Mixer and acid-hydrocarbon separation system and method

Abstract

The present invention relates to the technical field of organic matter separation and purification. Disclosed are a mixer and an acid-hydrocarbon separation system and method. The mixer comprises: a housing, wherein a mixing cavity is provided inside the housing, a first liquid inlet through which a raw material liquid enters the mixing cavity is provided on the head end of the housing, and a liquid mixture outlet through which a liquid mixture flows out of the mixing cavity is provided on the tail end of the housing; and a conveying pipe, the conveying pipe running through the mixing cavity via the head end of the housing and extending to the tail end of the housing, wherein a first port of the conveying pipe located at the head end extends out of the housing and forms a second liquid inlet, a second port of the conveying pipe located at the tail end is closed, the part of the conveying pipe located in the mixing cavity forms a spraying section, a plurality of spraying holes distributed at intervals and configured to spray to the mixing cavity a dispersed phase inputted through the second liquid inlet are provided in the pipe wall of the spraying section, and a first helical blade and a second helical blade which are distributed at an interval in the axial direction of the spraying section are provided on the periphery of the spraying section, with the helical direction of the first helical blade being opposite to the helical direction of the second helical blade. During an acid-hydrocarbon separation process, by using the mixer of the present invention, the amount of alkali liquor used in an alkali washing process and the salt content in washing water produced after water washing can be greatly reduced.

Description

Mixer and acid hydrocarbon separation system and method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Chinese patent application 202311434609.5 filed on October 31, 2023, the contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the technical field of organic matter separation and purification, and in particular to a mixer and an acid-hydrocarbon separation system and method. Background Art

[0004] During the acid-hydrocarbon separation process, the acid-hydrocarbon mixture first needs to be roughly separated, mainly by sedimentation or coalescence separation. Then, the separated oil phase (mainly containing hydrocarbons) is washed, such as alkali washing and water washing. The washing process mainly uses a stirred tank or static mixer for mixing. However, this process often has several problems. First, during the acid-hydrocarbon separation process, the incomplete separation of free acid and hydrocarbons results in a high amount of acid in the hydrocarbons, which greatly increases the alkali consumption during the alkali washing process. Second, because the alkali consumption of the washing process is greatly affected by the mixing effect, the traditional alkali washing process uses a stirred tank or static mixer, which often cannot achieve the optimal mixing effect, resulting in increased alkali consumption during the washing process.

[0005] Summary of the Invention

[0006] The present invention aims to overcome the problem of poor mixing during the washing process of acid-hydrocarbon separation in the prior art, which results in high alkali consumption during the washing process. The present invention provides a mixer and an acid-hydrocarbon separation system and method. During the acid-hydrocarbon separation process, the use of the mixer described herein can significantly reduce the amount of alkali solution used during the alkali washing process and the salt content in the wash water produced after water washing.

[0007] In order to achieve the above-mentioned objectives, the present invention provides a mixer on the one hand, which includes: an outer shell, a mixing chamber is provided inside the outer shell, a first liquid inlet is provided at the head end of the outer shell for the raw liquid to enter the mixing chamber, and a mixed liquid outlet is provided at the end of the outer shell for the mixed liquid to flow out of the mixing chamber; and a delivery pipe, the delivery pipe extends from the head end of the outer shell through the mixing chamber to the end of the outer shell, the first port of the delivery pipe at the head end extends out of the outer shell and forms a second liquid inlet, the second port of the delivery pipe at the end is closed, the part of the delivery pipe located in the mixing chamber forms an injection section, a plurality of injection holes are provided on the tube wall of the injection section for injecting the dispersed phase input through the second liquid inlet into the mixing chamber, the outer periphery of the injection section is provided with a first spiral blade and a second spiral blade spaced along its axial direction, and the spiral directions of the first spiral blade and the second spiral blade are opposite.

[0008] In some embodiments, the mixing chamber includes a first diameter-changing zone, a buffer zone, and a second diameter-changing zone distributed in sequence along the direction from the first liquid inlet to the mixed liquid outlet, and the first spiral blade and the second spiral blade are respectively located in the first diameter-changing zone and the second diameter-changing zone; and / or, the outer shell is cylindrical, the axial direction of the first liquid inlet is perpendicular to the axial direction of the outer shell, and the mixed liquid outlet is the same as the axial direction of the outer shell.

[0009] In some embodiments, the first variable diameter zone includes a first mixing section, a first expansion section and a first tapered section distributed in sequence along the axial direction of the injection section, the first mixing section is connected to the first liquid inlet, and the first tapered section is connected to the buffer zone; the diameter of the first tapered section gradually decreases along the direction from the first liquid inlet to the mixed liquid outlet, the minimum diameter of the first tapered section is the same as the diameter of the buffer zone, the maximum diameter of the first tapered section is the same as the diameter of the first expansion section, and the diameter of the first expansion section is larger than the diameter of the first mixing section.

[0010] In some embodiments, there is a first radial spacing between the wall of the first mixing section and the outer edge of the first spiral blade, the minimum radial spacing between the wall of the first tapered section and the outer edge of the first spiral blade is a second radial spacing, there is a third radial spacing between the outer wall of the injection section and the wall of the first mixing section, and the first radial spacing and the second radial spacing are 1 / 8-1 / 4 of the third radial spacing.

[0011] In some embodiments, a first spiral linear ridge surrounding the first spiral blade is provided on the wall surface of the first expansion section, and a spiral direction of the first spiral linear ridge is opposite to that of the first spiral blade.

[0012] In some embodiments, the axial length of the buffer zone is less than or equal to the axial length of the first mixing section.

[0013] In some embodiments, the axial length of the second variable diameter zone is smaller than the axial length of the first variable diameter zone; the second variable diameter zone includes a second mixing section, a second expansion section and a second tapered section distributed in sequence along the axial direction of the injection section, the second mixing section is connected to the buffer zone, and the second tapered section is connected to the mixed liquid outlet; the diameter of the second tapered section gradually decreases along the direction from the second liquid inlet to the mixed liquid outlet, the minimum diameter of the second tapered section is the same as the diameter of the mixed liquid outlet, the maximum diameter of the second tapered section is the same as the diameter of the second expansion section, the diameter of the second expansion section is larger than the diameter of the second mixing section, and the diameter of the second mixing section is equal to the diameter of the buffer zone.

[0014] In some embodiments, there is a fourth radial spacing between the wall of the second mixing section and the outer edge of the second spiral blade, the minimum radial spacing between the wall of the second tapered section and the outer edge of the second spiral blade is a fifth radial spacing, there is a sixth radial spacing between the outer wall of the injection section and the wall of the second mixing section, and the fourth radial spacing and the fifth radial spacing are 1 / 8-1 / 4 of the sixth radial spacing.

[0015] In some embodiments, a second spiral linear convex pattern surrounding the second spiral blade is provided on the wall surface of the second expansion section, and the spiral direction of the second spiral linear convex pattern is opposite to the spiral direction of the second spiral blade.

[0016] In some embodiments, all the injection holes are distributed in multiple rows and columns on the injection section, and the number of injection holes located in the first variable diameter zone is greater than the number of injection holes located in the second variable diameter zone; in the axial direction of the injection section, the spacing between two adjacent injection holes in the buffer zone is smaller than the spacing between two adjacent injection holes in the second variable diameter zone.

[0017] In some embodiments, the diameter of the injection hole gradually decreases from its liquid inlet end to its liquid outlet end, and a third spiral convex pattern distributed around the axis of the injection hole is provided on the hole wall of the injection hole. The injection hole extends obliquely from its liquid inlet end to its liquid outlet end toward the head end of the outer shell.

[0018] The second aspect of the present invention provides an acid hydrocarbon separation system, comprising a sedimentation separation device, a coalescence separation unit, an alkali washing unit and a water washing unit connected in sequence, wherein the alkali washing unit comprises a first mixer and a first separator connected in sequence, wherein the first mixer is the mixer described above.

[0019] A third aspect of the present invention provides a method for separating acid hydrocarbons, the method comprising the following steps:

[0020] (1) subjecting the acid-hydrocarbon mixture to sedimentation separation to obtain a first oil phase;

[0021] (2) subjecting the first oil phase to coalescence separation, so that the acid content of the separated second oil phase is less than 5% of the acid content of the first oil phase, preferably 0.1-4.2%;

[0022] (3) performing a first mixing of the second oil phase and an alkali solution, and performing a first enhanced separation on the obtained mixed solution to obtain a third oil phase;

[0023] (4) Washing the third oil phase with water.

[0024] According to the mixer described in the present invention, the main phase (such as an acid-hydrocarbon mixture) can enter the mixing chamber from the first liquid inlet, the dispersed phase (such as alkali solution or water) can enter the injection section of the delivery pipe from the second liquid inlet, and the dispersed phase is injected into the main phase of the mixing chamber from the injection hole, thereby forming a mixed liquid. On the one hand, the mixed liquid will flow in a spiral manner along the first spiral blade and the second spiral blade. The spirally flowing mixed liquid has a tangential velocity, and a shear stress gradient is formed in the mixed liquid so that the dispersed phase is sheared and broken into small droplets, thereby enabling the dispersed phase to be fully mixed in the main phase during the rotational flow. On the other hand, when the mixed liquid leaves the area where the first spiral blade is located and begins to enter the area where the second spiral blade is located, due to the different spiral directions of the first spiral blade and the second spiral blade, the flow state of the mixed liquid will change dramatically and form a violent turbulence, thereby further improving the mixing effect.

[0025] Moreover, during the acid-hydrocarbon separation process, by using the mixer described in the present invention in the alkali washing process, the alkali solution and the acid-hydrocarbon mixture can be fully mixed to obtain a better neutralization and deacidification effect, thereby significantly reducing the amount of alkali solution used in the alkali washing process and the salt content in the washing water generated after water washing.

[0026] According to the acid-hydrocarbon separation method of the present invention, the acid-hydrocarbon mixture is first subjected to sedimentation separation, and then the oil phase obtained after the sedimentation separation is subjected to agglomeration separation to remove more than 95% of the acid. This can significantly reduce the amount of alkali solution used in the subsequent alkali washing process and the salt content in the washing water produced after water washing. In the subsequent alkali washing process, the combined operation mode of first fully mixing and then enhanced separation can further reduce the amount of alkali solution used, and obtain a better purification effect, so that the impurity content in the separated purified hydrocarbon product is significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a schematic diagram of an acid-hydrocarbon separation system according to the present invention;

[0028] FIG2 is a schematic structural diagram of a particle agglomeration and separation device in the acid-hydrocarbon separation system according to the present invention;

[0029] FIG3 is a schematic cross-sectional view of the mixer according to the present invention;

[0030] FIG4 is a schematic cross-sectional view of the outer shell of the mixer according to the present invention;

[0031] FIG5 is an enlarged schematic diagram of portion A in FIG4 ;

[0032] FIG6 is an enlarged schematic diagram of portion B in FIG4 ;

[0033] FIG7 is a schematic diagram showing the distribution of the third spiral convex pattern in the mixer according to the present invention;

[0034] FIG8 is a schematic structural diagram of a separator in the acid-hydrocarbon separation system according to the present invention.

[0035] Description of Reference Numerals

[0036] 1. Outer shell; 11. Mixing chamber; 12. First liquid inlet; 13. Mixed liquid outlet; 14. First diameter-reducing zone; 141. First mixing section; 142. First expansion section; 143. First tapered section; 144. First spiral convex pattern; 15. Buffer zone; 16. Second diameter-reducing zone; 161. Second mixing section; 162. Second expansion section; 163. Second tapered section; 164. Second spiral convex pattern;

[0037] 2. Delivery pipe; 21. Injection section; 22. Second liquid inlet; 23. Injection hole; 24. First spiral blade; 25. Second spiral blade; 26. Third spiral convex pattern;

[0038] 100. Sedimentation separation device; 200. Particle agglomeration separation device; 2-1. First liquid distributor; 2-2. First bed layer; 2-3. Backwash water interception plate; 2-4. Second bed layer; 2-5. Acid collection structure; 2-6. Support plate; 2-7. First interface meter; 300. First mixer; 400. First separator; 4-1. Second liquid distributor; 4-2. Rectifier; 4-3. First demulsification separation structure; 4-4. Second demulsification separation structure; 4-5. Third demulsification separation structure; 4-6. Second interface meter; 500. Second mixer; 600. Second separator. DETAILED DESCRIPTION

[0039] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0040] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate relative importance or implicitly specify the quantity of the technical features indicated. Therefore, unless otherwise specified, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features; "plurality" means two or more. The term "comprising" and any variations thereof are intended to be non-exclusive inclusion, and one or more other features, integers, steps, operations, units, components, and / or combinations thereof may be present or added.

[0041] In addition, terms indicating orientation or positional relationships such as “center,” “lateral,” “up,” “down,” “vertical,” “horizontal,” “top,” “bottom,” “inside,” and “outside” are described based on the orientation or relative positional relationships shown in the accompanying drawings. They are merely simplified descriptions for the convenience of describing the present application, and do not indicate that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present application.

[0042] As shown in Figures 3 and 4, the mixer of the present invention comprises an outer shell 1 and a delivery pipe 2. A mixing chamber 11 is provided within the outer shell 1. A first liquid inlet 12 is provided at the front end of the outer shell 1 for admitting the raw liquid into the mixing chamber 11, and a mixed liquid outlet 13 is provided at the rear end of the outer shell 1 for allowing the mixed liquid to exit the mixing chamber 11. The delivery pipe 2 extends from the front end of the outer shell 1 through the mixing chamber 11 to the rear end of the outer shell 1. A first port at the front end of the delivery pipe 2 extends outside the outer shell 1 and forms a second liquid inlet 22. The second port at the rear end of the delivery pipe 2 is closed. The portion of the delivery pipe 2 located within the mixing chamber 11 forms an injection section 21. The wall of the injection section 21 is provided with a plurality of spaced-apart injection holes 23 for injecting the dispersed phase introduced through the second liquid inlet 22 into the mixing chamber 11. The outer periphery of the injection section 21 is provided with first and second spiral blades 24 and 25 spaced-apart along its axial direction. The first and second spiral blades 24 and 25 have opposite spiral directions.

[0043] Specifically, the main phase (such as an acid-hydrocarbon mixture) can enter the mixing chamber 11 from the first liquid inlet 12, and the dispersed phase (such as alkali solution or water) can enter the injection section 21 of the delivery pipe 2 from the second liquid inlet 22, and the dispersed phase is injected into the main phase of the mixing chamber 11 from the injection hole 23, thereby forming a mixed liquid. On the one hand, the mixed liquid will flow in a spiral manner along the first spiral blade 24 and the second spiral blade 25. The spirally flowing mixed liquid has a tangential velocity, and a shear stress gradient is formed in the mixed liquid so that the dispersed phase is sheared and broken into small droplets, thereby enabling the dispersed phase to be fully mixed in the main phase during the rotational flow. On the other hand, when the mixed liquid leaves the area where the first spiral blade 24 is located and begins to enter the area where the second spiral blade 25 is located, due to the different spiral directions of the first spiral blade 24 and the second spiral blade 25, the flow state of the mixed liquid will change dramatically and form a violent turbulence, thereby further improving the mixing effect.

[0044] In some embodiments, the spiral direction of the first spiral blade 24 is toward the first liquid inlet 12, and the spiral direction of the first spiral blade 24 is toward the mixed liquid outlet 13. In other embodiments, the spiral direction of the first spiral blade 24 is toward the mixed liquid outlet 13, and the spiral direction of the first spiral blade 24 is toward the first liquid inlet 12.

[0045] As shown in Figures 1 and 2, in some embodiments of the present invention, the mixing chamber 11 includes a first diameter-changing zone 14, a buffer zone 15, and a second diameter-changing zone 16 distributed in sequence along the direction from the first liquid inlet 12 to the mixed liquid outlet 13, and the first spiral blade 24 and the second spiral blade 25 are respectively located in the first diameter-changing zone 14 and the second diameter-changing zone 16.

[0046] Specifically, the first variable diameter zone 14 and the second variable diameter zone 16 may include multiple sections with different diameters. The flow state of the mixed liquid in the first variable diameter zone 14 and the second variable diameter zone 16 will continuously change, thereby facilitating mixing between the main phase and the dispersed phase.

[0047] As shown in FIG1 and FIG2 , in some embodiments of the present invention, the outer shell 1 is cylindrical, the axial direction of the first liquid inlet 12 is perpendicular to the axial direction of the outer shell 1 , and the mixed liquid outlet 13 is axially aligned with the outer shell 1 .

[0048] Specifically, when the main phase enters the mixing chamber 11 from the first liquid inlet 12, the main phase will turn once, and turbulence will occur, which helps to fully mix the dispersed phase into the main phase. In some embodiments, the ratio of the length of the first spiral blade 24 to the axial length of the first variable diameter zone 14 is (0.9 to 1):1. Preferably, the length of the first spiral blade 24 is the same as the axial length of the first variable diameter zone 14. In some embodiments, the ratio of the length of the second spiral blade 25 to the axial length of the second variable diameter zone 16 is (0.9 to 1):1. Preferably, the length of the second spiral blade 25 is the same as the axial length of the second variable diameter zone 16.

[0049] As shown in Figures 1 and 2, in some embodiments of the present invention, the first diameter-varying section 14 includes a first mixing section 141, a first expansion section 142, and a first tapered section 143, which are sequentially distributed along the axial direction of the injection section 21. The first mixing section 141 is connected to the first liquid inlet 12, and the first tapered section 143 is connected to the buffer zone 15. The diameter of the first tapered section 143 gradually decreases along the direction from the first liquid inlet 12 to the mixed liquid outlet 13. The minimum diameter of the first tapered section 143 is the same as the diameter of the buffer zone 15, and the maximum diameter of the first tapered section 143 is the same as the diameter of the first expansion section 142. The diameter of the first expansion section 142 is larger than the diameter of the first mixing section 141.

[0050] Specifically, the first mixing section 141 is cylindrical, so the first mixing section 141 has a consistent diameter. This creates a relatively stable flow environment for the mixed liquid, facilitating spiral flow of the mixed liquid in the first mixing section 141 under the guidance of the first spiral blade 24. During the spiral flow of the mixed liquid, the mixed liquid has a tangential velocity, and a shear stress gradient is formed in the mixed liquid, causing the dispersed phase to be sheared and broken into small droplets, thereby enabling the dispersed phase to be fully mixed with the main phase during the rotational flow. The first expansion section 142 is cylindrical, so the first expansion section 142 has a consistent diameter, but the diameter of the first expansion section 142 is larger than the diameter of the first mixing section 141. Due to the sudden increase in the diameter of the first expansion section 142, the flow rate of the mixed liquid in the first expansion section 142 will drop suddenly, and the pressure will increase. At this time, the flow rate of the mixed liquid near the wall of the first expansion section 142 is low, while the flow rate of the mixed liquid near the injection section 21 is high, that is, a large flow rate difference is formed in the first expansion section 142. This flow rate difference can cause the mixed liquid in the first expansion section 142 to have a violent secondary vortex. This secondary vortex breaks up and mixes the dispersed phase, so that the dispersed phase is fully mixed in the main phase. The diameter of the first tapering section 143 gradually decreases, so the flow rate of the mixed liquid in the first tapering section will gradually increase. On the one hand, it prevents the droplets of the dispersed phase from aggregating and growing. On the other hand, it promotes the accelerated collision of the main phase and the dispersed phase under high-speed flow. On the other hand, it ensures that the mixed liquid has a higher flow rate before entering the second diameter-changing zone 16 (facilitating the formation of violent turbulence in the buffer zone 15). In addition, the first spiral blade 24 can guide the mixed liquid to always maintain a spiral flow in the first variable diameter area 14 , which is also convenient for forming a violent turbulence in the buffer area 15 .

[0051] As shown in Figure 1, in some embodiments of the present invention, there is a first radial spacing between the wall of the first mixing section 141 and the outer edge of the first spiral blade 24, the minimum radial spacing between the wall of the first tapered section 143 and the outer edge of the first spiral blade 24 is a second radial spacing, and there is a third radial spacing between the outer wall of the injection section 21 and the wall of the first mixing section 141, and the first radial spacing and the second radial spacing are 1 / 8-1 / 4 of the third radial spacing.

[0052] Specifically, the distance between the wall of the first mixing section 141 and the outer edge of the first spiral blade 24 is small, and the minimum radial distance between the wall of the first tapered section 143 and the outer edge of the first spiral blade 24 is small, so that all the mixed liquid in the first variable diameter zone 14 can flow spirally along the first spiral blade 24.

[0053] As shown in FIG. 3 , in some embodiments of the present invention, a first spiral linear ridge 144 surrounding the first spiral blade 24 is provided on the wall surface of the first expansion section 142 . The spiral direction of the first spiral linear ridge 144 is opposite to that of the first spiral blade 24 .

[0054] Specifically, the first spiral convex groove 144 will exert reverse resistance on the liquid, so that the flow velocity of the mixed liquid at the wall of the first expansion section 142 is reduced, and the flow velocity difference in the first expansion section 142 is expanded, the intensity of the secondary vortex is increased, and the dispersed phase is further broken up and mixed.

[0055] In some embodiments, the radial inner side of the first helical linear ridge 144 is located between the wall of the first expansion section 142 and the wall of the first mixing section 141 , and the thickness of the first helical linear ridge 144 is less than or equal to the wall thickness of the delivery tube 2 .

[0056] In some embodiments of the present invention, the axial length of the buffer zone 15 is less than or equal to the axial length of the first mixing section 141 .

[0057] Specifically, as the mixed liquid flows from the first variable diameter section 14 to the second variable diameter section 16, the spiral direction of the first spiral blade 24 is opposite to that of the second spiral blade 25. Therefore, the liquid needs to change its spiral flow direction to flow along the second spiral blade 25. Furthermore, after the liquid is accelerated in the first tapered section 143, it will have a higher flow rate. Therefore, the flow state of the mixed liquid in the buffer zone 15 undergoes a dramatic change. This dramatic change disrupts the original flow state of the dispersed phase and the main phase, forming intense turbulence and promoting thorough mixing. However, the axial length of the buffer zone 15 should not be too long. This will concentrate the turbulence and ensure that the dispersed phase and the main phase are in full contact within a relatively compact area.

[0058] In some embodiments of the present invention, the axial length of the second variable diameter section 16 is less than the axial length of the first variable diameter section 14. The second variable diameter section 16 includes a second mixing section 161, a second expansion section 162, and a second tapered section 163, which are sequentially distributed along the axial direction of the injection section 21. The second mixing section 161 is connected to the buffer zone 15, and the second tapered section 163 is connected to the mixed liquid outlet 13. The diameter of the second tapered section 163 gradually decreases along the direction from the second liquid inlet 22 to the mixed liquid outlet 13. The minimum diameter of the second tapered section 163 is the same as the diameter of the mixed liquid outlet 13, and the maximum diameter of the second tapered section 163 is the same as the diameter of the second expansion section 162. The diameter of the second expansion section 162 is larger than the diameter of the second mixing section 161, and the diameter of the second mixing section 161 is equal to the diameter of the buffer zone 15.

[0059] Specifically, the second diameter-changing zone 16 is closer to the mixed liquid outlet 13, so the time for the mixed liquid to flow from the second diameter-changing zone 16 to the mixed liquid outlet 13 is relatively short, which is not conducive to the sufficient mixing of the dispersed phase and the main phase, so the length of the second diameter-changing zone 16 can be relatively short. The second mixing section 161 is cylindrical, so the second mixing section 161 has a consistent diameter, so the flow environment of the mixed liquid is relatively stable, which facilitates the mixed liquid in the second mixing section 161 to form a spiral flow under the guidance of the second spiral blade 25. During the spiral flow of the mixed liquid, the mixed liquid has a tangential velocity, and the mixed liquid forms a shear stress gradient so that the dispersed phase is sheared and broken into small droplets, so that the dispersed phase can be fully mixed in the main phase during the rotational flow. The second expansion section 162 is cylindrical, so the second expansion section 162 has a consistent diameter, but the diameter of the second expansion section 162 is larger than the diameter of the second mixing section 161. Due to the sudden increase in the diameter of the second expansion section 162, the flow rate of the mixed liquid in the second expansion section 162 will drop suddenly, and the pressure will increase. At this time, the flow rate of the mixed liquid near the wall of the second expansion section 162 is low, while the flow rate of the mixed liquid near the injection section 21 is high, that is, a large flow rate difference is formed in the second expansion section 162. This flow rate difference can cause the mixed liquid in the second expansion section 162 to have a violent secondary vortex. This secondary vortex breaks up and mixes the dispersed phase, so that the dispersed phase is fully mixed in the main phase. The diameter of the second tapering section 163 gradually decreases, so the flow rate of the mixed liquid in the second tapering section will gradually increase. On the one hand, it prevents the droplets of the dispersed phase from aggregating and growing, and on the other hand, it promotes the accelerated collision of the main phase and the dispersed phase under high-speed flow.

[0060] As shown in Figure 1, in some embodiments of the present invention, there is a fourth radial spacing between the wall of the second mixing section 161 and the outer edge of the second spiral blade 25, the minimum radial spacing between the wall of the second tapered section 163 and the outer edge of the second spiral blade 25 is a fifth radial spacing, and there is a sixth radial spacing between the outer wall of the injection section 21 and the wall of the second mixing section 161. The fourth radial spacing and the fifth radial spacing are 1 / 8-1 / 4 of the sixth radial spacing.

[0061] Specifically, the distance between the wall of the second mixing section 161 and the outer edge of the second spiral blade 25 is small, and the minimum radial distance between the wall of the second tapered section 163 and the outer edge of the second spiral blade 25 is small, so that all the mixed liquid in the second variable diameter zone 16 can flow spirally along the second spiral blade 25.

[0062] As shown in FIG. 4 , in some embodiments of the present invention, a second spiral linear ridge 164 surrounding the second spiral blade 25 is provided on the wall surface of the second expansion section 162 . The spiral direction of the second spiral linear ridge 164 is opposite to that of the second spiral blade 25 .

[0063] Specifically, the second spiral convex groove 164 will exert reverse resistance on the liquid, so that the flow velocity of the mixed liquid at the wall of the second expansion section 162 is reduced, and the flow velocity difference in the second expansion section 162 is expanded, the intensity of the secondary vortex is increased, and the dispersed phase is further broken up and mixed.

[0064] In some embodiments, the radial inner side of the second helical linear ridge 164 is located between the wall of the second expansion section 162 and the wall of the second mixing section 161 , and the thickness of the second helical linear ridge 164 is less than or equal to the wall thickness of the delivery tube 2 .

[0065] In some embodiments of the present invention, all injection holes 23 are arranged in multiple rows and columns along the injection section 21 to spray the mixed liquid into various areas of the mixing chamber 11. Since the second tapering section 16 is closer to the mixed liquid outlet 13, the time it takes for the mixed liquid to flow from the second tapering section 16 to the mixed liquid outlet 13 is relatively short, which is not conducive to sufficient mixing of the main phase and the dispersed phase. Therefore, the number of injection holes 23 in the second tapering section 16 can be relatively small, while the number of injection holes 23 in the first tapering section 14 can be relatively large. In other words, the number of injection holes 23 in the first tapering section 14 is greater than the number of injection holes 23 in the second tapering section 16, allowing more dispersed phase to be fully mixed in the first tapering section 14 and the buffer zone 15, thereby reducing the amount of dispersed phase used. Furthermore, in the axial direction of the injection section 21, the spacing between two adjacent injection holes 23 in the buffer zone 15 is smaller than the spacing between two adjacent injection holes 23 in the second tapering section 16. Therefore, the distribution density of the injection holes 23 in the buffer zone 15 is relatively high, allowing the injection pipe to spray more dispersed phase into the buffer zone 15. Since intense turbulence is formed in the buffer zone 15 , the main phase and the dispersed phase are more likely to come into contact with each other and are mixed more fully.

[0066] As shown in Figure 5, in some embodiments of the present invention, the aperture of the injection hole 23 gradually decreases from its liquid inlet end to its liquid outlet end, and the hole wall of the injection hole 23 is provided with a third spiral linear convex pattern 26 distributed around the axis of the injection hole 23. The injection hole 23 extends obliquely from its liquid inlet end to its liquid outlet end toward the head end of the outer shell 1.

[0067] Specifically, the injection hole 23 is a tapered hole, and the dispersed phase will be accelerated to a certain extent in the injection hole 23, which increases the impact of the dispersed phase on the mixed liquid in the mixing chamber 11 and increases the disturbance of the mixed liquid; at the same time, the third spiral linear convex pattern 26 can guide the dispersed phase to flow in a spiral manner, further increasing the disturbance of the mixed liquid, so that the main phase and the dispersed phase are fully mixed.

[0068] As shown in Figures 1-3 and 8, the acid hydrocarbon separation system described in the present invention includes a sedimentation separation device 100, a coagulation separation unit, an alkali washing unit and a water washing unit connected in sequence, and the alkali washing unit includes a first mixer 300 and a first separator 400 connected in sequence, wherein the first mixer 300 is the mixer described above.

[0069] In the acid-hydrocarbon separation system of the present invention, the sedimentation separation device 100 can be used to preliminarily separate the mixed acid and hydrocarbons in the acid-hydrocarbon mixture, and a portion of the mixed acid is separated and discharged, and the separated first oil phase enters the subsequent coalescence separation unit for further processing.

[0070] In the acid-hydrocarbon separation system of the present invention, the sedimentation separation device 100 can be a gravity sedimentation tank. In a more preferred embodiment, the interior of the sedimentation separation device 100 is provided with a corrugated plate filler, and the feed port of the acid-hydrocarbon mixture is located above the corrugated plate filler. The mixed acid separated after sedimentation separation is discharged from the bottom of the sedimentation separation device 100, and the separated first oil phase is discharged from the upper outlet and enters the subsequent coalescence separation unit for further processing. Further preferably, the angle between the corrugated structure on the corrugated plate filler and the horizontal direction is 50° to 70°. In this article, the angle between the corrugated structure and the horizontal direction refers to the angle between the inclined surface of the corrugation and the horizontal direction.

[0071] In the acid-hydrocarbon separation system of the present invention, the coalescence separation unit preferably includes one or more particle coalescence separation devices 200, the inner cavity of each particle coalescence separation device 200 being provided with a particle bed formed by media particles, wherein the media particles are hydrophilic particles, or a combination of hydrophilic and hydrophobic particles. In the present invention, the first oil phase separated from the sedimentation separation device 100 is processed by the particle coalescence separation device 200, and acid droplets with a diameter of 15 μm or greater are fully removed (with a removal rate of over 95%), while the majority of acid droplets with a diameter of less than 15 μm are removed (with a removal rate of over 50%).

[0072] In some embodiments, the particle bed comprises two or more layers, specifically, for example, two, three, or four layers. Each particle bed layer can be filled with media particles of the same or different morphologies and different hydrophilicity, and / or each bed layer can be filled with media particles of a single size or of different sizes.

[0073] In the present invention, the particle size of the media particles can be 0.2 to 5 mm, preferably 0.5 to 3 mm. The shape of the media particles can be various regular three-dimensional structures (such as spherical) or various special-shaped structures.

[0074] In the present invention, the hydrophilic particles include but are not limited to at least one of minerals, ceramics and glass.

[0075] In the present invention, the hydrophobic particles include but are not limited to at least one of polypropylene, polystyrene and polyurethane.

[0076] In a more preferred embodiment, the number of particle agglomeration separation devices 200 in the acid hydrocarbon separation system is two or more, and they are connected in parallel. According to this preferred embodiment, the two or more particle agglomeration separation devices 200 can operate simultaneously, or they can be in a state of one on and one off. During the operation of the device, when the pressure drop of one of the particle agglomeration separation devices is large, there is a large amount of suspended particles intercepted and accumulated in the surface bed. At this time, the corresponding particle agglomeration separation device can be closed and backwashed to release the suspended particles accumulated on the bed. At the same time, other particle agglomeration separation devices can be enabled so that the entire treatment process can continue. Specifically, the working pressure of each particle agglomeration separation device is 0.01~0.1MPa, and the cross-sectional flow rate is 0.001~0.02m / s. When the pressure drop of the particle agglomeration separation device is greater than 0.08MPa, the corresponding particle agglomeration separation device is backwashed.

[0077] In a more preferred embodiment, the particle agglomeration and separation device 200 is a vertical separator as shown in Figure 2. The inner cavity of the particle agglomeration and separation device 200 is provided with a first liquid distributor 2-1, two or more particle beds and an acid collection structure 2-5 from top to bottom. The first oil phase is injected through an inlet arranged above the first liquid distributor 2-1. The two or more particle beds are used to capture and agglomerate the emulsified acid droplets in the first oil phase and intercept solid suspended matter and the surface of the particle bed. The oil phase obtained after treatment by the particle bed is discharged through an outlet arranged below the particle bed and enters a subsequent separation process for further treatment. The separated mixed acid is discharged through the outlet at the bottom of the acid collection structure 2-5. In one embodiment, the particle agglomeration and separation device 200 is provided with two bed layers, namely a first bed layer 2-2 and a second bed layer 2-4. A support plate 2-6 is provided at the bottom of each of the first and second bed layers 2-2 and 2-4, and a backwash water interception plate 2-3 is provided at the top. A certain gap is provided between the first and second bed layers 2-2 and 2-4. A backwash water inlet is provided below the second bed layer 2-4, and a backwash water outlet is provided above the first bed layer 2-2. During the backwash process, the backwash water can be provided by the wash water separated in the subsequent water washing unit.

[0078] In the particle agglomeration and separation device 200 , the first liquid distributor 2 - 1 may be a distribution plate structure.

[0079] In the particle agglomeration and separation device 200, the acid collecting structures 2-5 may be Y-shaped collectors for collecting the acid phase (ie, mixed acid) separated by the bed agglomeration.

[0080] In the particle agglomeration and separation device 200, preferably, a first interface meter 2-7 is provided at the bottom outlet of the acid collection structure 2-5 for monitoring the interface between the oil phase and the acid phase, as shown in FIG2.

[0081] In the acid-hydrocarbon separation system of the present invention, the coalescence separation unit preferably further comprises one or more fiber coalescence separation devices, each of which is connected in series with the particle coalescence separation device 200. The inner cavity of each fiber coalescence separation device is provided with a fiber bed layer formed by a fiber medium, wherein the fiber medium includes hydrophilic fibers and hydrophobic fibers. Furthermore, preferably, the fiber coalescence separation device is located downstream of the particle coalescence separation device 200 to further deacidify the oil phase obtained after treatment by the particle coalescence separation device 200.

[0082] In a preferred embodiment, the fiber bed is formed by stacking a plurality of fiber layers, each of which is woven from hydrophilic fibers and hydrophobic fibers. The hydrophilic fibers may be, for example, metal fibers (e.g., monel alloy). The hydrophobic fibers may be made of, for example, at least one of Teflon, polyvinyl chloride, and polyphenylene sulfide.

[0083] In the acid-hydrocarbon separation system of the present invention, the alkali washing unit includes a first mixer 300 and a first separator 400 connected in sequence. In the alkali washing unit, the oil phase separated from the particle agglomeration separation device 200 or the oil phase separated from the fiber agglomeration device is fully mixed with the alkali solution through the first mixer 300. Hydrocarbon droplets and water-soluble aqueous phase droplets are mutually wrapped or interlaced with multiple layers of liquid phase. In order to dismantle the multiple layers of liquid phase wrapping of immiscible droplets and also to aggregate droplets of the same phase, the mixed liquid formed by mixing the oil phase and the alkali solution is then demulsified and aggregated by the first separator 400 to form liquid phase stratification. The waste alkali solution and the neutralization product enter the aqueous phase and are located in the upper layer, while the hydrocarbons enter the oil phase and are located in the lower layer.

[0084] In a more preferred embodiment, as shown in Figure 8, the first separator 400 includes a second shell and a second liquid distributor 4-1, a rectifier 4-2, a first demulsification and separation structure 4-3, a second demulsification and separation structure 4-4 and a third demulsification and separation structure 4-5 arranged in sequence along the logistics flow direction in the inner cavity of the second shell, wherein the first demulsification and separation structure 4-3 is a hydrophilic fiber layer, the second demulsification and separation structure 4-4 is an interwoven layer of oleophilic fiber and hydrophilic fiber, and the third demulsification and separation structure 4-5 is a corrugated plate. Through such a structural configuration, the second liquid distributor 4-1 and the rectifier 4-2 can further disperse the mixed liquid obtained after mixing; the first demulsification and separation structure 4-3 can demulsify and separate the hydrocarbon droplets and the water-soluble phase droplets in the mixed liquid, such as separating two layers of droplets of hydrocarbon in water or hydrocarbon in water, or separating three layers of droplets into two layers of droplets after one layer is separated; the second demulsification and separation structure 4-4 can further separate the hydrocarbon droplets and the water-soluble phase droplets that have not been completely separated; the third demulsification and separation structure 4-5 allows the water-soluble phase droplets and the hydrocarbon droplets to be fully separated and form a liquid phase layer. Therefore, according to the above preferred embodiment, the separation effect of hydrocarbons and other components (such as acids, alkalis, salts, water, etc.) can be further improved, so that the water content of the separated oil phase is less than 400 mg / L.

[0085] In the first separator 400 , the second liquid distributor 4 - 1 may be a calandria-type liquid distributor or a disc-type liquid distributor.

[0086] In the first separator 400, the rectifier 4-2 is preferably a flat perforated structure, wherein the hole diameter can be 1 to 3 mm, the hole center distance can be 5 to 8 mm, and the perforation rate can be 20% to 40%.

[0087] In the first separator 400 , the angle between the corrugated structure on the corrugated plate and the horizontal direction may be 30° to 60°.

[0088] In the first separator 400, to further enhance the separation of aqueous phase droplets and hydrocarbon droplets, the corrugated plates are preferably constructed from alternating layers of oleophilic and hydrophilic materials. More preferably, holes are provided at both the crests and troughs of the corrugated plates. Further preferably, the number of holes distributed at the crests and troughs is equal, and the specific number of holes can be adjusted based on the actual conditions of the material being separated. This structural configuration allows small droplets to quickly aggregate and float after demulsification, accelerating the floating of aqueous phase droplets and their separation from hydrocarbon droplets, while also stabilizing the flow field of the two-phase fluid.

[0089] In the first separator 400, after the liquid phases are separated, the aqueous phase (e.g., a waste alkali phase or an aqueous phase containing salts) is located in the upper layer and is discharged through the waste liquid outlet; the oil phase is located in the lower layer and is discharged through the oil phase outlet. Preferably, a second interface meter 4-6 is provided at the waste liquid outlet of the first separator 400 to monitor the interface between the aqueous and oil phases.

[0090] In the acid hydrocarbon separation system of the present invention, the water washing unit can be a conventional water washing device in the art. Preferably, the water washing unit comprises a second mixer 500 and a second separator 600 connected to each other. In the water washing unit, the oil phase obtained after alkali washing may also contain some water-soluble compounds, such as salts. Salt-containing hydrocarbons may pose explosion hazards in subsequent production processes, so water washing is required to remove the salts.

[0091] In the acid hydrocarbon separation system of the present invention, the structures of the second mixer 500 and the first mixer 300 may be the same or different, and are preferably the same.

[0092] In the acid hydrocarbon separation system of the present invention, the structures of the second separator 600 and the first separator 400 may be the same or different, and are preferably the same.

[0093] The acid hydrocarbon separation method of the present invention comprises the following steps:

[0094] (1) subjecting the acid-hydrocarbon mixture to sedimentation separation to obtain a first oil phase;

[0095] (2) agglomerating and separating the first oil phase to obtain a second oil phase;

[0096] (3) performing a first mixing of the second oil phase and an alkali solution, and performing a first enhanced separation on the obtained mixed solution to obtain a third oil phase;

[0097] (4) Washing the third oil phase with water.

[0098] In the method of the present invention, the sedimentation separation process of step (1) can preliminarily separate the acid and hydrocarbon in the acid-hydrocarbon mixture, and a portion of the acid is separated and discharged, and the separated first oil phase is further processed in a subsequent separation process.

[0099] In the method of the present invention, the sedimentation separation process of step (1) can be implemented in a sedimentation separation device. In some embodiments, the sedimentation separation device is provided with a corrugated plate filler inside, and the feed port of the acid-hydrocarbon mixture is located above the corrugated plate filler. After sedimentation separation, the acid separated is discharged from the bottom of the sedimentation separation device, and the separated first oil phase is discharged from the upper outlet and enters a subsequent separation process for further processing.

[0100] In a preferred embodiment, the angle between the corrugated structure of the corrugated plate packing and the horizontal direction is 50° to 70°.

[0101] In the present invention, the sedimentation separation device may be a gravity sedimentation tank.

[0102] In the method described in the present invention, in step (2), the coagulation and separation process is such that the acid content in the separated second oil phase is less than 5% of the acid content in the first oil phase, preferably 0.1-4.2%. Specifically, for example, it can be 0.1%, 0.5%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 3.95%, 4%, 4.05%, 4.1%, 4.15% or 4.2%.

[0103] In the method of the present invention, in step (2), the agglomeration and separation process preferably includes:

[0104] contacting the first oil phase with medium particles to perform a first coalescence separation, wherein the medium particles are hydrophilic particles, or a combination of hydrophilic particles and hydrophobic particles;

[0105] Optionally, the oil phase obtained after the first coalescence and separation is contacted with a fiber medium to perform a second coalescence and separation, wherein the fiber medium includes hydrophilic fibers and hydrophobic fibers.

[0106] The first agglomeration and separation process can fully remove acid droplets with a diameter of more than 15 μm (removal rate of more than 95%), and at the same time remove most of the acid droplets with a diameter of less than 15 μm (removal rate of more than 50%).

[0107] In a preferred embodiment, the first coalescence separation process includes: passing the first oil phase from top to bottom through a particle bed formed by the media particles.

[0108] In the present invention, the particle size of the media particles can be 0.2 to 5 mm, preferably 0.5 to 3 mm. The shape of the media particles can be various regular three-dimensional structures (such as spherical) or various special-shaped structures.

[0109] In the present invention, the hydrophilic particles include but are not limited to at least one of mineral particles, ceramic particles and glass particles.

[0110] In the present invention, the hydrophobic particles include but are not limited to at least one of polypropylene particles, polystyrene particles and polyurethane particles.

[0111] In the method described in the present invention, under preferred circumstances, the first agglomeration and separation process of step (2) is implemented in two or more particle agglomeration and separation devices arranged in parallel, each of the particle agglomeration and separation devices is filled with a particle bed formed by the medium particles, the working pressure of each particle agglomeration and separation device is 0.01-0.1MPa, the cross-sectional flow rate is 0.001-0.02m / s, and when the pressure drop of the particle agglomeration and separation device is greater than 0.08MPa, the corresponding particle agglomeration and separation device is backwashed. According to the above preferred situation, the two or more particle agglomeration and separation devices can be operated simultaneously, or can be in a state of one on and one off. During the operation of the device, when the pressure drop of one of the particle agglomeration and separation devices is large, the particle suspension accumulated in the surface particle bed is large. At this time, the corresponding particle agglomeration and separation device can be closed and backwashed to release the particle suspension accumulated on the particle bed. At the same time, other particle agglomeration and separation devices can be activated so that the entire treatment process can be carried out continuously.

[0112] In a more preferred embodiment, the particle agglomeration and separation device is a vertical separator as shown in Figure 2. The inner cavity of the particle agglomeration and separation device 200 is provided with a first liquid distributor 2-1, two or more particle beds and an acid collection structure 2-5 from top to bottom. The first oil phase is injected through an inlet arranged above the first liquid distributor 2-1. The two or more particle beds are used to capture and agglomerate the emulsified acid droplets in the first oil phase and retain solid suspended matter on the surface of the particle bed. The second oil phase obtained after treatment by the particle bed is discharged through an outlet arranged below the particle bed and enters a subsequent separation process for further treatment. The separated acid is discharged through the outlet at the bottom of the acid collection structure 2-5. In one embodiment, the particle agglomeration and separation device 200 is provided with two bed layers, namely a first bed layer 2-2 and a second bed layer 2-4. A support plate 2-6 is provided at the bottom of each of the first and second bed layers 2-2 and 2-4, and a backwash water interception plate 2-3 is provided at the top. A certain gap is provided between the first and second bed layers 2-2 and 2-4. A backwash water inlet is provided below the second bed layer 2-4, and a backwash water outlet is provided above the first bed layer 2-2. During the backwash process, the backwash water can be provided by the wash water separated in the subsequent water washing process.

[0113] In the particle agglomeration and separation device 200 , the first liquid distributor 2 - 1 may be a distribution plate structure.

[0114] In the particle agglomeration and separation device 200, the acid collecting structures 2-5 may be Y-shaped collectors for collecting the acid phase (ie, mixed acid) separated by agglomeration of the particle bed.

[0115] In the particle agglomeration and separation device 200, preferably, a first interface meter 2-7 is provided at the bottom outlet of the acid collection structure 2-5 for monitoring the interface between the oil phase and the acid phase, as shown in FIG2.

[0116] In the method of the present invention, the acid can be further removed by the second coalescence separation. Preferably, the second coalescence separation process includes passing the oil phase obtained after the first coalescence separation from top to bottom through a fiber bed formed by the fiber medium. The fiber bed is formed by stacking multiple fiber layers, each of which is woven from hydrophilic fibers and hydrophobic fibers. The hydrophilic fibers can be, for example, metal fibers (such as monel alloy). The hydrophobic fibers can be made of, for example, at least one of Teflon, polyvinyl chloride, and polyphenylene sulfide.

[0117] In the method of the present invention, in step (3), the second oil phase separated in the coalescence separation process is first mixed with the alkali solution, and then the mixed solution obtained after the mixing is subjected to enhanced separation. The mixing process can fully mix the second oil phase with the alkali solution and cause a neutralization reaction. The enhanced separation process can cause the mixed solution to undergo demulsification and liquid phase stratification, and separate the product after the mixed acid alkali washing from the hydrocarbons, thereby achieving sufficient deacidification. In step (3), by fully mixing the second oil phase with the alkali solution, the hydrocarbon droplets and the water-soluble phase droplets soluble in water will wrap each other or be wrapped in multiple layers of liquid phase. In order to disassemble the multiple layers of liquid phase wrapping of the incompatible droplets and also to aggregate the droplets of the same phase, it is necessary to demulsify, aggregate and form liquid phase stratification on the mixed solution formed after the oil phase and the alkali solution are mixed. The waste alkali solution and the neutralization product enter the water-soluble phase and are located in the upper layer, and the hydrocarbons enter the oil phase and are located in the lower layer.

[0118] In a preferred embodiment, in step (3), the first mixing process is performed so that the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid obtained after mixing is less than 100 μm, preferably less than 40 μm (e.g., 10-40 μm). The smaller the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid, the more fully the oil phase and the alkali solution are mixed. In a more preferred embodiment, the first mixing process is performed in the mixer described above. According to this embodiment, the alkali solution and the acid-hydrocarbon mixture can be fully mixed to obtain a better neutralization and deacidification effect, thereby significantly reducing the amount of alkali solution used in the alkali washing process and the salt content in the washing water produced after water washing.

[0119] In a preferred embodiment, in step (3), the first enhanced separation process causes the water content in the separated third oil phase to be less than 600 mg / L, preferably less than 400 mg / L (such as 200-400 mg / L). The lower the water content in the oil phase, the better the desalination and dealkalization effects. In some embodiments, the first enhanced separation process is carried out in a horizontal separator as shown in Figure 8, and the horizontal separator includes a second shell and a second liquid distributor 4-1, a rectifier 4-2, a first demulsification separation structure 4-3, a second demulsification separation structure 4-4 and a third demulsification separation structure 4-5 arranged in sequence along the flow direction of the logistics in the inner cavity of the second shell, wherein the first demulsification separation structure 4-3 is a hydrophilic fiber layer, the second demulsification separation structure 4-4 is an interwoven layer of oleophilic fiber and hydrophilic fiber, and the third demulsification separation structure 4-5 is a corrugated plate. Through such a structural configuration, the second liquid distributor 4-1 and the rectifier 4-2 can further disperse the mixed liquid obtained after the first liquid-liquid micro-mixing; the first demulsification separation structure 4-3 can demulsify and separate the hydrocarbon droplets and the water-soluble phase droplets in the mixed liquid, such as separating two layers of droplets of water-enclosed hydrocarbons or hydrocarbon-enclosed water, or separating three layers of droplets into two layers of droplets after one layer is separated; the second demulsification separation structure 4-4 can further separate the hydrocarbon droplets and the water-soluble phase droplets that have not been completely separated; the third demulsification separation structure 4-5 allows the water-soluble phase droplets and the hydrocarbon droplets to be fully separated and form a liquid phase layer. Therefore, according to the above preferred embodiment, the separation effect of hydrocarbons and other components (such as acid, water, alkali, salt, etc.) can be further improved, so that the water content of the separated oil phase is less than 400 mg / L.

[0120] In the horizontal separator, the second liquid distributor 4 - 1 may be a tube-type liquid distributor or a disc-type liquid distributor.

[0121] In the horizontal separator, the rectifier 4 - 2 is preferably a flat perforated structure, wherein the pore diameter may be 1 to 3 mm, the pore center spacing may be 5 to 8 mm, and the perforation rate may be 20% to 40%.

[0122] In the horizontal separator, the angle between the corrugated structure on the corrugated plate and the horizontal direction can be 30° to 60°.

[0123] In the horizontal separator, to further enhance the separation of aqueous phase droplets and hydrocarbon droplets, the corrugated plates are preferably constructed from alternating layers of oleophilic and hydrophilic materials. More preferably, holes are provided at both the crests and troughs of the corrugated plates. Further preferably, the number of holes distributed at the crests and troughs is equal, and the specific number of holes can be adjusted based on the actual conditions of the material being separated. This structural configuration allows small droplets to quickly aggregate and float after demulsification, accelerating the floating of aqueous phase droplets and their separation from hydrocarbon droplets, while also stabilizing the flow field of the two-phase fluid.

[0124] In the horizontal separator, after liquid phase separation is formed, the waste alkali liquid phase is located in the upper layer and is discharged through the waste liquid outlet; the oil phase is located in the lower layer and is discharged through the oil phase outlet. Preferably, a second level meter 4-6 is provided at the waste liquid outlet of the horizontal separator to monitor the interface between the waste alkali liquid phase and the oil phase.

[0125] In the method described in the present invention, in step (3), during the alkali washing process, the volume flow ratio of the second oil phase to the alkali solution can be 1:(0.05-0.2), preferably 1:(0.05-0.18), more preferably 1:(0.08-0.15), and further preferably 1:(0.08-0.12).

[0126] In the method of the present invention, the alkali solution can be at least one of sodium hydroxide solution, potassium hydroxide solution and ammonia solution. The concentration of the alkali solution can be 10-40wt%, preferably 15-35wt%.

[0127] In the method of the present invention, the oil phase obtained after alkali washing may also contain some water-soluble mixtures, such as salts, etc. Salt-containing hydrocarbons may pose a risk of explosion in subsequent production processes, so water washing is required to remove the salts.

[0128] In the method of the present invention, in step (4), preferably, the water washing process includes: performing a second mixing of the third oil phase with water, and performing a second enhanced separation on the resulting mixed liquid. By mixing the third oil phase with water, hydrocarbon droplets and aqueous phase droplets will be mutually wrapped or interlaced with multiple layers of liquid phase. In order to break up the multiple layers of liquid phase wrapping of the immiscible droplets and also to aggregate the droplets of the same phase, it is necessary to perform an enhanced separation on the mixed liquid, so that the mixed liquid demulsifies, aggregates, and forms liquid phase stratification, with salts and the like entering the aqueous phase and being located in the upper layer, and purified hydrocarbons being located in the lower layer.

[0129] Preferably, the second mixing process is performed so that the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid obtained after mixing is less than 100 μm, preferably less than 40 μm (e.g., 10-40 μm). The smaller the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid, the more complete the mixing of the crude nitrobenzene and water.

[0130] In the present invention, the mixing device used in the second mixing process can be the same as or different from the mixing device used in the first mixing process, and is preferably the same. In a preferred embodiment, the mixing device used in the second mixing process is a horizontal mixer as shown in FIG3 .

[0131] Preferably, the second enhanced separation process reduces the water content of the separated purified hydrocarbons to less than 600 mg / L, preferably less than 400 mg / L (e.g., 200-400 mg / L). The lower water content in the purified hydrocarbons can reduce energy consumption in the subsequent distillation system.

[0132] In the present invention, the separator used in the second enhanced separation process can be the same as or different from the separator used in the first enhanced separation process, preferably the same. Preferably, the separator used in the second enhanced separation process is a horizontal separator as shown in Figure 4.

[0133] In the method described in the present invention, during the water washing process, the volume flow ratio of the third oil phase to water is 1:(0.1-0.6), preferably 1:(0.1-0.5), more preferably 1:(0.15-0.4), and further preferably 1:(0.2-0.3).

[0134] In the method of the present invention, the acid in the acid-hydrocarbon mixture may be at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid and hydrobromic acid.

[0135] In the method of the present invention, the hydrocarbon in the acid-hydrocarbon mixture may be an aromatic hydrocarbon, preferably at least one of nitroaromatic hydrocarbons (such as nitrobenzene, nitrotoluene), halogenated aromatic hydrocarbons and nitrohalogenated aromatic hydrocarbons (such as nitrochlorobenzene).

[0136] In some embodiments, the acid-hydrocarbon mixture is a nitration reaction product (i.e., a nitration solution), wherein the hydrocarbon to be separated and purified is nitrobenzene. Separating and purifying the nitration reaction product according to the acid-hydrocarbon separation method of the present invention can significantly reduce the amount of alkali solution used in the alkali washing process and the salt content in the wash water produced after water washing, and significantly reduce the nitrophenol content in the purified nitrobenzene finally separated.

[0137] In other embodiments, the acid-hydrocarbon mixture is a nitration reaction product containing nitrotoluene, wherein the hydrocarbon to be separated and purified is nitrotoluene. Separating and purifying the nitration reaction product containing nitrotoluene according to the acid-hydrocarbon separation method of the present invention can significantly reduce the amount of alkali solution used in the alkali washing process and the salt content in the wash water produced after water washing.

[0138] In other embodiments, the acid-hydrocarbon mixture is a nitration reaction product containing nitrochlorobenzene, wherein the hydrocarbon to be separated and purified is nitrochlorobenzene. Separating and purifying the nitration reaction product containing nitrochlorobenzene according to the acid-hydrocarbon separation method of the present invention can significantly reduce the amount of alkali solution used in the alkali washing process and the salt content in the wash water produced after water washing.

[0139] The mixer and acid-hydrocarbon separation system and method of the present invention are further illustrated by examples below. The examples are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operating processes, but the scope of protection of the present invention is not limited to the following examples.

[0140] The experimental methods in the following examples, unless otherwise specified, are all conventional methods in the art. The experimental materials used in the following examples, unless otherwise specified, are all commercially available.

[0141] In the following examples and comparative examples, the amount of acid in the first oil phase obtained after sedimentation separation and the second oil phase obtained after coalescence separation was determined according to the acid-base titration method;

[0142] The median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid obtained by the first mixer and the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid obtained by the second mixer are measured using an electron microscope and a particle size counter;

[0143] The water content of the third oil phase separated in the first separator and the water content of the purified hydrocarbon finally separated are measured using a Karl Fischer moisture meter;

[0144] The nitrophenol content of the final separated purified hydrocarbons was determined spectrophotometrically;

[0145] The salt content of the wash water generated during the washing process was determined using ion chromatography.

[0146] Example 1

[0147] (1) Acid hydrocarbon separation system

[0148] The structure of the acid hydrocarbon separation system used in this embodiment is shown in Figures 1-8. Specifically, as shown in Figure 1, the acid hydrocarbon separation system includes a sedimentation separation device 100, two mutually parallel particle agglomeration separation devices 200, a first mixer 300, a first separator 400, a second mixer 500 and a second separator 600; the sedimentation separation device 100 is a gravity sedimentation tank, and a corrugated plate filler is arranged inside it; the particle agglomeration separation device 200 is a vertical separator as shown in Figure 2, and its inner cavity is sequentially provided with a first liquid distributor 2-1, two beds formed by medium particles (i.e., a first bed layer 2-2 and a second bed layer 2-4) and an acid collection structure 2-5 from top to bottom, and a backwash water interception plate 2-3 is provided on the top of each bed layer, and a support plate 2-6 is provided on the bottom. An oil phase inlet is provided above a liquid distributor 2-1, and the oil phase inlet is connected to the oil phase outlet of the sedimentation separation device 100. An outlet for discharging mixed acid is provided at the bottom of the acid collection structure 2-5. An oil phase outlet is provided below the second bed layer 2-4 (located on the side of the device), a backwash water inlet is provided below the second bed layer 2-4, and a backwash water outlet is provided above the first bed layer 2-2; the first mixer 300 and the second mixer 500 are the same, and both are horizontal mixers as shown in Figure 3, including an outer shell 1 and a conveying pipe 2, a mixing chamber 11 is provided inside the outer shell 1, a first liquid inlet 12 for the raw material liquid to enter the mixing chamber 11 is provided at the head end of the outer shell 1, and a mixed liquid outlet 13 for the mixed liquid to flow out of the mixing chamber 11 is provided at the end of the outer shell 1.The delivery pipe 2 extends from the head end of the outer shell 1 through the mixing chamber 11 to the end of the outer shell 1, the first port of the delivery pipe 2 at the head end extends out of the outer shell 1 and forms a second liquid inlet 22, the second port of the delivery pipe 2 at the end is closed, and the part of the delivery pipe 2 located in the mixing chamber 11 forms an injection section 21, and a plurality of injection holes 23 are provided on the tube wall of the injection section 21 for injecting the dispersed phase input through the second liquid inlet 22 into the mixing chamber 11. The outer periphery of the injection section 21 is provided with a first spiral blade 24 and a second spiral blade 25 distributed along its axial direction, and the spiral directions of the first spiral blade 24 and the second spiral blade 25 are opposite, the first liquid inlet 12 of the first mixer 300 is connected to the oil phase outlet in the particle agglomeration separation device 200, and the second liquid inlet 22 is used for injecting alkali solution; the second liquid inlet 22 of the second mixer 500 is used for injecting water; the first separator 400 and the second separator 600 are the same, and both are horizontal as shown in Figure 8 The separator includes a shell and a second liquid distributor 4-1, a rectifier 4-2, a first demulsification and separation structure 4-3, a second demulsification and separation structure 4-4 and a third demulsification and separation structure 4-5 arranged in sequence along the logistics flow direction in the inner cavity of the shell, wherein the first demulsification and separation structure 4-3 is a hydrophilic fiber layer, the second demulsification and separation structure 4-4 is an interwoven layer of oleophilic fiber and hydrophilic fiber, and the third demulsification and separation structure 4-5 is a corrugated plate; the first separator 400 has a liquid inlet, an oil phase outlet and a waste alkali liquid outlet for discharging waste alkali liquid, the second separator 600 has an oil phase outlet and a washing water outlet for discharging washing water, wherein the mixed liquid outlet 13 of the first mixer 300 is connected to the liquid inlet of the first separator 400, the oil phase outlet of the first separator 400 is connected to the first liquid inlet 12 of the second mixer 500, and the mixed liquid outlet 13 of the second mixer 500 is connected to the liquid inlet of the second separator 600.

[0149] (2) Acid hydrocarbon separation method

[0150] The nitration liquid (i.e., the nitration reaction product containing nitrobenzene) is injected into the sedimentation separation device 100, and the nitration liquid is subjected to gravity sedimentation separation through the corrugated plate filler. The angle between the corrugated structure on the corrugated plate filler and the horizontal direction is 60°. The separated mixed acid is discharged from the bottom outlet, and the separated first oil phase is transported from the upper outlet to the particle agglomeration separation device 200.

[0151] The first oil phase (acid content of 12000 mg / L) from the sedimentation separation device 100 was heated to 6 m 3 / h of flow rate enters the particle agglomeration and separation device 200 for treatment, wherein the first bed layer 2-2 is formed by filling glass particles with a particle size of 0.6 to 1.2 mm, and the second bed layer 2-4 is formed by filling polystyrene particles with a particle size of 0.3 to 0.8 mm and ceramic particles with a volume ratio of 1:2. The ratio of the height of the first bed layer 2-2 to the second bed layer 2-4 is 1:1, and the amount of acid in the separated second oil phase is 463 mg / L.

[0152] The second oil phase from the particle agglomeration and separation device 200 enters the first mixer 300, and alkali solution (sodium hydroxide solution with a concentration of 15wt%) is injected through the second liquid inlet 22, wherein the volume flow ratio of the alkali solution to the second oil phase is 0.1:1. The obtained mixed liquid enters the first separator 400, and the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid is 34μm.

[0153] The mixed liquid from the first mixer 300 is demulsified and the liquid phase is separated in the first separator 400. The rectifier 4-2 is a perforated flat plate with a pore diameter of 2 mm, a hole center spacing of 6 mm, and a perforation rate of 25%. The volume specific surface area of ​​the first demulsification and separation structure 4-3 is 5000 m 2 / m 3 The porosity is 0.75, the structure depth is 400mm, and all hydrophilic fibers are woven in an X-shaped weaving method; the volume specific surface area of ​​the second demulsification separation structure 4-4 is 5000m 2 / m 3 The porosity is 0.75, the structural depth is 400mm, the hydrophilic and hydrophobic fiber ratio is 1:1, and it is woven using the Ω-type fiber weaving method; the structural depth of the third demulsification and separation structure 4-5 is 400mm, the angle between the corrugated structure on the corrugated plate and the horizontal direction is 30°, and the material is polypropylene and monel alloy arranged alternately. The third oil phase is separated from the liquid phase stratification, and the water content in the third oil phase is 381mg / L.

[0154] The third oil phase from the first separator 400 enters the second mixer 500, and water is injected through the second liquid inlet 22, wherein the volume flow ratio of water to the third oil phase is 0.2:1. The resulting mixed liquid enters the second separator 600, and the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid is 28 μm.

[0155] The mixed liquid from the second mixer 500 is demulsified and liquid-phase separated in the second separator 600, and washing water is separated from the liquid-phase separated liquid and used to backwash the particle agglomeration separation device 200, and purified nitrobenzene is separated from the liquid-phase separated liquid, wherein the water content is 342 mg / L and the nitrophenol content is 5 ppm; the salt content in the washing water is 4251 mg / L.

[0156] Example 2

[0157] The acid hydrocarbon separation system is configured according to Example 1, wherein the acid hydrocarbon separation method is specifically as follows:

[0158] The nitration liquid (i.e., the nitration reaction product containing nitrobenzene) is injected into the sedimentation separation device 100, and the nitration liquid is subjected to gravity sedimentation separation through the corrugated plate filler. The angle between the corrugated structure on the corrugated plate filler and the horizontal direction is 50°. The separated mixed acid is discharged from the bottom outlet, and the separated first oil phase is transported from the upper outlet to the particle agglomeration separation device 200.

[0159] The first oil phase (acid content of 12000 mg / L) from the sedimentation separation device 100 was heated to 6 m 3 / h of flow rate enters the particle agglomeration and separation device 200 for treatment, wherein the first bed layer 2-2 is formed by filling ceramic particles with a particle size of 1.5 to 3.5 mm, and the second bed layer 2-4 is formed by filling polypropylene particles and glass particles with a particle size of 0.8 to 2.0 mm in a uniform mixture at a volume ratio of 1:1, and the ratio of the height of the first bed layer 2-2 to the second bed layer 2-4 is 1:1. The amount of acid in the separated second oil phase is 485 mg / L.

[0160] The second oil phase from the particle agglomeration separation device 200 enters the first mixer 300, and alkali solution (sodium hydroxide solution with a concentration of 15wt%) is injected through the second liquid inlet 22, wherein the volume flow ratio of the alkali solution to the second oil phase is 0.08:1. The obtained mixed liquid enters the first separator 400, and the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid is 37μm.

[0161] The mixed liquid from the first mixer 300 is demulsified and the liquid phase is separated in the first separator 400. The rectifier 4-2 is a perforated flat plate with a pore diameter of 1 mm, a hole center spacing of 5 mm, and a perforation rate of 20%. The volume specific surface area of ​​the first demulsification and separation structure 4-3 is 5000 m 2 / m 3 The porosity is 0.75, the structure depth is 400mm, and all hydrophilic fibers are woven in an X-shaped weaving method; the volume specific surface area of ​​the second demulsification separation structure 4-4 is 5000m 2 / m 3The porosity is 0.75, the structural depth is 400mm, the hydrophilic and hydrophobic fiber ratio is 1:1.5, and it is woven using the Ω-type fiber weaving method; the structural depth of the third demulsification and separation structure 4-5 is 400mm, the angle between the corrugated structure on the corrugated plate and the horizontal direction is 45°, and the material is polypropylene and monel alloy arranged alternately. The third oil phase is separated from the liquid phase stratification, and the water content in the third oil phase is 389mg / L.

[0162] The third oil phase from the first separator 400 enters the second mixer 500, and water is injected through the second liquid inlet 22, wherein the volume flow ratio of water to the third oil phase is 0.3:1. The resulting mixed liquid enters the second separator 600, and the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid is 33 μm.

[0163] The mixed liquid from the second mixer 500 is demulsified and liquid-phase separated in the second separator 600, and washing water is separated from the liquid-phase separated liquid and used to backwash the particle agglomeration separation device 200, and purified nitrobenzene is separated from the liquid-phase separated liquid, wherein the water content is 346 mg / L and the nitrophenol content is 6 ppm; the salt content in the washing water is 4432 mg / L.

[0164] Example 3

[0165] The acid hydrocarbon separation system is configured according to Example 1, wherein the acid hydrocarbon separation method is specifically as follows:

[0166] The nitration liquid (i.e., the nitration reaction product containing nitrobenzene) is injected into the sedimentation separation device 100, and the nitration liquid is subjected to gravity sedimentation separation through the corrugated plate filler. The angle between the corrugated structure on the corrugated plate filler and the horizontal direction is 70°. The separated mixed acid is discharged from the bottom outlet, and the separated first oil phase is transported from the upper outlet to the particle agglomeration separation device 200.

[0167] The first oil phase (acid content of 12000 mg / L) from the sedimentation separation device 100 was heated to 6 m 3 / h of flow rate enters the particle agglomeration and separation device 200 for processing, wherein the first bed layer 2-2 is formed by filling ore particles with a particle size of 2.5 to 4.5 mm, and the second bed layer 2-4 is formed by filling polyurethane particles and ceramic particles with a particle size of 1.8 to 3.0 mm with a volume ratio of 1:3. The height ratio of the first bed layer 2-2 to the second bed layer 2-4 is 1:1, and the amount of acid in the separated second oil phase is 498 mg / L.

[0168] The second oil phase from the particle agglomeration separation device 200 enters the first mixer 300, and alkali solution (sodium hydroxide solution with a concentration of 15wt%) is injected through the second liquid inlet 22, wherein the volume flow ratio of the alkali solution to the second oil phase is 0.12:1. The obtained mixed liquid enters the first separator 400, and the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid is 39μm.

[0169] The mixed liquid from the first mixer 300 is demulsified and the liquid phase is separated in the first separator 400. The rectifier 4-2 is a perforated flat plate with a pore diameter of 3 mm, a hole center distance of 8 mm, and a perforation rate of 40%. The volume specific surface area of ​​the first demulsification and separation structure 4-3 is 5000 m 2 / m 3 The porosity is 0.75, the structure depth is 400mm, and all hydrophilic fibers are woven in an X-shaped weaving method; the volume specific surface area of ​​the second demulsification separation structure 4-4 is 5000m 2 / m 3 The porosity is 0.75, the structural depth is 400mm, the hydrophilic and hydrophobic fiber ratio is 1:2, and it is woven using the Ω-type fiber weaving method; the structural depth of the third demulsification and separation structure 4-5 is 400mm, the angle between the corrugated structure on the corrugated plate and the horizontal direction is 60°, and the material is polypropylene and monel alloy arranged alternately. The third oil phase is separated from the liquid phase, and the water content in the third oil phase is 397mg / L.

[0170] The third oil phase from the first separator 400 enters the second mixer 500, and water is injected through the second liquid inlet 22, wherein the volume flow ratio of water to the third oil phase is 0.25:1. The resulting mixed liquid enters the second separator 600, and the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid is 38 μm.

[0171] The mixed liquid from the second mixer 500 is demulsified and liquid-phase separated in the second separator 600, and washing water is separated from the liquid-phase separated liquid and used to backwash the particle agglomeration separation device 200, and purified nitrobenzene is separated from the liquid-phase separated liquid, wherein the water content is 349 mg / L and the nitrophenol content is 8 ppm; the salt content in the washing water is 4573 mg / L.

[0172] Example 4

[0173] An acid-hydrocarbon separation system was configured according to Example 1 and implemented according to the method of Example 1, except that the acid-hydrocarbon separation system was further configured with a fiber agglomeration device, wherein the fiber bed in the fiber agglomeration device was formed by alternating hydrophilic and hydrophobic fibers. The oil phase outlet of the particle agglomeration separation device 200 was connected to the feed inlet of the fiber agglomeration device, and the oil phase outlet of the fiber agglomeration device was connected to the oil phase inlet of the first mixer 300. The hydrophilic fibers were monel alloy fibers, and the hydrophobic fibers were Teflon fibers. The volume ratio of the hydrophilic and hydrophobic fibers was 1:2. The volume flow ratio of the alkali solution to the second oil phase was 0.06:1.

[0174] As a result, the water content in the purified nitrobenzene finally separated was 337 mg / L, and the nitrophenol content was 3 ppm; the salt content in the washing water was 2158 mg / L.

[0175] Example 5

[0176] The acid-hydrocarbon separation system is configured according to Example 1, and the method of Example 1 is implemented, except that the second demulsification separation structure 4 - 4 is not configured in the first separator 400 and the second separator 600 .

[0177] As a result, the water content in the purified nitrobenzene finally separated was 556 mg / L, and the nitrophenol content was 15 ppm; the salt content in the washing water was 6954 mg / L.

[0178] Comparative Example 1

[0179] An acid-hydrocarbon separation system was configured according to Example 1 and implemented according to the method of Example 1, except that the particle agglomeration separation device 200 was replaced by a fiber filter element separator (purchased from Shanghai Anci Environmental Protection Technology Co., Ltd., model AFBP-1200), wherein the volume flow ratio of the alkali solution to the second oil phase (i.e., crude nitrobenzene) in the first mixer 300 was 0.35:1.

[0180] As a result, the water content in the purified nitrobenzene finally separated was 396 mg / L, and the nitrophenol content was 35 ppm; the salt content in the washing water was 11297 mg / L.

[0181] Comparative Example 2

[0182] An acid-hydrocarbon separation system was configured according to Example 1, and the method of Example 1 was implemented, except that no delivery pipe was provided in the mixer. Specifically, in the first mixer 300, the alkali solution and the second oil phase (i.e., crude nitrobenzene) were both injected through the first liquid inlet 12 on the outer shell; in the second mixer 500, water and the third oil phase were both injected through the first liquid inlet 12 on the outer shell. The volume flow ratio of the alkali solution to the second oil phase during the alkali washing process was 0.3:1.

[0183] As a result, the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid obtained in the first mixer 300 was greater than 100 μm; the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid obtained in the second mixer 500 was greater than 100 μm; the water content in the purified nitrobenzene finally separated was 382 mg / L, and the nitrophenol content was 42 ppm; the salt content in the washing water was 12219 mg / L.

[0184] Comparative Example 3

[0185] An acid-hydrocarbon separation system was configured according to Example 1, and the method of Example 1 was implemented, except that a centrifugal extractor was used instead of the first mixer 300 and the first separator 400 for alkali washing, and another centrifugal extractor was used instead of the second mixer 500 and the second separator 600 for water washing. During the alkali washing process, the volume flow ratio of the alkali solution to the second oil phase (i.e., crude nitrobenzene) was 1:1, and during the water washing process, the volume flow ratio of water to the third oil phase was 1:1.

[0186] As a result, the water content in the purified nitrobenzene finally separated was 849 mg / L, and the nitrophenol content was 46 ppm; the salt content in the washing water separated from the water washing process was 13237 mg / L.

[0187] The parameters of the logistics at each stage in the above embodiments and comparative examples are shown in Table 1 below.

[0188] Table 1

[0189] The results in Table 1 show that the separation and purification of the nitration reaction product containing nitrobenzene by the acid-hydrocarbon separation method of the present invention can achieve a good acid-hydrocarbon separation effect. The nitrophenol content in the separated purified nitrobenzene is significantly lower, the amount of alkali solution used is significantly less, and the salt content in the washing water produced after washing is significantly lower.

[0190] Example 6

[0191] An acid-hydrocarbon separation system was configured according to Example 1 to separate and purify the nitration reaction product containing nitrotoluene. The specific process is as follows:

[0192] The nitration liquid (i.e., the nitration reaction product containing nitrotoluene) is injected into the sedimentation separation device 100, and the nitration liquid is subjected to gravity sedimentation separation through the corrugated plate filler. The separated mixed acid is discharged from the bottom outlet, and the separated first oil phase is transported from the upper outlet to the particle agglomeration separation device 200.

[0193] The first oil phase (acid content of 11868 mg / L) from the sedimentation separation device 100 was heated to 6 m 3 / h flow rate into the particle agglomeration separation device 200 for treatment, and the acid content in the separated second oil phase is 457 mg / L.

[0194] The second oil phase from the particle agglomeration separation device 200 enters the first mixer 300, and alkali solution (sodium hydroxide solution with a concentration of 15wt%) is injected through the second liquid inlet 22, wherein the volume flow ratio of the alkali solution to the second oil phase is 0.15:1. The obtained mixed liquid enters the first separator 400, and the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid is 35μm.

[0195] The mixed liquid from the first mixer 300 is subjected to demulsification and liquid phase separation in the first separator 400, and a third oil phase is separated from the liquid phase separation. The water content in the third oil phase is 383 mg / L.

[0196] The third oil phase from the first separator 400 enters the second mixer 500, and water is injected through the second liquid inlet 22, wherein the volume flow ratio of water to the third oil phase is 0.25:1. The resulting mixed liquid enters the second separator 600, and the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid is 30 μm.

[0197] The mixed liquid from the second mixer 500 is demulsified and liquid-phase separated in the second separator 600, and washing water is separated from the liquid-phase separated liquid and used to backwash the particle agglomeration separation device 200, and purified nitrotoluene is separated from the liquid-phase separated liquid, wherein the water content is 341 mg / L and the salt content of the washing water is 4162 mg / L.

[0198] Comparative Example 4

[0199] An acid-hydrocarbon separation system was configured according to Example 6, and the method of Example 6 was implemented, except that no delivery pipe was configured in the mixer. Specifically, in the first mixer 300, the alkali solution and the second oil phase were both injected through the first liquid inlet 12 on the outer shell; in the second mixer 500, water and the third oil phase were both injected through the first liquid inlet 12 on the outer shell. The volume flow ratio of the alkali solution to the second oil phase during the alkali washing process was 0.36:1.

[0200] As a result, the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid obtained in the first mixer 300 was greater than 100 μm; the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid obtained in the second mixer 500 was greater than 100 μm; the water content in the finally separated purified nitrotoluene was 385 mg / L, and the salt content in the washing water was 11579 mg / L.

[0201] By comparing Example 6 with Comparative Example 4, it can be seen that the acid-hydrocarbon separation method of the present invention can be used to separate and purify the nitration reaction product containing nitrotoluene, and a better acid-hydrocarbon separation effect can be obtained. The amount of alkali solution used is significantly less, and the salt content in the washing water produced after water washing is significantly lower.

[0202] Example 7

[0203] An acid-hydrocarbon separation system was configured according to Example 1 to separate and purify the nitration reaction product containing nitrochlorobenzene. The specific process is as follows:

[0204] The nitration liquid (i.e., the nitration reaction product containing nitrochlorobenzene) is injected into the sedimentation separation device 100, and the nitration liquid is subjected to gravity sedimentation separation through the corrugated plate filler. The separated mixed acid is discharged from the bottom outlet, and the separated first oil phase is transported from the upper outlet to the particle agglomeration separation device 200.

[0205] The first oil phase (acid content of 11594 mg / L) from the sedimentation separation device 100 was heated to 6 m 3 / h flow rate into the particle agglomeration separation device 200 for treatment, and the acid content in the separated second oil phase is 453 mg / L.

[0206] The second oil phase from the particle agglomeration separation device 200 enters the first mixer 300, and alkali solution (sodium hydroxide solution with a concentration of 15wt%) is injected through the second liquid inlet 22, wherein the volume flow ratio of the alkali solution to the second oil phase is 0.12:1. The obtained mixed liquid enters the first separator 400, and the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid is 33μm.

[0207] The mixed liquid from the first mixer 300 is subjected to demulsification and liquid phase separation in the first separator 400, and a third oil phase is separated from the liquid phase separation. The water content in the third oil phase is 379 mg / L.

[0208] The third oil phase from the first separator 400 enters the second mixer 500, and water is injected through the second liquid inlet 22, wherein the volume flow ratio of water to the third oil phase is 0.23:1. The resulting mixed liquid enters the second separator 600, and the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid is 31 μm.

[0209] The mixed liquid from the second mixer 500 is demulsified and liquid-phase separated in the second separator 600, and washing water is separated from the liquid-phase separated liquid and used to backwash the particle agglomeration separation device 200, and purified nitrochlorobenzene is separated from the liquid-phase separated liquid, wherein the water content is 343 mg / L and the salt content in the washing water is 4129 mg / L.

[0210] Comparative Example 5

[0211] An acid-hydrocarbon separation system was configured according to Example 7, and the method of Example 7 was implemented, except that no delivery pipe was provided in the mixer. Specifically, in the first mixer 300, both the alkali solution and the second oil phase were injected through the first liquid inlet 12 on the outer shell; in the second mixer 500, both water and the third oil phase were injected through the first liquid inlet 12 on the outer shell. The volume flow ratio of the alkali solution to the second oil phase during the alkali washing process was 0.35:1.

[0212] As a result, the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid obtained in the first mixer 300 was greater than 100 μm; the median particle size of the hydrocarbon dispersed phase droplets in the mixed liquid obtained in the second mixer 500 was greater than 100 μm; the water content in the purified nitrochlorobenzene finally separated was 387 mg / L, and the salt content in the washing water was 11357 mg / L.

[0213] By comparing Example 7 with Comparative Example 5, it can be seen that the acid-hydrocarbon separation method of the present invention is used to separate and purify the nitration reaction product containing nitrochlorobenzene, which can achieve a better acid-hydrocarbon separation effect, the amount of alkali solution used is significantly less, and the salt content in the washing water produced after washing is significantly lower.

[0214] 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 mixer, characterized in that: include: An outer shell (1), wherein a mixing chamber (11) is provided inside the outer shell (1), a first liquid inlet (12) for allowing raw material liquid to enter the mixing chamber (11) is provided at the front end of the outer shell (1), and a mixed liquid outlet (13) for allowing mixed liquid to flow out of the mixing chamber (11) is provided at the rear end of the outer shell (1); and a delivery pipe (2), the delivery pipe (2) extending from the head end of the outer shell (1) through the mixing chamber (11) to the rear end of the outer shell (1), the first port of the delivery pipe (2) located at the head end protruding out of the outer shell (1) and forming a second liquid inlet (22), the second port of the delivery pipe (2) located at the rear end is closed, the portion of the delivery pipe (2) located in the mixing chamber (11) forms an injection section (21), a plurality of injection holes (23) arranged at intervals on the wall of the injection section (21) for injecting the dispersed phase input through the second liquid inlet (22) into the mixing chamber (11), the outer periphery of the injection section (21) is provided with a first spiral blade (24) and a second spiral blade (25) arranged at intervals along the axial direction thereof, the spiral directions of the first spiral blade (24) and the second spiral blade (25) being opposite.

2. The mixer according to claim 1, characterized in that The mixing chamber (11) comprises a first diameter-changing zone (14), a buffer zone (15) and a second diameter-changing zone (16) which are sequentially distributed along a direction from the first liquid inlet (12) to the mixed liquid outlet (13); the first spiral blade (24) and the second spiral blade (25) are respectively located in the first diameter-changing zone (14) and the second diameter-changing zone (16); And / or, the outer shell (1) is cylindrical, the axial direction of the first liquid inlet (12) is perpendicular to the axial direction of the outer shell (1), and the axial direction of the mixed liquid outlet (13) is the same as the axial direction of the outer shell (1).

3. The mixer according to claim 2, characterized in that The first diameter-changing zone (14) comprises a first mixing section (141), a first expansion section (142) and a first tapered section (143) which are sequentially distributed along the axial direction of the injection section (21); the first mixing section (141) is connected to the first liquid inlet (12); and the first tapered section (143) is connected to the buffer zone (15); The diameter of the first tapered section (143) is along the direction from the first liquid inlet (12) to the mixing The direction of the combined liquid outlet (13) gradually decreases, the minimum diameter of the first tapered section (143) is the same as the diameter of the buffer zone (15), the maximum diameter of the first tapered section (143) is the same as the diameter of the first expansion section (142), and the diameter of the first expansion section (142) is greater than the diameter of the first mixing section (141).

4. The mixer according to claim 3, characterized in that There is a first radial spacing between the wall surface of the first mixing section (141) and the outer edge of the first spiral blade (24), the minimum radial spacing between the wall surface of the first tapered section (143) and the outer edge of the first spiral blade (24) is a second radial spacing, and there is a third radial spacing between the outer wall surface of the injection section (21) and the wall surface of the first mixing section (141), and the first radial spacing and the second radial spacing are 1 / 8-1 / 4 of the third radial spacing.

5. The mixer according to claim 3, characterized in that A first spiral line convex pattern (144) surrounding the first spiral blade (24) is provided on the wall surface of the first expansion section (142), and the spiral direction of the first spiral line convex pattern (144) is opposite to the spiral direction of the first spiral blade (24).

6. The mixer according to claim 4, characterized in that The axial length of the second diameter-changing zone (16) is smaller than the axial length of the first diameter-changing zone (14); The second diameter-changing zone (16) comprises a second mixing section (161), a second expansion section (162) and a second tapered section (163) which are sequentially distributed along the axial direction of the injection section (21); the second mixing section (161) is connected to the buffer zone (15); and the second tapered section (163) is connected to the mixed liquid outlet (13); The diameter of the second tapered section (163) gradually decreases along the direction from the second liquid inlet (22) to the mixed liquid outlet (13), the minimum diameter of the second tapered section (163) is the same as the diameter of the mixed liquid outlet (13), the maximum diameter of the second tapered section (163) is the same as the diameter of the second expansion section (162), the diameter of the second expansion section (162) is larger than the diameter of the second mixing section (161), and the diameter of the second mixing section (161) is equal to the diameter of the buffer zone (15).

7. The mixer according to claim 6, characterized in that There is a fourth radial spacing between the wall surface of the second mixing section (161) and the outer edge of the second spiral blade (25), the minimum radial spacing between the wall surface of the second tapered section (163) and the outer edge of the second spiral blade (25) is a fifth radial spacing, and there is a sixth radial spacing between the outer wall surface of the injection section (21) and the wall surface of the second mixing section (161), and the fourth radial spacing and the fifth radial spacing are 1 / 8-1 / 4 of the sixth radial spacing.

8. The mixer according to claim 6, characterized in that A second spiral line convex pattern (164) surrounding the second spiral blade (25) is provided on the wall surface of the second expansion section (162), and the spiral direction of the second spiral line convex pattern (164) is opposite to the spiral direction of the second spiral blade (25).

9. The mixer according to claim 6, characterized in that All the injection holes (23) are distributed in multiple rows and columns on the injection section (21), and the number of the injection holes (23) located in the first diameter-changing area (14) is greater than the number of the injection holes (23) located in the second diameter-changing area (16); In the axial direction of the injection section (21), the distance between two adjacent injection holes (23) in the buffer zone (15) is smaller than the distance between two adjacent injection holes (23) in the second diameter-changing zone (16).

10. The mixer according to claim 9, characterized in that The diameter of the injection hole (23) gradually decreases from its liquid inlet end to its liquid outlet end, a third spiral convex pattern (26) is provided on the hole wall of the injection hole (23) and is distributed around the axis of the injection hole (23), and the injection hole (23) extends obliquely from its liquid inlet end to its liquid outlet end toward the head end of the outer shell (1).

11. An acid hydrocarbon separation system, characterized in that: It comprises a sedimentation separation device (100), a coalescence separation unit, an alkali washing unit and a water washing unit connected in sequence, wherein the alkali washing unit comprises a first mixer (300) and a first separator (400) connected in sequence, wherein the first mixer is the mixer according to any one of claims 1 to 10.

12. The acid hydrocarbon separation system according to claim 11, characterized in that: The sedimentation separation device (100) is a gravity sedimentation separator.

13. The acid hydrocarbon separation system according to claim 11 or 12, characterized in that: The agglomeration and separation unit comprises one or more particle agglomeration and separation devices (200), wherein the inner cavity of the particle agglomeration and separation device (200) is provided with a particle bed formed by medium particles, wherein the medium particles are hydrophilic particles, or a combination of hydrophilic particles and hydrophobic particles.

14. The acid hydrocarbon separation system according to claim 13, characterized in that: The coalescence separation unit also includes one or more fiber coalescence separation devices, which are connected in series with the particle coalescence separation device (200), and the inner cavity of the fiber coalescence separation device is provided with a fiber bed layer formed by fiber media, and the fiber media includes hydrophilic fibers and hydrophobic fibers.

15. The acid hydrocarbon separation system according to claim 14, characterized in that: The fiber bed layer is formed by stacking a plurality of fiber layers, and each fiber layer is woven from hydrophilic fibers and hydrophobic fibers.

16. The acid hydrocarbon separation system according to any one of claims 11 to 15, characterized in that: The first separator (400) comprises a second shell and a second liquid distributor (4-1), a rectifier (4-2), a first demulsification separation structure (4-3), a second demulsification separation structure (4-4) and a third demulsification separation structure (4-5) which are arranged in sequence along the flow direction of the logistics in the inner cavity of the second shell, wherein the first demulsification separation structure (4-3) is a hydrophilic fiber layer, the second demulsification separation structure (4-4) is an interlaced layer of oleophilic fibers and hydrophilic fibers, and the third demulsification separation structure (4-5) is a corrugated plate.

17. The acid hydrocarbon separation system according to claim 16, characterized in that: In the first separator (400), the corrugated plates are formed by staggered stacking of oleophilic material and hydrophilic material; Preferably, the angle between the corrugated structure on the corrugated plate and the horizontal direction is 30° to 60°; Preferably, holes are provided at both the crests and troughs of the corrugated plate.

18. The acid hydrocarbon separation system according to any one of claims 11 to 17, characterized in that: The water washing unit comprises a second mixer (500) and a second separator (600) which are connected to each other; Preferably, the second mixer (500) has the same structure as the first mixer (300); Preferably, the second separator (600) has the same structure as the first separator (400).

19. A method for separating acid hydrocarbons, characterized in that: The method comprises the following steps: (1) subjecting the acid-hydrocarbon mixture to sedimentation separation to obtain a first oil phase; (2) subjecting the first oil phase to agglomeration separation, so that the acid content in the separated second oil phase is less than 5% of the acid content in the first oil phase, preferably 0.1-4.2%; (3) performing a first mixing of the second oil phase and an alkali solution, and performing a first enhanced separation on the obtained mixed solution to obtain a third oil phase; (4) Washing the third oil phase with water.

20. The method according to claim 19, characterized in that In step (2), the agglomeration and separation process includes: contacting the first oil phase with medium particles to perform a first coalescence separation, wherein the medium particles are hydrophilic particles, or a combination of hydrophilic particles and hydrophobic particles; Optionally, the oil phase obtained after the first coalescence separation is contacted with a fiber medium for a second coalescence separation, wherein the fiber medium comprises hydrophilic fibers and hydrophobic fibers.

21. The method according to claim 20, characterized in that The particle size of the medium particles is 0.2-5 mm.

22. The method according to claim 20 or 21, characterized in that The hydrophilic particles are at least one of ore particles, ceramic particles and glass particles; and / or The hydrophobic particles are at least one of polypropylene particles, polystyrene particles and polyurethane particles.

23. The method according to any one of claims 20 to 22, characterized in that: The second coalescence separation process comprises: allowing the oil phase obtained after the first coalescence separation to pass from top to bottom through a fiber bed layer formed by the fiber medium; Preferably, the fiber bed layer is formed by stacking a plurality of fiber layers, and each of the fiber layers is woven from hydrophilic fibers and hydrophobic fibers.

24. The method according to claim 19, characterized in that In step (3), the first mixing process is performed so that the median particle size of hydrocarbon dispersed phase droplets in the mixed liquid obtained after mixing is less than 100 μm, preferably less than 40 μm.

25. The method according to claim 19, characterized in that In step (3), the first enhanced separation process makes the water content in the separated third oil phase be less than 600 mg / L, preferably less than 400 mg / L.

26. The method according to claim 19, 24 or 25, characterized in that In step (3), the volume flow ratio of the second oil phase to the alkali solution is 1:(0.05-0.2).

27. The method according to claim 19, characterized in that In step (4), the water washing process includes: performing a second mixing of the third oil phase and water, and performing a second enhanced separation on the obtained mixed liquid.

28. The method according to claim 27, characterized in that The second mixing process is performed so that the median particle size of hydrocarbon dispersed phase droplets in the mixed liquid obtained after mixing is less than 100 μm, preferably less than 40 μm.

29. The method according to claim 27, characterized in that The second enhanced separation process allows the water content in the separated purified hydrocarbon to be 600 mg / L or less, preferably 400 mg / L or less.

30. The method of claim 19, 27, 28 or 29, wherein: The volume flow ratio of the third oil phase to water is 1:(0.1-0.6).

31. The method according to any one of claims 19 to 30, characterized in that: The acid in the acid-hydrocarbon mixture is at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid and hydrobromic acid; and / or The hydrocarbon in the acid-hydrocarbon mixture is an aromatic hydrocarbon, preferably at least one of nitroaromatic hydrocarbons, halogenated aromatic hydrocarbons and nitrohalogenated aromatic hydrocarbons.

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