Technological method for purifying 1,4-butanediol and co-producing tetrahydrofuran

Abstract

The invention discloses a technological method for purifying 1,4-butanediol and co-producing tetrahydrofuran. The technological method comprises the following steps: a raw 1,4-butanediol material flow containing 2-(4-hydroxyl butoxy) tetrahydrofuran enters a 1,4-butanediol refining tower, and a 1,4-butanediol product is produced at the side line of the refining tower; and material flows rich in the 1,4-butanediol at the top and bottom of the refining tower enter a tetrahydrofuran reactor, dehydration cyclization is continuously carried out for producing the tetrahydrofuran through a palladium carried sulfonating ion exchange resin catalyst in the presence of hydrogen; after reaction, a raw tetrahydrofuran material flow enters a gas-liquid separator, a gas phase flow is reused or is discharged, and a liquid phase enters an azeotropic distillation tower; and azeotrope of tetrahydrofuran and water is obtained at the tower top and is separated to obtain the tetrahydrofuran product, liquid at the tower bottom enters a dehydration tower, and a material flow at the tower bottom returns to the tetrahydrofuran reactor. According to the technological method, the tetrahydrofuran with the high selectivity is produced while the 1,4-butanediol product with the high purity is separated out, the seperation problem of the 2-(4'-hydroxyl butoxy) tetrahydrofuran in the 1,4-butanediol product flow is solved, and the production cost is greatly reduced; and the technological method is suitable for industrial application.

Description

technical field

[0001] The invention relates to a process for refining crude 1,4-butanediol stream and co-producing tetrahydrofuran. Background technique

[0002] 1,4-Butanediol is an important basic organic chemical raw material, mainly used in the production of tetrahydrofuran, polybutylene terephthalate (PBT), γ-butyrolactone and polyurethane (PU). In recent years, due to the rapid growth in demand for thermoplastic elastic fibers and elastomers, the demand for PTMEG (polytetramethylene ether glycol) and PTMG (polytetrahydrofuran ether) as monomers has been strong, making the upstream raw material 1,4-butanedi The demand for alcohol is also growing rapidly, and major 1,4-butanediol producers in the world, such as BASF and DUPON, have expanded their production capacity. Tetrahydrofuran (THF) is a low-toxic solvent with high polarity, low boiling point and excellent performance. It is widely used as a solvent for surface coatings, anti-corrosion coatings and film coatings....

Examples

Embodiment 1

[0035] The crude 1,4-butanediol stream containing 0.36% 2-(4-hydroxybutoxy)tetrahydrofuran, 0.75% gamma-butyrolactone content, 98.89% 1,4-butanediol enters via line 1 Rectification tower A, the rectification tower adopts the conventional packing tower, operates under reduced pressure, controls tower top pressure 1.0kPa, reflux ratio 5.0, tower top reflux temperature 80 ℃, under this condition enters the stream of rectification tower A to pass separation, the side line 1,4-butanediol with a purity of 99.83% enters the product tank area through pipeline 3, and the overhead stream is composed of: 2-(4-hydroxybutoxy)tetrahydrofuran content 0.56%, γ-butyrolactone content 0.99%, The content of 4'-hydroxybutyl 4-hydroxybutyrate is 0.12%, and the content of 1,4-butanediol is 98.33%. Bottom stream composition: 2-(4-hydroxybutoxy)tetrahydrofuran content 0.02%, γ-butyrolactone content 0.01%, 4-hydroxybutyric acid 4'-hydroxybutyl ester content 0.24%, 1,4-butanedi The alcohol content is 9...

Embodiment 2

[0037] The crude 1,4-butanediol stream containing 0.5% 2-(4-hydroxybutoxy)tetrahydrofuran enters the rectification tower A through pipeline 1. The rectification tower adopts a conventional packed tower and is operated under reduced pressure to control the top pressure of 3.0 kPa, reflux ratio 15.0, the stream entering rectification tower A is separated, and 1,4-butanediol with a purity of 99.83% is obtained from the side line and enters the product tank area through line 3, and the bottom stream is all passed through line 5 and the tower from line 2 After mixing the 1,4-butanediol stream containing 0.94% 2-(4-hydroxybutoxy)tetrahydrofuran and the hot hydrogen coming from line 7, the hydrogen / butanediol molar ratio is controlled to be 8, and enter through line 6 In tetrahydrofuran reactor B, control the liquid hourly space velocity of 1,4-butanediol to 3.0h -1 , Carry out dehydration cyclization reaction under 110 ℃ of reaction temperature, reaction pressure 0.2MPa condition, t...

technical field

[0001] The invention relates to a process for refining crude 1,4-butanediol stream and co-producing tetrahydrofuran. Background technique

[0002] 1,4-Butanediol is an important basic organic chemical raw material, mainly used in the production of tetrahydrofuran, polybutylene terephthalate (PBT), γ-butyrolactone and polyurethane (PU). In recent years, due to the rapid growth in demand for thermoplastic elastic fibers and elastomers, the demand for PTMEG (polytetramethylene ether glycol) and PTMG (polytetrahydrofuran ether) as monomers has been strong, making the upstream raw material 1,4-butanedi The demand for alcohol is also growing rapidly, and major 1,4-butanediol producers in the world, such as BASF and DUPON, have expanded their production capacity. Tetrahydrofuran (THF) is a low-toxic solvent with high polarity, low boiling point and excellent performance. It is widely used as a solvent for surface coatings, anti-corrosion coatings and film coatings....

Examples

Embodiment 1

[0035] The crude 1,4-butanediol stream containing 0.36% 2-(4-hydroxybutoxy)tetrahydrofuran, 0.75% gamma-butyrolactone content, 98.89% 1,4-butanediol enters via line 1 Rectification tower A, the rectification tower adopts the conventional packing tower, operates under reduced pressure, controls tower top pressure 1.0kPa, reflux ratio 5.0, tower top reflux temperature 80 ℃, under this condition enters the stream of rectification tower A to pass separation, the side line 1,4-butanediol with a purity of 99.83% enters the product tank area through pipeline 3, and the overhead stream is composed of: 2-(4-hydroxybutoxy)tetrahydrofuran content 0.56%, γ-butyrolactone content 0.99%, The content of 4'-hydroxybutyl 4-hydroxybutyrate is 0.12%, and the content of 1,4-butanediol is 98.33%. Bottom stream composition: 2-(4-hydroxybutoxy)tetrahydrofuran content 0.02%, γ-butyrolactone content 0.01%, 4-hydroxybutyric acid 4'-hydroxybutyl ester content 0.24%, 1,4-butanedi The alcohol content is 9...

Embodiment 2

[0037] The crude 1,4-butanediol stream containing 0.5% 2-(4-hydroxybutoxy)tetrahydrofuran enters the rectification tower A through pipeline 1. The rectification tower adopts a conventional packed tower and is operated under reduced pressure to control the top pressure of 3.0 kPa, reflux ratio 15.0, the stream entering rectification tower A is separated, and 1,4-butanediol with a purity of 99.83% is obtained from the side line and enters the product tank area through line 3, and the bottom stream is all passed through line 5 and the tower from line 2 After mixing the 1,4-butanediol stream containing 0.94% 2-(4-hydroxybutoxy)tetrahydrofuran and the hot hydrogen coming from line 7, the hydrogen / butanediol molar ratio is controlled to be 8, and enter through line 6 In tetrahydrofuran reactor B, control the liquid hourly space velocity of 1,4-butanediol to 3.0h -1 , Carry out dehydration cyclization reaction under 110 ℃ of reaction temperature, reaction pressure 0.2MPa condition, t...

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