Device and method for preparing gradient acid strength carbon-based catalyst by regenerating inactivated activated carbon

Abstract

The invention discloses a device and a method for preparing a gradient acid strength carbon-based catalyst by regenerating inactivated activated carbon. The device comprises a charging hanging basket, a dipping device, a regeneration reactor, a condenser and a tail gas treatment device, the charging hanging basket is used for containing an inactivated activated carbon catalyst; the top of the dipping device is provided with an opening, an inner cavity is filled with deionized water and can contain a loading hanging basket, the top of an inner cavity of the regeneration reaction device can be opened and closed, water vapor is introduced into the inner cavity and can contain the loading hanging basket, and a plurality of microwave generators are arranged in an interlayer of the regeneration reaction device and used for emitting microwaves into the inner cavity of the regeneration reaction device; the inner cavity of the regeneration reaction device is sequentially connected with the condenser and the tail gas treatment device. According to the technical scheme, by means of the excellent wave absorbing property of deionized water, water molecules are induced to dissociate through microwaves to generate hydrogen protons and hydroxyl plasma free radicals, carbon sites on the surface are oxidized and dissociated under the high-temperature auxiliary effect, phosphoric acid active sites are released again, and a pore channel structure is remodeled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalyst regeneration, in particular to a device and method for regenerating deactivated activated carbon to prepare a carbon-based catalyst with gradient acid strength. BACKGROUND

[0002] Phenol is an important fine chemical intermediate, which is widely used in the production of high-value products such as medicines, spices, synthetic resins, and antioxidants. Currently, the industrial production of phenol mainly uses benzene and propylene derived from fossil fuels as raw materials through the isobenzene propylene synthesis method. With the continuous rise of environmental concerns, it is no longer appropriate to continue producing phenol from fossil-based resources, and it is necessary to use green and clean biomass as a substitute for fossil fuels to produce high-value phenolic chemicals. Current research shows that activated carbon with acid sites as a high specific surface area solid acid catalyst has good results and high potential in the directional preparation of phenolic compounds through biomass catalytic pyrolysis. Among them, phosphoric acid activated carbon has a high mesopore distribution and rich surface phosphorus functional groups, showing particularly superior directional enrichment performance.

[0003] In the field of directional pyrolysis, catalyst coking is an inevitable problem. The growth of coke will inevitably change the physical and chemical properties of the catalyst surface, and then change the product selectivity and yield. When the catalyst coking deactivation reaches a certain degree, it is usually necessary to regenerate the coked catalyst. Under the premise of not damaging the original structure of the catalyst, the pore structure and active sites are reshaped, so that the catalytic performance can be restored to prolong the service life and reduce the use cost. For non-carbon catalysts such as molecular sieves, etc., air, steam and other oxidants can be introduced for coke burning regeneration without damaging the pore structure. However, for carbon-based catalysts, the difficulty lies in that the carbon carrier itself is combustible, and the thermal regeneration method is not feasible. The existing regeneration methods, such as solvent regeneration method and secondary activation method, can only partially restore the activity, and the catalytic performance decreases significantly after regeneration. Moreover, the regeneration process may also cause secondary pollution. For example, the solvent regeneration method can only deactivate the active coke, and the cleaning solvent is easy to cause secondary pollution. The secondary activation method can restore the active sites, but it is difficult to reshape the damaged pore structure, and the process is complicated and not practical. Therefore, it is urgent to develop a new type of high-efficiency green deactivated activated carbon catalyst regeneration technology. SUMMARY

[0004] The present application aims to solve the defects of the prior art, and provides a device and method for regenerating deactivated activated carbon to prepare a carbon-based catalyst with gradient acid strength, which realizes green and efficient regeneration of deactivated activated carbon.

[0005] To solve the above technical problems, the technical solutions of the present application are as follows:

[0006] The first aspect provides a device for regenerating deactivated activated carbon to prepare a carbon-based catalyst with graded acid strength, characterized in that the device comprises a charging basket, an impregnation device, a regeneration reactor, a condenser and a tail gas treatment device.

[0007] The charging basket is used for containing the deactivated activated carbon catalyst.

[0008] The impregnation device comprises an impregnation device cavity and an impregnation device interlayer arranged outside the impregnation device cavity. The top of the impregnation device cavity is provided with an opening. Deionized water is filled in the impregnation device cavity, and the charging basket can be accommodated in the impregnation device cavity. The impregnation device interlayer is provided with a fluid for heating the impregnation device cavity.

[0009] The regeneration reactor comprises a regeneration reactor cavity and a regeneration reactor interlayer arranged outside the regeneration reactor cavity. The top of the regeneration reactor cavity is openable and closable. Water vapor is filled in the regeneration reactor cavity, and the charging basket can be accommodated in the regeneration reactor cavity. The regeneration reactor interlayer is provided with a plurality of microwave generators for emitting microwaves into the regeneration reactor cavity.

[0010] The regeneration reactor cavity is sequentially connected with the condenser and the tail gas treatment device.

[0011] Further, the regeneration reactor cavity is provided with a water vapor inlet and a water vapor outlet. The water vapor inlet is connected with a water vapor generator, and the water vapor outlet is connected with the condenser.

[0012] Further, the fluid in the impregnation device interlayer is nitrogen.

[0013] Further, the impregnation device interlayer is provided with a first nitrogen inlet and a first nitrogen outlet. The regeneration reactor cavity is provided with a second nitrogen inlet and a second nitrogen outlet. The first nitrogen inlet is connected with the second nitrogen outlet, and the second nitrogen inlet is connected with a nitrogen generator. The first nitrogen outlet is connected with the atmosphere.

[0014] Further, the regeneration reactor interlayer is provided with a heat preservation layer outside.

[0015] The second aspect provides a method for regenerating deactivated activated carbon to prepare a carbon-based catalyst with graded acid strength, characterized in that the device of the first aspect comprises the following steps.

[0016] Impregnation of the deactivated activated carbon: the deactivated activated carbon is loaded into the charging basket 1, and the charging basket is placed in the impregnation device cavity 2-1. Deionized water is injected into the impregnation device cavity 2-1 to a height that can submerge the charging basket. The impregnation is performed for a period of time.

[0017] Sweeping and preparing the regeneration reactor: take out the loading basket 1, drain the water and load into the inner cavity 3-1 of the regeneration reactor, close the top opening of the inner cavity of the regeneration reactor; introduce nitrogen into the inner cavity 3-1 of the regeneration reactor, and sweep the inner cavity 3-1 of the regeneration reactor to exhaust the air in the cavity;

[0018] Regeneration of the deactivated activated carbon: stop the introduction of nitrogen, introduce water vapor into the inner cavity 3-1 of the regeneration reactor, and open the microwave generator 3-3, and the regeneration temperature is controlled at 500-800 DEG C;

[0019] Post-processing: after regeneration, stop the introduction of water vapor, introduce nitrogen into the inner cavity 3-1 of the regeneration reactor, and sweep the inner cavity 3-1 of the regeneration reactor to below 100 DEG C, the gas swept out is introduced into the interlayer of the impregnation device for heating the deionized water in the inner cavity 2-1 of the impregnation device, the loading basket 1 is taken out, and the regeneration of the activated carbon catalyst is completed.

[0020] Further, in the impregnation step of the deactivated activated carbon, the activated carbon impregnation time is 10-60 min.

[0021] Further, in the sweeping and preparing the regeneration reactor step, the nitrogen sweeping time of the regeneration reactor is 10-30 min.

[0022] Further, in the deactivated activated carbon regeneration step, the regeneration time is 1-10 min.

[0023] Further, the deactivated activated carbon is carbon deposition deactivated phosphoric acid activated carbon.

[0024] Compared with the prior art, the beneficial effects of the present application are:

[0025] (1) In view of the problems of complex process and poor regeneration performance of the traditional deactivated activated carbon regeneration method, the present application provides a green and efficient microwave-induced regeneration method. By using the excellent wave-absorbing property of deionized water, using microwave to induce water molecules to dissociate to produce hydrogen protons and hydroxyl radical plasma, and under the action of high temperature, the surface carbon site is oxidized and dissociated, the phosphoric acid active site is released and the pore structure is remodeled, and the surface modification of the plasma produces new oxygen-containing functional group active sites, and finally a gradient acid strength carbon-based catalyst is prepared, which has a performance significantly better than the original untreated activated carbon catalyst;

[0026] (2) The heat generated in the regeneration process is recovered to heat the impregnation device, and the impregnation effect of the deionized water is strengthened, which significantly improves the performance of the regenerated activated carbon catalyst while ensuring the energy efficiency of the system.

[0027] (3) The device of the present invention fully utilizes the advantages of carbon materials and good water vapor absorption. Deionized water is immersed deep into the pores before regeneration, and water vapor is introduced during the regeneration process to achieve simultaneous regeneration of the catalyst particle surface and internal pores. It has high energy efficiency, is clean and green, and does not require the use of any chemical reagents during the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the overall structure of Example 1;

[0029] Figure 2 This is a structural schematic diagram of the impregnation device of Example 1;

[0030] Figure 3 This is a schematic structural diagram of the regeneration reactor of Example 1;

[0031] Figure 4 This is a flow chart of Example 2.

[0032] In the figure: 1. Charging basket; 2. Impregnation device; 3. Regeneration reactor; 4. Condenser; 5. Tail gas treatment device; 6. Nitrogen generator; 7. Water vapor generator; 2-1. Inner cavity of impregnation device; 2-2. Interlayer of impregnation device; 2-3. First nitrogen inlet; 2-4. First nitrogen outlet; 3-1. Inner cavity of regeneration reactor; 3-2. Interlayer of regeneration reactor; 3-3. Microwave generator; 3-4. Insulation layer; 3-5. Second nitrogen inlet; 3-6. Second nitrogen outlet; 3-7. Water vapor inlet; 3-8. Water vapor outlet. DETAILED DESCRIPTION

[0033] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0034] Example 1

[0035] like Figures 1-3 As shown, a device for regenerating deactivated activated carbon to prepare a graded acid strength carbon-based catalyst includes a charging basket 1, an impregnation device 2, a regeneration reactor 3, a condenser 4, an exhaust gas treatment device 5, a nitrogen generator 6, and a steam generator 7.

[0036] The loading hanging basket 1 is used to hold the deactivated activated carbon catalyst. Its surface is a hollow pore structure that can only accommodate liquid but not catalyst.

[0037] The impregnation device 2 comprises an impregnation device cavity 2-1, an impregnation device interlayer 2-2, a first nitrogen inlet 2-3 and a first nitrogen outlet 2-4. The impregnation device cavity 2-1 is open at the top and contains deionized water for impregnating the deactivated activated carbon catalyst, and the internal space can accommodate the loading basket 1. The first nitrogen inlet 2-3 and the first nitrogen outlet 2-4 are connected to the impregnation device interlayer 2-2, and are used to introduce fluid to heat the impregnation device cavity 2-1. The first nitrogen inlet 2-3 is connected to the regeneration reactor 3, and the first nitrogen outlet 2-4 is connected to the atmosphere.

[0038] The regeneration reactor 3 comprises a regeneration reactor cavity 3-1, a regeneration reactor interlayer 3-2, a microwave generator 3-3, a thermal insulation layer 3-4, a second nitrogen inlet 3-5, a second nitrogen outlet 3-6, a water vapor inlet 3-7 and a water vapor outlet 3-8. The regeneration reactor interlayer 3-2 is arranged outside the regeneration reactor cavity 3-1, the thermal insulation layer 3-4 is arranged outside the regeneration reactor interlayer 3-2, and the microwave generator 3-3 is uniformly arranged in the regeneration reactor interlayer 3-2 and can emit microwaves into the regeneration reactor cavity 3-1. The regeneration reactor cavity 3-1 is openable at the top and the internal space can accommodate the loading basket 1. The second nitrogen inlet 3-5, the second nitrogen outlet 3-6, the water vapor inlet 3-7 and the water vapor outlet 3-8 are all connected to the regeneration reactor cavity 3-1, and the second nitrogen outlet 3-6 is connected to the first nitrogen inlet 2-3 of the impregnation device 2.

[0039] The nitrogen generator 6 is connected to the second nitrogen inlet 3-5 of the regeneration reactor 3, and is used to provide nitrogen required for purging and cooling in the regeneration reactor cavity 3-1, and the nitrogen is separated from air.

[0040] The water vapor generator 7 is connected to the water vapor inlet 3-7 of the regeneration reactor 3, and is used to provide water vapor required for catalyst regeneration in the regeneration reactor cavity 3-1; the water vapor outlet 3-8 is connected to the condenser 4 and the tail gas treatment device 5 in sequence.

[0041] The working process and principle of the above device are explained and described by way of example two.

[0042] Example two

[0043] A method for regenerating deactivated activated carbon to prepare a carbon-based catalyst with stepwise acid strength using example one, as shown in the following steps: Figure 4

[0044] ​Deactivated Activated Carbon Impregnation: Load the deactivated activated carbon catalyst into the loading basket 1, which is then placed into the impregnation chamber 2-1. Deionized water is then injected into the chamber 2-1 to submerge the loading basket. The impregnation process lasts for 10-60 minutes. Due to the porous structure of activated carbon, this step allows water molecules to fully penetrate the pores of the activated carbon catalyst, ensuring that the activated carbon pores are also activated and regenerated during the subsequent regeneration phase, thereby improving activation and regeneration efficiency.

[0045] Purge and prepare the regeneration reactor: remove the loading basket 1, drain the water and load it into the regeneration reactor cavity 3-1, and close the top opening of the regeneration reactor cavity 3-1; close the water vapor inlet 3-7 and the water vapor outlet 3-8, open the second nitrogen inlet 3-5 and the second nitrogen outlet 3-6; turn on the nitrogen generator 6, and introduce nitrogen into the regeneration reactor cavity 3-1 to purge the regeneration reactor cavity 3-1. The purge time is 10-30 minutes to exhaust the air in the regeneration reactor cavity 3-1 to prevent the oxygen in the air from reacting with the activated carbon catalyst and being ignited in the subsequent regeneration stage.

[0046] Regeneration of Deactivated Activated Carbon: After purging, stop introducing nitrogen into the regeneration reactor cavity 3-1, close the second nitrogen inlet 3-5 and second nitrogen outlet 3-6, and open the steam inlet 3-7 and steam outlet 3-8. Turn on the steam generator 7 and continuously introduce high-temperature steam into the regeneration reactor cavity 3-1. Simultaneously, turn on the microwave generator 3-3, control the regeneration temperature to 500-800°C, and regenerate for 1-10 minutes. The gas exiting the steam outlet 3-8 is cooled by condenser 4, and after the exhaust treatment device 5 absorbs toxic and harmful gases, it is discharged in compliance with emission standards.

[0047] This step utilizes the excellent microwave absorption properties of water molecules and microwave-induced dissociation of water molecules to produce hydrogen protons and hydroxyl plasma radicals. With the assistance of high temperature, the carbon deposits on the surface of the deactivated activated carbon are oxidatively dissociated, releasing the phosphoric acid active sites and reshaping the activated carbon's pore structure. Simultaneously, the surface modification effect of the plasma generates new oxygen-containing functional group active sites, ultimately producing a graded acid strength carbon-based catalyst using the deactivated activated carbon. This catalyst has shown promising results and high potential for the targeted preparation of phenolic compounds via biomass catalytic pyrolysis. Specifically, phosphoric acid activated carbon, due to its high mesoporous distribution and abundant surface phosphorus-containing functional groups, exhibits excellent aromatization, alkylation, and isomerization capabilities for biomass feedstocks, thereby achieving targeted enrichment of phenolic compounds such as phenol. The resulting regenerated catalyst significantly outperforms the original untreated activated carbon catalyst.

[0048] Post-processing: After the regeneration of the deactivated activated carbon is completed, stop the water vapor inlet, close the water vapor generator 7 and the microwave generator 3-3, close the water vapor inlet 3-7 and the water vapor outlet 3-8, open the second nitrogen inlet 3-5 and the second nitrogen outlet 3-6, open the nitrogen generator 6, and blow the inner cavity 3-1 of the regeneration reactor to below 100°C. The high-temperature gas blown out is introduced into the interlayer 2-2 of the impregnation device through the first nitrogen inlet 2-4 to heat the deionized water in the inner cavity 2-1 of the impregnation device. Finally, the charging basket 1 is taken out, and the regeneration of the deactivated activated carbon catalyst is completed.

[0049] This step can recycle the heat generated during the regeneration of the activated carbon to heat the impregnation device, strengthen the impregnation effect of the deionized water, and fully utilize the waste heat. While ensuring the energy efficiency of the system, the performance of the regenerated activated carbon catalyst is significantly improved.

[0050] The above specific embodiments are only for illustrating the technical concept and structural features of the present application, and are intended to enable those skilled in the art to implement the present application. However, the above content does not limit the protection scope of the present application, and any equivalent changes or modifications made in accordance with the spirit and essence of the present application shall fall within the protection scope of the present application.

Claims

1. A device for regenerating deactivated activated carbon to prepare a graded acid strength carbon-based catalyst, characterized by: It comprises a charging hanging basket (1), an impregnation device (2), a regeneration reactor (3), a condenser (4), and an exhaust gas treatment device (5); The loading hanging basket (1) is used to hold the deactivated activated carbon catalyst; The immersion device (2) comprises an immersion device inner cavity (2-1) and an immersion device interlayer (2-2) arranged outside the immersion device inner cavity (2-1); an opening is provided at the top of the immersion device inner cavity (2-1); the immersion device inner cavity (2-1) is filled with deionized water and can accommodate a charging hanging basket (1); a fluid for heating the immersion device inner cavity (2-1) passes through the immersion device interlayer (2-2); The regeneration reaction device (3) comprises a regeneration reaction device inner cavity (3-1) and a regeneration reaction device interlayer (3-2) arranged outside the regeneration reaction device inner cavity (3-1); the top of the regeneration reaction device inner cavity (3-1) can be opened and closed; water vapor is passed through the regeneration reaction device inner cavity (3-1) and can accommodate a charging hanging basket (1); a plurality of microwave generators (3-3) are arranged in the regeneration reaction device interlayer (3-2) for emitting microwaves into the regeneration reaction device inner cavity (3-1); The inner cavity (3-1) of the regeneration reaction device is connected to the condenser (4) and the tail gas treatment device (5) in sequence.

2. The device for regenerating deactivated activated carbon to prepare a graded acid strength carbon-based catalyst according to claim 1, characterized in that: A water vapor inlet (3-7) and a water vapor outlet (3-8) are provided on the inner cavity (3-1) of the regeneration reaction device. The water vapor inlet (3-7) is connected to the water vapor generator (7), and the water vapor outlet (3-8) is connected to the condenser (4).

3. The device for regenerating deactivated activated carbon to prepare a graded acid strength carbon-based catalyst according to claim 1, characterized in that: The fluid in the interlayer (2-2) of the impregnation device is nitrogen.

4. The device for regenerating deactivated activated carbon to prepare a graded acid strength carbon-based catalyst according to claim 3, characterized in that: The impregnation device interlayer (2-2) is provided with a first nitrogen inlet (2-3) and a first nitrogen outlet (2-4), and the regeneration reaction device inner cavity (3-1) is provided with a second nitrogen inlet (3-5) and a second nitrogen outlet (3-6), the first nitrogen inlet (2-3) is connected to the second nitrogen outlet (3-6), the second nitrogen inlet (3-5) is connected to a nitrogen generator (6), and the first nitrogen outlet (2-4) is connected to the atmosphere.

5. The device for regenerating deactivated activated carbon to prepare a graded acid strength carbon-based catalyst according to claim 1, characterized in that: A heat-insulating layer (3-4) is provided outside the interlayer (3-2) of the regeneration reaction device.

6. A method for regenerating deactivated activated carbon to prepare a graded acid strength carbon-based catalyst, characterized in that: Using the device according to any one of claims 1 to 5, comprising the steps of: Impregnation of deactivated activated carbon: loading the deactivated activated carbon into the loading basket (1), placing the loading basket (1) into the inner cavity (2-1) of the impregnation device, injecting deionized water into the inner cavity (2-1) of the impregnation device to a height sufficient to submerge the loading basket (1), and impregnating for a period of time; Purging and preparing the regeneration reactor: taking out the loading basket (1), draining the water and then loading it into the regeneration reactor cavity (3-1), closing the top opening of the regeneration reactor cavity (3-1); introducing nitrogen into the regeneration reactor cavity (3-1), purging the regeneration reactor cavity (3-1), and exhausting the air in the cavity; Regeneration of deactivated activated carbon: stop introducing nitrogen, introduce water vapor into the inner cavity (3-1) of the regeneration reactor, turn on the microwave generator (3-3), and control the regeneration temperature to 500-800°C; Post-treatment: After the regeneration is completed, stop introducing water vapor, introduce nitrogen into the regeneration reactor cavity (3-1), purge the regeneration reactor cavity (3-1) to below 100°C, and introduce the purged gas into the impregnation device interlayer (2-2) to heat the deionized water in the impregnation device cavity (2-1), remove the loading basket (1), and complete the activated carbon catalyst regeneration.

7. The method for preparing a graded acid strength carbon-based catalyst by regenerating deactivated activated carbon according to claim 6, characterized in that: In the deactivated activated carbon impregnation step, the activated carbon impregnation time is 10-60 minutes.

8. The method for regenerating deactivated activated carbon to prepare a graded acid strength carbon-based catalyst according to claim 6, characterized in that: In the step of purging the regeneration reactor, the nitrogen purge time of the regeneration reactor (3) is 10-30 minutes.

9. The method for preparing a graded acid strength carbon-based catalyst by regenerating deactivated activated carbon according to claim 6, characterized in that: In the deactivated activated carbon regeneration step, the regeneration time is 1-10 minutes.

10. The method for regenerating deactivated activated carbon to prepare a graded acid strength carbon-based catalyst according to claim 6, characterized in that: The deactivated activated carbon is phosphoric acid activated carbon deactivated by carbon deposition.

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