Hydrogenation method for producing high viscosity index lubricating oil base oil

Abstract

The present invention discloses a hydrogenation method for producing a high viscosity index lubricating oil base oil. Waxy oil is used as a raw material, and firstly a hydrogenation treatment is performed; the effluent of the hydrogenation treatment is subjected to high pressure stripping to remove H 2 S and NH 3 After removing impurities, it first enters the first isomerization dewaxing reaction zone to complete the depth appropriate isomerization dewaxing reaction; then enters the supplementary refining reaction zone to obtain light lubricating oil base oil and heavy base oil components; the heavy base oil component enters the second isomerization dewaxing reaction zone in whole or in part; the second isomerization dewaxing reaction product and the first isomerization dewaxing reaction zone product enter the supplementary refining reaction zone together. The method of the present invention can obtain light and heavy lubricating oil base oils with high viscosity index while less supplementary refining catalyst is loaded, and high-quality special oil products are produced as by-products.

Description

Technical Field

[0001] The present invention relates to a hydrogenation method for producing a high viscosity index lubricating oil base oil, specifically, a method for producing a high viscosity index lubricating oil base oil by using one or more waxy oils selected from paraffin-based vacuum distillate oil, light deoiled oil, and shale oil vacuum distillate oil as raw materials through a two-stage process of hydrogenation treatment-high pressure hydrogen stripping / isomerization dewaxing-supplementary refining. Background Art

[0002] Traditional lubricating oil base oil production adopts solvent refining process, and its main two steps are to use solvent refining to remove non-ideal components such as aromatics and solvent dewaxing to ensure the low temperature flow properties of base oil. In addition, clay or hydrogenation refining is generally required.

[0003] The increasingly stringent environmental regulations and the rapid development of the machinery industry have put forward higher and higher requirements on the performance of lubricant base oils. At the same time, due to the deterioration of crude oil worldwide, the amount of crude oil suitable for the production of lubricants has gradually decreased. Therefore, the technology of producing lubricants by hydrogenation has developed rapidly. The hydrogenation process refers to the process of producing lubricant base oils by hydrocracking process or hydrotreating-isomerization dewaxing-hydrofining combined process. Its advantages are large raw material flexibility, high base oil yield, and high by-product value.

[0004] One disadvantage of the traditional hydroisomerization dewaxing process is that when full-fraction or wide-fraction waxy oil is used as feed, it is difficult to make both the light lubricating oil component and the heavy lubricating oil component meet the requirements of pour point and viscosity index at the same time. Generally speaking, when the pour point of the heavy lubricating oil component is qualified, the viscosity index loss of the light lubricating oil component is large, and it is difficult to produce API III light base oil products with a viscosity index>120; and when the viscosity index of the light lubricating oil component is qualified, the heavy component cannot be used as a qualified lubricating oil component.

[0005] In view of the above problems, the existing technology currently adopts pre-fractionation of waxy oil, and then uses each narrow fraction as feed for hydroisomerization dewaxing to solve the problem of producing high viscosity index light lubricating oil base oil. US5,580,442 proposes a method for producing high viscosity index lubricating oil base oil from hydrocracking tail oil. First, the hydrocracking tail oil is pre-fractionated under reduced pressure to cut out 100 viscosity 3mm 2 / s, 4mm 2 / s, 6 mm 2 / s and 8mm 2 / s four narrow fractions, these narrow fractions are hydroisomerized and dewaxed to produce 100 and 3mm viscosity with viscosity index>130 respectively. 2 / s, 4mm 2 / s, 6 mm 2 / s and 8mm 2 / s of four lubricant base oil products.

[0006] The use of narrow-fraction waxy oil as a feed for hydroisomerization dewaxing can solve the problem of producing light and heavy high-viscosity index lubricant base oils, but it requires the installation of multiple raw material tanks, which increases the construction investment of the device; and in actual production, the raw materials must be frequently switched and the process parameters must be frequently adjusted, which greatly increases the difficulty of device operation and produces a large number of unqualified products.

[0007] 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

[0008] In view of the shortcomings of the prior art, the present invention provides a hydrogenation method for producing a high viscosity index lubricant base oil. Using one or more waxy oils selected from paraffin-based vacuum distillate oil, light deoiling oil, and shale oil vacuum distillate oil as raw materials, a high viscosity index lubricant base oil is produced through a two-stage process of hydrogenation treatment-high pressure hydrogen stripping / isomerization dewaxing-supplementary refining.

[0009] A hydrogenation method for producing a high viscosity index lubricating oil base oil of the present invention comprises the following contents:

[0010] (1) One or more waxy oils selected from paraffin-based vacuum distillate, light deoiled oil, and shale oil vacuum distillate are mixed with hydrogen and then enter the hydroprocessing reaction zone, and are sequentially contacted with a hydrogenation protection catalyst, a hydrorefining catalyst, and a hydro-modifying catalyst for hydrogenation reaction. The hydro-modifying catalyst contains amorphous silica-alumina and modified Y molecular sieve;

[0011] (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;

[0012] (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 enters a cold low-fraction separator to separate the low-fraction gas. The cold low-fraction oil enters a H2S removal stripping tower to remove H2S and NH3, and is then pressurized and heat exchanged to be divided into two streams: one enters the first isomerization dewaxing reactor, and the other enters the supplementary refining reactor;

[0013] (4) The high-pressure stripping tower bottom oil obtained in step (2) is mixed with hydrogen and then enters the first isomerization dewaxing reactor together with the cold low fraction oil to perform an isomerization dewaxing reaction with an appropriate depth; the reaction effluent of the first isomerization dewaxing reactor enters the supplementary refining reaction zone to saturate olefins and aromatics;

[0014] (5) The reaction effluent obtained in the supplementary refining reaction zone of step (4) is subjected to gas-liquid separation, and the liquid product enters the fractionation system to obtain a light lubricating oil base oil product with a pour point that meets the requirements and a high viscosity index and a heavy base oil component with a higher pour point;

[0015] (6) All or part of the heavy base oil component obtained in step (5) enters the second isomerization dewaxing reaction zone to complete a deeper hydroisomerization reaction under appropriate conditions;

[0016] (7) The reaction effluent obtained in step (6) enters the supplementary refining reaction zone of step (4) for supplementary refining reaction.

[0017] Furthermore, the high-pressure stripping tower of 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.

[0018] Furthermore, the cold high-fraction gas phase obtained in step (3) is selectively de-HSed and then re-enters the hydroprocessing reactor as circulating hydrogen.

[0019] Furthermore, the paraffin-based distillate oil can be one or more of the following waxy oils: paraffin-based vacuum distillate oil, light deoiled oil, and shale oil vacuum distillate oil. The density of the waxy oil raw material at 20°C is generally 0.900-0.935 g / cm 3 The viscosity index of the waxy oil is generally 85-160, preferably 115-145. The distillation range of the waxy oil raw material is any range consisting of any two values ​​within the range of 140-600°C; preferably, the initial distillation point of the waxy oil fraction is 140-350°C, and the final distillation point is 400-600°C.

[0020] Furthermore, the split point temperature of the light base oil product and the heavy base oil component in step (5) is 450-520° C., that is, in the vacuum distillation tower, the distillation split temperature (actual boiling point temperature) of the light lubricating oil base oil product and the heavy lubricating oil base oil component is 450-520° C. The lubricating oil base oil with a boiling point lower than the split point is the light lubricating oil base oil, and the lubricating oil base oil component with a boiling point higher than the split point enters the isomerization dewaxing reactor for further reaction fractionation to obtain the heavy lubricating oil base oil.

[0021] 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.

[0022] 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, titanium oxide, etc.

[0023] Furthermore, the isomerization dewaxing catalyst used in the method of the present invention can be selected from the commonly used lubricating oil hydroisomerization catalyst in the art, and a commercial hydroisomerization catalyst can be used, or it can be prepared according to general knowledge in the art. The hydroisomerization catalyst carrier 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, pore volume is 0.15~0.60ml / g. The isomeric dewaxing catalysts in the two isomeric dewaxing reaction zones can be the same, or two or more isomeric dewaxing catalysts with different molecular sieves and metal contents can be graded.

[0024] Furthermore, the supplementary refining catalyst is a conventional reduction type hydrogenation refining catalyst, and its active metal is one or two of Pt and Pd, or metallic nickel. The weight content of active metal in the precious metal catalyst is generally 0.05% to 1%, and the weight content of nickel in the reduction type nickel catalyst is 30% to 80% in terms of oxide; the catalyst carrier is generally Al2O3 or Al2O3-SiO2, and can also selectively contain at least one of P, Ti, B, Zr, etc. 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.

[0025] Furthermore, the operating conditions of the hydroprocessing reaction zone 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 In the hydroprocessing reaction zone, the loading ratio of the hydrorefining catalyst to the hydromodification catalyst is 1:9 to 9:1, preferably 4:6 to 6:4.

[0026] Further, the reaction conditions of the two isomerization dewaxing reaction zones are: reaction temperature of 300°C to 380°C, preferably 310°C to 340°C, hydrogen partial pressure of 2.0MPa to 18.0MPa, preferably 10.0 to 15.0MPa, raw oil liquid volume space velocity of 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.

[0027] Furthermore, the reaction depth of the first isomerization dewaxing reaction zone is based on the qualified pour point of the light product (lubricating oil base oil of grades 4# and below), and the pour point of the heavy product will also be reduced to a certain extent. The isomerization depth of the second isomerization dewaxing reaction zone is based on the qualified pour point of the heavy product (lubricating oil base oil of grades 6# and above). At the same volumetric space velocity, the reaction temperature of the first isomerization dewaxing reaction zone is lower than that of the second isomerization dewaxing reaction zone, generally 10~20℃ lower. If the volumetric space velocity is 2.0h -1 When the reaction temperature of the first isomerization dewaxing reaction zone is 10-20°C lower than that of the second isomerization dewaxing reaction zone.

[0028] Further, the reaction conditions of the supplementary refining reaction zone 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.

[0029] Compared with the prior art, the method for producing cyclopentane rubber filler oil by a two-stage process of hydrotreatment-high-pressure hydrogen stripping / isomerization dewaxing-supplementary refining of the present invention has the following advantages:

[0030] 1. The two-stage hydrogenation process of high-pressure hydrogen stripping, hydrotreatment - high-pressure hydrogen stripping / 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. Most of the reaction feed (>85w%) 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;

[0031] 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 light lubricating oil base oil pour point being greatly excessive and the viscosity index loss being large when the heavy lubricating oil base oil pour point is qualified by adjusting the ratio of the two streams, thereby improving the liquid recovery and the target product yield.

[0032] 3. By controlling the conversion depth of the isomerization dewaxing process, the light and heavy components in the raw materials can reach the optimal dewaxing depth in different isomerization dewaxing reactors, thereby achieving the best balance between the pour point and viscosity index of light lubricant products and heavy lubricant base oil products.

[0033] 4. The heavy lubricating oil base oil product passes through the supplementary refining reactor twice, which reduces the interference of light products on the deep refining reaction of heavy products and increases the effective contact between heavy products and supplementary refining catalysts. It can deeply saturate trace amounts of nitrogen-containing polycyclic aromatic hydrocarbons that have the greatest impact on color and stability with 20-30% less precious metal supplementary refining catalysts (or by increasing the air velocity); the heavy lubricating oil base oil continues to reduce the pour point under suitable reaction conditions in the second isomerization dewaxing reaction zone. Since there is no interference from light white oil and light lubricating oil base oil, the second isomerization dewaxing reaction zone can be equipped with 30-40% less isomerization dewaxing catalyst, which can also reduce the carbon deposition tendency of the second isomerization dewaxing reactor and increase the service life of the isomerization dewaxing catalyst.

[0034] 5. The method of the present invention simultaneously produces a series of light white oils that meet the technical index requirements of light white oil (II) in NB / SH / T 0913-2015 and industrial white oil that meets the technical index requirements of industrial white oil (II) in NB / SH / T 0006-2017. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a process flow diagram of the method of the present invention. DETAILED DESCRIPTION

[0036] The method of the present invention is described in more detail below with reference to the accompanying drawings and specific embodiments.

[0037] Combination Figure 1 The method for producing high viscosity index lubricating oil base oil by hydrogenation of the present invention is as follows:

[0038] One or more waxy oils such as paraffin-based vacuum distillate, light deoiled oil, and shale oil vacuum distillate pass through pipeline 1, and after being mixed with circulating hydrogen from pipeline 2, first enter the hydroprocessing reaction zone 3 to undergo desulfurization, denitrogenation, deoxygenation, and aromatic saturation reactions; then the hydroprocessing product 4 enters the high-pressure hydrogen stripping tower 5, and stripping hydrogen 6 is blown into the bottom of the tower to obtain the bottom oil 7 from which H2S and NH3 are removed. 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 gas phase obtained by separation is returned to the hydroprocessing reaction system as circulating hydrogen through pipeline 2, and the liquid phase product enters the H2S removal stripping tower 10 through pipeline 9. The bottom oil 11 from which H2S and NH3 are removed is pressurized and heat exchanged, and then divided into two streams 13 and 14 according to a certain ratio, and enter the first isomerization dewaxing reactor 15 and the supplementary refining reactor 17 respectively. The high-pressure stripping tower bottom oil 7, the second-stage new hydrogen 12, and the second-stage circulating hydrogen 27 are mixed with the stream 13 and directly enter the first isomerization dewaxing reactor 15 to carry out isomerization decondensation reaction. The isomeric dewaxing product 16 is mixed with the logistics 14 and enters the supplementary refining reactor 17 for deep dearomatization reaction to improve the light and heat stability of the product. The supplementary refining reaction product 18 enters the separation system 19, which generally includes a high-pressure separator and a low-pressure separator. The low-fraction oil enters the fractionation system 20, which includes a normal pressure fractionation tower and a vacuum fractionation tower, to obtain a light lubricating oil base oil product with a high viscosity index and a heavy base oil component with a high pour point; then the heavy base oil component enters the second isomeric dewaxing reaction zone 26 in whole or in part to complete a deeper hydrogenation isomerization reaction under appropriate conditions, and the obtained reaction effluent enters the precious metal supplementary refining reaction zone together for deep supplementary refining reaction, and the heavy lubricating oil base oil circulation amount through the pipeline 25 is adjusted according to the product properties until the whole system reaches equilibrium, and finally a light white oil 21, an industrial white oil 22, a light high viscosity index lubricating oil base oil product 23 and a heavy high viscosity index lubricating oil base oil product 24 are obtained.

[0039] The specific contents and effects of the method of the present invention are described below by means of specific embodiments.

[0040] 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.

[0041] Table 1 Raw material properties

[0042]

[0043] Table 2 Physical and chemical properties of catalysts

[0044]

[0045] Example 1

[0046] The raw material is paraffin-based three-line oil 1 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 hydrogenation protective agents, hydrorefining catalysts and hydroreforming catalysts, wherein the series of hydrogenation protective agents: hydrorefining catalysts: hydroreforming 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.

[0047] Example 2

[0048] The raw material is paraffin-based three-line oil 2 listed in Table 1, and the same catalyst as in Example 1 is used. Figure 1 The process conditions and test results are shown in Tables 3 and 4.

[0049] Comparative Example 1

[0050] 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 discharged from the device, and all the bottom liquid (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.

[0051] 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.

[0052] Comparative Example 2

[0053] 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).

[0054] 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.

[0055] Table 3 Process conditions

[0056]

[0057] *, for fresh feed.

[0058] Table 4 Test results

[0059]

[0060] **, for fresh feed.

[0061] From the data in Table 3-4, it can be seen that by using paraffin-based vacuum distillate oil as raw material and adopting the two-stage process of hydroprocessing-high-pressure hydrogen stripping / isodewaxing-supplementary refining, products of equivalent quality to the conventional two-stage process of hydroprocessing / isodewaxing-supplementary refining can be produced. At the same time, the energy consumption of the conventional two-stage process of all feed pressure increase-depressurization-pressure increase, temperature increase-temperature decrease-temperature increase is avoided, the equipment area is reduced, and the energy consumption of the equipment is reduced by about 12%. In addition, since the cold high-fraction oil is subjected to conventional stripping and enters the isodewaxing reactor and the supplementary refining reactor respectively according to the optimized ratio, the viscosity index loss of the light lubricating oil base oil is reduced while ensuring that the pour point of the series of lubricating oil base oils is qualified, the light oil loss at the top of the conventional two-stage distillation process de-H2S stripping tower is reduced, and the liquid recovery and target product yield are improved. At the same time, it is difficult to achieve a balance in the reaction conditions between light lubricant base oil and heavy lubricant base oil in the conventional hydroprocessing / isomerization dewaxing-supplementary refining process. When the pour point of the heavy product is qualified, the liquid yield and the target product yield are both low, and the viscosity index loss is large. Comparative Example 2 uses the Shell process flow. Although the energy consumption is low, the cold low-fraction oil is directly fed into the fractionation system without hydrogenation supplementary refining, resulting in the oxidation stability of the entire product line being unqualified.

Claims

1. A hydrogenation method for producing a high viscosity index lubricating oil base oil, comprising the following: (1) One or more waxy oils selected from paraffin-based vacuum distillate, light deoiled oil, and shale oil vacuum distillate are mixed with hydrogen and then enter the hydroprocessing reaction zone, and sequentially contact with a hydrogenation protection catalyst, a hydrorefining catalyst, and a hydro-modifying catalyst for hydrogenation reaction; the hydro-modifying catalyst contains amorphous silica-alumina and 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 top 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 enters a cold low-fraction separator to separate the low-fraction gas. The cold low-fraction oil enters a H2S removal stripping tower to remove H2S and NH3, and is then pressurized and heat exchanged to be divided into two streams: one enters the first isomerization dewaxing reactor, and the other enters the supplementary refining reactor; (4) The high-pressure stripping tower bottom oil obtained in step (2) is mixed with hydrogen and then enters the first isomerization dewaxing reactor together with the cold low-fraction oil to perform isomerization decondensation reaction; the reaction effluent of the first isomerization dewaxing reactor enters the supplementary refining reactor; (5) The reaction effluent obtained from the supplementary refining reactor in step (4) is subjected to gas-liquid separation, and the liquid product enters the fractionation system to obtain a light lubricating oil base oil product and a heavy base oil component with a pour point that meets the requirements; (6) All or part of the heavy base oil component obtained in step (5) enters the second isomerization dewaxing reactor for hydroisomerization reaction; (7) the reaction effluent obtained in step (6) enters the supplementary refining reactor of step (4) for supplementary refining reaction; The stripping pressure of the high-pressure stripping tower in step (2) is the same as the pressure of the hydroprocessing reaction zone, and the operating pressure of the hydroprocessing reaction zone 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 area 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 in the hydroprocessing reaction zone.

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 reaction zone, and the amount of hydrogen used is equivalent to the sum of the chemical hydrogen consumption of the hydroprocessing reaction and the dissolved hydrogen of the hydroprocessing system.

5. The hydrogenation method according to claim 1, characterized in that The cold high-fraction gas phase obtained in step (3) is selectively de-HSed and then re-enters the hydroprocessing reactor as circulating hydrogen.

6. The hydrogenation method according to claim 1, characterized in that The density of the wax-containing oil at 20°C is 0.900-0.935 g / cm 3 .

7. The hydrogenation method according to claim 1, characterized in that The viscosity index of the waxy oil is 85-160.

8. The hydrogenation method according to claim 1, characterized in that The wax-containing oil has an initial boiling point of 140-350°C and a final boiling point of 400-600°C.

9. The hydrogenation method according to claim 1, characterized in that: The splitting temperature of the light lubricating oil base oil product and the heavy base oil component in step (5) is 450-520°C.

10. The hydrogenation method according to claim 1, characterized in that: Based on the weight of the catalyst, the hydrogenation and reforming catalyst contains 20wt% to 60wt% of amorphous silica-alumina, 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.

11. The hydrogenation method according to claim 1 or 9, characterized in that: The specific surface area of ​​the hydrogenation catalyst is 220 to 300 m 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.

12. The hydrogenation method according to claim 1, characterized in that: The first isomerization dewaxing reactor and the second isomerization dewaxing reactor are loaded with an isomerization dewaxing catalyst, wherein the isomerization dewaxing catalyst comprises a catalyst carrier and an active metal component; the catalyst carrier comprises alumina and a TON structured 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.

13. The hydrogenation method according to claim 12, 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.

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

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

16. 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.

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

1.

18. The hydrogenation method according to claim 1, characterized in that: The reaction depth of the first isomerization dewaxing reactor is based on the qualified pour point of lubricating base oils of grades 4# and below; the isomerization depth of the second isomerization dewaxing reactor is based on the qualified pour point of lubricating base oils of grades 6# and above.

19. The hydrogenation method according to claim 17 or 18, characterized in that: At the same volumetric space velocity, the reaction temperature of the first isomerization dewaxing reactor is lower than the reaction temperature of the second isomerization dewaxing reactor.

20. The hydrogenation method according to claim 19, characterized in that The reaction temperature of the first isomerization dewaxing reactor is 10-20°C lower than the reaction temperature of the second isomerization dewaxing reactor.

21. 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.

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