A fixed bed reactor catalyst regeneration system and method of operation thereof

Abstract

The application discloses a fixed bed reactor catalyst regeneration system, which comprises a nitrogen buffer tank, a regeneration air heat exchanger, an air heater, a fixed bed reactor, a regeneration air release buffer tank and a nitrogen circulation mechanism, wherein the nitrogen circulation mechanism comprises a nitrogen filter tank, a regeneration circulation heat exchanger and a regeneration circulation compressor; the inside of the nitrogen filter tank is filled with adsorption balls, a nitrogen inlet pipe and a nitrogen outlet pipe are arranged at the top end of the nitrogen filter tank, and an adsorption ball adding mechanism and an adsorption ball discharge port are further arranged on the nitrogen filter tank. The application overcomes the defects of the prior art, is reasonable in design, and enables the regenerated gas to enter the nitrogen circulation mechanism for circulation and reuse by adding a nitrogen circulation machine, a small amount of new nitrogen is supplemented according to the regeneration condition, the self-circulation of a large amount of nitrogen is realized, a small amount of nitrogen is supplemented, and a small amount of nitrogen is discharged. While realizing the same regeneration effect, the regeneration cost is greatly reduced, and the interference of the regeneration process on other processes is reduced.

Description

Technical Field

[0001] This invention relates to the field of chemical engineering technology, and in particular to a catalyst regeneration system for a fixed-bed reactor and its operating method. Background Technology

[0002] Chinese invention patent CN114522626A discloses a phenol methylation reaction device that facilitates catalyst regeneration. The device includes a reaction vessel, in which a catalyst holding chamber is separated by an upper grid plate and a lower grid plate. The catalyst holding chamber is provided with a perforated tray, which slides in contact with the inner wall of the reaction vessel. Two vertical rods are rotatably installed on the top of the perforated tray, and the tops of the two vertical rods move through the upper grid plate. A horizontal plate is connected between the tops of the two vertical rods. The background section of the specification states: "Fixed-bed reactors are increasingly used in the chemical industry. In the production of m-cresol, currently, when producing m-cresol via the alkylation of phenol, the reactant mixture needs to be preheated to the minimum temperature required for the reaction before being introduced into the reaction apparatus. The reaction can only occur through the action of a catalyst. After a period of use, an oil film will form on the surface of the catalyst, which greatly reduces the catalytic effect. In order to regenerate the catalyst, in the existing technology, since the catalyst cannot be easily removed from the reaction apparatus, a mixture of nitrogen and a small amount of air is directly introduced into the reaction apparatus. Under the action of high temperature, the oil film on the surface of the catalyst is oxidized, thereby achieving the effect of catalyst regeneration."

[0003] Catalysts are key to fixed-bed reactions. After a period of use, the activity of catalysts will gradually decrease due to coking and other reasons. At this time, the catalyst needs to be regenerated. The regeneration method is to introduce a large amount of high-temperature nitrogen to increase the bed temperature and slowly pass air through it as needed to oxidize all organic matter, thus achieving the regeneration effect.

[0004] This process requires the introduction of large amounts of hot nitrogen to raise the temperature, which often results in insufficient nitrogen pressure in the utility system, affecting the safe production of other processes. Furthermore, heating with large amounts of nitrogen requires a significant amount of heat, leading to substantial energy waste. Summary of the Invention

[0005] To address the problems mentioned in the background section, the present invention provides a fixed-bed reactor catalyst regeneration system and its operating method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A catalyst regeneration system for a fixed-bed reactor includes a nitrogen buffer tank, a regeneration air heat exchanger, an air heater, a fixed-bed reactor, a regeneration venting buffer tank, and a nitrogen circulation mechanism, wherein the nitrogen circulation mechanism includes a nitrogen filter tank, a regeneration circulation heat exchanger, and a regeneration circulation compressor.

[0008] The nitrogen filter canister is filled with adsorption balls. A nitrogen inlet pipe and a nitrogen outlet pipe are installed at the top of the nitrogen filter canister. An adsorption ball adding mechanism and an adsorption ball outlet are also installed on the nitrogen filter canister.

[0009] Preferably, the nitrogen filter canister has a vertically mounted rotating shaft inside, and multiple partition plates are fixed on the outside of the rotating shaft. An inclined guide plate is fixed between adjacent partition plates near the bottom. The guide plate has ventilation holes. A rotary drive box is installed at the top of the nitrogen filter canister to drive the rotating shaft to rotate. U-shaped connecting pipes are installed at both the top and bottom of the nitrogen filter canister.

[0010] Preferably, a rack is slidably mounted in the rotary drive box via a slide rail. The rack is driven by a push rod motor. The top of the rotating shaft extends to the rotary drive box, and a spur gear is mounted at the top of the power input shaft. The spur gear meshes with the rack, and a one-way transmission mechanism is provided between the spur gear and the power input shaft.

[0011] Preferably, the one-way transmission mechanism includes a ratchet, which is fixed to the top end of the power input shaft, and a spur gear is rotatably mounted on the top end of the ratchet. A pawl is rotatably mounted on the side of the spur gear near the ratchet, and a metal spring is installed between the pawl and the spur gear.

[0012] Preferably, the adsorption ball adding mechanism includes an adding tube, and an adding funnel is installed at the top of the adding tube.

[0013] Preferably, the top of the adding funnel is fitted with a cap, and a conveying screw is installed inside the adding tube, which is driven by a rotary motor.

[0014] Preferably, the plurality of partition plates are evenly distributed around the drive shaft, and the horizontal height of the guide plate on the side closer to the drive shaft is greater than the horizontal height of the guide plate on the side farther from the drive shaft.

[0015] A method for operating a catalyst regeneration system in a fixed-bed reactor includes the following steps:

[0016] S1: The nitrogen buffer tank contains regeneration gas made up of nitrogen and a small amount of air. The regeneration gas flows through the regeneration air heat exchanger and the air heater. After being heated by the air heater, it enters the fixed bed reactor from the top of the tower.

[0017] S2: High-temperature regeneration gas heats the catalyst in the fixed-bed reactor, thereby oxidizing the organic matter on the catalyst surface, thus completing the catalyst regeneration. The regeneration gas finally flows out from the bottom of the fixed-bed reactor and enters the regeneration air heat exchanger.

[0018] S3: The regenerated gas flowing out from the bottom of the fixed-bed reactor retains residual heat, which is used to preheat the low-temperature regenerated gas from the nitrogen buffer tank through the heat exchange of the regenerated air heat exchanger.

[0019] S4: After heat exchange, the regenerated gas is filtered by the nitrogen filter canister in the nitrogen circulation mechanism to remove solid impurities. After being heated by the regeneration circulation heat exchanger and pressurized by the regeneration circulation compressor, it is reused.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. By adding a nitrogen circulation machine, the regeneration gas can enter the nitrogen circulation mechanism for recycling and reuse. New nitrogen is added in small amounts according to the regeneration situation, achieving large-scale self-circulation of nitrogen with minimal replenishment and emission. While achieving the same regeneration effect, this significantly reduces regeneration costs and minimizes interference with other processes.

[0022] 2. The design of the nitrogen filter tank: the regeneration gas enters the interior of the nitrogen filter tank through the nitrogen inlet pipe, and then flows through each independent space through the U-shaped connecting pipe, thereby extending the residence time and flow distance of the regeneration gas in the nitrogen filter tank, thus improving the adsorption effect of the adsorber on impurity particles in the regeneration gas.

[0023] 3. By adding a rotary drive box to the top of the nitrogen filter tank, each time the push rod motor shortens and then extends, it drives the rotating shaft to rotate by an angle. This allows the adsorption balls in different independent spaces to be pushed sequentially toward the adsorption ball adding mechanism and the adsorption ball discharge port. The adsorption ball adding mechanism adds adsorption balls to the independent spaces, and the adsorption ball discharge port discharges the adsorption balls from the independent spaces, thus achieving efficient addition and removal of adsorption balls. After a period of use, the adsorption balls need to be discharged and cleaned before they can be reused, making it more convenient to clean and replace the adsorption balls. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a catalyst regeneration system for a fixed-bed reactor according to the present invention;

[0026] Figure 2 This is a schematic diagram of the prior art process of the present invention;

[0027] Figure 3 This is a top-view perspective view of a nitrogen filter tank in a fixed-bed reactor catalyst regeneration system according to the present invention.

[0028] Figure 4 This is a perspective view of a nitrogen filter tank in a fixed-bed reactor catalyst regeneration system according to the present invention, taken from an overhead angle.

[0029] Figure 5 This is a front-view sectional view of the gas filter tank in a catalyst regeneration system of a fixed-bed reactor according to the present invention.

[0030] Figure 6 This is a schematic diagram showing the distribution relationship between the rotating shaft and the partition plate in a fixed-bed reactor catalyst regeneration system according to the present invention;

[0031] Figure 7 This is a top-view sectional view of a nitrogen filter tank in a catalyst regeneration system of a fixed-bed reactor according to the present invention.

[0032] Figure 8 This is a schematic diagram showing the position of the rotary drive box in a catalyst regeneration system of a fixed-bed reactor according to the present invention;

[0033] Figure 9 for Figure 8 Enlarged diagram of position A;

[0034] Figure 10 This is a schematic diagram of the ratchet and spur gear engagement relationship from a first perspective in a catalyst regeneration system of a fixed-bed reactor according to the present invention;

[0035] Figure 11 A schematic diagram of the ratchet and spur gear engagement relationship from a second perspective in a catalyst regeneration system for a fixed-bed reactor according to the present invention;

[0036] In the diagram: 1. Nitrogen filter tank, 101. Nitrogen inlet pipe, 102. Nitrogen outlet pipe, 103. U-shaped connecting pipe, 2. Rotary shaft, 201. Divider plate, 202. Guide plate, 203. Power input shaft, 204. Ratchet, 205. Spur gear, 206. Pawl, 207. Metal spring, 3. Rotary drive box, 301. Push rod motor, 302. Rack, 303. Slide rail, 4. Adsorption ball adding mechanism, 401. Adding pipe, 402. Adding funnel, 403. Conveying screw, 404. Rotary motor, 405. Cover, 5. Nitrogen buffer tank, 6. Regenerated air heat exchanger, 7. Air heater, 8. Fixed bed reactor, 9. Regenerated circulation heat exchanger, 10. Regenerated circulation compressor, 11. Regenerated venting buffer tank, 12. Adsorption ball outlet. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Example 1

[0039] Reference Figure 1-4 A catalyst regeneration system for a fixed-bed reactor includes a nitrogen buffer tank 5, a regeneration air heat exchanger 6, an air heater 7, a fixed-bed reactor 8, a regeneration venting buffer tank 11, and a nitrogen circulation mechanism. The nitrogen circulation mechanism includes a nitrogen filter tank 1, a regeneration circulation heat exchanger 9, and a regeneration circulation compressor 10.

[0040] The nitrogen filter tank 1 is filled with adsorption balls. A nitrogen inlet pipe 101 and a nitrogen outlet pipe 102 are installed at the top of the nitrogen filter tank 1. An adsorption ball adding mechanism 4 and an adsorption ball outlet 12 are also installed on the nitrogen filter tank 1. The regeneration gas, formed by mixing nitrogen with a small amount of air, flows out from the bottom of the fixed-bed reactor 8 after catalyst regeneration. The regeneration gas contains impurities and fine dust particles. The regeneration gas is introduced into the nitrogen filter tank 1 through the nitrogen inlet pipe 101. The adsorption balls inside the nitrogen filter tank 1 have porous surfaces, which adsorb and remove impurities from the regeneration gas. The filtered regeneration gas enters the nitrogen circulation mechanism for circulation and reuse. New nitrogen is added in small amounts according to the regeneration situation, achieving a large-scale self-circulation of nitrogen with small-scale replenishment and discharge. While achieving the same regeneration effect, this significantly reduces regeneration costs and minimizes interference with other processes during regeneration.

[0041] Example 2

[0042] Reference Figure 3-7The difference between this embodiment and Embodiment 1 is that a vertically arranged rotating shaft 2 is rotatably installed inside the nitrogen filter tank 1. Multiple partition plates 201 are fixed on the outside of the rotating shaft 2. An inclined guide plate 202 is fixed near the bottom between adjacent partition plates 201. The guide plate 202 has a vent hole. A rotary drive box 3 is installed at the top of the nitrogen filter tank 1. The rotary drive box 3 is used to drive the rotating shaft 2 to rotate. U-shaped connecting pipes 103 are installed at both the top and bottom of the nitrogen filter tank 1. The partition plates 201 can divide the interior of the nitrogen filter tank 1 into multiple independent spaces. The U-shaped connecting pipes 103 are used to connect the various independent spaces. During filtration, the regeneration gas enters the interior of the nitrogen filter tank 1 through the nitrogen inlet pipe 101, and then flows through the various independent spaces through the guidance of the U-shaped connecting pipes 103, thereby extending the residence time and flow distance of the regeneration gas in the nitrogen filter tank 1, thereby improving the adsorption effect of the adsorber on impurity particles in the regeneration gas.

[0043] Example 3

[0044] Reference Figure 8-11 The difference between this embodiment and embodiment 2 is that a rack 302 is slidably installed in the rotary drive box 3 via a slide rail 303. The rack 302 is driven by a push rod motor 301. The top power input shaft 203 of the rotating shaft 2 extends to the rotary drive box 3, and a spur gear 205 is installed at the top of the power input shaft 203. The spur gear 205 meshes with the rack 302, and a one-way transmission mechanism is provided between the spur gear 205 and the power input shaft 203. The push rod motor 301 can push the rack 302 to move horizontally, and the meshing between the rack 302 and the spur gear 205 can drive the spur gear 205 to rotate.

[0045] To achieve unidirectional transmission, the unidirectional transmission mechanism includes a ratchet 204, which is fixed to the top of the power input shaft 203. A spur gear 205 is rotatably mounted on the top of the ratchet 204. A pawl 206 is rotatably mounted on the side of the spur gear 205 near the ratchet 204. A metal spring 207 is installed between the pawl 206 and the spur gear 205. When the push rod motor 301 shortens, the rack 302 drives the spur gear 205 to rotate clockwise. At this time, the pawl 206 is engaged on the outside of the ratchet 204, thereby driving the ratchet 204 to rotate clockwise, which in turn drives the rotating shaft 2 to rotate clockwise. This angle is the same as the included angle between adjacent partition plates 201 (if there are four partition plates 201, then adjacent...). The included angle between the partition plates 201 is 90 degrees. When the push rod motor 301 extends, the metal spring 207 is compressed. The spur gear 205 rotates counterclockwise and cannot drive the ratchet 204 to rotate. Therefore, every time the push rod motor 301 shortens and then extends, it will drive the rotating shaft 2 to rotate by an angle. This allows the adsorption balls in different independent spaces to be pushed sequentially toward the adsorption ball adding mechanism 4 and the adsorption ball discharge outlet 12. The adsorption ball adding mechanism 4 can add adsorption balls to the independent spaces, and the adsorption balls in the independent spaces can be discharged through the adsorption ball discharge outlet 12, thereby achieving the effect of efficiently adding and discharging adsorption balls. After a period of use, the adsorption balls need to be discharged and cleaned before they can be used again.

[0046] Multiple partition plates 201 are evenly distributed around the drive shaft 2. The horizontal height of the guide plate 202 on the side closer to the drive shaft 2 is greater than the horizontal height of the guide plate 202 on the side farther away from the drive shaft 2. When the adsorption ball is discharged, the adsorption ball can automatically flow out from the adsorption ball discharge port 12 due to the presence of the guide plate 202.

[0047] Example 4

[0048] Please refer to Figure 5 The difference between this embodiment and embodiment 1 is that the adsorption ball adding mechanism 4 includes an adding tube 401, an adding funnel 402 is installed at the top of the adding tube 401, a cap 405 is installed at the top of the adding funnel 402, and a conveying screw 403 is installed inside the adding tube 401. The conveying screw 403 is driven by a rotary motor 404. When adding adsorption balls, the adsorption balls are placed into the adding funnel 402, and the rotary motor 404 is turned on to drive the conveying screw 403 to rotate, so that the adsorption balls can be added into the nitrogen filter tank 1 through the adding tube 401.

[0049] Example 5

[0050] A method for operating a catalyst regeneration system in a fixed-bed reactor includes the following steps:

[0051] S1: Nitrogen buffer tank 5 contains regeneration gas made up of nitrogen and a small amount of air. The regeneration gas flows through regeneration air heat exchanger 6 and air heater 7. After being heated by air heater 7, it enters fixed bed reactor 8 from the top of the tower.

[0052] S2: High-temperature regeneration gas heats the catalyst in the fixed-bed reactor 8, thereby oxidizing the organic matter on the catalyst surface, thus completing the catalyst regeneration. The regeneration gas finally flows out from the bottom of the fixed-bed reactor 8 and enters the regeneration air heat exchanger 6.

[0053] S3: The regenerated gas flowing out from the bottom of the fixed bed reactor 8 retains residual heat, which is used to preheat the low-temperature regenerated gas from the nitrogen buffer tank 5 through the heat exchange of the regenerated air heat exchanger 6.

[0054] S4: After heat exchange, the regenerated gas is filtered by the nitrogen filter tank 1 in the nitrogen circulation mechanism to remove solid impurity particles present in the regenerated gas. After being heated by the regeneration circulation heat exchanger 9 and pressurized by the regeneration circulation compressor 10, it is reused.

[0055] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0056] In this invention, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," "link," and "fix" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0057] The control method of this invention is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge in the field. Furthermore, since this invention is mainly used to protect mechanical devices, the control method and circuit connection will not be explained in detail here.

[0058] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A catalyst regeneration system for a fixed-bed reactor, comprising a nitrogen buffer tank (5), a regeneration air heat exchanger (6), an air heater (7), a fixed-bed reactor (8), a regeneration venting buffer tank (11), and a nitrogen circulation mechanism, characterized in that: The nitrogen circulation mechanism includes a nitrogen filter tank (1), a regeneration circulation heat exchanger (9), and a regeneration circulation compressor (10). During operation, the nitrogen buffer tank (5) contains regeneration gas made up of nitrogen and a small amount of air. The regeneration gas flows through the regeneration air heat exchanger (6) and the air heater (7). After being heated by the air heater (7), it enters the fixed bed reactor (8) from the top of the tower. The catalyst in the fixed-bed reactor (8) is heated by high-temperature regeneration gas, thereby oxidizing the organic matter on the surface of the catalyst and completing the regeneration of the catalyst. The regeneration gas eventually flows out from the bottom of the fixed-bed reactor (8) and enters the regeneration air heat exchanger (6). The regenerated gas flowing out from the bottom of the fixed bed reactor (8) retains residual heat, which is used to preheat the low-temperature regenerated gas from the nitrogen buffer tank (5) through the heat exchange of the regenerated air heat exchanger (6). After heat exchange, the regenerated gas is filtered by the nitrogen filter canister (1) in the nitrogen circulation mechanism to remove solid impurity particles present in the regenerated gas. After being heated by the regeneration circulation heat exchanger (9) and pressurized by the regeneration circulation compressor (10), it can be used again. The nitrogen filter canister (1) is filled with adsorption balls. A nitrogen inlet pipe (101) and a nitrogen outlet pipe (102) are installed at the top of the nitrogen filter canister (1). An adsorption ball adding mechanism (4) and an adsorption ball outlet (12) are also installed on the nitrogen filter canister (1). The nitrogen filter canister (1) is internally mounted with a vertically arranged rotating shaft (2). Multiple partition plates (201) are fixed on the outside of the rotating shaft (2). An inclined guide plate (202) is fixed between adjacent partition plates (201) near the bottom. The guide plate (202) has a vent hole. A rotary drive box (3) is installed at the top of the nitrogen filter canister (1). The rotary drive box (3) is used to drive the rotating shaft (2) to rotate. U-shaped connecting pipes (103) are installed at both the top and bottom of the nitrogen filter canister (1). A rack (302) is slidably mounted inside the rotary drive box (3) via a slide rail (303). The rack (302) is driven by a push rod motor (301). The top power input shaft (203) of the rotating shaft (2) extends to the rotary drive box (3). A spur gear (205) is mounted on the top of the power input shaft (203). The spur gear (205) meshes with the rack (302). A one-way transmission mechanism is provided between the spur gear (205) and the power input shaft (203). The one-way transmission mechanism includes a ratchet (204), which is fixed to the top of the power input shaft (203), and a spur gear (205) is rotatably mounted on the top of the ratchet (204). A pawl (206) is rotatably mounted on the side of the spur gear (205) near the ratchet (204), and a metal spring (207) is installed between the pawl (206) and the spur gear (205).

2. The catalyst regeneration system for a fixed-bed reactor according to claim 1, characterized in that: The adsorption ball adding mechanism (4) includes an adding tube (401) with an adding funnel (402) installed at the top of the adding tube (401).

3. The catalyst regeneration system for a fixed-bed reactor according to claim 2, characterized in that: The top of the adding funnel (402) is fitted with a cap (405), and the inside of the adding tube (401) is fitted with a conveying screw (403), which is driven by a rotary motor (404).

4. The catalyst regeneration system for a fixed-bed reactor according to claim 1, characterized in that: Multiple partition plates (201) are evenly distributed around the drive shaft (2), and the horizontal height of the guide plate (202) on the side closer to the drive shaft (2) is greater than the horizontal height of the guide plate (202) on the side farther away from the drive shaft (2).

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