A method for producing transformer oil base oil by blending coking diesel

Abstract

The present invention relates to a method for producing transformer oil base oil by blending coking diesel, the method comprising the following steps: (1) subjecting mixed raw oil and hydrogen to hydrodecondensation treatment to obtain hydrodecondensation product oil; the mixed raw oil comprises hydrogenated diesel and coking diesel; the catalyst used for the hydrodecondensation treatment comprises a first catalyst; the first catalyst is also subjected to nitrogen resistance treatment before the hydrodecondensation treatment; (2) subjecting the hydrodecondensation product oil obtained in step (1) and hydrogen to supplementary refining treatment to obtain refined oil; (3) subjecting the refined oil obtained in step (2) to fractionation to obtain transformer oil base oil. The method provided by the present invention can not only process coking diesel with a high nitrogen content, but also can continuously and stably produce products such as transformer oil base oil, and has high industrial and economic value.

Description

Technical Field

[0001] The invention relates to the technical field of transformer oil base oil, and in particular to a method for producing transformer oil base oil by blending coking diesel. Background Art

[0002] Transformer oil refers to a type of transformer oil used in oil-filled electrical equipment such as transformers, reactors, mutual inductors, bushings, oil switches, etc., to play the role of insulation, cooling and arc extinguishing. Its main raw materials are cycloalkyl and paraffin-based crude oils. Cycloalkyl oil has excellent low-temperature performance and can produce transformer oil base oil without complex and expensive dewaxing process. However, cycloalkyl oil is a rare resource and it is difficult to meet the current market demand.

[0003] CN106833740A discloses a method for preparing transformer oil base oil, comprising the following steps: subjecting cycloalkane fraction oil to hydrofining treatment under the action of a catalyst to obtain hydrofining product oil; subjecting the hydrofining product oil to hydroisomerization to obtain hydroisomerization product oil; subjecting the hydroisomerization product oil to hydrosupplementary refining to obtain three-stage hydrogenation product oil; and then subjecting the hydroisomerization product oil to atmospheric and vacuum fractionation, and the fraction greater than 280°C is the transformer oil base oil. This method requires processes such as hydrofining treatment, hydroisomerization and hydrosupplementary refining, which greatly increases the production cost and energy consumption of the device.

[0004] CN102311785A discloses a method for producing lubricating base oil by hydrogenating cycloalkyl distillate oil, which uses cycloalkyl distillate oil as raw material and adopts a series hydrogenation process of hydrotreatment-hydrogenation decondensation-hydrogenation supplementary refining to produce lubricating base oil. The catalyst used in the method needs to be subjected to hydrodenitrogenation and hydrodesulfurization, which not only complicates the process, but also greatly increases production cost and energy consumption.

[0005] CN104611034A discloses a method for producing a special lubricating oil base oil, comprising: mixing wax oil raw material with hydrogen, and then passing through at least two series-connected hydrogenation reaction zones in sequence, wherein each hydrogenation reaction zone comprises a hydrodegassing catalyst bed and a refining degassing catalyst composite bed filled with a hydrodegassing catalyst and a hydrorefining catalyst in sequence according to the material flow direction; the reaction effluent obtained from the last hydrogenation reaction zone is separated and fractionated to obtain lubricating oil base oil, white oil and other products. This method requires multiple hydrogenation reaction zones to be connected in series, which greatly increases the equipment investment, and the catalyst has not been hydrogenated, which may cause catalyst poisoning if used to process feedstock oil with a high nitrogen content.

[0006] At present, the storage volume of coking diesel produced by refineries is large, which is difficult to digest internally, and it is a low-quality oil with high sulfur and nitrogen content. If coking diesel can be used as a resource to prepare high-value-added transformer oil base oil, it will not only solve the storage problem of low-quality oil, but also generate higher economic value. However, coking diesel generally requires additional hydroprocessing steps, resulting in increased investment in hydroprocessing equipment; if hydroprocessing is not performed, it will lead to catalyst poisoning.

[0007] Therefore, how to use coking diesel to produce transformer oil base oil and realize the reuse of coking diesel is a problem that needs to be solved at present. Summary of the invention

[0008] In view of the above problems, the object of the present invention is to provide a method for producing transformer oil base oil by blending coker diesel. Compared with the prior art, the present invention only adopts a simple processing system consisting of hydrodecondensation and supplementary hydrofining, which can not only process coker diesel with a high nitrogen content, but also can continuously and stably produce products such as transformer oil base oil, and has high industrial value and economic value.

[0009] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0010] The present invention provides a method for producing transformer oil base oil by blending coking diesel, the method comprising the following steps:

[0011] (1) subjecting the mixed crude oil and hydrogen to a hydrodegradation treatment to obtain a hydrodegradation product oil;

[0012] The mixed stock oil includes hydrogenated diesel and coker diesel;

[0013] The catalyst used in the hydrodecondensation treatment includes a first catalyst;

[0014] The first catalyst is also subjected to nitrogen resistance treatment before being subjected to hydrodecondensation treatment;

[0015] (2) subjecting the hydrodecondensation product oil and hydrogen obtained in step (1) to additional refining treatment to obtain refined oil;

[0016] (3) fractionating the refined oil obtained in step (2) to obtain transformer oil base oil.

[0017] The mixed raw material oil used in the method of the present invention is blended with low-quality oil with high nitrogen content, namely coking diesel, thereby realizing high added value utilization of the low-quality oil.

[0018] In the existing research, the treatment of inferior oil generally requires a hydrotreatment step, which is used to remove impurities such as sulfur, nitrogen, oxygen and aromatic hydrocarbons in the raw oil to avoid poisoning of the decondensation catalyst. Compared with the existing process, the present invention does not need to adopt a separate hydrotreatment step. It only uses a simple process of hydrodecondensation treatment and supplementary refining treatment, and removes the skeleton aluminum contained in the catalyst by nitrogen-resistant treatment of the first catalyst. It can prepare a transformer oil base oil with low sulfur, low nitrogen, low decondensation and low aromatic characteristics, which not only realizes the high added value utilization of inferior oil, but also reduces equipment investment, saves energy consumption, achieves a higher product yield, and can operate stably.

[0019] Preferably, the mass percentage of coker diesel in the mixed feedstock oil is 1-20%, for example, it can be 1%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18% or 20%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] In the present invention, it is preferred to control the mass percentage of coker diesel in the mixed feedstock oil within a specific range, which can achieve stable utilization of high nitrogen content oil on the one hand, and is conducive to stable operation of the process on the other hand.

[0021] Preferably, the mixing temperature of the hydrogenated diesel and the coker diesel is 40-100°C, for example, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] Preferably, the mixing time of the hydrogenated diesel and the coker diesel is ≥10 min, for example, it can be 10 min, 12 min, 14 min, 16 min, 18 min or 20 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] Preferably, the temperature of the nitrogen resistance treatment is 550-650°C, for example, it can be 550°C, 560°C, 570°C, 580°C, 590°C, 600°C, 610°C, 620°C, 630°C, 640°C or 650°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] Preferably, the pressure of the nitrogen resistance treatment is 0.15-0.45 MPa, for example, it can be 0.15 MPa, 0.2 MPa, 0.25 MPa, 0.3 MPa, 0.35 MPa, 0.4 MPa or 0.45 MPa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] Preferably, the nitrogen resistance treatment time is 2-6 h, for example, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h or 6 h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] Preferably, the nitrogen resistance treatment comprises hydrothermal treatment.

[0027] In the present invention, the first catalyst contains a large number of various acidic centers such as B acid and L acid, and the nitrides in the feedstock oil, especially the basic nitrides, are easily combined with the proton acid in the first catalyst, thereby reducing the activity of the catalyst and thus shortening the service life of the catalyst. The present invention preferably controls the temperature, pressure and time of the nitrogen resistance treatment within a specific range, which can further improve the nitrogen resistance of the first catalyst, thereby increasing the service life of the catalyst.

[0028] Preferably, the first catalyst in step (1) comprises a first carrier and a first active metal oxide supported on the first carrier.

[0029] Preferably, the first active metal oxide comprises a Group VIII metal oxide and / or a Group VIB metal oxide.

[0030] Preferably, the Group VIII metal oxide in the first active metal oxide comprises nickel oxide.

[0031] Preferably, the Group VIB metal oxide in the first active metal oxide includes tungsten trioxide.

[0032] Preferably, the mass percentage of the Group VIII metal oxide in the first catalyst is 1-10%, for example, 1%, 2%, 4%, 6%, 8% or 10%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] Preferably, the mass percentage of the Group VIB metal oxide in the first catalyst is 1-16%, for example, 1%, 2%, 4%, 6%, 8%, 10%, 12%, 14% or 16%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0034] Preferably, the first carrier comprises a carrier support and a molecular sieve supported on the carrier support.

[0035] Preferably, the carrier support contains aluminum oxide.

[0036] Preferably, the raw materials for preparing the carrier support include: pseudo-boehmite, a peptizing agent, an extrusion aid, a pore expanding agent, a metal oxide aid and water.

[0037] In the present invention, the peptizing agent is not particularly limited and can be any peptizing agent commonly used in the art, such as nitric acid, acetic acid or citric acid; the extrusion aid is not particularly limited and can be any extrusion aid commonly used in the art, such as sesbania powder or methyl cellulose; the pore expanding agent is not particularly limited and can be any pore expanding agent commonly used in the art, such as carbon black, graphite or starch; the metal oxide auxiliary agent includes nickel oxide or copper oxide.

[0038] Preferably, in the preparation method of the carrier support, the mass ratio of pseudo-boehmite, peptizing agent, extrusion aid, pore expanding agent, metal oxide additive and water is 1:(0.01-0.06):(0.01-0.04):(0.1-0.3):(0.02-0.06):(1.0-1.5).

[0039] Preferably, the preparation method of the first catalyst in the present invention comprises: (a) mixing pseudo-boehmite, a peptizing agent, an extrusion aid, a pore expanding agent, a metal oxide additive and water, and then sequentially performing molding, drying and calcining to obtain a carrier support; (b) impregnating the mixed carrier support and the molecular sieve mother liquor, and then sequentially performing crystallization, washing, drying and calcining to obtain a first carrier; (c) impregnating the first carrier and the first active metal salt solution, and then sequentially performing drying and calcining to obtain a first catalyst.

[0040] Preferably, the mass percentage of the molecular sieve in the first catalyst is 8-40%, for example, it can be 8%, 10%, 15%, 20%, 25%, 30%, 35% or 40%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0041] Preferably, the molecular sieve comprises ZSM-5 type molecular sieve and / or β type molecular sieve.

[0042] In the present invention, the molecular sieve mother liquor comprises aluminum sulfate, silica sol, alkaline substance and water, the silica sol comprises silicon oxide, and the alkaline substance comprises sodium hydroxide and / or triethylamine.

[0043] Preferably, the reaction pressure of the hydrodecondensation treatment in step (1) is 11-16 MPa, for example, 11 MPa, 12 MPa, 13 MPa, 14 MPa, 15 MPa or 16 MPa, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0044] Preferably, the reaction temperature of the hydrodecondensation treatment is 260-360°C, for example, it can be 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C or 360°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] Preferably, the volume ratio of hydrogen to mixed feedstock oil is (600-1200):1, for example, it can be 600:1, 700:1, 800:1, 900:1, 1000:1, 1100:1 or 1200:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0046] Preferably, the volumetric space velocity of the hydrodecondensation treatment is 0.5-2h -1 , for example, it can be 0.5h -1 、0.7h -1 , 0.8h -1 , 1h -1 , 1.2h -1 , 1.4h -1 , 1.5h -1 , 1.6h -1 , 1.8h -1 or 2h -1 , but not limited to the listed values, other values ​​not listed in the numerical range are also applicable, preferably 0.7-1.5h -1 .

[0047] In the present invention, the volume space velocity of the hydrodecondensation treatment refers to the volume space velocity of the mixed feedstock oil.

[0048] Preferably, the catalyst used in the supplementary refining treatment in step (2) includes a second catalyst.

[0049] Preferably, the second catalyst includes a second carrier and a second active metal oxide and promoter atoms supported on the second carrier.

[0050] Preferably, the second active metal oxide comprises a Group VIII metal oxide and / or a Group VIB metal oxide.

[0051] Preferably, the Group VIII metal oxide in the second active metal oxide comprises nickel oxide.

[0052] Preferably, the Group VIB metal oxide in the second active metal oxide includes tungsten trioxide and / or molybdenum trioxide.

[0053] Preferably, the auxiliary atom 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 or a combination of titanium and zirconium.

[0054] Preferably, the mass percentage of the Group VIII metal oxide in the second catalyst is 4-10%, for example, it can be 4%, 5%, 6%, 7%, 8%, 9% or 10%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0055] Preferably, the mass percentage of the Group VIB metal oxide in the second catalyst is 15-30%, for example, it can be 15%, 16%, 18%, 20%, 22%, 25%, 28% or 30%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0056] Preferably, the mass percentage of the auxiliary agent atoms in the second catalyst is 1-10%, for example, 1%, 2%, 4%, 6%, 8% or 10%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0057] Preferably, the second carrier contains alumina.

[0058] Preferably, the raw materials for preparing the second carrier include pseudo-boehmite, a peptizing agent, an extrusion aid and water.

[0059] Preferably, the mass ratio of pseudo-boehmite, peptizing agent, extrusion aid and water in the raw materials for preparing the second carrier is 1:(0.01-0.06):(0.01-0.04):(1.0-1.5).

[0060] Preferably, the preparation method of the second catalyst comprises: (I) mixing pseudo-boehmite, a peptizing agent, an extrusion aid and water, and then sequentially molding, drying and calcining to obtain a second carrier; (II) preparing an auxiliary agent solution to impregnate the second carrier, and drying to obtain a treated second carrier; (III) preparing a second active metal salt solution A and an oil-in-water type microemulsion; (IV) impregnating the treated second carrier and the oil-in-water type microemulsion, and then drying and calcining, and then impregnating the product in a second active metal salt solution B, and then molding, drying and calcining to obtain a second catalyst.

[0061] In the present invention, the auxiliary agent solution includes a solution composed of auxiliary agents such as calcium nitrate, strontium nitrate or barium nitrate, the second active metal salt solution A refers to a mixed solution of nickel salt, molybdenum salt and auxiliary agent atoms, the oil-in-water type microemulsion is obtained by mixing an oil phase, a surfactant, a co-surfactant and the second active metal salt solution A, the oil phase refers to n-octane, isooctane, heptane or cyclohexane, the surfactant is generally a non-ionic surfactant, the co-surfactant is generally a C4-C6 alcohol, and the second active metal salt solution B refers to a mixed solution of tungsten salt and nickel salt.

[0062] Preferably, the reaction pressure of the supplementary refining treatment is 11-16 MPa, for example, 11 MPa, 12 MPa, 13 MPa, 14 MPa, 15 MPa or 16 MPa, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0063] Preferably, the reaction temperature of the supplementary refining treatment is 290-360°C, for example, it can be 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C or 360°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0064] In the present invention, the reaction temperature of the supplementary refining treatment is preferably controlled within a specific range, and the decomposition of impurities such as sulfur, nitrogen, oxygen and aromatics can be controlled by adjusting the temperature, thereby achieving stable operation without hydrogenation treatment and obtaining a transformer oil base oil with a low aromatic content.

[0065] Preferably, the volume ratio of the hydrogen to the hydrodegradation product oil is (600-1200):1, for example, it can be 600:1, 700:1, 800:1, 900:1, 1000:1, 1100:1 or 1200:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0066] Preferably, the volume space velocity of the supplementary refining treatment is 0.2-1.0h -1 , for example, it can be 0.2h -1 、0.3h -1 、0.6h -1 , 0.8h -1 or 1h -1 , but not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0067] In the present invention, the volume space velocity of the supplementary refining treatment refers to the volume space velocity of the oil produced by hydrodecondensation.

[0068] Preferably, the fractionation temperature of the transformer oil base oil in step (3) is greater than 280°C, for example, it can be 285°C, 290°C, 295°C or 300°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0069] Preferably, the fractionation also produces light white oil and naphtha.

[0070] Preferably, the fractionation temperature of the naphtha is less than 155°C, for example, it can be 150°C, 145°C or 140°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0071] Preferably, the mass percentage of aromatics in the naphtha is less than 0.2wt%, for example, it can be 0.18wt%, 0.16wt% or 0.14wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0072] The naphtha obtained by the invention has a sulfur content of less than 1.0 mg / kg, a nitrogen content of less than 1.0 mg / kg, an aromatic hydrocarbon content of less than 0.2 wt%, and a color (Saybolt) of +30.

[0073] Preferably, the distillation temperature of the light white oil is 155-280°C, for example, it can be 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C, 200°C, 240°C, 260°C or 280°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0074] Preferably, the light white oil includes any one of W1-40, W1-60, W1-90 or W1-110, or a combination of at least two thereof.

[0075] Preferably, the mass percentage of aromatics in the light white oil W1-40 or W1-60 is less than 0.2wt%, for example, it can be 0.18wt%, 0.16wt% or 0.14wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0076] Preferably, the mass percentage of aromatics in the light white oil W1-90 or W1-110 is less than 0.5wt%, for example, it can be 0.48wt%, 0.46wt% or 0.44wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0077] In the light white oil obtained by the present invention, the sulfur content of light white oil W1-40 and W1-60 is less than 1.0 mg / kg, the nitrogen content is less than 1.0 mg / kg, the aromatics are less than 0.2wt%, and the color (Saybolt) is +30; the sulfur content of light white oil W1-90 and W1-110 is less than 1.0 mg / kg, the nitrogen content is less than 1.0 mg / kg, the aromatics are less than 0.5wt%, and the color (Saybolt) is +30. The above light white oil meets the NB / SH / T0913-2015 standard.

[0078] Preferably, the transformer oil base oil has a sulfur content of <1.0 mg / kg, a nitrogen content of <1.0 mg / kg, an aromatic hydrocarbon content of <0.5 wt %, and a pour point of <-57°C.

[0079] As a preferred technical solution of the present invention, the method comprises the following steps:

[0080] (1) Mixing raw material oil and hydrogen, wherein the mixed raw material oil includes hydrogenated diesel and coker diesel, the mass percentage of coker diesel in the mixed raw material oil is 1-20%, the reaction pressure is 11-16 MPa, the reaction temperature is 260-360° C., the volume ratio of hydrogen to the mixed raw material oil is (600-1200):1, and the volume space velocity is 0.5-2.0 h -1 Hydrodecondensation treatment is performed under the conditions of to obtain hydrodecondensation product oil;

[0081] The mixing temperature of the hydrogenated diesel and the coker diesel is 40-100°C, and the mixing time is ≥10min;

[0082] The catalyst used in the hydrodecondensation treatment includes a first catalyst, and the first catalyst is subjected to a nitrogen resistance treatment before the hydrodecondensation treatment, and the nitrogen resistance treatment includes: hydrothermally treating the first catalyst at a temperature of 550-650° C. and a pressure of 0.15-0.45 MPa for 2-6 hours;

[0083] (2) the hydrocondensation product oil obtained in step (1) and hydrogen are reacted under the action of a second catalyst at a reaction temperature of 290-360° C., with a volume ratio of hydrogen to the hydrocondensation product oil of (600-1200):1 and a volume space velocity of 0.2-1.0 h -1 Under the conditions of , additional refining treatment is carried out to obtain refined oil;

[0084] (3) fractionating the refined oil obtained in step (2) to obtain naphtha at a fractionation temperature of less than 155° C., to obtain light white oil at a fractionation temperature of 155-280° C., and to obtain transformer oil base oil at a fractionation temperature of more than 280° C.

[0085] Compared with the prior art, the present invention has the following beneficial effects:

[0086] (1) The method provided by the present invention omits the traditional hydroprocessing process, and can not only process low-quality raw oil with high nitrogen content, but also prepare transformer oil base oil with the characteristics of low sulfur, low nitrogen, low condensation and low aromatics, which meets the requirements of T-40℃ transformer oil base oil (general purpose) in GB2536-2011 standard, and the product yield is high. The pour point of the transformer oil base oil reaches below -48℃, the aromatic content reaches below 7.76wt%, the nitrogen content reaches below 8.3mg / kg, and the yield of the transformer oil base oil reaches above 37.6%. Under better conditions, the pour point of the transformer oil base oil reaches -57℃, the aromatic content reaches below 0.43wt%, the nitrogen content reaches below 1mg / kg, and the yield of the transformer oil base oil reaches above 44.7%.

[0087] (2) The method provided by the present invention reduces equipment energy consumption and investment costs, can operate continuously and stably, and can further obtain naphtha and light white oil (I) that meets the NB / SH / T0913-2015 standard, and has high industrial and economic value. DETAILED DESCRIPTION

[0088] The technical solution of the present invention is further described below by specific implementation methods. 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.

[0089] Specifically provided is a method for preparing a first catalyst, comprising: (a) mixing pseudo-boehmite, a peptizing agent, an extrusion aid, a pore expanding agent, a metal oxide auxiliary agent precursor and water, and then sequentially performing molding, drying and roasting to obtain a carrier support; (b) impregnating the mixed carrier support and a molecular sieve mother liquor, and then sequentially performing crystallization, washing, drying and roasting to obtain a first carrier; (c) impregnating the first carrier and a first active metal salt solution, and then sequentially performing drying and roasting to obtain a first catalyst.

[0090] Preparation Example 1

[0091] This preparation example provides a method for preparing a first catalyst, the method comprising the following steps:

[0092] (a) 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 weight of 71wt%, 18.4g of nitric acid with a concentration of 65%, 10g of sesbania powder, 71g of carbon black, and a nickel nitrate additive (purchased from Huaihua Heng'an Petrochemical Co., Ltd., Ni(NO 3 ) 2 6H 2O>98wt%) 60g and deionized water 754g and mixed, then extruded into cylindrical bars with an outer diameter of 6mm and an inner hollow diameter of 2.5mm, and dried to a solid content of 65% under constant humidity and temperature conditions, and a punching device was used to prepare particles with a diameter of 1.5mm and a length of 3-10mm, and then dried at 130°C for 8 hours, and then calcined at 900°C for 3 hours to obtain a carrier support;

[0093] (b) 7.52 g of aluminum sulfate, 320 g of silica sol containing 30 wt% of silicon oxide (purchased from Qingdao Ocean Chemical Co., Ltd.), 2.15 g of sodium hydroxide, 1.81 g of triethylamine and 80 g of water were weighed to prepare a ZSM-5 molecular sieve mother solution, and the mixed carrier support and the molecular sieve mother solution were impregnated, and crystallized at 180° C. for 36 hours, then washed to neutrality, dried at 130° C. for 8 hours, and then calcined at 550° C. for 3 hours to obtain a first carrier;

[0094] (c) 30.3 g of nickel nitrate was weighed to prepare a first active metal salt solution containing 0.019 g / mL of nickel oxide, and the first carrier was impregnated with the solution. After the impregnation, the material was dried at 120° C. for 8 hours and calcined at 450° C. for 3 hours to obtain a first catalyst.

[0095] A method for preparing a second catalyst is specifically provided, comprising: (I) mixing pseudo-boehmite, a peptizing agent, an extrusion aid and water, and then sequentially molding, drying and calcining to obtain a second carrier; (II) preparing an auxiliary agent solution to impregnate the second carrier, and drying to obtain a treated second carrier; (III) preparing a second active metal salt solution A and an oil-in-water type microemulsion; (IV) impregnating the treated second carrier and the oil-in-water type microemulsion, and then drying and calcining, and then impregnating the product in a second active metal salt solution B, and then molding, drying and calcining to obtain a second catalyst.

[0096] Preparation Example 2

[0097] This preparation example provides a method for preparing a second catalyst, comprising:

[0098] (I) Weigh the pore volume of 1.095 mL / g and the specific surface area of ​​328 m produced by the aluminum sulfate method 2 500 g of pseudo-boehmite (dry basis 71 wt%), 18.4 g of nitric acid (concentration 65%), 10 g of sesbania powder and 694 g of deionized water were mixed, extruded and dried at 120° C. for 10 hours, and then calcined at 750° C. for 3 hours to obtain a second carrier;

[0099] (II) preparing 90 mL of a calcium nitrate solution containing 0.02 g / mL of calcium oxide as an auxiliary solution, impregnating 100 g of the second carrier, and drying at 140° C. for 8 hours to obtain a treated second carrier;

[0100] (III) MoO was prepared by mass percentage. 3 The second active metal salt solution A is 22%, NiO is 3.5%, P is 2.0%, wherein MoO 3 The concentration is 0.344 g / mL, the NiO concentration is 0.055 g / mL, and the P concentration is 0.031 g / mL;

[0101] Take 35.2 mL of the second active metal salt solution A, add 26.5 g of isooctane (density 0.6919), 5.0 g of polyoxyethylene glycol octylphenyl ether (density 1.06) and 8.0 g of n-pentanol (density 0.82), stir well for 50 min, and obtain 88 mL of water-in-oil microemulsion with a particle size of less than 6 nm;

[0102] (IV) Preparation of WO 3 A second active metal salt solution B having a concentration of 0.582 g / mL and a NiO concentration of 0.10 g / mL;

[0103] The second carrier treated with oil-in-water microemulsion impregnation was dried at 120°C for 8 hours, and then calcined at 450°C for 3 hours. The product was then impregnated in a second active metal salt solution B, dried at 120°C for 10 hours, and then calcined at 500°C for 3 hours to obtain a second catalyst.

[0104] Example 1

[0105] This embodiment provides a method for producing transformer oil base oil by blending coking diesel, the method comprising the following steps:

[0106] (1) Mixing raw material oil and hydrogen, wherein the mixed raw material oil includes hydrogenated diesel and coker diesel, and the mass percentage of coker diesel in the mixed raw material oil is 20%, at a reaction pressure of 15 MPa, a reaction temperature of 290° C., a volume ratio of hydrogen to the mixed raw material oil of 900:1, and a volume space velocity of 1 h -1 Hydrodecondensation treatment is performed under the conditions of to obtain hydrodecondensation product oil;

[0107] The mixing temperature of the hydrogenated diesel and the coker diesel is 70°C and the mixing time is 15 minutes;

[0108] The catalyst used in the hydrodecondensation treatment is the first catalyst provided in Preparation Example 1. The first catalyst is also subjected to nitrogen resistance treatment before the hydrodecondensation treatment. The nitrogen resistance treatment comprises: subjecting the first catalyst to hydrothermal treatment for 3 hours at a temperature of 600° C. and a pressure of 0.3 MPa;

[0109] (2) the hydrodecondensation product oil obtained in step (1) and hydrogen are reacted under the action of a second catalyst at a reaction temperature of 340° C., a volume ratio of hydrogen to the hydrodecondensation product oil of 900:1, and a volume space velocity of 0.4 h / min. -1 The second catalyst is the second catalyst provided in Preparation Example 2;

[0110] (3) fractionating the refined oil obtained in step (2) to obtain naphtha at a fractionation temperature of less than 155° C., to obtain light white oil at a fractionation temperature of 155-280° C., and to obtain transformer oil base oil at a fractionation temperature of more than 280° C.

[0111] Example 2

[0112] This embodiment provides a method for producing transformer oil base oil by blending coking diesel, the method comprising the following steps:

[0113] (1) Mixing raw material oil and hydrogen, wherein the mixed raw material oil includes hydrogenated diesel and coker diesel, and the mass percentage of coker diesel in the mixed raw material oil is 1%, the reaction pressure is 11 MPa, the reaction temperature is 280° C., the volume ratio of hydrogen to the mixed raw material oil is 600:1, and the volume space velocity is 0.8 h -1 Hydrodecondensation treatment is performed under the conditions of to obtain hydrodecondensation product oil;

[0114] The mixing temperature of the hydrogenated diesel and the coker diesel is 40°C and the mixing time is 30 minutes;

[0115] The catalyst used in the hydrodecondensation treatment is the first catalyst provided in Preparation Example 1. The first catalyst is also subjected to nitrogen resistance treatment before the hydrodecondensation treatment. The nitrogen resistance treatment comprises: subjecting the first catalyst to hydrothermal treatment for 2 hours at a temperature of 550° C. and a pressure of 0.15 MPa;

[0116] (2) the hydrodecondensation product oil obtained in step (1) and hydrogen are reacted under the action of a second catalyst at a reaction temperature of 300° C., a volume ratio of hydrogen to the hydrodecondensation product oil of 600:1, and a volume space velocity of 0.3 h / min. -1 The second catalyst is the second catalyst provided in Preparation Example 2;

[0117] (3) fractionating the refined oil obtained in step (2) to obtain naphtha at a fractionation temperature of less than 155° C., to obtain light white oil at a fractionation temperature of 155-280° C., and to obtain transformer oil base oil at a fractionation temperature of more than 280° C.

[0118] Example 3

[0119] This embodiment provides a method for producing transformer oil base oil by blending coking diesel, the method comprising the following steps:

[0120] (1) Mixing raw material oil and hydrogen, wherein the mixed raw material oil includes hydrogenated diesel and coker diesel, and the mass percentage of coker diesel in the mixed raw material oil is 10%, at a reaction pressure of 16 MPa, a reaction temperature of 290° C., a volume ratio of hydrogen to the mixed raw material oil of 1200:1, and a volume space velocity of 1.5 h -1 Hydrodecondensation treatment is performed under the conditions of to obtain hydrodecondensation product oil;

[0121] The mixing temperature of the hydrogenated diesel and the coker diesel is 100° C. and the mixing time is 50 min.

[0122] The catalyst used in the hydrodecondensation treatment is the first catalyst provided in Preparation Example 1. The first catalyst is also subjected to nitrogen resistance treatment before the hydrodecondensation treatment. The nitrogen resistance treatment comprises: subjecting the first catalyst to hydrothermal treatment for 4 hours at a temperature of 650° C. and a pressure of 0.45 MPa;

[0123] (2) the hydrodecondensation product oil obtained in step (1) and hydrogen are reacted under the action of a second catalyst at a reaction temperature of 320° C., a volume ratio of hydrogen to the hydrodecondensation product oil of 1200:1, and a volume space velocity of 0.8 h / min. -1 The second catalyst is the second catalyst provided in Preparation Example 2;

[0124] (3) fractionating the refined oil obtained in step (2) to obtain naphtha at a fractionation temperature of less than 155° C., to obtain light white oil at a fractionation temperature of 155-280° C., and to obtain transformer oil base oil at a fractionation temperature of more than 280° C.

[0125] Example 4

[0126] This embodiment provides a method for producing transformer oil base oil by blending coker diesel. The difference between the method and the method in embodiment 1 is that the mass percentage of coker diesel in the mixed raw oil is 50%.

[0127] Example 5

[0128] This embodiment provides a method for producing transformer oil base oil by blending coking diesel. The difference between the method and the method in embodiment 1 is that the temperature of the nitrogen resistance treatment is 500°C.

[0129] Example 6

[0130] This embodiment provides a method for producing transformer oil base oil by blending coking diesel. The difference between the method and the method in embodiment 1 is that the temperature of the nitrogen resistance treatment is 700°C.

[0131] Example 7

[0132] This embodiment provides a method for producing transformer oil base oil by blending coking diesel. The method is different from that of Embodiment 1 only in that the pressure of the nitrogen resistance treatment is 0.1 MPa.

[0133] Example 8

[0134] This embodiment provides a method for producing transformer oil base oil by blending coking diesel. The method is different from that of Embodiment 1 only in that the pressure of the nitrogen resistance treatment is 0.5 MPa.

[0135] Example 9

[0136] This embodiment provides a method for producing transformer oil base oil by blending coking diesel. The method is different from that of Embodiment 1 only in that the reaction temperature of the supplementary refining treatment is 280°C.

[0137] Comparative Example 1

[0138] This comparative example provides a method for producing transformer oil base oil by blending coking diesel, which is different from Example 1 only in that the first catalyst is not subjected to nitrogen resistance treatment.

[0139] Taking Example 1 as an example, the properties of the hydrogenated diesel, the mixed stock oil and the obtained transformer oil base oil were tested, as shown in Table 1.

[0140] Taking Example 1 and Comparative Example 1 as examples, the methods provided in Example 1 and Comparative Example 1 were continuously operated for 300 h and 2500 h, respectively, and the properties of the transformer oil base oil and the inlet and outlet pressure increments were obtained as shown in Table 2.

[0141] The pour points, aromatics contents, nitrogen contents and yields of the transformer oil base oils prepared in Examples 1-9 and Comparative Example 1 are shown in Table 3.

[0142] Table 1

[0143]

[0144] In Table 1, “-” means that the data is not available.

[0145] As can be seen from Table 1, the sulfur content, nitrogen content and aromatic content of the mixed stock oil blended with 20% coker diesel are significantly increased compared with hydrogenated diesel, indicating that the properties of the mixed stock oil have deteriorated. However, after being treated by the method provided by the present invention, the aromatic content in the obtained transformer oil base oil reaches 0.36%, the pour point reaches -57°C, the nitrogen content and the sulfur content are both below 1.0 mg / kg, and it has the characteristics of low sulfur, low nitrogen, low condensation and low aromaticity, meeting the requirements of T-40°C transformer oil base oil (general purpose) in GB2536-2011 standard.

[0146] Table 2

[0147]

[0148] The “benchmark” in Table 2 refers to the set inlet and outlet pressure increments after 300 hours of operation.

[0149] It can be seen from Table 2 that compared with Comparative Example 1, Example 1 uses the first catalyst that has been subjected to nitrogen resistance treatment. The data in Table 2 show that Example 1 can reduce the growth rate of the pressure drop, which is more conducive to the long-term operation of the device, and at the same time, the pour point of the transformer oil base oil is lower.

[0150] Table 3

[0151]

[0152] From the data in Table 3, we can see the following points:

[0153] (1) It can be seen from the data of Examples 1-9 that the method provided by the present invention can not only process inferior raw oil, but also prepare transformer oil base oil with excellent performance, wherein the pour point of the transformer oil base oil reaches below -48°C, the aromatics content reaches below 7.76wt%, the nitrogen content reaches below 8.3mg / kg, and the yield of the transformer oil base oil reaches above 37.6%. Under preferred conditions, the pour point of the transformer oil base oil reaches -57°C, the aromatics content reaches below 0.43wt%, the nitrogen content reaches below 1mg / kg, and the yield of the transformer oil base oil reaches above 44.7%.

[0154] (2) A comprehensive comparison of the data of Example 1 and Example 4 shows that the mass percentage of coker diesel in the mixed feedstock oil in Example 1 is 20%, compared with 50% in Example 4. The aromatics content and nitrogen content in Example 1 are significantly lower than those in Example 4. It can be seen that the present invention preferably controls the mass percentage of coker diesel in the mixed feedstock oil, which can further ensure the quality of the transformer oil base oil.

[0155] (3) Comprehensive comparison of the data of Example 1 and Examples 5-6 shows that the temperature of the nitrogen resistance treatment in Example 1 is 600°C, compared with 500°C and 700°C in Examples 5-6, respectively. The yield of the transformer oil base oil in Example 1 is significantly higher than that in Example 5, and the pour point of the transformer oil base oil in Example 1 is significantly lower than that in Example 6. It can be seen that the present invention preferably controls the temperature of the nitrogen resistance treatment, which can further improve the yield of the transformer oil base oil and improve the low-condensation property of the transformer oil base oil.

[0156] (4) Comprehensive comparison of the data of Example 1 and Examples 7-8 shows that the pressure of the nitrogen resistance treatment in Example 1 is 0.3 MPa, compared with 0.1 MPa and 0.5 MPa in Examples 7-8, respectively. The yield in Example 1 is significantly higher than that in Example 7, and the pour point in Example 1 is significantly lower than that in Example 8. It can be seen that the present invention preferably controls the pressure of the nitrogen resistance treatment, which can further improve the yield of the transformer oil base oil and improve the low-condensation properties of the transformer oil base oil.

[0157] (5) A comprehensive comparison of the data of Example 1 and Example 9 shows that the temperature of the supplementary refining treatment in Example 1 is 340°C, compared with 280°C in Example 9. The nitrogen content in Example 1 is significantly lower than that in Example 9. It can be seen that the present invention preferably controls the temperature of the supplementary refining treatment, which can further reduce the nitrogen content of the transformer oil base oil.

[0158] (6) Comprehensively comparing the data of Example 1 and Comparative Example 1, it can be seen that the only difference between Comparative Example 1 and Example 1 is that the first catalyst is not subjected to nitrogen resistance treatment, and the yield of transformer oil base oil in Example 1 is significantly higher than that in Comparative Example 1. It can be seen that the present invention can significantly improve the yield of transformer oil base oil by subjecting the first catalyst to nitrogen resistance treatment.

[0159] In summary, the method provided by the present invention can process low-quality raw oil with a high nitrogen content to obtain a transformer oil base oil with the characteristics of low sulfur, low nitrogen, low freezing point and low aromaticity, which meets the requirements of T-40°C transformer oil base oil (general purpose) in the GB2536-2011 standard, and has a high product yield.

[0160] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for producing transformer oil base oil by co-refining coker diesel oil, characterized in that, the method comprises the following steps: (1) Subjecting the mixed feedstock oil and hydrogen to hydrodewaxing treatment to obtain hydrodewaxing product oil; The mixed feedstock oil includes hydrogenated diesel oil and coker diesel oil; The catalyst used in the hydrodewaxing treatment includes a first catalyst; The first catalyst is also subjected to nitrogen resistance treatment before the hydrodewaxing treatment; (2) Subjecting the hydrodewaxing product oil obtained in step (1) and hydrogen to supplementary refining treatment to obtain refined oil; (3) Fractionating the refined oil obtained in step (2) to obtain transformer oil base oil; Among them, the first catalyst in step (1) is a catalyst prepared by the following preparation method. The related preparation method includes: (a) Mixing pseudoboehmite, peptizing agent, extrusion aid, pore-expanding agent, precursor of metal oxide promoter and water, and then successively performing shaping, drying and calcination to obtain a carrier support; (b) Mixing the carrier support and molecular sieve mother liquor for impregnation, and then successively performing crystallization, washing, drying and calcination to obtain a first carrier; (c) Impregnating the first carrier and the first active metal salt solution, and then successively performing drying and calcination to obtain the first catalyst; The first catalyst in step (1) includes a first carrier and a first active metal oxide supported on the first carrier; The first carrier includes a carrier support and a molecular sieve supported on the carrier support; The molecular sieve includes ZSM-5 type molecular sieve and / or β type molecular sieve; The temperature of the nitrogen resistance treatment in step (1) is 550-650 °C; The pressure of the nitrogen resistance treatment is 0.15-0.45 MPa; The time of the nitrogen resistance treatment is 2-6 h; The method of the nitrogen resistance treatment includes hydrothermal treatment; The mass percentage content of coker diesel oil in the mixed feedstock oil in step (1) is 1-20%.

2. The method according to claim 1, characterized in that, the mixing temperature of the hydrogenated diesel oil and the coker diesel oil is 40-100 °C.

3. The method according to claim 1, characterized in that, the mixing time of the hydrogenated diesel oil and the coker diesel oil is ≥10 min.

4. The method according to claim 1, characterized in that, the first active metal oxide includes Group VIII metal oxide and / or Group VIB metal oxide.

5. The method according to claim 4, characterized in that, the Group VIII metal oxide in the first active metal oxide includes nickel oxide.

6. The method according to claim 4, characterized in that, the Group VIB metal oxide in the first active metal oxide includes tungsten trioxide.

7. The method according to claim 4, characterized in that, the mass percentage content of the Group VIII metal oxide in the first catalyst is 1-10%.

8. The method according to claim 4, characterized in that, the mass percentage content of the Group VIB metal oxide in the first catalyst is 1-16%.

9. The method according to claim 1, characterized in that, the carrier support contains alumina.

10. The method according to claim 1, characterized in that, The mass percentage of molecular sieve in the first catalyst is 8-40%.

11. The method according to claim 1, It is characterized in that The reaction pressure of the hydrodecondensation treatment in step (1) is 11-16 MPa.

12. The method according to claim 1, It is characterized in that The reaction temperature of the hydrodecondensation treatment is 260-360°C.

13. The method according to claim 1, It is characterized in that The volume ratio of the hydrogen to the mixed feedstock oil is (600-1200):

1.

14. The method according to claim 1, It is characterized in that The volume space velocity of the hydrodecondensation treatment is 0.5-2h -1 .

15. The method according to claim 14, It is characterized in that The volume space velocity of the hydrodecondensation treatment is 0.7-1.5h -1 .

16. The method according to claim 1, It is characterized in that The catalyst used in the supplementary refining treatment in step (2) includes a second catalyst.

17. The method according to claim 16, It is characterized in that The second catalyst includes a second carrier and a second active metal oxide and promoter atoms supported on the second carrier.

18. The method according to claim 17, It is characterized in that The second active metal oxide comprises a Group VIII metal oxide and / or a Group VIB metal oxide.

19. The method according to claim 18, It is characterized in that The Group VIII metal oxide in the second active metal oxide includes nickel oxide.

20. The method according to claim 18, It is characterized in that The Group VIB metal oxide in the second active metal oxide includes tungsten trioxide and / or molybdenum trioxide.

21. The method according to claim 17, It is characterized in that The auxiliary atom includes any one of phosphorus, fluorine, boron, titanium or zirconium, or a combination of at least two thereof.

22. The method according to claim 18, It is characterized in that The mass percentage of the Group VIII metal oxide in the second catalyst is 4-10%.

23. The method according to claim 18, It is characterized in that The mass percentage of the Group VIB metal oxide in the second catalyst is 15-30%.

24. The method according to claim 17, It is characterized in that The mass percentage of the auxiliary agent atoms in the second catalyst is 1-10%.

25. The method according to claim 17, It is characterized in that The second carrier contains alumina.

26. The method according to claim 1, It is characterized in that The reaction pressure of the supplementary refining treatment in step (2) is 11-16 MPa.

27. The method according to claim 1, It is characterized in that The reaction temperature of the supplementary refining treatment is 290-360°C.

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

1.

29. The method according to claim 1, It is characterized in that The volumetric space velocity of the supplementary refining treatment is 0.2 - 1.0 h -1 .

30. The method according to claim 1, It is characterized in that The distillation temperature of the transformer oil base oil in step (3) is greater than 280°C.

31. The method according to claim 1, It is characterized in that The fractionation in step (3) also produces light white oil and naphtha.

32. The method according to claim 31, It is characterized in that The fractionation temperature of the naphtha is less than 155°C.

33. The method according to claim 31, It is characterized in that The fractionation temperature of the light white oil is 155-280°C.

34. The method according to claim 31, It is characterized in that The light white oil includes any one of W1-40, W1-60, W1-90 or W1-110, or a combination of at least two thereof.

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