Hydrodesulfurization and hydrodenitrogenation catalyst, and preparation method and application thereof

Abstract

The application provides a hydrodesulfurization and denitrification catalyst and a preparation method and application thereof, and the preparation method comprises the following steps: uniformly mixing manganese salt and zirconium salt, dissolving the mixture, and adding a phosphoric acid solution to obtain a heteroatom precursor solution; uniformly mixing and stirring gamma-alumina and the heteroatom precursor solution, drying the mixture, and obtaining a heteroatom modified gamma-alumina precursor; uniformly dissolving and mixing citric acid and nitric acid to obtain an acid solution; uniformly mixing the heteroatom modified gamma-alumina precursor and sesbania powder, adding the acid solution, rolling, extruding into a strip, drying, and calcining to obtain a hydrodesulfurization and denitrification catalyst carrier; configuring tungsten salt and nickel salt into an impregnation solution, impregnating the hydrodesulfurization and denitrification catalyst carrier in a saturated impregnation mode, drying, and calcining to obtain the hydrodesulfurization and denitrification catalyst. The hydrodesulfurization and denitrification catalyst prepared by the method has high desulfurization and denitrification activity for poor-quality wax oil, and the yield of paraffin is also improved.

Description

Technical Field

[0001] This invention relates to a hydrodesulfurization and denitrogenation catalyst, and more particularly to a hydrodesulfurization and denitrogenation catalyst for the hydrorefining process of inferior wax oil, its preparation method, and its application in the hydrodesulfurization and denitrogenation of inferior wax oil, belonging to the field of petrochemical catalyst technology. Background Technology

[0002] Inferior wax oils, including those from thermal processing such as coking wax oil and thermal cracking wax oil, are products of residual oil thermal processing. They are rich in heavy aromatics, gums, sulfur, and nitrogen, making them difficult to process. Currently, some refineries blend them into straight-run wax oils for catalytic cracking. However, due to the characteristics of inferior wax oils, they will reduce the activity of catalytic cracking catalysts, decrease light oil yield and quality, increase coke production, and reduce the processing capacity of catalytic cracking units.

[0003] Chinese patent CN108452844A provides a hydrogenation catalyst using Al2O3-(ETS-10)-TiO2-La2O3-graphene composite oxide as a support and Ni and Mo as active metal components. However, this catalyst suffers from drawbacks such as complex support structure and high cost.

[0004] Chinese patent CN105749925A discloses a heavy oil hydrogenation catalyst using hydrothermally treated silicon- or fluorine-containing alumina as a support and molybdenum, nickel, and cobalt as active metals. However, this method has drawbacks such as complex operation and high cost.

[0005] Chinese patent CN111558377A provides a method using C12A7-O 2- -C12A7-H--C12A7-e - A hydrodesulfurization and denitrification catalyst supported on Al2O3 composite oxide is proposed. However, this catalyst has a complex structure, making it difficult to apply industrially.

[0006] Chinese patent CN111298800A discloses a hydrodesulfurization catalyst, comprising a heteroatom-modified γ-alumina support and an active component. The heteroatom-modified γ-alumina support is composed of heteroatom oxides and γ-alumina, and the heteroatoms can be manganese, iron, cobalt, gallium, niobium, rhenium, and lanthanides. However, this catalyst can only be used for desulfurization processes and has not been shown to be effective for denitrification or improving the yield of alkanes. Furthermore, the highest desulfurization rate of this catalyst is only 87%, indicating low desulfurization efficiency and poor catalyst selectivity. In addition, this catalyst is only suitable for diesel hydrodesulfurization, and the dry point of the diesel feedstock is below 350°C, making it unsuitable for wax oil fractions with a dry point below 520°C.

[0007] In summary, current hydrodesulfurization and denitrification catalysts based on various modified alumina supports still suffer from drawbacks such as demanding preparation conditions, complex preparation methods, and low hydrodesulfurization activity. Therefore, developing a hydrodesulfurization catalyst with a simple preparation method and good hydrodesulfurization effect has become the focus of current research. Summary of the Invention

[0008] The purpose of this invention is to provide a method for preparing a hydrodesulfurization and denitrogenation catalyst. The hydrodesulfurization and denitrogenation catalyst obtained by this method can simultaneously improve the desulfurization rate, denitrogenation activity, and alkane yield, and can be used in the hydrorefining process of inferior wax oil.

[0009] This invention discloses a method for preparing a hydrodesulfurization and denitrogenation catalyst, which includes the following steps:

[0010] (1) After mixing manganate and zirconium salt evenly, dissolve them and add phosphoric acid solution to obtain heteroatom precursor solution. The mass ratio of manganate to zirconium salt to phosphoric acid, based on the corresponding oxides, is MnO:ZrO2:P2O5 = 60wt%:(20-30)wt%:(10-20)wt%.

[0011] (2) After mixing and stirring the γ-alumina with the heteroatom precursor solution evenly, the mixture is dried to obtain the heteroatom-modified γ-alumina precursor.

[0012] (3) Dissolve and mix citric acid and nitric acid evenly to obtain an acid solution, wherein the amount of citric acid and nitric acid added is 6-9 wt% and 3-5 wt% of the mass of the hydrodesulfurization and denitrification catalyst support, respectively;

[0013] (4) Mix heteroatom modified γ-alumina precursor with guar powder evenly, add acid solution prepared in step (3), roll, extrude into strips, dry, and calcine to obtain hydrodesulfurization and denitrification catalyst support.

[0014] (5) Prepare an impregnation solution by mixing tungsten salt, nickel salt and ethylenediaminetetraacetic acid, impregnate the hydrodesulfurization and denitrification catalyst support, dry and calcine to obtain the hydrodesulfurization and denitrification catalyst.

[0015] The method for preparing the hydrodesulfurization and denitrogenation catalyst of the present invention includes a manganate salt that is at least one of potassium permanganate, manganese sulfate, and manganese nitrate; and a zirconium salt that is at least one of zirconium oxychloride, zirconium tetrachloride, and zirconium n-propoxide.

[0016] In the preparation method of the hydrodesulfurization and denitrogenation catalyst of the present invention, in step (2), the heteroatom modified γ-alumina precursor is composed of 11-20 wt% heteroatom precursor oxide and 80-89 wt% γ-alumina.

[0017] In the preparation method of the hydrodesulfurization and denitrification catalyst of the present invention, in step (4), the atomically modified γ-alumina precursor accounts for 92-95 wt% of the mass of the hydrodesulfurization and denitrification catalyst support, and the guar gum powder accounts for 5%-8% of the mass of the hydrodesulfurization and denitrification catalyst support.

[0018] In the preparation method of the hydrodesulfurization and denitrification catalyst of the present invention, in step (5), the amount of nickel salt added in the impregnation solution is 2-10 wt% of the mass of the hydrodesulfurization and denitrification catalyst based on NiO, the amount of tungsten salt added is 20-28 wt% of the mass of the hydrodesulfurization and denitrification catalyst based on WO3, and the amount of ethylenediaminetetraacetic acid added is 2-8 wt% of the mass of the hydrodesulfurization and denitrification catalyst.

[0019] The method for preparing the hydrodesulfurization and denitrification catalyst of the present invention, wherein the specific surface area of ​​the hydrodesulfurization and denitrification catalyst is 180-350 m². 2 / g, pore volume is 0.4-0.8cm³ 3 / g, with an average pore size of 6-10nm and a particle size of 20-40 mesh.

[0020] In the preparation method of the hydrodesulfurization and denitrogenation catalyst of the present invention, in step (5), the impregnation time is 1-2 h; the drying temperature is 100-120℃ and the time is 2-4 h; the calcination temperature is 500-600℃ and the time is 3-6 h.

[0021] The present invention also provides a hydrodesulfurization and denitrogenation catalyst obtained by the above preparation method.

[0022] The present invention further provides the application of the hydrodesulfurization and denitrogenation catalyst obtained by the above preparation method in the hydrorefining process of inferior Russian oil and wax.

[0023] In the application of this invention, the reaction conditions for the hydrorefining process are as follows: reaction temperature 320-400℃, hydrogen partial pressure 10-17 MPa, hydrogen-to-oil volume ratio 500-1000:1, and liquid hourly space velocity 1.5-2.5 h⁻¹. -1 .

[0024] The preparation method of the hydrodesulfurization and denitrogenation catalyst of the present invention involves modifying γ-alumina with a composite heteroatom precursor solution. The use of P modification improves the acidity of the hydrodesulfurization and denitrogenation catalyst support. The heteroatom precursor solution prepared by composite heteroatoms manganese and zirconium with an organic complexing solvent is more conducive to the interaction between γ-alumina and the active metal, increasing the number of stacked layers and sulfidation degree of the active phase, and improving the dispersion, resulting in a support with good pore properties and suitable acidity distribution. The prepared hydrodesulfurization and denitrogenation catalyst can simultaneously improve the hydrodesulfurization and denitrogenation activities and the alkane yield in the hydrorefining of inferior wax oil, with a desulfurization rate ≥98%, a denitrogenation rate ≥99%, and an alkane yield increase of at least 6%. It is suitable for the hydrorefining process of heavier distillate oils. Detailed Implementation

[0025] In order to provide a clearer understanding of the purpose, technical solution and beneficial effects of the present invention, the technical solution of the present invention is described in detail and completely below, but it should not be regarded as a limitation on the scope of implementation of the present invention.

[0026] Example 1

[0027] (1) Add 7.3g of potassium permanganate and 3.1g of zirconium tetrachloride to 30g of deionized water and mix them evenly. Then gradually add 0.76g of phosphoric acid and stir thoroughly to obtain heteroatom precursor solution A1.

[0028] (2) 44.5g of γ-alumina was impregnated with heteroatom precursor solution A1 in equal volume, and after mixing and stirring evenly, it was dried at 120℃ for 2h to obtain heteroatom modified γ-alumina precursor.

[0029] (3) Add 3g of citric acid and 1.5g of nitric acid to 45g of deionized water to dissolve and mix evenly to prepare acid solution B1.

[0030] (4) Mix 47.5g of heteroatom-modified γ-alumina precursor with 2.5g of guar gum powder evenly, add the acid solution B1 prepared in step (3) dropwise, crush into blocks, extrude into strips, dry at 120℃ for 2h, and calcine at 550℃ for 4h to obtain a hydrodesulfurization and denitrification catalyst support.

[0031] (5) The water absorption rate of the hydrodesulfurization and denitrification catalyst support was measured to be 62%. 67.3 g of ammonium metatungstate, 53.4 g of nickel nitrate, and 2 g of ethylenediaminetetraacetic acid were dissolved in a beaker containing deionized water to prepare 100 mL of impregnation solution. 67 g of the hydrodesulfurization and denitrification catalyst support was taken, and the above impregnation solution was added to the support by an equal-volume impregnation method. The support was impregnated for 2 h, dried at 120 °C for 4 h, and calcined in air at 500 °C for 4 h to obtain hydrodesulfurization and denitrification catalyst C1.

[0032] Example 2

[0033] (1) Add 8.3g of manganese nitrate and 2.4g of zirconium oxychloride to 30g of deionized water and mix them evenly. Then gradually add 0.76g of phosphoric acid and stir thoroughly to obtain heteroatom precursor solution A2.

[0034] (2) 44.5g of γ-alumina was impregnated with heteroatom precursor solution A2 in equal volume, and after mixing and stirring evenly, it was dried at 120℃ for 2h to obtain heteroatom modified γ-alumina precursor.

[0035] (3) Add 3g of citric acid and 1.5g of nitric acid to 45g of deionized water to dissolve and mix evenly to prepare acid solution B2.

[0036] (4) Mix 47.5g of heteroatom-modified γ-alumina precursor with 2.5g of guar gum powder evenly, add acid solution B2 prepared in step (3) dropwise, crush into blocks, extrude into strips, dry at 120℃ for 2h, and calcine at 550℃ for 4h to obtain a hydrodesulfurization and denitrification catalyst support.

[0037] (5) The water absorption rate of the hydrodesulfurization and denitrification catalyst support was measured to be 62%. 67.3 g of ammonium metatungstate, 53.4 g of nickel nitrate, and 2 g of ethylenediaminetetraacetic acid were dissolved in a beaker containing deionized water to prepare 100 mL of impregnation solution. 67 g of the hydrodesulfurization and denitrification catalyst support was taken, and the above impregnation solution was added to the support by an equal-volume impregnation method. The support was impregnated for 2 h, dried at 120 °C for 4 h, and calcined in air at 500 °C for 4 h to obtain hydrodesulfurization and denitrification catalyst C2.

[0038] Example 3

[0039] (1) Add 7.85g of manganese sulfate monohydrate and 2.4g of zirconium oxychloride to 30g of deionized water and mix them evenly. Then gradually add 0.76g of phosphoric acid and stir thoroughly to obtain heteroatom precursor solution A3.

[0040] (2) 44.5g of γ-alumina was impregnated with heteroatom precursor solution A3 in equal volume, and after mixing and stirring evenly, it was dried at 120℃ for 2h to obtain heteroatom modified γ-alumina precursor.

[0041] (3) Add 3g of citric acid and 1.5g of nitric acid to 45g of deionized water to dissolve and mix evenly to prepare acid solution B3.

[0042] (4) Mix 47.5g of heteroatom-modified γ-alumina precursor with 2.5g of guar gum powder evenly, add acid solution B3 prepared in step (3) dropwise, crush into blocks, extrude into strips, dry at 120℃ for 2h, and calcine at 550℃ for 4h to obtain a hydrodesulfurization and denitrification catalyst support.

[0043] (5) The water absorption rate of the hydrodesulfurization and denitrification catalyst support was measured to be 62%. 67.3 g of ammonium metatungstate, 53.4 g of nickel nitrate, and 2 g of ethylenediaminetetraacetic acid were dissolved in a beaker containing deionized water to prepare 100 mL of impregnation solution. 67 g of the hydrodesulfurization and denitrification catalyst support was taken, and the above impregnation solution was added to the support by an equal-volume impregnation method. The support was impregnated for 2 h, dried at 120 °C for 4 h, and calcined in air at 500 °C for 4 h to obtain hydrodesulfurization and denitrification catalyst C3.

[0044] Example 4

[0045] (1) Add 7.3g of potassium permanganate and 2.1g of zirconium tetrachloride to 30g of deionized water and mix them evenly. Then gradually add 1.52g of phosphoric acid and stir thoroughly to obtain heteroatom precursor solution A4.

[0046] (2) 44.5g of γ-alumina was impregnated with heteroatom precursor solution A4 in equal volume. After mixing and stirring evenly, it was dried at 120℃ for 2h to obtain heteroatom modified γ-alumina precursor.

[0047] (3) Add 3g of citric acid and 1.5g of nitric acid to 45g of deionized water to dissolve and mix evenly to prepare acid solution B4.

[0048] (4) Mix 47.5g of heteroatom-modified γ-alumina precursor with 2.5g of guar gum powder evenly, add acid solution B4 prepared in step (3) dropwise, crush into blocks, extrude into strips, dry at 120℃ for 2h, and calcine at 550℃ for 4h to obtain a hydrodesulfurization and denitrification catalyst support.

[0049] (5) The water absorption rate of the hydrodesulfurization and denitrification catalyst support was measured to be 62%. 67.3 g of ammonium metatungstate, 53.4 g of nickel nitrate, and 2 g of ethylenediaminetetraacetic acid were dissolved in a beaker containing deionized water to prepare 100 mL of impregnation solution. 67 g of the hydrodesulfurization and denitrification catalyst support was taken, and the above impregnation solution was added to the support by an equal-volume impregnation method. The support was impregnated for 2 h, dried at 120 °C for 4 h, and calcined in air at 500 °C for 4 h to obtain hydrodesulfurization and denitrification catalyst C4.

[0050] Example 5

[0051] (1) Add 7.3g of potassium permanganate and 2.6g of zirconium tetrachloride to 30g of deionized water and mix them evenly. Then gradually add 1.14g of phosphoric acid and stir thoroughly to obtain heteroatom precursor solution A5.

[0052] (2) 44.5g of γ-alumina was impregnated with heteroatom precursor solution A5 in equal volume, and after mixing and stirring evenly, it was dried at 120℃ for 2h to obtain heteroatom modified γ-alumina precursor.

[0053] (3) Add 3g of citric acid and 1.5g of nitric acid to 45g of deionized water to dissolve and mix evenly to prepare acid solution B5.

[0054] (4) Mix 47.5g of heteroatom-modified γ-alumina precursor with 2.5g of guar gum powder evenly, add acid solution B5 prepared in step (3) dropwise, crush into blocks, extrude into strips, dry at 120℃ for 2h, and calcine at 550℃ for 4h to obtain a hydrodesulfurization and denitrification catalyst support.

[0055] (5) The water absorption rate of the hydrodesulfurization and denitrification catalyst support was measured to be 62%. 67.3 g of ammonium metatungstate, 53.4 g of nickel nitrate, and 2 g of ethylenediaminetetraacetic acid were dissolved in a beaker containing deionized water to prepare 100 mL of impregnation solution. 67 g of the hydrodesulfurization and denitrification catalyst support was taken, and the above impregnation solution was added to the support by an equal-volume impregnation method. The support was impregnated for 2 h, dried at 120 °C for 4 h, and calcined at 500 °C in air atmosphere for 4 h to obtain hydrodesulfurization and denitrification catalyst C5.

[0056] Example 6

[0057] (1) Add 13.4g of potassium permanganate and 5.7g of zirconium tetrachloride to 30g of deionized water and mix them evenly. Then gradually add 1.38g of phosphoric acid and stir thoroughly to obtain heteroatom precursor solution A6.

[0058] (2) 40g of γ-alumina was impregnated with heteroatom precursor solution A6 in equal volume, and after mixing and stirring evenly, it was dried at 120℃ for 2h to obtain heteroatom modified γ-alumina precursor.

[0059] (3) Add 3g of citric acid and 1.5g of nitric acid to 45g of deionized water to dissolve and mix evenly to prepare acid solution B6.

[0060] (4) Mix 47.5g of heteroatom-modified γ-alumina precursor with 2.5g of guar gum powder evenly, add the acid solution B6 prepared in step (3) dropwise, crush into blocks, extrude into strips, dry at 120℃ for 2h, and calcine at 550℃ for 4h to obtain a hydrodesulfurization and denitrification catalyst support.

[0061] (5) The water absorption rate of the hydrodesulfurization and denitrification catalyst support was measured to be 62%. 45.6 g of ammonium metatungstate, 16.4 g of nickel nitrate, and 2 g of ethylenediaminetetraacetic acid were dissolved in a beaker containing deionized water to prepare 100 mL of impregnation solution. 78 g of the hydrodesulfurization and denitrification catalyst support was taken, and the above impregnation solution was added to the support by an equal-volume impregnation method. The support was impregnated for 2 h, dried at 120 °C for 4 h, and calcined in air at 500 °C for 4 h to obtain hydrodesulfurization and denitrification catalyst C6.

[0062] Example 7

[0063] (1) Add 7.3g of potassium permanganate and 3.1g of zirconium tetrachloride to 30g of deionized water and mix them evenly. Then gradually add 0.76g of phosphoric acid and stir thoroughly to obtain heteroatom precursor solution A7.

[0064] (2) 44.5g of γ-alumina was impregnated with heteroatom precursor solution A7 in equal volume, and after mixing and stirring evenly, it was dried at 120℃ for 2h to obtain heteroatom modified γ-alumina precursor.

[0065] (3) Add 4.5g of citric acid and 2.5g of nitric acid to 45g of deionized water to dissolve and mix evenly to prepare acid solution B7.

[0066] (4) Mix 47.5g of heteroatom-modified γ-alumina precursor with 2.5g of guar gum powder evenly, add acid solution B7 prepared in step (3) dropwise, crush into blocks, extrude into strips, dry at 120℃ for 2h, and calcine at 550℃ for 4h to obtain a hydrodesulfurization and denitrification catalyst support.

[0067] (5) The water absorption rate of the hydrodesulfurization and denitrification catalyst support was measured to be 62%. 80.3 g of ammonium metatungstate, 102.4 g of nickel nitrate, and 8 g of ethylenediaminetetraacetic acid were dissolved in a beaker containing deionized water to prepare 100 mL of impregnation solution. 39 g of the hydrodesulfurization and denitrification catalyst support was taken, and the above impregnation solution was added to the support by an equal-volume impregnation method. The support was impregnated for 2 h, dried at 120 °C for 4 h, and calcined in air at 500 °C for 4 h to obtain hydrodesulfurization and denitrification catalyst C7.

[0068] Example 8

[0069] (1) Add 7.3g of potassium permanganate and 2.6g of zirconium tetrachloride to 30g of deionized water and mix them evenly. Then gradually add 1.14g of phosphoric acid and stir thoroughly to obtain heteroatom precursor solution A8.

[0070] (2) 44.5g of γ-alumina was impregnated with heteroatom precursor solution A8 in equal volume, and after mixing and stirring evenly, it was dried at 120℃ for 2h to obtain heteroatom modified γ-alumina precursor.

[0071] (3) Add 3g of citric acid and 1.5g of nitric acid to 45g of deionized water to dissolve and mix evenly to prepare acid solution B8.

[0072] (4) Mix 47.5g of heteroatom-modified γ-alumina precursor with 2.5g of guar gum powder evenly, add acid solution B8 prepared in step (3) dropwise, crush into blocks, extrude into strips, dry at 120℃ for 2h, and calcine at 550℃ for 4h to obtain a hydrogenation desulfurization and denitrification catalyst support.

[0073] (5) The water absorption rate of the hydrodesulfurization and denitrification catalyst support was measured to be 62%. 45.6 g of ammonium metatungstate, 16.4 g of nickel nitrate, and 2 g of ethylenediaminetetraacetic acid were dissolved in a beaker containing deionized water to prepare 100 mL of impregnation solution. 78 g of the hydrodesulfurization and denitrification catalyst support was taken, and the above impregnation solution was added to the support by an equal-volume impregnation method. The support was impregnated for 2 h, dried at 120 °C for 4 h, and calcined at 500 °C in air atmosphere for 4 h to obtain hydrodesulfurization and denitrification catalyst C8.

[0074] Comparative Example 1

[0075] The difference from Example 1 is that a γ-alumina support is used.

[0076] (1) Dissolve 67.7 g of aluminum nitrate in 180 mL of deionized water and stir until clear to obtain 1 mol·L⁻¹ -1 Aluminum nitrate solution was prepared; appropriate amounts of ammonia and deionized water were mixed and diluted at a volume ratio of 1:1; diluted ammonia was added dropwise to the aluminum nitrate solution at a water bath temperature of 50℃ with continuous stirring until the pH of the system was 10, and stirring was continued for 10 min; the resulting aluminum hydroxide suspension was aged at room temperature for 3 h, and then filtered until the pH of the supernatant and the liquid dripping from the bottom of the funnel was 7; the resulting filter cake was dried in an oven at 100℃ for 12 h and calcined at 550℃ for 4 h to obtain γ-alumina carrier; the γ-alumina carrier was pressed into tablets at 30 MPa and sieved to form 20-40 mesh particles.

[0077] (2) Weigh 67g of the above-mentioned γ-alumina support and determine its water absorption rate to be 62%. Then weigh 67.3g of ammonium metatungstate, 53.4g of nickel nitrate, and 2g of ethylenediaminetetraacetic acid and add them to a beaker containing deionized water to dissolve them, preparing 100mL of impregnation solution. Take 67g of the γ-alumina support and add the above impregnation solution to the support using an equal-volume impregnation method. Impregnate for 2h, dry at 120℃ for 4h, and calcine at 500℃ in air atmosphere for 4h to obtain the hydrogenation catalyst with γ-alumina support, named A1.

[0078] Comparative Example 2

[0079] The difference from Example 1 is that zirconium aluminum composite oxide is used as the catalyst support.

[0080] (1) Dissolve 67.7 g of aluminum nitrate in 180 mL of deionized water and stir until clear to obtain 1 mol·L⁻¹ -1 A solution of aluminum nitrate was prepared by dissolving 2.09 g of zirconium oxychloride in 13 mL of deionized water and stirring until clear, yielding a 0.5 mol·L⁻¹ solution. -1A zirconium oxychloride solution was prepared by mixing zirconium and aluminum oxychloride solutions to obtain a zirconium-aluminum mixed solution. A suitable amount of ammonia and deionized water were mixed and diluted at a volume ratio of 1:1. Under continuous stirring at a water bath temperature of 50℃, diluted ammonia was added dropwise to the zirconium-aluminum mixed solution until the pH of the system reached 10, and stirring was continued for 10 minutes. The resulting composite hydroxide suspension was aged at room temperature for 3 hours, and then filtered until the pH of the supernatant and the liquid dripping from the bottom of the funnel reached 7. The resulting filter cake was dried in a 100℃ oven for 12 hours and calcined at 550℃ for 4 hours to obtain a zirconium-aluminum composite oxide support with a zirconium oxide content of 8 wt%. This zirconium-aluminum composite oxide was extruded into strips, dried at 120℃ for 2 hours, and calcined at 550℃ for 4 hours to obtain a hydrodesulfurization and denitrification catalyst support.

[0081] (2) The water absorption rate of the hydrodesulfurization and denitrification catalyst support was measured to be 62%. 67.3 g of ammonium metatungstate, 53.4 g of nickel nitrate, and 2 g of ethylenediaminetetraacetic acid were dissolved in a beaker containing deionized water to prepare 100 mL of impregnation solution. 67 g of the hydrodesulfurization and denitrification catalyst support was taken, and the above impregnation solution was added to the support using an equal-volume impregnation method. The support was impregnated for 2 h, dried at 120 °C for 4 h, and calcined in air at 500 °C for 4 h to obtain hydrodesulfurization and denitrification catalyst A2.

[0082] Comparative Example 3

[0083] The difference from Example 1 is that phosphoric acid is not added during the preparation of the solution without heteroatom precursors.

[0084] (1) 7.3g of potassium permanganate and 3.1g of zirconium tetrachloride were added to 30g of deionized water and dissolved and mixed evenly to obtain the heteroatom precursor solution DA1.

[0085] (2) 44.5g of γ-alumina was impregnated with the heteroatom precursor solution DA1 in equal volume. After mixing and stirring evenly, it was dried at 120℃ for 2h to obtain the heteroatom modified γ-alumina precursor.

[0086] (3) Add 3g of citric acid and 1.5g of nitric acid to 45g of deionized water to dissolve and mix evenly to prepare acid solution DB1.

[0087] (4) Mix 47.5g of heteroatom-modified γ-alumina precursor with 2.5g of guar gum powder evenly, add the acid solution DB1 prepared in step (3) dropwise, crush into blocks, extrude into strips, dry at 120℃ for 2h, and calcine at 550℃ for 4h to obtain a hydrodesulfurization and denitrification catalyst support.

[0088] (5) The water absorption rate of the hydrodesulfurization and denitrification catalyst support was measured to be 62%. 67.3 g of ammonium metatungstate, 53.4 g of nickel nitrate, and 2 g of ethylenediaminetetraacetic acid were dissolved in a beaker containing deionized water to prepare 100 mL of impregnation solution. 67 g of the hydrodesulfurization and denitrification catalyst support was taken, and the above impregnation solution was added to the support by an equal-volume impregnation method. The support was impregnated for 2 h, dried at 120 °C for 4 h, and calcined in air at 500 °C for 4 h to obtain hydrodesulfurization and denitrification catalyst A3.

[0089] Comparative Example 4

[0090] The difference from Example 1 is that the γ-alumina is modified with manganese and zirconium heteroatoms. The heteroatomated γ-alumina precursor consists of 5 wt% heteroatomated precursor oxide and 95 wt% γ-alumina.

[0091] (1) Add 3.34g of potassium permanganate and 1.9g of zirconium tetrachloride to 30g of deionized water and mix them evenly. Then gradually add 0.76g of phosphoric acid and stir thoroughly to obtain heteroatom precursor solution DA2.

[0092] (2) 47.5g of γ-alumina was impregnated with the heteroatom precursor solution DA2 in equal volume. After mixing and stirring evenly, it was dried at 120℃ for 2h to obtain the heteroatom modified γ-alumina precursor.

[0093] (3) Add 3g of citric acid and 1.5g of nitric acid to 45g of deionized water to dissolve and mix evenly to prepare acid solution DB2.

[0094] (4) Mix 47.5g of heteroatom-modified γ-alumina precursor with 2.5g of guar gum powder evenly, add the acid solution DB2 prepared in step (3) dropwise, crush into blocks, extrude into strips, dry at 120℃ for 2h, and calcine at 550℃ for 4h to obtain a hydrodesulfurization and denitrification catalyst support.

[0095] (5) The water absorption rate of the hydrodesulfurization and denitrification catalyst support was measured to be 62%. 67.3 g of ammonium metatungstate, 53.4 g of nickel nitrate, and 2 g of ethylenediaminetetraacetic acid were dissolved in a beaker containing deionized water to prepare 100 mL of impregnation solution. 67 g of the hydrodesulfurization and denitrification catalyst support was taken, and the above impregnation solution was added to the support by an equal-volume impregnation method. The support was impregnated for 2 h, dried at 120 °C for 4 h, and calcined at 500 °C in air atmosphere for 4 h to obtain hydrodesulfurization and denitrification catalyst A4.

[0096] Example 9

[0097] This embodiment provides a comparative experiment on the performance of the catalyst in the hydrorefining of inferior wax oil.

[0098] The catalysts in Examples 1-8 and Comparative Examples 1-4 were used to conduct hydrorefining experiments on inferior wax oil. The raw materials used in the experiments were wax oil fractions with a dry point of ≤520℃ from a certain refinery, with a sulfur content of ≥3000μg / g and a nitrogen content of ≥1500μg / g.

[0099] The reaction conditions for evaluating the performance of the catalyst in the hydrorefining of inferior wax oil were: reaction temperature 375℃, hydrogen partial pressure 15MPa, hydrogen-to-oil volume ratio 1000:1, and space velocity 1.5h⁻¹. -1 .

[0100] The experimental evaluation results of catalyst properties and catalyst performance in the hydrorefining of inferior wax oil are shown in Table 1.

[0101] Table 1

[0102]

[0103]

[0104] Table 1 shows that, compared to the unmodified catalyst, the hydrodesulfurization and denitrification catalyst modified with manganese, zirconium, and phosphorus composite heteroatoms exhibits higher hydrotreating activity for inferior wax oil. When γ-alumina is modified using different methods, the catalyst exhibits varying hydrorefining activities for inferior wax oil, primarily determined by the mixing level of the composite heteroatoms (manganese, zirconium, phosphorus) with aluminum. When phosphoric acid is not added or the content of the heteroatom precursor oxide is reduced, the desulfurization, denitrification, and alkane yield of the catalyst are significantly decreased. The heteroatom precursor solution prepared by the present invention using composite heteroatoms (manganese, zirconium, and phosphoric acid) is more conducive to the interaction between γ-alumina and the active metals tungsten and nickel, increasing the number of stacked layers and the degree of sulfidation of the active phase, while simultaneously improving the denitrification rate and alkane yield. The desulfurization rate is ≥98%, the denitrification rate is ≥99%, and the alkane yield is increased by at least 6%.

[0105] The hydrodesulfurization and denitrogenation catalyst and its preparation method based on heteroatom-modified γ-alumina of the present invention are applicable to the hydrotreating process of inferior wax oil, and exhibit excellent performance in hydrodesulfurization, denitrogenation, and improving the yield of alkane in inferior wax oil.

[0106] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a hydrodesulfurization and denitrogenation catalyst, characterized in that, Includes the following steps: (1) After mixing manganate and zirconium salt evenly, dissolve them and add phosphoric acid solution to obtain heteroatom precursor solution. The mass ratio of manganate to zirconium salt to phosphoric acid, based on the corresponding oxides, is MnO:ZrO2:P2O5 = 60wt%:(20-30)wt%:(10-20)wt%; (2) After mixing and stirring the γ-alumina with the heteroatom precursor solution, the mixture is dried to obtain the heteroatom-modified γ-alumina precursor; (3) Dissolve and mix citric acid and nitric acid evenly to obtain an acid solution, wherein the amount of citric acid and nitric acid added is 6-9 wt% and 3-5 wt% of the mass of the hydrodesulfurization and denitrification catalyst support, respectively; (4) Mix heteroatom modified γ-alumina precursor with guar powder evenly, add the acid solution prepared in step (3), roll, extrude into strips, dry, and calcine to obtain a hydrodesulfurization and denitrification catalyst support. (5) Prepare an impregnation solution by mixing tungsten salt, nickel salt and ethylenediaminetetraacetic acid, impregnate the hydrodesulfurization and denitrification catalyst support, dry and calcine to obtain the hydrodesulfurization and denitrification catalyst; In step (2), the heteroatom-modified γ-alumina precursor is composed of 11-20 wt% heteroatom precursor oxide and 80-89 wt% γ-alumina.

2. The method for preparing the hydrodesulfurization and denitrogenation catalyst according to claim 1, characterized in that, The manganate is at least one of potassium permanganate, manganese sulfate, and manganese nitrate; the zirconium salt is at least one of zirconium oxychloride, zirconium tetrachloride, and zirconium n-propoxide.

3. The method for preparing the hydrodesulfurization and denitrogenation catalyst according to claim 1, characterized in that, In step (4), the heteroatom-modified γ-alumina precursor accounts for 92-95 wt% of the hydrodesulfurization and denitrification catalyst support, and guar gum powder accounts for 5%-8% of the hydrodesulfurization and denitrification catalyst support.

4. The method for preparing the hydrodesulfurization and denitrogenation catalyst according to claim 1, characterized in that, In step (5), the amount of nickel salt added in the impregnation solution is 2-10 wt% of the mass of the hydrodesulfurization and denitrification catalyst (calculated as NiO), the amount of tungsten salt added is 20-28 wt% of the mass of the hydrodesulfurization and denitrification catalyst (calculated as WO3), and the amount of ethylenediaminetetraacetic acid added is 2-8 wt% of the mass of the hydrodesulfurization and denitrification catalyst.

5. The method for preparing the hydrodesulfurization and denitrogenation catalyst according to claim 1, characterized in that, The specific surface area of ​​the hydrodesulfurization and denitrogenation catalyst is 180-350 m². 2 / g, pore volume 0.4-0.8 cm³ 3 / g, with an average pore size of 6-10 nm and a particle size of 20-40 mesh.

6. The method for preparing the hydrodesulfurization and denitrogenation catalyst according to claim 1, characterized in that, In step (5), the soaking time is 1-2 hours, the drying temperature is 100-120°C and the time is 2-4 hours, and the calcination temperature is 500-600°C and the time is 3-6 hours.

7. A hydrodesulfurization and denitrogenation catalyst obtained by the preparation method according to any one of claims 1-6.

8. The application of a hydrodesulfurization and denitrogenation catalyst obtained by the preparation method according to any one of claims 1-6 in the hydrorefining process of inferior Russian oil and wax.

9. The application according to claim 8, characterized in that, The reaction conditions for the hydrorefining process are as follows: reaction temperature 320-400℃, hydrogen partial pressure 10-17 MPa, hydrogen-to-oil volume ratio 500-1000:1, and liquid hourly space velocity 1.5-2.5 h⁻¹. -1 .

Images