CN111036282B - Supported catalyst, method for preparing same, and method for preparing alpha-olefin from synthesis gas - Google Patents

Abstract

The present disclosure relates to a supported catalyst, a preparation method thereof and a method for preparing alpha-olefin from synthesis gas, the catalyst comprises a carrier, and an active component and an auxiliary agent loaded on the carrier, wherein the carrier contains a manganese oxide molecular sieve OMS-1, the active component is one or more metal components selected from VIII group metals, and the auxiliary agent is one or more metal components selected from IIB group metals. Compared with the catalyst in the prior art, the supported catalyst has improved catalytic activity and target product selectivity, has the advantages of higher alpha-olefin yield and concentrated product carbon number when being used for preparing alpha-olefin from synthesis gas, and is beneficial to industrial popularization.

Description

Supported catalyst and method for preparing the same, and method for preparing alpha-olefin from synthesis gas

technical field

The present disclosure relates to a supported catalyst, a preparation method thereof, and a method for preparing alpha-olefins from synthesis gas.

Background technique

my country's energy resources are distributed in a situation of rich coal, more natural gas, and lack of oil. The indirect conversion of coal-based or natural gas into clean and efficient liquid fuels through Fischer-Tropsch (F-T) synthesis is an important aspect of rational utilization of resources and is an important way to alleviate the contradiction between oil supply and demand in my country. main technical approach. The process first converts coal or natural gas into syngas, which is then synthesized into liquid fuel through F-T. F-T synthesis technology includes two kinds of high-temperature F-T synthesis and low-temperature F-T synthesis. The operating temperature of the high-temperature F-T synthesis process is 300-350 ℃, and the operating pressure is about 1.5-2.5MPa; the operating temperature of the low-temperature F-T synthesis process is 210-250 ℃. The pressure is about 1.5-2.5MPa. The products synthesized by high temperature F-T can be processed to obtain environmentally friendly gasoline, diesel oil, solvent oil, olefins and oxygenates; the main product of low temperature F-T synthesis can be processed into special wax or by hydrocracking/isomerization to produce high-quality diesel , lubricating oil base oil, naphtha fraction is also an ideal cracking raw material. The traditional Fischer-Tropsch synthesis products mainly include linear alkanes, alkenes, aldols, and by-products water and carbon dioxide. The product composition is complex, but by adjusting the process conditions and catalyst composition, more alkenes can be produced. Linear α-olefin is an important organic raw material and intermediate, which is widely used in the production of comonomers, lubricating base oils, surfactants, polyolefin resins, plasticizers, dyes, pharmaceutical preparations, etc. Sasol Company of South Africa has built a set of production equipment for separating 1-pentene and 1-hexene from F-T synthetic products (rich in α-olefins) and successfully put into production. The alkene and 1-hexene are recovered as by-products, the industrial production cost is low, and high returns are obtained.

At present, the most widely used method for producing α-olefin is olefin oligomerization, but the production cost of this method is too high, and the linear α-olefin with odd number of carbons that also has market value cannot be produced. The cost of extracting linear 1-hexene from the crude product by the high temperature F-T Fischer-Tropsch synthesis technology of Sasol Company in South Africa is less than one third of that produced by Philips Company using the ethylene trimerization method. F-T synthesis can also obtain high value-added products such as 1-pentene and 1-heptene with odd carbon numbers. Therefore, the separation of α-olefins from Fischer-Tropsch synthesis products has important commercial value.

At present, iron-based catalysts are generally used in industry to produce olefins in slurry, fixed or fluidized bed processes. Under the low temperature F-T synthesis process conditions, the product has high content of heavy hydrocarbons and low content of olefins, which is not conducive to the production of α-olefins. South African company Sasol uses a high temperature fluidized bed process to produce gasoline and alpha-olefins. Although this process can obtain linear α-olefin with low carbon number, the carbon number distribution of the product α-olefin is too dispersed and the yield is low, which is not conducive to separation and purification.

Common iron-based F-T synthesis catalysts are mostly prepared by co-precipitation method: first, the active components are precipitated, filtered and washed, then mixed with the carrier, slurried, and finally dried and formed, which are applied to slurry bed reactors or fixed bed reactors. Precipitated iron F-T synthesis catalysts have poor mechanical stability, are easily broken during the reaction process, have serious carbon deposits, and are difficult to reduce the active components in the bulk phase. Since F-T synthesis is a strong exothermic reaction, when reacting in a fixed bed, it is difficult for the precipitated iron catalyst to take heat in the reactor, and it is easy to fly over temperature, resulting in rapid deactivation of the catalyst. The supported iron-based catalyst has good stability, uniform distribution of active components, high activity and long life.

CN102408908A discloses a solvent-phase Fischer-Tropsch synthesis method for producing linear α-olefins with various carbon numbers. Using polar solvent as reaction medium, the traditional granular Fischer-Tropsch synthesis catalyst is suspended or soaked in polar solvent phase to carry out Fischer-Tropsch synthesis reaction, since the generated hydrocarbon product is insoluble in the polar solvent and self-separates. However, the carbon number of linear α-olefins obtained by this method is too dispersed. CN103525456A discloses a method for preparing synthetic hydrocarbons from coal-to-olefins. The method uses the light oil part containing alpha-olefins and alkanes in coal-to-olefins to prepare synthetic hydrocarbon bases for high-quality lubricating oils under the action _of AlCl3 catalysts oil products. US4579986 discloses a method for preparing _C10 - _C20 olefins, converting CO and _H2 into a mixture of n-paraffins under the action of a cobalt-based catalyst, analyzing the fraction above _C20 ⁺ , and converting this fraction into a mixture containing C20+ by mild thermal cracking Hydrocarbon mixtures of C ₁₀ -C ₂₀ olefins. However, in this method, the α-olefin content is relatively low.

Therefore, it is of great practical significance to develop a catalyst that can make the α-olefin yield high and the carbon number of the product concentrated.

SUMMARY OF THE INVENTION

The purpose of the present disclosure is to provide a supported catalyst, a preparation method thereof, and a method for preparing α-olefin from synthesis gas, so as to overcome the defects of low yield of α-olefin and excessive dispersion of carbon number in the product of the existing catalyst.

In order to achieve the above object, a first aspect of the present disclosure: provide a supported catalyst, the catalyst includes a carrier, and active components and auxiliary agents supported on the carrier, the carrier contains manganese oxide molecular sieve OMS-1, The active component is one or more metal components selected from Group VIII metals, and the auxiliary agent is one or more metal components selected from Group IIB metals.

Optionally, based on the dry weight of the catalyst, the content of the carrier is 12-94% by weight, in terms of metal elements, the content of the active component is 1-70% by weight, and the content of the auxiliary agent 1 to 30% by weight.

Optionally, based on the dry weight of the catalyst, the content of the carrier is 30-91% by weight, in terms of metal elements, the content of the active component is 2-50% by weight, and the content of the auxiliary agent is 2 to 25% by weight.

Optionally, the active component is Fe component and/or Co component; the auxiliary agent is Zn component and/or Cd component.

Optionally, in terms of metal elements, the weight ratio of the active component to the auxiliary agent is 1:(0.2-5), preferably 1:(0.3-3).

The second aspect of the present disclosure provides a method for preparing the supported catalyst described in the first aspect of the present disclosure, the method comprising: supporting the active components and auxiliary agents on the carrier.

Optionally, the step of loading the active component and the auxiliary agent on the carrier includes: contacting the impregnation liquid containing the active component precursor and the auxiliary agent precursor with the carrier for impregnation;

The conditions of the impregnation include: the temperature is 10-80° C., preferably 20-60° C.; the time is 0.1-3 h, preferably 0.5-1 h.

Optionally, the active component precursor is nitrate, citrate, sulfate or chloride of the active component, or a combination of two or three of them; the auxiliary agent precursor is Nitrates, sulfates, carbonates or chlorides of the adjuvant, or a combination of two or three of them.

Optionally, the method also includes the steps of drying and roasting the material obtained after the load;

The drying conditions include: the temperature is 80-350°C, preferably 100-300°C; the time is 1-24 hours, preferably 2-12 hours;

The roasting conditions include: the temperature is 250°C～900°C, preferably 300°C～850°C, more preferably 350°C～800°C; the time is 0.5～12 hours, preferably 1～8 hours, more preferably 2～8 hours 6 hours.

A third aspect of the present disclosure provides a method for preparing α-olefin from synthesis gas, the method comprising the following steps:

(1) reducing the initial catalyst in a reducing atmosphere containing hydrogen to obtain the catalyst after the reduction treatment;

(2) contacting the synthesis gas with the catalyst after the reduction treatment obtained in step (1) to react;

Wherein, the initial catalyst is the supported catalyst described in the first aspect of the disclosure.

Optionally, in step (1), the conditions of the reduction treatment include: the space velocity is 1000-20000h ^-1 , preferably 2000-10000h ^-1 ; the temperature is 200-600°C, preferably 250-500°C; The rate is 1～30℃/min, preferably 5～15℃/min; the time is 1～20h, preferably 2～10h;

In step (2), the conditions of the reaction include: the reaction is carried out in a fixed-bed reactor, the reaction temperature is 280-320° C., the reaction pressure is 0.5-8 MPa, and the moles of H ₂ and CO in the synthesis gas are The ratio is (0.4˜2.5):1, and the space velocity of the syngas is 2000˜20000 h ⁻¹ .

Through the above technical solutions, compared with the catalysts in the prior art, the supported catalyst of the present disclosure has improved selectivity of the target product, and has higher α-olefin yield and product when used to prepare α-olefin from synthesis gas. The advantages of carbon number concentration (carbon number is concentrated in C ₅ -C ₁₅ , while the prior art is generally distributed in C ₅ -C ₃₀ ) is beneficial to industrialization.

Other features and advantages of the present disclosure will be described in detail in the detailed description that follows.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present disclosure, and constitute a part of the specification, and together with the following detailed description, are used to explain the present disclosure, but not to limit the present disclosure. In the attached image:

Fig. 1 is the XRD pattern of the carrier OMS-1 prepared in the Example.

Detailed ways

The specific embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure, but not to limit the present disclosure.

A first aspect of the present disclosure: provide a supported catalyst, the catalyst includes a carrier, and active components and auxiliary agents supported on the carrier, the carrier contains manganese oxide molecular sieve OMS-1, the active component is one or more metal components selected from Group VIII metals, and the auxiliary agent is one or more metal components selected from Group IIB metals.

After in-depth research, the inventors of the present disclosure found that when a special manganese oxide molecular sieve OMS-1 is used as a carrier, and the Group VIII metal component and the Group IIB metal component are used as the active component and auxiliary agent, respectively, the The resulting catalyst exhibits excellent selectivity to the target product. When the catalyst is used in the reaction of producing α-olefin from synthesis gas, higher yield of α-olefin can be obtained, and the carbon number of the product is concentrated (the carbon number is concentrated in C ₅ -C ₁₅ , while the prior art is generally in C ₅ - _C30 distribution).

According to the present disclosure, based on the dry weight of the catalyst, the content of the carrier may be 12-94 wt %, based on the metal element, the content of the active component may be 1-70 wt %, the auxiliary agent The content of can be 1 to 30% by weight. In order to further improve the target product selectivity of the catalyst, preferably, based on the dry weight of the catalyst, the content of the carrier is 30 to 91% by weight, and based on the metal element, the content of the active component is 2 ～50wt%, the content of the auxiliary agent is 2～25wt%; further preferably, based on the dry weight of the catalyst, the content of the carrier is 60～83wt%, in terms of metal elements, the The content of the active component is 8-30% by weight, and the content of the auxiliary agent is 3-12% by weight.

According to the present disclosure, the ratio of the active component and the auxiliary agent has a certain influence on the catalytic effect of the catalyst. In the present disclosure, in terms of metal elements, the weight ratio of the active component to the auxiliary agent may be 1:(0.2-5), preferably 1:(0.3-3).

Further, the active components may be Fe components and/or Co components, most preferably Fe components. The adjuvant may be a Zn component and/or a Cd component, most preferably a Zn component.

The second aspect of the present disclosure provides a method for preparing the supported catalyst described in the first aspect of the present disclosure, the method comprising: supporting the active components and auxiliary agents on the carrier.

According to the present disclosure, the manganese oxide molecular sieve OMS-1 can be used directly as the carrier, or the resulting mixture can be used as the carrier after being mixed with a suitable auxiliary (such as metal zirconium, etc.). Manganese oxide molecular sieve OMS-1 can be obtained commercially, or can be prepared by methods in the prior art, and the preparation steps can include, for example:

a. Mix the first aqueous solution containing the reduced manganese compound and the inorganic salt of magnesium with the alkaline second aqueous solution containing the oxidized manganese compound, and perform an aging reaction at 30-90°C, preferably 40-70°C for 10-50 hours, Preferably 15-40h, to obtain manganese oxide molecular sieve precursor;

b. Mix the manganese oxide molecular sieve precursor obtained in step a with the third aqueous solution containing inorganic salt of magnesium, and carry out a crystallization reaction at 100-200°C, preferably 120-180°C for 12-72 h, preferably 24-60 h , collect the solids.

Further, the oxidized manganese compound and the reduced manganese compound are relative; the oxidized manganese compound generally refers to a compound containing relatively high valence manganese (such as Mn ⁷⁺ , Mn ⁶⁺ , etc.), such as It can be potassium permanganate or potassium manganate; the reduced manganese compound generally refers to a compound containing relatively low valence manganese (eg Mn ²⁺ ), such as manganese sulfate, manganese nitrate or manganese chloride. The inorganic salt of magnesium can be magnesium chloride or magnesium nitrate. The weight ratio of the oxidized manganese compound, the reduced manganese compound and the inorganic salt of magnesium may be 1:(1-10):(0.1-5). The alkali in the second alkaline aqueous solution may be a common inorganic base, such as sodium hydroxide, potassium hydroxide, etc.; the alkali concentration of the second alkaline aqueous solution may be 1-20 wt %. Further, the preparation step may further include: in step a, heating the first aqueous solution and the alkaline second aqueous solution to 30-90° C., preferably 40-70° C., and then mixing. Through the above steps, the pure-phase octahedral manganese oxide molecular sieve OMS-1 whose XRD pattern conforms to JCPDS No.38-475 can be obtained.

The method of loading is not particularly limited in the present disclosure, and can be a method commonly used in the art, for example, a dipping method or a co-precipitation method can be used, and an impregnation method is preferred. The impregnation can be a one-time impregnation, or a step-by-step impregnation, and the step-by-step impregnation can be carried out by sequentially impregnating the active component and the auxiliary agent onto the carrier, or by dissolving the active component and the auxiliary agent together to form an impregnation solution. , and the impregnating liquid is impregnated on the carrier in two or more times.

In an optional embodiment of the present disclosure, the step of loading the active component and the auxiliary agent on the carrier may include: loading the impregnation solution containing the active component precursor and the auxiliary agent precursor with the carrier Contact for impregnation. The impregnation may be an equal volume impregnation method or a saturated impregnation method. The immersion conditions may be conventional, for example, the immersion conditions may include: a temperature of 10-80° C., preferably 20-60° C.; a time of 0.1-3 h, preferably 0.5-1 h.

Wherein, the active component precursor refers to a compound containing the active component, such as nitrate, citrate, sulfate or chloride of the active component, or two or three of them A combination of species; for example, when the active component is an Fe component, the active component precursor can be ferric nitrate, ferric citrate, ferric chloride, and the like. The adjuvant precursor refers to a compound containing an adjuvant, such as nitrate, sulfate, carbonate or chloride of the adjuvant, or a combination of two or three of them; for example, when When the auxiliary agent is a Zn component, the auxiliary agent precursor can be zinc nitrate, zinc chloride, zinc carbonate and the like. The immersion solution refers to a solution obtained by dissolving the active component precursor and the auxiliary agent precursor in a solvent. Wherein, the solvent can be, for example, water, ethanol, diethyl ether, etc., the amount of the solvent can be conventional, and there is no special limitation in the present disclosure.

In the above embodiment, the amount of the carrier, active component precursor, and auxiliary agent precursor is such that in the prepared catalyst, based on the dry weight of the catalyst, the content of the carrier is 12-94% by weight , preferably 30 to 91% by weight, in terms of metal elements, the content of the active component is 1 to 70% by weight, preferably 2 to 50% by weight, and the content of the auxiliary agent is 1 to 30% by weight, preferably What is necessary is just to be 2 to 25 weight%.

According to the present disclosure, the method further includes the steps of drying and roasting the material obtained after loading. The drying and calcining steps are conventional steps in the preparation of catalysts, and are not particularly limited in the present disclosure. For example, the drying conditions may include: the temperature is 80-350°C, preferably 100-300°C; and the time is 1-24 hours, preferably 2-12 hours. The conditions of the roasting may include: the temperature is 250 ℃～900 ℃, preferably 300 ℃～850 ℃, more preferably 350 ℃～800 ℃; the time is 0.5～12 hours, preferably 1～8 hours, more preferably 2 hours. ~6 hours.

A third aspect of the present disclosure provides a method for preparing α-olefin from synthesis gas, the method comprising the following steps:

(1) reducing the initial catalyst in a reducing atmosphere containing hydrogen to obtain the catalyst after the reduction treatment;

(2) contacting the synthesis gas with the catalyst after the reduction treatment obtained in step (1) to react;

Wherein, the initial catalyst is the supported catalyst described in the first aspect of the disclosure.

According to the present disclosure, in step (1), the supported catalyst described in the present disclosure is subjected to reduction treatment, and the active components can be reduced and activated to improve the catalytic effect of the catalyst. The conditions of the reduction treatment may include: the space velocity is 1000-20000h ^-1 , preferably 2000-10000h ^-1 ; the temperature is 100-800°C, preferably 200-600°C, more preferably 250-500°C; the time is 0.5-72h, preferably 1-36h, more preferably 2-24h. The reducing atmosphere can be pure hydrogen atmosphere or a mixed atmosphere of hydrogen and inert gas (such as nitrogen, argon, helium), and the partial pressure of hydrogen can be 0.1-4 MPa, preferably 0.1-2 MPa.

According to the present disclosure, the syngas contains CO and _H2 , and optionally _N2 . Contacting the synthesis gas with the supported catalyst for the reaction may be to contact the ready-made synthesis gas with the supported catalyst for the reaction, or to pass _CO and H into the reactor in proportion to contact with the catalyst together. reaction.

According to the present disclosure, in step (2), the reaction conditions may include: the reaction temperature is 280-320° C., the reaction pressure is 0.5-8 MPa, preferably 1-5 MPa; the moles of H ₂ and CO in the synthesis gas The ratio is (0.4-2.5):1, preferably (0.6-2.5):1, more preferably (0.8-2.2):1; the space velocity of the synthesis gas is 2000-20000 h ^-1 . In a preferred case, the reaction can be carried out in a fixed bed reactor. Wherein, the pressure refers to gauge pressure, and the space velocity refers to volume air velocity. When CO and H ₂ are respectively passed into the reactor according to the ratio of synthesis gas to be contacted with the catalyst to carry out the reaction, the space velocity of the synthesis gas is the total space velocity of CO and H ₂ .

The present disclosure will be further described in detail by the following examples, but it is not intended to limit the present disclosure.

In the following examples and comparative examples:

The content of active components and additives was determined by X-ray fluorescence spectroscopic analysis method RIPP 132-90 (Petrochemical Analysis Method (RIPP Experimental Method), edited by Yang Cuiding, Gu Kanying, Wu Wenhui, Science Press, September 1990, first edition, No. 371 -379 pages) measured.

In the embodiment, the preparation method of the carrier manganese oxide molecular sieve OMS-1 is as follows: dissolving 2.014 g of anhydrous manganese chloride and 0.636 g of magnesium chloride hexahydrate in 70 ml of deionized water, heating and stirring in a water bath at 50 ° C to fully dissolve, to obtain The first aqueous solution; dissolve 8.2 g of sodium hydroxide in 70 g of deionized water, add 1.012 g of potassium permanganate to it, and heat and stir in a 50°C water bath to fully dissolve it to obtain an alkaline second aqueous solution; The aqueous solution was added dropwise to the alkaline second aqueous solution, stirred in a water bath at 50°C for 6 hours, the obtained precipitate was suction filtered and washed with water at 80°C for 3 times to obtain the precursor of manganese oxide molecular sieve; 42.63g of magnesium chloride hexahydrate was added to 120g to remove In ionized water, a third aqueous solution was obtained, into which the manganese oxide molecular sieve precursor was added and stirred thoroughly, then transferred to a 250ml hydrothermal kettle, hydrothermally crystallized at 160°C for 36h, and the solid product was collected to obtain the carrier manganese oxide molecular sieve OMS- 1. Its XRD spectrum is shown in Figure 1, and it can be seen that it is a pure-phase octahedral manganese oxide molecular sieve OMS-1 conforming to JCPDS No.38-475.

Example 1

Dissolve 4.04 g of ferric nitrate nonahydrate and 2.98 g of zinc nitrate hexahydrate in 10 mL of deionized water, heat, stir and mix in a 50° C. water bath to obtain an immersion solution. Take the above impregnation solution, mix it with 10 g of carrier manganese oxide molecular sieve OMS-1, fully stir and impregnate it at 20 °C for 1 hour, then place it in an oven at 120 °C to dry for 5 hours, and bake it at 400 °C for 3 hours to obtain the catalyst A1 prepared in this example, The composition of catalyst A1 was 10 wt % Fe-10 wt % Zn/OMS-1 in terms of metal elements and based on the dry weight of the catalyst.

Example 2

Dissolve 8.08 g of ferric nitrate nonahydrate and 2.98 g of zinc nitrate hexahydrate in 10 mL of deionized water, heat, stir and mix in a water bath at 50° C. to obtain an immersion solution. Take the above impregnation solution, mix it with 10 g of carrier manganese oxide molecular sieve OMS-1, fully stir and impregnate it at 20 °C for 1 hour, then place it in an oven at 120 °C for 5 hours, and bake it at 400 °C for 3 hours to obtain the catalyst A2 prepared in this example, Catalyst A2 had a composition of 20 wt % Fe-10 wt % Zn/OMS-1 in terms of metal elements and based on the dry weight of the catalyst.

Example 3

Dissolve 5.91 g of cobalt nitrate hexahydrate and 1.36 g of cadmium carbonate in 10 mL of deionized water, heat and stir in a water bath at 50° C. to mix uniformly to obtain an immersion solution. Take the above impregnation solution, mix it with 10 g of carrier manganese oxide molecular sieve OMS-1, fully stir and impregnate it at 20 °C for 1 hour, then place it in an oven at 120 °C to dry for 5 hours, and bake it at 400 °C for 3 hours to obtain the catalyst A3 prepared in this example, Catalyst A3 had a composition of 20 wt % Co-10 wt % Cd/OMS-1 on a metal element basis and based on the dry weight of the catalyst.

Example 4

Dissolve 4.04 g of ferric nitrate nonahydrate, 2.12 g of cobalt nitrate hexahydrate, and 1.75 g of zinc nitrate hexahydrate in 10 mL of deionized water, and heat, stir and mix in a 50° C. water bath to obtain an immersion solution. Take the above impregnation solution, mix it with 10g of carrier manganese oxide molecular sieve OMS-1, fully stir and impregnate it at 20°C for 1 hour, then place it in an oven at 120°C to dry for 5 hours, and bake it at 400°C for 3 hours to obtain the catalyst A4 prepared in this example, Catalyst A4 had a composition of 10 wt % Fe-2 wt % Co-5 wt % Zn/OMS-1 in terms of metal elements and based on the dry weight of the catalyst.

Example 5

Dissolve 2.02 g of ferric nitrate nonahydrate and 5.83 g of zinc nitrate hexahydrate in 10 mL of deionized water, heat, stir and mix in a water bath at 50° C. to obtain an immersion solution. Take the above impregnation solution, mix it with 10 g of carrier manganese oxide molecular sieve OMS-1, fully stir and impregnate it at 20 °C for 1 hour, then place it in an oven at 120 °C to dry for 5 hours, and bake it at 400 °C for 3 hours to obtain the catalyst A5 prepared in this example, Catalyst A5 had a composition of 5 wt % Fe-25 wt % Zn/OMS-1 on a metal element basis and based on the dry weight of the catalyst.

Example 6

Dissolve 6.17 g of ferric nitrate nonahydrate and 1.68 g of zinc nitrate hexahydrate in 10 mL of deionized water, and heat, stir and mix in a 50° C. water bath to obtain an immersion solution. Take the above impregnation solution, mix it with 10g carrier manganese oxide molecular sieve OMS-1, fully stir and impregnate it at 20°C for 1h, then place it in an oven at 120°C for 5h, and bake it at 400°C for 3h to obtain the catalyst A6 prepared in this example, The composition of catalyst A6 was 16 wt % Fe-4 wt % Zn/OMS-1 on a metal element basis and based on the dry weight of the catalyst.

Example 7

Dissolve 2.02 g of ferric nitrate nonahydrate and 4.67 g of zinc nitrate hexahydrate in 10 mL of deionized water, heat, stir and mix in a 50° C. water bath to obtain an immersion solution. Take the above impregnation solution, mix it with 10 g of carrier manganese oxide molecular sieve OMS-1, fully stir and impregnate it at 20 °C for 1 hour, then place it in a 120 °C oven to dry for 5 hours, and bake it at 400 °C for 3 hours to obtain the catalyst A7 prepared in this example, The composition of catalyst A7 was 5 wt % Fe-15 wt % Zn/OMS-1 on a metal element basis and based on the dry weight of the catalyst.

Example 8

Dissolve 0.41 g of ferric nitrate nonahydrate and 9.74 g of zinc nitrate hexahydrate in 10 mL of deionized water, heat, stir and mix in a 50° C. water bath to obtain an immersion solution. Take the above impregnation solution, mix it with 10 g of carrier manganese oxide molecular sieve OMS-1, fully stir and impregnate it at 20 °C for 1 hour, then place it in an oven at 120 °C for 5 hours, and bake it at 400 °C for 3 hours to obtain the catalyst A8 prepared in this example, Catalyst A8 had a composition of 1 wt % Fe-30 wt % Zn/OMS-1 on a metal element basis and based on the dry weight of the catalyst.

Comparative Example 1

Dissolve 4.04 g of ferric nitrate nonahydrate in 10 mL of deionized water, heat and stir in a water bath at 50° C. to mix evenly to obtain an immersion solution. Take the above impregnation solution, mix it with 10 g of carrier manganese oxide molecular sieve OMS-1, fully stir and impregnate it at 20 °C for 1 hour, then place it in an oven at 120 °C for 5 hours, and bake it at 400 °C for 3 hours to obtain catalyst D1, calculated as metal element and The composition of catalyst D1 was 10 wt% Fe/OMS-1 based on the dry weight of the catalyst.

Comparative Example 2

Dissolve 2.98 g of zinc nitrate hexahydrate in 10 mL of deionized water, heat and stir in a water bath at 50° C. to mix evenly to obtain an immersion solution. Take the above impregnation solution, mix it with 10 g of carrier manganese oxide molecular sieve OMS-1, fully stir and impregnate it at 20 °C for 1 hour, then place it in an oven at 120 °C to dry for 5 hours, and bake it at 400 °C for 3 hours to obtain catalyst D2, calculated as metal element and The composition of catalyst D2 was 10 wt% Zn/OMS-1 based on the dry weight of the catalyst.

Test Example

The catalysts prepared in Examples 1-8 and Comparative Examples 1-2 were tested for their catalytic activity when used to catalyze the production of alpha-olefins from syngas.

The initial catalyst was loaded into the fixed-bed reactor, and H ₂ was introduced into the fixed-bed reactor. The pressure of the reactor was adjusted to 0.1 MPa, and the space velocity was 10000 h ^-1 . 4h for reduction treatment.

After the reduction treatment, the temperature of the reactor was lowered to 320° C., and the synthesis gas was introduced to start the reaction. The space velocity was 5000 h ⁻¹ , the pressure was 1.5 MPa, and the synthesis gas composition was H ₂ :CO:N ₂ =56:28:16( volume ratio), the exhaust gas composition was analyzed by on-line gas chromatography. The results measured after 50 hours of reaction are shown in Table 1.

in:

CO₂的选择性

α-烯烃的选择性(S_α-烯烯)以及C₅以上(C₅₊)烃类的选择性

分别通过以下公式计算得到：CO conversion (X _CO ), CH ₄ selectivity

_CO2 selectivity

Selectivity to alpha-olefins (S _{alpha-olefins} ) and selectivity to hydrocarbons above C ₅ (C ₅₊ )

They are calculated by the following formulas:

为生成CO₂的摩尔数，

为生成的CH₄的摩尔数，n_α-烯烃为生成α-烯烃的摩尔数，

为生成的CH₄、C₂烃、C₃烃和C₄烃的摩尔数之和。Among them, V ₁ and V ₂ respectively represent the volume of feed gas entering the reaction system and the volume of tail gas flowing out of the reaction system in a certain period of time under standard conditions; c _1,CO , c _2,CO represent the raw material gas and tail gas, respectively Molar content of CO. n _con is the number of moles of CO involved in the reaction,

is the number of moles of _CO2 produced,

is the moles of _CH4 produced, n is the moles of _α-olefins produced,

is the sum of moles of CH ₄ , C ₂ hydrocarbons, C ₃ hydrocarbons and C ₄ hydrocarbons produced.

Table 1

Note: The oil phase product comes from C ₅ ⁺ , and the oil phase product contains components such as alkanes, α-olefins, isomers, and oxygenates.

It can be seen from Table 1 that when the supported catalyst of the present disclosure is used in the reaction of synthesis gas to prepare α-olefin, the conversion rate of carbon monoxide is high, the selectivity of α-olefin is high, and the carbon number of the product is concentrated.

The preferred embodiments of the present disclosure have been described above in detail with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details of the above-mentioned embodiments. Various simple modifications can be made to the technical solutions of the present disclosure within the scope of the technical concept of the present disclosure. These simple modifications all fall within the protection scope of the present disclosure.

In addition, it should be noted that the various specific technical features described in the above-mentioned specific embodiments can be combined in any suitable manner unless they are inconsistent. In order to avoid unnecessary repetition, the present disclosure provides The combination method will not be specified otherwise.

In addition, the various embodiments of the present disclosure can also be arbitrarily combined, as long as they do not violate the spirit of the present disclosure, they should also be regarded as the contents disclosed in the present disclosure.

Claims (16)

1. A supported catalyst for preparing α-olefins whose carbon numbers are concentrated in C ₅ ～C ₁₅ from synthesis gas, is characterized in that, this supported catalyst comprises a carrier, and an active component that is supported on the carrier and auxiliary agent, the carrier contains manganese oxide molecular sieve OMS-1, the active component is one or more metal components selected from group VIII metals, and the auxiliary agent is selected from group IIB metals one or more of the metal components. 2. The supported catalyst according to claim 1, wherein, based on the dry weight of the supported catalyst, the content of the carrier is 12 to 94% by weight, in terms of metal elements, the active component The content of the auxiliary agent is 1 to 70% by weight, and the content of the auxiliary agent is 1 to 30% by weight. 3. The supported catalyst according to claim 2, wherein, based on the dry weight of the supported catalyst, the content of the carrier is 30 to 91% by weight, in terms of metal elements, the active component The content of the auxiliary agent is 2 to 50% by weight, and the content of the auxiliary agent is 2 to 25% by weight. 4 . The supported catalyst according to claim 1 , wherein the active components are Fe components and/or Co components; and the auxiliary agents are Zn components and/or Cd components. 5 . 5 . The supported catalyst according to claim 1 , wherein, in terms of metal elements, the weight ratio of the active component to the auxiliary agent is 1:(0.2~5). 6 . 6 . The supported catalyst according to claim 5 , wherein, in terms of metal elements, the weight ratio of the active component to the auxiliary agent is 1:(0.3~3). 7 . 7. A method for preparing the supported catalyst according to any one of claims 1 to 6, characterized in that, the method comprises: loading the active components and auxiliary agents on the carrier. 8. The method according to claim 7, wherein the step of loading the active component and the auxiliary agent on the carrier comprises: contacting the impregnation solution containing the active component precursor and the auxiliary agent precursor with the carrier to impregnate; The conditions of the impregnation include: the temperature is 10-80° C., and the time is 0.1-3 h. 9 . The method according to claim 8 , wherein the conditions of the impregnation include: a temperature of 20-60° C. and a time of 0.5-1 h. 10 . 10. The method of claim 8, wherein the active component precursor is nitrate, citrate, sulfate or chloride of the active component, or two or three of them combination; The adjuvant precursor is nitrate, sulfate, carbonate or chloride of the adjuvant, or a combination of two or three of them. 11. The method according to claim 7, wherein the method further comprises the steps of drying and roasting the material obtained after loading; The drying conditions include: the temperature is 80-350°C, and the time is 1-24 hours; The roasting conditions include: the temperature is 250°C to 900°C, and the time is 0.5 to 12 hours. 12. The method according to claim 11, wherein the drying conditions comprise: the temperature is 100-300°C, and the time is 2-12 hours; The roasting conditions include: the temperature is 300° C.˜850° C., and the time is 1˜8 hours. 13. The method according to claim 12, wherein the roasting conditions comprise: a temperature of 350°C to 800°C and a time of 2 to 6 hours. 14. A method for preparing α-olefins having carbon numbers concentrated in C ₅ to C ₁₅ from synthesis gas, the method comprising the steps of: (1) The initial catalyst is subjected to reduction treatment in a reducing atmosphere containing hydrogen to obtain a catalyst after reduction treatment; (2) contacting the synthesis gas with the catalyst after the reduction treatment obtained in step (1) for reaction; Wherein, the initial catalyst is the supported catalyst according to any one of claims 1 to 6. 15 . The method according to claim 14 , wherein, in step (1), the conditions for the reduction treatment include: a space velocity of 1000-20000 h ⁻¹ , a temperature of 100-800° C., and a time of 0.5-72 h; 15 . In step (2), the conditions of the reaction include: the reaction is carried out in a fixed bed reactor, the reaction temperature is 280-320 °C, the reaction pressure is 0.5-8 MPa, the moles of H ₂ and CO in the synthesis gas are The ratio is (0.4~2.5):1, and the space velocity of the syngas is 2000~20000 h ⁻¹ . 16 . The method according to claim 15 , wherein, in step (1), the conditions of the reduction treatment include: a space velocity of 2000-10000 h ⁻¹ , a temperature of 200-600° C., and a time of 1-36 h. 17 .

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