A method for separating and purifying hanging tetrahydrodicyclopentadiene
The one-step separation of hanging tetrahydrodicyclopentadiene at low reflux ratio and mild conditions by reducing pressure distillation solves the problem of by-product separation, achieves a high purity and safe production process, simplifies operation and reduces cost.
Patent Information
- Application Number
- CN202410091934.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-23
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2044-01-23
AI Technical Summary
In the prior art, when synthesizing hanging tetrahydrodicyclopentadiene, separation of by-products such as trans decahydronaphthalene and adamantane is difficult to achieve high purity, and the use of an azeotrope increases the separation load and production cost, and the azeotrope is For example, amines or alcohol amines have safety hazards.
Use reduced pressure distillation to separate from the mixture of hanging tetrahydrodicyclopentadiene, trans decahydronaphthalene, adamantane and bridge tetrahydrodicyclopentadiene, controlled distillation pressure between 60Pa and 100Pa and top temperature of 25 ℃-62℃, tower section insulation is 35℃-83℃, top sampling reflux ratio (4-7): 1, high-purity hanging tetrahydrodicyclopentadiene is separated by a one-step method.
The separation of high purity (99.8% or more) hanging tetrahydrodicyclopentadiene is achieved, with simple operation, mild conditions and short separation period, avoiding the safety hazards of using azeotropic agent and increased production costs.
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of separation of fine chemicals, and in particular relates to a method for separating and purifying exo-tetrahydrodicyclopentadiene. Background Art
[0002] Exo-THEDCPD has a wide range of applications as fuel, synthetic pharmaceutical intermediates, pesticide intermediates, veterinary drug intermediates, rubber and photosensitive materials. Currently, the synthesis of exo-THEDCPD is mainly synthesized by isomerization reaction of endo-THDCPD. However, in the actual reaction process, a certain amount of by-products are produced due to the catalytic reaction, such as trans-decalin and adamantane with similar boiling points, so that high-purity exo-THDCPD must be obtained by separation and purification after the reaction.
[0003] Patent CN106673941 B uses steam distillation to separate reaction solvents with a boiling point lower than that of tetrahydrodicyclopentadiene: the amount of water used is 0.1-1 times the reaction solvent in the mixture to be separated, the theoretical number of plates is 10-30, the distillation pressure is 101kPa, the reflux ratio is 0.1:1-1:1, the top temperature is 68℃-71℃, the bottom temperature is 81℃-85℃, the top produced liquid is separated, and the reaction solvent and water can be recycled. Multi-entrainer distillation is used to separate light by-products: the multi-entrainer is composed of 10%-90% water and 10%-90% organic oxygen-containing compounds. The dosage of the multi-element azeotropic agent is 0.1-5 times of the mass of the mixture to be separated, the theoretical plate number is 30-200, the distillation pressure is 101 kPa, the reflux ratio is 10:1-50:1, the tower top temperature is 80-100°C, the tower bottom temperature is 90-105°C, and the multi-element azeotropic distillation operation is carried out until the relative content ratio of trans-decalin and exo-tetrahydrodicyclopentadiene in the tower bottom mixture is (1.0%-1.5%) / (98.5%-99.0%), the tower top produced liquid is subjected to water separation, and the oxygen-containing organic matter in the multi-element azeotropic agent is separated from the light by-products through vacuum distillation and can be recycled. The method uses steam distillation to separate hanging tetrahydrodicyclopentadiene: the amount of water used is 1-8 times of the mixture to be separated, the number of theoretical plates is 30-200, the distillation pressure is 101 kPa, the reflux ratio is 5:1-50:1, the tower top temperature is 95°C-100°C, the tower bottom temperature is 95°C-105°C, and the content of hanging tetrahydrodicyclopentadiene in the tower top produced liquid is kept higher than 98.5%. The tower top produced liquid is separated by water to obtain hanging tetrahydrodicyclopentadiene with a purity of more than 98.5%. This distillation method requires the addition of an azeotropic agent, which additionally increases the separation load and production cost. In addition, amine or alcohol amine azeotropic agents have a pungent odor, poor storage stability, and potential safety hazards. Summary of the invention
[0004] The object of the present invention is to provide a method for separating and purifying exo-tetrahydrodicyclopentadiene.
[0005] A method for separating and purifying exo-tetrahydrodicyclopentadiene, which uses vacuum distillation to separate exo-tetrahydrodicyclopentadiene, trans-decahydronaphthalene, adamantane and bridging tetrahydrodicyclopentadiene from a mixture to obtain high-purity exo-tetrahydrodicyclopentadiene.
[0006] The mass percentages of the components in the mixture are: 75%-85% of exo-tetrahydrodicyclopentadiene, 2%-10% of trans-decahydronaphthalene, 0.1%-3% of adamantane, and 2%-20% of bridging tetrahydrodicyclopentadiene.
[0007] During the vacuum distillation operation, the distillation pressure needs to be controlled at 60Pa-100Pa, the tower top temperature at 25℃-62℃, the tower bottom temperature at 65℃-105℃, the upper section of the tower section at 35℃-45℃, the middle section of the tower section at 53℃-65℃, the lower section of the tower section at 68℃-83℃, and the tower top sampling reflux ratio (4-7): 1.
[0008] The high purity is that the purity of exo-tetrahydrodicyclopentadiene is above 99.8%.
[0009] Beneficial effects of the present invention: The present invention uses vacuum distillation to separate exo-tetrahydrodicyclopentadiene from trans-decahydronaphthalene, adamantane and bridging tetrahydrodicyclopentadiene in a one-step process under conditions of a relatively low reflux ratio and distillation temperature. The method has the characteristics of simple operation, mild conditions, and a short separation cycle. DETAILED DESCRIPTION
[0010] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.
[0011] Example 1
[0012] Take 500g of raw liquid (mass percentage composition: hanging tetrahydrodicyclopentadiene accounts for 75.3%, trans-decahydronaphthalene accounts for 3.7%, adamantane accounts for 0.1%, and bridge-tetrahydrodicyclopentadiene accounts for 20.9%) and add it to the bottom of the tower. On a distillation tower with a theoretical plate number of 50, the vacuum distillation method is adopted to control the distillation pressure to 82Pa, the top temperature to 37°C, the bottom temperature to 79°C, the upper section of the tower section to 42°C, the middle section to 60°C, the lower section to 70°C, the top sampling reflux ratio to 5:1, and continuous distillation for 10h to obtain hanging tetrahydrodicyclopentadiene with a purity of 99.81% in the top produced liquid.
[0013] Example 2
[0014] Take 500g of raw liquid (mass percentage composition: hanging tetrahydrodicyclopentadiene accounts for 78.1%, trans-decahydronaphthalene accounts for 2.8%, adamantane accounts for 0.3%, and bridge-tetrahydrodicyclopentadiene accounts for 18.8%). Add it into the bottom of the tower. On a distillation tower with a theoretical plate number of 50, use vacuum distillation to control the distillation pressure to 62Pa, the top temperature to 25°C, the bottom temperature to 65°C, the upper section of the tower to 35°C, the middle section to 55°C, the lower section to 68°C, the top sampling reflux ratio to 4:1, and continue distillation for 10h to obtain hanging tetrahydrodicyclopentadiene with a purity of 99.78% in the top produced liquid.
[0015] Example 3
[0016] Take 500g of raw liquid (mass percentage composition: 84.5% of hanging tetrahydrodicyclopentadiene, 4.8% of trans-decahydronaphthalene, 1.2% of adamantane, and 9.5% of bridge-tetrahydrodicyclopentadiene) and add it to the bottom of the tower. On a distillation tower with a theoretical plate number of 50, the vacuum distillation method is adopted, the distillation pressure is controlled to be 100Pa, the top temperature is 60°C, the bottom temperature is 100°C, the upper section of the tower is kept at 45°C, the middle section of the tower is kept at 65°C, the lower section of the tower is kept at 80°C, the top sampling reflux ratio is 7:1, and the distillation is continued for 10 hours to obtain hanging tetrahydrodicyclopentadiene with a purity of 99.62% in the top produced liquid.
[0017] Comparative Example 1
[0018] Take 500g of raw liquid (mass percentage composition: hanging tetrahydrodicyclopentadiene accounts for 65.3%, trans-decahydronaphthalene accounts for 3.7%, adamantane accounts for 0.1%, and bridge-tetrahydrodicyclopentadiene accounts for 30.9%) and add it to the bottom of the tower. On a distillation tower with a theoretical plate number of 50, the vacuum distillation method is adopted to control the distillation pressure to 82Pa, the top temperature to 37°C, the bottom temperature to 79°C, the upper section of the tower is kept at 42°C, the middle section of the tower is kept at 60°C, the lower section of the tower is kept at 70°C, the top sampling reflux ratio is 5:1, and the distillation is continued for 10 hours to obtain hanging tetrahydrodicyclopentadiene with a purity of 95.32% in the top produced liquid.
[0019] Comparative Example 2
[0020] Take 500g of raw liquid (mass percentage composition: hanging tetrahydrodicyclopentadiene accounts for 75.3%, trans-decahydronaphthalene accounts for 3.7%, adamantane accounts for 0.1%, and bridge-tetrahydrodicyclopentadiene accounts for 20.9%) and add it to the bottom of the tower. On a distillation tower with a theoretical plate number of 50, the vacuum distillation method is adopted to control the distillation pressure to 82Pa, the top temperature to 37°C, the bottom temperature to 79°C, the upper section of the tower is kept at 33°C, the middle section of the tower is kept at 60°C, the lower section of the tower is kept at 70°C, the top sampling reflux ratio is 5:1, and the distillation is continued for 10 hours to obtain hanging tetrahydrodicyclopentadiene with a purity of 97.23% in the top produced liquid.
[0021] Comparative Example 3
[0022] Take 500g of raw liquid (mass percentage composition: hanging tetrahydrodicyclopentadiene accounts for 75.3%, trans-decahydronaphthalene accounts for 3.7%, adamantane accounts for 0.1%, and bridge-tetrahydrodicyclopentadiene accounts for 20.9%) and add it to the bottom of the tower. On a distillation tower with a theoretical plate number of 50, the vacuum distillation method is adopted to control the distillation pressure to 82Pa, the top temperature to 37°C, the bottom temperature to 79°C, the upper section of the tower section to 47°C, the middle section to 60°C, the lower section to 70°C, the top sampling reflux ratio to 5:1, and continuous distillation for 10h to obtain hanging tetrahydrodicyclopentadiene with a purity of 97.16% in the top produced liquid.
[0023] Comparative Example 4
[0024] Take 500g of raw liquid (mass percentage composition: hanging tetrahydrodicyclopentadiene accounts for 75.3%, trans-decahydronaphthalene accounts for 3.7%, adamantane accounts for 0.1%, and bridge-tetrahydrodicyclopentadiene accounts for 20.9%) and add it to the bottom of the tower. On a distillation tower with a theoretical plate number of 50, the vacuum distillation method is adopted to control the distillation pressure to 82Pa, the top temperature to 37°C, the bottom temperature to 79°C, the upper section of the tower section to 42°C, the middle section to 52°C, the lower section to 70°C, the top sampling reflux ratio to 5:1, and continuous distillation for 10h to obtain hanging tetrahydrodicyclopentadiene with a purity of 96.66% in the top produced liquid.
[0025] Comparative Example 5
[0026] Take 500g of raw liquid (mass percentage composition: hanging tetrahydrodicyclopentadiene accounts for 75.3%, trans-decahydronaphthalene accounts for 3.7%, adamantane accounts for 0.1%, and bridge-tetrahydrodicyclopentadiene accounts for 20.9%) and add it to the bottom of the tower. On a distillation tower with a theoretical plate number of 50, the vacuum distillation method is adopted to control the distillation pressure to 82Pa, the top temperature to 37°C, the bottom temperature to 79°C, the upper section of the tower section to 42°C, the middle section to 66°C, the lower section to 70°C, the top sampling reflux ratio to 5:1, and continuous distillation for 10h to obtain hanging tetrahydrodicyclopentadiene with a purity of 96.87% in the top produced liquid.
[0027] Comparative Example 6
[0028] Take 500g of raw liquid (mass percentage composition: hanging tetrahydrodicyclopentadiene accounts for 75.3%, trans-decahydronaphthalene accounts for 3.7%, adamantane accounts for 0.1%, and bridge-tetrahydrodicyclopentadiene accounts for 20.9%) and add it to the bottom of the tower. On a distillation tower with a theoretical plate number of 50, the vacuum distillation method is adopted to control the distillation pressure to 82Pa, the top temperature to 37°C, the bottom temperature to 79°C, the upper section of the tower section to 42°C, the middle section to 60°C, the lower section to 70°C, the top sampling reflux ratio to 3:1, and continuous distillation for 10h to obtain hanging tetrahydrodicyclopentadiene with a purity of 96.23% in the top produced liquid.
[0029] Comparative Example 7
[0030] Take 500g of raw liquid (mass percentage composition: hanging tetrahydrodicyclopentadiene accounts for 75.3%, trans-decahydronaphthalene accounts for 3.7%, adamantane accounts for 0.1%, and bridge-tetrahydrodicyclopentadiene accounts for 20.9%) and add it to the bottom of the tower. On a distillation tower with a theoretical plate number of 50, the vacuum distillation method is adopted to control the distillation pressure to 82Pa, the top temperature to 37°C, the bottom temperature to 79°C, the upper section of the tower section to 42°C, the middle section to 60°C, the lower section to 70°C, the top sampling reflux ratio to 8:1, and continuous distillation for 10h to obtain hanging tetrahydrodicyclopentadiene with a purity of 96.34% in the top produced liquid.
[0031] 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 method for separating and purifying exo-tetrahydrodicyclopentadiene, characterized in that: High-purity exo-tetrahydrodicyclopentadiene is separated from a mixture of exo-tetrahydrodicyclopentadiene, trans-decahydronaphthalene, adamantane and bridging tetrahydrodicyclopentadiene by vacuum distillation; the mass percentages of the components in the mixture are: exo-tetrahydrodicyclopentadiene 75-85%, trans-decahydronaphthalene 2-10%, adamantane 0.1-3%, bridging tetrahydrodicyclopentadiene 2-20%; during the vacuum distillation, the absolute pressure is controlled to be 60Pa-100Pa, the tower top temperature is 25°C-62°C, the tower bottom temperature is 65°C-105°C, the upper section of the tower is kept at 35°C-45°C, the middle section of the tower is kept at 53°C-65°C, the lower section of the tower is kept at 68°C-83°C, and the tower top sampling reflux ratio is (4-7): 1; the high purity is above 99.8%.