A method for synthesizing aviation kerosene using mixed C4 raw materials

Abstract

In view of the current situation of aviation kerosene production technology in the prior art, the present invention provides a molecular sieve catalyst for preparing full-component aviation kerosene, and its preparation and application. The molecular sieve catalyst is composed of a metal and a molecular sieve; by weight, the content of the metal is 3.2-20 wt%; the molecular sieve is ZSM-5 or MCM-22 molecular sieve; the metal is composed of at least one of noble metals Au, Pt, Pd and their oxides and at least one of common metals Ni, Ga, Zn and their oxides. The weight ratio of the common metal to the noble metal is (4.2-15):1. Using the molecular sieve catalyst described above, the product obtained from the mixed C4 raw material under the matching reaction conditions has alkanes with carbon numbers distributed in C8-C 16 alkanes, as well as aromatic hydrocarbons, cycloalkanes and a small amount of unsaturated olefins, meeting the basic technical requirements of aviation kerosene, and having important application value and broad market prospects.

Description

Technical Field

[0001] The invention belongs to the field of chemistry and chemical engineering, and specifically relates to fuel energy technology, and in particular to a method for synthesizing aviation kerosene by using mixed C4. Background Art

[0002] The process route for preparing liquid fuels from coal or biomass-based raw materials is to directly convert syngas into liquid fuels such as gasoline and diesel under the action of a catalyst, and the tail gas is rich in mixed C4 components. In addition, catalytic cracking, steam cracking and catalytic reforming reactions in refineries will also produce a large amount of mixed C4 as a by-product. Since the boiling points of the various components in the mixed C4 are similar, the cost of separation and purification for separate use is too high, so it is often burned directly as civilian liquefied petroleum gas in the end, resulting in a huge waste of high-value-added C4 olefins. Therefore, the development of large-scale C4 comprehensive utilization technology is a technical problem that needs to be solved urgently.

[0003] With the rapid development of aviation industry and civil aviation, the use of aviation fuel has increased dramatically around the world. Jet fuel is a type of aviation fuel and is currently the most widely used jet fuel for large passenger aircraft. It is mainly composed of hydrocarbon compounds of different fractions, with carbon numbers ranging from C8 to C 16 The content of aromatic hydrocarbons does not exceed 25%. In the early stage, the preparation of aviation kerosene mainly adopted the refining and preparation process with petroleum as raw material. In recent years, the process of producing aviation kerosene by using C4 mixed olefins can provide a way to reuse petrochemical by-products on the one hand, and expand the path of non-petroleum synthetic aviation fuel on the other hand. It has good application prospects and practical value and has received more and more attention.

[0004] In the prior art, there are two main processes for synthesizing aviation kerosene by converting low-carbon olefins: one is to synthesize C4-C6 hydrocarbons mainly composed of alkanes and olefins by superposition or polymerization of low-carbon olefins as the main reaction; 12 Aviation gasoline or C9-C 16 Aviation kerosene components; one is the synthesis of aviation kerosene C8-C using aromatization of low-carbon olefins as the main reaction pathway 15 Aromatic components. Invention patent application 202011342275.5 discloses a "method for preparing bio-jet fuel". The application uses biomass deoxygenated oil after hydrodeoxygenation of biomass oil as raw material and uses a supported metal catalyst to prepare bio-jet fuel. The hydrocarbons generated are mainly C9~C 16 The one-step synthesis of all components of aviation kerosene including cycloalkanes, olefins, low-carbon aromatics and alkanes is of great significance for practical applications. However, no relevant reports have been seen so far. Summary of the invention

[0005] In view of the current status of aviation kerosene production technology in the prior art, the present invention provides a molecular sieve catalyst for preparing full-component aviation kerosene and its preparation and application. By using the molecular sieve catalyst and mixing C4 raw materials, high-quality aviation kerosene that meets the technical requirements of aviation fuel can be obtained, which has important application value and broad market prospects.

[0006] The technical solution of the present invention:

[0007] A molecular sieve catalyst for preparing full-component aviation kerosene, composed of metal and molecular sieve; the content of the metal is 3.2-20wt% by weight; the molecular sieve is ZSM-5 or MCM-22 molecular sieve; the metal is composed of at least one of the precious metals Au, Pt, Pd and their oxides and at least one of the common metals Ni, Ga, Zn and their oxides. The content of the precious metals Au, Pt, Pd and their oxides in the molecular sieve catalyst is 0.2-4wt%; the content of the common metals Ni, Ga, Zn and their oxides in the molecular sieve catalyst is 3-16wt%; the weight ratio of the common metal to the precious metal is (4.2-15):1. Preferably, the content of the precious metals Au, Pt, Pd and their oxides in the molecular sieve catalyst is 0.2-1wt%.

[0008] The molecular sieve catalyst is (1) a composite molecular sieve catalyst formed by physical mixing of metal and molecular sieve; or (2) a modified molecular sieve catalyst formed by metal supported on molecular sieve. The product obtained by using the molecular sieve-based catalyst under matching reaction conditions has a carbon number distribution in the range of C8-C 16 It contains alkanes, aromatic hydrocarbons, cycloalkanes and a small amount of unsaturated olefins, which meet the basic technical requirements of aviation kerosene and have important application value and broad market prospects.

[0009] The preparation method of the composite molecular sieve catalyst is specifically as follows: weigh appropriate amounts of metal / metal oxide and molecular sieve, mix them evenly, and obtain a composite ZSM-5 or MCM-22 catalyst.

[0010] The preparation methods of the metal-modified molecular sieve catalysts include two types: (1) Weigh an appropriate amount of metal soluble salt and dissolve it completely in water. Add ZSM-5 or MCM-22 molecular sieve powder, and carry out equal-volume impregnation or deposition precipitation at a temperature of 70-90 °C for 8-12 h to obtain the metal-modified ZSM-5 or MCM-22 molecular sieve catalyst. (2) Weigh an appropriate amount of metal soluble salt and dissolve it completely in water; drop it into the synthetic sol-gel containing a silicon source, an aluminum source, a template agent, an alkali source, and water, and stir until fully mixed; then carry out in-situ hydrothermal synthesis at a temperature of 150-180 °C for 72-96 hours, and after separation, washing, and drying, the metal-modified ZSM-5 or MCM-22 molecular sieve catalyst is obtained.

[0011] The application of the molecular sieve catalyst as described above is to synthesize full-component aviation kerosene from mixed C4 as the raw material.

[0012] A method for synthesizing full-component aviation kerosene based on mixed C4 raw materials is specifically as follows: Pass the mixed C4 raw materials through a fixed-bed reactor equipped with the molecular sieve catalyst as described above, and carry out polymerization, isomerization, cyclodehydrogenation, hydrogen transfer, and aromatization reactions under the conditions of a temperature of 260-430 °C, a pressure of 1.2-5 Mpa, and an air velocity of 0.2-4 h -1 to obtain full-component aviation kerosene. The aviation kerosene described includes alkanes and cycloalkanes with a carbon number distribution in C8-C 16 and low-carbon aromatics and unsaturated olefins with a carbon number distribution in C8-C 15 . Their relative contents meet the basic technical requirements of aviation fuel and can be directly used as aviation kerosene. The mixed C4 raw materials are a mixture of n-butene, isobutene, isobutane, n-butane, and a small amount of C3 and C5 hydrocarbons. Among them, the volume content of the C4 component is 10-100%, the volume fraction of low-carbon alkanes (alkanes below C5) is 0-20%, and the volume fraction of low-carbon olefins (olefins below C5) is not less than 30%. By adjusting the reaction conditions and the content of the catalyst components, the method described in this application can controllably change the content of each component in the oil product, so as to meet the demand for the product to the greatest extent. In addition, the method described in this application realizes almost complete conversion of the mixed C4 raw materials, the aviation kerosene yield can reach up to 95%, and the gas-phase by-products in the tail gas account for a very small proportion of the total gas-liquid mass, with a mass fraction less than 2%. Compared with the prior art, the technical effect is remarkable.

[0013] Preferably, before the reaction, the catalyst is activated at a temperature of 500 °C and in a nitrogen atmosphere for 1 h; after the temperature and pressure of the catalyst bed reach the aforementioned range, the mixed C4 raw materials are introduced for reaction.

[0014] Preferably, the product obtained from the reaction first passes through a hot trap at a temperature of 200 °C, the hot trap product is collected, then the uncondensed product enters a cold trap, the cold trap product is collected, and the tail gas enters a chromatograph for on-line analysis. This avoids the condensation and retention of heavy oil phase products in the system, realizes the direct and effective separation of the products and the catalyst, has a simple process flow, and reduces the production cost.

[0015] Catalytic principle: Molecular sieve ZSM-5 has an MFI-type three-dimensional pore structure and good acidity. Under the confinement of its pores, it has good oligomerization of light olefins and certain aromatization and cyclization properties. Molecular sieve MCM-22 has an MWW-type three-dimensional pore structure and has good shape-selective reforming, disproportionation, isomerization, alkylation and other properties. Metal Ni has good oligomerization and hydrogenation reaction properties, which is conducive to the formation of products with long carbon chains; noble metals Au, Pd and Pt have dehydrogenation aromatization of light alkanes and catalytic properties of aromatic ring cyclization, significantly reducing the unsaturated olefins in the products and being conducive to the formation of saturated alkanes; the addition of metals Ga and Zn also helps to further improve the formation of aromatic hydrocarbon products on the molecular sieve catalyst. Based on the respective catalytic properties of the aforementioned molecular sieves and metals, the inventor unexpectedly found that when the noble metals Au, Pt, Pd and common metals Ni, Ga, Zn are in specific ratios and contents, physical mixing or loading the metals on the molecular sieve can almost completely convert the mixed C4 raw material into effective components of aviation kerosene under certain temperature, pressure and air velocity conditions, and can also controllably change the content of each component in the oil product, producing unexpected technical effects.

[0016] Advantages of the present invention:

[0017] (1) The present invention provides a molecular sieve catalyst for producing full-component aviation kerosene. Using the described molecular sieve-based catalyst, the products obtained under matching reaction conditions include alkanes with carbon numbers distributed in C8-C 16 and aromatic hydrocarbons, naphthenes and a small amount of unsaturated olefins, meeting the basic technical requirements of aviation kerosene and having important application value and broad market prospects.

[0018] (2) The method for synthesizing aviation kerosene according to the present invention uses the aforementioned molecular sieve catalyst, adjusts the reaction conditions and the ratio of functional metal components in the catalyst, changes the organic synergy in the reaction process, and thus realizes the modulation of the product oil components to meet the market demand for the product to the greatest extent.

[0019] (3) The method for synthesizing aviation kerosene according to the present invention almost completely converts the mixed C4 raw material, and the aviation kerosene yield can reach up to 95%; the gas-phase by-products in the tail gas account for very little of the total gas-liquid mass, with a mass fraction of less than 2%. Compared with the prior art, the technical effect is remarkable.

[0020] (4) The method for synthesizing synthetic aviation kerosene according to the present invention uses a fixed-bed reactor to directly separate the oil product by combining a cold trap and a hot trap, which not only realizes the direct and effective separation of the product and the catalyst, but also has a simple process flow and is of great significance for industrial application. Detailed implementation manners

[0021] The present invention will be further described below in conjunction with embodiments.

[0022] Example 1: Preparation and application of molecular sieve catalyst Au / ZnO-ZSM-5

[0023] A method for synthesizing all components of aviation kerosene using mixed C4 as a raw material includes the following steps: passing the mixed C4 components through a fixed-bed reactor filled with a molecular sieve catalyst for multiphase catalytic reaction; wherein, the molecular sieve catalyst is a metal-modified ZSM-5 and MCM-22 molecular sieve catalyst, and its preparation method is:

[0024] (1) Physically mix 16 g of ZnO powder and 85 g of ZSM-5 (Si / Al is about 30) molecular sieve powder, and then use conventional extrusion molding to obtain a composite molecular sieve catalyst ZnO-ZSM-5. Among them, the content of Zn is 12.8 wt%.

[0025] (2) Dissolve 1 g of HAuCl4 in 200 ml of water to obtain a HAuCl4 solution, put 3 g of ZnO-ZSM-5 powder into 80 ml of water to form a suspension; heat up to 80 °C, under vigorous stirring, take 10 ml of the previously obtained HAuCl4 solution and add it dropwise to the above suspension, and continue stirring for 1 h; then cool to room temperature, filter and wash to obtain a modified molecular sieve catalyst Au / ZnO-ZSM-5. Among them, the content of Au is 1 wt%, and the content of Zn is 12.8 wt%.

[0026] (3) Take 1 g of the Au / ZnO-ZSM-5 molecular sieve catalyst obtained in step (1) and load it into a fixed bed, pass nitrogen to a pressure of 1.2 MPa, and heat up to 260 °C under the protection of a nitrogen stream. Then, introduce a mixed C4 olefin raw material (the specific composition is shown in Table 1), the olefin content in the raw material gas is about 54%, and the space velocity is 0.2 h -1 .

[0027] Table 1. Raw material composition in Example 1

[0028] Component n-Butane Isobutane n-Butene Isobutene 2-Butene Total Mass (%) 12 34 22 17 15 100

[0029] The reaction tail gas was analyzed online using an Agilent 7890A gas chromatograph. The oil samples collected by the hot trap and cold trap were analyzed offline using an Agilent 7820A gas chromatograph and a Shimadzu GCMS-QP2010 gas chromatograph-mass spectrometer. The results are shown in Table 2. As can be seen from Table 2, the conversion rate of the raw material gas is 99%. Among them, the products in the cold trap are mainly gasoline components with carbon numbers distributed in C5-C9, and the yield is about 14%; the carbon number distribution of the products in the hot trap is mainly in C5-C 16 is the aviation kerosene component, with a yield of 86%, which mainly includes 42.1% alkanes, 36.4% aromatics, 18.1% naphthenes, and 3.4% olefins in small amounts.

[0030] Table 2. Reaction results in Example 1

[0031]

[0032] Example 2: Preparation and application of modified molecular sieve catalyst Au-Ni / MCM-22

[0033] A method for synthesizing all components of aviation kerosene using mixed C4 as raw material, comprising the following steps:

[0034] (1) Dissolve 1 g of HAuCl4 in 200 ml of water to obtain a HAuCl4 solution. Put 3 g of Ni / MCM-22 molecular sieve (prepared in Example 2) powder into 80 ml of water to form a suspension; heat up to 80 °C, and with vigorous stirring, take 10 ml of the aforementioned obtained HAuCl4 solution and add it dropwise to the above suspension, and continue stirring for 1 h; then cool to room temperature, filter and wash to obtain the modified molecular sieve catalyst Au-Ni / MCM-22. Among them, the content of Au is 1 wt%, and the content of Ni is 4.2 wt%.

[0035] (2) Take 1 g of the Au-Ni / MCM-22 molecular sieve catalyst prepared in step (1) and load it into a fixed bed, pass nitrogen to a pressure of 2.0 MPa, and heat up to 280 °C under the protection of a nitrogen stream. Then, introduce the mixed C4 olefin raw material, and its raw material gas composition is shown in Table 3, and the reaction space velocity is 1.5 h -1 .

[0036] Table 3. Raw material gas composition in Example 2

[0037] Component n-Butane Isobutane n-Butene Isobutene 2-Butene Butadiene Total Mass (%) 6 2 12 26 11 43 100

[0038] The reaction tail gas was analyzed online using an Agilent 7890A gas chromatograph. The oil samples collected by the hot trap and cold trap were analyzed offline using an Agilent 7820A gas chromatograph and a Shimadzu GCMS-QP2010 gas chromatograph-mass spectrometer. The results are shown in Table 4. As can be seen from Table 6, the conversion rate of the raw material gas was 99.5%. Among them, the products were separated by the cold trap and the hot trap. The products in the cold trap were mainly gasoline components with carbon numbers distributed from C5 to C9, and the yield was about 5%. The carbon number distribution of the products in the hot trap was mainly in C5-C 16 was the aviation kerosene component, and the oil yield was 95%. It mainly included 58.4% alkanes, 15.1% aromatics, 20.4% naphthenes, and 6.1% olefins.

[0039] Table 4. Reaction results of Example 2

[0040]

[0041] Example 3: Preparation and application of modified molecular sieve catalyst Pt-Ga-Ni / ZSM-5

[0042] A method for synthesizing all components of aviation kerosene using mixed C4 as raw material, comprising the following steps:

[0043] (1) Dissolve 0.2 g of HPtCl4 ， 1 g of Ga(NO3)3 and 1 g of Ni(NO3)2 in 20 ml of water, heat up to 80 °C, put 3 g of ZSM-5 molecular sieve powder into it, stir vigorously for 1 h, dry and calcine to obtain the modified molecular sieve catalyst Pt-Ga-Ni / ZSM-5. Among them, the contents of metals Pt, Ga, and Ni were 3.7 wt%, 7.4 wt%, and 8.6 wt% respectively.

[0044] (2) Take 1 g of the Pt-Ga-Ni / ZSM-5 catalyst prepared in step (1) and load it into a fixed bed, pass nitrogen to a pressure of 1.2 MPa, and heat up to 460 °C under the protection of a nitrogen stream. Then, introduce the mixed C4 olefin raw material, and its raw material gas composition is shown in Table 5. The reaction space velocity is 2.5 h -1 .

[0045] Table 5. Raw material gas composition of Example 3

[0046] Component n-Butane Isobutane n-Butene Isobutene 2-Butene Butadiene C5 Total Mass (%) 9.9 11 8 22 11 28 10.1 100

[0047] The reaction tail gas was analyzed online using an Agilent 7890A gas chromatograph, and the oil samples collected from the hot trap and the cold trap were analyzed offline using an Agilent 7820A gas chromatograph and a Shimadzu GCMS-QP2010 gas chromatograph-mass spectrometer. The results are shown in Table 6. As shown in Table 10, the conversion rate of the raw gas was 99.5%. Among them, the product in the cold trap was mainly a gasoline component with a carbon number distribution of C5-C9, with a yield of about 12%; the product in the hot trap was mainly distributed in the C5-C 16 It is a component of aviation kerosene, with an oil yield of 88%, mainly including carbon number distribution in the range of C5-C 16 The content of cycloalkanes is 5.5%, aromatics is 20%, olefins is 2.2% and alkanes is 72.3%.

[0048] Table 6. Reaction results of Example 3

[0049]

[0050] Example 4: Preparation and application of modified molecular sieve catalyst Pd-Ga / ZSM-5

[0051] A method for synthesizing all components of aviation kerosene using mixed C4 as a raw material comprises the following steps:

[0052] (1) Hydrothermal synthesis of metal-modified (Ga)HZSM-5: First, tetrapropylammonium hydroxide and tetraethyl orthosilicate were mixed, wherein tetrapropylammonium hydroxide was used as a template and tetraethyl orthosilicate was used as a silicon source, and stirred at room temperature for 1 hour. Sodium aluminate was added to the above solution as an aluminum source, and stirring was continued for 1 hour, and then an appropriate amount of gallium nitrate solution was added, and the pH value was adjusted to 11 with urea solution. After being fully stirred and mixed, the mixture was heated at 180°C for 72 hours, and the crystallized mixture was separated, washed to neutrality, dried at 100°C overnight, and calcined at 540°C to remove the template to obtain a modified molecular sieve catalyst (3% Ga / ZSM-5. Among them, the Ga content was 3wt%. The molar ratio of tetraethyl orthosilicate, sodium aluminate, and tetrapropylammonium hydroxide was 1:0.03:1.6.

[0053] (2) Dissolve 1g of PdCl2 in 20ml of water to obtain a PdCl2 solution; put 3g of the Ga / ZSM-5 catalyst powder prepared in step (1) into water to form a suspension; heat to 80°C, drop the PdCl2 solution into the mixture under vigorous stirring, continue stirring for 1h, cool to room temperature, filter, and wash to form a modified molecular sieve catalyst Pd-Ga / ZSM-5, wherein the content of Pd is 0.2wt% and the content of Ga is 3wt%.

[0054] (3) Weigh 1 g of the Pd-Ga / ZSM-5 catalyst prepared in step (2) and load it into a fixed bed. Pass nitrogen gas until the pressure reaches 1.5 MPa, and heat it to 430 °C under the protection of a nitrogen gas stream. Then, introduce the mixed C4 olefin raw material. The composition of the raw material gas is shown in Table 7, and the space velocity is 2.5 h -1 .

[0055] Table 7. Composition of the raw material gas in Example 4

[0056] Component n-Butane Isobutane n-Butene Isobutene 2-Butene Butadiene C5 Total Mass (%) 3 6 25 23 15 27.2 0.8 100

[0057] The reaction tail gas was analyzed online using an Agilent 7890A gas chromatograph. The oil samples collected by the hot trap and cold trap were analyzed offline using an Agilent 7820A gas chromatograph and a Shimadzu GCMS-QP2010 gas chromatograph-mass spectrometer. The results are shown in Table 8. As can be seen from Table 12, the conversion rate of the raw material gas is 90%. Among them, the products in the cold trap are mainly gasoline components with carbon numbers distributed in C5-C9, and the yield is about 5%; the carbon number distribution of the products in the hot trap is mainly in C5-C 16 aviation kerosene components, and the oil yield is 83%, mainly including 8.5% naphthenes, 26.4% aromatics, 57.8% alkanes and 7.3% olefins.

[0058] Table 8. Reaction results of Example 4

[0059]

[0060] In summary, when using the composite molecular sieve catalyst / modified molecular sieve catalyst prepared in Examples 1-4 of this application to synthesize all components of aviation kerosene from mixed C4 as the raw material, the conversion rate of the raw material gas is 90-99.5%, indicating that the mixed C4 raw material is almost completely converted; the yield of aviation kerosene is 83-95% (the remaining products are aviation gasoline). The components of the obtained aviation kerosene mainly include naphthenes (5.5-20.4%), aromatics (15.1-36.4%), olefins (2.2-7.3%) and alkanes (42.1-72.3%). This shows that the products obtained using the multi-metal modified molecular sieve catalyst under the matching reaction conditions not only include alkanes with carbon numbers distributed in C5-C 16 alkanes, but also aromatic hydrocarbons, naphthenes and a small amount of unsaturated olefins, meeting the basic technical requirements of aviation kerosene.

[0061] At the same time, the aviation kerosene components prepared in Examples 1-4 all include naphthenes, aromatics, olefins and alkanes, and the carbon numbers are all C5-C 16, but the contents of each component are different. This is because the applicant can achieve precise control of the components of jet fuel by controlling the components and contents of metals in the catalyst, as well as the ratio of noble metals (Pt, Pd, Au) to common metals (Ni, Ga, Zn), and combining with matching reaction conditions, thereby maximizing the meeting of the market's demand for products, and having important industrial application prospects and economic benefit values.

[0062] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for synthesizing full-component aviation kerosene from mixed C4 raw materials, characterized in that: The specific method is as follows: passing the mixed C4 raw material through a fixed-bed reactor filled with a molecular sieve catalyst to carry out a catalytic reaction to obtain full-component aviation kerosene; the temperature condition of the catalytic reaction is 260 - 430 °C, the reaction pressure is 1.2 - 5 Mpa, and the space velocity is 0.2 - 4 h -1 ; the molecular sieve catalyst is composed of a molecular sieve and a metal. By weight, the content of the metal is 3.2 - 20 wt%; the molecular sieve is ZSM-5 or MCM-22 molecular sieve; the metal is composed of at least one of noble metals Au, Pt, Pd and their oxides and at least one of common metals Ni, Ga, Zn and their oxides; the weight ratio of the common metal to the noble metal is (4.2 - 15):

1.

2. The method for synthesizing a full-component aviation kerosene according to claim 1, characterized in that: The content of noble metals Au, Pt, Pd and their oxides in the molecular sieve catalyst is 0.2 - 4 wt%; the content of common metals Ni, Ga, Zn and their oxides in the molecular sieve catalyst is 3 - 16 wt%.

3. The method for synthesizing fully-composed aviation kerosene according to claim 2, wherein: In the mixed C4 raw material described, the volume fraction of light alkanes is 0 - 20%, and the volume fraction of light olefins is not less than 30%.

4. The method for synthesizing a full-component aviation kerosene according to any one of claims 1 to 3, characterized in that: Before the catalytic reaction, the molecular sieve catalyst is subjected to an activation treatment.

5. A molecular sieve catalyst for synthesizing full-component aviation kerosene from mixed C4 raw materials, characterized in that: The molecular sieve catalyst is composed of a metal and a molecular sieve. By weight, the content of the metal is 3.2 - 20 wt%; the molecular sieve is ZSM-5 or MCM-22 molecular sieve; the metal is composed of at least one of noble metals Au, Pt, Pd and their oxides and at least one of common metals Ni, Ga, Zn and their oxides; the content of noble metals Au, Pt, Pd and their oxides in the molecular sieve catalyst is 0.2 - 4 wt%; the content of common metals Ni, Ga, Zn and their oxides in the molecular sieve catalyst is 3 - 16 wt%; the weight ratio of the common metal to the noble metal is (4.2 - 15):

1.

6. The molecular sieve catalyst according to claim 5, wherein: The molecular sieve catalyst is (1) a composite molecular sieve catalyst formed by physical mixing of a metal and a molecular sieve; or (2) a modified molecular sieve catalyst formed by loading a metal on a molecular sieve.

7. The molecular sieve catalyst according to claim 6, wherein: The specific preparation method of the modified molecular sieve catalyst is: Weigh an appropriate amount of metal soluble salt in water, stir until completely dissolved, add ZSM-5 or MCM-22 molecular sieve powder, and carry out isovolumetric impregnation or deposition precipitation at 70 - 90 °C for 8 - 12 h to obtain the modified molecular sieve catalyst.

8. The molecular sieve catalyst according to claim 6, characterized in that: The specific preparation method of the modified molecular sieve catalyst is: Weigh an appropriate amount of metal soluble salt in water and stir until completely dissolved; drop it into the synthetic sol-gel containing a silicon source, an aluminum source, a template agent, an alkali source and water, and stir until fully mixed; then carry out in-situ hydrothermal synthesis at a temperature of 150 - 180 °C for 72 - 96 hours, and after separation, washing and drying, the modified molecular sieve catalyst is obtained.

9. Use of the molecular sieve catalyst according to any one of claims 5 - 8 in the synthesis of full-component aviation kerosene from a mixed C4 raw material.

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