Apparatus and method for the deacidification of a hydrocarbon phase

Abstract

This invention discloses a hydrocarbon phase deacidification device and method for the petrochemical industry, suitable for the deep purification of acidic hydrocarbon emulsions. The device includes a vertical / horizontal tank, integrating an intercepting wire mesh, a heterogeneous particle demulsification and deacidification unit, a primary / secondary series coalescing and settling unit, and a liquid collection and discharge unit. It is equipped with a multi-functional interface for material inlet / outlet and online backwashing. The heterogeneous particle bed exhibits a gradient distribution in particle size and wettability. The coalescing and settling unit includes a heterogeneous fiber module and a tapered perforated corrugated plate to enhance settling. The method involves separating the acidic hydrocarbon phase through demulsification, coalescence, and settling. The hydrocarbon phase is discharged from the top, and the acid phase is discharged from the bottom, with an integrated gas-water / steam online backwashing and regeneration process. This invention offers high separation accuracy, a compact and flexible structure, real-time monitoring and automated operation, long continuous operation cycles, and a deacidification efficiency exceeding 98%.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical technology, specifically relating to an apparatus and method for removing organic acids from hydrocarbons. It is particularly suitable for the deep purification and separation of acidic hydrocarbon emulsions generated in industries such as petrochemicals and coal chemicals. Background Technology

[0002] Organic acid corrosion in crude oil, distillate oils, and various chemical intermediates has long been a key technical challenge for the petrochemical and coal chemical industries. These organic acids not only severely corrode production equipment, shortening its lifespan and posing safety hazards, but also affect the stability of downstream processes and the quality of final products. Therefore, developing efficient hydrocarbon phase deacidification technologies and equipment is of great significance for ensuring the long-term safe operation of equipment, improving product quality, and achieving green production. Currently, commonly used industrial deacidification methods are mainly divided into chemical and physical methods. However, these methods all have varying degrees of bottlenecks in terms of efficiency, cost, applicability, and long-term stability.

[0003] Patent CN106497597A discloses a method for deacidifying high-acid crude oil using a phase transfer catalyst. This method accelerates the reaction and inhibits emulsification by adding a quaternary ammonium salt catalyst. However, this method falls under the category of chemical methods, introducing additional chemical reagents, increasing raw material costs, and potentially affecting the purity of downstream products. Furthermore, this method focuses on optimizing the reaction process, and its separation still relies on traditional static or electrostatic desalting equipment, without improving the physical separation capability for fine acid droplets; moreover, it cannot solve the problem of online cleaning and regeneration within the equipment.

[0004] Patent CN114195233A discloses a deacidification device for pickling waste acid. Its core technology involves using a special electrodialysis membrane for acid-salt separation, achieving high precision in removing fine acid droplets. However, the membrane module in this device is extremely expensive, and it requires rigorous pretreatment of the feed. Hydrocarbons in chemical intermediates often contain other impurities, leading to membrane fouling, which in turn causes a sharp decline in membrane flux and makes regeneration difficult. Furthermore, the electrodialysis process requires continuous electrical drive, resulting in high energy consumption.

[0005] Patent CN104927907A discloses a device for desulfurization and deacidification of alkylation products. This device integrates intercepting wire mesh packing, fiber membrane bed, and adsorption resin to achieve multi-stage physical separation. However, the process of this device is complex, requiring multiple units to be connected in series, resulting in low integration. Furthermore, the pores of its core separation medium (such as fiber membrane filter cartridges) are extremely small, making it prone to clogging when processing high-viscosity hydrocarbon phases or those containing solid impurities. The patent does not provide an effective online physical cleaning method. Summary of the Invention

[0006] Existing hydrocarbon phase deacidification methods, such as chemical methods, membrane separation methods, and other physical separation methods, suffer from inherent drawbacks, including reliance on chemical reagents, high cost and susceptibility to fouling of membrane modules, or limited functionality, susceptibility to clogging, and lack of efficient online regeneration capabilities. Therefore, there is an urgent need in the field to develop a novel integrated solution that can comprehensively overcome these shortcomings. To achieve this objective, this invention provides a purely physical hydrocarbon phase deacidification device and method that integrates efficient gradient coalescence, active guided sedimentation, and convenient online backwashing.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A device for hydrocarbon phase deacidification, characterized in that the device includes a tank, functional interfaces disposed in and around the tank, an intercepting wire mesh, a heterogeneous particle demulsification and deacidification unit, a coalescence sedimentation unit, and a liquid collection and discharge unit, wherein the coalescence sedimentation unit is a primary integrated coalescence sedimentation unit or a secondary series coalescence sedimentation unit.

[0009] When the coalescence settling unit is a single-stage integrated coalescence settling unit, the device mainly includes a vertical tank and, from top to bottom, an intercepting wire mesh, a heterogeneous particle demulsification and deacidification unit, a first coalescence settling unit, and a liquid collection and discharge unit with a first acid outlet at the bottom.

[0010] When the coalescence settling unit is a two-stage series coalescence settling unit, the device mainly includes: a vertical tank and, from top to bottom, an intercepting wire mesh, a heterogeneous particle demulsification and deacidification unit, a first coalescence settling unit, and a liquid collection and discharge unit with a first acid outlet at the bottom. A horizontal tank is connected in series at the outlet of the first coalescence settling unit. The tank contains a second coalescence settling unit. The lower rear end of the tank has an acid discharge bag and a second acid outlet. The first and second acid outlets are connected by pipelines.

[0011] The intercepting wire mesh is cylindrical, with its top end connected to the tank head via a flange, and reinforcing ribs and support rings arranged around the perimeter of the intercepting wire mesh.

[0012] The heterogeneous particle demulsification and deacidification unit includes a heterogeneous filter bed of stacked heterogeneous particles, which consists of particle media with progressively increasing particle size from top to bottom and alternating hydrophilic and hydrophobic surface properties. A support plate is provided under the filter bed, and filter caps are evenly distributed on the support plate.

[0013] The first coalescing and settling unit is located below the support plate, with a heterogeneous fiber module and a reinforced settling module arranged sequentially along the flow direction of hydrocarbon processing. Both the heterogeneous fiber module and the reinforced settling module are equipped with baffles above and below them. The first coalescing and settling unit includes a chamber formed by the support plate, the baffles, and the tank body, and the heterogeneous fiber module and reinforced settling module arranged within the chamber. The second coalescing and settling unit is located inside the horizontal tank and includes a heterogeneous fiber module and a reinforced settling module arranged sequentially from the front end to the rear end.

[0014] The heterogeneous fiber module comprises at least two fiber coalescing beds, each comprising a cylindrical filter element and hydrophilic-oleophilic heterogeneous woven fibers disposed on the filter element. The thickness of the fiber coalescing bed is 40%-60% of the tangent length of the vertical tank, and the outer diameter of the filter element is 0.8-0.9 times the inner diameter of the corresponding vertical tank. The enhanced settling module is composed of stacked tapered perforated corrugated plates, each corrugated plate having crest sections and trough sections, wherein the crest sections have channels specifically for hydrocarbons to pass through, and the shape and size of the corrugated plates match the baffle plate.

[0015] The liquid collection and discharge unit is located below the baffle plate and is connected to the bottom of the vertical tank.

[0016] The functional interfaces also include a backwash liquid outlet, a vent, a hydrocarbon inlet, and a top nitrogen inlet at the top of the vertical tank. The backwash liquid inlet, backwash steam inlet, and backwash nitrogen inlet are located on the side wall of the tank at the liquid collection and discharge unit. The hydrocarbon outlet is located on the side wall of the tank at the liquid collection and discharge unit or at the upper rear end of the horizontal tank.

[0017] Furthermore, the heterogeneous filter bed in the heterogeneous particle demulsification and deacidification unit is at least three-stage, with the thickness of each stage being 10%-15% of the tangent length of the vertical tank. The particle sizes of the first three stages are 0.5-1 mm, 1-2 mm, and 2-4 mm, respectively. The hydrophilic particles are selected from one or more of silica gel, alumina, glass beads, hydrophilic ceramics, and polymer materials with hydrophilic surface treatment. The hydrophobic particles are selected from one or more of polypropylene, polyethylene, polytetrafluoroethylene, and inorganic materials with hydrophobic surface treatment.

[0018] Furthermore, the number and specifications of the filter caps are determined according to the design flow rate of the device, and their total flow capacity is greater than 15% of the incoming liquid flow rate.

[0019] Furthermore, the hydrophilic fiber in the heterogeneous fiber module is selected from one or more of cotton fiber, viscose fiber, hydrophilic synthetic fiber, and surface-hydrophilic treated polyester fiber; the oleophilic fiber is selected from one or more of polypropylene fiber, polyester fiber, and polyamide fiber.

[0020] Furthermore, the reinforced settlement module has at least 5 layers of corrugated plates stacked on top of each other, with a plate spacing of 10-30mm and an inclination angle of 30°-60°.

[0021] Furthermore, the baffle is selected from one or more of the following: stepped baffle, fan-shaped baffle, and inclined baffle.

[0022] Furthermore, the number of reinforcing ribs in the intercepting wire mesh is 3-6, the number of support rings is not less than 1, and the aperture of the intercepting wire mesh is 0.3-0.4 mm.

[0023] Furthermore, the functional interfaces also include pressure gauge interfaces, level gauge interfaces, and discharge ports around the tank.

[0024] The intercepting wire mesh is used to prevent material from leaking during backwashing. Its support ring can also be used with clamps or overlapping stitching to achieve flexible adjustment of the length of the intercepting wire mesh.

[0025] The heterogeneous particle demulsification and deacidification unit captures acid droplets in the hydrocarbon phase through its special particulate medium, causing them to be retained, aggregate, and grow until they detach into larger droplets that are easily separated under the action of hydraulics and buoyancy, thus achieving initial coalescence separation. The coalescence sedimentation unit further promotes the final separation of the grown acid droplets from the hydrocarbon phase, achieving deep sedimentation separation.

[0026] The corrugated plates of the reinforced settling module have a large number of regularly distributed micro-protrusions and depressions on their panels. Multiple corrugated plates are stacked and coordinated through their inherent bending and tapering shapes, creating a large number of parallel, narrow separation channels with gradually changing cross-sections between the plates. This multi-level structure not only greatly increases the collision frequency and effective separation area between droplets and the solid surface, but also guides the fluid to generate micro-vortices through the periodic changes in the channel cross-section, further enhancing the collision and coalescence effect between droplets. The movement of droplets between the corrugated plates can be divided into three functional zones: the collision and coalescence zone (composed of tapering channels between the panels, achieving large-scale droplet collisions), the convergence and guiding zone (composed of panels with an inclination angle of 35-65°, guiding the flow of droplets), and the separation and rising zone (located at the crests and channels, achieving the separation of light and heavy components).

[0027] The aqueous (acidic) phase is difficult to pass through the wave crest channel due to surface tension and pressure, thus achieving path separation between the hydrocarbon and acid phases. The tapered channel and variable velocity flow field formed by the multi-layer panel maximize the collision probability and coalescence efficiency of droplets.

[0028] The baffle plate installed below the coalescence sedimentation unit is used to achieve efficient separation and diversion of hydrocarbons and acid droplets, and the baffle plate has various forms.

[0029] Stepped baffle: The flow velocity is gradually reduced through a multi-stage descending structure, which is suitable for working conditions that require step-by-step settling.

[0030] Fan-shaped baffle: The arc-shaped structure smoothly changes the direction of the fluid, reducing turbulence and dead zones.

[0031] Inclined baffles: These are installed at a specific angle to guide the flow and assist in gravity settling.

[0032] The baffle plate effectively prevents blockage of the hydrocarbon phase outlet and pipeline by isolating contaminants.

[0033] The support plate and baffle plate provide support for the heterogeneous particle demulsification and deacidification unit and the coalescence sedimentation unit. Several filter caps are installed on the support component under the heterogeneous particle demulsification and deacidification unit to provide support and limit movement. The support component under the coalescence sedimentation unit has a baffle plate structure, which serves to support, guide, separate, and block acid droplets and the emulsion layer, thus extending their residence time in the coalescence sedimentation unit.

[0034] The liquid collection and discharge unit is located below the baffle plate and connected to the bottom of the tank. It is used to collect and discharge the separated acid phase and ensure the purity of the upper hydrocarbon phase outlet fluid.

[0035] The tank is equipped with multiple functional interfaces, including a backwash liquid outlet, vent, hydrocarbon inlet, and top nitrogen inlet at the top; a backwash liquid inlet, steam inlet, hydrocarbon outlet, backwash nitrogen inlet, and acid outlet at the bottom; as well as pressure gauge interfaces, level gauge interfaces, and discharge ports around the tank, to achieve solid packing filling, material inlet and outlet, and selective introduction of backwash gas and liquid.

[0036] The interface of the level gauge is located on the tank wall of the liquid collection and discharge unit and is used to monitor the acid phase liquid level; the differential pressure gauge interface 1 is located above the heterogeneous particle demulsification and deacidification unit, and the differential pressure gauge interface 2 is located in the liquid collection and discharge unit. It is used to measure the pressure drop between the two to monitor the operating resistance of the separation unit and to trigger the backwash operation when the pressure drop reaches the set threshold.

[0037] The backwash liquid inlet and backwash gas inlet are connected to the liquid collection and discharge unit, which confines the acid sludge and contaminants stirred up during backwashing to the main liquid collection and discharge unit, so that they can be effectively discharged from the bottom acid outlet with the backwash liquid, avoiding them from entering the clean hydrocarbon phase outlet pipeline.

[0038] Meanwhile, flow control valves and pressure gauges are installed around each circulation pipe and the exhaust port at the top of the first chamber to precisely control the pressure and flow rate inside the tank.

[0039] The present invention also provides a method for deacidifying the hydrocarbon phase using the aforementioned acid-hydrocarbon separation device, comprising the following steps:

[0040] (1) The acidic hydrocarbon phase enters the heterogeneous particle demulsification and deacidification unit through the intercepting wire mesh from the hydrocarbon inlet, and the hydrocarbon phase collision, demulsification and growth are realized in the heterogeneous particle demulsification and deacidification unit;

[0041] (2) The treated hydrocarbons flow to the coalescence and sedimentation unit, where they are coalesced and separated by the heterogeneous fiber module and the enhanced sedimentation module. The emulsion layer is intercepted and the acid droplets are collected at the bottom.

[0042] (3) The acid phase collected at the bottom is discharged through the acid outlet, and the hydrocarbons are enriched upward and discharged through the hydrocarbon outlet.

[0043] Furthermore, it also includes a step of backwashing and regenerating the device, specifically:

[0044] (1) Process switching: Close the inlet of the acid-containing hydrocarbon phase and the outlet of the hydrocarbon phase, monitor the acid phase liquid through the boundary gauge and drain the liquid in the acid phase zone, and then close the acid outlet;

[0045] If there is residual liquid at the hydrocarbon phase outlet that has not been completely drained, open the top nitrogen inlet and simultaneously introduce nitrogen from the top of the tank to drain the liquid inside the tank, then close the corresponding valve.

[0046] (2) Gas-water backwashing: Close the top nitrogen inlet and acid outlet, open the backwash liquid outlet and backwash liquid inlet and backwash nitrogen inlet, and introduce backwash water and backwash nitrogen for deep backwashing;

[0047] When the backwashing effect is not good, replace the backwashing nitrogen with steam. After the backwashing is completed, use top nitrogen to drain the residual backwashing liquid from the tank.

[0048] (3) Process restoration: After backwashing is completed, close the backwash liquid outlet, backwash liquid inlet, and backwash nitrogen inlet; reopen the acid-containing hydrocarbon phase inlet and vent, and close the vent after the tank is filled with liquid, and open the hydrocarbon outlet to restore the normal process flow.

[0049] Beneficial effects

[0050] Compared with the prior art, the present invention has the following advantages:

[0051] (1) Pure physical separation, no chemical additives: avoids the consumption of chemical reagents and secondary pollution problems;

[0052] (2) Gradient coalescence design for high separation accuracy: Through a dual gradient particle bed of particle size and wettability, combined with fiber coalescence and corrugated plate to enhance sedimentation, the efficient removal of fine acid droplets is achieved;

[0053] (3) Compact structure and flexible expansion: Single tank integration and two-stage series connection can be flexibly switched to adapt to different working conditions;

[0054] (4) Online backwashing and regeneration, easy operation and maintenance: It is equipped with gas-water backwashing and steam-enhanced backwashing processes, and the separated medium can be regenerated online with a long continuous operation cycle;

[0055] (5) Real-time monitoring and automated operation: integrated differential pressure and interface monitoring can automatically trigger backwashing to ensure long-term stable operation of the device. Attached Figure Description

[0056] Figure 1 This is a flowchart of an apparatus and method for achieving hydrocarbon phase deacidification.

[0057] Among them: 1-1, vertical tank; 1-2, backwash liquid outlet; 1-3, hydrocarbon inlet; 1-4, top nitrogen inlet; 1-5, vent; 1-6, differential pressure gauge interface 1; 1-7, intercepting wire mesh; 1-8, heterogeneous filter bed; 1-9, filter cap; 1-10, support plate; 1-11, baffle plate; 1-12, heterogeneous fiber module; 1-13, enhanced sedimentation module; 1-15, discharge port; 1-16, hydrocarbon outlet; 1-17, backwash nitrogen inlet; 1-18, steam inlet; 1-19, backwash liquid inlet; 1-20, differential pressure gauge interface 2; 1-21, interface gauge interface 1; 1-22, interface gauge interface 2; 1-23, first acid outlet;

[0058] Figure 2 This is a schematic diagram of a tapered perforated corrugated folded plate structure.

[0059] Among them: 2-1, crest, 2-2, trough, 2-3, panel, 2-4, channel, 2-5, collision coalescence zone, 2-6, convergence guiding zone, 2-7, separation rising zone;

[0060] Figure 3 A schematic diagram of a wire mesh rectifier structure for interception.

[0061] Among them: 3-1, flange; 3-2, reinforcing rib; 3-3, support ring; 3-4, clamp; 3-5, metal wire mesh;

[0062] Figure 4 This is a schematic diagram of the combined process flow in the embodiment.

[0063] The components are as follows: 1-1, Vertical tank; 1-2, Backwash liquid outlet; 1-3, Hydrocarbon inlet; 1-4, Top nitrogen inlet; 1-5, Vent port; 1-6, Differential pressure gauge interface 1; 1-7, Intercepting wire mesh; 1-8, Heterogeneous filter bed; 1-9, Filter cap; 1-10, Support plate; 1-11, Baffle plate; 1-12, Heterogeneous fiber module; 1-13, Enhanced sedimentation module; 1-15, Discharge port; 1-17, Backwash nitrogen inlet; 1-18, Steam inlet; 1-19, Backwash liquid inlet; 1-20, Differential pressure gauge interface 2; 1-23, First acid outlet; 1-25, Horizontal tank; 1-26, Acid discharge bag; 1-27, Second acid outlet. Detailed Implementation

[0064] The present invention will be further described in detail below with reference to embodiments. It should be understood that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention still fall within the scope of protection of the present invention.

[0065] like Figure 1 As shown, the present invention provides an apparatus and method for hydrocarbon phase deacidification, comprising:

[0066] The vertical tank 1-1 is provided with an intercepting wire mesh 1-7, a heterogeneous particle demulsification and deacidification unit 1-8, a water filter cap 1-9, and a coalescence sedimentation unit 1-14 arranged sequentially from top to bottom along its inner edge. The water filter cap 1-9 is installed on the support component 1-10 for uniformly distributing filtered water. The coalescence sedimentation unit 1-14 is installed on the baffle plate 1-11 for further separating acid droplets.

[0067] The vertical tank is equipped with multiple functional interfaces: acidic hydrocarbon phases enter the tank through hydrocarbon inlet 1-3, treated hydrocarbons are discharged through hydrocarbon outlet 1-16, and acidic phases are discharged through acid outlet 1-23. The top of the tank has a vent 1-5 and a backwash liquid outlet 1-2, while the bottom has a backwash liquid inlet 1-19. If backwashing is incomplete, steam can be introduced through steam inlet 1-18 to enhance cleaning. Furthermore, the device is equipped with level gauges via level gauge interfaces 1-21 and 2-22 for monitoring the liquid level inside the tank. The discharge port 1-15 is located above the supporting components and is used for filling or replacing solid packing material.

[0068] Combination Figure 2 As shown, the coalescence sedimentation unit includes a heterogeneous fiber module 1-12 and a reinforced sedimentation module 1-13. The reinforced sedimentation module 1-13 uses a tapered perforated corrugated plate 2 to capture and enrich acid droplets. The corrugated plate includes a crest 2-1, a trough 2-2, a panel 2-3, and several channels 2-4 formed on the panel. Multiple layers of corrugated plates are stacked to form a collision coalescence zone 2-5, a convergence and guiding zone 2-6, and a separation and rising zone 2-7 for acid droplet movement, thereby enhancing the collision coalescence and separation effect of acid droplets.

[0069] Combination Figure 3 As shown, the intercepting wire mesh 3 is used to prevent material leakage during backwashing. One end of the intercepting wire mesh is equipped with a flange 3-1 for connection to the tank top cover. To enhance structural stability, reinforcing ribs 3-2 are arranged around the perimeter of the intercepting wire mesh. When the intercepting wire mesh is long, a support ring 3-3 is also provided, and multiple sections of the intercepting wire mesh are connected and their lengths adjusted via clamps 3-4.

[0070] The present invention also provides a method for achieving hydrocarbon phase deacidification using the above-described apparatus, comprising the following steps:

[0071] (1) The acidic hydrocarbon phase enters the heterogeneous particle demulsification and deacidification unit of the tank from the hydrocarbon inlet. In the heterogeneous particle demulsification and deacidification unit, it is treated by multiple layers of heterogeneous filter bed to realize the collision, aggregation and growth of acid droplets.

[0072] (2) The fluid after demulsification and deacidification treatment enters the coalescence sedimentation unit. Through the guidance and separation of the multi-layer corrugated plates in the coalescence sedimentation unit, the emulsion layer is effectively intercepted, and the acid phase gathers downward under the action of gravity and enters the liquid collection and discharge unit.

[0073] (3) The separated hydrocarbons are enriched in the upper layer of the liquid collection and discharge unit and discharged through the hydrocarbon outlet, while the acid phase is accumulated at the bottom of the liquid collection and discharge unit and discharged through the acid outlet.

[0074] (4) The device can perform online backwashing and enhanced backwashing operations to restore separation performance.

[0075] Furthermore, it also includes a step of backwashing and regenerating the device, specifically:

[0076] (1) Process switching: Close the inlet of the acid-containing hydrocarbon phase and the outlet of the hydrocarbon phase. After draining the acid phase through the interface gauge, close the acid outlet. If the liquid is not drained completely, the top nitrogen inlet can be opened and nitrogen can be introduced from the top of the tank to drain the liquid in the tank. Then close the corresponding valve.

[0077] (2) Gas-water backwashing: Close the top nitrogen inlet and acid outlet, open the backwash liquid outlet and backwash liquid inlet, and introduce backwash water and backwash gas for deep backwashing; if the backwashing effect is not good, the backwash gas can be replaced with steam to enhance the cleaning.

[0078] After backwashing is complete, use nitrogen gas from the top to purge the remaining backwash solution from the tank.

[0079] (3) Process restoration: After the backwashing is completed, close the backwash liquid inlet and outlet; reopen the acid-containing hydrocarbon phase inlet and vent, and close the vent after the tank is filled with liquid, and open the hydrocarbon outlet to restore the normal process flow.

[0080] Furthermore, the processing capacity of the aforementioned hydrocarbon phase deacidification device is 15-45 m³. 3 / h

[0081] Furthermore, the continuous operating cycle of the coalescing filter device is no less than 5 years, taking into account the interchangeability of the separation components.

[0082] Example 1

[0083] A petrochemical company uses the hydrocarbon phase deacidification unit described in this invention to demulsify and deacidify the mixed acid (a mixture of sulfuric acid and nitric acid) in the pickling nitrobenzene feedstock. The feedstock hydrocarbon phase is mainly composed of nitrobenzene (85%–90%) and benzene (10%–15%), with a density of 1.1–1.2 g / cm³; the residual acid phase (sulfuric acid 66%–70%, nitric acid <0.1%, density 1.8 g / cm³) is dispersed in the form of fine droplets, with a content of approximately 0.5–1 vol%. Calculations show that the mass concentration of the acid phase in the feedstock within the hydrocarbon phase is approximately 1.0 × 10⁻⁶. 4 mg / L, with a designed treatment capacity of 25 m³ / h.

[0084] The device is a vertical tank structure, with an intercepting wire mesh, a heterogeneous particle demulsification and deacidification unit, and a first coalescing sedimentation unit arranged sequentially from top to bottom. The heterogeneous particle demulsification and deacidification unit employs a three-level gradient bed structure, with bed thicknesses of 120 mm, 150 mm, and 180 mm from top to bottom, corresponding to porosities of 0.35–0.45, 0.45–0.60, and 0.55–0.70, respectively. The first coalescing sedimentation unit consists of a heterogeneous fiber module and a reinforced sedimentation module. The heterogeneous fiber module includes two heterogeneous fiber coalescing beds with a bed thickness of 300 mm. The reinforced sedimentation module adopts a tapered perforated corrugated plate structure with a plate spacing of 25 mm and an inclination angle of 50°, comprising eight layers of corrugated plates to form a multi-level collision-guidance-separation channel.

[0085] During operation, acid-containing nitrobenzene enters the unit through the hydrocarbon inlet and proceeds to the heterogeneous particle demulsification and deacidification unit. In the heterogeneous filter bed, acid droplets collide, coalesce, and gradually grow larger due to surface microchannels. Subsequently, the fluid passes through the filter water distribution component and uniformly enters the first coalescing and settling unit. In the heterogeneous fiber module, the fine acid droplets further coalesce; in the converging flow channel formed by corrugated plates, the acid droplets further collide and coalesce, settling and separating under gravity and guidance. The separated acid phase collects at the bottom of the tank and is periodically discharged through the acid outlet; the purified nitrobenzene accumulates at the top of the tank and is continuously discharged through the hydrocarbon outlet.

[0086] After treatment by the complete set of hydrocarbon phase deacidification unit, the acid content in the outlet nitrobenzene is stabilized below 1,000 mg / L, and the system deacidification efficiency exceeds 90%. The pressure drop during unit operation is less than 0.15 MPa, and the operation is stable and reliable, with a continuous operation cycle of not less than 5 years, meeting the requirements for long-term stable operation of chemical plants.

[0087] Example 2

[0088] A petrochemical company, under the same raw material conditions (the mass concentration of the acid phase in the nitrobenzene / benzene mixed hydrocarbon phase is approximately 1.0 × 10⁻⁶), 4(mg / L) A two-stage series deacidification device was designed based on the principle of this invention to further optimize the separation effect.

[0089] The device consists of two tanks connected in series: the first stage is a vertical deacidification tank, which has an intercepting wire mesh, a heterogeneous particle demulsification and deacidification unit and a first coalescence sedimentation unit arranged from top to bottom, and a first acid outlet collection and discharge unit at the bottom; the second stage is a horizontal deacidification tank, which has a second coalescence sedimentation unit arranged along the material flow direction, and an acid discharge bag and a second acid outlet at the lower rear of the tank. The first acid outlet and the second acid outlet are connected by pipelines.

[0090] The two tanks are connected in series by pipelines. The acidic hydrocarbon phase passes through the first-stage vertical tank for integrated coalescence sedimentation treatment, and then enters the second-stage horizontal tank for deep coalescence sedimentation. This significantly increases the overall residence time and separation path of the material, and further optimizes the separation effect.

[0091] During operation, acid-containing nitrobenzene enters the first-stage vertical tank through the hydrocarbon inlet, passing sequentially through an intercepting wire mesh, a heterogeneous particle demulsification and deacidification unit, and a coalescence sedimentation unit, completing initial demulsification and coalescence sedimentation. The separated acid phase is discharged through the first acid outlet, while the hydrocarbon phase, carrying residual fine acid droplets, enters the horizontal tank. In the two-stage series coalescence sedimentation unit of the horizontal tank, the hydrocarbon phase passes sequentially through the second heterogeneous fiber module and the second enhanced sedimentation module, achieving deep coalescence and final sedimentation separation. The separated acid phase is discharged through the acid discharge bag and the second acid outlet, while the purified hydrocarbon phase is continuously discharged from the upper hydrocarbon outlet at the rear end of the horizontal tank.

[0092] After processing by this two-stage series device, the acid content in the hydrocarbon phase outlet can be stabilized below 200 mg / L, and the system deacidification efficiency exceeds 98%. Compared with the single-tank integrated device in Example 1, this series scheme sacrifices some space compactness in exchange for better separation accuracy and processing effect, and is suitable for special working conditions with higher requirements for product purity, demonstrating the flexibility and scalability of the technical route of this invention.

[0093] The above embodiments demonstrate that both the highly integrated single-tank design in Embodiment 1 and the two-stage series design in Embodiment 2 rely on the core technology of this invention—a separation process combining heterogeneous particle demulsification and deacidification with heterogeneous fiber aggregation and corrugated plate-reinforced sedimentation. Embodiment 1 proves that this technology can achieve a balance between efficient separation and compact layout in a single device; Embodiment 2 further demonstrates that by modularizing and rationally connecting this core technology, the separation path and residence time can be flexibly expanded to achieve higher separation accuracy (outlet acid content <200 mg / L, efficiency >98%), meeting the needs of specific scenarios with extreme requirements for product purity. This fully demonstrates that the technical solution provided by this invention has high flexibility, scalability, and excellent separation performance, and can provide customized and efficient solutions for chemical plants with different processing needs and space conditions.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An apparatus for hydrocarbon phase deacidification, characterized in that, The device includes a tank, functional interfaces disposed inside and around the tank, an intercepting wire mesh, a heterogeneous particle demulsification and deacidification unit, a coalescence sedimentation unit, and a liquid collection and discharge unit. The coalescence sedimentation unit is a primary integrated coalescence sedimentation unit or a secondary series coalescence sedimentation unit. When the coalescence settling unit is a single-stage integrated coalescence settling unit, the device mainly includes a vertical tank and, from top to bottom, an intercepting wire mesh, a heterogeneous particle demulsification and deacidification unit, a first coalescence settling unit, and a liquid collection and discharge unit with a first acid outlet at the bottom. When the coalescence settling unit is a two-stage series coalescence settling unit, the device mainly includes: a vertical tank and, from top to bottom, an intercepting wire mesh, a heterogeneous particle demulsification and deacidification unit, a first coalescence settling unit, and a liquid collection and discharge unit with a first acid outlet at the bottom. A horizontal tank is connected in series at the outlet of the first coalescence settling unit. A second coalescence settling unit is provided in the tank. The lower part of the rear end of the tank is equipped with an acid discharge bag and a second acid outlet. The first and second acid outlets are connected by pipelines. The intercepting wire mesh is cylindrical, with its top end connected to the tank head via a flange. The intercepting wire mesh is provided with reinforcing ribs distributed tangentially and support rings distributed circumferentially. The heterogeneous particle demulsification and deacidification unit includes a heterogeneous filter bed of stacked heterogeneous particles, which consists of particle media with progressively increasing particle size from top to bottom and alternating hydrophilic and hydrophobic surface properties. A support plate is provided under the filter bed, and filter caps are evenly distributed on the support plate. The first coalescing and settling unit is located below the support plate, with a heterogeneous fiber module and a reinforced settling module arranged sequentially along the flow direction of hydrocarbon processing. Both the heterogeneous fiber module and the reinforced settling module are equipped with baffles above and below them. The first coalescing and settling unit includes a chamber formed by the support plate, the baffles, and the tank body, and the heterogeneous fiber module and reinforced settling module arranged within the chamber. The second coalescing and settling unit is located inside the horizontal tank and includes a heterogeneous fiber module and a reinforced settling module arranged sequentially from the front end to the rear end. The heterogeneous fiber module comprises at least two fiber coalescing beds, each comprising a cylindrical filter element and hydrophilic and oleophilic heterogeneous woven fibers disposed on the filter element. The thickness of the fiber coalescing bed is 40%-60% of the tangent length of the vertical tank, and the outer diameter of the filter element is 0.8-0.9 times the inner diameter of the corresponding vertical tank. The enhanced settling module is composed of stacked tapered perforated corrugated plates, each corrugated plate having crest sections and trough sections, wherein the crest sections have channels specifically for hydrocarbons to pass through, and the shape and size of the corrugated plates match the baffle plate. The liquid collection and discharge unit is located below the baffle plate and is connected to the bottom of the vertical tank. The functional interfaces also include a backwash liquid outlet, a vent, a hydrocarbon inlet, and a top nitrogen inlet at the top of the vertical tank. The backwash liquid inlet, backwash steam inlet, and backwash nitrogen inlet are located on the side wall of the tank at the liquid collection and discharge unit. The hydrocarbon outlet is located on the side wall of the tank at the liquid collection and discharge unit or at the upper rear end of the horizontal tank.

2. The apparatus for hydrocarbon phase deacidification as described in claim 1, characterized in that, The heterogeneous filter bed in the heterogeneous particle demulsification and deacidification unit has at least three levels, with the thickness of each level being 10%-15% of the tangent length of the vertical tank. The particle sizes of the first three levels are 0.5-1 mm, 1-2 mm, and 2-4 mm, respectively. The hydrophilic particles are selected from one or more of silica gel, alumina, glass beads, hydrophilic ceramics, and polymer materials with hydrophilic surface treatment. The hydrophobic particles are selected from one or more of polypropylene, polyethylene, polytetrafluoroethylene, and inorganic materials with hydrophobic surface treatment.

3. The apparatus for hydrocarbon phase deacidification as described in claim 1, characterized in that, The number and specifications of the filter caps are determined according to the design flow rate of the device, and their total flow capacity is greater than 15% of the incoming liquid flow rate.

4. The apparatus for hydrocarbon phase deacidification as described in claim 1, characterized in that, The hydrophilic fiber in the heterogeneous fiber module is selected from one or more of cotton fiber, viscose fiber, hydrophilic synthetic fiber, and surface-hydrophilic treated polyester fiber; the oleophilic fiber is selected from one or more of polypropylene fiber, polyester fiber, and polyamide fiber.

5. The apparatus for hydrocarbon phase deacidification as described in claim 1, characterized in that, The reinforced settlement module consists of at least 5 layers of corrugated plates, with a spacing of 10-30 mm between each layer and an inclination angle of 30°-60°.

6. The apparatus for hydrocarbon phase deacidification as described in claim 1, characterized in that, The liquid baffle is selected from one or more of the following: stepped liquid baffle, fan-shaped liquid baffle, and inclined baffle.

7. The apparatus for hydrocarbon phase deacidification as described in claim 1, characterized in that, The intercepting wire mesh has 3-6 reinforcing ribs, at least one support ring, and a mesh size of 0.3-0.4 mm.

8. The apparatus for hydrocarbon phase deacidification as described in claim 1, characterized in that, The functional interfaces also include pressure gauge interfaces, level gauge interfaces, and discharge ports around the tank.

9. A method for deacidifying hydrocarbon phases using the apparatus of claim 1, characterized in that, The method includes the following steps: (1) The acidic hydrocarbon phase enters the heterogeneous particle demulsification and deacidification unit through the intercepting wire mesh from the hydrocarbon inlet, and the hydrocarbon phase collision, demulsification and growth are realized in the heterogeneous particle demulsification and deacidification unit; (2) The treated hydrocarbons flow to the coalescence and sedimentation unit, where they are coalesced and separated by the heterogeneous fiber module and the enhanced sedimentation module. The emulsion layer is intercepted and the acid droplets are collected at the bottom. (3) The acid phase collected at the bottom is discharged through the acid outlet, and the hydrocarbons are enriched upward and discharged through the hydrocarbon outlet.

10. The method for deacidification of hydrocarbon phase as described in claim 8, characterized in that, The method further includes a step of backwashing and regenerating the device: (1) Process switching: Close the inlet of the acid-containing hydrocarbon phase and the outlet of the hydrocarbon phase, monitor the acid phase liquid through the boundary gauge and drain the liquid in the acid phase zone, and then close the acid outlet; If there is residual liquid at the hydrocarbon phase outlet that has not been completely drained, open the top nitrogen inlet and simultaneously introduce nitrogen from the top of the tank to drain the liquid inside the tank, then close the corresponding valve. (2) Gas-water backwashing: Close the top nitrogen inlet and acid outlet, open the backwash liquid outlet and backwash liquid inlet and backwash nitrogen inlet, and introduce backwash water and backwash nitrogen for deep backwashing; When the backwashing effect is not good, replace the backwashing nitrogen with steam. After the backwashing is completed, use top nitrogen to drain the residual backwashing liquid from the tank. (3) Process restoration: After backwashing is completed, close the backwash liquid outlet, backwash liquid inlet, and backwash nitrogen inlet; reopen the acid-containing hydrocarbon phase inlet and vent, and close the vent after the tank is filled with liquid, and open the hydrocarbon outlet to restore the normal process flow.

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