Method for separating benzene-n-propyl alcohol-water mixture through heat pump extractive distillation

Abstract

The invention relates to a method for separating a benzene-n-propyl alcohol-water mixture through heat pump extractive distillation and a device suitable for the method. According to the method, glycerin is used as an extraction agent, water containing benzene and n-propanol enters an extractive distillation tower for extractive distillation separation, benzene with the purity of 99.9% is extracted from the upper portion of the extractive distillation tower, materials on the lower portion of the extractive distillation tower enter another extractive distillation tower for separation, high-purity n-propanol is obtained at the top of the extractive distillation tower, the extraction agent and water are extracted from the bottom of the extractive distillation tower and then separated through a common distillation tower, and the high-purity extraction agent is obtained and then recycled. The method has the advantages of low energy consumption, simple process, high purity of benzene and n-propanol and the like, the adopted extraction agent glycerol is almost non-volatile, the loss of the extraction agent is reduced, and the method is easy to recover, good in chemical thermal stability, green and pollution-free.

Description

Technical field

[0001] The invention belongs to the field of chemical separation and purification, and specifically relates to a method for separating benzene-n-propanol-water mixture by heat pump extraction and rectification, and furthermore, relates to a method for separating benzene-n-propanol by heat pump extraction and rectification using glycerin as an extraction agent Alcohol-water mixture method.

Background technique

[0002] N-propanol and benzene are important organic solvents, which are widely used in fine chemicals, pharmaceuticals, coatings and other fields. N-propanol can be used as a raw material to synthesize propyl acetate, which is used in solvents, printing inks, cosmetic synthetic rubber, etc., and can also be used in the production of probenecid, erythromycin and other drugs. Benzene is one of the most commonly used organic solvents in industry, and can be used to produce important chemicals such as cyclohexane. Benzene and n-propanol exist in many ...

Examples

Embodiment 1

[0037] Take 100kmol / h of 30mol% benzene, 60mol% n-propanol and 10mol% n-propanol as an example:

[0038]The number of plates of the extractive distillation column (T1) is 32, the mixed material enters the extractive distillation column (T1) from the 29th plate, and the extractant glycerin enters the extractive distillation column (T1) from the 3rd plate, and the extractant The flow rate is 35kmol / h, the bottom stream enters the flash tank (F1) after heat exchange with the overhead stream compressed by the heat exchanger (H1) and the heat pump compressor (P1), and the separated gas stream is sent from the first 32 trays are returned to the extractive distillation column (T1), and the liquid flow enters the extractive distillation column (T2) from the 43rd column, and the extractive distillation column (T2) has 48 trays in total, and the extractant glycerol is supplied from the 3rd column The plate enters the extractive distillation column (T2), and the flow rate of the extracta...

Embodiment 2

[0040] Take the 100kmol / h aqueous solution with 25mol% benzene and 15mol% n-propanol as an example:

[0041] The number of plates of the extractive distillation column (T1) is 30, the mixed material enters the extractive distillation column (T1) from the 25th plate, and the extractant glycerin enters the extractive distillation column (T1) from the 5th plate, and the extractant The flow rate is 30kmol / h, the bottom stream enters the flash tank (F1) after heat exchange with the overhead stream compressed by the heat exchanger (H1) and the heat pump compressor (P1), and the separated gas stream is sent from the first 30 trays are refluxed to the extractive distillation column (T1), and the liquid stream enters the extractive distillation column (T2) from the 45th column, and the extractive distillation column (T2) has 49 trays in total, and the extractant glycerol is supplied from the 7th column The plate enters the extractive distillation column (T2), and the flow rate of the e...

Embodiment 3

[0043] Take the 100kmol / h aqueous solution containing 35mol% benzene and 5mol% n-propanol as an example:

[0044] The number of plates of the extractive distillation column (T1) is 37, the mixed material enters the extractive distillation column (T1) from the 30th plate, and the extractant glycerin enters the extractive distillation column (T1) from the 5th plate, and the extractant The flow rate is 42kmol / h. The bottom stream enters the flash tank (F1) after heat exchange with the overhead stream compressed by the heat exchanger (H1) and the heat pump compressor (P1). 37 trays return to the extractive distillation column (T1), and the liquid flow enters the extractive distillation column (T2) from the 40th column, and the extractive distillation column (T2) has a total of 43 trays, and the extractant glycerol is supplied from the 3rd column The plate enters the extractive distillation column (T2), and the flow rate of the extractant is 21 kmol / h. The bottom stream enters the...

Technical field

[0001] The invention belongs to the field of chemical separation and purification, and specifically relates to a method for separating benzene-n-propanol-water mixture by heat pump extraction and rectification, and furthermore, relates to a method for separating benzene-n-propanol by heat pump extraction and rectification using glycerin as an extraction agent Alcohol-water mixture method.

Background technique

[0002] N-propanol and benzene are important organic solvents, which are widely used in fine chemicals, pharmaceuticals, coatings and other fields. N-propanol can be used as a raw material to synthesize propyl acetate, which is used in solvents, printing inks, cosmetic synthetic rubber, etc., and can also be used in the production of probenecid, erythromycin and other drugs. Benzene is one of the most commonly used organic solvents in industry, and can be used to produce important chemicals such as cyclohexane. Benzene and n-propanol exist in many ...

Examples

Embodiment 1

[0037] Take 100kmol / h of 30mol% benzene, 60mol% n-propanol and 10mol% n-propanol as an example:

[0038]The number of plates of the extractive distillation column (T1) is 32, the mixed material enters the extractive distillation column (T1) from the 29th plate, and the extractant glycerin enters the extractive distillation column (T1) from the 3rd plate, and the extractant The flow rate is 35kmol / h, the bottom stream enters the flash tank (F1) after heat exchange with the overhead stream compressed by the heat exchanger (H1) and the heat pump compressor (P1), and the separated gas stream is sent from the first 32 trays are returned to the extractive distillation column (T1), and the liquid flow enters the extractive distillation column (T2) from the 43rd column, and the extractive distillation column (T2) has 48 trays in total, and the extractant glycerol is supplied from the 3rd column The plate enters the extractive distillation column (T2), and the flow rate of the extracta...

Embodiment 2

[0040] Take the 100kmol / h aqueous solution with 25mol% benzene and 15mol% n-propanol as an example:

[0041] The number of plates of the extractive distillation column (T1) is 30, the mixed material enters the extractive distillation column (T1) from the 25th plate, and the extractant glycerin enters the extractive distillation column (T1) from the 5th plate, and the extractant The flow rate is 30kmol / h, the bottom stream enters the flash tank (F1) after heat exchange with the overhead stream compressed by the heat exchanger (H1) and the heat pump compressor (P1), and the separated gas stream is sent from the first 30 trays are refluxed to the extractive distillation column (T1), and the liquid stream enters the extractive distillation column (T2) from the 45th column, and the extractive distillation column (T2) has 49 trays in total, and the extractant glycerol is supplied from the 7th column The plate enters the extractive distillation column (T2), and the flow rate of the e...

Embodiment 3

[0043] Take the 100kmol / h aqueous solution containing 35mol% benzene and 5mol% n-propanol as an example:

[0044] The number of plates of the extractive distillation column (T1) is 37, the mixed material enters the extractive distillation column (T1) from the 30th plate, and the extractant glycerin enters the extractive distillation column (T1) from the 5th plate, and the extractant The flow rate is 42kmol / h. The bottom stream enters the flash tank (F1) after heat exchange with the overhead stream compressed by the heat exchanger (H1) and the heat pump compressor (P1). 37 trays return to the extractive distillation column (T1), and the liquid flow enters the extractive distillation column (T2) from the 40th column, and the extractive distillation column (T2) has a total of 43 trays, and the extractant glycerol is supplied from the 3rd column The plate enters the extractive distillation column (T2), and the flow rate of the extractant is 21 kmol / h. The bottom stream enters the...

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