Catalyst recovery system for preparing mixed diamine through catalytic hydrogenation

Abstract

The invention relates to the technical field of catalyst recovery, in particular to a catalyst recovery system for preparing mixed diamine through catalytic hydrogenation, which comprises the following steps: S1, separating a catalyst from a reaction mixture, and collecting in a closed container; s2, feeding the separated catalyst into a washing tower through a conveying device, and introducing a washing solution, hot water at 60-80 DEG C and a 1-5% sodium hydroxide solution for washing; s3, feeding the washed catalyst into a dryer for drying; and S4, feeding the dried catalyst into a muffle furnace through a conveyor belt, and roasting to obtain the regenerated catalyst. The catalyst recovery system provided by the invention can efficiently recover the catalyst for mixed diamine production, and can improve the activity recovery rate of the regenerated catalyst.

Description

Technical Field

[0001] The invention relates to the technical field of catalyst recovery, and in particular to a catalyst recovery system for preparing mixed diamines by catalytic hydrogenation. Background Art

[0002] Mixed diamines are an important chemical intermediate, playing a key role in the synthesis of polyurethane, polyamide resin and a variety of fine chemicals. There are various preparation methods, among which catalytic hydrogenation has attracted much attention due to its high efficiency and environmental protection. The process of preparing mixed diamines by catalytic hydrogenation mainly depends on a suitable catalyst, which reduces the corresponding aromatic dinitro compounds to mixed diamines through catalytic action. At present, there are many catalysts used for catalytic hydrogenation to prepare mixed diamines, mainly including nickel-based catalysts, palladium-based catalysts, platinum-based catalysts, etc. Among them, nickel-based catalysts have attracted widespread attention due to their high hydrogenation activity and relatively low cost. Nickel-based catalysts such as skeleton nickel and Raney nickel have shown good catalytic performance in the hydrogenation reaction of aromatic compounds such as adiponitrile and p-phenylenediamine. However, as the catalyst is used for a longer time, its activity will gradually decrease, or even completely deactivate, and then the waste catalyst needs to be treated.

[0003] CN1782030A discloses a method for regenerating a hydrogenation catalyst, which comprises: 1) mixing a granular alkaline substance with a deactivated hydrogenation catalyst in a weight ratio of 5:95 to 50:50; 2) contacting the mixture of the granular alkaline substance and the deactivated hydrogenation catalyst with an oxygen-containing gas under oxidation regeneration reaction conditions; 3) separating and regenerating the hydrogenation catalyst. This patent provides a method for mixing a granular alkaline substance with a deactivated hydrogenation catalyst, contacting the mixture with an oxygen-containing gas under oxidation regeneration reaction conditions, and then separating and regenerating the hydrogenation catalyst, but does not deeply solve the fundamental problem of carbon deposition.

[0004] In the prior art, during the catalytic hydrogenation process, carbon deposits are easily formed on the catalyst surface, resulting in a decrease in catalyst activity. Especially for nickel-based catalysts, the carbon deposition problem is particularly serious due to their strong adsorption capacity for hydrocarbons. Carbon deposition not only reduces the activity of the catalyst, but also increases the difficulty of catalyst recovery. In addition to carbon deposition, the catalyst may also be deactivated due to poisoning (such as adsorption of certain impurity gases), sintering, wear and other reasons. At present, the catalyst recovery technology is still imperfect, especially for nickel-based catalysts. Due to their special physical and chemical properties, the separation, purification and other steps in the recovery process are technically difficult, resulting in a low recovery rate and a large amount of valuable catalyst materials being wasted. Summary of the invention

[0005] In order to solve the problems mentioned in the above background technology, the present invention provides a catalyst recovery system for preparing mixed diamines by catalytic hydrogenation.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A catalyst recovery system for preparing mixed diamines by catalytic hydrogenation comprises the following steps: S1. After the reaction is completed, the reaction mixture is sent to a separator through a pipeline, the temperature is controlled, and the separated catalyst is filtered and separated under normal pressure to obtain the separated catalyst, which is collected in a closed container; S2. The separated catalyst is sent to a washing tower through a conveying device, and washing liquid, 60-80°C hot water and 1-5% sodium hydroxide solution are introduced, and the catalyst is washed under stirring for 2-4 hours. After the washing is completed, the catalyst is continuously rinsed with 30-40°C warm water for 30-60 minutes to obtain a washed catalyst; S3, sending the washed catalyst into a dryer, drying it with hot air at 100-120°C for 4-6 hours to obtain a dried catalyst; S4. The dried catalyst is sent to a muffle furnace through a conveyor belt and calcined under nitrogen protection to obtain a regenerated catalyst.

[0007] Furthermore, in step S1, the temperature is controlled to be 20-50°C.

[0008] Furthermore, in step S2, the volume ratio of the washing liquid, hot water and 1-5% sodium hydroxide solution is (5-7): (20-22): (0.1-0.3).

[0009] Further, the washing liquid in step S2 is prepared by the following steps: Slowly add the alkyl polysaccharide into water and stir until it is completely dissolved. Then add sodium metasilicate, copolymer and sodium citrate and mix well. Then add the remaining water and continue stirring for 30-40 minutes to obtain a washing solution.

[0010] Furthermore, in step S4, the calcination temperature is 400-500° C., and the calcination time is 2-4 hours.

[0011] Further, the copolymer comprises the following steps to be prepared: A1. Add oleic acid into a reaction kettle containing a mixture of tetramethylammonium chloride and cobalt oxide, heat to 100-150° C., slowly add ethylene oxide under stirring, and after the reaction is completed, cool to room temperature and perform vacuum distillation to obtain polyoxyethylene oleate; A2, adding glycerol and potassium hydroxide into a reaction kettle, heating to 120-160°C, slowly adding propylene oxide under stirring, cooling to room temperature after the reaction is completed, and distilling under reduced pressure to obtain polypropylene glycol; A3. Add polyoxyethylene oleate and polypropylene glycol into a reactor, heat to 180°C, add stannous octoate under nitrogen protection, react for 4-6 hours, cool to room temperature after the reaction, add chloroform to dissolve the copolymer, stir evenly, filter, pour the filtrate into ice methanol, filter again, wash with ethanol several times, and dry at 60-80°C to constant weight to obtain polyoxyethylene oleate-polypropylene glycol copolymer.

[0012] Furthermore, the mass ratio of alkyl polysaccharide, water, sodium metasilicate, copolymer and sodium citrate is (10-15):200:(6-7):(2-3):(0.2-0.5), and the volume ratio of the first water addition to the second water addition is 7:3.

[0013] Furthermore, in step A1, the mass ratio of oleic acid, tetramethylammonium chloride, cobalt oxide and ethylene oxide is (1-1.5):(0.08-0.1):(0.01-0.02):(2-2.2).

[0014] Furthermore, in step A2, the mass ratio of glycerol, potassium hydroxide and propylene oxide is (1-1.2):(0.02-0.1):(4-5).

[0015] Furthermore, in step A3, the mass ratio of polyoxyethylene oleate, polypropylene glycol, stannous octoate and chloroform is (1-1.5):(1-1.5):(0.02-0.04):(4-5).

[0016] Beneficial effects of the present invention: 1. In the technical solution of the present invention, the copolymer is a key component in the washing liquid. Its molecular chain contains both hydrophilic polyoxyethylene segments and hydrophilic polypropylene glycol segments, forming an amphiphilic structure, so that the copolymer can form a stable adsorption layer at the water-oil interface, effectively reducing the surface tension. During the washing process, the lipophilic segments of the copolymer can be tightly adsorbed on the oil stains on the catalyst surface, while the hydrophilic segments extend to the washing liquid. Through the synergy of physical and chemical effects, the oil stains are stripped from the catalyst surface and dispersed into the washing liquid. At the same time, the alkyl polysaccharide in the washing liquid, as a non-ionic surfactant, also participates in the dirt stripping process, further enhancing the washing effect.

[0017] 2. In the technical solution of the present invention, sodium metasilicate and sodium citrate in the washing liquid also play an important role. Sodium metasilicate has good dispersibility and suspension, and can keep the dirt peeled off from the catalyst surface in a suspended state in the washing liquid to prevent it from being redeposited on the catalyst surface. A small amount of sodium citrate, as a chelating agent, can react with impurities such as metal ions on the catalyst surface to form a soluble complex, thereby effectively removing it from the catalyst surface. The synergistic effect of these components and copolymers jointly realizes the efficient removal of dirt and impurities on the catalyst surface, which not only improves the regeneration efficiency of the catalyst, but also prolongs the service life of the catalyst. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Unless otherwise specified, the raw materials used in the present invention are all conventional products purchased from the market.

[0020] Preparation Example 1 The copolymer comprises the following steps: A1. Add 10 kg of oleic acid into a reaction kettle containing 0.8 kg of tetramethylammonium chloride and 0.1 kg of cobalt oxide, heat to 100° C., slowly add 20 kg of ethylene oxide under stirring, and after the reaction is completed, cool to room temperature and perform vacuum distillation to obtain polyoxyethylene oleate; A2, 10kg glycerol and 0.2kg potassium hydroxide were added to a reactor, heated to 120°C, 40kg propylene oxide was slowly added under stirring, and after the reaction was completed, it was cooled to room temperature and distilled under reduced pressure to obtain polypropylene glycol; A3. Add 10 kg of polyoxyethylene oleate and 10 kg of polypropylene glycol into a reactor, heat to 180 ° C, add 0.2 kg of stannous octoate under nitrogen protection, react for 4 hours, cool to room temperature after the reaction, add 40 kg of chloroform, stir evenly, filter, pour the filtrate into 1000 mL of ice methanol, filter again, wash with ethanol several times, and dry at 60 ° C to constant weight to obtain polyoxyethylene oleate-polypropylene glycol copolymer.

[0021] The washing liquid comprises the following steps to prepare: Slowly add 10 kg of alkyl polysaccharide into 140 kg of water and stir until completely dissolved. Add 6 kg of sodium metasilicate, 2 kg of copolymer and 0.2 kg of sodium citrate and mix well. Add the remaining 60 kg of water and continue stirring for 30 minutes to obtain a washing liquid.

[0022] Preparation Example 2 The copolymer comprises the following steps: A1. Add 12.5 kg of oleic acid into a reaction kettle containing 0.9 kg of tetramethylammonium chloride and 0.15 kg of cobalt oxide, heat to 125° C., slowly add 21 kg of ethylene oxide under stirring, and after the reaction is completed, cool to room temperature and perform vacuum distillation to obtain polyoxyethylene oleate; A2, 11kg glycerol and 0.5kg potassium hydroxide were added to a reactor, heated to 140°C, 45kg propylene oxide was slowly added under stirring, and after the reaction was completed, it was cooled to room temperature and distilled under reduced pressure to obtain polypropylene glycol; A3. Add 12.5 kg of polyoxyethylene oleate and 12.5 kg of polypropylene glycol into a reactor, heat to 180 ° C, add 0.3 kg of stannous octoate under nitrogen protection, react for 5 hours, cool to room temperature after the reaction, add 45 kg of chloroform, stir evenly, filter, pour the filtrate into 1000 mL of ice methanol, filter again, wash with ethanol several times, and dry at 70 ° C to constant weight to obtain polyoxyethylene oleate-polypropylene glycol copolymer.

[0023] The washing liquid comprises the following steps to prepare: Slowly add 12.5 kg of alkyl polysaccharide into 140 kg of water and stir until completely dissolved. Add 6.5 kg of sodium metasilicate, 2.5 kg of copolymer and 0.4 kg of sodium citrate and mix well. Add the remaining 60 kg of water and continue stirring for 35 minutes to obtain a washing solution.

[0024] Preparation Example 3 The copolymer comprises the following steps: A1. Add 15 kg of oleic acid into a reaction kettle containing 1 kg of tetramethylammonium chloride and 0.2 kg of cobalt oxide, heat to 150° C., slowly add 22 kg of ethylene oxide under stirring, and after the reaction is completed, cool to room temperature and perform vacuum distillation to obtain polyoxyethylene oleate; A2, add 12kg glycerol and 1kg potassium hydroxide into a reactor, heat to 160°C, slowly add 50kg propylene oxide under stirring, after the reaction is completed, cool to room temperature, and distill under reduced pressure to obtain polypropylene glycol; A3. Add 15 kg of polyoxyethylene oleate and 15 kg of polypropylene glycol into a reactor, heat to 180 ° C, add 0.4 kg of stannous octoate under nitrogen protection, react for 6 hours, cool to room temperature after the reaction, add 50 kg of chloroform, stir evenly, filter, pour the filtrate into 1000 mL of ice methanol, filter again, wash with ethanol several times, and dry at 80 ° C to constant weight to obtain polyoxyethylene oleate-polypropylene glycol copolymer.

[0025] The washing liquid comprises the following steps to prepare: Slowly add 15 kg of alkyl polysaccharide into 140 kg of water and stir until completely dissolved. Add 7 kg of sodium metasilicate, 3 kg of copolymer and 0.5 kg of sodium citrate and mix well. Add the remaining 60 kg of water and continue stirring for 40 minutes to obtain a washing liquid.

[0026] Example 1

[0027] A catalyst recovery system for preparing mixed diamines by catalytic hydrogenation comprises the following steps: S1. After the reaction is completed, 100 kg of the reaction mixture (containing 1% Raney nickel catalyst) is sent to a separator through a pipeline, filtered and separated at 20°C and normal pressure to obtain the separated catalyst, which is collected in a closed container; S2, the separated catalyst is sent to a washing tower through a conveying device, and 5 kg of the washing liquid prepared in Preparation Example 1, 20 kg of 60 ° C hot water and 0.1 kg of 5% sodium hydroxide solution are introduced, and the catalyst is washed under stirring at a speed of 10 rpm for 2 hours. After the washing is completed, the catalyst is filtered to obtain the washed catalyst; S3, sending the washed catalyst into a dryer and drying it with hot air at 100°C for 4 hours until the moisture content of the catalyst is less than 1%, thereby obtaining a dried catalyst; S4. The dried catalyst is sent to a muffle furnace through a conveyor belt, and calcined at 400° C. for 2 h under nitrogen protection to obtain a regenerated catalyst.

[0028] Example 2

[0029] A catalyst recovery system for preparing mixed diamines by catalytic hydrogenation comprises the following steps: S1. After the reaction is completed, 100 kg of the reaction mixture (containing 1% Raney nickel catalyst) is sent to a separator through a pipeline, filtered and separated at 35°C and normal pressure to obtain the separated catalyst, which is collected in a closed container; S2, the separated catalyst is sent to a washing tower through a conveying device, and 6 kg of the washing liquid prepared in Preparation Example 2, 21 kg of hot water at 70°C and 0.2 kg of 3% sodium hydroxide solution are introduced, and the catalyst is washed under stirring at a speed of 10 rpm for 3 hours. After the washing is completed, the catalyst is filtered to obtain the washed catalyst; S3, sending the washed catalyst into a dryer and drying it with hot air at 110°C for 5 hours until the moisture content of the catalyst is less than 1%, thereby obtaining a dried catalyst; S4. The dried catalyst is sent into a muffle furnace via a conveyor belt, and calcined at 450° C. for 3 h under nitrogen protection to obtain a regenerated catalyst.

[0030] Example 3

[0031] A catalyst recovery system for preparing mixed diamines by catalytic hydrogenation comprises the following steps: S1. After the reaction is completed, 100 kg of the reaction mixture (containing 1% Raney nickel catalyst) is sent to a separator through a pipeline, filtered and separated at 50°C and normal pressure to obtain the separated catalyst, which is collected in a closed container; S2, the separated catalyst is sent to a washing tower through a conveying device, and 7kg of the washing liquid prepared in Preparation Example 3, 22kg of 80°C hot water and 0.3kg of 1% sodium hydroxide solution are introduced, and the catalyst is washed under stirring at a speed of 10rpm for 4h. After the washing is completed, the catalyst is filtered to obtain the washed catalyst; S3, sending the washed catalyst into a dryer and drying it with hot air at 120°C for 6 hours until the moisture content of the catalyst is less than 1%, thereby obtaining a dried catalyst; S4. The dried catalyst is sent into a muffle furnace through a conveyor belt, and calcined at 500° C. for 4 hours under nitrogen protection to obtain a regenerated catalyst.

[0032] Comparative Example 1 The difference between this comparative example and Example 1 is that no copolymer is added to the washing liquid, and the remaining steps are the same as those of Example 1.

[0033] Comparative Example 2 The difference between this comparative example and Example 2 is that no alkyl polysaccharide is added to the washing liquid, and the remaining steps are the same as those in Example 2.

[0034] Comparative Example 3 The difference between this comparative example and Example 3 is that sodium metasilicate is not added to the washing liquid, and the remaining steps are the same as those in Example 3.

[0035] The regenerated catalyst recovered from Examples 1-3 and Comparative Examples 1-3, the fresh Raney nickel catalyst (as a control group), the regenerated catalyst recovered from Examples 1-3 and the regenerated catalyst recovered from Comparative Examples 1-3 were reused in the production of mixed diamines.

[0036] The specific production steps of mixed diamines are as follows: 5.5 kg of mixed dinitrobenzenes (90.0% of meta-dinitrobenzene, 7.2% of o-dinitrobenzene, and 2.8% of p-dinitrobenzene), 2.5 kg of methanol and 2 kg of catalyst solution are added to a hydrogenation reactor in sequence, the hydrogen is compressed to 1.7 MPa and then introduced into the hydrogenation reactor, the reaction temperature is controlled to 80°C and the pressure is 1.2 MPa, the reaction is carried out for 6 hours, and a reducing liquid is obtained. After distillation and purification under normal pressure, a mixed diamine product is obtained.

[0037] The activity recovery rates of the regenerated catalysts prepared in Examples 1-3 and Comparative Examples 1-3 were calculated. Activity recovery rate = (conversion rate of the regenerated catalyst / conversion rate of the fresh catalyst) × 100%, conversion rate = (number of moles of the generated mixed diamine / number of moles of the reactants that can be converted into the mixed diamine) × 100%. The results are shown in Table 1: Table 1. Activity recovery rate of the regenerated catalysts obtained in Examples 1-3 and Comparative Examples 1-3

[0038] As shown in Table 1, the activity recovery rates of Examples 1-3 are 97.5%-97.9%, indicating that the washing solution prepared by Preparation Example 1, as well as the specified washing, drying and roasting conditions, can effectively remove impurities on the catalyst surface and restore most of its activity. The activity recovery rate of Comparative Example 1 dropped significantly to 85.6%. This may be because the copolymer was not added to the washing solution, resulting in a weakened washing effect. The copolymer may help remove certain specific impurities on the catalyst surface, such as oily residues or polymer fragments, which are difficult to completely remove when only other washing ingredients are used. The activity recovery rate of Comparative Example 2 is 88.3%. Alkyl polyglycosides were not added to the washing solution, resulting in a washing effect that was not as good as that of the embodiment. Alkyl polyglycosides may have excellent surface activity and dispersibility, which helps to better disperse and remove impurities on the catalyst surface. The activity recovery rate of Comparative Example 3 is 90.5%. Sodium metasilicate was not added to the washing solution, which also resulted in a decrease in the washing effect. Sodium metasilicate may help stabilize the pH value of the washing solution, or form a precipitate with certain impurities on the catalyst surface, thereby promoting its removal.

[0039] Copolymers may interact with oily residues or polymer fragments on the catalyst surface through their unique chemical structure, thereby removing them from the catalyst surface. The presence of copolymers may also improve the wettability and permeability of the washing liquid, allowing the washing liquid to penetrate deeper into the pores of the catalyst and remove more impurities. Alkyl polyglycosides have excellent surface activity and dispersibility, which can effectively disperse and remove impurities on the catalyst surface. They may also help maintain the stability of the washing liquid and prevent impurities from re-depositing on the catalyst surface through the balance of their hydrophilic and hydrophobic groups. Sodium metasilicate may help stabilize the pH of the washing liquid and prevent changes in the catalyst surface properties caused by changes in pH. It may also form precipitation with certain impurities on the catalyst surface, thereby promoting their removal.

[0040] In summary, the washing liquid prepared in Preparation Examples 1-3 has a significant effect when used for catalyst recovery in catalytic hydrogenation to prepare mixed diamines, so that the regenerated catalysts of Examples 1-3 have a higher activity recovery rate.

[0041] In the description of the specification, the description with reference to the terms "preparation example", "embodiment", "various embodiments" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or preparation example are included in at least one embodiment or preparation example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or preparation example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or preparation examples in a suitable manner.

[0042] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A catalyst recovery system for preparing mixed diamines by catalytic hydrogenation, characterized in that: The following steps are involved: S1. After the reaction is completed, the reaction mixture is sent to a separator through a pipeline, the temperature is controlled, and the separated catalyst is filtered and separated under normal pressure to obtain the separated catalyst, which is collected in a closed container; S2. The separated catalyst is sent to a washing tower through a conveying device, and washing liquid, 60-80°C hot water and 1-5% sodium hydroxide solution are introduced, and the catalyst is washed under stirring for 2-4 hours. After the washing is completed, the catalyst is continuously rinsed with 30-40°C warm water for 30-60 minutes to obtain a washed catalyst; S3, sending the washed catalyst into a dryer, drying it with hot air at 100-120°C for 4-6 hours to obtain a dried catalyst; S4, sending the dried catalyst into a muffle furnace through a conveyor belt, and calcining it under nitrogen protection to obtain a regenerated catalyst; The washing liquid in step S2 is prepared by the following steps: Slowly add the alkyl polysaccharide into water and stir until it is completely dissolved. Then add sodium metasilicate, copolymer and sodium citrate and mix well. Then add the remaining water and continue stirring for 30-40 minutes to obtain a washing solution.

2. A catalyst recovery system for preparing mixed diamines by catalytic hydrogenation according to claim 1, characterized in that: In step S1, the temperature is controlled to be 20-50°C.

3. A catalyst recovery system for preparing mixed diamines by catalytic hydrogenation according to claim 1, characterized in that: In step S2, the volume ratio of the washing liquid, hot water and 1-5% sodium hydroxide solution is (5-7): (20-22): (0.1-0.3).

4. A catalyst recovery system for preparing mixed diamines by catalytic hydrogenation according to claim 1, characterized in that: The calcination temperature in step S4 is 400-500° C., and the calcination time is 2-4 hours.

5. A catalyst recovery system for preparing mixed diamines by catalytic hydrogenation according to claim 1, characterized in that: The copolymer comprises the following steps: A1. Add oleic acid into a reaction kettle containing a mixture of tetramethylammonium chloride and cobalt oxide, heat to 100-150° C., slowly add ethylene oxide under stirring, and after the reaction is completed, cool to room temperature and perform vacuum distillation to obtain polyoxyethylene oleate; A2, adding glycerol and potassium hydroxide into a reaction kettle, heating to 120-160°C, slowly adding propylene oxide under stirring, cooling to room temperature after the reaction is completed, and distilling under reduced pressure to obtain polypropylene glycol; A3. Add polyoxyethylene oleate and polypropylene glycol into a reaction kettle, heat to 180°C, add stannous octoate under nitrogen protection, react for 4-6 hours, cool to room temperature after the reaction, add chloroform, stir evenly, filter, pour the filtrate into ice methanol, filter again, wash with ethanol several times, and dry at 60-80°C to constant weight to obtain a copolymer.

6. A catalyst recovery system for preparing mixed diamines by catalytic hydrogenation according to claim 1, characterized in that: The mass ratio of alkyl polyglycoside, water, sodium metasilicate, copolymer and sodium citrate is (10-15):200:(6-7):(2-3):(0.2-0.5), and the volume ratio of the first water addition to the second water addition is 7:

3.

7. A catalyst recovery system for preparing mixed diamines by catalytic hydrogenation according to claim 5, characterized in that: In step A1, the mass ratio of oleic acid, tetramethylammonium chloride, cobalt oxide and ethylene oxide is (1-1.5): (0.08-0.1): (0.01-0.02): (2-2.2).

8. A catalyst recovery system for preparing mixed diamines by catalytic hydrogenation according to claim 5, characterized in that: The mass ratio of glycerol, potassium hydroxide and propylene oxide in step A2 is (1-1.2):(0.02-0.1):(4-5).

9. A catalyst recovery system for preparing mixed diamines by catalytic hydrogenation according to claim 5, characterized in that: In step A3, the mass ratio of polyoxyethylene oleate, polypropylene glycol, stannous octoate and chloroform is (1-1.5):(1-1.5):(0.02-0.04):(4-5).

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