METHOD FOR PRODUCING BENZENE, TOLUENE AND P-XYLENE BY COUPLING CONVERSION OF NAPHTHA AND CARBON DIOXIDE

Abstract

A method for preparing a modified molecular sieve catalyst and a method for producing benzene, toluene and p-xylene by coupling conversion of naphtha and CO.sub.2 are provided. Preparing a modified molecular sieve catalyst includes subjecting a molecular sieve to metal modification by using a high temperature hydrothermal method, which includes: (1) preparing a soluble metal salt aqueous solution; (2) placing a zeolite molecular sieve to be metal-modified in the soluble metal salt aqueous solution, and impregnating the same at a temperature of 60-100 C.; and (3) draining the molecular sieve, followed by drying and calcination. Producing benzene, toluene and p-xylene by coupling conversion of naphtha and CO.sub.2 includes: (a) preparing a modified molecular sieve catalyst; and (b) enabling a raw material containing naphtha and CO.sub.2 to contact with the modified molecular sieve catalyst in a reactor for a reaction to produce benzene, toluene and p-xylene.

Claims

1. A method for preparing a modified molecular sieve catalyst used for catalyzing coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, wherein the method comprises subjecting a molecular sieve to metal modification by using a high temperature hydrothermal method, comprising the following steps: (1) preparing a soluble metal salt aqueous solution; (2) placing a zeolite molecular sieve to be metal-modified in the soluble metal salt aqueous solution, and impregnating the molecular sieve at a temperature in a range from 60 C. to 100 C.; and (3) draining the molecular sieve obtained in step (2), followed by drying and calcination to obtain the modified molecular sieve catalyst.

2. The method according to claim 1, wherein the solid-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 a metal salt in the soluble metal salt aqueous solution is in a range from 10% to 30%; the impregnating time is in a range from 2 hours to 10 hours; the step of drying is carried out in an air atmosphere at temperature in a range from 100 C. to 150 C.; and the step of calcination is carried out in an air atmosphere at temperature in a range from 500 C. to 700 C.

3. The method according to claim 1, wherein a metal used for the metal modification is at least one selected from a group consisting of La, Zn, Ga, Fe, Mo and Cr metals.

4. The method according to claim 1, wherein the modified zeolite molecular sieve catalyst consists of a modified HZSM-5 zeolite molecular sieve.

5. The method according to claim 1, wherein the modified zeolite molecular sieve catalyst comprises a modified HZSM-5 zeolite molecular sieve and a binder.

6. The method according to claim 1, wherein the method further comprises subjecting the molecular sieve to silanization modification after the metal modification.

7. The method according to claim 6, wherein the silanization modification is carried out by using an in situ chemical vapor deposition method, and comprises the following steps: (4) placing the metal-modified zeolite molecular sieve in a reactor; (5) introducing a material A containing a silanization reagent into the reactor at one time, wherein the introduced amount of the silanization reagent is in a range from 0.2 g/g solid to 0.3 g/g solid, and the silanization reagent is gaseous in the reactor; and (6) stopping the introduction of the material A into the reactor, raising the temperature of the reactor to 400 C. or above, and introducing air for calcination; wherein preferably, the temperature of the reactor is raised to a range from 400 C. to 550 C., and the air is introduced for calcination.

8. The method according to claim 6, wherein the silanization modification is carried out by using an in situ vapor atomic layer deposition method, and comprises the following steps: (4) placing the metal-modified zeolite molecular sieve in a reactor; (5) introducing a material A containing a silanization reagent into the reactor at n times, wherein the introduced amount of the silanization reagent each time is in a range from 0.03 g/g solid to 0.06 g/g solid, the silanization reagent is gaseous in the reactor, and the n is in a value range of 3 to 6; and (6) stopping the introduction of the material A into the reactor, raising the temperature of the reactor to 400 C. or above, and introducing air for calcination; wherein preferably, the temperature of the reactor is raised to a range from 400 C. to 550 C., and the air is introduced for calcination.

9. The method according to claim 6, wherein the silanization reagent used for the silanization modification is selected from at least one of compounds with the following chemical formula: ##STR00003## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently selected from C.sub.1-10 alkyl and C.sub.1-10 alkoxyl.

10. The method according to claim 9, wherein according to the silanization reagent used for the silanization modification, at least one of the R.sub.1, the R.sub.2, the R.sub.3 and the R.sub.4 is selected from C.sub.1-10 alkoxyl.

11. The method according to claim 9, wherein the silanization reagent is selected from at least one of tetraethyl silicate and tetramethyl silicate.

12. A method for producing benzene, toluene and p-xylene by coupling conversion of naphtha and CO.sub.2, wherein the method comprises the following steps: (a) preparing a modified molecular sieve catalyst by the method according to claim; and (b) enabling a raw material containing naphtha and CO.sub.2 to contact with the modified molecular sieve catalyst in a reactor for a reaction to produce benzene, toluene and p-xylene.

13. The method according to claim 12, wherein the raw material consists of naphtha and CO.sub.2.

14. The method according to claim 12, wherein the naphtha is at least one selected from a group consisting of hydrocracked naphtha, catalytic cracked naphtha, raffinate oil, topped oil and direct coal liquefied naphtha; preferably, the carbon number distribution of hydrocarbons in the naphtha is in a range of C.sub.4-C.sub.12; and preferably, the reactor is one of a fixed bed reactor, a fluidized bed reactor or a moving bed reactor.

15. The method according to claim 12, wherein conditions for the reaction of the naphtha and the CO.sub.2 are as follows: the reaction temperature is in a range from 450 C. to 650 C., the reaction pressure is in a range from 0.1 MPa to 3 MPa, the weight hourly space velocity of the naphtha is in a range from 0.1 h.sup.1 to 5 h.sup.1, and the weight hourly space velocity of the CO.sub.2 is in a range from 0.1 h.sup.1 to 5 h.sup.1.

16. A method for producing benzene, toluene and p-xylene by coupling conversion of naphtha and CO.sub.2, wherein the method comprises the following steps: (a) preparing a modified molecular sieve catalyst by the method according to claim 11; and (b) enabling a raw material containing naphtha and CO.sub.2 to contact with the modified molecular sieve catalyst in a reactor for a reaction to produce benzene, toluene and p-xylene.

17. The method according to claim 16, wherein the raw material consists of naphtha and CO.sub.2.

18. The method according to claim 16, wherein the naphtha is at least one selected from a group consisting of hydrocracked naphtha, catalytic cracked naphtha, raffinate oil, topped oil and direct coal liquefied naphtha; preferably, the carbon number distribution of hydrocarbons in the naphtha is in a range of C.sub.4-C.sub.12; and preferably, the reactor is one of a fixed bed reactor, a fluidized bed reactor or a moving bed reactor.

19. The method according to claim 16, wherein conditions for the reaction of the naphtha and the CO.sub.2 are as follows: the reaction temperature is in a range from 450 C. to 650 C., the reaction pressure is in a range from 0.1 MPa to 3 MPa, the weight hourly space velocity of the naphtha is in a range from 0.1 h.sup.1 to 5 h.sup.1, and the weight hourly space velocity of the CO.sub.2 is in a range from 0.1 h.sup.1 to 5 h.sup.1.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0103] The present application is described in detail below in conjunction with examples, but the present application is not limited to the examples.

[0104] Endpoints and any values of ranges disclosed in the present application are not limited to the exact ranges or values, and these ranges or values should be understood as including approximate ranges or values. For numeric ranges, endpoint values and individual point values of each range may be combined with each other to obtain one or more new numeric ranges, and these numeric ranges should be considered to be specifically disclosed herein.

[0105] The present application is described in detail below in conjunction with examples, but the present application is not limited to the examples.

[0106] Unless otherwise specified, raw materials used in the examples of the present application are purchased by commercial ways or prepared by known methods. An HZSM-5 zeolite molecular sieve used in the examples was purchased from Nankai Catalyst Factory.

[0107] Unless otherwise specified, analytical methods used in the examples are implemented with conventional setup of instruments or equipment and are conventional analytical methods.

[0108] In the examples of the present application, the type of naphtha is direct coal liquefied naphtha, which includes specific components as shown in the following table.

Composition of Direct Coal Liquefied Naphtha

[0109]

TABLE-US-00001 Aromatic Carbon number N-alkanes Isoalkanes Cycloalkanes hydrocarbons 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

[0110] In the examples of the present application, the inner diameter of a fixed bed reactor is 1.5 cm; and the inner diameter of a fixed fluidized bed reactor is 3 cm.

[0111] In the examples of the present application, only hydrocarbon products are listed, and other products obtained by a reaction of naphtha and CO.sub.2 are not listed.

Example 1 Preparation of a Zinc-Modified HZSM-5 Molecular Sieve Molded Sample Used in a Fixed Bed

[0112] 100 g of an HZSM-5 zeolite molecular sieve (Nankai Catalyst Factory, Si/Al=15) was placed in a 10 wt % zinc nitrate aqueous solution, where the mass ratio (namely solid-liquid ratio) of the HZSM-5 zeolite molecular sieve to the zinc nitrate aqueous solution was 1/10. The molecular sieve 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 a [Zn]HZSM-5 molecular sieve sample. Then, the sample was subjected to pressing molding, crushed and sieved to obtain molded molecular sieve particles with a particle size of 40-60 mesh, recorded as FX-[Zn]HZSM-5.

Example 2 Preparation of a Gallium-Modified HZSM-5 Molecular Sieve Molded Sample Used in a Fixed Bed

[0113] 100 g of an HZSM-5 zeolite molecular sieve (Nankai Catalyst Factory, Si/Al=15) was placed in a 10 wt % gallium nitrate aqueous solution, where the mass ratio (namely solid-liquid ratio) of the HZSM-5 zeolite molecular sieve to the gallium nitrate aqueous solution was 1/10. The molecular sieve 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 a [Ga]HZSM-5 molecular sieve sample. Then, the sample was subjected to pressing molding, crushed and sieved to obtain molded molecular sieve particles with a particle size of 40-60 mesh, recorded as FX-[Ga]HZSM-5.

3 Preparation of a Lanthanum-Modified HZSM-5 Molecular Sieve Molded Sample Used in a Fixed Bed

[0114] 100 g of an HZSM-5 zeolite molecular sieve (Nankai Catalyst Factory, Si/Al=15) was placed in a 10 wt % lanthanum nitrate aqueous solution, where the mass ratio (namely solid-liquid ratio) of the HZSM-5 zeolite molecular sieve to the lanthanum nitrate aqueous solution was 1/10. The molecular sieve 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 a [La]HZSM-5 molecular sieve sample. Then, the sample was subjected to pressing molding, crushed and sieved to obtain molded molecular sieve particles with a particle size of 40-60 mesh, recorded as FX-[La]HZSM-5.

Example 4 Preparation of an Iron-Modified HZSM-5 Molecular Sieve Molded Sample Used in a Fixed Bed

[0115] 100 g of an HZSM-5 zeolite molecular sieve (Nankai Catalyst Factory, Si/Al=15) was placed in a 10 wt % ferric nitrate aqueous solution, where the mass ratio (namely solid-liquid ratio) of the HZSM-5 zeolite molecular sieve to the ferric nitrate aqueous solution was 1/10. The molecular sieve 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 a [Fe]HZSM-5 molecular sieve sample. Then, the sample was subjected to pressing molding, crushed and sieved to obtain molded molecular sieve particles with a particle size of 40-60 mesh, recorded as FX-[Fe]HZSM-5.

Example 5 Preparation of a Chromium-Modified HZSM-5 Molecular Sieve Molded Sample Used in a Fixed Bed

[0116] 100 g of an HZSM-5 zeolite molecular sieve (Nankai Catalyst Factory, Si/Al=15) was placed in a 10 wt % chromium nitrate aqueous solution, where the mass ratio (namely solid-liquid ratio) of the HZSM-5 zeolite molecular sieve to the chromium nitrate aqueous solution was 1/10. The molecular sieve 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 a [Cr]HZSM-5 molecular sieve sample. Then, the sample was subjected to pressing molding, crushed and sieved to obtain molded molecular sieve particles with a particle size of 40-60 mesh, recorded as FX-[Cr]HZSM-5.

Example 6 Preparation of a Zinc-Modified HZSM-5 Molecular Sieve Molded Sample Used in a Fluidized Bed

[0117] 100 g of the [Zn]HZSM-5 molecular sieve sample prepared in Example 1 was mixed with an amorphous binder containing aluminum or silicon for spray drying and molding. Specific steps are as follows.

[0118] The [Zn]HZSM-5 molecular sieve sample, pseudo-boehmite, silica sol, xanthan gum (biological gum) and water were uniformly mixed, followed by beating, milling and defoaming to obtain slurry. The slurry includes the following parts by weight of components:

TABLE-US-00002 [Zn]HZSM-5 35 parts by weight, Al.sub.2O.sub.3 20 parts by weight, SiO.sub.2 45 parts by weight, H.sub.2O 240 parts by weight, and xanthan gum 1 part by weight.

[0119] The obtained slurry was subjected to spray drying and molding to obtain a microsphere particle sample with the particle size distribution of 20-100 m. Then, the microsphere particle sample was calcined in a Muffle furnace at 550 C. for 3 hours to obtain a [Zn]HZSM-5 molded molecular sieve with an abrasion index of 1.2, recorded as FL-[Zn]HZSM-5.

Example 7 Preparation of a Zinc-Gallium Composite Modified HZSM-5 Molecular Sieve Molded Sample Used in a Fixed Bed

[0120] 100 g of an HZSM-5 zeolite molecular sieve (Nankai Catalyst Factory, Si/Al=15) was placed in a 10 wt % mixed aqueous solution of zinc nitrate and gallium nitrate, where the mass ratio of the zinc nitrate to the gallium nitrate was 1/1, and the mass ratio (namely solid-liquid ratio) of the HZSM-5 zeolite molecular sieve to the mixed aqueous solution of the zinc nitrate and the gallium nitrate was 1/10. The molecular sieve 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 a [Zn,Ga]HZSM-5 molecular sieve sample. Then, the sample was subjected to pressing molding, crushed and sieved to obtain molded molecular sieve particles with a particle size of 40-60 mesh, recorded as FX-[Zn,Ga]HZSM-5.

Example 8 Preparation of a Zinc-Modified HZSM-5 Molecular Sieve Molded Sample Used in a Fixed Bed

[0121] 100 g of an HZSM-5 zeolite molecular sieve (Nankai Catalyst Factory, Si/Al=15) was placed in a 10 wt % zinc nitrate aqueous solution, where the mass ratio (namely solid-liquid ratio) of the HZSM-5 zeolite molecular sieve to the zinc nitrate aqueous solution was the same as that in Example 1. The molecular sieve 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 a [Zn]HZSM-5 molecular sieve sample. Then, the sample was subjected to pressing molding, crushed and sieved to obtain molded molecular sieve particles with a particle size of 40-60 mesh, recorded as FX-[Zn]HZSM-5-R.

Example 9 Preparation of a Zinc-Modified HZSM-5 Molecular Sieve Molded Sample Used in a Fixed Bed

[0122] 100 g of an HZSM-5 zeolite molecular sieve (Nankai Catalyst Factory, Si/Al=15) was placed in a 10 wt % zinc nitrate aqueous solution, where the mass ratio (namely solid-liquid ratio) of the HZSM-5 zeolite molecular sieve to the zinc nitrate aqueous solution was 1/1. The molecular sieve 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 a [Zn]HZSM-5 molecular sieve sample. Then, the sample was subjected to pressing molding, crushed and sieved to obtain molded molecular sieve particles with a particle size of 40-60 mesh, recorded as FX-[Zn]HZSM-5-A.

Example 10 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0123] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 1 was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. In the nitrogen atmosphere (controlled by a mass flow meter, 100 mL/min), tetraethyl silicate was pumped into the reactor at a weight hourly space velocity of 0.2 h.sup.1 at normal pressure. After feeding for 60 minutes, the feeding was stopped, where the introduced amount of the tetraethyl silicate was 0.2 g/g the catalyst. A resulting mixture was purged with nitrogen, heated to 550 C., and then calcined in an air atmosphere for 4 hours to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FXNCC-1.

[0124] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the CO.sub.2 was 0.8 h.sup.1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 1.

TABLE-US-00003 TABLE 1 Evaluation of reaction performance of a catalyst in Example 10 Conversion rate of naphtha (wt %) 80.12 Conversion rate of CO.sub.2 (wt %) 31.13 Selectivity of ethylene and propylene in hydrocarbon products 12.61 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 69.06 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 73.73 (wt %) Selectivity of PX in xylene products (wt %) 95.50 Composition of hydrocarbon products (wt %) Methane 2.29 Ethylene 5.4 Ethane 2.93 Propylene 7.21 Propane 3.26 C.sub.4 5.18 Benzene 19.3 Toluene 37.45 Ethylbenzene 1.34 P-xylene 12.31 M-xylene 0.39 O-xylene 0.19 C.sub.8+ aromatic hydrocarbons 2.75

Example 10-1 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0125] The reaction performance of a catalyst used for coupling conversion of naphtha and CO.sub.2 was evaluated in a micro-fixed bed reactor. Evaluation conditions are as follows. 5 g of the FX-[Zn]HZSM-5 prepared in Example 1 was loaded into a fixed bed reactor, and treated with nitrogen at 50 ml/min at 550 C. for 1 hour.

[0126] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the CO.sub.2 was 0.8 h.sup.1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 1-1.

TABLE-US-00004 TABLE 1-1 Evaluation of reaction performance of a catalyst in Example 10-1 Conversion rate of naphtha (wt %) 88.48 Conversion rate of CO.sub.2 (wt %) 35.53 Selectivity of ethylene and propylene in hydrocarbon products 7.32 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 63.00 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 77.60 (wt %) Selectivity of PX in xylene products (wt %) 24.30 Composition of hydrocarbon products (wt %) Methane 3.81 Ethylene 3.97 Ethane 5.03 Propylene 3.35 Propane 5.51 C.sub.4 0.73 Benzene 25.93 Toluene 34.53 Ethylbenzene 0.43 P-xylene 2.54 M-xylene 5.47 O-xylene 2.44 C.sub.8+ aromatic hydrocarbons 6.26

[0127] As can be seen by comparing Example 10 and Example 10-1, compared with the use of the HZSM-5 molecular sieve obtained only by metal modification as an active component of the catalyst, the use of the HZSM-5 molecular sieve obtained by metal modification and silanization modification as an active component of the catalyst can achieve higher selectivity of BTPX and higher selectivity of p-xylene in xylene.

Example 11 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0128] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of the FX-[Ga]HZSM-5 catalyst prepared in Example 2 was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. In the nitrogen atmosphere (controlled by a mass flow meter, 100 mL/min), tetraethyl silicate was pumped into the reactor at a weight hourly space velocity of 0.2 h.sup.1 at normal pressure. After feeding for 60 minutes, the feeding was stopped, where the introduced amount of the tetraethyl silicate was the same as that in Example 10. A resulting mixture was purged with nitrogen, heated to 550 C., and then calcined in an air atmosphere for 4 hours to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FXNCC-2.

[0129] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the CO.sub.2 was 0.8 h.sup.1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 2.

TABLE-US-00005 TABLE 2 Evaluation of reaction performance of a catalyst in Example 11 Conversion rate of naphtha (wt %) 79.78 Conversion rate of CO.sub.2 (wt %) 29.97 Selectivity of ethylene and propylene in hydrocarbon products 9.22 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 69.95 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 74.55 (wt %) Selectivity of PX in xylene products (wt %) 96.13 Composition of hydrocarbon products (wt %) Methane 1.67 Ethylene 5.0 Ethane 2.68 Propylene 6.21 Propane 4.3 C.sub.4 5.58 Benzene 18.19 Toluene 38.35 Ethylbenzene 1.45 P-xylene 13.41 M-xylene 0.37 O-xylene 0.17 C.sub.8+ aromatic hydrocarbons 2.61

Example 12 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0130] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of the FX-[La]HZSM-5 catalyst prepared in Example 3 was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. In the nitrogen atmosphere (controlled by a mass flow meter, 100 mL/min), tetraethyl silicate was pumped into the reactor at a weight hourly space velocity of 0.2 h.sup.1 at normal pressure. After feeding for 60 minutes, the feeding was stopped, where the introduced amount of the tetraethyl silicate was the same as that in Example 10. A resulting mixture was purged with nitrogen, heated to 550 C., and then calcined in an air atmosphere for 4 hours to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FXNCC-3.

[0131] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the CO.sub.2 was 0.8 h.sup.1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 3.

TABLE-US-00006 TABLE 3 Evaluation of reaction performance of a catalyst in Example 12 Conversion rate of naphtha (wt %) 78.41 Conversion rate of CO.sub.2 (wt %) 25.83 Selectivity of ethylene and propylene in hydrocarbon products 12.46 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 67.89 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 72.87 (wt %) Selectivity of PX in xylene products (wt %) 95.58 Composition of hydrocarbon products (wt %) Methane 3.37 Ethylene 5.53 Ethane 4.12 Propylene 6.93 Propane 3.22 C.sub.4 3.96 Benzene 20.58 Toluene 36.5 Ethylbenzene 1.15 P-xylene 10.81 M-xylene 0.38 O-xylene 0.12 C.sub.8+ aromatic hydrocarbons 3.33

Example 13 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0132] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of the FX-[Fe]HZSM-5 catalyst prepared in Example 4 was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. In the nitrogen atmosphere (controlled by a mass flow meter, 100 mL/min), tetraethyl silicate was pumped into the reactor at a weight hourly space velocity of 0.2 h.sup.1 at normal pressure. After feeding for 60 minutes, the feeding was stopped, where the introduced amount of the tetraethyl silicate was the same as that in Example 10. A resulting mixture was purged with nitrogen, heated to 550 C., and then calcined in an air atmosphere for 4 hours to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FXNCC-4.

[0133] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the CO.sub.2 was 0.8 h.sup.1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 4.

TABLE-US-00007 TABLE 4 Evaluation of reaction performance of a catalyst in Example 13 Conversion rate of naphtha (wt %) 77.80 Conversion rate of CO.sub.2 (wt %) 24.09 Selectivity of ethylene and propylene in hydrocarbon products 12.06 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 66.66 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 71.58 (wt %) Selectivity of PX in xylene products (wt %) 95.93 Composition of hydrocarbon products (wt %) Methane 2.82 Ethylene 4.95 Ethane 2.82 Propylene 7.11 Propane 4.16 C.sub.4 6.56 Benzene 17.12 Toluene 36.58 Ethylbenzene 1.46 P-xylene 12.96 M-xylene 0.41 O-xylene 0.14 C.sub.8+ aromatic hydrocarbons 2.91

Example 14 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0134] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of the FX-[Cr]HZSM-5 catalyst prepared in Example 5 was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. In the nitrogen atmosphere (controlled by a mass flow meter, 100 mL/min), tetraethyl silicate was pumped into the reactor at a weight hourly space velocity of 0.2 h.sup.1 at normal pressure. After feeding for 60 minutes, the feeding was stopped, where the introduced amount of the tetraethyl silicate was the same as that in Example 10. A resulting mixture was purged with nitrogen, heated to 550 C., and then calcined in an air atmosphere for 4 hours to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FXNCC-5.

[0135] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the CO.sub.2 was 0.8 h.sup.1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 5.

TABLE-US-00008 TABLE 5 Evaluation of reaction performance of a catalyst in Example 14 Conversion rate of naphtha (wt %) 79.90 Conversion rate of CO.sub.2 (wt %) 29.57 Selectivity of ethylene and propylene in hydrocarbon products 13.67 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 67.74 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 72.70 (wt %) Selectivity of PX in xylene products (wt %) 95.68 Composition of hydrocarbon products (wt %) Methane 2.03 Ethylene 5.28 Ethane 2.72 Propylene 8.39 Propane 3.09 C.sub.4 5.79 Benzene 18.32 Toluene 36.57 Ethylbenzene 1.59 P-xylene 12.85 M-xylene 0.42 O-xylene 0.16 C.sub.8+ aromatic hydrocarbons 2.79

Example 15 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0136] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed fluidized bed reactor. Conditions for on-line preparation of the catalyst are as follows. 10 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 6 was loaded into a fixed fluidized bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. In the nitrogen atmosphere (controlled by a mass flow meter, 200 mL/min), tetraethyl silicate was pumped into the reactor at a weight hourly space velocity of 0.2 h.sup.1 at normal pressure. After feeding for 75 minutes, the feeding was stopped, where the introduced amount of the tetraethyl silicate was 1.25 times of that in Example 9. A resulting mixture was purged with nitrogen, heated to 550 C., and then calcined in an air atmosphere for 4 hours to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FLNCC-1. The purpose of using 10 g of the FL-[Zn]HZSM-5 molecular sieve molded sample in this example was only to meet requirements of the micro-fixed fluidized bed reactor, the amount (10 g) enables the catalyst to stay in a fluidized state, and the amount of 5 g cannot enable the catalyst to stay in a fluidized state. In a case of using the micro-fixed fluidized bed reactor, the feeding time was 75 min for silanization modification, which was only used to carry out silanization modification to the same degree as that in Example 9.

[0137] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the CO.sub.2 was 0.8 h.sup.1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 6.

TABLE-US-00009 TABLE 6 Evaluation of reaction performance of a catalyst in Example 15 Conversion rate of naphtha (wt %) 79.27 Conversion rate of CO.sub.2 (wt %) 29.29 Selectivity of ethylene and propylene in hydrocarbon products 11.63 (wt %) Selectivity of BTX in hydrocarbon products (wt %) 67.86 Selectivity of aromatic hydrocarbons in hydrocarbon products 72.99 (wt %) Selectivity of PX in xylene products 96.13 Composition of hydrocarbon products (wt %) Methane 2.74 Ethylene 4.57 Ethane 2.52 Propylene 7.06 Propane 3.66 C.sub.4 6.46 Benzene 17.08 Toluene 37.13 Ethylbenzene 1.58 P-xylene 13.65 M-xylene 0.37 O-xylene 0.18 C.sub.8+ aromatic hydrocarbons 3.00

Example 16 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0138] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 1 was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. Then, a vapor atomic layer deposition method was used to carry out modification with a silanization reagent, specifically including the following steps: (1) introducing nitrogen (controlled by a mass flow meter, 200 mL/min) into a saturated flask filled with tetraethyl silicate (temperature 15 C.), then introducing the same into a reactor, namely introducing the nitrogen carrying the tetraethyl silicate into the reactor, and after feeding for 5 minutes, stopping the feeding; (2) carrying out purging with nitrogen, and raising the temperature to 550 C., followed by calcination in an air atmosphere for 1 hour; and (3) repeating steps (1) and (2) for 3 times to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FXNCC-6, where the amount of the tetraethyl silicate introduced for 4 times was equivalent to the amount introduced for one time in Example 10.

[0139] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 7.

TABLE-US-00010 TABLE 7 Evaluation of reaction performance of a catalyst in Example 16 Conversion rate of naphtha (wt %) 86.57 Conversion rate of CO.sub.2 (wt %) 34.16 Selectivity of ethylene and propylene in hydrocarbon products 8.78 (wt %) Selectivity of BTX in hydrocarbon products (wt %) 74.50 Selectivity of aromatic hydrocarbons in hydrocarbon products 78.48 (wt %) Selectivity of PX in xylene products 97.08 Composition of hydrocarbon products (wt %) Methane 2.45 Ethylene 4.05 Ethane 3.23 Propylene 4.73 Propane 3.91 C.sub.4 3.15 Benzene 20.31 Toluene 39.17 Ethylbenzene 0.71 P-xylene 15.02 M-xylene 0.32 O-xylene 0.13 C.sub.8+ aromatic hydrocarbons 2.82

Example 17 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0140] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of the FX-[Zn,Ga]HZSM-5 catalyst prepared in Example 7 was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. In the nitrogen atmosphere (controlled by a mass flow meter, 100 mL/min), tetraethyl silicate was pumped into the reactor at a weight hourly space velocity of 0.2 h.sup.1 at normal pressure. After feeding for 60 minutes, the feeding was stopped, where the introduced amount of the tetraethyl silicate was the same as that in Example 10. A resulting mixture was purged with nitrogen, heated to 550 C., and then calcined in an air atmosphere for 4 hours to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FXNCC-7.

[0141] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the CO.sub.2 was 0.8 h.sup.1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 8.

TABLE-US-00011 TABLE 8 Evaluation of reaction performance of a catalyst in Example 17 Conversion rate of naphtha (wt %) 81.31 Conversion rate of CO.sub.2 (wt %) 30.95 Selectivity of ethylene and propylene in hydrocarbon products 10.24 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 71.37 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 75.91 (wt %) Selectivity of PX in xylene products (wt %) 95.72 Composition of hydrocarbon products (wt %) Methane 2.57 Ethylene 4.82 Ethane 3.11 Propylene 5.42 Propane 4.29 C.sub.4 3.89 Benzene 20.47 Toluene 36.83 Ethylbenzene 0.94 P-xylene 14.07 M-xylene 0.40 O-xylene 0.23 C.sub.8+ aromatic hydrocarbons 2.96

Example 18 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0142] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of the FX-[Zn]HZSM-5-R catalyst prepared in Example 8 was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. In the nitrogen atmosphere (controlled by a mass flow meter, 100 mL/min), tetraethyl silicate was pumped into the reactor at a weight hourly space velocity of 0.2 h.sup.1 at normal pressure. After feeding for 60 minutes, the feeding was stopped, where the introduced amount of the tetraethyl silicate was the same as that in Example 10. A resulting mixture was purged with nitrogen, heated to 550 C., and then calcined in an air atmosphere for 4 hours to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FXNCC-8.

[0143] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the CO.sub.2 was 0.8 h.sup.1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 9.

TABLE-US-00012 TABLE 9 Evaluation of reaction performance of a catalyst in Example 18 Conversion rate of naphtha (wt %) 78.37 Conversion rate of CO.sub.2 (wt %) 30.81 Selectivity of ethylene and propylene in hydrocarbon products 15.99 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 62.62 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 67.38 (wt %) Selectivity of PX in xylene products (wt %) 95.39 Composition of hydrocarbon products (wt %) Methane 2.34 Ethylene 6.46 Ethane 2.96 Propylene 9.53 Propane 3.29 C.sub.4 8.06 Benzene 15.29 Toluene 34.58 Ethylbenzene 1.35 P-xylene 12.75 M-xylene 0.40 O-xylene 0.21 C.sub.8+ aromatic hydrocarbons 2.78

[0144] Compared with the selectivity of BTPX in Example 10, the HZSM-5 molecular sieve obtained by metal modification using a high temperature hydrothermal method can achieve higher selectivity of BTPX than that obtained by metal modification using a room temperature impregnation method.

Example 19 Preparation of a ZSM-5 Catalyst Modified with a Silanization Reagent Used in a Fixed Bed

[0145] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of a 40- to 60-mesh HZSM-5 molecular sieve catalyst was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. In the nitrogen atmosphere (controlled by a mass flow meter, 100 mL/min), tetraethyl silicate was pumped into the reactor at a weight hourly space velocity of 0.2 h.sup.1 at normal pressure. After feeding for 60 minutes, the feeding was stopped, where the introduced amount of the tetraethyl silicate was the same as that in Example 10. A resulting mixture was purged with nitrogen, heated to 550 C., and then calcined in an air atmosphere for 4 hours to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FXNCC-9.

[0146] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the CO.sub.2 was 0.8 h.sup.1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 9-1.

TABLE-US-00013 TABLE 9-1 Evaluation of reaction performance of a catalyst in Example 19 Conversion rate of naphtha (wt %) 80.76 Conversion rate of CO.sub.2 (wt %) 5.02 Selectivity of ethylene and propylene in hydrocarbon products 6.33 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 56.96 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 60.83 (wt %) Selectivity of PX in xylene products (wt %) 96.24 Composition of hydrocarbon products (wt %) Methane 15.04 Ethylene 3.56 Ethane 9.44 Propylene 2.77 Propane 5.31 C.sub.4 3.05 Benzene 20.36 Toluene 24.33 Ethylbenzene 0.64 P-xylene 12.27 M-xylene 0.32 O-xylene 0.16 C.sub.8+ aromatic hydrocarbons 2.75

Example 20 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0147] 5 g of the FXNCC-9 catalyst prepared in Example 19 was placed in a 10 wt % lanthanum nitrate aqueous solution, where the solid-liquid ratio of the HZSM-5 zeolite molecular sieve used in the FXNCC-9 catalyst to the lanthanum nitrate aqueous solution was the same as that in Example 3. The catalyst 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 a catalyst sample, recorded as FXNCC-10.

[0148] The reaction performance of the catalyst used for coupling conversion of naphtha and CO.sub.2 was evaluated in a micro-fixed bed reactor. Evaluation conditions are as follows. 5 g of the FXNCC-10 catalyst molded sample (40-60 mesh) was loaded into a fixed bed reactor, and the temperature was raised to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the CO.sub.2 was 0.8 h.sup.1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 10.

TABLE-US-00014 TABLE 10 Evaluation of reaction performance of a catalyst in Example 20 Conversion rate of naphtha (wt %) 82.54 Conversion rate of CO.sub.2 (wt %) 28.95 Selectivity of ethylene and propylene in hydrocarbon products 11.80 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 60.65 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 73.16 (wt %) Selectivity of PX in xylene products (wt %) 40.37 Composition of hydrocarbon products (wt %) Methane 3.56 Ethylene 5.11 Ethane 3.96 Propylene 6.69 Propane 4.31 C.sub.4 3.21 Benzene 21.39 Toluene 35.11 Ethylbenzene 1.06 P-xylene 4.15 M-xylene 3.94 O-xylene 2.19 C.sub.8+ aromatic hydrocarbons 5.32

[0149] By comparing with Example 12, the catalyst in this example achieves lower selectivity of BTPX and lower selectivity of p-xylene in xylene. The results indicate that when La is used for metal modification, a molecular sieve obtained by carrying out metal modification first and then carrying out silanization modification can achieve higher selectivity of BTPX and higher selectivity of p-xylene in xylene compared with a molecular sieve obtained by carrying out silanization modification first and then carrying out metal modification.

Example 21 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0150] A catalyst used for conversion of naphtha to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 1 was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. In the nitrogen atmosphere (controlled by a mass flow meter, 100 mL/min), tetraethyl silicate was pumped into the reactor at a weight hourly space velocity of 0.2 h.sup.1 at normal pressure. After feeding for 60 minutes, the feeding was stopped, where the introduced amount of the tetraethyl silicate was the same as that in Example 10. A resulting mixture was purged with nitrogen, heated to 550 C., and then calcined in an air atmosphere for 4 hours to obtain a fixed bed catalyst used for conversion of naphtha to produce benzene, toluene and p-xylene, named as FXNCC-1.

[0151] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of N.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material N.sub.2 to the naphtha was 0.51:1 (namely, an equivalent molar amount of N.sub.2 was used in this example to replace the CO.sub.2 in Example 10), the weight hourly space velocity of the naphtha was 1.0 h.sup.1, the weight hourly space velocity of the N.sub.2 was 0.51 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 11.

TABLE-US-00015 TABLE 11 Evaluation of reaction performance of a catalyst in Example 21 Conversion rate of naphtha (wt %) 75.98 Selectivity of ethylene and propylene in hydrocarbon products 16.13 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 55.94 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 60.32 (wt %) Selectivity of PX in xylene products (wt %) 95.65 Composition of hydrocarbon products (wt %) Methane 1.68 Ethylene 7.6 Ethane 5.98 Propylene 8.53 Propane 9.14 C.sub.4 6.75 Benzene 16.91 Toluene 29.35 Ethylbenzene 1.35 P-xylene 9.68 M-xylene 0.29 O-xylene 0.15 C.sub.8+ aromatic hydrocarbons 2.59

[0152] The N.sub.2 is used as a diluent in Example 21, and the CO.sub.2 is used as a raw material for reacting with the naphtha in Example 10, which can be seen by comparing the selectivity of aromatic hydrocarbons and the selectivity of BTPX in Examples 10 and 21. Specifically, the selectivity of aromatic hydrocarbons and the selectivity of BTPX in Example 10 are obviously higher than the selectivity of aromatic hydrocarbons in Example 21.

Example 22 Evaluation of Hydrothermal Stability of a Catalyst

[0153] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 1 was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. In the nitrogen atmosphere (controlled by a mass flow meter, 100 mL/min), tetraethyl silicate was pumped into the reactor at a weight hourly space velocity of 0.2 h.sup.1 at normal pressure. After feeding for 60 minutes, the feeding was stopped, where the introduced amount of the tetraethyl silicate was the same as that in Example 10. A resulting mixture was purged with nitrogen, heated to 550 C., and then calcined in an air atmosphere for 4 hours. Then, the mixture was heated to 900 C. in the nitrogen atmosphere, and treated for 1 hour in a 100% water vapor atmosphere (WHSV of water was 2 h.sup.1) to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FXNCC-11.

[0154] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 12.

TABLE-US-00016 TABLE 12 Evaluation of reaction performance of a catalyst in Example 22 Conversion rate of naphtha (wt %) 70.87 Conversion rate of CO.sub.2 (wt %) 20.96 Selectivity of ethylene and propylene in hydrocarbon products 17.24 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 59.28 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 62.87 (wt %) Selectivity of PX in xylene products (wt %) 96.43 Composition of hydrocarbon products (wt %) Methane 1.81 Ethylene 7.65 Ethane 3.77 Propylene 9.59 Propane 3.94 C.sub.4 10.37 Benzene 16.2 Toluene 32.56 Ethylbenzene 0.69 P-xylene 10.52 M-xylene 0.26 O-xylene 0.13 C.sub.8+ aromatic hydrocarbons 2.51

Example 23 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0155] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of the FX-[Zn]HZSM-5-R catalyst prepared in Example 8 was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. In the nitrogen atmosphere (controlled by a mass flow meter, 100 mL/min), tetraethyl silicate was pumped into the reactor at a weight hourly space velocity of 0.2 h.sup.1 at normal pressure. After feeding for 60 minutes, the feeding was stopped, where the introduced amount of the tetraethyl silicate was the same as that in Example 10. A resulting mixture was purged with nitrogen, heated to 550 C., and then calcined in an air atmosphere for 4 hours. Then, the mixture was heated to 900 C. in a nitrogen atmosphere, and treated for 1 hour in a 100% water vapor atmosphere (WHSV of water was 2 h.sup.1) to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FXNCC-12.

[0156] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 13.

TABLE-US-00017 TABLE 13 Evaluation of reaction performance of a catalyst in Example 23 Conversion rate of naphtha (wt %) 51.69 Conversion rate of CO.sub.2 (wt %) 15.62 Selectivity of ethylene and propylene in hydrocarbon products 31.54 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 41.59 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 44.90 (wt %) Selectivity of PX in xylene products (wt %) 96.16 Composition of hydrocarbon products (wt %) Methane 1.68 Ethylene 13.97 Ethane 2.68 Propylene 17.57 Propane 4.61 C.sub.4 14.59 Benzene 12.04 Toluene 21.03 Ethylbenzene 0.96 P-xylene 8.52 M-xylene 0.21 O-xylene 0.13 C.sub.8+ aromatic hydrocarbons 2.01

[0157] By comparing Examples 22 and 23, it can be seen that the catalyst obtained after hydrothermal treatment in Example 22 has obviously higher selectivity of aromatic hydrocarbons and higher selectivity of BTPX than the catalyst obtained after hydrothermal treatment in Example 23. Therefore, the hydrothermal stability of the metal-modified HZSM-5 prepared by a high temperature hydrothermal method is obviously better than that of the metal-modified HZSM-5 prepared by a room temperature impregnation method.

Example 24 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0158] A catalyst FXNCC-1 was prepared by the method in Example 10.

[0159] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 1:1, the weight hourly space velocity of the CO.sub.2 was 5 h.sup.1, the weight hourly space velocity of the naphtha was 5 h.sup.1, and the reaction pressure was 1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 14.

TABLE-US-00018 TABLE 14 Evaluation of reaction performance of a catalyst in Example 24 Conversion rate of naphtha (wt %) 83.19 Conversion rate of CO.sub.2 (wt %) 33.61 Selectivity of ethylene and propylene in hydrocarbon products 7.64 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 72.07 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 77.48 (wt %) Selectivity of PX in xylene products (wt %) 94.76 Composition of hydrocarbon products (wt %) Methane 3.13 Ethylene 3.47 Ethane 3.09 Propylene 4.17 Propane 5.01 C.sub.4 3.65 Benzene 20.88 Toluene 37.81 Ethylbenzene 1.54 P-xylene 13.38 M-xylene 0.48 O-xylene 0.26 C.sub.8+ aromatic hydrocarbons 3.13

Example 25 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0160] A catalyst FXNCC-1 was prepared by the method in Example 10.

[0161] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 1:1, the weight hourly space velocity of the CO.sub.2 was 0.1 h.sup.1, the weight hourly space velocity of the naphtha was 0.1 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 15.

TABLE-US-00019 TABLE 15 Evaluation of reaction performance of a catalyst in Example 25 Conversion rate of naphtha (wt %) 83.63 Conversion rate of CO.sub.2 (wt %) 34.25 Selectivity of ethylene and propylene in hydrocarbon products 5.88 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 73.32 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 79.69 (wt %) Selectivity of PX in xylene products (wt %) 92.53 Composition of hydrocarbon products (wt %) Methane 3.61 Ethylene 2.63 Ethane 3.56 Propylene 3.25 Propane 4.65 C.sub.4 2.61 Benzene 21.61 Toluene 38.09 Ethylbenzene 1.74 P-xylene 13.62 M-xylene 0.69 O-xylene 0.41 C.sub.8+ aromatic hydrocarbons 3.53

Example 26 Preparation of a Zinc-Modified HZSM-5 Molecular Sieve Molded Sample Used in a Fixed Bed

[0162] 100 g of an HZSM-5 zeolite molecular sieve (Nankai Catalyst Factory, Si/Al=15) was placed in a 30 wt % zinc nitrate aqueous solution, where the mass ratio (namely solid-liquid ratio) of the HZSM-5 zeolite molecular sieve to the zinc nitrate aqueous solution was 1/10. The molecular sieve 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 a [Zn]HZSM-5 molecular sieve sample. Then, the sample was subjected to pressing molding, crushed and sieved to obtain molded molecular sieve particles with a particle size of 40-60 mesh, recorded as FX-[Zn]HZSM-5-B.

Example 27 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0163] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of the FX-[Zn]HZSM-5-B catalyst prepared in Example 26 was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. In the nitrogen atmosphere (controlled by a mass flow meter, 100 mL/min), tetraethyl silicate was pumped into the reactor at a weight hourly space velocity of 0.2 h.sup.1 at normal pressure. After feeding for 60 minutes, the feeding was stopped, where the introduced amount of the tetraethyl silicate was 0.2 g/g the catalyst. A resulting mixture was purged with nitrogen, heated to 550 C., and then calcined in an air atmosphere for 4 hours to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FXNCC-13.

[0164] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the CO.sub.2 was 0.8 h.sup.1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 16.

TABLE-US-00020 TABLE 16 Evaluation of reaction performance of a catalyst in Example 27 Conversion rate of naphtha (wt %) 81.66 Conversion rate of CO.sub.2 (wt %) 30.09 Selectivity of ethylene and propylene in hydrocarbon products 10.61 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 70.28 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 74.71 (wt %) Selectivity of PX in xylene products (wt %) 95.04 Composition of hydrocarbon products (wt %) Methane 2.94 Ethylene 4.96 Ethane 3.21 Propylene 5.65 Propane 4.29 C.sub.4 4.24 Benzene 19.93 Toluene 37.90 Ethylbenzene 1.08 P-xylene 12.45 M-xylene 0.43 O-xylene 0.22 C.sub.8+ aromatic hydrocarbons 2.70

Example 28 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0165] A catalyst FXNCC-1 was prepared by the method in Example 10.

[0166] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:0.27, the weight hourly space velocity of the CO.sub.2 was 0.8 h.sup.1, the weight hourly space velocity of the naphtha was 0.27 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 17.

TABLE-US-00021 TABLE 17 Evaluation of reaction performance of a catalyst in Example 28 Conversion rate of naphtha (wt %) 82.73 Conversion rate of CO.sub.2 (wt %) 15.31 Selectivity of ethylene and propylene in hydrocarbon products 10.63 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 73.07 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 77.59 (wt %) Selectivity of PX in xylene products (wt %) 95.45 Composition of hydrocarbon products (wt %) Methane 2.07 Ethylene 4.72 Ethane 2.55 Propylene 5.91 Propane 3.15 C.sub.4 4.01 Benzene 21.06 Toluene 38.99 Ethylbenzene 1.21 P-xylene 13.02 M-xylene 0.41 O-xylene 0.21 C.sub.8+ aromatic hydrocarbons 2.69

Example 29 Preparation of a Catalyst Used for Producing Benzene, Toluene and p-Xylene and Reaction Evaluation

[0167] A catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene was prepared on-line in a micro-fixed bed reactor. Conditions for on-line preparation of the catalyst are as follows. 5 g of the FX-[Zn]HZSM-5 catalyst prepared in Example 1 was loaded into a fixed bed reactor, treated with nitrogen at 50 ml/min at 550 C. for 1 hour, and then cooled to 300 C. in a nitrogen atmosphere. Then, a vapor atomic layer deposition method was used to carry out modification with a silanization reagent, specifically including the following steps: (1) introducing nitrogen (controlled by a mass flow meter, 200 mL/min) into a saturated flask filled with tetraethyl silicate (temperature 10 C.), then introducing the same into a reactor, namely introducing the nitrogen carrying the tetraethyl silicate into the reactor, and after feeding for 5 minutes, stopping the feeding; (2) carrying out purging with nitrogen, and raising the temperature to 550 C., followed by calcination in an air atmosphere for 1 hour; and (3) repeating steps (1) and (2) for 5 times to obtain a fixed bed catalyst used for coupling conversion of naphtha and CO.sub.2 to produce benzene, toluene and p-xylene, named as FXNCC-14, where the amount of the tetraethyl silicate introduced for 6 times was equivalent to the amount introduced for one time in Example 10.

[0168] Then, the temperature was adjusted to a reaction temperature of 550 C. in a nitrogen atmosphere. A raw material naphtha was fed by a micro-feed pump, and the flow of CO.sub.2 was controlled by a mass flow meter. The mass ratio of the raw material CO.sub.2 to the naphtha was 0.8:1, the weight hourly space velocity of the naphtha was 1.0 h.sup.1, and the reaction pressure was 0.1 MPa. Reaction products were analyzed by on-line Agilent7890 gas chromatography, and sampling was carried out for analysis when a reaction was carried out for 30 minutes. Reaction results are shown in Table 18.

TABLE-US-00022 TABLE 18 Evaluation of reaction performance of a catalyst in Example 29 Conversion rate of naphtha (wt %) 86.61 Conversion rate of CO.sub.2 (wt %) 34.63 Selectivity of ethylene and propylene in hydrocarbon products 8.04 (wt %) Selectivity of benzene, toluene and PX in hydrocarbon products 75.08 (wt %) Selectivity of aromatic hydrocarbons in hydrocarbon products 78.62 (wt %) Selectivity of PX in xylene products 97.83 Composition of hydrocarbon products (wt %) Methane 2.51 Ethylene 3.95 Ethane 3.68 Propylene 4.09 Propane 4.09 C.sub.4 3.06 Benzene 20.88 Toluene 38.87 Ethylbenzene 0.69 P-xylene 15.33 M-xylene 0.23 O-xylene 0.11 C.sub.8+ aromatic hydrocarbons 2.51

[0169] In addition to the naphtha used in the above examples, any naphtha selected from hydrocracked naphtha, catalytic cracked naphtha, raffinate oil and topped oil or any mixture thereof may also be used in the present application.

[0170] The above descriptions are only several examples of the present application, and are not intended to limit the present application in any way. Although the present application is disclosed above through preferred examples, the examples are not intended to limit the present application. For any skilled person familiar with the art, various changes or modifications made by using the technical contents disclosed above without departing from the scope of technical schemes of the present application are considered as equivalent examples, which fall within the scope of the technical schemes.