CN104356039B - Preparation process of caprolactam - Google Patents
Preparation process of caprolactam Download PDFInfo
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- CN104356039B CN104356039B CN201410626659.8A CN201410626659A CN104356039B CN 104356039 B CN104356039 B CN 104356039B CN 201410626659 A CN201410626659 A CN 201410626659A CN 104356039 B CN104356039 B CN 104356039B
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
- C07D201/02—Preparation of lactams
- C07D201/04—Preparation of lactams from or via oximes by Beckmann rearrangement
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
- C07D201/16—Separation or purification
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D223/00—Heterocyclic compounds containing seven-membered rings having one nitrogen atom as the only ring hetero atom
- C07D223/02—Heterocyclic compounds containing seven-membered rings having one nitrogen atom as the only ring hetero atom not condensed with other rings
- C07D223/06—Heterocyclic compounds containing seven-membered rings having one nitrogen atom as the only ring hetero atom not condensed with other rings with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D223/08—Oxygen atoms
- C07D223/10—Oxygen atoms attached in position 2
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Other In-Based Heterocyclic Compounds (AREA)
- Processing Of Solid Wastes (AREA)
- Extraction Or Liquid Replacement (AREA)
Abstract
The invention discloses a preparation process of caprolactam. The preparation process comprises the following steps: carrying out Beckmann rearrangement on cyclohexanone-oxime and fuming sulphuric acid; firstly hydrolyzing the obtained rearrangement liquid, and then carrying out extraction separation to obtain a caprolactam extraction liquid; carrying out water reverse extraction on the extraction liquid to obtain an aqueous solution of caprolactam; and subsequently refining to obtain a caprolactam finished product. Sulfuric acid extracted and separated and the extraction agent re-extracted and separated in the process are recycled to a system for reuse after concentration and refining treatment. The process disclosed by the invention is used for avoiding the process of neutralizing ammonium water of the rearrangement liquid to produce ammonium sulfate, so that the production technology process of caprolactam is simplified, devices for neutralizing and crystallizing ammonium sulfate, separating, drying, packaging and the like are omitted, the conventional matched synthesis ammonia and sulfuric acid device in the conventional process is omitted, the investment cost and energy consumption of equipment are lowered, and meanwhile, generation of a byproduct ammonium sulfate is avoided.
Description
Technical field
The present invention relates to a kind of process for preparing caprolactam, the preparation work of the caprolactam of particularly a kind of no by-product sulphur ammonium
Skill.
Background technology
Caprolactam is the lactams that episilon amino caproic acid intramolecular is shunk, and is a kind of important Organic Chemicals.
Caprolactam be mainly used for by produce nylon-6, be then further processed into nylon fibre, engineering plastics, plastic sheeting
Deng.The preparation method of caprolactam is a lot, but these methods equal by-product sulphur ammonium, urged using oleum during Beckmann rearrangement
Agent enters rearrangement, and resetting the sulphuric acid terminating in rear rearrangement solution needs to be neutralized using ammonia, generates ammonium sulfate, to remove it
In sulphuric acid.Produce one ton of caprolactam, can 1.5～4.2 tons of by-product sulphur ammonium.Because sulphur ammonium is as a kind of poorly efficient chemical fertilizer containing N,
It is constantly subjected to its purposes and cost and the pressure of increasing by-product yield release, become restriction caprolactam industry development
A bottleneck.Therefore, seeking a kind of caprolactam preparation method of no by-product sulphur ammonium becomes the key of industry technological innovation.
Content of the invention
The present invention seeks to for a large amount of sulphur ammonium of by-product of caprolactam existing production technology presence, caprolactam product matter
Amount is difficult to the defect being lifted, and provides a kind of caprolactam of the no by-product sulphur ammonium that flow process is simple, energy consumption is low, product quality is high to prepare
Technique.
The present invention solve its technical problem adopt the technical scheme that such.A kind of process for preparing caprolactam, including
Following steps：
（1）Pass through separation, refined cyclohexanone-oxime and the oleum that carry out generating after Ammoximation reaction in temperature are
85～95 DEG C, pressure be normal pressure under carry out Beckmann rearrangement in rearrangement reactor, obtain rearrangement solution, its main component be oneself in
Amide, sulphuric acid and a small amount of impurity；
（2）By step（1）The rearrangement solution obtaining is 40～70 DEG C in temperature, and pressure is under normal pressure, adds pure water to carry out water
Solution, obtains the water solution A containing caprolactam and sulphuric acid；
（3）By step（2）The water solution A obtaining is 40～50 DEG C in temperature, and pressure is under normal pressure, adds in extraction tower
Extractant is extracted, and obtains the nothing of the organic extract liquid B containing 15%～25% caprolactam and caprolactam content ＜ 0.5%
Machine aqueous sulfuric acid C；
（4）By step（3）In the organic extract liquid B containing 15%～25% caprolactam that obtains carry out water back extraction, obtain
The organic extraction solution E of the aqueous solution D containing 20%～30% caprolactam and caprolactam content ＜ 0.1%；
Or the organic extract liquid B vacuum distillation that adds water of the caprolactam containing 15%～25% is separated, obtain containing 80%～
The organic extraction solution G of the aqueous solution F of 90% caprolactam and caprolactam content ＜ 0.1%；
（5）By step（3）The inorganic aqueous sulfuric acid C of the caprolactam content ＜ 0.5% obtaining is refined, and obtains 70%
～98% concentrated sulphuric acid, is mixed to get 10%～20% oleum, loops back shellfish with the oleum of 20%～65% newly adding
Gram graceful rearrangement reactor proceeds reaction cycle and uses；
Or the inorganic aqueous sulfuric acid C of caprolactam content ＜ 0.5% is refined, obtains dilute sulfuric acid, for Ore
Exploitation uses；
Or add calcium hydroxide to be prepared into calcium sulfate pair in the inorganic aqueous sulfuric acid C of caprolactam content ＜ 0.5%
Product；
（6）By step（4）The aqueous solution D containing 20%～30% caprolactam that obtains or will be containing 80%～90% in oneself
The aqueous solution F of amide is refined, and obtains highly purified caprolactam finished product；
（7）By step（4）The organic extraction solution E caprolactam content ＜ 0.1% of the caprolactam content ＜ 0.1% obtaining
Organic extraction solution G refined, be extracted liquid return extraction tower as extractant recycle.
The step of the present invention（1）In, cyclohexanone-oxime with oleum mol ratio is（1.1～1.8）: 1.
The step of the present invention（2）In, pure water with quality of caprolactam ratio is（1～5）:1.
The step of the present invention（3）In, extractant used be benzene or toluene or normal hexane or carbon tetrachloride or trichloroethane or
The compositionss of above material；Extractant with the mass ratio of caprolactam is（2～4）:1.
The step of the present invention（4）In, during water back extraction, water with the mass ratio of caprolactam is（3～4）:1；
During the vacuum distillation that adds water, the addition of water is the 10% ~ 20% of quality of caprolactam.
In the present invention, except specified otherwise, the content of each material is mass content.
The present invention obtains following technological progress：
（1）The present invention, the rearrangement solution obtaining during Beckmann rearrangement is first hydrolyzed, then carries out extract and separate and obtain oneself
Lactams extract, then carry out water back extraction or carry out vacuum distillation separation, obtain the aqueous solution of caprolactam, then carry out subsequent fine
Caprolactam finished product is obtained, avoids the process that rearrangement solution carries out in ammonia and produces sulphur ammonium, simplify caprolactam production
Technological process, eliminates in sulphur ammonium and the device unit such as crystallization, separation, dry, packaging, reduces equipment investment and energy consumption, with
When avoid the generation of by-product sulphur ammonium.
（2）Present invention process flow process is simple, decreases rearrangement solution ripening, ammonia neutralization, evaporation knot after Beckmann rearrangement
The operations such as crystalline substance, shorten technological process and production cycle, and extractant and oleum can recycle in process of production.
（3）The present invention, compared with traditional handicraft, is not required to supporting synthesis ammonia and sulfuric acid apparatus in the usual way, a small amount of ammonia and
Oleum only need to be purchased, and reduces the equipment investment of corollary apparatus.
Brief description
Fig. 1 is present invention process schematic flow sheet.
Specific embodiment
Following examples are used for the present invention is described.
Embodiment 1
With reference to the present invention process schematic flow sheet shown in Fig. 1, in rearrangement reactor, control temperature at 85～95 DEG C,
Pressure normal pressure, stops 10～60 minutes, and cyclohexanone-oxime and 8%～20% oleum occur Beckmann rearrangement, obtain again
Discharge opeing, main component is caprolactam, sulphuric acid and a small amount of impurity；
Rearrangement solution is 55 DEG C in temperature, pressure normal pressure, stop 30 minutes, hydrolyzer adds quality of caprolactam 2
Pure water again is hydrolyzed, and obtains the water solution A containing caprolactam, sulphuric acid；
Water solution A containing caprolactam, sulphuric acid is 45 DEG C in temperature, pressure normal pressure, add extraction in extraction tower
Agent benzene is extracted, and benzene is in a ratio of 4 with caprolactam:1, obtain the organic extract liquid B of the caprolactam containing 20%, and contain
There is the inorganic aqueous sulfuric acid C of caprolactam 0.4%；
The organic extract liquid B of the caprolactam containing 20% is carried out water back extraction, water is in a ratio of 3 with caprolactam:1, obtain
To containing the 23% aqueous solution D of caprolactam and the organic extraction solution E containing caprolactam 0.09%；
Inorganic aqueous sulfuric acid C containing caprolactam 0.4% is carried out refined and concentration, obtains 70%～98% dense sulfur
Acid, the oleum circuit being mixed to get 10%～20% with the oleum of 20%～65% newly adding returns Beckmann rearrangement
Device proceeds reaction cycle and uses；
The aqueous solution D of the caprolactam containing 23% is carried out subsequently after friendship, hydrogenation, triple effect evaporation, flash distillation and distillation,
Make highly purified caprolactam finished product；
Organic extraction solution E containing caprolactam 0.09% is carried out follow-up refinement treatment and is extracted liquid return extraction
Tower recycles as extractant.
Embodiment 2
With reference to the present invention process schematic flow sheet shown in Fig. 1, in rearrangement reactor, control temperature at 85～95 DEG C,
Pressure normal pressure, stops 10～60 minutes, and cyclohexanone-oxime and 8%～20% oleum occur Beckmann rearrangement, obtain again
Discharge opeing, main component is caprolactam, sulphuric acid and a small amount of impurity；
Rearrangement solution is 55 DEG C in temperature, pressure normal pressure, stop 30 minutes, hydrolyzer adds quality of caprolactam 2
Times pure water is hydrolyzed, and obtains the water solution A containing caprolactam and sulphuric acid；
Water solution A containing caprolactam, sulphuric acid is 45 DEG C in temperature, pressure normal pressure, add extraction in extraction tower
Agent benzene is extracted, and benzene and caprolactam are in a ratio of 4：1, obtain the organic extract liquid B of the caprolactam containing 20%, and contain
The inorganic aqueous sulfuric acid C of caprolactam 0.4%；
The water that organic extract liquid B containing caprolactam 20% is added quality of caprolactam 10% carries out vacuum distillation and divides
From obtaining the aqueous solution F of the caprolactam containing the 90% and organic extraction solution G containing caprolactam 0.09%；
Inorganic aqueous sulfuric acid C containing caprolactam 0.4% is refined, obtains dilute sulfuric acid, make for ore extraction
With；
The aqueous solution F of the caprolactam containing 90% is carried out, after follow-up triple effect evaporation, flash distillation and distillation, making high-purity
Caprolactam finished product.
Organic extraction solution G containing caprolactam 0.09% is carried out follow-up refinement treatment and is extracted liquid return extraction
Tower recycles as extractant.
Embodiment 3
With reference to the present invention process schematic flow sheet shown in Fig. 1, in rearrangement reactor, control temperature at 85～95 DEG C,
Pressure normal pressure, stops 10～60 minutes, and cyclohexanone-oxime and 8%～20% oleum occur Beckmann rearrangement, obtain again
Discharge opeing, main component is caprolactam, sulphuric acid and a small amount of impurity；
Rearrangement solution is 55 DEG C in temperature, pressure normal pressure, stop 30 minutes, hydrolyzer adds quality of caprolactam 2
Pure water again is hydrolyzed, and obtains the water solution A containing caprolactam, sulphuric acid；
Water solution A containing caprolactam, sulphuric acid is 45 DEG C in temperature, pressure normal pressure, add extraction in extraction tower
Agent benzene is extracted, and benzene is in a ratio of 4 with caprolactam:1, obtain the organic extract liquid B of the caprolactam containing 20%, and contain
There is the inorganic aqueous sulfuric acid C of caprolactam 0.4%；
The organic extract liquid B of the caprolactam containing 20% is carried out water back extraction, water is in a ratio of 3 with caprolactam:1, obtain
To containing the 23% aqueous solution D of caprolactam and the organic extraction solution E containing caprolactam 0.09%；
Add calcium hydroxide to be prepared into calcium sulfate side-product to the inorganic aqueous sulfuric acid C containing caprolactam 0.4%, carry
High productivity effect.
The aqueous solution D of the caprolactam containing 23% is carried out subsequently after friendship, hydrogenation, triple effect evaporation, flash distillation and distillation,
Make highly purified caprolactam finished product；
Organic extraction solution E containing caprolactam 0.09% is carried out follow-up refinement treatment and is extracted liquid return extraction
Tower recycles as extractant；
Embodiment 4 the present embodiment difference from Example 1 is to replace benzene extractant with toluene extractant.
Embodiment 5 the present embodiment difference from Example 2 is to replace benzene extractant with toluene extractant.
Embodiment 6 the present embodiment difference from Example 3 is to replace benzene extractant with toluene extractant.
Embodiment 7 the present embodiment difference from Example 1 is to replace benzene extractant with n-hexane extraction agent.
Embodiment 8 the present embodiment difference from Example 2 is to replace benzene extractant with n-hexane extraction agent.
Embodiment 9 the present embodiment difference from Example 3 is to replace benzene extractant with n-hexane extraction agent.
Embodiment 10 the present embodiment difference from Example 1 is to replace benzene extractant with carbon tetrachloride extraction agent.
Embodiment 11 the present embodiment difference from Example 2 is to replace benzene extractant with carbon tetrachloride extraction agent.
Embodiment 12 the present embodiment difference from Example 3 is to replace benzene extractant with carbon tetrachloride extraction agent.
Embodiment 13 the present embodiment difference from Example 1 is to replace benzene extractant with trichloroethane extractant.
Embodiment 14 the present embodiment difference from Example 2 is to replace benzene extractant with trichloroethane extractant.
Embodiment 15 the present embodiment difference from Example 3 is to replace benzene extractant with trichloroethane extractant.
In various embodiments above, except specified otherwise, the content of each material is mass content.
Claims (5)
1. a kind of process for preparing caprolactam is it is characterised in that comprise the following steps：
（1）By carrying out generating after Ammoximation reaction through separating, refined cyclohexanone-oxime and oleum in temperature for 85～
95 DEG C, pressure be normal pressure under carry out Beckmann rearrangement in rearrangement reactor, obtain rearrangement solution；
（2）By step（1）The rearrangement solution obtaining is 40～70 DEG C in temperature, and pressure is to add pure water under normal pressure, is hydrolyzed, obtains
Arrive the water solution A containing caprolactam and sulphuric acid；
（3）By step（2）The water solution A obtaining is 40～50 DEG C in temperature, and pressure is under normal pressure, adds extraction in extraction tower
Agent is extracted, and obtains organic extract liquid B and quality of caprolactam content ＜ 0.5% of mass content 15%～25% caprolactam
Inorganic aqueous sulfuric acid C；
（4）By step（3）In the organic extract liquid B of mass content 15%～25% caprolactam that obtains carry out water back extraction, obtain
The aqueous solution D of mass content 20%～30% caprolactam and the extraction solution E of quality of caprolactam content ＜ 0.1%；
Or the organic extract liquid B of the caprolactam of mass content 15%～25% is added water vacuum distillation separating treatment, obtains matter
The amount aqueous solution F of content 80%～90% caprolactam and organic extraction solution G of quality of caprolactam content ＜ 0.1%；
（5）By step（3）The inorganic aqueous sulfuric acid C of quality of caprolactam content ＜ 0.5% obtaining is refined, and obtains matter
The concentrated sulphuric acid of amount content 70%～98%, is mixed to get mass content with the oleum of the new mass content 20%～65% adding
10%～20% oleum, loops back Beckmann rearrangement device and proceeds reaction cycle use；
Or the inorganic aqueous sulfuric acid C of quality of caprolactam content ＜ 0.5% is refined, obtains dilute sulfuric acid；
Or add calcium hydroxide to be prepared into calcium sulfate in the inorganic aqueous sulfuric acid C of quality of caprolactam content ＜ 0.5%；
（6）By step（4）The aqueous solution D of mass content 20%～30% caprolactam that obtains or by mass content 80%～90%
The aqueous solution F of caprolactam is refined, and obtains caprolactam finished product；
（7）By step（4）The organic extraction solution E of quality of caprolactam content ＜ 0.1% obtaining and quality of caprolactam content
The organic extraction solution G of ＜ 0.1% is refined, and is extracted liquid and returns extraction tower as extractant recycling.
2. process for preparing caprolactam according to claim 1 is it is characterised in that step（1）In, cyclohexanone-oxime be fuming
The mol ratio of sulphuric acid is（1.1～1.8）: 1.
3. process for preparing caprolactam according to claim 1 is it is characterised in that step（2）In, pure water and caprolactam
Mass ratio is（1～5）:1.
4. process for preparing caprolactam according to claim 1 is it is characterised in that step（3）In, extractant is benzene or first
Benzene or the compositionss of normal hexane or carbon tetrachloride or trichloroethane or more material, extractant with the mass ratio of caprolactam is（2
～4）:1.
5. process for preparing caprolactam according to claim 1 is it is characterised in that step（4）In, during back extraction, water is interior with oneself
The mass ratio of amide is（3～4）:1；During the vacuum distillation that adds water, the addition of water is the 10% ~ 20% of quality of caprolactam.
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Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104910071A (en) * | 2015-05-08 | 2015-09-16 | 河北美邦工程科技股份有限公司 | Caprolactam preparation method |
| CN114805207A (en) * | 2022-04-14 | 2022-07-29 | 山东华鲁恒升化工股份有限公司 | Method for removing sulfuric acid in rearrangement solution by using membrane separation technology |
| CN115093354B (en) * | 2022-06-29 | 2024-01-16 | 中国天辰工程有限公司 | Method for synthesizing caprolactam through Beckmann rearrangement reaction |
| CN115819344A (en) * | 2023-01-13 | 2023-03-21 | 神马实业股份有限公司 | Process method for producing caprolactam and coproducing sulfuric ester by liquid phase Beckmann rearrangement |
Citations (4)
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|---|---|---|---|---|
| US3907781A (en) * | 1973-06-26 | 1975-09-23 | Stamicarbon | Process for recovery of {68 -caprolactam from a reaction mixture of {68 -caprolactam and sulphuric acid |
| CN1058588A (en) * | 1990-07-06 | 1992-02-12 | Dsm有限公司 | Handle the method for acid amides |
| CN1896056A (en) * | 2005-11-14 | 2007-01-17 | 中国石油化工股份有限公司 | Production of epsilon-caprolactam |
| CN101117327A (en) * | 2006-07-31 | 2008-02-06 | 中国石油化工股份有限公司 | Preparation method of aminocaprolactam |
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2014
- 2014-11-10 CN CN201410626659.8A patent/CN104356039B/en active Active
Patent Citations (4)
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|---|---|---|---|---|
| US3907781A (en) * | 1973-06-26 | 1975-09-23 | Stamicarbon | Process for recovery of {68 -caprolactam from a reaction mixture of {68 -caprolactam and sulphuric acid |
| CN1058588A (en) * | 1990-07-06 | 1992-02-12 | Dsm有限公司 | Handle the method for acid amides |
| CN1896056A (en) * | 2005-11-14 | 2007-01-17 | 中国石油化工股份有限公司 | Production of epsilon-caprolactam |
| CN101117327A (en) * | 2006-07-31 | 2008-02-06 | 中国石油化工股份有限公司 | Preparation method of aminocaprolactam |
Non-Patent Citations (1)
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Address after: 050035 office building, alliance headquarters, No. 1, No. 1, No. 1, No. 1, No. 1, Zhujiang Avenue, Hebei high tech Zone, 0801 Patentee after: Hebei Mei Bang engineering science and technology limited-liability company Address before: 050035 Shijiazhuang Changjiang Road, Hebei, No. 9 building high-tech international A-17L Patentee before: Hebei Meibang Engineering Technology Co., Ltd. |