A kind of transformer oil base oil and preparation method thereof

Abstract

The present invention relates to a transformer oil base oil and a preparation method thereof, wherein the preparation method comprises the following steps: (1) mixing raw oil with hydrogen, performing hydrotreatment, and obtaining hydrotreatment product oil; (2) mixing the hydrotreatment product oil with hydrogen, performing hydrodecondensation treatment under the action of a hydrodecondensation catalyst, and obtaining hydrodecondensation product oil; (3) mixing the hydrodecondensation product oil with hydrogen, performing refining treatment, and fractionating at a temperature greater than 275°C to obtain the transformer oil base oil. The preparation method of the present invention can prepare a transformer oil base oil having the characteristics of low sulfur, low nitrogen, low condensation and low aromaticity, and meets the requirements of T-40°C transformer oil (general purpose) base oil in GB2536-2011 standard.

Description

Technical Field

[0001] The invention relates to the technical field of transformer oil base oil, in particular to a transformer oil base oil and a preparation method thereof, in particular to a preparation method of a transformer oil base oil, naphtha and a drilling fluid lubricant base oil and the transformer oil base oil. Background Art

[0002] The preparation of transformer oil base oil is very important in crude oil processing and recovery.

[0003] CN102676127A discloses a method for preparing a low-fluorescence lubricant for drilling fluid, comprising the following steps: putting water in a reactor, then adding sodium dodecylbenzene sulfonate, sodium rosinate, oleic acid and white oil under heating and continuous stirring, then stirring and reacting for a period of time to fully mix the materials, thereby obtaining a low-fluorescence lubricant for drilling fluid. The disclosed product has the characteristics of being non-toxic, pollution-free, low-fluorescence interference, anti-jamming, good lubricity, etc., and has good compatibility with various types of mud, has no adverse effect on mud rheology, and can meet the requirements of exploration wells, detailed exploration wells, geological logging and environmental protection.

[0004] CN106753555A discloses a method for preparing low-freezing-point transformer oil by high-pressure hydrogenation, comprising: adding cycloalkane oil and a hydrogenation catalyst after sulfurization passivation treatment into a reactor, introducing hydrogen, heating to carry out a hydrogenation cracking reaction, performing gas-liquid separation after the reaction, adding a hydrodecondensation catalyst, introducing hydrogen, heating to carry out a shape-selective cracking reaction, performing gas-liquid separation after the reaction, and then adding activated clay for refining to obtain the low-freezing-point transformer oil. The method for preparing low-freezing-point transformer oil by high-pressure hydrogenation proposed by the present invention has a simple process and mild conditions. The prepared transformer oil not only has excellent low-temperature flowability, but also has a light color and good electrical properties. The method requires two gas-liquid separations and liquid-solid separations, which are complicated to operate and have high energy consumption. In addition, clay refining is required, which will bring about the problem of waste clay treatment.

[0005] CN106833740A discloses a method for preparing transformer oil base oil, comprising the following steps: (1) hydrofining cycloalkyl fraction oil under the action of a catalyst to obtain hydrofining product oil; (2) hydroisomerizing the hydrofining product oil to obtain hydroisomerization product oil; (3) supplementary hydrogenation refining of the hydroisomerization product oil to obtain three-stage hydrogenation product oil, and then atmospheric and vacuum distillation, and the fraction greater than 280°C is the transformer oil base oil. The process is a full hydrogen process under medium pressure conditions, and the obtained transformer oil base oil improves the oxidation stability of the transformer oil without adding a metal passivator, and retains some cycloalkyl characteristics, which can meet the requirements of the new transformer oil IEC60296-2012 standard. The yield of the transformer oil base oil produced by this process can be increased by more than 8% compared with the traditional process. The hydroisomerization catalyst in the disclosed preparation method is a precious metal catalyst with a mixture of SAPO-11 and ZSM-22 molecular sieves as a carrier and Pt / Pd as an active metal. The catalyst is expensive, resulting in a high production cost of transformer oil base oil.

[0006] CN113234483A discloses a method for preparing transformer oil base oil containing aromatic hydrocarbons. It solves the difficulty of fuel oil type refinery to produce transformer oil base oil containing appropriate amount of aromatic hydrocarbons by using existing hydrogenation device and process technology without carrying out atmospheric and vacuum device transformation. By carrying out catalyst grading transformation on hydrogenation and modification wax oil device, transformer oil base oil produced under medium pressure condition retains appropriate amount of aromatic hydrocarbons. The transformer oil base oil prepared by this method has the characteristics of good low temperature performance, gas evolution performance, solubility and oxidation stability, and meets the requirements of Class I (special grade) transformer oil base oil in GB2536-2011 standard. The hydrorefining product oil disclosed in it needs to be stripped by high-pressure hydrogen, which increases the hydrogen consumption and energy consumption of the device. In particular, the pour point of the base oil is -32°C and the sulfur content is greater than 70mg / kg when the reaction temperature of the isomerization decondensation catalyst is 370°C, which limits the application scope of the transformer oil base oil.

[0007] CN101386792A discloses a transformer oil base oil and its preparation method and application. The disclosed transformer oil base oil preparation method comprises the following steps: 1) refining SZ36-1 ordinary second-line distillate oil with furfural to obtain refined oil, and removing furfural to obtain dealdehyde refined oil; 2) denitrifying the dealdehyde refined oil to remove nitrogen residue to obtain denitrogenated refined oil; 3) adding kaolin to the denitrogenated refined oil to perform kaolin refining to obtain transformer oil base oil. The disclosed method cannot produce transformer oil with a low pour point, and there are problems such as low transformer oil yield and difficult treatment of waste kaolin.

[0008] Looking at the above-mentioned existing technologies, up to now, there is no processing technology for preparing low-freezing point and low-aromatic transformer oil base oil under medium pressure conditions using sulfurized catalysts. At present, the production technologies of low-freezing point and low-aromatic transformer oil base oil all use highly active reduced precious metal catalysts or sulfurized catalysts under high pressure conditions, which increases the construction and production costs of the equipment.

[0009] Therefore, it is very important to develop a method for preparing transformer oil base oil which can be simply and cost-effectively produced with the characteristics of low sulfur, low nitrogen, low condensation and low aromaticity. Summary of the invention

[0010] In view of the deficiencies in the prior art, the object of the present invention is to provide a transformer oil base oil and a preparation method thereof. The preparation method described in the present invention can prepare a transformer oil base oil with low sulfur, low nitrogen, low freezing point and low aromatic characteristics, and meets the requirements of T-40°C transformer oil (universal) base oil in the GB2536-2011 standard; the preparation method is simple and easy to operate, can meet the production requirements under medium pressure, has low cost, and can also prepare naphtha and a drilling fluid lubricant base oil that meets the Q / HXPF001-2019 standard by adjusting the fractionation temperature.

[0011] To achieve this object, the present invention adopts the following technical solutions:

[0012] In a first aspect, the present invention provides a method for preparing a transformer oil base oil, the preparation method comprising the following steps:

[0013] (1) mixing the feedstock oil with hydrogen and performing a hydrogenation treatment to obtain a hydrogenation product oil;

[0014] (2) mixing the hydrotreated product oil with hydrogen, and performing a hydrodegradation treatment under the action of a hydrodegradation catalyst to obtain a hydrodegradation product oil;

[0015] (3) The hydrodecondensation product oil is mixed with hydrogen, subjected to a refining treatment, and fractionated at a temperature greater than 275° C. (e.g., 280° C., 290° C., 300° C., etc.) to obtain the transformer oil base oil.

[0016] In the present invention, raw oil is mixed with hydrogen and subjected to hydrogenation treatment to remove heteroatoms such as sulfur, nitrogen, oxygen and the like in the raw material and saturate aromatic hydrocarbons to obtain hydrogenation product oil; the hydrogenation product oil is mixed with hydrogen and subjected to selective removal of macromolecular normal alkanes with high freezing points under the action of a hydrodecondensation catalyst to obtain hydrodecondensation product oil; the hydrodecondensation product oil is mixed with hydrogen and subjected to refining treatment to further saturate olefins and aromatic hydrocarbons, and then subjected to atmospheric and vacuum distillation, and the fraction greater than 275° C. is the transformer oil base oil.

[0017] Preferably, in step (1), the hydroprocessing is carried out under the action of a hydroprocessing catalyst.

[0018] Preferably, the hydroprocessing catalyst comprises an active metal oxide and a metal oxide promoter.

[0019] Preferably, the active metal oxide comprises a Group VIII metal oxide and / or a Group VIB metal oxide.

[0020] Preferably, the active metal oxide comprises nickel oxide and / or tungsten trioxide.

[0021] Preferably, the metal oxide auxiliary agent includes any one of SB, boric acid, phosphoric acid or sesbania, or a combination of at least two of them, wherein typical but non-limiting combinations include: a combination of SB and boric acid, a combination of phosphoric acid and sesbania, a combination of SB, boric acid, phosphoric acid and sesbania, etc.

[0022] In the present invention, SB refers to: high-purity pseudo-boehmite.

[0023] Illustratively, SB and Sesbania sesbania are in powdery structures.

[0024] Preferably, based on the total mass of the hydroprocessing catalyst as 100%, the mass percentage of the Group VIII metal oxide is 2.0%-6.0%, for example, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, etc.

[0025] Preferably, based on the total mass of the hydroprocessing catalyst as 100%, the mass percentage of the Group VIB metal oxide is 15%-30%, for example, 16%, 18%, 20%, 22%, 24%, 26%, 28%, etc.

[0026] Preferably, based on the total mass of the hydroprocessing catalyst being 100%, the mass percentage of the metal oxide promoter is 2.0%-5.0%, for example, 2.5%, 3%, 3.5%, 4%, 4.5%, etc.

[0027] In the present invention, the hydroprocessing catalyst is preferably used to reduce the sulfur, nitrogen, oxygen and aromatic content of the hydrogenated oil by removing heteroatoms such as sulfur, nitrogen and oxygen and saturating aromatics.

[0028] Preferably, the preparation method of the hydroprocessing catalyst comprises the following steps:

[0029] The compound containing active metal elements, the metal oxide additive and the slurry are mixed and filtered to obtain a filter cake and a filtrate;

[0030] The filtrate is formed into a binder, and the binder and the filter cake are pressed into a shape, dried and calcined to obtain the hydroprocessing catalyst.

[0031] Preferably, the slurry comprises water, silica and alumina.

[0032] Preferably, in step (1), the reaction pressure of the hydrotreatment is 8.0-10.0 MPa, for example, 8.2 MPa, 8.4 MPa, 8.6 MPa, 8.8 MPa, 9 MPa, 9.2 MPa, 9.4 MPa, 9.6 MPa, 9.8 MPa, etc.

[0033] Preferably, the reaction temperature of the hydrotreatment is 300-370°C, such as 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, etc.

[0034] Preferably, the volume ratio of hydrogen to feedstock oil is (600-1200):1, wherein 600-1200 can be 700, 800, 900, 1000, 1100, etc.

[0035] Preferably, the volume space velocity of the hydroprocessing is 0.2-1.0h -1 , for example 0.3h -1 、0.4h -1 、0.5h -1 、0.6h -1 、0.7h -1 , 0.8h -1 、0.9h -1 wait.

[0036] Preferably, in step (2), the hydrodegradation catalyst comprises a catalyst carrier and an active metal oxide disposed inside and / or on the surface of the catalyst carrier.

[0037] In the present invention, the hydrodegradation catalyst is preferably used to reduce the pour point of the hydrogenated oil by selectively removing macromolecular normal alkanes with high freezing points.

[0038] Preferably, the active metal oxide comprises a Group VIII metal oxide and / or a Group VIB metal oxide.

[0039] Preferably, based on the total mass of the hydrodegradation catalyst as 100%, the mass percentage of the Group VIII metal oxide is 1.0%-6.0%, for example 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, etc.

[0040] Preferably, based on the total mass of the hydrodecondensation catalyst as 100%, the mass percentage of the Group VIB metal oxide is 2.0%-10.0%, for example, 3%, 4%, 5%, 6%, 7%, 8%, 9%, etc.

[0041] Preferably, the active metal oxide comprises nickel oxide and / or tungsten trioxide.

[0042] Preferably, the catalyst carrier comprises a catalyst carrier support and a molecular sieve arranged inside and / or on the surface of the catalyst carrier support.

[0043] Preferably, based on the total mass of the hydrodegradation catalyst being 100%, the mass percentage of the molecular sieve is 8.0%-40.0%, for example, 10%, 15%, 20%, 25%, 30%, 35%, etc.

[0044] Preferably, the mother liquor of the molecular sieve comprises aluminum sulfate, silica sol, alkaline substance and water.

[0045] Preferably, the silica sol comprises silicon oxide.

[0046] Preferably, the alkaline substance comprises sodium hydroxide and / or triethylamine.

[0047] Preferably, the raw materials for preparing the catalyst carrier support include pseudo-boehmite, a peptizing agent, an extrusion aid, a pore expanding agent, a metal oxide aid and water.

[0048] In the present invention, a pore-enlarging agent of a certain particle size is added to the hydrodecondensation catalyst during the preparation process of the catalyst carrier support, so that the prepared support has a larger pore volume and pore diameter, and a large space is reserved for the subsequent molecular sieve synthesis. In addition, a certain auxiliary agent is added during the preparation process, and a spinel structure is formed with alumina after high-temperature calcination, which improves the strength and skeleton stability of the support. At the same time, the molecular sieve is synthesized in the pores of the support and coated on the surface of the pores of the support, so that the molecular sieve is exposed to the outside, which further improves the activity of the catalyst.

[0049] Preferably, the solid content of the catalyst carrier support is 50%-80%, for example, 55%, 60%, 65%, 70%, 75% and the like.

[0050] Preferably, based on the total mass of the hydrodegradation catalyst as 100%, the mass percentage of the metal oxide additive is 1.0%-6.0%, for example, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, etc.

[0051] Preferably, the preparation method of the hydrodegassing catalyst comprises the following steps: impregnating a catalyst carrier in an active metal salt solution, drying and calcining to obtain the hydrodegassing catalyst.

[0052] Preferably, the method for preparing the catalyst carrier comprises the following steps: immersing the catalyst carrier support body in a molecular sieve mother solution, and then crystallizing, washing, drying and calcining the catalyst carrier support body to obtain the catalyst carrier.

[0053] Preferably, the method for preparing the catalyst carrier support comprises the following steps: after mixing pseudo-boehmite, a peptizing agent, an extrusion aid and water, the mixture is molded, dried and calcined in sequence to obtain the catalyst carrier support.

[0054] As a preferred technical solution, the preparation method of the hydrodecondensation catalyst comprises the following steps:

[0055] After mixing pseudo-boehmite, a peptizing agent, an extrusion aid and water, the mixture is molded, dried and calcined in sequence to obtain a catalyst carrier support;

[0056] Mixing aluminum sulfate, silica sol, alkaline substances and water to obtain a molecular sieve mother solution;

[0057] The catalyst carrier support is immersed in a molecular sieve mother solution, and then the catalyst carrier support is crystallized, washed, dried and calcined to obtain a catalyst carrier;

[0058] The catalyst carrier is impregnated in an active metal salt solution, dried and calcined to obtain the hydrodecondensation catalyst.

[0059] Preferably, in step (2), the reaction pressure of the hydrodecondensation treatment is 8.0-10.0 MPa, such as 8.5 MPa, 9 MPa, 9.5 MPa, etc.

[0060] Preferably, the reaction temperature of the hydrodecondensation treatment is 280-340°C, such as 290°C, 300°C, 310°C, 320°C, 330°C, etc.

[0061] Preferably, the volume ratio of the hydrogen to the hydroprocessed oil is (600-1200):1, wherein 600-1200 may be 700, 800, 900, 1000, 1100, etc.

[0062] Preferably, the volumetric space velocity of the hydrodecondensation treatment is 0.8-3.0h -1 , for example 1h -1 , 1.2h -1 、 1.4h -1 , 1.6h -1 , 1.8h -1 , 2h -1 , 2.2h -1 , 2.4h -1 , 2.6h -1 , 2.8h -1wait.

[0063] Preferably, in step (3), the refining treatment is carried out under the action of a supplementary refining catalyst.

[0064] Preferably, the supplementary refined catalyst comprises a catalyst carrier and an active metal oxide and a promoter disposed inside and / or on the surface of the catalyst carrier.

[0065] Preferably, the active metal oxide comprises a Group VIII metal oxide and / or a Group VIB metal oxide.

[0066] Preferably, based on the total mass of the supplementary refined catalyst as 100%, the mass percentage of the Group VIII metal oxide is 4.0%-10.0%, for example 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, etc.

[0067] Preferably, based on the total mass of the supplementary refined catalyst as 100%, the mass percentage of the Group VIB metal oxide is 15%-30%, for example, 16%, 18%, 20%, 22%, 24%, 26%, 28%, etc.

[0068] Preferably, the adjuvant comprises a heteroatom.

[0069] Preferably, the heteroatom includes any one or a combination of at least two of phosphorus, fluorine, boron, titanium or zirconium, wherein typical but non-limiting combinations include: a combination of phosphorus and fluorine, a combination of boron, titanium and zirconium, and a combination of phosphorus, fluorine, boron, titanium and zirconium.

[0070] Preferably, the additive includes any one of a phosphorus-containing additive, a fluorine-containing additive, a boron-containing additive, a titanium-containing additive or a zirconium-containing additive, or a combination of at least two thereof, wherein typical but non-limiting combinations include: a combination of a phosphorus-containing additive and a fluorine-containing additive, a combination of a boron-containing additive, a titanium-containing additive and a zirconium-containing additive, a combination of a phosphorus-containing additive, a fluorine-containing additive, a boron-containing additive, a titanium-containing additive and a zirconium-containing additive, and the like.

[0071] Preferably, based on the total mass of the supplementary refined catalyst as 100%, the mass percentage of heteroatoms in the auxiliary agent is 1.0%-10.0%, for example, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, etc.

[0072] Preferably, the raw materials for preparing the catalyst carrier include pseudo-boehmite, a peptizing agent, an extrusion aid and water.

[0073] In the present invention, the supplementary refining catalyst is preferably used to further remove olefins and aromatics, thereby reducing the olefin and aromatics content of the hydrogenated oil.

[0074] Preferably, the preparation method of the supplementary refined catalyst comprises the following steps:

[0075] mixing any one of active metals, active metal salts or active metal oxides or a combination of at least two thereof with a solvent, an auxiliary agent, an oil phase and other additives to form a water-in-oil microemulsion;

[0076] After the catalyst carrier is impregnated with the water-in-oil microemulsion, it is dried and calcined, and then the treated catalyst carrier is impregnated in a solution containing any one or a combination of at least two of active metals, active metal salts or active metal oxides, and is dried and calcined again to obtain the supplementary refined catalyst.

[0077] Preferably, the method for preparing the catalyst carrier comprises the following steps: after mixing pseudo-boehmite, a peptizing agent, an extrusion aid and water, the mixture is molded, dried and calcined in sequence to obtain the catalyst carrier.

[0078] Preferably, the oil phase comprises any one of n-octane, heptane or cyclohexane or a combination of at least two thereof, wherein typical but non-limiting combinations include: a combination of n-octane and heptane, a combination of heptane and cyclohexane, a combination of n-octane, heptane and cyclohexane, etc.

[0079] Preferably, the other additives include surfactants and / or co-surfactants.

[0080] Preferably, in step (3), the reaction pressure of the refining treatment is 8.0-10.0 MPa, such as 8.5 MPa, 9 MPa, 9.5 MPa, etc.

[0081] Preferably, the reaction temperature of the refining treatment is 290-360°C, such as 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, etc.

[0082] Preferably, the volume ratio of the hydrogen to the hydrodegradation oil is (600-1200):1, wherein 600-1200 may be 700, 800, 900, 1000, 1100, etc.

[0083] Preferably, the volume space velocity of the refining treatment is 0.3-2.0h -1 , for example 0.4h -1 、0.6h -1 , 0.8h -1 , 1h -1 , 1.2h -1 , 1.4h -1 , 1.6h -1 , 1.8h -1 wait.

[0084] Preferably, the feedstock oil comprises any one of cycloalkyl normal second-line, cycloalkyl minus first-line or hydrogenated modified diesel, or a combination of at least two of them, wherein typical but non-limiting combinations include: a combination of cycloalkyl normal second-line and cycloalkyl minus first-line, a combination of cycloalkyl minus first-line and hydrogenated modified diesel, a combination of cycloalkyl normal second-line, cycloalkyl minus first-line and hydrogenated modified diesel, etc., and cycloalkyl normal second-line and / or cycloalkyl minus first-line are further preferred.

[0085] Preferably, the pressure of the single-stage medium-pressure hydrogenation is 8.0-10.0 MPa, such as 8.8 MPa, 9 MPa, 9.5 MPa, etc.

[0086] In a second aspect, the present invention provides a transformer oil base oil, wherein the transformer oil base oil is prepared by the preparation method described in the first aspect;

[0087] The transformer oil base oil has a sulfur content of less than 1.0 mg / kg (e.g., 0.8 mg / kg, 0.6 mg / kg, 0.4 mg / kg, 0.2 mg / kg, etc.), a nitrogen content of less than 1.0 mg / kg (e.g., 0.8 mg / kg, 0.6 mg / kg, 0.4 mg / kg, 0.2 mg / kg, etc.), a total aromatic hydrocarbon content of less than 10% (e.g., 8%, 6%, 4%, etc.), and a pour point of less than -57°C (e.g., -59°C, -60°C, -61°C, etc.).

[0088] In a third aspect, the present invention provides a method for preparing naphtha, the preparation method comprising the following steps:

[0089] (1) mixing the feedstock oil with hydrogen and performing a hydrogenation treatment to obtain a hydrogenation product oil;

[0090] (2) mixing the hydrotreated product oil with hydrogen, and performing a hydrodegradation treatment under the action of a hydrodegradation catalyst to obtain a hydrodegradation product oil;

[0091] (3) The hydrodecondensation product oil is mixed with hydrogen, subjected to a refining treatment, and fractionated at less than 215° C. (e.g., 210° C., 205° C., 200° C., 195° C., etc.) to obtain the naphtha.

[0092] In a fourth aspect, the present invention provides a method for preparing a drilling fluid lubricant base oil, the preparation method comprising the following steps:

[0093] (1) mixing the feedstock oil with hydrogen and performing a hydrogenation treatment to obtain a hydrogenation product oil;

[0094] (2) mixing the hydrotreated product oil with hydrogen, and performing a hydrodegradation treatment under the action of a hydrodegradation catalyst to obtain a hydrodegradation product oil;

[0095] (3) The hydrodecondensation oil is mixed with hydrogen, subjected to a refining treatment, and fractionated at 215-275° C. (e.g., 220° C., 230° C., 240° C., 250° C., 260° C., 270° C., etc.) to obtain the drilling fluid lubricant base oil.

[0096] In the present invention, the process parameters and raw materials involved in the preparation method of the transformer oil base oil are suitable for drilling fluid lubricant base oil and naphtha, and different products can be obtained only by adjusting the fractionation temperature.

[0097] Compared with the prior art, the present invention has the following beneficial effects:

[0098] (1) The method for preparing a transformer oil base oil of the present invention comprises adjusting the reaction gradation of a hydrogenation catalyst under a reaction pressure of 9.5 MPa, and obtaining a transformer oil base oil having a sulfur content of less than 1.0 mg / kg, a nitrogen content of less than 1.0 mg / kg, a total aromatic hydrocarbon content of less than 10%, and a pour point of less than -57°C under full hydrogenation process conditions, and meeting the index requirements of T-40°C transformer oil (general purpose) base oil in GB2536-2011 standard, and having the characteristics of low sulfur, low nitrogen, low condensation point and low aromaticity.

[0099] (2) The present invention solves the problem that a high-pressure hydrogenation process or a hydrogenation treatment-furfural refining-clay refining process is required when producing low-condensation and low-aromatic transformer oil base oil. The former increases the energy consumption and production cost of the device, and the latter affects the product yield and causes environmental pollution. The present invention adjusts the catalyst grading to achieve a high removal rate of sulfides, nitrides and aromatics in the raw materials. Low-condensation and low-aromatic transformer oil base oil can be directly produced under medium-pressure hydrogenation and moderate process conditions. The product properties are superior to those of the traditional transformer oil base oil production process and are equivalent to the high-pressure hydrogenation process, thereby reducing the production cost of the industrial device.

[0100] (3) The preparation method of the present invention is simple and easy to operate, can meet the production requirements under medium pressure, has low cost, and can also prepare naphtha and drilling fluid lubricant base oil that meets the Q / HX PF001-2019 standard by adjusting the distillation temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0101] Figure 1 It is a process flow chart of the preparation method described in Example 1 of the present invention. DETAILED DESCRIPTION

[0102] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0103] In the present invention, the raw materials used are obtained from China National Offshore Oil Corporation. Information on some of the raw materials is shown in Table 1:

[0104] Table 1

[0105]

[0106]

[0107] In the present invention, the process conditions in the hydroprocessing process of each embodiment are shown in Table 2:

[0108] Table 2

[0109]

[0110]

[0111] In Table 2, Example 4 and Example 3 correspond to two process parameters. Since the hydrodecondensation reaction temperatures are different, the pour points of the obtained hydrogenated oils are different. The present invention is designed to illustrate that the decondensation catalyst still has good pour point reduction performance at a lower temperature.

[0112] Example 1

[0113] This embodiment provides a method for preparing transformer oil base oil. The specific process parameters are shown in Table 2 and the process flow chart is shown in Figure 1 As shown, the preparation method comprises the following steps:

[0114] (1) mixing the raw oil (Suizhong 36-1 Changer Line, performance as shown in Table 1) with hydrogen, and performing a hydrotreatment under the action of a hydrotreatment catalyst to obtain a hydrotreatment product oil;

[0115] (2) mixing the hydrotreated product oil with hydrogen, and performing a hydrodegradation treatment under the action of a hydrodegradation catalyst to obtain a hydrodegradation product oil;

[0116] (3) mixing the hydrodecondensation product oil with hydrogen, and refining and fractionating the product oil under the action of a supplementary refining catalyst to obtain the transformer oil base oil;

[0117] Wherein, the hydroprocessing catalyst is obtained by the following preparation method, and the preparation method comprises the following steps:

[0118] (1) 100 g of calcined silicon- and phosphorus-containing alumina powder (wherein the mass fraction of SiO2 is 3.3%) P2O5 (mass fraction is 7%, the balance is Al2O3) is added to 300ml of water (the mass fraction of water in the obtained slurry is 75%), and after stirring for 5 minutes, 18.7g of boric acid (calculated by the mass of B2O3, the amount of boric acid added is 4.6% of the mass of the prepared hydrorefining catalyst), 73g of ammonium metatungstate (calculated by the mass of WO3, the amount of ammonium metatungstate added is 28.4% of the mass of the prepared hydrorefining catalyst) and 37g of nickel nitrate (calculated by the mass of NiO, the amount of nickel nitrate added is 4.1% of the mass of the prepared hydrorefining catalyst), and stirring is continued for 1h. After standing for 2h, it is filtered, and the filtrate is heated to 95°C, and 55g of SB powder (the amount added is 19% of the mass of the prepared hydrorefining catalyst) and 4ml of concentrated nitric acid (3.6% of the mass of the silicon-containing and phosphorus-containing alumina powder) are prepared as a binder for use.

[0119] (2) The wet filter cake was dried at 120°C for 8 h, crushed into powder, and mixed with 4 g of sesbania powder (the amount added was 4% of the mass of the silicon-containing and phosphorus-containing alumina powder) and the above-mentioned binder, and then formed into strips after rolling and extrusion. The mixture was allowed to stand at room temperature for 4 h, dried at 120°C for 4 h, and then calcined at 230°C for 1 h, 350°C for 1 h, and finally 480°C for 4 h to obtain a hydrogenation treatment catalyst.

[0120] The hydrodecondensation catalyst is obtained by the following preparation method, which comprises the following steps:

[0121] (1) Weigh the pore volume of aluminum sulfate produced by 1.095 mL / g and the specific surface area of ​​328 m 2 / g, 500g of pseudo-boehmite with a dry basis of 71%, 18.4g of nitric acid with a concentration of 65%, 10g of sesbania powder, 71g of carbon black, 60g of nickel nitrate additive (purchased from Huaihua Heng'an Petrochemical Co., Ltd., Ni(NO3)2·6H2O>98%) and 754g of deionized water were added into a roller and rolled and mixed, extruded into cylindrical bars with an outer diameter of 6mm and an internal hollow diameter of 2.5mm, and the bars were dried to a solid content of 65% under constant humidity and temperature conditions.

[0122] The cylindrical strip was punched with a punching device to form evenly arranged circular through holes with a diameter of 1.5 mm on the surface, and was made into particles with a length of 3 mm to 10 mm. After drying at 130°C for 8 hours, the particles were calcined at 900°C for 3 hours to obtain a catalyst carrier support.

[0123] (2) Weigh 7.52 g of aluminum sulfate, 320 g of silica sol containing 30% silicon oxide (purchased from Qingdao Ocean Chemical Co., Ltd., with a SiO2 content of 30%), 2.15 g of sodium hydroxide, 1.81 g of triethylamine and 80 g of water to prepare a ZSM-5 molecular sieve mother liquor; impregnate the above-mentioned carrier support with the prepared molecular sieve mother liquor, place the impregnated materials on the top of a gas phase reactor, add deionized water to the bottom of the gas phase reactor, react at 180°C for 36 hours, wash with deionized water to neutrality after the reaction, dry at 130°C for 8 hours, and then calcine at 550°C for 3 hours to obtain a catalyst carrier containing a ZSM-5 molecular sieve membrane.

[0124] (3) 30.3 g of nickel nitrate was weighed to prepare a solution containing 0.019 g / mL of nickel oxide and the solution was impregnated into the catalyst support. After the impregnation, the material was dried at 120° C. for 8 hours and calcined at 450° C. for 3 hours to obtain the hydrodegassing catalyst.

[0125] The supplementary refined catalyst is obtained by the following preparation method, which comprises the following steps:

[0126] (1) Weigh small pore alumina (pore volume 0.49 mL / g, specific surface area 229 m 3 / g) 40.5g, add 69.4g clean water and 8.1mL concentrated nitric acid, mix well, and make an adhesive;

[0127] (2) Weigh 126.3 g of HZSM-5 molecular sieve, 3.0 g of sesbania powder and the above-mentioned binder, mix and knead, and extrude into strips;

[0128] (3) The wet strips were dried at 100±10°C for 4 h and calcined at 730°C for 4 h to prepare a carrier;

[0129] (4) Dissolve 24.9 g of nickel nitrate in clean water to make a 200 ml solution;

[0130] (5) 100 g of the above-mentioned carrier was placed in the impregnation solution, impregnated for 2 h, then filtered, dried at 100° C. for 4 h, and calcined at 480° C. for 3 h to obtain the supplementary refined catalyst.

[0131] Taking Chinese patent CN105195231A as a comparative example, the reference pour point depressing catalyst is obtained by the following preparation method, which comprises the following steps:

[0132] (1) Take 50g of modified alumina, 100g of amorphous silica-alumina, 45g of USY molecular sieve and 310g of a binder prepared by peptizing nitric acid and SB alumina, knead and roll to make a paste that can be extruded, and extrude into strips. Dry at 110°C for 6 hours and calcine at 550°C for 4 hours to obtain a carrier;

[0133] (2) Take 7g of basic nickel carbonate, 20g of molybdenum trioxide, and 4g of phosphoric acid and dissolve them in 70ml of aqueous solution. Then, use the equal volume impregnation method to impregnate the Mo-Ni-P co-impregnation solution on 80g of the carrier for 2 hours, dry at 110°C for 6 hours, and calcine at 350°C for 2 hours to prepare the catalyst.

[0134] (3) Take 20g of tartaric acid and dissolve it in 15ml of water, then adjust the volume to 70ml, and use the equal volume impregnation method to impregnate 110g of the above catalyst. After 2 hours, dry it in the shade, dry it at 100℃ for 2 hours, and calcine it at 350℃ for 2 hours to obtain a reference degassing catalyst.

[0135] Specifically, the information of the hydrotreating catalyst, the hydrodegassing catalyst, the supplementary refining catalyst and the reference degassing catalyst is shown in Table 3:

[0136] Table 3

[0137]

[0138]

[0139] Example 2

[0140] The difference between this embodiment and embodiment 1 is that the raw oil is Suizhong 36-1 minus one line, the process parameters are shown in Table 2, and the rest are the same as embodiment 1.

[0141] Example 3

[0142] The difference between this embodiment and embodiment 1 is that the process parameters are different, as shown in Table 2, and the rest are the same as embodiment 1.

[0143] Example 4

[0144] The difference between this embodiment and embodiment 1 is that the process parameters are different, as shown in Table 2, and the rest are the same as embodiment 1.

[0145] Comparative Example 1

[0146] The difference between this comparative example and Example 1 is that the hydrodepressant catalyst is replaced with a commercially available reference depressant, and the process parameters are shown in Table 2. The rest are the same as Example 1.

[0147] Comparative Example 2

[0148] The difference between this comparative example and Example 1 is that the preparation method of the transformer oil base oil is a traditional production process, that is, a hydrogenation treatment-furfural refining-clay refining process.

[0149] Comparative Example 3

[0150] The difference between this comparative example and Example 1 is that the raw oil is hydrogenated modified diesel, and the raw material is subjected to a hydrodecondensation-supplementary refining test under high pressure conditions (produced by Shanghai Mairui Experimental Equipment Co., Ltd., with a catalyst loading of 200 mL and new hydrogen passing through once); the hydrogenated oil finally obtained is distilled, and the fraction with a distillation range of ≥275°C is the transformer oil base oil.

[0151] Performance Testing

[0152] 1. The fractionation temperature of Examples 1-4 and Comparative Examples 1-3 was controlled at >275°C to obtain transformer oil base oil. The performance test was performed according to T-40°C in GB2536-2011. The test results are summarized in Tables 4 and 5.

[0153] Table 4

[0154]

[0155]

[0156] Table 5

[0157]

[0158] According to the data in Table 4, in the preparation method of the present invention, the transformer oil base oil is prepared by using a medium pressure process of 9.5 MPa, and the sulfur and nitrogen contents of the obtained transformer oil base oil are both ≤1.0 mg / kg, the pour point is <-54°C, and the C A Value <1%, total aromatics <10%. From the hydrogenation kinetics, it can be seen that the higher the pressure, the more conducive it is to the effective removal of aromatics, especially for the deep removal of aromatics. At present, both at home and abroad, the deep removal of aromatics is carried out under high pressure conditions or using precious metal catalysts.

[0159] Compared with the conventional transformer oil base oil production technology in comparative example 2, the sulfur and nitrogen content, aromatics and pour point of the transformer oil base oil produced by medium-pressure hydrogenation are better than those of the conventional transformer oil, and at the same time, there is no problem of difficult treatment of waste clay; compared with the high-pressure transformer oil base oil production technology in comparative example 3, the sulfur and nitrogen content, aromatics and pour point of the transformer oil base oil produced by medium-pressure hydrogenation are comparable to those of the high-pressure production technology, and at the same time, the construction and production costs of the device are reduced.

[0160] It can be seen that the transformer oil base oil preparation method of the present invention is superior to the traditional transformer oil base oil production technology and is equivalent to the high-voltage transformer oil base oil production technology, which has no related application technology at home and abroad.

[0161] Analysis of the data in Table 5 shows that the hydrodegassing catalyst of the present invention still has a high degassing activity at a reaction temperature of 310°C. Compared with commercially available industrial catalysts, under the same catalyst grading conditions, the reaction temperature of the hydrodegassing stage of the present invention is 50°C lower, and the yield of the transformer oil base oil obtained is 10.9% higher than that of the commercially available industrial catalysts. Due to the high activity of the hydrodegassing catalyst, the influence of the future fluctuation of the pour point of raw materials in the refinery on the product properties is solved, and the raw material source of the device is broadened.

[0162] 2. The temperature of Examples 1-2 and Comparative Examples 2-3 was controlled at 215-275° C. to obtain a drilling fluid lubricant base oil. The performance test was carried out with reference to Q / HX PF001-2019. The test results are summarized in Table 6.

[0163] Table 6

[0164]

[0165]

[0166] Analysis of the data in Table 6 shows that the preparation method of the present invention can also be used to prepare drilling fluid lubricant base oil by adjusting the fractionation temperature, and the obtained drilling fluid lubricant base oil meets the requirements of Q / HX PF001-2019.

[0167] The applicant declares that the present invention illustrates the detailed method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed method, that is, it does not mean that the present invention must rely on the above-mentioned detailed method to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a transformer oil base oil, characterized in that: The preparation method comprises the following steps: (1) mixing the feedstock oil with hydrogen and performing a hydrogenation treatment to obtain a hydrogenation product oil; (2) mixing the hydrotreated product oil with hydrogen, and performing a hydrodegradation treatment under the action of a hydrodegradation catalyst to obtain a hydrodegradation product oil; (3) mixing the hydrodecondensation product oil with hydrogen, performing a refining treatment, and fractionating at a temperature greater than 275° C. to obtain the transformer oil base oil; In step (1), the hydroprocessing is carried out under the action of a hydroprocessing catalyst; The hydroprocessing catalyst comprises an active metal oxide and a metal oxide promoter; The active metal oxides include nickel oxide and tungsten trioxide; Based on the total mass of the hydroprocessing catalyst being 100%, the mass percentage of the metal oxide additive is 2.0%-5.0%; The metal oxide additive includes any one of boric acid, phosphoric acid or sesbania, or a combination of at least two thereof; The reactions of the hydroprocessing, hydrodecondensation and refining are each independently single-stage medium-pressure hydrogenation; The pressure of the single-stage medium pressure is 8.0-10.0 MPa; In step (3), the refining treatment is carried out under the action of a supplementary refining catalyst; The preparation method of the supplementary refined catalyst comprises the following steps: mixing any one of active metals, active metal salts or active metal oxides or a combination of at least two thereof with a solvent, an auxiliary agent, an oil phase and other additives to form a water-in-oil microemulsion; After impregnating the catalyst support with the water-in-oil microemulsion, drying and calcining, the treated catalyst support is then impregnated with a solution containing any one or a combination of at least two of active metals, active metal salts or active metal oxides, and then dried and calcined again to obtain the supplementary refined catalyst; The transformer oil base oil has a sulfur content of less than 1.0 mg / kg, a nitrogen content of less than 1.0 mg / kg, total aromatics of less than 10%, and a pour point of less than -57°C.

2. The preparation method according to claim 1, characterized in that: Based on the total mass of the hydroprocessing catalyst being 100%, the mass percentage of the nickel oxide is 2.0%-6.0%.

3. The preparation method according to claim 1, characterized in that: Based on the total mass of the hydroprocessing catalyst being 100%, the mass percentage of the tungsten trioxide is 15%-30%.

4. The preparation method according to claim 1, characterized in that: The preparation method of the hydroprocessing catalyst comprises the following steps: The compound containing active metal elements, the metal oxide additive and the slurry are mixed and filtered to obtain a filter cake and a filtrate; The filtrate is formed into a binder, and the binder and the filter cake are pressed into a shape, dried and calcined to obtain the hydroprocessing catalyst.

5. The preparation method according to claim 4, characterized in that: The slurry includes water, silica and alumina.

6. The preparation method according to claim 1, characterized in that: The reaction temperature of the hydrotreatment is 300-370°C.

7. The preparation method according to claim 1, characterized in that: The volume ratio of the hydrogen to the crude oil is (600-1200):

1.

8. The preparation method according to claim 1, characterized in that: The volume space velocity of the hydroprocessing is 0.2-1.0h -1 .

9. The preparation method according to claim 1, characterized in that: In step (2), the hydrodegradation catalyst comprises a catalyst carrier and an active metal oxide disposed inside and / or on the surface of the catalyst carrier.

10. The preparation method according to claim 9, characterized in that: The active metal oxide of the hydrodegradation catalyst comprises Group VIII metal oxides and / or Group VIB metal oxides.

11. The preparation method according to claim 10, characterized in that: Based on the total mass of the hydrodecondensation catalyst being 100%, the mass percentage of the Group VIII metal oxide is 1.0%-6.0%.

12. The preparation method according to claim 10, characterized in that: Based on the total mass of the hydrodecondensation catalyst being 100%, the mass percentage of the Group VIB metal oxide is 2.0%-10.0%.

13. The preparation method according to claim 10, characterized in that: The active metal oxide of the hydrodegradation catalyst includes nickel oxide and / or tungsten trioxide.

14. The preparation method according to claim 9, characterized in that: The catalyst carrier of the hydrodegradation catalyst comprises a catalyst carrier support and a molecular sieve arranged inside and / or on the surface of the catalyst carrier support.

15. The preparation method according to claim 14, characterized in that: Based on the total mass of the hydrodecondensation catalyst being 100%, the mass percentage of the molecular sieve is 8.0%-40.0%.

16. The preparation method according to claim 14, characterized in that: The mother liquor of the molecular sieve comprises aluminum sulfate, silica sol, alkaline substances and water.

17. The preparation method according to claim 16, characterized in that: The silica sol includes silicon oxide.

18. The preparation method according to claim 16, characterized in that: The alkaline substance includes sodium hydroxide and / or triethylamine.

19. The preparation method according to claim 14, characterized in that: The raw materials for preparing the catalyst carrier support of the hydrodegradation catalyst include pseudo-boehmite, peptizing agent, extrusion aid, pore expanding agent, metal oxide aid and water.

20. The preparation method according to claim 19, characterized in that: Based on the total mass of the hydrodecondensation catalyst being 100%, the mass percentage of the metal oxide additive is 1.0%-6.0%.

21. The preparation method according to claim 9, characterized in that: The preparation method of the hydrodegassing catalyst comprises the following steps: impregnating a catalyst carrier of the hydrodegassing catalyst into an active metal salt solution, drying and calcining to obtain the hydrodegassing catalyst.

22. The preparation method according to claim 9, characterized in that: The preparation method of the catalyst carrier of the hydrodegassing catalyst comprises the following steps: immersing the catalyst carrier support of the hydrodegassing catalyst in a molecular sieve mother liquid, and then crystallizing, washing, drying and calcining the catalyst carrier support of the hydrodegassing catalyst to obtain the catalyst carrier of the hydrodegassing catalyst.

23. The preparation method according to claim 14, characterized in that: The preparation method of the catalyst carrier support of the hydrodegassing catalyst comprises the following steps: mixing pseudo-boehmite, a peptizing agent, an extrusion aid and water, and then sequentially molding, drying and calcining to obtain the catalyst carrier support of the hydrodegassing catalyst.

24. The preparation method according to claim 1, characterized in that: The reaction temperature of the hydrodecondensation treatment is 280-340°C.

25. The preparation method according to claim 1, characterized in that: The volume ratio of the hydrogen to the hydroprocessed oil is (600-1200):

1.

26. The preparation method according to claim 1, characterized in that: The volume space velocity of the hydrodecondensation treatment is 0.8-3.0h -1 .

27. The preparation method according to claim 1, characterized in that: The supplementary refined catalyst comprises a catalyst carrier and an active metal oxide and an auxiliary agent arranged inside and / or on the surface of the catalyst carrier.

28. The preparation method according to claim 27, characterized in that: The active metal oxide of the refining catalyst comprises Group VIII metal oxides and / or Group VIB metal oxides.

29. The preparation method according to claim 28, characterized in that: Based on the total mass of the supplementary refined catalyst being 100%, the mass percentage of the Group VIII metal oxide is 4.0%-10.0%.

30. The preparation method according to claim 28, characterized in that: Based on the total mass of the supplementary refined catalyst being 100%, the mass percentage of the Group VIB metal oxide is 15%-30%.

31. The preparation method according to claim 27, characterized in that: The additive for refining the catalyst includes a heteroatom.

32. The preparation method according to claim 31, characterized in that: The heteroatom includes any one of phosphorus, fluorine, boron, titanium or zirconium, or a combination of at least two thereof.

33. The preparation method according to claim 27, characterized in that: The additive for supplementing and refining the catalyst includes any one of a phosphorus-containing additive, a fluorine-containing additive, a boron-containing additive, a titanium-containing additive or a zirconium-containing additive, or a combination of at least two thereof.

34. The preparation method according to claim 31, characterized in that: Taking the total mass of the supplementary refined catalyst as 100%, the mass percentage of heteroatoms in the auxiliary agent of the supplementary refined catalyst is 1.0%-10.0%.

35. The preparation method according to claim 27, characterized in that: The raw materials for preparing the carrier of the supplementary refined catalyst include pseudo-boehmite, a peptizing agent, an extrusion aid and water.

36. The preparation method according to claim 27, characterized in that: The preparation method of the catalyst carrier of the supplementary refined catalyst comprises the following steps: mixing pseudo-boehmite, a peptizing agent, an extrusion aid and water, and then sequentially molding, drying and calcining to obtain the catalyst carrier of the supplementary refined catalyst.

37. The preparation method according to claim 1, characterized in that: The oil phase includes any one of n-octane, heptane or cyclohexane, or a combination of at least two of them.

38. The preparation method according to claim 1, characterized in that: The other additives include surfactants and / or co-surfactants.

39. The preparation method according to claim 1, characterized in that: The reaction temperature of the refining treatment is 290-360°C.

40. The preparation method according to claim 1, characterized in that: The volume ratio of the hydrogen to the hydrodegradation oil is (600-1200):

1.

41. The preparation method according to claim 1, characterized in that The volume space velocity of the refining treatment is 0.3-2.0h -1 .

42. The preparation method according to claim 1, characterized in that The feedstock oil includes any one of cycloalkyl normal second-line diesel, cycloalkyl minus first-line diesel or hydrogenated modified diesel or a combination of at least two of them.

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