A method for preparing p-xylene

Abstract

The present application discloses a method for preparing p-xylene, wherein raw materials containing methanol, naphtha and CO2 are passed through a reactor equipped with a catalyst to react and generate p-xylene. By adding methanol, the product distribution is adjusted, and the selectivity of p-xylene is significantly improved. In addition, the components containing benzene and toluene in the aromatic product are returned to the reaction system and co-fed with the raw materials to react and generate p-xylene, thereby realizing the recycling of raw materials and having extremely high economic benefits. The method is simple in process and highly feasible, can greatly improve the selectivity and yield of p-xylene, has important application value, and provides a new way for the large-scale utilization of CO2.

Description

Technical Field

[0001] The present application relates to a method for preparing p-xylene, and in particular to a method for preparing p-xylene by coupling conversion of methanol, naphtha and CO2 on a zeolite molecular sieve-based catalyst, and belongs to the field of petrochemical industry. Background Art

[0002] With the development of modern industry, carbon dioxide (CO2), as the main greenhouse gas, has an increasing concentration in the atmosphere, leading to an increasingly prominent greenhouse effect. In 2020, global CO2 emissions reached 34 billion tons, and my country's CO2 emissions exceeded 10 billion tons. Therefore, the recovery, fixation and resource utilization of CO2 have become issues of close concern to countries around the world. From a resource perspective, CO2 is the cheapest carbon-1 resource in the world.

[0003] Aromatics represented by triphenyls (benzene, toluene, and paraxylene) are basic chemical raw materials. Among them, paraxylene is the most concerned product among aromatics, with a huge market size and a large dependence on imports. In 2019, the output of paraxylene was 13.46 million tons, and the import volume reached 15.94 million tons, with a foreign dependence of 52%. In industry, paraxylene is mainly produced by naphtha through catalytic reforming and aromatics combined units. There are many steps, complex processes, and huge investments. Therefore, a large part of aromatics comes from naphtha aromatics technology. Among them, aromatics produced by catalytic reforming of naphtha account for 80% of the amount of petroleum-based aromatics. Therefore, vigorously developing CO2 utilization technology, especially converting CO2 into aromatics, has important economic and social significance. On the one hand, it can solve the situation of insufficient chemicals in my country. On the other hand, due to the large market size of aromatics products, CO2 emissions can be reduced on a large scale.

[0004] CN108160104A discloses a catalyst for preparing aromatic hydrocarbons by hydrogenation of carbon dioxide, and its preparation method and application, wherein the catalyst is a nano-metal oxide & ZSM-5 molecular sieve catalyst which is mechanically mixed, ground or ball milled to obtain carbon dioxide hydrogenation products. 5+ CN107840778A discloses a method for producing aromatics by hydrogenating carbon dioxide under the action of a composite catalyst. The composite catalyst is composed of an iron-based carbon dioxide hydrogenation catalyst for producing low-carbon olefins as the first component, and is mixed with a metal-modified or unmodified molecular sieve that mainly plays the role of olefin aromatization. The CO2 conversion rate under the action of the composite catalyst is 33%, and the C 5+ The hydrocarbon selectivity can reach 65%, of which aromatic hydrocarbons account for C 5+The research shows that CO2 is first activated by metal oxides, and then reacts with hydrogen to generate intermediate components, which undergo carbon chain growth, transfer, and ring formation under the action of molecular sieves to generate aromatics. The above research is all about producing liquid hydrocarbons or aromatics through CO2 hydrogenation. In addition to technical indicators, the source of hydrogen is also a key issue restricting its industrial application. Summary of the invention

[0005] The present application provides a new technical route for producing aromatics using CO2, that is, using naphtha as a raw material and coupling it with CO2 to produce aromatics, which provides a new approach for aromatics production and large-scale utilization of CO2.

[0006] According to the first aspect of the present application, a method for preparing p-xylene is provided. The method can not only prepare xylene, but also obtain benzene and toluene, which can be recycled as reaction raw materials.

[0007] A method for preparing p-xylene comprises passing raw materials containing methanol, naphtha and CO2 through a reactor equipped with a catalyst to react and generate p-xylene.

[0008] Optionally, the reaction conditions are: reaction temperature 450-650°C, reaction pressure 0.1-3.5 MPa, naphtha weight space velocity 0.1-5 h -1 , CO2 weight space velocity 0.1~3h -1 , methanol weight space velocity 0.1~5h -1 .

[0009] Optionally, the reaction conditions are: reaction temperature 500-600°C, reaction pressure 0.1-3MPa, naphtha weight space velocity 0.5-2h -1 , CO2 weight space velocity 0.5~2h -1 , methanol weight space velocity 0.5~2h -1 .

[0010] Optionally, the reaction temperature is 500-600°C, the reaction pressure is 0.1-1 MPa, and the naphtha weight space velocity is 0.5-2 h -1 , CO2 weight space velocity 0.5~2h -1 , methanol weight space velocity 0.5~2h -1 .

[0011] Optionally, the reaction temperature is independently selected from any value of 450°C, 480°C, 500°C, 520°C, 550°C, 570°C, 600°C, 620°C, 650°C, or any range therebetween.

[0012] Optionally, the reaction pressure is independently selected from any value among 0.1 MPa, 0.15 MPa, 0.2 MPa, 0.5 MPa, 1.0 MPa, 1.5 MPa, 2.0 MPa, 2.5 MPa, 3 MPa, or any range therebetween.

[0013] Optionally, the naphtha weight space velocity is independently selected from 0.1h -1 , 0.2h -1 、0.5h -1 、0.7h -1 , 1h -1 , 1.2h -1 , 1.5h -1 , 2h -1 , 2.5h -1 , 3h -1 , 3.5h -1 , 4h -1 , 4.5h -1 , 5h -1 Any value in or any range between them.

[0014] Optionally, the CO2 weight space velocity is independently selected from 0.1h -1 、0.2h -1 、0.5h -1 、0.7h -1 , 1h -1 , 1.2h -1 , 1.5h -1 , 2h -1 , 2.5h -1 , 3h -1 Any value in or any range between them.

[0015] Optionally, the methanol weight space velocity is independently selected from 0.1h -1 、0.2h -1 、0.5h -1 、0.7h -1 , 1h -1 , 1.2h -1 , 1.5h -1 , 2h -1 , 2.5h -1 , 3h -1 , 3.5h -1 , 4h -1 , 4.5h -1 , 5h -1 Any value in or any range between them.

[0016] Optionally, the usage ratio of CO2, naphtha and methanol is 0.3-2:1:0.3-2.

[0017] Optionally, the usage ratio of CO2, naphtha and methanol is 0.3-1.5:1:0.3-1.5.

[0018] Optionally, the usage ratio of CO2, naphtha and methanol is 0.5-1.0:1:0.5-1.0.

[0019] Optionally, the usage ratio of CO2, naphtha and methanol is 1:3:2.

[0020] Optionally, the usage ratio of CO2, naphtha and methanol is 0.8:1:0.6.

[0021] Optionally, the usage ratio of CO2, naphtha and methanol is 0.8:1:1.2.

[0022] Optionally, the usage ratio of CO2, naphtha and methanol is 1.5:1:1.5.

[0023] Optionally, the components containing benzene and toluene in the mixture obtained by the reaction are separated from the obtained mixture, returned to the reaction system, and co-fed with the raw materials on the catalyst to react to produce paraxylene.

[0024] In the present application, the components containing benzene and toluene in the mixture obtained by the reaction are separated from the obtained mixture, that is, the components containing benzene and toluene in the by-product are returned to the reaction system, thereby realizing the recycling of raw materials.

[0025] Optionally, the catalyst is an acidic molecular sieve.

[0026] Optionally, the acidic molecular sieve is HZSM-5 zeolite molecular sieve.

[0027] Optionally, the HZSM-5 zeolite molecular sieve has a silicon-to-aluminum ratio Si / Al=10-50.

[0028] Optionally, the HZSM-5 zeolite molecular sieve has a silicon-to-aluminum ratio Si / Al=15.

[0029] In the present application, the silicon-to-aluminum ratio of the HZSM-5 zeolite molecular sieve is not the main factor affecting the catalytic activity, and the commonly used silicon-to-aluminum ratio Si / Al can be selected.

[0030] Optionally, the HZSM-5 zeolite molecular sieve is a metal-modified HZSM-5 zeolite molecular sieve.

[0031] Optionally, the metal used for metal modification is selected from at least one of La, Zn, Ga, Fe, Mo and Cr.

[0032] Optionally, the HZSM-5 zeolite molecular sieve is a metal-modified and silanization agent-modified HZSM-5 zeolite molecular sieve.

[0033] In the present application, the metal-modified and silanization agent-modified HZSM-5 zeolite molecular sieve refers to the HZSM-5 zeolite molecular sieve being subjected to metal modification and then to silanization agent modification.

[0034] Optionally, the silanizing agent used for the silanizing agent modification is selected from at least one of the compounds having the following chemical formula:

[0035]

[0036] Wherein R1, R2, R3 and R4 are each independently selected from C 1-10 Alkyl, C 1-10 At least one of the alkoxy groups.

[0037] Optionally, at least one of R1, R2, R3 and R4 is selected from C 1-10 of alkoxy.

[0038] Optionally, the silanization agent is selected from tetraethyl silicate and\or tetramethyl silicate.

[0039] Optionally, the metal modification method comprises: placing the HZSM-5 zeolite molecular sieve in a metal salt solution, impregnating, drying, and calcining to obtain the metal-modified HZSM-5 zeolite molecular sieve.

[0040] Optionally, the immersion conditions are as follows: immersion temperature is 60 to 100° C., and immersion time is 2 to 10 hours.

[0041] Optionally, the immersion conditions are as follows: immersion temperature is 70 to 90° C., and immersion time is 4 to 8 hours.

[0042] Optionally, the immersion temperature is independently selected from any value of 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, or any range therebetween.

[0043] Optionally, the immersion time is independently selected from any value among 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, or any range therebetween.

[0044] Optionally, the solid-liquid ratio of the HZSM-5 zeolite molecular sieve and the metal salt solution is 1:20 to 1:1.

[0045] Here, the solid-liquid ratio refers to the mass ratio.

[0046] Optionally, the solid-liquid ratio of the HZSM-5 zeolite molecular sieve and the metal salt solution is 1:10 to 1:1.

[0047] Optionally, the solid-to-liquid ratio of the HZSM-5 zeolite molecular sieve and the metal salt solution is independently selected from any value of 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1:1 or any range between two values.

[0048] Optionally, the metal salt is a soluble metal salt corresponding to the metal used for metal modification.

[0049] In the present application, the soluble metal salt may be a nitrate, sulfate, etc. corresponding to the metal used for metal modification, such as zinc nitrate, gallium nitrate, lanthanum nitrate, chromium nitrate, etc.

[0050] Optionally, in the metal modification method, the drying condition is: drying in an air atmosphere at 100-150°C.

[0051] Optionally, in the metal modification method, the calcination conditions are: calcination at 500-700° C. in an air atmosphere.

[0052] Optionally, the silanization agent modification method includes: contacting a material containing a silanization agent with a metal-modified HZSM-5 zeolite molecular sieve, purging with an inactive gas, and calcining to obtain the metal-modified and silanization agent-modified HZSM-5 zeolite molecular sieve.

[0053] Optionally, the contact treatment temperature is 250-450°C.

[0054] Optionally, the temperature of the contact treatment is 300-400°C.

[0055] Optionally, the weight space velocity of the silanization agent is 0.02 to 0.5 h -1 .

[0056] Optionally, the weight space velocity of the silanization agent is 0.05 to 0.4 h -1 .

[0057] Optionally, the temperature of the contact treatment is 300°C.

[0058] Optionally, the weight space velocity of the silanization agent is 0.2h -1 .

[0059] Optionally, the inert gas is selected from at least one of nitrogen, helium and argon.

[0060] Optionally, the temperature of the contact treatment is independently selected from any value of 250°C, 270°C, 300°C, 320°C, 350°C, 370°C, 400°C, 420°C, 450°C, or any range therebetween.

[0061] Optionally, the weight space velocity of the silanization agent is independently selected from 0.02h -1 , 0.05h -1 , 0.1h -1 , 0.15h -1 、0.2h -1 , 0.25h -1 、0.3h -1 , 0.35h -1 、0.4h -1 , 0.45h -1 、0.5h -1 Any value in or any range between them.

[0062] Optionally, in the silanization agent modification method, the calcination conditions are: calcination at a temperature of 400° C. to 650° C. with air passing therethrough.

[0063] Optionally, the reactor is a fixed bed reactor, a fluidized bed reactor or a moving bed reactor.

[0064] Optionally, the naphtha is selected from at least one of hydrocracking naphtha, catalytic cracking naphtha, raffinate, topped oil, and coal direct liquefaction naphtha.

[0065] Optionally, the carbon number distribution range of the hydrocarbons in the naphtha is C4-C 12 .

[0066] As another aspect of the present application, a process for preparing paraxylene is also provided, comprising: feeding a raw material containing naphtha, CO2 and methanol into a reaction system, contacting and reacting with a catalyst to obtain a mixture A, and the mixture A enters a first separation system to separate and obtain C 5+ Component, C 5+ The components enter the second separation system to separate paraxylene.

[0067] Optionally, C 5+ The components enter the second separation system, where they are separated into components containing benzene and toluene. The components containing benzene and toluene are co-fed into the reaction system together with the raw materials containing naphtha, CO2 and methanol.

[0068] In this application, unless otherwise specified, the data range given is selected from any value in the range and includes the endpoint value of the range.

[0069] In this application, C 1-10 Alkyl, C 1-10 The C in the alkoxy group 1-10 , means that the total number of carbon atoms in the alkyl and alkoxy groups is 1-10.

[0070] The beneficial effects of this application include:

[0071] 1) The method for preparing p-xylene by coupling naphtha and CO2 provided in the present application adjusts the product distribution by adding methanol, thereby significantly improving the selectivity of p-xylene.

[0072] 2) The method provided in the present application for preparing paraxylene by coupling naphtha and CO2, wherein methanol is added to the raw material, and the components containing benzene and toluene in the by-product are returned to the reaction system, thus realizing the recycling of the raw material and having extremely high economic benefits.

[0073] 3) The method for preparing p-xylene provided in the present application has a simple process and strong feasibility, can greatly improve the selectivity and yield of p-xylene, has important application value, and provides a new way for the large-scale utilization of CO2. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 Schematic diagram of the process flow for preparing paraxylene. DETAILED DESCRIPTION

[0075] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0076] Unless otherwise specified, the raw materials and catalysts in the examples of the present application were purchased from commercial channels and used directly without treatment, and the instruments and equipment used adopted the schemes and parameters recommended by the manufacturers.

[0077] In the embodiment, the inner diameter of the fixed bed reactor is 1.5 cm.

[0078] The method for preparing p-xylene provided in this application has a process flow diagram as shown in Figure 1 shown.

[0079] See also Figure 1 First, feed the raw material containing naphtha, CO2 and methanol into the reaction system, so that the raw material containing naphtha, CO2 and methanol contacts with the catalyst in the reaction system to react and obtain a mixture A. The mixture A enters the first separation system to separate other components and C 5+ Component. C 5+ The components enter the second separation system to separate components containing benzene and toluene, para-xylene and other C 5+ The components containing benzene and toluene are pumped back into the reaction system to generate p-xylene, and finally the p-xylene is separated.

[0080] 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:

[0081] Composition of coal direct liquefaction naphtha

[0082]

[0083]

[0084] Example 1 Preparation of HZSM-5 Molded Molecular Sieve Sample for Fixed Bed

[0085] 100 g of HZSM-5 zeolite molecular sieve raw powder (Nankai University Catalyst Plant, Si / Al=15) was calcined at 550°C for 4 hours in air atmosphere, pressed into tablets, crushed and sieved to obtain shaped molecular sieve particles with a particle size of 40-60 mesh, recorded as FX-HZSM-5.

[0086] Example 2 Preparation of zinc-modified HZSM-5 molecular sieve molded samples for fixed bed

[0087] 100 g of HZSM-5 zeolite molecular sieve (Nankai University Catalyst Factory, Si / Al=15) was placed in a 10 wt % zinc nitrate aqueous solution, with the mass ratio of HZSM-5 zeolite molecular sieve to zinc nitrate aqueous solution (i.e., solid-liquid ratio) being 1 / 10. The mixture was immersed in 80° C. for 6 hours, dried in an air atmosphere at 120° C. for 4 hours after being drained, and then calcined in an air atmosphere at 550° C. for 4 hours to obtain a [Zn]HZSM-5 molecular sieve sample. The sample was pressed into tablets, crushed, and sieved to obtain formed molecular sieve particles with a particle size of 40 to 60 meshes, which were recorded as FX-[Zn]HZSM-5.

[0088] Example 3 Preparation of Ga-modified HZSM-5 Molecular Sieve Molded Samples for Fixed Bed

[0089] 100 g of HZSM-5 zeolite molecular sieve (Catalyst Plant of Nankai University, Si / Al=15) was placed in a 10 wt % gallium nitrate aqueous solution, with the mass ratio of HZSM-5 zeolite molecular sieve to gallium nitrate aqueous solution (i.e., solid-liquid ratio) being 1 / 10. The mixture was immersed in 80° C. for 6 hours, dried in an air atmosphere at 120° C. for 4 hours after being drained, and then calcined in an air atmosphere at 550° C. for 4 hours. The [Ga]HZSM-5 molecular sieve sample was tableted, crushed, and sieved to obtain formed molecular sieve particles with a particle size of 40 to 60 mesh, which were recorded as FX-[Ga]HZSM-5.

[0090] Example 4 Preparation of lanthanum-modified HZSM-5 molecular sieve molded samples for fixed bed

[0091] 100 g of HZSM-5 zeolite molecular sieve (Catalyst Plant of Nankai University, Si / Al=15) was placed in a 10 wt % lanthanum nitrate aqueous solution, with the mass ratio of HZSM-5 zeolite molecular sieve to the lanthanum nitrate aqueous solution (i.e., solid-liquid ratio) being 1 / 10. The mixture was immersed in 90° C. for 4 hours, dried in an air atmosphere at 120° C. for 4 hours after being drained, and then calcined in an air atmosphere at 550° C. for 4 hours. The [La]HZSM-5 molecular sieve sample was tableted, crushed, and sieved to obtain formed molecular sieve particles with a particle size of 40 to 60 mesh, which were recorded as FX-[La]HZSM-5.

[0092] Example 5 Preparation of iron-modified HZSM-5 molecular sieve molded samples for fixed bed

[0093] 100 g of HZSM-5 zeolite molecular sieve (Nankai University Catalyst Plant, Si / Al=15) was placed in a 10 wt % ferric nitrate aqueous solution, with the mass ratio of HZSM-5 zeolite molecular sieve to ferric nitrate aqueous solution (i.e., solid-liquid ratio) being 1 / 10. The mixture was immersed in 70° C. for 8 hours, dried in an air atmosphere at 120° C. for 4 hours after being drained, and then calcined in an air atmosphere at 550° C. for 4 hours. The [Fe]HZSM-5 molecular sieve sample was tableted, crushed, and sieved to obtain formed molecular sieve particles with a particle size of 40 to 60 mesh, which were recorded as FX-[Fe]HZSM-5.

[0094] Example 6 Preparation of chromium-modified HZSM-5 molecular sieve molded samples for fixed bed

[0095] 100 g of HZSM-5 zeolite molecular sieve (Nankai University Catalyst Plant, Si / Al=15) was placed in a 10 wt % chromium nitrate aqueous solution, with the mass ratio of HZSM-5 zeolite molecular sieve to the chromium nitrate aqueous solution (i.e., solid-liquid ratio) being 1 / 10. The mixture was immersed in 70° C. for 8 hours, dried in an air atmosphere at 120° C. for 4 hours after being drained, and then calcined in an air atmosphere at 550° C. for 4 hours to obtain a [Cr]HZSM-5 molecular sieve sample. The sample was pressed into tablets, crushed, and sieved to obtain molecular sieve particles with a particle size of 40 to 60 meshes, which were recorded as FX-[Cr]HZSM-5.

[0096] Example 7 Preparation of Zinc-modified HZSM-5 Molded Molecular Sieve Samples for Fluidized Bed

[0097] 100 g of the [Zn]HZSM-5 molecular sieve sample prepared in Example 2 was mixed with an amorphous binder containing aluminum or silicon and spray-dried to form a shaped product. The specific steps are as follows:

[0098] The [Zn]HZSM-5 molecular sieve sample, pseudo-boehmite, silica sol, xanthan gum (bio-gum) and water are uniformly mixed, and a slurry is obtained by beating, grinding and defoaming. The weight proportions of each component in the slurry are:

[0099]

[0100] The obtained slurry was spray dried to obtain a microsphere particle sample with a particle size distribution of 20 to 100 μm; after the microsphere particle sample was calcined at 550° C. in a muffle furnace for 3 hours, a [Zn]HZSM-5 formed molecular sieve with a wear index of 1.2 was obtained, which was recorded as FL-[Zn]HZSM-5.

[0101] Example 8 Evaluation of the reaction of methanol, naphtha and CO2 coupled conversion to produce aromatics

[0102] The reaction of methanol, naphtha and CO2 coupling conversion to aromatics was evaluated in a micro fixed bed reactor. The reaction conditions are as follows: 5 grams of the FX-HZSM-5 catalyst prepared in Example 1 was loaded into a fixed bed reactor and first treated with 50 ml / min nitrogen at 550°C for 1 hour. Then, methanol, naphtha and CO2 were co-fed; methanol and naphtha raw materials were fed with a micro feed pump, and the CO2 flow rate was controlled by a mass flowmeter, the raw material CO2: naphtha: methanol (mass ratio) = 1:3:2, and the naphtha weight space velocity was 1.0 h -1 , CO2 weight space velocity 0.33h -1 , methanol weight space velocity 0.67h -1 , reaction pressure 1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 1.

[0103] Table 1 Evaluation results of catalyst reaction in Example 8

[0104]

[0105]

[0106] Example 9 Evaluation of the reaction of methanol, naphtha and CO2 coupled conversion to produce aromatics

[0107] The reaction of methanol, naphtha and CO2 coupling conversion to aromatics was evaluated in a micro fixed bed reactor. The reaction conditions are as follows: 5 grams of the FX-[Zn]HZSM-5 catalyst prepared in Example 2 was loaded into a fixed bed reactor and first treated with 50 ml / min nitrogen at 550°C for 1 hour. Then, methanol, naphtha and CO2 were co-fed; methanol and naphtha raw materials were fed with a micro feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) = 0.8:1:0.6, and the naphtha weight space velocity was 1.0 h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1, reaction pressure 0.1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 2.

[0108] Table 2 Evaluation results of catalyst reaction in Example 9

[0109]

[0110]

[0111] Example 10 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce benzene, toluene and p-xylene

[0112] The catalyst for the coupled conversion of naphtha and CO2 to produce benzene, toluene and p-xylene was prepared online in a micro fixed bed reactor. The conditions for preparing the catalyst online were as follows: 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 2 was loaded into a fixed bed reactor, first treated with 50 ml / min nitrogen at 550°C for 1 hour, and then cooled to 300°C in a nitrogen atmosphere. In a nitrogen atmosphere (mass flow meter control, 100 ml / min), tetraethyl silicate was pumped into the reactor, and the weight space velocity of tetraethyl silicate was 0.2 h / min. -1 , atmospheric pressure. After 60 minutes of feeding, the feeding was stopped, purged with nitrogen, heated to 550°C, and calcined in air atmosphere for 4 hours to obtain a fixed bed catalyst for the coupling conversion of naphtha and CO2 to produce benzene, toluene and p-xylene, named FXNCC-1.

[0113] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1 , reaction pressure 0.1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 3.

[0114] Table 3 Evaluation results of catalyst reaction in Example 10

[0115]

[0116]

[0117] Example 11 Preparation and reaction evaluation of catalyst for producing p-xylene by coupling conversion of methanol, naphtha and CO2

[0118] The operation was the same as 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-1.

[0119] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1 , reaction pressure 0.1MPa. According to the methanol, naphtha and CO2 in Example 10, benzene and toluene in the reaction product are composed and prepared into raw materials, and are fed with a micro-feed pump (equivalent to separating benzene and toluene from the methanol, naphtha and CO2 reaction product, and pumping them back into the fixed bed reactor with a micro-feed pump). The reaction product is analyzed by online Agilent7890 gas chromatography, and sampling and analysis are performed when the reaction is 30min. The reaction result is shown in Table 4.

[0120] Table 4 Reaction evaluation results of catalyst in Example 11

[0121]

[0122]

[0123] Example 12 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce benzene, toluene and p-xylene

[0124] The catalyst for the coupled conversion of naphtha and CO2 to produce benzene, toluene and p-xylene was prepared online in a micro fixed bed reactor. The conditions for preparing the catalyst online were as follows: 5 g of the FX-[Ga]HZSM-5 catalyst prepared in Example 3 was loaded into a fixed bed reactor, first treated with 50 ml / min nitrogen at 550°C for 1 hour, and then cooled to 300°C in a nitrogen atmosphere. In a nitrogen atmosphere (mass flow meter control, 100 ml / min), tetraethyl silicate was pumped into the reactor, and the weight space velocity of tetraethyl silicate was 0.2 h / min. -1 , atmospheric pressure. After 60 minutes of feeding, the feeding was stopped, purged with nitrogen, heated to 550°C, and calcined in air atmosphere for 4 hours to obtain a fixed bed catalyst for the coupling conversion of naphtha and CO2 to produce benzene, toluene and p-xylene, named FXNCC-2.

[0125] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1 , reaction pressure 0.1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 5.

[0126] Table 5 Evaluation results of catalyst reaction in Example 12

[0127]

[0128]

[0129] Example 13 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce p-xylene

[0130] The operation was the same as in Example 12 to obtain a fixed bed catalyst for the coupled conversion of naphtha and CO2 to produce benzene, toluene and p-xylene, named FXNCC-2.

[0131] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1 , reaction pressure 0.1MPa. According to the methanol, naphtha and CO2 in Example 12, benzene and toluene in the reaction product are composed and prepared into raw materials, and are fed with a micro-feed pump (equivalent to separating benzene and toluene from the methanol, naphtha and CO2 reaction product, and pumping them back into the fixed bed reactor with a micro-feed pump). The reaction product is analyzed by an online Agilent7890 gas chromatograph, and sampling and analysis are performed when the reaction is 30min. The reaction result is shown in Table 6.

[0132] Table 6 Reaction evaluation results of catalyst in Example 13

[0133]

[0134]

[0135] Example 14 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce p-xylene

[0136] The catalyst for the coupled conversion of naphtha and CO2 to produce p-xylene was prepared online in a micro fixed bed reactor. The conditions for preparing the catalyst online were as follows: 5 g of the FX-[La]HZSM-5 catalyst prepared in Example 4 was loaded into a fixed bed reactor, first treated with 50 ml / min nitrogen at 550°C for 1 hour, and then cooled to 300°C in a nitrogen atmosphere. In a nitrogen atmosphere (mass flow meter control, 100 ml / min), tetraethyl silicate was pumped into the reactor, and the weight space velocity of tetraethyl silicate was 0.2 h / min. -1 , atmospheric pressure. After 60 minutes of feeding, the feeding was stopped, purged with nitrogen, heated to 550°C, and calcined in air atmosphere for 4 hours to obtain a fixed bed catalyst for the coupling conversion of naphtha and CO2 to produce p-xylene, named FXNCC-3.

[0137] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1 , reaction pressure 0.1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 7.

[0138] Table 7 Catalyst reaction evaluation results of Example 14

[0139]

[0140]

[0141] Example 15 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce p-xylene

[0142] The operation was the same as in Example 14 to obtain a fixed-bed catalyst for producing p-xylene by coupling conversion of naphtha and CO2, named FXNCC-3.

[0143] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1, reaction pressure 0.1MPa. According to the methanol, naphtha and CO2 in Example 14, benzene and toluene in the reaction product are composed and prepared into raw materials, and are fed with a micro-feed pump (equivalent to separating benzene and toluene from the methanol, naphtha and CO2 reaction product, and pumping them back into the fixed bed reactor with a micro-feed pump). The reaction product is analyzed by an online Agilent7890 gas chromatograph, and sampling and analysis are performed when the reaction is 30min. The reaction result is shown in Table 8.

[0144] Table 8 Reaction evaluation results of catalyst in Example 15

[0145]

[0146]

[0147] Example 16 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce p-xylene

[0148] The catalyst for the coupled conversion of naphtha and CO2 to produce p-xylene was prepared online in a micro fixed bed reactor. The conditions for preparing the catalyst online were as follows: 5 g of the FX-[Fe]HZSM-5 catalyst prepared in Example 5 was loaded into a fixed bed reactor, first treated with 50 ml / min nitrogen at 550°C for 1 hour, and then cooled to 300°C in a nitrogen atmosphere. In a nitrogen atmosphere (mass flow meter control, 100 ml / min), tetraethyl silicate was pumped into the reactor, and the weight space velocity of tetraethyl silicate was 0.2 h / min. -1 , atmospheric pressure. After 60 minutes of feeding, the feeding was stopped, purged with nitrogen, heated to 550°C, and calcined in air atmosphere for 4 hours to obtain a fixed bed catalyst for the coupling conversion of naphtha and CO2 to produce p-xylene, named FXNCC-4.

[0149] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1 , reaction pressure 0.1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 9.

[0150] Table 9 Evaluation results of catalyst reaction in Example 16

[0151]

[0152]

[0153] Example 17 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce p-xylene

[0154] The operation was the same as in Example 16 to obtain a fixed-bed catalyst for producing p-xylene by coupling conversion of naphtha and CO2, named FXNCC-4.

[0155] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1 , reaction pressure 0.1MPa. According to the methanol, naphtha and CO2 in Example 16, benzene and toluene in the reaction product are composed and prepared into raw materials, and are fed with a micro-feed pump (equivalent to separating benzene and toluene from the methanol, naphtha and CO2 reaction product, and pumping them back into the fixed bed reactor with a micro-feed pump). The reaction product is analyzed by online Agilent7890 gas chromatography, and sampling and analysis are performed when the reaction is 30min. The reaction results are shown in Table 10.

[0156] Table 10 Reaction evaluation results of catalyst in Example 17

[0157]

[0158]

[0159] Example 18 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce p-xylene

[0160] The catalyst for the coupled conversion of naphtha and CO2 to produce p-xylene was prepared online in a micro fixed bed reactor. The conditions for preparing the catalyst online were as follows: 5 g of the FX-[Cr]HZSM-5 catalyst prepared in Example 6 was loaded into a fixed bed reactor, first treated with 50 ml / min nitrogen at 550°C for 1 hour, and then cooled to 300°C in a nitrogen atmosphere. In a nitrogen atmosphere (mass flow meter control, 100 ml / min), tetraethyl silicate was pumped into the reactor, and the weight space velocity of tetraethyl silicate was 0.2 h / min. -1 , atmospheric pressure. After 60 minutes of feeding, the feeding was stopped, purged with nitrogen, heated to 550°C, and calcined in air atmosphere for 4 hours to obtain a fixed bed catalyst for the coupling conversion of naphtha and CO2 to produce p-xylene, named FXNCC-5.

[0161] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1 , reaction pressure 0.1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 11.

[0162] Table 11 Catalyst reaction evaluation results of Example 18

[0163]

[0164]

[0165] Example 19 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce p-xylene

[0166] The operation was the same as in Example 18 to obtain a fixed-bed catalyst for producing p-xylene by coupling conversion of naphtha and CO2, named FXNCC-5.

[0167] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1 , reaction pressure 0.1MPa. According to the methanol, naphtha and CO2 in Example 18, benzene and toluene in the reaction product are composed and prepared into raw materials, and are fed with a micro-feed pump (equivalent to separating benzene and toluene from the methanol, naphtha and CO2 reaction product, and pumping them back into the fixed bed reactor with a micro-feed pump). The reaction product is analyzed by an online Agilent7890 gas chromatograph, and a sample is taken for analysis when the reaction is 30min. The reaction result is shown in Table 12.

[0168] Table 12 Reaction evaluation results of catalyst in Example 19

[0169]

[0170]

[0171] Example 20 Preparation and reaction evaluation of catalyst for coupling conversion of methanol, naphtha and CO2 to produce p-xylene

[0172] The catalyst for the coupled conversion of naphtha and CO2 to produce p-xylene was prepared online in a micro-fixed fluidized bed reactor. The conditions for preparing the catalyst online were as follows: 10 g of the FL-[Zn]HZSM-5 catalyst prepared in Example 7 was loaded into a fixed fluidized bed reactor, first treated with 50 ml / min nitrogen at 550°C for 1 hour, and then cooled to 300°C in a nitrogen atmosphere. In a nitrogen atmosphere (mass flow meter controlled, 200 ml / min), tetraethyl silicate was pumped into the reactor, and the weight space velocity of tetraethyl silicate was 0.2 h / min. -1 , atmospheric pressure. After 75 minutes of feeding, the feeding was stopped, purged with nitrogen, heated to 550°C, and calcined in air atmosphere for 4 hours to obtain a fixed bed catalyst for the coupling conversion of naphtha and CO2 to produce p-xylene, named FLNCC-1.

[0173] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1 , reaction pressure 0.1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 13.

[0174] Table 13 Evaluation results of catalyst reaction in Example 20

[0175]

[0176]

[0177] Example 21 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce p-xylene

[0178] The operation was the same as that in Example 20 to obtain a fixed bed catalyst for producing p-xylene by coupling conversion of naphtha and CO2, which was named FLNCC-1.

[0179] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1, reaction pressure 0.1MPa. According to the methanol, naphtha and CO2 in Example 20, benzene and toluene in the reaction product are composed and prepared into raw materials, and are fed with a micro-feed pump (equivalent to separating benzene and toluene from the methanol, naphtha and CO2 reaction product, and pumping them back into the fixed bed reactor with a micro-feed pump). The reaction product is analyzed by an online Agilent7890 gas chromatograph, and sampling and analysis are performed when the reaction is 30min. The reaction results are shown in Table 14.

[0180] Table 14 Reaction evaluation results of catalyst in Example 21

[0181]

[0182]

[0183] Comparative Example 1 Preparation and reaction evaluation of catalyst for coupling conversion of naphtha and CO2 to produce benzene, toluene and p-xylene

[0184] The catalyst for the coupled conversion of naphtha and CO2 to produce benzene, toluene and p-xylene was prepared online in a micro fixed bed reactor. The conditions for preparing the catalyst online were as follows: 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 2 was loaded into a fixed bed reactor, first treated with 50 ml / min nitrogen at 550°C for 1 hour, and then cooled to 300°C in a nitrogen atmosphere. In a nitrogen atmosphere (mass flow meter control, 100 ml / min), tetraethyl silicate was pumped into the reactor, and the weight space velocity of tetraethyl silicate was 0.2 h / min. -1 , atmospheric pressure. After 60 minutes of feeding, the feeding was stopped, purged with nitrogen, heated to 550°C, and calcined in air atmosphere for 4 hours to obtain a fixed bed catalyst for the coupling conversion of naphtha and CO2 to produce benzene, toluene and p-xylene, named FXNCC-1.

[0185] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; the naphtha raw material was fed with 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 naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , reaction pressure 0.1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 15.

[0186] Table 15 Evaluation of reaction performance of catalyst in comparative example 1

[0187]

[0188]

[0189] It can be seen that when there is no methanol in the raw material, the content of p-xylene in the hydrocarbon product composition is 12.31%, and compared with Example 10, due to the addition of methanol, the content of p-xylene is increased to 32.53%. Therefore, the addition of methanol greatly improves the selectivity of p-xylene.

[0190] Example 22 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce benzene, toluene and p-xylene

[0191] The catalyst for the coupled conversion of naphtha and CO2 to produce benzene, toluene and p-xylene was prepared online in a micro fixed bed reactor. The conditions for preparing the catalyst online were as follows: 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 2 was loaded into a fixed bed reactor, first treated with 50 ml / min nitrogen at 550°C for 1 hour, and then cooled to 300°C in a nitrogen atmosphere. In a nitrogen atmosphere (mass flow meter control, 100 ml / min), tetraethyl silicate was pumped into the reactor, and the weight space velocity of tetraethyl silicate was 0.2 h / min. -1 , atmospheric pressure. After 60 minutes of feeding, the feeding was stopped, purged with nitrogen, heated to 550°C, and calcined in air atmosphere for 4 hours to obtain a fixed bed catalyst for the coupling conversion of naphtha and CO2 to produce benzene, toluene and p-xylene, named FXNCC-1.

[0192] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:1.2, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 1.2h -1 , reaction pressure 0.1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 16.

[0193] Table 16 Example 22 Catalyst reaction evaluation results

[0194]

[0195]

[0196] It can be seen that, compared with Example 10, when the amount of methanol added increases, the p-xylene content in the hydrocarbon product composition increases from 32.53% to 44.36%, which further illustrates that the addition of methanol increases the selectivity of p-xylene.

[0197] Example 23 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce benzene, toluene and p-xylene

[0198] The catalyst for the coupled conversion of naphtha and CO2 to produce benzene, toluene and p-xylene was prepared online in a micro fixed bed reactor. The conditions for preparing the catalyst online were as follows: 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 2 was loaded into a fixed bed reactor, first treated with 50 ml / min nitrogen at 550°C for 1 hour, and then cooled to 400°C in a nitrogen atmosphere. In a nitrogen atmosphere (mass flow meter control, 100 ml / min), tetraethyl silicate was pumped into the reactor, and the weight space velocity of tetraethyl silicate was 0.2 h / min. -1 , atmospheric pressure. After 60 minutes of feeding, the feeding was stopped, purged with nitrogen, heated to 550°C, and calcined in air atmosphere for 4 hours to obtain a fixed bed catalyst for the coupling conversion of naphtha and CO2 to produce benzene, toluene and p-xylene, named FXNCC-6.

[0199] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1 , reaction pressure 0.1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 17.

[0200] Table 17 Example 23 Catalyst reaction evaluation results

[0201]

[0202] Example 24 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce benzene, toluene and p-xylene

[0203] The catalyst for the coupled conversion of naphtha and CO2 to produce benzene, toluene and p-xylene was prepared online in a micro fixed bed reactor. The conditions for preparing the catalyst online were as follows: 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 2 was loaded into a fixed bed reactor, first treated with 50 ml / min nitrogen at 550°C for 1 hour, and then cooled to 300°C in a nitrogen atmosphere. In a nitrogen atmosphere (mass flow meter control, 100 ml / min), tetraethyl silicate was pumped into the reactor, and the weight space velocity of tetraethyl silicate was 0.4 h / min. -1, atmospheric pressure. After 60 minutes of feeding, the feeding was stopped, purged with nitrogen, heated to 550°C, and calcined in air atmosphere for 4 hours to obtain a fixed bed catalyst for the coupling conversion of naphtha and CO2 to produce benzene, toluene and p-xylene, named FXNCC-7.

[0204] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1 , reaction pressure 0.1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 18.

[0205] Table 18 Catalyst reaction evaluation results of Example 24

[0206]

[0207] Example 25 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce benzene, toluene and p-xylene

[0208] A catalyst for the coupled conversion of naphtha and CO2 to produce benzene, toluene and p-xylene was prepared online in a micro fixed bed reactor. The conditions for preparing the catalyst online were as follows: 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 2 was loaded into a fixed bed reactor, first treated with 50 ml / min nitrogen at 550°C for 1 hour, and then cooled to 300°C in a nitrogen atmosphere. In a nitrogen atmosphere (mass flow meter control, 100 ml / min), tetraethyl silicate was pumped into the reactor, and the weight space velocity of tetraethyl silicate was 0.05 h / min. -1 , atmospheric pressure. After 240 minutes of feeding, the feeding was stopped, purged with nitrogen, heated to 550°C, and calcined in air atmosphere for 4 hours to obtain a fixed bed catalyst for the coupling conversion of naphtha and CO2 to produce benzene, toluene and p-xylene, named FXNCC-8.

[0209] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1, reaction pressure 0.1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 19.

[0210] Table 19 Catalyst reaction evaluation results of Example 25

[0211]

[0212] Example 26 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce benzene, toluene and p-xylene

[0213] The catalyst for the coupled conversion of naphtha and CO2 to produce benzene, toluene and p-xylene was prepared online in a micro fixed bed reactor. The conditions for preparing the catalyst online were as follows: 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 2 was loaded into a fixed bed reactor, first treated with 50 ml / min nitrogen at 550°C for 1 hour, and then cooled to 300°C in a nitrogen atmosphere. In a nitrogen atmosphere (mass flow meter control, 100 ml / min), tetraethyl silicate was pumped into the reactor, and the weight space velocity of tetraethyl silicate was 0.2 h / min. -1 , atmospheric pressure. After 60 minutes of feeding, the feeding was stopped, purged with nitrogen, heated to 550°C, and calcined in air atmosphere for 4 hours to obtain a fixed bed catalyst for the coupling conversion of naphtha and CO2 to produce benzene, toluene and p-xylene, named FXNCC-1.

[0214] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 0.8:1:0.6, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 0.8h -1 , methanol weight space velocity 0.6h -1 , reaction pressure 3MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 20.

[0215] Table 20 Catalyst reaction evaluation results of Example 26

[0216]

[0217]

[0218] Example 27 Preparation and reaction evaluation of catalyst for the coupled conversion of methanol, naphtha and CO2 to produce benzene, toluene and p-xylene

[0219] The catalyst for the coupled conversion of naphtha and CO2 to produce benzene, toluene and p-xylene was prepared online in a micro fixed bed reactor. The conditions for preparing the catalyst online were as follows: 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 2 was loaded into a fixed bed reactor, first treated with 50 ml / min nitrogen at 550°C for 1 hour, and then cooled to 300°C in a nitrogen atmosphere. In a nitrogen atmosphere (mass flow meter control, 100 ml / min), tetraethyl silicate was pumped into the reactor, and the weight space velocity of tetraethyl silicate was 0.2 h / min. -1 , atmospheric pressure. After 60 minutes of feeding, the feeding was stopped, purged with nitrogen, heated to 550°C, and calcined in air atmosphere for 4 hours to obtain a fixed bed catalyst for the coupling conversion of naphtha and CO2 to produce benzene, toluene and p-xylene, named FXNCC-1.

[0220] Then, the temperature was adjusted to a reaction temperature of 550°C under a nitrogen atmosphere; methanol and naphtha raw materials were fed with a micro-feed pump, and the CO2 flow rate was controlled by a mass flow meter. The raw material CO2: naphtha: methanol (mass ratio) was 1.5:1:1.5, and the naphtha weight space velocity was 1.0h -1 , CO2 weight space velocity 1.5h -1 , methanol weight space velocity 1.5h -1 , reaction pressure 0.1MPa. The reaction product was analyzed by online Agilent7890 gas chromatography, and samples were taken for analysis after 30min of reaction. The reaction results are shown in Table 21.

[0221] Table 21 Catalyst reaction evaluation results of Example 27

[0222]

[0223]

[0224] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing p-xylene, characterized in that: Feedstock containing methanol, naphtha and CO2 is passed through a reactor equipped with a catalyst to react and generate paraxylene; The catalyst is a metal-modified HZSM-5 zeolite molecular sieve; The metal used for metal modification is selected from at least one of La, Zn, Ga, Fe, Mo and Cr.

2. The method according to claim 1, characterized in that The reaction conditions are: reaction temperature 450-650°C, reaction pressure 0.1-3.5 MPa, naphtha weight space velocity 0.1-5 h -1 , CO2 weight space velocity 0.1~3h -1 , methanol weight space velocity 0.1~5h -1 .

3. The method according to claim 1, characterized in that The reaction conditions are: reaction temperature 500-600°C, reaction pressure 0.1-3MPa, naphtha weight space velocity 0.5-2h -1 , CO2 weight space velocity 0.5~2h -1 , methanol weight space velocity 0.5~2h -1 .

4. The method according to claim 1, characterized in that: The usage ratio of CO2, naphtha and methanol is 0.3~2:1:0.3~2.

5. The method according to claim 1, characterized in that The usage ratio of CO2, naphtha and methanol is 0.3~1.5:1:0.3~1.

5.

6. The method according to claim 1, characterized in that The components containing benzene and toluene in the mixture obtained by the reaction are separated from the obtained mixture, returned to the reaction system, and co-fed with the raw materials on the catalyst to react to produce p-xylene.

7. The method according to claim 1, characterized in that The silicon-aluminum ratio Si / Al of the HZSM-5 zeolite molecular sieve is 10-50.

8. The method according to claim 1, characterized in that The HZSM-5 zeolite molecular sieve is a HZSM-5 zeolite molecular sieve modified by metal and silanization agent.

9. The method according to claim 8, characterized in that The silanizing agent used for the silanizing agent modification is selected from at least one of the compounds having the following chemical formula: Wherein R1, R2, R3 and R4 are each independently selected from C 1-10 Alkyl, C 1-10 At least one of the alkoxy groups.

10. The method according to claim 9, characterized in that At least one of R1, R2, R3 and R4 is selected from C 1-10 of alkoxy.

11. The method according to claim 9, characterized in that The silanization agent is selected from tetraethyl silicate and\or tetramethyl silicate.

12. The method according to claim 1, characterized in that The metal modification method comprises: placing the HZSM-5 zeolite molecular sieve in a metal salt solution, impregnating, drying and calcining to obtain the metal modified HZSM-5 zeolite molecular sieve.

13. The method according to claim 12, characterized in that The immersion conditions are as follows: immersion temperature is 60 to 100° C. and immersion time is 2 to 10 hours.

14. The method according to claim 12, characterized in that The solid-to-liquid ratio of the HZSM-5 zeolite molecular sieve to the metal salt solution is 1:20 to 1:

1.

15. The method according to claim 12, characterized in that The metal salt is a soluble metal salt corresponding to the metal used for metal modification.

16. The method according to claim 8, characterized in that The silanization agent modification method comprises: contacting a material containing a silanization agent with a metal-modified HZSM-5 zeolite molecular sieve, purging with an inactive gas, and calcining to obtain the metal-modified and silanization agent-modified HZSM-5 zeolite molecular sieve.

17. The method according to claim 16, characterized in that The temperature of the contact treatment is 250-450°C.

18. The method according to claim 16, characterized in that The weight space velocity of the silanization agent is 0.02 to 0.5 h -1 .

19. The method according to claim 1, characterized in that The reactor is a fixed bed reactor, a fluidized bed reactor or a moving bed reactor.

Images