CN113976136B

CN113976136B - Preparation method of hydrodemetallization catalyst

Info

Publication number: CN113976136B
Application number: CN202110607011.6A
Authority: CN
Inventors: 郭士刚; 季洪海; 凌凤香; 王少军; 谷明镝
Original assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2020-07-27
Filing date: 2021-06-01
Publication date: 2023-10-10
Anticipated expiration: 2041-06-01
Also published as: CN113976136A

Abstract

The invention discloses a preparation method of a hydrodemetallization catalyst. The method comprises the following steps: (1) Crushing a vanadium-poisoned molybdenum-nickel heavy oil hydrogenation catalyst, and roasting to obtain a material A; (2) Mixing the material A, ammonium bicarbonate and water, transferring the mixed material into a pressure-resistant container for hydrothermal treatment, carrying out solid-liquid separation on the material subjected to the hydrothermal treatment, drying the solid material to obtain a material B, standing the separated liquid phase for a period of time, carrying out filtering treatment, and concentrating filtrate to obtain a solution C; (3) And (3) uniformly mixing the material B and pseudo-boehmite, then adding the solution C, uniformly mixing, adding a peptizing agent into the mixed material, kneading and molding, drying and roasting the molded product to obtain a carrier, and loading active components into the hydrodemetallization catalyst. The method can well remove vanadium in the waste catalyst, and the regenerated catalyst with higher pore volume and specific surface is prepared by utilizing each component of the waste catalyst, so that the production cost is reduced, and the environmental pollution is reduced.

Description

Preparation method of hydrodemetallization catalyst

Technical Field

The invention belongs to the field of catalyst preparation, and particularly relates to a preparation method of a hydrodemetallization catalyst.

Background

With the increase of poor quality and heavy quality of crude oil, efficient conversion of heavy oil and improvement of the yield of light oil products have become an important trend in the development of oil refining technology. The fixed bed hydrogenation technology of residual oil is an effective means for realizing the high-efficiency conversion of heavy oil. By adopting the technical route, impurities such as metal, sulfur, nitrogen, carbon residue and the like in residual oil can be effectively removed, high-quality feed is provided for catalytic cracking, and the stricter environmental protection regulation requirements are met while the light oil product is increased. During heavy oil processing, metal compounds therein are decomposed, and metal impurities are deposited on the inner and outer surfaces of the catalyst to block the pore channels, even causing poisoning and deactivation of the catalyst.

In the using process, the catalyst becomes waste due to losing the original activity of the catalyst, and the waste catalyst rich in metal is abandoned, so that resources are wasted and the environment is polluted. Recently, environmental regulations are increasingly stringent for the disposal of spent catalysts. There are several methods of disposal of spent catalyst, such as landfill treatment, metal recovery, regeneration or reuse, using it as a raw material to produce other useful products to solve the spent catalyst problem.

CN102441440a discloses a method for preparing a hydrotreating catalyst from a spent catalyst. Grinding a waste hydrotreating catalyst, adding raw materials such as alumina, a binder, an acid solution or an alkaline solution and the like into the ground powder, kneading, forming, drying and roasting a formed sample to obtain a new hydrotreating catalyst. In the method, the spent catalyst is utilized to prepare a new hydrotreating catalyst, but the pore volume of the catalyst needs to be further improved.

CN106669847B discloses a method for preparing alumina carrier, which comprises the following steps: (1) Extracting, roasting and screening the deactivated hydrodemetallization catalyst; (2) Carrying out saturated impregnation treatment on the catalyst sieved in the step (1) by adopting an organic acid solution, filtering and drying after impregnation; (3) And (3) carrying out saturated impregnation treatment on the deactivated hydrodemetallization catalyst dried in the step (2) by adopting alkali solution, and then filtering, drying and roasting. (4) And (3) carrying out saturated impregnation treatment on the deactivated hydrodemetallization catalyst baked in the step (3) by adopting alkali solution, and then filtering, drying and baking to obtain the demetallization catalyst carrier. The preparation process of the method is complex, and in addition, the specific surface area and pore volume of the alumina carrier need to be further improved.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a preparation method of a hydrodemetallization catalyst. The method can well remove vanadium in the waste catalyst, and the regenerated catalyst with higher pore volume and specific surface is prepared by utilizing each component of the waste catalyst, so that the production cost is reduced, and the environmental pollution is reduced.

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

(1) Crushing a vanadium-poisoned molybdenum-nickel heavy oil hydrogenation catalyst to a certain granularity, and roasting to obtain a material A;

(2) Mixing the material A, ammonium bicarbonate and water, transferring the mixed material into a pressure-resistant container for hydrothermal treatment, carrying out solid-liquid separation on the material subjected to the hydrothermal treatment, drying the solid material to obtain a material B, standing the separated liquid phase for a period of time, carrying out filtering treatment, and concentrating filtrate to obtain a solution C;

(3) Uniformly mixing the material B and pseudo-boehmite, then adding the solution C, uniformly mixing, adding a peptizing agent into the mixed material, kneading and molding, and drying and roasting the molded product to obtain a carrier;

(4) Impregnating the carrier in the step (3) with hydrogenation active component impregnating solution, and drying and roasting the material to obtain the hydrodemetallization catalyst.

In the method of the invention, the vanadium-poisoned molybdenum-nickel heavy oil hydrogenation catalyst in the step (1) generally refers to a catalyst which is deactivated or does not meet the reaction requirement due to the deposition of heavy metals such as vanadium, iron and the like and carbon deposit in the hydrotreating process of hydrodemetallization, hydrodesulphurization, denitrification and the like of wax oil and residual oil; the vanadium content is 5-30% by weight of the catalyst, the active component molybdenum of the catalyst is 3-20% by weight of the oxide, and the nickel is 2-15% by weight of the oxide.

In the method of the invention, the vanadium-poisoned molybdenum-nickel heavy oil in the step (1) is hydrogenated and crushed to a mesh number of more than 80 mesh, preferably more than 200 mesh, and more preferably 400-800 mesh. The roasting temperature is 700-950 ℃ and the roasting time is 6-12 hours.

In the method, the mass ratio of the ammonium bicarbonate to the material A in the step (2) is 4:1-8:1, and the mass ratio of the water to the sum of the ammonium bicarbonate and the material A is 1.5:1-3:1, preferably 2:1-3:1; the material A, ammonium bicarbonate and water can be added in any order for mixing, the mixing temperature is generally room temperature, and the temperature can be properly increased for further facilitating the dissolution of ammonium bicarbonate in water, but the operation is not necessary.

In the method of the invention, the conditions of the hydrothermal treatment in the step (2) are as follows: the temperature is 120-160 ℃, and the treatment time is 4-8 hours. The pressure-resistant container is generally a high-pressure reaction kettle.

In the method of the invention, the solid-liquid separation mode in the step (2) can adopt modes such as filtration, centrifugation and the like.

In the process of the present invention, the standing in the step (2) may be carried out at room temperature, generally at not less than 0℃and not more than 30℃and preferably at a standing temperature of 1 to 10℃for a time period of usually 72 to 168 hours, as long as the weight of the solution-precipitated crystals does not increase.

In the method of the invention, the concentration in the step (2) is generally evaporation concentration, and the concentration is concentrated until the concentration of molybdenum in the solution is 0.5-5g/100mL calculated by oxide.

In the method, the drying temperature in the step (2) is 60-160 ℃ and the drying time is 4-8 hours.

In the method, the mass ratio of the material B to the pseudo-boehmite in the step (3) is 1:10-3:10.

In the method, the mass ratio of the solution C to the pseudo-boehmite in the step (3) is 3:10-5:10.

In the method, the kneading molding in the step (3) is performed by a conventional method in the field, and an extrusion aid can be added according to requirements in the molding process, wherein the extrusion aid is sesbania powder. The peptizing agent is one or more of hydrochloric acid, nitric acid, sulfuric acid, acetic acid or oxalic acid, and the concentration of the peptizing agent is 0.1-3 wt%.

In the method, the drying temperature in the step (3) is 100-160 ℃ and the drying time is 6-10 hours; the roasting temperature is 600-750 ℃ and the roasting time is 4-6 hours; the calcination is carried out in an oxygen-containing atmosphere, preferably in an air atmosphere.

In the method, the impregnating solution of the hydrogenation active metal component 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 5-15g/100mL in terms of metal oxide, the content of the VIII group metals is 2.0-4.5g/100mL in terms of metal oxide, and the impregnation can be performed by equal-volume impregnation or supersaturation. The drying temperature is 80-160 ℃, the drying time is 6-10 hours, the roasting temperature is 450-550 ℃, and the roasting time is 4-8 hours.

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

(1) The invention takes the vanadium-poisoned waste catalyst as the raw material, effectively removes the metal vanadium and molybdenum deposited on the surface of the waste catalyst and in the pore canal through simple hydrothermal treatment, and greatly improves the specific surface area of the treated waste catalyst.

(2) When the waste catalyst is hydrothermally treated in ammonium bicarbonate solution, alumina is crystallized under the airtight and weakly alkaline hydrothermal conditions to grow crystal grains, and when the waste catalyst is kneaded with pseudo-boehmite for forming, the pore volume and the macropore content of the final alumina carrier are improved due to the existence of large crystal grains.

(3) After the waste catalyst is subjected to hydrothermal treatment, metallic elements molybdenum and vanadium exist in filtrate, the filtrate is subjected to standing and filtering to effectively remove vanadium, and the rest metallic molybdenum is added during kneading and forming of an alumina carrier, so that active metallic molybdenum in the waste catalyst is reused.

(4) The method is simple, the partially activated waste catalyst is used for replacing the alumina raw material, waste is changed into valuable, the production cost is reduced, and the environmental pollution is reduced.

Detailed Description

The technical scheme and effect of the present invention will be further described with reference to the following examples, but is not limited thereto. In the present invention, wt% represents mass fraction.

BET method: application N ₂ Physical adsorption-desorption characterization examples and comparative examples the pore structure of the carriers were as follows: using ASAP-2420 type N ₂ The physical adsorption-desorption instrument characterizes the structure of the sample hole. And (3) taking a small amount of sample, vacuum-treating for 3-4 hours at 300 ℃, and finally placing the product under the condition of low temperature (-200 ℃) of liquid nitrogen for nitrogen adsorption-desorption test. Wherein the specific surface area is obtained according to BET equation, and the distribution ratio of pore volume and pore diameter below 30nm is obtained according to BJH model.

Mercury pressing method: the pore diameter distribution of the carriers of the examples and comparative examples was characterized by mercury intrusion, and the specific procedure was as follows: the sample well distribution was characterized using a fully automatic mercury porosimeter of the united states of america, autoPore 9500. The sample is weighed into an dilatometer after drying and is degassed for 30 minutes under vacuum conditions given by the maintenance instrument, and filled with mercury. The dilatometer was then placed in an autoclave and vented. Then, the step-up and step-down tests were performed. 130 degrees of mercury contact angle and 0.4815 N.cm of mercury interfacial tension ^-1 The distribution ratio of the pore diameter of 100nm or more is measured by mercury porosimetry.

XRF characterization: analyzing sample components by using a Japan-based ZSX100 e-type X-ray fluorescence spectrometer, and performing light path atmosphere on a target Rh: vacuum conditions.

And determining the nitrogen content in the oil product by adopting an NB/SH/T0704-2010 standard method.

And (3) measuring the sulfur content in the oil product by adopting an SH/T0689-2000 standard method.

And (3) determining the carbon residue content in the oil product by adopting an SH/T0266-92 standard method.

And determining the Ni and V contents in the oil product by using a GB/T34099-2017 standard method.

The V+Ni removal rate is calculated according to the following formula:

percent v+ni removal = (feedstock metal v+ni content-product metal v+ni content)/feedstock metal v+ni content x 100%

The spent catalyst employed in the examples was the spent catalyst (MoO-containing) of a fixed bed residuum hydrogenation industrial plant ₃ ：6.3wt%，NiO：10.2 wt %，V ₂ O ₅ ：23.4 wt %，Fe ₂ O ₃ ：0.4 wt %，Al ₂ O ₃ :47.3 wt%, C:11.3 wt%) oil on the surface of the catalyst was removed by extraction and dried.

Example 1

(1) Taking waste catalyst crushed to more than 500 meshes, and roasting at 850 ℃ for 8 hours;

(2) Weighing 100 g of the waste catalyst and 550 g of ammonium bicarbonate, adding 1600 g of distilled water, stirring for 20 minutes, and transferring the mixed material into an autoclave for sealing heat treatment under the following heat treatment conditions: heating at 145 ℃ for 5.5 hours, filtering the material after the hydrothermal treatment, drying a filter cake at 110 ℃ for 6 hours, standing the filtrate at 5 ℃ for 144 hours to separate out crystals, then filtering, determining that the separated crystals are ammonium vanadate, concentrating the filtrate into a molybdenum-containing solution, wherein the concentration of the solution is 200mL, and determining that the molybdenum content is 2.9g/100mL calculated by oxide;

(3) Weighing 100 g of pseudo-boehmite (manufactured by Shandong aluminum industry Co., ltd.), drying a filter cake 15g in the step (2), mixing 1.5 g of sesbania powder uniformly, adding 35mL of concentrated solution obtained after standing and filtering in the step (2), continuously mixing, adding a proper amount of aqueous solution dissolved with 3g of acetic acid, kneading, extruding strips, forming, drying the formed product at 140 ℃ for 6 hours, and roasting at 700 ℃ in air for 5 hours to obtain a carrier;

(4) 30 g of the alumina carrier is weighed and placed in a spray-dipping roller pot, the alumina carrier is sprayed and dipped in a Mo-Ni-P solution with the concentration of molybdenum oxide of 6.3g/100mL and the concentration of nickel oxide of 2.3g/100mL in a saturated dipping mode, the dipped catalyst is dried at 120 ℃, and then baked for 5 hours at 450 ℃ to prepare the catalyst Cat-1, wherein the catalyst property is shown in table 1.

Example 2

The procedure of example 1 was followed except that the spent catalyst was calcined at 950℃and the ammonium bicarbonate addition was 650 g, the hydrothermal treatment at 135℃and the treatment time was 4.5 hours, the dry cake addition was 20 g and the concentrated solution addition was 40mL, to give catalyst Cat-2, the catalyst properties of which are shown in Table 1.

Example 3

The procedure of example 1 was followed except that the spent catalyst was calcined at 750℃and the ammonium bicarbonate was added in an amount of 450 g, the hydrothermal treatment was conducted at 150℃and the treatment time was 6.5 hours, the dried cake was added in an amount of 10 g and the concentrated solution was added in an amount of 30mL to obtain catalyst Cat-3, and the catalyst properties were shown in Table 1.

Example 4

The procedure of example 1 was followed except that the spent catalyst was calcined at 750℃and the ammonium bicarbonate was added in an amount of 450 g, the hydrothermal treatment was conducted at 150℃and the treatment time was 6.5 hours, the dried cake was added in an amount of 10 g and the concentrated solution was added in an amount of 45mL to obtain catalyst Cat-4, and the catalyst properties were shown in Table 1.

Comparative example 1

As in example 1, except that the addition amount of ammonium bicarbonate was 200 g, ammonium molybdate crystals were not precipitated in the filtrate, and the concentration of molybdenum in the concentrated solution was 0.31g/100mL as oxide, comparative catalyst Cat-5 was prepared, and the catalyst properties are shown in Table 1.

Comparative example 2

As in example 1, except that ammonium bicarbonate was changed to the same amount of ammonium carbonate, ammonium molybdate crystals were precipitated in the filtrate, and the concentration of molybdenum in the concentrated solution was 2.3g/100mL as oxide, comparative catalyst Cat-6 was prepared, and the catalyst properties are shown in Table 1.

Comparative example 3

Comparative catalyst Cat-7 was prepared as in example 1 except that no filtrate was added during the molding of alumina, and the catalyst properties are shown in Table 1.

Comparative example 4

As in example 1, but in this example, the catalyst was Cat-8, and the catalyst properties are shown in Table 1, in comparison with the commercially available fresh catalyst.

TABLE 1 catalyst Properties

Catalytic performance evaluation:

the hydrodemetallization catalyst (Cat-1-Cat-8) prepared by the method is subjected to catalytic performance evaluation, and the evaluation method is as follows:

the vacuum residuum listed in table 2 was used as a raw material, and evaluated on a small fixed bed residuum hydrogenation reactor, the catalyst was stripes 2-3 mm long, and the reaction conditions were as follows: the reaction temperature was 387 ℃, the hydrogen partial pressure was 15.7MPa, and the liquid hourly space velocity was 1.0 hour ^-1 The hydrogen oil volume ratio is 758, the content of each impurity in the generated oil is measured after the reaction is carried out for 1500 hours, the impurity removal rate is calculated, and the evaluation result is shown in table 3.

TABLE 2 oil Properties of raw materials

TABLE 3 comparison of hydrogenation performance of catalysts

Claims

1. The preparation method of the hydrodemetallization catalyst is characterized by comprising the following steps: (1) Crushing a vanadium-poisoned molybdenum-nickel heavy oil hydrogenation catalyst to a certain granularity, and roasting to obtain a material A; (2) Mixing the material A, ammonium bicarbonate and water, transferring the mixed material into a pressure-resistant container for hydrothermal treatment, carrying out solid-liquid separation on the material subjected to the hydrothermal treatment, drying the solid material to obtain a material B, standing the separated liquid phase for a period of time, carrying out filtering treatment, and concentrating filtrate to obtain a solution C; (3) Uniformly mixing the material B and pseudo-boehmite, then adding the solution C, uniformly mixing, adding a peptizing agent into the mixed material, kneading and molding, and drying and roasting the molded product to obtain a carrier; (4) Impregnating the carrier in the step (3) with hydrogenation active component impregnating solution, and drying and roasting the material to obtain a hydrodemetallization catalyst; the vanadium-poisoned molybdenum-nickel heavy oil hydrogenation catalyst in the step (1) comprises, by weight of the catalyst, 5% -30% of vanadium, 3% -20% of active component molybdenum of the catalyst, and 2% -15% of nickel; the mass ratio of the ammonium bicarbonate to the material A in the step (2) is 4:1-8:1; the mass ratio of the water to the sum of the ammonium bicarbonate and the material A in the step (2) is 1.5:1-3:1; the conditions of the hydrothermal treatment in the step (2) are as follows: the temperature is 120-160 ℃, and the treatment time is 4-8 hours.

2. The method according to claim 1, characterized in that: and (3) carrying out hydrogenation crushing on the vanadium-poisoned molybdenum-nickel heavy oil in the step (1) until the mesh number is more than 80.

3. The method according to claim 1, characterized in that: the roasting temperature in the step (1) is 700-950 ℃ and the roasting time is 6-12 hours.

4. The method according to claim 1, characterized in that: the standing temperature in the step (2) is not lower than 0 ℃ and not higher than 30 ℃, and the standing time is 72-168 hours.

5. The method according to claim 1, characterized in that: concentrating the solution in the step (2) until the concentration of molybdenum in the solution is 0.5-5g/100mL calculated by oxide.

6. The method according to claim 1, characterized in that: the drying temperature in the step (2) is 60-160 ℃, and the drying time is 4-8 hours.

7. The method according to claim 1, characterized in that: the mass ratio of the material B to the pseudo-boehmite in the step (3) is 1:10-3:10.

8. The method according to claim 1, characterized in that: the mass ratio of the solution C to the pseudo-boehmite in the step (3) is 3:10-5:10.

9. The method according to claim 1, characterized in that: the drying temperature in the step (3) is 100-160 ℃, and the drying time is 6-10 hours; the roasting temperature is 600-750 ℃ and the roasting time is 4-6 hours.

10. The method according to claim 1, characterized in that: the hydrogenation active component impregnating solution 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 5-15g/100mL in terms of metal oxide, and the content of the VIII group metals is 2.0-4.5g/100mL in terms of metal oxide, and the impregnation is performed by equal volume impregnation or supersaturation.