HYDROCRACKING CATALYST, PROCESS FOR PREPARING THE SAME AND USE THEREOF

Abstract

The present invention relates to a hydrocracking catalyst, a process for preparing the same and use thereof The present catalyst comprises a cracking component and a hydrogenation component, wherein the cracking component comprises from 0 to 20 wt. % of a molecular sieve and from 20 wt. % to 60 wt. % of an amorphous silica-alumina, the hydrogenation component comprises at least one hydrogenation metal in a total amount of from 34 wt. % to 75 wt. % calculated by the mass of oxides, each amount is based on the total weight of the catalyst. The present catalyst is prepared by directly mixing an acidic component powder material with an impregnating solution, impregnating, filtering, drying, molding, and drying and calcining.

Claims

1. A process for preparing a hydrocracking catalyst, comprising the steps of (1) homogeneously mixing a precursor for an amorphous silica-alumina with an optional molecular sieve and an optional alumina; (2) formulating an impregnating solution comprising at least one hydrogenation metal; (3) impregnating the mixed powder in step (1) with the impregnating solution in step (2); and (4) filtering, drying, pulverizing, adding an adhesive or a peptizing agent, molding, drying, and calcining to obtain the hydrocracking catalyst.

2. The process according to claim 1, wherein the precursor for the amorphous silica-alumina is an amorphous gelatinous silica-alumina dry powder prepared by a method comprising (1) conducting a neutralization and gelatinization reaction of an acidic aluminum salt solution with a mixed solution of alkaline sodium silicate and sodium aluminate at a temperature ranging from 20 C. to 80 C. and a pH value ranging from 4.0 to 9.5; (2) adding at least one organosilicon source after gelatinization, wherein the at least one organosilicon source is chosen from organic silicon oils or silicon esters, the at least one organosilicon is added in an amount ranging from 5% to 40% relative to the total silicon amount present in the amorphous gelatinous silica-alumina dry powder, ageing at a temperature ranging from 60 C. to 80 C., a pH value ranging from 6.0 to 10.0, for an ageing time ranging from 60 minutes to 300 minutes to obtain a sol; (3) filtering and washing the sol obtained in step (2); and (4) drying and pulverizing a filter cake obtained in step (3) to obtain the amorphous gelatinous silica-alumina dry powder.

3. The process according to claim 1, wherein the hydrocracking catalyst comprises 0% to 20% by weight of the molecular sieve, 20% to 60% by weight of the amorphous silica-alumina, 34% to 75% by weight of the at least one hydrogenation metal (calculated based on the weight of metal oxides), wherein all the weight percentages are relative to the total weight of the hydrocracking catalyst, and wherein the hydrocracking catalyst has a specific surface area ranging from 150 m.sup.2/g to 350 m.sup.2/g, a pore volume ranging from 0.20 cm.sup.3/g to 0.50 cm.sup.3/g, and a product (MS) of the weight percentage of the at least one hydrogenation metal (M) and the specific surface area (S) is equal to or higher than 100 m.sup.2/g.

4. The process according to claim 1, wherein the at least one hydrogenation metal is chosen from W, Mo, Ni or Co.

5. The process according to claim 3, wherein the MS ranges from 100 to 170 m.sup.2/g.

6. The process according to claim 3, wherein the MS ranges from 120 to 160 m.sup.2/g.

7. The process according to claim 3, wherein the weight percentage of the at least one hydrogenation metal is ranges from 40% to 60%.

8. The process according to claim 3, wherein the specific surface area of the hydrocracking catalyst ranges from 160 m.sup.2/g to 300 m.sup.2/g, and the pore volume of the hydrocracking catalyst ranges from 0.30 cm.sup.3/g to 0.45 cm.sup.3/g.

9. The process according to claim 3, wherein the hydrocracking catalyst further comprises alumina, clay, and/or at least one auxiliary agent chosen from phosphorous, fluorine, boron, titanium, or zirconium.

10. The process according to claim 1, wherein the optional molecular sieve is chosen from Y-type molecular sieves, molecular sieves, ZSM-5 molecular sieves, SAPO molecular sieves, or MCM-41 mesoporous molecular sieves.

11. The process according to claim 3, wherein the amorphous silica-alumina has a specific surface area ranging from 400 m.sup.2/g to 650 m.sup.2/g, a pore volume ranging from 1.0 cm.sup.3/g to 2.0 cm.sup.3/g, a silica amount ranging from 20% to 80% by weight relative to the total weight of the amorphous silica-alumina, an average pore diameter ranging from 10 nm to 20 nm, and an infrared acid amount ranging from 0.3 mmol/g to 0.8 mmol/g.

12. The process according to claim 3, wherein the amorphous silica-alumina has a specific surface area ranging from 400 to 550 m.sup.2/g, a pore volume ranging from 1.2 cm.sup.3/g to 1.6 cm.sup.3/g, a silica amount ranging from 30% to 65% by weight relative to the total weight of the at least one amorphous silica-alumina, and an average pore diameter ranging from 10 to 15 nm.

13. The process according to claim 1, wherein the at least one hydrogenation metal is W or Mo.

14. The process according to claim 1, where in the at least one hydrogenation metal is W or Ni.

15. A single-stage hydrocracking process, wherein a vacuum gas oil is in contact with the hydrocracking catalyst produced according to the process of claim 1 in the presence of hydrogen gas.

16. The single-stage hydrocracking process according to claim 15, wherein the hydrocracking reaction is conducted at a temperature ranging from 350 C. to 480 C. and a pressure ranging from 8 MPa to 20 MPa, with an vacuum gas oil having a liquid hourly volume space velocity ranging from 0.4 h.sup.1 to 5 h.sup.1, and with a volume ratio of hydrogen gas to vacuum gas oil under the standard condition ranging from 100:1 to 3,000:1.

17. The single-stage hydrocracking process according to claim 15, wherein, providing a hydrorefining catalyst in an amount ranging from 5% to 90% by volume relative to the volume of the hydrocracking catalyst upstream or downstream from the hydrocracking catalyst.

18. The single-stage hydrocracking process according to claim 17, wherein the hydrorefining catalyst is in an amount ranging from 30% to 80% by volume relative to the volume of the hydrocracking catalyst.

19. The single-stage hydrocracking process according to claim 15, wherein the vacuum gas oil has a final boiling point temperature ranging from 500 C. to 630 C.

Description

EXAMPLE 1

Comparison Example

[0054] 578 g of macroporous alumina (produced by Tianjin Tianjiu Co., Ltd, having a pore volume of 0.82 ml/g, a specific surface area of 323 m.sup.2/g and a dry basis of 71.1%), and 386 g microporous alumina (SB powder produced by SASOL Germany GmbH) were used to prepare an adhesive (having a dry basis of 26.2%). 6 g of sesbania powder was added, and milled for 30 min. A suitable amount of distillated water was added to enable the mixture to be in an extrudable paste form. The mixture was extruded into a bar form, wherein the pore plate of the bar extruder is in a clover form having a diameter of 1.5 mm. The wet bar was dried at 120 C. for 4 h, calcined at 550 C. for 3 h, and numbered HF-1S. Two parts of HF-1S support, 120 g for each part, were respectively and oversaturatedly impregnated in a tungsten-nickel solution (having a WO.sub.3 amount of 43.1 g/100 ml, and a NiO amount of 7.2 g/100 ml) and a molybdenum-nickel solution (having a MoO.sub.3 amount of 40.7 g/100 ml, and a NiO amount of 6.5 g/100 ml). After impregnation, the catalyst was calcined at 480 C. to prepare the catalyst products numbered HF-1A and HF-1B respectively.

EXAMPLE 2

Comparison Example

[0055] Macroporous alumina in Example 1 was changed to silicon-modified macroporous alumina in the same amount which was prepared according to the patent application CN200510047483.1, and the others were the same as those in Example 1, to prepare the support numbered HF-25 and the catalysts numbered HF-2A and HF-2B.

EXAMPLE 3

Comparison Example

[0056] The impregnating solutions in Example 2 were adjusted, wherein the tungsten-nickel solution had a WO.sub.3 amount of 51.5 g/100 ml, and a NiO amount of 11.4 g/100 ml); and the molybdenum-nickel solution had a MoO.sub.3 amount of 50.3 g/100 ml, and a NiO amount of 12.4 g/100 ml), and the others were the same as those in Example 2, to prepare the support numbered HF-35 and the catalysts numbered HF-3A and HF-3B.

EXAMPLE 4

Comparison Example

[0057] 578 g of Tianjiu macroporous alumina (produced by Tianjin Tianjiu Co., Ltd, having a pore volume of 0.82 ml/g, a specific surface area of 323 m.sup.2/g and a dry basis of 71.1%, which are the same as those in Example 1) was hydrothermally treated for 40 min at a temperature of 560 C. and a vapor pressure of 0.1 MPa. Three metal impregnating solutions were prepared: the tungsten-nickel solution (having a WO.sub.3 amount of 12.1 g/100 ml, and a NiO amount of 2.1 g/100 ml), the molybdenum-nickel solution (having a MoO.sub.3 amount of 11.7 g/100 ml, and a NiO amount of 1.8 g/100 ml), and the tungsten-molybdenum-nickel solution (having a WO.sub.3 amount of 6.3 g/100 ml, a MoO.sub.3 amount of 7.7 g/100 ml, and a NiO amount of 2.6 g/100ml). The hydrothermally treated alumina powder was added into each 800 ml stirring metal impregnating solution, impregnated for 120 min, filtered, dried at 120 C. for 4 h, pulverized, and sifted with 180 meshes. The resultant powder was mixed with a suitable amount of sesbania powder; dilute nitric acid having a concentration of 4 gHNO.sub.3/100 ml was added for molding, wherein the form of the bar-extrusion pore plate was clover having a diameter of 1.5 mm. The wet bar was dried at 120 C. for 4 h, calcined at 480 C. for 3 h, and numbered HF-4A, HF-4B and HF-4C respectively.

EXAMPLE 5

[0058] Macroporous alumina in Example 4 was changed to the same amount of macroporous gelatineous amorphous silica-alumina powder (having a pore volume of 1.32 ml/g, a specific surface area of 485 m.sup.2/g, a dry basis of 75.4% and a silica amount of 54.4% (based on the dry basis), an average pore diameter of 12.7 nm and an infrared acid amount of 0.66 mmol/g); a suitable amount of microporous alumina adhesive was added during molding; and the others were the same as those in Example 4, to prepare the catalysts numbered HF-5A, HF-5B and HF-5C respectively.

[0059] Macroporous gelatineous amorphous silica-alumina powder was prepared by the steps of parallel-flow adding dropwise 6,000 ml of a AlCl.sub.3 solution containing 5 g/100 mL of Al.sub.2O.sub.3 and a mixed solution of sodium aluminate and sodium silicate containing 5 g/100 mL of Al.sub.2O.sub.3 and 15 g/100 mL of SiO.sub.2 into a stirring gelatinization reaction tank having a temperature of 65 C., maintaining the pH value to be 8.0, the reaction contact lasting 40 min until the completion of the dripping of the AlCl.sub.3 solution, continuing to stir for 10 min, adding dropwise 120 mL of tetra ethyl ortho-silicate for 20 min, adjusting the slurry pH value to 9.0 with 5% sodium hydroxide solution and ageing for 1.5 h, filtering the product, washing three times with a deionized water in a solid/liquid ratio of 1:20 at 70 C., drying the resultant filter cake at 120 C. for 3 h to obtain about 1,200 g of macroporous gelatineous amorphous silica-alumina powder.

EXAMPLE 6

[0060] Macroporous amorphous silica-alumina prepared by the following process and the macroporous alumina in Example 4 were used in a mass ratio of 4:1 (the total amount thereof being 578 g). The concentrations of the impregnating solutions were adjusted as follows: the tungsten-nickel solution was adjusted to have a W03 amount of 18.0 g/100 ml and a NiO amount of 2.8 g/100ml, the molybdenum-nickel solution was adjusted to have a MoO.sub.3 amount of 17.8 g/100 ml and a NiO amount of 2.9 g/100 ml, and the tungsten-molybdenum-nickel solution was adjusted to have a WO.sub.3 amount of 8.7 g/100 ml, a MoO.sub.3 amount of 9.9 g/100 ml, and a NiO amount of 3.5 g/100 ml. The others were the same as those in Example 5. The catalysts numbered HF-6A, HF-6B and HF-6C were prepared respectively.

[0061] Macroporous amorphous silica-alumina (having the properties of a pore volume of 1.40 ml/g, a specific surface area of 550 m.sup.2/g, a dry basis of 74.3% and a silica amount of 40.5% (based on the dry basis), an average pore diameter of 13.6 nm and an infrared acid amount of 0.61 mmol/g) was prepared by the steps comprising parallel-flow adding dropwise 16,000 ml of a AlCl.sub.3 solution containing 5 g/100 mL of Al.sub.2O.sub.3 and a mixed solution of sodium aluminate and sodium silicate containing 5 g/100 mL of Al.sub.2O.sub.3 and 15 g/100 mL of SiO.sub.2 into a stirring gelatinization reaction tank having a temperature of 65 C., maintaining the pH value to be 8.0, the reaction contact lasting 40 min until the completion of the dripping of the AlCl.sub.3 solution, continuing to stir for 10 min, adding dropwise 2,800 mL of organic silicon oil containing 10 g/100 mL of SiO.sub.2 (having a brand No. 5001, produced by Shangyu City Fine Chemical Plant, Zhejiang, China) for 40 min, adjusting the slurry pH value to 9.0 with 5% sodium hydroxide solution and ageing for 1.5 h, filtering the product, washing three times with a deionized water having a solid/liquid ratio of 1:20 at 70 C., drying the resultant filter cake at 120 C. for 3 h to obtain about 2,400 g of macroporous gelatineous amorphous silica-alumina powder.

[0062] Meanwhile, to the combination of macroporous amorphous silica-alumina and macroporous alumina in the same amounts stated in this Example was added an adhesive, molded, dried at 120 C. for 4 h, calcined at 550 C. for 3 h to obtain a catalyst support numbered HF-3S. Three parts of the HF-3S support were prepared and impregnated two times with the impregnating solutions of HF-6A, HF-6B and HF-6C, wherein the impregnating solutions were the tungsten-nickel solution, the molybdenum-nickel solution and the tungsten-molybdenum-nickel solution as stated in this Example; the impregnation method consisted of the first impregnation step, the first drying step at 120 C. for 5 h after the first impregnation, the second impregnation step, the second drying step under the same conditions to the first drying step, and a calcination step at 480 C. for 2 h. The catalysts numbered HF-6A-1, HF-6B-2 and HF-6C-3 were prepared (HF-6A-1, HF-6B-2 and HF-6C-3 are the comparison examples of the present invention)

EXAMPLE 7

[0063] The concentrations of the impregnating solutions in Example 5 were adjusted as follows: the tungsten-nickel solution was adjusted to have a WO.sub.3 amount of 20.8 g/100 ml and a NiO amount of 3.4 g/100 ml, the molybdenum-nickel solution was adjusted to have a MoO.sub.3 amount of 21.3 g/100 ml and a NiO amount of 4.1 g/100 ml, and the tungsten-molybdenum-nickel solution was adjusted to have a WO.sub.3 amount of 8.4 g/100ml, a MoO.sub.3 amount of 12.1 g/100 ml, and a NiO amount of 4.3 g/100 ml. Meanwhile, a modified Y molecular sieve (having a silica-alumina molar ratio of 13, an Na.sub.2O amount of equal to or less than 0.1 wt. %, and an infrared acid amount of 0.8 mmol/g) in an amount of 5% by weight of the final catalyst mass was used. The others were the same as those in Example 5. The catalysts numbered HF-7A, HF-7B and HF-7C were prepared respectively.

EXAMPLE 8

[0064] The concentrations of the impregnating solutions in Example 5 were adjusted as follows: the tungsten-nickel solution was adjusted to have a WO.sub.3 amount of 24.3 g/100 ml, and a NiO amount of 4.0 g/100 ml, the molybdenum-nickel solution was adjusted to have a MoO.sub.3 amount of 25.3 g/100 ml and a NiO amount of 5.4 g/100 ml, and the tungsten-molybdenum-nickel solution was adjusted to have a WO.sub.3 amount of 8.9 g/100 ml, a MoO.sub.3 amount of 15.4 g/100 ml, and a NiO amount of 4.9 g/100 ml. The others were the same as those in Example 5. The catalysts numbered HF-8A, HF-8B and HF-8C were prepared respectively.

[0065] In this Example, the physical and chemical analyses and activity evaluation of the catalysts in each example were conducted, and the physical and chemical properties of the catalysts in each example were listed in Table 1.

TABLE-US-00001 TABLE 1 Physicochemical properties of the catalysts No. HF-1A HF-2A HF-3A HF-4A HF-5A HF-6A HF-6A-1 HF-7A HF-8A WO.sub.3, % 23.2 27.9 34.1 26.6 27.1 41.6 41.2 48.2 56.2 NiO, % 5.5 6.4 10.1 6.8 7.5 9.9 10.5 12.1 14.2 Total metal 28.7 34.3 44.2 33.4 34.6 51.5 51.7 60.3 70.4 amount M, % S, m.sup.2/g 188 264 200 210 321 261 156 180 153 V, ml/g 0.330 0.401 0.347 0.340 0.454 0.421 0.284 0.340 0.291 R, nm 7.8 9.1 8.0 8.1 11.3 9.7 7.3 7.9 7.3 M S 54 91 88 70 111 134 81 109 108 No. HF-1B HF-2B HF-3B HF-4B HF-5B HF-6B HF-6B-1 HF-7B HF-8B MoO.sub.3, % 22.9 28.2 35.1 25.7 28.4 42.6 42.5 46.9 54.6 NiO, % 4.9 6.3 9.8 6.5 7.7 11.1 11.3 10.1 16.4 Total metal 27.8 34.5 44.9 32.2 36.1 53.7 53.8 57.0 71.0 amount M, % S, m.sup.2/g 197 277 187 234 350 278 168 213 164 V, ml/g 0.354 0.399 0.326 0.421 0.471 0.415 0.276 0.364 0.312 R, nm 8.0 9.4 7.2 9.8 12.1 10.6 6.7 8.4 8.0 M S 55 96 84 75 126 149 90 121 116 No. HF-4C HF-5C HF-6C HF-6C-1 HF-7C HF-8C WO.sub.3, % 13.4 14.6 18.5 18.2 16.7 20.6 MoO.sub.3, % 14.7 16.4 22.4 23.1 26.1 30.1 NiO, % 5.8 6.9 10.9 10.4 9.7 13.4 Total metal 33.9 37.9 51.8 51.7 52.5 64.1 amount M, % S, m.sup.2/g 211 341 286 149 231 200 V, ml/g 0.366 0.424 0.397 0.247 0.350 0.332 R, nm 8.4 11.0 10.1 6.6 9.0 7.9 M S 72 129 148 77 121 128 R represents the average pore diameter.

[0066] The evaluation apparatus was a 200 ml small-scale hydrogenation unit, and the catalyst was presulphurized before the activity evaluation. The properties of the raw materials and the technological conditions used for evaluating the catalyst activity were listed in Tables 2 and 3, and the comparison results of relative hydrodenitrogenation activity of the catalysts were listed in Table 4.

TABLE-US-00002 TABLE 2 Main properties of the feedstock Density, (20 C.)/g .Math. cm.sup.3 0.9164 Boiling range/ C. IBP/10% 328/376 30%/50% 400/430 70%/90% 455/499 95%/FBP 514/531 Condensation point/ C. 34 Refraction/n.sub.D.sup.70 1.4899 Carbon residue, mass % 0.32 S, mass % 1.60 N, mass % 0.1475

TABLE-US-00003 TABLE 3 Operating conditions of the pilot plant tests Reaction hydrogen partial pressure, MPa 14.7 Liquid hourly volume space velocity, h.sup.1 1.0 hydrogen/oil volume ratio 1000:1 Average reaction temperature, C. 385

TABLE-US-00004 TABLE 4 Comparison results of relative hydrodenitrogenation activity of the catalysts Catalysts HF-1A HF-1B HF-2A HF-3A HF-4A HF-4B HF-4C HF-5A HF-5B HF-5C Relative 100 103 95 94 105 107 102 114 122 118 hydrodenitrogenation activity, % Catalysts HF-6A HF-6B HF-6C HF-6A-1 HF-6B-2 HF-6C-1 HF-7C HF-8A Relative 116 126 123 93 98 96 127 124 hydrodenitrogenation activity, %

TABLE-US-00005 TABLE 5 Hydrocracking test results FC-30 (produced by Sinopec Catalysts HF-6A-1 HF-6B-1 HF-6C-1 HF-6A HF-6B HF-6C HF-7A Group) Average reaction 397 395 395 387 385 386 385 391 temperature, C.* Once-through 60 60 60 60 60 60 60 60 conversion rate, mass %** Selectivity of middle- 78 79 79 86 86 87 87 84 distillate yield, mass %** BMCI of tail oil 17 16 16 11 11 10 10 13 *Other conditions were the same as those in Table 3, and the evaluation apparatus was 200 ml small-scale hydrogenation unit. **Once-through conversion rate was the mass percentage of the product having a temperature of less than 370 C. relative to the feedstock; and the selectivity of middle oil was the mass percentage of the product having a temperature of less than 370 C. relative to the reaction product (aviation kerosene + diesel oil).