Apparatus and method for continuous separation of magnetically separable catalyst

Abstract

The application discloses a device for continuously separating a magnetically separable catalyst, which comprises a vertical container including an upper cylinder and a lower cylinder; a clear liquid outlet is arranged at the top of the upper cylinder and used for discharging clear liquid after the catalyst is separated; a feed liquid inlet is arranged on the lateral wall of the lower cylinder and used for adding catalyst-containing feed liquid; at least two electromagnetic coils are respectively sleeved on the outer side of the upper cylinder and arranged along the axial direction of the upper cylinder; and a central pipe is located at the bottom of the lower cylinder and extends into the interior of the lower cylinder; a washing water inlet is arranged at the bottom of the central pipe; and a catalyst outlet is further arranged on the central pipe and used for discharging separated catalyst. The device and method of the application realize continuous separation and washing of catalyst particles, and have high catalyst recovery rate and simple operation.

Description

Technical Field

[0001] This invention relates to the field of catalyst separation technology, and more specifically to a continuous separation apparatus and method for magnetically separable catalysts. Background Technology

[0002] Catalysts can alter the rate of chemical reactions without changing the chemical equilibrium, making them crucial mediators in chemical reactions and widely used in industries such as petrochemicals and biopharmaceuticals. Catalysts are primarily reported through patents; due to technological secrecy, the preparation technologies for many catalysts are controlled by a few foreign companies. Given the high price, large consumption, and low utilization rate of catalysts, the recycling and reuse of catalysts is of paramount importance.

[0003] In existing catalyst particle separation and recovery processes, filtration is mostly used to recover catalyst particles, which can reduce catalyst loss. However, catalyst particles easily pass through the filter screen, resulting in low recovery efficiency, especially for catalysts with very small particle sizes. Fine catalyst particles easily pass through the filter cloth, making separation and recovery of such catalysts even more difficult. With the development of catalyst preparation technology, solid catalysts containing metals such as iron and nickel are widely used, especially in slurry bed reactors. Because iron and nickel are magnetic, the catalyst particles also possess a certain degree of magnetism and can be magnetized. Due to the magnetic nature of these catalysts, utilizing an external magnetic field to achieve their recovery and reuse has become an important research direction in the field of catalyst separation. Consequently, the technology of using magnetic separators for catalyst separation has developed. This type of separator can effectively replace traditional filtration separation methods, especially in the separation of small-diameter catalyst particles. Currently, the separation of catalysts using magnetic separators mainly uses electromagnets. When energized, a magnetic field is generated, and the catalyst particles are adsorbed onto the electromagnet. When the power is turned off, the electromagnet loses its magnetism, and the catalyst particles detach from the magnet, achieving catalyst separation and collection.

[0004] CN103846161A discloses a solid-liquid separation method that uses magnetic separation to recover catalysts. The slurry passes through a magnetic separation zone, where solid catalyst particles are adsorbed. The magnetic field is then removed, causing the adsorbed catalyst particles to desorb and settle by gravity, then be circulated back to the slurry bed reactor. However, this method requires the electromagnet to be switched on and off, resulting in high energy consumption.

[0005] CN108067350A discloses a magnetic separation device that separates magnetic particle catalysts by setting a cylinder and a magnet that moves up and down inside the cylinder in the separation chamber, and using a steel wire rope to drive the movement of the two magnets. This device has many moving parts, a complex structure, and is not convenient to operate. Summary of the Invention

[0006] The purpose of this invention is to overcome the problem that catalysts in the prior art cannot be continuously recycled, and to provide an apparatus and method for continuous separation of magnetically separable catalysts. The apparatus and method of this invention achieve continuous separation of catalysts with high separation efficiency, and also achieve catalyst washing during the separation process.

[0007] To achieve the above objectives, a first aspect of the present invention provides an apparatus for the continuous separation of magnetically separable catalysts, the apparatus comprising:

[0008] A vertical container includes an upper cylinder and a lower cylinder; the top of the upper cylinder is provided with a clear liquid outlet for discharging the clear liquid after the catalyst is separated; the side wall of the lower cylinder is provided with a feed liquid inlet for adding a feed liquid containing the catalyst.

[0009] At least two electromagnetic coils are respectively looped around the outside of the upper cylinder and arranged along the axial direction of the upper cylinder; and

[0010] A central tube is located at the bottom of the lower cylinder and extends into the interior of the lower cylinder; a washing water inlet is provided at the bottom of the central tube; a catalyst outlet is also provided on the central tube for discharging the separated catalyst.

[0011] A second aspect of the present invention provides a method for continuous separation of magnetically separable catalysts, employing the aforementioned apparatus, the method comprising:

[0012] The catalyst-containing liquid from the reactor enters the aforementioned device through the liquid inlet. The catalyst-containing liquid passes through the dense magnetic field area from bottom to top. The catalyst is captured and aggregated under the action of magnetic force. Then, under the action of gravity, the catalyst enters the central tube, is washed with washing water, and is discharged from the catalyst outlet, circulating back to the reactor. The clear liquid after the catalyst is separated continues to flow upward and is discharged from the clear liquid outlet.

[0013] The beneficial technical effects achieved by the present invention through the above technical solution are as follows:

[0014] 1) The device for continuous separation of magnetically separable catalysts proposed in this invention uses at least two electromagnetic coils outside the upper cylinder to capture and aggregate the catalyst under the action of a magnetic field. Then, the catalyst flows out from the central tube under the action of gravity, thereby realizing continuous separation and washing of catalyst particles, with high catalyst recovery rate and simple operation.

[0015] 2) The device of the present invention has a central tube at the bottom. This design allows water to be introduced during the catalyst separation process to wash away the reaction products adhering to the catalyst surface, improving the catalyst separation degree and reducing contamination of other reaction products. The device of the present invention has no moving parts, is simple and continuous to operate, easy to implement, and has low requirements for magnetic field distribution, thus reducing cost burden.

[0016] 3) The device and method of the present invention achieve continuous separation of catalysts, and the catalyst solid content in the clear liquid after separation is low, the separation efficiency is high, and the catalyst can be continuously recycled, which can improve the utilization efficiency of the catalyst and reduce the consumption of catalyst. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a device for continuous separation of magnetically separable catalysts according to one embodiment of the present invention;

[0018] Figure 2 This is the embodiment of the present invention. Figure 1 The diagram shows a process flow diagram for catalyst separation using the separation device shown. Detailed Implementation

[0019] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0020] The first aspect of this invention provides an apparatus for the continuous separation of magnetically separable catalysts, such as... Figure 1 As shown, the device includes:

[0021] The vertical container 1 includes an upper cylinder 11 and a lower cylinder 12; the top of the upper cylinder 11 is provided with a clear liquid outlet N2 for discharging the clear liquid after the catalyst is separated; the side wall of the lower cylinder 12 is provided with a feed liquid inlet N7 for adding a feed liquid containing the catalyst.

[0022] At least two electromagnetic coils 2 are respectively looped around the outside of the upper cylinder 11 and arranged along the axial direction of the upper cylinder 11; and

[0023] The central tube 3 is located at the bottom of the lower cylinder 12 and extends into the interior of the lower cylinder 12; a washing water inlet N10 is provided at the bottom of the central tube 3; and a catalyst outlet N8 is also provided on the central tube 3 for discharging the separated catalyst.

[0024] The device of the present invention comprises at least two Helmholtz coils, each independently connected to a transformer. The Helmholtz coils provide a magnetic field, which captures and aggregates a magnetic catalyst. The catalyst then flows out of the central tube under gravity, and new catalyst continuously flows out of the central tube as the catalyst flows out.

[0025] In this invention, the effect of magnetic separation on solid catalyst particles comes from two aspects. One is the presence of a magnetic medium, which can be attracted by a magnet, such as iron. Preferably, the solid catalyst particles are 100-400 mesh in size and have a density significantly greater than the liquid (i.e., a settling time of less than 20 seconds in a static liquid). Typical examples include industrial-grade Raney nickel and amorphous nickel particles. The other factor is the upward fluid velocity. Since the density of solid particles is greater than that of the fluid, solids naturally tend to settle in static fluids. When the upward flow velocity exceeds the initial fluidization velocity of the bed, the bed expands, and the particles tend to fluidize. At this point, when the magnetic field is activated, the bed immediately tightens, requiring an even higher flow velocity to expand and fluidize again. Therefore, the magnetic field significantly increases the initial fluidization velocity of the bed, thereby increasing the processing air velocity and reducing equipment size. The magnetic capture separator of this invention can simultaneously perform capture, washing, and high-concentration slurry transport operations.

[0026] In this invention, the upper cylinder 11 and the lower cylinder 12 are connected by a flange 13.

[0027] In this invention, the washing water inlet N10 is located at the bottom of the central tube 3, which allows water to be introduced to wash away the reaction products adhering to the catalyst surface, thereby reducing the pollution of the reaction system during recycling.

[0028] In this invention, the magnetically separable catalyst refers to a catalyst containing magnetizable components, specifically solid particles containing magnetic materials, including but not limited to: iron-containing catalysts and nickel-containing catalysts. Preferably, the device of this invention can capture and recover fine-particle catalysts, with a preferred catalyst particle size of 100-400 mesh.

[0029] The device of the present invention, such as Figure 1 As shown, it also includes pressure gauge mounting port K1, pressure gauge mounting port K3, and thermometer mounting port K2, as well as other auxiliary instrument ports.

[0030] In some embodiments of the present invention, the length-to-diameter ratio of the vertical container is 4-8:1, for example, 4:1, 5:1, 6:1, 7:1, 8:1, and any value within the range of any two values, preferably 5-6:1.

[0031] In some embodiments, the height Dk of the vertical container is 3-10m, preferably 5-7m.

[0032] In some embodiments of the present invention, the ratio of the length of the upper cylinder to the length of the lower cylinder is 5-9:1, for example, 5:1, 6:1, 7:1, 8:1, 9:1, and any value within the range of any two values, preferably 6-8:1.

[0033] In some embodiments of the present invention, the length-to-diameter ratio of the central tube is 4-12:1, for example, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, and any value within the range of any two values, preferably 6-10:1. The length-to-diameter ratio of the central tube must meet the washing requirements; if it is too short, the washing will not be sufficient; if it is too long, installation will be inconvenient.

[0034] In some embodiments of the present invention, the ratio of the diameter of the central tube to the diameter of the lower cylinder is 0.05-0.3:1, for example, 0.05:1, 0.1:1, 0.15:1, 0.2:1, 0.25:1, 0.3:1, and any value within the range of any two values, preferably 0.1-0.25:1. If the ratio of the diameter of the central tube to the diameter of the lower cylinder is too large, the catalyst separation degree is low and the washing liquid volume is large; if the ratio of the diameter of the central tube to the diameter of the lower cylinder is too small, the catalyst is not easy to flow out from the central tube.

[0035] In some embodiments of the present invention, the diameter of the upper cylinder is the same as the diameter of the lower cylinder.

[0036] In some embodiments of the present invention, the upper opening of the central tube is higher than the liquid inlet.

[0037] In this invention, the length of the central tube must first meet the washing requirements. If the central tube is too short, washing will be insufficient; if the central tube is too long, installation will be inconvenient. If the feed inlet is too high, the area below the feed inlet will become a fluid dead zone, resulting in wasted space. Furthermore, for smaller central tubes (e.g., 25mm diameter), the flushing effect at the feed inlet can prevent catalyst bridging at the central tube inlet, thus preventing the catalyst from exiting the central tube. For larger diameters (greater than 50mm), the flushing effect can be ignored.

[0038] In some preferred embodiments of the present invention, the upper opening of the central tube is 30-200 mm higher than the liquid inlet, for example, any value in the range of 30 mm, 50 mm, 80 mm, 100 mm, 120 mm, 150 mm, 180 mm, 200 mm, and any two of these values, preferably 50-150 mm higher.

[0039] In some embodiments of the present invention, the device includes 2-16 electromagnetic coils, for example, any value within the range of 2, 4, 5, 6, 8, 10, 12, 14, 15, 16, or any two of these values, preferably 4-10 electromagnetic coils. Adjacent groups of electromagnetic coils are of the same size, and the magnetic field strength can be adjusted according to the actual separation conditions.

[0040] In this invention, the current and voltage of the electromagnetic coils are supplied by two cabinets respectively. Each group consists of 2-4 electromagnetic coils and one cabinet. The voltage is adjusted between 50V and 200V, and the current is controlled by adjusting the voltage to keep the current constant at 10-14A.

[0041] In some embodiments of the present invention, the interval between two adjacent sets of electromagnetic coils is 0.5-5m, for example, 0.5m, 1m, 2m, 3m, 4m, 5m, and any value in the range of any two values, preferably 1-4m.

[0042] In some embodiments of the present invention, the height Db of each set of electromagnetic coils is 0.1-1m, for example, 0.1m, 0.2m, 0.3m, 0.4m, 0.5m, 0.6m, 0.7m, 0.8m, 0.9m, 1m, and any value within the range of any two values, preferably 0.4-0.8m.

[0043] In some embodiments of the present invention, the inner diameter of each set of electromagnetic coils is 0.5-3m, for example, 0.5m, 0.8m, 1m, 1.5m, 2m, 2.5m, 3m, or any value within the range of any two values; the outer diameter is 1-4m, for example, 1m, 1.5m, 2m, 2.5m, 3m, 3.5m, 4m, or any value within the range of any two values.

[0044] In some embodiments of the present invention, each set of electromagnetic coils 2 is provided with a water inlet N3a and a water outlet N3b to reduce the temperature of the electromagnetic coils so as to ensure that the operating temperature of the electromagnetic coils is 40-70°C.

[0045] In this invention, during use, water is introduced into the inlet of each set of electromagnetic coils and discharged from the outlet to cool the electromagnetic coils and dissipate the heat generated by the electromagnetic coils in a timely manner.

[0046] In this invention, a thermocouple is embedded in the middle of the electromagnetic coil to detect the temperature rise. The electromagnetic coil is cooled according to the temperature rise. Forced water cooling can be used, with cooling water entering from N3a and exiting from N3b after heat extraction.

[0047] In some embodiments of the present invention, the bottom of the lower cylinder 12 is also provided with a catalyst discharge outlet N9 for completely discharging the catalyst during shutdown and accident handling.

[0048] In some embodiments of the present invention, a fresh catalyst replenishment port N1 is provided at the top of the upper cylinder 11. A fresh catalyst feeding pipeline is provided at the fresh catalyst replenishment port N1, which extends into the interior of the upper cylinder 11 for adding fresh catalyst.

[0049] In this invention, after the catalyst is discharged, fresh catalyst needs to be added to maintain the catalyst interface position in the magnetic separator. The catalyst in the magnetic separator can be maintained in quantity and activity through intermittent input and output, or through continuous input and output to maintain catalyst balance. Both methods require that fresh catalyst be added to the system promptly before the catalyst becomes deactivated; otherwise, the hydrogenation quality will not meet requirements. Simultaneously, a catalyst discharge line is arranged at the bottom of the magnetic separator for completely discharging the catalyst from the magnetic separator when necessary, typically used during shutdowns and accident handling.

[0050] In some embodiments of the invention, the device further includes a current sensor for monitoring the current in each electromagnetic coil.

[0051] In some embodiments of the present invention, a current alarm is provided on the current sensor, and the current alarm is set to 6A-10A.

[0052] In this invention, when a low current alarm is triggered, to prevent the catalyst inside the device from being carried out due to demagnetization, an interlock action is activated to shut off the valve and stop the discharge. The cause of the low current is quickly identified, the fault is promptly eliminated, and normal operation is restored.

[0053] A second aspect of the present invention provides a method for the continuous separation of magnetically separable catalysts, which employs the aforementioned apparatus, such as... Figure 1 As shown, the method includes:

[0054] The catalyst-containing liquid from the reactor enters the aforementioned device through the liquid inlet N7. The catalyst-containing liquid passes through the dense magnetic field area from bottom to top. The catalyst is captured and aggregated under the action of magnetic force. Then, under the action of gravity, the catalyst enters the central tube 3. After being washed with washing water, it is discharged from the catalyst outlet N8 and recycled back to the reactor. The clear liquid after the catalyst is separated continues to flow upward and is discharged from the clear liquid outlet N2.

[0055] In this invention, to achieve better magnetic separation and ensure that the catalyst does not flow out with the liquid in granular form, it is necessary to control the magnetic field strength of the magnetic separator and the fluid velocity of the catalyst slurry. When the catalyst particle size is greater than 50 mesh, the magnetic field strength acting on the magnetic separator is greater than 50 Gauss, and the fluid velocity of the catalyst-containing continuous phase is greater than 0.01 cm / s. Preferably, when the catalyst particle size is 100-400 mesh, the magnetic field strength acting on the magnetic separator is 100-20000 Gauss, and the fluid velocity of the catalyst-containing continuous phase is 0.1-500 cm / s.

[0056] This invention enables continuous catalyst separation. The method allows magnetic catalysts to be captured under the influence of a magnetic field. The catalyst aggregates due to the combined effects of the magnetic field and fluid, and then flows out of the central tube under gravity. As one catalyst flows out, new catalyst continuously exits the central tube. Microscopically, within the entire magnetic field range, the catalyst particles are constantly tumbling, moving up and down and left and right, creating a turbulent fluid flow. Therefore, across the entire cross-section of the magnetic field, the particles can be considered uniformly distributed, with all having a chance to exit the central tube. Looking longitudinally through the magnetic field, due to the tumbling effect, particles within a certain distance of the central tube inlet also have an equal chance of exiting. Particles below the central tube are pushed upwards towards the inlet by the fluid entering the magnetic separator. Particles further above the central tube have no chance of falling into it; these particles can be considered a catalyst buffer, addressing occasional needs of the bed. The total amount of this catalyst is extremely small compared to the total system catalyst amount (less than 10%) and does not pose a problem for the effective use of the catalyst. On the contrary, it is essential to ensure the system's flexible adjustment.

[0057] In this invention, the continuous phase fluid (containing catalyst feed liquid) flows from bottom to top. The dispersed phase (catalyst particles) settles from top to bottom. Preferably, the magnetic field direction is parallel to gravity.

[0058] The magnetic capture separator of this invention can capture and aggregate magnetically separable catalysts from fluids, thereby separating the hydrogenation catalyst from the fluid and clarifying the fluid. Its main working principle is as follows: Fluid containing solid catalyst particles enters the magnetic capture separator and passes through a dense magnetic field zone from bottom to top. The solid catalyst particles are aggregated into a specific state under the combined action of the magnetic field and the fluid. In this state, the solid catalyst particles gradually aggregate into clusters under the influence of the magnetic field. After reaching a certain weight, they settle downwards under gravity. Throughout this process, the solid catalyst particles are in a relatively stable state of motion. Finally, the solid catalyst particles captured and aggregated by the magnetic field are led out through a central tube, washed, and returned directly to the hydrogenation reactor from the catalyst outlet. The clarified liquid continues to flow upwards from the top clarified liquid outlet. This process achieves continuous separation and washing of catalyst particles, resulting in high catalyst recovery and simple operation.

[0059] In this invention, two ammeters and two indicator lights are used to monitor the coil operation during catalyst separation. When one coil malfunctions, its indicator light illuminates, and the magnetic field strength is controlled by a constant current, which is then adjusted by regulating the voltage.

[0060] In this invention, during the catalyst discharge process, water can be introduced into the washing water inlet N10 at the bottom of the central tube 3 to contact the catalyst entering the central tube 3, washing away the reaction products adhering to the catalyst surface and reducing contamination of the reaction system during recycling. Because the diameter of the central tube is very small, a small amount of water can be introduced to continuously wash the catalyst.

[0061] In some embodiments of the present invention, the concentration of the catalyst in the catalyst-containing feed solution is 2-10 wt%, for example, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, and any value within the range of any two values.

[0062] In some embodiments of the present invention, at the upper opening of the central tube, the concentration of the catalyst is 20-30 wt%, for example, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, and any value within a range of any two values.

[0063] In some embodiments of the present invention, the concentration of the catalyst in the clarified liquid is 0-0.5 wt%, for example 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, and any value within a range of any two values.

[0064] In this invention, the fluid flows from bottom to top, filling the entire container. After the catalyst-containing liquid enters the aforementioned device, the catalyst is captured and aggregated under the action of a magnetic field, and the clear liquid flows upward under pressure. The catalyst particle concentration in the liquid entering through N7 is only 2-10 wt%. After entering, the particles are trapped and concentrated, reaching a concentration between 20-30 wt%, while the clear liquid continues to flow upward. Compared to the flow rate flowing in through N7, the flow rate flowing out through the central tube is extremely small, with a slurry concentration between 25-35 wt%. A portion of the liquid entrained from N7 is replaced and washed by the washing liquid. (The central tube contains fluid in two directions: solid particles flowing downwards and washing liquid flowing upwards, where the washing liquid replaces the reaction liquid flowing downwards). The washing liquid rinses the catalyst, and the washed-off reaction liquid flows out of the magnetic separator from bottom to top with the washing liquid. The central tube contains fluid in two directions: solid particles flowing downwards and washing liquid flowing upwards, where the washing liquid replaces the reaction liquid flowing downwards.

[0065] In some embodiments of the present invention, the particle size of the catalyst is greater than 50 mesh.

[0066] In some preferred embodiments of the present invention, the particle size of the catalyst is 100-400 mesh, for example, 100 mesh, 120 mesh, 150 mesh, 180 mesh, 200 mesh, 250 mesh, 280 mesh, 300 mesh, 350 mesh, 380 mesh, 400 mesh, and any value within the range of any two values, preferably 150-350 mesh.

[0067] In this invention, in order to achieve better magnetic separation effect, it is necessary to control the particle size of the catalyst. If the catalyst particle size is too large, a larger magnetic field strength is required to capture it. If the catalyst particle size is too small, the catalyst is easily dispersed in the magnetic separator and flows out with the liquid.

[0068] In some embodiments of the present invention, the catalyst is a nickel catalyst, an amorphous alloy catalyst with nickel as the main active component, or a supported catalyst with nickel and iron as the main active components.

[0069] In some embodiments of the present invention, the fluid velocity of the catalyst-containing liquid is less than the particle carry-out velocity of the catalyst.

[0070] In this invention, the catalyst aggregates into a specific state under the combined action of a magnetic field and a fluid, in which the flow velocity of the continuous phase is less than the fluid velocity U when the catalyst particles are carried out. t :

[0071]

[0072] In equation (1),

[0073] U t : Particle carry-out velocity;

[0074] ρ s Solid density;

[0075] d p : Diameter of solid particles;

[0076] ρ l Liquid density;

[0077] μ l Liquid viscosity;

[0078] H: Magnetic field strength;

[0079] g: acceleration due to gravity.

[0080] Fluid velocity and magnetic field strength significantly affect the operating state of a magnetically stabilized bed. At low fluid velocities, the bed particles remain stationary, exhibiting a fixed bed configuration. As the fluid velocity exceeds the minimum fluidization velocity, the bed exhibits three states depending on the magnetic field strength: granular, chain-like, and magnetically aggregated. When the magnetic field strength is very low, the magnetization of the particles is low, resulting in weak interparticle interactions, and the particles exist as individual particles moving freely within the bed. When the magnetic field strength increases to a certain value, particles dimerize, trimerize, or even multi-merge, aligning into chains along the magnetic field lines. The bed operation becomes very stable; macroscopically, only weak motion is observed within the bed, while microscopically, particles tumble and move left and right, with this motion increasing with fluid velocity. As the magnetic field strength continues to increase, particles agglomerate, resulting in a relatively low bed porosity, channeling of the liquid, and an unstable bed surface. When the fluid velocity exceeds the particle carry-out velocity, the particles are fully fluidized, exhibiting granular free motion. The upper interface of the bed becomes unclear, and some fine particles are carried out by the liquid.

[0081] In some embodiments of the present invention, the flow rate of the washing liquid is greater than the outflow rate of the catalyst; preferably, the flow rate of the washing liquid is 1-15 times the outflow rate of the catalyst, for example, any value in the range of 1, 2, 4, 5, 8, 10, 12, 15 and any two of these values, preferably 5-10 times.

[0082] The present invention will be described in detail below through examples, but the scope of protection of the present invention is not limited to the following description. Unless otherwise specified in the following examples and comparative examples, conditions were performed under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available products. All pressures in the present invention are gauge pressures.

[0083] In the following examples, the catalyst used is an amorphous high-hydrogenation-activity nickel catalyst, the specifications of which are shown in Table 1. Figure 1 The dimensional data of the device shown is shown in Table 2, the design conditions data is shown in Table 3, and the design conditions data of the electromagnetic coil is shown in Table 4.

[0084] Table 1 Specifications of Amorphous Catalysts

[0085]

[0086] Table 2 Dimensional data, unit: mm

[0087] Da Db Dc Dd De Df Dg Dh Di 3320 680 400 200 150 800 300 700 1600 Dj Dk Dl Dm Dn Do Dp Dq 2800 5590 670 200 1000 2100 1200 100

[0088] Table 3 Design Condition Data

[0089] project Design conditions Operating temperature, °C 55 Operating pressure, MPa 2.0 Catalyst concentration (solid content), wt% 20-30 structure Vertical, external magnetic field coil winding Equipment inner diameter, mm 1000 Operating medium Water, BDO, BED, catalyst particles, hydrogen Magnetic field strength, Oe 350

[0090] Table 4. Electromagnetic Coil Design Conditions Data

[0091] project Electromagnetic coil design conditions Operating temperature (ambient), °C 60 Operating cycle, h / a 7200 Magnetic field induction intensity, Gauss 600 Magnetic field voltage, V Adjustable, 380V rectified to 330V Current, A 12 Coil inner diameter, mm 1200 Coil outer diameter, mm 2100 Number of coils, 4 Height of each coil, mm 650 Coil mounting spacing, mm 300 electromagnetic coil material Copper Power, kW 3.2 Coil weight / piece, kg 44600 Connection method Four coils are connected in parallel, in pairs.

[0092] Example 1

[0093] The simplified process flow diagram used in this embodiment is as follows: Figure 2 As shown, the separation device used is as follows: Figure 1 As shown.

[0094] The reaction product 1,4-butanediol (BDO) containing catalyst from the reactor enters the separation unit through pipeline a at a flow rate of 6853.8 kg / h, of which the amount of catalyst is 325.53 kg / h, i.e., the catalyst content is 4.75 wt%. Under the action of a stable magnetic field, most of the catalyst is captured and collected, and after entering the central tube, it is washed by washing water at a flow rate of 2000 kg / h through pipeline d. Then, it is returned to the reactor for recycling through pipeline c. The clear liquid after most of the catalyst has been removed enters the subsequent process through pipeline b at a flow rate of 7680.93 kg / h, and the catalyst flow rate in the clear liquid is 1.3 kg / h, i.e., the catalyst content is 0.017 wt%.

[0095] The results show that after passing through the separation device, approximately 99.6% of the catalyst was separated from the BDO aqueous solution, and the catalyst was continuously recycled back to the reactor.

[0096] Example 2

[0097] The simplified process flow diagram used in this embodiment is as follows: Figure 2 As shown, the separation device used is as follows: Figure 1 As shown.

[0098] The reaction product 1,4-butenediol (BED) containing catalyst from the reactor enters the separation unit through pipeline a at a flow rate of 5200 kg / h, with a catalyst amount of 272.22 kg / h and a catalyst content of 5.24 wt%. Under the action of a stable magnetic field, most of the catalyst is captured and collected, and after entering the central tube, it is washed by washing water at a flow rate of 2000 kg / h through pipeline d. Then, it is returned to the reactor for recycling through pipeline c. The clear liquid after most of the catalyst has been removed enters the subsequent process through pipeline b at a flow rate of 6084.91 kg / h, with a catalyst flow rate of 1.09 kg / h and a catalyst content of 0.018 wt%.

[0099] The results show that after passing through the separation device, approximately 99.6% of the catalyst was separated from the BED aqueous solution, and the catalyst was continuously recycled back to the reactor.

[0100] Examples 3-9

[0101] Examples 3-9 illustrate the effect of the magnetic field strength of the present invention on the solid content at the top outlet of the magnetic separator.

[0102] Separation was performed according to the method in Example 1, with different magnetic field strengths controlled. The results are shown in Table 5.

[0103] Table 5

[0104] serial number Magnetic field strength, Gauss Solid content at the top outlet of the magnetic separator, wt%. Example 3 50 3.0 Example 4 80 2.6 Example 5 600 0.02 Example 6 650 0.02 Example 7 700 0.019 Example 8 750 0.018 Example 9 800 0.018

[0105] As shown in Table 5, the data from Examples 3 and 4 indicate that when the magnetic field strength is too low, most of the catalyst cannot be separated. The data from Examples 7-9 show that once the magnetic field strength reaches a certain level, further increases in magnetic field strength have little impact on the separation effect. This demonstrates that a low magnetic field strength results in the catalyst particles being in a granular state, preventing the separation of most of the catalyst. When the magnetic field strength is sufficient to prevent the catalyst particles from becoming granular, the magnetic field strength has little effect on the separation effect. Therefore, an appropriate magnetic field strength can be selected as needed.

[0106] Examples 10-19

[0107] Examples 10-19 illustrate the effect of the flow rate of the washing water in this invention on the concentration of the reaction product at the bottom outlet of the magnetic separator.

[0108] The catalyst was separated according to the method in Example 1, and different flow rates of washing water were introduced to wash the catalyst. The results are shown in Table 6.

[0109] Table 6

[0110]

[0111]

[0112] As shown in Table 6, the data from Examples 10-14 indicate that when the amount of washing water is too small, the catalyst washing effect is poor; as the amount of washing water increases, the catalyst washing effect gradually improves. The data from Examples 15-19 show that when the amount of washing water exceeds a certain value, the catalyst washing effect tends to stabilize. Furthermore, excessive washing increases the energy consumption of the subsequent product purification system. Therefore, provided that the washing is thorough, it is unnecessary to continuously introduce washing water.

[0113] When no washing liquid is introduced, some of the reaction products at the bottom of the magnetic separator adhere to the catalyst and return to the reactor. These reaction products will affect the hydrogenation reaction effect, indicating that it is necessary to wash the catalyst during the catalyst recycling process. This invention achieves catalyst washing simply and ingeniously by setting a central tube in the magnetic separator and introducing washing water for washing, eliminating the need for an external washing device and reducing the equipment process.

[0114] Comparative Example

[0115] Patent CN103846161B, which uses the same catalytic system, separates the catalyst by intermittently switching the electromagnet on and off. The energizing time is maintained at 2-1800s, and the de-energizing time is maintained at 1-1200s. This requires frequent switching on and off, resulting in high energy consumption. Furthermore, the material after magnetic separation needs to be further separated by a filter, making the process long and the operation complex.

[0116] The results above show that the method of the present invention has the advantages of high catalyst recovery rate, reduced catalyst consumption, simple and easy operation, and can reduce catalyst consumption.

[0117] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A device for continuous separation of magnetically separable catalysts, characterized in that, The device includes: A vertical container includes an upper cylinder and a lower cylinder; the top of the upper cylinder is provided with a clear liquid outlet for discharging the clear liquid after the catalyst is separated; the side wall of the lower cylinder is provided with a feed liquid inlet for adding a feed liquid containing the catalyst. At least two electromagnetic coils are respectively encircled on the outside of the upper cylinder and arranged along the axial direction of the upper cylinder; the interval between two adjacent sets of electromagnetic coils is 0.5-5m; the height Db of each set of electromagnetic coils is 0.1-1m; and A central tube is located at the bottom of the lower cylinder and extends into the interior of the lower cylinder; a washing water inlet is provided at the bottom of the central tube; a catalyst outlet is also provided on the central tube for discharging the separated catalyst; the upper opening of the central tube is higher than the feed liquid inlet; the length-to-diameter ratio of the central tube is 4-12:1; the ratio of the diameter of the central tube to the diameter of the lower cylinder is 0.05-0.3:

1.

2. The apparatus according to claim 1, wherein, The length-to-diameter ratio of the vertical container is 4-8:1; And / or, the ratio of the length of the upper cylinder to the length of the lower cylinder is 5-9:1; And / or, the diameter of the upper cylinder is the same as the diameter of the lower cylinder.

3. The apparatus according to claim 1 or 2, wherein, The upper opening of the central tube is 30-200mm higher than the liquid inlet.

4. The apparatus according to claim 3, wherein, The upper opening of the central tube is 50-150 mm higher than the liquid inlet.

5. The apparatus according to claim 1 or 2, wherein, The device includes 2-16 electromagnetic coils.

6. The apparatus according to claim 1 or 2, wherein, The bottom of the lower cylinder is also provided with a catalyst discharge outlet, which is used to completely discharge the catalyst during shutdown and accident handling. And / or, the top of the upper cylinder is also provided with a fresh catalyst replenishment port, and a fresh catalyst feeding pipeline is provided at the fresh catalyst replenishment port, which extends into the interior of the upper cylinder for adding fresh catalyst.

7. The apparatus according to claim 1 or 2, wherein, The device also includes a current sensor for monitoring the current in each set of electromagnetic coils.

8. The apparatus according to claim 7, wherein, The current sensor is equipped with a current alarm, and the current alarm is set to 6A-10A.

9. A method for continuous separation of magnetically separable catalysts, characterized in that, The method, employing the apparatus according to any one of claims 1-8, comprises: The catalyst-containing liquid from the reactor is introduced into the device according to any one of claims 1-8 through the liquid inlet. The catalyst-containing liquid passes through the magnetic field-dense area in the device from bottom to top. The catalyst is captured and aggregated under the action of magnetic force. Then, under the action of gravity, the catalyst enters the central tube, is washed with washing water, and is discharged from the catalyst outlet and recycled back to the reactor. The clear liquid after the catalyst is separated continues to flow upward and is discharged from the clear liquid outlet. The concentration of the catalyst in the catalyst-containing feed solution is 2-10 wt%; the particle size of the catalyst is 100-400 mesh; the magnetic field strength of the dense magnetic field zone is 100-20000 Gauss; and the flow rate of the washing water is greater than the outflow rate of the catalyst.

10. The method according to claim 9, wherein, At the upper inlet of the central tube, the catalyst concentration is 20-30 wt%. And / or, the concentration of the catalyst in the clear liquid is 0-0.5 wt%.

11. The method according to claim 9, wherein, The catalyst is a nickel catalyst, an amorphous alloy catalyst with nickel as the main active component, or a supported catalyst with nickel and iron as the main active components.

12. The method according to claim 9, wherein, The flow rate of the catalyst-containing continuous phase is less than the particle carry-out velocity of the catalyst, where the carry-out velocity refers to the velocity at which the catalyst is in a granular form due to the flow rate of the continuous phase. And / or, the flow rate of the washing water is 5-10 times the outflow rate of the catalyst.

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