CN116020478A

CN116020478A - Grading method of hydrotreating catalyst

Info

Publication number: CN116020478A
Application number: CN202111243451.4A
Authority: CN
Inventors: 杨占林; 丁思佳; 刘奕; 彭绍忠; 王会刚; 姜虹; 王继锋; 王方朝; 王平
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: 2021-10-25
Filing date: 2021-10-25
Publication date: 2023-04-28

Abstract

The invention discloses a grading method of hydrotreating catalysts, which is characterized in that M hydrotreating catalysts are filled in the flowing direction of a material flow, wherein M is at least 2, preferably M is at least 3, more preferably M is 3-7, M can be 2, 3, 4 or 5, preferably M is 3, the molar concentration of nickel atoms on the surface of the Mth hydrotreating catalyst is higher than that of nickel atoms on the surface of the Mth hydrotreating catalyst, and the average reaction temperature of the Mth hydrotreating catalyst bed is higher than that of the Mth hydrotreating catalyst bed. The method can not only improve the total denitrification performance of the hydrotreating reactor, but also improve the aromatic saturation performance of the catalyst system.

Description

Grading method of hydrotreating catalyst

Technical Field

The invention relates to a grading method of a hydrotreating catalyst, in particular to a grading method of a hydrotreating catalyst with deep denitrification and high hydrogenation saturation performance.

Background

In modern oil refining technology, hydrocracking refers to those hydrogenation processes which change more than 10% of macromolecular compounds in raw materials into micromolecular compounds through hydrogenation reaction, has the characteristics of strong raw material adaptability, large production scheme flexibility, good product quality and the like, can directly convert various heavy and inferior feeds into high-quality jet fuels, diesel oil, lubricating oil base materials, chemical naphtha and tail oil steam cracking ethylene raw materials and the like which are urgently needed in the market, and has become one of the most important heavy oil deep processing processes in the modern oil refining and petrochemical industry, and has been increasingly widely applied at home and abroad.

The heart of the hydrocracking technology is a catalyst, including a pretreatment catalyst and a cracking catalyst. Wherein the hydrocracking pretreatment catalyst has the main functions of: the hydrogenation removes sulfur, nitrogen, oxygen, heavy metal and other impurities contained in the raw materials, and the hydrogenation saturates the polycyclic aromatic hydrocarbon, thereby improving the property of the oil product. Because nitrides, especially basic nitrides, in the feed oil can poison the acid centers of cracking catalysts, hydrodenitrogenation performance is an important indicator for measuring hydrocracking pretreatment catalysts.

The industrial device is an adiabatic reactor, the reaction temperature is greatly increased along with the progress of the reaction, the partial pressure of hydrogen is reduced, the partial pressures of hydrogen sulfide and ammonia are increased, the nitrogen content in the reactant is reduced, and the residual nitrogen-containing compound is a molecule which is difficult to carry out denitrification reaction, and is generally of a multi-side chain structure. The reaction conditions of the upper and lower beds of the catalyst are greatly different. In order to adapt to different reaction environments, the catalyst grading system can be developed, the service performance of the catalyst is improved to the maximum extent, and the service period is prolonged.

CN 112725014A discloses a grading method for hydrotreating catalyst, the method is to load N catalyst beds, N is an integer greater than 2, wherein the catalyst loaded in the mth catalyst bed has the highest acid content of 250-500 ℃, m is an integer greater than 1 and less than N, the acid content of the catalyst loaded in the catalyst beds from 1 to m is in an increasing trend, the acid content of the catalyst loaded in the catalyst beds from m to N is in a decreasing trend, and the reaction temperature of the catalyst beds is in an increasing trend along the stream. The method can not only improve the total denitrification and desulfurization performance of the hydrotreating reactor, but also improve the stability of the performance of the catalyst system.

CN 109718867A relates to the field of hydrofining catalysts, and discloses a hydrofining catalyst system and application thereof, a preparation method of the hydrofining catalyst and a hydrofining method of distillate. The catalyst system comprises first and second catalyst beds; the first catalyst comprises alumina, a hydrodesulfurization catalytically active component and a carboxylic acid; the second catalyst comprises an inorganic refractory component, a hydrodesulfurization catalytically active component and a carboxylic acid; the second inorganic refractory component comprises amorphous silica alumina and/or molecular sieves and alumina; the first and second catalysts each have a pore diameter of 4-40nm and a pore diameter of 100-300nm, and a pore volume of 4-40nm is 60-95% of the total pore volume, and a pore volume of 100-300nm is 0.5-30% of the total pore volume. The first and second catalysts have pore diameters of 100-300nm, the performance is better, the preparation process is shortened, and the capability of treating distillate oil of the catalyst system is improved.

CN 106669861A discloses a hydrocracking catalyst grading method and a catalytic diesel hydrogenation conversion process. The hydrocracking catalyst grading method provided by the invention comprises the following steps: dividing the hydrocracking reactor into 2-8 reaction areas along the material flow direction, mixing and filling a hydrocracking catalyst and a regenerated catalyst in each reaction area, wherein the mass ratio of the hydrocracking catalyst to the regenerated catalyst in each reaction area is 10:1-1:10, and gradually reducing the mass ratio of the hydrocracking catalyst to the regenerated catalyst in each reaction area along the material flow direction. The invention also provides a catalytic diesel oil hydro-conversion process utilizing the catalyst grading. The invention improves the hydrogenation selectivity of diesel oil/gasoline components in the conversion process and improves the yield of high-octane gasoline products by grading and filling catalysts with different reaction performances in the cracking reactor.

The prior art is studied from the aspects of catalyst activity and catalyst granularity, and the influence on the surface property of the catalyst is not considered, especially the surface property of the catalyst has important influence on denitrification reaction.

Disclosure of Invention

Aiming at the problems existing in the prior art, the invention provides a grading method of a hydrotreating catalyst, which is suitable for the hydrotreating process of various distillate oil, and can not only improve the total denitrification performance of a hydrotreating reactor, but also improve the aromatic saturation performance of a catalyst system.

A grading method of hydrotreating catalyst, wherein M hydrotreating catalysts are filled in the flow direction of the stream, M is at least 2, preferably M is at least 3, more preferably M is 3-7, M may be 2, 3, 4 or 5, preferably M is 3, the molar concentration of nickel atoms on the surface of the M hydrotreating catalyst is higher than the molar concentration of nickel atoms on the surface of the M-1 hydrotreating catalyst, and the average reaction temperature of the M hydrotreating catalyst bed is higher than the average reaction temperature of the 1 st hydrotreating catalyst bed.

Further, in the above method, the molar concentration of nickel atoms on the surface of the Mth hydrotreating catalyst is 3% -80%, preferably 5% -30% higher than that on the surface of the Mth hydrotreating catalyst, and the average reaction temperature of the Mth hydrotreating catalyst is 10 ℃ -60 ℃ higher than that of the 1 st hydrotreating catalyst, and more preferably 20 ℃ -50 ℃ higher.

Further, in the above method, when M is 3, the average reaction temperature of the M-1 th hydroprocessing catalyst bed is higher than or equal to the M-2 nd hydroprocessing catalyst bed

The average reaction temperature of the layers is preferably above 10℃to 40 ℃.

Further, in the method, the filling volume ratio of the adjacent catalyst beds is 1:20-20:1, preferably 1:10-10:1, and more preferably 1:5-5:1.

Further, the process described in the above process is capable of treating a wide variety of distillate feedstocks, including various diesel fuels, VGO, CGO, DAO, and blends of two or more thereof, and has the following principal properties: the range of the distillation range, the initial distillation point is more than 180 ℃, and the final distillation point is less than 600 ℃; density of 0.8000-0.9500/g.cm ^-3 (20 ℃ C.); nitrogen content of 100-6000 mug.g ^-1 The method comprises the steps of carrying out a first treatment on the surface of the Sulfur content of 0.05% -3.0%.

Further, the hydrotreating catalyst described in the above process contains group VIB and group VIII metal components. Wherein the active metal of VIB group is W and/or Mo, the active metal of VIII group is Ni and/or Co, and the active metal in the final hydrotreating catalyst is generally as follows by weight of oxide: the content of the VIB group metal oxide is 9-50%, and the content of the VIII group metal oxide is 1-15%. The catalyst support is a porous refractory oxide such as alumina, silica-alumina, alumina in which silica-alumina is dispersed, silica-coated alumina, magnesia, zirconia, boria, titania, and the like. According to the use requirement of the catalyst, one or more of proper auxiliary agents such as fluorine, phosphorus, boron, magnesium, zirconium and the like can be added.

Further, the reaction conditions in the above method are as follows: the reaction pressure is 3MPa to 20MPa, preferably 8MPa to 17MPa, and the airspeed is 0.2h ^-1 ~4.0h ^-1 Preferably 0.8h ^-1 ~2.0h ^-1 The reaction temperature is 260-430 ℃, preferably 300-400 ℃.

In the method of the invention, the molar concentration of the nickel atoms on the surface of the hydrotreating catalyst is detected by an XPS analysis method, and the molar concentration of the nickel atoms on the surface of the hydrotreating catalyst is generally in the range of 0.1% -10%, preferably 0.5% -2.5%.

Further, the hydrotreating catalysts having different surface nickel atom concentrations in the above-described process may be prepared using commercially available products, or by any of the existing catalyst conditioning techniques. If more nickel is introduced in the preparation of the catalyst, different inorganic or organic auxiliary agents are introduced in the preparation process of the carrier and the catalyst, the heat treatment temperature of the catalyst is changed, and the distribution of nickel atoms is improved. Taking introduction of different inorganic or organic auxiliary agents in the preparation process of the carrier and the catalyst as an example, the inorganic auxiliary agents are one or more of fluorine, silicon, phosphorus, boron, magnesium, zirconium and the like, and the organic auxiliary agents are one or more of nitrogen-containing organic compounds, sulfur-containing organic compounds and oxygen-containing organic compounds. The inorganic or organic auxiliary may be introduced at any stage, such as any stage or stages prior to, simultaneously with and subsequent to the impregnation of the group VIB and group VIII metal components. The nitrogen-containing organic compound is an organic compound containing at least one covalent bond nitrogen atom, such as: ethanolamine, diethanolamine, triethanolamine, ethylenediamine tetraacetic acid (EDTA), nitrilotriacetic acid (NTA), and cyclohexanediamine tetraacetic acid, and the like. The sulfur-containing organic compound is an organic compound containing at least one covalent bond sulfur atom, such as mercaptan (general formula R-SH), thioether (general formula R-S-R) and disulfide (general formula R-S-S-R), wherein R in the sulfur-containing compound is an alkyl group containing 1-10 carbon atoms, such as ethanethiol, ethanepropyl sulfide, dimethyl disulfide and the like. The sulfur-containing organic compound may contain one or more substitutions of carboxyl, carbonyl, ester, ether, hydroxyl, mercapto groups, such as thioglycolic acid, mercaptopropionic acid, dimercaptopropanol, and the like. In addition to the above sulfur-containing compounds, sulfones and sulfoxides such as dimethyl sulfoxide, dimethyl sulfone, and the like may be contained. The oxygen-containing organic compound is an organic compound containing at least one carbon atom and one oxygen atom. The oxygen containing moiety may be a carboxyl, carbonyl, hydroxyl moiety or a combination thereof. These substances may be acids such as acetic acid, oxalic acid, malonic acid, tartaric acid, malic acid, citric acid, etc., alcohols such as ethylene glycol, propylene glycol, butylene glycol, glycerol, trimethylolethane, etc., ethers such as diethylene glycol, dipropylene glycol, triethylene glycol, tributylene glycol, tetraethylene glycol, polyethylene glycol, etc., saccharides such as glucose, fructose, lactose, maltose, sucrose, etc., ketones, phenols, aldehydes, and lipids. The drying and/or calcination heat treatment temperatures also have an important effect on the concentration of nickel atoms on the surface of the hydrotreating catalyst. The surface nickel atom concentration of the hydrotreating catalyst with the same nickel element mass content is higher when the hydrotreating catalyst is treated at low temperature; the surface nickel atom concentration of the hydrotreating catalyst with the same nickel element mass content is lower when the hydrotreating catalyst is treated at high temperature. The low temperature and the high temperature are relative, the treatment temperature ranges from 80 ℃ to 700 ℃, for example, the heat treatment temperature can be defined as 80 ℃ to 300 ℃, and the treatment temperature is preferably 120 ℃ to 200 ℃ and is treated at the low temperature; the heat treatment temperature is 350 ℃ to 800 ℃, preferably 400 ℃ to 600 ℃ and is regarded as high-temperature treatment.

The method adopts different heat treatment modes, has different surface nickel atom concentrations, adopts a high-temperature heat treatment mode for the catalyst, has relatively low surface nickel atom concentration and has good reaction effect at low temperature; the catalyst adopts a low-temperature heat treatment mode, the concentration of nickel atoms on the surface is relatively high, and the reaction effect is good at high temperature. The temperature of the reactor in the material flow direction is gradually increased, and the graded filling mode of the catalyst is beneficial to improving the integral denitrification effect of the device and improving the hydrogenation saturation performance of the catalyst system.

Detailed Description

X-ray photoelectron spectroscopy (XPS) using Multilab 2000 type spectrometer manufactured by American thermoelectric corporation (VG), excitation source MgK alpha, analysis chamber vacuum degree higher than 10 ^-6 Pa, C1s (284.6 ev) is taken as an internal standard, and the nuclear power effect is corrected. The ratio of the atomic concentration of each species on the surface of the sample is obtained by converting the peak area of XPS spectrum of the detected species according to the Wagner sensitivity factor. (molar content of target element = number of target element atoms/number of atoms of all elements of the catalyst surface x 100%).

The following examples further illustrate the details of the present invention, but are not to be construed as limiting the invention to the examples, wherein the following examples and comparative examples are by mass percent unless otherwise specified. The pore structures of the alumina supports used in the examples and comparative examples are shown in Table 1.

TABLE 1 physicochemical Properties of the vector

Example 1

The preparation methods of the catalysts used in the examples and comparative examples are given in this example, but the following preparation methods are not exclusive and do not limit the present invention, and the main properties of the prepared oxidation state catalysts are shown in Table 2.

The preparation method of the catalyst A comprises the following steps: the alumina carrier Z is impregnated with an impregnating solution containing Mo and Ni in an equal volume, wherein the impregnating solution contains diethylene glycol, and the mole ratio of the diethylene glycol to nickel atoms is 1:1, dried at 120℃for 3 hours and calcined at 550℃for 2 hours, the catalyst obtained was designated A.

The preparation method of the catalyst B comprises the following steps: the alumina carrier Z is impregnated with an impregnating solution containing Mo and Ni in an equal volume, wherein the impregnating solution contains diethylene glycol, and the mole ratio of the diethylene glycol to nickel atoms is 1:1, drying at 120 ℃ for 3 hours, and roasting at 450 ℃ for 2 hours, the obtained catalyst is denoted as B.

The preparation method of the catalyst C comprises the following steps: the alumina carrier Z is impregnated with an impregnating solution containing Mo and Ni in an equal volume, wherein the impregnating solution contains diethylene glycol, and the mole ratio of the diethylene glycol to nickel atoms is 1:1, dried at 120℃for 3 hours, the catalyst obtained is designated C.

TABLE 2 catalyst physicochemical Properties

Example 2

This example gives an evaluation of the loading scheme of the catalyst. Three reaction beds are arranged along the flow direction of the reactants, the volumes of the beds are respectively 10mL, 30mL and 60mL, and the reaction temperatures are respectively controlled to be 350 ℃, 350 ℃ and 380 ℃.

Test No. PS1: the three reaction beds are sequentially filled with a catalyst A, a catalyst B and a catalyst C along the flow direction of the reactants.

Test No. PS2: the three reaction beds are sequentially filled with a catalyst A, a catalyst A and a catalyst C along the flow direction of the reactants.

Test No. PS3: the three reaction beds are sequentially filled with a catalyst B, a catalyst B and a catalyst C along the flow direction of the reactants.

Comparative example 1

This comparative example gives an evaluation of the loading scheme of the catalyst. Three reaction beds are arranged along the flow direction of the reactants, the volumes of the beds are respectively 10mL, 30mL and 60mL, and the reaction temperatures are respectively controlled to be 350 ℃, 350 ℃ and 380 ℃.

Test No. PD1: the three reaction beds are sequentially filled with a catalyst C, a catalyst B and a catalyst A along the flow direction of the reactants.

Test No. PD2: the three reaction beds are sequentially filled with a catalyst B, a catalyst B and a catalyst B along the flow direction of the reactants.

Test No. PD3: the three reaction beds are sequentially filled with a catalyst C, a catalyst C and a catalyst C along the flow direction of the reactants.

Example 3

This example is an activity evaluation experiment of the catalyst.

The catalyst activity evaluation experiment is carried out on a three-tube serial small hydrogenation device, and the catalyst is presulfided before the activity evaluation. The catalyst evaluation condition is that the total pressure of the reaction is 14.5MPa, the liquid hourly space velocity is 1.0 h ^-1 Hydrogen oil volume ratio 1000:1, the properties of the raw oil for activity evaluation experiments are shown in Table 3, and the results of activity evaluation are shown in Table 4.

TABLE 3 Properties of raw oil

Table 4500 hour catalyst Activity evaluation results

As can be seen from the evaluation results of the 500-hour catalyst activity in Table 4, the catalyst system has greatly improved denitrification activity and better aromatic saturation performance compared with the comparative example by the loading method of the hydrotreating catalyst of the invention, and can provide high-quality feed for the hydrocracking section.

Claims

1. A method for grading a hydrotreating catalyst, characterized by: the grading method is characterized in that M hydrotreating catalysts are filled along the flow direction of a material flow, wherein M is at least 2, preferably M is at least 3, more preferably M is 3-7, the molar concentration of nickel atoms on the surface of the Mth hydrotreating catalyst is higher than that of the surface of the Mth hydrotreating catalyst and the molar concentration of nickel atoms on the surface of the Mth hydrotreating catalyst, and the average reaction temperature of the Mth hydrotreating catalyst bed is higher than that of the Mth hydrotreating catalyst bed and the Mth hydrotreating catalyst bed.

2. The method according to claim 1, characterized in that: the molar concentration of nickel atoms on the surface of the Mth hydrotreating catalyst is 3-80% higher than that of the Mth hydrotreating catalyst, and the average reaction temperature of the Mth hydrotreating catalyst is 10-60 ℃ higher than that of the 1 st hydrotreating catalyst.

3. The method according to claim 2, characterized in that: the molar concentration of nickel atoms on the surface of the Mth hydrotreating catalyst is 5-30% higher than that of the Mth hydrotreating catalyst, and the average reaction temperature of the Mth hydrotreating catalyst is 20-50 ℃ higher than that of the 1 st hydrotreating catalyst.

4. The method according to claim 1, characterized in that: and when M is 3, the average reaction temperature of the M-1 th hydrotreating catalyst bed is higher than or equal to the average reaction temperature of the M-2 nd hydrotreating catalyst bed.

5. The method according to claim 4, wherein: when M is 3, the average reaction temperature of the M-1 th hydrotreating catalyst bed is 10-40 ℃ higher than that of the M-2 nd hydrotreating catalyst bed.

6. The method according to claim 1, characterized in that: the filling volume ratio of adjacent different catalysts is 1:20-20:1, preferably 1:10-10:1, and more preferably 1:5-5:1.

7. The method according to claim 1, characterized in that: the raw materials are various diesel oils and VGO, CGO, DAO and mixed oil of two or more of them.

8. The method according to claim 1, characterized in that: the raw materials have the following properties: the range of the distillation range, the initial distillation point is more than 180 ℃, and the final distillation point is less than 600 ℃; the density is 0.8000-0.9500/g.cm ^-3 (20 ℃ C.); nitrogen content of 100-6000 mug.g ^-1 The method comprises the steps of carrying out a first treatment on the surface of the Sulfur content is 0.05% -3.0%.

9. The method according to claim 1, characterized in that: the hydrotreating catalyst contains VIB group and VIII group metal components.

10. The method according to claim 9, wherein: the active metal of VIB group is W and/or Mo, the active metal of VIII group is Ni and/or Co, the content of VIB group metal oxide in the final hydrotreating catalyst is 9% -50% and the content of VIII group metal oxide is 1% -15% based on the weight of oxide.

11. The method according to claim 9, wherein: the catalyst carrier is one or more of alumina, silica-alumina, magnesia, zirconia, boron oxide and titania.

12. The method according to claim 1, characterized in that: the reaction conditions were as follows: the reaction pressure is 3MPa to 20MPa, and the airspeed is 0.2h ^-1 ~4.0h ^-1 The reaction temperature is 260-430 ℃.

13. The method according to claim 12, wherein: the reaction conditions were as follows: the reaction pressure is 8 MPa-17 MPa, and the reaction pressure is emptyThe speed is 0.8h ^-1 ~2.0h ^-1 The reaction temperature is 300-400 ℃.