阅读说明：本技术 一种渣油加氢脱金属催化剂的制备方法 (Preparation method of residual oil hydrodemetallization catalyst ) 是由 季洪海 张会成 王少军 凌凤香 沈智奇 于 2019-03-13 设计创作，主要内容包括：本发明公开了一种渣油加氢脱金属催化剂的制备方法,包括：(1)制备棒状氧化铝团簇体；(2)用含加氢活性组分I的浸渍液浸渍棒状氧化铝团簇体,混捏成型、干燥、焙烧,得到载体I；(3)载体I与碳酸氢铵、水混合后密封热处理,处理后物料经干燥、焙烧,得到载体II；(4)用含加氢活性组分II的浸渍液浸渍载体II,经干燥、焙烧,得到载体III；(5)用含加氢活性组分III的浸渍液浸渍载体III,经干燥、焙烧制得加氢脱金属催化剂。该方法制备的加氢脱金属催化剂孔道贯通且孔分布适宜,活性组分呈非均匀分布,该催化剂用于重油加氢脱金属过程,具有较高的加氢脱金属活性和活性稳定性及较强的沥青质转化能力。(The invention discloses a preparation method of a residual oil hydrodemetallization catalyst, which comprises the following steps: (1) preparing a rod-shaped alumina cluster body; (2) dipping the rod-shaped alumina cluster body by dipping liquid containing the hydrogenation active component I, kneading, molding, drying and roasting to obtain a carrier I; (3) mixing the carrier I with ammonium bicarbonate and water, carrying out sealing heat treatment, drying and roasting the treated material to obtain a carrier II; (4) impregnating the carrier II with an impregnating solution containing a hydrogenation active component II, and drying and roasting to obtain a carrier III; (5) and impregnating the carrier III with an impregnating solution containing a hydrogenation active component III, drying and roasting to obtain the hydrogenation demetallization catalyst. The hydrodemetallization catalyst prepared by the method has through pore passages and proper pore distribution, active components are non-uniformly distributed, and the catalyst is used in the heavy oil hydrodemetallization process and has high hydrodemetallization activity, high activity stability and high asphaltene conversion capacity.)

1. A preparation method of a residual oil hydrodemetallization catalyst is characterized by comprising the following steps: (1) preparing a rod-shaped alumina cluster body; (2) dipping the rod-shaped alumina cluster body obtained in the step (1) by using dipping solution containing a hydrogenation active component I, drying to obtain a modified rod-shaped alumina cluster body, kneading the modified rod-shaped alumina cluster body and pseudo-boehmite, molding, drying and roasting to obtain a carrier I; (3) mixing the carrier I with ammonium bicarbonate and water, carrying out sealing heat treatment, drying and roasting the treated material to obtain a carrier II; (4) unsaturated spraying and impregnating the carrier II with an impregnating solution containing a hydrogenation active component II, drying and roasting to obtain a carrier III; (5) and (3) impregnating the carrier III with an impregnating solution containing a hydrogenation active component III, and drying and roasting the carrier to obtain the hydrodemetallization catalyst.

2. The method of claim 1, wherein: the rod-shaped alumina cluster body in the step (1) is prepared by adopting the following method: immersing alumina powder in ammonium bicarbonate water solution for sealing heat treatment, carrying out solid-liquid separation after the heat treatment, and drying solid-phase materials.

3. The method of claim 2, wherein: the mass ratio of the amount of the ammonium bicarbonate aqueous solution to the alumina powder is 5:1-10:1, and the mass concentration of the ammonium bicarbonate aqueous solution is 10-20%; the sealing heat treatment temperature is 120-160 ℃, and the treatment time is 4-8 hours.

4. The method of claim 1, wherein: the rod-shaped alumina cluster body in the step (1) is a cluster body structure formed by disordered and mutually staggered rod-shaped alumina, the outer diameter of the rod-shaped alumina cluster body is 5-20 mu m, rod-shaped alumina accounts for more than 85% of the rod-shaped alumina cluster body, preferably more than 90%, the rest is spherical or ellipsoidal alumina, the length of a single rod-shaped alumina is 1-5 mu m, and the diameter is 100-300 nm.

5. The method of claim 1, wherein: the hydrogenation active component is VIB group metal and/or VIII group metal, the VIB group metal is selected from one or two of Mo and W, and the VIII group metal is selected from one or two of Co and Ni; based on the weight of the hydrodemetallization catalyst, the total content of the hydrogenation active components is 2.3-28.0 percent calculated by metal oxides, and the content of the VIII group metal is 0.3-8.0 percent calculated by metal oxides.

6. The method of claim 1, wherein: the impregnation liquid containing the hydrogenation active metal component I in the step (2) is a solution containing VIB group and/or VIII group metals, wherein the VIB group metals are selected from one or more of W, Mo, the VIII group metals are selected from one or more of Co and Ni, the content of the VIB group metals is 1.5-3.0g/100mL calculated by metal oxides, the content of the VIII group metals is 0.2-0.6g/100mL calculated by metal oxides, and the using amount of the solution is the saturated water absorption amount of the rodlike alumina cluster body.

7. The method of claim 1, wherein: the mass ratio of the modified rodlike alumina cluster body to the pseudo-boehmite in the step (2) is 1:5-1: 1.

8. The method of claim 1, wherein: the mass ratio of the ammonium bicarbonate to the carrier I in the step (3) is 1:1-2.5:1, the mass ratio of the water to the carrier I is 5:1-8:1, the sealing heat treatment temperature is 120-.

9. The method of claim 1, wherein: the impregnation liquid containing the hydrogenation active component II in the step (4) is a solution containing VIB group and/or VIII group metals, wherein the VIB group metals are selected from one or more of W, Mo, the VIII group metals are selected from one or more of Co and Ni, the content of the VIB group metals is 0.5-1.5g/100mL calculated by metal oxides, the content of the VIII group metals is 0.3-0.7g/100mL calculated by metal oxides, and the using amount of the solution is 5% -10% of the saturated water absorption amount of the carrier II in the step (3).

10. The method of claim 1, wherein: the impregnation liquid containing the hydrogenation active component III in the step (5) is a solution containing VIB group and/or VIII group metals, wherein the VIB group metals are selected from one or more of W, Mo, the VIII group metals are selected from one or more of Co and Ni, the content of the VIB group metals is 8-15g/100mL calculated by metal oxides, the content of the VIII group metals is 2.5-4.0g/100mL calculated by metal oxides, and equal-volume impregnation or supersaturated impregnation is adopted during impregnation.

Technical Field

The invention relates to the field of catalyst preparation, in particular to a preparation method of a residual oil hydrodemetallization catalyst.

Background

With the deterioration and heaviness of crude oil, the efficient conversion of heavy oil and the improvement of the yield of light oil products become an important trend in the development of oil refining technology. The residue fixed bed hydrogenation technology is an effective means for realizing the high-efficiency conversion of heavy oil. By adopting the technical route, the impurities such as metal, sulfur, nitrogen, carbon residue and the like in the residual oil can be effectively removed, high-quality feed is provided for catalytic cracking, and the strict environmental protection regulation requirements are met while the yield of light oil products is increased. During the processing of heavy oil, the metal compounds therein are decomposed, and the metal impurities are deposited on the inner and outer surfaces of the catalyst to block the pore channels, even cause the catalyst to be poisoned and deactivated, so that the metal impurities contained therein must be removed firstly during the catalytic cracking of heavy oil. The hydrodemetallization catalyst mainly removes metal impurities including nickel and vanadium in raw oil, so as to protect downstream catalysts from losing activity due to deposition of a large amount of metals.

At present, most of the industrialized Hydrodemetallization (HDM) catalysts are Ni-Mo/Al₂O₃Catalyst of which Al₂O₃The pore structure of the support can significantly affect its catalytic activity as well as its stability. The results of previous studies show that: suitable Al₂O₃The pore size distribution of the carrier can provide a proper diffusion rate of metal compounds, the existence of a certain proportion of super-large pores in the alumina carrier can promote the diffusion and deposition of macromolecular asphaltene molecules, reduce the blockage of coke deposition to orifices, and even under the condition of serious nickel and vanadium deposition, the large pores can also allow the macromolecules to pass through, thereby improving the stability of the catalyst.

CN101890372A discloses an alumina carrier and a preparation method thereof. The alumina carrier is aluminum hydroxide gel prepared by a fused salt super-solubilization micelle method as a raw material, and the gel contains a surfactant and hydrocarbon components, so that after molding and roasting, nano alumina particles formed by dehydrating polymerized aluminum hydroxide still have a rod-like basic structure and are randomly stacked into a frame structure. The process for preparing the macroporous alumina carrier by the technology is complex.

CN106268969A discloses a catalyst carrier, a preparation method thereof and a demetallization catalyst thereof. The catalyst carrier is formed by stacking a plurality of nano rod-shaped alumina monomers, the catalyst carrier is provided with open pore channels, the length of each nano rod-shaped alumina monomer is 100-500nm, and the diameter of each nano rod-shaped alumina monomer is 10-50 nm. The catalyst carrier is formed by stacking a plurality of nano-rod-shaped alumina monomers, the formed pore channel is large, and the catalyst carrier is favorable for the diffusion of macromolecules such as colloid, asphaltene and the like, but also has the defect of complex preparation process.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a preparation method of a residual oil hydrodemetallization catalyst. The hydrodemetallization catalyst prepared by the method has through pore passages and proper pore distribution, active components are non-uniformly distributed, and the catalyst is used in the heavy oil hydrodemetallization process and has high hydrodemetallization activity, high activity stability and high asphaltene conversion capacity.

The preparation method of the residual oil hydrodemetallization catalyst comprises the following steps:

(1) preparing a rod-shaped alumina cluster body;

(2) dipping the rod-shaped alumina cluster body obtained in the step (1) by using dipping solution containing a hydrogenation active component I, drying to obtain a modified rod-shaped alumina cluster body, kneading the modified rod-shaped alumina cluster body and pseudo-boehmite, molding, drying and roasting to obtain a carrier I;

(3) mixing the carrier I with ammonium bicarbonate and water, carrying out sealing heat treatment, drying and roasting the treated material to obtain a carrier II;

(4) unsaturated spraying and impregnating the carrier II with an impregnating solution containing a hydrogenation active component II, drying and roasting to obtain a carrier III;

(5) and (3) impregnating the carrier III with an impregnating solution containing a hydrogenation active component III, and drying and roasting the carrier to obtain the hydrodemetallization catalyst.

In the method of the invention, the rod-like alumina cluster body in the step (1) is prepared by the following method: immersing alumina powder in ammonium bicarbonate water solution for sealing heat treatment, carrying out solid-liquid separation after the heat treatment, and drying solid-phase materials. The alumina powder is gamma-alumina powder prepared according to the prior art or sold on the market. The preparation method is generally a method for roasting pseudo-boehmite, wherein the roasting temperature is 450-600 ℃, the roasting time is 4-8 hours, and the pseudo-boehmite can be prepared by a precipitation method, an aluminum alkoxide hydrolysis method, an inorganic salt sol-gel method, a hydrothermal method, a vapor deposition method and the like. The mass ratio of the amount of the ammonium bicarbonate aqueous solution to the alumina powder is 5:1-10:1, and the mass concentration of the ammonium bicarbonate aqueous solution is 10% -20%. The sealing heat treatment temperature is 120-160 ℃, and the treatment time is 4-8 hours. The solid-liquid separation can adopt modes of filtration, centrifugation and the like, and the solid-liquid separation process generally comprises a washing process.

In the method, the rod-shaped alumina cluster body in the step (1) is a cluster body structure formed by disordered and staggered rod-shaped alumina, the outer diameter of the rod-shaped alumina cluster body is 5-20 mu m, wherein the rod-shaped alumina accounts for more than 85% of the rod-shaped alumina cluster body, preferably more than 90%, the rest is spherical or ellipsoidal alumina, the length of a single rod-shaped alumina is 1-5 mu m, and the diameter is 100-300 nm.

In the method of the present invention, the hydrogenation active component may be an active metal component adopted in a conventional residue hydrotreating catalyst, and is generally a group VIB metal and/or a group VIII metal, the group VIB metal is generally selected from one or two of Mo and W, and the group VIII metal is generally selected from one or two of Co and Ni. Based on the weight of the hydrodemetallization catalyst, the total content of the hydrogenation active components is 2.3-28.0% calculated by metal oxides, preferably the content of VIB group metals is 2.5-20.0% calculated by metal oxides, and the content of VIII group metals is 0.3-8.0% calculated by metal oxides. The hydrogenation active component I, the hydrogenation active component II and the hydrogenation active component III can be the same or different. The hydrogenation active component I is preferably Mo and Ni, the hydrogenation active component II is preferably Mo and Ni, and the hydrogenation active component III is preferably Mo and Ni.

In the method, the impregnation liquid containing the hydrogenation active metal component I in the step (2) is a solution containing VIB group and/or VIII group metals, wherein the VIB group metal is selected from one or more of W, Mo, the VIII group metal is selected from one or more of Co and Ni, the content of the VIB group metal is 1.5-3.0g/100mL calculated by metal oxides, the content of the VIII group metal is 0.2-0.6g/100mL calculated by metal oxides, and the using amount of the solution is the saturated water absorption amount of the rodlike alumina cluster body.

In the method of the present invention, the pseudoboehmite described in the step (2) may be a pseudoboehmite prepared by any method, for example, prepared by a precipitation method, an aluminum alkoxide hydrolysis method, an inorganic salt sol-gel method, a hydrothermal method, a vapor deposition method, and the like.

In the method, the mass ratio of the modified rodlike alumina cluster body in the step (2) to the pseudo-boehmite is 1:5-1: 1.

In the method of the invention, the kneading molding in the step (2) is carried out by adopting the conventional method in the field, and in the molding process, the conventional molding auxiliary agent, such as one or more of peptizer, extrusion assistant and the like, can be added according to the requirement. The peptizing agent is one or more of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, oxalic acid and the like; the extrusion aid is sesbania powder.

In the method of the invention, the drying condition in the step (2) is drying at 80-160 ℃ for 6-10 hours, and the roasting is roasting at 450-750 ℃ for 4-8 hours.

In the method, the mass ratio of the ammonium bicarbonate to the carrier I in the step (3) is 1:1-2.5:1, the mass ratio of the water to the carrier I is 5:1-8:1, the sealing heat treatment temperature is 120-160 ℃, and the treatment time is 4-8 hours. The drying temperature is 80-160 ℃, the drying time is 6-10 hours, and the roasting is carried out for 4-8 hours at the temperature of 450-750 ℃.

In the method, the impregnation liquid containing the hydrogenation active component II in the step (4) is a solution containing VIB group and/or VIII group metals, wherein the VIB group metals are selected from one or more of W, Mo, the VIII group metals are selected from one or more of Co and Ni, the content of the VIB group metals is 0.5-1.5g/100mL calculated by metal oxides, the content of the VIII group metals is 0.3-0.7g/100mL calculated by metal oxides, and the using amount of the solution is 5% -10% of the saturated water absorption amount of the carrier II in the step (3). The drying temperature is 80-160 ℃, the drying time is 6-10 hours, and the roasting is 4-8 hours at the temperature of 450-550 ℃.

In the method, the impregnation liquid containing the hydrogenation active component III in the step (5) is a solution containing VIB group and/or VIII group metals, wherein the VIB group metal is selected from one or more of W, Mo, the VIII group metal is selected from one or more of Co and Ni, the content of the VIB group metal is 8-15g/100mL calculated by metal oxides, the content of the VIII group metal is 2.5-4.0g/100mL calculated by metal oxides, and equal-volume impregnation or supersaturated impregnation can be adopted during impregnation. The drying temperature is 80-160 ℃, the drying time is 6-10 hours, and the roasting is 4-8 hours at the temperature of 450-550 ℃.

Compared with the prior art, the invention has the following advantages:

(1) the alumina carrier for the hydrodemetallization catalyst contains micron-sized rod-shaped alumina clusters, the rod-shaped alumina clusters are integrally dispersed in the carrier, rod-shaped aluminas in the rod-shaped alumina clusters are staggered, the pore structure of the alumina carrier is effectively regulated and controlled, the alumina carrier is in a double-peak pore shape, namely the pore diameter is concentrated in 10-30nm and 180-plus-500 nm, particularly the proportion of 180-plus-500 nm is obviously increased, the pore channels are communicated with each other, the mass transfer and diffusion of macromolecular reactants are facilitated, and the metal capacity is high, so that the catalyst has high activity, good stability and the operation period of the device can be prolonged.

(2) The rodlike alumina cluster body is pre-impregnated with partial active metal components, and the active metal components are loaded in the alumina carrier along with the rodlike alumina cluster body when the carrier is formed, so that the content of active metals at macropores of the final hydrodemetallization catalyst is increased, the utilization rate of the macropores of the catalyst is improved, and the hydrodemetallization activity and the anti-metal deposition capacity of the catalyst are obviously improved.

(3) When the alumina carrier is subjected to sealing heat treatment in an ammonium bicarbonate aqueous solution, the alumina carrier crystal grains grow secondarily in a closed, hydrothermal and alkaline atmosphere, rod-shaped alumina with the diameter of about 100-300nm and the size of about 1-12 mu m is formed on the surface of the alumina carrier, and the rod-shaped alumina is crossed to form loose open pore channels, so that the phenomenon that metal elements are deposited on the outer surface of the catalyst to block the pore channels of the catalyst can be effectively prevented, and the catalyst has excellent permeability.

(4) When the carrier of the alumina with the rod-shaped structure grows on the surface, the unsaturated spraying and dipping of part of the active metal components are carried out, so that the content of the active metal components on the surface of the catalyst is increased, and during hydrogenation reaction, macromolecular reactants in the raw oil can effectively transfer mass and diffuse in open pores formed by the rod-shaped structure on the surface, and meanwhile, as the content of the active metal in the rod-shaped structure on the surface of the catalyst is higher, the catalytic activity on the surface of the catalyst is enhanced, and the asphaltene conversion capability is improved.

Drawings

FIG. 1 shows a rod-like alumina cluster A₁Scanning electron micrograph (c).

FIG. 2 shows a rod-like alumina cluster A₂Scanning electron micrograph (c).

FIG. 3 is a scanning electron micrograph of the support II of example 1.

Detailed Description

The following examples are provided to further illustrate the technical solutions of the present invention, but the present invention is not limited to the following examples. In the present invention, wt% is a mass fraction.

Application N₂Physical adsorption-desorption characterization of the pore structures of the catalysts in the examples and the comparative examples, the specific operations are as follows: adopting ASAP-2420 type N₂And the physical adsorption-desorption instrument is used for characterizing the pore structure of the sample. A small amount of samples are taken to be treated for 3 to 4 hours in vacuum at the temperature of 300 ℃, and finally, the product is placed under the condition of liquid nitrogen low temperature (-200 ℃) to be subjected to nitrogen absorption-desorption test. Wherein the specific surface area is obtained according to a BET equation, and the distribution rate of the pore volume and the pore diameter below 50nm is obtained according to a BJH model.

Mercury pressing method: the mercury porosimeter is used for representing the pore diameter distribution of the catalysts in the examples and the comparative examples, and the specific operation is as follows: and characterizing the distribution of sample holes by using an American microphone AutoPore9500 full-automatic mercury porosimeter. The sample is dried, weighed, placed in an expansion gauge, degassed for 30 minutes under vacuum conditions maintained for the instrument, and filled with mercury. The dilatometer was then placed in the autoclave and vented. And then carrying out a voltage boosting and reducing test. The mercury contact angle is 130 degrees, and the mercury interfacial tension is 0.485N.cm^-1The distribution ratio of pore diameter of 100nm or more is measured by mercury intrusion method.

A scanning electron microscope is used for representing the microstructure of the catalyst, and the specific operation is as follows: and a JSM-7500F scanning electron microscope is adopted to represent the microstructure of the carrier, the accelerating voltage is 5KV, the accelerating current is 20 muA, and the working distance is 8 mm. The alumina powder adopted in the embodiment and the comparative example is prepared by a method of aluminum sulfate and sodium metaaluminate.

Preparation of rod-like alumina cluster:

weighing 200 g of alumina powder, placing the alumina powder into 1200 g of ammonium bicarbonate aqueous solution with the mass concentration of 17.5wt%, sealing the alumina powder in a closed high-pressure kettle, carrying out heat treatment at 130 ℃ for 7 hours, filtering and washing the alumina powder, and drying the alumina powder at 110 ℃ for 6 hours to obtain a rod-shaped alumina cluster A₁，A₁The scanning electron micrograph of (a) is shown in FIG. 1.

Weighing 200 g of alumina powder, placing the alumina powder into 1600 g of ammonium bicarbonate aqueous solution with the mass concentration of 13.5wt%, sealing the alumina powder in a closed high-pressure kettle, carrying out heat treatment for 5 hours at 140 ℃, filtering and washing the alumina powder, and drying the alumina powder for 6 hours at 110 ℃ to prepare a rod-shaped alumina cluster A₂，A₂The scanning electron micrograph of (a) is shown in FIG. 2.