalyst is reduced by the in-situ reduction method. After the reduction is completed, directly switch the process conditions to the synthesis reaction conditions in the reactor used for reduction and start the reaction;

[0061] Reactor specifications: Millimeter fluidized bed reactor;

[0062] Catalyst loading: 50 g;

[0063] Reduction conditions are: temperature 450 °C

[0064] Pressure 1.0 MPa

[0065] Catalyst load (actual reaction volume space velocity) 1000 h -1

[0066] Reducing gas H2

[0067] Reduction time 12 h

[0068] Synthesis reaction conditions are: reaction temperature 370 °C

[0069] Reaction pressure 1.0 MPa

[0070] Catalyst load (actual reaction volume space velocity) 1100 h -1

[0071] Raw material ratio (mol) H2 / CO = 3 / 1

[0072] The initial activity of the catalyst is calibrated at 100 h of the synthesis reaction.

[0073]

Example 3

[0074] Dissolve 1 mol of Fe(NO3)3·9H2O in water to prepare a 0.5 mol / L Fe element solution; after co-flowing it with a 10% ammonia water solution containing 3.5 mol NH3 and filtering, a fresh Fe(OH)3 precipitate is obtained; dissolve 0.2 mol of Co(NO3)2·6H2O in water to prepare a 35 wt% Co element solution; take a 35 wt% aluminum sol containing 86.1 g Al2O3 and 10.4 g of 15 nm nano TiN powder and mix them with the Co solution and the Fe(OH)3 precipitate, and beat the mixture in a water bath at 80 °C, while adjusting the pH value of the slurry to 5 with 25 wt% ammonia water; dissolve 0.05 mol of NaOH in water to prepare a 30 wt% Na element solution, add it to the above slurry and continue to beat in a water bath at 80 °C for 0.5 h, while adjusting the solid content of the slurry to 35 wt%; spray-dry the slurry to form a shape, the inlet temperature of the spray dryer is 320 °C, the outlet temperature is 190 °C, and the hot air medium is a mixture of air: nitrogen = 1:5; then carry out calcination, first calcine in air atmosphere at 400 °C for 1 h, and then calcine in nitrogen atmosphere at 600 °C for 1 h to obtain a catalyst, and its composition is: 50 wt% Fe 100 Co 20 Na5Ox +50 wt% Al 100 O 150 Ti 10 N 10 ; By XPS detection, the molar ratio of surface Al to Ti of the prepared catalyst is 100:28. The obtained catalyst has a hollow structure, and the average wall thickness is 5 / 8 of the average radius of the catalyst microsphere particles.

[0075] The catalyst is reduced by in-situ reduction method. After the reduction is completed, the process conditions are directly switched to the synthesis reaction conditions in the reactor used for reduction to start the reaction;

[0076] Reactor specifications: Millimeter fluidized bed reactor;

[0077] Catalyst loading: 50 g;

[0078] Reduction conditions are: temperature 450 °C

[0079] Pressure 1.0 MPa

[0080] Catalyst load (actual volumetric space velocity of the reaction) 1000 h -1

[0081] Reducing gas H2

[0082] Reduction time 12 h

[0083] Synthesis reaction conditions are: reaction temperature 370 °C

[0084] Reaction pressure 1.0 MPa

[0085] Catalyst load (actual volumetric space velocity of the reaction) 1100 h -1

[0086] Raw material ratio (molar) H2 / CO = 3 / 1

[0087] The initial activity of the catalyst is calibrated at 100 h of the synthesis reaction.

[0088]

Example 4

[0089] Dissolve 1 mol of Fe(NO3)3·9H2O in water to prepare a 0.5 mol / L Fe element solution; after co-currently flowing it with a 10% ammonia water solution containing 3.5 mol of NH3 and filtering, a fresh Fe(OH)3 precipitate is obtained; dissolve 0.1 mol of Co(NO3)2·6H2O in water to prepare a 35 wt% Co element solution; take a 35 wt% aluminum sol containing 49.5 g of Al2O3 and 9.0 g of 20 nm nano TiN powder, mix them with the Co solution and the Fe(OH)3 precipitate, and beat the pulp in a water bath at 80 °C. At the same time, adjust the pH value of the pulp to 5 with 25 wt% ammonia water; dissolve 0.01 mol of NaOH in water to prepare a 30 wt% Na element solution, add it to the above-mentioned pulp, continue to beat the pulp in a water bath at 80 °C for 0.5 h, and at the same time adjust the solid content of the pulp to 35 wt%; spray-dry the pulp to form a shape. The inlet temperature of the spray dryer is 300 °C, the outlet temperature is 150 °C, and the hot air medium is a mixed gas of air: nitrogen = 1:3; then carry out roasting, first roast in an air atmosphere at 350 °C for 5 h, and then roast in a nitrogen atmosphere at 700 °C for 0.6 h to obtain a catalyst, and its composition is: 60 wt% Fe 100 Co 10 Na1O x +40 wt% Al 100 O 150 Ti 15 N 15 ; After XPS detection, the molar ratio of surface Al to Ti of the prepared catalyst is 100:32. The obtained catalyst has a hollow structure, and the average wall thickness is 1 / 3 of the average radius of the catalyst microsphere particles.

[0090] The catalyst is reduced by the in-situ reduction method. After the reduction is completed, directly switch the process conditions to the synthesis reaction conditions in the reactor used for reduction to start the reaction;

[0091] Reactor specifications: Millimeter fluidized bed reactor;

[0092] Catalyst loading: 50 grams;

[0093] The reduction conditions are: temperature 450 °C

[0094] Pressure 1.0 MPa

[0095] Catalyst load (actual reaction volume space velocity) 1000 h-1 -1

[0096] Reducing gas H2

[0097] Reduction time 12 hours

[0098] The synthesis reaction conditions are: reaction temperature 370 °C

[0099] Reaction pressure: 1.0 MPa

[0100] Catalyst loading (actual reaction volume space velocity): 1100 h⁻¹ -1

[0101] Raw material ratio (mole): H₂ / CO = 3 / 1

[0102] The initial activity calibration of the catalyst was carried out for 100 h in the synthesis reaction.

[0103]

Example 5

[0104] Dissolve 1 mol of Fe(NO₃)₃·9H₂O in water to prepare a 0.5 mol / L Fe element solution; after co-currently flowing it with a 10% ammonia water solution containing 3.5 mol of NH₃ and filtering, a fresh Fe(OH)₃ precipitate is obtained; dissolve 0.1 mol of Co(NO₃)₂·6H₂O in water to prepare a 35 wt% Co element solution; take a 35 wt% aluminum sol containing 79.6 g of Al₂O₃ and 9.7 g of 20 nm nano TiN powder, mix them with the Co solution and the Fe(OH)₃ precipitate, and pulp them in a water bath at 80 °C. At the same time, adjust the pH value of the slurry to 5 with 25 wt% ammonia water; dissolve 0.017 mol of RbOH in water to prepare a 30 wt% Rb element solution, add it to the above slurry, continue to pulp in a water bath at 80 °C for 0.5 h, and at the same time adjust the solid content of the slurry to 35 wt%; spray-dry the slurry to form a shape, the inlet temperature of the spray dryer is 350 °C, the outlet temperature is 200 °C, and the hot air medium is a mixture of air: nitrogen = 1:8; then carry out calcination, first calcine in air atmosphere at 400 °C for 1 h, and then calcine in nitrogen atmosphere at 680 °C for 3 h to obtain a catalyst, and its composition is: 50 wt% Fe 100 Co 10 Rb 1.7 O x + 50 wt% Al 100 O 150 Ti 10 N 10 ; by XPS detection, the molar ratio of surface Al to Ti of the prepared catalyst is 100:26. The obtained catalyst has a hollow structure, and the average wall thickness is 2 / 3 of the average radius of the catalyst microsphere particles.

[0105] The catalyst was reduced by in-situ reduction method. After the reduction was completed, the process conditions were directly switched to the synthesis reaction conditions in the reactor used for reduction to start the reaction;

[0106] Reactor specifications: Millimeter fluidized bed reactor;

[0107] Catalyst loading: 50 g;

[0108] The reduction conditions are: temperature 450 °C

[0109] pressure 1.0 MPa

[0110] Catalyst load (actual reaction volume space velocity) 1000 h-1 -1

[0111] Reducing gas H2

[0112] Reduction time 12 h

[0113] The synthesis reaction conditions are: reaction temperature 370 °C

[0114] reaction pressure 1.0 Mpa

[0115] Catalyst load (actual reaction volume space velocity) 1100 h-1 -1

[0116] Raw material ratio (mol) H2 / CO = 3 / 1

[0117] The initial activity of the catalyst is calibrated at 100 h of the synthesis reaction.

[0118]

Example 6

[0119] Dissolve 1 mol of Fe(NO3)3·9H2O in water to prepare a 0.5 mol / L Fe element solution; after co-currently flowing it with a 10% ammonia water solution containing 3.5 mol NH3 and filtering, a fresh Fe(OH)3 precipitate is obtained; dissolve 0.1 mol of Co(NO3)2·6H2O in water to prepare a 35 wt% Co element solution; take a 35 wt% aluminum sol containing 79.6 g of Al2O3 and 9.7 g of 20 nm nano TiN powder, mix them with the Co solution and the Fe(OH)3 precipitate, and make a slurry in a water bath at 80 °C, while adjusting the pH value of the slurry to 5 with 25 wt% ammonia water; dissolve 0.05 mol of NaOH in water to prepare a 30 wt% Na element solution, add it to the above slurry and continue to make a slurry in a water bath at 80 °C for 0.5 h, while adjusting the solid content of the slurry to 35 wt%; spray-dry the slurry to form a shape, the inlet temperature of the sprayer is 300 °C, the outlet temperature is 180 °C, and the hot air medium is a mixture of air: nitrogen = 1:4; then carry out calcination, first calcine in air atmosphere at 450 °C for 3 h, and then calcine in nitrogen atmosphere at 700 °C for 0.5 h to obtain a catalyst, and its composition is: 50 wt% Fe 100 Co 10 Na5O x +50 wt% Al 100 O 150 Ti 10 N10 ; The catalyst is detected by XPS, and the molar ratio of Al to Ti on the surface of the prepared catalyst is 100:28. In the whole catalyst, the molar ratio of aluminum element in the aluminum oxide to titanium element in the titanium nitride is 100:10. The obtained catalyst has a hollow structure, and the average wall thickness is 7 / 16 of the average radius of the catalyst microsphere particles.

[0120] The catalyst is reduced by the in-situ reduction method. After the reduction is completed, the process conditions are directly switched to the synthesis reaction conditions in the reactor used for reduction to start the reaction;

[0121] Reactor specifications: Millimeter fluidized bed reactor;

[0122] Catalyst loading: 50 grams;

[0123] The reduction conditions are: temperature 450 °C

[0124] Pressure 1.0 MPa

[0125] Catalyst load (actual reaction volume space velocity) 1000 h-1 -1

[0126] Reducing gas H2

[0127] Reduction time 12 hours

[0128] The synthesis reaction conditions are: reaction temperature 370 °C

[0129] Reaction pressure 1.0 MPa

[0130] Catalyst load (actual reaction volume space velocity) 1100 h-1 -1

[0131] Raw material ratio (molar) H2 / CO = 3 / 1

[0132] The initial activity calibration of the catalyst is carried out at 100 h of the synthesis reaction

[0133]

Example 7

[0134] Dissolve 1 mol of Fe(NO3)3·9H2O in water to prepare a 0.5 mol / L Fe element solution; after countercurrent flow with a 10% ammonia water solution containing 3.5 mol of NH3, filter to obtain fresh Fe(OH)3 precipitate; dissolve 0.1 mol of Co(NO3)2·6H2O in water to prepare a 35 wt% Co element solution; take a 35 wt% aluminum sol containing 79.6 g of Al2O3 and 9.7 g of 20 nm nano TiN powder, mix with the Co solution and the Fe(OH)3 precipitate, and beat the pulp in a water bath at 80 °C. At the same time, adjust the pH value of the pulp to 5 with 25 wt% ammonia water; dissolve 0.05 mol of NaOH in water to prepare a 30 wt% Na element solution, add it to the above-mentioned pulp, continue to beat the pulp in a water bath at 80 °C for 0.5 h, and at the same time adjust the solid content of the pulp to 35 wt%; spray-dry the pulp to form a shape, the inlet temperature of the spray dryer is 350 °C, the outlet temperature is 200 °C, and the hot air medium is a mixture of air: nitrogen = 1:7; then carry out roasting, first roast in air atmosphere at 420 °C for 2 h, and then roast in nitrogen atmosphere at 580 °C for 4 h to obtain a catalyst, and its composition is: 50 wt% Fe 100 Co 10 Na5O x +50 wt% Al 100 O 150 Ti 10 N 10 ; The surface Al / Ti molar ratio of the prepared catalyst is 100:32 as detected by XPS. In the whole catalyst, the molar ratio of aluminum element in the aluminum oxide to titanium element in the titanium nitride is 100:10. The obtained catalyst is a hollow structure, and the average wall thickness is 5 / 16 of the average radius of the catalyst microsphere particles.

[0135] The catalyst is reduced by in-situ reduction method. After the reduction is completed, directly switch the process conditions to synthesis reaction conditions in the reactor used for reduction to start the reaction;

[0136] Reactor specifications: Millimeter fluidized bed reactor;

[0137] Catalyst loading: 50 g;

[0138] Reduction conditions are: temperature 450 °C

[0139] Pressure 1.0 MPa

[0140] Catalyst load (actual volume space velocity of reaction) 1000 h-1 -1

[0141] Reducing gas H2

[0142] Reduction time 12 h

[0143] The synthesis reaction conditions are as follows: reaction temperature 370 °C

[0144] Reaction pressure 1.0 MPa

[0145] Catalyst loading (actual reaction volume space velocity) 1100 h-1 -1

[0146] Raw material ratio (mole) H2 / CO = 3 / 1

[0147] The initial activity calibration of the catalyst is carried out at 100 h of the synthesis reaction.

[0148]

Comparative Example 1

[0149] Dissolve 1 mol of Fe(NO3)3·9H2O in water to prepare a 0.5 mol / L Fe element solution; after co-currently flowing it with a 10% ammonia water solution containing 3.5 mol NH3 and then filtering, fresh Fe(OH)3 precipitate is obtained; dissolve 0.1 mol of Co(NO3)2·6H2O in water to prepare a 35 wt% Co element solution; take a 35 wt% aluminum sol containing 79.6 g Al2O3 and 9.7 g of 20 nm nano TiN powder, mix them with the Co solution and the Fe(OH)3 precipitate, and beat the pulp in a water bath at 80 °C. At the same time, adjust the pH value of the pulp to 5 with 25 wt% ammonia water; dissolve 0.05 mol of NaOH in water to prepare a 30 wt% Na element solution, add it to the above pulp and continue to beat the pulp in a water bath at 80 °C for 0.5 h, and at the same time adjust the solid content of the pulp to 35 wt%; spray-dry the pulp to form a shape, the inlet temperature of the spray dryer is 320 °C, the outlet temperature is 190 °C, and the hot air medium is air, and then carry out roasting. First, roast in air atmosphere at 400 °C for 1 h, and then roast in nitrogen atmosphere at 600 °C for 1 h to obtain a catalyst, and its composition is: 50 wt% Fe 100 Co 10 Na5O x + 50 wt% Al 100 O 150 Ti 10 N 10 . After XPS detection, the molar ratio of surface Al to Ti of the prepared catalyst is 100:46.

[0150] The catalyst is reduced by in-situ reduction method. After the reduction is completed, directly switch the process conditions to the synthesis reaction conditions in the reactor used for reduction and start the reaction;

[0151] Reactor specifications: Millimeter fluidized bed reactor;

[0152] Catalyst loading: 50 g;

[0153] The reduction conditions are as follows: temperature 450 °C

[0154] pressure 1.0 Mpa

[0155] catalyst loading (actual volumetric space velocity of the reaction) 1000 h-1 -1

[0156] reduction gas H2

[0157] reduction time 12 h

[0158] The synthesis reaction conditions are as follows: reaction temperature 370 °C

[0159] reaction pressure 1.0 Mpa

[0160] catalyst loading (actual volumetric space velocity of the reaction) 1100 h-1 -1

[0161] raw material ratio (mole) H2 / CO = 3 / 1

[0162] The initial activity calibration of the catalyst was carried out at 100 h of the synthesis reaction, and the results are shown in Table 1 below. The results of the long-term operation of 2000 h are shown in Table 1 below.

[0163]

Comparative Example 2

[0164] Dissolve 1 mol of Fe(NO3)3·9H2O in water to prepare a 0.5 mol / L Fe element solution; after co-flowing it with a 10% ammonia water solution containing 3.5 mol NH3 and filtering, a fresh Fe(OH)3 precipitate is obtained; dissolve 0.1 mol of Co(NO3)2·6H2O in water to prepare a 35 wt% Co element solution; take a 35 wt% aluminum sol containing 79.6 g of Al2O3 and 9.7 g of 20 nm nano TiN powder and mix them with the Co solution and the Fe(OH)3 precipitate, and beat the mixture in a water bath at 80 °C, while adjusting the pH value of the slurry to 5 with 25 wt% ammonia water; dissolve 0.05 mol of NaOH in water to prepare a 30 wt% Na element solution, add it to the above slurry and continue to beat the mixture in a water bath at 80 °C for 0.5 h, while adjusting the solid content of the slurry to 35%; spray-dry the slurry to form a shape, the inlet temperature of the spray dryer is 320 °C, the outlet temperature is 190 °C, and the hot air medium is a mixture of air:nitrogen = 1:5; then carry out roasting, first roast in an air atmosphere at 400 °C for 1 h, and then roast in an air atmosphere at 600 °C for 1 h to obtain a catalyst, and its composition is: 50 wt% Fe 100 Co 10 Na5O x + 50 wt% Al 100 O 150 Ti 10 N10 As detected by XPS, the molar ratio of Al to Ti on the surface of the prepared catalyst is 100:13.

[0165] The catalyst was reduced by the in-situ reduction method. After the reduction was completed, the process conditions were directly switched to the synthesis reaction conditions in the reactor used for reduction to start the reaction;

[0166] Reactor specifications: Millimeter fluidized bed reactor;

[0167] Catalyst loading: 50 g;

[0168] The reduction conditions were: temperature 450 °C

[0169] Pressure 1.0 Mpa

[0170] Catalyst load (actual reaction volume space velocity) 1000 h -1

[0171] Reducing gas H2

[0172] Reduction time 12 h

[0173] The synthesis reaction conditions were: reaction temperature 370 °C

[0174] Reaction pressure 1.0 Mpa

[0175] Catalyst load (actual reaction volume space velocity) 1100 h -1

[0176] Raw material ratio (molar) H2 / CO = 3 / 1

[0177] The initial activity calibration of the catalyst was carried out at 100 h of the synthesis reaction, and the results are shown in Table 1 below.

[0178] Table 1:

[0179]

[0180]

[0181] In Table 1, C2 + refers to the total hydrocarbons above C2 (including olefins and alkanes), C2-C4 olefins / C2+ refers to the weight percentage of C2-C4 olefins in the total C2+ hydrocarbons in the product, C5-C12 olefins / C2+ refers to the weight percentage of C5-C12 olefins in the total C2+ hydrocarbons in the product, and C13-C20 olefins / C2+ refers to the weight percentage of C13-C20 olefins in the total C2+ hydrocarbons in the product.

[0182] As can be seen from Table 1 above, compared with Comparative Examples 1-2, the examples of the present invention have higher CO conversion rate and higher olefin selectivity. Specifically, in the examples, the CO conversion rate, C2+ selectivity, C2-C4 olefins / C2+, C5-C12 olefins / C2+, and C13-C20 olefins / C2+ are all significantly higher than those in the comparative examples.

[0183] The present invention has been described in detail above in conjunction with specific embodiments and exemplary examples, but these descriptions should not be construed as limiting the present invention. Those skilled in the art understand that without departing from the spirit and scope of the present invention, various equivalent substitutions, modifications or improvements can be made to the technical solutions and implementation manners of the present invention, and these all fall within the scope of the present invention. The protection scope of the present invention is subject to the appended claims.

Claims

1. A hollow microsphere catalyst, which comprises a carrier and an active component, wherein the carrier comprises alumina and titanium nitride, and the active component comprises a composition with the following general formula: Fe 100 Co a M b O x , wherein, M is selected from at least one of alkali metals, a = 3 - 30, b = 0.7 - 15, and x is the total number of oxygen atoms required to satisfy the valence of each element in the catalyst.

2. The hollow microsphere catalyst according to claim 1, wherein the alkali metal is selected from at least one of sodium, potassium, and rubidium; and / or, a = 5 - 20; and / or, b＝1～10。 3. The hollow microsphere catalyst according to claim 1, wherein in the overall catalyst, the molar ratio of aluminum element in the alumina to titanium element in the titanium nitride is 100:(2 - 20); and / or, on the surface of the catalyst, the molar ratio of aluminum element in the alumina to titanium element in the titanium nitride is 100:(22 - 40).

4. The hollow microsphere catalyst according to any one of claims 1 to 3, characterized in that Based on the total weight of the catalyst being 100 wt%, the carrier accounts for 20 - 80 wt%, and the active component accounts for 20 - 80 wt%; preferably, the carrier accounts for 40 - 60 wt%, and the active component accounts for 40 - 60 wt%.

5. A method for preparing a hollow microsphere catalyst, preferably for preparing the hollow microsphere catalyst according to any one of claims 1 to 4, wherein, The preparation method includes: (1) separately preparing aqueous solutions of soluble iron salt, soluble cobalt salt, and alkali metal compound; (2) mixing the aqueous solution of soluble iron salt with a precipitant to obtain a precipitate; (3) mixing and slurrying the aqueous solution of soluble cobalt salt with alumina sol, titanium nitride powder, and the precipitate, and adjusting the pH to obtain slurry I; (4) adding the aqueous solution of alkali metal compound to slurry I and continuing to slurry to obtain slurry II; (5) spray-drying and calcining slurry II to obtain the hollow microsphere catalyst.

6. The preparation method according to claim 5, wherein the alkali metal compound is selected from at least one of nitrate compounds, hydrochloride compounds, sulfate compounds, and hydroxides of alkali metals. Preferably, the alkali metal is selected from at least one of sodium, potassium, and rubidium; and / or, the soluble iron salt is selected from at least one of iron nitrate, iron chloride, and iron sulfate; and / or, the soluble cobalt salt is selected from at least one of cobalt nitrate, cobalt chloride, and cobalt sulfate; and / or, the precipitant is selected from basic precipitants, preferably at least one of ammonia water, potassium carbonate, and sodium hydroxide.

7. The preparation method according to claim 5, wherein the molar ratio of iron element in the soluble iron salt to cobalt element in the soluble cobalt salt is 100:(3 - 30), preferably 100:(5 - 20); and / or, the molar ratio of iron element in the soluble iron salt to alkali metal element in the alkali metal compound is 100:(0.7 - 15), preferably 100:(1 - 10); and / or, the molar ratio of aluminum element in the alumina sol to titanium element in the titanium nitride is 100:(2 - 20).

8. The preparation method according to claim 5, characterized in that, Based on the total weight of the oxides corresponding to soluble iron salts, the oxides corresponding to soluble cobalt salts, the oxides corresponding to alkali metal compounds, alumina in the alumina sol, and titanium nitride powder being 100 wt%, the total amount of alumina in the alumina sol and titanium nitride powder is 20 - 80 wt%, preferably 40 - 60 wt%, and the total amount of the oxides corresponding to soluble iron salts, the oxides corresponding to soluble cobalt salts, and the oxides corresponding to alkali metal compounds is 20 - 80 wt%, preferably 40 - 60 wt%.

9. The preparation method according to claim 5, wherein in step (3), the pH is adjusted to 1 - 5; and / or in step (4), the solid content in the slurry II is 10 - 50 wt%.

10. The preparation method according to claim 5, wherein the spray drying is carried out in the presence of a hot air medium, and the hot air medium is a mixture of air and an inert gas. Preferably, the volume ratio of air to the inert gas is preferably 1:(2 - 10); and / or the spray drying is carried out in a spray dryer, the inlet temperature of the spray dryer is 300 - 400 °C, and the outlet temperature is 150 - 250 °C.

11. The preparation method according to claim 5, characterized in that, The calcination includes primary calcination and secondary calcination. The primary calcination is carried out in an air atmosphere, and the secondary calcination is carried out in a protective atmosphere. The protective atmosphere is selected from at least one of nitrogen and inert gas, preferably nitrogen and / or helium; Preferably, the conditions for the primary calcination include: temperature of 350 - 500 °C and time of 0.5 - 5 h; and / or the conditions for the secondary calcination include: temperature of 550 - 750 °C and time of 0.5 - 5 h.

12. A catalyst obtained by using the preparation method according to any one of claims 5 - 11.

13. The application of the catalyst according to any one of claims 1 - 4 or the catalyst obtained by using the preparation method according to any one of claims 5 - 11 in the reaction of synthesizing syngas into lower olefins.

Images