A method and system for micro-interface enhanced diesel hydrodesulfurization reaction

Abstract

The present invention relates to the field of diesel processing, and discloses a method and system for micro-interface enhanced diesel hydrodesulfurization reaction. The method is carried out in a micro-interface generation system, comprising: (1) introducing crude oil and gas feed into the micro-interface generation system for mixing to obtain a gas-liquid emulsion; (2) sequentially introducing the gas-liquid emulsion into a first hydrogenation reaction zone containing a hydrogenation catalyst I and a second hydrogenation reaction zone containing a hydrogenation catalyst II for hydrogenation reaction, and introducing supplemental hydrogen into the inlet of the second hydrogenation reaction zone to obtain an ultra-deep desulfurization reaction effluent; (3) separating the ultra-deep desulfurization reaction effluent to obtain a gas phase product that can be used for recycling and a clean diesel product. The method for micro-interface enhanced diesel hydrodesulfurization reaction provided by the present invention effectively combines a micro-interface system with a trickle bed system, thereby improving the desulfurization efficiency of the crude oil under relatively mild process conditions.

Description

Technical Field

[0001] The present invention relates to the field of diesel processing, and in particular to a method and system for micro-interface enhanced diesel hydrodesulfurization reaction. Background Art

[0002] Fixed-bed gas-liquid-solid three-phase reactors are widely used in various reaction devices in the chemical industry. Although they are simple to operate and highly adaptable to raw materials, the bubbles within fixed-bed reactors are relatively large (typically 3-10 mm), resulting in a reduced mass transfer area between the gas and liquid phases and a lower reaction rate.

[0003] In order to improve the mass transfer efficiency of the fixed bed reactor, the reaction temperature or the reaction pressure needs to be increased during operation to increase the mass transfer rate and strengthen the reaction process; however, high temperature and high pressure operation will increase energy consumption and increase production costs.

[0004] Given the increasingly stringent diesel standards both domestically and internationally, the production of ultra-low sulfur diesel has become a research hotspot for major R&D institutions. For example, the National VI diesel standard for hydrodesulfurization (HDS) requires a sulfur content of less than 10 μg / g. This requires high catalyst activity and demanding process conditions, posing new challenges to maintaining high-activity diesel hydrotreating units over long periods of time.

[0005] Therefore, under current process conditions, it is necessary to improve the mass transfer efficiency and reaction activity between the gas and liquid phases to enhance the efficiency of the hydrodesulfurization reaction.

[0006] CN109225073A discloses a micro-packed bed hydrogenation reaction apparatus and a method for performing a hydrogenation reaction. This method disperses hydrogen into a solution containing a substrate to be hydrogenated using a micro-mixer to produce a gas-liquid mixed fluid containing micron-sized bubbles. The gas-liquid mixed fluid is then passed through a micro-packed bed filled with a hydrogenation catalyst to complete the hydrogenation process. However, due to the small size of the catalyst, the reaction pressure drop increases significantly, resulting in unstable reaction operation.

[0007] CN110465249A discloses a method and device for regulating the fractal structure of large and small bubbles to enhance mass transfer. This method uses the fractal dimension of the bubble size within a bubble reactor to accurately describe the bubble size distribution, and precisely controls the fractal dimension of the bubbles within the bubble reactor using a fractal bubble generation method to improve the mass transfer reaction performance of the bubble reactor.

[0008] CN109550418A and CN109966939A disclose a cyclonic microbubble generator and a venturi microbubble generator, respectively. After using these two microbubble generators in a gas-liquid reactor, the gas-liquid mass transfer efficiency is greatly improved.

[0009] CN110652941A discloses a microbubble hydrogenation reactor, which provides a membrane tube microbubble generating device in the catalyst bed to input gas into the catalyst bed in the form of microbubbles, thus solving the problem of uneven distribution of microbubbles in the axial direction in the prior art.

[0010] However, the existing process conditions mainly focus on the formation of microbubbles or systems where large and small bubbles coexist, and do not take into account the flow of microbubbles in the entire reactor system and their changes as the reaction proceeds. At the same time, no detailed consideration is given to the different reaction characteristics in the reactor, making it difficult to fully utilize the effect of microbubbles in the hydrodesulfurization process. Summary of the Invention

[0011] The purpose of the present invention is to overcome the defects of the prior art in that the desulfurization efficiency is low due to limited gas-liquid mass transfer and / or excessive process energy consumption.

[0012] In order to achieve the above object, the first aspect of the present invention provides a method for micro-interface enhanced diesel hydrodesulfurization reaction, which is carried out in a micro-interface generation system and comprises:

[0013] (1) introducing the feedstock oil and the gas feed into the micro-interface generating system for mixing to obtain a gas-liquid emulsion;

[0014] (2) sequentially introducing the gas-liquid emulsion into a first hydrogenation reaction zone containing a hydrogenation catalyst I and a second hydrogenation reaction zone containing a hydrogenation catalyst II for hydrogenation reaction, and introducing supplemental hydrogen into the inlet of the second hydrogenation reaction zone to obtain an ultra-deep desulfurization reaction effluent; controlling the structure and size of the hydrogenation catalyst I and the hydrogenation catalyst II so that the logistics dispersion performance of the hydrogenation catalyst II is stronger than the logistics dispersion performance of the hydrogenation catalyst I;

[0015] (3) separating the ultra-deep desulfurization reaction effluent to obtain a gaseous product that can be used for recycling and a clean diesel product with a sulfur content of less than 10 μg / g;

[0016] Wherein, in step (1), the mixing conditions are controlled so that the characteristic dispersion size in the micro-interface generation system is 10 μm-600 μm.

[0017] A second aspect of the present invention provides a system for micro-interface enhanced diesel hydrodesulfurization reaction, the system comprising:

[0018] Gas phase feeding unit;

[0019] Liquid phase feeding unit;

[0020] a micro-interface generating unit, wherein the gas-phase feeding unit and the liquid-phase feeding unit are connected to the micro-interface generating unit through pipelines, so that the gas-phase raw material introduced by the gas-phase feeding unit and the liquid-phase raw material introduced by the liquid-phase feeding unit can be mixed in the micro-interface generating unit to form a gas-liquid emulsion;

[0021] A hydrogenation reaction unit is provided with a first hydrogenation reaction zone and a second hydrogenation reaction zone connected in series, so that the gas-liquid emulsion from the micro-interface generating unit can enter the hydrogenation reaction unit to participate in the hydrogenation reaction to obtain an ultra-deep desulfurization reaction effluent; and a supplementary hydrogen feed port is provided at the inlet of the second hydrogenation reaction zone, so that hydrogen can enter the second hydrogenation reaction zone through the supplementary hydrogen feed port;

[0022] A separation unit is connected to the hydrogenation reaction unit and is used to separate the ultra-deep desulfurization reaction effluent.

[0023] The method for micro-interface enhanced diesel hydrodesulfurization reaction provided by the present invention effectively combines a micro-interface system with a trickle bed system, thereby improving the desulfurization efficiency of the crude oil under relatively mild process conditions.

[0024] In addition, the method for micro-interface enhanced diesel hydrodesulfurization reaction provided by the present invention also has the following specific advantages:

[0025] (1) The method provided by the present invention can effectively combine the microinterface system with the trickle bed reaction system; the microinterface system is used in the first hydrogenation reaction zone, which can effectively promote the gas-liquid mass transfer process and increase the reaction rate of the desulfurization reaction of easily removable sulfides; the multi-dimensional perturbation trickle bed system is used in the second hydrogenation reaction zone, which can effectively promote the reaction rate of the desulfurization reaction of difficult-to-remove sulfides, and ultimately achieve ultra-deep desulfurization of the crude oil.

[0026] (2) The method provided by the present invention can be carried out using a numerical range of hydrogen-to-oil volume ratio that is significantly lower than that in the prior art, thereby effectively reducing energy consumption while reducing hydrogen consumption.

[0027] (3) The method provided by the present invention includes two hydrogenation reaction zones, which can flexibly adjust the hydrogen distribution state of the two hydrogenation reaction zones according to different raw material and product requirements, and has good raw material adaptability and industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a process flow diagram of a method for micro-interface enhanced diesel hydrodesulfurization reaction according to a preferred embodiment of the present invention;

[0029] Figure 21 is a schematic process flow diagram of the method for micro-interface enhanced diesel hydrodesulfurization reaction described in Comparative Example 1 of the present invention;

[0030] Figure 3 Schematic diagram of the process flow of the method for micro-interface enhanced diesel hydrodesulfurization reaction described in Comparative Example 3 of the present invention;

[0031] Figure 4 It is a schematic diagram of the proportion of bubbles of various sizes in the first hydrogenation reaction zone and the second hydrogenation reaction zone in a preferred embodiment of the present invention.

[0032] Description of Reference Numerals

[0033] 1. Raw oil 2. Raw material buffer tank

[0034] 3. Raw material pump 4. Hydrogen

[0035] 5. Micro-interface generation system 6. Gas-liquid emulsion

[0036] 7. First hydrogenation reaction zone 8. Second hydrogenation reaction zone

[0037] 9. Hydrogen replenishment 10. Heat exchanger

[0038] 11. Ultra-deep desulfurization reaction effluent with heat exchange

[0039] 12. Gas phase logistics 13. High pressure separator

[0040] 14. Liquid logistics 15. Circulating hydrogen purification system

[0041] 16. Circulating hydrogen compressor 17. Pretreated crude oil DETAILED DESCRIPTION

[0042] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0043] As mentioned above, the first aspect of the present invention provides a method for micro-interface enhanced diesel hydrodesulfurization reaction, which is carried out in a micro-interface generation system and comprises:

[0044] (1) introducing the feedstock oil and the gas feed into the micro-interface generating system for mixing to obtain a gas-liquid emulsion;

[0045] (2) sequentially introducing the gas-liquid emulsion into a first hydrogenation reaction zone containing a hydrogenation catalyst I and a second hydrogenation reaction zone containing a hydrogenation catalyst II for hydrogenation reaction, and introducing supplemental hydrogen into the inlet of the second hydrogenation reaction zone to obtain an ultra-deep desulfurization reaction effluent; controlling the structure and size of the hydrogenation catalyst I and the hydrogenation catalyst II so that the logistics dispersion performance of the hydrogenation catalyst II is stronger than the logistics dispersion performance of the hydrogenation catalyst I;

[0046] (3) separating the ultra-deep desulfurization reaction effluent to obtain a gaseous product that can be used for recycling and a clean diesel product with a sulfur content of less than 10 μg / g;

[0047] Wherein, in step (1), the mixing conditions are controlled so that the characteristic dispersion size in the micro-interface generation system is 10 μm-600 μm.

[0048] The "characteristic dispersion size in the micro-interface generation system" of the present invention refers to the size distribution of bubbles in the logistics, which is obtained by OMIS online imaging technology testing.

[0049] Preferably, in step (1), the micro-interface generating system is selected from at least one of a pneumatic micro-interface generator, a liquid-driven micro-interface generator and a gas-liquid linkage micro-interface generator.

[0050] Preferably, in step (1), the initial distillation point of the feedstock oil is 180-260°C, and the final distillation point of the feedstock oil is 320-400°C.

[0051] More preferably, in step (1), the feedstock oil is selected from at least one of straight-run diesel, coker diesel, and catalytic diesel.

[0052] Preferably, the density of the raw oil at 20°C is 0.800-0.980 g / cm 3 The refractive index at 20°C is 1.4500-1.5800, the nitrogen content is 100-1000μg / g, the sulfur content is 1000-15000μg / g, the mass content of hydrogen is 8.50-13.50%, and the mass content of carbon is 86.50-91.50%.

[0053] Preferably, in step (1), the mixing conditions are controlled so that the average diameter of the microbubbles contained in the obtained gas-liquid emulsion is 40 μm to 1000 μm. More preferably, in step (1), the mixing conditions are controlled so that the average diameter of the microbubbles contained in the obtained gas-liquid emulsion is 50 μm to 500 μm.

[0054] Preferably, the mixing conditions at least meet the following requirements: mixing time of 1-30 min, mixing temperature of 30-200° C., and mixing pressure of 0.1-1 MPa.

[0055] According to a preferred specific embodiment, in step (1), the method also includes: before introducing the crude oil and the gas feed into the micro-interface generating system, first pressurizing the crude oil, and then introducing the pressurized crude oil and the gas feed into the micro-interface generating system for mixing.

[0056] The present invention has no particular requirements for the operating conditions of the pressurization treatment. Those skilled in the art may employ known pressurization treatment operations, which will not be described in detail herein and should not be construed as limiting the present invention. Furthermore, the present invention utilizes the pressurization treatment to uniformly mix the feedstock oil and the gas feed prior to entering the micro-interface generation system, thereby satisfying the micro-interface generation system's requirements for the characteristic dispersion size of the gas-liquid emulsion.

[0057] Preferably, in step (2), the process conditions of the first hydrogenation reaction zone at least meet the following requirements: hydrogen partial pressure of 3-12 MPa, reaction temperature of 200-420°C, hydrogen-to-oil volume ratio of 80-1400:1, liquid hourly volume space velocity of 0.3-8.0h -1 More preferably, in step (2), the process conditions of the first hydrogenation reaction zone at least meet the following requirements: hydrogen partial pressure of 5-10 MPa, reaction temperature of 300-400°C, hydrogen to oil volume ratio of 100-1200:1, liquid hourly volume space velocity of 0.5-6.0 h -1 .

[0058] According to a preferred embodiment, in step (2), the method further comprises: after performing the first hydrogenation reaction in the first hydrogenation reaction zone, directly introducing the obtained first hydrogenation reaction effluent into the second hydrogenation reaction zone without separation to perform the second hydrogenation reaction.

[0059] Preferably, in step (2), the process conditions of the second hydrogenation reaction zone at least meet the following requirements: hydrogen partial pressure of 3-12 MPa, reaction temperature of 200-420°C, hydrogen-to-oil volume ratio of 180-1600:1, liquid hourly volume space velocity of 0.3-6.0h -1 More preferably, in step (2), the process conditions of the second hydrogenation reaction zone at least meet the following requirements: hydrogen partial pressure of 5-10 MPa, reaction temperature of 300-400°C, hydrogen to oil volume ratio of 200-1400:1, liquid hourly volume space velocity of 0.5-6.0 h -1 .

[0060] According to a particularly preferred embodiment, in step (2), the hydrogen-to-oil volume ratio of the second hydrogenation reaction zone is higher than that of the first hydrogenation reaction zone, and the difference between the hydrogen-to-oil volume ratio of the second hydrogenation reaction zone and the hydrogen-to-oil volume ratio of the first hydrogenation reaction zone is 100-300 Nm 3 / m 3 .

[0061] Preferably, in the present invention, at least one hydrogenation catalyst bed is independently provided in the first hydrogenation reaction zone and the second hydrogenation reaction zone, and each of the hydrogenation catalyst beds contains the hydrogenation catalyst; after the feedstock oil and the gas feed are mixed in the micro-interface generating system, they enter from the lower part of the first hydrogenation reaction zone and flow upward to enter the catalyst bed.

[0062] More preferably, 1 to 4 hydrogenation catalyst beds are independently provided in the first hydrogenation reaction zone and the second hydrogenation reaction zone.

[0063] Preferably, in step (2), the hydrogenation catalyst I and the hydrogenation catalyst II are different and are each independently selected from at least one of the hydrogenation catalysts having the following characteristics:

[0064] The hydrogenation catalyst contains a carrier and an active metal component supported on the carrier, wherein the active metal element in the active metal component is at least one of nickel, cobalt, molybdenum and tungsten; and the carrier is selected from at least one of alumina, alumina-silicon oxide and titanium oxide.

[0065] More preferably, in the hydrogenation catalyst, based on the total weight of the hydrogenation catalyst, the content of the active metal component in terms of oxide is 5-45 wt%, and the content of the carrier is 55-95 wt%.

[0066] Further preferably, in the hydrogenation catalyst, based on the total weight of the hydrogenation catalyst, the content of the nickel element calculated as oxide is 1-8 weight %, the content of the cobalt element calculated as oxide is 0-30 weight %, the content of the molybdenum element calculated as oxide is 0-30 weight %, and the content of the tungsten element calculated as oxide is 20-28 weight %.

[0067] According to a particularly preferred embodiment, in the hydrogenation catalyst, the carrier is alumina, and the content of the carrier is 60-90 wt % based on the total weight of the hydrogenation catalyst.

[0068] Preferably, in step (2), the shape of the hydrogenation catalyst I is at least one of cylindrical, butterfly, and clover-shaped; the shape of the hydrogenation catalyst II is at least one of porous foam, honeycomb cylindrical, and Raschig ring.

[0069] Preferably, in step (2), the hydrogenation catalyst loading volume ratio of the first hydrogenation reaction zone to the second hydrogenation reaction zone is 1:0.3-1. More preferably, in step (2), the hydrogenation catalyst loading volume ratio of the first hydrogenation reaction zone to the second hydrogenation reaction zone is 1:0.5-1.

[0070] Preferably, the second hydrogenation reaction zone is a trickle bed reactor.

[0071] According to a preferred specific embodiment, in step (3), the method further includes: before separating the ultra-deep desulfurization reaction effluent, first subjecting the ultra-deep desulfurization reaction effluent to a heat exchange treatment to obtain a heat exchange ultra-deep desulfurization reaction effluent with a temperature of 30-200°C, and then separating the heat exchange ultra-deep desulfurization reaction effluent.

[0072] In the present invention, there are no special requirements for the operating conditions of the heat exchange treatment. Those skilled in the art can adopt known heat exchange treatment operations, which will not be described in detail in the present invention. Those skilled in the art should not understand this as a limitation to the present invention.

[0073] In the present invention, a large number of desulfurization, denitrogenation and aromatic saturation reactions will occur in the first hydrogenation reaction zone, and the active hydrogen on the surface of the hydrogenation catalyst I will be consumed rapidly. If the mass transfer rate of hydrogen cannot match the rate of hydrogen consumption, on the one hand, the reaction rates of the desulfurization reaction and the denitrogenation reaction will be affected, and on the other hand, a carbon deposition reaction will occur on the surface of the hydrogenation catalyst I, thereby affecting the activity and stability of the hydrogenation catalyst I. Therefore, the present invention adopts a microinterface system in the first hydrogenation reaction zone to give full play to the advantages of the microinterface in promoting gas-liquid mass transfer, so as to improve the mass transfer efficiency of hydrogen.

[0074] Furthermore, as the hydrogenation reaction continues, the content of sulfides in the feed oil is further reduced, and the sulfides in the feed oil are converted from easily removed sulfides to sulfides that are more difficult to remove (such as 4,6-dimethyldiphenylthiophene sulfides). At this time, the key factor affecting the desulfurization reaction is no longer the active hydrogen concentration on the surface of the hydrogenation catalyst I, but the diffusion degree of the sulfides in the feed oil on the surface of the hydrogenation catalyst I and the diffusion degree of the first hydrogenation reaction effluent.

[0075] In the present invention, the first hydrogenation reaction zone is mainly composed of microbubble flow. Due to the physical properties of the microbubble flow, the diffusion rate of the first hydrogenation reaction effluent will be reduced, which will affect the diffusion and mass transfer efficiency of the sulfides in the raw oil to a certain extent, and thus affect the final ultra-deep desulfurization effect.

[0076] Preferably, the present invention introduces the hydrogen circulating in the gas-phase feed unit into the second hydrogenation reaction zone to adjust the gas distribution in the second hydrogenation reaction zone, generating a multi-dimensional bubble disturbance system, so that the 4,6-dimethyldiphenylthiophene sulfide that is more difficult to remove is easy to diffuse and enrich between the active sites of the hydrogenation catalyst II, thereby accelerating its reaction rate and ultimately achieving the purpose of ultra-deep desulfurization.

[0077] As mentioned above, the second aspect of the present invention provides a system for micro-interface enhanced diesel hydrodesulfurization reaction, the system comprising:

[0078] Gas phase feeding unit;

[0079] Liquid phase feeding unit;

[0080] a micro-interface generating unit, wherein the gas-phase feeding unit and the liquid-phase feeding unit are connected to the micro-interface generating unit through pipelines, so that the gas-phase raw material introduced by the gas-phase feeding unit and the liquid-phase raw material introduced by the liquid-phase feeding unit can be mixed in the micro-interface generating unit to form a gas-liquid emulsion;

[0081] A hydrogenation reaction unit is provided with a first hydrogenation reaction zone and a second hydrogenation reaction zone connected in series, so that the gas-liquid emulsion from the micro-interface generating unit can enter the hydrogenation reaction unit to participate in the hydrogenation reaction to obtain an ultra-deep desulfurization reaction effluent; and a supplementary hydrogen feed port is provided at the inlet of the second hydrogenation reaction zone, so that hydrogen can enter the second hydrogenation reaction zone through the supplementary hydrogen feed port;

[0082] A separation unit is connected to the hydrogenation reaction unit and is used to separate the ultra-deep desulfurization reaction effluent.

[0083] Preferably, the gas phase feeding unit comprises a gas raw material feeding port, a new hydrogen compressor, and a circulating hydrogen compressor, and the gas phase feeding unit can provide power and raw materials for the transportation of hydrogen.

[0084] More preferably, a diversion pipe is provided at the outlet of the circulating hydrogen compressor for transporting the supplementary hydrogen to the micro-interface generating unit and the inlet of the second hydrogenation reaction zone respectively.

[0085] Preferably, the liquid-phase feeding unit comprises a feed port for crude oil, a raw material buffer tank, and a raw material pump, and the liquid-phase feeding unit can provide power for the transportation of crude oil.

[0086] Preferably, the raw oil is introduced into the raw material pump through the raw material buffer tank and subjected to a pressure-boosting treatment to obtain pretreated raw oil.

[0087] Preferably, the micro-interface generating unit contains a micro-interface generator, which is used to mix the liquid feed and the gas feed in the micro-interface generator, convert the kinetic energy of the gas and / or liquid into bubble surface energy, break the gas to form microbubbles, and mix the liquid feed with the microbubbles to form the gas-liquid emulsion.

[0088] Preferably, the hydrogenation reaction unit contains a first hydrogenation reaction zone and a second hydrogenation reaction zone, and the first hydrogenation reaction zone and the second hydrogenation reaction zone are each independently provided with a hydrogenation catalyst bed. The hydrogenation reaction unit is used to introduce the gas-liquid emulsion into the first hydrogenation reaction zone and the second hydrogenation reaction zone for hydrogenation reaction to obtain an ultra-deep desulfurization reaction effluent.

[0089] Preferably, the first hydrogenation reaction zone is connected to the micro-interface generating unit, and the second hydrogenation reaction zone is connected to the first hydrogenation reaction zone.

[0090] Preferably, a gas-liquid distributor is provided between the first hydrogenation reaction zone and the second hydrogenation reaction zone, so that the logistics obtained from the outlet of the first hydrogenation reaction zone is redistributed and then enters the second hydrogenation reaction zone for hydrogenation reaction.

[0091] More preferably, a gas-liquid distributor is provided between the first hydrogenation reaction zone and the second hydrogenation reaction zone, so that the logistics obtained from the outlet of the first hydrogenation reaction zone generates a multi-dimensional bubble disturbance system, and then enters the second hydrogenation reaction zone for hydrogenation reaction after redistribution.

[0092] The present invention has no limitation on the gas-liquid distributor, and a gas-liquid distributor well known to those skilled in the art can be used; however, preferably, in order to obtain a better gas-liquid distribution effect, the structure of the gas-liquid distributor is selected from at least one of a bubble type, a sieve plate type, a grooved plate type, and a nozzle type.

[0093] More preferably, the structure of the gas-liquid distributor is at least one selected from a combination of a nozzle type and a bubble cap type, and a combination of a grooved plate type and a sieve plate type.

[0094] Further preferably, the structure of the gas-liquid distributor is a combination of a nozzle type and a bubble cap type.

[0095] Preferably, the second hydrogenation reaction zone is a trickle bed reactor.

[0096] Preferably, the separation unit is connected to the second hydrogenation reaction zone and is used for performing gas-liquid separation on the ultra-deep desulfurization reaction effluent.

[0097] The following combination Figure 1 Preferred embodiments of the present invention are described in detail, but the present invention is not limited thereto.

[0098] exist Figure 1 The method of the present invention comprises:

[0099] S1: Feedstock oil 1 is introduced into feedstock pump 3 via feedstock buffer tank 2, the feedstock oil 1 is pressurized to obtain pretreated feedstock oil, and the pretreated feedstock oil is mixed with hydrogen 4 in micro-interface generation system 5 to obtain gas-liquid emulsion 6;

[0100] S2: introducing the gas-liquid emulsion into a first hydrogenation reaction zone 7 containing a hydrogenation catalyst I to carry out a first hydrogenation reaction to obtain a first hydrogenation reaction effluent; directly introducing the first hydrogenation reaction effluent into a second hydrogenation reaction zone 8 containing a hydrogenation catalyst II without separation, and carrying out a second hydrogenation reaction under the action of supplemental hydrogen 9 to obtain an ultra-deep desulfurization reaction effluent;

[0101] S3: introducing the ultra-deep desulfurization reaction effluent into a heat exchanger 10 for heat exchange treatment to obtain a heat-exchanged ultra-deep desulfurization reaction effluent 11, and separating the heat-exchanged ultra-deep desulfurization reaction effluent 11 in a high-pressure separator 13 to obtain a gaseous phase stream 12 and a liquid phase stream 14, respectively;

[0102] S4: The gaseous phase stream 12 is sequentially introduced into the circulating hydrogen purification system 15 and the circulating hydrogen compressor 16 via a pipeline to obtain a gaseous phase product that can be used for circulation; the liquid phase stream 14 exits the device via a pipeline.

[0103] The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, all raw materials used are commercially available.

[0104] The raw oils used in the examples are all industrial diesel raw materials, among which diesel raw materials A and diesel raw materials B are both mixed raw materials of straight-run diesel and catalytic diesel; diesel raw materials C is a mixed raw material of straight-run diesel, coking gasoline diesel and catalytic diesel, and its main properties are shown in Table 1.

[0105] In the present invention, the distillation range of the raw oil is tested according to the provisions of the national standard GB / T6536-2010 ASTM D86.

[0106] In the examples of the present invention, the hydrogenation catalyst I used is an industrial catalyst developed by the China Petroleum and Chemical Research Institute, which is a butterfly-shaped nickel-molybdenum-tungsten hydrogenation catalyst with alumina as the carrier. Based on the total mass of the hydrogenation catalyst I, the hydrogenation catalyst I contains 23.0% by weight of tungsten oxide (WO3), 2.3% by weight of nickel oxide (NiO), 2.4% by weight of molybdenum oxide (MoO3), and the remainder is an alumina carrier.

[0107] In the examples of the present invention, the hydrogenation catalyst II used is a catalyst prepared by selecting a honeycomb column-shaped alumina carrier. WO3, basic nickel carbonate, and glycerol are respectively added to an aqueous solution containing phosphoric acid, and heated and stirred until completely dissolved to obtain an impregnation solution containing active metals. After the impregnation solution and the carrier are evenly mixed, they are dried at 120°C for 5 hours to prepare a honeycomb column-shaped oxidized catalyst. The honeycomb column-shaped oxidized catalyst is calcined at 400°C for 3 hours to obtain hydrogenation catalyst II, which contains 24.5% by weight of tungsten oxide (WO3) and 4.5% by weight of nickel oxide (NiO) based on the total mass of the hydrogenation catalyst II, and the balance is an alumina carrier.

[0108] In the examples of the present invention, the micro-interface generation system used is a membrane dispersion micro-mixer (the average pore size of the membrane is 5 μm, and it is a pneumatic micro-interface reaction system generator).

[0109] Table 1

[0110] Diesel crude oil number Diesel feedstock A Diesel feedstock B Diesel feedstock C <![CDATA[Refractive index (n D 20 )]]> 1.4735 1.4894 1.5177 <![CDATA[Density (20 °C) / (g / cm 3 )]]> 0.8484 0.8677 0.9028 Carbon mass fraction / % 86.85 87.33 88.68 Hydrogen mass fraction / % 13.15 12.67 11.32 Nitrogen mass content / (μg / g) 259 321 443 Sulfur mass content / (μg / g) 12310 10890 9500 Distillation range (ASTM-D86) / ℃ Initial distillation point 193 211 216 10％ 240 253 252 30％ 273 281 275 50％ 291 298 291 70％ 315 321 315 90％ 353 355 345 Final distillation point 384 385 376

[0111] Example 1

[0112] The raw oil used in this embodiment is diesel raw material A, according to Figure 1 The process flow chart shown is as follows:

[0113] S1: introducing feedstock oil into a feedstock pump via a feedstock buffer tank, subjecting the feedstock oil to a pressurization treatment to obtain pretreated feedstock oil, and mixing the pretreated feedstock oil with hydrogen in a micro-interface generation system to obtain a gas-liquid emulsion;

[0114] The mixing conditions at least meet the following requirements: mixing time of 10 min, mixing temperature of 50° C., and mixing pressure of 0.6 MPa;

[0115] S2: introducing the gas-liquid emulsion into a first hydrogenation reaction zone containing hydrogenation catalyst I to carry out a first hydrogenation reaction to obtain a first hydrogenation reaction effluent; directly introducing the first hydrogenation reaction effluent into a second hydrogenation reaction zone containing hydrogenation catalyst II without separation, and carrying out a second hydrogenation reaction under the action of supplemental hydrogen to obtain an ultra-deep desulfurization reaction effluent;

[0116] The hydrogenation catalyst loading volume ratio of the first hydrogenation reaction zone and the second hydrogenation reaction zone is 1:0.8; the first hydrogenation reaction zone is a hydrogenation reactor with a front micro-interface generation system, and the second hydrogenation reaction zone is a trickle bed reactor;

[0117] S3: introducing the ultra-deep desulfurization reaction effluent into a heat exchanger for heat exchange treatment to obtain heat-exchanged ultra-deep desulfurization reaction effluent, and separating the heat-exchanged ultra-deep desulfurization reaction effluent in a high-pressure separator to obtain a gas phase stream and a liquid phase stream respectively;

[0118] wherein, after the heat exchange treatment, a heat exchange ultra-deep desulfurization reaction effluent having a temperature of 100° C. is obtained;

[0119] S4: The gaseous phase flow is sequentially introduced into the circulating hydrogen purification system and the circulating hydrogen compressor via pipelines to obtain a gaseous phase product that can be used for circulation; the liquid phase flow is taken out of the device as a product.

[0120] The main reaction conditions and main properties of the product in this example are shown in Table 2.

[0121] Example 2

[0122] The raw oil used in this embodiment is diesel raw material B, according to Figure 1 Specifically, the main reaction conditions and main properties of the product in this example are shown in Table 2.

[0123] Example 3

[0124] The raw oil used in this embodiment is diesel raw material C, according to Figure 1 Specifically, the main reaction conditions and main properties of the product in this example are shown in Table 2.

[0125] Table 2

[0126]

[0127]

[0128] Comparative Example 1

[0129] The raw oil used in this comparative example is diesel raw material A, according to Figure 2 The process flow diagram shown is carried out with Figure 1 The difference is that this comparative example does not contain supplemental hydrogen, specifically:

[0130] S1: Feedstock oil 1 is introduced into feedstock pump 3 via feedstock buffer tank 2, the feedstock oil 1 is pressurized to obtain pretreated feedstock oil, and the pretreated feedstock oil is mixed with hydrogen 4 in micro-interface generation system 5 to obtain gas-liquid emulsion 6;

[0131] S2: introducing the gas-liquid emulsion into a first hydrogenation reaction zone 7 containing a hydrogenation catalyst I to carry out a first hydrogenation reaction to obtain a first hydrogenation reaction effluent; the first hydrogenation reaction effluent is directly introduced into a second hydrogenation reaction zone 8 containing a hydrogenation catalyst II without separation to carry out a second hydrogenation reaction to obtain an ultra-deep desulfurization reaction effluent; the first hydrogenation reaction zone 7 is a hydrogenation reactor with a pre-microinterface generation system, and the second hydrogenation reaction zone 8 is a trickle bed reactor;

[0132] S3: introducing the ultra-deep desulfurization reaction effluent into a heat exchanger 10 for heat exchange treatment to obtain a heat-exchanged ultra-deep desulfurization reaction effluent 11, and separating the heat-exchanged ultra-deep desulfurization reaction effluent 11 in a high-pressure separator 13 to obtain a gaseous phase stream 12 and a liquid phase stream 14, respectively;

[0133] S4: The gaseous phase stream 12 is sequentially introduced into the circulating hydrogen purification system 15 and the circulating hydrogen compressor 16 via a pipeline to obtain a gaseous phase product that can be used for circulation; the liquid phase stream 14 exits the device via a pipeline.

[0134] The main reaction conditions and main properties of the product in this comparative example 1 are shown in Table 2.

[0135] Compared with the results of Example 1, it can be seen that in this comparative example, since microbubble generators are used in both the first hydrogenation reaction zone and the second hydrogenation reaction zone, the characteristic dispersion size of the bubbles in the logistics can be within the microbubble size range.

[0136] Compared with Example 1, the results of this comparative example show that the desulfurization and denitrification reactions in the second hydrogenation reaction zone are insufficient. Therefore, the sulfur content of the hydrogenated product obtained in this comparative example exceeds 10 μg / g, which does not meet the National VI diesel standard requirement.

[0137] Comparative Example 2

[0138] The raw oil used in this comparative example is diesel raw material A, according to Figure 1 The process flow chart shown in Example 1 is different from that in Example 1:

[0139] In this comparative example, the hydrogenation catalysts loaded in the first hydrogenation reaction zone and the second hydrogenation reaction zone are both hydrogenation catalyst I.

[0140] Specifically, the main reaction conditions and main properties of the product in this comparative example are shown in Table 2.

[0141] Comparison with the results of Example 1 shows that while the sulfur content of the hydrogenated product in this comparative example is below 10 μg / g, this result was achieved under conditions with a relatively high volume of hydrogen and oil. This means that this comparative example fails to highlight the advantages of combining the micro-interface process with the trickle bed process, resulting in higher energy consumption.

[0142] Comparative Example 3

[0143] The raw oil used in this comparative example is diesel raw material A, according to Figure 3 The process flow diagram shown is carried out with Figure 1 The difference is that this comparative example does not contain a micro-interface generating system, specifically:

[0144] S1: introducing the raw material oil 1 into the raw material pump 3 through the raw material buffer tank 2, and the raw material oil 1 is subjected to a pressure-boosting treatment to obtain pretreated raw material oil 17;

[0145] S2: introducing the pretreated feedstock oil and hydrogen 4 into a first hydrogenation reaction zone 7 containing a hydrogenation catalyst I to carry out a first hydrogenation reaction to obtain a first hydrogenation reaction effluent; directly introducing the first hydrogenation reaction effluent into a second hydrogenation reaction zone 8 containing a hydrogenation catalyst II without separation, and carrying out a second hydrogenation reaction under the action of supplemental hydrogen 9 to obtain an ultra-deep desulfurization reaction effluent;

[0146] Wherein, the hydrogenation catalyst loading volume ratio of the first hydrogenation reaction zone and the second hydrogenation reaction zone is 1:0.8; the first hydrogenation reaction zone is a trickle bed reactor, and the second hydrogenation reaction zone is a trickle bed reactor;

[0147] S3: introducing the ultra-deep desulfurization reaction effluent into a heat exchanger 10 for heat exchange treatment to obtain a heat-exchanged ultra-deep desulfurization reaction effluent 11, and separating the heat-exchanged ultra-deep desulfurization reaction effluent in a high-pressure separator 13 to obtain a gaseous phase stream 12 and a liquid phase stream 14, respectively;

[0148] wherein, after the heat exchange treatment, a heat exchange ultra-deep desulfurization reaction effluent having a temperature of 100° C. is obtained;

[0149] S4: The gaseous phase stream 12 is sequentially introduced into the circulating hydrogen purification system 15 and the circulating hydrogen compressor 16 via pipelines to obtain a gaseous phase product that can be used for circulation; the liquid phase stream 14 is discharged from the device as a product.

[0150] The main reaction conditions and product properties in this comparative example are shown in Table 2.

[0151] Compared with the result of Example 1, the sulfur content of the product of this comparative example exceeds 10 μg / g.

[0152] As can be seen from Table 2, the micro-interface-enhanced diesel hydrodesulfurization method provided by the present invention organically combines a micro-interface system with a trickle bed system, taking into account the reaction characteristics of the ultra-deep desulfurization process. This improves the desulfurization efficiency of industrial diesel under relatively mild process conditions. Specifically, the mass sulfur content of the clean diesel products obtained in Examples 1-3 was no more than 7.2 μg / g.

[0153] The present invention exemplarily provides the typical bubble distribution law in Example 1, such as Figure 4 As shown in . Figure 4 It can be seen that the proportion of bubbles of 20-100 μm in the logistics in the first hydrogenation reaction zone can reach more than 80%, realizing the design effect of micro-interface enhanced mass transfer; in the second hydrogenation reaction zone, in addition to the bubble distribution of 20-100 μm and 100-1000 μm, bubbles >1 mm appear, thus forming a logistics form of multi-size bubble disturbance.

[0154] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for micro-interface enhanced diesel hydrodesulfurization reaction, characterized in that: The method is carried out in a micro-interface generation system and includes: (1) introducing the crude oil and the gas feed into the micro-interface generation system for mixing to obtain a gas-liquid emulsion; (2) sequentially introducing the gas-liquid emulsion into a first hydrogenation reaction zone containing a hydrogenation catalyst I and a second hydrogenation reaction zone containing a hydrogenation catalyst II for hydrogenation reaction, and introducing supplemental hydrogen into the inlet of the second hydrogenation reaction zone to obtain an ultra-deep desulfurization reaction effluent; controlling the structure and size of the hydrogenation catalyst I and the hydrogenation catalyst II so that the logistics dispersion performance of the hydrogenation catalyst II is stronger than the logistics dispersion performance of the hydrogenation catalyst I; The shape of the hydrogenation catalyst I is at least one of a cylindrical, butterfly, and cloverleaf shape; the shape of the hydrogenation catalyst II is at least one of a porous foam shape, a honeycomb cylindrical shape, and a Raschig ring shape; The second hydrogenation reaction zone is a trickle bed reactor; (3) separating the ultra-deep desulfurization reaction effluent to obtain a gaseous product that can be used for recycling and a clean diesel product with a sulfur content of less than 10 μg / g; Wherein, in step (1), the mixing conditions are controlled so that the characteristic dispersion size in the micro-interface generation system is 10 μm-600 μm.

2. The method according to claim 1, wherein The micro-interface generating system is selected from at least one of a pneumatic micro-interface generator, a liquid-driven micro-interface generator and a gas-liquid linkage micro-interface generator.

3. The method according to claim 1, wherein In step (1), the initial distillation point of the raw oil is 180-260°C, and the final distillation point of the raw oil is 320-400°C.

4. The method according to claim 1, wherein In step (1), the raw oil is selected from at least one of straight-run diesel, coker diesel, and catalytic diesel.

5. The method according to any one of claims 1 to 4, wherein: In step (1), the mixing conditions are controlled so that the average diameter of the microbubbles contained in the obtained gas-liquid emulsion is 40 μm-1000 μm.

6. The method according to any one of claims 1 to 4, wherein: In step (1), the mixing conditions at least meet the following requirements: mixing time of 1-30 min, mixing temperature of 30-200° C., and mixing pressure of 0.1-1 MPa.

7. The method according to any one of claims 1 to 4, wherein: In step (2), the process conditions of the first hydrogenation reaction zone at least meet the following requirements: hydrogen partial pressure of 3-12 MPa, reaction temperature of 200-420°C, hydrogen-to-oil volume ratio of 80-1400:1, liquid hourly volume space velocity of 0.3-8.0 h -1 .

8. The method according to claim 7, wherein: In step (2), the process conditions of the first hydrogenation reaction zone at least meet the following requirements: hydrogen partial pressure of 5-10 MPa, reaction temperature of 300-400°C, hydrogen-to-oil volume ratio of 100-1200:1, liquid hourly volume space velocity of 0.5-6.0 h -1 .

9. The method according to any one of claims 1 to 4, wherein: In step (2), the process conditions of the second hydrogenation reaction zone at least meet the following requirements: hydrogen partial pressure of 3-12 MPa, reaction temperature of 200-420°C, hydrogen-to-oil volume ratio of 180-1600:1, liquid hourly volume space velocity of 0.3-6.0 h -1 .

10. The method according to claim 9, wherein: In step (2), the process conditions of the second hydrogenation reaction zone at least meet the following requirements: hydrogen partial pressure of 5-10 MPa, reaction temperature of 300-400°C, hydrogen-to-oil volume ratio of 200-1400:1, liquid hourly volume space velocity of 0.5-6.0 h -1 .

11. The method according to any one of claims 1 to 4, wherein: In step (2), the hydrogenation catalyst I and the hydrogenation catalyst II are different and are each independently selected from at least one of the hydrogenation catalysts having the following characteristics: The hydrogenation catalyst contains a carrier and an active metal component supported on the carrier, wherein the active metal element in the active metal component is at least one of nickel, cobalt, molybdenum and tungsten; and the carrier is selected from at least one of alumina, alumina-silicon oxide and titanium oxide.

12. The method according to claim 11, wherein: In the hydrogenation catalyst, based on the total weight of the hydrogenation catalyst, the content of nickel element calculated as oxide is 1-8 weight %, the content of cobalt element calculated as oxide is 0-30 weight %, the content of molybdenum element calculated as oxide is 0-30 weight %, and the content of tungsten element calculated as oxide is 20-28 weight %.

13. The method according to any one of claims 1 to 4, wherein: In step (2), the hydrogenation catalyst loading volume ratio of the first hydrogenation reaction zone and the second hydrogenation reaction zone is 1:0.3-1.

14. The method according to claim 13, wherein: In step (2), the hydrogenation catalyst loading volume ratio of the first hydrogenation reaction zone and the second hydrogenation reaction zone is 1:0.5-1.

15. A system for micro-interface enhanced diesel hydrodesulfurization reaction, characterized in that: The system is used to implement the method for micro-interface enhanced diesel hydrodesulfurization reaction according to any one of claims 1 to 14, and the system comprises: Gas phase feeding unit; Liquid phase feeding unit; a micro-interface generating unit, wherein the gas-phase feeding unit and the liquid-phase feeding unit are connected to the micro-interface generating unit through pipelines, so that the gas-phase raw material introduced by the gas-phase feeding unit and the liquid-phase raw material introduced by the liquid-phase feeding unit can be mixed in the micro-interface generating unit to form a gas-liquid emulsion; A hydrogenation reaction unit is provided, wherein the hydrogenation reaction unit is provided with a first hydrogenation reaction zone and a second hydrogenation reaction zone connected in series, so that the gas-liquid emulsion from the micro-interface generating unit can enter the hydrogenation reaction unit to participate in the hydrogenation reaction to obtain an ultra-deep desulfurization reaction effluent; and a supplementary hydrogen feed port is provided at the inlet of the second hydrogenation reaction zone, so that hydrogen can enter the second hydrogenation reaction zone through the supplementary hydrogen feed port; a separation unit, which is in communication with the hydrogenation reaction unit and is used to separate the ultra-deep desulfurization reaction effluent; The second hydrogenation reaction zone is a trickle bed reactor.

16. The system according to claim 15, wherein: A gas-liquid distributor is provided between the first hydrogenation reaction zone and the second hydrogenation reaction zone, so that the logistics obtained from the outlet of the first hydrogenation reaction zone are redistributed and then enter the second hydrogenation reaction zone for hydrogenation reaction.

17. The system according to claim 16, wherein: The structure of the gas-liquid distributor is selected from at least one of a bubble type, a sieve plate type, a grooved disc type, and a nozzle type.

18. The system according to claim 17, wherein: The structure of the gas-liquid distributor is a combination of a nozzle type and a bubble cap type.

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