A catalyst recovery and regeneration system

Abstract

This invention discloses a catalyst recovery and regeneration system, comprising an advanced oxidation unit and a first-stage recovery subsystem. The first-stage recovery subsystem includes a first extractant storage tank, a first reaction vessel, a first centrifuge, a first vacuum separator, and a first plate and frame filter press. The second-stage recovery subsystem includes a second extractant storage tank, a second reaction vessel, a second centrifuge, a second vacuum separator, and a second plate and frame filter press. The third-stage recovery subsystem includes a third extractant storage tank, a third reaction vessel, a third centrifuge, a third vacuum separator, and a third plate and frame filter press. This invention avoids the environmental pollution problems caused by the use of strong acids and alkalis. Compared with methods such as heat treatment and mechanical grinding, it can more effectively restore the activity of the catalyst. Furthermore, it is relatively simple to operate, has low cost, and possesses significant economic value and environmental benefits.

Description

Technical Field

[0001] This utility model relates to the field of resource recycling and catalyst preparation technology, and in particular to a catalyst recycling and regeneration system. Background Technology

[0002] Cu-Bi catalysts, due to their unique catalytic properties, have been widely used in various organic synthesis reactions. For example, in the acetylene-aldehyde process for the production of 1,4-butanediol (BDO), Cu-Bi catalysts can efficiently catalyze the reaction of formaldehyde and acetylene to produce 1,4-butynediol, which can be further processed to obtain the important chemical raw material 1,4-butanediol. However, with long-term use, Cu-Bi catalysts gradually lose activity, leading to a decrease in reaction efficiency and requiring periodic replacement. Currently, the main methods for treating spent Cu-Bi catalysts are as follows:

[0003] 1. Direct disposal: This method is the simplest, but it will cause a huge waste of resources, and the discarded catalyst contains heavy metals such as Cu and Bi, which will cause serious pollution to the environment.

[0004] 2. Chemical leaching: This method uses strong acid or alkali solutions to leach the spent catalyst, dissolving active components such as Cu and Bi in the solution. The catalyst is then recovered through precipitation, electrolysis, or other methods. The advantage of this method is its relatively high recovery efficiency. However, the disadvantages include environmental pollution from the chemical reagents used, a complex processing procedure, and high costs.

[0005] 3. Thermal regeneration: The spent catalyst is roasted or reduced at high temperatures to remove surface carbon deposits and other impurities, restoring some of its activity. However, this method often only partially restores the catalyst's activity, and high-temperature treatment may also alter the catalyst's structure, affecting its final catalytic performance.

[0006] 4. Mechanical Grinding Regeneration: Mechanical grinding refines the particles of spent catalyst, increasing the specific surface area and thus improving its activity. However, this method has limited effect on catalyst activity recovery, and impurities may be introduced during the grinding process, affecting the catalyst's catalytic performance. Therefore, it is necessary to propose a highly efficient, environmentally friendly, and economical recycling and regeneration system for spent Cu-Bi catalysts. Summary of the Invention

[0007] In view of the above-mentioned shortcomings of the prior art, the present invention provides a catalyst recovery and regeneration system.

[0008] To achieve the above-mentioned objectives, the technical solution adopted by this utility model is as follows:

[0009] A catalyst recovery and regeneration system is provided, comprising an advanced oxidation unit and a first-stage recovery subsystem. The first-stage recovery subsystem includes a first extractant storage tank, a first reactor, a first centrifuge, a first vacuum separator, and a first plate and frame filter press. The feed end of the first reactor is connected to the output end of the advanced oxidation unit via a pipeline; the liquid inlet of the first reactor is connected to the output end of the first extractant storage tank via a pipeline; the discharge end of the first reactor is connected to the feed end of the first centrifuge via a pipeline; the discharge end of the first centrifuge is connected to the discharge end of the first vacuum separator via a pipeline; the discharge end of the first vacuum separator is connected to the feed end of the first plate and frame filter press via a pipeline; and the liquid outlets of the first centrifuge, the first vacuum separator, and the first plate and frame filter press are all connected to the first extractant storage tank via pipelines.

[0010] Furthermore, it also includes a second-stage recovery subsystem, which includes a second extractant storage tank, a second reaction vessel, a second centrifuge, a second vacuum separator, and a second plate and frame filter press. The feed end of the second reaction vessel is connected to the discharge end of the first plate and frame filter press via a first conveying pipe. The liquid inlet of the second reaction vessel is connected to the output end of the second extractant storage tank via a pipe. The discharge end of the second reaction vessel is connected to the feed end of the second centrifuge via a pipe. The discharge end of the second centrifuge is connected to the discharge end of the second vacuum separator via a pipe. The discharge end of the second vacuum separator is connected to the feed end of the second plate and frame filter press via a pipe. The liquid outlet pipes of the second centrifuge, the second vacuum separator, and the second plate and frame filter press are all connected to the second extractant storage tank via pipes.

[0011] Furthermore, it also includes a third-level recovery subsystem, which comprises a third extractant storage tank, a third reaction vessel, a third centrifuge, a third vacuum separator, and a third plate and frame filter press. The feed end of the third reaction vessel is connected to the discharge end of the second plate and frame filter press via a pipeline. The liquid inlet of the third reaction vessel is connected to the output end of the third extractant storage tank via a second conveying pipeline. The discharge end of the third reaction vessel is connected to the feed end of the third centrifuge via a pipeline. The discharge end of the third centrifuge is connected to the discharge end of the third vacuum separator via a pipeline. The discharge end of the third vacuum separator is connected to the feed end of the third plate and frame filter press via a pipeline. The liquid outlet pipes of the third centrifuge, the third vacuum separator, and the third plate and frame filter press are all connected to the third extractant storage tank via pipelines.

[0012] Furthermore, both the first and second conveying pipes are screw conveyors.

[0013] The beneficial effects of this utility model are as follows:

[0014] The recycling system of this invention oxidizes the waste Cu-Bi catalyst, causing the bonds of the mixed polymer carbon deposits to break (some carbon deposits are oxidized and removed in gaseous form). Then, it uses organic solvents for stepwise extraction, allowing the remaining carbon deposits to be gradually released into the organic solvents. Finally, after separation, a solid phase rich in active components is obtained, which can be mixed with a new catalyst and used to prepare a new process catalyst.

[0015] The recycling and regeneration method of this invention includes steps such as catalyst dispersion, advanced oxidation, stepwise extraction, centrifugal separation, solid-liquid separation, and mixing with a new support to prepare the catalyst. Compared with the prior art, this invention eliminates the use of strong acids and alkalis, reduces environmental pollution, and is simple to operate and low in cost. It can effectively restore catalyst activity, realize resource recycling, and has significant economic and environmental benefits.

[0016] The advanced oxidation method of this invention can break the bonds of the polymer carbon deposit components, so as to facilitate subsequent stepwise extraction. At the same time, some carbon deposits are oxidized into gas and removed, reducing the amount of subsequent extractant used. The stepwise extraction uses organic solvents with different polarities, which can extract and separate polar and non-polar carbon deposit components as much as possible, thereby obtaining high-purity Cu-Bi active components.

[0017] The method of this invention avoids the environmental pollution problems caused by the use of strong acids and alkalis. At the same time, compared with methods such as heat treatment and mechanical grinding, it can more effectively restore the activity of the catalyst. Moreover, it is relatively simple to operate, has low cost, and has significant economic value and environmental benefits. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the catalyst recovery and regeneration system in this utility model;

[0019] The symbols for the main components in the diagram are explained below:

[0020] 1. Batching silo; 2. First extractant storage tank; 3. Second extractant storage tank; 4. Third extractant storage tank; 5. Advanced oxidation unit; 6. First reactor; 7. Second reactor; 8. Third reactor; 9. First centrifuge; 10. First vacuum separator; 11. First plate and frame filter press; 12. Second centrifuge; 13. Second vacuum separator; 14. Second plate and frame filter press; 15. Third centrifuge; 16. Third vacuum separator; 17. Third plate and frame filter press. Detailed Implementation

[0021] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0022] Example 1

[0023] like Figure 1 As shown, the catalyst recovery and regeneration system includes a spent catalyst raw material storage tank 1, an advanced oxidation unit 5, and a first-stage recovery subsystem. The advanced oxidation unit 5 is either a low-temperature plasma oxidation unit or a superoxide oxidation unit. The first-stage recovery subsystem includes a first extractant storage tank 2, a first reactor 6, a first centrifuge 9, a first vacuum separator 10, and a first plate and frame filter press 11. The feed end of the first reactor 6 is connected to the output end of the advanced oxidation unit 5 via a pipeline; the liquid inlet end of the first reactor 6 is connected to the output end of the first extractant storage tank 2 via a pipeline; the discharge end of the first reactor 6 is connected to the feed end of the first centrifuge 9 via a pipeline; the discharge end of the first centrifuge 9 is connected to the discharge end of the first vacuum separator 10 via a pipeline; the discharge end of the first vacuum separator 10 is connected to the feed end of the first plate and frame filter press 11 via a pipeline; and the liquid outlet pipes of the first centrifuge 9, the first vacuum separator 10, and the first plate and frame filter press 11 are all connected to the first extractant storage tank 2 via pipelines.

[0024] The catalyst recovery and regeneration system employs a non-oxidized, single-organic-solvent extraction method. The catalyst recovery and regeneration method includes the following steps:

[0025] S1: Weigh 100g of waste Cu-Bi catalyst and add it to the first reaction vessel 6;

[0026] S2: Add 200 mL of methanol to the first reaction vessel 6 and stir well to ensure that the spent Cu-Bi catalyst is fully in contact with the methanol;

[0027] S3: Heat the first reaction vessel 6 to 30°C, maintain atmospheric pressure, and stir for 2 hours; then raise the temperature to 40°C and the pressure to 0.2 MPa, and continue stirring for 2 hours.

[0028] S4: After the reaction is completed, the reaction mixture is centrifuged using the first centrifuge 9 at a speed of 4000 rpm to separate the organic phase and the solid phase.

[0029] S5: The separated organic phase is distilled to remove the solvent and obtain a solid powder rich in Cu-Bi active components;

[0030] S6: The regenerated spent Cu-Bi catalyst was mixed with new Cu-Bi catalyst at a mass ratio of 1:9. The newly prepared catalyst was used in the acetylacetonate-aldehyde process to produce 1,4-butanediol under the following conditions: temperature 90℃, pressure 0.5MPa, and reaction time 6h. Testing showed that the formaldehyde conversion rate reached 84%, and the 1,4-butanediol selectivity reached 86%.

[0031] The catalyst recovery and regeneration system employs low-temperature plasma oxidation and single-solvent extraction. The catalyst recovery and regeneration method includes the following steps:

[0032] S1: Weigh 250g of waste Cu-Bi catalyst and disperse it in the reaction water tank (125g / L) of the low-temperature plasma oxidation device.

[0033] S2: Control the reaction temperature to 65℃ during oxidation, continue oxidation for 3 hours, and then enter the first reaction vessel 6;

[0034] S3: Add 250 mL of ethanol to the first reaction vessel 6 and stir until homogeneous, so that the catalyst and solvent are in full contact.

[0035] S4: Heat the first reaction vessel 6 to 30°C, maintain normal pressure, and stir the reaction for 2 hours;

[0036] S5: After the reaction is complete, the mixture is centrifuged using the first centrifuge 9 at a speed of 4000 rpm to separate the organic phase and the solid phase.

[0037] S6: The separated organic phase is distilled to remove the solvent and obtain a solid powder rich in Cu-Bi active components;

[0038] S7: The regenerated spent Cu-Bi catalyst was mixed with new Cu-Bi catalyst at a mass ratio of 1:9. The newly prepared catalyst was used in the acetylacetonate-aldehyde process to produce 1,4-butanediol under the following conditions: temperature 90℃, pressure 0.75MPa, and reaction time 6.5h. Testing showed that the formaldehyde conversion rate reached 89%, and the 1,4-butanediol selectivity reached 91%.

[0039] Example 2

[0040] The difference between Example 2 and Example 1 lies in the method of catalyst recovery and regeneration. This example also includes a second-stage recovery subsystem, which comprises a second extractant storage tank 3, a second reactor 7, a second centrifuge 12, a second vacuum separator 13, and a second plate and frame filter press 14. The feed end of the second reactor 7 is connected to the discharge end of the first plate and frame filter press 11 via a first conveying pipe. The liquid inlet of the second reactor 7 is connected to the output end of the second extractant storage tank 3 via a pipe. The discharge end of the second reactor 7 is connected to the feed end of the second centrifuge 12 via a pipe. The discharge end of the second centrifuge 12 is connected to the discharge end of the second vacuum separator 13 via a pipe. The discharge end of the second vacuum separator 13 is connected to the feed end of the second plate and frame filter press 14 via a pipe. The liquid outlet pipes of the second centrifuge 12, the second vacuum separator 13, and the second plate and frame filter press 14 are all connected to the second extractant storage tank 3 via pipes. The first conveying pipe is preferably a screw conveyor.

[0041] The catalyst recovery and regeneration system employs low-temperature plasma oxidation and stepwise extraction. The catalyst recovery and regeneration method includes the following steps:

[0042] S1: Weigh 200g of waste Cu-Bi catalyst and disperse it in the reaction water tank (100g / L) of the low-temperature plasma oxidation device.

[0043] S2: The reaction temperature is controlled at 60℃ during oxidation, and the oxidation is continued for 2.5 hours, after which it enters the first reaction vessel 6;

[0044] S3: Add 350 mL of methanol to the first reaction vessel 6 and stir until homogeneous, so that the waste Cu-Bi catalyst is fully in contact with the methanol;

[0045] S4: Heat the first reaction vessel 6 to 40°C, maintain atmospheric pressure, and stir the reaction for 2.5 hours. Then, pass the mixture through the first centrifuge 9 and the first vacuum separator 10. and The first plate and frame filter press 11 performs solid-liquid separation with a vacuum degree of 0.08 MPa and a plate and frame pressure of 4 MPa, yielding an organic phase and a first solid phase.

[0046] S5: The solid phase generated in the first reactor 6 is transferred to the second reactor 7. 400 mL of a mixture of petroleum ether and acetone (volume ratio 1:1) is added to the filtered waste Cu-Bi catalyst. The mixture is stirred until homogeneous, ensuring full contact between the waste Cu-Bi catalyst and the solvent. The temperature in the second reactor 7 is raised to 40°C and the pressure is raised to 0.3 MPa. The reaction is continued for 2 hours with stirring.

[0047] S6: After the reaction is completed, the mixture generated in the second reactor 7 is separated into solid and liquid phases by passing it through the second centrifuge 12, the second vacuum separator 13, and the second plate and frame filter press 14. The vacuum degree is 0.08 MPa and the plate and frame pressure is 4 MPa. The organic phase and the second solid phase are obtained. The second solid phase is filtered to obtain the regenerated waste Cu-Bi catalyst.

[0048] S7: The regenerated spent Cu-Bi catalyst was mixed with new Cu-Bi catalyst at a mass ratio of 1:9 and used in the acetylacetonate-aldehyde process to produce 1,4-butanediol. The reaction conditions were: temperature 80℃, pressure 0.45MPa, and reaction time 8h. Testing showed that the formaldehyde conversion rate reached 92% and the 1,4-butanediol selectivity reached 95%.

[0049] Example 3

[0050] The difference between Example 3 and Example 2 lies in the catalyst recovery and regeneration method. This example also includes a third-stage recovery subsystem, which comprises a third extractant storage tank 4, a third reaction vessel 8, a third centrifuge 15, a third vacuum separator 16, and a third plate and frame filter press 17. The feed end of the third reaction vessel 8 is connected to the discharge end of the second plate and frame filter press 14 via a pipeline. The liquid inlet of the third reaction vessel 8 is connected to the output end of the third extractant storage tank 4 via a second conveying pipeline. The discharge end of the third reaction vessel 8 is connected to the feed end of the third centrifuge 15 via a pipeline. The discharge end of the third centrifuge 15 is connected to the discharge end of the third vacuum separator 16 via a pipeline. The discharge end of the third vacuum separator 16 is connected to the feed end of the third plate and frame filter press 17 via a pipeline. The liquid outlets of the third centrifuge 15, the third vacuum separator 16, and the third plate and frame filter press 17 are all connected to the third extractant storage tank 4 via pipelines. The second conveying pipeline is preferably a screw conveyor. The first reactor 6, the second reactor 7, and the third reactor 9 can preferably be ozone catalytic reaction towers. The first centrifugal separator 9, the second centrifugal separator 12, and the third centrifugal separator 15 can preferably be horizontal screw discharge sedimentation centrifuges, manufactured by Xiangtan Centrifuge Co., Ltd., LW series. The first vacuum separator 10, the second vacuum separator 13, and the third vacuum separator 16 can preferably be vacuum ceramic filters, manufactured by Yantai Tongxing Industrial Group of Nuclear Industry, TC series. The first plate and frame filter press 11, the second plate and frame filter press 14, and the third plate and frame filter press 17 can preferably be ultra-high pressure plate and frame filter presses, manufactured by Zhengzhou Dingsheng (model CGYB-2000).

[0051] The catalyst recovery and regeneration system employs superoxide oxidation and stepwise extraction. The catalyst recovery and regeneration method includes the following steps:

[0052] S1: Weigh 150g of spent Cu-Bi catalyst and disperse it in the reaction water tank of the superoxide oxidation unit. The concentration of the spent Cu-Bi catalyst is 150g / L.

[0053] S2: Control the reaction temperature of the superoxide oxidation device to 50℃, continue oxidation for 2.5h, and then enter the first reaction vessel 6;

[0054] S3: Add 300 mL of petroleum ether to the first reactor 6, stir evenly to ensure that the waste Cu-Bi catalyst is fully in contact with the petroleum ether, heat the first reactor 6 to 25°C, maintain normal pressure, and stir the reaction for 1 hour.

[0055] S4: The primary mixture generated in a reaction vessel 6 is subjected to solid-liquid separation by a first centrifuge 9, a first vacuum separator 10 and a first plate and frame filter press 11 to obtain a first organic phase and a first solid phase. The vacuum degree is 0.08 MPa and the plate and frame pressure is 4 MPa.

[0056] S5: After filtering the first solid phase in step S4, transfer it to the second reactor 7. Add 300 mL of toluene to the second reactor 7 and stir until homogeneous to ensure that the catalyst and solvent are in full contact. Raise the temperature in the second reactor 7 to 55°C and the pressure to 0.25 MPa, and continue stirring for 2 hours.

[0057] S6: After the reaction is completed, the secondary mixture generated in the second reaction vessel 7 is separated into solid and liquid phases by passing it through the second centrifuge 12, the second vacuum separator 13, and the second plate and frame filter press 14. The vacuum degree is 0.08 MPa and the plate and frame pressure is 4 MPa, to obtain the second organic phase and the second solid phase.

[0058] S7: After filtering the second solid phase, transfer it to the third reactor 8. Add 300 mL of methanol to the third reactor 8 and stir until homogeneous, so that the catalyst and solvent are in full contact. Set the temperature of the third reactor 8 to 30°C and the pressure to atmospheric pressure, and continue stirring for 2 hours.

[0059] S8: After the reaction is completed, the three mixtures generated in the third reactor 8 are separated into solid and liquid phases by passing them through the third centrifuge 15, the third vacuum separator 16 and the third plate and frame filter press 17. The vacuum degree is 0.08 MPa and the plate and frame pressure is 4 MPa. The third organic matter and the third solid phase are obtained. The third solid phase is filtered to obtain the regenerated waste Cu-Bi catalyst.

[0060] S9: The regenerated waste Cu-Bi catalyst was mixed with the new catalyst at a mass ratio of 1:9 and used in the acetylacetonate-aldehyde process to produce 1,4-butanediol. The reaction conditions were: temperature 85℃, pressure 0.4MPa, and reaction time 7h. Testing showed that the formaldehyde conversion rate reached 92% and the 1,4-butanediol selectivity reached 96%.

[0061] Working process and principle: The working principle of the second-stage recovery subsystem and the third-stage recovery subsystem is the same as that of the first-stage recovery subsystem. Taking the working principle of the second-stage recovery subsystem as an example, the waste Cu-Bi catalyst is transported from the feed silo 1 to the advanced oxidation unit 5 and enters the reaction water tank of the advanced oxidation unit 5 for oxidation. After oxidation, it enters the reaction vessel 6 for extraction. After extraction, it passes through the first centrifuge 9, the first vacuum separator 10 and the first plate and frame filter press 11 in sequence to achieve centrifugal separation, vacuum separation and plate and frame filter press separation to obtain solid and liquid materials. The solid material can enter the reaction vessel of the next-stage recovery subsystem for extraction again, and the liquid material is recovered to the extractant storage tank for reuse. The first-stage recovery subsystem, the second-stage recovery subsystem and the third-stage recovery subsystem work together to realize the step-by-step extraction operation of the catalyst.

Claims

1. A catalyst recovery regeneration system characterized by, It includes an advanced oxidation unit (5) and a first-stage recovery subsystem; The first-stage recovery subsystem includes a first extractant storage tank (2), a first reaction vessel (6), a first centrifuge (9), a first vacuum separator (10), and a first plate and frame filter press (11). The feed end of the first reactor (6) is connected to the output end of the advanced oxidation device (5) through a pipe. The liquid inlet of the first reactor (6) is connected to the output end of the first extractant storage tank (2) through a pipe. The discharge end of the first reactor (6) is connected to the feed end of the first centrifuge (9) through a pipe. The discharge end of the first centrifuge (9) is connected to the discharge end of the first vacuum separator (10) through a pipe. The discharge end of the first vacuum separator (10) is connected to the feed end of the first plate and frame filter press (11) through a pipe. The liquid outlet pipes of the first centrifuge (9), the first vacuum separator (10) and the first plate and frame filter press (11) are all connected to the first extractant storage tank (2) through a pipe.

2. The catalyst recovery and regeneration system according to claim 1, characterized by, It also includes a second-stage recovery subsystem, which includes a second extractant storage tank (3), a second reactor (7), a second centrifuge (12), a second vacuum separator (13), and a second plate and frame filter press (14). The feed end of the second reactor (7) is connected to the discharge end of the first plate and frame filter press (11) through a first conveying pipe. The liquid inlet of the second reactor (7) is connected to the output end of the second extractant storage tank (3) through a pipe. The discharge end of the second reactor (7) is connected to the feed end of the second centrifuge (12) through a pipe. The discharge end of the second centrifuge (12) is connected to the discharge end of the second vacuum separator (13) through a pipe. The discharge end of the second vacuum separator (13) is connected to the feed end of the second plate and frame filter press (14) through a pipe. The liquid outlet pipes of the second centrifuge (12), the second vacuum separator (13), and the second plate and frame filter press (14) are all connected to the second extractant storage tank (3) through a pipe.

3. The catalyst recovery and regeneration system according to claim 2, characterized in that, It also includes a third-level recovery subsystem, which comprises a third extractant storage tank (4), a third reaction vessel (8), a third centrifuge (15), a third vacuum separator (16), and a third plate and frame filter press (17). The feed end of the third reaction vessel (8) is connected to the discharge end of the second plate and frame filter press (14) via a pipeline, and the liquid inlet end of the third reaction vessel (8) is connected to the output end of the third extractant storage tank (4) via a second conveying pipeline. The discharge end of the third centrifuge (15) is connected to the feed end of the third centrifuge (15) through a pipe. The discharge end of the third centrifuge (15) is connected to the discharge end of the third vacuum separator (16) through a pipe. The discharge end of the third vacuum separator (16) is connected to the feed end of the third plate and frame filter press (17) through a pipe. The liquid outlet pipes of the third centrifuge (15), the third vacuum separator (16) and the third plate and frame filter press (17) are all connected to the third extractant storage tank (4) through a pipe.

4. The catalyst recovery and regeneration system according to claim 3, characterized in that, Both the first and second conveying pipelines are screw conveyors.

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