CN114904472A - Additive for efficiently separating caprolactam, and caprolactam separation method and system without participation of ammonia or alkali - Google Patents
Additive for efficiently separating caprolactam, and caprolactam separation method and system without participation of ammonia or alkali Download PDFInfo
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- CN114904472A CN114904472A CN202210607126.XA CN202210607126A CN114904472A CN 114904472 A CN114904472 A CN 114904472A CN 202210607126 A CN202210607126 A CN 202210607126A CN 114904472 A CN114904472 A CN 114904472A
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- sulfate
- caprolactam
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- ammonia
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- JBKVHLHDHHXQEQ-UHFFFAOYSA-N epsilon-caprolactam Chemical compound O=C1CCCCCN1 JBKVHLHDHHXQEQ-UHFFFAOYSA-N 0.000 title claims abstract description 202
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 title claims abstract description 79
- 238000000926 separation method Methods 0.000 title claims abstract description 49
- 229910021529 ammonia Inorganic materials 0.000 title claims abstract description 39
- 239000003513 alkali Substances 0.000 title claims abstract description 28
- 239000000654 additive Substances 0.000 title claims abstract description 13
- 230000000996 additive effect Effects 0.000 title claims abstract description 13
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims abstract description 148
- 238000000034 method Methods 0.000 claims abstract description 75
- 150000002148 esters Chemical class 0.000 claims abstract description 74
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 70
- 230000017105 transposition Effects 0.000 claims abstract description 56
- 230000008569 process Effects 0.000 claims abstract description 52
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 50
- 239000000243 solution Substances 0.000 claims description 134
- 238000001704 evaporation Methods 0.000 claims description 114
- 230000008020 evaporation Effects 0.000 claims description 102
- 238000002156 mixing Methods 0.000 claims description 74
- 239000007788 liquid Substances 0.000 claims description 71
- 238000002425 crystallisation Methods 0.000 claims description 66
- 230000008025 crystallization Effects 0.000 claims description 66
- 238000000605 extraction Methods 0.000 claims description 59
- 239000012071 phase Substances 0.000 claims description 42
- 239000011259 mixed solution Substances 0.000 claims description 38
- 239000003795 chemical substances by application Substances 0.000 claims description 37
- 239000002253 acid Substances 0.000 claims description 36
- 239000013078 crystal Substances 0.000 claims description 32
- 235000003891 ferrous sulphate Nutrition 0.000 claims description 29
- 239000011790 ferrous sulphate Substances 0.000 claims description 29
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 claims description 29
- 229910000359 iron(II) sulfate Inorganic materials 0.000 claims description 29
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 28
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 claims description 27
- 229910052921 ammonium sulfate Inorganic materials 0.000 claims description 27
- 235000011130 ammonium sulphate Nutrition 0.000 claims description 27
- OTYBMLCTZGSZBG-UHFFFAOYSA-L potassium sulfate Chemical compound [K+].[K+].[O-]S([O-])(=O)=O OTYBMLCTZGSZBG-UHFFFAOYSA-L 0.000 claims description 25
- 229910052939 potassium sulfate Inorganic materials 0.000 claims description 25
- 235000011151 potassium sulphates Nutrition 0.000 claims description 25
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 claims description 19
- 239000012452 mother liquor Substances 0.000 claims description 19
- 229910052938 sodium sulfate Inorganic materials 0.000 claims description 19
- 235000011152 sodium sulphate Nutrition 0.000 claims description 19
- 239000007791 liquid phase Substances 0.000 claims description 17
- 150000003839 salts Chemical class 0.000 claims description 17
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 claims description 16
- 230000000694 effects Effects 0.000 claims description 12
- 230000005945 translocation Effects 0.000 claims description 11
- 239000002585 base Substances 0.000 claims description 10
- 229910052943 magnesium sulfate Inorganic materials 0.000 claims description 8
- 235000019341 magnesium sulphate Nutrition 0.000 claims description 8
- GRLPQNLYRHEGIJ-UHFFFAOYSA-J potassium aluminium sulfate Chemical compound [Al+3].[K+].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O GRLPQNLYRHEGIJ-UHFFFAOYSA-J 0.000 claims description 8
- 239000002904 solvent Substances 0.000 claims description 8
- 229940103272 aluminum potassium sulfate Drugs 0.000 claims description 7
- 229910000365 copper sulfate Inorganic materials 0.000 claims description 7
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 claims description 7
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 claims description 6
- QCUOBSQYDGUHHT-UHFFFAOYSA-L cadmium sulfate Chemical compound [Cd+2].[O-]S([O-])(=O)=O QCUOBSQYDGUHHT-UHFFFAOYSA-L 0.000 claims description 6
- 229910000331 cadmium sulfate Inorganic materials 0.000 claims description 6
- NWONKYPBYAMBJT-UHFFFAOYSA-L zinc sulfate Chemical compound [Zn+2].[O-]S([O-])(=O)=O NWONKYPBYAMBJT-UHFFFAOYSA-L 0.000 claims description 6
- 229910000368 zinc sulfate Inorganic materials 0.000 claims description 6
- 229960001763 zinc sulfate Drugs 0.000 claims description 6
- 238000009833 condensation Methods 0.000 claims description 4
- 230000005494 condensation Effects 0.000 claims description 4
- 230000009471 action Effects 0.000 claims description 3
- 229910021653 sulphate ion Inorganic materials 0.000 claims 1
- VEZUQRBDRNJBJY-UHFFFAOYSA-N cyclohexanone oxime Chemical compound ON=C1CCCCC1 VEZUQRBDRNJBJY-UHFFFAOYSA-N 0.000 abstract description 10
- 238000006237 Beckmann rearrangement reaction Methods 0.000 abstract description 8
- 230000008707 rearrangement Effects 0.000 abstract description 5
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 21
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 21
- 238000003756 stirring Methods 0.000 description 14
- 239000010413 mother solution Substances 0.000 description 11
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 9
- 238000010586 diagram Methods 0.000 description 7
- 239000007787 solid Substances 0.000 description 7
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 6
- 238000010992 reflux Methods 0.000 description 6
- 239000003054 catalyst Substances 0.000 description 5
- WFDIJRYMOXRFFG-UHFFFAOYSA-N acetic acid anhydride Natural products CC(=O)OC(C)=O WFDIJRYMOXRFFG-UHFFFAOYSA-N 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000000725 suspension Substances 0.000 description 4
- JTNCEQNHURODLX-UHFFFAOYSA-N 2-phenylethanimidamide Chemical compound NC(=N)CC1=CC=CC=C1 JTNCEQNHURODLX-UHFFFAOYSA-N 0.000 description 3
- 238000005119 centrifugation Methods 0.000 description 3
- 238000004821 distillation Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229910000343 potassium bisulfate Inorganic materials 0.000 description 3
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 230000007062 hydrolysis Effects 0.000 description 2
- 238000006460 hydrolysis reaction Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000006386 neutralization reaction Methods 0.000 description 2
- CHKVPAROMQMJNQ-UHFFFAOYSA-M potassium bisulfate Chemical compound [K+].OS([O-])(=O)=O CHKVPAROMQMJNQ-UHFFFAOYSA-M 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000012266 salt solution Substances 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 2
- HIFJUMGIHIZEPX-UHFFFAOYSA-N sulfuric acid;sulfur trioxide Chemical compound O=S(=O)=O.OS(O)(=O)=O HIFJUMGIHIZEPX-UHFFFAOYSA-N 0.000 description 2
- 230000008719 thickening Effects 0.000 description 2
- 239000002562 thickening agent Substances 0.000 description 2
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- 229920006052 Chinlon® Polymers 0.000 description 1
- 125000003182 D-alloisoleucine group Chemical group [H]N([H])[C@@]([H])(C(=O)[*])[C@](C([H])([H])[H])([H])C(C([H])([H])[H])([H])[H] 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- JZRWCGZRTZMZEH-UHFFFAOYSA-N Thiamine Natural products CC1=C(CCO)SC=[N+]1CC1=CN=C(C)N=C1N JZRWCGZRTZMZEH-UHFFFAOYSA-N 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 125000003158 alcohol group Chemical group 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 229940010514 ammonium ferrous sulfate Drugs 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 229920006351 engineering plastic Polymers 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000010931 ester hydrolysis Methods 0.000 description 1
- -1 ester sulfate Chemical class 0.000 description 1
- 239000003456 ion exchange resin Substances 0.000 description 1
- 229920003303 ion-exchange polymer Polymers 0.000 description 1
- 239000002608 ionic liquid Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000006462 rearrangement reaction Methods 0.000 description 1
- 239000011973 solid acid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- KYMBYSLLVAOCFI-UHFFFAOYSA-N thiamine Chemical compound CC1=C(CCO)SCN1CC1=CN=C(C)N=C1N KYMBYSLLVAOCFI-UHFFFAOYSA-N 0.000 description 1
- 229960003495 thiamine Drugs 0.000 description 1
- 235000019157 thiamine Nutrition 0.000 description 1
- 239000011721 thiamine Substances 0.000 description 1
Images
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0053—Details of the reactor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D11/00—Solvent extraction
- B01D11/04—Solvent extraction of solutions which are liquid
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D9/00—Crystallisation
- B01D9/0018—Evaporation of components of the mixture to be separated
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D9/00—Crystallisation
- B01D9/02—Crystallisation from solutions
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
- C07D201/16—Separation or purification
-
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/54—Improvements relating to the production of bulk chemicals using solvents, e.g. supercritical solvents or ionic liquids
Abstract
An additive for efficiently separating caprolactam and a caprolactam separation method and a system without participation of ammonia or alkali, wherein after Beckmann rearrangement, in the process of removing caprolactam, a method for preparing caprolactam by Beckmarm rearrangement of cyclohexanone oxime is realized by using a sulfuric acid additive and reacting sulfate with rearranged transposition ester through water, and the purpose of separating caprolactam is achieved without participation of ammonia or alkali; the system is simpler.
Description
Technical Field
The invention relates to an additive for separating caprolactam prepared by cyclohexanone oxime Beckmann rearrangement, a method and a system.
Background
Caprolactam has molecular formula of C6H11NO, molecular weight of 113.16, white crystal at normal temperature and melting point of 69.3 ℃, is an important chemical product and is widely applied to the manufacture of chinlon and engineering plastics. The preparation method of caprolactam is more, and the preparation of caprolactam by Beckmann rearrangement of cyclohexanone oxime is one of the most industrialized methods at present. At present, concentrated sulfuric acid or fuming sulfuric acid is adopted in 90% of devices in the world as a catalyst, cyclohexanone oxime is subjected to Beckmann rearrangement process, ammonia is used as a neutralization reaction raw material in the process although the selectivity of the process is high, and a large amount of ammonium sulfate with low additional value is generated. Under the circumstances, enterprises at home and abroad have been dedicated to develop a low-sulfur ammonium rearrangement process and a sulfur acid by-product-free process, BASF develops a process using phosphoric acid as a catalyst, lnwenta performs a rearrangement reaction using acetic acid and acetic anhydride as a mixed catalyst in the presence of an ion exchange resin, and then removes caprolactam by using cold water without a step of neutralizing ammonia, DSM uses a solid acid as a catalyst, and under the precondition of advocating "atomic economy" and "environmental economy", an ionic liquid catalytic system and Beckmann rearrangement under a supercritical condition are successively developed at home and abroad, but various new technologies and new processes have different advantages and disadvantages.
Under the condition, the invention greatly reduces the generation of ammonium sulfate, which is an by-product in the process of preparing caprolactam by Beckmann rearrangement of cyclohexanone oxime in the presence of concentrated sulfuric acid or fuming sulfuric acid as a catalyst, greatly improves the production efficiency of caprolactam and reduces the production cost of caprolactam.
Disclosure of Invention
The invention aims to provide an additive for efficiently separating caprolactam, a caprolactam separation method without ammonia or alkali participation and a system thereof, which can ensure that ammonia gas or alkali is not required to neutralize sulfuric acid and ammonium sulfate is not generated in the process of removing caprolactam after Beckmann rearrangement.
The technical scheme for realizing the invention is that an additive for efficiently separating caprolactam is a sulfate solution;
the Beckmarm rearranged translocated ester is mixed with a sulfate solution.
Further, the sulfate number ratio of the translocation ester to the sulfate solution is 1: 1.5-0.1.
Further, the sulfate solution is one or a combination of more of ammonium sulfate, sodium sulfate, potassium sulfate and ferrous sulfate;
or one of ammonium sulfate, sodium sulfate, potassium sulfate and ferrous sulfate and one or any combination of copper sulfate, aluminum potassium sulfate, aluminum sulfate, cadmium sulfate, zinc sulfate and magnesium sulfate;
or any combination of ammonium sulfate, sodium sulfate, potassium sulfate and ferrous sulfate and one or any combination of copper sulfate, aluminum potassium sulfate, aluminum sulfate, cadmium sulfate, zinc sulfate and magnesium sulfate.
Further, the Beckmarm rearranged translocated ester is mixed with a sulfate solution at a temperature of 10-130 ℃.
A caprolactam separation method without ammonia or alkali comprises mixing and separating;
mixing, namely mixing the Beckmarm rearranged transposition ester with a sulfate solution to form a mixed solution;
in the separation, the mixed solution is extracted (generally, the extracting agent can be any one of phenol, benzene, toluene and the like) to separate caprolactam, or the mixed solution is evaporated to separate caprolactam.
Further, in the mixing step, the ratio of the sulfate radical of the translocation ester to the sulfate radical of the sulfate salt solution is 1: 1.5-0.1.
Further, the mixed solution is evaporated to separate caprolactam, wherein the evaporation temperature is 10-130 ℃.
Further, an extraction agent is added to the mixed solution.
Further, the caprolactam separation method without participation of ammonia or alkali also comprises evaporative crystallization;
and (3) evaporating and crystallizing, namely evaporating and concentrating the raffinate acid sulfate solution after extracting and separating caprolactam from the mixed solution under normal pressure or negative pressure and single effect or multiple effect to crystallize the crystal salt.
Further, the caprolactam separation method without participation of ammonia or alkali also comprises subsequent treatment, namely performing subsequent treatment after evaporation and crystallization;
and in the subsequent treatment, the crystallized salt is subjected to subsequent extraction by using a 10:1-4 alcohol-water mixed solution at the temperature of 0-70 ℃ under normal pressure, sulfate crystals are separated, the mother liquor after the sulfate crystals are separated is distilled, the alcohol is recovered by gas phase condensation, and the sulfuric acid solution is obtained in a liquid phase.
Further, in the separation process, in the normal pressure or negative pressure and single-effect or multi-effect evaporation process, when the quantity ratio of sulfate radicals to the solvent in the solution is more than or equal to 1: 4, forming an aqueous caprolactam phase layer at the upper liquid level and an acid sulfate solution at the lower part.
Further, after the separation, a subsequent treatment step is carried out;
and (3) performing subsequent treatment, namely performing subsequent extraction on the acid sulfate solution by using a 10:1-4 alcohol-water mixed solution at the normal pressure and the temperature of 0-70 ℃ to form sulfate crystals, distilling the mother solution after the sulfate crystals are separated, condensing a gas phase to recover alcohol, and obtaining a sulfuric acid solution from a liquid phase.
A caprolactam separation system without ammonia or alkali participation comprises a mixing reactor or a mixing reactor and an extraction tower;
in the mixed reactor, Beckmarm rearranged transposition ester and a sulfate solution are mixed in the mixed reactor to generate mixed liquid, and the mixed liquid realizes extraction and separation in the mixed reactor;
or the mixing reactor is connected with the extraction tower;
in the mixed reactor, Beckmarm rearranged transposition ester and a sulfate solution are mixed in the mixed reactor to generate a mixed liquid;
in the extraction tower, the mixed liquid is input into the extraction tower to extract caprolactam under the action of an extracting agent, and a raffinate phase is discharged out of the extraction tower.
Furthermore, the system also comprises an evaporator, and the evaporator is connected with the extraction tower;
and the raffinate phase discharged from the extraction tower enters the evaporator.
A caprolactam separation system without ammonia or alkali participation comprises an evaporative crystallization reactor;
the Beckmarm rearranged translocation ester is mixed with a sulfate solution in an evaporative crystallization reactor to generate a mixed liquid, and the mixed liquid is separated in the evaporative crystallization reactor through evaporation.
The invention has the advantages that 1) sulfate is used as a hydrolysis material of the sulfuric acid transposition ester, so that the transposition ester is hydrolyzed and then generates ion reaction again, because the alkalinity of the sulfate is stronger than that of the transposition ester after hydrolysis, the hydrolyzed sulfate is preferentially combined with the sulfate after the external conditions are changed to generate acid sulfate, the acid sulfate is crystallized and separated out, so that the constraint of the sulfate radical in the transposition ester on caprolactam is weakened, then the caprolactam is removed from the system, and ammonia or alkali is not needed to participate in neutralization in the whole process, namely, ammonium sulfate is not generated.
2) The acid sulfate is converted into sulfate and sulfuric acid, the extracting liquid containing the sulfuric acid is distilled to separate the extracting agent and the sulfuric acid, the sulfuric acid can be concentrated and reused for Beckmann rearrangement, and the sulfate is reused as a transposition ester hydrolysis material, so that the cyclic utilization is realized to the maximum extent.
3) Compared with the existing separation device, the device has higher efficiency and does not contain a thiamine removal device.
Drawings
FIG. 1 is a logic diagram of a caprolactam separation process without ammonia or base involvement.
FIG. 2 is a logic diagram of a caprolactam separation process without ammonia or base involvement (II).
FIG. 3 is a schematic diagram of a caprolactam separation system of FIG. 1 without the presence of ammonia or base.
FIG. 4 is a schematic diagram of the caprolactam separation system of FIG. 2 without the presence of ammonia or base.
FIG. 5 is a schematic diagram of an optimized system for the caprolactam separation system described in FIG. 3 without the participation of ammonia or alkali.
FIG. 6 is a logic diagram of a caprolactam separation process without ammonia or base involvement (III).
FIG. 7 is a schematic diagram of the caprolactam separation system of FIG. 6 without the presence of ammonia or base.
As shown in the figure, a mixing reactor 1, an extraction tower 2, an evaporator 3 and an evaporation crystallization reactor 4.
Detailed Description
An additive for efficiently separating caprolactam is a sulfate solution; the Beckmarm rearranged translocated ester is mixed with a sulfate solution. Preferably, the ratio of the number of sulfate groups of the translocation ester to the number of sulfate groups of the sulfate solution is 1: 1.5-0.1, and the sulfate radical amount is calculated by mol in the actual adding process, and is generally the amount calculated by theory.
Further preferably, the sulfate solution (generally, the sulfate is a liquid obtained by adding water to the sulfate) is one or a combination of any several of ammonium sulfate, sodium sulfate, potassium sulfate and ferrous sulfate;
or one of ammonium sulfate, sodium sulfate, potassium sulfate and ferrous sulfate and one or any combination of copper sulfate, aluminum potassium sulfate, aluminum sulfate, cadmium sulfate, zinc sulfate and magnesium sulfate;
or any combination of several of ammonium sulfate, sodium sulfate, potassium sulfate and ferrous sulfate and one or more of copper sulfate, aluminum potassium sulfate, aluminum sulfate, cadmium sulfate, zinc sulfate and magnesium sulfate.
Preferably, the Beckmarm rearranged translocated ester is mixed with a sulfate solution at a temperature of 10-130 ℃. As shown in figure 1, a caprolactam separation method without ammonia or alkali participation comprises mixing, separation, evaporative crystallization and subsequent treatment;
and mixing, namely mixing the Beckmarm rearranged transposition ester with a sulfate solution to form a mixed solution, wherein the number ratio of sulfate radicals of the transposition ester to sulfate radicals of the sulfate solution is 1: 1.5-0.1, and the temperature during mixing is 10-80 ℃;
separating, namely extracting and separating caprolactam from the mixed solution, wherein the extracting agent is any one of phenol, benzene, toluene and the like;
evaporating and crystallizing, namely evaporating and concentrating the raffinate acid sulfate solution after extracting and separating caprolactam from the mixed solution under normal pressure or negative pressure and single effect or multiple effect to crystallize salt;
the subsequent treatment, the crystallized salt is extracted by 10:1-4 alcohol-water mixed solution under normal pressure and 0-70 ℃ (alcohol is used as subsequent extractant, generally 2.5-4 times of methanol and water of the crystallized salt are used for extraction, the ratio of methanol and water is 4:1, the stirring speed is 60-120 r/min at normal temperature after 5-30min of stirring, sulfate crystals and mother liquor containing sulfuric acid are separated (the mother liquor is subjected to extraction removal by absolute pressure of 0.5-0.6kgf/cm2, 10-50% dilute sulfuric acid solution is obtained at the tower bottom), wherein sulfuric acid can be used for Beckmarm rearrangement, the sulfate crystals are mixed as sulfate solution after being added with water (cold suspected solution of evaporation water generated in the evaporation and crystallization process), preferably, the mother liquor is distilled under normal pressure or negative pressure in the subsequent treatment process, condensing the gas phase to recover alcohol, and obtaining sulfuric acid solution in the liquid phase.
As shown in fig. 3, a caprolactam separation system without participation of ammonia or alkali comprises a mixing reactor 1 and an extraction tower 2, wherein the mixing reactor 1 is connected with the extraction tower 2, preferably further comprises an evaporator 3, the evaporator 3 is connected with the extraction tower 2, wherein the mixing step is carried out in the mixing reactor 1, the separation step is carried out in the extraction tower 2, and the evaporative crystallization step is carried out in the evaporator 3;
in the mixed reactor 1, the Beckmarm rearranged transposition ester and the sulfate solution are mixed in the mixed reactor 1 to generate mixed liquid;
in the extraction tower 2, the mixed liquid is input into the extraction tower 2 to extract caprolactam under the action of an extracting agent, and an extraction raffinate phase is discharged out of the extraction tower;
and the raffinate phase discharged from the extraction tower 2 enters the evaporator 3, and the subsequent treatment is carried out in a crystallization thickener and a centrifuge.
As shown in FIG. 5, a caprolactam separation system without participation of ammonia or alkali comprises a mixing reactor 1, wherein mixing, separation (requiring addition of any one of an extraction agent such as phenol, benzene, toluene and the like), evaporative crystallization are carried out in the mixing reactor, the mixing reactor is preferably a two-effect negative pressure evaporator, the one-effect evaporation temperature is 80-85 ℃, the evaporation absolute pressure is 0.5-0.6, the two-effect evaporation temperature is controlled at 60-65 ℃, the evaporation pressure is 0.2-0.3kgf/cm2, the feeding amount of a translocation ester is 95-108kg per hour, the ammonium sulfate solution is fed with 248-260kg per hour, the caprolactam is extracted by toluene, the evaporation water amount is 170-180kg, and the subsequent treatment is carried out in a crystallization thickener and a centrifuge.
As shown in FIG. 2, a caprolactam separation method without ammonia or alkali comprises mixing, separation and subsequent treatment;
and mixing, namely mixing the Beckmarm rearranged transposition ester with a sulfate solution to form a mixed solution, wherein the number ratio of sulfate radicals of the transposition ester to sulfate radicals of the sulfate solution is 1: 1.5-0.1;
separating, namely separating caprolactam from the mixed solution in an evaporation mode, wherein the evaporation temperature is 10-130 ℃, an extracting agent is not required to be added, and in the normal pressure or negative pressure and single-effect or multi-effect evaporation process, when the quantity ratio of sulfate radicals to a solvent in the solution is more than or equal to 1: 4, forming an aqueous caprolactam phase layer at the upper liquid level, and preparing an acid sulfate solution at the lower part;
and (3) performing subsequent treatment, namely discharging an acid sulfate solution from the lower part, performing subsequent extraction (the extracting agent is alcohol) on the acid sulfate solution by using a 10:1-4 alcohol-water mixed solution at the normal pressure and the temperature of 0-70 ℃, forming sulfate crystals, distilling mother liquor after separating the sulfate crystals, condensing a gas phase to recover alcohol, and obtaining a sulfuric acid solution from a liquid phase.
As shown in FIG. 6, a caprolactam separation method without ammonia or alkali participation comprises mixing, separation and subsequent treatment;
and mixing, namely mixing the Beckmarm rearranged transposition ester with a potassium sulfate solution to form a mixed solution, wherein the number ratio of sulfate radicals of the transposition ester to sulfate radicals of the potassium sulfate solution is 1: 1.5-0.1;
separating, namely separating caprolactam from the mixed solution in an evaporation mode, wherein the evaporation temperature is 10-130 ℃, an extracting agent is not required to be added, and in the normal pressure or negative pressure and single-effect or multi-effect evaporation process, when the quantity ratio of sulfate radicals to a solvent in the solution is more than or equal to 1: 4, forming an aqueous caprolactam phase layer at the upper liquid level, and preparing an acid sulfate solution at the lower part;
and in the subsequent treatment, acid sulfate solution is discharged from the lower part of the treatment tank, crystallization is carried out at 45 ℃, crystallization separation is carried out to generate potassium bisulfate, mother liquor is returned to the mixing step, alcohol is recycled by gas phase condensation, and sulfuric acid solution is obtained by liquid phase.
As shown in FIG. 4, a caprolactam separation system without participation of ammonia or alkali comprises an evaporative crystallization reactor 4; the Beckmarm rearranged transposition ester is mixed with a sulfate solution in an evaporative crystallization reactor 4 to generate a mixed liquid, and the mixed liquid is separated in the evaporative crystallization reactor 4 through evaporation. The subsequent treatment is carried out in a thick crystallizing device and a centrifuge, and alcohol is required to be added for subsequent extraction in the subsequent treatment.
As shown in FIG. 7, a caprolactam separation system without ammonia or base participation using the process of FIG. 6 comprises an evaporative crystallization reactor 4; the Beckmarm rearranged translocated ester is mixed with a sulfate solution in a mixing reactor to form a mixed liquid, and the mixed liquid is separated by evaporation in the mixing reactor.
The subsequent treatment is carried out in a thick crystallizing device and a centrifuge, and alcohol is not required to be added in the subsequent treatment for subsequent extraction.
Embodiment one (using the method and system shown in fig. 1 and 3):
1. preparing ammonium sulfate (one of sodium sulfate and potassium sulfate can be selected) into sulfate solution with the concentration of 35-43% by using water (or condensed liquid generated in the evaporation crystallization process), and mixing the transposition ester in a mixing reactor at 72-75 ℃, wherein the sulfate radical of the transposition ester and the sulfate radical of the sulfate salt solution have the ratio of 1: 0.2-1.3.
2. Adding the mixed solution into an extraction tower, adding an extracting agent into the extraction tower, extracting caprolactam, inputting a raffinate phase into an evaporation crystallizer for evaporation crystallization, adding an alcohol-acting extracting agent into acid sulfate liquid of the evaporation crystallizer to extract sulfate crystals, distilling a mother solution at normal pressure or negative pressure, condensing a gas phase to recover alcohol, and condensing a liquid phase to obtain a sulfuric acid solution.
Embodiment two (using the method and system shown in fig. 1 and 3):
1. preparing ammonium sulfate into sulfate solution with concentration of 40-42% by using water (or condensed liquid generated in evaporation crystallization process), and mixing transposition ester in a mixing reactor at 70-75 ℃, wherein the sulfate radical of the transposition ester and the sulfate radical of the sulfate solution have a ratio of 1: 0.3-1.5.
2. Adding the mixed solution into an extraction tower, adding an extracting agent into the extraction tower, extracting caprolactam, inputting a raffinate phase into an evaporation crystallizer for evaporation crystallization, adding an alcohol-acting extracting agent into acid sulfate liquid of the evaporation crystallizer to extract sulfate crystals, distilling a mother solution at normal pressure or negative pressure, condensing a gas phase to recover alcohol, and condensing a liquid phase to obtain a sulfuric acid solution.
Example three (using the methods and systems shown in fig. 1 and 3):
1. sodium sulfate was prepared as a 48% strength sulfate solution with water (or as a condensed liquid from evaporative crystallization), and the transposed ester was mixed in a mixing reactor at 65-69 ℃ with the ratio of sulfate of the transposed ester to sulfate of the sulfate solution being 1: 0.7-0.8.
2. Adding the mixed solution into an extraction tower, adding an extracting agent into the extraction tower, extracting caprolactam, inputting a raffinate phase into an evaporation crystallizer for evaporation crystallization, adding an alcohol-acting extracting agent into acid sulfate liquid of the evaporation crystallizer to extract sulfate crystals, distilling a mother solution at normal pressure or negative pressure, condensing a gas phase to recover alcohol, and condensing a liquid phase to obtain a sulfuric acid solution.
Example three (using the methods and systems shown in fig. 1 and 3):
1. sodium sulfate is prepared into a sulfate solution with the concentration of 45% by using water (or condensed liquid generated in the evaporation and crystallization process), and rearrangement translocation esters are mixed in a mixing reactor at the temperature of 62-64 ℃, wherein the sulfate radical of the translocation ester and the sulfate radical of the sulfate solution have the ratio of 1: 1.2-0.4.
2. Adding the mixed solution into an extraction tower, adding an extracting agent into the extraction tower, extracting caprolactam, inputting a raffinate phase into an evaporation crystallizer for evaporation crystallization, adding an alcohol-acting extracting agent into acid sulfate liquid of the evaporation crystallizer to extract sulfate crystals, distilling a mother solution at normal pressure or negative pressure, condensing a gas phase to recover alcohol, and condensing a liquid phase to obtain a sulfuric acid solution.
Embodiment four (using the methods and systems shown in fig. 1 and 3):
1. sodium sulfate is prepared into sulfate solution with the concentration of 53% by using water (or condensed liquid generated in the evaporation and crystallization process), and rearrangement translocation esters are mixed in a mixing reactor at 60-64 ℃, wherein the sulfate radical of the translocation ester and the sulfate radical of the sulfate solution have the ratio of 1: 1.3-0.4.
2. Adding the mixed solution into an extraction tower, adding an extracting agent into the extraction tower, extracting caprolactam, inputting a raffinate phase into an evaporation crystallizer for evaporation crystallization, adding an alcohol-acting extracting agent into acid sulfate liquid of the evaporation crystallizer to extract sulfate crystals, distilling a mother solution at normal pressure or negative pressure, condensing a gas phase to recover alcohol, and condensing a liquid phase to obtain a sulfuric acid solution.
Example five (using the methods and systems shown in fig. 1 and 3):
1. preparing sodium sulfate and copper sulfate into sulfate solution with concentration of 48% by using water (or condensed liquid generated in the process of evaporation crystallization), and mixing the transposition ester in a mixing reactor at 30-40 ℃, wherein the sulfate radical of the transposition ester and the sulfate radical of the sulfate solution have the ratio of 1: 1.2-0.1.
2. Adding the mixed solution into an extraction tower, adding an extracting agent into the extraction tower, extracting caprolactam, inputting a raffinate phase into an evaporation crystallizer for evaporation crystallization, adding an alcohol-acting extracting agent into acid sulfate liquid of the evaporation crystallizer to extract sulfate crystals, distilling a mother solution at normal pressure or negative pressure, condensing a gas phase to recover alcohol, and condensing a liquid phase to obtain a sulfuric acid solution.
Example six (using the methods and systems shown in fig. 1 and 3):
1. preparing potassium sulfate into sulfate solution with concentration of 38-43% by using water (or condensed liquid generated in evaporation crystallization process), and mixing transposition ester in a mixing reactor at 20-34 ℃, wherein the sulfate radical of the transposition ester and the sulfate radical of the sulfate solution have the ratio of 1: 1.5-0.3.
2. Adding the mixed solution into an extraction tower, adding an extracting agent into the extraction tower, extracting caprolactam, inputting a raffinate phase into an evaporation crystallizer for evaporation crystallization, adding an alcohol-acting extracting agent into an acid sulfate liquid of the evaporation crystallizer to extract sulfate crystals, distilling a mother solution at normal pressure or negative pressure, condensing a gas phase to recover alcohol, and condensing a liquid phase to obtain a sulfuric acid solution.
Embodiment seven (using the method and system shown in fig. 1 and 3):
1. preparing potassium sulfate and magnesium sulfate into sulfate solution with the concentration of 50-60% by using water (or condensed liquid generated in the evaporation crystallization process), and mixing the transposition ester in a mixing reactor at the temperature of 10-30 ℃, wherein the sulfate quantity ratio of the transposition ester to the sulfate solution is 1: 1.2-0.4.
2. Adding the mixed solution into an extraction tower, adding an extracting agent into the extraction tower, extracting caprolactam, inputting a raffinate phase into an evaporation crystallizer for evaporation crystallization, adding an alcohol-acting extracting agent into acid sulfate liquid of the evaporation crystallizer to extract sulfate crystals, distilling a mother solution at normal pressure or negative pressure, condensing a gas phase to recover alcohol, and condensing a liquid phase to obtain a sulfuric acid solution.
Example eight (using the methods and systems shown in fig. 1 and 3):
1. preparing potassium sulfate, magnesium sulfate and ferrous sulfate into sulfate solution with the concentration of 40-52% by using water (or condensed liquid generated in the evaporation and crystallization process), and mixing the transposition ester in a mixing reactor at the temperature of 10-24 ℃, wherein the sulfate radical of the transposition ester and the sulfate radical of the sulfate solution are mixed in the ratio of 1: 1.5-0.4.
2. Adding the mixed solution into an extraction tower, adding an extracting agent into the extraction tower, extracting caprolactam, inputting a raffinate phase into an evaporation crystallizer for evaporation crystallization, adding an alcohol-acting extracting agent into acid sulfate liquid of the evaporation crystallizer to extract sulfate crystals, distilling a mother solution at normal pressure or negative pressure, condensing a gas phase to recover alcohol, and condensing a liquid phase to obtain a sulfuric acid solution.
Example nine (using the methods and systems shown in fig. 1 and 3):
1. preparing potassium sulfate, aluminum potassium sulfate and ferrous sulfate into sulfate solution with the concentration of 40% by using water (or condensed liquid generated in the evaporation crystallization process), and mixing the transposition ester in a mixing reactor at the temperature of 10-30 ℃, wherein the sulfate of the transposition ester and the sulfate of the sulfate solution are mixed in the number ratio of 1: 1.2-0.2.
2. Adding the mixed solution into an extraction tower, adding an extracting agent into the extraction tower, extracting caprolactam, inputting a raffinate phase into an evaporation crystallizer for evaporation crystallization, adding an alcohol-acting extracting agent into acid sulfate liquid of the evaporation crystallizer to extract sulfate crystals, distilling a mother solution at normal pressure or negative pressure, condensing a gas phase to recover alcohol, and condensing a liquid phase to obtain a sulfuric acid solution.
Example ten (using the method and system shown in fig. 1 and 5)
1. Preparing ammonium sulfate into sulfate solution with the concentration of 45-51% by using water (or condensed liquid generated in the process of evaporative crystallization), mixing the sulfate solution with Beckmarm rearranged transposition ester in a mixing reactor 1, introducing toluene to extract caprolactam, and mixing the sulfate of the transposition ester with the sulfate of the sulfate solution according to the ratio of 1: 1.5 to 0.1, the mixing reactor 1 is a two-effect negative pressure evaporator, the one-effect evaporation temperature is 80 to 85 ℃, the absolute evaporation pressure is 0.5 to 0.6, the two-effect evaporation temperature is controlled between 60 and 65 ℃, and the evaporation pressure is 0.2 to 0.3kgf/cm 2. Feeding the transposition ester at 92-103kg per hour, feeding the ammonium sulfate solution at 252-260kg per hour, and evaporating the water at 172-180kg, and heating by using low-pressure steam hot water of 1.2kgf/cm 2;
2. adding the mixture into a thick crystallization device of 280 plus 310kg of acid sulfate every hour, then adding the mixture into a centrifuge for centrifugation, adding crystal salt and first mother liquor, refluxing the first mother liquor to a mixing reactor 1, extracting crystal salt solids by using methanol and water which are 3.5 times of the weight of the crystal salt solids, wherein the ratio of the methanol to the water is 4:1, stirring at normal temperature for 5-30min, stirring at the rotating speed of 60-120 r/min, separating and separating ammonium sulfate and second mother liquor again, refluxing the ammonium sulfate to the mixing reactor 1, removing an extracting agent from the second mother liquor by using absolute pressure of 0.5-0.6kgf/cm2, and obtaining 10-50% of dilute sulfuric acid solution at the bottom of the tower.
EXAMPLE eleven (Using the method and System illustrated in FIGS. 1 and 5)
1. Preparing potassium sulfate into sulfate solution with the concentration of 42-48% by using water (or condensed liquid generated in the process of evaporative crystallization), mixing the sulfate solution with Beckmarm rearranged transposition ester in a mixing reactor 1, introducing toluene to extract caprolactam, and mixing the sulfate of the transposition ester with the sulfate of the sulfate solution according to the ratio of 1: 1.4 to 0.3, the mixing reactor 1 is a double-effect negative pressure evaporator, the temperature of the first-effect evaporation is 75 to 80 ℃, the absolute pressure of the evaporation is 0.4 to 0.6, the temperature of the second-effect evaporation is controlled between 62 to 66 ℃, and the evaporation pressure is 0.2 to 0.3kgf/cm 2. Feeding the transposition ester by 81-107kg per hour, feeding the ammonium sulfate solution by 246-262kg per hour, and evaporating the water by 168-181kg per hour, and heating by adopting low-pressure steam hot water of 1.3kgf/cm 2;
2. adding 250-320kg of acid sulfate into a thick crystallizing and thickening device every hour, then adding into a centrifuge for centrifugation, adding crystallized salt and first mother liquor, refluxing the first mother liquor to the mixing reactor 1, extracting the crystallized salt solid with 2-5 times of methanol and water in a ratio of 5:1-1.6, stirring at normal temperature for 5-30min, stirring at a rotating speed of 60-120 r/min, separating and separating ammonium sulfate and second mother liquor again, refluxing the ammonium sulfate to the mixing reactor 1, removing the extractant from the second mother liquor by absolute pressure of 0.5-0.6kgf/cm2, and obtaining 10-50% of dilute sulfuric acid solution at the bottom of the tower.
Example twelve (Using the method and System illustrated in FIGS. 1 and 5)
1. Preparing potassium sulfate and potassium aluminum sulfate into sulfate solution with the concentration of 42-48% by using water (or condensed liquid generated in the evaporation crystallization process), mixing the sulfate solution with Beckmarm rearranged transposition ester in a mixing reactor 1, introducing toluene to extract caprolactam, and mixing the sulfate of the transposition ester with the sulfate of the sulfate solution according to the ratio of 1: 1.4 to 1, the mixing reactor 1 is a double-effect negative pressure evaporator, the temperature of the first-effect evaporation is 83 to 86 ℃, the absolute pressure of the evaporation is 0.4 to 0.6, the temperature of the second-effect evaporation is 57 to 65 ℃, and the evaporation pressure is 0.2 to 0.3kgf/cm 2. Feeding the transposition ester by 81-107kg per hour, feeding the ammonium sulfate solution by 246-262kg per hour, and evaporating the water by 168-181kg per hour, and heating by adopting low-pressure steam hot water of 1.3kgf/cm 2;
2. adding 320kg of acid sulfate into a thick crystallizing and thickening device at 250 per hour, then adding the mixture into a centrifuge for centrifugation, refluxing the first mother liquor to the mixing reactor 1, extracting the crystallized salt solid with 3-4 times of methanol and water at a ratio of 5:1-1.3 at normal temperature for 5-30min, stirring at a stirring speed of 60-120 r/min, separating and separating ammonium sulfate from the second mother liquor again, refluxing the ammonium sulfate to the mixing reactor 1, removing the extractant from the second mother liquor by absolute pressure of 0.5-0.6kgf/cm2, and obtaining 10-50% dilute sulfuric acid solution at the bottom of the tower.
Embodiment thirteen (using the method and system shown in fig. 2 and 4)
1. Preparing potassium sulfate and ferrous sulfate into sulfate solution (suspension solution) with the concentration of 30-40% by using water (or condensed liquid generated in the evaporation crystallization process), mixing the sulfate solution with Beckmarm rearranged transposition ester in an evaporation crystallization reactor 4 at the temperature of 70-75 ℃, and extracting caprolactam through evaporation, wherein the ratio of the sulfate radical of the transposition ester to the sulfate radical of the sulfate solution is 1: 1.5 to 0.1, the evaporative crystallization reactor 4 is a one-effect negative pressure evaporator, the absolute pressure is 0.4 to 0.48kgf/cm2, and the evaporation temperature is controlled at 70 to 75 ℃. The feeding amount of the transposition ester is 90-110kg per hour, the feeding amount of the potassium sulfate and ferrous sulfate solution is 81-93kg per hour, and the evaporation water amount is 198-283 kg;
2. in the normal pressure or negative pressure and single effect or multiple effect evaporation process, when the quantity ratio of sulfate radical to solvent in the solution is more than or equal to 1: 4, forming a water-containing caprolactam phase layer on the upper liquid level, crystallizing at 45 ℃ to separate out crystal salt by using an acid sulfate solution at the lower part, centrifugally separating to obtain acid potassium sulfate, ferrous sulfate and a third mother liquid, returning the third mother liquid to the evaporative crystallization reactor 4, pouring the crystal acid potassium sulfate and the ferrous sulfate into a mixed solution of ethanol and water according to the mass ratio of 1:3.5, stirring for 5-30min at normal temperature and the stirring speed of 60-120 r/min, centrifugally separating to obtain solid potassium sulfate, ferrous sulfate and a fourth mother liquid, returning the potassium sulfate and the ferrous sulfate to the evaporative crystallization reactor 4, feeding the fourth mother liquid to a next process 8 for distillation, removing an extracting agent from the fourth mother liquid at the negative pressure absolute pressure of 0.5-0.6kgf/cm2, and obtaining a 10-50% dilute sulfuric acid solution at the bottom of the tower.
Fourteen embodiments (using the method and system shown in fig. 2 and 4)
1. Preparing sodium sulfate and ferrous sulfate into a sulfate solution (suspension solution) with the concentration of 30-35% by using water (or condensed liquid generated in the evaporation crystallization process), mixing the sulfate solution with Beckmarm rearranged transposition ester in an evaporation crystallization reactor 4 at the temperature of 70-75 ℃, and extracting caprolactam by evaporation, wherein the sulfate number ratio of the transposition ester sulfate to the sulfate solution is 1: 1.4-0.7, wherein the evaporative crystallization reactor 4 is a one-effect negative pressure evaporator, the absolute pressure is 0.4-0.5kgf/cm2, and the evaporation temperature is controlled at 70-75 ℃. Feeding the transposition ester by 90-110kg per hour, feeding the sodium sulfate and the ferrous sulfate by 75-105kg per hour, and evaporating the water by 198-283 kg;
2. in the normal pressure or negative pressure and single effect or multiple effect evaporation process, when the quantity ratio of sulfate radical to solvent in the solution is more than or equal to 1: 4, forming an aqueous caprolactam phase layer on the upper liquid level, crystallizing at 45 ℃ to separate out crystal salt by using an acid sulfate solution at the lower part, centrifugally separating to obtain acidic sodium sulfate, ferrous sulfate and a third mother liquid, returning the third mother liquid to the evaporation crystallization reactor 4, pouring the crystalline acid sodium sulfate and the ferrous sulfate into a mixed solution of ethanol and water according to the mass ratio of 1:3.2-3.6, stirring for 5-30min at normal temperature and the stirring speed of 60-120 r/min, centrifugally separating to obtain solid ferrous sulfate and a fourth mother liquid, returning the sodium sulfate and the ferrous sulfate to the evaporation crystallization reactor 4, sending the fourth mother liquid to the next process 8 for distillation, removing an extracting agent from the fourth mother liquid at the negative pressure absolute pressure of 0.5-0.6kgf/cm2, and obtaining a dilute sulfuric acid solution of 10-50% at the bottom of the tower.
Sixteen embodiments (using the method and system shown in fig. 2 and 4)
1. Preparing ferrous sulfate into a sulfate solution (suspension solution) with the concentration of 20-45% by using water (or condensed liquid generated in the evaporation crystallization process), mixing the sulfate solution with Beckmarm rearranged transposition ester in an evaporation crystallization reactor 4 at the temperature of 76-78 ℃, and extracting caprolactam through evaporation, wherein the sulfate radical quantity ratio of the transposition ester to the sulfate radical quantity of the sulfate solution is 1: 1.4-0.1, wherein the evaporative crystallization reactor 4 is a one-effect negative pressure evaporator, the absolute pressure is 0.4-0.48kgf/cm2, and the evaporation temperature is controlled at 70-75 ℃. Feeding the transposition ester by 90-110kg per hour, feeding the ferrous sulfate solution by 81-93kg per hour, and evaporating the water by 198-283 kg;
2. in the normal pressure or negative pressure and single-effect or multi-effect evaporation process, when the quantity ratio of sulfate radical to solvent in the solution is more than or equal to 1: 4, forming an aqueous caprolactam phase layer on the upper liquid level, crystallizing and separating out crystal salt at the lower part of the aqueous caprolactam phase layer by using an acid ferrous sulfate solution at the temperature of 45 ℃, centrifugally separating to obtain acid ferrous sulfate and a third mother liquid, returning the third mother liquid to the evaporative crystallization reactor 4, pouring the crystallized acid ferrous sulfate into a mixed solution of ethanol and water according to the mass ratio of 1:3.5, stirring the mixture for 5 to 30 minutes at normal temperature and the stirring speed of 60 to 120 revolutions per minute, centrifugally separating to obtain solid ferrous sulfate and a fourth mother liquid, returning ammonium sulfate and ferrous sulfate to the evaporative crystallization reactor 4, feeding the fourth mother liquid to the next process 8 for distillation, removing an extracting agent from the fourth mother liquid at the negative pressure absolute pressure of 0.5 to 0.6kgf/cm2, and obtaining a 10 to 50 percent dilute sulfuric acid solution at the bottom of the tower.
Seventeen embodiment (Using the method and System shown in FIGS. 6 and 7)
1. Preparing potassium sulfate into sulfate solution (suspension solution) with the concentration of 30% by using water (or condensed liquid generated in the evaporation crystallization process), mixing the sulfate solution with Beckmarm rearranged transposition ester in an evaporation crystallization reactor 4 at the temperature of 80-85 ℃, and extracting caprolactam through evaporation, wherein the number ratio of sulfate radicals of the transposition ester to sulfate radicals of the sulfate solution is 1: 1.2 to 0.3, the evaporative crystallization reactor 4 is a one-effect negative pressure evaporator, the absolute pressure is 0.5 to 0.6kgf/cm2, and the evaporation temperature is controlled between 80 and 85 ℃. Feeding the translocation ester by 81-110kg per hour, feeding the potassium sulfate solution by 240-268kg per hour, evaporating the water by 165-283kg, wherein the mass ratio of sulfate radical to water is more than or equal to 2: 3;
2. in the normal pressure or negative pressure and single effect or multiple effect evaporation process, when the quantity ratio of sulfate radical to solvent in the solution is more than or equal to 1: 4, forming an aqueous caprolactam phase layer on the upper liquid level, crystallizing the acid sulfate solution at 45 ℃ to separate out crystal salt, centrifugally separating to obtain potassium bisulfate, returning the mother liquid to the evaporation crystallization reactor 4, and taking the potassium bisulfate as a product or continuously extracting by methanol or ethanol to obtain dilute sulfuric acid and potassium sulfate.
Claims (16)
1. An additive for efficiently separating caprolactam is characterized in that: the additive is sulfate solution;
the Beckmarm rearranged translocated ester is mixed with a sulfate solution.
2. The additive for efficiently separating caprolactam according to claim 1, which is characterized in that: the sulfate radical quantity ratio of the transposition ester to the sulfate radical quantity of the sulfate radical solution is 1: 1.5-0.1.
3. The additive for efficiently separating caprolactam according to claim 1 or 2, which is characterized in that: the sulfate solution is one or the combination of any more of ammonium sulfate, sodium sulfate, potassium sulfate and ferrous sulfate;
or one of ammonium sulfate, sodium sulfate, potassium sulfate and ferrous sulfate and one or any combination of copper sulfate, aluminum potassium sulfate, aluminum sulfate, cadmium sulfate, zinc sulfate and magnesium sulfate;
or any combination of several of ammonium sulfate, sodium sulfate and potassium sulfate and one or more of copper sulfate, aluminum potassium sulfate, aluminum sulfate, cadmium sulfate, zinc sulfate and magnesium sulfate.
4. The additive for efficiently separating caprolactam according to claim 1 or 2, which is characterized in that: the Beckmarm rearranged translocated ester is mixed with a sulphate solution at a temperature of 10-130 ℃.
5. A caprolactam separation method without participation of ammonia or alkali is characterized in that: the method comprises mixing and separating;
mixing the Beckmarm rearranged transposition ester with a sulfate solution to form a mixed solution;
and separating the caprolactam from the mixed solution by extraction or separating the caprolactam from the mixed solution by evaporation.
6. The process of claim 5, wherein the caprolactam separation process is carried out without ammonia or alkali, and wherein: in the mixing step, the sulfate number ratio of the transposition ester to the sulfate solution is 1: 1.5-0.1.
7. The process of claim 5, wherein the caprolactam separation process is carried out without ammonia or alkali, and wherein: the process of separating caprolactam from the mixed solution in an evaporation mode, wherein the evaporation temperature is 10-130 ℃.
8. The process of claim 5, wherein the caprolactam separation process is carried out without ammonia or alkali, and wherein: and adding an extracting agent into the mixed solution.
9. A process according to any of claims 5 to 6 for the separation of caprolactam free from ammonia or base, characterized in that: the method also comprises evaporative crystallization;
and (3) evaporating and crystallizing, namely evaporating and concentrating the raffinate acid sulfate solution after extracting and separating caprolactam from the mixed solution under normal pressure or negative pressure and single effect or multiple effect to crystallize the crystal salt.
10. The process of claim 9, wherein the caprolactam separation process is carried out without ammonia or alkali, and wherein: the method also comprises the following treatment, after evaporation and crystallization, the following treatment is carried out;
and in the subsequent treatment, the crystallized salt is subjected to subsequent extraction by using a 10:1-4 alcohol-water mixed solution at the normal pressure and the temperature of 0-70 ℃, and sulfate crystals are separated.
11. The process of claim 10 for the separation of caprolactam without ammonia or base, wherein: in the subsequent treatment process, the mother liquor is distilled under normal pressure or negative pressure, alcohol is recovered by gas phase condensation, and sulfuric acid solution is obtained by liquid phase.
12. A process according to any of claims 5 to 8 for the separation of caprolactam free from ammonia or base, characterized in that: in the separation process, in the normal pressure or negative pressure and single-effect or multi-effect evaporation process, when the quantity ratio of sulfate radicals to the solvent in the solution is more than or equal to 1: 4, forming an aqueous caprolactam phase layer at the upper liquid level and an acid sulfate solution at the lower part.
13. The process of claim 12, wherein the caprolactam separation process is carried out without ammonia or alkali, and wherein: after said separation, there is a further processing step;
and in the subsequent treatment, the acid sulfate solution is subjected to subsequent extraction at the temperature of 0-70 ℃ under normal pressure by using a 10:1-4 alcohol-water mixed solution, sulfate crystals are formed, mother liquor obtained after the sulfate crystals are separated is distilled, alcohol is recovered by gas phase condensation, and a sulfuric acid solution is obtained by liquid phase.
14. A caprolactam separation system without participation of ammonia or alkali is characterized in that: the system comprises a mixing reactor or the mixing reactor and an extraction tower,
in the mixed reactor, Beckmarm rearranged transposition ester and sulfate solution are mixed in the mixed reactor to generate mixed liquid, and the mixed liquid is added with an extracting agent to realize extraction separation in the mixed reactor;
or the mixing reactor is connected with the extraction tower;
in the mixed reactor, Beckmarm rearranged transposition ester and a sulfate solution are mixed in the mixed reactor to generate a mixed liquid;
in the extraction tower, the mixed liquid is input into the extraction tower to extract caprolactam under the action of an extracting agent, and an extraction raffinate phase is discharged out of the extraction tower.
15. The caprolactam separation system without ammonia or alkali participation as claimed in claim 14, wherein: the system also comprises an evaporator, and the evaporator is connected with the extraction tower;
and the raffinate phase discharged from the extraction tower enters the evaporator.
16. A caprolactam separation system without participation of ammonia or alkali is characterized in that: the system comprises an evaporative crystallization reactor;
the Beckmarm rearranged translocation ester is mixed with a sulfate solution in an evaporative crystallization reactor to generate a mixed liquid, and the mixed liquid is separated in the evaporative crystallization reactor through evaporation.
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| CN114907265A (en) * | 2022-01-28 | 2022-08-16 | 陕西科原环保节能科技有限公司 | Additive for efficiently separating caprolactam, and caprolactam separation method and system |
| CN114907265B (en) * | 2022-01-28 | 2023-10-20 | 陕西科原环保节能科技有限公司 | Additive for efficiently separating caprolactam and caprolactam separation method and system |
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| CN114904472B (en) | 2024-03-29 |
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