Preparation equipment of activated carbon loaded metal palladium catalyst

Abstract

The utility model relates to preparation equipment of an activated carbon loaded metal palladium catalyst, which comprises an activated carbon adsorption device, a metal palladium adsorption device, a metal palladium adsorption device, a metal palladium adsorption device, a metal palladium adsorption device, a metal palladium adsorption device and a metal palladium adsorption device, and is characterized in that the activated carbon adsorption device is used for adsorbing, reducing and washing activated carbon; the activated carbon adsorption device is provided with a liquid inlet communicated with the top of the cavity, a liquid outlet communicated with the bottom of the cavity, and an extraction opening communicated with the cavity; the preparation kettle is used for preparing or storing a palladium chloride aqueous solution, a reducing agent aqueous solution and a washing agent, the preparation kettle is provided with a liquid return port and a liquid outlet, and the liquid outlet is communicated with the liquid inlet. According to the utility model, air in the activated carbon micro-channels is extracted as far as possible during cyclic adsorption, so that a palladium chloride aqueous solution can be conveniently replaced and enter the activated carbon micro-channels, metal palladium is loaded into the activated carbon micro-channels, the loss of the metal palladium is reduced, and the service life of a catalyst is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model belongs to fine chemical technology field, concretely relates to a kind of preparation equipment of active carbon supported metal palladium catalyst. BACKGROUND

[0002] The preparation method of prior art for preparing active carbon supported metal palladium catalyst is as follows: first, adsorbing palladium chloride in palladium chloride aqueous solution with active carbon in reaction kettle; then, adding reducing agent to reduce palladium chloride adsorbed on active carbon into metal palladium; finally, washing inorganic salt in active carbon to obtain active carbon supported metal palladium catalyst. The preparation method mainly has the following problems:

[0003] 1, metal palladium mainly adheres to the outer surface and macropore of active carbon, and the loading of metal palladium in catalyst will decrease rapidly during use;

[0004] 2, the uniformity of catalyst is poor. INVENTION CONTENTS

[0005] The utility model aims at providing a kind of preparation equipment of active carbon supported metal palladium catalyst, especially a kind of preparation equipment of active carbon supported metal palladium catalyst with good uniformity and metal palladium not easy to lose.

[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the utility model is as follows:

[0007] A kind of preparation equipment of active carbon supported metal palladium catalyst, comprising:

[0008] Active carbon adsorption device: it is used to carry out adsorption, reduction and washing of active carbon, the active carbon adsorption device has a cavity for accommodating active carbon, the active carbon adsorption device is provided with a liquid inlet communicated with the top of the cavity, a liquid outlet communicated with the bottom of the cavity and a gas outlet communicated with the cavity;

[0009] Preparation kettle: it is used to prepare or store palladium chloride aqueous solution, reducing agent aqueous solution and detergent, the preparation kettle has a liquid return port and a liquid outlet, and the liquid outlet is communicated with the liquid inlet.

[0010] The above technical scheme is preferably, the active carbon adsorption device includes a cylinder body and a first hole plate, the cavity is formed in the inside of the cylinder body, the liquid inlet and the liquid outlet are respectively arranged at the upper and lower ends of the cylinder body, the first hole plate is arranged in the cavity and located between the liquid inlet and the liquid outlet to support active carbon, and the gas outlet is arranged on the cylinder body below the first hole plate.

[0011] Further preferably, the activated carbon adsorption device further comprises a second perforated plate, which is arranged in the chamber and above the first perforated plate.

[0012] Still further preferably, the cylinder comprises an upper head, a first cylinder segment, a second cylinder segment, and a lower head, the upper head and the first cylinder segment are detachably connected, the first cylinder segment and the second cylinder segment are detachably connected, the first perforated plate is arranged between the first cylinder segment and the second cylinder segment, and the second perforated plate is arranged between the upper head and the first cylinder segment.

[0013] Still further preferably, the liquid inlet is arranged on the upper head, the liquid outlet is arranged on the lower head, and the gas outlet is arranged on the second cylinder segment.

[0014] Still further preferably, the bottom of the upper head is provided with a flange, the top of the first cylinder segment is provided with a flange, and the flanges are provided with through holes, and the upper head and the first cylinder segment are connected through the flanges.

[0015] The bottom of the first cylinder segment is provided with a flange, the top of the second cylinder segment is provided with a flange, and the flanges are provided with through holes, and the first cylinder segment and the second cylinder segment are connected through the flanges.

[0016] Still further preferably, the first perforated plate and / or the second perforated plate are ceramic sintered plates or metal sintered plates.

[0017] Preferably, the liquid outlet and the liquid return port are in communication.

[0018] Further preferably, a circulating pump is arranged on the communication pipeline between the liquid outlet and the liquid inlet and / or the communication pipeline between the liquid outlet and the liquid return port.

[0019] Further preferably, a control valve is arranged on the communication pipeline between the liquid outlet and the liquid inlet and / or the communication pipeline between the liquid outlet and the liquid return port.

[0020] In the preparation process of activated carbon supported metal palladium catalyst, it is found that when metal palladium crystallites mainly adhere to the micropore channels of activated carbon, the loss of metal palladium is the least during the repeated use of the catalyst, and on the contrary, when the metal palladium crystallites mainly adhere to the outer surface of activated carbon or the inner surface of macropore channels, the loss of metal palladium is more during the repeated use of the catalyst, resulting in the increase of the use cost of the catalyst. In order to improve the service life of the activated carbon supported metal palladium catalyst, it is necessary to make the metal palladium crystallites be adsorbed by the micropore channels of activated carbon as much as possible, and when the preparation process of the activated carbon supported metal palladium catalyst is combined, it is necessary for the aqueous solution of palladium chloride to enter the micropore channels of activated carbon as much as possible and be reduced to palladium crystallites by a reducing agent during the reduction process. Thus, the problem of how to make the aqueous solution of palladium chloride enter the micropore channels of activated carbon arises. The commercial activated carbon is usually used as the raw material for preparing the activated carbon supported metal palladium catalyst. The commercial activated carbon has a low water content, a small weight loss, and the micropore channels are completely filled with air. In order to make the aqueous solution of palladium chloride enter the micropore channels of activated carbon, the air in the micropore channels must be replaced, but no matter air or the aqueous solution of palladium chloride, when the size is extremely small, the surface tension increases, and the difficulty of replacing the air in the micropore channels by the aqueous solution of palladium chloride increases.

[0021] In order to solve the problem, first, during the adsorption of the aqueous solution of palladium chloride by activated carbon, the pressure is reduced, and it is hoped that the air in the micropore channels of activated carbon can be taken out from the micropore channels by negative pressure, so that the aqueous solution of palladium chloride can enter the micropore channels of activated carbon, but the final effect is not ideal, and the prepared catalyst is still prone to the problem of loss of metal palladium. The reason is that when the adsorption is carried out in the reaction kettle, the surface of activated carbon also bears the static pressure of the aqueous solution of palladium chloride, and this part of static pressure affects the escape of air from the micropore channels. Therefore, the present application adopts the adsorption in the activated carbon adsorption device and the preparation process of the catalyst. When the adsorption is carried out in the activated carbon adsorption column device, the air in the micropore channels of the catalyst no longer bears the static pressure of the liquid, and it is easier to escape from the micropore channels, so that the aqueous solution of palladium chloride is easier to enter the micropore channels of activated carbon, and the metal palladium crystallites formed after reduction are also not easy to lose.

[0022] Thanks to the use of the above technical solution, the present application has the following advantages compared with the prior art:

[0023] The present application can remove the air in the micropore channels of activated carbon as much as possible during the circulation adsorption, so that the aqueous solution of palladium chloride can be replaced and enter the micropore channels of activated carbon, and the metal palladium can be loaded into the micropore channels of activated carbon, thereby reducing the loss of metal palladium and improving the service life of the catalyst. The prepared activated carbon supported metal palladium catalyst is not easy to lose metal palladium, the catalyst has a long service life, and has good uniformity. BRIEF DESCRIPTION OF DRAWINGS

[0024] ATTACHED Figure 1 It is a schematic view of the activated carbon supported metal palladium catalyst preparation equipment in the present embodiment.

[0025] In the attached diagrams above:

[0026] 1. Configuration kettle; 10. Liquid return port; 11. Liquid outlet;

[0027] 2. Activated carbon adsorption device; 200. Liquid inlet; 201. Liquid outlet; 202. Gas extraction port; 210. Upper end cap; 211. First section; 212. Second section; 213. Lower end cap; 22. First perforated plate; 23. Second perforated plate;

[0028] 3. Circulating pump;

[0029] 4. Sodium carbonate aqueous solution metering tank;

[0030] 5. Sodium formate aqueous solution metering tank. Detailed Implementation

[0031] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0032] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] like Figure 1 The apparatus shown is for preparing an activated carbon-supported palladium catalyst. The apparatus mainly includes a preparation vessel 1 and an activated carbon adsorption device 2. Wherein:

[0034] The preparation vessel 1 is used to prepare or store palladium chloride aqueous solution, reducing agent aqueous solution, and detergent. The preparation vessel 1 has a return port 10 and an outlet port 11. A separate preparation vessel 1 can be set up for each of the palladium chloride aqueous solution, reducing agent aqueous solution, and detergent. In this embodiment, only one preparation vessel 1 is set up, and the palladium chloride aqueous solution, reducing agent aqueous solution, and detergent are all prepared and used in one preparation vessel 1.

[0035] The activated carbon adsorption device 2 is used for adsorption, reduction and washing of activated carbon. The activated carbon adsorption device 2 has a chamber for accommodating activated carbon, and is provided with a liquid inlet 200 communicated with the top of the chamber, a liquid outlet 201 communicated with the bottom of the chamber, and a gas outlet 202 communicated with the chamber. The liquid outlet 11 of the preparation kettle 1 is communicated with the liquid inlet 200 of the activated carbon adsorption device 2, and the aqueous palladium chloride solution, the aqueous reducing agent and the washing agent are transported into the chamber of the activated carbon adsorption device 2. In the embodiment, the liquid outlet 201 of the activated carbon adsorption device 2 is communicated with the liquid return port 10 of the preparation kettle 1, and a circulating pump 3 is arranged on the connecting pipeline between the liquid outlet 11 and the liquid inlet 200 and / or the connecting pipeline between the liquid outlet 201 and the liquid return port 10. In the figure, the circulating pump 3 is arranged on the connecting pipeline between the liquid outlet 11 and the liquid inlet 200.

[0036] In addition, a control valve for controlling the opening and closing of the connecting pipeline is arranged on the connecting pipeline between the liquid outlet 11 and the liquid inlet 200 and the connecting pipeline between the liquid outlet 201 and the liquid return port 10, so as to facilitate the control of the opening and closing of the liquid in the circulating pipeline or the further control of the flow of the liquid. The control valve also has a certain adjusting function, and can adjust the flow according to different parameters such as the load of metal palladium, the particle size of activated carbon and the concentration of aqueous palladium chloride, so as to achieve the best preparation effect.

[0037] In one embodiment of the embodiment, the activated carbon adsorption device 2 includes a cylinder, a first hole plate 22 and a second hole plate 23. The cylinder forms a chamber inside, and the upper and lower ends of the cylinder are respectively provided with a liquid inlet 200 and a liquid outlet 201. The first hole plate 22 and the second hole plate 23 are arranged in the chamber and located between the liquid inlet 200 and the liquid outlet 201. The second hole plate 23 is located above the first hole plate 22, and the gas outlet 202 is arranged on the cylinder below the first hole plate 22.

[0038] The cylinder includes an upper head 210, a first cylinder segment 211, a second cylinder segment 212 and a lower head 213.

[0039] In view of the fact that the activated carbon adsorption device 2 needs to withstand pressure, the upper head 210 and the lower head 213 preferably adopt a spherical head and an elliptical head, both of which have relatively strong pressure resistance and can withstand the output pressure head of the circulating pump 3, but cannot adopt a conical head, a flat bottom head or a butterfly head, all of which have poor pressure resistance and cannot withstand the output pressure head of the circulating pump 3. The liquid inlet 200 is arranged at the top center of the upper head 210, which facilitates uniform distribution of the liquid to the activated carbon layer and reduces the adverse effects of wall effects; the liquid outlet 201 is arranged at the bottom center of the lower head 213, which facilitates clean discharge of the liquid in the activated carbon adsorption device 2; and the gas suction port 202 is arranged at the upper part of the second cylinder segment 212 and leaves a gas-liquid separation zone at the bottom of the second cylinder segment 212, so that the liquid is not sucked away during gas suction, and the gas suction port 202 is as close as possible to the first perforated plate 22, which can reduce the pressure loss of the liquid flow and reduce the resistance of gas suction.

[0040] In order to make the activated carbon adsorption device 2 have the greatest flexibility, the upper head 210 and the first cylinder segment 211 are detachably connected, the first cylinder segment 211 and the second cylinder segment 212 are detachably connected, the first perforated plate 22 is arranged between the first cylinder segment 211 and the second cylinder segment 212, and the second perforated plate 23 is arranged between the upper head 210 and the first cylinder segment 211. The loading of activated carbon is very critical and cannot have air holes, short circuits and the like. The detachable connection of the upper head 210 and the first cylinder segment 211 and the detachable connection of the first cylinder segment 211 and the second cylinder segment 212 can meet the requirement of uniform loading of activated carbon in the activated carbon adsorption device 2. In actual loading, the dry method is adopted to slowly load the activated carbon layer by layer on the first perforated plate 22, the loading amount can be slightly more than the upper surface of the first cylinder segment 211, and then the second perforated plate 23 is pressed on the activated carbon layer to more fully play the distribution role of the second perforated plate 23.

[0041] In the embodiment, the bottom of the upper head 210 is provided with a flange, the flange is provided with a through hole, the top of the first cylinder segment 211 is provided with a flange, the flange is provided with a through hole, and the upper head 210 and the first cylinder segment 211 are connected by bolts; the bottom of the first cylinder segment 211 is provided with a flange, the flange is provided with a through hole, the top of the second cylinder segment 212 is provided with a flange, the flange is provided with a through hole, and the first cylinder segment 211 and the second cylinder segment 212 are connected by bolts. Although the bolt connection is not convenient to disassemble and assemble, it can meet the requirement of pressure resistance. If a catalyst prepared by using relatively large particle size activated carbon, the resistance of the liquid flowing between the activated carbon gaps is small, quick release connection or reaction kettle clamp connection can also be adopted to improve the convenience of disassembly and assembly under the premise of meeting the requirement of pressure resistance.

[0042] The first perforated plate 22 constitutes a support structure of activated carbon, and the activated carbon is placed on the first perforated plate 22. The tiny holes on the first perforated plate 22 block the activated carbon from leaking out of the small holes, but have no effect on the smooth passage of the liquid.

[0043] The liquid inlet 200 is arranged at the top center of the upper head 210. Although it can promote the uniform distribution of liquid in the activated carbon layer, it can form an impact cavity in the center of the activated carbon layer, which is more obvious when the liquid flow is large. In order to make the liquid more evenly distributed in the activated carbon layer and achieve the best negative pressure adsorption effect, the second perforated plate 23 is arranged. The second perforated plate 23 can play three roles: first, avoid the formation of a cavity on the surface of the activated carbon layer; second, evenly distribute the liquid to the surface of the activated carbon layer; third, it can apply a pre-tightening force to the activated carbon layer, reduce the air holes inside the activated carbon layer, avoid non-uniform flow states such as short circuit, and make the liquid flow more evenly inside the activated carbon layer. The most important result is that the liquid can be evenly distributed in the activated carbon layer, so that the activated carbon in each area can evenly contact the liquid, and a good activated carbon supported metal palladium catalyst can be prepared.

[0044] The first perforated plate 22 and the second perforated plate 23 are ceramic sintered plates or metal sintered plates. These two kinds of perforated plates have the advantages of being solid and durable, and the pore channels are uniform. However, when selecting, the average pore diameter must be smaller than the average particle size of the activated carbon.

[0045] The following specific examples of activated carbon supported metal palladium catalysts prepared by the above device are given:

[0046] Activated carbon adsorption column device parameters:

[0047] The diameter of the first cylinder segment is 0.45m;

[0048] The height of the first cylinder segment is 0.25m;

[0049] The material of the first perforated plate is a metal sintered plate;

[0050] The material of the second perforated plate is a ceramic sintered plate.

[0051] The following specific embodiments of the preparation of the activated carbon supported metal palladium catalyst of the present embodiment are described in detail. The main steps include:

[0052] (1) Negative pressure circulation adsorption: loading activated carbon in activated carbon adsorption device, circulating to activated carbon adsorption device to pass in aqueous solution of palladium chloride, making aqueous solution of palladium chloride flow through activated carbon, wherein: mixing palladium chloride, deionized water and hydrochloric acid, stirring to dissolve, obtaining aqueous solution of palladium chloride, so that the mass concentration of aqueous solution of palladium chloride is 0.05-1.0%, the temperature of aqueous solution of palladium chloride (negative pressure circulation adsorption temperature) is controlled at 5-25℃, the ratio of activated carbon mass to palladium chloride mass in aqueous solution of palladium chloride is 8-160:1; at the same time, keeping the activated carbon adsorption device to be pumped, the vacuum degree of activated carbon adsorption device is controlled at-0.085MPa--0.090MPa, the flow of aqueous solution of palladium chloride is 1.2-1.5m 3 / h, the circulation adsorption time is 1.0-1.5 / h.

[0053] When configuring aqueous solution of palladium chloride, the mass concentration of aqueous solution of palladium chloride is 0.05-1.0%, which maximizes the adsorption effect of activated carbon. The activated carbon supported palladium catalyst belongs to noble metal catalyst, and the loading amount is generally not more than 5%. If high concentration aqueous solution of palladium chloride is used for adsorption, the total amount of aqueous solution of palladium chloride needs to be reduced, which is easy to cause the problem that activated carbon cannot be infiltrated by aqueous solution of palladium chloride, resulting in uneven adsorption. The concentration of aqueous solution of palladium chloride is preferably not more than 1%. At the same time, the concentration of aqueous solution of palladium chloride cannot be too dilute, because adsorption and desorption belong to a dynamic equilibrium process. The more dilute the concentration of aqueous solution of palladium chloride is, the more conducive to the desorption process, but the less conducive to the adsorption. Further preferably, the mass concentration of aqueous solution of palladium chloride is 0.05-0.4%, and more preferably, the mass concentration of aqueous solution of palladium chloride is 0.05-0.09%.

[0054] In the adsorption process: using lower adsorption temperature is also a key factor to improve the effect of adsorption. The lower the adsorption temperature is, the stronger the adsorption capacity of activated carbon to palladium chloride in aqueous solution of palladium chloride is. The lower the adsorption temperature is, the smaller the gas viscosity in the micropore channel of activated carbon is, which is more easily pumped away by vacuum. Although the low temperature and high viscosity of aqueous solution of palladium chloride are not conducive to the diffusion to the micropore channel of activated carbon, the circulation flow rate of aqueous solution of palladium chloride can be increased in the adsorption process in activated carbon adsorption device, the relative speed of aqueous solution of palladium chloride on the surface of activated carbon is increased, the turbulent effect is improved, and the diffusion of aqueous solution of palladium chloride to the micropore channel of activated carbon is promoted. At the same time, the low adsorption temperature can also reduce the saturated vapor pressure of water, avoiding the adverse effect of water vaporization on adsorption under negative pressure condition. Further preferably, the temperature of aqueous solution of palladium chloride is controlled at 5-17℃, and more preferably, the temperature of aqueous solution of palladium chloride is controlled at 5-7℃.

[0055] The mass concentration of the aqueous solution of palladium chloride determines the effect of the activated carbon adsorption. In the preparation of the catalyst, the operation is also carried out under the saturated adsorption capacity of the activated carbon. When the total amount of the palladium chloride in the aqueous solution of palladium chloride exceeds the saturated adsorption capacity of the activated carbon, a large amount of palladium chloride microcrystals will be attached to the outer surface and large pores of the catalyst, which will eventually cause the loss of a large amount of metal palladium and the short service life of the catalyst. The adsorption under the above ratio will not cause the loss of a large amount of metal palladium. Further preferably, the ratio of the mass of the activated carbon to the mass of the palladium chloride in the aqueous solution of palladium chloride is 20-160:1, and more preferably, the ratio of the mass of the activated carbon to the mass of the palladium chloride in the aqueous solution of palladium chloride is 40-160:1.

[0056] (2) Neutralization: after the negative pressure circulation adsorption is completed, the temperature of the aqueous solution of palladium chloride is controlled at 15±2℃, the vacuum degree of the activated carbon adsorption device is controlled at -0.085 to -0.090 MPa, and a neutralizing agent aqueous solution is slowly added to the aqueous solution of palladium chloride, the pH of the solution is controlled at 6-8, the neutralizing agent of the neutralizing agent aqueous solution is sodium carbonate or sodium bicarbonate, and the circulation neutralization time is 30 min.

[0057] After the adsorption is completed, the neutralizing agent aqueous solution is added to the aqueous solution of palladium chloride, the pH value of the solution is adjusted to 6-8, after the circulation adsorption is completed, the aqueous solution of palladium chloride can be discharged, the alkaline aqueous solution can be prepared again, or the neutralizing agent aqueous solution can be directly supplemented to the aqueous solution of palladium chloride to adjust the pH value, which has the advantages of convenient operation, less wastewater and reduced preparation period of the catalyst. The neutralizing agent in the neutralizing agent aqueous solution is selected from sodium carbonate or sodium bicarbonate.

[0058] (3) Reduction: the reducing agent aqueous solution is circulated to the activated carbon adsorption device, so that the reducing agent aqueous solution continuously flows through the activated carbon, wherein: the mass ratio of the reducing agent in the reducing agent aqueous solution to the palladium chloride in the aqueous solution of palladium chloride is 1-5:1, the temperature (reduction temperature) of the reducing agent aqueous solution is controlled at 50-90℃, the reducing agent in the reducing agent aqueous solution is sodium formate; at the same time, the activated carbon adsorption device is kept to be pumped, the vacuum degree of the activated carbon adsorption device is controlled at -0.02 to -0.03 MPa, and the circulation reduction time is 30 min.

[0059] The mass ratio of the reducing agent in the reducing agent aqueous solution to the palladium chloride in the aqueous solution of palladium chloride is preferably 1-2:1. The reducing agent in the reducing agent aqueous solution is sodium formate.

[0060] In the reduction process: the reduction reaction belongs to exothermic reaction, the reaction speed needs to be properly controlled to avoid temperature rising, the preparation process of catalyst in the activated carbon adsorption device, the temperature in the activated carbon adsorption device can be controlled by the flow of circulating pump, in the reaction kettle, the activated carbon rotates with the liquid around the stirring shaft, although the absolute speed of activated carbon is very large, but the relative speed of activated carbon to liquid is very small, the problem of internal temperature rising of activated carbon particles is easy to appear, and in the activated carbon adsorption device, the relative speed of liquid and activated carbon is large, the reaction heat of activated carbon particle surface and internal pore is more easily taken away by liquid, and the problem of temperature rising does not appear. Further preferably, the temperature of the aqueous solution of reducing agent is controlled at 60±5℃.

[0061] (4), washing: circulating to the activated carbon adsorption device to pass the washing agent, so that the washing agent flows through the activated carbon continuously, until the set washing time is reached, the activated carbon is taken out, and the activated carbon supported palladium catalyst is obtained.

[0062] The above is the case that the aqueous solution of palladium chloride and the aqueous solution of reducing agent are configured in the same configuration kettle and circulated with the activated carbon adsorption device; for the case that after the negative pressure circulation adsorption is completed, the aqueous solution of palladium chloride in the configuration kettle is completely discharged, the aqueous solution of reducing agent is recharged in the configuration kettle and circulated with the activated carbon adsorption device, or the aqueous solution of palladium chloride and the aqueous solution of reducing agent are configured in separate configuration kettles and circulated with the activated carbon adsorption device, the neutralization step can be omitted.

[0063] Example 1

[0064] Loading activated carbon adsorption device:

[0065] Slowly load coconut shell carbon into the activated carbon adsorption device layer by layer: 20Kg (200 mesh), ensure uniform paving during loading process, the last activated carbon layer is slightly higher than the top surface of the first cylinder segment, place the second perforated plate on the activated carbon layer, press the upper head on the second perforated plate, and tighten the bolts between the flange through hole of the upper head and the flange through hole of the first cylinder.

[0066] Negative pressure circulation adsorption:

[0067] Put deionized water: 250Kg, hydrochloric acid: 1.00Kg (content: 36.5%), and palladium chloride: 1.000Kg (content: 99.695%) into the configuration kettle, dissolve under stirring, open the low temperature water inlet valve of the configuration kettle jacket, control the temperature of the aqueous solution of palladium chloride in the configuration kettle at 15℃, open the vacuum valve on the air outlet of the activated carbon adsorption device, control the vacuum degree of the configuration kettle and the activated carbon adsorption device at-0.085MPa, and keep the pressure for 30 minutes. Open the circulating pump and control the circulating pump flow: 1.2m 3 / h circulation adsorption, the circulation adsorption time is about 1.0 / h.

[0068] Neutralization:

[0069] The sodium carbonate aqueous solution (sodium carbonate mass concentration: 8%) was added to the sodium carbonate aqueous solution metering tank in advance, and the vacuum cycle adsorption was completed. The temperature of the prepared aqueous solution of palladium chloride in the preparation kettle was controlled at 15°C, and the vacuum degree of the preparation kettle and the activated carbon adsorption device was controlled at -0.085 MPa. The sodium carbonate aqueous solution was slowly added to the preparation kettle, and the final pH of the preparation kettle was controlled at 7.0. After the sodium carbonate aqueous solution was added dropwise, the neutralization was cycled for 30 minutes.

[0070] Reduction:

[0071] The prepared sodium formate aqueous solution (sodium formate: 2.0 Kg, deionized water: 20 Kg) was added to the sodium formate aqueous solution metering tank in advance. After the cycle neutralization was completed, the preparation kettle jacket hot water inlet valve was opened, the temperature of the neutralization liquid in the preparation kettle was controlled at 60°C, and the vacuum degree of the preparation kettle and the activated carbon adsorption device was controlled at -0.03 MPa. The sodium formate aqueous solution was slowly added to the preparation kettle, and the dropwise addition time was controlled to be ≥1.5 h. After the sodium formate aqueous solution was added dropwise, the reduction was cycled for 30 minutes.

[0072] Washing:

[0073] The circulating pump was closed, and the residual sodium formate aqueous solution in the activated carbon adsorption device was blown dry with air. The sodium formate aqueous solution in the preparation kettle was discharged, and deionized water: 200 kg was added to the preparation kettle. The circulating pump was opened and cycled for 10 minutes for washing. After washing was completed, the circulating pump was closed, and the residual washing water in the activated carbon adsorption device was blown dry with air. The washing water in the preparation kettle was discharged. Deionized water: 200 Kg was added to the preparation kettle again, and the preparation kettle was washed four times according to the method described above, for a total of five times.

[0074] Discharge:

[0075] After washing was completed, the activated carbon in the activated carbon adsorption device was taken out, and the activated carbon supported metal palladium catalyst: 40.156 Kg (water content: 48.7%, wet product metal palladium content: 1.494%) was obtained.

[0076] Evaluation:

[0077] A three-necked flask with a thermometer and a reflux condenser was charged with wet product catalyst: 20 g and methanol: 150 ml. The outer wall of the three-necked flask was heated with hot water, and stirring was started with a stirring speed of 500 r / min. Reflux stirring was carried out for 30 minutes, and then the catalyst was filtered while hot. The filtered catalyst was again charged into the three-necked flask, and methanol: 150 ml was added. Reflux stirring was carried out for 30 minutes, and this process was repeated four more times, for a total of five times. The final catalyst was dried and detected for metal palladium content: 2.837%, and the metal palladium loss rate was 2.61%.

[0078] Example 2

[0079] The process equipment and process parameters of Example 2 are basically the same as those of Example 1, except that hydrochloric acid: 0.125 Kg (content: 36.5%) and palladium chloride: 0.125 Kg (content: 99.695%) are put into the circulating kettle during the adsorption process, and sodium formate aqueous solution (sodium formate: 0.260 Kg, deionized water: 2.6 Kg) is put into the sodium formate aqueous solution metering tank in advance for reduction during the reduction process.

[0080] Finally, after washing is completed, the activated carbon in the activated carbon adsorption column is taken out, and an activated carbon loaded metal palladium catalyst is obtained: 43.265 Kg (water content: 53.6%, wet product metal palladium content: 0.173%).

[0081] Evaluation is carried out in the same way as in Example 1, and finally the metal palladium content of the obtained catalyst after drying is detected: 0.365%, and the metal palladium loss rate is: 2.14%.

[0082] Example 3

[0083] The process equipment and process parameters of Example 3 are basically the same as those of Example 1, except that hydrochloric acid: 2.50 Kg (content: 36.5%) and palladium chloride: 2.500 Kg (content: 99.695%) are put into the circulating kettle during the adsorption process, and sodium formate aqueous solution (sodium formate: 5.0 Kg, deionized water: 50 Kg) is put into the sodium formate aqueous solution metering tank in advance for reduction during the reduction process.

[0084] Finally, after washing is completed, the activated carbon in the activated carbon adsorption column is taken out, and an activated carbon loaded metal palladium catalyst is obtained: 44.514 Kg (water content: 51.7%, wet product metal palladium content: 3.370%).

[0085] Evaluation is carried out in the same way as in Example 1, and finally the metal palladium content of the obtained catalyst after drying is detected: 6.661%, and the metal palladium loss rate is: 4.53%.

[0086] Example 4

[0087] The process equipment and process parameters of Example 4 are basically the same as those of Example 1, except that the temperature of the aqueous solution in the circulating kettle is controlled at 5°C during the adsorption and neutralization processes.

[0088] Finally, after washing is completed, the activated carbon in the activated carbon adsorption column is taken out, and an activated carbon loaded metal palladium catalyst is obtained: 40.472 Kg (water content: 49.1%, wet product metal palladium content: 1.483%).

[0089] The final catalyst was dried and the metal palladium content was measured: 2.782%, the metal palladium loss rate: 4.43%.

[0090] Example 5

[0091] The process equipment and process parameters of Example 5 were basically the same as those of Example 1, except that the temperature of the aqueous solution in the circulating kettle was controlled at 25°C during the adsorption and neutralization process.

[0092] Finally, after washing, the activated carbon in the activated carbon adsorption column was taken out, and an activated carbon supported metal palladium catalyst was obtained: 40.156 Kg (moisture content: 48.7%, wet product metal palladium content: 1.494%).

[0093] The final catalyst was dried and the metal palladium content was measured: 2.782%, the metal palladium loss rate: 4.43%.

[0094] Example 6

[0095] The process equipment and process parameters of Example 6 were basically the same as those of Example 1, except that sodium formate aqueous solution (sodium formate: 1.0 Kg, deionized water: 10 Kg) was pre- fed into the sodium formate aqueous solution metering tank for reduction during the reduction process.

[0096] Finally, after washing, the activated carbon in the activated carbon adsorption column was taken out, and an activated carbon supported metal palladium catalyst was obtained: 41.036 Kg (moisture content: 49.8%, wet product metal palladium content: 1.462%).

[0097] The final catalyst was dried and the metal palladium content was measured: 2.782%, the metal palladium loss rate: 4.43%.

[0098] Example 7

[0099] The process equipment and process parameters of Example 7 were basically the same as those of Example 1, except that sodium formate aqueous solution (sodium formate: 5.0 Kg, deionized water: 50 Kg) was pre- fed into the sodium formate aqueous solution metering tank for reduction during the reduction process.

[0100] Finally, after washing, the activated carbon in the activated carbon adsorption column was taken out, and an activated carbon supported metal palladium catalyst was obtained: 42.474 Kg (moisture content: 51.5%, wet product metal palladium content: 1.413%).

[0101] The final catalyst was dried and the metal palladium content was measured: 2.782%, the metal palladium loss rate: 4.43%.

[0102] Example 8

[0103] The process equipment and process parameters of Example 8 are basically the same as those of Example 1, except that the temperature of the water solution in the circulating kettle is controlled at 30°C during the adsorption and neutralization process.

[0104] Finally, after washing, the activated carbon in the activated carbon adsorption column is taken out, and an activated carbon supported metal palladium catalyst is obtained: 42.474 Kg (water content: 51.5%, wet product metal palladium content: 1.413%).

[0105] The final catalyst is dried and detected for metal palladium content: 2.767%, and the metal palladium loss rate: 4.98%, according to the same evaluation method as Example 1.

[0106] As can be seen from Example 8, when the temperature of the adsorption and neutralization process exceeds the set temperature, the metal palladium loss rate will greatly increase.

[0107] Example 9

[0108] The process equipment and process parameters of Example 9 are basically the same as those of Example 1, except that hydrochloric acid: 2.75 Kg (content: 36.5%) and palladium chloride: 2.75 Kg (content: 99.695%) are added to the circulating kettle during the adsorption process. The sodium formate aqueous solution (sodium formate: 5.5 Kg, deionized water: 55 Kg) is added to the sodium formate aqueous solution metering tank in advance for reduction.

[0109] Finally, after washing, the activated carbon in the activated carbon adsorption column is taken out, and an activated carbon supported metal palladium catalyst is obtained: 43.738 Kg (water content: 50.5%, wet product metal palladium content: 3.773%).

[0110] The final catalyst is dried and detected for metal palladium content: 7.233%, and the metal palladium loss rate: 5.09%, according to the same evaluation method as Example 1.

[0111] As can be seen from Example 9, when the mass concentration of the palladium chloride aqueous solution exceeds the set range, the metal palladium loss rate will greatly increase.

[0112] Comparative Example 1

[0113] The process equipment and process parameters of Comparative Example 1 are basically the same as those of Example 1, except that the activated carbon is directly added to the circulating kettle for the adsorption, neutralization, and reduction processes (all under normal pressure), and the product is filtered and washed after reduction.

[0114] Finally, after washing, an activated carbon supported metal palladium catalyst is obtained: 43.644 Kg (water content: 52.8%, wet product metal palladium content: 1.375%).

[0115] The final catalyst was dried and the metal palladium content was detected: 2.661%, the metal palladium loss rate: 8.62%.

[0116] From the comparative example 1, when only the circulation adsorption, neutralization and reduction are carried out, the metal palladium loss rate is very high.

[0117] Comparative example 2

[0118] The process parameters of the comparative example 2 are basically the same as those of the example 1, except that the activated carbon is immersed in the reaction kettle under negative pressure adsorption, neutralization and reduction, and after reduction, the filter cylinder is used for filtration and washing.

[0119] Finally, after washing, the activated carbon supported metal palladium catalyst is obtained: 44.017 Kg (water content: 53.2%, wet product metal palladium content: 1.363%).

[0120] The final catalyst was dried and the metal palladium content was detected: 2.671%, the metal palladium loss rate: 8.24%.

[0121] From the comparative example 2, when prepared by vacuum immersion and reduction, the metal palladium loss rate is very high.

[0122] Comparative example 3

[0123] The process parameters of the comparative example 3 are basically the same as those of the example 1, except that the activated carbon is first put into the reaction kettle, vacuumized to-0.085 MPa, then the palladium chloride solution is added in the reaction kettle for immersion adsorption, after the adsorption is completed, neutralization and reduction are carried out, and after reduction, the filter cylinder is used for filtration and washing.

[0124] Finally, after washing, the activated carbon supported metal palladium catalyst is obtained: 45.677 Kg (water content: 54.9%, wet product metal palladium content: 1.314%).

[0125] The final catalyst was dried and the metal palladium content was detected: 2.614%, the metal palladium loss rate: 10.20%.

[0126] From the comparative example 3, when prepared by vacuum treatment first, then immersion and reduction, the metal palladium loss rate is very high.

[0127] The above examples are only for illustrating the technical concept and characteristics of the present application, the purpose is to enable the person skilled in the art to understand the content of the present application and to implement it, and it cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

Claims

1. An apparatus for preparing a palladium catalyst supported on activated carbon, characterized in that: The application relates to a device for adsorbing, reducing and washing active carbon, which comprises a cavity for containing active carbon, a liquid inlet on the top of the cavity, a liquid outlet on the bottom of the cavity and a gas outlet connected with the cavity. The device for adsorbing, reducing and washing active carbon comprises a cylinder, a first hole plate, the cavity is formed in the cylinder, the liquid inlet and the liquid outlet are arranged on the upper end and the lower end of the cylinder respectively, the first hole plate is arranged in the cavity and between the liquid inlet and the liquid outlet for supporting active carbon, and the gas outlet is arranged on the cylinder below the first hole plate. The device for adsorbing, reducing and washing active carbon further comprises a second hole plate, which is arranged in the cavity and above the first hole plate.

2. The apparatus for preparing an activated carbon-supported metal palladium catalyst according to claim 1, characterized by: The cylinder comprises an upper head, a first cylinder segment, a second cylinder segment and a lower head, the upper head and the first cylinder segment are detachably connected, the first hole plate is arranged between the first cylinder segment and the second cylinder segment, and the second hole plate is arranged between the upper head and the first cylinder segment.

3. The apparatus for producing an activated carbon-supported metal palladium catalyst according to claim 2, characterized by: The liquid inlet is arranged on the upper head, the liquid outlet is arranged on the lower head, and the gas outlet is arranged on the second cylinder segment.

4. The apparatus for preparing an activated carbon-supported metal palladium catalyst according to claim 3, characterized by: The bottom of the upper head is provided with a flange, the top of the first cylinder segment is provided with a flange, through holes are arranged on the flanges, and the upper head and the first cylinder segment are connected through the flanges.

5. The apparatus for preparing an activated carbon-supported metal palladium catalyst according to claim 4, characterized by: The bottom of the first cylinder segment is provided with a flange, the top of the second cylinder segment is provided with a flange, through holes are arranged on the flanges, and the first cylinder segment and the second cylinder segment are connected through the flanges.

6. The apparatus for preparing an activated carbon-supported metal palladium catalyst according to claim 4, characterized by: The first hole plate and / or the second hole plate are ceramic sintered plates or metal sintered plates. The liquid outlet is connected with the liquid return port.

7. The apparatus for preparing an activated carbon-supported metal palladium catalyst according to claim 3, characterized by: A circulating pump is arranged on the connecting pipeline between the liquid outlet and the liquid inlet and / or the connecting pipeline between the liquid outlet and the liquid return port.

8. The apparatus for preparing an activated carbon-supported metal palladium catalyst according to claim 1, characterized by: Control valves are arranged on the connecting pipeline between the liquid outlet and the liquid inlet and the connecting pipeline between the liquid outlet and the liquid return port.

9. The apparatus for preparing an activated carbon-supported metal palladium catalyst according to claim 8, characterized by: ​ 10. The apparatus for preparing an activated carbon-supported metal palladium catalyst according to claim 8, characterized by: ​

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