Crude oil pretreatment coupling device and method
By combining magnetic and electric fields, a crude oil pretreatment device using a magnetic separation unit and multi-stage electrode plate coalescing packing solves the problem of separating solid impurities and salts in heavy and inferior crude oil, achieving efficient oil-water separation and stable equipment operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2021-10-29
- Publication Date
- 2026-06-02
Smart Images
Figure CN116064087B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of petrochemical technology, and in particular to a crude oil pretreatment coupling device and method. Background Technology
[0002] In recent years, with the increasing trend of crude oil becoming inferior and heavier, heavy and inferior crude oil has high salt content, high viscosity, high density, and severe emulsification. Moreover, crude oil contains certain solid impurities, which bring many problems to the subsequent dehydration, desalting, oil-water separation and subsequent processing of crude oil. The main problems are: (1) Solid impurities in crude oil are prone to causing equipment and pipeline blockage and scaling during the post-processing process, and the system pressure increases; (2) Solid impurities are not easily polarized in traditional electro-desalting, which affects the electro-desalting effect; (3) When using traditional filtration and coalescence methods to process crude oil, it is easy to cause problems such as filter element blockage and coalescence packing blockage.
[0003] In existing technologies, crude oil pretreatment generally employs electrostatic desalting. This method first injects a small amount of water into the oil to wash and dissolve the salts, and then uses electrostatic desalting technology to separate the oil and water. However, with the increasing trend of crude oil deterioration and severe emulsification, electrostatic desalting technology has low demulsification efficiency, resulting in problems such as large amounts of demulsifier required, unsatisfactory oil-water separation effect, low efficiency of oil-water separation equipment, and severe entrainment of the two phases.
[0004] For the pretreatment of heavy and low-quality crude oil, the removal of solid impurities and the effective separation of oil and water are crucial. Currently, there is a lack of efficient pretreatment processes, complete sets of equipment, and methods for heavy and low-quality crude oil, which can solve problems such as filter element and coalescing packing blockage, excessive demulsifier dosage, unsatisfactory oil-water separation, and severe phase entrainment in existing traditional processes.
[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention
[0006] The purpose of this invention is to provide a crude oil pretreatment coupling device and method, which uses a magnetic field to remove solid impurities and other impurities such as salts existing in the form of solid slag from crude oil, and performs deep separation of oil and water in crude oil through an electric field and a coalescence field. The crude oil pretreatment is completed in the same device, which not only improves the processing efficiency, but also effectively extends the operating cycle of the device.
[0007] To achieve the above objectives, according to a first aspect of the present invention, the present invention provides a crude oil pretreatment coupling device, comprising: a magnetic separation unit, which is a cylindrical structure and has multiple layers of magnetic media inside, the magnetic separation unit receiving crude oil after fully mixing with injected water, demulsifier, magnetic seed and flocculant, and adsorbing flocculated precipitates with magnetic seed as the core in the crude oil through the action of a gradient magnetic field; an oil-water deep separation unit, which has multiple parallel electrode plates and coalescing packing arranged in upper and lower stages, the oil-water deep separation unit receiving crude oil after magnetic separation, the crude oil flowing through the multiple stages of coalescing packing in sequence, and under the action of electric field and coalescing packing, the tiny water droplets in the crude oil coalesce into large water droplets; and a sedimentation unit, which separates the dehydrated crude oil after deep oil-water separation by sedimentation.
[0008] Furthermore, in the above technical solution, the multi-level parallel electrode plates can be arranged in an alternating manner to form a multi-level coalescing packing-filled folded flow channel.
[0009] Furthermore, in the above technical solution, the electrode plates can be configured as two-stage or four-stage, and alternating current can be applied between adjacent electrode plates.
[0010] Furthermore, in the above technical solution, the radial dimension of the folded flow channel can decrease sequentially from bottom to top; the packing precision of the coalescing packing material filling the folded flow channel can increase sequentially from bottom to top.
[0011] Furthermore, in the above technical solution, when the electrode plate is of two stages, the electric field strength in the two stages of the flow channel in the folded-back flow channel is 600V / cm and 900V / cm, respectively; when the electrode plate is of four stages, the electric field strength in the four stages of the flow channel in the folded-back flow channel is 600V / cm, 800V / cm, 1000V / cm and 1200V / cm, respectively.
[0012] Furthermore, in the above technical solution, the coalescing filler can be in the form of sheets, rods, spheres, tetrahedrons or hexahedrons, and can be assembled by mixing and weaving oleophilic and hydrophobic fibers into X-shaped, V-shaped, 8-shaped, Ω-shaped, teardrop-shaped or rhomboid structures.
[0013] Furthermore, in the above technical solution, the coalescing filler is preferably made of an X-shaped mixture of oleophilic and hydrophobic polyurethane fiber and hydrophilic and oleophobic polypropylene fiber in a 1:3 ratio.
[0014] Furthermore, in the above technical solution, a magnetic field generating device is provided on the outside of the cylindrical structure, and the multilayer magnetic concentrating medium can be a stainless steel grid arranged at intervals.
[0015] Furthermore, in the above technical solution, the diameter of the stainless steel wire of the grille can be 0.45 to 0.55 mm; the spacing between the stainless steel wires can be 1.5 to 2.5 mm; the spacing between adjacent grille layers can be 10 to 15 mm; the extension directions of the stainless steel wires of adjacent grille layers are staggered, and the staggering angle of the extension directions can be 0 to 90°.
[0016] Furthermore, in the above technical solution, the magnetic field generating device can be an electromagnetic induction coil wound around a cylindrical structure, generating a magnetic field strength of 4500 to 5500 G.
[0017] Furthermore, in the above technical solution, the front end of the first-stage flow channel in the foldback flow channel may be provided with a rectifier and distributor, which is a uniformly distributed perforated plate with a certain thickness.
[0018] To achieve the above objectives, according to a second aspect of the present invention, the present invention provides a crude oil pretreatment coupling method, comprising the following steps: A. By using a gradient magnetic field, multilayer magnetic media adsorbs flocculated precipitates in crude oil with magnetic seeds as the core, thereby removing solid impurities and other impurities such as salts existing in the form of solid slag; B. By using multi-level parallel electrode plates and coalescing packing, tiny water droplets in crude oil are coalesced into large water droplets, thereby performing deep oil-water separation of crude oil; C. The dehydrated crude oil after deep oil-water separation is subjected to sedimentation separation.
[0019] Furthermore, in the above technical solution, the crude oil in step A is crude oil that has been heated and mixed with water and demulsifier.
[0020] Furthermore, in the above technical solution, the crude oil heating temperature can be 75-85℃; the amount of water added is 5-15 wt% of the crude oil mass; the demulsifier can be polyoxyethylene polyoxypropylene alcohol ether, and the amount added is 0.005-0.01 wt% of the crude oil mass.
[0021] Furthermore, in the above technical solution, the magnetic seed can be metallic Fe, and the amount added is 0.05 to 0.1 wt% of the crude oil mass; the flocculant can be polyacrylamide, and the amount added is 0.05 to 0.1 wt% of the crude oil mass.
[0022] Furthermore, in the above technical solution, the operating conditions for step A are as follows: temperature is 80-90℃, and pressure is atmospheric pressure to 0.5MPa.
[0023] Compared with the prior art, the present invention has the following beneficial effects:
[0024] 1) According to the inventors' research, the mesh-type grid has a good separation effect. Since heavy, low-quality crude oil has high viscosity and is prone to clogging, a horizontally staggered grid is used for separation. The magnetic separation unit in this invention uses a layered grid built into the magnetic filter cylinder, with the stainless steel wires of each layer staggered at an angle, making it less prone to clogging when crude oil passes through. When the grid size, arrangement angle, and arrangement interval are within the preferred range of this invention, the interaction between the stainless steel wires is strong. This strong interaction bends the magnetic lines of force in the space as much as possible, resulting in a wider distribution of magnetic field strength on the plane. The multi-layered grids are staggered and magnetized in the magnetic field, and their surfaces can generate a gradient magnetic field (i.e., a non-uniform magnetic field along the radial direction of the magnetic filter cylinder), which can effectively separate solid impurities in the crude oil.
[0025] 2) The four-stage electrode plate and four-stage coalescing packing of this invention are suitable for treating low-quality crude oil with a high degree of emulsification. The crude oil flows sequentially and in reverse through four layers of channels from bottom to top, and under the action of an electric field, the emulsified micro-droplets migrate rapidly within the electric field, accelerating the capture, coalescence, and growth of these micro-droplets in the coalescing packing. The packing precision increases sequentially from the lower to the upper layers, allowing the unseparated micro-droplets in the lower layers to undergo deep coalescence and separation in the upper layers, ultimately achieving deep dehydration of the crude oil. Experiments have shown that increasing the number of stages of the electrode plate and coalescing packing can significantly improve the dehydration and desalination effect.
[0026] 3) This invention couples magnetic fields, electric fields, coalescence fields, etc. in the same device to achieve concentrated and deep separation of oil and water, while effectively removing solid impurities and other impurities such as salts in the form of solid slag from crude oil.
[0027] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, and to make the above and other objects, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with reference to the accompanying drawings. Attached Figure Description
[0028] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the crude oil pretreatment coupling device of the present invention (the arrow in the figure indicates the direction of crude oil flow).
[0029] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of the crude oil pretreatment coupling device of the present invention (the arrow in the figure indicates the direction of crude oil flow).
[0030] Figure 3 This is a cross-sectional schematic diagram of the magnetic separation unit in the crude oil pretreatment coupling device of the present invention.
[0031] Figure 4 This is a schematic diagram of the multi-layer stainless steel grid arrangement of the magnetic separation unit of the present invention.
[0032] Explanation of key figure labels:
[0033] 1-Crude oil inlet, 2-Distribution orifice plate, 3-DC power supply, 4-Magnetic separation unit, 41-Magnetic filter cylinder, 42-Electromagnetic induction coil, 43-Stainless steel grid, 5-Solid slag outlet, 6-First baffle, 7-Rectifier distributor, 8-AC power supply, 9-First-stage coalescing packing, 10-First-stage electrode plate, 11-Second-stage coalescing packing, 12-Second-stage electrode plate, 13-Second baffle, 14-Purified crude oil outlet, 15-Level gauge, 16-Unit water tank, 17-Aqueous phase outlet, 18-Third-stage coalescing packing, 19-Third-stage electrode plate, 20-Fourth-stage coalescing packing, 21-Fourth-stage electrode plate. Detailed Implementation
[0034] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.
[0035] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.
[0036] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “upper,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” that element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.
[0037] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.
[0038] The crude oil pretreatment coupling device of the present invention mainly includes a magnetic separation unit for separating solid impurities and other impurities such as salts existing in the form of solid slag from crude oil, an oil-water deep separation unit for deep separation of crude oil, and a sedimentation unit after oil-water deep separation. All units are arranged in the same pretreatment device, and the connection sequence of the units is described below. Figure 1 or Figure 2 The above units will be explained separately below according to the direction of crude oil flow.
[0039] Before entering the magnetic separation unit, the crude oil is heated to 70℃~90℃ (preferably 75~85℃), and water, demulsifier, magnetic seed, and flocculant are injected and thoroughly mixed. Volatile salts, fixed ammonium salts, and water-soluble metal salts are removed from the crude oil by water washing; the addition of a demulsifier reduces the interfacial tension between oil and water, making water droplets easier to coalesce; the addition of magnetic seed and flocculant generates a flocculent precipitate with the magnetic seed as its core. Subsequently, the magnetic separation unit of this invention removes solid impurities and other impurities such as salts existing in the form of solid slag from the crude oil. The amount of water added can be 0.5~20wt% (preferably 5~15wt%) of the crude oil mass, and the demulsifier can be polyoxyethylene polyoxypropylene alcohol ether, with an addition amount of 0.001~0.05wt% (preferably 0.005~0.01wt%) of the crude oil mass. The flocculant can be one or a mixture of two or more of polyacrylamide, polyoxypropylene, polyvinyl alcohol, and polyethylene glycol, added at a rate of 0.01–0.5 wt% (preferably 0.05–0.1 wt%) of the crude oil mass. The magnetic seed can be Fe, added at a rate of 0.01–0.5 wt% (preferably 0.05–0.1 wt%) of the crude oil mass, and then introduced into the magnetic separation unit of the crude oil pretreatment coupling device of this invention.
[0040] Magnetic separation unit:
[0041] like Figures 1 to 4 As shown, the magnetic separation unit 4 of this invention has a cylindrical structure and contains multiple layers of magnetically concentrated media. This magnetic separation unit 4 utilizes the gradient magnetic field to adsorb flocculated precipitates with magnetic seeds as the core in crude oil through the multiple layers of magnetically concentrated media. Specifically, after static mixing, the crude oil enters the cylindrical structure (i.e., magnetic filter cylinder 41, preferably an aluminum cylinder) of the magnetic separation unit 4 through the distribution perforated plate 2 from the crude oil inlet 1. The magnetic filter cylinder 41 is fixed on the distribution perforated plate 2, and multiple cylinders can be arranged as needed, with the arrangement direction parallel to the flow direction of the crude oil. A magnetic field generating device is provided outside the magnetic filter cylinder 41. The magnetic field generating device is an electromagnetic induction coil 42 wound around the magnetic filter cylinder 41 (which generates a magnetic field by being energized by a DC power supply 3). See [link to relevant documentation]. Figure 3 The generated magnetic field strength ranges from 0 to 6000 G, with a preferred range of 4500 to 5500 G used in this invention. The multilayer magnetic concentrating medium can be a spaced-apart stainless steel grid 43 (made of SUS430 stainless steel). The diameter of the stainless steel wires in the grid is preferably 0.45 to 0.55 mm. Further... Figure 4As shown, the spacing d between the stainless steel wires is preferably 1.5 to 2.5 mm; the spacing L between adjacent grid layers is preferably 10 to 15 mm, and the extension directions of the stainless steel wires in adjacent grid layers are staggered (i.e., Figure 4 The extension directions of the magnetic filter cylinder 43a, 43b, 43c, and 43d are staggered at an angle of 0 to 90°, preferably 30°. The operating conditions of the magnetic filter cylinder 41 are as follows: temperature 80 to 90°C, pressure atmospheric pressure to 0.5 MPa.
[0042] The magnetic filter cylinder 41 is used to separate magnetic flocs in crude oil. Research by the inventors has shown that grid-type grids offer good separation performance. However, due to the high viscosity and tendency to clog heavy, low-quality crude oil, a horizontally staggered grid arrangement is employed. Stainless steel grids 43 are arranged regularly at a specific angle within the magnetic filter cylinder 41. When the grid size, arrangement angle, and spacing are within the aforementioned preferred range, the interaction between the stainless steel wires is strong. This strong interaction bends the magnetic lines of force in the space as much as possible, resulting in a wider distribution of the magnetic field strength on the plane. The multi-layered grids are staggered and magnetized in the magnetic field, generating a gradient magnetic field (i.e., a non-uniform magnetic field along the radial direction of the magnetic filter cylinder) on their surface, effectively separating solid impurities from salts and other impurities existing in the form of solid slag in the crude oil. After a period of adsorption, the DC power supply is turned off, and the solid particles fall off and are discharged from the solid slag outlet 5.
[0043] The magnetic separation unit of this invention incorporates horizontally staggered stainless steel grids. These grids are magnetized in a magnetic field, generating a gradient magnetic field on their surface. Solid particles in the crude oil mix evenly with the magnetic seeds and flocculants, forming flocculent precipitates with the magnetic seeds at their core. During flow, these precipitates are adsorbed onto the grids, achieving the separation of solid particles from the crude oil—that is, crude oil desolidification. Some salt impurities existing in the form of solid slag are also removed, resulting in higher separation efficiency. The magnetically separated crude oil is blocked by the first baffle 6, and can only flow to the oil-water deep separation unit via the rectifier and distributor 7 at the bottom of the device.
[0044] Oil-water deep separation unit:
[0045] like Figure 1 , 2 As shown, the rectifier distributor 7 is an open plate with evenly distributed circular holes of a certain thickness, installed at the front end of the oil-water deep separation unit, which consists of multi-stage electrode plates and multi-stage coalescing packing. It rectifies the crude oil after magnetic filtration, ensuring smooth flow. The oil-water deep separation unit is fixed between the first baffle 6 and the second baffle 13, and is equipped with multiple parallel electrode plates and coalescing packing arranged vertically. The oil-water deep separation unit receives the magnetically separated crude oil, which flows sequentially through the multi-stage coalescing packing. Under the action of the electric field and the coalescing packing, tiny water droplets in the crude oil can coalesce into larger droplets. Two embodiments of the oil-water deep separation unit of this invention are provided, which are described below.
[0046] Example 1
[0047] The properties of the crude oil in Example 1 are shown in Table 1. It is characterized by high density, high viscosity, and severe emulsification.
[0048] Table 1 Crude Oil Properties Data
[0049]
[0050] like Figure 1 As shown, the oil-water deep separation unit of the present invention is provided with two stages of parallel-arranged electrode plates and coalescing packing. Specifically, there is a primary electrode plate 10 and a secondary electrode plate 12, and a primary coalescing packing 9 filled between the bottom of the device and the primary electrode plate 10, and a secondary coalescing packing 11 filled between the primary electrode plate 10 and the secondary electrode plate 12. Preferably, but not limitingly, the parallel-arranged primary electrode plate 10 and secondary electrode plate 12 are arranged alternately, as shown in the reference. Figure 1 Specifically, the left end of the primary electrode plate 10 is fixed to the first baffle 6, and the right end of the secondary electrode plate 12 is fixed to the second baffle 13, forming a two-stage coalescing packing channel. The crude oil enters from the left side of the primary coalescing packing 9 and exits from the right side, then enters from the right side of the secondary coalescing packing 11 and exits from the left side. Under the combined action of the electric field between the two electrode plates and the coalescing field of the two-stage coalescing packing, deep oil-water separation occurs, and the oil overflows from the top of the second baffle 13 into the settling unit.
[0051] Furthermore, either direct current (DC) or alternating current (AC) can be applied between the primary electrode plate 10 and the secondary electrode plate 12, and the current can be either pulsed or non-pulsed. When AC current is applied between the two electrode plates, the primary electrode plate 10 is connected to the live wire of the power supply, and the secondary electrode plate 12 is grounded. Preferably, but not limitingly, the radial dimension of the folded-back flow channel decreases from bottom to top, meaning the distance between the two electrode plates is less than the distance between the primary electrode plate and the bottom of the device, resulting in a higher electric field strength in the upper flow channel than in the lower flow channel. Specifically, the electric field strengths in the two flow channels are 600 V / cm and 900 V / cm, respectively. Simultaneously, the packing precision of the coalescing packing material filling the folded-back flow channel increases sequentially from bottom to top, meaning the packing precision of the secondary coalescing packing material 11 in the upper flow channel is higher than that of the primary coalescing packing material 9. This arrangement allows for the gradual coalescence of finer water droplets, effectively improving the oil-water separation depth.
[0052] Furthermore, the coalescing filler can be in the form of sheets, rods, spheres, tetrahedrons, or hexahedrons, and is assembled from a mixture of oleophilic and hydrophobic fibers woven into X-shaped, V-shaped, 8-shaped, Ω-shaped, teardrop-shaped, or rhomboid structures. In this embodiment, the primary coalescing filler 9 and the secondary coalescing filler 11 are woven into an X-shape from a mixture of oleophilic and hydrophobic polyurethane fibers and hydrophobic and hydrophobic polypropylene fibers in a 1:3 ratio.
[0053] The two-stage electrode plates and two-stage coalescing packing are suitable for crude oils with moderate water content and emulsification levels. The crude oil flows sequentially and back through the lower and upper channels, and under the influence of the electric field, the emulsified micro-droplets migrate rapidly between the electric fields, accelerating their capture, aggregation, and growth within the coalescing packing. The packing precision increases progressively from the lower to the upper layer, allowing any unseparated micro-droplets in the lower layer to undergo deep coalescence and separation in the upper packing, ultimately achieving deep dehydration of the crude oil.
[0054] The crude oil treated by the magnetic separation unit of the present invention and the oil-water deep separation unit of Example 1 has a solid content of 0.05wt% to 0.07wt%, a salt content of 2.5 to 2.8mg / L, and a water content of 0.25wt% to 0.28wt%.
[0055] Example 2
[0056] like Figure 2 As shown, this embodiment still uses the same crude oil as in Embodiment 1, but differs from Embodiment 1 in that it employs four parallel-arranged electrode plates and coalescing packing. Specifically, it consists of a primary electrode plate 10, a secondary electrode plate 12, a tertiary electrode plate 19, and a quaternary electrode plate 21, along with primary coalescing packing 9 filling the bottom of the device and the primary electrode plate 10, secondary coalescing packing 11 filling the first-stage electrode plate 10 and the second-stage electrode plate 12, tertiary coalescing packing 18 filling the second-stage electrode plate 12 and the tertiary electrode plate 19, and quaternary coalescing packing 20 filling the third-stage electrode plate 19 and the quaternary electrode plate 21. Similar to Embodiment 1, the crude oil flows sequentially and in a zigzag pattern along the four-stage coalescing packing layer from bottom to top. Preferably, but not limitingly, the electric field strengths within the four-stage flow channels in the zigzag flow channels are 600 V / cm, 800 V / cm, 1000 V / cm, and 1200 V / cm, respectively.
[0057] The four-stage electrode plate and four-stage coalescing packing are suitable for treating low-quality crude oil with a high degree of emulsification. The crude oil flows sequentially and in reverse through four layers of channels from bottom to top, and under the influence of an electric field, the emulsified micro-droplets migrate rapidly within the electric field, accelerating their capture, aggregation, and growth within the coalescing packing. The packing precision increases progressively from the bottom to the top, allowing unseparated micro-droplets in the lower layers to undergo deep coalescence and separation in the upper layers, ultimately achieving deep dehydration of the crude oil. Increasing the number of stages of the electrode plates and coalescing packing significantly improves the dehydration and desalination effect.
[0058] The crude oil treated by the magnetic separation unit of the present invention and the oil-water deep separation unit of Example 2 has a solid content of 0.05-0.07 wt%, a salt content of 2.2-2.4 mg / L, and a water content of 0.20-0.23 wt%.
[0059] The oil-water deep separation unit of this invention utilizes an electric field to drive the rapid migration of tiny water droplets. By leveraging the effects of media interception and wetting coalescing, it provides a wide range of media sites for droplet coalescence, solving the problem of low droplet collision interception efficiency in electric field coalescence. Through the combined action of the electric field and the coalescence field, tiny water droplets more easily coalesce into larger droplets, which are then separated during subsequent sedimentation. All of the above processes employ physical demulsification, offering advantages such as high efficiency, energy saving, and environmental friendliness.
[0060] Settlement unit:
[0061] A settling unit is located at the rear end of the deep oil-water separation unit and is used to separate the crude oil after deep oil-water separation. The settling unit has a vertically installed second baffle 13. The purified crude oil after deep separation and dehydration flows out from the purified crude oil outlet 14 at the top of the settling unit, while the water after deep separation flows out from the aqueous phase outlet 17 at the water tank 16, achieving the settling separation of crude oil and water after deep separation. A level gauge 15 can be installed at the water tank 16 to monitor the liquid level of the aqueous phase.
[0062] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. Any simple modifications, equivalent changes, and alterations made to the foregoing exemplary embodiments should fall within the scope of protection of the present invention.
Claims
1. A crude oil pretreatment coupling device, characterized in that, include: The magnetic separation unit is a cylindrical structure with multiple layers of magnetic media inside. This magnetic separation unit receives and thoroughly mixes injected water, demulsifier, magnetic seeds, and flocculant with crude oil. Under the action of a gradient magnetic field, the multiple layers of magnetic media adsorb flocculated precipitates in the crude oil with magnetic seeds as the core. A magnetic field generating device is provided on the outside of the cylindrical structure. The multiple layers of magnetic media are stainless steel grids arranged at intervals. The stainless steel wires of adjacent grid layers extend in an interlaced direction. The oil-water deep separation unit is equipped with multiple parallel electrode plates and coalescing packing. The oil-water deep separation unit receives the crude oil after magnetic separation. The crude oil flows through the multiple stages of coalescing packing in sequence. Under the action of the electric field and the coalescing packing, the tiny water droplets in the crude oil coalesce into larger water droplets. The multiple parallel electrode plates are arranged in an alternating manner to form a folding flow channel filled with the multiple stages of coalescing packing. The settling unit separates the dehydrated crude oil after deep oil-water separation by settling.
2. The crude oil pretreatment coupling device according to claim 1, characterized in that, The electrode plates are two-stage or four-stage, and an alternating current is applied between adjacent electrode plates.
3. The crude oil pretreatment coupling device according to claim 2, characterized in that, The radial dimension of the folded flow channel decreases sequentially from bottom to top; the packing precision of the coalescing packing material filling the folded flow channel increases sequentially from bottom to top.
4. The crude oil pretreatment coupling device according to claim 3, characterized in that, When the electrode plate has two stages, the electric field strengths in the two stages of the flow channel in the folded flow channel are 600V / cm and 900V / cm, respectively; when the electrode plate has four stages, the electric field strengths in the four stages of the flow channel in the folded flow channel are 600V / cm, 800V / cm, 1000V / cm and 1200V / cm, respectively.
5. The crude oil pretreatment coupling device according to claim 1, characterized in that, The coalescing filler is in the form of sheets, rods, spheres, tetrahedrons, or hexahedrons, and is assembled from a mixture of oleophilic and hydrophobic fibers woven into X-shaped, V-shaped, 8-shaped, Ω-shaped, teardrop-shaped, or rhomboid structures.
6. The crude oil pretreatment coupling device according to claim 5, characterized in that, The coalescing filler is woven into an X-shape by mixing oleophilic and hydrophobic polyurethane fibers and hydrophilic and oleophilic polypropylene fibers in a 1:3 ratio.
7. The crude oil pretreatment coupling device according to claim 1, characterized in that, The diameter of the stainless steel wires in the grille is 0.45 to 0.55 mm; the spacing between the stainless steel wires is 1.5 to 2.5 mm; the spacing between adjacent layers of the grille is 10 to 15 mm; the stagger angle of the extension direction of the stainless steel wires in adjacent layers of the grille is 0 to 90°, and the stagger angle is not zero.
8. The crude oil pretreatment coupling device according to claim 7, characterized in that, The magnetic field generating device is an electromagnetic induction coil wound around the cylindrical structure, which generates a magnetic field strength of 4500-5500G.
9. The crude oil pretreatment coupling device according to claim 1, characterized in that, The first-stage flow channel in the foldback channel is equipped with a rectifier and a uniformly distributed perforated plate with a certain thickness.
10. A crude oil pretreatment coupling method, characterized in that, Using the apparatus as described in any one of claims 1 to 9, the method includes the following steps: A. By using a gradient magnetic field, multilayer magnetic media adsorb the flocculent precipitate with magnetic seeds as the core in crude oil, thereby removing solid impurities and salts in the form of solid slag from the crude oil. B. Through the parallel arrangement of multiple levels of electrode plates and coalescing packing, tiny water droplets in crude oil are coalesced into large water droplets, thus achieving deep oil-water separation in crude oil. C. Sedimentation separation is performed on the dehydrated crude oil after deep oil-water separation.
11. The crude oil pretreatment coupling method according to claim 10, characterized in that, The crude oil in step A is crude oil that has been heated and mixed with water, demulsifier, magnetic seed and flocculant.
12. The crude oil pretreatment coupling method according to claim 11, characterized in that, The crude oil is heated to a temperature of 75–85°C; the amount of water added is 5–15 wt% of the crude oil mass; the demulsifier is polyoxyethylene polyoxypropylene alcohol ether, and the amount added is 0.005–0.01 wt% of the crude oil mass.
13. The crude oil pretreatment coupling method according to claim 11, characterized in that, The magnetic seed is metallic Fe, and the amount added is 0.05 to 0.1 wt% of the crude oil mass; the flocculant is polyacrylamide, and the amount added is 0.05 to 0.1 wt% of the crude oil mass.
14. The crude oil pretreatment coupling method according to claim 10, characterized in that, The operating conditions for step A are as follows: temperature is 80-90°C, and pressure is atmospheric pressure to 0.5MPa.