A method for regenerating a catalyst for producing diaminodicyclohexylmethane
By regenerating the catalyst through calcination, washing, and activation steps, the problems of decreased catalyst activity and pore sintering were solved, resulting in extended catalyst life and reduced production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WANHUA CHEM GRP CO LTD
- Filing Date
- 2022-09-08
- Publication Date
- 2026-07-10
AI Technical Summary
Existing catalysts suffer from reduced efficiency and increased costs during the production of diaminodicyclohexylmethane due to decreased activity and pore sintering, and current regeneration methods cannot effectively solve these problems.
The catalyst is regenerated through roasting, washing, and activation steps. Tar is removed by roasting with high-carbon alcohol compounds, residues are cleaned by washing with highly polar organic solvents, and the catalyst is activated under high-pressure hydrogen.
It significantly improves catalyst lifetime and H12MDA yield, reduces production costs, and maintains the stability of the trans-trans isomer.
Abstract
Description
Technical Field
[0001] This invention relates to a method for regenerating a catalyst in the production process of diaminodicyclohexylmethane. Background Technology
[0002] Diaminodicyclohexylmethane (H) 12 MDA is an important alicyclic diamine, mainly used in the preparation of alicyclic dicyclohexylmethane diisocyanate (H2O). 12 MDI) or used directly as an epoxy resin curing agent. 12 MDI can be used to process various environmentally friendly polyurethane coatings and adhesives with good transparency and resistance to yellowing. (The last part, "H," appears to be a continuation of the previous sentence and is left untranslated.) 12 MDA-cured epoxy resins possess excellent heat resistance, dielectric properties, solvent resistance, mechanical properties, as well as superior optical and weather resistance properties, making them suitable for applications in damping materials, optical materials, coatings, engineering plastics, adhesives, and other fields.
[0003] Preparation of H 12 MDA primarily employs supported noble metal catalysts in fixed-bed or high-pressure autoclave reactors for the catalytic hydrogenation of diaminodiphenylmethane (MDA) to achieve high product yields and low trans-trans isomer ratios. Due to the high cost of noble metal catalysts, continuous recycling is necessary to reduce production costs. However, during catalyst recycling, the catalyst's activity and selectivity gradually decline. There are two main reasons for this activity decay: First, prolonged operation causes continuous abrasion of the catalyst particles by the high-shear agitator, resulting in smaller particles that are lost into the reaction mother liquor. This problem can be mitigated by using high-strength catalyst supports or optimizing gas mass transfer to reduce abrasion. Second, with repeated recycling, the pores and active sites on the catalyst surface are increasingly covered by high-boiling-point tar, leading to a gradual decrease in catalyst activity and selectivity. This further results in the formation of more secondary amine tar and an increased trans-trans isomer ratio. Simultaneously, as the catalyst becomes coated with viscous tar, the catalyst particles become more viscous, significantly extending product filtration time and potentially causing premature catalyst removal and retirement, thus reducing production efficiency and increasing operating costs. This issue requires the periodic regeneration of deactivated catalysts to further reduce the cost of catalyst usage per ton of product.
[0004] US3071551A describes a method for regenerating rhodium catalysts through direct heating. This method involves heating the poisoned and deactivated Rh catalyst to 200-300°C in a single-step reaction and continuing this process for 2-24 hours for regeneration. However, this technique cannot avoid the problem that the sintering of the support during the high-temperature heating process leads to a decrease in the catalyst's micropores and specific surface area, which negatively impacts the activity of the regenerated catalyst.
[0005] CN103816923A describes an ultrasonic cleaning and regeneration scheme for ruthenium catalysts, which uses ultrasonic cleaning technology to remove tar adhering to the catalyst surface, followed by oxidative regeneration and drying reduction. However, due to the limitations of ultrasonic technology, tar deep within the catalyst pores cannot be completely removed by ultrasonic cleaning.
[0006] CN113893866A introduces a H 12 The MDA catalyst regeneration method uses an acidic aqueous solution at a specific temperature and pressure to react amine tar adsorbed on the catalyst to generate hydroxyl-substituted tar, thus eliminating the alkalinity of the tar. Further regeneration and activation are achieved through washing with an organic solvent, thereby desorbing and separating the tar from the catalyst. However, this technique, using an acidic aqueous solution, places high demands on the materials of the production equipment. Furthermore, the incomplete hydroxyl substitution reaction of the tar can affect the catalyst regeneration efficiency.
[0007] Therefore, there is an urgent need in this field to study a method for catalyst regeneration in the production process of diaminodicyclohexylmethane, while overcoming the shortcomings of the existing methods. Summary of the Invention
[0008] The purpose of this invention is to provide a catalyst regeneration process for the production of diaminodicyclohexylmethane via hydrogenation reaction using MDA as a raw material and under the action of a metal-supported catalyst. The entire catalyst regeneration process is completed through calcination, washing, and activation. This process can significantly improve catalyst lifetime while effectively maintaining the stability of the trans-trans isomers, greatly reducing production costs.
[0009] To achieve the above objectives, the present invention adopts the following technical solution:
[0010] A kind of H 12 The catalyst regeneration method in the MDA production process includes the following steps:
[0011] 1) Calcination step: Add higher alcohol compounds to the catalyst and calcine them.
[0012] 2) Washing steps: Add highly polar organic solvent and wash and clean.
[0013] 3) Activation step: Add hydrogen gas to activate and regenerate.
[0014] The catalyst comprises a combination of a metal and a support, wherein the metal comprises any one or at least two combinations of Group VIIIB metals; more preferably, the metal comprises any one or at least two combinations of Pt, Rh, Ru, Ir or Pd, and even more preferably Rh and / or Ru;
[0015] Preferably, the carrier comprises any one or at least two combinations of rare earth, diatomaceous earth, alumina, lithium aluminate, zirconium oxide, spinel, silicon oxide or silicon aluminum oxide, more preferably alumina and / or zirconium oxide;
[0016] More preferably, the catalyst is Rh / Al2O3 and / or Rh / ZrO2.
[0017] More preferably, the metal content is 3-6 wt%, preferably 4-5 wt%, based on the weight of the catalyst.
[0018] In the calcination step, higher alcohols are added to the catalyst for calcination treatment;
[0019] Preferably, the molecular formula of the higher alcohol compound is OH-(CH2). n -OH, 10≥n≥6, more preferably 1,6-hexanediol and 1,8-octanediol;
[0020] Preferably, the amount of the higher alcohol compound added is 10-100 times the mass of the catalyst, and more preferably 20-50 times;
[0021] Preferably, the roasting temperature is 300℃-400℃, more preferably 320℃-350℃; the roasting time is 6h-24h, more preferably 8h-12h.
[0022] In the washing step, the highly polar organic solvent is selected from at least one of methanol, ethanol, dioxane, dichloroethane, acetone, and tetrahydrofuran, more preferably tetrahydrofuran; the amount of the highly polar organic solvent added is 50-500 times the mass of the catalyst, preferably 100-200 times; the washing time is 1-5 hours, preferably 2 hours.
[0023] In the activation step, the hydrogen pressure is 2-10 MPa, preferably 6-8 MPa; the activation and regeneration reaction temperature is 150-250℃, preferably 180-200℃; and the activation time is 1-10 h, preferably 5-7 h.
[0024] Preferably, both the activation step and the hydrogenation reaction are carried out in the same organic solvent; preferably, the solvent is selected from at least one of cyclohexane, dioxane, tetrahydrofuran, cyclohexylamine, dicyclohexylamine, methanol, ethanol, isopropanol, n-butanol, 2-butanol, or methylcyclohexane, more preferably tetrahydrofuran. The amount of solvent used in the activation step is 50-200 times the mass of the catalyst.
[0025] Preferably, the H of the present invention 12In the MDA production process, the hydrogenation reaction feedstock MDA contains 96-100 wt% of 4,4'-diaminodiphenylmethane, 0-2 wt% of 2,4'-diaminodiphenylmethane, and 0-2 wt% of N-methyl-4,4'-diaminodiphenylmethane, based on the weight of MDA; preferably, it contains 99-100 wt% of 4,4'-diaminodiphenylmethane, 0-0.5 wt% of 2,4'-diaminodiphenylmethane, and 0-0.5 wt% of N-methyl-4,4'-diaminodiphenylmethane, based on the weight of MDA.
[0026] Preferably, the amount of catalyst added is 0.5-5 wt% of the weight of the MDA, more preferably 1-3 wt%, and even more preferably 1.5-2 wt%.
[0027] Preferably, the concentration of MDA in the hydrogenation reaction is 30-60 wt%, more preferably 40-50 wt%, based on the total weight of the MDA and the solvent;
[0028] Preferably, the hydrogenation reaction temperature is 100-250℃, more preferably 150-200℃, and even more preferably 170-190℃;
[0029] Preferably, the absolute pressure of the hydrogenation reaction is 3-15 MPa, more preferably 5-10 MPa, and even more preferably 6-8 MPa;
[0030] Preferably, the reactor comprises an intermittent high-pressure autoclave reactor with a catalyst filtration device;
[0031] Preferably, the catalyst filtration device is a built-in filter or an external filter, and more preferably a built-in filter for the autoclave;
[0032] Preferably, when H in the product liquid 12 When the MDA content drops below 80%, or the content of trans-trans isomers exceeds 20%, it indicates that the catalyst activity has decreased and regeneration is required.
[0033] Compared with the prior art, the positive effects of the present invention are as follows:
[0034] This invention addresses the degradation of catalyst activity after repeated use by calcining. At a specific temperature, the tar adhering to the catalyst undergoes high-temperature thermal decomposition into small-molecule compounds, thereby converting the high-boiling-point tar into low-boiling-point alkane products. During the calcination heating process, most of these decomposition products are vaporized and separated from the catalyst. However, during vaporization, the presence of surface tension easily causes the pores of the porous support in the catalyst to shrink, leading to sintering and collapse of some pores. To prevent pore sintering from causing a decrease in catalyst regeneration activity, this invention adds a high-carbon alcohol compound during the calcination process. Utilizing its high boiling point, high decomposition temperature, and low surface tension, this compound fills the catalyst pores during calcination, slowing down the sintering and collapse process. Furthermore, this invention uses a highly polar organic solvent to thoroughly wash away any remaining small-molecule compounds and high-carbon alcohol compounds after calcination, and finally, high-pressure hydrogen is introduced to complete the activation and regeneration process.
[0035] This invention can effectively improve the regeneration activity of catalysts while effectively maintaining the stability of the content of trans-trans isomers, thus greatly reducing the cost of using precious metal catalysts. Detailed Implementation
[0036] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.
[0037] Unless otherwise specified, the raw materials used in the following examples or comparative examples are all commercially available industrial-grade conventional raw materials. The main raw materials and testing instrument information are as follows:
[0038] The 4wt% Rh / Al2O3 and 5wt% Rh / ZrO2 catalysts were purchased from Xi'an Kaili Company. wt% refers to the metal content.
[0039] MDA-100 is derived from WANAMINE MDA-100. It contains 99.5 wt% 4,4'-MDA, 0.35 wt% N-methyl-4,4'-MDA, and 0.15 wt% 2,4'-MDA.
[0040] Gas chromatography was performed using an Agilent 7890 series DB-5 capillary column, with an FID detector temperature of 300℃, an initial column temperature of 160℃, a rate of increase to 300℃ of 10℃ / min, and a residence time of 20min.
[0041] Example 1
[0042] In a 1L autoclave equipped with a built-in filter, 6g of Rh / Al₂O₃ catalyst with a metal content of 4wt% was added, along with 200g of MDA-100 and 200g of tetrahydrofuran. The mixture was purged three times with N₂ at 1MPa (absolute pressure), followed by three purgings with H₂ at 1MPa (absolute pressure), and then pressurized to 5MPa (absolute pressure) with H₂. The temperature was raised to 190℃. During the reaction, H₂ was continuously introduced into the autoclave via a hydrogen flow controller to maintain the reaction pressure at 6MPa (absolute pressure). H₂ supply was stopped when the hydrogen flow rate reading on the flow controller fell below 100 sccm. The reaction was stopped when the pressure drop in the autoclave was less than 0.01MPa / min, and the autoclave was cooled and depressurized. When the autoclave temperature dropped to 50℃, the product liquid was filtered and separated from the catalyst using N₂ at a pressure not exceeding 0.6MPa (absolute pressure) through the built-in filter, and the product liquid was analyzed by gas chromatography. After the product liquid is filtered clean, add 200g of MDA-100 and 200g of tetrahydrofuran, and repeat the above steps to recycle the catalyst. The reaction results are shown in Table 1.
[0043] Table 1. Results of catalyst reuse reaction in Example 1
[0044] Apply batch / Run <![CDATA[H 12 MDA content / %]]> anti-anti isomer content / % Other contents / % 1 94.5 16.3 5.5 10 91.9 16.8 8.1 20 90.1 17.5 9.9 30 88.4 18.5 11.6 40 85.1 19.2 14.9 50 82.0 21.0 18.0
[0045] As can be seen from Table 1, when the catalyst is reused 50 times, H 12 The MDA yield has decreased to 82%, the content of trans-trans isomers exceeds 20%, and the catalyst activity has significantly decreased.
[0046] Example 2
[0047] In a 1L autoclave equipped with a built-in filter, 2g of Rh / ZrO2 catalyst with a metal content of 5wt% was added, along with 200g of MDA-100 and 300g of tetrahydrofuran. The mixture was purged three times with N2 at 1MPa (absolute pressure), followed by three purgings with H2 at 1MPa (absolute pressure), and then pressurized to 5MPa (absolute pressure) with H2. The temperature was raised to 170℃. During the reaction, H2 was continuously introduced into the autoclave via a hydrogen flow controller to maintain the reaction pressure at 8MPa (absolute pressure). H2 supply was stopped when the hydrogen flow rate reading on the flow controller fell below 100 sccm. The reaction was stopped when the pressure drop in the autoclave was less than 0.01MPa / min, and the autoclave was cooled and depressurized. When the autoclave temperature dropped to 50℃, the product liquid was filtered and separated from the catalyst using N2 at no more than 0.6MPa (absolute pressure) through the built-in filter, and the product liquid was analyzed by gas chromatography. After the product liquid is filtered clean, add 200g of MDA-100 and 300g of tetrahydrofuran, and repeat the above steps to recycle the catalyst. The reaction results are shown in Table 2.
[0048] Table 2. Results of catalyst reuse reaction in Example 2
[0049] Apply Batch / Run <![CDATA[H 12 MDA content / %]]> anti-anti isomer content / % Other contents / % 1 92.1 14.7 7.9 10 90.5 15.3 9.5 20 88.3 15.9 11.7 30 85.9 16.6 14.1 40 83.2 17.3 16.8 50 81.2 18.2 18.8 55 78.9 19.0 21.1
[0050] As can be seen from Table 2, when the catalyst is reused 55 times, H 12 The MDA yield has decreased to below 80%, the content of trans-trans isomers has increased to 19%, and the catalyst activity has significantly decreased.
[0051] Example 3
[0052] In a 1L autoclave equipped with a built-in filter, 10g of Ru / Al₂O₃ catalyst with a metal content of 4wt% was added, along with 200g of MDA-100 and 200g of tetrahydrofuran. The mixture was purged three times with N₂ at 1MPa (absolute pressure), followed by three purgings with H₂ at 1MPa (absolute pressure), and then pressurized to 5MPa (absolute pressure) with H₂. The temperature was raised to 150℃. During the reaction, H₂ was continuously introduced into the autoclave via a hydrogen flow controller to maintain the reaction pressure at 10MPa (absolute pressure). H₂ supply was stopped when the hydrogen flow rate reading on the flow controller fell below 100 sccm. The reaction was stopped when the pressure drop in the autoclave was less than 0.01MPa / min, and the autoclave was cooled and depressurized. When the autoclave temperature dropped to 50℃, the product liquid was filtered and separated from the catalyst using N₂ at a pressure not exceeding 0.6MPa (absolute pressure) through the built-in filter, and the product liquid was analyzed by gas chromatography. After the product liquid is filtered clean, add 200g of MDA-100 and 200g of tetrahydrofuran, and repeat the above steps to recycle the catalyst. The reaction results are shown in Table 3.
[0053] Table 3. Results of catalyst reuse reaction in Example 3
[0054] Apply batch / Run <![CDATA[H 12 MDA content / %]]> anti-anti isomer content / % Other contents / % 1 96.5 18.2 3.5 10 95.9 18.8 4.1 20 93.1 18.5 6.9 30 90.1 19.1 9.9 40 86.7 19.6 13.3 50 83.5 19.8 16.5 60 80.8 19.8 19.2 70 77.2 20.1 22.8
[0055] As can be seen from Table 3, when the catalyst is reused 70 times, H 12 The MDA yield has decreased to 77.2%, the content of anti-anti-isomers exceeds 20%, and the catalyst activity has significantly decreased.
[0056] Example 4
[0057] When the catalyst from Example 1 was reused for 50 batches, its activity showed a significant decrease. At this point, 120g of 1,6-hexanediol was added to the reactor, and the feed valve and vent valve were kept open and connected to the atmosphere. The reactor was heated to 300°C and maintained for 12 hours. Subsequently, the reactor was cooled to below 40°C, and 600g of tetrahydrofuran was added to wash the catalyst for approximately 2 hours. The tetrahydrofuran washing liquid was then filtered out of the reactor through a built-in filter. Finally, 300g of tetrahydrofuran was added to the reactor and the catalyst was activated for 5 hours at 200°C and 6MPa hydrogen gas.
[0058] After the catalyst regeneration process was completed, a hydrogenation reaction was carried out according to the feed ratio and reaction conditions of Example 1. The reaction results are shown in Table 4.
[0059] Table 4. Results of catalyst reuse reaction in Example 4
[0060] Apply batch / Run <![CDATA[H 12 MDA content / %]]> anti-anti isomer content / % Other contents / % 51 92.5 16.8 7.5 60 90.7 17.3 9.3 70 88.2 17.8 11.8 80 86.3 18.2 13.7 90 83.1 19.0 16.9 100 81.7 19.4 18.3 105 78.2 19.8 21.8
[0061] As can be seen from Table 4, the catalyst activity was significantly restored, and H in Run51 12 MDA yield rose to 92.5%, up to batch number 105, H 12 MDA yield only dropped below 80%.
[0062] Example 5
[0063] When the catalyst from Example 2 was reused for 55 batches, its activity showed a significant decrease. At this point, 100g of 1,8-octanediol was added to the reactor, and the feed valve and vent valve were kept open and connected to the atmosphere. The reactor was heated to 400°C and maintained for 8 hours. Subsequently, the reactor was cooled to below 40°C, and 400g of tetrahydrofuran was added to wash the catalyst for approximately 2 hours. The tetrahydrofuran washing liquid was then filtered out of the reactor through a built-in filter. Finally, 300g of tetrahydrofuran was added to the reactor and the catalyst was activated for 7 hours at 180°C and 8MPa hydrogen gas.
[0064] After the catalyst regeneration process was completed, the hydrogenation reaction was carried out according to the feed ratio and reaction conditions of Example 2. The reaction results are shown in Table 5.
[0065] Table 5. Results of catalyst reuse reaction in Example 5
[0066] Apply Batch / Run <![CDATA[H 12 MDA content / %]]> anti-anti isomer content / % Other contents / % 56 91.7 16.9 8.3 60 90.8 17.2 9.2 70 88.5 17.8 11.5 80 86.5 18.0 13.5 90 84.2 18.2 15.8 100 81.8 18.9 18.2 110 77.8 19.4 22.2
[0067] As can be seen from Table 5, the catalyst activity was significantly restored, and H in Run56 12 MDA yield rose to 91.7% until lot number 110, H 12 MDA yield only dropped below 80%.
[0068] Example 6
[0069] When the catalyst from Example 3 was reused for 70 batches, its activity showed a significant decrease. At this point, 200g of 1,8-hexanediol was added to the reactor, and the feed valve and vent valve were kept open and connected to the atmosphere. The reactor was heated to 400°C and maintained for 12 hours. Subsequently, the reactor was cooled to below 40°C, and 500g of methanol was added to wash the catalyst for approximately 5 hours. The methanol washing liquid was then filtered out of the reactor through a built-in filter. Finally, 500g of tetrahydrofuran was added to the reactor and the catalyst was activated for 5 hours at 200°C and 6MPa hydrogen gas.
[0070] After the catalyst regeneration process was completed, the hydrogenation reaction was carried out according to the feed ratio and reaction conditions of Example 3. The reaction results are shown in Table 6.
[0071] Table 6. Results of catalyst reuse reaction in Example 6
[0072] Apply Batch / Run <![CDATA[H 12 MDA content / %]]> anti-anti isomer content / % Other contents / % 71 94.8 18.9 5.2 80 92.7 19.2 7.3 90 88.2 19.6 11.8 100 84.3 19.8 15.7 110 79.8 20.0 20.2
[0073] As can be seen from Table 6, the catalyst activity was significantly restored, and H in Run71 12 MDA yield rose to 94.8% until lot number 110, H 12 MDA yield only dropped below 80%.
[0074] Comparative Example 1
[0075] Except for the absence of 1,6-hexanediol, the other conditions were the same as in Example 4, and the reaction results are shown in Table 7.
[0076] Table 7 shows the reaction results of Comparative Example 1 using the same catalyst.
[0077] Apply batch / Run <![CDATA[H 12 MDA content / %]]> anti-anti isomer content / % Other contents / % 110 80.7 20.5 19.3 120 77.8 22.9 22.2 130 73.8 23.1 26.2
[0078] As can be seen from Table 7, if 1,6-hexanediol is not added during the calcination process, the catalyst activity cannot be effectively restored. 12 MDA yield continues to decline.
[0079] Comparative Example 2
[0080] Except for the absence of tetrahydrofuran washing catalyst, the other conditions were the same as in Example 5, and the reaction results are shown in Table 8.
[0081] Table 8 shows the reaction results of Comparative Example 2 using the same catalyst.
[0082] Apply Batch / Run <![CDATA[H 12 MDA content / %]]> anti-anti isomer content / % Other contents / % 120 86.2 18.5 13.8 125 83.6 18.8 16.4 130 81.6 19.3 18.4 135 78.6 19.8 21.4
[0083] As can be seen from Table 8, when tetrahydrofuran is not used for washing, although the catalyst activity is somewhat restored, it still cannot achieve the reaction effect of Example 5.
[0084] Comparative Example 3
[0085] Except for not performing hydrogen activation, the other conditions were the same as in Example 6, and the reaction results are shown in Table 9.
[0086] Table 9 shows the reaction results of Comparative Example 3 using the same catalyst.
[0087] Apply Batch / Run <![CDATA[H 12 MDA content / %]]> anti-anti isomer content / % Other contents / % 115 77.8 20.5 22.2 120 75.6 21.3 24.4
[0088] As can be seen from Table 9, the catalyst activity cannot be effectively recovered without high-pressure hydrogen activation. 12 MDA yield remains below 80%.
Claims
1. A kind of H 12 The catalyst regeneration method in the MDA production process is characterized by... The regeneration method is a catalyst regeneration process used in the production of diaminodicyclohexylmethane via hydrogenation reaction using MDA as raw material and under the action of a metal-supported catalyst. When the catalyst activity decreases, the catalyst is regenerated using a method including the following steps: 1) Calcination step: Add a higher alcohol compound to the catalyst and calcine it; wherein, the higher alcohol compound has the molecular formula OH-(CH2)n-OH, 10≥n≥6, the amount of the higher alcohol compound added is 10-100 times the mass of the catalyst, the calcination temperature is 300℃-400℃, and the time is 6h-24h. 2) Washing step: Add at least one of methanol, ethanol, dioxane, dichloroethane, acetone and tetrahydrofuran, the amount of which is 50-500 times the mass of the catalyst, and wash and clean. 3) Activation step: Add hydrogen gas to activate and regenerate.
2. The catalyst regeneration method according to claim 1, characterized in that, The catalyst comprises a combination of a metal and a support: The metal includes any one or at least two combinations of Group VIIIB metals; The carrier includes any one or at least two combinations of rare earth, diatomaceous earth, alumina, lithium aluminate, zirconium oxide, spinel, silicon oxide, or silicon aluminum oxide.
3. The catalyst regeneration method according to claim 2, characterized in that, The metal includes any one or at least two combinations of Pt, Rh, Ru, Ir or Pd; The carrier is alumina and / or zirconium oxide.
4. The catalyst regeneration method according to claim 2, characterized in that, The catalyst is Rh / Al2O3 and / or Rh / ZrO2.
5. The catalyst regeneration method according to claim 2, characterized in that, The metal content is 3-6 wt% based on the weight of the metal-supported catalyst.
6. The catalyst regeneration method according to claim 1, characterized in that, The higher alcohol compound is 1,6-hexanediol and / or 1,8-octanediol.
7. The catalyst regeneration method according to claim 1, characterized in that, The amount of the higher alcohol compound added is 20-50 times the mass of the catalyst.
8. The catalyst regeneration method according to claim 1, characterized in that, In the activation step, the hydrogen pressure is 2-10 MPa, the activation and regeneration reaction temperature is 150-250℃, and the time is 1-10 h.
9. The catalyst regeneration method according to claim 1 or 8, characterized in that, The solvent used in the activation step is selected from at least one of cyclohexane, dioxane, tetrahydrofuran, cyclohexylamine, dicyclohexylamine, methanol, ethanol, isopropanol, n-butanol, 2-butanol, or methylcyclohexane.
10. The catalyst regeneration method according to claim 9, characterized in that, The amount of solvent used in the activation step is 50-200 times the mass of the catalyst.
11. The catalyst regeneration method according to any one of claims 1-5, characterized in that, When H in the product liquid 12 When the MDA content drops below 80%, or the content of trans-trans isomers exceeds 20%, it indicates a decrease in catalyst activity.