Method for directly preparing p-xylene from synthetic gas and aromatic hydrocarbon

Abstract

A method for directly preparing p-xylene from synthetic gas and aromatic hydrocarbon. The method includes contacting the feedstock containing synthetic gas and aromatic hydrocarbon excluding p-xylene with the catalyst in the reaction zone under reaction conditions sufficient to convert at least part of the feedstock to obtain a reaction effluent containing p-xylene; and separating p-xylene from the reaction effluent, where the catalyst includes a highly dispersed metal oxide material confined by an inert carrier, an acidic molecular sieve, and optionally at least one of graphite powder and dispersant, where in the highly dispersed metal oxide material confined by the inert carrier, the inert carrier is at least one of silicon oxide and alumina, and the content of the metal oxide in terms of metal is less than or equal to 10% by mass calculated based on the weight of the highly dispersed metal oxide material confined by the inert carrier.

Claims

1. A method for directly preparing p-xylene from synthetic gas and an aromatic hydrocarbon, comprising: contacting a feedstock containing synthetic gas and an aromatic hydrocarbon excluding p-xylene with a catalyst in a reaction zone under reaction conditions sufficient to convert at least part of the feedstock to obtain a reaction effluent containing p-xylene; and separating p-xylene from the reaction effluent, wherein the catalyst comprises a metal oxide material confined by an inert carrier, an acidic molecular sieve, and at least one selected from graphite powder and dispersant; wherein the inert carrier is at least one selected from silicon oxide and alumina; wherein the content of the metal oxide material in terms of metal is less than or equal to 10% by mass calculated based on the weight of the metal oxide material confined by the inert carrier; and wherein the acidic molecular sieve is a modified acidic molecular sieve selected from the group consisting of modified acidic ZSM-5 molecular sieve, modified acidic ZSM-11 molecular sieve and mixtures thereof.

2. The method according to claim 1, further comprising at least one of: the reaction zone comprises a fixed bed reactor, or multiple fixed bed reactors in series and/or parallel; the reaction conditions comprise: a reaction temperature in a range of 300° C. to 450° C., a reaction pressure in a range of 0.5 MPa to 10.0 MPa, a molar ratio of hydrogen to carbon monoxide in the synthetic gas in a range of 1:9 to 9:1, a weight hourly space velocity of aromatic hydrocarbon in a range of 0.01 h.sup.−1 to 20 h.sup.−1, and a volume hourly space velocity of synthetic gas in the standard state in a range of 1000.sup.−1 to 20000 h.sup.−1; the metal oxide material is an oxide of at least one of zinc, chromium, zirconium, copper, manganese, platinum and palladium; the content of the metal oxide material in terms of metal in the metal oxide material confined by the inert carrier is less than or equal to 5% by weight calculated based on the weight of the metal oxide material confined by the inert carrier; the particle size of the metal oxide material in the metal oxide material confined by the inert carrier is less than or equal to 100 nm; the modified acidic molecular sieve is provided by modifying acidic ZSM-5 molecular sieve or acidic ZSM-11 molecular sieve, wherein the modification is one or more of modification by phosphorus, modification by boron, modification by silicon, modification by an alkaline earth metal, and modification by a rare earth metal; the atomic ratio of silicon to aluminum (Si/AI) in the modified acidic ZSM-5 and ZSM-11 molecular sieves is 3 to 200; the particle shape of the catalyst is spherical, bar-shaped, cylindrical, semi-cylindrical, prismatic, clover-shaped, ring-shaped, pellet-shaped, regular or irregular particle-shape or flake; and the aromatic hydrocarbon excluding p-xylene is at least one aromatic hydrocarbon having the following general formula: ##STR00006## wherein, R.sub.9, R.sub.10, R.sub.11, R.sub.12, R.sub.13 and R.sub.14 are each independently selected from hydrogen, or a C.sub.1-C.sub.10 hydrocarbyl.

3. The method according to claim 1, wherein the catalyst comprises the metal oxide material confined by the inert carrier in an amount ranging from 10% to 90% by weight, the acidic molecular sieve in an amount ranging from 10% to 90% by weight, the graphite powder in an amount ranging from 0% to 10% by weight and the dispersant in an amount ranging from 0% to 40% by weight; wherein the total content of the metal oxide material confined by the inert carrier and the acidic molecular sieve is in a range of 60% to 100% by weight; and wherein the weight percentage is calculated based on the total weight of the catalyst.

4. The method according to claim 1, wherein the catalyst comprises the metal oxide material confined by the inert carrier in an amount ranging from 20% to 80% by weight, the acidic molecular sieve in an amount ranging from 20% to 80% by weight, the graphite powder in an amount ranging from 0% to 5% by weight and the dispersant in an amount ranging from 0% to 30% by weight; and wherein the weight percentage is calculated based on the total weight of the catalyst.

5. The method according to claim 1, wherein the average particle size of the metal oxide material confined by the inert carrier is less than or equal to 5 mm, and the average particle size of the acidic molecular sieve particles is less than or equal to 5 mm.

6. The method according to claim 1, wherein the catalyst is prepared by a method comprising the following steps: (1) providing a metal oxide material confined by the inert carrier; (2) providing a modified acidic molecular sieve; (3) mixing the metal oxide material confined by the inert carrier obtained in step (1) with the modified acidic molecular sieve obtained in step (2) and at least one selected from graphite powder and dispersant to obtain a mixture, and molding the mixture.

7. The method according to claim 6, the method for preparing the catalyst further comprising at least one of the following features: in step (1), the metal oxide material confined by the inert carrier is prepared by a precipitation-calcination method, or by a sol-gel method; the modified acidic molecule is one selected from the group consisting of phosphorus-modified, boron-modified, silicon-modified, alkaline earth metal-modified and/or rare earth metal-modified ZSM-5 molecular sieve, and phosphorus-modified, boron-modified, silicon-modified, alkaline earth metal-modified and/or rare earth metal-modified ZSM-11 molecular sieve; and in step (3), the mixture is molded into catalyst particles by an extrusion method or a molding method.

8. The method according to claim 6, wherein in step (1) of the method for preparing the catalyst, the metal oxide material confined by the inert carrier is provided by a method comprising the steps as follows: formulating a mixed metal salt aqueous solution from a catalytically active metal salt and an aluminum salt; contacting the mixed metal salt aqueous solution with a precipitant aqueous solution to co-precipitate the metal ions in the mixed metal salt aqueous solution; aging the solution mixture; and washing, drying and calcining the precipitate to obtain the metal oxide material confined by the inert carrier.

9. The method according to claim 8, further comprising at least one of the following features: the catalytically active metal salt and aluminum salt are one selected from hydrochloride, sulfate and nitrate; the precipitant aqueous solution is one selected from sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, ammonia water, sodium hydroxide, potassium hydroxide and mixtures thereof; the co-precipitation is carried out at a temperature in a range of 0° C. to 90° C.; the pH value during the co-precipitation is in a range of 7.0 to 8.5; the time for aging is not less than 1 hour; and the calcination is carried out at a temperature in a range of 300° C. to 700° C.

10. The method according to claim 6, wherein in step (1) of the method for preparing the catalyst, the metal oxide material confined by the inert carrier is provided by a method comprising the steps: adding an aqueous solution of a catalytically active metal salt and an aqueous solution of a precipitant together into siloxane-based compound, so that a co-precipitation and sol-gel reaction can be carried out, and then washing, drying and then calcining the obtained gel to prepare the metal oxide material confined by the inert carrier.

11. The method according to claim 10, wherein the precipitant comprises ammonium carbonate, ammonia water, ammonium bicarbonate, ammonium dihydrogen carbonate, urea and mixtures thereof; the siloxane-based compound is an alkyl orthosilicate, preferably selected from methyl orthosilicate, ethyl orthosilicate, n-propyl orthosilicate, isopropyl orthosilicate, tetrabutyl orthosilicate, isobutyl orthosilicate, tert-butyl orthosilicate or mixtures thereof.

12. The method according to claim 1, wherein the aromatic hydrocarbon excluding p-xylene comprises benzene, toluene, ethylbenzene, m-xylene, o-xylene, cumene, sym-trimethylbenzene, sym-tetramethylbenzene, biphenyl and mixtures thereof.

13. The method according to claim 1, wherein the reaction conditions comprise: a reaction temperature in a range of 320° C. to 400° C., a reaction pressure in a range of 5.0 MPa to 10.0 MPa, a molar ratio of hydrogen to carbon monoxide in the synthetic gas in a range of 1:9 to 1:1, a mass space velocity of aromatic hydrocarbon in a range of 0.5 h.sup.−1 to 3 h.sup.−1, and a volumetric space velocity of synthetic gas in a range of 1000 h.sup.−1 to 4000 h.sup.−1.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows the XRD pattern of material A in Example 1.

(2) FIG. 2 shows the XRD pattern of the material REF-1 in Comparative Example 1.

DETAILED DESCRIPTION

(3) The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

(4) Unless otherwise specified, the raw materials in the embodiments of the present invention are purchased through commercial ways.

(5) In the examples, two Agilent 7890 gas chromatographs with a gas autosampler, a TCD detector connected to a TDX-1 packed column, and a FID detector connected to a FFAP and PLOT-Q capillary column are used for automatic gas composition analysis.

(6) In the examples, conversion rate and selectivity are calculated based on the number of moles of carbon:

(7) Conversion rate of carbon monoxide=[(the number of moles of carbon in carbon monoxide in the feed)−(the number of moles of carbon in carbon monoxide in the discharge)]÷(the number of moles of carbon in carbon monoxide in the feed)×100%

(8) Conversion rate of toluene=[(the number of moles of carbon in toluene in the feed)−(the number of moles of carbon in toluene in the discharge)]÷(the number of moles of carbon in toluene in the feed)×100%;

(9) Selectivity to xylene=(the number of moles of carbon in xylene in the discharge)÷(the number of moles of carbon in all hydrocarbon products in the discharge−the number of moles of carbon in raw material of toluene)×100%

(10) Proportion of p-xylene=(the number of moles of carbon in p-xylene in the discharge)÷(the number of moles of carbon in all xylene in the discharge)×100%

(11) When the raw material is other aromatic hydrocarbon, the calculation method is consistent with toluene.

Highly Dispersed Metal Oxide Materials with Inert Carrier Confinement

Example 1

(12) 1 L of a mixed nitrate aqueous solution containing 0.05 mol/L of Zn.sup.2+ and 1.0 mol/L of Al.sup.3+ was prepared, 0.5 mol/L of ammonia solution was added in, the temperature was controlled to be 70° C. and the pH was controlled to be 7.2 simultaneously in the coprecipitation reaction to coprecipitate metal ions. After the reaction, the reaction mixture was aged at 70° C. for 4 h. The precipitate was filtered, washed with deionized water, dried, and calcined at 500° C. for 4 h to obtain a highly dispersed zinc oxide material confined by the inert carrier of alumina, numbered A. A contains zinc in an amount of 8.3% by weight. The XRD pattern is shown in FIG. 1.

Example 2

(13) 1 L of a mixed nitrate aqueous solution containing 0.02 mol/L of Zn.sup.2+, 0.02 mol/L of Cr.sup.3+ and 1.0 mol/L of Al.sup.3+ was prepared, with 1.0 mol/L of ammonium carbonate solution added in, and the temperature was controlled to be 70° C. and the pH was controlled to be 7.5 simultaneously in the coprecipitation reaction to coprecipitate metal ions. After the reaction, the reaction mixture was aged at 70° C. for 4 h. The precipitate was filtered, washed with deionized water, dried, and calcined at 500° C. for 4 h to obtain a highly dispersed zinc-chromium oxide material confined by the inert carrier of alumina, numbered B. B contains zinc in an amount of 3.1% by weight and chromium in an amount of 2.5% by weight.

Example 3

(14) 1 L of a mixed nitrate aqueous solution containing 0.01 mol/L of Zn.sup.2+, 0.01 mol/L of Zr.sup.4+ and 1.0 mol/L of Al.sup.3+ was prepared, 1.2 mol/L of sodium carbonate solution was added in, the temperature was controlled to be 70° C. and the pH was controlled to be 7.5 simultaneously in the coprecipitation reaction to coprecipitate metal ions. After the reaction, the reaction mixture was aged at 70° C. for 4 h. The precipitate was filtered, washed with deionized water, dried, and calcined at 500° C. for 4 h to obtain a highly dispersed zinc-zirconium oxide material confined by the inert carrier of alumina, numbered C. C contains zinc in an amount of 1.5% by weight and zirconium in an amount of 2.1% by weight.

Example 4

(15) 1 L of a mixed nitrate aqueous solution containing 0.01 mol/L of Zn.sup.2+, 0.02 mol/L of Cu.sup.2+ and 1.0 mol/L of Al.sup.3+ was prepared, with 1.5 mol/L of potassium carbonate solution added in, and the temperature was controlled to be 70° C. and the pH was controlled to be 7.9 simultaneously in the coprecipitation reaction to coprecipitate metal ions. After the reaction, the reaction mixture was aged at 70° C. for 4 h. The precipitate was filtered, washed with deionized water, dried, and calcined at 500° C. for 4 h to obtain a highly dispersed zinc-copper oxide material confined by the inert carrier of alumina, numbered D. D contains zinc in an amount of 1.5% by weight and copper in an amount of 3.1% by weight.

Example 5

(16) 100 mL of a mixed nitrate aqueous solution containing 0.2 mol/L of Zn.sup.2+, 0.2 mol/L of Cr.sup.3+ was prepared, and 100 ml of 1.0 mol/L urea aqueous solution was prepared. The above two solutions were added dropwise into 1 mol of ethyl orthosilicate and reacted for 24 h at room temperature to obtain a gel. The gel was washed with deionized water, dried at 100° C., and calcined at 500° C. for 4 h to obtain a highly dispersed zinc-chromium oxide material confined by the inert carrier of silicon dioxide, numbered E. E contains zinc in an amount of 1.8% by weight and chromium in an amount of 1.5% by weight.

Example 6

(17) 100 mL of a mixed nitrate aqueous solution containing 0.2 mol/L of Zn.sup.2+, 0.2 mol/L of Zr.sup.4+ was prepared, and 100 ml of 1.0 mol/L urea aqueous solution was prepared. The above two solutions were added dropwise into 1 mol of ethyl orthosilicate and reacted for 24 h at room temperature to obtain a gel. The gel was washed with deionized water, dried at 100° C., and calcined at 500° C. for 4 h to obtain a highly dispersed zinc-zirconium oxide material confined by the inert carrier of silicon oxide, numbered F. F contains zinc in an amount of 1.8% by weight and zirconium in an amount of 2.5% by weight.

Comparative Example 1

(18) 100 mL of a mixed nitrate aqueous solution containing 1.0 mol/L of Zn.sup.2+, 0.50 mol/L of Cr.sup.3+ and 0.20 mol/L of Al.sup.3+ was prepared, with 1.0 mol/L of ammonium carbonate solution added in, and the temperature was controlled to be 70° C. and the pH was controlled to be 7.5 simultaneously in the coprecipitation reaction to coprecipitate metal ions. After the reaction, the reaction mixture was aged at 70° C. for 4 h. The precipitate was filtered, washed with deionized water, dried, and calcined at 500° C. for 4 h to obtain a zinc-chromium-aluminum composite oxide, numbered REF-1. The XRD pattern of REF-1 is shown in FIG. 2.

Preparation of Modified Acidic Molecular Sieve

Example 7

(19) The sodium-type ZSM-5 (obtained from catalyst factory of Nankai University) with Si/Al=25 (atomic ratio) was exchanged for 3 times with 0.8 mol/L ammonium nitrate aqueous solution at 80° C. (the volume ratio of ammonium nitrate aqueous solution to molecular sieve was 20:1) to obtain ammonium type ZSM-5 molecular sieve. The ammonium-type ZSM-5 molecular sieve was calcined at 550° C. for 4 h in an air atmosphere, and then immersed in (NH.sub.4).sub.2HPO.sub.4 aqueous solution (content of P in the aqueous solution was 5% by weight) with an equal volume as the ammonium-type ZSM-5 molecular sieve for 24 hours at room temperature, dried, and then calcined at 550° C. for 4 h in an air atmosphere to obtain an acidic ZSM-5 molecular sieve containing 4% of P by weight, numbered G.

Example 8

(20) The sodium-type ZSM-5 (obtained from catalyst factory of Nankai University) with Si/Al=200 (atomic ratio) was exchanged for 3 times with 0.8 mol/L ammonium nitrate aqueous solution at 80° C. (the volume ratio of ammonium nitrate aqueous solution to molecular sieve was 20:1) to obtain ammonium-type ZSM-5 molecular sieve. The ammonium-type ZSM-5 molecular sieve was calcined at 550° C. for 4 h in an air atmosphere, and then immersed in H.sub.3BO.sub.3 aqueous solution (content of B in the aqueous solution is 10% by weight) with an equal volume as the ammonium-type ZSM-5 molecular sieve for 24 hours at room temperature, dried, and then calcined at 550° C. for 4 h in an air atmosphere to obtain an acidic ZSM-5 molecular sieve containing 8% of B by weight, numbered H.

Example 9

(21) The sodium-type ZSM-11 (obtained from Aoke company) with Si/Al=40 (atomic ratio) was exchanged for 3 times with 0.8 mol/L ammonium nitrate aqueous solution at 80° C. (the volume ratio of ammonium nitrate aqueous solution to molecular sieve was 20:1) to obtain ammonium-type ZSM-11 molecular sieve. The ammonium-type ZSM-11 molecular sieve was calcined at 550° C. for 4 h in an air atmosphere, and then immersed in H.sub.3BO.sub.3 aqueous solution (content of B in the aqueous solution is 10% by weight) with an equal volume as the ammonium-type ZSM-11 molecular sieve for 24 hours at room temperature, dried, and then calcined at 550° C. for 4 h in an air atmosphere to obtain an acidic ZSM-11 molecular sieve containing 8% of B by weight, numbered I.

Example 10

(22) The sodium-type ZSM-5 (obtained from Aoke company) with Si/Al=3 (atomic ratio) was exchanged for 3 times with 0.8 mol/L ammonium nitrate aqueous solution at 80° C. (the volume ratio of ammonium nitrate aqueous solution to molecular sieve was 20:1) to obtain ammonium-type ZSM-5 molecular sieve. The ammonium-type ZSM-5 molecular sieve was calcined at 550° C. for 4 h in an air atmosphere, and then treated with a cyclohexane solution of ethyl orthosilicate (the content of Si in the solution was 10% by weight) at 50° C. for 4 hours. The reaction mixture was evaporated to dryness and calcined at 550° C. for 4 h under an air atmosphere to obtain an acidic ZSM-5 molecular sieve containing 8% of Si by weight (excluding the original Si in the molecular sieve), numbered J.

Example 11

(23) The sodium-type ZSM-5 (obtained from Fuxu Company) with Si/Al=80 (atomic ratio) was exchanged for 3 times with 0.8 mol/L ammonium nitrate aqueous solution at 80° C. (the volume ratio of ammonium nitrate aqueous solution to molecular sieve was 20:1) to obtain ammonium-type ZSM-5 molecular sieve. 500 g of the ammonium-type ZSM-5 molecular sieve was calcined at 550° C. for 4 h in an air atmosphere, and then treated with 1 L/min of nitrogen carrying tetramethylsilane with a volume fraction of 5% at 200° C. for 3 hours. And then calcined at 550° C. for 4h under an air atmosphere to obtain an acidic ZSM-5 molecular sieve containing 2% of Si by weight (excluding the original Si in the molecular sieve), numbered K.

Example 12

(24) The sodium-type ZSM-5 (obtained from catalyst factory of Nankai University) with Si/Al=60 (atomic ratio) was exchanged for 3 times with 0.8 mol/L ammonium nitrate aqueous solution at 80° C. (the volume ratio of ammonium nitrate aqueous solution to molecular sieve was 20:1) to obtain ammonium-type ZSM-5 molecular sieve. The ammonium-type ZSM-5 molecular sieve was calcined at 550° C. for 4 h in an air atmosphere, and then immersed in mixed aqueous solution of magnesium nitrate and cerium nitrate (the content of Mg and Ce in the aqueous solution are 5% and 1.3% by weight, respectively) with an equal volume as the ammonium-type ZSM-5 molecular sieve for 24 hours at room temperature, dried, and then calcined at 550° C. for 4 h in an air atmosphere to obtain an acidic ZSM-5 molecular sieve containing 4% of Me and 1% of Ce by weight, numbered L.

Preparation of Catalyst

Example 13

(25) 20 parts by mass of the highly dispersed metal oxide material A confined by the inert carrier from Example 1, 70 parts by mass of acidic molecular sieve G from Example 7, 5 parts by mass of graphite powder, and 5 parts by mass of silicon oxide as a dispersant were mixed uniformly, and then sliced into a columnar catalyst with a diameter of 4 mm and a height of 4 mm using a tablet machine, numbered M. The preparation scheme is summarized in Table 1.

Examples 14-18

(26) The preparation method is similar to Example 13, and the specific scheme is shown in Table 1.

Comparative Example 2

(27) 20 parts by mass of the metal composite oxide REF-1 from Comparative Example 1, 70 parts by mass of the acidic molecular sieve G from Example 7, 5 parts by mass of graphite powder, and 5 parts by mass of silicon oxide as a dispersant were uniformly mixed, and then sliced into a columnar catalyst with a diameter of 4 mm and a height of 4 mm using a tablet machine, numbered REF-2.

Example 19

(28) 75 parts by mass of the highly dispersed metal oxide material A confined by the inert carrier from Example 1, and 25 parts by mass of the acidic molecular sieve G from Example 7 were uniformly mixed and crushed into a powder of less than 0.05 mm, and then tableted and screened to prepare a granular catalyst with a size in a range of 1-2 mm, numbered S, and the preparation scheme is summarized in Table 1.

Examples 20-24

(29) The preparation method is similar to Example 19, and the specific scheme is shown in Table 1.

Comparative Example 3

(30) 75 parts by mass of the metal composite oxide REF-1 from Comparative Example 1 and 25 parts by mass of the acidic molecular sieve G from Example 7 were uniformly mixed and crushed into a powder of less than 0.05 mm, and then tableted and screened to prepare a granular catalyst with a size in a range of 1-2 mm, numbered REF-3.

(31) TABLE-US-00001 TABLE 1 preparation scheme for catalyst No. of highly dispersed No. of metal oxide material modified acidic Graphite No. of No. of confined by inert molecular sieve powder dispersant Example catalyst carrier(by mass %) (by mass %) (by mass %) (by mass %) 13 M A (20%) G (70%) 5% silicon oxide (5%) 14 N B (30%) H (55%) 3% silicon oxide (12%) 15 O C (40%) I (20%) 2% silicon oxide (38%) 16 P D (70%) J (20%) 5% silicon oxide (5%) 17 Q E (45%) K (45%) 2% silicon oxide (8%) 18 R F (60%) L (25%) 5% silicon oxide (10%) 19 S A (75%) G (25%) 0 0 20 T B (10%) H (90%) 0 0 21 U C (90%) I (10%) 0 0 22 V D (50%) J (50%) 0 0 23 W E (80%) K (20%) 0 0 24 X F (65%) L (35%) 0 0

Performance Test of Catalyst

Example 25

(32) 200 g of the catalyst M was loaded into a stainless steel reaction tube with an inner diameter of 28 mm, and activated with 1000 ml/min of hydrogen at 300° C. for 4 h. Then the hydrogen flow was switched to a synthetic gas flow and toluene flow was introduced, a reaction was carried out under the following conditions: reaction temperature (T)=400° C., reaction pressure (P)=7.0 MPa, gas volume space velocity (GHSV) under standard conditions=6000 h.sup.−1, the volume ratio of CO to H.sub.2 in the synthetic gas was 1:1, mass space velocity (WHSV) of toluene =1.0 h.sup.−1 After the reaction had stabilized, the product was analyzed by gas chromatography. The reaction results are shown in Table 2.

Examples 26-30

(33) Example 25 was repeated, but the catalyst M in Example 25 was replaced with the catalyst N-R. The reaction results are shown in Table 2.

Comparative Example 4

(34) Example 25 was repeated, but the catalyst M in Example 25 was replaced with the catalyst REF-2. The reaction results are shown in Table 2.

(35) TABLE-US-00002 TABLE 2 Catalytic reaction results in Examples 25-30 and Comparative Example 4 Conversion Conversion rate of carbon rate of Selectivity Ratio of Catalyst monoxide (%) toluene (%) to xylene (%) P-xylene (%) Example 25 M 34.5 28.5 93.6 98.5 Example 26 N 36.1 27.1 88.9 97.6 Example 27 O 30.3 20.3 86.0 94.1 Example 28 P 24.4 21.7 90.0 97.3 Example 29 Q 27.7 22.9 90.9 98.2 Example 30 R 26.3 22.5 92.1 93.8 Comparative REF-2 8.2 14.9 42.0 94.0 Example 4

Example 31

(36) 5 g of the catalyst S was loaded into a stainless steel reaction tube with an inner diameter of 8 mm, and activated with 50 ml/min of hydrogen at 300° C. for 4 h. Then the hydrogen flow was switched to a synthetic gas flow and toluene flow was introduced, a reaction was carried out under the following conditions: reaction temperature (T)=400° C., reaction pressure (P)=4.0 MPa, gas volume space velocity (GHSV) under standard conditions=4000 h.sup.−1 , the volume ratio of CO to H.sub.2 in the synthetic gas was 1.5:1, mass space velocity (WHSV) of toluene=0.5.sup.−1. After 500 h of the reaction, the products were analyzed by gas chromatography. The reaction results are shown in Table 3.

Examples 32-36

(37) Reaction conditions and reaction results are shown in Table 3. Other operations were the same as in Example 31.

Comparative Example 5

(38) 5 g of catalyst REF-3 was placed in a stainless steel reaction tube with an inner diameter of 8 mm, and activated with 50 ml/min hydrogen at 300° C. for 4 h, a reaction was carried out under the following conditions: reaction temperature (T)=400° C., reaction pressure (P)=4.0 MPa, the volumetric space velocity of synthetic gas (GHSV) under standard conditions=4000 h.sup.−1, the volume fraction of hydrogen in the synthetic gas (mixed gas of CO and H.sub.2) V (H.sub.2)%=40%, mass space velocity (WHSV) of toluene=0.5 h.sup.−1. After 500 h of reaction, the products were analyzed by gas chromatography. The reaction results are shown in Table 3.

(39) TABLE-US-00003 TABLE 3 Catalytic reaction results in Examples 31-36 and Comparative Example 5 Conversion rate of Conversion Ratio carbon rate of Selectivity of P- reaction monoxide toluene to xylene xylene Catalyst condition (%) ( % ) ( % ) ( % ) Example 31 S T = 400° C.; 25.8 78.2 87.8 98.8 P = 4.0 MPa; WHSV = 0.5 h.sup.−1; GHSV = 4000 h.sup.−1; V(H.sub.2) % = 40% Example 32 T T = 370° C.; 57.9 100 93.9 97.9 P = 10.0 MPa; WHSV = 0.01 h.sup.−1; GHSV = 20000 h.sup.−1; V(H.sub.2) % = 90% Example 33 U T = 300° C.; 12.2 15.5 82.0 94.3 P = 0.5 MPa; WHSV h.sup.−1; GHSV = 1000 h.sup.−1; V(H.sub.2) % = 10% Example 34 V T = 450° C.; 50.3 8.4 98.2 99.3 P = 3.0 MPa; WHSV = 20 h.sup.−1; GHSV = 8000 h.sup.−1; V(H.sub.2) % = 65% Example 35 W T = 390° C.; 31.3 29.7 96.0 98.8 P = 5.0 MPa; WHSV = 2 h.sup.−1; GHSV = 7000 h.sup.−1; V(H.sub.2) % = 30% Example 36 X T = 340° C.; 26.9 52.5 83.6 92.8 P = 7.0 MPa; WHSV = 1 h.sup.−1; GHSV = 12000 h.sup.−1; V(H.sub.2) % = 75% Comparative REF-3 T = 400° C.; 8.9 17.9 45.0 95.0 Example 5 P = 4.0 MPa; WHSV = 0.5 h.sup.−1; GHSV = 4000 h.sup.−1; V(H.sub.2) % = 40%

Regeneration Performance Test of Catalyst

Example 37

(40) The deactivated catalyst in Example 25 was treated with a mixture of 2 vol % oxygen and 98 vol % nitrogen at 550° C. for 10 h to regenerate the catalyst for one round. It was then reacted under the conditions of Example 25. A total of five rounds of regeneration were performed in the same way. The catalytic activity data after 500 h of reaction for each round were selected for comparison. The results are shown in Table 4.

(41) TABLE-US-00004 TABLE 4 Test results of regeneration performance of catalyst in Example 37 Conversion Conversion Life Regeneration rate of carbon rate of Selectivity Ratio of of each times monoxide (%) toluene (%) to xylene (%) P-xylene (%) round (h) 1 35.4 28.9 94.2 98.3 3300 2 34.1 28.1 93.3 98.0 3400 3 32.2 27.4 93.5 96.9 3200 4 29.5 27.1 93.6 97.3 3500 5 30.5 26.9 94.0 96.9 3200

Example 38

(42) The deactivated catalyst in Example 31 was treated with a mixture of 2 vol % oxygen and 98 vol % nitrogen at 550° C. for 10 h to regenerate the catalyst for one round. It was then reacted under the conditions of Example 31. A total of five rounds of regeneration were performed in the same way. The catalytic activity data after 500 h of reaction for each round were selected for comparison. The results are shown in Table 5.

(43) TABLE-US-00005 TABLE 5 Test results of regeneration performance of catalyst in Example 38 Conversion Conversion Life Regeneration rate of carbon rate of Selectivity Ratio of of each times monoxide (%) toluene (%) to xylene (%) P-xylene (%) round (h) 1 25.4 77.9 85.1 97.7 3200 2 25.9 77.7 86.4 98.2 3300 3 25.1 78.0 85.3 96.8 3100 4 25.5 77.1 85.4 97.1 3400 5 25.7 76.9 83.7 96.8 3100

Examples 39-44

(44) Example 25 was repeated, but the raw material of toluene was replaced with other aromatic hydrocarbon. The reaction results are shown in Table 6.

(45) TABLE-US-00006 TABLE 6 Catalytic reaction results raw material Conversion Conversion No. of ofaromatic rate of carbon rate of aromatic Selectivity Ratio of Example hydrocarbon monoxide (%) hydrocarbon (%) to xylene (%) P-xylene (%) 39 benzene 25.1 90.1 65.2 97.4 40 ethylbenzene 26.0 88.8 70.1 96.5 41 isopropylbenzene 24.1 67.1 58.9 95.2 42 sym- 24.3 66.6 71.3 94.8 trimethylbenzene 43 sym- 21.7 64.3 65.1 95.5 tetramethylbenzene 44 biphenyl 20.4 85.7 75.3 94.6

(46) The above is only a few embodiments of the present invention, and does not limit the present invention in any form. Although the present invention is disclosed in the above preferred embodiments, it is not intended to limit the present invention. Without departing from the scope of the technical solutions of the present invention, slight changes or modifications according to the technical content disclosed above by anyone skilled in the art are equivalent to equivalent implementation cases and all fall within the scope of the technical solutions.