Process for producing special oil products using a catalyst containing a beta-type molecular sieve and a shape-selective molecular sieve catalyst

Abstract

The present application relates to the field of special oil production, and discloses a method for producing special oil by using a Beta-type molecular sieve catalyst and a shape-selective molecular sieve catalyst. The method comprises: carrying out first hydrocracking reaction of hydrogen and mixed distillate oil with a first hydrocracking catalyst to obtain a first product, wherein the first hydrocracking catalyst comprises a first carrier and a first metal component, the first carrier contains a Beta-type molecular sieve, and the first metal component is a group VIB metal component; and carrying out second hydrocracking reaction of the first product with a second hydrocracking catalyst. The mixed distillate oil comprises a kerosene fraction and a diesel fraction, the mass content of the diesel fraction is 60-90% and the mass content of the kerosene fraction is 10-40% based on the total mass of the mixed distillate oil, and the organic nitrogen content of the mixed distillate oil is not higher than 60 μg / g. The method can obtain special oil products with low freezing point, high flash point and low viscosity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of special oil production, and particularly relates to a method for producing special oil by using a Beta-type molecular sieve catalyst and a shape-selective molecular sieve catalyst. BACKGROUND

[0002] The rectifier-inverter technology for converting alternating current into direct current power transmission requires special and better performance of the converter transformer oil, which has a low kinematic viscosity, a high flash point, excellent oxidation aging stability, high cleanliness, and gas separation.

[0003] In the currently operated power grid, the 800kV, 1000kV and above voltage level ultra-high voltage power grid in China adopts the rectifier-inverter technology, which requires better performance of the transformer oil, which not only requires moderate kinematic viscosity, but also requires maximum reduction of the condensation point of the oil and increase of the low-temperature fluidity of the oil. The dual requirements of high-temperature stability and low-temperature fluidity make extensive research in the technical development of special oil.

[0004] CN106753555B discloses a method for preparing low-aromatic transformer oil by pressure hydrogenation of naphthenic base oil fraction, which comprises the following steps: 1) the naphthenic base oil fraction enters a first hydrogenation reactor, and passes through a hydrogenation refining reaction zone and a deep de-aromatic reaction zone to realize hydrogenation removal of sulfur and nitrogen compounds in the oil and hydrogenation saturation of aromatic hydrocarbons; 2) the reaction stream enters a second reactor, and passes through a selective ring-opening reaction zone, an isomerization condensation reaction zone and a supplemental refining reaction zone to realize selective ring-opening of polycyclic compounds, isomerization of paraffin (branched chain) and saturation of cracked olefins; and 3) the reaction product is separated by gas-liquid separation and rectification to obtain a low-aromatic transformer oil fraction and a clean light oil fraction. The method is suitable for upgrading transformer oil base oil from naphthenic base crude oil and coal-based oil fraction, has the characteristics of simple process flow, small device investment scale and high operation safety, and has the technical advantages of high yield of transformer oil base oil, good product quality and environmental friendliness.

[0005] The prior art mainly prepares the product by means of naphthenic base fraction hydrogenation refining, high-density secondary processing diesel fraction hydrogenation cracking and naphthenic base VGO fraction hydrogenation cracking. This limits the application of the product due to the limited source of raw materials. SUMMARY

[0006] The present application aims to overcome the problems in the prior art and provides a method for producing special oil by using a Beta-type molecular sieve catalyst and a shape-selective molecular sieve catalyst. The method can produce special oil with low freezing point, low viscosity and high flash point.

[0007] To achieve the above object, the present application provides a method for producing special oil, comprising the following steps:

[0008] (1) subjecting hydrogen and mixed distillate oil to first hydrocracking reaction with a first hydrocracking catalyst to obtain a first product, wherein the first hydrocracking catalyst comprises a first carrier and a first metal component supported on the first carrier, the first carrier contains Beta-type molecular sieve, and the first metal component is a Group VIB metal component;

[0009] (2) subjecting the first product obtained in step (1) to second hydrocracking reaction with a second hydrocracking catalyst, wherein the second hydrocracking catalyst comprises a second carrier and a second metal component supported on the second carrier, the second carrier contains MFI-type molecular sieve, and the second metal component comprises a Group VIB metal component and a Group VIII metal component;

[0010] wherein the mixed distillate oil comprises kerosene fraction and diesel fraction, the mass content of diesel fraction is 60-90% and the mass content of kerosene fraction is 10-40% based on the total mass of the mixed distillate oil;

[0011] wherein the organic nitrogen content of the mixed distillate oil is not higher than 60 μg / g.

[0012] Preferably, the density of the kerosene fraction is 0.82-0.9 g / cm 3 , and the distillation range is 165-290℃.

[0013] Preferably, the density of the diesel fraction is 0.85-0.95 g / cm 3 , and the distillation range is 170-375℃.

[0014] Preferably, the second hydrocracking reaction temperature is 60-200℃ higher than the first hydrocracking reaction temperature, preferably 80-200℃ higher.

[0015] The present application has the following advantages:

[0016] The present application uses low-nitrogen mixed distillate oil with specific composition to produce special oil through simple two-step hydrocracking, wherein the first hydrocracking catalyst containing Beta-type molecular sieve and single-metal active component and the second hydrocracking catalyst containing MFI-type molecular sieve and double-metal active component are reasonably graded in the hydrocracking process, so that the special oil obtained has higher comprehensive performance and is suitable for use as transformer oil, especially as extra-high voltage transformer oil. DETAILED DESCRIPTION

[0017] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not critical to the invention. Any numeric range recited is intended to include all values from the lower value to the upper value, inclusive of both values, and to also include any value approximately or about the value. For numeric ranges, the endpoints are combined with the individual points to form new numeric ranges that are considered disclosed herein.

[0018] In the present invention, the density of the diesel oil, kerosene fraction is the density at 20℃.

[0019] In the present invention, the dry basis of a substance refers to the solid product obtained by calcining the substance at 600℃ for 3 hours.

[0020] In the present invention, "optional" means non-essential, and can be understood as containing or not containing, adding or not adding, using or not using.

[0021] In one aspect of the present invention, a method for producing a special oil product is provided, which comprises the following steps:

[0022] (1) subjecting hydrogen and mixed distillate oil to first hydrocracking reaction with a first hydrocracking catalyst to obtain a first product, wherein the first hydrocracking catalyst comprises a first carrier and a first metal component supported on the first carrier, and the first carrier contains a Beta-type molecular sieve and the first metal component is a Group VIB metal component;

[0023] (2) subjecting the first product obtained in step (1) to second hydrocracking reaction with a second hydrocracking catalyst to obtain the special oil product, wherein the second hydrocracking catalyst comprises a second carrier and a second metal component supported on the second carrier, and the second carrier contains an MFI-type molecular sieve and the second metal component comprises a Group VIB metal component and a Group VIII metal component;

[0024] wherein the mixed distillate oil comprises a kerosene fraction and a diesel oil fraction, and the mass content of the diesel oil fraction is 60-90% and the mass content of the kerosene fraction is 10-40% based on the total mass of the mixed distillate oil;

[0025] wherein the organic nitrogen content of the mixed distillate oil is not higher than 60 μg / g.

[0026] In the present invention, the organic nitrogen content of the mixed distillate oil is not higher than 60 μg / g, preferably not higher than 30 μg / g. The use of mixed distillate oil meeting the above requirements is more conducive to obtaining the target product of the present invention.

[0027] Preferably, the mass content of the diesel oil fraction is 70-90% and the mass content of the kerosene fraction is 10-30% based on the total mass of the mixed distillate oil.

[0028] According to the present application, preferably, the density of the kerosene fraction is 0.82-0.9 g / cm 3 .

[0029] According to the present application, preferably, the distillation range of the kerosene fraction is 165-290°C.

[0030] According to the present application, preferably, the density of the diesel fraction is 0.85-0.95 g / cm 3 .

[0031] According to the present application, preferably, the distillation range of the diesel fraction is 170-375°C.

[0032] The present application adopts the mixed fraction oil with the above-mentioned characteristics to more easily obtain the special oil product with low freezing point, high flash point and low viscosity as described in the present application.

[0033] The present application does not have a particular limitation on the source of the mixed fraction oil, as long as the mixed fraction oil satisfying the above-mentioned requirements is within the usable range of the present application. The mixed fraction oil satisfying the above-mentioned requirements can be directly used, or the mixed fraction oil satisfying the above-mentioned requirements can be obtained by a conventional method, such as hydrofining.

[0034] When treated by a conventional method, the present application does not have a particular limitation on the conditions of the conventional method, as long as the mixed fraction oil satisfying the above-mentioned requirements is obtained.

[0035] According to some embodiments of the present application, the first hydrocracking catalyst comprises a first support and a first metal component supported on the first support, wherein the first support contains a Beta-type molecular sieve, and the first metal component is a Group VIB metal component. In order to obtain the target product as described in the present application, preferably, the first hydrocracking catalyst does not contain a Group VIII metal component. By using this preferred embodiment, the first hydrocracking catalyst uses a single-metal hydrogenation component in combination with a support containing a Beta-type molecular sieve, which is beneficial to the conversion of the heavy fraction in the mixed fraction oil into the special oil product.

[0036] According to the present application, preferably, the content of the first metal component in the first hydrocracking catalyst is 5-30% by weight, and more preferably 10-25% by weight, based on the dry weight of the first hydrocracking catalyst.

[0037] According to the present application, preferably, the content of the first support in the first hydrocracking catalyst is 70-95% by weight, and more preferably 75-90% by weight, based on the dry weight of the first hydrocracking catalyst.

[0038] In the first hydrocracking catalyst, the content of each component adds up to 100%.

[0039] In the present application, the Group VIB metal component can be a conventional selection in the art. Preferably, the Group VIB metal component is Mo and / or W, preferably W. With this preferred embodiment, conversion of heavy distillates into special oil products can be promoted.

[0040] According to the present application, preferably, the Beta-type molecular sieve has a molar ratio of SiO2 / Al2O3 of 10-300, preferably 20-120.

[0041] According to the present application, preferably, the Beta-type molecular sieve has a specific surface area of 350-800 m 2 / g, preferably 400-600 m 2 / g.

[0042] According to the present application, preferably, the Beta-type molecular sieve has a pore volume of 0.1-0.6 mL / g, preferably 0.2-0.5 mL / g.

[0043] The Beta-type molecular sieve with the above characteristics is advantageous for conversion of heavy distillates into special oil products.

[0044] According to the present application, preferably, in the first hydrocracking catalyst, the first carrier further comprises a heat-resistant inorganic oxide.

[0045] The heat-resistant inorganic oxide in the present application refers to a porous material with a maximum use temperature of not less than 600°C. The heat-resistant inorganic oxide can improve the strength of the hydrocracking catalyst and improve and adjust the physicochemical properties of the hydrocracking catalyst, such as improving the pore structure of the catalyst.

[0046] The heat-resistant inorganic oxide in the present application has a wide selection range, and various heat-resistant inorganic oxides commonly used in the art can be used. Preferably, the heat-resistant inorganic oxide is selected from at least one of silicon oxide, aluminum oxide, zirconium oxide and titanium oxide, preferably aluminum oxide.

[0047] According to the present application, preferably, the content of the Beta-type molecular sieve is 40-90 wt%, preferably 40-80 wt%, and the content of the heat-resistant inorganic oxide is 10-60 wt%, preferably 20-60 wt%, based on the total weight of the first carrier.

[0048] The preparation method of the above-mentioned first hydrocracking catalyst is not particularly limited in the present application and can be obtained by a conventional method, or can be obtained by commercial purchase, and the present application is not particularly limited in this regard.

[0049] In the present application, the second hydrocracking catalyst comprises a second carrier and a second metal component supported on the second carrier, wherein the second carrier contains an MFI type molecular sieve, and the second metal component comprises a Group VIB metal component and a Group VIII metal component. With this preferred embodiment, the second hydrocracking catalyst uses a bimetallic hydrogenation component in combination with a carrier containing an MFI type molecular sieve, which is beneficial to obtaining the special oil product with low viscosity, low freezing point and high flash point as described in the present application.

[0050] According to the present application, preferably, the content of the second metal component in the second hydrocracking catalyst is 5-30% by weight, preferably 10-30% by weight, based on the dry basis weight of the second hydrocracking catalyst.

[0051] According to the present application, preferably, the mass ratio of the Group VIB metal component to the Group VIII metal component is 1:0.05-0.4, preferably 1:0.1-0.35, based on the oxide.

[0052] In the present application, the Group VIB metal component can be a conventional selection in the art. Preferably, the Group VIB metal component is Mo and / or W.

[0053] In the present application, the Group VIII metal component can be a conventional selection in the art. Preferably, in the second hydrocracking catalyst, the Group VIII metal component is Ni and / or Co.

[0054] According to the present application, preferably, the second hydrocracking catalyst further contains an additive selected from at least one of phosphorus, fluorine and boron.

[0055] According to the present application, preferably, the content of the additive in the second hydrocracking catalyst is 1-8% by weight, based on the dry basis mass of the second hydrocracking catalyst.

[0056] According to the present application, preferably, the second hydrocracking catalyst further contains an organic additive.

[0057] According to the present application, preferably, the content of the organic additive in the second hydrocracking catalyst is 0.5-15% by weight, based on the total weight of the second hydrocracking catalyst.

[0058] According to the present application, preferably, the organic additive is selected from at least one of an alcohol compound, a carboxylic acid compound and an organic amine compound.

[0059] The present application has a wide range of selection for the type of carboxylic acid compound, which can be various carboxylic acid compounds commonly used in the art. Preferably, the carboxylic acid compound is selected from at least one of acetic acid, maleic acid, oxalic acid, aminotriacetic acid, aminoacetic acid, citric acid, tartaric acid and malic acid.

[0060] The kind of the alcohol compound is not particularly limited, and can be any alcohol compound known in the art. Preferably, the alcohol compound is at least one selected from the group consisting of ethylene glycol, glycerol, polyethylene glycol, diethylene glycol and butanediol.

[0061] The kind of the organic amine compound is not particularly limited, and can be any organic amine compound known in the art. Preferably, the organic amine compound is at least one selected from the group consisting of ethylenediamine, diethylenetriamine, cyclohexanediaminetetraacetic acid, ethylenediaminetetraacetic acid and ethylenediaminetetraacetic acid ammonium.

[0062] In the second hydrocracking catalyst, the content of each component adds up to 100%.

[0063] According to the present application, preferably, the SiO2 / Al2O3 molar ratio of the MFI type molecular sieve is 15-300, preferably 20-80.

[0064] According to the present application, preferably, the specific surface area of the MFI type molecular sieve is 180-650 m 2 / g, preferably 300-450 m 2 / g.

[0065] According to the present application, preferably, the pore volume of the MFI type molecular sieve is 0.1-0.6 mL / g, preferably 0.2-0.5 mL / g.

[0066] The MFI type molecular sieve with the above characteristics is advantageous for obtaining the special oil product with low viscosity, low freezing point and high flash point.

[0067] The kind of the MFI type molecular sieve is not particularly limited, and can be any MFI type molecular sieve known in the art. Preferably, the MFI type molecular sieve is ZSM-5 molecular sieve.

[0068] The source of the MFI type molecular sieve is not particularly limited, and can be commercially available or prepared by a conventional method.

[0069] According to the present application, preferably, in the second hydrocracking catalyst, the second carrier further contains a heat-resistant inorganic oxide. The use of the heat-resistant inorganic oxide according to the present application can improve the strength of the hydrocracking catalyst, and improve and adjust the physicochemical properties of the hydrocracking catalyst, such as improving the pore structure of the catalyst.

[0070] The kind of the heat-resistant inorganic oxide in the second carrier can be the same as that in the first carrier, which is not described herein.

[0071] According to the present application, preferably, the content of the MFI type molecular sieve is 40-90 wt%, preferably 40-80 wt%, and the content of the heat-resistant inorganic oxide is 10-60 wt%, preferably 20-60 wt%, based on the total weight of the second carrier.

[0072] The present application does not particularly limit the preparation method of the second hydrocracking catalyst, as long as the second hydrocracking catalyst with the above composition can be prepared. In order to further improve the catalytic performance of the second hydrocracking catalyst, the present application further provides a preparation method of the second hydrocracking catalyst.

[0073] Preferably, the preparation method of the second hydrocracking catalyst comprises the following steps:

[0074] (a) mixing the MFI type molecular sieve with optional heat-resistant inorganic oxide precursor to prepare a second carrier;

[0075] (b) introducing the second metal component, optional adjuvant and optional organic additive into the second carrier by impregnation method.

[0076] In the present application, the method for preparing the second carrier in step (a) is well known to those skilled in the art, and the present application does not particularly limit it. For example, the method in step (a) can comprise: mixing the MFI type molecular sieve with optional heat-resistant inorganic oxide precursor into a shape, and then drying and calcining to obtain the second carrier. The heat-resistant inorganic oxide precursor can be a conventional choice in the art. The shaping in step (a) can be carried out by any method conventional in the art, for example, the shaping can be carried out by tabletting, balling or extruding, etc. The conditions for drying and calcining in step (a) can be carried out by a method conventional in the art, and the present application does not particularly limit it.

[0077] The present application also does not particularly limit the shape of the prepared second carrier, which can be spherical, strip-shaped (including solid or hollow strip-shaped), block-shaped, etc. The strip-shaped can be clover-shaped, four-leaf clover-shaped, etc. and their deformations.

[0078] According to the present application, preferably, step (b) comprises: introducing the second metal component, optional adjuvant and optional organic additive into the second carrier by impregnation method.

[0079] Preferably, in step (b), the step of introducing the second metal component into the second carrier by impregnation method comprises: contacting the second carrier with an impregnation solution containing the second metal precursor, optional adjuvant precursor and optional organic additive, and then drying and optionally calcining.

[0080] In the present application, when the auxiliary agent is introduced, the second metal component and the auxiliary agent can be introduced together or separately, and the present application does not have any requirement in this regard. The present application takes the way of introducing together as an example.

[0081] The present application does not have any particular limitation on the temperature of the contacting in step (b), which can be any temperature that the impregnation solution can reach. The present application also does not have any particular limitation on the time of the contacting, as long as the required amount of the metal precursor can be loaded on the carrier. Generally, the higher the temperature of the contacting and the greater the concentration of the impregnation solution, the shorter the time required to reach the same impregnation amount (i.e. the weight difference of the carrier after impregnation and before impregnation); vice versa. When the required impregnation amount and conditions are determined, the appropriate contacting time can be easily selected. The specific operation of the impregnation method is well known to those skilled in the art, and the impregnation method can be a saturated impregnation method or a supersaturated impregnation method. The environment of the impregnation method is not particularly limited, and the method can be performed under sealed conditions or in an open environment according to the conventional method in the art, and the lost solvent can be supplemented or not supplemented during the contacting. Various gases, such as air, nitrogen, water vapor, etc., can be introduced or not introduced during the contacting.

[0082] The present application does not have any particular limitation on the type and amount of the solvent in the impregnation solution, which can be performed according to the conventional method in the art.

[0083] Preferably, the second metal precursor is a soluble compound of the second metal, which is preferably at least one selected from the group consisting of an oxide of the second metal, an inorganic salt of the second metal, and an organic compound of the second metal. For example, the inorganic salt of the second metal can be at least one selected from the group consisting of a nitrate of the second metal, a carbonate of the second metal, a basic carbonate of the second metal, a hypophosphite of the second metal, a phosphate of the second metal, a sulfate of the second metal, and a chloride of the second metal. The organic substituent in the organic compound of the second metal can be at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an amine group, a ketone group, an ether group, and an alkyl group.

[0084] The auxiliary agent precursor in the present application can be a conventional selection in the art, as long as it contains the auxiliary agent element. For example, a soluble salt of the auxiliary agent, an inorganic acid of the auxiliary agent, etc.

[0085] The present application does not have any particular limitation on the order of adding the above-mentioned substances during step (b), which can be added together or separately. The present application takes the way of adding together as an example.

[0086] The drying and calcination in step (b) are conventional steps for preparing catalysts, and are not particularly limited. For example, the drying in step (b) can be performed at a temperature of 80-350°C, preferably 100-300°C, for a time period of 0.5-24 hours, preferably 1-12 hours. The calcination in step (b) can be performed at a temperature of 350-600°C, preferably 400-550°C, for a time period of 0.2-12 hours, preferably 1-10 hours.

[0087] According to the present application, preferably, the second hydrocracking reaction temperature is 60-200°C higher than the first hydrocracking reaction temperature, preferably 80-200°C higher. With this preferred embodiment, the low-viscosity, low-freezing-point, high-flash-point special oil product of the present application is obtained.

[0088] According to the present application, preferably, the conditions of the first hydrocracking reaction include a reaction pressure of 10-17 MPa, a reaction temperature of 240-380°C, a hydrogen / oil volume ratio of 700-1300:1, and a liquid hourly space velocity of 0.5-3 h -1 .

[0089] According to the present application, preferably, the conditions of the second hydrocracking reaction include a reaction pressure of 10-17 MPa, a reaction temperature of 330-430°C, a hydrogen / oil volume ratio of 700-1300:1, and a liquid hourly space velocity of 0.5-4 h -1 .

[0090] In the present application, the first hydrocracking catalyst and the second hydrocracking catalyst can be loaded in different reaction zones of the same reactor, or in different reactors, and the selection can be made according to the actual situation, and the present application does not have a particular limitation in this regard.

[0091] The hydrocracking reaction of the present application can be performed in any reactor that is sufficient for the hydrocarbon feedstock to be contacted with the catalyst under hydrocracking conditions, such as a fixed bed reactor, a moving bed reactor, a boiling bed reactor, or a slurry bed reactor, and the present application does not have a particular limitation in this regard.

[0092] According to the present application, preferably, the second hydrocracking reaction product obtained in step (2) is subjected to fractionation to obtain a special oil product.

[0093] According to the present application, preferably, the initial boiling point of the special oil product is 220-240°C. With this preferred embodiment, the flash point of the special oil product is improved.

[0094] Preferably, the first hydrocracking catalyst and the second hydrocracking catalyst are pre-sulfurized before use.

[0095] The specific conditions of the pre-vulcanization are not particularly limited in the present application, and can be performed according to the methods commonly used in the art.

[0096] The pre-vulcanization can be performed outside the device or in situ vulcanization inside the device to convert it into a vulcanate type.

[0097] According to the present application, preferably, the freezing point of the special oil is not higher than -60℃; the flash point is not lower than 135℃; the density is not greater than 895 kg / m 3 ; the 40℃ kinematic viscosity value is not greater than 11 mm 2 / s.

[0098] Compared with the existing special oil products, the special oil of the present application has higher high-temperature stability and better low-temperature fluidity, higher comprehensive performance, and better adaptability, which is beneficial to expand the application range.

[0099] The special oil of the present application can be applied to various application occasions, and is more suitable for use as transformer oil, and is particularly preferably suitable for use as extra-high voltage transformer oil.

[0100] The present application will be described in detail below through examples.

[0101] In the following examples, the density, 40℃ kinematic viscosity value, and flash point of the special oil of the present application are measured according to the GB2536-90 standard, and the freezing point of the special oil of the present application is measured according to the GB6537-2018 standard.

[0102] The pore volume and specific surface area of the molecular sieve are measured by static low-temperature adsorption capacity method using an ASAP 2400 type automatic adsorption instrument of the American Micromertics Instrument Company (using the national standard GB / T5816-1995 method), and the specific method is as follows: vacuum degassing at 250℃, 1.33Pa for 4h, using nitrogen as the adsorbate, contacting with the adsorbate at-196℃, and reaching adsorption equilibrium statically; the amount of nitrogen adsorbed by the adsorbent is calculated from the difference between the nitrogen inlet amount and the residual amount in the gas phase after adsorption, and then the pore size distribution is calculated by BJH formula, and the specific surface area and pore volume are calculated by BET formula;

[0103] The crystal structure of the molecular sieve is measured by a D5005 type X-ray diffractometer of the German Siemens Company, and the industry standard SH / T0339-92 method. The experimental conditions are as follows: Cu target, Ka radiation, solid detector, tube voltage 40kV, tube current 40mA, step scanning, step size 0.02°, pre-setting time 2s, scanning range 5°-70°. The diffraction angle position refers to the 2θ angle value of the highest peak of the diffraction peak;

[0104] The silicon content and the aluminum content of the molecular sieve were determined by a 3271E X-ray fluorescence spectrometer from Rigaku Denki Kogyo K.K., Japan. The determination method was as follows: the powder sample was pressed into a tablet, rhodium target, laser voltage 50 kV, laser current 50 mA, the spectral line intensity of each element was detected by a scintillation counter and a proportional counter, and the element content was quantitatively and semi-quantitatively analyzed by an external standard method;

[0105] The content of each component of the catalyst was calculated by the amount of the raw material.

[0106] Example 1

[0107] Pseudo-boehmite (produced by Sinopec Catalyst Changling Branch, trade name PB90, dry basis 68 wt%) was mixed with Beta molecular sieve (dry basis 85 wt%, specific surface area 438 m 2 / g, molar ratio of silicon to aluminum 25, pore volume 0.37 mL / g), extruded into tri-lobed strips with an outer circle diameter of 1.6 mm, dried at 120 ℃ for 3 h, and calcined at 600 ℃ for 3 h to obtain a first carrier. The first carrier was impregnated with a 152 mL aqueous solution containing 55 g of ammonium metatungstate at room temperature, then dried at 120 ℃ for 3 h, and calcined at 480 ℃ for 4 h to obtain a first hydrocracking catalyst C-Beta-1. The composition thereof is shown in Table 1.

[0108] Pseudo-boehmite (produced by Sinopec Catalyst Changling Branch, trade name PB90, dry basis 71 wt%) was mixed with ZSM-5 molecular sieve (dry basis 95 wt%, specific surface area 332 m 2 / g, molar ratio of silicon to aluminum 30, pore volume 0.32 mL / g), extruded into tri-lobed strips with an outer circle diameter of 1.6 mm, dried at 120 ℃ for 3 h, and calcined at 600 ℃ for 3 h to obtain a second carrier. After cooling to room temperature, a 75 mL aqueous solution containing 51 wt% of basic nickel carbonate, 61 wt% of phosphoric acid, and citric acid was heated to complete dissolution, and the second carrier prepared by the above method was impregnated, dried at 120 ℃ for 3 h to obtain a catalyst C-MFI-1. The composition thereof is shown in Table 1.

[0109] Hydrocracking activity tests were carried out on a fixed bed hydrocracking device using mixed distillate-1 (kerosene fraction 20 wt%, diesel fraction 80 wt%) described in Table 2. In the hydrocracking section, C-Beta-1 and C-MFI-1 were arranged in two reactors in sequence respectively to carry out two hydrocracking reactions in turn along the flow direction. The above catalysts were subjected to programmed temperature sulfurization before use: straight-run kerosene containing 2% by mass of dimethyl disulfide was used as sulfurizing oil, the temperature was raised to 230 ℃ at a rate of 20 ℃ / h from 110 ℃, and maintained for 6 h; then the temperature was raised to 360 ℃ at a rate of 20 ℃ / h, and maintained for 6 h.

[0110] C-Beta-1 and C-MFI-1 catalyst loading volume ratio was 1.5, reaction pressure 10.5 MPa, hydrogen oil volume ratio 750, liquid hourly space velocity was 1.5 h -1 , the first hydrocracking reaction temperature was 280°C, the second hydrocracking reaction temperature was 380°C, the second hydrocracking reaction product was fractionated, and the component with a cutting temperature of 220°C or higher was a special oil product. The special oil product in the generated oil was analyzed, and the results are shown in Table 3.

[0111] Example 2

[0112] Pseudo-boehmite (dry basis 68 wt%) was mixed with Beta zeolite (dry basis 85 wt%, specific surface area 558 m 2 / g, Si / Al molar ratio 90, pore volume 0.43 mL / g), extruded into tri-lobal strips with an inscribed circle diameter of 1.6 mm, dried at 120°C for 3 h, and calcined at 600°C for 3 h to obtain a first carrier. 200 g of the first carrier was impregnated with a 152 mL aqueous solution containing ammonium metatungstate, dried at 120°C for 3 h, and calcined at 480°C for 4 h to obtain a first hydrocracking catalyst C-Beta-2. Its composition is shown in Table 1.

[0113] Pseudo-boehmite (71 wt%) was mixed with ZSM-5 zeolite (dry basis 95 wt%, specific surface area 401 m 2 / g, Si / Al molar ratio 70, pore volume 0.38 mL / g), extruded into tri-lobal strips with an inscribed circle diameter of 1.6 mm, dried at 120°C for 3 h, and calcined at 600°C for 3 h to obtain a second carrier. A 75 mL aqueous solution containing 51 wt% basic nickel carbonate, 61 wt% phosphoric acid, and citric acid was impregnated into the second carrier prepared by the above method at room temperature until complete dissolution, dried at 120°C for 3 h to obtain a second hydrocracking catalyst C-MFI-2. Its composition is shown in Table 1.

[0114] Hydrocracking activity tests were carried out on a fixed bed reaction device using mixed distillate oil-1 described in Table 2. In the flow direction, C-Beta-2 and C-MFI-2 were placed in two reactors in sequence respectively to carry out two hydrocracking reactions in turn. The above catalysts were subjected to programmed temperature sulfuration before use: using straight-run kerosene containing 2% by mass of dimethyl disulfide as sulfuration oil, the temperature was raised to 230°C at a rate of 20°C / h, and maintained for 6 h; then the temperature was raised to 360°C at a rate of 20°C / h, and maintained for 6 h.

[0115] C-Beta-2 and C-MFI-2 catalyst loading volume ratio was 1.5, reaction pressure 15 MPa, hydrogen oil volume ratio 1200, liquid hourly space velocity was 0.8 h -1The first hydrocracking reaction temperature is 240°C, the second hydrocracking reaction temperature is 330°C, the second hydrocracking reaction product is fractionated, and the component with a cutting temperature of 240°C or higher is a special oil product. The special oil product in the generated oil is analyzed, and the results are shown in Table 3.

[0116] Table 1

[0117]

[0118]

[0119] Example 3

[0120] The method of Example 1 is followed, except that the mixed oil fraction-2 described in Table 2 is used. The special oil product in the generated oil is analyzed, and the results are shown in Table 3.

[0121] Comparative Example 1

[0122] 103 g of pseudo-boehmite (produced by Sinopec Catalyst Changling Branch, trade name PB90, dry basis 71 wt%) is mixed with 422 g of ZSM-5 molecular sieve (produced by Sinopec Catalyst Changling Branch, specific surface area 325 m 2 / g, framework silica-alumina ratio 70, pore volume 0.31 mL / g, dry basis 95 wt%), extruded into a three-leaf shape with an inscribed circle diameter of 1.6 mm, dried at 120°C for 3 h, calcined at 600°C for 3 h, to obtain a carrier. After cooling to room temperature, 150 g of the carrier is impregnated with 75 ml of a standard solution of NiW (38.4 g of nickel nitrate and 44 g of ammonium metatungstate, and an appropriate amount of water are mixed and stirred uniformly, heated to 80°C, completely dissolved, and water is added to adjust to 75 ml to obtain the standard solution), dried at 120°C for 3 h, to obtain catalyst R-1.

[0123] Hydrocracking activity tests are carried out on a fixed bed hydrocracking device using the mixed fraction oil-1 described in Table 2 as the raw material. An industrial catalyst RN-411 (produced by Sinopec Catalyst Changling Branch) is used in the refining section, and catalyst R-1 is used in the cracking section. The volume ratio of the refining catalyst to the cracking catalyst is 1.5, the reaction pressure is 10.5 MPa, the hydrogen to oil volume ratio is 750, the refining liquid space velocity is 1.5 h -1 , the refining temperature is 330°C, the cracking temperature is 280°C, and the special oil product in the generated oil is analyzed, and the results are shown in Table 3.

[0124] Comparative Example 2

[0125] The method of Example 1 was followed, except that C-Beta-1 and C-MFI-1 were exchanged in position, i.e. the first hydrocracking reaction used C-MFI-1 and the second hydrocracking reaction used C-Beta-1. The special oil products in the generated oil were analyzed, and the results are shown in Table 3.

[0126] Table 2

[0127]

[0128] Table 3

[0129]

[0130] As can be seen from the results in Table 3, the special oil products obtained by the method of the present application have low viscosity, low freezing point and high flash point, and have higher comprehensive performance. The special oil products described in the present application are suitable for use as transformer oil, and are more suitable for use as extra-high voltage transformer oil.

[0131] The above describes preferred embodiments of the present application, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including various technical features being combined in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application, and all fall within the protection scope of the present application.

Claims

1. A method of producing specialty oil products, characterized by, The method comprises the following steps: (1) hydrogen and mixed distillate oil are subjected to first hydrocracking reaction with a first hydrocracking catalyst to obtain a first product, the first hydrocracking catalyst is a first carrier and a first metal component supported on the first carrier, wherein the first carrier contains a Beta-type molecular sieve, and the first metal component is a Group VIB metal component; (2) the first product obtained in step (1) is subjected to second hydrocracking reaction with a second hydrocracking catalyst, the second hydrocracking catalyst is a second carrier and a second metal component supported on the second carrier, wherein the second carrier contains an MFI-type molecular sieve, and the second metal component is a Group VIB metal component and a Group VIII metal component; the second hydrocracking reaction product obtained in step (2) is subjected to fractionation to obtain a special oil product; the initial boiling point of the special oil product is 220-240℃; wherein the mixed distillate oil comprises a kerosene fraction and a diesel fraction, and the mass content of the diesel fraction is 60-90% and the mass content of the kerosene fraction is 10-40% based on the total mass of the mixed distillate oil; wherein the organic nitrogen content of the mixed distillate oil is not higher than 60μg / g; wherein the second hydrocracking reaction temperature is 60-200℃ higher than the first hydrocracking reaction temperature.

2. The method according to claim 1, wherein the mass content of the diesel fraction is 70-90% and the mass content of the kerosene fraction is 10-30% based on the total mass of the mixed distillate oil.

3. The method according to claim 1, wherein The kerosene fraction has a density of 0.82-0.9 g / cm3 at 20°C 3 , and a distillation range of 165-290°C. and / or the diesel fraction has a density at 20°C of 0.85-0.95 g / cm3 3 , a distillation range of 170-375°C.

4. The method of claim 1, wherein, the content of the first metal component in the first hydrocracking catalyst is 5-30% by weight based on the dry basis weight of the first hydrocracking catalyst; and / or the content of the first carrier in the first hydrocracking catalyst is 70-95% by weight based on the dry basis weight of the first hydrocracking catalyst.

5. The method of claim 4, wherein, the content of the first metal component in the first hydrocracking catalyst is 10-25% by weight based on the dry basis weight of the first hydrocracking catalyst; and / or the content of the first carrier in the first hydrocracking catalyst is 75-90% by weight based on the dry basis weight of the first hydrocracking catalyst.

6. The method according to claim 1, wherein the Group VIB metal component in the first hydrocracking catalyst is Mo and / or W.

7. The method according to any one of claims 1-6, wherein The SiO2 / Al2O3 molar ratio of the Beta-type molecular sieve is 10-300; the specific surface area of the Beta-type molecular sieve is 350-800 m 2 / g; and the pore volume of the Beta-type molecular sieve is 0.1-0.6 mL / g.

8. The method according to claim 7, wherein The SiO2 / Al2O3 molar ratio of the Beta-type molecular sieve is 20-120; the specific surface area of the Beta-type molecular sieve is 400-600 m 2 / g; and the pore volume of the Beta-type molecular sieve is 0.2-0.5 mL / g.

9. The method according to any one of claims 1-6, wherein the first carrier further contains a heat-resistant inorganic oxide in the first hydrocracking catalyst; the content of the Beta-type molecular sieve is 40-90% by weight based on the total weight of the first carrier; and the content of the heat-resistant inorganic oxide is 10-60% by weight based on the total weight of the first carrier. the heat-resistant inorganic oxide is selected from at least one of silicon oxide, aluminum oxide, zirconium oxide and titanium oxide.

10. The method according to claim 9, wherein The content of the Beta-type molecular sieve is 40-80% by weight, based on the total weight of the first carrier; and the content of the heat-resistant inorganic oxide is 20-60% by weight.

11. The method of any one of claims 1-6, wherein, The content of the second metal component in the second hydrocracking catalyst is 5-30% by weight, based on the dry weight of the second hydrocracking catalyst.

12. The method of claim 11, wherein, The content of the second metal component in the second hydrocracking catalyst is 10-30% by weight, based on the dry weight of the second hydrocracking catalyst.

13. The method according to any one of claims 1-6, wherein, The mass ratio of the Group VIB metal component to the Group VIII metal component in the second hydrocracking catalyst is 1:0.05-0.4, based on the oxides.

14. The method according to claim 13, wherein, The mass ratio of the Group VIB metal component to the Group VIII metal component in the second hydrocracking catalyst is 1:0.1-0.35, based on the oxides.

15. The method according to any one of claims 1-6, wherein, The Group VIB metal component in the second hydrocracking catalyst is Mo and / or W; The Group VIII metal component in the second hydrocracking catalyst is Ni and / or Co.

16. The method according to any one of claims 1-6, wherein, The second hydrocracking catalyst further comprises an auxiliary selected from at least one of phosphorus, fluorine and boron; The content of the auxiliary in the second hydrocracking catalyst is 1-8% by weight, based on the dry weight of the second hydrocracking catalyst.

17. The method according to claim 16, wherein, The second hydrocracking catalyst further comprises an organic additive; The content of the organic additive in the second hydrocracking catalyst is 0.5-15% by weight, based on the total weight of the second hydrocracking catalyst; The organic additive is selected from at least one of an alcohol compound, a carboxylic acid compound and an organic amine compound.

18. The method according to claim 17, wherein, The carboxylic acid compound is selected from at least one of acetic acid, maleic acid, oxalic acid, amino triacetic acid, amino acetic acid, citric acid, tartaric acid and malic acid; The alcohol compound is selected from at least one of ethylene glycol, glycerol, polyethylene glycol and butanediol; The organic amine compound is selected from at least one of ethylenediamine, diethylenetriamine, cyclohexanediaminetetraacetic acid, ethylenediaminetetraacetic acid and ammonium ethylenediaminetetraacetate.

19. The method according to claim 17, wherein, The alcohol compound is diethylene glycol.

20. The method according to any one of claims 1-6, wherein, The MFI type molecular sieve has a SiO2 / Al2O3 molar ratio of 15-300; a specific surface area of 180-650 m 2 / g; and a pore volume of 0.1-0.6 mL / g.

21. The method according to claim 20, wherein, The SiO2 / Al2O3 molar ratio of the MFI type molecular sieve is 20-80; the specific surface area of the MFI type molecular sieve is 300-450 m 2 / g; the pore volume of the MFI type molecular sieve is 0.2-0.5 mL / g.

22. The method according to any one of claims 1-6, wherein, The MFI-type molecular sieve is ZSM-5 molecular sieve.

23. The method according to claim 17, wherein, The second carrier in the second hydrocracking catalyst further comprises a heat-resistant inorganic oxide. the content of the MFI-type molecular sieve is 40-90% by weight, and the content of the heat-resistant inorganic oxide is 10-60% by weight, based on the total weight of the second carrier; the heat-resistant inorganic oxide is at least one selected from the group consisting of silicon oxide, aluminum oxide, zirconium oxide and titanium oxide.

24. The method according to claim 23, wherein, the content of the MFI-type molecular sieve is 40-80% by weight, and the content of the heat-resistant inorganic oxide is 20-60% by weight, based on the total weight of the second carrier.

25. The method of claim 23, wherein, the preparation method of the second hydrocracking catalyst comprises the following steps: (a) mixing the MFI-type molecular sieve with optional heat-resistant inorganic oxide precursor to prepare a second carrier; (b) introducing a second metal component, optional adjuvant and optional organic additive to the second carrier by impregnation method.

26. The method according to any one of claims 1-6, wherein, the second hydrocracking reaction temperature is 80-200℃ higher than the first hydrocracking reaction temperature.

27. The method according to any one of claims 1-6, wherein, The conditions of the first hydrocracking reaction include: a reaction pressure of 10-17 MPa; a reaction temperature of 240-380°C; a hydrogen to oil volume ratio of 700-1300: 1; a liquid hourly space velocity of 0.5-3 h -1 ; The conditions of the second hydrocracking reaction include a reaction pressure of 10-17 MPa, a reaction temperature of 330-430°C, a hydrogen to oil volume ratio of 700-1300: 1, a liquid hourly space velocity of 0.5-4 h -1 .

28. The method according to any one of claims 1-6, wherein, The freezing point of the special oil is not higher than -60 DEG C; the flash point is not lower than 135 DEG C; the density is not greater than 895 kg / m 3 ; the 40 DEG C kinematic viscosity value is not greater than 11 mm 2 / s.

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