Method for Coupled Conversion of Naphtha and Carbon Dioxide to Produce Benzene, Toluene and p-Xylene

Abstract

The present application discloses a method for the coupled conversion of naphtha and CO2 into benzene, toluene and p-xylene. The method includes feeding a raw material containing naphtha and CO2 into a reactor filled with a zeolite molecular sieve catalyst to carry out a reaction to generate benzene, toluene and p-xylene, wherein the zeolite molecular sieve catalyst includes a modified zeolite molecular sieve. The method of the present application provides a new technical route for the large-scale production of benzene, toluene and p-xylene (i.e., BTPX) using CO2. This method overcomes the defects of limited hydrogen resources and high costs in the prior art. Using the modified HZSM-5 molecular sieve as the catalyst active ingredient, the selectivity of BTPX in hydrocarbon products is as high as 75.08%, and the selectivity of p-xylene in xylenes is above 92%.

Description

Technical Field

[0001] The present invention belongs to the field of petrochemical industry, and particularly relates to a method for coupling the conversion of naphtha and CO2 to produce benzene, toluene and p-xylene, and more particularly to a method for coupling the conversion of naphtha and CO2 to produce benzene, toluene and p-xylene by using a modified zeolite molecular sieve catalyst. Background Art

[0002] With the development of industry, the content of carbon dioxide (CO2) in the atmosphere is increasing day by day, resulting in an increasingly serious greenhouse effect. Recycling and utilizing CO2 has become the focus of research by scientific researchers.

[0003] In addition, benzene, toluene and xylene (hereinafter referred to as BTPX) are basic chemical products with a large market consumption. The current technical route for producing BTPX mainly involves the catalytic reforming of naphtha.

[0004] Although researchers have found that hydrogenation of carbon dioxide in the presence of hydrogen can be used to prepare BTPX. However, all such routes involve the production of liquid hydrocarbons or BTPX by hydrogenating carbon dioxide, and their technical indicators are difficult to achieve, and the source of hydrogen has also become a key problem restricting industrial applications. Summary of the Invention

[0005] In order to solve the above technical problems, the inventors of the present application have creatively discovered that using naphtha as a raw material and coupling it with CO2 as a raw material to produce benzene, toluene and p-xylene is a new technical route for using CO2 to produce benzene, toluene and p-xylene, providing a new way for the production of benzene, toluene and p-xylene and the large-scale utilization of CO2.

[0006] On the one hand, the present application provides a method for coupling the conversion of naphtha and CO2 to produce benzene, toluene and p-xylene, the method comprising feeding a raw material containing naphtha and CO2 into a reactor equipped with a zeolite molecular sieve catalyst to effect a reaction to produce benzene, toluene and p-xylene, wherein the zeolite molecular sieve catalyst comprises a modified zeolite molecular sieve.

[0007] Optionally, the modified zeolite molecular sieve is a zeolite molecular sieve modified by metal and silanization.

[0008] Optionally, the modified zeolite molecular sieve is a zeolite molecular sieve obtained by first performing metal modification and then performing silanization modification.

[0009] Optionally, the metal in the metal-modified zeolite molecular sieve is selected from at least one of La, Zn, Ga, Fe, Mo, Cr metals.

[0010] Optionally, the metal modification is performed using a bimetal of Zn and Ga.

[0011] Optionally, the modified zeolite molecular sieve is a zeolite molecular sieve modified only by silanization.

[0012] Optionally, the zeolite molecular sieve catalyst consists of a modified zeolite molecular sieve.

[0013] Optionally, the modified zeolite molecular sieve is a modified HZSM-5 zeolite molecular sieve.

[0014] Optionally, the metal modification is prepared by a high temperature hydrothermal method, which comprises the following steps:

[0015] (1) preparing a soluble metal salt aqueous solution;

[0016] (2) placing the zeolite molecular sieve to be metal-modified in the aqueous solution of the soluble metal salt and immersing it at a temperature of 60 to 100° C.; and

[0017] (3) draining the molecular sieve obtained in step (2), drying and calcining.

[0018] Optionally, the solid-liquid ratio of the modified zeolite molecular sieve to the soluble metal salt aqueous solution is 1 / 10 to 1 / 1 (mass ratio), and the mass concentration of the metal salt in the soluble metal salt aqueous solution is 10% to 30%; the impregnation time is 2 to 10 hours; the drying step is carried out in an air atmosphere at 100 to 150°C; and the calcination step is carried out in an air atmosphere at 500 to 700°C.

[0019] Optionally, in step (1), the soluble metal salt aqueous solution is heated to any value or a range determined by any two values of the following temperatures: 60°C, 70°C, 80°C, 90°C and 100°C.

[0020] Optionally, in step (2), the immersion time is any value or a range determined by any two values of the following time periods: 2 hours, 4 hours, 6 hours, 8 hours and 10 hours.

[0021] Optionally, the silanization modification adopts an in-situ chemical vapor deposition method, which comprises the following steps:

[0022] (1) placing a solid containing a zeolite molecular sieve to be modified by silanization in a reactor;

[0023] (2) introducing material A containing a silanization agent into the reactor at one time, wherein the amount of the silanization agent introduced is 0.2 to 0.3 g / g solid, and the silanization agent is in a gaseous state in the reactor;

[0024] (3) Stop feeding material A into the reactor, raise the reactor temperature to above 400°C and introduce air for calcination.

[0025] Specifically, the silanization modification adopts an in-situ chemical vapor deposition method, which includes the following steps:

[0026] (1) placing a solid containing a zeolite molecular sieve to be silanized in a reactor, and performing an activation treatment with nitrogen at a high temperature (e.g., 450-550° C.), and then cooling the solid to a silanization modification temperature (the temperature ensures that the silanization agent is in a gas phase in the reactor) in a nitrogen atmosphere;

[0027] (2) introducing material A containing all the silanization reagent into the reactor at one time and continuously for a predetermined time, wherein material A is a silanization reagent using nitrogen as a carrier gas;

[0028] (3) Stop feeding material A into the reactor, raise the reactor temperature to above 400° C. (e.g., 550° C.), and introduce air for calcination to complete the silanization modification of the zeolite molecular sieve.

[0029] Optionally, the silanization modification adopts an in-situ gas phase atomic layer deposition method, which comprises the following steps:

[0030] (1) placing a solid containing a metal-modified or unmodified zeolite molecular sieve in a reactor;

[0031] (2) introducing material A containing a silanization agent into the reactor in n times, wherein the amount of the silanization agent introduced each time is 0.03 to 0.06 g / (g zeolite molecular sieve), and the silanization agent is in a gaseous state in the reactor, wherein the value of n is in the range of 3 to 6;

[0032] (3) Stop feeding material A into the reactor, raise the reactor temperature to above 400°C and introduce air for calcination.

[0033] Specifically, the silanization modification adopts an in-situ gas phase atomic layer deposition method, which includes the following steps:

[0034] (1) placing a solid containing a metal-modified or unmodified zeolite molecular sieve in a reactor;

[0035] (2) nitrogen as a carrier gas is passed through a saturated bottle containing a silanization agent, and then the carrier gas carries the silanization agent into a reactor for a predetermined time; and the silanization agent is activated with nitrogen at a high temperature (e.g., 450-550° C.), and then cooled to a silanization modification temperature (this temperature ensures that the silanization agent is in a gas phase in the reactor) under a nitrogen atmosphere;

[0036] (3) Stop introducing the silylating reagent and nitrogen gas as the carrier gas into the reactor, raise the temperature of the reactor to above 400 °C (e.g., 550 °C), and introduce air for calcination to complete the primary silylation modification of the zeolite molecular sieve;

[0037] (4) Repeat steps (2) and (3) n times.

[0038] Optionally, "in-situ chemical vapor deposition method" and "in-situ gas-phase atomic layer deposition method" both refer to that after the silylation modification of the molecular sieve in the reactor, without removing the modified molecular sieve, it is used for the coupling conversion reaction of naphtha and CO2 in the same reactor. This in-situ gas-phase silylation method reduces steps such as catalyst transportation, loading, and washing, and greatly reduces costs.

[0039] Optionally, the silylating reagent used for the silylation modification is selected from at least one of the compounds with the following chemical formulas:

[0040]

[0041] wherein R1, R2, R3, and R4 are each independently selected from C 1-10 alkyl groups and C 1-10 alkoxy groups.

[0042] Optionally, at least one of R1, R2, R3, and R4 is selected from C 1-10 alkoxy groups.

[0043] Optionally, the silylating reagent is selected from at least one of tetraethyl orthosilicate and tetramethyl orthosilicate.

[0044] Optionally, the modified zeolite molecular sieve is a zeolite molecular sieve that has been successively subjected to metal modification, silylation modification, and in-situ steam modification.

[0045] Specifically, the steam modification is carried out through the following steps: introducing steam into the reactor where the molecular sieve modified by in-situ silylation is located, and heating it to 700 - 900 °C under a nitrogen atmosphere for a predetermined period of time.

[0046] Optionally, the raw material consists of naphtha and CO2.

[0047] Optionally, the naphtha is selected from at least one of hydrocracked naphtha, catalytically cracked naphtha, raffinate oil, topped oil, and direct coal liquefaction naphtha.

[0048] Optionally, the carbon number distribution range of the hydrocarbons in the naphtha is C4 - C 12 .

[0049] Optionally, the reactor is one of a fixed-bed reactor, a fluidized-bed reactor, or a moving-bed reactor.

[0050] Optionally, the conditions for the reaction of naphtha and CO2 are as follows: the reaction temperature is 450 - 650 °C, the reaction pressure is 0.1 - 3 MPa, the weight hourly space velocity of the naphtha is 0.1 - 5 h -1 , and the weight hourly space velocity of CO2 is 0.1 - 5 h -1 .

[0051] Optionally, the reaction temperature is selected from any value among 450 °C, 500 °C, 550 °C, and 650 °C, or a range value determined by any two numerical values.

[0052] Optionally, the reaction pressure is selected from any value among 0.1 MPa, 1 MPa, and 3 MPa, or a range value determined by two numerical values.

[0053] Optionally, the weight hourly space velocity of the naphtha is selected from any value among 0.1 h -1 , 1 h -1 , and 5 h -1 , or a range value determined by any two numerical values.

[0054] Optionally, the weight hourly space velocity of CO2 is selected from any value among 0.1 h -1 , 0.3 h -1 , and 5 h -1 , or a range value determined by any two numerical values.

[0055] Optionally, the reaction time is 30 minutes - 120 minutes.

[0056] Optionally, the mass ratio of CO2 to naphtha is 0.8:0.27 - 0.8:1;

[0057] Optionally, the mass ratio of CO2 to naphtha is any value among 0.8:0.27, 0.8:1, and 1:1, or a range value determined by any two numerical values.

[0058] Optionally, the zeolite molecular sieve catalyst further includes a binder.

[0059] In this application, the preparation method of the zeolite molecular sieve catalyst for fluidized bed is as follows: the zeolite molecular sieve modified by metal is mixed evenly with the binder in water, and after beating, colloidal milling, and defoaming, a slurry is obtained. The obtained slurry is formed by conventional spray drying and calcined to obtain the zeolite molecular sieve for fluidized bed; wherein the binder includes an amorphous binder containing aluminum or silicon, preferably pseudoboehmite or silica sol.

[0060] Specifically, the method for the coupled conversion of naphtha and CO2 to BTPX is as follows:

[0061] (1) Load the zeolite molecular sieve catalyst into the reactor, and first pre-treat it with an inert gas such as nitrogen at a predetermined temperature, and adjust it to the reaction temperature under a nitrogen atmosphere;

[0062] (2) Feed naphtha and CO₂. Among them, naphtha is fed using a micro-feeding pump, and the feed rate of CO₂ is controlled by a flow meter, and the reaction pressure is controlled within a predetermined range;

[0063] (3) After naphtha and CO₂ react for a predetermined time, analyze the products by gas chromatography.

[0064] The "hydrocracked naphtha" in this application refers to the heavy naphtha produced by the hydrocracking reaction of heavy oil.

[0065] The "catalytically cracked naphtha" in this application refers to the naphtha produced by the catalytic cracking of vacuum gas oil and atmospheric residue.

[0066] The "raffinate" in this application refers to the fraction oil remaining after extracting aromatics from the catalytic reformate rich in aromatics.

[0067] The "topped oil" in this application refers to the light fraction with a boiling point lower than 60 °C obtained during the distillation of straight-run gasoline.

[0068] The "coal direct liquefaction naphtha" in this application refers to the naphtha produced by a coal direct liquefaction unit.

[0069] In this application, the coupling conversion of naphtha and CO₂ to aromatics means that CO₂ reacts with naphtha as a raw material to prepare aromatics.

[0070] On the other hand, this application provides a method for silanizing and modifying a molecular sieve catalyst, and this method includes the following steps:

[0071] (1) Place a solid containing metal-modified or unmodified zeolite molecular sieve in a reactor;

[0072] (2) Feed material A containing a silanizing reagent into the reactor in n times, where the feeding amount of the silanizing reagent each time is 0.03 - 0.06 g / g solid, and the silanizing reagent is in a gaseous state in the reactor, and the value range of n is 3 - 6;

[0073] (3) Stop feeding material A into the reactor, raise the reactor temperature to above 400 °C and pass in air for calcination.

[0074] Specifically, the silanization modification adopts in-situ gas-phase atomic layer deposition method, which includes the following steps:

[0075] (1) Place a solid containing metal-modified or unmodified zeolite molecular sieve in a reactor;

[0076] (2) Pass nitrogen gas, which serves as the carrier gas, through a saturated bottle containing a silylating reagent. Subsequently, the carrier gas carries the silylating reagent into the reactor and continues for a predetermined time; and under high-temperature conditions (such as 450 - 550 °C), it is activated with nitrogen gas, and then cooled to the silylation modification temperature in a nitrogen atmosphere (this temperature ensures that the silylating reagent is in a gaseous state in the reactor);

[0077] (3) Stop passing the silylating reagent and the nitrogen gas serving as the carrier gas into the reactor. Raise the temperature of the reactor to above 400 °C (such as 550 °C) and pass air for calcination to complete the primary silylation modification of the zeolite molecular sieve;

[0078] (4) Repeat steps (2) and (3) n times.

[0079] On the other hand, the present application provides a method for modifying a molecular sieve catalyst, which includes the following steps:

[0080] (1) Prepare an aqueous solution of a soluble metal salt;

[0081] (2) Place the zeolite molecular sieve in the aqueous solution of the soluble metal salt and impregnate it at a temperature of 60 - 100 °C for a certain time; and

[0082] (3) After draining the modified molecular sieve obtained in step (2), perform drying and calcination;

[0083] (4) Place the metal-modified molecular sieve obtained in step (3) in a reactor;

[0084] (5) Pass material A containing a silylating reagent into the reactor in n portions, where the amount of the silylating reagent passed each time is 0.03 - 0.06 g / g solid, and the silylating reagent is in a gaseous state in the reactor, where the value range of n is 3 - 6;

[0085] (6) Stop passing material A into the reactor. Raise the temperature of the reactor to above 400 °C and pass air for calcination to obtain a molecular sieve that is first metal-modified and then gas-phase silylated-modified.

[0086] Optionally, the solid-liquid ratio of the modified zeolite molecular sieve to the aqueous solution of the soluble metal salt is 1 / 10 - 1 / 1 (mass ratio), the mass concentration of the metal salt in the aqueous solution of the soluble metal salt is 10% - 30%; the impregnation time is 2 - 10 hours; the drying step is carried out under an air atmosphere at 100 - 150 °C; the calcination step is carried out under an air atmosphere and at 500 - 700 °C.

[0087] Optionally, in step (1), the aqueous solution of soluble metal salt is heated to any value or a range value determined by any two of the following temperatures: 60°C, 70°C, 80°C, 90°C, and 100°C.

[0088] Optionally, in step (2), the impregnation time is any value or a range value determined by any two of the following times: 2 hours, 4 hours, 6 hours, 8 hours, and 10 hours.

[0089] Optionally, the zeolite molecular sieve is HZSM-5 hydrogen-type molecular sieve.

[0090] Optionally, the metal in the metal-modified zeolite molecular sieve is selected from at least one of La, Zn, Ga, Fe, Mo, and Cr metals.

[0091] Optionally, the silanization reagent used for silanization modification is selected from at least one of the compounds with the following chemical formulas:

[0092]

[0093] wherein R1, R2, R3, and R4 are each independently selected from C 1-10 alkyl, C 1-10 alkoxy.

[0094] Optionally, at least one of R1, R2, R3, and R4 is selected from C 1-10 alkoxy.

[0095] Optionally, the silanization reagent is selected from at least one of tetraethyl silicate and tetramethyl silicate.

[0096] The beneficial effects that can be produced by this application include:

[0097] 1) This application provides a new technical route for large-scale production of benzene, toluene, and p-xylene (i.e., BTPX) using CO2, which overcomes the defects of limited hydrogen resources and high cost in the prior art.

[0098] 2) In this application, using the modified HZSM-5 molecular sieve as the catalyst active ingredient, the selectivity of BTPX in hydrocarbon products is as high as 75.08%, and the selectivity of p-xylene in xylene is above 92%;

[0099] 3) In this application, compared with using only the metal-modified HZSM-5 molecular sieve as the catalyst active ingredient, using the metal-modified and silanized HZSM-5 molecular sieve as the catalyst active ingredient can achieve higher selectivity of BTPX and p-xylene in xylene;

[0100] 4) In this application, compared with the silanization using the in-situ chemical vapor deposition method, the silanization modification using the in-situ gas-phase atomic layer deposition method enables higher BTPX selectivity and para-xylene selectivity in xylene when the modified HZSM-5 molecular sieve is used as the active ingredient. Detailed Embodiments

[0101] The present application will be described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0102] In the ranges disclosed in this application, the endpoints and any values of the ranges are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values and the individual point values of each range, 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.

[0103] The present application will be described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0104] Unless otherwise specified, the raw materials in the embodiments of the present application are all purchased through commercial channels or prepared by known methods. The HZSM-5 zeolite molecular sieve in the embodiments is purchased from the Catalyst Factory of Nankai University.

[0105] Unless otherwise specified, the analysis methods in the embodiments all adopt the conventional settings and conventional analysis methods of the instruments or equipment.

[0106] In the embodiments of the present application, the type of naphtha is coal direct liquefaction naphtha, and its specific composition is shown in the following table:

[0107] Composition of Coal Direct Liquefaction Naphtha

[0108] Carbon number n-alkane iso-alkane naphthene aromatic hydrocarbon 6 0.03 0.00 0.00 0.00 7 3.76 0.71 31.85 1.60 8 9.36 2.62 27.53 1.94 9 2.03 2.44 13.88 0.40 10 0.15 0.75 0.74 0.07 11 0.01 0.03 0.10 0.00 Total 15.34 6.55 74.10 4.01

[0109] In the embodiments of the present application, the inner diameter of the fixed-bed reactor is 1.5 cm; the inner diameter of the fixed fluidized-bed reactor is 3 cm.

[0110] In the products of the embodiments of the present application, only hydrocarbon products are listed, and other products generated by the reaction of naphtha and CO2 are not listed.

[0111] Example 1 Preparation of a Shaped Sample of Zinc-Modified HZSM-5 Molecular Sieve for Fixed Bed

[0112] 100 g of HZSM-5 zeolite molecular sieve (manufactured by the Catalyst Factory of Nankai University, Si / Al = 15) was placed in an aqueous solution of zinc nitrate with a concentration of 10 wt%. The mass ratio of the HZSM-5 zeolite molecular sieve to the aqueous solution of zinc nitrate (i.e., the solid-liquid ratio) was 1 / 10. It was impregnated at 80 °C for 6 hours, drained, dried in an air atmosphere at 120 °C for 4 hours, and then calcined in an air atmosphere at 550 °C for 4 hours to obtain the [Zn]HZSM-5 molecular sieve sample. It was tableted, crushed, and screened to obtain formed molecular sieve particles with a particle size of 40 - 60 mesh, denoted as FX-[Zn]HZSM-5.

[0113] Preparation of Formed Sample of Gallium-Modified HZSM-5 Molecular Sieve for Fixed Bed in Example 2

[0114] 100 g of HZSM-5 zeolite molecular sieve (manufactured by the Catalyst Factory of Nankai University, Si / Al = 15) was placed in an aqueous solution of gallium nitrate with a concentration of 10 wt%. The mass ratio of the HZSM-5 zeolite molecular sieve to the aqueous solution of gallium nitrate (i.e., the solid-liquid ratio) was 1 / 10. It was impregnated at 80 °C for 6 hours, drained, dried in an air atmosphere at 120 °C for 4 hours, and then calcined in an air atmosphere at 550 °C for 4 hours to obtain the [Ga]HZSM-5 molecular sieve sample. It was tableted, crushed, and screened to obtain formed molecular sieve particles with a particle size of 40 - 60 mesh, denoted as FX-[Ga]HZSM-5.

[0115] Preparation of Formed Sample of Lanthanum-Modified HZSM-5 Molecular Sieve for Fixed Bed in Example 3

[0116] 100 g of HZSM-5 zeolite molecular sieve (manufactured by the Catalyst Factory of Nankai University, Si / Al = 15) was placed in an aqueous solution of lanthanum nitrate with a concentration of 10 wt%. The mass ratio of the HZSM-5 zeolite molecular sieve to the aqueous solution of lanthanum nitrate (i.e., the solid-liquid ratio) was 1 / 10. It was impregnated at 90 °C for 4 hours, drained, dried in an air atmosphere at 120 °C for 4 hours, and then calcined in an air atmosphere at 550 °C for 4 hours to obtain the [La]HZSM-5 molecular sieve sample. It was tableted, crushed, and screened to obtain formed molecular sieve particles with a particle size of 40 - 60 mesh, denoted as FX-[La]HZSM-5.

[0117] Preparation of Formed Sample of Iron-Modified HZSM-5 Molecular Sieve for Fixed Bed in Example 4

[0118] 100 g of HZSM-5 zeolite molecular sieve (manufactured by the Catalyst Factory of Nankai University, Si / Al = 15) was placed in an aqueous solution of iron nitrate with a concentration of 10 wt%, where the mass ratio of HZSM-5 zeolite molecular sieve to the aqueous solution of iron nitrate (i.e., solid-liquid ratio) was 1 / 10. It was impregnated at 70 °C for 8 hours, drained, dried in an air atmosphere at 120 °C for 4 hours, and then calcined in an air atmosphere at 550 °C for 4 hours to obtain the [Fe]HZSM-5 molecular sieve sample. It was tableted, formed, crushed, and screened to obtain shaped molecular sieve particles with a particle size of 40 - 60 mesh, denoted as FX-[Fe]HZSM-5.

[0119] Example 5 Preparation of a chromium-modified HZSM-5 molecular sieve shaped sample for fixed bed

[0120] 100 g of HZSM-5 zeolite molecular sieve (manufactured by the Catalyst Factory of Nankai University, Si / Al = 15) was placed in an aqueous solution of chromium nitrate with a concentration of 10 wt%, where the mass ratio of HZSM-5 zeolite molecular sieve to the aqueous solution of chromium nitrate (i.e., solid-liquid ratio) was 1 / 10. It was impregnated at 70 °C for 8 hours, drained, dried in an air atmosphere at 120 °C for 4 hours, and then calcined in an air atmosphere at 550 °C for 4 hours to obtain the [Cr]HZSM-5 molecular sieve sample. It was tableted, formed, crushed, and screened to obtain shaped molecular sieve particles with a particle size of 40 - 60 mesh, denoted as FX-[Cr]HZSM-5.

[0121] Example 6 Preparation of a zinc-modified HZSM-5 shaped molecular sieve sample for fluidized bed

[0122] 100 g of the [Zn]HZSM-5 molecular sieve sample prepared in Example 1 was mixed with an amorphous binder containing aluminum or silicon and spray-dried into shape. The specific steps were as follows:

[0123] The [Zn]HZSM-5 molecular sieve sample, pseudoboehmite, silica sol, xanthan gum (biological gum), and water were mixed evenly, and after beating, colloid milling, and defoaming, a slurry was obtained; the weight fractions of each component in the slurry were:

[0124]

[0125] The obtained slurry was spray-dried into shape to obtain a microsphere particle sample with a particle size distribution of 20 - 100 μm; after the microsphere particle sample was calcined in a muffle furnace at 550 °C for 3 hours, a [Zn]HZSM-5 shaped molecular sieve with a attrition index of 1.2 was obtained, denoted as FL-[Zn]HZSM-5.

[0126] Example 7 Preparation of a zinc- and gallium-composite-modified HZSM-5 molecular sieve shaped sample for fixed bed

[0127] 100 g of HZSM-5 zeolite molecular sieve (manufactured by the Catalyst Factory of Nankai University, Si / Al = 15) was placed in an aqueous solution of zinc nitrate and gallium nitrate with a concentration of 10 wt%, where the mass ratio of zinc nitrate to gallium nitrate was 1 / 1. The mass ratio of the HZSM-5 zeolite molecular sieve to the aqueous solution of zinc nitrate and gallium nitrate (i.e., the solid-liquid ratio) was 1 / 10. It was impregnated at 80 °C for 6 hours, drained, dried in an air atmosphere at 120 °C for 4 hours, and then calcined in an air atmosphere at 550 °C for 4 hours to obtain the [Zn,Ga]HZSM-5 molecular sieve sample. It was tableted, crushed, and sieved to obtain formed molecular sieve particles with a particle size of 40 - 60 mesh, denoted as FX-[Zn,Ga]HZSM-5.

[0128] Preparation of a Zinc-Modified HZSM-5 Molecular Sieve Formed Sample for Fixed Bed in Example 8

[0129] 100 g of HZSM-5 zeolite molecular sieve (manufactured by the Catalyst Factory of Nankai University, Si / Al = 15) was placed in an aqueous solution of zinc nitrate with a concentration of 10 wt%. The mass ratio of the HZSM-5 zeolite molecular sieve to the aqueous solution of zinc nitrate (i.e., the solid-liquid ratio) was the same as that in Example 1. It was impregnated at room temperature (20 °C) for 6 hours, drained, dried in an air atmosphere at 120 °C for 4 hours, and then calcined in an air atmosphere at 550 °C for 4 hours to obtain the [Zn]HZSM-5 molecular sieve sample. It was tableted, crushed, and sieved to obtain formed molecular sieve particles with a particle size of 40 - 60 mesh, denoted as FX-[Zn]HZSM-5-R.

[0130] Preparation of a Zinc-Modified HZSM-5 Molecular Sieve Formed Sample for Fixed Bed in Example 9

[0131] 100 g of HZSM-5 zeolite molecular sieve (manufactured by the Catalyst Factory of Nankai University, Si / Al = 15) was placed in an aqueous solution of zinc nitrate with a concentration of 10 wt%. The mass ratio of the HZSM-5 zeolite molecular sieve to the aqueous solution of zinc nitrate (i.e., the solid-liquid ratio) was 1 / 1. It was impregnated at 80 °C for 6 hours, drained, dried in an air atmosphere at 120 °C for 4 hours, and then calcined in an air atmosphere at 550 °C for 4 hours to obtain the [Zn]HZSM-5 molecular sieve sample. It was tableted, crushed, and sieved to obtain formed molecular sieve particles with a particle size of 40 - 60 mesh, denoted as FX-[Zn]HZSM-5-A.

[0132] Preparation and Reaction Evaluation of a Catalyst for Benzene, Toluene, and p-Xylene in Example 10

[0133] The catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene is prepared online in a micro fixed-bed reactor. The conditions for the online preparation of the catalyst are as follows: 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 1 is loaded into the fixed-bed reactor, first treated with 50 mL / min of nitrogen at 550 °C for 1 hour, and then cooled to 300 °C under a nitrogen atmosphere. Under a nitrogen atmosphere (controlled by a mass flow meter, 100 mL / min), tetraethyl orthosilicate is pumped into the reactor, and the weight hourly space velocity of tetraethyl orthosilicate is 0.2 h -1 , at atmospheric pressure. After feeding for 60 min, the feeding is stopped, the feeding amount of tetraethyl orthosilicate is 0.2 g / g of the above catalyst, purged with nitrogen, heated to 550 °C, and calcined in an air atmosphere for 4 hours to obtain the fixed-bed catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene, named FXNCC-1.

[0134] Then, the temperature is adjusted to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material is fed by a micro-feeding pump, the CO2 flow rate is controlled by a mass flow meter, the raw material CO2:naphtha (mass ratio)=0.8:1, and the weight hourly space velocity of CO2 is =0.8 h -1 , and the weight hourly space velocity of naphtha is 1.0 h -1 , and the reaction pressure is 0.1 MPa. The reaction products are analyzed by on-line Agilent 7890 gas chromatography, and samples are taken for analysis at 30 min of the reaction. The reaction results are shown in Table 1.

[0135] Table 1 Evaluation of the reaction performance of the catalyst in Example 10

[0136]

[0137] Preparation and reaction evaluation of the catalyst for preparing benzene, toluene and p-xylene in Example 10-1

[0138] The reaction performance of the catalyst for the coupled conversion of naphtha and CO2 is evaluated in a micro fixed-bed reactor. The evaluation conditions are as follows: 5 g of the FX-[Zn]HZSM-5 prepared in Example 1 is loaded into the fixed-bed reactor and first treated with 50 mL / min of nitrogen at 550 °C for 1 hour.

[0139] Then, the reaction temperature is 550 °C under a nitrogen atmosphere; the naphtha raw material is fed by a micro-feeding pump, the CO2 flow rate is controlled by a mass flow meter, the raw material CO2:naphtha (mass ratio)=0.8:1, and the weight hourly space velocity of CO2 is =0.8 h -1 , and the weight hourly space velocity of naphtha is 1.0 h -1 , and the reaction pressure is 0.1 MPa. The reaction products are analyzed by on-line Agilent 7890 gas chromatography, and samples are taken for analysis at 30 min of the reaction. The reaction results are shown in Table 1-1.

[0140] Table 1-1 Reaction performance evaluation of the catalyst in Example 10-1

[0141]

[0142] By comparing Example 10 and Example 10-1, it can be seen that, compared with using only metal-modified HZSM-5 molecular sieve as the catalyst active ingredient, using metal-modified and silanized HZSM-5 molecular sieve as the catalyst active ingredient can achieve higher BTPX selectivity and para-xylene selectivity in xylene.

[0143] Example 11 Preparation and reaction evaluation of the catalyst for benzene, toluene and para-xylene

[0144] In a micro fixed-bed reactor, a catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and para-xylene was prepared online. The conditions for online catalyst preparation are as follows: Load 5 g of the FX-[Ga]HZSM-5 catalyst prepared in Example 2 into the fixed-bed reactor, first treat it with 50 mL / min of nitrogen at 550 °C for 1 hour, and then cool it to 300 °C under a nitrogen atmosphere. Under a nitrogen atmosphere (controlled by a mass flow meter, 100 mL / min), tetraethyl orthosilicate was pumped into the reactor, and the weight hourly space velocity of tetraethyl orthosilicate was 0.2 h -1 , at atmospheric pressure. After 60 min of feeding, stop feeding. The feeding amount of tetraethyl orthosilicate is the same as that in Example 10. Purge with nitrogen, heat up to 550 °C, and calcine in an air atmosphere for 4 hours to obtain a fixed-bed catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and para-xylene, named FXNCC-2.

[0145] Then, adjust the temperature to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material is fed by a micro-feeding pump, and the CO2 flow rate is controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of CO2 is = 0.8 h -1 , the weight hourly space velocity of naphtha is 1.0 h -1 , and the reaction pressure is 0.1 MPa. The reaction products were analyzed by on-line Agilent 7890 gas chromatography, and samples were taken for analysis at 30 min of the reaction. The reaction results are shown in Table 2.

[0146] Table 2 Reaction performance evaluation of the catalyst in Example 11

[0147]

[0148] Example 12 Preparation and reaction evaluation of the catalyst for benzene, toluene and para-xylene

[0149] The catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene was prepared online in a micro fixed-bed reactor. The conditions for the online preparation of the catalyst are as follows: 5 g of the FX-[La]HZSM-5 catalyst prepared in Example 3 was loaded into the fixed-bed reactor, first treated with 50 mL / min of nitrogen at 550 °C for 1 hour, and then cooled to 300 °C under a nitrogen atmosphere. Under a nitrogen atmosphere (controlled by a mass flowmeter, 100 mL / min), tetraethyl orthosilicate was pumped into the reactor, and the weight hourly space velocity of tetraethyl orthosilicate was 0.2 h -1 , at atmospheric pressure. After 60 min of feeding, the feeding was stopped. The feeding amount of tetraethyl orthosilicate was the same as that in Example 10, purged with nitrogen, heated to 550 °C, and calcined in an air atmosphere for 4 hours to obtain a fixed-bed catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene, named FXNCC-3.

[0150] Then, the temperature was adjusted to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material was fed by a micro-feeding pump, and the CO2 flow rate was controlled by a mass flowmeter. The raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of CO2 was = 0.8 h -1 , and the weight hourly space velocity of naphtha was 1.0 h -1 , and the reaction pressure was 0.1 MPa. The reaction products were analyzed by an online Agilent 7890 gas chromatograph, and samples were taken for analysis at 30 min of the reaction. The reaction results are shown in Table 3.

[0151] Table 3 Evaluation of the reaction performance of the catalyst in Example 12

[0152]

[0153]

[0154] Preparation and reaction evaluation of the catalyst for benzene, toluene and p-xylene in Example 13

[0155] The catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene was prepared online in a micro fixed-bed reactor. The conditions for the online preparation of the catalyst are as follows: 5 g of the FX-[Fe]HZSM-5 catalyst prepared in Example 4 was loaded into the fixed-bed reactor, first treated with 50 mL / min of nitrogen at 550 °C for 1 hour, and then cooled to 300 °C under a nitrogen atmosphere. Under a nitrogen atmosphere (controlled by a mass flowmeter, 100 mL / min), tetraethyl orthosilicate was pumped into the reactor, and the weight hourly space velocity of tetraethyl orthosilicate was 0.2 h -1, at atmospheric pressure. After feeding for 60 min, the feeding was stopped. The feeding amount of tetraethyl orthosilicate was the same as that in Example 10. It was purged with nitrogen, heated to 550 °C, and calcined in an air atmosphere for 4 hours to obtain a fixed-bed catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene, and p-xylene, named FXNCC-4.

[0156] Then, the temperature was adjusted to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material was fed by a micro-feeding pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of CO2 was = 0.8 h -1 , and the weight hourly space velocity of naphtha was 1.0 h -1 , and the reaction pressure was 0.1 MPa. The reaction products were analyzed by an on-line Agilent 7890 gas chromatograph, and samples were taken for analysis at 30 min of the reaction. The reaction results are shown in Table 4.

[0157] Table 4 Evaluation of the reaction performance of the catalyst in Example 13

[0158]

[0159]

[0160] Example 14 Preparation and reaction evaluation of a catalyst for benzene, toluene, and p-xylene

[0161] A fixed-bed catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene, and p-xylene was prepared on-line in a micro fixed-bed reaction device. The conditions for on-line catalyst preparation were as follows: 5 g of the FX-[Cr]HZSM-5 catalyst prepared in Example 5 was loaded into a fixed-bed reactor, first treated with 50 mL / min of nitrogen at 550 °C for 1 hour, and then cooled to 300 °C under a nitrogen atmosphere. Under a nitrogen atmosphere (controlled by a mass flow meter, 100 mL / min), tetraethyl orthosilicate was pumped into the reactor, and the weight hourly space velocity of tetraethyl orthosilicate was 0.2 h -1 , at atmospheric pressure. After feeding for 60 min, the feeding was stopped. The feeding amount of tetraethyl orthosilicate was the same as that in Example 10. It was purged with nitrogen, heated to 550 °C, and calcined in an air atmosphere for 4 hours to obtain a fixed-bed catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene, and p-xylene, named FXNCC-5.

[0162] Then, the temperature was adjusted to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material was fed by a micro-feeding pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of CO2 was = 0.8 h -1 , and the weight hourly space velocity of naphtha was 1.0 h -1, the reaction pressure was 0.1 MPa. The reaction products were analyzed by on-line Agilent 7890 gas chromatography, and samples were taken for analysis after 30 min of reaction. The reaction results are shown in Table 5.

[0163] Table 5 Evaluation of the reaction performance of the catalyst in Example 14

[0164]

[0165]

[0166] Example 15 Preparation and reaction evaluation of catalysts for benzene, toluene and p-xylene

[0167] In a micro fixed fluidized bed reactor, a catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene was prepared on-line. The conditions for on-line catalyst preparation were as follows: 10 g of the FL-[Zn]HZSM-5 catalyst prepared in Example 6 was loaded into the fixed fluidized bed reactor, first treated with 50 mL / min of nitrogen at 550 °C for 1 h, and then cooled to 300 °C under a nitrogen atmosphere. Under a nitrogen atmosphere (controlled by a mass flow meter, 200 mL / min), tetraethyl orthosilicate was pumped into the reactor, and the weight hourly space velocity of tetraethyl orthosilicate was 0.2 h -1 , atmospheric pressure. After 75 min of feeding, the feeding was stopped. The feeding amount of tetraethyl orthosilicate was 1.25 times that of Example 9, purged with nitrogen, heated to 550 °C, and calcined in an air atmosphere for 4 h to obtain a fixed bed catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene, named FLNCC-1. The purpose of using 10 g of the shaped molecular sieve sample FL-[Zn]HZSM-5 in this example was only to meet the requirements of the micro fixed fluidized bed reactor, and at this amount (10 g), the catalyst could be in a fluidized state, while at a content of 5 g, it could not ensure that the catalyst was in a fluidized state. When using a micro fixed fluidized bed reactor, the feeding time for silylation modification was 75 min only to perform the same degree of silylation modification as in Example 9.

[0168] Then, the temperature was adjusted to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material was fed by a micro-feeding pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of CO2 was = 0.8 h -1 , the weight hourly space velocity of naphtha was 1.0 h -1 , the reaction pressure was 0.1 MPa. The reaction products were analyzed by on-line Agilent 7890 gas chromatography, and samples were taken for analysis after 30 min of reaction. The reaction results are shown in Table 6.

[0169] Table 6 Evaluation of the reaction performance of the catalyst in Example 15

[0170]

[0171]

[0172] Example 16 Preparation and Reaction Evaluation of Catalysts for Producing Benzene, Toluene and p-Xylene

[0173] In a micro fixed-bed reaction device, a catalyst for the coupled conversion of naphtha and CO2 to produce benzene, toluene and p-xylene was prepared online. The conditions for online catalyst preparation were as follows: 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 1 was loaded into a fixed-bed reactor, first treated with 50 mL / min of nitrogen at 550 °C for 1 hour, and then cooled to 300 °C under a nitrogen atmosphere. Then, silanization reagent modification was carried out by gas-phase atomic layer deposition. The specific steps were as follows: (1) Nitrogen (controlled by a mass flow meter, 200 mL / min) passed through a saturated bottle containing tetraethyl orthosilicate (temperature 15 °C) and then entered the reactor, that is, tetraethyl orthosilicate was carried into the reactor by nitrogen. The feeding was stopped after 5 min of feeding; (2) Purged with nitrogen and heated to 550 °C, and calcined in an air atmosphere for 1 hour; (3) Steps (1) and (2) were repeated 3 times, and the amount of tetraethyl orthosilicate introduced 4 times was equivalent to the amount introduced once in Example 10, to obtain a fixed-bed catalyst for the coupled conversion of naphtha and CO2 to produce benzene, toluene and p-xylene, named FXNCC-6.

[0174] Then, the temperature was adjusted to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material was fed by a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of naphtha was 1.0 h -1 , and the reaction pressure was 0.1 MPa. The reaction products were analyzed by on-line Agilent 7890 gas chromatography, and samples were taken for analysis at 30 min of the reaction. The reaction results are shown in Table 7.

[0175] Table 7 Reaction Performance Evaluation of the Catalyst in Example 16

[0176]

[0177]

[0178] Example 17 Preparation and Reaction Evaluation of Catalysts for Producing Benzene, Toluene and p-Xylene

[0179] The catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene is prepared online in a micro fixed-bed reactor. The conditions for the online preparation of the catalyst are as follows: 5 g of the FX-[Zn,Ga]HZSM-5 catalyst prepared in Example 7 is loaded into the fixed-bed reactor, first treated with 50 mL / min of nitrogen at 550 °C for 1 hour, and then cooled to 300 °C under a nitrogen atmosphere. Under a nitrogen atmosphere (controlled by a mass flow meter, 100 mL / min), tetraethyl orthosilicate is pumped into the reactor, and the weight hourly space velocity of tetraethyl orthosilicate is 0.2 h -1 , at atmospheric pressure. After 60 min of feeding, the feeding is stopped, and the feeding amount of tetraethyl orthosilicate is the same as that in Example 10, purged with nitrogen, heated to 550 °C, and calcined in an air atmosphere for 4 hours to obtain a fixed-bed catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene, named FXNCC-7.

[0180] Then, the temperature is adjusted to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material is fed by a micro-feeding pump, and the CO2 flow rate is controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of CO2 is = 0.8 h -1 , and the weight hourly space velocity of naphtha is 1.0 h -1 , and the reaction pressure is 0.1 MPa. The reaction products are analyzed by an online Agilent 7890 gas chromatograph, and samples are taken for analysis at 30 min of the reaction. The reaction results are shown in Table 8.

[0181] Table 8 Evaluation of the reaction performance of the catalyst in Example 17

[0182]

[0183]

[0184] Preparation and reaction evaluation of the catalyst for benzene, toluene and p-xylene in Example 18

[0185] The catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene is prepared online in a micro fixed-bed reactor. The conditions for the online preparation of the catalyst are as follows: 5 g of the FX-[Zn]HZSM-5-R catalyst prepared in Example 8 is loaded into the fixed-bed reactor, first treated with 50 mL / min of nitrogen at 550 °C for 1 hour, and then cooled to 300 °C under a nitrogen atmosphere. Under a nitrogen atmosphere (controlled by a mass flow meter, 100 mL / min), tetraethyl orthosilicate is pumped into the reactor, and the weight hourly space velocity of tetraethyl orthosilicate is 0.2 h -1, at atmospheric pressure. After feeding for 60 min, the feeding was stopped, and the feeding amount of tetraethyl orthosilicate was the same as that in Example 10. It was purged with nitrogen, heated to 550 °C, and calcined in an air atmosphere for 4 hours to obtain a fixed-bed catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene, and p-xylene, named FXNCC-8.

[0186] Then, the temperature was adjusted to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material was fed by a micro-feeding pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of CO2 was = 0.8 h -1 , and the weight hourly space velocity of naphtha was 1.0 h -1 , and the reaction pressure was 0.1 MPa. The reaction products were analyzed by an on-line Agilent 7890 gas chromatograph, and samples were taken for analysis at 30 min of the reaction. The reaction results are shown in Table 9.

[0187] Table 9 Evaluation of the reaction performance of the catalyst in Example 18

[0188]

[0189]

[0190] By comparing with the selectivity of BTPX in Example 10, the HZSM-5 molecular sieve modified by the high-temperature hydrothermal method can achieve a higher BTPX selectivity than that modified by the room-temperature impregnation method.

[0191] Preparation of the ZSM-5 catalyst modified with a silanization reagent for the fixed bed in Example 19

[0192] A catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene, and p-xylene was prepared on-line in a micro fixed-bed reaction device. The conditions for on-line catalyst preparation were as follows: 5 g of 40-60 mesh HZSM-5 molecular sieve catalyst was loaded into a fixed-bed reactor, first treated with 50 mL / min of nitrogen at 550 °C for 1 hour, and then cooled to 300 °C under a nitrogen atmosphere. Under a nitrogen atmosphere (controlled by a mass flow meter, 100 mL / min), tetraethyl orthosilicate was pumped into the reactor, and the weight hourly space velocity of tetraethyl orthosilicate was 0.2 h -1 , at atmospheric pressure. After feeding for 60 min, the feeding was stopped, and the feeding amount of tetraethyl orthosilicate was the same as that in Example 10. It was purged with nitrogen, heated to 550 °C, and calcined in an air atmosphere for 4 hours to obtain a fixed-bed catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene, and p-xylene, named FXNCC-9.

[0193] Then, adjust the temperature to the reaction temperature of 550 °C under a nitrogen atmosphere; feed the naphtha raw material with a micro-feed pump, control the CO2 flow rate with a mass flow meter, the raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of CO2 is = 0.8 h -1 , and the weight hourly space velocity of naphtha is 1.0 h -1 , and the reaction pressure is 0.1 MPa. The reaction products are analyzed by an on-line Agilent 7890 gas chromatograph, and samples are taken for analysis at 30 min of the reaction. The reaction results are shown in Table 9-1.

[0194] Table 9-1 Evaluation of the reaction performance of the catalyst in Example 19

[0195]

[0196]

[0197] Example 20 Preparation and reaction evaluation of a catalyst for preparing benzene, toluene and p-xylene

[0198] Place 5 g of the FXNCC-9 catalyst prepared in Example 19 in a 10 wt% lanthanum nitrate solution. The solid-liquid ratio of the HZSM-5 zeolite molecular sieve used in the FXNCC-9 catalyst to the lanthanum nitrate aqueous solution is the same as in Example 3. Immerse it at 90 °C for 4 hours, drain it, and dry it in an air atmosphere at 120 °C for 4 hours. Then, calcine it in an air atmosphere at 550 °C for 4 hours to obtain a catalyst sample, denoted as FXNCC-10.

[0199] Evaluate the performance of the catalyst for the coupled conversion reaction of naphtha and CO2 in a micro fixed-bed reaction device. The evaluation conditions are as follows: Load 5 g (40-60 mesh) of the shaped catalyst sample FXNCC-11 into the fixed-bed reactor, and heat it to the reaction temperature of 550 °C under a nitrogen atmosphere; feed the naphtha raw material with a micro-feed pump, control the CO2 flow rate with a mass flow meter, the raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of CO2 is = 0.8 h -1 , and the weight hourly space velocity of naphtha is 1.0 h -1 , and the reaction pressure is 0.1 MPa. The reaction products are analyzed by an on-line Agilent 7890 gas chromatograph, and samples are taken for analysis at 30 min of the reaction. The reaction results are shown in Table 10.

[0200] Table 10 Evaluation of the reaction performance of the catalyst in Example 19

[0201]

[0202]

[0203] Compared with Example 12, the selectivities of BTPX and p-xylene in xylene achieved by the catalyst of this example are lower. This shows that when La is used for metal modification, compared with silanization modification first and then metal modification, the molecular sieve obtained by metal modification first and then silanization modification can achieve higher selectivities of BTPX and p-xylene in xylene.

[0204] Preparation and Reaction Evaluation of the Catalyst for Producing Benzene, Toluene and p-Xylene in Example 21

[0205] The catalyst for naphtha conversion to benzene, toluene and p-xylene was prepared online in a micro fixed-bed reactor. The conditions for online catalyst preparation are as follows: 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 1 was loaded into the fixed-bed reactor, first treated with 50 mL / min of nitrogen at 550 °C for 1 hour, and then cooled to 300 °C under a nitrogen atmosphere. Under a nitrogen atmosphere (controlled by a mass flow meter, 100 mL / min), tetraethyl orthosilicate was pumped into the reactor, and the weight hourly space velocity of tetraethyl orthosilicate was 0.2 h -1 , at atmospheric pressure. After feeding for 60 min, the feeding was stopped. The feeding amount of tetraethyl orthosilicate was the same as that in Example 10, purged with nitrogen, heated to 550 °C, and calcined in an air atmosphere for 4 hours to obtain the fixed-bed catalyst for naphtha conversion to benzene, toluene and p-xylene, named FXNCC-1.

[0206] Then, the temperature was adjusted to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material was fed by a micro-feeding pump, and the N2 flow rate was controlled by a mass flow meter. The raw material N2:naphtha (mass ratio) = 0.51:1 (i.e., in this example, an equimolar amount of N2 was used to replace CO2 in Example 10), the weight hourly space velocity of naphtha was 1.0 h -1 , and the weight hourly space velocity of N2 was = 0.51 h -1 , and the reaction pressure was 0.1 MPa. The reaction products were analyzed by on-line Agilent 7890 gas chromatography, and samples were taken for analysis at 30 min of the reaction. The reaction results are shown in Table 11.

[0207] Table 11 Reaction Performance Evaluation of the Catalyst in Example 21

[0208]

[0209] In Example 21, N2 was used as a diluent; while in Example 10, CO2 was used as the raw material for reacting with naphtha, which can be reflected by comparing the aromatic selectivity and BTPX selectivity of Example 10 and 21. Specifically, the aromatic selectivity and BTPX selectivity in Example 10 are significantly higher than those in Example 21.

[0210] Example 22 Evaluation of Hydrothermal Stability of Catalyst

[0211] In a micro fixed-bed reactor, a catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene, and p-xylene was prepared online. The conditions for online catalyst preparation were as follows: 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 1 was loaded into the fixed-bed reactor. First, it was treated with 50 mL / min of nitrogen at 550 °C for 1 hour, and then cooled to 300 °C under a nitrogen atmosphere. Under a nitrogen atmosphere (controlled by a mass flow meter, 100 mL / min), tetraethyl orthosilicate was pumped into the reactor, and the weight hourly space velocity of tetraethyl orthosilicate was 0.2 h -1 , at atmospheric pressure. After feeding for 60 min, the feeding was stopped. The feeding amount of tetraethyl orthosilicate was the same as that in Example 10, and it was purged with nitrogen, heated to 550 °C, and calcined in an air atmosphere for 4 hours. Then, it was heated to 900 °C under a nitrogen atmosphere and treated in a 100% steam (water WHSV = 2 h -1 ) atmosphere for 1 hour to obtain a fixed-bed catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene, and p-xylene, named FXNCC-11.

[0212] Then, the temperature was adjusted to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material was fed by a micro-feeding pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of naphtha was 1.0 h -1 , and the reaction pressure was 0.1 MPa. The reaction products were analyzed by an online Agilent 7890 gas chromatograph, and samples were taken for analysis at 30 min of the reaction. The reaction results are shown in Table 12.

[0213] Table 12 Evaluation of the Reaction Performance of the Catalyst in Example 22

[0214]

[0215] Example 23 Preparation and Reaction Evaluation of a Catalyst for Benzene, Toluene, and p-Xylene

[0216] In a micro fixed-bed reactor, a catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene, and p-xylene was prepared online. The conditions for online catalyst preparation were as follows: 5 g of the FX-[Zn]HZSM-5-R catalyst prepared in Example 8 was loaded into the fixed-bed reactor. First, it was treated with 50 mL / min of nitrogen at 550 °C for 1 hour, and then cooled to 300 °C under a nitrogen atmosphere. Under a nitrogen atmosphere (controlled by a mass flow meter, 100 mL / min), tetraethyl orthosilicate was pumped into the reactor, and the weight hourly space velocity of tetraethyl orthosilicate was 0.2 h -1, at atmospheric pressure. After 60 minutes of feeding, the feeding was stopped. The feeding rate of tetraethyl orthosilicate was the same as that in Example 10. It was purged with nitrogen, heated to 550 °C, and calcined in an air atmosphere for 4 hours. Then, it was heated to 900 °C in a nitrogen atmosphere and treated in a 100% steam (water WHSV = 2 h -1 ) atmosphere for 1 hour to obtain a fixed-bed catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene, and p-xylene, named FXNCC-12.

[0217] Then, the temperature was adjusted to the reaction temperature of 550 °C in a nitrogen atmosphere; the naphtha raw material was fed by a micro-feeding pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of naphtha was 1.0 h -1 , and the reaction pressure was 0.1 MPa. The reaction products were analyzed by an on-line Agilent 7890 gas chromatograph, and samples were taken for analysis at 30 minutes of reaction. The reaction results are shown in Table 13.

[0218] Table 13 Reaction performance evaluation of the catalyst in Example 23

[0219]

[0220] It can be seen from the comparison between Example 22 and Example 23 that the catalyst after hydrothermal treatment in Example 22 is significantly superior to the catalyst after hydrothermal treatment in Example 23 in terms of aromatic selectivity and BTPX selectivity. Therefore, the hydrothermal stability of the metal-modified HZSM-5 prepared by the high-temperature hydrothermal method is significantly better than that of the metal-modified HZSM-5 prepared by the room-temperature impregnation method.

[0221] Preparation and reaction evaluation of the catalyst for benzene, toluene, and p-xylene in Example 24

[0222] The catalyst FXNCC-1 was prepared by the method of Example 10.

[0223] Then, the temperature was adjusted to the reaction temperature of 550 °C in a nitrogen atmosphere; the naphtha raw material was fed by a micro-feeding pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 1:1, and the weight hourly space velocity of CO2 was = 5 h -1 , and the weight hourly space velocity of naphtha was 5 h -1 , and the reaction pressure was 1 MPa. The reaction products were analyzed by an on-line Agilent 7890 gas chromatograph, and samples were taken for analysis at 30 minutes of reaction. The reaction results are shown in Table 14.

[0224] Table 14 Reaction performance evaluation of the catalyst in Example 24

[0225]

[0226] Example 25 Preparation and Reaction Evaluation of Catalysts for Benzene, Toluene and p-Xylene

[0227] The catalyst FXNCC-1 was prepared by the method of Example 10.

[0228] Then, the temperature was adjusted to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material was fed by a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 1:1, and the weight hourly space velocity of CO2 was = 0.1 h -1 , and the weight hourly space velocity of naphtha was 0.1 h -1 , and the reaction pressure was 0.1 MPa. The reaction products were analyzed by on-line Agilent 7890 gas chromatography, and samples were taken for analysis at 30 min of reaction. The reaction results are shown in Table 15.

[0229] Table 15 Reaction Performance Evaluation of the Catalyst in Example 25

[0230]

[0231] Example 26 Preparation of Shaped Samples of Zn-Modified HZSM-5 Molecular Sieves for Fixed Beds

[0232] 100 g of HZSM-5 zeolite molecular sieve (manufactured by Nankai University Catalyst Factory, Si / Al = 15) was placed in an aqueous solution of zinc nitrate with a concentration of 30 wt%. The mass ratio of HZSM-5 zeolite molecular sieve to the aqueous solution of zinc nitrate (i.e., the solid-liquid ratio) was 1 / 10. It was impregnated at 80 °C for 4 hours, drained, dried in an air atmosphere at 120 °C for 4 hours, and then calcined in an air atmosphere at 550 °C for 4 hours to obtain the [Zn]HZSM-5 molecular sieve sample. It was pressed into tablets, crushed, and sieved to obtain shaped molecular sieve particles with a particle size of 40-60 mesh, denoted as FX-[Zn]HZSM-5-B.

[0233] Example 27 Preparation and Reaction Evaluation of Catalysts for Benzene, Toluene and p-Xylene

[0234] In a micro fixed-bed reaction device, a catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene was prepared on-line. The conditions for on-line catalyst preparation were as follows: 5 g of the FX-[Zn]HZSM-5-B catalyst prepared in Example 1 was loaded into a fixed-bed reactor, first treated with 50 mL / min of nitrogen at 550 °C for 1 hour, and then cooled to 300 °C under a nitrogen atmosphere. Under a nitrogen atmosphere (controlled by a mass flow meter, 100 mL / min), tetraethyl orthosilicate was pumped into the reactor, and the weight hourly space velocity of tetraethyl orthosilicate was 0.2 h -1, under atmospheric pressure. After feeding for 60 min, the feeding was stopped. The feeding amount of tetraethyl orthosilicate was 0.2 g / g of the above catalyst. It was purged with nitrogen, heated to 550 °C, and calcined in an air atmosphere for 4 h to prepare a fixed-bed catalyst for the coupling conversion of naphtha and CO2 to benzene, toluene, and p-xylene, named FXNCC-13.

[0235] Then, the temperature was adjusted to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material was fed by a micro-feeding pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of CO2 was = 0.8 h -1 , and the weight hourly space velocity of naphtha was 1.0 h -1 , and the reaction pressure was 0.1 MPa. The reaction products were analyzed by an on-line Agilent 7890 gas chromatograph, and samples were taken for analysis at 30 min of the reaction. The reaction results are shown in Table 16.

[0236] Table 16 Reaction performance evaluation of the catalyst in Example 27

[0237]

[0238] Example 28 Preparation and reaction evaluation of a catalyst for benzene, toluene, and p-xylene

[0239] The catalyst FXNCC-1 was prepared by the method of Example 10.

[0240] Then, the temperature was adjusted to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material was fed by a micro-feeding pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 0.8:0.27, and the weight hourly space velocity of CO2 was = 0.8 h -1 , and the weight hourly space velocity of naphtha was 0.27 h -1 , and the reaction pressure was 0.1 MPa. The reaction products were analyzed by an on-line Agilent 7890 gas chromatograph, and samples were taken for analysis at 30 min of the reaction. The reaction results are shown in Table 17.

[0241] Table 17 Reaction performance evaluation of the catalyst in Example 28

[0242]

[0243] Example 29 Preparation and reaction evaluation of a catalyst for benzene, toluene, and p-xylene

[0244] The catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene is prepared online in a micro fixed-bed reactor. The conditions for the online preparation of the catalyst are as follows: 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 1 is loaded into a fixed-bed reactor, first treated with nitrogen at 550 °C for 1 hour at a flow rate of 50 mL / min, and then cooled to 300 °C under a nitrogen atmosphere. Then, silanization reagent modification is carried out by gas-phase atomic layer deposition method, and the specific steps are as follows: (1) Nitrogen (controlled by a mass flow meter, 200 mL / min) passes through a saturator containing tetraethyl orthosilicate (temperature 10 °C) and then enters the reactor, that is, tetraethyl orthosilicate is carried into the reactor by nitrogen, and the feeding stops after 5 min of feeding; (2) Purge with nitrogen and heat up to 550 °C, and calcine in an air atmosphere for 1 hour; (3) Repeat steps (1) and (2) 5 times, where the amount of tetraethyl orthosilicate introduced 6 times is equivalent to the amount introduced once in Example 10, to obtain a fixed-bed catalyst for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene, named FXNCC-14.

[0245] Then, adjust the temperature to the reaction temperature of 550 °C under a nitrogen atmosphere; the naphtha raw material is fed by a micro-feeding pump, and the CO2 flow rate is controlled by a mass flow meter. The raw material CO2:naphtha (mass ratio) = 0.8:1, and the weight hourly space velocity of naphtha is 1.0 h -1 , and the reaction pressure is 0.1 MPa. The reaction products are analyzed by an online Agilent 7890 gas chromatograph, and samples are taken for analysis at 30 min of the reaction. The reaction results are shown in Table 18.

[0246] Table 18 Reaction performance evaluation of the catalyst in Example 29

[0247]

[0248] In addition to the naphtha used in the above examples, the present application can also use any naphtha selected from hydrocracked naphtha, catalytic cracked naphtha, raffinate oil, and topped oil or any mixture thereof.

[0249] As described above, only several embodiments of the present application are shown, and the present application is not limited in any form. Although the present application is disclosed with preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art, without departing from the technical solution of the present application, makes some changes or modifications using the technical content disclosed above, which are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

Claims

1. A method for the coupled conversion of naphtha and CO2 to benzene, toluene and p-xylene, characterized in that, The method comprises introducing a raw material containing naphtha and CO2 into a reactor containing a zeolite molecular sieve catalyst to react and generate benzene, toluene and p-xylene, wherein the zeolite molecular sieve catalyst comprises a modified zeolite molecular sieve; The modified zeolite molecular sieve is a zeolite molecular sieve modified by metal modification and silanization; The zeolite molecular sieve is HZSM-5 zeolite molecular sieve; The modified zeolite molecular sieve is a zeolite molecular sieve obtained by first undergoing metal modification and then undergoing silanization modification; The metal used for the metal modification is selected from at least one of La, Zn, Ga, Fe, Mo, and Cr metals; The metal modification is prepared by a high temperature hydrothermal method, which comprises the following steps: (1) preparing a soluble metal salt aqueous solution; (2) placing the zeolite molecular sieve to be metal-modified in the aqueous solution of the soluble metal salt and immersing it at a temperature of 60 to 100° C.; as well as (3) draining the molecular sieve obtained in step (2), drying and calcining.

2. The method according to claim 1, wherein The solid-to-liquid ratio of the zeolite molecular sieve to be metal-modified to the soluble metal salt aqueous solution is 1 / 10 to 1 / 1, and the mass concentration of the metal salt in the soluble metal salt aqueous solution is 10% to 30%; the impregnation time is 2 to 10 hours; the drying step is carried out in an air atmosphere at 100 to 150° C.; and the calcination step is carried out in an air atmosphere at 500 to 700° C.

3. The method according to claim 1, wherein The silanization modification adopts an in-situ chemical vapor deposition method, which includes the following steps: (1) placing a solid containing a zeolite molecular sieve to be modified by silanization in a reactor; (2) introducing material A containing a silanization agent into the reactor at one time, wherein the amount of the silanization agent introduced is 0.2 to 0.3 g / g solid, and the silanization agent is in a gaseous state in the reactor; (3) Stop feeding material A into the reactor, raise the reactor temperature to above 400°C and introduce air for calcination.

4. The method according to claim 1, wherein The silanization modification adopts an in-situ gas phase atomic layer deposition method, which includes the following steps: (1) placing a solid containing a metal-modified or unmodified zeolite molecular sieve in a reactor; (2) introducing material A containing a silanization agent into the reactor in n times, wherein the amount of the silanization agent introduced each time is 0.03 to 0.06 g / g solid, and the silanization agent is in a gaseous state in the reactor, wherein the value of n is in the range of 3 to 6; (3) Stop feeding material A into the reactor, raise the reactor temperature to above 400°C and introduce air for calcination.

5. The method according to claim 1, wherein The silanization agent used in the silanization modification is selected from at least one of the compounds of the following chemical formulas: wherein R1, R2, R3, and R4 are each independently selected from C 1-10 alkyl groups and C 1-10 alkoxy groups.

6. The method according to claim 5, characterized in that, At least one of R1, R2, R3 and R4 is selected from alkoxy groups of C 1-10 as described below.

7. The method according to claim 5, wherein The silanization agent is selected from at least one of tetraethyl silicate and tetramethyl silicate.

8. The method according to claim 1, wherein The raw material consists of naphtha and CO2.

9. The method according to claim 1, characterized in that, The naphtha is selected from at least one of hydrocracking naphtha, catalytic cracking naphtha, raffinate, tops, and coal direct liquefaction naphtha.

10. The method according to claim 1, characterized in that The carbon number distribution range of hydrocarbons in the naphtha is C4 - C 12 .

11. The method according to claim 1, wherein The reactor is one of a fixed bed reactor, a fluidized bed reactor or a moving bed reactor.

12. The method according to claim 1, wherein The conditions for the reaction of naphtha and CO2 are as follows: the reaction temperature is 450 - 650 °C, the reaction pressure is 0.1 - 3 MPa, the weight hourly space velocity of the naphtha is 0.1 - 5 h -1 , and the weight hourly space velocity of CO2 is 0.1 - 5 h -1 .

13. The method according to claim 1, wherein The zeolite molecular sieve catalyst also includes a binder.

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