A method for two-stage hydrogenation and dewaxing of environmentally friendly aromatic oil

Abstract

The invention discloses a two-stage hydrogenation and dewaxing method for environmentally friendly aromatic oil. The invention adopts two-stage hydrogenation and adds a dewaxing step between the two stages. In the dewaxing step, a nickel-doped platinum / γ-Al2O3 catalyst is prepared, the dewaxing efficiency in the dewaxing step is improved, the aromatic loss is reduced, the viscosity of the product is slightly affected, the prepared environmentally friendly aromatic oil product has high purity and better quality, and the catalyst has a long service life.

Description

Technical Field

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

[0002] Aromatic oil, also known as aromatic hydrocarbons or aromatics, refers to hydrocarbons containing a benzene ring structure in the molecule. It is one of the basic products and basic raw materials of petrochemical industry. Aromatic oil has good rubber compatibility, high temperature resistance, low volatility and other characteristics. It can significantly improve the processing performance of rubber, enhance the resistance of rubber products to weathering, oxidation, friction and aging, and help mix and disperse fillers in rubber. It is widely used in industries such as recycled rubber and various rubber products.

[0003] Traditional aromatic oil contains a large amount of polycyclic aromatic hydrocarbons. Due to the introduction of aromatic oil, tires and rubber products contain polycyclic aromatic hydrocarbons to a greater or lesser extent. However, some polycyclic aromatic hydrocarbons have been scientifically proven 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. With the improvement of people's awareness of the hazards of polycyclic aromatic hydrocarbons and environmental awareness, Western developed countries have taken a series of measures to reduce the emission of polycyclic aromatic hydrocarbons to reduce their harm to human health and the environment.

[0004] CN102311784A discloses a method for producing environmentally friendly aromatic oil by hydroprocessing. Raw oil and hydrogen are sequentially passed through a hydroprocessing reforming reaction zone and a hydrorefining reaction zone under hydroprocessing conditions. The hydroprocessing reforming reaction zone uses a hydroprocessing reforming catalyst containing amorphous silica-alumina and modified Y zeolite.

[0005] CN201811652326.7 applied for a combined method for producing lubricating base oil and environmentally friendly aromatic oil. The API I lubricating base oil with very low polycyclic aromatic content produced by the "old three sets" process is subjected to solvent extraction, and the extraction depth is controlled to further reduce the aromatics in the residual oil; then it is subjected to hydrorefining and hydromodification to improve the color and stability, increase the viscosity index, and reach the API III lubricating base oil index; at the same time, aromatics are enriched in the extracted oil, so that the polycyclic aromatic content in the extracted oil is <3.0%, and the aromatic content is >20%, and excellent rubber filling oil for the tire industry is obtained.

[0006] However, the existing environmentally friendly aromatic oil preparation technology scheme will lose more aromatics in order to reduce polycyclic aromatics to meet environmental quality indicators. 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

[0007] In order to solve the above technical problems, the present invention provides a method for two-stage hydrogenation and dewaxing of environmentally friendly aromatic oil, which belongs to the technical field of environmentally friendly aromatic oil preparation.

[0008] A method for two-stage hydrogenation and dewaxing of environmentally friendly aromatic oil, the specific method comprising the following steps:

[0009] Step 1: The crude oil from the tank farm passes through the crude oil / 150N base oil heat exchanger, then passes through the dewaxing product / hydroprocessing feed heat exchanger, the hydroprocessing product / hydroprocessing feed heat exchanger, and then is heated to the required reaction temperature by the reaction feed heating furnace before entering the hydroprocessing reactor;

[0010] Step 2: The reaction effluent from the bottom of the reactor is heat exchanged in the hydroprocessing product / dewaxing feed heat exchanger and then enters the high-pressure stripping tower to remove light components and hydrogen sulfide;

[0011] Step 3: The liquid phase at the bottom of the high-pressure stripping tower passes through the dewaxing product / dewaxing feed heat exchanger and the hydroprocessing product / dewaxing feed heat exchanger for heat exchange, and then passes through the reactor start-up electric heater to enter the dewaxing reactor. The dewaxing reaction product passes through the dewaxing product / dewaxing feed heat exchanger and the dewaxing product / hydroprocessing feed heat exchanger in turn for heat exchange and then enters the hydrogenation supplementary refining reactor;

[0012] Step 4: The reaction effluent of the hydrogenation supplementary refining reactor directly enters the hot high-pressure separator for gas-liquid separation, the hot high-fraction gas enters the high-pressure stripping tower to strip the hydrotreatment reaction effluent, the hot high-fraction oil enters the hot low-pressure separator under liquid level control, the high-pressure stripping tower top gas passes through the high-pressure stripping tower top gas / dewaxing mixed hydrogen heat exchanger and the hot high-fraction gas air cooler in turn and is cooled to 50-70°C and enters the cold high-pressure separator for oil, gas and water three-phase separation;

[0013] Step 5: The hot low-fraction oil and the cold low-fraction oil are mixed and then enter 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°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 gas phase is compressed by the low-pressure tail gas compressor and combined with the cold low-fraction gas to be sent to the desulfurization part. The water phase is pressurized by the acid water pump and enters the sulfur-containing wastewater flash tank. The oil phase is pressurized by the crude naphtha pump and is divided into two streams, one as the top reflux and the other as the stabilization tower feed. After heat exchange in the light white oil / stabilization tower feed heat exchanger, it enters the light white oil stabilization tower;

[0014] Step 6: The bottom oil of the atmospheric tower is heated to 355-365℃ 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 divided into two parts. One part is sent to the tank area as a product, and the other part is mixed with 150N base oil in a ratio of 1:1 as a 350N base oil product and sent to the tank area.

[0015] As a further supplement, the process also includes a light white oil stabilization step: crude naphtha from the atmospheric tower top reflux pump is used as the feed of the light white oil stabilization tower, and is heat exchanged to 140-160°C by the light white oil / stabilization tower feed heat exchanger before entering the light white oil stabilization tower; the top gas of the stabilization tower is cooled to 35-45°C by the stabilization tower top water cooler and then enters the stabilization tower top reflux tank for gas, oil and water three-phase separation; the gas phase goes to the desulfurization part, and the oil phase is pressurized by the stabilization tower top reflux pump and all is used as the top reflux; the sulfur-containing wastewater enters the sulfur-containing wastewater flash tank; the bottom oil of the light white oil stabilization tower is the light white oil product, which is cooled to 35-45°C by the light white oil / stabilization tower feed heat exchanger, the light white oil air cooler and the light white oil water cooler and then sent to the tank area.

[0016] As a further supplement, the process also includes a solvent regeneration step: the rich amine liquid is heat exchanged to 96-98°C by a lean-rich solvent primary heat exchanger, and then enters a solvent regeneration tower; the top gas of the solvent regeneration tower is cooled by an air cooler at the top of the solvent regeneration tower and a water cooler at the top of the solvent regeneration tower, and then enters an acid gas separator tank; the high-concentration acid gas poured out of the top is sent to a sulfur recovery device under pressure control; the lean amine liquid at the bottom of the regeneration tower is cooled to 50-55°C by a lean liquid air cooler, and then enters a solvent buffer tank, and then enters the reaction part after being pressurized by a low-pressure lean solvent pump.

[0017] As a further supplement, the reaction conditions of the first step are: hydrogen pressure 11-16 MPa, temperature 380-420°C, hydrogen-to-oil ratio 800-1200, volume space velocity 0.8-1.2 h -1 .

[0018] As a further supplement, the loading amount of the hydrogenation catalyst is: 10-15% of the volume percentage of the hydroprocessing reactor; the hydrogenation catalyst is a nickel-molybdenum hydrogenation catalyst.

[0019] As a further supplement, the raw material oil is paraffin-based and cycloalkyl vacuum wax oil with a distillation range of 320-560 and an aromatic hydrocarbon content of no more than 30%.

[0020] As a further supplement, the reaction conditions of the third step are: pressure: 13-17 MPa, temperature 320-380°C, space velocity: 1.5-1.9 h -1 .

[0021] As a further supplement, the loading amount of the dewaxing catalyst is 1.7-4.5% of the volume percentage of the dewaxing reactor.

[0022] As a further supplement, the reaction conditions of the fourth step are: hydrogen pressure 11-16 MPa, temperature 380-420°C, hydrogen-to-oil ratio 800-1200, volume space velocity 1.6-2.0 h -1 .

[0023] As a further supplement, the loading amount of the catalyst in the hydrogenation supplementary refining reactor is: 2-6% of the volume percentage of the hydrogenation supplementary refining reactor; the hydrogenation catalyst is a palladium catalyst.

[0024] As a further supplement, the reaction conditions of the fifth step are: the atmospheric tower pressure is 0.1-0.15MP, and the feed temperature is 300-320°C.

[0025] As a further supplement, the reaction conditions of the sixth step are: vacuum tower pressure -95kpa, feed temperature 300-320°C.

[0026] As a further supplement, the dewaxing catalyst in the third step is a nickel-doped platinum / γ-Al2O3 catalyst, and its preparation method is as follows:

[0027] S1: Add 500-600 parts of deionized water, 4-8 parts of mercaptosiloxane, and 80-90 parts of γ-Al2O3 particles in a stirring kettle by weight, stir at 60-70°C for 10-20h, filter, wash and dry to obtain mercapto-modified γ-Al2O3;

[0028] S2: Add 100-120 parts of thiol-modified γ-Al2O3, 0.06-1.5 parts of mercaptoacetamide, 11-15 parts of nickel acrylate, 3-5 parts of triethylamine, 500-700 parts of toluene, and 2-5 parts of sodium silicate nonahydrate, mix well, stir at 80-90° C. for 1-5 hours, then filter and dry to obtain a catalyst carrier;

[0029] S3: Take 600-800 parts of a methanol solution containing chloroplatinic acid and chloroauric acid, wherein the content of platinum in the solution is 2-6 g / L, the content of gold is 0.5-3 g / L, and 100-120 parts of a catalyst carrier, stir at 50-60° C. for 1-4 h, then stand for 18-22 h, then filter and dry;

[0030] S4: Reduce 100-120 parts of the catalyst precursor in a hydrogen atmosphere at a hydrogen flow rate of 0.5-2 BV / hr, a pressure of 0.5-1.1 MPa, a reduction temperature of 120-135° C., and a reduction time of 1-3 h, filter, and dry to obtain a platinum catalyst.

[0031] As a further supplement, the mercaptosiloxane is selected from one or a combination of 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane and mercaptopropylmethyldimethoxysilane.

[0032] Compared with the prior art, the production method of environmentally friendly aromatic oil of the present invention prepares a nickel-doped platinum / γ-Al2O3 catalyst, which improves the dewaxing efficiency in the dewaxing step, reduces aromatic losses, and has little effect on the viscosity of the product. The prepared environmentally friendly aromatic oil product has high purity and better quality, and the catalyst has a long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is the process flow chart of the environmentally friendly aromatic oil hydrogenation unit. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with specific embodiments. These embodiments are only used to illustrate the present invention and cannot limit the scope of protection of the present invention.

[0035] Embodiment 1:

[0036] A method for two-stage hydrogenation and dewaxing of environmentally friendly aromatic oil, the specific method comprising the following steps:

[0037] Step 1: The crude oil from the tank farm passes through the crude oil / 150N base oil heat exchanger, then passes through the dewaxing product / hydroprocessing feed heat exchanger, the hydroprocessing product / hydroprocessing feed heat exchanger, and then is heated to the required reaction temperature by the reaction feed heating furnace before entering the hydroprocessing reactor;

[0038] Step 2: The reaction effluent from the bottom of the reactor is heat exchanged in the hydroprocessing product / dewaxing feed heat exchanger and then enters the high-pressure stripping tower to remove light components and hydrogen sulfide;

[0039] Step 3: The liquid phase at the bottom of the high-pressure stripping tower passes through the dewaxing product / dewaxing feed heat exchanger and the hydroprocessing product / dewaxing feed heat exchanger for heat exchange, and then passes through the reactor start-up electric heater to enter the dewaxing reactor. The dewaxing reaction product passes through the dewaxing product / dewaxing feed heat exchanger and the dewaxing product / hydroprocessing feed heat exchanger in turn for heat exchange and then enters the hydrogenation supplementary refining reactor;

[0040] Step 4: The reaction effluent of the hydrogenation supplementary refining reactor directly enters the hot high-pressure separator for gas-liquid separation, the hot high-fraction gas enters the high-pressure stripping tower to strip the hydrotreatment reaction effluent, the hot high-fraction oil enters the hot low-pressure separator under liquid level control, the high-pressure stripping tower top gas passes through the high-pressure stripping tower top gas / dewaxing mixed hydrogen heat exchanger and the hot high-fraction gas air cooler in turn, cooled to 50°C, and enters the cold high-pressure separator for oil, gas and water three-phase separation;

[0041] Step 5: The hot low-fraction oil and the cold low-fraction oil are mixed and then enter 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 gas phase is compressed by the low-pressure tail gas compressor and combined with the cold low-fraction gas to be sent to the desulfurization part. The water phase is pressurized by the acid water pump and enters the sulfur-containing wastewater flash tank. The oil phase is pressurized by the crude naphtha pump and is divided into two streams, one as the top reflux and the other as the stabilization tower feed. After heat exchange in the light white oil / stabilization tower feed heat exchanger, it enters the light white oil stabilization tower;

[0042] Step 6: The bottom oil of the atmospheric tower is heated to 355℃ by the vacuum tower feed heating furnace and enters the vacuum tower. The bottom oil of the vacuum tower is 500N base oil. It is cooled by the 500N base oil product air cooler and divided into two parts. One part is sent to the tank area as a product, and the other part is mixed with 150N base oil in a ratio of 1:1 as a 350N base oil product and sent to the tank area.

[0043] It also includes a light white oil stabilization step: crude naphtha from the atmospheric tower top reflux pump is used as the light white oil stabilization tower feed, and enters the light white oil stabilization tower after being heat exchanged to 140°C by the light white oil / stabilization tower feed heat exchanger; the top gas of the stabilization tower is cooled to 35°C by the stabilization tower top water cooler and then enters the stabilization tower top reflux tank for gas, oil and water three-phase separation; the gas phase goes to the desulfurization part, and the oil phase is pressurized by the stabilization tower top reflux pump and all is used as the top reflux; the sulfur-containing wastewater enters the sulfur-containing wastewater flash tank; the bottom oil of the light white oil stabilization tower is the light white oil product, which is cooled to 35°C by the light white oil / stabilization tower feed heat exchanger, the light white oil air cooler and the light white oil water cooler and then sent to the tank area.

[0044] The process also includes a solvent regeneration step: the rich amine liquid is heat exchanged to 96°C by a lean-rich solvent primary heat exchanger and then enters a solvent regeneration tower; the top gas of the solvent regeneration tower is cooled by an air cooler at the top of the solvent regeneration tower and a water cooler at the top of the solvent regeneration tower and then enters an acid gas separator tank; the high-concentration acid gas poured out of the top is sent to a sulfur recovery device under pressure control; the lean amine liquid at the bottom of the regeneration tower is cooled to 50°C by a lean liquid air cooler and then enters a solvent buffer tank, and then enters a reaction part after being pressurized by a low-pressure lean solvent pump.

[0045] The reaction conditions of the first step are: hydrogen pressure 11 MPa, temperature 380°C, hydrogen-to-oil ratio 800, volume space velocity 0.8 h -1 .

[0046] The loading amount of the hydrogenation catalyst is: 10% of the volume percentage of the hydrogenation treatment reactor; the hydrogenation catalyst is a nickel-molybdenum hydrogenation catalyst.

[0047] The raw material oil is paraffin-based and cycloalkyl-based vacuum wax oil, with a distillation range of 320 and an aromatic hydrocarbon content of no more than 30%.

[0048] The reaction conditions of the third step are: pressure: 13 MPa, temperature 320°C, space velocity: 1.5 h -1 .

[0049] The loading amount of the dewaxing catalyst is 1.7% of the volume percentage of the dewaxing reactor.

[0050] The reaction conditions of the fourth step are: hydrogen pressure 11 MPa, temperature 380°C, hydrogen-to-oil ratio 800, volume space velocity 1.6 h -1 .

[0051] The loading amount of the catalyst in the hydrogenation supplementary refining reactor is: 2% of the volume percentage of the hydrogenation supplementary refining reactor; the hydrogenation catalyst is a palladium catalyst.

[0052] The reaction conditions of the fifth step are: the atmospheric tower pressure is 0.1MP, and the feed temperature is 300°C.

[0053] The reaction conditions of the sixth step are: vacuum tower pressure -95kpa, feed temperature 300°C.

[0054] The dewaxing catalyst in the third step is a nickel-doped platinum / γ-Al2O3 catalyst, and its preparation method is as follows:

[0055] S1: Add 500 kg of deionized water, 4 kg of mercaptosiloxane, and 80 kg of γ-Al2O3 particles into a stirring kettle, stir at 60°C for 20 h, filter, wash and dry to obtain mercapto-modified γ-Al2O3;

[0056] S2: Add 100 kg of thiol-modified γ-Al2O3, 0.06 kg of mercaptoacetamide, 11 kg of nickel acrylate, 3 kg of triethylamine, 500 kg of toluene, and 2 kg of sodium silicate nonahydrate, mix well, stir at 80°C for 5 hours, then filter and dry to obtain a catalyst carrier;

[0057] S3: Take 600 kg of methanol solution containing chloroplatinic acid and chloroauric acid, wherein the content of platinum in the solution is 2 g / L, the content of gold is 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;

[0058] S4: Reduce 100 kg of catalyst precursor in a hydrogen atmosphere with a hydrogen flow rate of 0.5 BV / hr, a pressure of 0.5 MPa, a reduction temperature of 120° C., and a reduction time of 1 h. Filter and dry to obtain a platinum catalyst.

[0059] The mercaptosiloxane is 3-mercaptopropyltriethoxysilane.

[0060] Example 2

[0061] A method for two-stage hydrogenation and dewaxing of environmentally friendly aromatic oil, the specific method comprising the following steps:

[0062] Step 1: The crude oil from the tank farm passes through the crude oil / 150N base oil heat exchanger, then passes through the dewaxing product / hydroprocessing feed heat exchanger, the hydroprocessing product / hydroprocessing feed heat exchanger, and then is heated to the required reaction temperature by the reaction feed heating furnace before entering the hydroprocessing reactor;

[0063] Step 2: The reaction effluent from the bottom of the reactor is heat exchanged in the hydroprocessing product / dewaxing feed heat exchanger and then enters the high-pressure stripping tower to remove light components and hydrogen sulfide;

[0064] Step 3: The liquid phase at the bottom of the high-pressure stripping tower passes through the dewaxing product / dewaxing feed heat exchanger and the hydroprocessing product / dewaxing feed heat exchanger for heat exchange, and then passes through the reactor start-up electric heater to enter the dewaxing reactor. The dewaxing reaction product passes through the dewaxing product / dewaxing feed heat exchanger and the dewaxing product / hydroprocessing feed heat exchanger in turn for heat exchange and then enters the hydrogenation supplementary refining reactor;

[0065] Step 4: The reaction effluent of the hydrogenation supplementary refining reactor directly enters the hot high-pressure separator for gas-liquid separation, the hot high-fraction gas enters the high-pressure stripping tower to strip the hydrotreatment reaction effluent, the hot high-fraction oil enters the hot low-pressure separator under liquid level control, the high-pressure stripping tower top gas passes through the high-pressure stripping tower top gas / dewaxing mixed hydrogen heat exchanger and the hot high-fraction gas air cooler in turn and is cooled to 56°C before entering the cold high-pressure separator for oil, gas and water three-phase separation;

[0066] Step 5: The hot low-fraction oil and the cold low-fraction oil are mixed and then enter 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 56°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 gas phase is compressed by the low-pressure tail gas compressor and combined with the cold low-fraction gas to be sent to the desulfurization part. The water phase is pressurized by the acid water pump and enters the sulfur-containing wastewater flash tank. The oil phase is pressurized by the crude naphtha pump and is divided into two streams, one as the top reflux and the other as the stabilization tower feed. After heat exchange in the light white oil / stabilization tower feed heat exchanger, it enters the light white oil stabilization tower;

[0067] Step 6: The bottom oil of the atmospheric tower is heated to 360℃ by the vacuum tower feed heating furnace and enters the vacuum tower. The bottom oil of the vacuum tower is 500N base oil. It is cooled by the 500N base oil product air cooler and divided into two parts. One part is sent to the tank area as a product, and the other part is mixed with 150N base oil in a ratio of 1:1 as a 350N base oil product and sent to the tank area.

[0068] It also includes a light white oil stabilization step: crude naphtha from the atmospheric tower top reflux pump is used as the light white oil stabilization tower feed, and is heat exchanged to 145°C by the light white oil / stabilization tower feed heat exchanger before entering the light white oil stabilization tower, the top gas of the stabilization tower is cooled to 40°C by the stabilization tower top water cooler and then enters the stabilization tower top reflux tank for gas, oil and water three-phase separation, the gas phase goes to the desulfurization part, the oil phase is pressurized by the stabilization tower top reflux pump and all is used as the top reflux, the sulfur-containing wastewater enters the sulfur-containing wastewater flash tank, the bottom oil of the light white oil stabilization tower is the light white oil product, which is cooled to 40°C by the light white oil / stabilization tower feed heat exchanger, the light white oil air cooler and the light white oil water cooler and then sent to the tank area.

[0069] The process also includes a solvent regeneration step: the rich amine liquid is heat exchanged to 96°C by a lean-rich solvent primary heat exchanger and then enters a solvent regeneration tower; the top gas of the solvent regeneration tower is cooled by an air cooler at the top of the solvent regeneration tower and a water cooler at the top of the solvent regeneration tower and then enters an acid gas separator tank; the high-concentration acid gas poured out of the top is sent to a sulfur recovery device under pressure control; the lean amine liquid at the bottom of the regeneration tower is cooled to 50°C by a lean liquid air cooler and then enters a solvent buffer tank, and then enters a reaction part after being pressurized by a low-pressure lean solvent pump.

[0070] The reaction conditions of the first step are: hydrogen pressure 13 MPa, temperature 390°C, hydrogen-to-oil ratio 900, volume space velocity 0.9 h -1 .

[0071] The loading amount of the hydrogenation catalyst is: 12% of the volume percentage of the hydrogenation treatment reactor; the hydrogenation catalyst is a nickel-molybdenum hydrogenation catalyst.

[0072] The raw material oil is paraffin-based and cycloalkyl-based vacuum wax oil, with a distillation range of 380 and an aromatic hydrocarbon content of no more than 30%.

[0073] The reaction conditions of the third step are: pressure: 14 MPa, temperature 340°C, space velocity: 1.6 h -1 .

[0074] The loading amount of the dewaxing catalyst is 2.3% of the volume percentage of the dewaxing reactor.

[0075] The reaction conditions of the fourth step are: hydrogen pressure 13 MPa, temperature 390°C, hydrogen-to-oil ratio 900, volume space velocity 1.7 h -1 .

[0076] The loading amount of the catalyst in the hydrogenation supplementary refining reactor is: 3% of the volume percentage of the hydrogenation supplementary refining reactor; the hydrogenation catalyst is a palladium catalyst.

[0077] The reaction conditions of the fifth step are: the atmospheric tower pressure is 0.12MP, and the feed temperature is 300°C.

[0078] The reaction conditions of the sixth step are: vacuum tower pressure -95kpa, feed temperature 300°C.

[0079] The dewaxing catalyst in the third step is a nickel-doped platinum / γ-Al2O3 catalyst, and its preparation method is as follows:

[0080] S1: Add 520 kg of deionized water, 5 kg of mercaptosiloxane, and 80 kg of γ-Al2O3 particles into a stirring kettle, stir at 60°C for 18 h, filter, wash and dry to obtain mercapto-modified γ-Al2O3;

[0081] S2: Add 105 kg of thiol-modified γ-Al2O3, 0.30 kg of mercaptoacetamide, 12 kg of nickel acrylate, 4 g of triethylamine, 600 kg of toluene, and 3 kg of sodium silicate nonahydrate, mix well, stir at 80°C for 4 hours, then filter and dry to obtain a catalyst carrier;

[0082] S3: Take 700 kg of methanol solution containing chloroplatinic acid and chloroauric acid, wherein the content of platinum in the solution is 3 g / L, the content of gold is 2 g / L, and 110 kg of catalyst carrier, stir at 55°C for 3 h, then stand for 20 h, then filter and dry;

[0083] S4: Reduce 110 kg of catalyst precursor in a hydrogen atmosphere at a hydrogen flow rate of 1.0 BV / hr, a pressure of 0.7 MPa, a reduction temperature of 125° C., and a reduction time of 2 h. Filter and dry to obtain a platinum catalyst.

[0084] The mercaptosiloxane is 3-mercaptopropyltrimethoxysilane.

[0085] Example 3

[0086] A method for two-stage hydrogenation and dewaxing of environmentally friendly aromatic oil, the specific method comprising the following steps:

[0087] Step 1: The crude oil from the tank farm passes through the crude oil / 150N base oil heat exchanger, then passes through the dewaxing product / hydroprocessing feed heat exchanger, the hydroprocessing product / hydroprocessing feed heat exchanger, and then is heated to the required reaction temperature by the reaction feed heating furnace before entering the hydroprocessing reactor;

[0088] Step 2: The reaction effluent from the bottom of the reactor is heat exchanged in the hydroprocessing product / dewaxing feed heat exchanger and then enters the high-pressure stripping tower to remove light components and hydrogen sulfide;

[0089] Step 3: The liquid phase at the bottom of the high-pressure stripping tower passes through the dewaxing product / dewaxing feed heat exchanger and the hydroprocessing product / dewaxing feed heat exchanger for heat exchange, and then passes through the reactor start-up electric heater to enter the dewaxing reactor. The dewaxing reaction product passes through the dewaxing product / dewaxing feed heat exchanger and the dewaxing product / hydroprocessing feed heat exchanger in turn for heat exchange and then enters the hydrogenation supplementary refining reactor;

[0090] Step 4: The reaction effluent of the hydrogenation supplementary refining reactor directly enters the hot high-pressure separator for gas-liquid separation, the hot high-fraction gas enters the high-pressure stripping tower to strip the hydrotreatment reaction effluent, the hot high-fraction oil enters the hot low-pressure separator under liquid level control, the high-pressure stripping tower top gas passes through the high-pressure stripping tower top gas / dewaxing mixed hydrogen heat exchanger and the hot high-fraction gas air cooler in turn, cooled to 60°C, and enters the cold high-pressure separator for oil, gas and water three-phase separation;

[0091] Step 5: The hot low-fraction oil and the cold low-fraction oil are mixed and then enter 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 gas phase is compressed by the low-pressure tail gas compressor and combined with the cold low-fraction gas to be sent to the desulfurization part. The water phase is pressurized by the acid water pump and enters the sulfur-containing wastewater flash tank. The oil phase is pressurized by the crude naphtha pump and is divided into two streams, one as the top reflux and the other as the stabilization tower feed. After heat exchange in the light white oil / stabilization tower feed heat exchanger, it enters the light white oil stabilization tower;

[0092] Step 6: The bottom oil of the atmospheric tower is heated to 360℃ by the vacuum tower feed heating furnace and enters the vacuum tower. The bottom oil of the vacuum tower is 500N base oil. It is cooled by the 500N base oil product air cooler and divided into two parts. One part is sent to the tank area as a product, and the other part is mixed with 150N base oil in a ratio of 1:1 as a 350N base oil product and sent to the tank area.

[0093] It also includes a light white oil stabilization step: crude naphtha from the atmospheric tower top reflux pump is used as a light white oil stabilization tower feed, and is heat exchanged to 150°C by a light white oil / stabilization tower feed heat exchanger before entering the light white oil stabilization tower, the top gas of the stabilization tower is cooled to 40°C by a stabilization tower top water cooler, and then enters a stabilization tower top reflux tank for gas, oil and water three-phase separation, the gas phase goes to the desulfurization part, the oil phase is pressurized by the stabilization tower top reflux pump and all is used as the top reflux, the sulfur-containing wastewater enters the sulfur-containing wastewater flash tank, the bottom oil of the light white oil stabilization tower is the light white oil product, which is cooled to 40°C by a light white oil / stabilization tower feed heat exchanger, a light white oil air cooler, and a light white oil water cooler, and then sent to the tank area.

[0094] The process also includes a solvent regeneration step: the rich amine liquid is heat exchanged to 97°C by a lean-rich solvent primary heat exchanger and then enters a solvent regeneration tower; the top gas of the solvent regeneration tower is cooled by an air cooler at the top of the solvent regeneration tower and a water cooler at the top of the solvent regeneration tower and then enters an acid gas separator tank; the high-concentration acid gas poured out of the top is sent to a sulfur recovery device under pressure control; the lean amine liquid at the bottom of the regeneration tower is cooled to 52°C by a lean liquid air cooler and then enters a solvent buffer tank, and then enters the reaction part after being pressurized by a low-pressure lean solvent pump.

[0095] The reaction conditions of the first step are: hydrogen pressure 14 MPa, temperature 400°C, hydrogen-to-oil ratio 1100, volume space velocity 1.1 h -1 .

[0096] The loading amount of the hydrogenation catalyst is: 14% of the volume percentage of the hydrogenation treatment reactor; the hydrogenation catalyst is a nickel-molybdenum hydrogenation catalyst.

[0097] The raw material oil is paraffin-based and cycloalkyl vacuum wax oil, with a distillation range of 480 and an aromatic hydrocarbon content of no more than 30%.

[0098] The reaction conditions of the third step are: pressure: 16 MPa, temperature 360°C, space velocity: 1.7 h -1 .

[0099] The loading amount of the dewaxing catalyst is 3.6% of the volume percentage of the dewaxing reactor.

[0100] The reaction conditions of the fourth step are: hydrogen pressure 15 MPa, temperature 410°C, hydrogen-to-oil ratio 1100, volume space velocity 1.9 h -1 .

[0101] The loading amount of the catalyst in the hydrogenation supplementary refining reactor is: 5% of the volume percentage of the hydrogenation supplementary refining reactor; the hydrogenation catalyst is a palladium catalyst.

[0102] The reaction conditions of the fifth step are: the atmospheric tower pressure is 0.14MP, and the feed temperature is 310°C.

[0103] The reaction conditions of the sixth step are: vacuum tower pressure -95 kPa, feed temperature 310°C.

[0104] The dewaxing catalyst in the third step is a nickel-doped platinum / γ-Al2O3 catalyst, and its preparation method is as follows:

[0105] S1: Add 550 kg of deionized water, 7 kg of mercaptosiloxane, and 85 kg of γ-Al2O3 particles into a stirring kettle, stir at 70°C for 10 h, filter, wash and dry to obtain mercapto-modified γ-Al2O3;

[0106] S2: Add 110 kg of thiol-modified γ-Al2O3, 0.9 kg of mercaptoacetamide, 14 kg of nickel acrylate, 4 kg of triethylamine, 650 kg of toluene, and 4 kg of sodium silicate nonahydrate, mix well, stir at 90°C for 3 h, then filter and dry to obtain a catalyst carrier;

[0107] S3: Take 800 kg of methanol solution containing chloroplatinic acid and chloroauric acid, wherein the content of platinum in the solution is 5 g / L, the content of gold is 1 g / L, and 110 kg of catalyst carrier, stir at 55°C for 3 h, then stand for 20 h, then filter and dry;

[0108] S4: Reduce 110 kg of catalyst precursor in a hydrogen atmosphere with a hydrogen flow rate of 1.5 BV / hr, a pressure of 0.9 MPa, a reduction temperature of 130° C., and a reduction time of 3 h. Filter and dry to obtain a platinum catalyst.

[0109] The mercaptosiloxane is mercaptopropylmethyldimethoxy.

[0110] Example 4

[0111] A method for two-stage hydrogenation and dewaxing of environmentally friendly aromatic oil, the specific method comprising the following steps:

[0112] Step 1: The crude oil from the tank farm passes through the crude oil / 150N base oil heat exchanger, then passes through the dewaxing product / hydroprocessing feed heat exchanger, the hydroprocessing product / hydroprocessing feed heat exchanger, and then is heated to the required reaction temperature by the reaction feed heating furnace before entering the hydroprocessing reactor;

[0113] Step 2: The reaction effluent from the bottom of the reactor is heat exchanged in the hydroprocessing product / dewaxing feed heat exchanger and then enters the high-pressure stripping tower to remove light components and hydrogen sulfide;

[0114] Step 3: The liquid phase at the bottom of the high-pressure stripping tower passes through the dewaxing product / dewaxing feed heat exchanger and the hydroprocessing product / dewaxing feed heat exchanger for heat exchange, and then passes through the reactor start-up electric heater to enter the dewaxing reactor. The dewaxing reaction product passes through the dewaxing product / dewaxing feed heat exchanger and the dewaxing product / hydroprocessing feed heat exchanger in turn for heat exchange and then enters the hydrogenation supplementary refining reactor;

[0115] Step 4: The reaction effluent of the hydrogenation supplementary refining reactor directly enters the hot high-pressure separator for gas-liquid separation, the hot high-fraction gas enters the high-pressure stripping tower to strip the hydrotreatment reaction effluent, the hot high-fraction oil enters the hot low-pressure separator under liquid level control, the high-pressure stripping tower top gas passes through the high-pressure stripping tower top gas / dewaxing mixed hydrogen heat exchanger and the hot high-fraction gas air cooler in turn and is cooled to 70°C before entering the cold high-pressure separator for oil, gas and water three-phase separation;

[0116] Step 5: The hot low-fraction oil and the cold low-fraction oil are mixed and then enter 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 enter the atmospheric tower top reflux tank for gas, oil and water three-phase separation. The gas phase is compressed by the low-pressure tail gas compressor and combined with the cold low-fraction gas to be sent to the desulfurization part. The water phase is pressurized by the acid water pump and enters the sulfur-containing wastewater flash tank. The oil phase is pressurized by the crude naphtha pump and is divided into two streams, one as the top reflux and the other as the stabilization tower feed. After heat exchange in the light white oil / stabilization tower feed heat exchanger, it enters the light white oil stabilization tower;

[0117] Step 6: The bottom oil of the atmospheric tower is heated to 365℃ by the vacuum tower feed heating furnace and enters the vacuum tower. The bottom oil of the vacuum tower is 500N base oil. It is cooled by the 500N base oil product air cooler and divided into two parts. One part is sent to the tank area as a product, and the other part is mixed with 150N base oil in a ratio of 1:1 as a 350N base oil product and sent to the tank area.

[0118] It also includes a light white oil stabilization step: crude naphtha from the atmospheric tower top reflux pump is used as a light white oil stabilization tower feed, and is heat exchanged to 160°C by a light white oil / stabilization tower feed heat exchanger before entering the light white oil stabilization tower, the top gas of the stabilization tower is cooled to 45°C by a stabilization tower top water cooler, and then enters a stabilization tower top reflux tank for gas, oil and water three-phase separation, the gas phase goes to the desulfurization part, the oil phase is pressurized by the stabilization tower top reflux pump and all is used as the top reflux, the sulfur-containing wastewater enters the sulfur-containing wastewater flash tank, the bottom oil of the light white oil stabilization tower is the light white oil product, which is cooled to 45°C by a light white oil / stabilization tower feed heat exchanger, a light white oil air cooler, and a light white oil water cooler, and then sent to the tank area.

[0119] The process also includes a solvent regeneration step: the rich amine liquid is heat exchanged to 98°C by a lean-rich solvent primary heat exchanger and then enters a solvent regeneration tower; the top gas of the solvent regeneration tower is cooled by an air cooler at the top of the solvent regeneration tower and a water cooler at the top of the solvent regeneration tower and then enters an acid gas separator tank; the high-concentration acid gas poured out of the top is sent to a sulfur recovery device under pressure control; the lean amine liquid at the bottom of the regeneration tower is cooled to 55°C by a lean liquid air cooler and then enters a solvent buffer tank, and then enters a reaction part after being pressurized by a low-pressure lean solvent pump.

[0120] The reaction conditions of the first step are: hydrogen pressure 16 MPa, temperature 420°C, hydrogen-to-oil ratio 1200, volume space velocity 1.2 h -1 .

[0121] The loading amount of the hydrogenation catalyst is: 15% of the volume percentage of the hydrogenation treatment reactor; the hydrogenation catalyst is a nickel-molybdenum hydrogenation catalyst.

[0122] The raw material oil is paraffin-based and cycloalkyl vacuum wax oil, with a distillation range of 560 and an aromatic hydrocarbon content of no more than 30%.

[0123] The reaction conditions of the third step are: pressure: 17 MPa, temperature 380°C, space velocity: 1.9 h -1 .

[0124] The loading amount of the dewaxing catalyst is 4.5% of the volume percentage of the dewaxing reactor.

[0125] The reaction conditions of the fourth step are: hydrogen pressure 16 MPa, temperature 420°C, hydrogen-to-oil ratio 1200, volume space velocity 2.0 h -1 .

[0126] The loading amount of the catalyst in the hydrogenation supplementary refining reactor is: 6% of the volume percentage of the hydrogenation supplementary refining reactor; the hydrogenation catalyst is a palladium catalyst.

[0127] The reaction conditions of the fifth step are: the atmospheric tower pressure is 0.15MP, and the feed temperature is 320°C.

[0128] The reaction conditions of the sixth step are: vacuum tower pressure -95 kPa, feed temperature 320°C.

[0129] The dewaxing catalyst in the third step is a nickel-doped platinum / γ-Al2O3 catalyst, and its preparation method is as follows:

[0130] S1: Add 600 kg of deionized water, 8 kg of mercaptosiloxane, and 90 kg of γ-Al2O3 particles into a stirring kettle, stir at 70°C for 16 h, filter, wash and dry to obtain mercapto-modified γ-Al2O3;

[0131] S2: Add 120 kg of thiol-modified γ-Al2O3, 1.5 kg of mercaptoacetamide, 15 kg of nickel acrylate, 5 kg of triethylamine, 700 kg of toluene, and 5 kg of sodium silicate nonahydrate, mix well, stir at 90°C for 4 hours, then filter and dry to obtain a catalyst carrier;

[0132] S3: Take 800 kg of methanol solution containing chloroplatinic acid and chloroauric acid, wherein the content of platinum in the solution is 6 g / L, the content of gold is 0.5 g / L, and 120 kg of catalyst carrier, stir at 60°C for 4 h, then stand for 18 h, then filter and dry;

[0133] S4: Reduce 120 kg of catalyst precursor in a hydrogen atmosphere at a hydrogen flow rate of 2 BV / hr, a pressure of 1.1 MPa, a reduction temperature of 135° C., and a reduction time of 3 h. Filter and dry to obtain a platinum catalyst.

[0134] The mercaptosiloxane is 3-mercaptopropyltriethoxysilane.

[0135] Comparative Example

[0136] A method for two-stage hydrogenation and dewaxing of environmentally friendly aromatic oil, the specific method comprising the following steps:

[0137] Step 1: The crude oil from the tank farm passes through the crude oil / 150N base oil heat exchanger, then passes through the dewaxing product / hydroprocessing feed heat exchanger, the hydroprocessing product / hydroprocessing feed heat exchanger, and then is heated to the required reaction temperature by the reaction feed heating furnace before entering the hydroprocessing reactor;

[0138] Step 2: The reaction effluent from the bottom of the reactor is heat exchanged in the hydroprocessing product / dewaxing feed heat exchanger and then enters the high-pressure stripping tower to remove light components and hydrogen sulfide;

[0139] Step 3: The liquid phase at the bottom of the high-pressure stripping tower passes through the dewaxing product / dewaxing feed heat exchanger and the hydroprocessing product / dewaxing feed heat exchanger for heat exchange, and then passes through the reactor start-up electric heater to enter the dewaxing reactor. The dewaxing reaction product passes through the dewaxing product / dewaxing feed heat exchanger and the dewaxing product / hydroprocessing feed heat exchanger in turn for heat exchange and then enters the hydrogenation supplementary refining reactor;

[0140] Step 4: The reaction effluent of the hydrogenation supplementary refining reactor directly enters the hot high-pressure separator for gas-liquid separation, the hot high-fraction gas enters the high-pressure stripping tower to strip the hydrotreatment reaction effluent, the hot high-fraction oil enters the hot low-pressure separator under liquid level control, the high-pressure stripping tower top gas passes through the high-pressure stripping tower top gas / dewaxing mixed hydrogen heat exchanger and the hot high-fraction gas air cooler in turn, cooled to 50°C, and enters the cold high-pressure separator for oil, gas and water three-phase separation;

[0141] Step 5: The hot low-fraction oil and the cold low-fraction oil are mixed and then enter 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 gas phase is compressed by the low-pressure tail gas compressor and combined with the cold low-fraction gas to be sent to the desulfurization part. The water phase is pressurized by the acid water pump and enters the sulfur-containing wastewater flash tank. The oil phase is pressurized by the crude naphtha pump and is divided into two streams, one as the top reflux and the other as the stabilization tower feed. After heat exchange in the light white oil / stabilization tower feed heat exchanger, it enters the light white oil stabilization tower;

[0142] Step 6: The bottom oil of the atmospheric tower is heated to 355℃ by the vacuum tower feed heating furnace and enters the vacuum tower. The bottom oil of the vacuum tower is 500N base oil. It is cooled by the 500N base oil product air cooler and divided into two parts. One part is sent to the tank area as a product, and the other part is mixed with 150N base oil in a ratio of 1:1 as a 350N base oil product and sent to the tank area.

[0143] It also includes a light white oil stabilization step: crude naphtha from the atmospheric tower top reflux pump is used as the light white oil stabilization tower feed, and enters the light white oil stabilization tower after being heat exchanged to 140°C by the light white oil / stabilization tower feed heat exchanger; the top gas of the stabilization tower is cooled to 35°C by the stabilization tower top water cooler and then enters the stabilization tower top reflux tank for gas, oil and water three-phase separation; the gas phase goes to the desulfurization part, and the oil phase is pressurized by the stabilization tower top reflux pump and all is used as the top reflux; the sulfur-containing wastewater enters the sulfur-containing wastewater flash tank; the bottom oil of the light white oil stabilization tower is the light white oil product, which is cooled to 35°C by the light white oil / stabilization tower feed heat exchanger, the light white oil air cooler and the light white oil water cooler and then sent to the tank area.

[0144] The process also includes a solvent regeneration step: the rich amine liquid is heat exchanged to 96°C by a lean-rich solvent primary heat exchanger and then enters a solvent regeneration tower; the top gas of the solvent regeneration tower is cooled by an air cooler at the top of the solvent regeneration tower and a water cooler at the top of the solvent regeneration tower and then enters an acid gas separator tank; the high-concentration acid gas poured out of the top is sent to a sulfur recovery device under pressure control; the lean amine liquid at the bottom of the regeneration tower is cooled to 50°C by a lean liquid air cooler and then enters a solvent buffer tank, and then enters a reaction part after being pressurized by a low-pressure lean solvent pump.

[0145] The reaction conditions of the first step are: hydrogen pressure 11 MPa, temperature 380°C, hydrogen-to-oil ratio 800, volume space velocity 0.8 h -1 .

[0146] The loading amount of the hydrogenation catalyst is: 10% of the volume percentage of the hydrogenation treatment reactor; the hydrogenation catalyst is a nickel-molybdenum hydrogenation catalyst.

[0147] The raw material oil is paraffin-based and cycloalkyl-based vacuum wax oil, with a distillation range of 320 and an aromatic hydrocarbon content of no more than 30%.

[0148] The reaction conditions of the third step are: pressure: 13 MPa, temperature 320°C, space velocity: 1.5 h -1 .

[0149] The reaction conditions of the fourth step are: hydrogen pressure 11 MPa, temperature 380°C, hydrogen-to-oil ratio 800, volume space velocity 1.6 h -1 .

[0150] The loading amount of the catalyst in the hydrogenation supplementary refining reactor is: 2% of the volume percentage of the hydrogenation supplementary refining reactor; the hydrogenation catalyst is a palladium catalyst.

[0151] The reaction conditions of the fifth step are: the atmospheric tower pressure is 0.1MP, and the feed temperature is 300°C.

[0152] The reaction conditions of the sixth step are: vacuum tower pressure -95kpa, feed temperature 300°C.

[0153] Evaluation of Examples

[0154] The results of the analysis of the crude oil used in the examples of the present invention and the comparative examples are as follows:

[0155] Analyze Project Test methods Analyze the results Density (20℃)kg / m3 GB / T1884 920.6 Kinematic viscosity mm2 / s 40℃ GB / T265 36.07 Kinematic viscosity mm2 / s 100℃ GB / T265 5.46 Sulfur content (m / m)% GB / T17040 2.05 Chlorine content mg / kg ASTM D7536 1.2 Aromatic content (m / m) % SH / T0725 25 Saturated hydrocarbons (m / m)% SH / T0725 75 Acid value mg(KOH) / g GB / T7304 0.39

[0156] Example and comparative example Environmentally friendly aromatic oil analysis test results:

[0157]

[0158]

Claims

1. A method for two-stage hydrogenation and dewaxing of environmentally friendly aromatic oil, comprising the following steps: Step 1: The crude oil from the tank farm passes through the crude oil / 150N base oil heat exchanger, then passes through the dewaxing product / hydroprocessing feed heat exchanger, the hydroprocessing product / hydroprocessing feed heat exchanger, and then is heated to the required reaction temperature by the reaction feed heating furnace before entering the hydroprocessing reactor; Step 2: The reaction effluent from the bottom of the hydroprocessing reactor is heat exchanged in the hydroprocessing product / dewaxing feed heat exchanger and then enters the high-pressure stripping tower to remove light components and hydrogen sulfide; Step 3: The liquid phase at the bottom of the high-pressure stripping tower passes through the dewaxing product / dewaxing feed heat exchanger and the hydroprocessing product / dewaxing feed heat exchanger for heat exchange, and then passes through the reactor start-up electric heater to enter the dewaxing reactor. The dewaxing reaction product passes through the dewaxing product / dewaxing feed heat exchanger and the dewaxing product / hydroprocessing feed heat exchanger in turn for heat exchange and then enters the hydrogenation supplementary refining reactor; Step 4: The reaction effluent of the hydrogenation supplementary refining reactor directly enters the hot high-pressure separator for gas-liquid separation, and obtains hot high-fraction oil and hot high-fraction gas. The hot high-fraction gas enters the high-pressure stripping tower for stripping, and the hot high-fraction oil enters the hot low-pressure separator under liquid level control. The top gas of the high-pressure stripping tower passes through the high-pressure stripping tower top gas / dewaxing mixed hydrogen heat exchanger and the hot high-fraction gas air cooler in turn, and is cooled to 50-70°C and enters the cold high-pressure separator for oil, gas and water three-phase separation. Step 5: The hot low-fraction oil and the cold low-fraction oil are mixed and then enter 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. The gas phase in the atmospheric tower top reflux tank three-phase separation is compressed by the low-pressure tail gas compressor and combined with the cold low-fraction gas to be sent to the desulfurization part. The water phase in the atmospheric tower top reflux tank three-phase separation is pressurized by the acidic water pump and enters the sulfur-containing wastewater flash tank. The oil phase in the atmospheric tower top reflux tank three-phase separation is pressurized by the crude naphtha pump and is divided into two streams, one as the atmospheric tower top reflux, and the other as the light white oil stabilization tower feed and enters the light white oil stabilization tower after heat exchange in the light white oil / stabilization tower feed heat exchanger; Step 6: The bottom oil of the atmospheric tower is heated to 355-365℃ by the vacuum tower feed heating furnace and enters the vacuum tower. The bottom oil of the vacuum tower is 500N base oil. It is cooled by the 500N base oil product air cooler and divided into two parts. One part is sent to the tank area as a product, and the other part is mixed with 150N base oil in a ratio of 1:1 as a 350N base oil product and sent to the tank area; The reaction conditions of the hydroprocessing reactor are: hydrogen pressure 11-16 MPa, temperature 380-420°C, hydrogen-to-oil ratio 800-1200, volume space velocity 0.8-1.2 h -1 ; The loading amount of the hydrotreating catalyst is 10-15% of the volume percentage content of the hydrotreating reactor; the hydrotreating catalyst is a nickel-molybdenum hydrogenation catalyst; the feedstock is a paraffinic and cycloalkyl vacuum wax oil, a distillation range of 320-560, aromatic hydrocarbons not more than 30%; The loading amount of the dewaxing catalyst is 1.7-4.5% of the volume percentage content of the dewaxing reactor; The loading amount of the catalyst in the hydrofining reactor is 2-6% of the volume percentage of the hydrofining reactor; the hydrofining catalyst is a palladium catalyst; The dewaxing catalyst is a nickel-doped platinum / γ-Al2O3 catalyst, and its preparation method is as follows: S1: Add 500-600 parts of deionized water, 4-8 parts of mercaptosiloxane, and 80-90 parts of γ-Al2O3 particles in a stirring kettle by weight, stir at 60-70°C for 10-20h, filter, wash and dry to obtain mercapto-modified γ-Al2O3; S2: Add 100-120 parts of thiol-modified γ-Al2O3, 0.06-1.5 parts of mercaptoacetamide, 11-15 parts of nickel acrylate, 3-5 parts of triethylamine, 500-700 parts of toluene, and 2-5 parts of sodium silicate nonahydrate, mix well, stir at 80-90°C for 1-5h, then filter and dry to obtain a catalyst carrier; S3: Take 600-800 parts of a methanol solution containing chloroplatinic acid and chloroauric acid, wherein the content of platinum in the solution is 2-6 g / L, the content of gold is 0.5-3 g / L, and 100-120 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: 100-120 parts of the catalyst precursor are reduced in a hydrogen atmosphere at a hydrogen flow rate of 0.5-2BV / hr, a pressure of 0.5-1.1MPa, a reduction temperature of 120-135°C, a reduction time of 1-3h, filtered, and dried to obtain a nickel-doped platinum / γ-Al2O3 catalyst; The mercaptosiloxane is selected from one or a combination of 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane and mercaptopropylmethyldimethoxysilane.

2. The method for two-stage hydrogenation and dewaxing of environmentally friendly aromatic oil according to claim 1, characterized in that: The process also includes a light white oil stabilization step: crude naphtha from a reflux pump at the top of an atmospheric tower is used as feed to a light white oil stabilization tower, and is heat exchanged to 140-160° C. by a light white oil / stabilization tower feed heat exchanger before entering the light white oil stabilization tower; the top gas of the light white oil stabilization tower is cooled to 35-45° C. by a water cooler at the top of the stabilization tower, and then enters a reflux tank at the top of the stabilization tower for separation of gas, oil and water; the gas phase of the three-phase separation is sent to the desulfurization part, and the oil phase is pressurized by a reflux pump at the top of the stabilization tower, and all of them are used as top reflux of the light white oil stabilization tower, and sulfur-containing wastewater enters a flash tank for sulfur-containing wastewater; the bottom oil of the light white oil stabilization tower is a light white oil product, and is cooled to 35-45° C. by a light white oil / stabilization tower feed heat exchanger, a light white oil air cooler and a light white oil water cooler, and then is sent to a tank area.

3. The method for two-stage hydrogenation and dewaxing of environmentally friendly aromatic oil according to claim 1, characterized in that: The atmospheric tower pressure is 0.1-0.15MP, and the feed temperature is 300-320℃.

4. The method for two-stage hydrogenation and dewaxing of environmentally friendly aromatic oil according to claim 1, characterized in that: Vacuum tower pressure -95kpa.

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