A preparation device and method for activated carbon-supported metal palladium catalyst

Abstract

The present invention discloses a preparation device and method of an activated carbon-supported metal palladium catalyst. The preparation method of the activated carbon-supported metal palladium catalyst comprises the following steps: filling activated carbon into a first adsorption column; preparing a palladium chloride aqueous solution in a preparation kettle; sending the palladium chloride aqueous solution to the first adsorption column by a circulating pump, the palladium chloride aqueous solution passes through the first adsorption column, passes through the first liquid outlet, and then returns to the preparation kettle via the first liquid outlet pipeline, repeating multiple times; introducing a reducing agent into the first adsorption column for reduction; adding distilled water to the preparation kettle, sending the distilled water to the first adsorption column by a circulating pump, the distilled water passes through the first adsorption column, passes through the first liquid outlet, and then returns to the preparation kettle via the first liquid outlet pipeline, repeating multiple times; taking out the activated carbon in the first adsorption column and washing it with distilled water to obtain an activated carbon-supported palladium catalyst. The loading of metal palladium in the activated carbon-supported metal palladium catalyst prepared by the present invention is basically unchanged and the activity is stable during the application process.

Description

Technical Field

[0001] The invention relates to a device and a method for preparing an activated carbon-supported metal palladium catalyst. Background Art

[0002] Activated carbon-supported palladium catalyst, commonly known as palladium-carbon catalyst. It is a commonly used precious metal catalyst for catalytic hydrogenation or catalytic dehydrogenation. Due to the high activity of palladium-carbon catalyst, it is widely used in the field of fine chemical technology. The existing technology uses adsorption and reduction to prepare activated carbon-supported palladium catalysts, but there are common problems: 1. The loading of metal palladium will drop rapidly during the application process, the catalyst activity will decrease, and the number of applications will be small; 2. The uniformity of a single batch of catalysts is poor, and the performance of the entire batch of catalysts cannot be accurately evaluated through small tests.

[0003] Chinese invention patent CN106607020A relates to a method for preparing a highly active palladium-carbon catalyst. In Example 1, the following experimental scheme is disclosed: 240 mg of tetrachloropalladic acid and 24 mg of polyvinyl pyrrolidone are weighed respectively, 30 ml of distilled water is added to dissolve, and the mixture is placed in an ultrasonic bath for 30 min for standby use. 1.0 g of activated carbon and 50 mg of glucose are weighed respectively and added to the above solution. After mixing evenly, the mixture is heated to 40 ° C and stirred for 12 h. The mixture is reacted at a microwave power of 350 W for 2 min. After filtering, washing and drying, a highly active palladium-carbon catalyst is obtained. This method will encounter the following problems in practical applications: 1. The loading of metal palladium decreases rapidly during the application process, the catalyst activity decreases, and the number of applications is small; 2. The uniformity of a single batch of catalysts is poor, and the performance cannot be accurately evaluated through a small test. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a device and method for preparing an activated carbon-supported metal palladium catalyst, wherein the loading amount of metal palladium in the prepared activated carbon-supported metal palladium catalyst remains basically unchanged and the activity is stable during the application process.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme:

[0006] A preparation device for an activated carbon-supported metal palladium catalyst, comprising:

[0007] A preparation kettle, which is used to prepare a palladium chloride aqueous solution, and the preparation kettle has an outlet and an inlet for introducing materials or circulating liquid;

[0008] A first adsorption column having a first cavity for accommodating activated carbon, wherein the first adsorption column comprises a first liquid inlet connected to an upper portion of the first cavity and a first liquid outlet connected to a lower portion of the first cavity;

[0009] Wherein, the first liquid inlet is connected to the outlet of the preparation kettle through a first circulation pipeline, and the first liquid outlet is connected to the first liquid outlet pipeline.

[0010] In a preferred embodiment, the preparation device further comprises:

[0011] A second adsorption column having a second cavity for accommodating activated carbon, the second adsorption column comprising a second liquid inlet connected to an upper portion of the second cavity and a second liquid outlet connected to a lower portion of the second cavity;

[0012] The second liquid inlet is connected to the outlet of the preparation kettle through a second circulation pipeline, and the second liquid outlet is connected to the first liquid inlet of the first adsorption column through a second liquid outlet pipeline;

[0013] The inlet of the preparation kettle includes a circulating liquid inlet, and the first liquid outlet pipeline is connected to the circulating liquid inlet.

[0014] More preferably, the preparation device has an adsorption and reduction working state and a washing working state. In the adsorption and reduction working state, the outlet is connected to the first liquid inlet, the outlet is disconnected from the second liquid inlet, and the first liquid outlet is connected to the circulating liquid inlet; in the washing working state, the outlet is connected to the second liquid inlet, the outlet is disconnected from the first liquid inlet, the second liquid outlet is connected to the first liquid inlet, and the first liquid outlet is connected to the circulating liquid inlet.

[0015] Furthermore, the first circulation pipeline and / or the second circulation pipeline is provided with a circulation pump for delivering the material in the preparation kettle to the first adsorption column or the second adsorption column and circulating it multiple times; the first circulation pipeline, the first liquid outlet pipeline, the second circulation pipeline and the second liquid outlet pipeline are respectively provided with control valves for controlling the on-off of the pipeline.

[0016] Furthermore, the first cavity and the second cavity respectively have a columnar main body, the activated carbon is located in the columnar main body, and the ratio of the diameter of the columnar main body of the second cavity to the diameter of the columnar main body of the first cavity is 1.5~4:1.

[0017] Further, a first sintered plate and a first support plate are provided in the first cavity, the first support plate is located below the first sintered plate to form a columnar main body for accommodating activated carbon therebetween, the first support plate is covered with a filter medium, the first liquid inlet is located above the first sintered plate, and the first liquid outlet is located below the first support plate; and / or a second sintered plate and a second support plate are provided in the second cavity, the second support plate is located below the second sintered plate to form a columnar main body for accommodating activated carbon therebetween, the second support plate is covered with a filter medium, the second liquid inlet is located above the second sintered plate, and the second liquid outlet is located below the second support plate.

[0018] In a preferred embodiment, the inlet of the preparation kettle includes a feeding port for feeding a reducing agent and / or a distilled water inlet for feeding distilled water.

[0019] In a preferred embodiment, the preparation kettle has a jacket, a cooling medium inlet for introducing a cooling medium into the jacket, and a heating medium inlet for introducing a heating medium into the jacket.

[0020] The present invention also adopts the following technical solution:

[0021] A method for preparing an activated carbon-supported metal palladium catalyst, using the preparation device as described above, the preparation method comprises the following steps:

[0022] (1) Filling the first adsorption column with activated carbon;

[0023] (2) preparing or introducing a palladium chloride aqueous solution into a preparation kettle;

[0024] (3) The palladium chloride aqueous solution in the preparation kettle is sent to the first liquid inlet of the first adsorption column through the first circulation pipeline by a circulation pump, and the palladium chloride aqueous solution passes through the first adsorption column, passes through the first liquid outlet, and then returns to the preparation kettle through the first liquid outlet pipeline; repeating multiple times until the set circulation adsorption time is reached;

[0025] (4) adding a reducing agent to the preparation kettle, and passing the reducing agent in the preparation kettle into the first adsorption column through a circulation pump for reduction;

[0026] (5) Add distilled water to the preparation kettle, and send the distilled water in the preparation kettle to the first liquid inlet of the first adsorption column through the circulation pump. After passing through the first adsorption column, the distilled water passes through the first liquid outlet and then returns to the preparation kettle through the first liquid outlet pipeline; repeat multiple times until the set circulation elution time is reached;

[0027] (6) The activated carbon in the first adsorption column is taken out and washed with distilled water to obtain an activated carbon-supported palladium catalyst.

[0028] In a preferred embodiment, in step (1), activated carbon is also loaded into the second adsorption column; in step (3), the palladium chloride aqueous solution is only fed into the first adsorption column without passing through the second adsorption column; in step (5), a circulating pump feeds the distilled water in the preparation kettle into the second adsorption column, and the water flowing through the second adsorption column enters the first adsorption column to elute the activated carbon therein, and then enters the preparation kettle; this is repeated multiple times, so that the distilled water circulates through the first adsorption column and the second adsorption column;

[0029] In step (1), the activated carbon in the first adsorption column comes from the activated carbon in the second adsorption column treated in step (5) in the previous preparation process.

[0030] In a preferred embodiment, in step (4), alkali is added to the preparation kettle to adjust the pH value, and then sodium formate is added as a reducing agent, so that the sodium formate solution is circulated through the first adsorption column multiple times. After the reduction is completed, the sodium formate solution in the preparation kettle is discharged.

[0031] In a preferred embodiment, in step (1), the mass of the activated carbon in the second adsorption column is not less than the mass of the activated carbon in the first adsorption column.

[0032] In a preferred embodiment, in step (2), the mass concentration of the palladium chloride aqueous solution is 0.1-2%.

[0033] In a preferred embodiment, the ratio of the mass of activated carbon in the first adsorption column to the mass of palladium chloride in the palladium chloride aqueous solution is 1-30:1.

[0034] In a preferred embodiment, in step (3), the temperature of the cyclic adsorption is 20-60°C.

[0035] In a preferred embodiment, in step (4), the temperature of the reduction reaction is 50-90°C.

[0036] In a preferred embodiment, the mass ratio of the reducing agent in step (4) to the palladium chloride in the palladium chloride aqueous solution in step (1) is 1-5:1.

[0037] In a preferred embodiment, the ratio of the flow rate of the circulating pump in step (5) to the flow rate of the circulating pump in step (3) is 1.5-4:1.

[0038] The present invention adopts the above solution, which has the following advantages compared with the prior art:

[0039] In the present invention, activated carbon is placed in an adsorption column, and palladium chloride solution, reducing agent, etc. can be circulated through the activated carbon in the adsorption column (for example, flowing from top to bottom), and then distilled water is circulated through the activated carbon in the adsorption column to flush and clean the activated carbon. The metal palladium loaded in the activated carbon is distributed more evenly, and it is not easy to cause the problem of metal palladium loss during subsequent use, which increases the number of times the catalyst is applied and reduces the cost of using the catalyst. Therefore, the metal palladium loading of the activated carbon-loaded metal palladium catalyst prepared by the present invention remains basically unchanged during the application process, the catalyst activity is stable, and the number of applications is large; 2. The uniformity of a single batch of catalysts is good, and the performance of the entire batch of catalysts can be accurately evaluated through small tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0041] Figure 1 It is a schematic diagram of a preparation device of an activated carbon-supported metal palladium catalyst according to an embodiment of the present invention.

[0042] Figure 2 Schematic diagram of the structure of a first adsorption column according to an embodiment of the present invention.

[0043] Figure 3 Schematic diagram of the structure of a second adsorption column according to an embodiment of the present invention.

[0044] Reference numerals:

[0045] 1. Preparation kettle; 11. Outlet; 12. Circulating liquid inlet; 13. Agitator; 14. Feeding port; 15. Distilled water inlet; 16. Jacket; 161. Hot water pipe; 162. Cold water pipe;

[0046] 2. first adsorption column; 21. first cavity; 22. first liquid inlet; 23. first liquid outlet; 24. first sintering plate; 25. first support plate; 26. first circulation pipeline; 27. first liquid outlet pipeline;

[0047] 3. second adsorption column; 31. second chamber; 32. second liquid inlet; 33. second liquid outlet; 34. second sintering plate; 35. second support plate; 36. second circulation pipeline; 37. second liquid outlet pipeline;

[0048] 4. Circulation pump;

[0049] 5. Material barrel;

[0050] 6. Control valve. DETAILED DESCRIPTION

[0051] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0052] It should be noted that the directional terms "upper" and "lower" mentioned in the claims and the specification are defined according to the flow direction of the fluid in the reactor. Figure 1 As shown, "up" corresponds to Figure 1 The lower side of the paper, "lower" corresponds to Figure 1 The upper side of the paper.

[0053] Reference Figures 1 to 3 As shown, a preparation device for an activated carbon-supported metal palladium catalyst mainly comprises a preparation kettle 1, a first adsorption column 2, a second adsorption column 3, a circulation pump 4 and a material barrel 5. Among them, the preparation kettle 1 is used to prepare materials such as palladium chloride aqueous solution, the first adsorption column 2 and the second adsorption column 3 are used to accommodate activated carbon, the circulation pump 4 is used to make the circulation flow in the preparation kettle 1 pass through the first adsorption column 2 or the first adsorption column 2 and the second adsorption column 3 for multiple times, and the material barrel 5 is used to receive the residual material discharged from the preparation kettle 1.

[0054] The bottom of the preparation kettle 1 is provided with an outlet 11, and the material in the preparation kettle 1 flows out of the preparation kettle 1 from the outlet 11, for example, into the first adsorption column 2 or the second adsorption column 3, or directly discharged to the material barrel 5; the top is provided with a circulating liquid inlet 12, for the circulating liquid from the first adsorption column 2 to flow back to the preparation kettle 1. The preparation kettle 1 is also provided with a stirrer 13, which is used to stir the material in the preparation kettle 1 to mix it. The preparation kettle 1 also has a plurality of inlets for introducing materials or circulating liquids, as follows: the top of the preparation kettle 1 is further provided with a feeding port 14, which is used to put palladium chloride, sodium bicarbonate or sodium carbonate (used to adjust the pH of the solution in the preparation kettle 1), sodium formate (used as a reducing agent), etc. into the preparation kettle 1; the top of the preparation kettle 1 is also provided with a distilled water inlet 15, which is used to introduce distilled water into the preparation kettle 1 to prepare a solution or use it as an eluent. The preparation kettle 1 also has a jacket 16, a refrigerant inlet for introducing a cooling medium into the jacket 16, and a heat medium inlet for introducing a heating medium into the jacket 16. Specifically, the jacket 16 is connected to a hot water pipe 161 and a cold water pipe 162 for supplying cold water or hot water into and out of the jacket 16.

[0055] The first adsorption column 2 has a first cavity 21 for accommodating activated carbon. The first adsorption column 2 includes a first liquid inlet 22 connected to the upper part of the first cavity 21 and a first liquid outlet 23 connected to the lower part of the first cavity 21. The first liquid inlet 22 is connected to the outlet 11 of the preparation kettle 1 through a first circulation pipeline 26, and the first liquid outlet 23 is connected to the circulating liquid inlet 12 of the preparation kettle 1 through a first liquid outlet pipeline 27.

[0056] The second adsorption column 3 has a second chamber 31 for accommodating activated carbon. The second adsorption column 3 includes a second liquid inlet 32 ​​connected to the upper part of the second chamber 31 and a second liquid outlet 33 connected to the lower part of the second chamber 31. The second liquid inlet 32 ​​is connected to the outlet 11 of the preparation kettle 1 through a second circulation pipeline 36, and the second liquid outlet 33 is connected to the first liquid inlet 22 of the first adsorption column 2 through a second liquid outlet pipeline 37.

[0057] The first circulation pipeline 26 and the second circulation pipeline 36 share a part of the pipeline, and the circulation pump 4 is arranged on the part of the shared pipeline, which is used to send the material in the preparation kettle 1 to the first adsorption column 2 or the second adsorption column 3 and circulate multiple times. In addition, the first circulation pipeline 26, the second circulation pipeline 36, the first liquid outlet pipeline 27 and the second liquid outlet pipeline 37 are respectively provided with control valves 6 for controlling the on-off of the pipeline.

[0058] The preparation device has an adsorption and reduction working state and a washing working state. In the adsorption and reduction working state, the outlet 11 is connected to the first liquid inlet 22, the outlet 11 is disconnected from the second liquid inlet 32, and the first liquid outlet 23 is connected to the circulating liquid inlet 12; in the washing working state, the outlet 11 is connected to the second liquid inlet 32, the outlet 11 is disconnected from the first liquid inlet 22, the second liquid outlet 33 is connected to the first liquid inlet 22, and the first liquid outlet 23 is connected to the circulating liquid inlet 12. That is to say, the preparation device has two working states. In the first working state (i.e., the adsorption and reduction working state), the preparation kettle 1 and the first adsorption column 2 are connected through the first circulation pipeline 26 and the first liquid outlet pipeline 27 to form a circulation loop, and the circulation pump 4 is operated to make the palladium chloride aqueous solution or ammonium formate solution in the preparation kettle 1 flow in the circulation loop, so that it flows through the activated carbon in the first adsorption column 2 multiple times. In the second working state (i.e., the washing working state), the preparation kettle 1, the first adsorption column 2 and the second adsorption column 3 are connected, that is, the preparation kettle 1, the second circulation pipeline 36, the second adsorption column 3, the second liquid outlet pipeline 37, the first adsorption column 2 and the first liquid outlet pipeline 27 are connected to form a circulation loop, and the circulation pump 4 is operated to make the distilled water in the preparation kettle 1 flow in the circulation loop, so that it flows through the second adsorption column 3 and the first adsorption column 2 multiple times and sequentially to flush the activated carbon in the first adsorption column 2.

[0059] like Figure 2 and Figure 3As shown, the first cavity 21 and the second cavity 31 respectively have a columnar main body, which is generally cylindrical, and the activated carbon is located in the columnar main body. The ratio of the diameter of the columnar main body of the second cavity 31 to the diameter of the columnar main body of the first cavity 21 is 1.5~4:1. The volume of the columnar main body of the second cavity 31 should not be less than the volume of the columnar main body of the first cavity 21. Further, a first sintered plate 24 and a first support plate 25 are provided in the first cavity 21, and the first support plate 25 is located below the first sintered plate 24 to form the above-mentioned columnar main body for accommodating the activated carbon therebetween. The first support plate 25 is covered with a filter medium, the first liquid inlet 22 is located above the first sintered plate 24, and the first liquid outlet 23 is located below the first support plate 25. A second sintered plate 34 and a second support plate 35 are provided in the second cavity 31. The second support plate 35 is located below the second sintered plate 34 to form the above-mentioned columnar main body for accommodating activated carbon therebetween. The second support plate 35 is covered with a filter medium, the second liquid inlet 32 ​​is located above the second sintered plate 34, and the second liquid outlet 33 is located below the second support plate. Fabric medium can be selected as the filter medium. Specifically in this embodiment, the first support plate 25 and the second support plate 35 are hollowed out or have channels that allow liquid to pass through, and the filter medium is preferably a filter cloth; the first sintered plate 24 and the second sintered plate 34 are metal sintered plates or ceramic sintered plates.

[0060] The method for preparing an activated carbon-supported metal palladium catalyst using the above-mentioned preparation device generally comprises the following steps:

[0061] Step (1): Filling the adsorption column

[0062] Activated carbon is loaded into the first adsorption column 2 and the second adsorption column 3. The loading process can be wet or dry. The wet loading process is complicated, but the catalyst uniformity is better. The dry loading process is simple and the uniformity is slightly worse. The first adsorption column 2 and the second adsorption column 3 are loaded with the same mass of activated carbon, so that a palladium-carbon catalyst with stable performance can be prepared during continuous production. When the mass of activated carbon loaded in the second adsorption column 3 is less than that in the first adsorption column 2, the activated carbon required to fill the first adsorption column 2 needs to be supplemented when the activated carbon in the second adsorption column 3 is transferred to the first adsorption column 2. A sintered plate is added to the top of the activated carbon in the adsorption column. The sintered plate mainly plays a distribution role and can evenly distribute the liquid on the upper surface of the activated carbon. Fill the adsorption column with activated carbon as much as possible, which is more conducive to the uniform distribution of the liquid material by the sintered plate.

[0063] Step (2), preparing palladium chloride aqueous solution

[0064] The activated carbon-supported metal palladium catalyst is prepared by external circulation, and the mass concentration of the palladium chloride aqueous solution is optimal when it is 0.1-2%. Hydrochloric acid needs to be added when preparing the palladium chloride aqueous solution, and the dissolution of palladium chloride can be accelerated when the pH value is adjusted to 1-3. The mass ratio of the activated carbon loaded in the first adsorption column 2 to the mass ratio of palladium chloride in the palladium chloride aqueous solution is 1-30:1, which can meet the requirements of producing palladium carbon catalysts of all specifications with a metal palladium loading of 0.5-10wt%.

[0065] Step (3), the activated carbon in the first adsorption column 2 cyclically adsorbs palladium chloride

[0066] The palladium chloride aqueous solution is transported into the first adsorption column 2 through the circulation pump 4 for cyclic adsorption. At this time, the palladium chloride aqueous solution cannot enter the second adsorption column 3. The palladium chloride aqueous solution will gradually diffuse into the micropores of the activated carbon until the palladium chloride concentration in the preparation kettle 1 no longer decreases. This process takes about 0.5 to 1.0 hours. The temperature of cyclic adsorption is 20 to 60 ° C. Low temperature is conducive to increasing the saturated adsorption capacity of activated carbon for palladium chloride, but if the temperature is too low, the viscosity of the palladium chloride aqueous solution increases and reduces the adsorption rate. Taking all factors into consideration, it is more appropriate to use an adsorption temperature of 20 to 60 ° C.

[0067] Step (4), reducing the palladium chloride adsorbed on the activated carbon in the first adsorption column 2

[0068] Sodium bicarbonate or sodium carbonate is added to the preparation kettle 1 to adjust the pH value to be close to neutral, and then a calculated amount of sodium formate is added to the preparation kettle 1, and the mass ratio of sodium formate to palladium chloride in step (2) is 1-5:1. The palladium chloride can be completely reduced, and too many ions can be avoided from being introduced into the catalyst, which increases the burden of subsequent washing. The temperature of the reduction reaction is 50-90°C, and the higher the temperature, the higher the catalyst activity. However, if the temperature is too high, the reduction reaction is too intense, and there are certain safety hazards. This process takes about 0.5-1.0 hours. After the reduction reaction is completed, the sodium formate solution in the preparation kettle 1 is discharged.

[0069] Step (5): Elution

[0070] Add distilled water to the preparation kettle 1, and the distilled water in the preparation kettle 1 is transported into the second adsorption column 3 through the circulation pump 4, then through the first adsorption column 2, and finally into the preparation kettle 1 for circulation elution. The elution process increases the flow rate of the circulation pump 4 to 1.5~4:1 of the flow rate during the adsorption process. The ratio of the diameter of the columnar main body of the second adsorption column 3 to the diameter of the columnar main body of the first adsorption column 2 is 1.5~4:1, and the ratio of the linear velocity of the liquid material in the first adsorption column 2 to the linear velocity in the second adsorption column 3 is: 2.25~14.0:1. During the elution process, the liquid in the first adsorption column 2 has a very high speed, so that the metal palladium microcrystals that are not firmly adsorbed on the outer surface and outer pores of the activated carbon can be eluted and enter the preparation kettle 1, and then transported into the second adsorption column 3 through the circulation pump 4. The liquid flow rate in the second adsorption column 3 is much lower than that of the first adsorption column 2, and this part of the eluted metal palladium microcrystals will be adsorbed by the activated carbon in the second adsorption column 3. After a period of elution, all the metal palladium microcrystals that were not firmly adsorbed by the activated carbon in the first adsorption column 2 were eluted and captured by the activated carbon in the second adsorption column 3. The first adsorption column 2 obtained a firmly adsorbed activated carbon-loaded metal palladium catalyst, which is not prone to the problem of metal palladium loss during subsequent use and has a longer life, effectively increasing the number of applications and reducing the cost of using the catalyst. At the same time, after a long period of liquid flushing, the distribution of the activated carbon in the first adsorption column 2 is more uniform, and the experimental results can better represent the performance of the entire batch of catalysts when evaluating the performance of the catalyst.

[0071] Step (6): Washing

[0072] The activated carbon-supported palladium catalyst in the first adsorption column 2 is taken out, and washed with distilled water in a filter cylinder to wash away other ions carried in the catalyst, and finally the activated carbon-supported palladium catalyst is obtained. The activated carbon in the second adsorption column 3 is transferred to the first adsorption column 2 and used as new activated carbon to prepare the next batch of catalysts. The activated carbon in the second adsorption column 3 contains the palladium metal eluted from the activated carbon in the first adsorption column 2. Through this preparation method, the palladium metal microcrystals that were originally lost due to poor adsorption during the use of the catalyst in the later stage are recycled at the source of the catalyst preparation, which reduces the unit consumption of palladium chloride and the use cost of the catalyst.

[0073] The present invention is described in detail below by way of examples, but the present invention is not limited to these examples. Example

[0074] Preparation of palladium chloride aqueous solution:

[0075] Add 1.00 kg of palladium chloride, 500.0 kg of distilled water, and appropriate amount of concentrated hydrochloric acid into a palladium chloride aqueous solution preparation kettle. Cool the kettle jacket with cooling water, control the temperature in the kettle at 20-30°C, and stir to dissolve for 0.5 hours.

[0076] Packing adsorption column:

[0077] The diameter of the first adsorption column is 300 mm, and the diameter of the second adsorption column is 500 mm.

[0078] Add 200 mesh activated carbon (coconut shell carbon): 30.0 kg to the first adsorption column, add 200 mesh activated carbon (coconut shell carbon): 30.0 kg to the second adsorption column,

[0079] Adsorption:

[0080] Start the circulation pump and control the circulation pump flow rate to 600Kg / h. Transport the palladium chloride aqueous solution in the preparation kettle to the first adsorption column through the circulation pump for adsorption (the palladium chloride aqueous solution must not be transported to the second adsorption column at this time), control the temperature in the preparation kettle to 20~30℃ for circulation adsorption, and the circulation adsorption lasts for about 0.5~1.0 hours. After the circulation adsorption is completed, stop the circulation pump.

[0081] Neutralization and reduction:

[0082] After the cyclic adsorption is completed, slowly add sodium carbonate solid to the preparation kettle for neutralization, and the neutralization end point is pH=6~8. After neutralization is completed, slowly add sodium formate: 2.0Kg, stir and dissolve. Pass hot water or steam into the jacket of the preparation kettle for heating, and control the temperature in the preparation kettle at 50~90℃. After dissolution is completed, turn on the circulation pump and control the circulation pump flow rate: about 300Kg / h. The sodium formate solution in the preparation kettle is transported to the first adsorption column for cyclic reduction, and the total reduction time is about 0.5~1.0 hours.

[0083] Elution:

[0084] After the cyclic adsorption is completed, turn off the circulation pump. Release the aqueous solution in the preparation kettle. Add 100Kg of distilled water to the preparation kettle, and pass cooling water into the jacket of the preparation kettle for cooling. Turn on the circulation pump and control the circulation pump flow rate to 300Kg / h. The distilled water in the preparation kettle is transported to the first adsorption column through the circulation pump to wash the inorganic salts. After 10 minutes of cyclic washing, the washing water is released. Add 500Kg of distilled water to the preparation kettle, turn on the circulation pump, and control the circulation pump flow rate to 1500Kg / h. The distilled water in the preparation kettle is transported to the second adsorption column through the circulation pump, then enters the first adsorption column, and finally enters the preparation kettle for cyclic elution. The total cyclic elution time is about 2~6h.

[0085] washing:

[0086] After the cyclic elution is completed, turn off the circulation pump, take out the activated carbon-supported metal palladium catalyst in the first adsorption column, and wash it with distilled water in the filter cylinder. Wash until no chloride ions are detected in the filtrate. Obtained activated carbon-supported metal palladium catalyst: 61.5Kg, water content: 50.4wt%, metal palladium content: 0.82wt%. The amount of activated carbon in the second adsorption column: 60.3Kg, water content: 50.0wt%, metal palladium content: 0.153wt%. The distilled water in the preparation kettle is used in the preparation of the next batch of palladium chloride aqueous solution. Example

[0087] The process equipment and process parameters of Example 2 are basically the same as those of Example 1, except that: the activated carbon in the second adsorption column in Example 1 is put into the first adsorption column, and 30.0 kg of new activated carbon (coconut shell carbon) with a mesh size of 200 is put into the second adsorption column. Finally, an activated carbon-supported metal palladium catalyst is obtained: 60.4 kg, with a water content of 49.3 wt%, and a metal palladium content of 0.99 wt%. The mass of activated carbon in the second adsorption column: 60.0 kg, the water content: 49.8 wt%, and the metal palladium content: 0.146 wt%. The distilled water in the preparation kettle is used in the preparation of the next batch of palladium chloride aqueous solution. Example

[0088] The process equipment and process parameters of Example 3 are basically the same as those of Example 1, except that: the activated carbon in the second adsorption column in Example 2 is put into the first adsorption column, and 30.0 kg of new activated carbon (coconut shell carbon) with a mesh size of 200 is put into the second adsorption column. Finally, the activated carbon-supported metal palladium catalyst is obtained: 59.2 kg, water content: 48.3 wt%, and metal palladium content: 1.01 wt%. The mass of activated carbon in the second adsorption column: 60.5 kg, water content: 50.3 wt%, and metal palladium content: 0.138 wt%. The distilled water in the preparation kettle is used in the preparation of the next batch of palladium chloride aqueous solution. Example

[0089] The process equipment and process parameters of Example 4 are basically the same as those of Example 1, except that: 1. The palladium chloride feed amount is increased from 1.00Kg to 5.00Kg; the sodium formate feed amount is increased from 2.0Kg to 10.0Kg; 3. The activated carbon in the second adsorption column in Example 3 is put into the first adsorption column, and 200 mesh new activated carbon (coconut shell carbon): 30.0Kg is put into the second adsorption column. Finally, the activated carbon-supported metal palladium catalyst is obtained: 61.3Kg, water content: 46.7wt%, metal palladium content: 4.3wt%. The mass of activated carbon in the second adsorption column: 60.1Kg, water content: 49.3wt%, metal palladium content: 0.72wt%. The distilled water in the preparation kettle is used in the preparation of the next batch of palladium chloride aqueous solution. Example

[0090] The process equipment and process parameters of Example 5 are basically the same as those of Example 4, except that: the activated carbon in the second adsorption column in Example 4 is put into the first adsorption column, and 30.0 kg of new activated carbon (coconut shell carbon) with a mesh size of 200 is put into the second adsorption column. The activated carbon-supported metal palladium catalyst is obtained: 59.7 kg, water content: 44.8 wt%, and metal palladium content: 4.9 wt%. The mass of activated carbon in the second adsorption column: 59.6 kg, water content: 48.9 wt%, and metal palladium content: 0.79 wt%. The distilled water in the preparation kettle is used in the preparation of the next batch of palladium chloride aqueous solution. Example

[0091] The process equipment and process parameters of Example 6 are basically the same as those of Example 5, except that the activated carbon in the second adsorption column in Example 5 is put into the first adsorption column, and 30.0 kg of new activated carbon (coconut shell carbon) with a mesh size of 200 is put into the second adsorption column. Finally, an activated carbon-supported metal palladium catalyst is obtained: 59.3 kg, water content: 44.4 wt%, and metal palladium content: 5.01 wt%. The mass of activated carbon in the second adsorption column: 60.2 kg, water content: 49.4 wt%, and metal palladium content: 0.75 wt%. The distilled water in the preparation kettle is used in the preparation of the next batch of palladium chloride aqueous solution.

[0092] During the preparation process, the activated carbon-supported metal palladium catalyst prepared in the above embodiment has washed down the metal that is not firmly adsorbed and easily lost through the distilled water circulation, and is used on the activated carbon in the second adsorption column, so that the catalyst is not prone to the problem of metal palladium loss during subsequent use and has a longer lifespan, effectively increasing the number of applications and reducing the cost of using the catalyst. At the same time, the activated carbon in the first adsorption column is rinsed with liquid for a long time, and the distribution of the activated carbon is more uniform. When the catalyst performance is evaluated, the experimental results can better represent the performance of the entire batch of catalysts. Moreover, the metal palladium microcrystals that were originally lost due to weak adsorption during the use of the catalyst in the later stage are recycled at the source of the catalyst preparation, reducing the unit consumption of palladium chloride and the cost of using the catalyst.

[0093] The above embodiment is only for illustrating the technical concept and features of the present invention, and is a preferred embodiment. Its purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and it cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A preparation device for an activated carbon-supported metal palladium catalyst, characterized in that: include: A preparation kettle, which is used to prepare a palladium chloride aqueous solution, and the preparation kettle has an outlet and an inlet for introducing materials or circulating liquid; A first adsorption column having a first cavity for accommodating activated carbon, wherein the first adsorption column comprises a first liquid inlet connected to an upper portion of the first cavity and a first liquid outlet connected to a lower portion of the first cavity; Wherein, the first liquid inlet is connected to the outlet of the preparation kettle through a first circulation pipeline, and the first liquid outlet is connected to the first liquid outlet pipeline; A second adsorption column having a second cavity for accommodating activated carbon, the second adsorption column comprising a second liquid inlet connected to an upper portion of the second cavity and a second liquid outlet connected to a lower portion of the second cavity; The second liquid inlet is connected to the outlet of the preparation kettle through a second circulation pipeline, and the second liquid outlet is connected to the first liquid inlet of the first adsorption column through a second liquid outlet pipeline; The inlet of the preparation kettle includes a circulating liquid inlet, and the first liquid outlet pipeline is connected to the circulating liquid inlet; The preparation device has an adsorption and reduction working state and a washing working state. In the adsorption and reduction working state, the outlet is connected to the first liquid inlet, the outlet is disconnected from the second liquid inlet, and the first liquid outlet is connected to the circulating liquid inlet; in the washing working state, the outlet is connected to the second liquid inlet, the outlet is disconnected from the first liquid inlet, the second liquid outlet is connected to the first liquid inlet, and the first liquid outlet is connected to the circulating liquid inlet; A first sintered plate and a first support plate are provided in the first cavity, the first support plate is located below the first sintered plate to form a columnar main body for accommodating activated carbon therebetween, the first support plate is covered with a filter medium, the first liquid inlet is located above the first sintered plate, and the first liquid outlet is located below the first support plate; and / or, a second sintered plate and a second support plate are provided in the second cavity, the second support plate is located below the second sintered plate to form a columnar main body for accommodating activated carbon therebetween, the second support plate is covered with a filter medium, the second liquid inlet is located above the second sintered plate, and the second liquid outlet is located below the second support plate; The inlet of the preparation kettle includes a feeding port for feeding a reducing agent and / or a distilled water inlet for introducing distilled water; the preparation kettle has a jacket, a refrigerant inlet for introducing a cooling medium into the jacket, and a heat medium inlet for introducing a heating medium into the jacket.

2. The preparation device according to claim 1, characterized in that: The first circulation pipeline and / or the second circulation pipeline is provided with a circulation pump for delivering the material in the preparation kettle to the first adsorption column or the second adsorption column and circulating it multiple times; the first circulation pipeline, the first liquid outlet pipeline, the second circulation pipeline and the second liquid outlet pipeline are respectively provided with control valves for controlling the on-off of the pipeline.

3. The preparation device according to claim 1, characterized in that: The first cavity and the second cavity respectively have a columnar main body, the activated carbon is located in the columnar main body, and the ratio of the diameter of the columnar main body of the second cavity to the diameter of the columnar main body of the first cavity is 1.5~4:

1.

4. A method for preparing an activated carbon-supported metal palladium catalyst, characterized in that: Using the preparation device according to any one of claims 1 to 3, the preparation method comprises the following steps: (1) Filling the first adsorption column with activated carbon; (2) preparing or introducing a palladium chloride aqueous solution into a preparation kettle; (3) The palladium chloride aqueous solution in the preparation kettle is sent to the first liquid inlet of the first adsorption column through the first circulation pipeline by a circulation pump, and the palladium chloride aqueous solution passes through the first adsorption column, passes through the first liquid outlet, and then returns to the preparation kettle through the first liquid outlet pipeline; repeating multiple times until the set circulation adsorption time is reached; (4) adding a reducing agent to the preparation kettle, and passing the reducing agent in the preparation kettle into the first adsorption column through a circulation pump for reduction; (5) adding distilled water to the preparation kettle, and sending the distilled water in the preparation kettle to the first liquid inlet of the first adsorption column through a circulation pump; the distilled water passes through the first adsorption column, passes through the first liquid outlet, and then returns to the preparation kettle through the first liquid outlet pipeline; Repeat several times until the set cycle elution time is reached; (6) taking out the activated carbon in the first adsorption column and washing it with distilled water to obtain an activated carbon-supported palladium catalyst; In step (1), activated carbon is also loaded into the second adsorption column; in step (3), the palladium chloride aqueous solution is only fed into the first adsorption column without passing through the second adsorption column; in step (5), a circulating pump feeds the distilled water in the preparation kettle into the second adsorption column, and the water flowing through the second adsorption column enters the first adsorption column to elute the activated carbon therein, and then enters the preparation kettle; Repeat several times to make the distilled water circulate through the first adsorption column and the second adsorption column; In step (1), the activated carbon in the first adsorption column comes from the activated carbon in the second adsorption column treated in step (5) in the previous preparation process.

5. The preparation method according to claim 4, characterized in that: In step (4), alkali is added to the preparation kettle to adjust the pH value, and then sodium formate is added as a reducing agent, so that the sodium formate solution is circulated through the first adsorption column for multiple times. After the reduction is completed, the sodium formate solution in the preparation kettle is discharged.

6. The preparation method according to claim 4, characterized in that: In step (2), the mass concentration of the palladium chloride aqueous solution is 0.1-2%; and the ratio of the mass of activated carbon in the first adsorption column to the mass of palladium chloride in the palladium chloride aqueous solution is 1-30:

1.

7. The preparation method according to claim 4, characterized in that: In step (3), the temperature of the cyclic adsorption is 20~60℃.

8. The preparation method according to claim 4, characterized in that: In step (4), the temperature of the reduction reaction is 50-90° C.; the mass ratio of the reducing agent to the palladium chloride in the palladium chloride aqueous solution in step (1) is 1-5:

1.

9. The preparation method according to claim 4, characterized in that: The ratio of the flow rate of the circulating pump in step (5) to the flow rate of the circulating pump in step (3) is 1.5-4:1.

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