A METHOD FOR PREPARING A CATALYST FOR INFERIOR RESIDUAL OIL SUSPENDED BED HYDROCRACKING

Abstract

The present invention belongs to the technical field of petroleum processing, and specifically relates to a method for preparing a catalyst for inferior residual oil suspended bed hydrocracking. Using sol-gel method and hydrothermal method, a mesoporous γ-Fe.sub.2O.sub.3 catalyst suitable for inferior residual oil suspended bed hydrocracking with a high specific surface area was prepared, based on FeCl.sub.3.6H.sub.2O, Fe.sub.2(SO.sub.4).sub.3.xH.sub.2O as inorganic iron source, and cheap sawdust powder as template. The present invention proposes to prepare a γ-Fe.sub.2O.sub.3 material with a mesoporous structure, a high specific surface area and a high pore volume using cheap raw materials and a simple and green synthesis process. The material as a catalyst has a good application effect in the heavy oil suspended bed hydrocracking reaction with a small amount, therefore having good commercial and industrial application value.

Claims

1. A method for preparing a catalyst for inferior residual oil suspended bed hydrocracking, wherein the method comprises the steps of: (1) adding an inorganic iron source to deionized water to prepare an inorganic iron source solution, then immersed in a water bath; (2) preparing an alkaline solution, which is slowly added to the inorganic iron source solution prepared in step (1) until final pH is 7.0-12.0; (3) crushing the sawdust, followed by screening to obtain sawdust powder with the required particle size; (4) dissolving the sawdust powder prepared in step (3) in a mixed solution of deionized water and absolute ethanol, with addition of organic solvent and alkali simultaneously, then immersed by stirring in a water bath, and set aside; (5) adding the gel-like substance obtained from step (4) to the specimen prepared in step (2), with stirring quickly to form a gel substance; (6) after the gel obtained from step (5) is left to stand, then dried, roasted, washed and dried again to prepare the catalyst.

2. The method for preparing a catalyst for inferior residual oil suspended bed hydrocracking according to claim 1, wherein the inorganic iron source used in step (1) is FeCl.sub.3.6H.sub.2O or Fe.sub.2(SO.sub.4).sub.3.xH.sub.2O with higher purity than industrial purity, and the prepared inorganic iron source solution has a concentration of 2-8 mol/L.

3. The method for preparing a catalyst for inferior residual oil suspended bed hydrocracking according to claim 1, wherein immersing in a water bath in step (1) is carried out at a speed of 400-700 r/min under a temperature of 50-90° C. for 0.5-5 h.

4. The method for preparing a catalyst for inferior residual oil suspended bed hydrocracking according to claim 1, wherein the alkaline solution used in step (2) is NaOH solution at a concentration of 2-7 mol/L; a main component of a mixture formed in step (2) is Fe(OH).sub.3.

5. The method for preparing a catalyst for inferior residual oil suspended bed hydrocracking according to claim 1, wherein the sawdust powder in step (3) has a particle size of 20-40 mesh.

6. The method for preparing a catalyst for inferior residual oil suspended bed hydrocracking according to claim 1, wherein the prepared sawdust powder from step (3) is dissolved in a mixed solution of deionized water and absolute ethanol in step (4), wherein the weight ratio of deionized water to sawdust powder is 2:1-10:1; the weight ratio of deionized water to absolute ethanol is 2:1-6:1.

7. The method for preparing a catalyst for inferior residual oil suspended bed hydrocracking according to claim 1, wherein the organic solvent used in step (4) is isopropanol and glacial acetic acid, the alkali is NaOH, wherein the weight ratio of the added sawdust powder to the added isopropanol and the added sawdust powder to the added glacial acetic acid are both 10:1-10:3; the weight ratio of the added sawdust powder to the added NaOH is 10:3-10:8; the stirring in a water bath in step (4) is carried out at a speed of 500-700 r/min under a temperature of 50-90° C. for 1-5 h; the gel substance finally obtained in step (4) has a pH of 7.0-10.0.

8. The method for preparing a catalyst for inferior residual oil suspended bed hydrocracking according to claim 1, wherein the stirring quickly in step (5) is carried out at a speed of 1000-1300 r/min under room temperature for 10-60 min; the gel substance finally formed in step (5) has a pH of 9.0-12.0; the weight ratio of the added gel-like substance obtained from step (4) to the specimen prepared in step (2) is 1:10-4:6.

9. The method for preparing a catalyst for inferior residual oil suspended bed hydrocracking according to claim 1, wherein the standing time of the gel obtained from step (5) in step (6) is carried out under a temperature of 20-70° C. for 0.5-5 h, the first drying is carried out under a temperature of 80-170° C. for 5-9 h, calcining is carried out under a temperature of 380-500° C. for 2-7 h.

10. A catalyst for inferior residual oil suspended bed hydrocracking prepared by the method of any one of claims 1-9, wherein the catalyst is mesoporous γ-Fe.sub.2O.sub.3, with an average pore diameter of 7.00-15.00 nm, a pore volume of 0.03-0.35 cm.sup.3/g, and a specific surface area of 14.0-140.0 m.sup.2/g.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 is a wide-angle XRD pattern of the mesoporous Fe.sub.2O.sub.3 catalyst prepared by the present invention;

[0027] FIG. 2 is a diagram showing the nitrogen absorption and desorption of the mesoporous Fe.sub.2O.sub.3 catalyst prepared in the present invention;

[0028] FIG. 3 is a pore size distribution diagram of the mesoporous Fe.sub.2O.sub.3 catalyst prepared in the present invention;

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The present invention will be further described below in combination with the drawings and specific embodiments, but the protection scope of the present invention is not limited this.

[0030] In order to avoid repetition, the raw materials used in the specific embodiments are described in a unified manner as follows, and details are not repeated in the examples.

[0031] The iron salt has higher purity than industrial purity.

[0032] The NaOH has higher purity than industrial purity.

Example 1

[0033] (1) 27.05 g of FeCl.sub.3.6H.sub.2O was added to 39.2 ml of deionized water to prepare 2 mol/L FeClk solution under room temperature, then heated and stirred in a water bath under 80′C for 1 h;
(2) 6 mol/L of NaOH solution was prepared, which was added drop by drop to the FeCl.sub.3 solution prepared in step (1) followed by production of red-brown floccules until the pH value of the solvent in the red-brown floccules greater than 11.2;
(3) the sawdust was crushed, followed by screening to obtain sawdust powder with a size between 20-30 mesh;
(4) 5 g of the sawdust powder prepared in step (3) was dissolved in a mixed solution of 40 ml deionized water and anhydrous ethanol (in mass ratio, deionized water:anhydrous ethanol=3:1), with addition of 2 g isopropanol, 5 g glacial acetic acid and 5 g NaOH (granular) simultaneously, followed by stirring under room temperature, then ultrasonic treatment for 1 h, and finally stirring in a water bath under 80° C. for 1.5 h;
(5) the final products of step (4) were added to the red-brown floccules prepared in step (2), with stirring quickly for 1 min to form a gel;
(6) after scaling the final gel made in step (5) in the reactor, it was left to stand at room temperature for 2 h, followed by drying under 150° C. for 5 h, and then roasting under 450′C for 3 h. Until the furnace temperature naturally dropped to room temperature, the sample was taken out and washed with a mixed solution of deionized water and alcohol, and then the sample was put in a 60° C. oven for drying, and finally the dried material was sealed and stored. Marked as Fe.sub.2O.sub.3-1.

[0034] The prepared iron oxide was γ-Fe.sub.2O.sub.3, with a specific surface area of 113.4 m.sup.2/g, a pore volume of 0.28 cm.sup.3/g, and an average pore diameter of 8.6 nm. The results of the catalyst used in the residual oil suspended bed hydrocracking reaction were shown in Table 1.

Example 2

[0035] (1) 27.05 g of FeCl.sub.3.6H.sub.2O was added to 39.2 ml of deionized water to prepare 2 mol/L FeCl.sub.3 solution under room temperature, then heated and stirred in a water bath under 80′C for 1 h;
(2) 6 mol/L of NaOH solution was prepared, which was added drop by drop to the FeCl.sub.3 solution prepared in step (1) followed by production of red-brown floccules until the pH value of the solvent in the red-brown floccules greater than 11.2;
(3) the sawdust was crushed, followed by screening to obtain sawdust powder with a size between 20-30 mesh;
(4) 10 g of the sawdust powder prepared in step (3) was dissolved in a mixed solution of 40 ml deionized water and anhydrous ethanol (in mass ratio, deionized water:anhydrous ethanol=3:1), with addition of 2 g isopropanol, 5 g glacial acetic acid and 5 g NaOH (granular) simultaneously, followed by stirring under room temperature, then ultrasonic treatment for 1 h, and finally stirring in a water bath under 80′C for 1.5 h;
(5) the final products of step (4) were added to the red-brown floccules prepared in step (2), with stirring quickly for 1 min to form a gel;
(6) after sealing the final gel made in step (5) in the reactor, it was left to stand at room temperature for 2 h, followed by drying under 150° C. for 5 h, and then roasting under 450° C. for 3 h. Until the furnace temperature naturally dropped to room temperature, the sample was taken out and washed with a mixed solution of deionized water and alcohol, and then the sample was put in a 60° C. oven for drying, and finally the dried material was sealed and stored. Marked as Fe.sub.2O.sub.3.2.

[0036] The prepared iron oxide was γ-Fe.sub.2O.sub.3, with a specific surface area of 116.6 m.sup.2/g, a pore volume of 0.24 cm.sup.3/g, and an average pore diameter of 9.0 nm. The results of the catalyst used in the residual oil suspended bed hydrocracking reaction were shown in Table 1.

Example 3

[0037] (1) 27.05 g of FeCl.sub.3.6H.sub.2O was added to 39.2 ml of deionized water to prepare 2 mol/L FeCl.sub.3 solution under room temperature, then heated and stirred in a water bath under 80° C. for 1 h;
(2) 6 mol/L of NaOH solution was prepared, which was added drop by drop to the FeCl.sub.3 solution prepared in step (1) followed by production of red-brown floccules until the pH value of the solvent in the red-brown floccules greater than 11.2;
(3) the sawdust was crushed, followed by screening to obtain sawdust powder with a size between 20-30 mesh;
(4) 10 g of the sawdust powder prepared in step (3) was dissolved in a mixed solution of 40 ml deionized water and anhydrous ethanol (in mass ratio, deionized water:anhydrous ethanol=3:1), with addition of 2 g isopropanol, 5 g glacial acetic acid and 5 g NaOH (granular) simultaneously, followed by stirring under room temperature, then ultrasonic treatment for 1 h, and finally stirring in a water bath under 80° C. for 1.5 h;
(5) the final products of step (4) were added to the red-brown floccules prepared in step (2), with stirring quickly for 1 min to form a gel;
(6) the final gel produced in step (5) was sealed in a high-pressure hydrothermal reactor with treatment under 150′C or 6 h, followed by drying under 150° C. for 6 h, and then roasting under 450′C for 3 h. Until the furnace temperature naturally dropped to room temperature, the sample was taken out and washed with a mixed solution of deionized water and alcohol, and then the sample was put in a 60° C. furnace for drying, and finally the dried material was scaled and stored. Marked as Fe.sub.2O.sub.3.3.

[0038] The prepared iron oxide was γ-Fe.sub.2O.sub.3, with a specific surface area of 126.4 m.sup.2/g, a pore volume of 0.35 cm.sup.3/g, and an average pore diameter of 9.5 nm. The results of the catalyst used in the residual oil suspended bed hydrocracking reaction were shown in Table 1.

Example 4

[0039] (1) 27.05 g of FeCl.sub.3.6H.sub.2O was added to 39.2 ml of deionized water to prepare 2 mol/L FeCl.sub.3 solution under room temperature, then heated and stirred in a water bath under 80′C for 1 h;
(2) 6 mol/L of NaOH solution was prepared, which was added drop by drop to the FeCl.sub.3 solution prepared in step (1) followed by production of red-brown floccules until the pH value of the solvent in the red-brown floccules greater than 11.2;
(3) the sawdust was crushed, followed by screening to obtain sawdust powder with a size between 20-30 mesh;
(4) 5 g of the sawdust powder prepared in step (3) was dissolved in a mixed solution of 40 ml deionized water and anhydrous ethanol (in mass ratio, deionized water: anhydrous ethanol=3:1), with addition of 2 g isopropanol, 5 g glacial acetic acid and 5 g NaOH (granular) simultaneously, followed by stirring under room temperature, then ultrasonic treatment for 1 h, and finally stirring in a water bath under 80° C. for 1.5 h;
(5) the final products of step (4) were added to the red-brown floccules prepared in step (2), with stirring quickly for 1 min to form a gel;
(6) after sealing the final gel made in step (5) in the reactor, it was left to stand at room temperature for 2 h, followed by drying under 150′C for 5 h, and then roasting under 500° C. for 3 h. Until the furnace temperature naturally dropped to room temperature, the sample was taken out and washed with a mixed solution of deionized water and alcohol, and then the sample was put in a 60° C. oven for drying, and finally the dried material was sealed and stored. Marked as Fe.sub.2O.sub.3.4.

[0040] The prepared iron oxide was γ-Fe.sub.2O.sub.3, with a specific surface area of 71.1 m.sup.2/g, a pore volume of 0.20 cm.sup.3/g, and an average pore diameter of 15.3 nm. The results of the catalyst used in the residual oil suspended bed hydrocracking reaction were shown in Table 1.

Example 5

[0041] (1) 27.05 g of FeCl.sub.3.6H.sub.2O was added to 39.2 ml of deionized water to prepare 2 mol/L. FeCl.sub.3 solution under room temperature, then heated and stirred in a water bath under 80′C for 1 h;
(2) 6 mol/L. of NaOH solution was prepared, which was added drop by drop to the FeCl.sub.3 solution prepared in step (1) followed by production of red-brown floccules until the pH value of the solvent in the red-brown floccules greater than 11.2;
(3) the sawdust was crushed, followed by screening to obtain sawdust powder with a size between 20-30 mesh;
(4) 5 g of the sawdust powder prepared in step (3) was dissolved in a mixed solution of 40 ml deionized water and anhydrous ethanol (in mass ratio, deionized water:anhydrous ethanol=3:1), with addition of 2 g isopropanol, 5 g glacial acetic acid and 5 g NaOH (granular) simultaneously, followed by stirring under room temperature, then ultrasonic treatment for 1 h, and finally stirring in a water bath under 80′C for 1.5 h;
(5) the final products of step (4) were added to the red-brown floccules prepared in step (2), with stirring quickly for 1 min to form a gel;
(6) after sealing the final gel made in step (5) in the reactor, it was left to stand at room temperature for 2 h. followed by drying under 150° C. for 5 h, and then roasting under 500° C. for 6 h. Until the furnace temperature naturally dropped to room temperature, the sample was taken out and washed with a mixed solution of deionized water and alcohol, and then the sample was put in a 60° C. oven for drying, and finally the dried material was sealed and stored. Marked as Fe.sub.2O.sub.3.5.

[0042] The prepared iron oxide was γ-Fe.sub.2O.sub.3, with a specific surface area of 13.4 m.sup.2/g, a pore volume of 0.02 cm.sup.3/g, and an average pore diameter of 16.6 nm. The results of the catalyst used in the residual oil suspended bed hydrocracking reaction were shown in Table 1.

[0043] FIG. 1 illustrated that the synthesized sample was γ-Fe.sub.2O.sub.3,

[0044] FIG. 2 illustrated that the synthesized γ-Fe.sub.2O.sub.3 had a mesoporous structure;

[0045] FIG. 3 illustrated the mesoporous average pore diameter of the synthesized γ-Fe.sub.2O.sub.3 was about 15 nm.

TABLE-US-00001 TABLE 1 Gasoline and diesel Product distribution (wt %) Conversion yield Middle Decompression Decompression Catalyst rate (wt %) (wt %) Gas Naphtha distillate fraction residual oil Coke Fe.sub.2O.sub.3-1 86.6 51.6 22.7 23.1 28.5 12.3 10.6 2.8 Fe.sub.2O.sub.3-2 90.9 60.0 21.3 25.7 34.2 9.7 8.0 1.1 Fe.sub.2O.sub.3-3 87.0 57.2 23.8 27.9 29.3 6.0 11.0 2.0 Fe.sub.2O.sub.3-4 89.0 54.6 21.9 23.7 30.9 12.5 8.7 2.3 Fe.sub.2O.sub.3-5 88.8 52.2 22.5 20.9 31.3 14.1 8.5 2.7

[0046] The above examples are only preferred examples of the present invention, and are not intended to limit the scope of protection of the present invention. Any changes made by adopting the design principle of the present invention and performing non-creative work on this basis shall fall within the protection scope of the present invention.