Method for improving adsorption performance through modification on molecular sieve

Abstract

The present invention belongs to the technical field of organic chemistry purification, and relates to a method for improving adsorption performance through modification on a molecular sieve. The method is characterized in that a molecular sieve is subjected to loading or exchange modification with a soluble metal salt or heteropoly acid and the like, and the modified molecular sieve is used to adsorb 2-heptanone in a cyclohexanone finished product, wherein the 2-heptanone content in the cyclohexanone after the adsorbing is less than 5 ppm, such that the product quality is substantially improved, and the product competitiveness is strong. According to the present invention, the modified molecular sieve can be applied multiple times, and provides high adsorption quantity compared with the unmodified molecular sieve, and the molecular sieve achieving the saturated adsorption state can be recycled after the molecular sieve is subjected to the desorption treatment.

Description

technical field

[0001] The invention belongs to the technical field of organic chemical purification, and in particular relates to a method for improving adsorption performance by molecular sieve modification. Background technique

[0002] Cyclohexanone is an important organic intermediate widely used in fiber, synthetic rubber, industrial coatings, pharmaceuticals, pesticides and other industries. Due to the rapid development of the polyamide industry, cyclohexanone has also developed rapidly as a raw material for the production of caprolactam. The by-products 2-hexanone and 2-heptanone produced in the production process of cyclohexanone are important factors affecting the quality of caprolactam. The content is not high but difficult to remove, which is an urgent problem to be solved. At present, there are research reports that 2-hexanone and 2-heptanone in cyclohexanone are adsorbed and removed by adsorbents, but due to the unsatisfactory adsorption effect and treatment ca...

Examples

Embodiment 1

[0024] Molecular sieve modification: 5g of powdered ZSM-5 molecular sieve with a silicon-aluminum ratio of 200 was activated at 200°C, and 4mL of a 0.05mol / L lanthanum nitrate aqueous solution was prepared, and the above-mentioned molecular sieve was added under stirring, soaked for 10h, 150°C Dry at 500°C for 6 hours to obtain La-modified ZSM-5 molecular sieve.

[0025] Molecular sieve adsorption: Take 400mL of industrial cyclohexanone product in an iodine measuring bottle, cover the stopper, and add 2g of modified ZSM-5 molecular sieve to it, and put it in a water bath shaker for adsorption. The temperature was 20°C, the shaking speed was 10r / min, and it was filtered after adsorption for 0.5h. The filtrate was analyzed by gas chromatography, and 2-heptanone was not detected.

Embodiment 2

[0027] Molecular sieve modification: 10g of powdered ZSM-5 molecular sieve with a silicon-aluminum ratio of 80, activated at 70°C, added to 9mL of ethanol solution with a concentration of 0.05mol / L phosphotungstic acid, stirred and refluxed at 60°C for 2h, then filtered , dried at 80°C, and calcined at 600°C for 12 hours to obtain ZSM-5 molecular sieve modified with phosphotungstic acid.

[0028] Molecular sieve adsorption: Take 300mL of industrial cyclohexanone product in an iodine measuring bottle, cover the stopper, the content of 2-heptanone is 58.3ppm, add 1g of modified ZSM-5 molecular sieve to it, and put it in a water bath shaker for adsorption. The adsorption temperature was 40°C, the shaking rate was 120r / min, and it was filtered after 48 hours of adsorption. The filtrate was analyzed by gas chromatography, and 2-heptanone was not detected.

Embodiment 3

[0030] Molecular sieve modification: 20g of MCM-41 powdered molecular sieve, activated at 70°C, prepared 10mL aqueous solution of cobalt nitrate with a concentration of 0.2mol / L, added the above molecular sieve under stirring, after stirring for 0.5h, dried at 150°C, dried at 300°C Calcined for 2 hours to obtain Co-modified MCM-41 molecular sieve.

[0031] Molecular sieve adsorption: Take 20mL of industrial cyclohexanone product in an iodine measuring bottle, cover the stopper, the content of 2-heptanone is 40.5ppm, add 6g of modified MCM-41 molecular sieve to it, and put it on a magnetic stirrer for stirring and adsorption , the adsorption temperature was 70°C, the stirring rate was 200r / min, after 6 hours of adsorption, it was filtered, and the filtrate was analyzed by gas chromatography, and 2-heptanone was not detected.

technical field

[0001] The invention belongs to the technical field of organic chemical purification, and in particular relates to a method for improving adsorption performance by molecular sieve modification. Background technique

[0002] Cyclohexanone is an important organic intermediate widely used in fiber, synthetic rubber, industrial coatings, pharmaceuticals, pesticides and other industries. Due to the rapid development of the polyamide industry, cyclohexanone has also developed rapidly as a raw material for the production of caprolactam. The by-products 2-hexanone and 2-heptanone produced in the production process of cyclohexanone are important factors affecting the quality of caprolactam. The content is not high but difficult to remove, which is an urgent problem to be solved. At present, there are research reports that 2-hexanone and 2-heptanone in cyclohexanone are adsorbed and removed by adsorbents, but due to the unsatisfactory adsorption effect and treatment ca...

Examples

Embodiment 1

[0024] Molecular sieve modification: 5g of powdered ZSM-5 molecular sieve with a silicon-aluminum ratio of 200 was activated at 200°C, and 4mL of a 0.05mol / L lanthanum nitrate aqueous solution was prepared, and the above-mentioned molecular sieve was added under stirring, soaked for 10h, 150°C Dry at 500°C for 6 hours to obtain La-modified ZSM-5 molecular sieve.

[0025] Molecular sieve adsorption: Take 400mL of industrial cyclohexanone product in an iodine measuring bottle, cover the stopper, and add 2g of modified ZSM-5 molecular sieve to it, and put it in a water bath shaker for adsorption. The temperature was 20°C, the shaking speed was 10r / min, and it was filtered after adsorption for 0.5h. The filtrate was analyzed by gas chromatography, and 2-heptanone was not detected.

Embodiment 2

[0027] Molecular sieve modification: 10g of powdered ZSM-5 molecular sieve with a silicon-aluminum ratio of 80, activated at 70°C, added to 9mL of ethanol solution with a concentration of 0.05mol / L phosphotungstic acid, stirred and refluxed at 60°C for 2h, then filtered , dried at 80°C, and calcined at 600°C for 12 hours to obtain ZSM-5 molecular sieve modified with phosphotungstic acid.

[0028] Molecular sieve adsorption: Take 300mL of industrial cyclohexanone product in an iodine measuring bottle, cover the stopper, the content of 2-heptanone is 58.3ppm, add 1g of modified ZSM-5 molecular sieve to it, and put it in a water bath shaker for adsorption. The adsorption temperature was 40°C, the shaking rate was 120r / min, and it was filtered after 48 hours of adsorption. The filtrate was analyzed by gas chromatography, and 2-heptanone was not detected.

Embodiment 3

[0030] Molecular sieve modification: 20g of MCM-41 powdered molecular sieve, activated at 70°C, prepared 10mL aqueous solution of cobalt nitrate with a concentration of 0.2mol / L, added the above molecular sieve under stirring, after stirring for 0.5h, dried at 150°C, dried at 300°C Calcined for 2 hours to obtain Co-modified MCM-41 molecular sieve.

[0031] Molecular sieve adsorption: Take 20mL of industrial cyclohexanone product in an iodine measuring bottle, cover the stopper, the content of 2-heptanone is 40.5ppm, add 6g of modified MCM-41 molecular sieve to it, and put it on a magnetic stirrer for stirring and adsorption , the adsorption temperature was 70°C, the stirring rate was 200r / min, after 6 hours of adsorption, it was filtered, and the filtrate was analyzed by gas chromatography, and 2-heptanone was not detected.