CN114130418B

CN114130418B - Method for regenerating hydrogenation catalyst

Info

Publication number: CN114130418B
Application number: CN202010917663.5A
Authority: CN
Inventors: 关月明; 王永林; 袁胜华; 张�成
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: 2020-09-03
Filing date: 2020-09-03
Publication date: 2023-09-01
Anticipated expiration: 2040-09-03
Also published as: CN114130418A

Abstract

The invention provides a regeneration method of a hydrogenation catalyst. The method comprises the following steps: (1) Mixing the deactivated hydrogenation catalysts A1 and A2, immersing the mixture in a solvent, and carrying out ultrasonic treatment to obtain a catalyst B and a mixed material mixed with black powder; (2) Recovering the catalyst B, and filtering the mixed material mixed with the black powder to obtain powder C; (3) Grinding the catalyst B into powder, and sieving to obtain catalyst powder D; the catalyst powder D is molded, dried and roasted to obtain a regenerated carrier; (4) dissolving the powder C in liquid paraffin and stirring; then soaking the catalyst on a regenerated carrier, cooling, carbonizing, and performing hydrothermal treatment to obtain the regenerated hydrogenation catalyst. The method does not need to additionally supplement active metal components, the regenerated catalyst has good desulfurization performance, the dosage of vulcanizing agent can be reduced, the vulcanizing time can be shortened, and the obtained regenerated hydrogenation catalyst has reasonable pore structure, strength and metal distribution.

Description

Method for regenerating hydrogenation catalyst

Technical Field

The present invention relates to a catalyst regeneration method, and more particularly, to a method for preparing a hydrodesulfurization catalyst by using a spent catalyst regeneration.

Background

The residual oil hydrogenation technology has the characteristics of strong raw material adaptability, simple production operation flow and the like, can provide high-quality raw materials for the downstream catalytic cracking process, and becomes one of the most important heavy oil processing technologies in modern oil refining and petrochemical industry. In particular, in recent years, the hydrotreatment amount of the residuum in China is increasing, and the demand for residuum hydrogenation catalysts is also increasing greatly. In addition, the residual oil has high contents of metal, colloid and asphaltene, so that the operation period of the residual oil hydrogenation device is generally 1-2 years, and the catalyst cannot be regenerated. So that a large amount of residual oil hydrogenation catalyst exists annually, and is treated as solid waste after a small amount of metal is extracted.

The surface of the catalyst is generally coated with a layer of carbon deposit, and the carbon deposit covers the metal active site on the surface of the catalyst, which is an important cause of catalyst deactivation. The common catalyst regeneration process is to perform high-temperature carbon burning and sulfur burning treatment after removing residual oil on the catalyst. The high temperature treatment process can cause the active metal to gather to influence the activity of the catalyst, so that the activity of the regenerated catalyst is far lower than that of the fresh agent. At the same time, the pore structure of the catalyst cannot be restored to the extent of the fresh agent due to the blocking effect of deposited metal and other substances, so that the diffusion resistance of the raw oil on the catalyst is increased. In addition, the strength of the regenerant subjected to high-temperature treatment is greatly reduced, and the regenerant is easy to break in the transportation and reaction processes, so that the pressure drop of the bed layer is influenced.

In addition, the commonly used active components of hydrogenation catalysts are typically nickel and/or cobalt, molybdenum and/or tungsten, and to increase activity and stability, such catalysts typically have to be presulfided prior to use to convert the hydrogenating metal component to sulfide. Therefore, the catalyst regeneration process is accompanied by the oxidation reaction of sulfides while being burned. Partial SO under high temperature oxygen enrichment ₂ Will be converted into SO ₃ . These sulfur-containing substances react with water in the regeneration atmosphere to form sulfurous acid and sulfuric acid, which tend to deteriorate the performance of the regenerated catalyst. In addition, the regenerated catalyst needs to be vulcanized again to convert the oxidized metal into metal sulfide, so that the catalyst has hydrogenation activity. The pure high-temperature oxidation regeneration not only wastes the original sulfur element on the catalyst, but also needs to supplement a part of new sulfur element.

CN1125474C discloses a method for regenerating hydrogenation catalyst, which comprises preheating the deactivated hydrogenation catalyst, heating for 1-7 hours at 300-350 deg.c, heating for 1-7 hours at 400-500 deg.c, heating for 1-10 hours at 550-600 deg.c, and naturally cooling to obtain the regenerated catalyst.

CN1921942a discloses a method for recovering the activity of a spent hydrotreating catalyst, comprising subjecting a spent hydrotreating catalyst with carbon deposition to a char treatment to obtain an intermediate catalyst with a carbon content reduced to 0.5-2.5% by total, contacting the intermediate catalyst with a solution of a chelating agent containing nitrogen and aging, wherein the aging time exceeds 10 hours, and finally drying to obtain a regenerated catalyst, wherein more than 50% of the amount of the introduced chelating agent remains in the dried catalyst.

CN1782030a discloses a hydrogenation catalyst regeneration method, which comprises: 1) Mixing granular alkaline matters with deactivated hydrogenation catalyst in the weight ratio of 5 to 95-50 to 50; 2) Contacting the mixture of particulate alkaline material and deactivated hydrogenation catalyst with an oxygen-containing gas under oxidative regeneration reaction conditions; 3) Separating and regenerating the hydrogenation catalyst.

In summary, the prior art adopts the conventional sulfur and carbon burning method, and the physicochemical property and structure of the regenerated hydrogenation catalyst can not meet the requirements of industrial production. Therefore, it is necessary to develop an effective regeneration method for hydrogenation catalysts.

Disclosure of Invention

In view of the shortcomings of the prior art, the invention aims to provide a method for preparing a hydrodesulfurization catalyst by regenerating a spent catalyst. The method does not need to additionally supplement active metal components, the obtained regenerated catalyst has good desulfurization performance, the dosage of vulcanizing agent can be reduced, the vulcanizing time can be shortened, and the obtained regenerated hydrogenation catalyst has reasonable pore structure, strength and metal distribution.

The invention provides a regeneration method of a hydrogenation catalyst, which comprises the following steps:

(1) Mixing the deactivated hydrogenation catalysts A1 and A2, immersing the mixture in a solvent, and carrying out ultrasonic treatment to obtain a catalyst B and a mixed material mixed with black powder;

(2) Recovering the catalyst B, and filtering the mixed material mixed with the black powder to obtain powder C;

(3) Grinding the catalyst B into powder, and sieving to obtain catalyst powder D; the catalyst powder D is molded, dried and roasted to obtain a regenerated carrier;

(4) Dissolving the powder C in liquid paraffin and stirring; then soaking the catalyst on a regenerated carrier, cooling, carbonizing, and performing hydrothermal treatment to obtain the regenerated hydrogenation catalyst.

Wherein, the deactivated hydrogenation catalyst A1 and A2 are both sulfurated deactivated hydrogenation catalysts. The sulfurized deactivated hydrogenation catalyst is generally preserved in a solvent before the regeneration reaction to avoid contacting with water and air, wherein the solvent can be alcohols, ethers, diesel oil, aviation kerosene and the like.

Preferably, before step (1) is performed, the deactivated hydrogenation catalysts A1 and A2 are first deoiled, and the deoiling process may be performed by conventional methods in the art, such as: and placing the deactivated hydrogenation catalyst in toluene solvent, and performing heating extraction treatment for more than 24 hours.

In the step (1), the deactivated hydrogenation catalyst A1 at least contains active metal molybdenum, and the content of the active metal molybdenum in terms of oxide is 10% -25% based on the weight of the fresh catalyst of the deactivated hydrogenation catalyst A1.

In the step (1), the deactivated hydrogenation catalyst A2 is a bulk hydrofining catalyst, the catalyst at least contains active metals molybdenum and tungsten, and the content of all active metals calculated as oxides is 40% -80% based on the weight of the fresh catalyst from which the deactivated hydrogenation catalyst A2 is derived; wherein, the content of the active metal molybdenum is 10% -30% based on oxide, and the content of the active metal tungsten is 20% -60% based on oxide.

In the step (1), the mass ratio of the deactivated hydrogenation catalyst A1 to the deactivated hydrogenation catalyst A2 is as follows: 9.5:0.5 to 7.5:2.5.

In step (1), the content of deposited metal (deposited metal includes metallic iron and vanadium) on the deactivated hydrogenation catalyst A1 is less than 2.5% by weight of the deactivated hydrogenation catalyst A1 based on the weight of the fresh catalyst from which the metal is derived.

In step (1), the content of deposited metal (deposited metal includes metallic iron and vanadium) on the deactivated hydrogenation catalyst A2 is less than 0.3% by weight of the deactivated hydrogenation catalyst A2 based on the weight of the fresh catalyst from which the metal is derived.

In the step (1), the solvent is one or more of ethanol, isopropanol, polyvinylpyrrolidone, dimethyl sulfoxide and dimethylformamide, or an aqueous solution of one or more substances.

In the step (1), the ultrasonic treatment time is 0.5-3 hours; the working frequency of the ultrasonic wave is 35-40 KHz.

The ultrasonic treatment is preferably intermittent ultrasonic treatment, specifically, first ultrasonic treatment is performed firstly, then first standing is performed, then second ultrasonic treatment is performed, and then second standing is performed.

In the step (3), the particle size of the powder D is preferably smaller than 200 mesh, for example, 300 mesh, 400 mesh, etc.

And (3) adding an extrusion aid in the forming process. The extrusion aid can be one or more of sesbania powder, starch and polyethanol, and the dosage of the extrusion aid accounts for 0.5-6.0 wt% of the mass of the alumina in the material. The molding can be performed according to the need to obtain a conventional shape, such as extruding strips to obtain strips with the shape of four-leaf grass with the length of 2-8 mm.

In the step (3), the drying conditions are as follows: drying for 1-6 hours at 80-135 ℃, wherein the roasting conditions are as follows: roasting for 2-8 hours at 400-850 ℃.

In the step (4), the volume of the liquid paraffin used is the water absorption volume of the regenerated carrier.

In step (4), the cooling conditions are cooling at less than 5 ℃.

In the step (4), the carbonization is carried out in an inert atmosphere at a temperature of 300-450 ℃, for 3-8 hours and under a pressure of 1.0-2.5 MPa. The inert atmosphere is nitrogen and/or a live or inert gas, preferably argon.

In the step (5), the temperature of the hydrothermal treatment is 700-800 ℃, the water vapor is saturated water vapor, the flow rate of the water vapor is 0.1-0.5L/s, and the time is 0.5-2 hours.

The hydrogenation catalyst regeneration method provided by the invention is widely applicable to the regeneration of various hydrogenation catalysts used in the petroleum refining process after deactivation, and produces a new catalyst suitable for the hydrodesulfurization process.

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

(1) The method can simultaneously regenerate two hydrogenation catalysts, and has wide application range.

(2) The invention adopts the two deactivated hydrogenation catalysts A1 and A2 to produce a new catalyst suitable for the hydrodesulfurization process, and the regenerated catalyst has higher hydrodesulfurization activity compared with the fresh hydrogenation catalyst of the deactivated hydrogenation catalyst A1.

(3) The invention adopts specific treatment to realize that most active metal molybdenum is selectively taken out from the deactivated hydrogenation catalyst, and other active metals loaded on the catalyst are not influenced, and metals deposited on the deactivated catalyst can be converted into active metals, so that the active metal loading on the regenerated hydrogenation catalyst is equivalent to that of the original hydrogenation catalyst without additionally introducing new active metal components.

(4) In the method, the paraffin is rapidly cooled and solidified, so that the molybdenum sulfide uniformly dispersed in the paraffin phase is not deposited for enough time, the uniformly dispersed state is maintained, and the high uniform dispersion of the molybdenum sulfide on the surface of the catalyst carrier is realized. And further high-temperature treatment is carried out to decompose and carbonize paraffin, so that a small amount of carbon deposit is formed on the surface of the catalyst, and the effect of pre-carbon deposit is achieved. Meanwhile, the carbon deposition is controlled through hydrothermal treatment, so that two active centers of hydrogenation and pyrolysis are balanced in activity, the performance of the catalyst is improved, and the formation of hot spots is avoided to a certain extent.

(5) The method can take out most of sulfur elements in the deactivated hydrogenation catalyst and keep the sulfur elements in the form of molybdenum sulfide, so that the usage amount of the vulcanizing agent can be reduced in the presulfiding stage, the time of the vulcanizing stage is shortened, and sulfate radical generation during burning in the conventional catalyst regeneration method is avoided to influence the performance of the catalyst.

(6) The method of the invention skillfully utilizes the carbon deposit on the deactivated hydrogenation catalyst, retains the carbon deposit in the ground catalyst powder, forms the catalyst powder, and plays a role in pore-forming in the subsequent decarburization roasting process. The pore structure of the regenerated catalyst obtained by the method can be equivalent to that of the original catalyst, and other pore expanding agents are not required to be introduced in the preparation process.

Detailed Description

The following examples are provided to further illustrate the technical aspects of the present invention, but are not limited thereto.

Example 1

(1) Taking out the deactivated sulfurized residual oil hydrogenating catalyst from the reactor, and sealing with alcohol liquid. The catalyst was immersed in a toluene solution using a fat extractor, heated to a state where toluene was boiled and refluxed for condensation, and maintained for 24 hours, and after completion of extraction, vacuum drying was performed to obtain an inactive catalyst A1 (the active metal molybdenum content was 16% by weight based on the weight of the active catalyst of the inactive hydrogenation catalyst A1, and the total content of deposited metal iron and vanadium contained was 1.33% by weight based on the weight of the active catalyst of the inactive hydrogenation catalyst).

(2) The deactivated sulfurized bulk hydrofining catalyst is sampled from the reactor and sealed with ethanol. The catalyst was immersed in a toluene solution using a fat extractor, heated to a state where toluene was boiled and refluxed for condensation, and maintained for 24 hours, and after extraction, the catalyst was dried under vacuum to obtain an inactive hydrogenation catalyst A2 (the active metal molybdenum content was 24% by oxide, the active metal tungsten content was 33% by oxide, and the total content of all active metals was 70% by oxide based on the weight of the active catalyst of the inactive hydrogenation catalyst A2, and the deposited metal iron and vanadium contained was less than 0.3% by elemental metal content).

(3) 90g of the deactivated catalyst A1 obtained in the step (1) and 10g of the deactivated catalyst A2 obtained in the step (2) are weighed, fully mixed and immersed in 400mL of ethanol aqueous solution, wherein the volume ratio of ethanol to water is 1:1. The beaker containing the aqueous ethanol solution and the deactivated catalyst was placed in an ultrasonic generator at a frequency of 40KHz, sonicated for 15 minutes, allowed to stand for 10 minutes, sonicated for 15 minutes, and allowed to stand. This process was repeated until the sonication time reached 1 hour. At this time, the mixture was black, and the mixture was filtered through a 40-mesh sieve to recover the catalyst B. The sieved mixture was then filtered to give powder C. Powder C was stored under nitrogen.

(4) Drying the catalyst B obtained in the step (3), grinding into powder by using an air flow mill, sieving by using a 200-mesh sieve, and collecting undersize powder D.

(5) Adding a proper amount of sesbania powder, deionized water and dilute nitric acid into the sieved powder D, kneading and extruding the mixture to prepare strips with the shape of four-leaf grass with the length of 2-8 mm. Then drying for 4 hours at 120 ℃, and roasting for 3 hours at 650 ℃ to obtain the regenerated carrier.

(6) Molybdenum sulfide powder C was dissolved in liquid paraffin with a paraffin volume of 334mL. Fully stirring to fully disperse molybdenum sulfide in paraffin, soaking on a regenerated carrier, quickly cooling at 2 ℃ after fully soaking to quickly solidify liquid paraffin to obtain a catalyst precursor, and then loading the catalyst precursor into a reactor. At a pressure of 1.5MPa, nitrogen was introduced into the reactor at a flow rate of 10L/h. The catalyst precursor is subjected to constant temperature pre-carbon deposition treatment for 5 hours at 350 ℃ to obtain the catalyst E.

(7) And carrying out hydrothermal treatment on the catalyst E at the temperature of 700 ℃ and the saturated steam flow rate of 0.25L/s, and keeping the temperature for 0.5 hour to obtain the regenerated catalyst.

Example 2

(3) 80g of the deactivated catalyst A1 obtained in the step (1) and 20g of the deactivated catalyst A2 obtained in the step (2) are weighed, fully mixed and immersed in 400mL of polyvinylpyrrolidone aqueous solution, and the polyvinylpyrrolidone concentration is 0.2g/mL. The beaker containing the ketone and catalyst was placed in an ultrasonic generator at a frequency of 35KHz. Ultrasound was continued for 15 minutes. Standing for 10 min, performing ultrasonic treatment for 15min, and standing. This process was repeated until the sonication time reached 45 minutes. At this time, the mixture was black, and the mixture was filtered through a 40-mesh sieve to recover the catalyst B. The sieved mixture was then filtered to give powder C, which was stored under nitrogen.

(5) Adding a proper amount of sesbania powder, deionized water and dilute nitric acid into the sieved powder D, kneading and extruding the mixture to prepare strips with the shape of four-leaf grass with the length of 2-8 mm. Then drying for 4 hours at 110 ℃, and roasting for 3 hours at 650 ℃ to obtain the regenerated carrier.

(6) Molybdenum sulfide powder C was dissolved in liquid paraffin with a paraffin volume of 334mL. The molybdenum sulfide is thoroughly dispersed in the paraffin wax and then impregnated on the regenerated support. After full impregnation, the liquid paraffin is rapidly cooled at 3 ℃ to be rapidly solidified, and the catalyst precursor is obtained. The catalyst precursor is then charged to the reactor. At a pressure of 1.5MPa, nitrogen was introduced into the reactor at a flow rate of 10L/h. The catalyst precursor is subjected to constant temperature pre-carbon deposition treatment for 5 hours at 400 ℃ to obtain the catalyst E.

(7) And (3) carrying out hydrothermal treatment on the catalyst E, wherein the temperature of the hydrothermal treatment is 750 ℃, the saturated steam flow is 0.25L/s, and the temperature is kept for 1 hour to obtain the regenerated catalyst.

Example 3

(3) 80g of the deactivated catalyst A1 obtained in the step (1) and 20g of the deactivated catalyst A2 obtained in the step (2) are weighed, fully mixed and immersed in 400mL of isopropanol-ethanol solution, and the solution is placed in an ultrasonic generator with the frequency of 40KHz. Ultrasound was continued for 20 minutes. Standing for 10 min, performing ultrasonic treatment for 20 min, and standing. This process was repeated until the sonication time reached 2h. At this time, the mixture was black, and the mixture was filtered through a 40-mesh sieve to recover the catalyst B. The sieved mixture was then filtered to obtain molybdenum sulfide powder C. Powder C was stored under nitrogen.

(7) And (3) carrying out hydrothermal treatment on the catalyst E, wherein the temperature of the hydrothermal treatment is 750 ℃, the saturated steam flow is 0.4L/s, and the temperature is kept for 1.5 hours to obtain the regenerated catalyst.

Example 4

Wherein, the deactivated vulcanized residual oil hydrogenation catalyst A1 used in the examples and the comparative examples related to the invention is a fresh hydrogenation catalyst prepared by the following method:

1450g (pore volume 0.9mL/g, specific surface 295 m) of pseudo-boehmite was weighed ² Per g), adding proper amount of sesbania powder, deionized water and dilute nitric acid, kneading and extruding to obtain the invented product whose length is 2-8 mmIs a clover-shaped strip. Then drying for 4 hours at 120 ℃, and roasting for 3 hours at 630 ℃ to obtain the catalyst carrier B-1.

Weighing 112g of molybdenum oxide, 48g of basic nickel carbonate, adding 250mL of water, uniformly mixing, adding 56g of 85wt% phosphoric acid, heating for dissolution, and fixing the volume to obtain an impregnating solution, and directly impregnating the impregnating solution on 500g of carrier B-1 by adopting a spray impregnation method. Drying at 120 deg.c for 4 hr and roasting at 470 deg.c for 3 hr to obtain fresh hydrogenating catalyst A1-1.

Example 5

The deactivated hydrogenation catalyst A2 used in the examples and comparative examples related to the invention is a fresh hydrogenation catalyst prepared by the following method:

the tungsten source, the nickel source and the aluminum source are mixed according to m (WO ₃ )∶m( NiO)∶m( Al ₂ O ₃ ) Preparing a metal mixed solution with the molar ratio of 1.35:0.51:1.23, forming colloid by parallel flow of the metal mixed solution and ammonia water to prepare an active metal reactant containing W-Ni-Al, filtering, and adding the active metal reactant into the W-Ni-Al reactant according to m (MoO ₃ )∶m( Al ₂ O ₃ ) MoO was added uniformly in a molar ratio of =1:1.23 ₃ The solid powder of the catalyst is obtained, and the catalyst precursor containing W-Mo-Ni-Al is obtained, and is formed after being dried, washed and roasted to prepare the fresh hydrogenation catalyst A2-1.

Comparative example 1

(1) Step (1) of example 1 was followed to obtain deactivated catalyst A1, which was dried for use.

(2) And (3) carrying out programmed temperature oxidation decarburization and desulfurization on the deactivated catalyst A1 to obtain a regenerated catalyst. The temperature programming process is as follows; raising the temperature of the high-temperature furnace to 250 ℃ at a speed of 3 ℃/min, and roasting for 3 hours; then, the temperature is raised to 390 ℃ at the same temperature rising speed, and roasting is carried out for 3 hours; then, the temperature was raised to 500℃at the same rate of temperature rise, and the catalyst was calcined for 2 hours to obtain a regenerated catalyst.

Comparative example 2

(2) And (3) carrying out programmed temperature oxidation decarburization and desulfurization on the deactivated catalyst A1 to obtain a regenerated catalyst. The temperature programming process is as follows; raising the temperature of the high-temperature furnace to 250 ℃ at a speed of 3 ℃/min, and roasting for 3 hours; then, the temperature is raised to 390 ℃ at the same temperature rising speed, and roasting is carried out for 3 hours; then, the temperature was raised to 500℃at the same rate of temperature rise, and the catalyst was calcined for 2 hours to obtain a regenerated catalyst F1.

(3) Weighing 21g of molybdenum oxide, adding 500mL of water, uniformly mixing, adding 29g of 85wt% phosphoric acid, and heating for dissolution; after stopping heating, 14.6g of nickel nitrate is added; finally, 43g of ammonium metatungstate is added, and the impregnation liquid is obtained after constant volume. The impregnation solution was directly impregnated on 1kg of the carrier F1 by the spray impregnation method. Then drying at 120 ℃ for 4h and roasting at 460 ℃ for 3h to obtain the catalyst F1-1.

Note that: in order to analyze physicochemical properties such as pore structure of regenerated catalyst, the catalyst should be changed from sulfided state to oxidized state. The regenerated catalysts obtained in examples 1 to 3 were thus placed in air, calcined at 200℃for 4 hours and then programmed to 450℃for 4 hours, and the oxidation state catalysts obtained were further characterized.

Test example 1

The catalysts obtained in examples 1 to 4 and comparative examples 1 to 2 were subjected to pore structure analysis under the same conditions using a nitrogen adsorption/desorption apparatus model ASAP 2420 from Michael company of America. Analytical data are shown in table 1:

table 1 comparison of pore structure properties of catalysts

	Pore volume/cm ³ ·g ^-1	Specific surface area/m ² ·g ^-1
			Example 1	0.49	177
Example 2	0.48	185
			Example 3	0.49	180
Example 4 (fresh catalyst A1-1)	0.47	166
			Comparative example 1	0.33	115
Comparative example 2	0.27	130

As shown by the pore structure analysis results in Table 1, the conventional method for regenerating the catalyst by burning carbon and sulfur loses a large amount of pore volume and specific surface area, and the regenerated catalyst cannot restore the pore structure characteristics of the original fresh catalyst. The simple method for additionally loading active metal on the conventional regenerated catalyst can not meet the requirement of the residual oil hydrogenation process in the pore structure. The regeneration method of the invention can restore the pore structure property of the catalyst to the level of fresh agent.

Test example 2

The catalysts described in examples 1 to 5 and comparative examples 1 to 2 were subjected to analysis of the content of the major active metal oxide on the catalysts under the same conditions. The analytical data are shown in Table 2, and the results show that the total amount of active metal on the regenerated catalyst of the method of the invention is higher than that of the fresh catalyst. The method can convert the metal deposited on the deactivated catalyst into active metal, fully utilizes the advantages of the regenerated catalyst, solves the problem of regeneration of the residual oil hydrogenation catalyst, can prepare a new catalyst more suitable for hydrodesulfurization, and saves a vulcanization step.

Table 2 active metal content comparison of catalysts

	Molybdenum oxide, wt%	Nickel oxide, wt%	Tungsten oxide, wt%	Total wt%
					Example 1	16.2	6.0	3.3	25.5
Example 2	15.7	6.5	3.3	25.5
					Example 3	15.8	6.3	3.3	25.4
Example 4 (fresh catalyst A1-1)	17.1	4.0		21.1
					Example 5 (fresh catalyst A2-1)	24.5	12.5	33.0	70.0
Comparative example 1	14.3	5.5		19.8
					Comparative example 2	15.3	6.5	3.3	25.1

Test example 3

Analysis was performed under the same conditions using ultraviolet fluorescence, equivalent to the method of American society for testing and materials standard ASTM D5453-1993. The catalysts obtained in examples 1 to 5 and comparative examples 1 to 2 were subjected to sulfur element content analysis. The results obtained are shown in Table 3 below:

TABLE 3 comparison of elemental sulfur content of catalysts

	Sulfur content, wt%
		Example 1	7.2
Example 2	6.1
		Example 3	6.3
Example 4 (fresh catalyst A1-1)	0
		Example 5 (fresh catalyst A2-1)	0
Comparative example 1	0.5
		Comparative example 2	0.2

As can be seen from the results in Table 3, the regenerated catalyst of the present invention has a much higher sulfur content than the fresh hydrogenation catalyst of example 4, and thus also exceeds the catalyst regenerated by conventional methods. It is explained that most of the active metals on the regenerated catalyst are already in sulfided state, so that the amount of sulfiding agent used will be reduced in the catalyst sulfiding step prior to start-up of the apparatus; meanwhile, the vulcanizing time can be reduced, and the enterprise cost is reduced.

Test example 4

The catalysts obtained in examples 1 to 4 and comparative examples 1 to 2 were subjected to analysis of the compressive strength of catalyst single particles under the same conditions. The results obtained are shown in Table 4, and the results indicate that: the strength loss of the catalyst prepared by the conventional regeneration method is serious; the particle strength of the catalyst according to the process of the invention can be restored to a level substantially comparable to that of fresh catalyst.

Table 4 comparison of catalyst strengths

	Intensity (N/cm)
		Example 1	131
Example 2	137
		Example 3	130
Example 4 (fresh catalyst A1-1)	140
		Comparative example 1	89
Comparative example 2	101

Test example 5

The catalysts prepared in examples 1 to 3, example 4, fresh catalyst A1-1 and comparative example were subjected to residuum hydrogenation in a small fixed bed hydrogenation reactor under the same industrial conditions and the same catalyst volume. The raw oil adopts vacuum residuum, the properties and technological conditions are shown in Table 5, and the desulfurization activity is shown in Table 6.

TABLE 5 raw oil Properties and reaction Process conditions

Nature of raw oil
		Sulfur, wt%	2.8
Nitrogen, μg/g	2840
		Carbon residue, wt%	11.7
Process conditions
		Reaction pressure, MPa	14.7
Volume space velocity, h ^-1	0.4
		Reaction temperature, DEG C	365
Hydrogen to oil volume ratio	500:1

Table 6 comparison of desulfurization Activity of catalysts

Numbering device	Example 1	Example 2	Example 3	Example 4	Comparative example 1	Comparative example 2
							Desulfurization rate of 48 hours of operation%	91	93	93	89	81	85

As can be seen from the results in Table 6, after 48 hours of operation, the catalyst of the present invention had higher desulfurization activity than the regenerated catalyst of the comparative example and the fresh catalyst. The desulfurization performance of the hydrogenation catalyst regenerated and prepared by the method is better.

The method can effectively recover the properties of the regenerated catalyst such as pore structure, strength and the like. In addition, the regenerated catalyst has great advantages in the vulcanization step, can reduce the vulcanization time and the vulcanizing agent consumption, and saves the cost for refining enterprises.

The regenerated catalyst described in comparative examples 1 and 2 is a conventional regenerated catalyst, and the desulfurization activity of the regenerated catalyst of the method of the present invention is far higher than that of the regenerated catalyst obtained in comparative example. This is because a portion of the metals removed from the feed oil is deposited on the deactivated hydrogenation catalyst. These metals cover the active centers of the catalyst, and greatly reduce the catalyst activity. In addition, the metal is easy to deposit at the inlet of the catalyst pore canal, so that the diffusion of residual oil molecules is seriously hindered, and the residual oil molecules cannot enter the inside of the catalyst pore canal. The number of active centers on the inner surface of the catalyst pore canal is far higher than that of the outer surface of the catalyst, so that the larger the diffusion resistance is, the fewer effective active centers are on the catalyst, so that the lower the desulfurization activity of the catalyst for residual oil is, and the regeneration method can well solve the problems.

Claims

1. A method for regenerating a hydrogenation catalyst comprising the steps of:

(4) Dissolving the powder C in liquid paraffin and stirring; then soaking the catalyst on a regenerated carrier, cooling, carbonizing, and performing hydrothermal treatment to obtain a regenerated hydrogenation catalyst;

in the step (1), the deactivated hydrogenation catalyst A1 at least contains active metal molybdenum, wherein the content of the active metal molybdenum in terms of oxide is 10% -25% based on the weight of the fresh catalyst of the deactivated hydrogenation catalyst A1;

in the step (1), the deactivated hydrogenation catalyst A2 is a bulk hydrofining catalyst, the catalyst at least contains active metals molybdenum and tungsten, and the content of all active metals calculated as oxides is 40% -80% based on the weight of the fresh catalyst from which the deactivated hydrogenation catalyst A2 is derived; wherein, the content of active metal molybdenum is 10% -30% in terms of oxide, and the content of active metal tungsten is 20% -60% in terms of oxide;

in the step (1), the mass ratio of the deactivated hydrogenation catalyst A1 to the deactivated hydrogenation catalyst A2 is as follows: 9.5:0.5 to 7.5:2.5;

in the step (1), the solvent is one or more of ethanol, isopropanol, polyvinylpyrrolidone, dimethyl sulfoxide and dimethylformamide, or an aqueous solution of one or more substances;

in the step (1), the ultrasonic treatment time is 0.5-3 hours; the working frequency of the ultrasonic wave is 35-40 KHz;

the ultrasonic treatment adopts intermittent ultrasonic treatment, specifically, first ultrasonic treatment is carried out, then first standing is carried out, second ultrasonic treatment is carried out, then second standing is carried out, the process is repeated until the total ultrasonic treatment time reaches 0.5-3 hours, wherein the standing time of each time is preferably 5-15 min.

2. A regeneration method according to claim 1, characterized in that: in the step (3), the drying conditions are as follows: drying for 1-6 hours at 80-135 ℃, wherein the roasting conditions are as follows: roasting for 2-8 hours at 400-850 ℃.

3. A regeneration method according to claim 1, characterized in that: in the step (4), the volume of the liquid paraffin used is the water absorption volume of the regenerated carrier.

4. A regeneration method according to claim 1, characterized in that: in the step (4), the carbonization is required to be carried out in an inert atmosphere, the required temperature is 300-450 ℃, the time is 3-8 hours, and the required pressure is 1.0-2.5 MPa.

5. A regeneration method according to claim 1, characterized in that: in the step (5), the temperature of the hydrothermal treatment is 700-800 ℃, the water vapor is saturated water vapor, the flow rate of the water vapor is 0.1-0.5L/s, and the time is 0.5-2 hours.