Catalyst and preparation method thereof, and method for recycling residual polymer in kettle during musk-T production process

Abstract

The present invention relates to a catalyst and a preparation method thereof, wherein the catalyst comprises a carrier and an active component loaded on the carrier, wherein the active component is a complex formed by a metal salt and a thiazolium salt, and the metal salt is selected from at least one of a palladium salt, a zinc salt, and an iron salt; the present invention also relates to a method for recycling residual polymers in a musk-T production process, comprising the following steps: mixing the catalyst, the residual polymers in the kettle and a solvent, performing a depolymerization reaction, and obtaining tridecanedioic acid through post-treatment. The residual polymers in the kettle are depolymerized by the catalyst of the present invention, and after the depolymerization is completed, there is no need to use strong acid acidification and water washing, the equipment is less corrosive, a large amount of waste salt and wastewater are not generated, the process is clean, environmentally friendly, efficient, and low in energy consumption, and the production efficiency and yield of musk-T products can be effectively improved, and the production cost can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of fine chemical industry, in particular to a catalyst and a preparation method thereof, and a method for recycling residual polymer in a kettle in the production process of Musk-T. Background Art

[0002] Musk-T, also known as Kunlun Musk, has a chemical name of 1,4-dioxacycloheptadecane-5,17-dione. It is a colorless or slightly yellow viscous liquid and an important macrolide musk fragrance. Musk-T is a high-grade fixative with a scent type close to that of natural musk. It is non-toxic, has a pure aroma, and has a long-lasting fragrance. It has a good rounding and flavoring effect in blending spices and can be widely used in the preparation of various high-grade flavors, especially in the preparation of various high-grade perfumes, shampoos, and cosmetics.

[0003] The difficulty in the industrial production of Musk-T is that after the reactants are polymerized, a high-viscosity polyester is obtained. During the depolymerization process, as the reaction proceeds, the viscosity of the polyester further increases, thereby reducing the heat transfer efficiency. In the later stage of the reaction, the polyester in the system becomes semi-solid or solid, making heat transfer difficult. Not only is the reaction yield low, but there is also a large amount of residue in the reactor, which contains a large amount of high-viscosity polymers. The annual output of Musk-T is about 10,000 tons, and the residue is about 1,000 tons. If it is directly treated as solid waste, it will not only increase the post-processing cost and fail to achieve continuous production, but also cause huge waste of resources and environmental pollution.

[0004] Patent CN105884742A returns the residual liquid of the kettle containing dimers and trimers to the depolymerization kettle for re-depolymerization, forming a closed cycle without generating "three wastes". Although this method can increase some products, the recovery is limited. At the same time, a large amount of energy consumption is increased in the recovery process, and the economic benefit ratio is not strong.

[0005] Patent CN111620773A discloses a method for preparing dibasic acid from musk-T still residue, which uses zinc salt as a catalyst in a strong alkaline environment to depolymerize still residue into tridecanedioic acid, and obtains tridecanedioic acid crystals after multiple crystallization and washing. However, the strong alkali and dilute acid used in this process will corrode the equipment, and acid-base neutralization will produce a large amount of wastewater and waste liquid, which does not conform to the concept of green chemical industry.

[0006] Patent CN109053427A discloses a method for recycling the depolymerization residue of musk-T. Under high temperature and high pressure, the depolymerization residue is treated with an inorganic base such as sodium hydroxide, potassium hydroxide, etc., and then the depolymerization liquid is acidified with concentrated hydrochloric acid or sulfuric acid, and repeatedly washed with 3-8 times the amount of water fed, and finally tridecanedioic acid is obtained. It can be seen that this method uses a large amount of strong alkali and strong acid, which will not only corrode the production equipment and increase the equipment investment, but also produce a large amount of waste salt and wastewater, and does not meet the production requirements of green environmental protection.

[0007] Patent CN114276229A discloses a method for recycling musk-T still residue, which uses Lewis acid-type imidazole ionic liquid as a catalyst and alcohols as a solvent to depolymerize musk-T still residue to generate tridecanedioic acid. However, the ionic liquid catalyst used in this method is relatively expensive and is mostly used in laboratory research, and the product yield is not high.

[0008] Therefore, developing an efficient, environmentally friendly, and low-energy method for recovering musk-T residue to reduce resource waste and improve the comprehensive yield of products is of great practical significance for the large-scale industrial production of musk-T products. Summary of the invention

[0009] Based on this, it is necessary to provide a catalyst and a preparation method thereof, and a method for recycling residual polymers in the production process of musk-T in order to solve the above problems. The catalyst is used to depolymerize residual polymers in the kettle. After the depolymerization is completed, there is no need to use strong acid for acidification and water washing. It is less corrosive to the equipment and does not produce a large amount of waste salt and wastewater. The process is clean, environmentally friendly, efficient, and low in energy consumption, which can effectively improve the production efficiency and yield of musk-T products and reduce production costs.

[0010] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a catalyst for depolymerizing the residual polymer in the production process of musk-T, the catalyst comprising a carrier and an active component loaded on the carrier, wherein the active component is a complex formed by a metal salt and a thiazolium salt, and the metal salt is selected from at least one of a palladium salt, a zinc salt, and an iron salt.

[0011] In one embodiment, the metal salt is selected from at least two of palladium salts, zinc salts, and iron salts;

[0012] And / or, the thiazolium salt is at least one selected from 3-(carboxymethyl)benzothiazolium bromide, 3-methylbenzothiazolium iodide, 3-ethyl-2-methylbenzothiazolium iodide, 3-benzylthiazolium bromide, 3-benzyl-4-methylthiazolium chloride, and N-allylbenzothiazolium bromide;

[0013] And / or, the carrier is selected from at least one of γ-Al2O3, SBA-15, TS-1, SBA-16, ZSM-5, HZSM-5, MCM-41, and MCM-48.

[0014] In one embodiment, the molar ratio of the metal element in the metal salt to the thiazolium salt is 1:3-1:10;

[0015] And / or, the molar ratio of the metal element in the metal salt to the carrier is 0.005:1-0.09:1.

[0016] In one embodiment, the molar ratio of the metal element in the metal salt to the thiazolium salt is 1:5-1:9;

[0017] And / or, the molar ratio of the metal element in the metal salt to the carrier is 0.01:1-0.07:1.

[0018] The present invention also provides a method for preparing the catalyst, comprising the following steps:

[0019] mixing a metal salt, a thiazolium salt and a solvent to obtain a formulation;

[0020] A carrier is added to the preparation for adsorption, and the catalyst is obtained after removing the solvent.

[0021] In one embodiment, in the step of mixing the metal salt, the thiazolium salt and the solvent, the temperature is 80° C.-120° C. and the time is 2 hours-4 hours.

[0022] In one embodiment, in the step of adding a carrier to the formulation for adsorption, the temperature is 40° C.-80° C. and the time is 4 hours-6 hours.

[0023] The present invention also provides a method for recycling residual polymer in the process of producing Musk-T, comprising the following steps:

[0024] The catalyst, the residual polymer in the still and the solvent are mixed, and a depolymerization reaction is carried out, and tridecanedioic acid is obtained through post-treatment.

[0025] In one embodiment, the mass ratio of the catalyst to the still residual polymer is 0.01:1-0.1:1;

[0026] And / or, the mass ratio of the solvent to the still residual polymer is 1:1-5:1;

[0027] And / or, in the step of performing the depolymerization reaction, the temperature is 100°C-160°C.

[0028] In one embodiment, the mass ratio of the catalyst to the still residue polymer is 0.05:1-0.07:1;

[0029] And / or, the mass ratio of the solvent to the still residual polymer is 1:1-3:1;

[0030] And / or, in the step of performing the depolymerization reaction, the temperature is 120°C-160°C.

[0031] In the catalyst of the present invention, the thiazolium salt and the metal salt can form a stable complex through chelation, and the selectivity of the catalyst can be effectively improved by adjusting the steric hindrance of the complex, and the occurrence of side reactions can be suppressed. In addition, the complex is modified on the carrier so that the active metal is evenly distributed in the carrier, forming a large number of metal active sites with catalytic activity, thereby improving the efficiency of the reaction. Therefore, the catalyst of the present invention is used to depolymerize the residual polymer in the reactor, and after the depolymerization is completed, there is no need to use strong acid acidification and water washing, the equipment is less corrosive, and a large amount of waste salt and wastewater are not generated. The process is clean, environmentally friendly, efficient, and low in energy consumption, and the production efficiency and yield of Musk-T products can be effectively improved, and the production cost can be reduced. DETAILED DESCRIPTION

[0032] For ease of understanding of the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific implementation methods or embodiments, and are not intended to limit the present invention. The optional scope of the term "and / or" used herein includes any one of two or more related listed items, and also includes any and all combinations of related listed items, and the combinations include any two related listed items, any more related listed items, or all related listed items.

[0034] The present invention provides a catalyst for depolymerizing still residue polymers in the production process of musk-T, comprising a carrier and an active component loaded on the carrier, wherein the active component is a complex formed by a metal salt and a thiazolium salt, and the metal salt is selected from at least one of a palladium salt, a zinc salt and an iron salt.

[0035] Preferably, the carrier is a mesoporous carrier, which can not only support the active components of the catalyst, but also provide a place for the reaction with its large specific surface area and pores, thereby regulating the selectivity. Optionally, it is selected from at least one of γ-Al2O3, SBA-15, TS-1, SBA-16, ZSM-5, HZSM-5, MCM-41, and MCM-48, preferably at least one of SBA-15, SBA-16, HZSM-5, TS-1, and MCM-41, and more preferably at least one of SBA-16, HZSM-5, and TS-1.

[0036] Optionally, the metal salt is selected from at least one of nitrates or their hydrates, hydrochlorides or their hydrates, sulfates or their hydrates, and acetates or their hydrates. For example, the palladium salt is selected from at least one of palladium nitrate or its hydrate, palladium chloride or its hydrate, palladium sulfate or its hydrate, and palladium acetate or its hydrate. The zinc salt is selected from at least one of zinc nitrate or its hydrate, zinc chloride or its hydrate, zinc sulfate or its hydrate, and zinc acetate or its hydrate. The iron salt is selected from at least one of ferric nitrate or its hydrate, ferric chloride or its hydrate, ferric sulfate or its hydrate, and ferric acetate or its hydrate.

[0037] Preferably, the active component is a complex formed by at least two metal salts of palladium salt, zinc salt and iron salt and thiazolium salt, which has a better effect.

[0038] Optionally, the thiazolium salt is selected from at least one of 3-(carboxymethyl)benzothiazolium bromide, 3-methylbenzothiazolium iodide, 3-ethyl-2-methylbenzothiazolium iodide, 3-benzylthiazolium bromide, 3-benzyl-4-methylthiazolium chloride, and N-allylbenzothiazolium bromide, preferably at least one of 3-(carboxymethyl)benzothiazolium bromide, 3-ethyl-2-methylbenzothiazolium iodide, 3-benzylthiazolium bromide, and 3-benzyl-4-methylthiazolium chloride.

[0039] In the catalyst of the present invention, the thiazolium salt and the metal salt can form a stable complex through chelation. By adjusting the steric hindrance of the complex, the selectivity of the catalyst can be effectively improved and the occurrence of side reactions can be suppressed. In addition, the complex is modified on the carrier so that the active metal is evenly distributed in the carrier, forming a large number of metal active sites with catalytic activity, thereby improving the efficiency of the reaction.

[0040] Therefore, when the catalyst of the present invention is used to depolymerize the residual polymer in the reactor, there is no need to use strong acid for acidification and water washing after the depolymerization is completed. The corrosion to the equipment is small, and a large amount of waste salt and wastewater are not generated. The process is clean, environmentally friendly, efficient, and low in energy consumption. The production efficiency and yield of Musk-T products can be effectively improved, and the production cost can be reduced.

[0041] Optionally, the molar ratio of the metal element in the metal salt to the thiazolium salt is 1:3-1:10, preferably 1:3-1:9, and more preferably 1:5-1:9.

[0042] Optionally, the molar ratio of the metal element in the metal salt to the carrier is 0.005:1-0.09:1, preferably 0.01:1-0.09:1, and more preferably 0.01:1-0.07:1.

[0043] The present invention also provides a method for preparing the catalyst, comprising the following steps:

[0044] S11, mixing a metal salt, a thiazolium salt and a solvent to obtain a preparation;

[0045] S12, adding a carrier to the preparation for adsorption, and removing the solvent to obtain a catalyst.

[0046] In step S11, the solvent is preferably one that can disperse the metal salt and the thiazolium salt, and water is preferred.

[0047] Preferably, in the step of mixing the metal salt, the thiazolium salt and the solvent in step S11, the temperature is 80° C.-120° C. and the time is 2 hours-4 hours, so that the metal salt and the thiazolium salt can form a complex better.

[0048] Preferably, in step S12 of adding a carrier to the formulation for adsorption, the temperature is 40° C.-80° C. and the time is 4 hours-6 hours, which is beneficial to improving the adsorption rate and adsorption effect of the complex on the carrier.

[0049] The preparation method of the catalyst of the present invention is simple, the conditions are mild, and the preparation process is environmentally friendly.

[0050] The present invention also provides a method for recycling residual polymer in the process of producing Musk-T, comprising the following steps:

[0051] The catalyst, the residual polymer in the still and the solvent are mixed, and a depolymerization reaction is carried out, and tridecanedioic acid is obtained through post-treatment.

[0052] Optionally, the mass ratio of the catalyst to the still residual polymer is 0.01:1-0.1:1, preferably 0.03:1-0.09:1, and more preferably 0.05:1-0.07:1.

[0053] Optionally, the solvent is based on the ability to disperse the residual polymer, preferably at least one of ethylene glycol, ethanol, isopropanol, toluene, xylene, and water, preferably at least one of ethylene glycol and water. Preferably, the mass ratio of the solvent to the residual polymer is 1:1-5:1, preferably 1:1-3:1, which is conducive to saving energy consumption for post-processing.

[0054] Optionally, in the step of performing the depolymerization reaction, the temperature is 100°C-160°C, preferably 120°C-160°C.

[0055] It should be noted that the post-treatment includes filtering to recover the catalyst and distilling under reduced pressure to recover the solvent, and the recovered catalyst and solvent can be reused.

[0056] Hereinafter, the catalyst and its preparation method, and the method for recycling the residual polymer in the production process of Musk-T will be further described through the following specific examples.

[0057] Catalyst Preparation Example 1

[0058] At room temperature, add 2.35g of Zn(OAc)2·2H2O and 3.99g of Pd(NO3)2·2H2O to 20g of purified water and stir until completely dissolved. Then add 23.4g of 3-(carboxymethyl)benzothiazolium bromide, raise the temperature to 100°C, keep stirring for 4 hours, and then cool to 60°C. Then add 10.0g of dry SBA-16 carrier and continue stirring for 6 hours. Remove moisture by vacuum rotary evaporation, and place the resulting solid in an oven at 80°C and dry to constant weight to obtain a catalyst, expressed as 1.0% Pd-7.0% Zn / SBA-16@3-(carboxymethyl)benzothiazolium bromide, marked as catalyst 1.

[0059] Catalyst Preparation Examples 2-21

[0060] By changing the types and amounts of the metal salt, thiazolium salt and carrier, the following catalysts were obtained according to the method of Example 1, as shown in Tables 1 and 2.

[0061] Table 1

[0062]

[0063]

[0064] Table 2

[0065]

[0066]

[0067] Note: Except for some slightly different conditions in Example 2 and Example 3, the conditions in other examples are exactly the same as those in Example 1.

[0068] Specifically, the mixing temperature of Example 2 is 100° C., the mixing time is 4 hours, the adsorption temperature is 80° C., and the adsorption time is 6 hours. The mixing temperature of Example 3 is 80° C., the mixing time is 4 hours, the adsorption temperature is 40° C., and the adsorption time is 4 hours.

[0069] Experimental study on the recovery and utilization of residual polymer in the production process of Musk-T

[0070] The musk-T polymer kettle residue was homemade in the laboratory, specifically: tridecanedioic acid and ethylene glycol were added into the reactor in a molar ratio of 1:2, the temperature was raised to 160°C, and the reaction was continued until the acid value was <5 mgKOH / g. Under a vacuum degree of 0.09 MPa, the unreacted ethylene glycol was evaporated under reduced pressure, and then the product was placed in a depolymerization reactor. After ensuring that the system pressure was <50 Pa, the system was heated to 280°C. Musk-T was continuously distilled out during the process until no product was distilled out. At this time, the residue at the bottom of the kettle was a viscous syrup-like liquid, which was a purple-brown solid after cooling. This was the musk-T polymer kettle residue in the production process, which was the raw material for the following recycling experiments.

[0071] Recycling Example 1

[0072] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 4.5g of catalyst 1, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 4 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 144.0g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 36.30g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 85.6%.

[0073] Recycling Example 2

[0074] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 50g of ethylene glycol, and 0.5g of catalyst 1, heat up, start stirring when the residual polymer melts, heat to 160°C and react for 5 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 47.0g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 34.90g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 84.1%.

[0075] Recycling Example 3

[0076] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 1.5g of catalyst 1, heat up, start stirring when the residual polymer melts, heat to 160°C and react for 5 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 142.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 35.1g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 85.2%.

[0077] Recycling Example 4

[0078] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 250g of ethylene glycol, and 3.5g of catalyst 1, heat up, start stirring when the residual polymer melts, heat to 160°C and react for 4 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 237.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 35.75g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 85.2%.

[0079] Recycling Example 5

[0080] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethanol, and 3.5g of catalyst 2, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 5 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethanol, and the vacuum degree is further adjusted to 0.8kPa to obtain 34.30g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 83.1%.

[0081] Recycling Example 6

[0082] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of isopropanol, and 3.5g of catalyst 3, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 6 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent isopropanol, and the vacuum degree is further adjusted to 0.8kPa to obtain 34.90g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 84.6%.

[0083] Recycling Example 7

[0084] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of toluene, and 3.5g of catalyst 4, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 5 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 144.0g of solvent toluene, and the vacuum degree is further adjusted to 0.8kPa to obtain 33.05g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 83.2%.

[0085] Recycling Example 8

[0086] In a 250mL three-necked flask, add 50.0g of residual polymer from the production process of Musk-T, 150g of xylene, and 3.5g of catalyst 5, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 5 hours, filter after the reaction, filter out the catalyst for later use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent xylene, and the vacuum degree is further adjusted to 0.8kPa to obtain 35.80g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 85.0%.

[0087] Recycling Example 9

[0088] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of water, and 3.5g of catalyst 6, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 5 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 144.0g of solvent water, and the vacuum degree is further adjusted to 0.8kPa to obtain 33.65g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 84.0%.

[0089] Recycling Example 10

[0090] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 7, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 6 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 34.10g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 83.5%.

[0091] Recycling Example 11

[0092] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 8, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 4 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 36.00g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 85.4%.

[0093] Recycling Example 12

[0094] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 9, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 4 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 39.25g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 87.6%.

[0095] Recycling Example 13

[0096] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 100g of ethylene glycol, and 5.0g of catalyst 10, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 6 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 97.0g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 30.65g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 83.2%.

[0097] Recycling Example 14

[0098] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 11, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 4 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 36.80g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 86.5%.

[0099] Recycling Example 15

[0100] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 12, heat up, start stirring when the residual polymer melts, heat to 160°C and react for 6 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 35.25g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 83.4%.

[0101] Recycling Example 16

[0102] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 13, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 6 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 36.20g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 82.5%.

[0103] Recycling Example 17

[0104] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 14, heat up, start stirring when the residual polymer melts, heat to 160°C and react for 6 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 34.75g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 81.2%.

[0105] Recycling Example 18

[0106] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 15, heat up, start stirring when the residual polymer melts, heat to 160°C and react for 6 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 31.05g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 80.8%.

[0107] Recycling Example 19

[0108] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 16, heat up, start stirring when the residual polymer melts, heat to 160°C and react for 6 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 29.35g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 75.6%.

[0109] Recycling Example 20

[0110] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 17, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 6 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 32.65g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 79.2%.

[0111] Recycling Example 21

[0112] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 18, heat up, start stirring when the residual polymer melts, heat to 160°C and react for 7 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 27.80g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 74.1%.

[0113] Recycling Example 22

[0114] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 19, heat up, start stirring when the residual polymer melts, heat to 120°C and react for 4 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 34.90g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 80.6%.

[0115] Recycling Example 23

[0116] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 20, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 7 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 25.10g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 72.5%.

[0117] Recycling Example 24

[0118] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 21, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 7 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 17.85g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 65.1%.

[0119] Recycling Example 25

[0120] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and then add the catalyst 1 recovered from the recycling example 1, heat up, start stirring when the residual polymer melts, heat to 150°C and react for 3.5 hours, filter after the reaction, filter out the catalyst for standby use. The filtrate is subjected to reduced pressure distillation, the vacuum degree is controlled to 0.09MPa, and 145.5g of solvent ethylene glycol is obtained. The vacuum degree is further adjusted to 0.8kPa to obtain 36.84g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 85.2%.

[0121] Recycling Example 26

[0122] In a 250mL three-necked flask, add 50.0g of the residual polymer in the production process of Musk-T, 150g of ethylene glycol, and 3.5g of catalyst 9, heat up, start stirring when the residual polymer melts, heat to 100°C and react for 5 hours, filter after the reaction, filter out the catalyst for use. The filtrate is subjected to reduced pressure distillation, and the vacuum degree is controlled to 0.09MPa to obtain 145.5g of solvent ethylene glycol, and the vacuum degree is further adjusted to 0.8kPa to obtain 37.61g of distillate, and the selectivity of tridecanedioic acid detected by gas chromatography is 87.2%.

[0123] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0124] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A catalyst for depolymerizing the still residue polymer in the production process of musk-T, characterized in that: The catalyst comprises a carrier and an active component supported on the carrier, wherein the active component is a complex formed by a metal salt and a thiazolium salt, and the metal salt is selected from at least one of a palladium salt, a zinc salt, and an iron salt, and the thiazolium salt is selected from at least one of 3-(carboxymethyl)benzothiazolium bromide, 3-methylbenzothiazolium iodide, 3-ethyl-2-methylbenzothiazolium iodide, 3-benzylthiazolium bromide, 3-benzyl-4-methylthiazolium chloride, and N-allylbenzothiazolium bromide, and the molar ratio of the metal element in the metal salt to the thiazolium salt is 1:3-1:10, and the molar ratio of the metal element in the metal salt to the carrier is 0.005:1-0.09:

1.

2. The catalyst according to claim 1, characterized in that The metal salt is selected from at least two of palladium salts, zinc salts, and iron salts; And / or, the carrier is selected from at least one of γ-Al2O3, SBA-15, TS-1, SBA-16, ZSM-5, HZSM-5, MCM-41, and MCM-48.

3. The catalyst according to claim 1, characterized in that The molar ratio of the metal element in the metal salt to the thiazolium salt is 1:5-1:9; And / or, the molar ratio of the metal element in the metal salt to the carrier is 0.01:1-0.07:

1.

4. A method for preparing a catalyst as claimed in any one of claims 1 to 3, characterized in that: The following steps are involved: mixing a metal salt, a thiazolium salt and a solvent to obtain a formulation; A carrier is added to the preparation for adsorption, and the catalyst is obtained after removing the solvent.

5. The method for preparing the catalyst according to claim 4, characterized in that: In the step of mixing the metal salt, the thiazolium salt and the solvent, the temperature is 80° C. to 120° C. and the time is 2 hours to 4 hours.

6. The method for preparing the catalyst according to claim 4, characterized in that: In the step of adding a carrier to the preparation for adsorption, the temperature is 40° C.-80° C. and the time is 4 hours-6 hours.

7. A method for recycling residual polymers in the production process of Musk-T, characterized in that: The following steps are involved: The catalyst as claimed in any one of claims 1 to 3, residual polymer in a still and a solvent are mixed, depolymerized and then post-treated to obtain tridecanedioic acid.

8. The method for recycling the residual polymer in the production process of Musk-T according to claim 7, characterized in that: The mass ratio of the catalyst to the still residual polymer is 0.01:1-0.1:1; And / or, the mass ratio of the solvent to the still residual polymer is 1:1-5:1; And / or, in the step of performing the depolymerization reaction, the temperature is 100°C-160°C.

9. The method for recycling the residual polymer in the production process of Musk-T according to claim 8, characterized in that: The mass ratio of the catalyst to the still residual polymer is 0.05:1-0.07:1; And / or, the mass ratio of the solvent to the still residual polymer is 1:1-3:1; And / or, in the step of performing the depolymerization reaction, the temperature is 120°C-160°C.

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