Catalyst cyclic regeneration dust removal process and device

Abstract

The invention discloses a catalyst cyclic regeneration dust removal process and device. The process provided by the invention comprises the following steps: feeding a regenerated catalyst from a regenerator to screen and remove dust by virtue of gravity or lifting gas of a lifter, and separating the regenerated catalyst into catalyst particles and catalyst dust under a closed condition; catalyst particles are conveyed to the reduction chamber through the feeding hopper by virtue of lifting gas or gravity of the lifter, and enter the reactor to participate in reaction after being changed into a reduction state from an oxidation state; the separated catalyst dust is used for recovering precious metal; and the spent catalyst flowing out of the reactor is sent to the regenerator to enter the next circulation of the catalyst. The device mainly comprises a regenerator, a catalyst screening and dust removing device, a feeding hopper, a reduction chamber, a reactor, a catalyst recycling tank, a dust collecting barrel and a lifter. The device can reduce potential safety hazards of deformation and fracture of internal components and pressure drop increase of the reactor caused by dust blockage, and ensures safe and stable operation of the device.

Description

Technical Field

[0001] The present invention belongs to the field of petrochemical engineering, and relates to a process for removing catalyst dust. Specifically, it relates to a catalyst circulation and regeneration dust removal process and device. Background Art

[0002] Reactors in continuous reforming, alkane dehydrogenation, light hydrocarbon aromatization and other units are usually arranged in an overlapping or side-by-side manner. For reactors arranged in an overlapping and side-by-side manner in pairs, the catalyst enters the first and second reactors, the lower hopper and then the catalyst elevator by gravity from the reduction chamber in sequence, and is then lifted to the upper hopper of the third reactor by the lifting gas. From the upper hopper of the third reactor, it enters the third and fourth reactors by gravity in sequence. The carbon-containing spent catalyst is lifted to the regeneration system after coming out of the last reactor. After removing the coke through processes such as burning, oxychlorination, and calcination in the regeneration system, the regenerated catalyst is lifted to the reduction chamber by the elevator (or L-valve group) to complete the catalyst circulation. Uninterrupted catalyst transportation is the key to achieving continuous reaction, and catalyst lifting is the key to ensuring the continuous cyclic flow of the catalyst between the reaction and regeneration systems. The catalyst circulation methods for other reactor arrangement types are similar to those for reactors arranged in an overlapping manner in pairs, with the difference being that for side-by-side arranged reactors, the catalyst between each reactor needs to be lifted by the lifting gas, and for overlapping arranged reactors, the catalyst between reactors flows by gravity.

[0003] Due to catalyst wear, burning, drying, production fluctuations, etc., catalyst fines and dust will be generated. When the catalyst fines and dust continue to increase and accumulate in the elevator, it will cause difficult fluidization of the catalyst and affect lifting, and the fines and dust will further wear and generate more dust during the lifting process. In the prior art, the regenerant containing dust is directly lifted by the elevator and then enters the downstream equipment. For example, in a patent for a countercurrent moving bed continuous reforming unit and a catalyst circulation method (CN103789015A) and a continuous reforming unit with four reaction zones (CN01115290.7), in such cases, there is a situation where the fragmented regenerated catalyst directly enters the reactor, resulting in blockage of the internal components of the reactor, deformation, rupture of the internal components, and an increase in pressure drop. In severe cases, it may lead to unplanned shutdown of the unit. Summary of the Invention

[0004] In order to solve the problems in the prior art that the dust generated during the catalyst circulation and lifting process causes deformation, rupture of the internal components of the reactor, and an increase in pressure drop, and may lead to shutdown of the unit in severe cases, the present invention provides a catalyst circulation and regeneration dust removal process and device.

[0005] The catalyst circulation and regeneration dust removal process provided by the present invention includes the following steps:

[0006] 1) The regenerated catalyst from the regenerator is sent to the catalyst screening and dust removal device by gravity or the lifting gas of the elevator for screening and dust removal treatment. The screening and dust removal treatment is carried out under closed conditions, and the regenerated catalyst is separated into catalyst particles and catalyst dust.

[0007] 2) The separated catalyst particles are sent to the feed hopper. The catalyst particles in the feed hopper are sent to the reduction chamber by the lifting gas of the elevator or gravity. In the reduction chamber, the catalyst particles change from the oxidized state to the reduced state and regain their activity. The catalyst with restored activity enters the reactor to participate in the reaction. The separated catalyst dust is used for precious metal recovery.

[0008] 3) The carbon-containing spent catalyst after the reaction in the reactor is sent to the regenerator, and is regenerated into regenerated catalyst in the regenerator, entering the next cycle of the catalyst.

[0009] The operating pressure of the screening and dust removal treatment process is 0.25 - 1.10 MPa gauge pressure, the operating temperature is 150 - 200 °C, and the screening accuracy of the regenerated catalyst is 14 - 18 mesh.

[0010] The operating pressure of the reactor is 0.33 - 0.70 MPa gauge pressure, and the operating temperature is 400 - 550 °C.

[0011] As an improvement, an anti-blowing cleaning step is provided during the catalyst screening and dust removal treatment process, and the anti-blowing cleaning step does not affect the continuous and normal progress of the catalyst screening and dust removal treatment process during operation.

[0012] As an improvement, a nitrogen supplement step is provided during the process of transporting catalyst particles to the feed hopper to ensure that the catalyst screening and dust removal treatment process is carried out in a nitrogen environment and ensure the safe operation of the device.

[0013] As an improvement, the separated catalyst dust is first discharged to the catalyst recovery tank. During the discharging process, the pressure in the catalyst recovery tank is kept equal to the operating pressure of the screening and dust removal. After the discharging is completed, the discharging channel is closed. After the catalyst dust in the catalyst recovery tank is naturally cooled to room temperature, it is sent to the dust collection bucket, and the catalyst dust in the dust collection bucket is sealed and sent for precious metal recovery.

[0014] The present invention also provides a device for implementing the process of the present invention, mainly including a regenerator, a catalyst screening and dust removal device, a feed hopper, a reduction chamber and a reactor connected in sequence, and also including a catalyst recovery tank and a dust collection bucket connected to the catalyst screening and dust removal device in sequence, and also including an elevator; wherein, the elevator is arranged between the regenerator and the catalyst screening and dust removal device, or between the feed hopper and the reduction chamber.

[0015] The present invention has the following beneficial effects:

[0016] 1) The present invention introduces a closed screening and dust removal process for catalysts, achieving precise screening of catalyst particles and catalyst dust, screening out more than 95% of the broken catalysts generated during the catalyst recycling and regeneration process, reducing the safety hazards of deformation, rupture of internal components and increased reactor pressure drop caused by dust blockage in the reactor, and ensuring the safe and stable operation of the device.

[0017] 2) The catalyst dust screened out in the present invention is sent to the catalyst manufacturer for precious metal recovery, without causing environmental pollution.

[0018] 3) By introducing a backwashing and cleaning step, when the pressure difference between the upper and lower parts of the catalyst screening and dust removal device reaches the limit value, the backwashing and cleaning operation is started. During the operation of the backwashing and cleaning step, the catalyst screening and dust removal device still maintains normal screening, ensuring the continuous operation of the device without interruption.

[0019] 4) By setting a nitrogen supplementation step, the feed hopper is completely isolated from the reduction chamber and the oil and gas system, ensuring that the catalyst screening and dust removal process is carried out in a nitrogen environment and the device operation is safe.

[0020] 5) The process of the present invention can be used in reforming units, dehydrogenation units and light hydrocarbon aromatization units. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of the catalyst recycling and regeneration dust removal device of the present invention;

[0022] Figure 2 is another schematic structural diagram of the catalyst recycling and regeneration dust removal device of the present invention.

[0023] In the figure: 1 - regenerator, 2 - elevator, 3 - catalyst screening and dust removal device, 4 - feed hopper, 5 - reduction chamber, 6 - reactor, 7 - catalyst recovery tank, 8 - dust collection bucket, 9 - nitrogen supplementation pipeline. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] As Figure 1 shown, the device for implementing the process of the present invention includes a regenerator 1, an elevator 2, a catalyst screening and dust removal device 3, a feed hopper 4, a reduction chamber 5 and a reactor 6 connected in sequence, as well as a catalyst recovery tank 7 and a dust collection bucket 8 connected to the catalyst screening and dust removal device 3 in sequence, and a nitrogen supplementation pipeline 9 connected to the feed hopper 4; wherein, the position of the elevator 2 is lower than that of the catalyst screening and dust removal device 3, the catalyst recovery tank 7 and the dust collection bucket 8 are located below the catalyst screening and dust removal device in sequence, and the reduction chamber 5 and the reactor 6 are located below the feed hopper 4 in sequence.

[0026] Combined with Figure 1The process of the present invention is further described as follows: The regenerated catalyst from the regenerator 1 is sent to the catalyst screening and dust removal device 3 by the lifting gas of the elevator 2 for screening and dust removal treatment. The screening and dust removal treatment is carried out under closed conditions, and the regenerated catalyst is separated into catalyst particles and catalyst dust. The separated catalyst particles are sent to the feed hopper 4, and the catalyst particles in the feed hopper 4 are sent to the reduction chamber 5 by gravity. The catalyst particles in the reduction chamber 5 change from the oxidized state to the reduced state and regain their activity. The catalyst with restored activity enters the reactor 6 to participate in the reaction. The carbon-containing spent catalyst after the reaction in the reactor 6 is sent to the regenerator 1, and is regenerated into the regenerated catalyst in the regenerator 1, entering the next cycle of the catalyst. The separated catalyst dust is first discharged to the catalyst recovery tank 7. During the discharging process, the pressure in the catalyst recovery tank 7 is kept equal to the operating pressure of the catalyst screening and dust removal device 3. After the discharging is completed, the discharging channel is closed. After the catalyst dust naturally cools down to room temperature in the catalyst recovery tank 7, it is sent to the dust collection bucket 8. The catalyst dust in the dust collection bucket 8 is sealed and sent for precious metal recovery. During the screening and dust removal treatment process of the catalyst screening and dust removal device 3, an anti-blowing cleaning step is set. During the anti-blowing cleaning operation, the catalyst screening and dust removal device 3 still operates continuously and normally. During the process of transporting the catalyst particles to the feed hopper 4, a nitrogen supplement step is provided. Through the nitrogen supplement pipeline 9, it is ensured that the screening and dust removal treatment process of the catalyst is carried out in a nitrogen environment, ensuring the safe operation of the device.

[0027] As Figure 2 shown, the difference from the Figure 1 device shown is that: The elevator 2 is arranged between the feed hopper 4 and the reduction chamber 5, and the position of the elevator 2 is lower than that of the reduction chamber 5; The regenerator 1 is located above the catalyst screening and dust removal device 3 and is directly connected to it.

[0028] Combined with Figure 2 the further description of the process of the present invention, the difference from the Figure 1 process described is that: The regenerated catalyst from the regenerator 1 is sent to the catalyst screening and dust removal device 3 by gravity for screening and dust removal treatment. The screening and dust removal treatment is carried out under closed conditions, and the regenerated catalyst is separated into catalyst particles and catalyst dust. The separated catalyst particles are sent to the feed hopper 4, and the catalyst particles in the feed hopper 4 are sent to the reduction chamber 5 by the lifting gas of the elevator 2. The catalyst particles in the reduction chamber 5 change from the oxidized state to the reduced state and regain their activity. The catalyst with restored activity enters the reactor 6 to participate in the reaction.

[0029] The driving modes of the catalyst screening and dust removal device 3 include but are not limited to motor drive and ultrasonic drive.

[0030] The above are only typical embodiments of the present invention, and there is no any formal limitation on the present invention. Any person skilled in the relevant art, without departing from the technical solution of the present invention, any changes or modifications made using the above content should be regarded as equivalent examples of equivalent changes. All content that does not depart from the technical solution of the present invention, any equivalent changes made to the above embodiments according to the technical essence of the present invention, are within the scope of the technical solution of the present invention.

Claims

1. A catalyst recycling and regeneration dust removal process, characterized in that: The following steps are involved: 1) The regenerated catalyst from the regenerator is sent to the catalyst screening and dust removal device for screening and dust removal by gravity or the lifting gas of the lifter. The screening and dust removal process is carried out under closed conditions, and the regenerated catalyst is separated into catalyst particles and catalyst dust; 2) The separated catalyst particles are sent to the feed hopper, and the catalyst particles in the feed hopper are sent to the reduction chamber by the lifting gas of the lifter or gravity. The catalyst particles in the reduction chamber are converted from an oxidized state to a reduced state to restore activity, and the restored catalyst enters the reactor to participate in the reaction; the separated catalyst dust is used to recover precious metals; 3) The carbon-containing catalyst to be regenerated after the reaction in the reactor is sent to the regenerator, where it is regenerated to generate a regenerated catalyst and enters the next cycle of the catalyst.

2. The catalyst recycling and regeneration dust removal process according to claim 1 is characterized in that: The operating pressure of the screening and dust removal process is 0.25-1.10 MPa, the operating temperature is 150-200° C., and the screening accuracy of the regenerated catalyst is 14-18 meshes.

3. The catalyst recycling and regeneration dust removal process according to claim 1 is characterized in that: The operating pressure of the reactor is 0.33-0.70 MPa, and the operating temperature is 400-550°C.

4. The catalyst recycling and regeneration dust removal process according to claim 1 is characterized in that: The catalyst screening and dust removal process is provided with a backflush cleaning step, which does not affect the continuous and normal progress of the catalyst screening and dust removal process during operation.

5. The catalyst recycling and regeneration dust removal process according to claim 1 is characterized in that: A nitrogen supplementation step is provided in the process of conveying the catalyst particles to the feed hopper to ensure that the catalyst screening and dust removal process is carried out in a nitrogen environment.

6. The catalyst recycling and regeneration dust removal process according to claim 1 is characterized in that: The separated catalyst dust is first discharged into a catalyst recovery tank. During the unloading process, the pressure in the catalyst recovery tank is kept equal to the operating pressure of the screening dust removal. After the unloading is completed, the unloading channel is closed. After the catalyst dust is naturally cooled to room temperature in the catalyst recovery tank, it is sent to a dust collection barrel. The catalyst dust in the dust collection barrel is sealed and sent for recovery of precious metals.

7. A catalyst recycling and regeneration dust removal device for implementing the catalyst recycling and regeneration dust removal process according to any one of claims 1 to 6, characterized in that: It mainly includes a regenerator, a catalyst screening and dust removal device, a feed hopper, a reduction chamber and a reactor which are connected in sequence, and also includes a catalyst recovery tank and a dust collection barrel which are connected in sequence with the catalyst screening and dust removal device, and also includes a lifter; wherein the lifter is arranged between the regenerator and the catalyst screening and dust removal device, and the position of the lifter is lower than the catalyst screening and dust removal device; or the lifter is arranged between the feed hopper and the reduction chamber, and the position of the lifter is lower than the reduction chamber, and the regenerator is located above the catalyst screening and dust removal device and is directly connected to it.

8. The catalyst recycling and regeneration dust removal device according to claim 7 is characterized in that: The feed hopper is connected with a nitrogen supplement pipeline.

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