Catalyst for preparing aviation fuel from Fischer-Tropsch products and method for preparing said catalyst

Abstract

A catalyst for preparing aviation fuel from synthetic oil obtained by Fischer-Tropsch process, including: between 20 and 50 percent by weight of an amorphous aluminum silicate, between 5 and 20 percent by weight of alumina, between 20 and 60 percent by weight of a hydrothermally modified zeolite, between 0.5 and 1.0 percent by weight of a Sesbania powder, between 0.5 and 5 percent by weight of nickel oxide, and between 5 and 15 percent by weight of molybdenum oxide. The invention also provides a method for preparing the catalyst.

Claims

1. A catalyst, comprising: between 20 and 50 percent by weight of an amorphous aluminum silicate; between 5 and 20 percent by weight of alumina; between 20 and 60 percent by weight of a hydrothermally modified zeolite; between 0.5 and 1.0 percent by weight of a Sesbania powder; between 0.5 and 5 percent by weight of nickel oxide; and between 5 and 15 percent by weight of molybdenum oxide.

2. The catalyst of claim 1, comprising: between 30 and 45 percent by weight of the amorphous aluminum silicate; between 8 and 15 percent by weight of alumina; between 25 and 50 percent by weight of the hydrothermally modified zeolite; between 0.6 and 0.8 percent by weight of the Sesbania powder; between 2.5 and 4.5 percent by weight of nickel oxide; and between 8 and 12 percent by weight of molybdenum oxide.

3. The catalyst of claim 1, wherein the hydrothermally modified zeolite is a steam-modified dealuminized ZSM-22 zeolite.

4. The catalyst of claim 1, wherein the hydrothermally modified zeolite is a steam-modified dealuminized hydrogen-type ZSM-22 zeolite.

5. The catalyst of claim 4, wherein the steam has a temperature of between 300 and 900 C., a pressure of between 0.1 and 2.0 megapascal, and holds for between 2 and 4 hrs.

6. The catalyst of claim 4, wherein the steam has a temperature of between 500 and 800 C., a pressure of between 0.1 and 0.5 megapascal, and holds between 2 and 3.5 hrs.

7. The catalyst of claim 1, wherein the catalyst has a specific area of between 200 and 300 m.sup.2/g; micropores of the catalyst having a pore volume of between 0.4 and 0.8 mL/g and a pore size distribution of between 4 and 10 nm accounts for between 65 and 85% of total pores; and a total acidity of the catalyst measured using a NH.sub.3-TPD method is between 0.4 and 1.0 mmol/g.

8. A method for preparing the catalyst of claim 4, comprising: 1) adding a potassium-type ZSM-22 zeolite to a NH.sub.4NO.sub.3 solution for ion exchange, filtering, washing, and drying a resulting zeolite; 2) repeating 1) for two or three times, and calcining the zeolite to yield a hydrogen-type ZSM-22 zeolite; 3) introducing steam to the hydrogen-type ZSM-22 zeolite for hydrothermal treatment to yield the dealuminized hydrogen-type ZSM-22 zeolite; 4) mixing the dealuminized hydrogen-type ZSM-22 zeolite with the amorphous aluminum silicate, adding alumina as the binder, adding a diluted nitric acid solution for modulation, and adding the Sesbania powder as an extrusion aid, mixing, kneading, and pressing to form masses, and extruding the masses to form strips; 5) drying and calcining the strips to yield a catalyst carrier; 6) mixing a soluble molybdenum salt and a soluble nickel salt to prepare an aqueous solution, dispersing the aqueous solution by an ultrasonic wave to acquire an active soaking solution; and 7) soaking the catalyst carrier into the active soaking solution to load active components on the carrier, aging, drying, and calcining to acquire a catalyst product.

9. The method of claim 8, wherein in 1), the potassium-type ZSM-22 zeolite has a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 is between 20 and 160.

10. The method of claim 8, wherein in 1), the molar ratio of SiO.sub.2/Al.sub.2O.sub.3 of the potassium-type ZSM-22 zeolite is between 30 and 100.

11. The method of claim 8, wherein in 1), a concentration of the NH.sub.4NO.sub.3 solution is between 1.0 and 2.0 mol/L; and the potassium-type ZSM-22 zeolite was added in the NH.sub.4NO.sub.3 solution for ion exchange, the ion exchange is performed in condition of water bath at a temperature of between 60 and 110 C. for between 1 and 4 hrs.

12. The method of claim 8, wherein in 1), the concentration of the NH.sub.4NO.sub.3 solution is between 1.0 and 1.5 mol/L; and the ion exchange is performed in condition of water bath at a temperature of between 80 and 100 C. for between 2 and 4 hrs.

13. The method of claim 8, wherein in 3), the hydrothermal treatment of the hydrogen-type ZSM-22 zeolite by the steam is performed at a temperature of between 300 and 900 C. and a pressure of between 0.1 and 2.0 megapascal for between 2 and 4 hrs.

14. The method of claim 8, wherein in 3), the hydrothermal treatment of the hydrogen-type ZSM-22 zeolite by the steam is performed at the temperature of between 500 and 800 C., the pressure of between 0.1 and 0.5 megapascal for between 2 and 3.5 hrs.

15. The method of claim 8, wherein in 4), the amorphous aluminum silicate has a specific area of between 250 and 400 m.sup.2/g, and SiO.sub.2 accounts for between 20 and 50 w.t % of a total weight of the amorphous aluminum.

16. The method of claim 8, wherein in 4), the amorphous aluminum silicate has a specific area of between 250 and 300 m.sup.2/g, and SiO.sub.2 accounts for between 30 and 50 w.t % of a total weight of the amorphous aluminum.

17. The method of claim 8, wherein in 4), the dilute nitric acid solution has a concentration of between 3 and 8 percent by weight.

18. The method of claim 8, wherein in 5), the strips are dried at a temperature of between 80 and 120 C. for between 6 and 24 hrs.

19. The method of claim 8, wherein in 5), the strips are dried at a temperature of between 100 and 120 C. for between 6 and 12 hrs.

20. The method of claim 8, wherein in 5), the strips are dried at a temperature of between 500 and 600 C. for between 4 and 8 hrs.

21. The method of claim 8, wherein in 5), the catalyst carrier adopts a cylinder shape, a trefoil shape, or a quatrefoil shape.

22. The method of claim 8, wherein in 6), the soluble molybdenum salt is ammonium molybdate or sodium molybdate; and the soluble nickel salt is nickel nitrate.

23. The method of claim 8, wherein in 6), a time for the treatment of the ultrasonic wave is between 0.5 and 1.5 hrs.

24. The method of claim 8, wherein in 7), the aging treatment is conducted at room temperature for between 12 and 24 hrs; the drying is conducted at a temperature of between 100 and 120 C. for between 10 and 14 hrs; and the calcination is conducted at a temperature of between 500 and 600 C. for between 4 and 8 hrs.

25. The method of claim 8, wherein in 7), the aging treatment is conducted at room temperature for between 16 and 20 hrs; the drying is conducted at a temperature of between 110 and 120 C. for between 10 and 12 hrs; and the calcination is conducted at a temperature of between 550 and 600 C. for between 4 and 6 hrs.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

(1) For further illustrating the invention, experiments detailing a catalyst for preparing an aviation fuel from synthetic oil obtained by Fischer-Tropsch process and a method for preparing the same are described below. It should be noted that the following examples are intended to describe and not to limit the invention.

(2) Properties of the synthetic oil obtained by Fischer-Tropsch process prepared by biomass as the raw material are shown in Table 1.

(3) TABLE-US-00001 TABLE 1 Properties of synthetic oil obtained by Fischer-Tropsch process as raw material Distillation Density Freezing Viscosity range ( C.) (20 C., kg/m.sup.3) point ( C.) (20 C., mm.sup.2/s) 100-350 820 20 6.82

EXAMPLE 1

(4) 1) 200 g of a K-ZSM-22 zeolite having a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 of 40 was add to a NH.sub.4NO.sub.3 solution having a concentration of 1.5 mol/L according to a weight ratio of the K-ZSM-22 zeolite to the NH.sub.4NO.sub.3 solution of 1:10 for performing ion exchange. A resulting mixture was stirred at a constant temperature for 2 hrs in condition of a water bath at a temperature of 100 C. The mixture after treatment was then filtered to collect a resulting zeolite. The zeolite was then washed and dried at 120 C. for 4 hrs.

(5) 2) The operation of 1) was repeated for three times, and the zeolite was thereafter calcined at 550 C. for 6 hrs to yield an H-ZSM-22 zeolite.

(6) 3) The H-ZSM-22 zeolite was placed in a baking furnace. Steam was introduced to the baking furnace for hydrothermal treatment at 500 C. and 0.2 megapascal for 4 hrs to yield a dealuminized H-ZSM-22 zeolite.

(7) 4) 50.0 g of the dealuminized H-ZSM-22 zeolite, 125.0 g of an amorphous aluminum silicate, and 37.5 g of alumina as a binder were added to a diluted nitric acid solution having a concentration of 5.0 percent by weight for modulation. 2.0 g of a Sesbania powder as an extrusion aid was added. A resulting mixture was uniformly mixed, kneaded, pressed into masses, and the masses were then extruded to form trefoil-shaped strips.

(8) 5) The trefoil-shaped strips were placed in an oven, dried at 120 C. for 6 hrs, calcined at 500 C. for 8 hrs, and then cooled to the room temperature to yield a catalyst carrier.

(9) 6) 42.0 g of sodium molybdate and 40.8 g of nickel nitrate were mixed to form an aqueous solution, and the aqueous solution was dispersed for 1 hr to acquire an active soaking solution.

(10) 7) The catalyst carrier was soaked into the active soaking solution to load active components on the carrier. The active component-loaded carrier was then aged at room temperature for 24 hrs, dried in an oven at 100 C. for 14 hrs, calcined at 500 C. for 8 hrs, and then cooled to the room temperature to yield a catalyst A.

(11) The catalyst A comprises: 20.0 percent by weight of a modified H-ZSM-22 zeolite, 50.0 percent by weight of the amorphous aluminum silicate, 15.0 percent by weight of alumina, 0.8 percent by weight of the Sesbania powder, 4.2 percent by weight of nickel oxide, and 10.0 percent by weight of molybdenum oxide.

(12) Physicochemical properties of the catalyst A are listed in Table 2, and evaluation results and product properties of the catalyst A are listed in Table 3.

(13) TABLE-US-00002 TABLE 2 Physicochemical properties of catalysts Catalyst A B C D E F G H Specific 263 248 233 251 260 294 275 218 area(m.sup.2/g) Pore 0.53 0.58 0.50 0.68 0.75 0.80 0.59 0.42 volume(mL/ g) Average pore 5.89 8.65 6.05 8.43 7.92 7.32 7.11 6.24 size(nm) 4-10 nm 65.1 83.6 76.8 78.4 72.2 70.3 73.4 68.9 pore size distribution (%) Total acidity 0.80 0.42 0.57 0.51 0.62 0.73 0.65 0.92 measured using NH.sub.3-TPD method (mmol/g)

(14) TABLE-US-00003 TABLE 3 Evaluation results and properties of products Catalyst A B C D E F G H Conversion 90.8 87.2 86.5 85.8 82.5 86.7 81.3 83.2 (percent by weight) Selectivity 68.4 94.7 89.5 92.3 85.6 78.5 87.3 60.3 (%) of aviation fuel (150-270 C.) Freezing 48 62 55 56 53 49 52 50 point ( C.) Density 794.4 785.2 787.5 789.3 790.4 802.6 791.0 814.2 (20 C., kg/m.sup.3) Viscosity 4.8 5.1 5.3 5.6 5.4 5.2 6.5 6.1 (20 C., mm.sup.2/s) Flash point 48 60 56 58 55 50 52 50 ( C.)

EXAMPLE 2

(15) 1) 200 g of a K-ZSM-22 zeolite having a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 of 50 was add to a NH.sub.4NO.sub.3 solution having a concentration of 1.0 mol/L according to a weight ratio of the K-ZSM-22 zeolite to the NH.sub.4NO.sub.3 solution of 1:10 for performing ion exchange. A resulting mixture was stirred at a constant temperature for 4 hrs in condition of a water bath at a temperature of 80 C. The mixture after treatment was then filtered to collect a resulting zeolite. The zeolite was then washed and dried at 120 C. for 4 hrs.

(16) 2) The operation of 1) was repeated for three times, and the zeolite was thereafter calcined at 550 C. for 6 hrs to yield an H-ZSM-22 zeolite.

(17) 3) The H-ZSM-22 zeolite was placed in a baking furnace. Steam was introduced to the baking furnace for hydrothermal treatment at 650 C. and 0.1 megapascal for 3 hrs to yield a dealuminized H-ZSM-22 zeolite.

(18) 4) 50.0 g of the dealuminized H-ZSM-22 zeolite, 20.0 g of an amorphous aluminum silicate, and 19.2 g of alumina as a binder were added to a diluted nitric acid solution having a concentration of 5.0 percent by weight for modulation. 0.8 g of a Sesbania powder as an extrusion aid was added. A resulting mixture was uniformly mixed, kneaded, pressed into masses, and the masses were then extruded to form trefoil-shaped strips.

(19) 5) The trefoil-shaped strips were placed in an oven, dried at 100 C. for 12 hrs, calcined at 550 C. for 6 hrs, and then cooled to the room temperature to yield a catalyst carrier.

(20) 6) 6.8 g of ammonium molybdate and 19.5 g of nickel nitrate were mixed to form an aqueous solution, and the aqueous solution was dispersed for 1 hr to acquire an active soaking solution.

(21) 7) The catalyst carrier was soaked into the active soaking solution to load active components on the carrier. The active component-loaded carrier was then aged at room temperature for 18 hrs, dried in an oven at 120 C. for 10 hrs, calcined at 550 C. for 6 hrs, and then cooled to the room temperature to yield a catalyst B.

(22) The catalyst B comprises: 50.0 percent by weight of a modified H-ZSM-22 zeolite, 20.0 percent by weight of the amorphous aluminum silicate, 19.2 percent by weight of alumina, 0.8 percent by weight of the Sesbania powder, 5.0 percent by weight of nickel oxide, and 5.0 percent by weight of molybdenum oxide.

(23) Physicochemical properties of the catalyst B are listed in Table 2, and evaluation results and product properties of the catalyst B are listed in Table 3.

EXAMPLE 3

(24) 1) 200 g of a K-ZSM-22 zeolite having a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 of 60 was add to a NH.sub.4NO.sub.3 solution having a concentration of 2.0 mol/L according to a weight ratio of the K-ZSM-22 zeolite to the NH.sub.4NO.sub.3 solution of 1:10 for performing ion exchange. A resulting mixture was stirred at a constant temperature for 3 hrs in condition of a water bath at a temperature of 90 C. The mixture after treatment was then filtered to collect a resulting zeolite. The zeolite was then washed and dried at 120 C. for 4 hrs.

(25) 2) The operation of 1) was repeated for three times, and the zeolite was thereafter calcined at 550 C. for 6 hrs to yield an H-ZSM-22 zeolite.

(26) 3) The H-ZSM-22 zeolite was placed in a baking furnace. Steam was introduced to the baking furnace for hydrothermal treatment at 800 C. and 0.5 megapascal for 2 hrs to yield a dealuminized H-ZSM-22 zeolite.

(27) 4) 50.0 g of the dealuminized H-ZSM-22 zeolite, 16.7 g of an amorphous aluminum silicate, and 7.7 g of alumina as a binder were added to a diluted nitric acid solution having a concentration of 5.0 percent by weight for modulation. 0.7 g of a Sesbania powder as an extrusion aid was added. A resulting mixture was uniformly mixed, kneaded, pressed into masses, and the masses were then extruded to form trefoil-shaped strips.

(28) 5) The trefoil-shaped strips were placed in an oven, dried at 110 C. for 10 hrs, calcined at 600 C. for 4 hrs, and then cooled to the room temperature to yield a catalyst carrier.

(29) 6) 5.7 g of ammonium molybdate and 16.2 g of nickel nitrate were mixed to form an aqueous solution, and the aqueous solution was dispersed for 1 hr to acquire an active soaking solution.

(30) 7) The catalyst carrier was soaked into the active soaking solution to load active components on the carrier. The active component-loaded carrier was then aged at room temperature for 12 hrs, dried in an oven at 110 C. for 12 hrs, calcined at 600 C. for 4 hrs, and then cooled to the room temperature to yield a catalyst C.

(31) The catalyst C comprises: 60.0 percent by weight of a modified H-ZSM-22 zeolite, 20.0 percent by weight of the amorphous aluminum silicate, 9.2 percent by weight of alumina, 0.8 percent by weight of the Sesbania powder, 5.0 percent by weight of nickel oxide, and 5.0 percent by weight of molybdenum oxide.

(32) Physicochemical properties of the catalyst C are listed in Table 2, and evaluation results and product properties of the catalyst C are listed in Table 3.

EXAMPLE 4

(33) 1) 200 g of a K-ZSM-22 zeolite having a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 of 80 was add to a NH.sub.4NO.sub.3 solution having a concentration of 1.0 mol/L according to a weight ratio of the K-ZSM-22 zeolite to the NH.sub.4NO.sub.3 solution of 1:10 for performing ion exchange. A resulting mixture was stirred at a constant temperature for 4 hrs in condition of a water bath at a temperature of 80 C. The mixture after treatment was then filtered to collect a resulting zeolite. The zeolite was then washed and dried at 120 C. for 4 hrs.

(34) 2) The operation of 1) was repeated for three times, and the zeolite was thereafter calcined at 550 C. for 6 hrs to yield an H-ZSM-22 zeolite.

(35) 3) The H-ZSM-22 zeolite was placed in a baking furnace. Steam was introduced to the baking furnace for hydrothermal treatment at 650 C. and 0.1 megapascal for 3 hrs to yield a dealuminized H-ZSM-22 zeolite.

(36) 4) 50.0 g of the dealuminized H-ZSM-22 zeolite, 42.8 g of an amorphous aluminum silicate, and 28.6 g of alumina as a binder were added to a diluted nitric acid solution having a concentration of 5.0 percent by weight for modulation. 1.2 g of a Sesbania powder as an extrusion aid was added. A resulting mixture was uniformly mixed, kneaded, pressed into masses, and the masses were then extruded to form trefoil-shaped strips.

(37) 5) The trefoil-shaped strips were placed in an oven, dried at 120 C. for 6 hrs, calcined at 600 C. for 4 hrs, and then cooled to the room temperature to yield a catalyst carrier.

(38) 6) 23.7 g of ammonium molybdate and 11.1 g of nickel nitrate were mixed to form an aqueous solution, and the aqueous solution was dispersed for 1 hr to acquire an active soaking solution.

(39) 7) The catalyst carrier was soaked into the active soaking solution to load active components on the carrier. The active component-loaded carrier was then aged at room temperature for 24 hrs, dried in an oven at 110 C. for 12 hrs, calcined at 600 C. for 4 hrs, and then cooled to the room temperature to yield a catalyst D.

(40) The catalyst D comprises: 35.0 percent by weight of a modified H-ZSM-22 zeolite, 30.0 percent by weight of the amorphous aluminum silicate, 20 percent by weight of alumina, 0.8 percent by weight of the Sesbania powder, 2.0 percent by weight of nickel oxide, and 12.2 percent by weight of molybdenum oxide.

(41) Physicochemical properties of the catalyst D are listed in Table 2, and evaluation results and product properties of the catalyst D are listed in Table 3.

EXAMPLE 5

(42) 1) 200 g of a K-ZSM-22 zeolite having a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 of 90 was add to a NH.sub.4NO.sub.3 solution having a concentration of 1.0 mol/L according to a weight ratio of the K-ZSM-22 zeolite to the NH.sub.4NO.sub.3 solution of 1:10 for performing ion exchange. A resulting mixture was stirred at a constant temperature for 4 hrs in condition of a water bath at a temperature of 80 C. The mixture after treatment was then filtered to collect a resulting zeolite. The zeolite was then washed and dried at 120 C. for 4 hrs.

(43) 2) The operation of 1) was repeated for three times, and the zeolite was thereafter calcined at 550 C. for 6 hrs to yield an H-ZSM-22 zeolite.

(44) 3) The H-ZSM-22 zeolite was placed in a baking furnace. Steam was introduced to the baking furnace for hydrothermal treatment at 650 C. and 0.1 megapascal for 3 hrs to yield a dealuminized H-ZSM-22 zeolite.

(45) 4) 50.0 g of the dealuminized H-ZSM-22 zeolite, 100 g of an amorphous aluminum silicate, and 60.5 g of alumina as a binder were added to a diluted nitric acid solution having a concentration of 5.0 percent by weight for modulation. 2.0 g of a Sesbania powder as an extrusion aid was added. A resulting mixture was uniformly mixed, kneaded, pressed into masses, and the masses were then extruded to form cylinder-shaped strips.

(46) 5) The cylinder-shaped strips were placed in an oven, dried at 110 C. for 10 hrs, calcined at 500 C. for 8 hrs, and then cooled to the room temperature to yield a catalyst carrier.

(47) 6) 34.0 g of ammonium molybdate and 7.8 g of nickel nitrate were mixed to form an aqueous solution, and the aqueous solution was dispersed for 1 hr to acquire an active soaking solution.

(48) 7) The catalyst carrier was soaked into the active soaking solution to load active components on the carrier. The active component-loaded carrier was then aged at room temperature for 12 hrs, dried in an oven at 100 C. for 14 hrs, calcined at 500 C. for 8 hrs, and then cooled to the room temperature to yield a catalyst E.

(49) The catalyst E comprises: 20.0 percent by weight of a modified H-ZSM-22 zeolite, 40.0 percent by weight of the amorphous aluminum silicate, 24.2 percent by weight of alumina, 0.8 percent by weight of the Sesbania powder, 5.0 percent by weight of nickel oxide, and 10.0 percent by weight of molybdenum oxide.

(50) Physicochemical properties of the catalyst E are listed in Table 2, and evaluation results and product properties of the catalyst E are listed in Table 3.

EXAMPLE 6

(51) 1) 200 g of a K-ZSM-22 zeolite having a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 of 100 was add to a NH.sub.4NO.sub.3 solution having a concentration of 2.0 mol/L according to a weight ratio of the K-ZSM-22 zeolite to the NH.sub.4NO.sub.3 solution of 1:10 for performing ion exchange. A resulting mixture was stirred at a constant temperature for 3 hrs in condition of a water bath at a temperature of 90 C. The mixture after treatment was then filtered to collect a resulting zeolite. The zeolite was then washed and dried at 120 C. for 4 hrs.

(52) 2) The operation of 1) was repeated for three times, and the zeolite was thereafter calcined at 550 C. for 6 hrs to yield an H-ZSM-22 zeolite.

(53) 3) The H-ZSM-22 zeolite was placed in a baking furnace. Steam was introduced to the baking furnace for hydrothermal treatment at 800 C. and 0.5 megapascal for 2 hrs to yield a dealuminized H-ZSM-22 zeolite.

(54) 4) 50.0 g of the dealuminized H-ZSM-22 zeolite, 100.0 g of an amorphous aluminum silicate, and 48.0 g of alumina as a binder were added to a diluted nitric acid solution having a concentration of 5.0 percent by weight for modulation. 2.0 g of a Sesbania powder as an extrusion aid was added. A resulting mixture was uniformly mixed, kneaded, pressed into masses, and the masses were then extruded to form quatrefoil-shaped strips.

(55) 5) The quatrefoil-shaped strips were placed in an oven, dried at 120 C. for 6 hrs, calcined at 500 C. for 6 hrs, and then cooled to the room temperature to yield a catalyst carrier.

(56) 6) 51.1 g of ammonium molybdate and 7.8 g of nickel nitrate were mixed to form an aqueous solution, and the aqueous solution was dispersed for 1 hr to acquire an active soaking solution.

(57) 7) The catalyst carrier was soaked into the active soaking solution to load active components on the carrier. The active component-loaded carrier was then aged at room temperature for 20 hrs, dried in an oven at 120 C. for 10 hrs, calcined at 550 C. for 6 hrs, and then cooled to the room temperature to yield a catalyst F.

(58) The catalyst F comprises: 20.0 percent by weight of a modified H-ZSM-22 zeolite, 40.0 percent by weight of the amorphous aluminum silicate, 19.2 percent by weight of alumina, 0.8 percent by weight of the Sesbania powder, 5.0 percent by weight of nickel oxide, and 15.0 percent by weight of molybdenum oxide.

(59) Physicochemical properties of the catalyst F are listed in Table 2, and evaluation results and product properties of the catalyst E are listed in Table 3.

EXAMPLE 7

(60) 1) 200 g of a K-ZSM-22 zeolite having a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 of 30 was add to a NH.sub.4NO.sub.3 solution having a concentration of 2.0 mol/L according to a weight ratio of the K-ZSM-22 zeolite to the NH.sub.4NO.sub.3 solution of 1:10 for performing ion exchange. A resulting mixture was stirred at a constant temperature for 3 hrs in condition of a water bath at a temperature of 90 C. The mixture after treatment was then filtered to collect a resulting zeolite. The zeolite was then washed and dried at 120 C. for 4 hrs.

(61) 2) The operation of 1) was repeated for three times, and the zeolite was thereafter calcined at 550 C. for 6 hrs to yield an H-ZSM-22 zeolite.

(62) 3) The H-ZSM-22 zeolite was placed in a baking furnace. Steam was introduced to the baking furnace for hydrothermal treatment at 800 C. and 0.5 megapascal for 2 hrs to yield a dealuminized H-ZSM-22 zeolite.

(63) 4) 50.0 g of the dealuminized H-ZSM-22 zeolite, 41.3 g of an amorphous aluminum silicate, and 18.8 g of alumina as a binder were added to a diluted nitric acid solution having a concentration of 5.0 percent by weight for modulation. 1.0 g of a Sesbania powder as an extrusion aid was added. A resulting mixture was uniformly mixed, kneaded, pressed into masses, and the masses were then extruded to form quatrefoil-shaped strips.

(64) 5) The quatrefoil-shaped strips were placed in an oven, dried at 100 C. for 10 hrs, calcined at 500 C. for 8 hrs, and then cooled to the room temperature to yield a catalyst carrier.

(65) 6) 17.0 g of ammonium molybdate and 5.8 g of nickel nitrate were mixed to form an aqueous solution, and the aqueous solution was dispersed for 1 hr to acquire an active soaking solution.

(66) 7) The catalyst carrier was soaked into the active soaking solution to load active components on the carrier. The active component-loaded carrier was then aged at room temperature for 24 hrs, dried in an oven at 100 C. for 14 hrs, calcined at 500 C. for 8 hrs, and then cooled to the room temperature to yield a catalyst G.

(67) The catalyst G comprises: 40.0 percent by weight of a modified H-ZSM-22 zeolite, 33.0 percent by weight of the amorphous aluminum silicate, 15 percent by weight of alumina, 0.8 percent by weight of the Sesbania powder, 1.2 percent by weight of nickel oxide, and 10.0 percent by weight of molybdenum oxide.

(68) Physicochemical properties of the catalyst G are listed in Table 2, and evaluation results and product properties of the catalyst G are listed in Table 3.

EXAMPLE 8

(69) 1) 200 g of a K-ZSM-22 zeolite having a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 of 30 was add to a NH.sub.4NO.sub.3 solution having a concentration of 1.5 mol/L according to a weight ratio of the K-ZSM-22 zeolite to the NH.sub.4NO.sub.3 solution of 1:10 for performing ion exchange. A resulting mixture was stirred at a constant temperature for 2 hrs in condition of a water bath at a temperature of 100 C. The mixture after treatment was then filtered to collect a resulting zeolite. The zeolite was then washed and dried at 120 C. for 4 hrs.

(70) 2) The operation of 1) was repeated for three times, and the zeolite was thereafter calcined at 550 C. for 6 hrs to yield an H-ZSM-22 zeolite.

(71) 3) The H-ZSM-22 zeolite was placed in a baking furnace. Steam was introduced to the baking furnace for hydrothermal treatment at 500 C. and 0.2 megapascal for 4 hrs to yield a dealuminized H-ZSM-22 zeolite.

(72) 4) 50.0 g of the dealuminized H-ZSM-22 zeolite, 18.2 g of an amorphous aluminum silicate, and 7.5 g of alumina as a binder were added to a diluted nitric acid solution having a concentration of 5.0 percent by weight for modulation. 0.7 g of a Sesbania powder as an extrusion aid was added. A resulting mixture was uniformly mixed, kneaded, pressed into masses, and the masses were then extruded to form quatrefoil-shaped strips.

(73) 5) The quatrefoil-shaped strips were placed in an oven, dried at 100 C. for 12 hrs, calcined at 600 C. for 4 hrs, and then cooled to the room temperature to yield a catalyst carrier.

(74) 6) 18.6 g of ammonium molybdate and 4.3 g of nickel nitrate were mixed to form an aqueous solution, and the aqueous solution was dispersed for 1 hr to acquire an active soaking solution.

(75) 7) The catalyst carrier was soaked into the active soaking solution to load active components on the carrier. The active component-loaded carrier was then aged at room temperature for 12 hrs, dried in an oven at 120 C. for 10 hrs, calcined at 600 C. for 4 hrs, and then cooled to the room temperature to yield a catalyst H.

(76) The catalyst H comprises: 55.0 percent by weight of a modified H-ZSM-22 zeolite, 20.0 percent by weight of the amorphous aluminum silicate, 8.2 percent by weight of alumina, 0.8 percent by weight of the Sesbania powder, 1.0 percent by weight of nickel oxide, and 15.0 percent by weight of molybdenum oxide.

(77) Physicochemical properties of the catalyst H are listed in Table 2, and evaluation results and product properties of the catalyst H are listed in Table 3.

(78) It is known from Table 3 that when adopting the catalyst of the invention, the aviation fuel has much higher selectivity and conversion and very low freezing point, which satisfies the requirement of GB 6537-2006 No. 3 jet fuel.

(79) Unless otherwise indicated, the numerical ranges involved in the invention include the end values. While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.