A hydrogenation process and system for animal and vegetable oils

Abstract

This invention discloses a hydrogenation process and system for animal and vegetable oils. The process includes the following steps: 1) Animal and vegetable oil raw materials are mixed with hydrogen and then fed into a fluidized bed hydrogenation reactor for reaction. The reaction effluent is separated to obtain gaseous and liquid phase effluents; 2) The liquid phase effluent obtained in step 1) is processed in a purification unit to obtain purified oil; 3) The purified oil obtained in step 2) is fed into a hydrorefining reactor for hydrorefining reaction. The reaction effluent is fractionated to obtain jet fuel and biodiesel. The hydrogenation process provided by this invention, combined with the characteristics of hydrogenation of animal and vegetable oils, offers a highly efficient technical route for the hydrogenation of animal and vegetable oils to produce biodiesel.

Description

Technical Field

[0001] This invention pertains to renewable energy processing methods, specifically a hydrogenation process, particularly a hydrogenation process for producing high-quality biodiesel and jet fuel using animal and vegetable oils as raw materials and employing reactors such as fluidized beds. Background Technology

[0002] Animal and vegetable oils originate from plants, animals, or microorganisms and are renewable resources. Especially in today's era of advocating green energy and a circular economy, the comprehensive utilization of animal and vegetable oils has gained attention from refining technology patent holders worldwide. Animal and vegetable oils are characterized by high impurity content, high oxygen content, high metal content, and the presence of unsaturated double bonds. Traditional fixed-bed hydrogenation technology for processing these oils presents several problems: complex pretreatment processes require sophisticated systems to meet downstream fixed-bed processing requirements, resulting in high energy consumption and investment costs; fixed-bed operation has high energy consumption due to the large heat release during hydrogenation, necessitating large circulation ratios for feedstock dilution, leading to high unit operation energy consumption and a large number of beds in the fixed-bed reactor; biological feedstocks are prone to polymerization reactions, easily causing coking and blockage of heat exchangers; furthermore, the water generated during hydrogenation is prone to pulverization, causing increased bed pressure drop and hindering long-term operation.

[0003] Patents CN112592739A and CN112410053A respectively describe a combined process for producing biodiesel from animal and vegetable oils using a fluidized bed reactor as a pre-hydrogenation reactor. In patent CN112592739A, animal and vegetable oils are mixed with hydrogen, heated, and mixed with a liquid catalyst before entering the fluidized bed reactor for hydrogenation saturation and deoxygenation reactions. The liquid phase product from the hydrogenation reaction enters a vacuum fractionation system for fractionation. The light components and middle fractions are used as feedstock for downstream fixed-bed hydrorefining units to produce biodiesel, while the tailings are disposed of as road asphalt additives. In patent CN112410053A, oil-based feedstocks undergo a pre-hydrogenation process using an upflow reactor. The liquid phase product from the reaction enters a vacuum distillation tower for fractionation to obtain light and heavy intermediate products. Part of the heavy intermediate product is recycled back to the feedstock system, and the other part is disposed of as asphalt. Studies have shown that the average carbon number of animal and vegetable oils is C17-C19. After deoxygenation through hydrotreating, the average carbon number is C16-C18, resulting in a very concentrated distillation range. Except for possible mechanical impurities, all oil fractions can be used as feedstock for downstream deep hydrorefining and hydrocracking. In the patents mentioned above that use upflow reactors as pretreatment reactors, all of them employ vacuum fractionation to process the pretreated oil. While removing impurities, this inevitably leads to oil loss. Furthermore, to ensure the fractionation effect of the fractionation system, it is necessary to set up an atmospheric pressure tower feed heater and a vacuum furnace, which results in high overall energy consumption of the unit and is not conducive to improving the overall economic efficiency of the unit.

[0004] Therefore, from the perspective of improving liquid yield and reducing energy consumption of the equipment, it is necessary to improve the existing process technology or catalyst system. Summary of the Invention

[0005] The inventors discovered that existing technologies all involve cutting and discarding the tail oil after pre-hydrogenation of animal and vegetable oils, resulting in significant liquid yield loss and high energy consumption. To address these shortcomings, this invention, through studying the changing reaction patterns of animal and vegetable oil hydrogenation, proposes a hydrogenation process and system for animal and vegetable oils. This process, tailored to the characteristics of animal and vegetable oil hydrogenation, provides a highly efficient technical route for the hydrogenation of animal and vegetable oils to produce biodiesel.

[0006] The first aspect of this invention provides a hydrogenation process for animal and vegetable oils, the process comprising the following:

[0007] 1) Animal and vegetable oil raw materials are mixed with hydrogen and then enter the fluidized bed hydrogenation reaction unit for reaction. The reaction effluent is separated to obtain gas phase and liquid phase effluent.

[0008] 2) The liquid effluent obtained in step 1) enters the purification unit for processing to obtain purified oil;

[0009] 3) The purified oil obtained in step 2) enters the hydrorefining reaction unit for hydrorefining reaction, and the reaction effluent is fractionated to obtain jet fuel and biodiesel.

[0010] Furthermore, in the above-mentioned hydrogenation process for animal and vegetable oils, in step 1), the animal and vegetable oil raw materials are at least one of soybean oil, palm oil, rapeseed oil, micro-animal and vegetable oils, and animal fats.

[0011] Furthermore, in the above-mentioned hydrogenation process for animal and vegetable oils, in step 1), the animal and vegetable oil raw materials are pretreated and then mixed with hydrogen before entering the fluidized bed hydrogenation reaction unit for reaction. The main purpose of the pretreatment is to remove solid impurities and moisture from the raw materials. The pretreatment process includes desolidification and dehydration. The desolidification and dehydration processes can be carried out using any means available on the market that can achieve the above objectives. The desolidification process can be carried out using one or more of the following: centrifugal separation, static sedimentation separation, filtration separation, cyclone separation, and inorganic membrane filtration. The dehydration process can be carried out using one or more of the following: flash dehydration, coalescence dehydration, and adsorbent adsorption dehydration.

[0012] Furthermore, in the above-mentioned hydrogenation process for animal and vegetable oils, in step 1), the fluidized bed hydrogenation reaction unit can be equipped with one fluidized bed reactor or two or more fluidized bed reactors; the fluidized bed reactor can be one or more of a boiling bed reactor and a slurry bed reactor.

[0013] Furthermore, in the above-mentioned hydrogenation process for animal and vegetable oils, in step 1), the mixing of the animal and vegetable oil raw materials with hydrogen can be carried out by pre-furnace hydrogen mixing or post-furnace hydrogen mixing, preferably post-furnace hydrogen mixing; the specific process of post-furnace hydrogen mixing is as follows: after heat exchange, the animal and vegetable oil raw materials are mixed with hot hydrogen obtained by heating in a hydrogen heating furnace.

[0014] Furthermore, in the above-mentioned hydrogenation process for animal and vegetable oils, in step 1), the fluidized bed hydrogenation reaction unit is loaded with a hydrogenation catalyst. The hydrogenation catalyst includes a support and an active component. The support includes alumina, and the active component is selected from Group VIII and / or Group VIB metals, preferably Mo and / or Ni. When both Mo and Ni are included, the mass content of the active component Mo is not less than 6.0% (based on oxides), and the mass content of the active component Ni is not less than 2.0% (based on oxides). The specific surface area of ​​the hydrogenation catalyst is not less than 160 m². 2 / g, pore volume not less than 0.42cm 3 / g, bulk density not less than 0.8g / cm³ 3 The pore size is not less than 12 nm. The hydrogenation catalyst can be either the FEC-10 catalyst or the FFT-1B catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.

[0015] Furthermore, in the above-mentioned hydrogenation process for animal and vegetable oils, in step 1), the operating conditions of the fluidized bed hydrogenation reaction unit are: reaction pressure 2~18MPa, reaction temperature 250~400℃, and volume hourly space velocity 0.1~2.0h. -1 The hydrogen-to-oil volume ratio is 200-1000; preferred operating conditions are: reaction pressure 4-10 MPa, reaction temperature 300-360℃, and volume hourly space velocity 0.2-1.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 300-800.

[0016] Furthermore, in the above-mentioned hydrogenation process for animal and vegetable oils, in step 2), the purification unit includes a primary purification unit and a secondary purification unit; the liquid effluent obtained in step 1) enters the primary purification unit for processing to obtain primary purified oil; the primary purified oil is mixed with hydrogen and then enters the secondary purification unit to obtain secondary purified oil.

[0017] Furthermore, in the above-mentioned hydrogenation process of animal and vegetable oils, in step 2), the liquid effluent obtained in step 1) is treated by a primary purification unit to remove catalyst powder. The primary purification unit can be any equipment in the art capable of solid-liquid separation, such as a filter, centrifuge, or settling device. Specifically, in this invention, if a filter is used, the filter screen size is no greater than 0.25 mm; if a centrifuge is used, the centrifuge speed must be no less than 2500 r / min, the centrifugation time no less than 10 min, and the corresponding operating temperature no less than 80°C; if a settling device is used, the settling temperature must be no less than 100°C, and the settling time no less than 30 min.

[0018] Furthermore, in the aforementioned hydrogenation process for animal and vegetable oils, in step 2), the secondary purification unit can employ a membrane separation device, which includes a filter medium with a pore size of 10 nm to 100 nm. The primary purified oil and hydrogen pass through the filter medium in a mixed or separate manner under pressure differential. Filtered impurities remain on one side, while the purified oil and hydrogen enter the other side, resulting in secondary purified oil under high pressure differential and nanopore size. The secondary purified oil comprises an oil phase and hydrogen, which exist in emulsion form. The secondary purification unit achieves deep desolidification of the purified oil and, through the membrane separation device, ensures uniform dispersion and thorough mixing of the oil phase and hydrogen.

[0019] Furthermore, in the above-mentioned hydrogenation process for animal and vegetable oils, in step 2), the operating conditions of the secondary purification unit are as follows: operating pressure 0.1~8.0MPa, operating temperature 50~280℃, and volume ratio of primary purified oil to hydrogen 80~300; preferably, the operating pressure is 0.5~6.0MPa, the operating temperature is 80~200℃, and the volume ratio of primary purified oil to hydrogen is 120~250.

[0020] Furthermore, in the above-mentioned hydrogenation process for animal and vegetable oils, in step 3), the hydrogenation refining reaction unit is equipped with at least one hydrogenation refining reactor; the hydrogenation refining reactor can be a traditional fixed-bed feed reactor or a bottom-feed upflow reactor.

[0021] Furthermore, in the above-mentioned hydrogenation process for animal and vegetable oils, in step 3), the hydrogenation refining reaction unit typically includes 1 to 6 catalyst beds, preferably 2 to 4 catalyst beds. The hydrogenation refining catalyst packed in the hydrogenation refining reaction unit can be a conventional hydrogenation refining catalyst in the art, wherein the active metal of the hydrogenation refining catalyst can be one or more of nickel, cobalt, molybdenum, and tungsten, with the following weight percentages: nickel and / or cobalt 0.1% to 12% (based on oxides), molybdenum and / or tungsten 5% to 15% (based on oxides); the support can be one or more of alumina, silica, alumina-silica, or titanium dioxide. The bulk density of the hydrogenation refining catalyst is 0.4 to 0.9 g / cm³. 3 Specific surface area is 100-200 m² 2 / g.

[0022] Furthermore, in the above-mentioned hydrogenation process for animal and vegetable oils, in step 3), the operating conditions of the hydrogenation refining reaction unit are as follows: reaction pressure 2~18MPa, reaction temperature 250~400℃, and volume hourly space velocity 0.5~3.0h. -1 The hydrogen-to-oil volume ratio is 500-1800; the preferred operating conditions are as follows: reaction pressure 6-12 MPa, reaction temperature 300-360℃, and volume hourly space velocity 1.0-1.8 h⁻¹. -1 The hydrogen-to-oil volume ratio is 800-1500.

[0023] A second aspect of the present invention provides a hydrogenation treatment system for animal and vegetable oils, comprising:

[0024] The fluidized bed hydrogenation reaction unit is used to receive animal and vegetable oil raw materials, and to react them under the action of hydrogen and hydrogenation catalyst. The reaction effluent is processed by the separation unit to obtain gas phase and liquid phase effluent.

[0025] The purification unit is used to receive the liquid effluent from the fluidized bed hydrogenation reaction unit and purify it to obtain purified oil.

[0026] The hydrorefining reaction unit receives purified oil from the purification unit and reacts it under the action of hydrogen and hydrorefining catalyst. The reaction effluent is then processed by the separation unit to obtain the target product.

[0027] Furthermore, in the above-mentioned hydrogenation treatment system for animal and vegetable oils, the fluidized bed hydrogenation reaction unit is equipped with a pretreatment device, which includes a desolidification device and a dehydration device. The desolidification device can be one or more of a centrifuge, a settling device, a filter, a hydrocyclone separator, and an inorganic membrane filter, and the dehydration device can be one or more of a flash tank, a coalescing dehydration filter, and an adsorption dehydration device.

[0028] Furthermore, in the aforementioned hydrogenation system for animal and vegetable oils, the fluidized bed hydrogenation reaction unit is equipped with at least one fluidized bed reactor; the fluidized bed reactor is a boiling bed reactor and / or a slurry bed reactor; the boiling bed reactor is a boiling bed reactor with a built-in three-phase separator developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd., the boiling bed reactor is divided into a straight section, a variable diameter section and an enlarged section, wherein the straight section is an empty cylinder without internal components, the enlarged section contains a separator for gas, liquid and solid three-phase separation, the three-phase separator divides the enlarged section into an inner ring, a middle ring and an outer ring, the gas, liquid and solid phases first enter the inner ring, the gas flashes and escapes from the top of the reactor, the liquid and solid phases enter the middle ring zone, the solid returns to the main reaction zone of the reactor through the feed port at the bottom of the middle ring zone, and the liquid phase enters the outer ring and flows out of the reactor through the liquid phase extraction port of the outer ring.

[0029] Furthermore, in the aforementioned animal and vegetable oil hydrogenation system, the fluidized bed hydrogenation reaction unit is equipped with a hydrogen heater and a start-up furnace. After heat exchange, the animal and vegetable oil feedstocks are mixed with hot hydrogen obtained from the hydrogen heater before entering the fluidized bed reactor. The fluidized bed hydrogenation reaction unit does not have a feedstock heater; the start-up furnace is only used during start-up sulfidation, which minimizes the risk of coking of the animal and vegetable oil feedstocks in the heat exchange system.

[0030] Furthermore, in the above-mentioned hydrogenation treatment system for animal and vegetable oils, the separation unit includes a gas-liquid separation unit and a fractionation unit. The gas-liquid separation unit includes a hot high-pressure separator, a cold high-pressure separator, a hot low-pressure separator, and a cold low-pressure separator; the fractionation unit includes a fractionation tower.

[0031] Furthermore, in the aforementioned hydrogenation treatment system for animal and vegetable oils, the purification unit includes:

[0032] The primary purification unit is used to receive the liquid effluent from the fluidized bed hydrogenation reaction unit and obtain primary purified oil through desolidification treatment;

[0033] The secondary purification unit receives hydrogen and primary purified oil from the primary purification unit. The hydrogen and primary purified oil undergo deep desolidification and oil-gas mixing under pressure difference to obtain secondary purified oil.

[0034] Furthermore, in the above-mentioned hydrogenation treatment system for animal and vegetable oils, the primary purification unit is equipped with at least one solid-liquid separation device, which is at least one of a filter, a centrifuge, or a settling device; the secondary purification unit is equipped with at least one membrane separation device, which contains a filter medium with a pore size of 10nm to 100nm.

[0035] Furthermore, in the above-mentioned hydrogenation treatment system for animal and vegetable oils, the hydrogenation refining reaction unit is equipped with at least one hydrogenation refining reactor, preferably 1 to 2 hydrogenation refining reactors are connected in series.

[0036] Compared with the prior art, the advantages of the present invention are as follows:

[0037] (1) The present invention develops a purification unit to replace the traditional fractionation operation, which can significantly reduce the energy consumption of the device while improving the liquid yield;

[0038] (2) The present invention develops a two-stage purification unit process. In the second-stage purification unit, the oil phase is deeply purified by means of a high-precision filter medium. On the other hand, under the action of high pressure difference, hydrogen is dispersed in the oil in the form of nano-sized microbubbles, which greatly increases the hydrogen content in the purified oil. Compared with the traditional hydrogen dissolution technology, the dissolved hydrogen in the oil is increased by more than 200%, which can meet the hydrogen consumption needs of the subsequent hydrogenation reaction. The circulating hydrogen compressor required for the subsequent hydrogenation refining reaction unit can be eliminated, which greatly reduces energy consumption. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of a hydrogenation process for animal and vegetable oils.

[0040] Among them, 1-hydrogen heater, 2-fluidized bed reactor, 3-hot high-pressure separator, 4-hot low-pressure separator, 5-primary purification unit, 6-secondary purification unit, 7-circulating hydrogen compressor, 8-feed heater for hydrorefining reactor, 9-hydrorefining reactor, 10-fractionation tower, 21-animal and vegetable oil raw materials, 22-discharged solids and moisture, 23-mixed hydrogen, 24-pretreated animal and vegetable oil raw materials, 25-gas phase effluent from fluidized bed reaction, 26-liquid phase effluent from fluidized bed reaction, 27-high-pressure gas, 28-hot high-pressure oil, 29-hot low-pressure gas, 30-hot low-pressure oil, 31-primary solid slag, 32-secondary solid slag, 33-secondary purified oil, 34-hot feed to refining reactor, 35-product of refining reactor, 36-jet fuel, 37-biodiesel, 38-new hydrogen. Implementation

[0041] The method provided by the present invention will now be described with reference to the accompanying drawings.

[0042] Animal and vegetable oil raw materials 21 enter the pretreatment unit, where solids and water 22 are removed to obtain pretreated animal and vegetable oil raw materials 24. The pretreated animal and vegetable oil raw materials 24 are mixed with hot hydrogen obtained from hydrogen heating furnace 1 and fed into fluidized bed reactor 2. Under the action of a catalyst and hydrogen, a hydrogenation reaction is carried out. The reaction effluent is separated to obtain gaseous effluent 25 and liquid effluent 26. Liquid effluent 26 enters the thermal high-efficiency separator 3, where it is separated to obtain thermal high-efficiency gas 27 and thermal high-efficiency oil 28. Gaseous effluent 25 and thermal high-efficiency gas 27 are mixed, pressurized by a circulating hydrogen compressor, and then mixed with fresh hydrogen to obtain mixed hydrogen 23, which is then recycled to the fluidized bed hydrogenation reaction. Unit: Hot high-temperature oil 28 enters the hot low-temperature separator 4 for separation to obtain hot low-temperature gas 29 and hot low-temperature oil 30. The hot low-temperature oil enters the primary purification unit 5 to obtain primary solid slag 31 and primary purified oil. The primary purified oil is mixed with hydrogen 39 and enters the secondary purification unit 6 to obtain secondary solid slag 32 and secondary purified oil 33. The primary solid slag 31 and secondary solid slag 32 are mixed and enter the solid slag storage tank 11 and then discharged. The secondary purified oil 33 is heated by the feed heater 8 of the hydrorefining reactor and then enters the hydrorefining reactor 9 for deep refining under the action of the hydrorefining catalyst. The hydrorefining reaction product 35 enters the fractionation tower 10 for fractionation to obtain jet fuel 36 and biodiesel 37.

[0043] The following embodiments will further illustrate the method provided by the present invention, but do not limit the present invention.

[0044] The specific properties of the animal and vegetable oil raw materials used in the embodiments and comparative examples of this invention are shown in Table 1.

[0045] The fluidized bed hydrogenation reaction unit of this invention includes a fluidized bed reactor, which is a fluidized bed hydrogenation reactor with a built-in three-phase separator developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd. The fluidized bed hydrogenation catalyst is a commercially available FES-30 microsphere fluidized bed hydrogenation catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd. The hydrorefining reaction unit includes a hydrorefining reactor with three catalyst beds, and the hydrorefining catalyst used is a commercially available FF-66 hydrogenation catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.

[0046] Table 1. Properties of Raw Materials

[0047]

[0048] Example 1

[0049] Using the method of this invention, the raw material first enters the pretreatment unit. Deconsolidation in the pretreatment unit is performed by centrifugation under the following conditions: centrifuge speed 2800 r / min, centrifugation time 10 min, centrifugation temperature 85℃. Dehydration is performed by flash evaporation at a temperature of 102℃ and a pressure of 90 kPa. The pretreated raw material then enters a fluidized bed reactor. The operating conditions of the fluidized bed reactor are: reaction pressure 5 MPa, reaction temperature 310℃, and volume hourly space velocity 0.8 h⁻¹. -1 The hydrogen-to-oil volume ratio is 400. The liquid effluent from the fluidized bed reactor enters the primary purification unit, which uses a 0.25mm filter. The primary purified oil is mixed with fresh hydrogen and enters the secondary purification unit, which uses a membrane separation device with a ceramic membrane as the filter medium. The pore size of the filter medium is 20nm-40nm-80nm from the outside to the inside. The hydrogen-to-primary purified oil volume ratio is 150. The operating pressure of the secondary purification unit is 2.0MPa, and the operating temperature is 100℃. The secondary purified oil is heated in a heater and then enters the refining reactor. The operating conditions of the refining reactor are: reaction pressure 7MPa, reaction temperature 330℃, and volume hourly space velocity 1.6h⁻¹. -1 The hydrogen-to-oil volume ratio was 1000, and the reaction products entered the fractionation system to obtain jet fuel and biodiesel. Specific experimental results are shown in Tables 2 and 3.

[0050] Example 2

[0051] Using the method of this invention, the raw material first enters the pretreatment unit. Deconsolidation in the pretreatment unit is performed by centrifugation under the following conditions: centrifuge speed 3000 r / min, centrifugation time 12 min, centrifugation temperature 90℃; dehydration is performed by flash evaporation at a temperature of 105℃ and a pressure of 85 kPa; the pretreated raw material then enters a fluidized bed reactor. The operating conditions of the fluidized bed reactor are: reaction pressure 7 MPa, reaction temperature 330℃, and volume hourly space velocity 0.5 h⁻¹. -1 The hydrogen-to-oil volume ratio is 600. The liquid effluent from the fluidized bed reactor enters the primary purification unit, which uses centrifugation at 2800 r / min for 12 min at an operating temperature of 85℃. The secondary purification unit uses a membrane separation device with a ceramic membrane as the filter medium, with pore sizes of 30nm-50nm-70nm from the outside in. The hydrogen-to-primary purified oil volume ratio is 180. The secondary purification unit operates at a pressure of 4.0 MPa and a temperature of 120℃. The secondary purified oil is heated in a furnace before entering the refining reactor, which operates at a pressure of 9 MPa, a temperature of 340℃, and a volume hourly space velocity (VHSV) of 1.4 h⁻¹. -1 The hydrogen-to-oil volume ratio was 1200, and the reaction products entered the fractionation system to obtain jet fuel and biodiesel. Specific experimental results are shown in Tables 2 and 3.

[0052] Example 3

[0053] Using the method of this invention, the raw material first enters the pretreatment unit. Deconsolidation in the pretreatment unit is performed by centrifugation under the following conditions: centrifuge speed 3200 r / min, centrifugation time 15 min, centrifugation temperature 90℃. Dehydration is performed by flash evaporation at a temperature of 108℃ and a pressure of 85 kPa. The pretreated raw material then enters a fluidized bed reactor. The operating conditions of the fluidized bed reactor are: reaction pressure 9 MPa, reaction temperature 350℃, and volume hourly space velocity 0.3 h⁻¹. -1 The hydrogen-to-oil volume ratio is 700. The liquid effluent from the fluidized bed reactor enters the primary purification unit, which uses a static sedimentation method at a settling temperature of 110℃ for 30 minutes. The primary purified oil is then mixed with fresh hydrogen and enters the secondary purification unit at a hydrogen-to-primary purified oil volume ratio of 200. The secondary purification unit uses a membrane separation device with sintered metal wire as the filter medium, with pore sizes ranging from 10nm to 30nm to 50nm from the outside in. The secondary purification unit operates at a pressure of 6.0MPa and a temperature of 180℃. The secondary purified oil is heated in a furnace before entering the refining reactor, which operates at a pressure of 11MPa, a temperature of 350℃, and a volume hourly space velocity (VHSV) of 1.2h⁻¹. -1 The hydrogen-to-oil volume ratio was 1400. The reaction products entered the fractionation system to obtain jet fuel and biodiesel. Specific experimental results are shown in Tables 2 and 3.

[0054] Example 4

[0055] Example 4 operates under basically the same conditions as Example 3, except for the purification unit. The primary purification unit uses a 0.20mm filter. The primary purified oil and fresh hydrogen are mixed and enter the secondary purification unit. The secondary purification unit uses a membrane separation device. The filter medium is a ceramic membrane, and the pore size of the filter medium is 10nm-30nm-50nm-70nm from the outside to the inside.

[0056] Comparative Example 1

[0057] Comparative Example 1 is the same as Example 1, except that the purification unit between the fluidized bed reactor and the refining reactor is removed in Comparative Example 1. Instead, an atmospheric and vacuum distillation system is set up. The product of the fluidized bed hydrogenation reaction is frequently depressurized and distilled. The light and intermediate components obtained by distillation are used as feed to the fixed bed refining reactor, and the heavy components are thrown off. Other operating conditions are the same as in Example 1.

[0058] Comparative Example 2

[0059] Comparative Example 2 is the same as Example 2, except that in Comparative Example 2, only a primary purification unit is set between the fluidized bed reactor and the refining reactor, and the secondary purification unit is eliminated. The primary purified oil is mixed with hydrogen and heated in a heater before entering the refining reactor. Other operating conditions are the same as in Example 1.

[0060] Comparative Example 3

[0061] Comparative Example 3 is the same as Example 3, except that: the liquid effluent from the fluidized bed reactor enters the primary purification unit, and the primary purified oil directly enters the secondary purification unit for treatment to obtain secondary purified oil; the secondary purified oil is mixed with hydrogen and heated in a heater before entering the refining reactor, and other operating conditions are the same as in Example 3.

[0062] Table 2. Fluidized bed reaction conditions and hydrogenation-produced oil

[0063]

[0064] Table 3. Properties and yield of oil produced by hydrogenation in the refining reactor (relative to fresh feed)

[0065]

[0066] Note: The above data is based on data after 1200 hours of operation.

[0067] As can be seen from the above embodiments and comparative examples, the hydrogenation treatment process and reaction system for animal and vegetable oils of the present invention organically combines a fluidized bed reactor with a fixed bed refining reactor, and sets up a purification unit between different reactors, thereby improving the feed stability of subsequent devices, improving the overall liquid recovery, operating cycle and product properties of the device, and reducing energy consumption.

Claims

1. A hydrogenation process for animal and vegetable oils, characterized in that: The process includes the following: 1) Animal and vegetable oil raw materials are mixed with hydrogen and then enter the fluidized bed hydrogenation reaction unit for reaction. The reaction effluent is separated to obtain gas phase and liquid phase effluent. 2) The liquid effluent obtained in step 1) enters the purification unit for desolidification treatment to obtain purified oil; 3) The purified oil obtained in step 2) enters the hydrorefining reaction unit for hydrorefining reaction, and the reaction temperature of the hydrorefining reaction unit is 250~400℃; the hydrorefining reaction effluent is fractionated to obtain jet fuel and biodiesel, and the yield of biodiesel is above 78.9 wt%. In step 2), the purification unit includes a primary purification unit and a secondary purification unit; the liquid effluent obtained in step 1) enters the primary purification unit for processing to obtain primary purified oil; the primary purified oil is mixed with hydrogen and then enters the secondary purification unit to obtain secondary purified oil. In step 2), the liquid effluent obtained in step 1) is treated by a primary purification unit to remove catalyst powder; In step 2), the secondary purification unit uses a membrane separation device, which includes a filter medium with a pore size of 10nm to 100nm. In step 2), the operating conditions of the secondary purification unit are as follows: operating pressure 0.1~8.0MPa, operating temperature 50~280℃, and volume ratio of primary purification oil to hydrogen 80~300.

2. The hydrogenation process for animal and vegetable oils according to claim 1, characterized in that: In step 1), the animal and vegetable oil raw materials are at least one of soybean oil, palm oil, rapeseed oil and animal fat.

3. The hydrogenation process for animal and vegetable oils according to claim 1, characterized in that: In step 1), the animal and vegetable oil raw materials are pretreated and then mixed with hydrogen before entering the fluidized bed hydrogenation reaction unit for reaction. The pretreatment process includes solidification treatment and dehydration treatment. The solidification treatment adopts one or more of centrifugal separation, static sedimentation separation and filtration separation, and the dehydration treatment adopts one or more of flash dehydration, coalescence dehydration and adsorption dehydration.

4. The hydrogenation process for animal and vegetable oils according to claim 1, characterized in that: In step 1), the fluidized bed reactor in the fluidized bed hydrogenation reaction unit is a boiling bed reactor and / or a slurry bed reactor.

5. The hydrogenation process for animal and vegetable oils according to claim 1, characterized in that: In step 1), the animal and vegetable oil raw materials are mixed with hydrogen by pre-furnace hydrogen mixing or post-furnace hydrogen mixing; the specific process of post-furnace hydrogen mixing is as follows: after heat exchange, the animal and vegetable oil raw materials are mixed with hot hydrogen obtained by heating in a hydrogen heating furnace.

6. The hydrogenation process for animal and vegetable oils according to claim 5, characterized in that: In step 1), the animal and vegetable oil raw materials are mixed with hydrogen using a post-furnace hydrogen mixing method.

7. The hydrogenation process for animal and vegetable oils according to claim 1, characterized in that: In step 1), the fluidized bed hydrogenation reaction unit is loaded with a hydrogenation treatment catalyst, which includes a support and an active component. The support includes alumina, and the active component is selected from Group VIII and / or Group VIB metals. The specific surface area of ​​the hydrogenation treatment catalyst is not less than 160 m². 2 / g, pore volume not less than 0.42cm 3 / g, bulk density not less than 0.8g / cm³ 3 The aperture is not less than 12nm.

8. The hydrogenation process for animal and vegetable oils according to claim 7, characterized in that: The active components are Mo and / or Ni.

9. The hydrogenation process for animal and vegetable oils according to claim 1, characterized in that: In step 1), the operating conditions of the fluidized bed hydrogenation reaction unit are: reaction pressure 2~18MPa, reaction temperature 250~400℃, and volume hourly space velocity 0.1~2.0h. -1 The hydrogen-to-oil volume ratio is 200-1000.

10. The hydrogenation process for animal and vegetable oils according to claim 9, characterized in that: In step 1), the operating conditions of the fluidized bed hydrogenation reaction unit are: reaction pressure 4~10MPa, reaction temperature 300~360℃, and volume hourly space velocity 0.2~1.0h. -1 The hydrogen-to-oil volume ratio is 300-800.

11. The hydrogenation process for animal and vegetable oils according to claim 1, characterized in that: In step 2), the primary purification unit employs one or more of the following: a filter, a centrifuge, and a settling device.

12. The hydrogenation process for animal and vegetable oils according to claim 1, characterized in that: In step 2), the operating conditions of the secondary purification unit are as follows: operating pressure 0.5~6.0MPa, operating temperature 80~200℃, and volume ratio of primary purification oil to hydrogen 120~250.

13. The hydrogenation process for animal and vegetable oils according to claim 1, characterized in that: In step 3), the hydrorefining reaction unit is equipped with at least one hydrorefining reactor; the hydrorefining reactor is a fixed-bed feed reactor and / or an upflow reactor.

14. The hydrogenation process for animal and vegetable oils according to claim 1, characterized in that: In step 3), the hydrorefining reaction unit includes 1 to 6 catalyst beds.

15. The hydrogenation process for animal and vegetable oils according to claim 14, characterized in that: In step 3), the hydrorefining reaction unit includes 2 to 4 catalyst beds.

16. The hydrogenation process for animal and vegetable oils according to claim 1, characterized in that: The active metal of the hydrorefining catalyst packed in the hydrorefining reaction unit is one or more of nickel, cobalt, molybdenum, and tungsten, with the following weight percentages: nickel and / or cobalt as oxides: 0.1%–12%; molybdenum and / or tungsten as oxides: 5%–15%; the support is one or more of alumina, silica, and titanium oxide; and the bulk density of the hydrorefining catalyst is 0.4–0.9 g / cm³. 3 Specific surface area is 100-200 m² 2 / g.

17. The hydrogenation process for animal and vegetable oils according to claim 1, characterized in that: In step 3), the operating conditions of the hydrorefining reaction unit are as follows: reaction pressure 2~18MPa, volume hourly space velocity 0.5~3.0h. -1 The hydrogen-to-oil volume ratio is 500-1800.

18. The hydrogenation process for animal and vegetable oils according to claim 17, characterized in that: In step 3), the operating conditions of the hydrorefining reaction unit are as follows: reaction pressure 6~12MPa, reaction temperature 300~360℃, and volume hourly space velocity 1.0~1.8h. -1 The hydrogen-to-oil volume ratio is 800-1500.

19. A hydrogenation treatment system for animal and vegetable oils required to implement the hydrogenation treatment process described in claim 1, characterized in that: include: The fluidized bed hydrogenation reaction unit is used to receive animal and vegetable oil raw materials, and to react them under the action of hydrogen and hydrogenation catalyst. The reaction effluent is processed by the separation unit to obtain gas phase and liquid phase effluent. The purification unit is used to receive the liquid effluent and hydrogen from the fluidized bed hydrogenation reaction unit and purify it to obtain purified oil; the purification process includes solidification treatment and oil-gas mixing. The hydrorefining reaction unit is used to receive purified oil from the purification unit, and react it under the action of hydrogen and hydrorefining catalyst. The reaction effluent is processed by the separation unit to obtain the target product. The purification unit includes: The primary purification unit is used to receive the liquid effluent from the fluidized bed hydrogenation reaction unit and obtain primary purified oil through desolidification treatment; The secondary purification unit receives hydrogen and primary purified oil from the primary purification unit. The hydrogen and primary purified oil undergo deep desolidification and oil-gas mixing under pressure difference to obtain secondary purified oil.

20. The animal and vegetable oil hydrogenation treatment system according to claim 19, characterized in that: The fluidized bed hydrogenation reaction unit is equipped with a pretreatment device, which includes a solidification treatment device and a dehydration treatment device. The solidification treatment device is one or more of a centrifuge, a settling device, a filter, and a hydrocyclone separator, and the dehydration treatment device is one or more of a flash tank, a coalescing dehydration filter, and an adsorption dehydration device.

21. The animal and vegetable oil hydrogenation treatment system according to claim 19, characterized in that: The fluidized bed hydrogenation reaction unit is equipped with at least one fluidized bed reactor; the fluidized bed reactor is a boiling bed reactor and / or a slurry bed reactor.

22. The animal and vegetable oil hydrogenation treatment system according to claim 21, characterized in that: The fluidized bed reactor is a fluidized bed reactor with a built-in three-phase separator. The fluidized bed reactor is divided into a straight section, a variable diameter section, and an enlarged section. The straight section is an empty cylinder without internal components. The enlarged section contains a separator for gas, liquid, and solid three-phase separation. The three-phase separator divides the enlarged section into an inner ring, a middle ring, and an outer ring. The gas, liquid, and solid phases first enter the inner ring. The gas flashes and escapes from the top of the reactor. The liquid and solid phases enter the middle ring. The solid phase returns to the main reaction zone of the reactor through the feed port at the bottom of the middle ring. The liquid phase enters the outer ring and flows out of the reactor through the liquid phase extraction port of the outer ring.

23. The animal and vegetable oil hydrogenation treatment system according to claim 19, characterized in that: The fluidized bed hydrogenation reaction unit is equipped with a hydrogen heater and a start-up furnace. After heat exchange, the animal and vegetable oil raw materials are mixed with the hot hydrogen obtained by heating in the hydrogen heater and then enter the fluidized bed reactor. The fluidized bed hydrogenation reaction unit is not equipped with a raw material heater, and the start-up furnace is only used during start-up sulfidation.

24. The animal and vegetable oil hydrogenation treatment system according to claim 19, characterized in that: The separation unit includes a gas-liquid separation unit and a fractionation unit. The gas-liquid separation unit includes a hot high-pressure separator, a cold high-pressure separator, a hot low-pressure separator, and a cold low-pressure separator. The fractionation unit includes a fractionation tower.

25. The animal and vegetable oil hydrogenation treatment system according to claim 19, characterized in that: The hydrorefining reaction unit is equipped with at least one hydrorefining reactor.

26. The animal and vegetable oil hydrogenation treatment system according to claim 25, characterized in that: One to two hydrorefining reactors are connected in series in the hydrorefining reaction unit.

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