CN1766053A - Distillate oil hydrotreating catalyst and preparation method thereof - Google Patents

Abstract

The invention discloses a hydrocracking catalyst for distillate oil, which comprises alumina, ZSM-23 elite and Y-shape elite modified by cation exchange with VIB and VIII groups metal as carriers, and active metal constituents from VIB and VIII groups; adjusting acid distribution of Y-shape elite special the B and L acids. This invention has well open-loop, hydrogenation and isomerization activity, increase hexadecane value in maximum limit, and ensures high diesel yield.

Description

Distillate oil hydrotreating catalyst and preparation method thereof

technical field

The invention relates to a distillate oil hydrotreating catalyst and a preparation method thereof, in particular to a hydrotreating catalyst for producing low-condensation clean diesel oil through hydrogenation of inferior diesel fractions and a preparation method thereof.

Background technique

Due to the rapid development of catalytic cracking technology in my country, fluidized catalytic cracking (FCC) and heavy oil fluidized catalytic cracking (RFCC) units dominate the secondary processing, resulting in catalytic diesel (LCO) accounting for about one-third of the total diesel one. However, the impurity content in catalytic diesel is high, the stability is poor, and the content of aromatics is high, especially the cetane number is low. With the development of catalytic technology towards deep processing, the quality of catalytic diesel will become worse. However, the new environmental regulations put forward more stringent requirements on the quality of diesel. Therefore, how to further improve the quality of diesel oil is an important issue that people pay attention to.

On the other hand, most of the crude oil in my country is paraffin-based crude oil with a high freezing point. Especially in winter, the temperature in the vast northern regions of our country is low, not only clean diesel oil is needed, but also low-condensation clean diesel oil is needed. In order to solve this contradiction, most refineries adopt the operation method of reducing the dry point of diesel oil to produce low-condensation diesel oil, which reduces the output of diesel oil. This method not only does not meet the current social demand for increasing the diesel-gasoline ratio, but also reduces the economic benefits of enterprises.

In fact, increasing the cetane number of diesel oil is contradictory to lowering the freezing point by isomerization. For different hydrocarbons with the same carbon number, the cetane number of alkanes is the highest, and the cetane number of aromatic hydrocarbons, especially fused-ring aromatic hydrocarbons The value is the smallest. Moreover, the higher the degree of isomerization of hydrocarbons, the more the number of rings, the lower the cetane number. With the increase of the side chain length of cycloalkane and aromatic hydrocarbons, the higher the cetane number, but with the The increase in chain branching reduces the cetane number. While the degree of isomerization is high, the freezing point of the diesel fraction is low. However, if the degree of isomerization is too high, cracking reactions are prone to occur, reducing the yield of diesel products, and the catalyst is prone to carbon deposition and deactivation.

At present, the technologies for improving the quality of diesel oil and lowering the freezing point of diesel oil are mainly hydrocracking technology for high-yield diesel oil, MCI technology for increasing the cetane number of diesel oil, and hydrodecondensation and isomerization decondensation technologies. The hydrocracking technology using prolific diesel oil is mainly a hydrocracking catalyst developed for the production of high-quality low-point diesel oil from heavy distillates, such as USP4,985,134, USP4,820,402, CN1393522A, etc., although the quality of diesel products has a relatively large Increase, the freezing point depression is large, but the pressure level is high, and the diesel yield is low. However, although the freezing point of the hydrogen depreciation technology is large, the yield of diesel oil is low, such as USP 5833840, USP 5965474, and USP 5286370. The MCI technology to increase the cetane number of diesel oil can meet the requirements of raising the cetane number of diesel oil, but the pour point depresses the range is not large, the same isomerism pour point depressing technology, such as USP6153548, 5932088, can meet the pour point depressing requirements, but It cannot meet the requirement of increasing the cetane number of diesel oil at the same time.

In order to increase the cetane number of diesel oil while lowering the freezing point of diesel oil and ensure a certain yield of diesel oil, groups and processes are now mostly used, such as hydrofinishing and/or hydrocracking and hydrodecondensation, hydrogenation upgrading and Hydrogen decondensation, hydrogenation modification and isomerism depreciation, etc. can achieve better results.

CN1257107A discloses a method for producing high-quality low-condensation diesel oil from distillate oil, which is to react directly in series with hydrofinishing and hydrodecondensation. The NiO content of the hydrofining catalyst is relatively high, and the anti-coking performance is good; the hydrodepreciation catalyst is a VIB group and/or VIII group non-noble metal catalyst supported on ZSM-5 zeolite. Due to the pore characteristics of ZSM-5, positive After the alkanes enter, they can only be diffused by cracking into small molecules, so the yield of diesel oil is low. Moreover, although the combined process of hydrofining and hydrodecondensation can prolong the life of the depreciation catalyst, remove impurities such as sulfur and nitrogen in the distillate, and improve its oxidation stability to a certain extent, it cannot effectively improve the diesel cetane value.

Contents of the invention

The object of the present invention is to provide a distillate oil hydrotreating catalyst and a preparation method thereof. The catalyst is used to deal with low-quality diesel fractions, which can maximize the cetane number, lower the freezing point, and maintain a higher diesel yield.

The distillate hydrotreating catalyst of the present invention comprises the following components: modified Y zeolite, ZSM-23 zeolite, alumina and active metal. Wherein the active metal component is one or more of Group VIB and Group VIII metals. The properties of the modified Y zeolite used are as follows: the modified Y zeolite contains 2wt%-10wt% of Group VIB and/or Group VIII metal elements, the SiO ₂ /Al ₂ O ₃ molar ratio is 9.0-12.9, and the crystal The cell constant is 2.440-2.459nm, the specific surface area is 550-650m ² /g, the pore volume is 0.340-0.370ml/g, the infrared acidity is 1.37-1.60mmol/g, and the molar ratio of B acid to L acid is 1:3 - 1:5, Na ₂ O weight content < 0.2%, preferably < 0.15%, most preferably < 0.1%. The metal elements of group VIB and/or group VIII are one or more of W, Ni, Co, Fe and Mo.

The content of each component in the catalyst of the present invention is as follows: based on the weight percentage of the catalyst, the content of the VIB group metal oxide is 10%-30%, preferably 10%-25%; the VIII group metal oxide The content is 1%-10%, preferably 1%-9%, most preferably 3%-8%; the content of modified Y zeolite is 1%-20%, preferably 5%-15%; ZSM- The content of 23 zeolite is 1%-30%, preferably 5%-20%; the content of alumina is 5%-80%, preferably 15%-70%, preferably 20%-60%; The content of the mixture is 0-30%, preferably 0-20%.

The hydrotreating catalyst of the present invention uses modified Y zeolite, ZSM-23 zeolite and alumina as carriers, wherein two different zeolites are used as the main acidic component of the catalyst, and alumina is the auxiliary acidic component and main acidic component of the catalyst. carrier components.

The distillate hydrotreating catalyst of the present invention has a specific surface area of 150-210m ² /g and a pore volume of 0.24-0.29ml/g, wherein the pore distribution with a pore diameter of 4-10nm accounts for 75%-85% of the total pore volume, Infrared acidity is 0.32-0.38mmol/g.

The modified Y zeolite used in the present invention is prepared as follows:

(1) Put superhydrophobic Y zeolite in water, wherein the weight ratio of zeolite to water is 1:2-10, preferably 1:3.8, heat up to 60°C-90°C, and stir for 0.5-2.0 hours.

(2) Take one or more of the soluble salts containing Group VIB and/or Group VIII metals to prepare a solution, add it to the solution of the above step (1), adjust the pH value of the solution with ammonia water, and control the pH value to 4 -10, the solution is aged at 50-90°C for 2-4 hours with stirring and fully exchanged, filtered, and dried at 100°C-150°C for 8-24 hours.

The superhydrophobic Y zeolite is obtained by hydrothermally treating the Y zeolite at 500-600° C. and 0.01-0.30 MPa for 1-10 hours. The properties of the Y zeolite are as follows: the NaO content is lower than 0.2wt%, the silicon-aluminum molar ratio is 6-40 (chemical method), and the unit cell constant is 2.440-2.460nm. The Y zeolite can be prepared from NH ₄ NaY zeolite by a fluorosilicate liquid-phase dealumination method, such as the method described in CN 1026313C.

The distillate oil hydrotreating catalyst preparation step of the present invention comprises:

(1) Mix the modified Y zeolite, ZSM-23 zeolite and alumina evenly;

(2) Add adhesive to the mixture of step (1) or directly add peptizer solution and knead into paste, extrude;

(3) drying the above molded product at 100-150°C for 0.5-24 hours, and calcining at 350-700°C for 1-12 hours to obtain a catalyst carrier;

(4) preparing an impregnating solution containing VIB group metals and/or VIII group metals;

(5) The catalyst carrier obtained in step (3) is immersed in the solution prepared in step (4), dried at 100-150° C. for 0.5-24 hours, and calcined at 350-700° C. for 1-12 hours to obtain a finished catalyst.

The drying temperature of the carrier and the catalyst is preferably 100-140° C., and the drying time is preferably 1-8 hours.

The calcination temperature of the carrier and the catalyst is preferably 400-650° C., and the calcination time is preferably 1-8 hours.

The most commonly used group VIB metals involved in the distillate oil hydrotreating catalyst of the present invention are Mo and/or W, and the most commonly used group VIII metals are one or more of Fe, Ni and Co.

Because the catalyst of the present invention adopts Y zeolite modified by metal cations, the acid distribution of the modified Y zeolite, especially the ratio of B acid and L acid is more reasonable, so the catalyst of the present invention can effectively reduce the cracking of diesel fraction , to ensure the yield of diesel oil, to promote hydrogenation and saturation ring opening of aromatics, but also to improve the anti-coking ability of the catalyst and prolong the service life of the catalyst.

In addition, because the catalyst of the present invention adopts ZSM-23 zeolite, the elliptical non-intersecting straight channels formed by its ten-membered rings have better isomerization selectivity and shape selectivity. In ZSM-23, only straight-chain alkanes can enter the channels The reaction takes place and the branch remains at the pore opening. Moreover, due to the better ellipticity of ZSM-23, it provides space for molecules to form branched chain hydrocarbons in the pores, and the synergistic effect with modified Y zeolite can not only improve the selectivity of the isomerization reaction of the catalyst, but also maximize the While increasing the cetane number, the freezing point of diesel oil is greatly reduced.

The catalyst of the present invention has better ring-opening, hydrogenation and isomerization activities, is suitable for treating low-quality diesel oil fractions, and can maximize the cetane number, lower the freezing point, and improve product quality under relatively mild reaction conditions. And maintain a higher diesel yield.

Detailed ways

The ZSM-23 zeolite used in the distillate hydrotreating catalyst of the present invention can adopt all ZSM-23 zeolites suitable for the present invention in the prior art, and its properties are as follows: SiO ₂ /Al ₂ O ₃ molar ratio (chemical method) 40-100, preferably 50-90, Na ₂ O weight content <0.2%, preferably <0.15%, most preferably <0.1%, infrared acidity is 0.1-0.4mmol/g, preferably 0.15-0.4mmol /g.

The ZSM-23 zeolite in the catalyst of the present invention is preferably selected from small grain ZSM-23 zeolite, whose particle diameter is 1-100 nm. For example, ZSM-23 zeolite with small grains prepared by the method in US Patent No. 5,160,500.

The aluminum oxide used in the present invention can adopt the aluminum oxide commonly used when preparing the hydrogenation catalyst carrier, preferably adopt the alumina modified by the auxiliary agent, and the auxiliary agent (calculated by element) content is 3wt%-7wt%, wherein The additives mentioned above are one or more of boron, fluorine and zirconium. The properties of the modified alumina: the specific surface area is 320-370m ² /g, and the pore volume is 0.7-1.1ml/g. The modified alumina can adopt the preparation method in the Chinese patent CN1458232A: the alumina precursor is prepared by the conventional method, preferably carbonization method, the filter cake is taken, beaten, and the temperature is raised to 50-90°C, preferably 65-75°C, Add a certain amount of additives, stir at 50-90°C for 5-120 minutes, preferably 30-90 minutes, filter and dry to obtain modified alumina.

The catalyst of the present invention can use small-pore refractory inorganic oxides as the binder component of the catalyst when the carrier is prepared, such as one of clay, silica, alumina, silica-alumina, zirconia and titania-magnesia Various types, preferably small-pore alumina, its properties are as follows: specific surface area 220-300m ² /g, pore volume 0.45-0.52ml/g. The weight content of the binder component in the final catalyst is 0-30%, preferably 0-20%.

When the catalyst carrier of the present invention is prepared, the adhesive component may not be added, but the peptizing acid may be directly added, kneaded and extruded to shape.

In the process of catalyst preparation in the present invention, an extrusion aid can be used for extruding, and the commonly used extrusion aid can be one of the following: turnip powder, citric acid, oxalic acid, cellulose, starch, polymer surfactant, etc. or several.

The peptizing agent involved in the present invention can be: one or more of aluminum sulfate, citric acid, nitric acid, acetic acid, oxalic acid and the like.

The shape of the molded carrier can be flake, spherical, cylindrical strip and special-shaped strip (clover, four-leaf clover), preferably cylindrical strip and special-shaped strip (clover, four-leaf clover). The diameter of the carrier can be a thin strip of 0.8-2.0 mm and a thick strip of >2.5 mm.

The characteristics of the catalyst of the present invention are illustrated below through specific examples.

The specific surface area and pore volume of the product of the present invention are obtained by using ASAP2400, low-temperature nitrogen adsorption (77K), and calculating according to the BET formula. The acid content and acid properties were measured by infrared spectrometer, and the adsorbent used was pyridine.

Example 1

Preparation of modified Y zeolite Y-A:

(1) Treat Y zeolite under 0.1MPa, 550°C water vapor for 2 hours to obtain superhydrophobic Y zeolite YW; wherein Y zeolite is produced by Wenzhou Catalyst Factory, and its properties are as follows: silicon-aluminum molar ratio (chemical method) 10.01, unit cell The constant is 2.448nm, the Na ₂ O content is 0.05wt%, and the dry basis is 75wt%.

(2) Put 300 grams of superhydrophobic Y zeolite in 1000 ml of water, stir and heat up to 60°C.

(3) Mix 181g nickel nitrate and 29g cobalt nitrate into 240ml solution, add ammonia water to the above zeolite solution, control the pH value to be equal to 6, after adding, the solution is aged for 2 hours, filtered, and dried at 110°C for 8 hours. obtained, denoted as Y-A, and its physical and chemical properties are shown in Table 1.

Example 2

Preparation of modified Y zeolite Y-B:

Step (1) is with embodiment 1;

Step (2) Put 300 grams of superhydrophobic Y zeolite in 1500 ml of water, stir and heat up to 80° C., add 97.8 g of ferric nitrate and stir evenly.

Step (3) 360g nickel nitrate and 62g cobalt nitrate are made into 200ml solution, and add in the above-mentioned zeolite solution together with ammonia water, control the pH value to be equal to 5, after adding, the solution is aged for 2 hours, after filtering, dry at 110°C for 8 Hours, recorded as Y-B, its physical and chemical properties are shown in Table 1.

Example 3

Preparation of modified Y zeolite Y-C:

Step (1) Treat Y zeolite under 0.1MPa and 600°C water vapor for 1 hour to obtain superhydrophobic Y zeolite; wherein Y zeolite is produced by Wenzhou Catalyst Factory, and its properties are as follows: silicon-aluminum molar ratio (chemical method) 10.01, unit cell The constant is 2.448nm, the Na ₂ O content is 0.05wt%, and the dry basis is 75wt%.

Step (2) Put 400 grams of superhydrophobic Y zeolite in 1600 ml of water, stir and heat up to 75°C.

Step (3) Mix 416.3g nickel nitrate and 69.6g cobalt nitrate into 460ml solution, add ammonia water to the above-mentioned zeolite solution, control the pH value to be equal to 6, aging the solution for 2 hours after adding, filter and dry at 110°C It was prepared in 8 hours, recorded as Y-C, and its physical and chemical properties are shown in Table 1.

Example 4

Preparation of Small Crystal ZSM-23 Zeolite Z-A

(1) Preparation of small-grain ZSM-23 zeolite (prepared according to the method of Example 14 in US Patent No. 5,160,500).

A solution was prepared by mixing 1 part of aluminum sulfate (by weight, the same below), 2 parts of sodium hydroxide (50 wt%), 2 parts of sodium chloride, and 30 parts of water. This solution was mixed with a second solution consisting of 14 parts PPG HiSil 233 (amorphous silica) and 55 parts water. 4 parts of pyrrolidine and 1 part of ZSM-23 seed crystals (prepared from the previous batch) and 3 parts of ethanol were added to the above solution and the solution was stirred vigorously for about half an hour. The reactants were added to the autoclave and heated to 290°F with stirring , keep this temperature for 66 hours. The reaction crystalline material was then filtered, washed, and then dried overnight at 250°F. (According to the results of the electron microscope, the crystalline species is ZSM-23, and the particle diameter is 100nm.) The crystalline product calcined at 1000°F for 16 hours is ZSM-23 zeolite.

(2) Preparation of ZSM-23 zeolite Z-A

Take 500g of the above-mentioned ZSM-23 zeolite and place it in a high-temperature roasting furnace, raise the temperature to 700 °C at a rate of about 100 °C/hour, then roast at a constant temperature for 12 hours, and cool down to room temperature to obtain the deaminated ZSM-23 zeolite. ₄ NO ₃ solution, stirred at constant temperature at 55°C for 6 hours, the liquid-solid ratio was 10, then filtered and washed with water until neutral. The zeolite filter cake after acid treatment is dried at 110-220°C. Put the above-mentioned zeolite in a high-temperature closed roasting furnace, raise the temperature to 550 °C at a rate of about 200 °C/hour, and feed 100% water vapor at the same time, control the pressure at 0.1 MPa, roast at constant temperature and pressure for 2 hours, and then use 3.0N The NH ₄ NO ₃ solution was stirred at a constant temperature of 90°C for 6 hours, the liquid-solid ratio was 10, and then filtered and washed with water until neutral. The zeolite filter cake after acid treatment is dried at 110-220°C to obtain zeolite ZA. Its physical and chemical properties are listed in Table 1. The zeolite has a silicon-aluminum molar ratio of 90 (chemical method), and a NaO% content of <0.15wt%.

Example 5

Preparation of non-small grain ZSM-23 zeolite Z-B

(1) Preparation of non-small grain ZSM-23 zeolite (prepared by the method of Example 2 in USP4,076,842)

To prepare a batch of ZSM-23 molecular sieves, first prepare a solution containing 2.64 grams of sodium aluminate (43.1wt% Al ₂ O ₃ , 33.1wt% Na ₂ O and 24.7wt% H ₂ O), 48 grams of H ₂ O and 0.27 gram of NaOH (50% NaOH solution), then 28.8 grams of pyrrolidine, followed by 132 grams of silica gel (30 wt% SiO ₂ and 70 wt% H ₂ O), and the solution was mixed until a homogeneous colloid was formed. The colloidal solution composition and molar ratio are as follows:

R+/(R ⁺ +M. ⁺ )＝0.93

Here, M is Na and R ⁺ is a nitrogen-containing cation derived from pyrrolidine

OH ⁻ /SiO ₂ =0.048

Pyrrolidine-derived OH ^- ions are not counted

H ₂ O/OH ^- = 246

Pyrrolidine-derived OH ^- ions are not counted

SiO ₂ /Al ₂ O ₃ =59.1

The mixture was held at 350°F for 7 days, during which time the crystallization process was completed. The crystalline product was filtered from solution, washed continuously with water for about 16 hours, and then dried at 230°F. The crystalline product calcined at 1000°F for 16 hours was ZSM-23 zeolite, and physical analysis showed a specific surface area of 226 ^m² /g.

(2) Preparation of ZSM-23 zeolite Z-B

Take 500g of the above-mentioned ZSM-23 zeolite and place it in a high-temperature roasting furnace, raise the temperature to 700 °C at a rate of about 100 °C/hour, then roast at a constant temperature for 12 hours, and cool down to room temperature to obtain the deaminated ZSM-23 zeolite. ₄ NO ₃ solution, stirred at constant temperature at 55°C for 6 hours, the liquid-solid ratio was 10, then filtered and washed with water until neutral. The zeolite filter cake after acid treatment is dried at 110-220°C. Put the above-mentioned zeolite in a high-temperature closed roasting furnace, raise the temperature to 550 °C at a rate of about 200 °C/hour, and feed 100% water vapor at the same time, control the pressure at 0.1 MPa, roast at constant temperature and pressure for 2 hours, and then use 3.0N The NH ₄ NO ₃ solution was stirred at a constant temperature of 90°C for 6 hours, the liquid-solid ratio was 10, and then filtered and washed with water until neutral. The zeolite filter cake after acid treatment is dried at 110-220°C to obtain zeolite ZB. Its physical and chemical properties are listed in Table 1. The molar ratio of silicon to aluminum of the zeolite is 69.3 (chemical method), and the NaO% content is <0.15wt%.

Example 6

Preparation of modified alumina L-1

Get the filter cake after the washing of the aluminum oxide precursor prepared by the carbonization method, measure its dry basis as 20wt%, get the filter cake 6000 grams, add 24 liters of deionized water, beating, and add 200 grams of BF ₃ ether solution (BF ₃ content 46.8wt%), heated up to 65°C, stirred for 1 hour, filtered, and dried at 110°C for 4 hours. The sample was L-1, whose physical and chemical properties are shown in Table 1.

Example 7

Preparation of modified alumina L-2.

Take 800 g of the washed filter cake of the alumina precursor prepared by the aluminum sulfate method, add 4 liters of deionized water, stir evenly, then heat up to 85 ° C, add 11 g of ammonium fluoroborate, continue stirring for 30 minutes, and dry at 110 ° C for 4 hours. The physical and chemical properties of sample L-2 are shown in Table 1.

Table 1 Physicochemical properties of samples Example number 1 2 3 4 5 6 7 Sample serial number YA YB YC ZA ZB L-1 L-2 NiO, wt% 4.12 6.3 8.9 - - - - CoO, wt% 0.57 0.89 0.73 - - - - Fe,wt% - 1.19 - - - - - Auxiliary (calculated by element) content, - - - - - 6.3 5.9 Specific surface area, m ² /g 612 574 556 245 220 360 320 Pore volume, ml/g 0.362 0.353 0.347 - - 0.88 0.92 Infrared acidity, mmol/g 1.476 1.575 1.529 0.31 0.27 - - The molar ratio of B acid to L acid 1:3.5 1:4.6 1:4.8 - - - - SiO ₂ /Al ₂ O ₃ molar ratio 9.87 9.59 11.2 90 69.3 - - Cell constant, nm 2.441 2.444 2.451 - - - - Na ₂ O content, wt% 0.15 0.15 0.15 <0.15 <0.15 - - Particle diameter, nm - - - 100 - - -

Example 8

Preparation of the distillate oil hydrogenation catalyst of the present invention.

46.2 grams of YA, 41.7 grams of ZA, 445 grams of L-1, and 318 grams of adhesive (dry basis 30wt%) prepared by SB powder (pore volume 0.46ml/g, specific surface area 260m ² /g), put into the mill In the press, grind until the paste can be extruded, extruded, dried at 110°C for 4 hours, roasted at 550°C for 3 hours, impregnated with ammonium metatungstate and nickel nitrate aqueous solution, dried at 110°C for 4 hours, and roasted at 500°C for 3 hours. Catalyst C-1 was obtained. The physical and chemical properties of the catalyst are listed in Table 2.

Example 9

Preparation of distillate oil hydrogenation catalyst of the present invention.

37.7 grams of YA, 71.7 grams of ZA, 495 grams of L-1, and 367 grams of adhesive (dry basis 30wt%) prepared by SB powder (pore volume 0.46ml/g, specific surface area 260m ² /g) were put into the mill In the press, grind until the paste can be extruded, extruded, dried at 110°C for 4 hours, roasted at 550°C for 3 hours, impregnated with ammonium metatungstate and nickel nitrate aqueous solution, dried at 110°C for 4 hours, and roasted at 500°C for 3 hours. Catalyst C-2 was obtained, and its physicochemical properties are shown in Table 2.

Example 10

35.16 gram of YB, 31.3 gram of ZB, 286 gram of L-2, 209 gram of adhesive (dry basis 30wt%) prepared by SB powder (pore volume 0.46ml/g, specific surface area 260m ² /g), put into mill In the press, grind until the paste can be extruded, extruded, dried at 110°C for 4 hours, roasted at 550°C for 3 hours, impregnated with ammonium metatungstate and nickel nitrate aqueous solution, dried at 110°C for 4 hours, and roasted at 480°C for 3 hours. Catalyst C-3 was obtained, and its physicochemical properties are shown in Table 2.

Example 11

The distillate oil hydrogenation catalyst C-4 of the present invention is prepared.

51.5 grams of YC, 196 grams of ZA, 546 grams of L-1, and 500 grams of adhesive (dry basis 30wt%) prepared by SB powder (pore volume 0.46ml/g, specific surface area 260m ² /g) were put into a mill In the press, grind until the paste can be extruded, extruded, dried at 120°C for 4 hours, roasted at 550°C for 3 hours, impregnated with ammonium metatungstate and nickel nitrate aqueous solution, dried at 110°C for 4 hours, and roasted at 520°C for 3 hours. Catalyst C-4 was obtained, and its physicochemical properties are shown in Table 2.

Example 12

Preparation of distillate oil hydrogenation catalyst C-5 of the present invention.

96.2 grams of YA, 32.6 grams of ZA, 357 grams of L-1, 500 grams of adhesive (dry basis 30wt%) prepared by SB powder (pore volume 0.46ml/g, specific surface area 260m ² /g), put into the mill In the press, grind until the paste can be extruded, extruded, dried at 110°C for 4 hours, roasted at 550°C for 3 hours, impregnated with ammonium metatungstate and nickel nitrate aqueous solution, dried at 110°C for 4 hours, and roasted at 500°C for 3 hours. Catalyst C-5 was obtained. The physical and chemical properties of the catalyst are listed in Table 2.

Example 13

Preparation of distillate oil hydrogenation catalyst C-6 of the present invention.

The method and composition are basically similar to those in Example 8, keeping the contents of YA and ZA unchanged, replacing the modified alumina with SB powder (pore volume 0.46ml/g, specific surface area 260m ² /g), and the obtained catalyst is C-6, Its physical and chemical properties are listed in Table 2.

Comparative example-1

This example is the preparation of reference catalyst J-1.

The method and composition are basically similar to those in Example 8, except that the ZA component is removed. The final composition of the catalyst is: YA 15wt%, modified alumina 30wt%, WO ₃ 22.32wt%, NiO 5.12wt%, CoO 0.14wt%, and the balance is small-pore alumina. The physical and chemical properties of the catalyst are listed in Table 2.

Comparative example-2

This example is the preparation of reference catalyst J-2.

The method and composition are basically similar to Example 8, keeping the ZA content unchanged, and replacing the YA component with the superhydrophobic Y zeolite YW (produced by Wenzhou Catalyst Factory) that has not undergone cation exchange in Example 1. The final composition of the catalyst is: ZA 10wt%, superhydrophobic Y zeolite 8wt%, modified alumina 35wt%, WO ₃ 23.65wt%, NiO 4.79wt%, and the balance is small-pore alumina. The physical and chemical properties of the catalyst are listed in Table 2.

Table 2 Catalyst Physicochemical Properties Catalyst of the embodiment of the present invention Comparative example Catalyst number C-1 C-2 C-3 C-4 C-5 C-6 J-1 J-2 NiO, wt% 5.12 5.78 4.93 6.11 4.58 4.87 5.12 4.79 CoO, wt% 0.14 0.14 0.12 0.12 0.15 0.16 0.14 - WO ₃ , wt% 25.71 24.60 24.73 23.56 24.62 23.57 22.32 23.65 Fe,wt% - - 0.69 - - - - - Modified Y zeolite, wt% 7 5 8 5 14 7 15 8(YW) ZSM-23 zeolite, wt% 8 12 9 twenty four 6 8 - 10 Alumina, wt% 65 63 63 51 50 65 60 57 Binder, wt% margin margin margin margin margin margin margin margin Specific surface area, m ² /g 189 183 187 200 207 155 164 172 Pore volume, ml/g 0.287 0.245 0.276 0.249 0.289 0.253 0.334 0.303 4-10nm pore volume fraction, % 80 82 80 84 79 82 71 69 Infrared acidity, mmol/g 0.369 0.341 0.343 0.345 0.372 0.366 0.451 0.397

Examples 14-19

This example illustrates the distillate hydrogenation activity of the catalyst provided by the present invention.

The hydrogenation and isomerization activities of catalysts C-1 to C-6 were evaluated using Guangzhou Petrochemical as feedstock oil. The properties of raw oil are shown in Table 3. The reaction was carried out on a 200ml hydrogenation unit. The reaction conditions are: reaction temperature 360°C, hydrogen partial pressure 6.5 MPa, liquid hourly space velocity 1.2 hours ^-1 , hydrogen-oil volume ratio 700:1. The product properties are listed in Table 4.

Comparative example 3-4

This comparative example illustrates the distillate hydrogenation activity of the reference catalyst.

The hydrogenation and isomerization activities of catalysts J-1 and J-2 were evaluated using Guangzhou Petrochemical as feedstock oil. The properties of raw oil are shown in Table 3. The reaction was carried out on a 200ml hydrogenation unit. The reaction conditions are: reaction temperature 360°C, hydrogen partial pressure 6.5 MPa, liquid hourly space velocity 1.2 hours ^-1 , hydrogen-oil volume ratio 700:1. The product properties are listed in Table 4.

Table 3 Raw Oil Properties Raw oil raw material Density, g/ ^cm3 0.9126 Distillation range, ℃ IBP/10% 175/227 50%/90% 279/348 95%/EP 359/370 Sulfur, wt% 0.55 Nitrogen, μg/g 711 freezing point, ℃ -3 cetane number 25 Aromatics, wt% 56.8

Table 4 Evaluation results of isomerization depreciation catalysts for diesel hydrotreating serial number Example 14 Example 15 Example 16 Example 17 Example 18 Example 19 comparative example Comparative example 4 Density, g/ ^cm3 0.8664 0.8635 0.8678 0.8629 0.8642 0.8775 0.8777 0.8773 Distillation range, ℃ IBP/10% 183/217 178/227 169/219 161/215 172/225 167/219 172/216 182/225 30%/50% 241/262 243/264 243/265 241/266 239/262 243/268 240/262 242/263 70%/90% 291/334 293/324 293/335 291/327 291/333 294/337 292/337 292/333 95%/EP 348/368 350/369 356/367 348/367 351/365 356/367 357/369 350/368 Diesel yield, wt% 98.2 98.1 97.9 99.3 97.4 97.1 95.7 94.7 cetane number 34.7 34.7 34.5 34.6 35.9 33.9 32.2 33.8 cetane number increase 9.7 9.7 9.5 9.6 10.9 8.9 7.2 8.8 freezing point, ℃ -twenty four -27 -25 -29 -twenty four -twenty one -15 -16 Nitrogen, μg.g ^-1 2.8 2.7 3.0 2.8 2.6 2.7 2.6 3.2 Sulfur, μg.g ^-1 27 27 29 25 twenty two 29 35 36

It can be seen from the data in Table 1 that although the total infrared acidity of the modified Y-type zeolite has little change, the proportion of B acid is greatly reduced, while the increase of the proportion of L acid is greatly improved. As can be seen from the reaction results in Table 4, compared with Comparative Example 4, the catalyst of the present invention is extremely beneficial to reducing the cracking of diesel oil fractions, ensuring the yield of diesel oil, improving the cetane number of diesel oil and the selectivity of isomerization reaction.

The modified Y zeolite and ZSM-23 zeolite are used in the catalyst of the present invention at the same time. Through the synergistic effect of the two zeolites, the catalyst has better ring-opening ability of aromatic hydrocarbons and better isomerization activity at the same time, and the pore size of the catalyst is 4-10nm The pore distribution accounts for 75%-90% of the total pore volume, and the pore size is very concentrated, which is conducive to the diffusion of raw material oil and better catalytic activity. As can be seen from the results in Table 4, the catalyst of the present invention is used to improve the quality of diesel oil cuts, and has a very high yield of diesel oil cuts and a good pour point depressing effect. Under the same yield of diesel oil cuts, the freezing point of the product is reduced by 16- At 23°C, the cetane number increases by 8.9-10.9 units, which is obviously better than that of the comparative catalyst.

In the catalyst of the present invention, compared with the catalyst prepared by non-small grain ZSM-23 zeolite, the catalyst reaction active center containing small grain ZSM-23 zeolite increases, and the channel of small grain ZSM-23 zeolite becomes shorter, which is beneficial to the reaction Diffusion of products and products, so that the yield of diesel oil is increased, and the freezing point is lowered to a greater extent. Among the catalysts of the present invention, the catalyst prepared by using modified alumina is compared with the catalyst prepared by ordinary alumina (Example 8 and Example 13), the yield of diesel oil is high, the cetane number increase is large, and the freezing point is lowered. big.

In addition, the activity and selectivity of the catalyst did not decrease after 1200 hours of operation, indicating that the catalyst of the present invention has low cracking activity, high diesel isomerization pour point depressing activity, hydrogenation modification activity and good stability.

Claims (13)

1, a kind of catalyst for hydrogenation of fraction oil, wherein active metal component is one or more in group vib and the group VIII metal, it is characterized in that described catalyzer is a carrier with modified Y zeolite, ZSM-23 zeolite and aluminum oxide, contain group vib and/or group VIII metallic element 2wt%～10wt% in the described modified Y zeolite, SiO ₂/ Al ₂O ₃Mol ratio is 9.0-12.9, and lattice constant is 2.440-2.459nm, and specific surface area is 550-650m ²/ g, pore volume are 0.340-0.370ml/g, and infrared acidity is 1.37～1.60mmol/g, and wherein the mol ratio of B acid and L acid is 1: 3～1: 5, Na ₂O weight content＜0.2%.

2, according to the described catalyzer of claim 1, it is characterized in that each components contents is as follows in the described catalyzer: the weight with catalyzer is benchmark, the content of group vib metal oxide is 10%-30%, and the content of group VIII metal oxide is 1%-10%; The content of modified Y zeolite is 1%-20%; The content of ZSM-23 zeolite is 1%-30%; The content of aluminum oxide is 5%-80%; The content of tackiness agent is 0-30%.

3, according to the described catalyzer of claim 1, it is characterized in that each components contents is as follows in the described catalyzer: the weight with catalyzer is benchmark, and the content of group vib metal oxide is 10%-25%; The content of group VIII metal oxide is 1%-9%; The content of modified Y zeolite is 5%-15%; The content of ZSM-23 zeolite is 5%-20%; The content of aluminum oxide is 15%-70%; The content of tackiness agent is 0-20%.

4,, it is characterized in that group vib in the described modified Y zeolite and/or group VIII metallic element are one or more among W, Ni, Co, Fe, the Mo according to the described catalyzer of claim 1.

5, according to the described catalyzer of claim 1, the specific surface area that it is characterized in that described catalyzer is 150-210m ²/ g, pore volume are 0.24-0.29ml/g, and wherein the aperture accounts for the 75%-85% of total pore volume in the pore distribution of 4-10nm, and infrared acidity is 0.32-0.38mmol/g.

6,, it is characterized in that the character of employed ZSM-23 zeolite is as follows: SiO according to the described catalyzer of claim 1 ₂/ Al ₂O ₃Mol ratio is 40-100, and infrared acidity is 0.1-0.4mmol/g, Na ₂O weight content＜0.2%.

7, catalyzer according to claim 6 is characterized in that described ZSM-23 zeolite is fine grain ZSM-5-23 zeolite, and its particle diameter is 1-100nm.

8, according to the described catalyzer of claim 1, it is characterized in that employed aluminum oxide is the aluminum oxide through additive modification, auxiliary agent content is counted 3wt%-7wt% with element, and wherein said auxiliary agent is one or more in boron, fluorine and the zirconium; The character of this modified aluminas: specific surface area is 320-370m ²/ g, pore volume are 0.7～1.1ml/g.

9, according to the described catalyzer of claim 1, it is characterized in that in the described active metal component, the group vib metal is Mo and/or W, the group VIII metal is one or more among Fe, Ni and the Co.

10, the arbitrary described Preparation of catalysts method of claim 1～9 comprises the steps:

(1) modified Y zeolite, ZSM-23 zeolite and aluminum oxide are mixed;

(2) in the mixture of step (1), add tackiness agent or directly add peptizing agent solution and mix and pinch into paste, extruded moulding;

(3),,, obtain support of the catalyst at 350～700 ℃ of roasting 1-12 hours 100～150 ℃ of dryings 0.5～24 hour with above-mentioned forming composition;

(4) preparation contains the dipping solution of group vib metal and/or group VIII metal;

(5) support of the catalyst of gained in 100～150 ℃ of dryings 0.5～24 hour, at 350～700 ℃ of roasting 1-12 hours, obtains the catalyzer finished product in the solution of step (4) configuration behind the dipping in the step (3).

11, in accordance with the method for claim 10, it is characterized in that used modified Y zeolite prepares as follows:

(1) super-hydrophobic Y zeolite is placed water, its mesolite is 1 with the ratio of the weight of water: 2-10, be warming up to 60 ℃-90 ℃, and stirred 0.5-2.0 hour;

(2) get and contain in group vib and/or the group VIII metal soluble salt one or more and be mixed with solution, add in above-mentioned steps (1) solution, with ammoniacal liquor regulator solution pH value, control pH value is 4-10, solution is under 50-90 ℃, stir fully exchange in aging 2-4 hour, after the filtration, made in dry 8-24 hour at 100 ℃-150 ℃.

12, in accordance with the method for claim 11, it is characterized in that described super-hydrophobic Y zeolite be by Y zeolite at 500～600 ℃, obtain after hydrothermal treatment consists 1-10 hour under 0.01～0.30MPa condition; Wherein the character of Y zeolite is as follows: NaO content is lower than 0.2wt%, silica alumina ratio 6-40, lattice constant 2.440-2.460nm.

13, Preparation of catalysts method according to claim 10 is characterized in that the described super-hydrophobic Y zeolite of step (1) and the ratio of the weight of water are 1: 3-8.