A hydrogenation method for producing naphthenic rubber filler oil

Abstract

The invention discloses a hydrogenation method for producing cycloalkyl rubber filling oil. Cycloalkyl vacuum distillate oil is used as raw material, and firstly subjected to hydrogenation treatment; the effluent of the hydrogenation treatment reaction is stripped by high-pressure hydrogen to remove impurities such as H2S and NH3, and then enters the hydrogenation supplementary refining reaction zone; the reaction product is fractionated to separate the light white oil product; the obtained heavy component enters the isomerization dewaxing reaction zone in whole or in part to carry out hydrogenation isomerization reaction; the hydrogenation isomerization reaction product and the raw material enter the hydrogenation supplementary refining reaction zone together to carry out deep supplementary refining reaction. The method of the invention can obtain high-quality cycloalkyl rubber filling oil products while less supplementary refining catalyst is installed, and high-quality special oil products are produced as by-products, and the energy consumption caused by the two-stage method of boosting-depressurization-boosting and heating-cooling-heating is greatly reduced, and the process is simple and occupies less space.

Description

Technical Field

[0001] The present invention relates to a hydrogenation method for producing naphthenic rubber extension oil, specifically a hydrogenation method for producing naphthenic special oil products by using naphthenic vacuum distillate oil as raw material through a two-stage process of hydrogenation treatment-high-pressure hydrogen stripping / isomerization dewaxing-supplementary refining. Background Art

[0002] Cycloalkane crude oil has the characteristics of high density, high viscosity, low wax content, high aromatic and cycloalkane content, and low pour point. It is often used as a raw material to produce low-condensation lubricant base oil that does not require viscosity-temperature performance, such as transformer oil, refrigeration oil, rubber filler oil, etc. The traditional production of lubricant base oil adopts solvent technology. The two main steps are solvent refining to remove non-ideal components such as aromatics, and solvent dewaxing to ensure the low-temperature flow properties of the base oil. Nowadays, the technology of hydrogenation for producing lubricating oil is developing rapidly. The hydrogenation method refers to the process method of producing lubricating base oil by hydrogenation treatment or hydrocracking-hydrogenation decondensation or isodewaxing-hydrogenation refining combined process. The hydrogenation method has the advantages of high product quality, no environmental problems, and high base oil yield, and gradually replaces the traditional solvent process.

[0003] In the prior art, a variety of hydrogenation processes can be used to produce cycloalkyl lubricating base oils. CN1990833A discloses a method for producing transformer oil using cycloalkyl oil as raw material through a two-stage process of hydrogenation treatment-hydrogenation refining. This method does not improve the pour point and requires the selection of suitable raw materials to obtain the ideal product. CN1676585A reports a method for producing lubricating base oil by hydrogenation treatment-hydrogenation decondensation-supplementary refining. The hydrogenation product of this method must be subjected to gas-liquid separation before the liquid product can enter the hydrodecondensation process. CN161376838A introduces a method for producing lubricating base oil by a two-stage hydrogenation process of hydrogenation treatment-hydrogenation decondensation-supplementary refining. In this method, the hydrogenation product does not need to be separated and directly enters the hydrodecondensation and supplementary refining reaction zone.

[0004] Shell has announced a method of using high-pressure steam stripping to directly remove H2S and NH3 from hydrotreated products, which then enters precious metal hydrodewaxing and supplementary refining reactors to produce cyclopentane rubber filler oil. The method has three industrial applications in China, but since the cold high-fraction oil containing H2S and NH3 without deep dearomatization is directly incorporated into the distillation system, all products have poor color and stability. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a hydrogenation method for producing naphthenic rubber filler oil. Specifically, it is a method for producing naphthenic special oil products by using naphthenic vacuum distillate oil as raw material through a two-stage process of hydrogenation treatment-high-pressure hydrogen stripping / isomerization dewaxing-supplementary refining.

[0006] A hydrogenation method for producing cycloalkyl rubber extension oil of the present invention comprises the following contents:

[0007] (1) The cycloalkyl vacuum distillate oil is mixed with hydrogen and then enters a hydroprocessing reactor, and sequentially contacts with a hydroprotection catalyst, a hydrofining catalyst and a hydromodification catalyst to perform a hydrogenation reaction; the hydromodification catalyst contains amorphous silica-alumina and a modified Y molecular sieve;

[0008] (2) The hydrotreatment effluent obtained in step (1) enters a high-pressure stripping tower from the top, and hydrogen is injected into the bottom of the tower as a stripping medium. After stripping, a bottom oil from which H2S and NH3 are removed and a top effluent containing H2S, NH3, hydrogen and part of light oil are obtained;

[0009] (3) The effluent obtained in step (2) containing H2S, NH3, hydrogen and part of the light oil enters a cold high-pressure separator after heat exchange, and the cold high-fraction oil containing H2S and NH3 enters a cold low-fraction to separate the low-fraction gas, and then the cold low-fraction oil enters a H2S removal stripping tower to remove H2S and NH3, and is divided into two streams after pressure increase and heat exchange: one enters an isomerization dewaxing reactor, and the other enters a supplementary refining reactor;

[0010] (4) The high-pressure stripping tower bottom oil obtained in step (2) is mixed with hydrogen and then enters a hydrogenation refining reactor together with the cold low-fraction oil from which H2S and NH3 have been removed to saturate olefins and aromatics;

[0011] (5) The reaction effluent obtained in step (4) enters a separation system to obtain a series of light white oils that meet the technical index requirements of light white oil (II) in NB / SH / T 0913-2015 and heavy cycloalkane fraction oil with a higher pour point;

[0012] (6) The heavy cycloalkane fraction obtained in step (5), a portion of the cold low fraction oil from which H2S and NH3 have been removed in step (3), and hydrogen are sequentially passed through an isomerization dewaxing reactor and a supplementary refining reactor to perform a hydroisomerization reaction and a supplementary refining reaction;

[0013] (7) The reaction effluent obtained in step (6) enters a separation system to obtain cycloalkyl specialty oil products (transformer oil, refrigeration oil and a series of rubber filler oils) with pour points meeting the requirements and good stability, and a series of light white oils meeting the technical index requirements of light white oil (II) in NB / SH / T 0913-2015.

[0014] Furthermore, the high-pressure stripping tower in step (2) includes a packing, such as a rolled hole θ ring packing. The selection of the packing is common knowledge of those skilled in the art. Preferably, a ZnO bed is also provided at the lower part of the packing zone, and the ZnO bed can be used to remove a small amount of H2S that is not stripped cleanly due to operation fluctuations. The operating conditions of the high-pressure stripping tower are well known to those skilled in the art. For example, the stripping conditions include: a stripping temperature of 150 to 400°C, preferably the outlet temperature of the hydrotreating reaction zone, a stripping pressure that is the same as the pressure of the hydrotreating reaction zone, and a hydrogen consumption that is higher than the chemical hydrogen consumption of the hydrotreating reaction zone, preferably equivalent to the sum of the chemical hydrogen consumption of the hydrotreating (including hydrofining and hydromodification) reaction and the dissolved hydrogen of the hydrotreating system.

[0015] Furthermore, the cold high-fraction gas phase obtained in step (3) can be re-entered into the hydroprocessing reactor as circulating hydrogen after selective removal of H2S.

[0016] Furthermore, the naphthenic distillate oil can be at least one of naphthenic distillate oil, coal tar hydrocracking tail oil or catalytic cracking diesel fraction. The aromatic content of the naphthenic distillate is generally 30 to 99 wt%, and the density at 20°C is generally 0.923 to 0.955 g / cm 3 The distillation range of the cycloalkane distillate oil raw material is any range formed by any two values ​​within the range of 140 to 600°C; preferably, the initial distillation point of the cycloalkane distillate oil is 140 to 350°C, and the final distillation point is 400 to 600°C.

[0017] Furthermore, the hydrotreating catalyst described in step (1) is a conventional hydrotreating catalyst in the art, such as a diesel hydrotreating catalyst or a hydrocracking pretreatment catalyst. Hydrotreating catalysts generally use Group VIB and / or Group VIII metals as active components and use alumina or silicon-containing alumina as a carrier. Group VIB metals are generally Mo and / or W, and Group VIII metals are generally Co and / or Ni. Based on the weight of the catalyst, the content of Group VIB metals is 10wt% to 50wt% in terms of oxide, and the content of Group VIII metals is 3 to 15wt% in terms of oxide; its properties are as follows: specific surface area is 100 to 350m 2 / g, pore volume is 0.15~0.6mL / g. Commercial catalysts that can be selected include 3936, 3996, FF-16, FF-26, FF-36, FF-46, FF-56, FF-66 and other hydrofining catalysts developed by Fushun Petrochemical Research Institute of Sinopec. It can also be a catalyst with similar functions developed by foreign catalyst companies, such as UOP's HC-K, HC-P catalysts, Topsoe's TK-555, TK-565 catalysts, and AKZO's KF-847, KF-848, etc.

[0018] Furthermore, the hydro-modification catalyst contains amorphous silica-alumina and modified Y molecular sieve. Based on the weight of the catalyst, the hydro-modification catalyst contains 20wt% to 60wt% amorphous silica-alumina, 5wt% to 25wt% modified Y zeolite, 10wt% to 30wt% of Group VIB metal in terms of oxide, and 4wt% to 15wt% of Group VIII metal in terms of oxide. The specific surface area of ​​the hydro-modification catalyst is generally 220 to 300m 2 / g, pore volume is 0.3-0.6mL / g, pore volume with pore diameter of 3-10nm accounts for 75%-95% of the total pore volume, preferably 85%-95%, infrared acidity is 0.30-0.5mmol / g. The properties of the amorphous silica-alumina used are as follows: containing 10wt%-60wt% of silicon oxide, specific surface area of ​​400-650m 2 / g, pore volume of 1.0-1.8mL / g, infrared acidity of 0.34-0.50mmol / g, pore volume of pores with a pore diameter of 4-10nm accounts for 85%-95% of the total pore volume, and pore volume of >15nm accounts for less than 5% of the total pore volume; the preferred properties are as follows: containing 10wt%-35wt% of silicon oxide, specific surface area of ​​530-650m 2 / g, pore volume is 1.2-1.5mL / g. The modified Y zeolite has the following properties: SiO2 / Al2O3 molar ratio is 40-60, unit cell constant is 2.425-2.440nm, relative crystallinity is 80-100%, infrared acidity is 0.1-0.5mmol / g, among which medium-strong acid at 250-550℃ is concentrated, accounting for 60-70% of the total acid, and specific surface area is 600-900m 2 / g, pore volume 0.3~0.6mL / g, of which the pore volume of secondary mesopores of 4~15nm accounts for 40%~50% of the total pore volume. The hydrogenation reforming catalyst may also contain one or more of the components such as alumina, zirconium oxide, and titanium oxide.

[0019] Furthermore, the isomerization dewaxing catalyst used in the method of the present invention can select the commonly used lubricating oil hydroisomerization catalyst in the art, and can use commercial hydroisomerization catalysts, or can be prepared according to general knowledge in the art. The hydroisomerization catalyst includes a carrier and an active metal component; the catalyst carrier includes alumina and a TON structure molecular sieve, and part of silicon oxide can also be added to the carrier; the active metal component is one or more of Pt, Pd, Ru and Rh. The TON structure molecular sieve is selected from at least one of NU-10 molecular sieve, ZSM-22 molecular sieve, ZSM-23 molecular sieve, ZSM-48 molecular sieve, etc., preferably ZSM-22 molecular sieve. Based on the weight of the hydroisomerization catalyst, the content of the TON structure molecular sieve is 30wt%~80wt%, preferably 40wt%~70wt%; the content of the active metal component is 0.1wt%~5.0wt%; the optional auxiliary component is one or more of boron, fluorine, chlorine and phosphorus, and the content in the catalyst is 0.1wt%~5.0wt%. The specific surface area of ​​the hydroisomerization catalyst is 150~500m 2 / g, and the pore volume is 0.15~0.60mL / g.

[0020] Furthermore, the supplementary refining catalyst is a conventional reduction type hydrorefining catalyst. The active metal of the reduction type hydrorefining catalyst is one or two of Pt and Pd, or metallic nickel; the weight content of the active metal in the noble metal catalyst is generally 0.05% to 1%; the weight content of nickel in the reduction type nickel catalyst as an oxide is 30% to 80%. The catalyst carrier is generally Al2O3 or Al2O3-SiO2, and may also contain one or more of P, Ti, B, and Zr as an auxiliary agent. The catalyst needs to be conventionally reduced before use to ensure that the hydrogenation active metal is in a reduced state during the reaction. Ordinary commercial catalysts in this field can be selected, or prepared according to ordinary methods in this field.

[0021] Furthermore, the operating conditions of the hydroprocessing reactor are: hydrogen partial pressure 5.0-18.0 MPa, preferably 10.0-16.0 MPa; reaction temperature 230-430°C, preferably 350-410°C; hydrogen-to-oil volume ratio 200-1500, preferably 600:1-1000:1; volume space velocity 0.1-10.0 h -1 , preferably 0.3 h -1 ~0.5h -1 The loading ratio of the hydrotreating catalyst to the hydrorefining catalyst in the hydrotreating reaction zone is 1:9 to 9:1, preferably 4:6 to 6:4.

[0022] Further, the reaction conditions of the isomerization dewaxing reactor are: reaction temperature is 300°C to 380°C, preferably 310°C to 340°C, hydrogen partial pressure is 2.0MPa to 18.0MPa, preferably 10.0 to 15.0MPa, and the raw oil liquid volume space velocity is 0.2h -1 ~6.0h -1 , preferably 0.4 h -1 ~1.0h -1 , the volume ratio of hydrogen to oil is 400:1 to 1500:1, preferably 600:1 to 800:1.

[0023] Furthermore, the reaction conditions of the supplementary refining reactor are: reaction temperature is 200°C to 300°C, preferably 210°C to 280°C, hydrogen partial pressure is 6.0MPa to 18.0MPa, preferably 10.0 to 15.0MPa, volume space velocity is 0.2h -1 ~3.0h -1 , preferably 0.3h -1 ~0.6h -1 , the volume ratio of hydrogen to oil is 400:1 to 1500:1, preferably 600:1 to 800:1.

[0024] Furthermore, the cycloalkyl special oil product obtained in step (5) includes one or more of transformer oil, refrigeration oil and a series of rubber filler oils.

[0025] Compared with the prior art, the method of the present invention has the following beneficial effects:

[0026] 1. The two-stage hydrogenation process of high-pressure hydrogen stripping, hydrotreatment - isomerization decondensation - deep supplementary refining is adopted, which avoids the need to set up two sets of fractionation systems in the traditional two-stage hydrogenation process to avoid the influence of H2S and NH3 on the precious metal catalyst. At the same time, most of the reaction feed (>87w%) of the two-stage hydrogenation process of high-pressure hydrogen stripping, hydrotreatment - isomerization decondensation - deep supplementary refining is a one-time pressure-raising process, which avoids the process of pressure-raising, pressure-reducing and re-pressurizing of all raw oil between the two reaction zones of the traditional two-stage process device, saving electricity consumption. At the same time, the stripping hydrogen injected at the bottom of the high-pressure stripping tower is also a part of the supplementary hydrogen entering the circulating hydrogen system of the hydrotreatment device; the operating temperature of the high-pressure stripping tower is adjusted, and the bottom effluent can directly enter the isomerization dewaxing reactor, and there is no need to set up an isomerization dewaxing feed heating furnace, which avoids the energy loss in the process of heating, cooling and reheating of all reaction products in the traditional two-stage process, saving electricity consumption and fuel gas consumption, and saving land.

[0027] 2. The effluent from the top of the high-pressure stripping tower enters the cold high-pressure separator after heat exchange. After separating the gas phase circulating hydrogen, the cold high-fraction oil containing H2S and NH3 is depressurized and enters the cold low-pressure separator to separate the low-fraction gas. The cold low-fraction oil enters the conventional H2S removal stripping tower to remove H2S and NH3. After heat exchange, it is divided into two streams, one enters the isomerization dewaxing reactor, and the other enters the supplementary refining reactor. This not only solves the problem of the Shell process cold high-fraction oil directly entering the distillation system and affecting the product color and stability, but also solves the problem of the by-product light white oil pour point being greatly excessive when the heavy rubber filler oil pour point is qualified by adjusting the ratio of the two streams, thereby improving the liquid recovery and the target product yield.

[0028] 3. During the desulfurization and denitrogenation process of hydrotreating of cycloalkyl vacuum distillate oil, hydrogenolysis is usually performed to produce 15-20% of light white oil fraction with a temperature of <280°C. There is no pour point requirement for this part of light white oil fraction. At the same time, the heavy components of cycloalkyl have low wax content and low difficulty in decondensation. Through the reverse series process, only the heavy components that need to be decondensed can pass through the isomerization dewaxing reaction zone, thereby achieving the best balance between the pour point and yield of light white oil, transformer oil and rubber filler oil products.

[0029] 4. In the method of the present invention, after the light product is separated from the fractionation tower, the obtained heavy product is passed through the supplementary refining reaction zone again, which reduces the interference of the light product on the deep refining reaction of the heavy product, can increase the effective contact between the heavy product and the catalyst, and can deeply saturate the trace amount of condensed aromatic hydrocarbons containing nitrogen atoms that have the greatest impact on color and stability when about 20% less precious metal supplementary refining catalyst is installed or at a higher space velocity. At the same time, since light white oil and some light products with qualified pour points are cut out, the isodewaxing reaction zone can be equipped with 30-40% less isodewaxing catalyst, and most of the raw oil passes through the supplementary refining reactor first, which can saturate aromatic hydrocarbons in large quantities, reduce the carbon deposition tendency of the feed of the isodewaxing reactor, and thus increase the service life of the isodewaxing catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a process flow diagram of the method of the present invention. DETAILED DESCRIPTION

[0031] The method of the present invention is described in more detail below with reference to the accompanying drawings and specific embodiments.

[0032] Combination Figure 1The method for producing cyclopentane rubber filler oil by hydrogenation of the present invention is as follows: cyclopentane vacuum distillate oil passes through pipeline 1, is mixed with circulating hydrogen from pipeline 2, and first enters hydroprocessing reaction zone 3 to carry out desulfurization, denitrogenation, deoxygenation and aromatic saturation reaction; then the hydroprocessing product 4 enters high-pressure hydrogen stripping tower 5, and stripping hydrogen 6 is blown into the bottom of the tower to obtain tower bottom oil 7 from which H2S and NH3 are removed, and the top of the high-pressure stripping tower enters the separation system 8 of the hydroprocessing section, and the separation system 8 generally includes a high-pressure separator and a low-pressure separator; the separated gas phase is returned to the hydroprocessing reaction system as circulating hydrogen through pipeline 2, and the liquid phase product enters the H2S removal steam stripping tower through pipeline 9. The bottom oil 11 from the stripping tower 10, from which H2S and NH3 have been removed, is pressurized and heat exchanged and then divided into two streams 13 and 14 according to a certain ratio. The bottom oil 7 from the high-pressure stripping tower is mixed with the stream 13 and the new hydrogen 12 and enters the supplementary refining reactor 15 to remove most of the aromatic hydrocarbons that affect the stability of the product. The supplementary refining reaction product 16 enters the separation system 17. The separation system 17 generally includes a high-pressure separator and a low-pressure separator. The low-pressure oil enters the fractionation system 18. The fractionation system includes a normal-pressure fractionation tower and a vacuum fractionation tower to obtain light naphtha, light white oil and cycloalkyl products (including transformer oil, refrigeration oil and a series of cycloalkyl rubber filler oils). Then, the supplementary refined product heavy fraction 22 is mixed with the logistics 14 and directly enters the isomerization dewaxing reactor 23 for isomerization decondensation reaction to improve the low-temperature performance of the product, and then enters the supplementary refining reactor 17 for deep dearomatization reaction. After the cycle reaches equilibrium, light naphtha 19, light white oil 20 and cycloalkyl products 21 (including transformer oil, refrigeration oil and a series of cycloalkyl rubber filler oils) with qualified pour point and good light and thermal stability are obtained.

[0033] The specific contents and effects of the method of the present invention are described below by means of specific embodiments.

[0034] The following examples will further illustrate the method provided by the present invention, but the scope of the present invention is not limited thereby. The properties of the raw materials treated by the present invention are shown in Table 1, and the physical and chemical properties of the catalyst used are shown in Table 2.

[0035] Table 1 Raw material properties

[0036]

[0037] Table 2 Physical and chemical properties of catalysts

[0038]

[0039] Example 1

[0040] The raw materials are the naphthenic oil listed in Table 1, and the physical and chemical properties of the catalyst are shown in Table 2. The hydroprocessing zone is filled with a series of hydroprotective agents, hydrofining catalysts and hydromodification catalysts, where the series of hydroprotective agents: hydrofining catalysts: hydromodification catalysts = 1:5.5:3.5 (volume). See the principle flow chart. Figure 1 The process conditions and test results are shown in Tables 3 and 4.

[0041] Example 2

[0042] The raw materials are the cycloalkyl oil listed in Table 1, and the same catalyst as in Example 1 is used. Figure 1 . Process conditions and test results are shown in Tables 3~4.

[0043] Comparative Example 1

[0044] Comparative Example 1 adopts the traditional two-stage hydrogenation process. The process flow is as follows: the hydroprocessed product first enters the hot high-pressure separator, and then enters the cold high-pressure separator after gas phase heat exchange. The cold high-fraction gas phase enters the circulating hydrogen system, and the cold high-fraction oil enters the cold low-fraction after decompression, and the top of the separator is the low-fraction gas; the hot high-fraction oil enters the hot low-fraction after decompression, and the top is the low-fraction gas; the hot low-fraction oil (most of the product) and the cold low-fraction oil are mixed and then all enter the dehydrogen sulfide stripping tower (pressure is about 1MPa), and a small amount of hydrogen sulfide gasoline is discharged from the top of the tower and all liquids (sulfur content <10µg.g -1 , nitrogen content <2µg.g -1 ) After heating and pressure increase, it enters the second stage isomerization dewaxing-supplementary refining stage; the supplementary refined product is subjected to gas-liquid separation and fractionation to obtain various products.

[0045] Comparative Example 1 uses the same raw materials and the same catalyst as in Example 1. The process conditions and test results are shown in Table 3-4.

[0046] Comparative Example 2

[0047] Comparative Example 2 adopts the Shell process ("Research on the Application of High-Pressure Hydrogen Stripping in the Production Process of Fully Hydrogenated Lubricant Oil", Xue Nan, "Petroleum Refining and Chemical Industry", October 2019).

[0048] Comparative Example 2 uses the same raw materials and catalyst as in Example 1. The process is that the hydrotreated product directly enters the isomerization dewaxing-supplementary refining section after high-pressure stripping, the hot high-fraction gas phase enters the cold low-pressure separator, the cold low-fraction gas is returned to the reaction system as circulating hydrogen, and the cold low-fraction oil directly enters the subsequent fractionation system for fractionation to obtain various products. The results are shown in Tables 3-4.

[0049] Table 3 Process conditions

[0050]

[0051] **, for fresh feed.

[0052] Table 4 Test results

[0053]

[0054] **, for fresh feed.

[0055] From the data in Table 3-4, it can be seen that the reverse series process of two-stage hydroprocessing-high-pressure hydrogen stripping / isodewaxing-supplementary refining is adopted with cycloalkyl vacuum distillate as raw material. By separating light white oil and light cycloalkyl products that do not require high isodewaxing and supplementary refining, the influence of light products on the reaction of heavy products in the isodewaxing reaction zone and supplementary refining reaction zone is reduced. Under the condition of about 20~25% less isodewaxing catalyst and supplementary refining catalyst, products of equivalent quality to the conventional hydroprocessing / isodewaxing-supplementary refining two-stage process can be produced. At the same time, the energy consumption of all the feed pressure increase-depressurization-pressure increase, temperature increase-temperature decrease-temperature increase processes of the conventional two-stage process is avoided, the equipment area is reduced, and the energy consumption of the equipment is reduced by about 11%. In addition, since the cold high-fraction oil is subjected to conventional stripping and enters the isodewaxing reactor and supplementary refining reactor respectively according to the optimized ratio, the light oil loss at the top of the H2S stripping tower in the conventional two-stage distillation process is greatly reduced, and the liquid recovery and target product yield are improved. Comparative Example 2 adopts the Shell process flow. Although it has lower energy consumption, the aromatics in the cold low-fraction oil directly enter the distillation system without hydrogenation and refining, resulting in the oxidation stability of the entire line of products failing to meet the requirements.

Claims

1. A hydrogenation method for producing cycloalkyl rubber extension oil, comprising the following contents: (1) The cycloalkyl vacuum distillate oil is mixed with hydrogen and then enters a hydroprocessing reactor, and sequentially contacts with a hydroprotection catalyst, a hydrofining catalyst and a hydromodification catalyst to perform a hydrogenation reaction; the hydromodification catalyst contains amorphous silica-alumina and a modified Y molecular sieve; (2) The hydrotreatment effluent obtained in step (1) enters a high-pressure stripping tower from the top, and hydrogen is injected into the bottom of the tower as a stripping medium. After stripping, a bottom oil from which H2S and NH3 are removed and a top effluent containing H2S, NH3, hydrogen and part of light oil are obtained; (3) The effluent obtained in step (2) containing H2S, NH3, hydrogen and part of the light oil enters a cold high-pressure separator after heat exchange, and the cold high-fraction oil containing H2S and NH3 enters a cold low-fraction to separate the low-fraction gas, and then the cold low-fraction oil enters a H2S removal stripping tower to remove H2S and NH3, and is divided into two streams after pressure increase and heat exchange: one enters an isomerization dewaxing reactor, and the other enters a supplementary refining reactor; (4) The high-pressure stripping tower bottom oil obtained in step (2) is mixed with hydrogen and then enters the supplementary refining reactor together with the cold low-fraction oil from which H2S and NH3 are removed, and contacts and reacts with the supplementary refining catalyst; (5) The reaction effluent obtained in step (4) enters a separation system to obtain a series of light white oils and heavy cycloalkane fraction oils that meet the technical index requirements of light white oil (II) in NB / SH / T 0913-2015; (6) a portion of the heavy cycloalkane fraction obtained in step (5), a stream of the cold low fraction oil from which H2S and NH3 are removed in step (3), and hydrogen are sequentially passed through an isomerization dewaxing reactor and a supplementary refining reactor to perform a hydroisomerization reaction and a supplementary refining reaction; (7) The reaction effluent obtained in step (6) enters a separation system to obtain a cycloalkyl special oil product having a pour point that meets the requirements and good stability and a series of light white oils that meet the technical index requirements of light white oil (II) in NB / SH / T 0913-2015; the cycloalkyl special oil product includes one or more of the series of rubber filler oils; in, The stripping pressure of the high-pressure stripping tower in step (2) is the same as the pressure of the hydroprocessing reactor. The reaction pressure of the hydroprocessing reactor is 5.0 to 18.0 MPa in terms of hydrogen partial pressure.

2. The hydrogenation method according to claim 1, characterized in that: A ZnO bed is arranged at the lower part of the packing zone in the high-pressure stripping tower.

3. The hydrogenation method according to claim 1, characterized in that: The stripping temperature of the high-pressure stripping tower is 150-400° C., and the amount of hydrogen used is higher than the chemical hydrogen consumption of the hydroprocessing reactor.

4. The hydrogenation method according to claim 3, characterized in that: The stripping temperature of the high-pressure stripping tower is the outlet temperature of the hydroprocessing reactor, and the amount of hydrogen used is equivalent to the sum of the chemical hydrogen consumption and dissolved hydrogen of the hydroprocessing reactor.

5. The hydrogenation method according to claim 1, characterized in that: The cold high-fraction gas phase obtained in step (3) re-enters the hydroprocessing reactor as circulating hydrogen after selective removal of H2S.

6. The hydrogenation method according to claim 1, characterized in that: The aromatic content of the cycloalkane vacuum distillate oil is 30-99 wt%, and the density at 20°C is 0.923-0.955 g / cm 3 .

7. The hydrogenation method according to claim 1, characterized in that: The initial distillation point of the cycloalkyl vacuum distillate oil is 140-350°C, and the final distillation point is 400-600°C.

8. The hydrogenation method according to claim 1, characterized in that: Based on the weight of the catalyst, the hydrogenation reforming catalyst contains 20wt% to 60wt% of amorphous silicon aluminum, 5wt% to 25wt% of modified Y molecular sieve, 10wt% to 30wt% of Group VIB metal in terms of oxide, and 4wt% to 15wt% of Group VIII metal in terms of oxide.

9. The hydrogenation method according to claim 1 or 8, characterized in that: The specific surface area of ​​the hydrogenation catalyst is 220-300m 2 / g, the pore volume is 0.3-0.6mL / g, the pore volume with a pore diameter of 3-10nm accounts for 75%-95% of the total pore volume, and the infrared acidity is 0.30-0.5mmol / g.

10. The hydrogenation method according to claim 1, characterized in that: The isomerization dewaxing reactor is loaded with a hydroisomerization catalyst, which includes a carrier and an active metal component; the catalyst carrier includes alumina and a TON structure molecular sieve, the active metal component is one or more of Pt, Pd, Ru and Rh, and the optional auxiliary component is one or more of boron, fluorine, chlorine and phosphorus.

11. The hydrogenation method according to claim 10, characterized in that: The TON structure molecular sieve is at least one of NU-10 molecular sieve, ZSM-22 molecular sieve, ZSM-23 molecular sieve and ZSM-48 molecular sieve.

12. The hydrogenation method according to claim 1, characterized in that: The supplementary refining catalyst loaded in the supplementary refining reactor is a reduction type hydrorefining catalyst; the active metal of the reduction type hydrorefining catalyst is one or two of Pt and Pd, or metallic nickel; the catalyst carrier is Al2O3 or Al2O3-SiO2, containing one or more of P, Ti, B, and Zr as an auxiliary agent.

13. The hydrogenation method according to claim 1, characterized in that: The operating conditions of the hydroprocessing reactor are: reaction temperature 230-430°C, hydrogen-to-oil volume ratio 200-1500, volume space velocity 0.1-10.0h -1 .

14. The hydrogenation method according to claim 1, characterized in that: The loading ratio of the hydrotreating catalyst to the hydromodification catalyst is 1:9 to 9:

1.

15. The hydrogenation method according to claim 1, characterized in that: The reaction conditions of the isomerization dewaxing reactor are: reaction temperature of 300°C to 380°C, hydrogen partial pressure of 2.0MPa to 18.0MPa, raw oil liquid volume space velocity of 0.2h -1 ~6.0h -1 , hydrogen-oil volume ratio 400:1~1500:

1.

16. The hydrogenation method according to claim 1, characterized in that: The reaction conditions of the supplementary refining reactor are: reaction temperature of 200°C to 300°C, hydrogen partial pressure of 6.0MPa to 18.0MPa, volume space velocity of 0.2h -1 ~3.0h -1 , hydrogen-oil volume ratio 400:1~1500:

1.

17. The hydrogenation method according to claim 1, characterized in that: The cycloalkyl specialty oil obtained in step (7) also includes transformer oil and / or refrigeration oil.

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