CN111995611A - A kind of synthesis technique of caprolactone - Google Patents

Abstract

The invention provides a synthesis process of caprolactone, which is characterized in that poly-6-hydroxycaproic acid (6-hydroxycaproic acid oligomer) stays in a catalyst bed layer for a plurality of times at a certain temperature and under a certain pressure, and the obtained product is dehydrated in a distillation tower at a certain temperature and under a certain pressure to obtain the caprolactone. The invention has the beneficial effects that: (1) the method has the advantages of simple steps, simplicity and high reaction progress. (2) The poly-6-hydroxycaproic acid is easy to obtain. (3) The yield of caprolactone reaches over 84 percent.

Description

A kind of synthesis technique of caprolactone

technical field

The invention belongs to the chemical industry, relates to the field of synthesis of caprolactone, and in particular relates to a synthesis process of caprolactone.

Background technique

Caprolactone is a new type of polyester monomer. It is mainly used in the production of synthetic rubber, synthetic fibers and synthetic resins. It is also used in the synthesis of polycaprolactone, adipic acid, adipamide, adhesives, etc. It can be blended with various resins to improve its gloss, impermeability and anti-sticking properties.

Patent CN 106397386 B relates to a method of adding cyclohexanone, pro-oxidant acrolein and catalyst carbon material to an organic solvent, using molecular oxygen as an oxidant, and stirring under the conditions of a pressure of 0.1-2MPa and a temperature of 60-100°C The reaction is carried out for 0.1 to 24 hours to obtain a method for obtaining caprolactone. In this method, the oxidation capacity of molecular oxygen is weak, a co-oxidant needs to be added, and the selectivity of caprolactone reaches more than 54%.

Patent CN 111018823 A relates to a kind of reaction kettle where cyclohexanone, catalyst and organic solvent are added to oxygen pressure of 0.1-1MPa, the temperature is raised to 30-90°C under stirring, methacrolein is slowly added, and After continuing to stir for 1-12 h, a mixed solution of ε-caprolactone, cyclohexanone, methacrylic acid, methacrolein and an organic solvent is obtained. After the mixed solution is subjected to secondary rectification in a rectifying tower, ε-caprolactone and methacrylic acid are respectively obtained. The method has a complicated process and the yield of caprolactone can reach more than 63%.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problems, the present invention provides a specific experimental scheme: the poly-6-hydroxycaproic acid (6-hydroxycaproic acid oligomer) is kept in a catalyst bed at a certain temperature and a certain pressure for a certain period of time, and the obtained product is obtained. Caprolactone is obtained by dehydration in a distillation column at a certain temperature and pressure.

The catalyst bed is selected from one or more of a slurry bed, a fixed bed, a fluidized bed, and a moving bed.

The catalyst is selected from one or more of α-Al ₂ O ₃ and molecular sieves such as Y-type, β-type, ZSM-5 type, TS-1 and MCM-22 type molecular sieves.

The added amount of the catalyst is 50%-200% of the mass of poly-6-hydroxycaproic acid.

The temperature is: 200-380°C, preferably 250-300°C.

The reaction pressure is: -0.1-2MPa.

The residence time is 0.05-10 h.

The residence time is 0.05-5h.

The distillation temperature is 100-120°C.

The distillation pressure is -0.1--0.025MPa.

The beneficial effects of the present invention are:

(1) The steps of the present invention are simple, the method is concise, and the reaction progress is fast.

(2) The yield of caprolactone is more than 84%.

Detailed ways

The present invention is further described below in conjunction with examples. However, the protection scope of the present invention is not limited to this.

Example 1

500g of poly-6-hydroxyhexanoic acid was held in a fixed bed with 250g α-Al2O3 catalyst at a temperature of 240°C and a pressure of -0.1MPa for 0.05h, and then dehydrated at a temperature of 100°C and a pressure of -0.1MPa to obtain caprolactone. The yield of ester was 84.2%.

Example 2

500g poly-6-hydroxyhexanoic acid was held in a fixed bed with 250g α-Al2O3 catalyst at a temperature of 260°C and a pressure of -0.1MPa for 0.05h, and then dehydrated at a temperature of 100°C and a pressure of -0.1MPa to obtain caprolactone. The yield of ester was 87.0%.

Example 3

500g poly-6-hydroxyhexanoic acid was held in a fixed bed with 500g α-Al2O3 catalyst at a temperature of 260°C and a pressure of -0.08MPa for 0.05h, and then dehydrated at a temperature of 100°C and a pressure of -0.08MPa to obtain caprolactone. The yield of ester was 84.9%.

Example 4

500g of poly-6-hydroxyhexanoic acid was held in a fixed bed with 250g α-Al2O3 catalyst at a temperature of 280°C and a pressure of -0.1MPa for 0.5h, and then dehydrated at a temperature of 100°C and a pressure of -0.1MPa to obtain caprolactone. The yield of ester was 89.5%.

Example 5

500g of poly-6-hydroxyhexanoic acid was held in a moving bed with 500g α-Al2O3 catalyst at a temperature of 320°C and a pressure of -0.1MPa for 1 hour, and then dehydrated at a temperature of 110°C and a pressure of -0.1MPa to obtain caprolactone. The yield was 88.9%.

Example 6

500g of poly-6-hydroxycaproic acid was kept at 300°C and pressure of -0.08MPa in a moving bed with 750g of α-Al2O3 catalyst for 2h, and then dehydrated at 100°C and -0.08MPa to obtain caprolactone. The yield was 92%.

Example 7

500 g of poly-6-hydroxyhexanoic acid was held in a slurry bed with 250 g of ZSM-5 molecular sieve catalyst at a temperature of 260 °C and a pressure of -0.1 MPa for 2 hours, and then dehydrated at a temperature of 100 °C and a pressure of -0.06 MPa to obtain The yield of caprolactone was 86.9%.

Example 8

500 g of poly-6-hydroxyhexanoic acid was held in a slurry bed with 250 g of ZSM-5 molecular sieve catalyst at a temperature of 280 °C and a pressure of -0.1 MPa for 3 h, and then dehydrated at a temperature of 110 °C and a pressure of -0.1 MPa to obtain The yield of caprolactone was 89.8%.

Example 9

500 g of poly-6-hydroxyhexanoic acid was held in a fixed bed with 500 g of ZSM-5 molecular sieve catalyst at a temperature of 260 °C and a pressure of -0.1 MPa for 0.05 h, and then dehydrated at a temperature of 100 °C and a pressure of -0.1 MPa to obtain The yield of caprolactone was 85.0%.

Example 10

500g poly-6-hydroxyhexanoic acid was held in a fixed bed with 750g ZSM-5 molecular sieve catalyst at a temperature of 280°C and a pressure of -0.1MPa for 0.05h, and then dehydrated at a temperature of 110°C and a pressure of -0.1MPa to obtain The yield of caprolactone was 92.7%.

Example 11

500g of poly-6-hydroxyhexanoic acid was held in a fixed bed with 250g β-type molecular sieve catalyst at a temperature of 280°C and a pressure of -0.1MPa for 0.05h, and then dehydrated at a temperature of 100°C and a pressure of -0.1MPa to obtain caprolactone. The yield of ester was 84.9%.

Example 12

500g of poly-6-hydroxyhexanoic acid was held in a fixed bed with 500g β-type molecular sieve catalyst at a temperature of 280°C and a pressure of -0.1MPa for 0.05h, and then dehydrated at a temperature of 110°C and a pressure of -0.1MPa to obtain caprolactone. The yield of ester was 91.0%.

Example 13

500g of poly-6-hydroxyhexanoic acid was held in a fixed bed of 750g β-type molecular sieve catalyst at a temperature of 280°C and a pressure of -0.1MPa for 0.05h, and then dehydrated at a temperature of 120°C and a pressure of -0.1MPa to obtain caprolactone. The yield of ester was 94.5%.

Example 14

500g of poly-6-hydroxyhexanoic acid was held in a fixed bed of 750g β-type molecular sieve catalyst at a temperature of 300°C and a pressure of -0.08MPa for 0.05h, and then dehydrated at a temperature of 120°C and a pressure of -0.08MPa to obtain caprolactone. The yield of ester was 95.1%.

The experimental data of Examples 1-14 are summarized in the following table:

It can be seen from the above table that the yield of caprolactone of the present invention is more than 84%.

Claims (10)

1. A synthesis process of caprolactone is characterized in that: poly 6-hydroxycaproic acid (6-hydroxycaproic acid oligomer) stays in a catalyst bed layer for a certain time at a certain temperature and under a certain pressure, and the obtained product is dehydrated in a distillation tower at a certain temperature and under a certain pressure to obtain caprolactone.

2. The process according to claim 1, wherein the synthesis of caprolactone comprises: the reaction equation is as follows:

3. the process according to claim 1, wherein the synthesis of caprolactone comprises:

the catalyst bed is selected from: one or more of a slurry bed, a fixed bed, a fluidized bed and a moving bed;

the catalyst is selected from: alpha-Al₂O₃Molecular sieves such as one or more of Y-type, beta-type, ZSM-5 type, TS-1 and MCM-22 type molecular sieves;

the adding amount of the catalyst is 50-200% of the mass of the poly-6-hydroxycaproic acid.

4. The process according to claim 1, wherein the synthesis of caprolactone comprises:

the temperature is as follows: 200 ℃ and 380 ℃.

5. The process according to claim 1, wherein the synthesis of caprolactone comprises:

the temperature is as follows: 250 ℃ to 300 ℃.

6. The process according to claim 1, wherein the synthesis of caprolactone comprises:

the reaction pressure is as follows: -0.1-2 MPa.

7. The process according to claim 1, wherein the synthesis of caprolactone comprises:

the residence time is 0.05-10 h.

8. The process according to claim 1, wherein the synthesis of caprolactone comprises:

the residence time is 0.05-5 h.

9. The process according to claim 1, wherein the synthesis of caprolactone comprises:

the distillation temperature is as follows: 100-120 ℃.

10. The process according to claim 1, wherein the synthesis of caprolactone comprises:

the distillation pressure is-0.1-0.025 MPa.