A two-stage hydrogenation method for environmentally friendly aromatic oil

Abstract

The invention discloses a two-stage hydrogenation method for environmentally friendly aromatic oil, which consists of two stages. In the first stage, the feed will be demetallized and hydrotreated to remove metals and impurities such as sulfur and nitrogen; the feed will also undergo mild hydrocracking to increase the viscosity index; the hydrocracking catalyst will be hydrotreated in the presence of hydrogen; in the second stage, the treated feed will be hydroisomerized and dewaxed, wherein the first-stage liquid product is treated on a noble metal dewaxing and noble metal hydrofining catalyst in the presence of hydrogen to reduce the pour point and hydrofining, thereby obtaining high-purity environmentally friendly aromatic oil.

Description

Technical Field

[0001] The invention relates to the technical field of petrochemical engineering, in particular to a two-stage hydrogenation method for environmentally friendly aromatic oil. Background Art

[0002] Traditional aromatic oil (DAE) contains a large amount of polycyclic aromatic hydrocarbons (also called polycyclic aromatic hydrocarbons). Due to the introduction of aromatic oil, tires and rubber products contain polycyclic aromatic hydrocarbons to a greater or lesser extent. Benzopyrene (BaP) is a typical polycyclic aromatic hydrocarbon, which has been scientifically confirmed by the Committee on Toxicity, Ecotoxicity and the Environment (CSTEE) to be carcinogenic, mutagenic and toxic to the reproductive system. During the use of rubber products, polycyclic aromatic hydrocarbons will inevitably spread into the environment and come into contact with humans, thus endangering the health of humans and the environment. TDAE (treated aromatic oil) is produced by refining the original aromatic oil to remove toxic polycyclic aromatic hydrocarbons. It is an ideal substitute for aromatic oil in crown rubber, sidewall rubber and tyre wear-resistant rubber.

[0003] CN201010248231.6 applies for a method for preparing environmentally friendly aromatic oil from catalytic cracking oil slurry. The method uses a low-polarity alkyl solvent and a high-polarity solvent such as furfural, N-methylpyrrolidone, dimethyl sulfoxide, etc. to perform dual-solvent multiple extractions on the catalytic cracking oil slurry to prepare environmentally friendly aromatic oil that complies with EU Directive 2005 / 69 / EC. The obtained environmentally friendly aromatic oil contains less than 3% toxic polycyclic aromatic hydrocarbons and less than 0.1 ppm benzopyrene. The oil can be used as environmentally friendly rubber filler oil and environmentally friendly aromatic oil for other purposes.

[0004] CN102146297A discloses a method for producing environmentally friendly aromatic oil, which uses JT-3 aromatic oil produced by Suzhou Jiutai Group as raw material, uses furfural as solvent and uses a multi-stage extraction tower to extract it, and the raffinate flowing out of the tower top is heated by heat-conducting oil to remove furfural to obtain raffinate oil, and the obtained raffinate oil is adsorbed by an adsorption tower containing an adsorbent to remove various polycyclic aromatic hydrocarbons therein, thereby obtaining an environmentally friendly aromatic oil product. The present invention uses a multi-stage extraction tower to replace the existing packing tower as an extraction tower, which significantly improves production efficiency; after the extraction is completed, the adsorbent adsorption separation method is used to remove various polycyclic aromatic hydrocarbons in the raffinate oil, so that the obtained environmentally friendly aromatic oil product has higher purity and better quality.

[0005] However, under the conditions of hydrogenation refining, in order to reduce the polycyclic aromatic hydrocarbons to meet the environmental quality indicators, the existing technical means will lose a lot of aromatic hydrocarbons, and the two indicators cannot be taken into account at the same time. At the same time, the hydrogen consumption is large and the production cost is high. In addition, it will also affect the purity of the environmentally friendly aromatic oil products. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a two-stage hydrogenation method for environmentally friendly aromatic oil, which belongs to the technical field of petrochemical industry.

[0007] The environmentally friendly aromatic oil project consists of a lubricating oil production unit, a supporting dry gas desulfurization unit and a solvent regeneration unit; the lubricating oil production unit includes a reaction part, a fractionation part, a light white oil stabilization part and public works within the boundary area;

[0008] The hydrotreater consists of two stages; in the first stage, the feed will be demetallized and hydrotreated to remove metals and impurities such as sulfur and nitrogen; the feed will also undergo mild hydrocracking to increase the viscosity index; the hydrocracking catalyst is hydrotreated in the presence of hydrogen;

[0009] In the second stage, the treated feed is subjected to hydroisomerization dewaxing, wherein the liquid product of the first stage is treated over a noble metal dewaxing and noble metal hydrofinishing catalyst in the presence of hydrogen to reduce the pour point and hydrofinish;

[0010] The specific method includes the following steps:

[0011] S1: First stage hydrogenation:

[0012] The crude oil from the tank area is heated by the heat exchanger and then heated to the required temperature by the reaction feed heating furnace before entering the hydroprocessing reactor; the reaction effluent from the bottom of the reactor is heat exchanged and then enters the high-pressure stripping tower to remove light components and hydrogen sulfide;

[0013] Further, the reaction conditions are: hydrogen pressure 11-16MPa; temperature 380-420°C; hydrogen-oil ratio 800-1200; volume space velocity 0.8-1.2h -1 ;

[0014] Further, the loading amount of the hydrogenation catalyst is: 10-15% of the volume percentage of the hydroprocessing reactor;

[0015] S2: Dewaxing:

[0016] The liquid phase at the bottom of the high-pressure stripping tower is heat exchanged in the heat exchanger and then passes through the reactor start-up electric heater to enter the dewaxing reactor;

[0017] Further, the reaction conditions are: pressure: 13-17 MPa; temperature 320-380°C; space velocity: 1.5-1.9 h -1 ;

[0018] Furthermore, the loading amount of the dewaxing catalyst is 1.7-4.5% of the volume percentage of the dewaxing reactor;

[0019] S3: Second stage hydrogenation:

[0020] The dewaxing reaction product enters the hydrogenation refining reactor after heat exchange in the heat exchanger; the reaction effluent of the hydrogenation refining reactor directly enters the hot high-pressure separator for gas-liquid separation;

[0021] Further, the reaction conditions are: hydrogen pressure 11-16MPa; temperature 380-420°C; hydrogen-oil ratio 800-1200; volume space velocity 1.6-2.0h -1 ;

[0022] Furthermore, the loading amount of the hydrogenation catalyst in the second stage is: 2-6% of the volume percentage of the hydrogenation supplementary refining reactor;

[0023] S4: atmospheric distillation:

[0024] The hot low-pressure oil and the cold low-pressure oil are mixed and then sent to the atmospheric tower feed heating furnace to be heated to a certain temperature and then sent to the atmospheric tower; the top oil and gas of the tower are cooled to 50-70℃ by the atmospheric tower top air cooler and then sent to the atmospheric tower top reflux tank for gas, oil and water three-phase separation. The bottom oil of the atmospheric tower is pressurized by the atmospheric tower bottom pump and then sent to the vacuum tower feed heating furnace after heat exchange; the top reflux is used as the feed of the stabilization tower and enters the light white oil stabilization tower after heat exchange;

[0025] Further, the reaction conditions are: atmospheric tower pressure is 0.1-0.15MP, feed temperature is 300-320°C;

[0026] S5: Vacuum distillation:

[0027] The bottom oil of the atmospheric tower is heated to 300-380℃ by the vacuum tower feed heating furnace and then enters the vacuum tower. The bottom oil of the vacuum tower is 500N base oil, which is cooled by the 500N base oil product air cooler and sent to the tank area as a product.

[0028] Furthermore, the reaction conditions are: vacuum tower pressure -95 kPa, feed temperature 300-320°C.

[0029] Furthermore, the feedstock oil is paraffin-based and cycloalkyl-based vacuum wax oil; the distillation range is 320-560, and the aromatic hydrocarbons are not more than 30%.

[0030] Furthermore, the vacuum tower is composed of 3-6 sections of structured packing above the feed, 7-12 layers of tower trays are arranged below the feed, and the vacuum tower is provided with 3-5 side line extractions and 1-3 over-vaporized oil circulations.

[0031] Furthermore, the fourth section of structured packing is an oil absorption section, which is used to remove heavy components in the rising gas to achieve separation of 150N base oil and 500N base oil.

[0032] Furthermore, 150N base oil is extracted from the lower part of the third stage filler, and after heat exchange and cooling, it is divided into two streams, one of which is mixed with 500N base oil in a ratio of 1:1 and is discharged from the device as a 350N base oil product, and the other is discharged from the device as a 150N base oil product.

[0033] Furthermore, 60N base oil is extracted from the lower part of the second stage packing and sent to the tank area after cooling.

[0034] Furthermore, the catalyst in the first stage hydrogenation process is a nickel-molybdenum hydrogenation catalyst.

[0035] Furthermore, the dewaxing process catalyst is a palladium catalyst.

[0036] Furthermore, the catalyst for the second stage hydrogenation process can be a nickel-doped palladium / γ-Al2O3 catalyst, and its preparation method is as follows:

[0037] S1: Add 600-700 parts of deionized water, 3-5 parts of γ-aminopropyl triethoxysiloxane, and 50-62 parts of γ-Al2O3 particles into a stirring kettle by weight, stir at 60-70°C for 10-20h, filter, wash with water, and dry to obtain amino-modified γ-Al2O3.

[0038] S2: Add 150-170 parts of amino-modified γ-Al2O3, 0.03-0.5 parts of stabilizer, 6-10 parts of nickel acrylate, 4-8 parts of triethylamine, 500-1200 parts of methanol, and 3-6 parts of sodium silicate nonahydrate, mix well, stir at 60-70°C for 1-4h, then filter and dry to obtain a catalyst carrier;

[0039] S3: Take 1000-1200 parts of a methanol solution containing chloropalladic acid and chloroauric acid, wherein the content of palladium in the solution is 2-5 g / L, the content of gold is 0.3-1 g / L, and 100-130 parts of a catalyst carrier, stir at 50-60°C for 1-4 h, then stand for 18-22 h, then filter, and dry.

[0040] S4: Reduce 110-200 parts of the catalyst precursor in a hydrogen atmosphere at a hydrogen flow rate of 0.5-2BV / hr, a pressure of 0.3-1MPa, a reduction temperature of 120-155°C, a reduction time of 1-4h, filter, and dry to obtain a palladium catalyst.

[0041] Furthermore, the stabilizer is one or more of 2,4,6-trimethylpyridine, N,N-dimethyl-4-aminopyridine, N,N'-dimethylpiperazine, and 3-(dimethylamino)propylimidazole.

[0042] Compared with the prior art, the production method of environmentally friendly aromatic oil of the present invention adopts a two-stage hydrogenation method, wherein the first stage hydrogenation is followed by dewaxing and then secondary hydrogenation refining, so that the obtained environmentally friendly aromatic oil product has high purity and better quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a flowchart of the process of the present invention. DETAILED DESCRIPTION

[0044] The technical solutions of the present invention are described below by listing some specific embodiments, but the protection scope of the present invention is not limited to the listed embodiments:

[0045] Embodiment 1:

[0046] A method for two-stage hydrogenation of environmentally friendly aromatic oil, comprising the following steps:

[0047] S1: First stage hydrogenation:

[0048] The crude oil from the tank area is heated by the heat exchanger and then heated to the required temperature by the reaction feed heating furnace before entering the hydroprocessing reactor; the reaction effluent from the bottom of the reactor is heat exchanged and then enters the high-pressure stripping tower to remove light components and hydrogen sulfide;

[0049] The reaction conditions are: hydrogen pressure 11MPa; temperature 380℃; hydrogen-oil ratio 800; volume space velocity 0.8h -1 ;

[0050] The loading amount of the hydrogenation catalyst is: 10% of the volume percentage of the hydroprocessing reactor;

[0051] S2: Dewaxing:

[0052] The liquid phase at the bottom of the high-pressure stripping tower is heat exchanged in the heat exchanger and then passes through the reactor start-up electric heater to enter the dewaxing reactor;

[0053] Reaction conditions: pressure: 13 MPa; temperature 320°C; space velocity: 1.5 h -1 ;

[0054] The loading amount of the dewaxing catalyst is 1.7% of the volume percentage of the dewaxing reactor;

[0055] S3: Second stage hydrogenation:

[0056] The dewaxing reaction product enters the hydrogenation refining reactor after heat exchange in the heat exchanger; the reaction effluent of the hydrogenation refining reactor directly enters the hot high-pressure separator for gas-liquid separation;

[0057] The reaction conditions are: hydrogen pressure 11 MPa; temperature 380°C; hydrogen-to-oil ratio 800; volumetric space velocity 1.6 h -1 ;

[0058] The loading amount of the hydrogenation catalyst in the second stage is: 2% of the volume percentage of the hydrogenation supplementary refining reactor;

[0059] S4: atmospheric distillation:

[0060] The hot low-pressure oil is mixed with the cold low-pressure oil and then enters the atmospheric tower feed heating furnace to be heated to a certain temperature and then sent to the atmospheric tower; the top oil and gas of the tower are cooled to 50°C by the atmospheric tower top air cooler and then enter the atmospheric tower top reflux tank for gas, oil and water three-phase separation. The bottom oil of the atmospheric tower is pressurized by the atmospheric tower bottom pump and then sent to the vacuum tower feed heating furnace after heat exchange; the top reflux is used as the feed of the stabilization tower and enters the light white oil stabilization tower after heat exchange;

[0061] The reaction conditions are: atmospheric tower pressure is 0.1MP, feed temperature is 300°C;

[0062] S5: Vacuum distillation:

[0063] The bottom oil of the atmospheric tower is heated to 300℃ by the vacuum tower feed heating furnace and then enters the vacuum tower. The bottom oil of the vacuum tower is 500N base oil, which is cooled by the 500N base oil product air cooler and sent to the tank area as a product.

[0064] The reaction conditions are: vacuum tower pressure -95 kPa, feed temperature 300 °C.

[0065] The raw material oil is paraffin-based and cycloalkyl-based vacuum wax oil; the distillation range is 320, and the aromatic hydrocarbon content is not more than 30%.

[0066] The vacuum tower is composed of 4 sections of structured packing above the feed, 10 layers of tower trays are arranged below the feed, and the vacuum tower is provided with 3 side line extractions and 1 over-vaporized oil circulation.

[0067] The fourth section of structured packing is an oil absorption section, which is used to remove heavy components in the ascending gas to achieve the separation of 150N base oil and 500N base oil.

[0068] 150N base oil is extracted from the lower part of the third stage filler, and after heat exchange and cooling, it is divided into two streams, one stream is mixed with 500N base oil in a ratio of 1:1 and is discharged from the device as a 350N base oil product, and the other stream is discharged from the device as a 150N base oil product.

[0069] The 60N base oil is extracted from the lower part of the second stage packing and sent to the tank area after cooling.

[0070] The catalyst in the first stage hydrogenation process is a nickel-molybdenum hydrogenation catalyst.

[0071] The dewaxing process catalyst is a palladium catalyst.

[0072] The catalyst for the second stage hydrogenation process can be a nickel-doped palladium / γ-Al2O3 catalyst, and its preparation method is as follows:

[0073] S1: Add 600 kg of deionized water, 3 kg of γ-aminopropyl triethoxysiloxane, and 50 kg of γ-Al2O3 particles into a stirring kettle, stir at 60°C for 20 hours, filter, wash with water, and dry to obtain amino-modified γ-Al2O3.

[0074] S2: Add 150 kg of amino-modified γ-Al2O3, 0.03 kg of stabilizer, 6 kg of nickel acrylate, 4 kg of triethylamine, 500 kg of methanol, and 3 kg of sodium silicate nonahydrate, mix well, stir at 60° C. for 4 h, then filter and dry to obtain a catalyst carrier;

[0075] S3: Take 1000 kg of methanol solution containing chloropalladic acid and chloroauric acid, wherein the content of palladium in the solution is 2 g / L, the content of gold is 0.3 g / L, and 100 kg of catalyst carrier, stir at 50°C for 4 h, then stand for 18 h, then filter and dry.

[0076] S4: Reduce 110 kg of catalyst precursor in a hydrogen atmosphere with a hydrogen flow rate of 0.5 BV / hr, a pressure of 0.3 MPa, a reduction temperature of 120° C., and a reduction time of 1 h. Filter and dry to obtain a palladium catalyst.

[0077] The stabilizer is 2,4,6-trimethylpyridine.

[0078] Example 2

[0079] A method for two-stage hydrogenation of environmentally friendly aromatic oil, comprising the following steps:

[0080] S1: First stage hydrogenation:

[0081] The crude oil from the tank area is heated by the heat exchanger and then heated to the required temperature by the reaction feed heating furnace before entering the hydroprocessing reactor; the reaction effluent from the bottom of the reactor is heat exchanged and then enters the high-pressure stripping tower to remove light components and hydrogen sulfide;

[0082] The reaction conditions are: hydrogen pressure 13MPa; temperature 390℃; hydrogen-oil ratio 900; volume space velocity 0.9h -1 ;

[0083] The loading amount of the hydrogenation catalyst is: 12% by volume of the hydroprocessing reactor;

[0084] S2: Dewaxing:

[0085] The liquid phase at the bottom of the high-pressure stripping tower is heat exchanged in the heat exchanger and then passes through the reactor start-up electric heater to enter the dewaxing reactor;

[0086] Reaction conditions: pressure: 14 MPa; temperature 340°C; space velocity: 1.6 h -1 ;

[0087] The loading amount of the dewaxing catalyst is 2.1% by volume of the dewaxing reactor;

[0088] S3: Second stage hydrogenation:

[0089] The dewaxing reaction product enters the hydrogenation refining reactor after heat exchange in the heat exchanger; the reaction effluent of the hydrogenation refining reactor directly enters the hot high-pressure separator for gas-liquid separation;

[0090] The reaction conditions are: hydrogen pressure 13MPa; temperature 390℃; hydrogen-oil ratio 900; volume space velocity 1.7h -1 ;

[0091] The loading amount of the hydrogenation catalyst in the second stage is: 3% of the volume percentage of the hydrogenation supplementary refining reactor;

[0092] S4: atmospheric distillation:

[0093] The hot low-pressure oil is mixed with the cold low-pressure oil and then enters the atmospheric tower feed heating furnace to be heated to a certain temperature and then sent to the atmospheric tower; the top oil and gas of the tower are cooled to 60°C by the atmospheric tower top air cooler and then enter the atmospheric tower top reflux tank for gas, oil and water three-phase separation. The bottom oil of the atmospheric tower is pressurized by the atmospheric tower bottom pump and then sent to the vacuum tower feed heating furnace after heat exchange; the top reflux is used as the feed of the stabilization tower and enters the light white oil stabilization tower after heat exchange;

[0094] The reaction conditions are: atmospheric tower pressure is 0.12MP, feed temperature is 300°C;

[0095] S5: Vacuum distillation:

[0096] The bottom oil of the atmospheric tower is heated to 320℃ by the vacuum tower feed heating furnace and enters the vacuum tower. The bottom oil of the vacuum tower is 500N base oil, which is cooled by the 500N base oil product air cooler and sent to the tank area as a product.

[0097] The reaction conditions are: vacuum tower pressure -95 kPa, feed temperature 305 °C.

[0098] The raw material oil is paraffin-based and cycloalkyl-based vacuum wax oil; the distillation range is 380, and the aromatic hydrocarbon content is not more than 30%.

[0099] The vacuum tower is composed of 4 sections of structured packing above the feed, 10 layers of tower trays are arranged below the feed, and the vacuum tower is provided with 3 side line extractions and 1 over-vaporized oil circulation.

[0100] The fourth section of structured packing is an oil absorption section, which is used to remove heavy components in the ascending gas to achieve the separation of 150N base oil and 500N base oil.

[0101] 150N base oil is extracted from the lower part of the third stage filler, and after heat exchange and cooling, it is divided into two streams, one stream is mixed with 500N base oil in a ratio of 1:1 and is discharged from the device as a 350N base oil product, and the other stream is discharged from the device as a 150N base oil product.

[0102] The 60N base oil is extracted from the lower part of the second stage packing and sent to the tank area after cooling.

[0103] The catalyst in the first stage hydrogenation process is a nickel-molybdenum hydrogenation catalyst.

[0104] The dewaxing process catalyst is a palladium catalyst.

[0105] The catalyst for the second stage hydrogenation process can be a nickel-doped palladium / γ-Al2O3 catalyst, and its preparation method is as follows:

[0106] S1: Add 625 kg of deionized water, 4 kg of γ-aminopropyl triethoxysiloxane, and 53 kg of γ-Al2O3 particles into a stirring kettle, stir at 63°C for 18 hours, filter, wash with water, and dry to obtain amino-modified γ-Al2O3.

[0107] S2: Add 158 kg of amino-modified γ-Al2O3, 0.12 kg of stabilizer, 7 kg of nickel acrylate, 5 kg of triethylamine, 780 kg of methanol, and 4 kg of sodium silicate nonahydrate, mix well, stir at 62° C. for 3 h, then filter and dry to obtain a catalyst carrier;

[0108] S3: Take 1050 kg of methanol solution containing chloropalladic acid and chloroauric acid, wherein the content of palladium in the solution is 3 g / L, the content of gold is 0.5 g / L, and 110 kg of catalyst carrier, stir at 53°C for 3 h, then stand for 20 h, then filter and dry.

[0109] S4: Reduce 135 kg of catalyst precursor in a hydrogen atmosphere at a hydrogen flow rate of 1 BV / hr, a pressure of 0.5 MPa, a reduction temperature of 135° C., and a reduction time of 3 h. Filter and dry to obtain a palladium catalyst.

[0110] The stabilizer is N,N-dimethyl-4-aminopyridine.

[0111] Example 3

[0112] A method for two-stage hydrogenation of environmentally friendly aromatic oil, comprising the following steps:

[0113] S1: First stage hydrogenation:

[0114] The crude oil from the tank area is heated by the heat exchanger and then heated to the required temperature by the reaction feed heating furnace before entering the hydroprocessing reactor; the reaction effluent from the bottom of the reactor is heat exchanged and then enters the high-pressure stripping tower to remove light components and hydrogen sulfide;

[0115] The reaction conditions are: hydrogen pressure 14 MPa; temperature 410°C; hydrogen-to-oil ratio 1100; volumetric space velocity 1.1 h -1 ;

[0116] The loading amount of the hydrogenation catalyst is: 14% by volume of the hydroprocessing reactor;

[0117] S2: Dewaxing:

[0118] The liquid phase at the bottom of the high-pressure stripping tower is heat exchanged in the heat exchanger and then passes through the reactor start-up electric heater to enter the dewaxing reactor;

[0119] Reaction conditions: pressure: 16 MPa; temperature 360°C; space velocity: 1.7 h -1 ;

[0120] The loading amount of the dewaxing catalyst is 3.4% of the volume percentage of the dewaxing reactor;

[0121] S3: Second stage hydrogenation:

[0122] The dewaxing reaction product enters the hydrogenation refining reactor after heat exchange in the heat exchanger; the reaction effluent of the hydrogenation refining reactor directly enters the hot high-pressure separator for gas-liquid separation;

[0123] The reaction conditions are: hydrogen pressure 15 MPa; temperature 410°C; hydrogen-to-oil ratio 1100; volumetric space velocity 1.9 h -1 ;

[0124] The loading amount of the hydrogenation catalyst in the second stage is: 5% of the volume percentage of the hydrogenation supplementary refining reactor;

[0125] S4: atmospheric distillation:

[0126] The hot low-pressure oil and the cold low-pressure oil are mixed and then sent to the atmospheric tower feed heating furnace to be heated to a certain temperature and then sent to the atmospheric tower; the top oil and gas of the tower are cooled to 65°C by the atmospheric tower top air cooler and then sent to the atmospheric tower top reflux tank for gas, oil and water three-phase separation. The bottom oil of the atmospheric tower is pressurized by the atmospheric tower bottom pump and then sent to the vacuum tower feed heating furnace after heat exchange; the top reflux is used as the feed of the stabilization tower and enters the light white oil stabilization tower after heat exchange;

[0127] The reaction conditions are: atmospheric tower pressure is 0.14MP, feed temperature is 315℃;

[0128] S5: Vacuum distillation:

[0129] The bottom oil of the atmospheric tower is heated to 360℃ by the vacuum tower feed heating furnace and then enters the vacuum tower. The bottom oil of the vacuum tower is 500N base oil, which is cooled by the 500N base oil product air cooler and sent to the tank area as a product.

[0130] The reaction conditions are: vacuum tower pressure -95 kPa, feed temperature 315 °C.

[0131] The raw material oil is paraffin-based and cycloalkyl-based vacuum wax oil; the distillation range is 480, and the aromatic hydrocarbon content is not more than 30%.

[0132] The vacuum tower is composed of 4 sections of structured packing above the feed, 10 layers of tower trays are arranged below the feed, and the vacuum tower is provided with 3 side line extractions and 1 over-vaporized oil circulation.

[0133] The fourth section of structured packing is an oil absorption section, which is used to remove heavy components in the ascending gas to achieve the separation of 150N base oil and 500N base oil.

[0134] 150N base oil is extracted from the lower part of the third stage filler, and after heat exchange and cooling, it is divided into two streams, one stream is mixed with 500N base oil in a ratio of 1:1 and is discharged from the device as a 350N base oil product, and the other stream is discharged from the device as a 150N base oil product.

[0135] The 60N base oil is extracted from the lower part of the second stage packing and sent to the tank area after cooling.

[0136] The catalyst in the first stage hydrogenation process is a nickel-molybdenum hydrogenation catalyst.

[0137] The dewaxing process catalyst is a palladium catalyst.

[0138] The catalyst for the second stage hydrogenation process can be a nickel-doped palladium / γ-Al2O3 catalyst, and its preparation method is as follows:

[0139] S1: Add 700 kg of deionized water, 4 kg of γ-aminopropyl triethoxysiloxane, and 58 kg of γ-Al2O3 particles into a stirring kettle, stir at 67°C for 13 h, filter, wash with water, and dry to obtain amino-modified γ-Al2O3.

[0140] S2: Add 165 kg of amino-modified γ-Al2O3, 0.38 kg of stabilizer, 9 kg of nickel acrylate, 7 kg of triethylamine, 1000 kg of methanol, and 5 kg of sodium silicate nonahydrate, mix well, stir at 67° C. for 2 h, then filter and dry to obtain a catalyst carrier;

[0141] S3: Take 1150 kg of methanol solution containing chloropalladic acid and chloroauric acid, wherein the content of palladium in the solution is 4 g / L, the content of gold is 0.8 g / L, and 120 kg of catalyst carrier, stir at 56°C for 2 h, then let stand for 20 h, then filter and dry.

[0142] S4: Reduce 175 kg of catalyst precursor in a hydrogen atmosphere at a hydrogen flow rate of 1.5 BV / hr, a pressure of 0.8 MPa, a reduction temperature of 142° C., and a reduction time of 2 h. Filter and dry to obtain a palladium catalyst.

[0143] The stabilizer is N,N'-dimethylpiperazine.

[0144] Example 4

[0145] A method for two-stage hydrogenation of environmentally friendly aromatic oil, comprising the following steps:

[0146] S1: First stage hydrogenation:

[0147] The crude oil from the tank area is heated by the heat exchanger and then heated to the required temperature by the reaction feed heating furnace before entering the hydroprocessing reactor; the reaction effluent from the bottom of the reactor is heat exchanged and then enters the high-pressure stripping tower to remove light components and hydrogen sulfide;

[0148] The reaction conditions are: hydrogen pressure 16MPa; temperature 420℃; hydrogen-oil ratio 1200; volume space velocity 1.2h -1 ;

[0149] The loading amount of the hydrogenation catalyst is: 15% of the volume percentage of the hydroprocessing reactor;

[0150] S2: Dewaxing:

[0151] The liquid phase at the bottom of the high-pressure stripping tower is heat exchanged in the heat exchanger and then passes through the reactor start-up electric heater to enter the dewaxing reactor;

[0152] Reaction conditions: pressure: 17 MPa; temperature 380°C; space velocity: 1.9 h -1 ;

[0153] The loading amount of the dewaxing catalyst is 4.5% of the volume percentage of the dewaxing reactor;

[0154] S3: Second stage hydrogenation:

[0155] The dewaxing reaction product enters the hydrogenation refining reactor after heat exchange in the heat exchanger; the reaction effluent of the hydrogenation refining reactor directly enters the hot high-pressure separator for gas-liquid separation;

[0156] The reaction conditions are: hydrogen pressure 16MPa; temperature 420℃; hydrogen-oil ratio 1200; volume space velocity 2.0h -1 ;

[0157] The loading amount of the hydrogenation catalyst in the second stage is: 6% of the volume percentage of the hydrogenation supplementary refining reactor;

[0158] S4: atmospheric distillation:

[0159] The hot low-pressure oil and the cold low-pressure oil are mixed and then sent to the atmospheric tower feed heating furnace to be heated to a certain temperature and then sent to the atmospheric tower; the top oil and gas of the tower are cooled to 70°C by the atmospheric tower top air cooler and then sent to the atmospheric tower top reflux tank for gas, oil and water three-phase separation. The bottom oil of the atmospheric tower is pressurized by the atmospheric tower bottom pump and then sent to the vacuum tower feed heating furnace after heat exchange; the top reflux is used as the feed of the stabilization tower and enters the light white oil stabilization tower after heat exchange;

[0160] The reaction conditions are: atmospheric tower pressure is 0.15MP, feed temperature is 320℃;

[0161] S5: Vacuum distillation:

[0162] The bottom oil of the atmospheric tower is heated to 380℃ by the vacuum tower feed heating furnace and enters the vacuum tower. The bottom oil of the vacuum tower is 500N base oil, which is cooled by the 500N base oil product air cooler and sent to the tank area as a product.

[0163] The reaction conditions are: vacuum tower pressure -95 kPa, feed temperature 320 °C.

[0164] The raw material oil is paraffin-based and cycloalkyl-based vacuum wax oil; the distillation range is 560, and the aromatic hydrocarbon content is not more than 30%.

[0165] The vacuum tower is composed of 4 sections of structured packing above the feed, 10 layers of tower trays are arranged below the feed, and the vacuum tower is provided with 3 side line extractions and 1 over-vaporized oil circulation.

[0166] The fourth section of structured packing is an oil absorption section, which is used to remove heavy components in the ascending gas to achieve the separation of 150N base oil and 500N base oil.

[0167] 150N base oil is extracted from the lower part of the third stage filler, and after heat exchange and cooling, it is divided into two streams, one stream is mixed with 500N base oil in a ratio of 1:1 and is discharged from the device as a 350N base oil product, and the other stream is discharged from the device as a 150N base oil product.

[0168] The 60N base oil is extracted from the lower part of the second stage packing and sent to the tank area after cooling.

[0169] The catalyst in the first stage hydrogenation process is a nickel-molybdenum hydrogenation catalyst.

[0170] The dewaxing process catalyst is a palladium catalyst.

[0171] The catalyst for the second stage hydrogenation process can be a nickel-doped palladium / γ-Al2O3 catalyst, and its preparation method is as follows:

[0172] S1: Add 600 kg of deionized water, 5 kg of γ-aminopropyl triethoxysiloxane, and 62 kg of γ-Al2O3 particles into a stirring kettle, stir at 70°C for 10 hours, filter, wash with water, and dry to obtain amino-modified γ-Al2O3.

[0173] S2: Add 170 kg of amino-modified γ-Al2O3, 0.5 kg of stabilizer, 10 kg of nickel acrylate, 8 kg of triethylamine, 1200 kg of methanol, and 6 kg of sodium silicate nonahydrate, mix well, stir at 70° C. for 4 h, then filter and dry to obtain a catalyst carrier;

[0174] S3: Take 1200 kg of methanol solution containing chloropalladic acid and chloroauric acid, wherein the content of palladium in the solution is 5 g / L, the content of gold is 1 g / L, and 130 kg of catalyst carrier, stir at 60°C for 1 hour, then stand for 22 hours, then filter and dry.

[0175] S4: Reduce 200 kg of catalyst precursor in a hydrogen atmosphere with a hydrogen flow rate of 2 BV / hr, a pressure of 1 MPa, a reduction temperature of 155° C., and a reduction time of 4 h. Filter and dry to obtain a palladium catalyst.

[0176] The stabilizer is 3-(dimethylamino)propylimidazole.

[0177] Evaluation of Examples

[0178]

Claims

1. A method for two-stage hydrogenation of environmentally friendly aromatic oil, characterized in that: The following steps are involved: S1: First stage hydrogenation: The crude oil from the tank area is heated by the heat exchanger and then heated to the required temperature by the reaction feed heating furnace before entering the hydroprocessing reactor; the reaction effluent from the bottom of the hydroprocessing reactor is heat exchanged and then enters the high-pressure stripping tower to remove light components and hydrogen sulfide; The reaction conditions of the hydroprocessing reactor are: hydrogen pressure 11-16MPa; temperature 380-420℃; hydrogen-oil ratio 800-1200; volume space velocity 0.8-1.2h -1 ; The loading amount of the hydroprocessing catalyst is 10-15% of the volume percentage of the hydroprocessing reactor; S2: Dewaxing: The liquid phase at the bottom of the high-pressure stripping tower is heat exchanged in the heat exchanger and then passes through the reactor start-up electric heater to enter the dewaxing reactor; The reaction conditions of the dewaxing reactor are: pressure: 13-17 MPa; temperature 320-380°C; space velocity: 1.5-1.9 h -1 ; The loading amount of the dewaxing catalyst is 1.7-4.5% of the volume percentage of the dewaxing reactor; the dewaxing catalyst is a palladium catalyst; S3: Second stage hydrogenation: The dewaxing reaction product enters the hydrogenation refining reactor after heat exchange in the heat exchanger; the reaction effluent of the hydrogenation refining reactor directly enters the hot high-pressure separator for gas-liquid separation; The reaction conditions of the hydrogenation refining reactor are: hydrogen pressure 11-16MPa; temperature 380-420℃; hydrogen-oil ratio 800-1200; volume space velocity 1.6-2.0h -1 ; The loading amount of the hydrorefining catalyst is 2-6% of the volume percentage of the hydrorefining reactor; S4: atmospheric distillation: The hot low-fraction oil is mixed with the cold low-fraction oil and then enters the atmospheric tower feed heating furnace to be heated to a certain temperature and then sent to the atmospheric tower; the atmospheric tower top oil and gas are cooled to 50-70°C by the atmospheric tower top air cooler and then enter the atmospheric tower top reflux tank for gas, oil and water three-phase separation, and the atmospheric tower bottom oil is pressurized by the atmospheric tower bottom pump and then sent to the vacuum tower feed heating furnace after heat exchange; the atmospheric tower top reflux is used as the stabilization tower feed and enters the light white oil stabilization tower after heat exchange; The atmospheric tower pressure is 0.1-0.15MP, and the feed temperature is 300-320℃; S5: Vacuum distillation: The bottom oil of the atmospheric tower is heated to 300-380℃ by the vacuum tower feed heating furnace and enters the vacuum tower. The bottom oil of the vacuum tower is 500N base oil, which is cooled by the 500N base oil product air cooler and sent to the tank area as a product; the vacuum tower pressure is -95kPa, and the feed temperature is 300-320℃; The hydrogenation supplementary refining catalyst is a nickel-doped palladium / γ-Al2O3 catalyst, and its preparation method is as follows: S1: Add 600-700 parts of deionized water, 3-5 parts of γ-aminopropyl triethoxysiloxane, and 50-62 parts of γ-Al2O3 particles in a stirring kettle, stir at 60-70°C for 10-20h, filter, wash with water, and dry to obtain amino-modified γ-Al2O3; S2: Add 150-170 parts of amino-modified γ-Al2O3, 0.03-0.5 parts of stabilizer, 6-10 parts of nickel acrylate, 4-8 parts of triethylamine, 500-1200 parts of methanol, and 3-6 parts of sodium silicate nonahydrate, mix well, stir at 60-70°C for 1-4h, then filter and dry to obtain a catalyst carrier; S3: Take 1000-1200 parts of a methanol solution containing chloropalladic acid and chloroauric acid, wherein the content of palladium in the solution is 2-5 g / L, the content of gold is 0.3-1 g / L, and 100-130 parts of a catalyst carrier, stir at 50-60° C. for 1-4 h, then stand for 18-22 h, then filter and dry to obtain a catalyst precursor; S4: Reduce 110-200 parts of the catalyst precursor in a hydrogen atmosphere at a hydrogen flow rate of 0.5-2BV / hr, a pressure of 0.3-1MPa, a reduction temperature of 120-155°C, and a reduction time of 1-4h, filter, and dry to obtain a nickel-doped palladium / γ-Al2O3 catalyst.

2. A method for two-stage hydrogenation of environmentally friendly aromatic oil as claimed in claim 1, characterized in that: The raw material oil is paraffin-based and cycloalkyl-based vacuum wax oil with a distillation range of 320-560 and an aromatic hydrocarbon content of no more than 30%.

3. A method for two-stage hydrogenation of environmentally friendly aromatic oil as claimed in claim 1, characterized in that: The vacuum tower is composed of 3-6 sections of structured packing above the feed, 7-12 layers of tower trays are arranged below the feed, and the vacuum tower is provided with 3-5 side line extractions and 1-3 over-vaporized oil circulations.

4. A method for two-stage hydrogenation of environmentally friendly aromatic oil as claimed in claim 3, characterized in that: The fourth section of the vacuum tower structured packing is the oil absorption section, which is used to remove the heavy components in the rising gas to achieve the separation of 150N base oil and 500N base oil.

5. A method for two-stage hydrogenation of environmentally friendly aromatic oil as claimed in claim 3, characterized in that: 150N base oil is extracted from the lower part of the structured packing in the third section of the vacuum tower and is divided into two streams after heat exchange and cooling. One stream is mixed with 500N base oil in a ratio of 1:1 and is discharged from the device as a 350N base oil product, and the other stream is discharged from the device as a 150N base oil product.

6. A method for two-stage hydrogenation of environmentally friendly aromatic oil as claimed in claim 3, characterized in that: 60N base oil is extracted from the lower part of the structured packing in the second section of the vacuum tower and sent to the tank area after cooling.

7. A method for two-stage hydrogenation of environmentally friendly aromatic oil as claimed in claim 1, characterized in that: The hydroprocessing catalyst is a nickel-molybdenum hydrogenation catalyst.

8. The method for two-stage hydrogenation of environmentally friendly aromatic oil according to claim 1, characterized in that: The stabilizer is one or more of 2,4,6-trimethylpyridine, N,N-dimethyl-4-aminopyridine, N,N'-dimethylpiperazine, and 3-(dimethylamino)propylimidazole.

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