CN113751064A

CN113751064A - Hydrogenation catalyst composition and hydroisomerization process

Info

Publication number: CN113751064A
Application number: CN202010497322.7A
Authority: CN
Inventors: 毕云飞; 杨清河; 梁世航; 邢恩会; 王永睿; 郭庆洲; 黄卫国
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2020-06-04
Filing date: 2020-06-04
Publication date: 2021-12-07

Abstract

The invention relates to the field of hydroisomerization, in particular to a catalyst composition and a hydroisomerization method. The catalyst composition comprises a first catalyst and a second catalyst, wherein the first catalyst contains a carrier and an active metal component loaded on the carrier, and is characterized in that the carrier contains a ZSM-48 molecular sieve with a low silica-alumina ratio, and the preparation method of the ZSM-48 molecular sieve with the low silica-alumina ratio comprises the following steps: (1) preparing a pure silicon ZSM-48 molecular sieve intermediate with the relative crystallinity of more than or equal to 90 percent in the presence of inorganic alkali; (2) and (3) supplementing aluminum to the pure silicon ZSM-48 molecular sieve intermediate under the condition of inorganic alkali and recovering the product. The catalyst composition is used for Fischer-Tropsch wax modification to produce the lubricating oil base oil, so that a good pour point depression effect can be obtained, and the lubricating oil base oil is high in yield and high in viscosity index.

Description

Hydrogenation catalyst composition and hydroisomerization process

Technical Field

The invention relates to the field of hydrocarbon oil hydroisomerization, in particular to an isomerization catalyst composition and a hydrocarbon oil raw material hydroisomerization method.

Background

When raw oil with higher paraffin content is used for producing low-freezing point diesel oil or lubricating oil base oil, dewaxing treatment is required to reduce the freezing point and improve the low-temperature fluidity of the product. Isomerization of paraffins in the presence of a hydroisomerization catalyst can significantly improve the low temperature fluidity of the oil while maintaining a suitable viscosity.

The support material for hydroisomerization catalysts usually contains different types of molecular sieves, and a molecular sieve material having high acidity and high specific surface area is an excellent acidic catalyst. Meanwhile, the molecular sieve material has strong chemical stability and hydrothermal stability, and is difficult to be corroded and dissolved by reactants to be damaged. Compared with the commonly used homogeneous catalysts, the molecular sieve material catalyst can be directly recycled without separation, and simultaneously, the environment and products are not polluted, so that the preparation of new molecular sieve materials and the construction of new forms of known molecular sieves are always the research hotspots in the field.

CN104353484A discloses a preparation method of a cheap strong-acid hierarchical pore Beta zeolite, relating to a preparation method of a hierarchical pore Beta zeolite. The invention aims to solve the problem of acidity weakening of the existing desilication post-treatment hierarchical pore Beta zeolite molecular sieve. The method comprises the following steps: (1) calcining Beta zeolite to obtain microporous hydrogen type Beta zeolite; (2) adding the microporous hydrogen type Beta zeolite into an alkaline solution, stirring, washing and drying to obtain sodium type desiliconized hierarchical porous Beta zeolite; (3) adding the sodium desiliconized hierarchical pore Beta zeolite into an ammonium nitrate aqueous solution for exchange, and calcining to obtain hydrogen desiliconized hierarchical pore Beta zeolite; (4) and (3) adding the hydrogen-type desiliconized hierarchical pore Beta zeolite into an acid solution, stirring, washing, drying, and then repeating the step (3) to obtain the strong-acid hierarchical pore Beta zeolite.

In addition, CN103964458A discloses a Beta zeolite with high silica-alumina ratio hierarchical pore canals and a preparation method thereof. CN103073020A discloses a hierarchical pore zeolite molecular sieve and a preparation method and application thereof. CN1703490A discloses a catalyst combination method for producing lube base oil. The invention relates to a process for converting waxes containing heavy components to high quality lube basestocks by using a linear mesoporous molecular sieve having a near circular pore structure with an average diameter of 0.50nm to 0.65nm, wherein the difference between the maximum and minimum diameters is 0.05nm or less, followed by a molecular sieve beta zeolite catalyst. Both catalysts comprise one or more group VIII metals. For example, a cascaded two-bed catalyst system consisting of a first bed Pt/ZSM-48 catalyst followed by a second bed Pt/beta catalyst facilitates the treatment of heavy lube oils.

Disclosure of Invention

The invention aims to provide a hydrogenation catalyst composition, which is characterized by comprising a first catalyst and a second catalyst, wherein the first catalyst comprises a carrier containing a ZSM-48 molecular sieve with a low silica-alumina ratio and an active metal component loaded on the carrier, and the second catalyst comprises a carrier containing a ten-membered ring silica-alumina molecular sieve and an active metal component loaded on the carrier; the preparation method of the ZSM-48 molecular sieve with the low silica-alumina ratio is characterized by comprising the following steps: (1) carrying out hydrothermal crystallization on a first mixture of a silicon source, inorganic alkali and a first organic template agent to obtain a pure silicon ZSM-48 molecular sieve intermediate with the relative crystallinity of more than or equal to 90%, wherein the molar ratio of the first mixture is as follows: m⁺/SiO₂＝0.01～0.30、R1/SiO₂＝0.01～0.50、H₂O/SiO₂5-100, M is an alkali metal, and R1 is a first organic template;

(2) mixing the pure silicon ZSM-48 molecular sieve intermediate obtained in the step (1) with an aluminum sourceMixing inorganic base and an optional second organic template agent to obtain a second mixture, supplementing aluminum and recovering a product, wherein the molar ratio of the second mixture is as follows: SiO2₂/Al₂O₃＝5～500、M⁺/SiO₂＝0.01～0.30、R₂/SiO₂＝0～0.50、H₂O/SiO₂And R2 is a second organic template agent, wherein R is 5-30.

The catalyst composition is applied to processing of hydrocarbon oil raw materials, particularly used for isomerization reactions of hydrocarbon oil raw materials rich in paraffin, such as cracking tail oil isomerization, biological aviation kerosene production, C5C6 isomerization, Fischer-Tropsch synthetic wax processing and the like, and the obtained target product has low pour point and high yield.

Specifically, the present invention includes the following:

the present invention provides a catalyst composition comprising a first catalyst and a second catalyst; the first catalyst and the second catalyst both contain a carrier and an active metal component supported on the carrier; the carrier of the first catalyst contains a ZSM-48 molecular sieve with low silica-alumina ratio; the carrier of the second catalyst contains a ten-membered ring silicoaluminophosphate molecular sieve.

According to the catalyst composition provided by the invention, the carrier of the first catalyst and the second catalyst can also contain a molecular sieve with other configurations and/or a heat-resistant inorganic oxide component except the molecular sieve, the molecular sieve with other configurations can be selected from one or more of ZSM-22 molecular sieve, ZSM-23 molecular sieve, SAPO-11 molecular sieve, ZSM-5 molecular sieve, SSZ-32 molecular sieve and Eu-1 molecular sieve, and the heat-resistant inorganic oxide except the molecular sieve is selected from one or more of alumina, alumina-magnesia, silica-alumina-titania, silica-alumina-magnesia and silica-alumina-zirconia. When the respective carriers contain the molecular sieves with other configurations and/or the refractory inorganic oxide components except the molecular sieves, the carrier of the first catalyst contains 10-100 wt% of the ZSM-48 molecular sieve, 0-90 wt% of the molecular sieves with other configurations and 0-60 wt% of the refractory inorganic oxide components except the molecular sieves. The content of the ten-membered ring silicon-aluminum molecular sieve in the second catalyst is 10-100 wt%, the content of the molecular sieve with other configuration is 0-90 wt%, and the content of the heat-resistant inorganic oxide except the molecular sieve is 0-60 wt%.

The mole ratio of silicon oxide to aluminum oxide in the low-silicon-aluminum-ratio ZSM-48 molecular sieve is preferably SiO₂/Al₂O₃Less than or equal to 200, for example, 20-200.

According to the catalyst composition provided by the invention, aluminum in the low silica-alumina ratio ZSM-48 molecular sieve is basically present in the framework of the molecular sieve; preferably, by²⁷And (3) an Al MAS (MASs spectrometry) NMR spectrum for characterization, wherein the aluminum in the low-silica-alumina-ratio ZSM-48 molecular sieve exists in a framework aluminum form.

According to the catalyst composition provided by the invention, the active metal in the first catalyst and the active metal in the second catalyst are active metal components commonly used in hydroisomerization catalysts, and may be the same or different, and specifically, the active metal may be at least one of group VIII metal components, and is preferably at least one of group VIII noble metal components. The active metal content and the carrier content in the first catalyst and the second catalyst can be the same or different, and can be the content of a conventional isomerization catalyst, for example, the content of the carrier is 99-99.9 wt% based on the catalyst, and the content of the active metal component in a reduced state is 0.1-1.0 wt%.

The preparation method of the first catalyst and the second catalyst of the invention is a conventional method, for example, according to the requirements of each component in the product, the active metal component is introduced into the carrier by an impregnation method, and then subsequent drying and optional roasting are carried out.

In order to obtain the first catalyst or the second catalyst in the catalyst composition, the respective molecular sieve, the low silica alumina ratio ZSM-48 molecular sieve or the ten-membered ring silica alumina molecular sieve can be obtained firstly, the molecular sieve is used as a carrier or the molecular sieve with other configurations and/or the heat-resistant inorganic oxide components except the molecular sieve are used for preparing the carrier, and then the active metal components are loaded by adopting the conventional method to obtain the first catalyst or the second catalyst. The method for forming the carrier by the ZSM-48 molecular sieve or the ten-membered ring silicon-aluminum molecular sieve with low silicon-aluminum ratio and other configuration molecular sieves and/or heat-resistant inorganic oxides is a conventional method in the field, generally, the carrier raw material can be mixed and added with a proper auxiliary agent for extrusion molding, and then the corresponding carrier is obtained by drying and optional roasting.

The supporting method of the present invention is not particularly limited as long as it is sufficient to support the active metal component on the support, and a preferable method is an impregnation method comprising preparing an impregnation solution of the metal-containing compound and thereafter impregnating the support with the solution. The impregnation method is a conventional method, and for example, the impregnation method can be excess liquid impregnation and pore saturation impregnation. The compound containing the active metal component is selected from one or more soluble compounds of the compounds, such as tetraammineplatinum dichloride, chloroplatinic acid, platinum acetate, platinum nitrate, tetrachlorodiamminepalladium, chloropalladate, palladium acetate and palladium nitrate.

When the catalyst further contains an auxiliary, the method for introducing the auxiliary component may be any method, for example, the carrier may be impregnated after the compound containing the auxiliary component and the compound containing the active metal component are prepared into a mixed solution; or preparing a compound containing the auxiliary agent component into a solution separately, impregnating the carrier and roasting. When the adjuvant component and the active metal are introduced separately to the support, it is preferred that the support is first impregnated with a solution containing the compound of the adjuvant component and calcined, followed by impregnation with a solution containing the compound of the active metal component. Wherein, the roasting temperature is 400-600 ℃, preferably 420-500 ℃, and the roasting time is 2-6 hours, preferably 3-6 hours.

According to the preparation method provided by the invention, the catalyst is used as a reference, and the content of active metal in the final catalyst in a reduction state is 0.1-1.0 wt%.

In the catalyst composition of the present invention, the arrangement of the first catalyst and the second catalyst is not particularly limited. In a particular application or reactor, the first catalyst may be disposed upstream and the second catalyst downstream along the flow of the reactant stream such that the reactant material first contacts and reacts with the first catalyst and then contacts and reacts with the second catalyst; alternatively, the second catalyst may be disposed upstream and the first catalyst disposed downstream such that the reaction mass first contacts the second catalyst for reaction and then contacts the first catalyst for reaction; or the first catalyst and the second catalyst are arranged in a staggered way, so that the reaction materials are sequentially and alternately in contact reaction with the first catalyst and the second catalyst. Preferably, the first catalyst is disposed upstream.

The ratio of the first catalyst to the second catalyst is not particularly limited in the present invention, and may be selected conventionally or specifically depending on the nature of the reaction material and the purpose of processing, and for example, the weight ratio of the first catalyst to the second catalyst may be 1:0.1 to 10, preferably 1:2 to 5.

The invention also provides a hydrocarbon oil raw material hydroisomerization method, which comprises the step of carrying out contact reaction on the hydrocarbon oil raw material and any one of the combined catalysts provided by the invention under the hydroisomerization condition.

The hydroisomerization conditions in the process of the invention are conventional conditions, such as: the temperature is 250-400 ℃, preferably 300-350 ℃; the pressure is 1-30MPa, preferably 5-20 MPa; the space velocity is 0.1-3h^-1Preferably 0.5 to 2h^-1(ii) a The volume ratio of the hydrogen to the oil is 50-1000, preferably 400-600.

According to the hydroisomerization method provided by the invention, the hydrocarbon oil raw material is preferably raw oil rich in paraffin, preferably one or more of self-cracking tail oil, biological aviation kerosene production raw material, C5C6 isomerization raw material and Fischer-Tropsch synthetic wax.

Drawings

FIG. 1 is an XRD spectrum of a sample of the molecular sieve synthesized in preparation example 1;

FIG. 2 shows a sample of the molecular sieve synthesized in preparation example 1²⁷Al MAS NMR spectrum.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The invention provides a catalyst composition, which comprises a first catalyst and a second catalyst, wherein the first catalyst contains a carrier containing a ZSM-48 molecular sieve with a low silica-alumina ratio and an active metal component loaded on the carrier, and the second catalyst contains a carrier containing a ten-membered ring silica-alumina molecular sieve and an active metal component loaded on the carrier; the preparation method of the ZSM-48 molecular sieve with the low silica-alumina ratio is characterized by comprising the following steps:

(1) carrying out hydrothermal crystallization on a first mixture of a silicon source, inorganic alkali and a first organic template agent to obtain a pure silicon ZSM-48 molecular sieve intermediate with the relative crystallinity of more than or equal to 90%, wherein the molar ratio of the first mixture is as follows: m⁺0.01-0.30% of/SiO 2, 0.01-0.50% of R1/SiO2, 5-100% of H2O/SiO2, wherein M is an alkali metal, and R1 is a first organic template;

(2) mixing the pure silicon ZSM-48 molecular sieve intermediate obtained in the step (1) with an aluminum source, an inorganic base and an optional second organic template agent to obtain a second mixture, supplementing aluminum and recovering a product, wherein the molar ratio of the second mixture is as follows: 5-500% SiO2/Al2O3, M⁺/SiO2＝0.01～0.30、R₂0-0.50% of/SiO 2, 5-30% of H2O/SiO2, and R2 is a second organic template.

The preparation method of the first catalyst and the second catalyst in the present invention is not particularly limited, and the supported catalyst can be prepared according to a conventional method for preparing a supported catalyst by using the carrier defined in the present invention. The supporting method of the present invention is not particularly limited as long as it is sufficient to support the active metal component on the support, and a preferable method is an impregnation method comprising preparing an impregnation solution of the metal-containing compound and thereafter impregnating the support with the solution. The impregnation method is a conventional method, and for example, the impregnation method can be excess liquid impregnation and pore saturation impregnation. The compound containing the active metal component is selected from one or more soluble compounds in the compound.

In the case of the first catalyst and the second catalyst, it is also possible to introduce a promoter component, such as a phosphorus component, which enhances the catalyst performance. When the catalyst further contains an additional component such as phosphorus, the additional component may be introduced by any method, for example, a compound containing the component such as phosphorus and a compound containing an active metal component may be formulated into a mixed solution, and then the carrier may be impregnated; or preparing a compound containing phosphorus and the like into a solution separately, impregnating the carrier and roasting. When the additive component such as phosphorus and the like and the active metal are introduced separately into the carrier, it is preferable that the carrier is first impregnated with a solution containing a compound of the additive component and calcined, and then impregnated with a solution containing a compound of the active metal component. Wherein, the roasting temperature is 400-600 ℃, preferably 420-500 ℃, and the roasting time is 2-6 hours, preferably 3-6 hours.

According to the catalyst provided by the invention, the silicon source, the aluminum source and the template agent in the step of preparing the low silica-alumina ratio ZSM-48 molecular sieve are all conventionally selected in the field, for example, the silicon source is a silicon-containing compound which can be stably dispersed in an aqueous phase and form a uniform colloidal solution, and preferably at least one of silica sol, white carbon black or ethyl orthosilicate; the aluminum source is selected from one or more of aluminum chloride, aluminum sulfate, aluminum hydroxide, sodium metaaluminate and aluminum sol, and is preferably sodium metaaluminate and/or aluminum sol; the first organic template and the second organic template are respectively and independently selected from one or a mixture of more of ethylenediamine, 1, 3-propanediamine, 1, 4-butanediamine, 1, 5-pentanediamine, 1, 6-hexanediamine, 1, 7-heptanediamine, 1, 8-octanediamine, 1, 9-nonanediamine and the diamine with substituent groups; the organic template is preferably at least one member selected from the group consisting of ethylenediamine, 1, 5-pentamethylenediamine, 1, 6-hexamethylenediamine, 1, 7-heptamethylenediamine, and substituted diamines, preferably 1, 6-hexamethylenediamine. When the templating agent is added in step (2), the second templating agent is preferably the same as the first templating agent, more preferably, both the first and second templating agents are 1, 6-hexanediamine. The inorganic base is preferably NaOH and/or KOH.

According to the catalyst provided by the invention, the raw material ratio can be adjusted according to the requirements of the final low silica alumina ratio ZSM-48 molecular sieve, and preferably, in the hydrothermal crystallization step, the molar ratio of the first mixture is as follows: m⁺/SiO₂＝0.01～0.20、R1/SiO₂＝0.03～0.30、H₂O/SiO₂20-50 parts of the total weight; in the aluminum supplementing step, the molar ratio of the second mixture is as follows: SiO2₂/Al₂O₃＝20～200、M⁺/SiO²＝0.01～0.20、R₂/SiO₂＝0～0.20、H₂O/SiO₂＝5～20。

According to the catalyst provided by the invention, the purpose of the hydrothermal crystallization in the step (1) is to obtain a pure silicon ZSM-48 molecular sieve intermediate with the crystallinity of more than or equal to 90%, preferably more than or equal to 95%, the temperature of the hydrothermal crystallization is preferably 100-180 ℃, more preferably 140-180 ℃, and the time of the hydrothermal crystallization is preferably 4-240 hours, more preferably 12-96 hours. In the present invention, the pure silicon molecular sieve refers to a molecular sieve having a silicon-aluminum molecular ratio of more than 500 as determined by an XRF method, in which no aluminum is contained or a very small amount of aluminum taken in by the silicon source itself is contained. Therefore, in order to obtain a pure silicon molecular sieve with higher purity, no aluminum source is added in the step (1), and the silicon source can be controlled, preferably, SiO in the silicon source₂/Al₂O₃Not less than 300.

According to the catalyst of the invention, the pure silicon ZSM-48 molecular sieve obtained in the step (1) is used as an intermediate product, and the form of the pure silicon ZSM-48 molecular sieve is selected from one of the following forms: (a) a molecular sieve slurry; (b) filtering and washing the molecular sieve slurry to obtain a molecular sieve filter cake; (c) filtering, washing and drying the molecular sieve raw powder; (d) filtering, washing, drying and roasting to remove the molecular sieve of the organic template agent. Then, the intermediates in the above forms are subjected to the reaction in the step (2). To better obtain the desired pure silicon ZSM-48 molecular sieve intermediate, a small amount of pure silicon ZSM-48 seed crystals may be added to the first mixture. Wherein the small amount is, for example, within about 1 wt%, or within about 0.5 wt%, or within about 0.1 wt% of the total pure silicon ZSM-48 molecular sieve, relative to the total amount of pure silicon ZSM-48 molecular sieve prepared in step (1).

The ten-membered ring silica-alumina molecular sieve in the second catalyst may be a commercial product or may be prepared according to the existing method, which is not limited thereto. In the catalyst composition of the present invention, the type of the ten-membered ring aluminosilicate molecular sieve is not particularly limited, and may be, for example, at least one of a ZSM-22 molecular sieve, a ZSM-23 molecular sieve, a SAPO-11 molecular sieve, a ZSM-5 molecular sieve, an SSZ-32 molecular sieve and an Eu-1 molecular sieve. Preferably, the ten-membered ring silicoaluminophosphate molecular sieve is a ZSM-22 molecular sieve and/or a SAPO-11 molecular sieve. Generally, the preparation of the ten-membered ring silicon-aluminum molecular sieve can be divided into steps of colloid formation, crystallization, post-treatment and the like, and the conditions of each step are the conventional conditions.

The present invention will be described in detail with reference to examples, but the scope of the present invention is not limited thereto.

In the examples below, the chemical composition of the molecular sieve was determined by X-ray fluorescence (XRF). The relative crystallinity is expressed by percentage according to the ratio of the sum of the peak heights of two characteristic diffraction peaks of 20-24 degrees of 2 theta of an X-ray diffraction (XRD) spectrum of the obtained product and a ZSM-48 molecular sieve standard sample. The ZSM-48 molecular sieve synthesized using the method of example 5 in US4423021 was used as a standard and its crystallinity was determined to be 100%. XRD was measured on a SIMENS D5005 model X-ray diffractometer with CuK α radiation, 44 kv, 40 ma and a scan speed of 2 °/min. XRF test instruments and conditions: the working voltage is 30kV, the working current is 100mA, the PET crystal, the standard collimator, the PC detector and the visual field grating are 30 mm.

²⁷The Al MAS NMR spectrum is obtained by a Bruker AVANCE III 600WB type nuclear magnetic resonance spectrometer test, and the test conditions are as follows: the resonance frequency is 78.155MHz, the magic angle rotating speed is 5kHz, the pulse width is 1.6 mus, the cycle delay time is 1s, and the scanning times are 8000 times.

ZSM-48 molecular sieve preparation

Preparation example 1

400g of silica sol (Shandong Yiming Industrial Co., Ltd., 30% SiO)₂) 7g of NaOH, 48g of 1, 6-hexanediamine (analytical grade, chemical Co., Ltd., national pharmaceutical Co., Ltd.) and 260g ofWater was mixed well and the reaction mixture had the following composition (moles/mole, expressed as oxides): m⁺/SiO₂＝0.1；R/SiO₂＝0.2；H₂O/SiO₂15. The mixture is put into a crystallization kettle, the temperature is raised to 160 ℃, and hydrothermal dynamic crystallization is carried out for 48 hours. After crystallization, pure silicon ZSM-48 molecular sieve raw powder with the crystallinity of 90 percent is obtained by filtering, washing and drying.

The molecular sieve was supplemented with aluminium, 20g of the above pure silica molecular sieve was mixed homogeneously with 2.26g of sodium metaaluminate, 0.8g of naoh, 53g of water, the mixture having the following composition (mol/mol, expressed as oxides): SiO2₂/Al₂O₃＝110，M⁺/SiO₂＝0.1，H₂O/SiO₂9. And uniformly mixing the mixture, putting the mixture into a crystallization kettle, heating the mixture to 150 ℃, and carrying out hydrothermal crystallization for 23 hours. After crystallization, filtering, washing and drying to obtain the silicon-aluminum molecular sieve S1.

By XRD testing (FIG. 1), sample S1 was ZSM-48 with a relative crystallinity of 99% and a silica to alumina ratio of 100. From²⁷As can be seen in the Al MAS NMR spectrum (FIG. 2), the complete insertion of aluminum into the framework produced skeletal aluminum, with no significant non-skeletal aluminum.

Preparation example 2

281g of tetraethoxysilane (containing 28% SiO)₂Beijing Chemicals company), 10.5g NaOH, 16.5g 1, 6-hexanediamine and 378g water were mixed thoroughly and homogeneously, the reaction mixture having the following composition (mol/mol, expressed as oxides): m⁺/SiO₂＝0.2；R/SiO₂＝0.1；H₂O/SiO₂16. The mixture is put into a crystallization kettle, the temperature is raised to 160 ℃, and hydrothermal dynamic crystallization is carried out for 48 hours. After crystallization, the molecular sieve slurry (obtained by filtering, washing and drying the molecular sieve slurry, and determining the crystallinity of the obtained pure silicon molecular sieve to be 91%) is directly used for aluminum supplement.

The above pure silica molecular sieve slurry, containing 20g dry basis, was mixed well with 4.9g sodium metaaluminate, 1g naoh, 0.5g 1, 6-hexanediamine and appropriate amount of water, the mixture having the following composition (moles/mole, expressed as oxides): SiO2₂/Al₂O₃＝51，M⁺/SiO₂＝0.17，R/SiO₂＝0.01，H₂O/SiO ₂20. And uniformly mixing the mixture, putting the mixture into a crystallization kettle, heating the mixture to 160 ℃, and carrying out hydrothermal crystallization for 24 hours. After crystallization, filtering, washing and drying to obtain the silicon-aluminum molecular sieve S2.

XRD showed that sample B2 was ZSM-48 with 98% relative crystallinity and 50% Si/Al ratio.²⁷The Al MAS NMR spectrum showed that the complete insertion of aluminum into the framework produced framework aluminum, with no significant non-framework aluminum.

Preparation example 3

200g of silica sol, 6.7g of NaOH,18g of 1, 6-hexamethylenediamine and 220g of water are mixed thoroughly and homogeneously, the reaction mixture having the following composition (moles/mole, expressed in the form of the oxides): m⁺/SiO₂＝0.167；R/SiO₂＝0.15；H₂O/SiO ₂20. The mixture is put into a crystallization kettle, the temperature is raised to 140 ℃, and hydrothermal dynamic crystallization is carried out for 48 hours. After crystallization, pure silicon ZSM-48 molecular sieve raw powder with the crystallinity of 93 percent is obtained by filtering, washing and drying.

31g of pure silicon molecular sieve was mixed homogeneously with 4.8g of sodium metaaluminate, 2g of NaOH, 14g of 1, 6-hexanediamine (analytical purity, chemical reagents of the national pharmaceutical group Ltd.), 137g of water, the mixture having the following composition (mol/mol, expressed as oxides): SiO2₂/Al₂O₃＝80，M⁺/SiO₂＝0.15，R/SiO₂＝0.23，H₂O/SiO₂15. And uniformly mixing the mixture, putting the mixture into a crystallization kettle, heating the mixture to 160 ℃, and carrying out hydrothermal crystallization for 20 hours. After crystallization, the molecular sieve S3 is obtained by filtering, washing and drying.

XRD showed that sample S3 was ZSM-48 with a relative crystallinity of 105% and a silica to alumina ratio of 78.²⁷The Al MAS NMR spectrum showed that the complete insertion of aluminum into the framework produced framework aluminum, with no significant non-framework aluminum. Relative crystallinity of S3, 105%, silicon to aluminum ratio 78.

Preparation example 4

200g of silica sol, 10g of NaOH, 12g of 1, 6-hexamethylenediamine and 400g of water are mixed thoroughly and homogeneously, the reaction mixture having the following composition (moles/mole, expressed in the form of the oxides): m⁺/SiO₂＝0.25；R/SiO₂＝0.1；H₂O/SiO ₂30. The mixture is put into a crystallization kettle, the temperature is raised to 160 ℃, and hydrothermal dynamic crystallization is carried out for 48 hours. Filtering, washing and drying after crystallization is finished, and roasting for 3 hours at 580 ℃ to obtain the pure silicon ZSM-48 molecular sieve (the crystallinity is 95%).

The molecular sieve was supplemented with aluminium, 20g of the above pure silica molecular sieve was mixed homogeneously with 5g of sodium metaaluminate, 1.4g of naoh, 120g of water, the mixture having the following composition (mol/mol, expressed in oxide form): SiO2₂/Al₂O₃＝50，M⁺/SiO₂＝0.2，H₂O/SiO ₂20. And uniformly mixing the mixture, putting the mixture into a crystallization kettle, heating the mixture to 160 ℃, and carrying out hydrothermal crystallization for 23 hours. After crystallization, filtering, washing and drying to obtain the silicon-aluminum molecular sieve S4.

XRD showed that sample S4 was ZSM-48 with 102% relative crystallinity and 48 Si/Al ratio.²⁷The Al MAS NMR spectrum showed that the complete insertion of aluminum into the framework produced framework aluminum, with no significant non-framework aluminum.

Preparation example 5

140g of ethyl orthosilicate (containing 28% SiO)₂Beijing Chemicals company), 2.2g of NaOH, 16g of 1, 6-hexanediamine and 360g of water were mixed thoroughly and homogeneously, the reaction mixture having the following composition (mol/mol, expressed in the form of the oxides): m⁺/SiO₂＝0.08；R/SiO₂＝0.2；H₂O/SiO ₂30. The mixture is put into a crystallization kettle, the temperature is raised to 160 ℃, and hydrothermal dynamic crystallization is carried out for 48 hours. After crystallization, the aluminum is directly supplemented by molecular sieve slurry (the molecular sieve slurry is filtered, washed and dried, and the crystallinity of the obtained pure silicon molecular sieve is determined to be 96%).

The above pure silica molecular sieve slurry, containing 40g dry basis, was mixed well with 4.9g sodium metaaluminate, 0.08g naoh, 8g1, 6-hexanediamine and appropriate amount of water, the mixture having the following composition (moles/mole, expressed as oxides): SiO2₂/Al₂O₃＝102，M⁺/SiO₂＝0.05，R/SiO₂＝0.1，H₂O/SiO ₂20. And uniformly mixing the mixture, putting the mixture into a crystallization kettle, heating the mixture to 160 ℃, and carrying out hydrothermal crystallization for 24 hours. After crystallization, filtering, washing and drying to obtain the silicon-aluminum molecular sieve S5.

XRD showed that sample B5 was ZSM-48 with a relative crystallinity of 105% and a silica to alumina ratio of 99.²⁷The Al MAS NMR spectrum showed that the complete insertion of aluminum into the framework produced framework aluminum, with no significant non-framework aluminum.

Preparation example 6

200g of silica sol, 4g of NaOH, 30g of 1, 6-hexamethylenediamine and 220g of water are mixed thoroughly and homogeneously, the reaction mixture having the following composition (moles/mole, expressed in the form of the oxides): m⁺/SiO₂＝0.1；R/SiO₂＝0.25；H₂O/SiO ₂20. The mixture is put into a crystallization kettle, the temperature is raised to 140 ℃, and hydrothermal dynamic crystallization is carried out for 48 hours. After crystallization is finished, the ZSM-48 filter cake is used as an intermediate product for the next step of aluminum supplement, and the crystallinity of the molecular sieve is measured to be 95%.

58g of pure silicon molecular sieve were mixed homogeneously with 4.8g of sodium metaaluminate, 4.5g of NaOH, 23g of 1, 6-hexanediamine (analytical purity, national chemical group, Ltd.), 310g of water, the mixture having the following composition (mol/mol, expressed as oxides): SiO2₂/Al₂O₃＝151，M⁺/SiO₂＝0.15，R/SiO₂＝0.2，H₂O/SiO₂18. And uniformly mixing the mixture, putting the mixture into a crystallization kettle, heating the mixture to 160 ℃, and carrying out hydrothermal crystallization for 20 hours. After crystallization, filtering, washing and drying to obtain the silicon-aluminum molecular sieve S6.

XRD showed that sample S6 was ZSM-48 with a relative crystallinity of 105% and a silica to alumina ratio of 140.²⁷The Al MAS NMR spectrum showed that the complete insertion of aluminum into the framework produced framework aluminum, with no significant non-framework aluminum.

Preparation example 7

45 g of white carbon black and 1.25 g of analytically pure Al are taken₂(SO₄)₃·18H₂O, 1.88 g of analytically pure NaOH and 39.3 g of hexamethylenediamine are used. Mixing hexanediamine, white carbon black and 200g of deionized water, and adding NaOH and Al₂(SO₄)₃·18H₂O and 272 g of deionized water, then mixing the two solutions, stirring for 1h, transferring the mixture into a reaction kettle, and crystallizing the mixture for 72 hours at 160 ℃. And after crystallization, filtering, washing and drying to obtain the molecular sieve S7 with the silicon-aluminum structure.

XRD shows that sample S7 is ZSM-48 with relative crystallinity of 99% and Si/Al ratio of 190.²⁷The Al MAS NMR spectrum showed that the complete insertion of aluminum into the framework produced framework aluminum, with no significant non-framework aluminum.

Preparation example 8

400g of silica sol, 13.56g of sodium metaaluminate, 48g of 1, 6-hexamethylenediamine, 4.8g of NaOH and 315g of water are mixed homogeneously, the mixture having the following molar composition: SiO2₂/Al₂O₃＝110、M⁺/SiO₂＝0.1、R/SiO₂＝0.2,H₂O/SiO₂And (9) uniformly mixing the mixture, putting the mixture into a crystallization kettle, and heating the mixture to 160 ℃ for hydrothermal crystallization for 50 hours. After crystallization, a molecular sieve sample S8 is obtained through filtering, washing and drying, and the sample is a ZSM-22 molecular sieve with a silica-alumina ratio of 98 through XRD test.

Preparation example 9

The difference from example 1 is that the hydrothermal dynamic crystallization is changed to 12h, 24h and 36h, and the corresponding ZSM-48 molecular sieve intermediate product crystallinities are 0%, 26% and 78%, respectively. And (3) carrying out hydrothermal aluminum supplement on the three ZSM-48 molecular sieves which are not completely crystallized to respectively obtain three molecular sieve samples S9-11. XRD tests show that the three samples are ZSM-5 molecular sieves with the silica-alumina ratio of 98.

Preparation of ten-membered ring molecular sieve:

preparation example 10

36.3 g of a 40% by weight SiO solution were taken₂1.77 g of analytically pure Al₂(SO₄)₃·18H₂O, 3.94 g of analytically pure KOH and 8.44 g of hexamethylenediamine are used. Mixing hexamethylenediamine with silica sol, adding KOH and Al₂(SO₄)₃·18H₂O and 89.4 g of deionized water, then mixing the two solutions, stirring for 1 hour, transferring the mixture into a reaction kettle, and crystallizing for 72 hours at 160 ℃. The synthesized molecular sieve is a ZSM-22 molecular sieve and is named as S12.

Examples of preparation of catalysts

The molecular sieves S1-S7 and S12 obtained in the above preparation examples 1-7 and 10 were used to prepare catalysts, and the procedure was: 60 grams of molecular sieve was mixed with 20 grams of alumina and mixed with 80 grams of a 2% nitric acid solution. And forming on a strip extruding machine. The shaped support was calcined at 600 ℃ for 4 hours. 0.5% of Pt was supported on the carrier, and then calcined in air and reduced in hydrogen gas at 400 ℃ for 4 hours, respectively. Wherein the catalysts obtained from S1-S6 are respectively named as CI-1 to CI-6, and the catalysts obtained from S7 and S12 are respectively DCI-1 and CII-1.

Examples 1 to 7

The obtained catalyst and a commercial catalyst RIW-2 are loaded in a first reactor and a second reactor of a high-pressure hydrogenation reactor according to the scheme in the table 1 to obtain the catalyst composition. The cracking tail oil raw material is injected into a reactor from top to bottom for reaction. And after the reaction is finished, distilling the product to cut off light components with the temperature of less than 370 ℃, and analyzing the components with the temperature of more than 370 ℃ and calculating the yield.

TABLE 1 filling scheme

Examples	First reactor	Second reactor
			1	CI-1，80g	CII，100g
2	CI-2，100g	CII，100g
			3	CI-3，100g	CII，80g
4	CI-4，100g	CII，100g
			5	CI-5，200g	RIW-2，100g
6	CI-6，80g	RIW-2，100g
			Comparative example 1	DCI-1，80g	CII，100g

TABLE 2 cracked tail oil Properties

Analysis item	Analyzing data	Analytical method
			Density/(kg/m) at 20 DEG C³)	843.6	SH/T0604-2000
Kinematic viscosity/(mm)²/s)
			80℃	7.021	GB/T 265-88
100℃	4.664	GB/T 265-88
			Pour point/. degree.C	+42
Mass fraction of nitrogen/(μ g/g)	<1
			Sulfur mass fraction/(μ g/g)	3	SH/T 0842-2010

TABLE 3

TABLE 4

As can be seen from the data in Table 4 above, the Fischer-Tropsch wax modification method for producing lubricating base oil according to the present invention can achieve a good pour point depressing effect, and the lubricating base oil has high yield and high viscosity index.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A catalyst composition comprising a first catalyst comprising a support comprising a low silica to alumina ratio ZSM-48 molecular sieve and an active metal component supported on the support, and a second catalyst comprising a support comprising a ten-membered ring silica alumina molecular sieve and an active metal component supported on the support; the preparation method of the ZSM-48 molecular sieve with the low silica-alumina ratio is characterized by comprising the following steps:

(1) carrying out hydrothermal crystallization on a first mixture of a silicon source, inorganic alkali and a first organic template agent to obtain a pure silicon ZSM-48 molecular sieve intermediate with the relative crystallinity of more than or equal to 90%, wherein the molar ratio of the first mixture is as follows: m⁺/SiO₂＝0.01～0.30、R1/SiO₂＝0.01～0.50、H₂O/SiO₂5-100, M is an alkali metal, and R1 is a first organic template;

(2) mixing the pure silicon ZSM-48 molecular sieve intermediate obtained in the step (1) with an aluminum source, an inorganic base and an optional second organic template agent to obtain a second mixture, supplementing aluminum and recovering a product, wherein the molar ratio of the second mixture is as follows: SiO2₂/Al₂O₃＝5～500、M⁺/SiO₂＝0.01～0.30、R₂/SiO₂＝0～0.50、H₂O/SiO₂And R2 is a second organic template agent, wherein R is 5-30.

2. The catalyst composition of claim 1, wherein the carrier of the first catalyst may further contain a molecular sieve with other configurations and/or a heat-resistant inorganic oxide other than the molecular sieve, wherein the molecular sieve with other configurations is one or more selected from a ZSM-22 molecular sieve, a ZSM-23 molecular sieve, a SAPO-11 molecular sieve, a ZSM-5 molecular sieve, an SSZ-32 molecular sieve and a Eu-1 molecular sieve, and the heat-resistant inorganic oxide other than the molecular sieve is one or more selected from alumina, alumina-magnesia, silica-alumina-titania, silica-alumina-magnesia and silica-alumina-zirconia; on the basis of a carrier, the content of the low silica alumina ratio ZSM-48 molecular sieve is 10-100 wt%, the content of the molecular sieve with other configuration is 0-90 wt%, and the content of the heat-resistant inorganic oxide except the molecular sieve is 0-60 wt%; the decatomic ring silicon-aluminum molecular sieve in the second catalyst is selected from one or more of ZSM-22 molecular sieve, ZSM-23 molecular sieve, SAPO-11 molecular sieve, ZSM-5 molecular sieve, SSZ-32 molecular sieve and Eu-1 molecular sieve.

3. The catalyst composition of claim 1, wherein the low silica to alumina ratio ZSM-48 molecular sieve has a silica to alumina molar ratio of SiO₂/Al₂O₃≤200。

4. The catalyst composition of claim 1, wherein the aluminum in the low silica to alumina ratio ZSM-48 molecular sieve is present as framework aluminum.

5. The catalyst composition of claim 1, wherein the silicon source is a silicon-containing compound capable of being stably dispersed in an aqueous phase and forming a uniform colloidal solution, preferably at least one of silica sol, silica white or ethyl orthosilicate; the aluminum source is selected from one or more of aluminum chloride, aluminum sulfate, aluminum hydroxide, sodium metaaluminate and aluminum sol, and is preferably sodium metaaluminate and/or aluminum sol; the first organic template and the second organic template are respectively and independently selected from one or a mixture of more of ethylenediamine, 1, 3-propanediamine, 1, 4-butanediamine, 1, 5-pentanediamine, 1, 6-hexanediamine, 1, 7-heptanediamine, 1, 8-octanediamine, 1, 9-nonanediamine and the diamine with substituent groups; the organic template is preferably at least one member selected from the group consisting of ethylenediamine, 1, 5-pentamethylenediamine, 1, 6-hexamethylenediamine, 1, 7-heptamethylenediamine, and substituted diamines, preferably 1, 6-hexamethylenediamine.

6. The catalyst composition of claim 1, wherein the molar ratio of the first mixture is: m⁺/SiO₂＝0.01～0.20、R1/SiO₂＝0.03～0.30、H₂O/SiO₂20-50 parts of the total weight; the molar ratio of the second mixture is as follows: SiO2₂/Al₂O₃＝20～200、M⁺/SiO²＝0.01～0.20、R₂/SiO₂＝0～0.20、H₂O/SiO₂＝5～20。

7. The catalyst composition of claim 1 wherein the inorganic base is NaOH and/or KOH.

8. The catalyst composition of claim 1, wherein when the templating agent is added in step (2), the second templating agent is the same as the first templating agent, preferably both the first and second templating agents are 1, 6-hexanediamine.

9. The catalyst composition of claim 1, wherein the crystallinity of the pure silicon ZSM-48 molecular sieve intermediate in step (1) is greater than or equal to 95%.

10. The catalyst composition of claim 1 wherein a small amount of pure silicon ZSM-48 seed crystals are added to said first mixture.

11. The catalyst composition of claim 1, wherein the conditions for hydrothermal crystallization in step (1) comprise: the temperature is 100-180 ℃, preferably 140-180 ℃, and the time is 4-240 hours, preferably 12-96 hours.

12. The catalyst composition of claim 1 wherein the active metal component of the first and second catalysts is independently selected from at least one of a group VIII noble metal component; preferably, the active metal components in the first and second catalysts are independently at least one selected from group VIII noble metal components; in the first catalyst, the content of the carrier containing the ZSM-48 molecular sieve with the low silica-alumina ratio is 99-99.9 wt%, and the content of active metal components in a reduced state is 0.1-1.0 wt%; in the second catalyst, the content of the carrier containing the ten-membered ring molecular sieve is 99-99.9 wt%, and the content of the active metal component in a reduced state is 0.1-1.0 wt%.

13. The catalyst composition of any of claims 1-12, wherein the first catalyst is disposed upstream and the second catalyst is disposed downstream in a flow direction of the reactant stream; or the second catalyst is disposed upstream and the first catalyst is disposed downstream.

14. The catalyst composition according to any one of claims 1 to 13, wherein the weight ratio of the first catalyst to the second catalyst is from 1:0.1 to 10, preferably from 1:2 to 5.

15. A hydroisomerization process comprising contacting a hydrocarbon oil feedstock with a catalyst composition according to any of claims 1-14 under hydroisomerization conditions.

16. The process of claim 15, wherein the hydroisomerization conditions comprise: the temperature is 250-400 ℃, preferably 300-350 ℃; the pressure is 1-30MPa, preferably 5-20 MPa; the space velocity is 0.1-3h^-1Preferably 0.5 to 2h^-1(ii) a The volume ratio of the hydrogen to the oil is 50-1000, preferably 400-600.

17. The method of claim 16, wherein the hydrocarbon oil feedstock is selected from one or more of cracked tail oil, bio-aviation kerosene production feedstock, C5C6 isomerization feedstock, Fischer-Tropsch wax.