Device and method for washing and desalting oil product

Abstract

The invention relates to an oil product salt leaching device and method, the device comprises at least one washing desalter, at least one oil-water separator and at least one magnetic transmission device, a washing desalter tank body is internally provided with a lipophilic coalescence filler block and a hydrophilic coalescence filler block, and the lipophilic coalescence filler block and the hydrophilic coalescence filler block are located at two sides of a magnetic medium and are fixed to form a washing desalting module; the magnet is movably fixed on the slide way and is driven by a magnet transmission device to do reciprocating motion in the slide way along the axial direction; a liquid outlet is formed in the side wall of the tank body and is connected with an oil-water separator. The contact mass transfer between the heavy inferior oil product and water can be greatly enhanced, so that the salt in the oil product can be more efficiently removed; firstly, an oil product to be treated and water are dispersed through the coalescence filler, an oil-water contact interface is continuously updated through vibration and up-and-down floating of the coalescence filler under the action of a magnetic field in the flowing process, a large oil-water contact surface is kept, and the salt leaching efficiency is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of petrochemical engineering, and particularly relates to a process system for washing and desalting oil products and a desalting process method using the same. Background Art

[0002] The salt content in oil products directly affects the corrosion of subsequent equipment and has an adverse effect on the activity of catalysts, so desalting treatment is required. In recent years, with the development of secondary processing technology and coal chemical technology, more specific requirements have been put forward for the salt content of oil products after desalting. Generally, deep desalting is required so that the salt content in the desalted oil products is not more than 3 mg / L.

[0003] Currently, at home and abroad, the main methods for removing salts are electro - desalting methods or a combination of chemical and electro - desalting methods. For general light raw oil or oil product processing enterprises, it is easy to meet the index that the salt content in the desalted oil products is not more than 3 mg / L by using electro - desalting methods. However, for those raw oils with high viscosity and high density and poor properties, the existing electro - desalting technologies are difficult to meet the standard. Even if a large amount of demulsifier is added, the salt content can only be reduced to 5 - 8 mg / L at most, resulting in serious salt deposition corrosion and product quality problems in subsequent devices. In addition, with the increase of heavy and inferior crude oil and the development of the coal - to - oil industry, the existing electro - desalting technologies are even more difficult to meet the desalting requirements. After a large number of experimental and industrial application effect comparison studies, it is found that a large part of the reason for the poor desalting effect of heavy and inferior oil products is the poor hydrophilicity and high viscosity of heavy and inferior oil products, which result in unsatisfactory mass transfer effect of oil - water mixing contact, making it difficult for the injected water to mix deeply with the oil products to dissolve the salt in the water and remove it.

[0004] CN201911250606.X proposes a crude oil electro - desalting device and method, including a high - frequency / high - voltage pulsed AC power supply system, an electro - desalter, a floating emulsified oil collector, an incoming oil pipeline, a pumping pipeline, a reinjection pipeline, a chemical addition pipeline, a heating device, and a compact tube - type electric field demulsifier; the incoming oil pipeline is arranged at the upper part of the electro - desalter, the floating emulsified oil collector is arranged in the emulsion layer and is connected to the bottom inlet of the compact tube - type electric field demulsifier; the top outlet of the compact tube - type electric field demulsifier is connected to the bottom of the electro - desalter. This method uses traditional electro - desalting methods, and based on the fact that there are many components in heavy and inferior oil products and the differences between various oil products are large, and many macromolecular compounds are difficult to be polarized, so the electro - desalting method has no general applicability for heavy and inferior oil products, and it has been proved in industrial applications that the desalting effect does not meet the standard.

[0005] CN201910660850.7 proposes an overweight extra-heavy oil treatment system and method. The treatment system includes a heat exchange device, a heating device, and a separation and electro-de-salting device. The heat exchange device and the heating device are connected and convey the crude oil preliminarily heated by the heat exchange device to the heating device. The heating device heats the crude oil at a high temperature and conveys it to the separation and electro-de-salting device for separation and electro-de-salting to obtain gas phase, water phase, and refined oil. The water phase and the refined oil are respectively conveyed to the heat exchange device through pipelines to preliminarily heat the crude oil. This method still uses the electro-de-salting method, and for overweight extra-heavy oil raw materials, there are still problems such as many macromolecular compounds being difficult to be polarized, no general applicability, and unqualified desalting effect.

[0006] CN200610105277.6 proposes a tar electric field purification technology. The method includes the following steps: ① Prepare the mixed oil. Mix coal tar and dilution oil (diesel oil or hydrogenated produced oil) in a mass ratio of 1:(0 - 0.25) with a mixing pump, add a demulsifier, etc., and heat to 130 - 150 °C; ② Primary electro-dehydration. After heating, the tar and the purified water are mixed and enter the electric field for dehydration; ③ Secondary electro-dehydration. The tar and the purified water are mixed and enter the electric field for dehydration; ④ Tertiary electro-dehydration. The tar and the purified water are mixed and enter the electric field for dehydration; ⑤ Sewage discharge. The sewage containing impurities removed from the coal tar is discharged from the primary electro-dehydration. The above method still uses the electro-de-salting and dehydration method to purify the coal tar, and there are problems such as incomplete separation of the oil and water phases, unsatisfactory desalting effect, and no general applicability.

[0007] In summary, if we want to achieve deep desalting of heavy and inferior crude oil, the uniform and effective mixing of oil and water, and the full contact and mass transfer between oil and water are an important part of the desalting process. It is necessary to develop new processes and equipment to solve the problems existing in the traditional electro-de-salting process of the existing technology, such as poor mixing effect of oil and water for washing salt, serious entrainment of oil and water phases with each other, and unqualified salt content. Summary of the Invention

[0008] Aiming at the deficiencies of the existing technology, the present invention provides a device and method for washing and desalting oil products, which can effectively improve the contact and mass transfer efficiency between oil and water, so as to enable heavy and inferior oil products to achieve the effect of deep washing and desalting, and has wide applicability to different types of heavy and inferior oil products.

[0009] The technical object of the present invention is achieved through the following technical solutions:

[0010] The technical object of the first aspect of the present invention is to provide a device for washing and desalting oil products. The device includes at least one washing and desalting device, at least one oil-water separator, and at least one magnetic drive device;

[0011] The washing desalination device includes a tank body, in which an oil-loving coalescing filler block, a water-loving coalescing filler block, a magnetic medium and a slideway are arranged. The oil-loving coalescing filler block and the water-loving coalescing filler block are arranged on both sides of the magnetic medium and fixed thereto, forming a washing desalination module, which is axially arranged in the tank body in the direction of the oil-loving coalescing filler block, the magnetic medium and the water-loving coalescing filler block. The slideway is axially fixed on both side walls of the tank body, and the washing desalination module is movably fixed on the slideway. The magnet driving device is arranged outside the washing desalination device and can drive the magnetic medium to drive the washing desalination module to make a reciprocating movement along the axis in the slideway. Liquid inlets are respectively arranged at both axial ends of the tank body close to the oil-loving coalescing filler block and the water-loving coalescing filler block and far from the magnetic medium, and a liquid outlet is arranged on the side wall of the tank body, which is connected to an oil-water separator.

[0012] Further, the oil-loving coalescing filler block and the water-loving coalescing filler block are respectively made of fiber filaments with oil-loving functions and fiber filaments with water-loving functions, so that they have a coalescing function. Generally, the fiber filaments can be woven into corresponding block structures according to the shape of the washing desalination device and placed in the washing desalination device, or the fiber filaments can be woven into sheets and stacked in layers axially to form blocks and placed in the washing desalination device. Preferably, when the fiber filaments are woven, they are preferably woven into patterns with any one of the concave-convex structures on the surface such as X-shaped, V-shaped, 8-shaped, Ω-shaped, water droplet-shaped or rhombus-shaped, which have better coalescing functions.

[0013] Further, the fiber filaments with oil-loving functions are selected from at least one of polyester fiber filaments, nylon fiber filaments, polyurethane fiber filaments, polypropylene fiber filaments, polyacrylonitrile fiber filaments and polyvinyl chloride fiber filaments, or are selected from fiber filaments whose surfaces are subjected to physical or chemical oil-loving treatments.

[0014] Further, the fiber filaments with water-loving functions are selected from high molecular polymers containing hydrophilic groups such as carboxyl (-COOH), amide (-CONH-), amino (-NH2-) or hydroxyl (-OH) in the main chain or side chain, and the more the number of hydrophilic groups contained, the better the hydrophilicity. Specifically, they are selected from at least one of polypropylene fibers, polyamide fibers and acrylic fibers, or are selected from fiber filaments whose materials are subjected to physical or chemical water-loving treatments.

[0015] Furthermore, the magnet drive device is used to drive the magnetic medium to oscillate and move periodically or aperiodically along the slideway, so as to continuously update the contact interface between the oil and water phases, force the two-phase deep contact to occur, dissolve the salt wrapped in the oil product in the water, and achieve the purpose of strengthening the mass transfer of the oil and water phases in contact; specifically, the magnet drive device includes a magnetic medium, a fixed shaft sleeve, a crank connecting rod and a motor. One end of the fixed shaft sleeve is connected to the crank connecting rod, the other end is connected to the magnet, and the other end of the crank connecting rod is connected to the motor. The crank connecting rod rotates clockwise or counterclockwise driven by the motor, so as to drive the magnetic medium to move through the crank connecting rod, and the magnetic medium then drives the magnetic medium in the washing and desalting module to move through the magnetic field force.

[0016] Furthermore, in principle, the magnetic medium in the magnet drive device and the magnetic medium in the washing and desalting module can be any substance that exhibits magnetism under the action of a magnetic field. Ferromagnetic substances are preferred, and bar magnets are further preferred.

[0017] Furthermore, the movement of the magnetic medium driven by the magnet drive device is vibration or axial movement. Preferably, vibration and axial movement occur simultaneously, which is more conducive to breaking through the mass transfer interface between the water phase and the oil phase and strengthening the washing and desalting function; by controlling the magnetic drive device, the amplitude and frequency of its vibration and movement can be controlled, so as to strengthen the surface mass transfer between the raw materials and enhance the washing and desalting effect. In principle, the amplitude of the magnet drive device is not quantified as long as vibration occurs. In practical applications, it is preferably 1-12 cm; the rotation frequency of the magnet drive device is the number of times the turntable completes periodic changes per unit time, that is, the number of rotations per unit time, generally 1-50 revolutions per minute; the magnetic medium is generally a bar magnet, and the bar magnet is placed parallel or at any angle to the magnetic medium in the washing and desalting module, and its length can be equal to or unequal to that of the bar magnet.

[0018] Furthermore, the length of the slideway is longer than the height of the washing and desalting module, so that the washing and desalting module can move axially. As a preference, the height of the washing and desalting module is 1 / 10-9 / 10 of the length of the slideway, preferably 3 / 10-7 / 10.

[0019] Generally speaking, if the floating space of the washing and desalting module is too small, it indicates that a large amount of coalescing packing is filled, and the function of forcing the material to migrate through vibration and floating is weakened, that is, the improvement degree of enhancing the washing and desalting effect cannot reach the best effect; while if the floating space of the washing and desalting module is too large, it indicates that the amount of coalescing packing filled is small. Although the function of forcing the material to migrate through vibration and floating is strengthened, due to the small amount of coalescing packing, the functions of dispersing and coalescing the material are weakened, and the improvement degree of enhancing the washing and desalting effect also cannot reach the best effect. Therefore, only when the height and slideway length of the washing and desalting module maintain a relatively appropriate ratio can the washing and desalting effect be guaranteed.

[0020] The oil-water separator has its inlet end connected to the liquid outlet of the washing and desalting device, and is used for separating the oil-water mixture after enhanced washing and desalting. The residence time is generally 10 min to 120 min; the oil-water separation can adopt any one or more of the methods such as gravity sedimentation, hydrocyclone separation, baffle enhanced sedimentation, coalescing packing separation, etc. Preferably, the combination of coalescing packing and baffle is adopted inside, which can minimize the residence time and the entrainment of oil and water with each other.

[0021] Furthermore, when two or more washing and desalting devices are provided in the device, the washing and desalting devices are arranged in parallel. The magnetic medium can be set such that all the washing and desalting devices are an integral body, and the washing and desalting modules in all the washing and desalting devices move in the same direction as a whole, or a separate magnetic medium can be provided in each washing and desalting device, and the washing and desalting modules in each washing and desalting device can be respectively controlled by a magnetic drive device.

[0022] Furthermore, when two or more washing and desalting devices are provided in the device, preferably, the oleophilic coalescing packing blocks and the hydrophilic coalescing packing blocks in the washing and desalting modules in every two adjacent washing and desalting devices are arranged staggeredly in the axial direction. That is, in the first washing and desalting device, if the oleophilic coalescing packing blocks in the washing and desalting module are arranged above or to the left of the hydrophilic coalescing packing blocks, then in the second washing and desalting device, the oleophilic coalescing packing blocks in the washing and desalting module are arranged below or to the right of the hydrophilic coalescing packing blocks.

[0023] The technical object of the second aspect of the present invention is to provide a method for washing and desalting oil products by using the above device. The oil product to be treated and water are respectively introduced into the liquid inlets at both axial ends of the washing and desalting device. The magnetic drive device is started, and under the action of the magnetic field, the magnetic medium drives the washing and desalting module to vibrate and reciprocate axially, so as to strengthen the contact mass transfer between the injected water and the oil product, and make the salt in the oil product fully dissolve in the water; after completion, the mixture is introduced into the oil-water separator from the liquid outlet on the side wall of the tank body to separate the oil and water, and the desalting is completed.

[0024] Those skilled in the art should understand that when introducing the oil product to be treated and water into the liquid inlets at both axial ends of the washing and desalting device of the present invention, there are no special restrictions. Among them, it is more preferable to introduce the oil product to be treated into the liquid inlet close to the hydrophilic coalescing filler block, and inject water into the liquid inlet close to the oleophilic coalescing filler block. This is because when introducing the oil product to be treated into the hydrophilic coalescing filler block of the washing and desalting device, it is more conducive to the coalescence of water droplets contained in the raw oil and the dispersion of the oil phase; when water is introduced into the oleophilic coalescing filler block, it is more conducive to the dispersion of water on the surface of the coalescing filler, providing more ideal conditions and a larger contact surface for the mass transfer of the oil and water phases. Under the action of the coalescing filler, the oil product and water are continuously dispersed and coalesced, and at the same time, vibration and reciprocating movement along the axis occur, realizing a more sufficient and comprehensive mixing contact between water and the oil product.

[0025] Furthermore, when multiple washing and desalting devices are provided, the raw oil and water can all be added from a certain washing and desalting device, or added from several washing and desalting devices in a certain proportion, or added from each washing and desalting device.

[0026] Furthermore, the oil product to be treated is any one or more of crude oil, distillate oil, waste oil, coal tar, gutter oil, anthracene oil, plastic oil, lubricating oil, waste oil, etc.

[0027] Furthermore, the injection amount of water is related to the salt content in the oil product to be treated, the requirements for desalting depth, the type of oil product, etc. Generally, the weight of the injected water accounts for 1wt% - 30wt% of the weight of the oil product to be treated, preferably 5wt% - 20wt%.

[0028] Furthermore, the operating parameters in the washing and desalting device are as follows: the temperature is from normal temperature to 180°C, preferably 60 - 120°C; the pressure is 0.1 - 5.0MPa, preferably 0.3 - 2.0MPa.

[0029] In the above method, those skilled in the art should understand that for the oil-water mixture coming out of the washing and desalting module, after entering the oil-water separator, if the density of the oil phase is greater than that of the water phase, the water is separated from the upper part of the oil-water separator, and the oil is separated from the lower part; if the density of the oil phase is less than that of the water phase, the oil is separated from the upper part of the oil-water separator, and the water is separated from the lower part.

[0030] Compared with the prior art, the advantages of the present invention are:

[0031] (1) The device and method of the present invention can significantly enhance the mass transfer of heavy and inferior oil products in contact with water, thereby more efficiently removing salts from the oil products. First, the oil product to be treated and water are dispersed through coalescing fillers. During the flow process, under the action of a magnetic field, through the vibration and up-and-down floating of the coalescing fillers, on the one hand, it can enable water to break through the oil-water interface to achieve the purpose of deep contact mass transfer, and effectively prevent phenomena such as channeling and short-circuit flow. On the other hand, the material is continuously droplet broken to form fine droplets, so that the oil-water contact interface is continuously updated and a large oil-water contact surface is maintained, greatly improving the salt washing efficiency.

[0032] (2) In almost all existing oil product desalting technologies, electro-desalting technology is adopted. Due to the high viscosity and complex composition of heavy and inferior oil products, on the one hand, conventional oil-water mixing technologies are difficult to achieve deep contact, affecting the desalting effect, which is the main reason for the unqualified desalting effect. On the other hand, many macromolecular compounds in heavy and inferior oil products cannot be polarized in an electric field, so good oil-water separation effect cannot be achieved, which also affects the salt washing effect. The present invention abandons electro-desalting technology and develops a brand-new device and method for washing and desalting heavy and inferior oils, which has the advantages of simple process, high desalting efficiency, small water injection volume, etc. Description of the Drawings

[0033] Figure 1 is a schematic diagram of an oil product washing and desalting device with a single washing and desalting device in Example 1.

[0034] Figure 2 is a schematic diagram of an oil product washing and desalting device with multiple parallel arranged washing and desalting devices in Example 2. Detailed Embodiments

[0035] The present invention will be described in detail below with reference to the description of the drawings and embodiments, but the present invention is not limited thereby.

[0036] Example 1

[0037] This example provides an oil product washing and desalting device with a single washing and desalting device, as Figure 1 shown, which includes a washing and desalting device 100, an oil-water separator 700, and a magnetic drive device 800;

[0038] The washing desalting device 100 includes a tank body 101. Inside the tank body 101, an oil-loving coalescing packing block 102, a water-loving coalescing packing block 103, a bar magnet I 104 and a slideway 105 are arranged. The oil-loving coalescing packing block 102 is arranged on the upper side of the bar magnet I 104, and the water-loving coalescing packing block 103 is arranged on the lower side of the bar magnet I 104. The packing blocks are fixed to the bar magnet I 104 to form a washing desalting module. The slideway 105 is axially fixed on the two side walls of the tank body. The washing desalting module is movably fixed on the slideway 105. The magnet driving device 800 is arranged outside the washing desalting device and includes a bar magnet II 801, a fixed shaft sleeve 802, a crank connecting rod 803 and a motor 804, which can drive the bar magnet I 104 to drive the washing desalting module to make a reciprocating movement along the axis in the slideway 105. At the two axial ends of the tank body 101 close to the oil-loving coalescing packing block 102 and the water-loving coalescing packing block 103 and far from the bar magnet I 104, a filling port I 106 and an oil filling port I 107 are respectively arranged. A liquid outlet 108 is arranged on the side wall of the tank body 101, which is connected to an oil-water separator 700. The oil-water separator is provided with an upper outlet 701 and a lower outlet 702.

[0039] Embodiment 2

[0040] This embodiment provides an oil product washing desalting device provided with n washing desalting devices arranged in parallel, as Figure 2 shown, including a washing desalting device I 100, a washing desalting device II 200,..., a washing desalting device M 500, a washing desalting device N 600, an oil-water separator 700 and a magnetic driving device 800;

[0041] The basic structures of the washing desalting devices ranked at the 1st, 3rd,..., (n - 1)th positions are the same as those in Embodiment 1. The positions of the oil-loving coalescing packing block 102 and the water-loving coalescing packing block 103 in the washing desalting devices ranked at the 2nd, 4th,..., nth positions are opposite to those of the packing blocks in the washing desalting devices ranked at the 1st, 3rd,..., (n - 1)th positions, and the positions of the water injection ports and the oil injection ports are also opposite.

[0042] The process of washing salt from the oil product using this device is as follows: First, the oil product 1 to be treated is divided into no more than n strands and respectively introduced into the water-loving coalescing packing blocks 103 of each washing desalting device. The water injection 2 is divided into no more than n strands and respectively introduced into the oil-loving coalescing packing blocks 102 of each washing desalting device. The magnetic driving device 800 is started. Contact mass transfer and washing desalting occur in the oil-water two-phase washing desalting module. The oil-water mixture 108 after completing washing desalting is connected to the inlet of the oil-water separator 700. After oil-water separation, the desalted oil phase 701 (or 702) and the water phase 701 (or 702) are obtained.

[0043] Embodiment 3

[0044] The oil product to be processed is heavy and inferior raw oil, and its properties are shown in Table 1.

[0045] Table 1.

[0046]

[0047] The oil product is processed by using the oil product washing and desalting device of Example 1. In the washing and desalting module, the lipophilic coalescing filler block 102 is first woven into a sheet-like V-shaped pattern with two lipophilic fibers, namely polyester fiber filaments and nylon fiber filaments, and then stacked and bundled on the bar magnet I 104; the hydrophilic coalescing filler block 103 is woven into a sheet-like V-shaped pattern with two hydrophilic fibers, namely polypropylene fibers and acrylic fibers, and is symmetrically stacked and bundled on the bar magnet I 104 with the lipophilic coalescing filler block 102. Among them, the amplitude of the magnet drive device 800 is 8 cm, and the rotation frequency is 5 revolutions per minute.

[0048] The washing and desalting process is as follows: all the oil product to be processed 1 is introduced into the hydrophilic coalescing filler block 103 of the washing and desalting device 100, and all the water injection 2 is introduced into the lipophilic coalescing filler block 102 of the washing and desalting device 100. Under the action of the magnet drive device 800, the bar magnet I 104 drives the washing and desalting module to vibrate and move up and down, so as to strengthen the contact mass transfer between the water injection and the oil product, and fully dissolve the salt in the oil product in the water; after the salt washing is completed by the washing and desalting module, it enters the oil-water separator to separate the oil and water, and the desalting process is completed.

[0049] The operating parameters of the washing and desalting are as follows: the temperature is 118 °C, the pressure is 1.1 MPa, and the mass of the water injection accounts for 10% of the mass of the oil product to be processed.

[0050] The oil-water separator adopts the principle of gravity sedimentation. 18 layers of corrugated plates are filled inside the oil-water separator, and the residence time is 30 min. The desalting results are shown in Table 3.

[0051] Example 4

[0052] The oil product to be processed is heavy and inferior raw oil, and its properties are shown in Table 1.

[0053] The oil product washing and desalting device is as in Example 2, and a total of 6 washing and desalting devices are set, namely washing and desalting device I 100, washing and desalting device II 200,..., washing and desalting device M 500, N 600. Among them, the weaving and stacking methods of the lipophilic coalescing filler block and the hydrophilic coalescing filler block in each washing and desalting device are the same as those in Example 3. Among them, the amplitude of the magnet drive device is 12 cm, and the rotation frequency is 3 revolutions per minute.

[0054] The washing and desalting process is as follows: The oil product 1 to be processed is divided into six streams. Three of them are respectively introduced into the hydrophilic coalescing packing blocks in the washing and desalting devices ranked 1st, 3rd, and 5th, and the other three are respectively introduced into the lipophilic coalescing packing blocks in the washing and desalting devices ranked 2nd, 4th, and 6th; The water injection 2 is also divided into six streams. Three of them are respectively introduced into the lipophilic coalescing packing blocks in the washing and desalting devices ranked 1st, 3rd, and 5th, and the other three are respectively introduced into the hydrophilic coalescing packing blocks in the washing and desalting devices ranked 2nd, 4th, and 6th. Under the action of the magnet drive device 800, the magnetic medium drives the modules in the washing and desalting to vibrate and move up and down, thereby strengthening the contact mass transfer between the water injection and the oil product, and fully dissolving the salt in the oil product in the water; After the salt washing is completed by the washing and desalting module, it enters the oil-water separator 700, and the oil and water are separated to complete the desalting process.

[0055] The operating parameters of the washing and desalting are as follows: the temperature is 118 °C, the pressure is 1.1 MPa, and the mass of the water injection accounts for 8% of the mass of the oil product to be processed.

[0056] The oil-water separator 700 is filled with coalescing separation packing and 18 layers of corrugated plates, and the residence time is 20 min; The desalting results are shown in Table 3.

[0057] Example 5

[0058] The oil product washing and desalting device is as in Example 2, with a total of 6 washing and desalting devices. The washing and desalting process is as follows: The oil product 1 to be processed is divided into two streams, which are respectively introduced into the hydrophilic coalescing packing blocks in the washing and desalting devices ranked 1st and 3rd. The water injection 2 is also divided into two streams, which are respectively introduced into the lipophilic coalescing packing blocks in the washing and desalting devices ranked 1st and 3rd. Under the action of the magnet drive device 800, the magnetic medium drives the modules in the washing and desalting to vibrate and move up and down, thereby strengthening the contact mass transfer between the water injection and the oil product, and fully dissolving the salt in the oil product in the water; After the salt washing is completed by the washing and desalting module, it enters the oil-water separator, and the oil and water are separated to complete the desalting process.

[0059] The operating parameters of the washing and desalting are as follows: the temperature is 85 °C, the pressure is 0.3 MPa, and the mass of the water injection accounts for 12% of the mass of the oil product to be processed.

[0060] The oil-water separator 700 is internally filled with coalescing separation packing and 18 layers of corrugated plates, and the residence time is 20 min; The desalting results are shown in Table 3.

[0061] Example 6

[0062] The oil product to be processed is coal tar raw material, and its properties are shown in Table 2.

[0063] Table 2.

[0064]

[0065]

[0066] The oil washing and desalting device is as in Example 2, and a total of 6 washing and desalting modules are provided. Among them, the amplitude of the magnet drive device is 10 cm, and the rotation frequency is 5 revolutions per minute.

[0067] The washing and desalting process is as follows: All the oil to be treated is introduced from the hydrophilic filler side of the washing and desalting module 1. The water injection is divided into 6 streams and introduced from the lipophilic filler sides of the washing and desalting modules 1, 2, 3, 4, 5, and 6 respectively. Under the action of the magnet drive device 800, the magnetic medium drives the modules in the washing and desalting to vibrate and move up and down, thereby strengthening the contact mass transfer between the water injection and the oil, and fully dissolving the salt in the oil in the water; after the washing and desalting by the module is completed, it enters the oil-water separator, and the oil and water are separated to complete the desalting process.

[0068] The operating parameters of the washing and desalting are as follows: the temperature is 85 °C, the pressure is 0.5 MPa, and the mass of the water injection accounts for 10% of the mass of the oil to be treated.

[0069] The inside of the oil-water separator is filled with coalescing separation packing and 18 layers of corrugated plates, and the residence time is 20 min; the desalting results are shown in Table 3.

[0070] Comparative Example 1

[0071] The heavy raw oil in Table 1 is desalted by using the conventional three-stage electro-desalting + gravity sedimentation method.

[0072] The three-stage electro-desalting equipment is an electro-desalting and dehydration device, and its structure is as follows: horizontal structure, internally divided into upper and lower spaces, the upper part is the electric field space, the lower part is the oil-water separation space, and there is a control section for the water and oil interface in the middle; there are several horizontal electrode plates in the electric field space, and there are also hanging insulators, hanging plates, lead insulating rods, oil inlet nozzles, flow meters, etc. High-voltage electricity is transmitted to the electrode plates to form a high-voltage electric field, and a weak electric field is formed between the lower electrode plate at the bottom of the dehydrator and the water level. The gravity sedimentation equipment uses a conventional baffle powder separator, with 55 layers of baffle plates inside, and the residence time is 30 min;

[0073] The operating conditions are as follows: operating temperature: 120 °C; operating pressure: 1.2 MPa; the total water injection volume is 20% of the mass of the raw oil.

[0074] The desalting results are shown in Table 3.

[0075] Comparative Example 2

[0076] The heavy raw oil in Table 1 is desalted by using the four-stage electro-desalting + hydrocyclone separator method.

[0077] The four-stage electro-desalting equipment is an electro-desalting and dehydration device, and its structure is the same as that in Comparative Example 1.

[0078] The operating conditions are as follows: operating temperature: 120 °C; operating pressure: 1.2 MPa; the total water injection volume is 20% of the mass of the feedstock oil.

[0079] The desalting results are shown in Table 3.

[0080] Comparative Example 3

[0081] A conventional three-stage electric desalting method was used to desalt the coal tar feedstock in Table 2.

[0082] The settings of the electro-dehydrator are the same as those in Comparative Example 1.

[0083] The operating conditions are as follows: operating temperature 85 °C; operating pressure 0.3 MPa; the total water injection volume is 25% of the mass of the feedstock oil.

[0084] Table 3.

[0085] Item Salt content after desalination, mg / L Example 3 2.42 Example 4 2.36 Example 5 2.37 Example 6 2.55 Comparative Example 1 14.71 Comparative Example 2 13.63 Comparative Example 3 15.56

[0086] From the above experiments, it can be seen that compared with the traditional electric desalting and dehydration technology, the device and method of the present invention have the advantages of simple process flow, high desalting efficiency, and small water injection volume. Especially for those heavy / low-quality oils with high density, high viscosity, and high salt content, due to the large mass transfer resistance in the two-phase mixing and contact of oil and water, on the one hand, the desalting depth far fails to meet the requirement of 3 mg / L; while using the device method of the present invention can effectively improve the mass transfer efficiency of the oil and water contact, enabling the heavy and low-quality oils to achieve the effect of deep washing and desalting, and having wide applicability to different types of heavy and low-quality oils with high salt content.

Claims

1. An apparatus for washing and desalting oil products, characterized in that, The device includes at least one washing desalter, at least one oil-water separator, and at least one magnetic drive device; The washing desalter includes a tank body, in which an oilophilic coalescing packing block, a hydrophilic coalescing packing block, a magnetic medium, and a slideway are arranged. The oilophilic coalescing packing block and the hydrophilic coalescing packing block are arranged on both sides of the magnetic medium and fixed thereto, forming a washing desalting module, which is axially arranged in the tank body in the direction of the oilophilic coalescing packing block, the magnetic medium, and the hydrophilic coalescing packing block. The slideway is axially fixed on both side walls of the tank body, and the washing desalting module is movably fixed on the slideway. The magnet drive device is arranged outside the washing desalter and can drive the magnetic medium to drive the washing desalting module to reciprocate axially in the slideway; at both axial ends of the tank body close to the oilophilic coalescing packing block and the hydrophilic coalescing packing block and far from the magnetic medium, liquid inlets are respectively arranged, and a liquid outlet is arranged on the side wall of the tank body, which is connected to the oil-water separator.

2. The apparatus according to claim 1, characterized in that, The oilophilic coalescing packing block and the hydrophilic coalescing packing block are respectively made of fiber filaments with oilophilic functions and fiber filaments with hydrophilic functions woven into patterns with any one of the concave-convex structure surfaces in the shape of X, V, 8, Ω, water droplet, or rhombus, so as to have a coalescing function.

3. The apparatus according to claim 2, characterized in that, The fiber filaments with oilophilic functions are selected from at least one of polyester fiber filaments, nylon fiber filaments, polyurethane fiber filaments, polypropylene fiber filaments, polyacrylonitrile fiber filaments, and polyvinyl chloride fiber filaments, or are selected from fiber filaments whose surfaces are subjected to physical or chemical oilophilic treatment.

4. The apparatus according to claim 2, characterized in that, The fiber filaments with hydrophilic functions are selected from high molecular polymers whose main chains or side chains contain hydrophilic groups such as carboxyl, amide, amino, or hydroxyl groups.

5. The apparatus according to claim 4, characterized in that, The fiber filaments with hydrophilic functions are selected from at least one of polypropylene fibers, polyamide fibers, and acrylic fibers, or are selected from fiber filaments whose materials are subjected to physical or chemical hydrophilic treatment.

6. The apparatus according to claim 1, characterized in that, The magnet drive device includes a magnetic medium, a fixed shaft sleeve, a crank connecting rod, and a motor. One end of the fixed shaft sleeve is connected to the crank connecting rod, and the other end is connected to the magnet. The other end of the crank connecting rod is connected to the motor. The crank connecting rod rotates clockwise or counterclockwise under the drive of the motor, so as to drive the magnetic medium to move through the crank connecting rod, and the magnetic medium then drives the magnetic medium in the washing desalting module to move through the magnetic field force.

7. The apparatus according to claim 6, characterized in that, The amplitude of the magnet drive device is 1-12 cm; the rotation frequency of the magnet drive device is 1-50 revolutions per minute.

8. The apparatus according to claim 1, characterized in that, The length of the slideway is longer than the height of the washing desalting module, so that the washing desalting module can move axially. The height of the washing desalting module is 1 / 10-9 / 10 of the length of the slideway.

9. The apparatus according to claim 1, characterized in that, The inlet end of the oil-water separator is connected to the liquid outlet of the washing desalter, and the oil-water separation adopts any one or more of gravity sedimentation, hydrocyclone separation, baffle plate enhanced sedimentation, and coalescing packing separation.

10. The apparatus according to claim 1, characterized in that, When two or more washing and desalting devices are provided in the device, the washing and desalting devices are arranged side by side, the magnetic medium is set such that all the washing and desalting devices are an integral whole, and the washing and desalting modules in all the washing and desalting devices move in the same direction as a whole. Alternatively, a separate magnetic medium is provided in each washing and desalting device, and the washing and desalting modules in each washing and desalting device can be separately controlled by a magnetic drive device.

11. The apparatus according to claim 10, characterized in that, When two or more washing and desalting devices are provided in the device, the lipophilic coalescing packing blocks and the hydrophilic coalescing packing blocks of the washing and desalting modules in every two adjacent washing and desalting devices are arranged staggeredly in the axial direction.

12. A method for washing and desalting oil products using the apparatus according to claim 1, comprising: The oil product to be treated and water are respectively introduced into the liquid inlets at both axial ends of the washing and desalting device. The magnetic drive device is started, and under the action of the magnetic field, the magnetic medium drives the washing and desalting module to vibrate and reciprocate axially, so as to strengthen the mass transfer of the injected water and the oil product, and make the salt in the oil product fully dissolve in the water. After completion, the mixture is introduced into the oil-water separator from the liquid outlet on the side wall of the tank body, and the oil and water are separated to complete desalting.

13. The method according to claim 12, characterized in that, When the oil product to be treated and water are respectively introduced into the liquid inlets at both axial ends of the washing and desalting device, the oil product to be treated is introduced into the liquid inlet close to the hydrophilic coalescing packing block, and water is injected into the liquid inlet close to the lipophilic coalescing packing block.

14. The method according to claim 12, characterized in that, When multiple washing and desalting devices are provided, the raw oil and water are all added from a certain washing and desalting device, or added from several washing and desalting devices in a certain proportion, or added from each washing and desalting device.

15. The method according to claim 12, characterized in that, The oil product to be treated is any one or more of crude oil, fraction oil, dirty oil, coal tar, gutter oil, anthracene oil, plastic oil, lubricating oil and waste oil.

16. The method according to claim 12, characterized in that, The weight of the injected water accounts for 1wt%-30wt% of the weight of the oil product to be treated.

17. The method according to claim 12, characterized in that, The operating parameters in the washing and desalting device are as follows: the temperature is normal temperature - 180°C, and the pressure is 0.1 - 5.0 MPa.

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