CN118751176B - Energy-saving device and method for preparing aminocapronitrile from cyclohexanone oxime liquid phase rearrangement product - Google Patents
Energy-saving device and method for preparing aminocapronitrile from cyclohexanone oxime liquid phase rearrangement product Download PDFInfo
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- CN118751176B CN118751176B CN202411195574.9A CN202411195574A CN118751176B CN 118751176 B CN118751176 B CN 118751176B CN 202411195574 A CN202411195574 A CN 202411195574A CN 118751176 B CN118751176 B CN 118751176B
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- caprolactam
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- 238000000034 method Methods 0.000 title claims abstract description 66
- VEZUQRBDRNJBJY-UHFFFAOYSA-N cyclohexanone oxime Chemical compound ON=C1CCCCC1 VEZUQRBDRNJBJY-UHFFFAOYSA-N 0.000 title claims abstract description 50
- FHKPTEOFUHYQFY-UHFFFAOYSA-N 2-aminohexanenitrile Chemical compound CCCCC(N)C#N FHKPTEOFUHYQFY-UHFFFAOYSA-N 0.000 title claims abstract description 25
- 230000008707 rearrangement Effects 0.000 title claims abstract description 19
- 239000007791 liquid phase Substances 0.000 title claims abstract description 17
- JBKVHLHDHHXQEQ-UHFFFAOYSA-N epsilon-caprolactam Chemical compound O=C1CCCCCN1 JBKVHLHDHHXQEQ-UHFFFAOYSA-N 0.000 claims abstract description 508
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 170
- 238000006243 chemical reaction Methods 0.000 claims abstract description 108
- 238000000605 extraction Methods 0.000 claims abstract description 98
- 239000007788 liquid Substances 0.000 claims abstract description 81
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 claims abstract description 54
- 229910052921 ammonium sulfate Inorganic materials 0.000 claims abstract description 54
- 235000011130 ammonium sulphate Nutrition 0.000 claims abstract description 54
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 44
- 239000002994 raw material Substances 0.000 claims abstract description 36
- 238000001704 evaporation Methods 0.000 claims abstract description 34
- 230000008020 evaporation Effects 0.000 claims abstract description 34
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 claims description 81
- 239000012071 phase Substances 0.000 claims description 76
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 66
- 239000000243 solution Substances 0.000 claims description 57
- UAEPNZWRGJTJPN-UHFFFAOYSA-N methylcyclohexane Chemical compound CC1CCCCC1 UAEPNZWRGJTJPN-UHFFFAOYSA-N 0.000 claims description 46
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 claims description 33
- 230000009615 deamination Effects 0.000 claims description 33
- 238000006481 deamination reaction Methods 0.000 claims description 33
- 239000012535 impurity Substances 0.000 claims description 33
- GDOPTJXRTPNYNR-UHFFFAOYSA-N methylcyclopentane Chemical compound CC1CCCC1 GDOPTJXRTPNYNR-UHFFFAOYSA-N 0.000 claims description 32
- 238000004065 wastewater treatment Methods 0.000 claims description 32
- 238000004176 ammonification Methods 0.000 claims description 31
- 239000011259 mixed solution Substances 0.000 claims description 28
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 claims description 28
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 claims description 24
- 238000001816 cooling Methods 0.000 claims description 24
- GYNNXHKOJHMOHS-UHFFFAOYSA-N methyl-cycloheptane Natural products CC1CCCCCC1 GYNNXHKOJHMOHS-UHFFFAOYSA-N 0.000 claims description 23
- 239000000203 mixture Substances 0.000 claims description 19
- 239000000463 material Substances 0.000 claims description 16
- 229910021529 ammonia Inorganic materials 0.000 claims description 13
- 238000002156 mixing Methods 0.000 claims description 9
- 239000011541 reaction mixture Substances 0.000 claims description 5
- 238000001914 filtration Methods 0.000 claims description 3
- 230000003472 neutralizing effect Effects 0.000 claims description 3
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 claims description 2
- 239000008096 xylene Substances 0.000 claims description 2
- 230000000694 effects Effects 0.000 claims 2
- 150000002894 organic compounds Chemical class 0.000 claims 1
- KBMSFJFLSXLIDJ-UHFFFAOYSA-N 6-aminohexanenitrile Chemical compound NCCCCCC#N KBMSFJFLSXLIDJ-UHFFFAOYSA-N 0.000 abstract description 51
- 239000003054 catalyst Substances 0.000 abstract description 29
- 238000007670 refining Methods 0.000 abstract description 29
- 238000005265 energy consumption Methods 0.000 abstract description 15
- 238000004519 manufacturing process Methods 0.000 abstract description 10
- 238000005342 ion exchange Methods 0.000 abstract description 8
- 238000006116 polymerization reaction Methods 0.000 abstract description 8
- 238000004821 distillation Methods 0.000 abstract description 7
- 239000000571 coke Substances 0.000 abstract description 5
- 238000007086 side reaction Methods 0.000 abstract description 4
- 238000006386 neutralization reaction Methods 0.000 abstract description 3
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 abstract 1
- 235000011114 ammonium hydroxide Nutrition 0.000 abstract 1
- 238000005538 encapsulation Methods 0.000 abstract 1
- 239000003921 oil Substances 0.000 description 49
- HGCIXCUEYOPUTN-UHFFFAOYSA-N cyclohexene Chemical compound C1CCC=CC1 HGCIXCUEYOPUTN-UHFFFAOYSA-N 0.000 description 42
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 36
- 239000000047 product Substances 0.000 description 24
- URLKBWYHVLBVBO-UHFFFAOYSA-N Para-Xylene Chemical group CC1=CC=C(C)C=C1 URLKBWYHVLBVBO-UHFFFAOYSA-N 0.000 description 20
- 238000004064 recycling Methods 0.000 description 14
- 239000003795 chemical substances by application Substances 0.000 description 13
- 238000011084 recovery Methods 0.000 description 13
- HPXRVTGHNJAIIH-UHFFFAOYSA-N cyclohexanol Chemical compound OC1CCCCC1 HPXRVTGHNJAIIH-UHFFFAOYSA-N 0.000 description 11
- 230000018044 dehydration Effects 0.000 description 11
- 238000006297 dehydration reaction Methods 0.000 description 11
- 238000002474 experimental method Methods 0.000 description 11
- 239000007864 aqueous solution Substances 0.000 description 10
- BGTOWKSIORTVQH-UHFFFAOYSA-N cyclopentanone Chemical compound O=C1CCCC1 BGTOWKSIORTVQH-UHFFFAOYSA-N 0.000 description 10
- 239000002245 particle Substances 0.000 description 10
- 238000010992 reflux Methods 0.000 description 10
- 239000007787 solid Substances 0.000 description 10
- 238000004811 liquid chromatography Methods 0.000 description 9
- NAQMVNRVTILPCV-UHFFFAOYSA-N hexane-1,6-diamine Chemical compound NCCCCCCN NAQMVNRVTILPCV-UHFFFAOYSA-N 0.000 description 8
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 8
- 239000002351 wastewater Substances 0.000 description 8
- 239000006227 byproduct Substances 0.000 description 7
- 238000005984 hydrogenation reaction Methods 0.000 description 7
- 238000013112 stability test Methods 0.000 description 7
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 5
- IJQAOQPOJZUGIA-UHFFFAOYSA-N azepan-2-one benzene Chemical compound c1ccccc1.O=C1CCCCCN1 IJQAOQPOJZUGIA-UHFFFAOYSA-N 0.000 description 5
- 238000002309 gasification Methods 0.000 description 5
- 239000002808 molecular sieve Substances 0.000 description 5
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 5
- IFTRQJLVEBNKJK-UHFFFAOYSA-N Ethylcyclopentane Chemical compound CCC1CCCC1 IFTRQJLVEBNKJK-UHFFFAOYSA-N 0.000 description 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- WNLRTRBMVRJNCN-UHFFFAOYSA-N adipic acid Chemical compound OC(=O)CCCCC(O)=O WNLRTRBMVRJNCN-UHFFFAOYSA-N 0.000 description 4
- 239000003153 chemical reaction reagent Substances 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 150000002825 nitriles Chemical class 0.000 description 4
- AVXURJPOCDRRFD-UHFFFAOYSA-N Hydroxylamine Chemical compound ON AVXURJPOCDRRFD-UHFFFAOYSA-N 0.000 description 3
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- SLUNEGLMXGHOLY-UHFFFAOYSA-N benzene;hexane Chemical compound CCCCCC.C1=CC=CC=C1 SLUNEGLMXGHOLY-UHFFFAOYSA-N 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000000945 filler Substances 0.000 description 3
- AILKHAQXUAOOFU-UHFFFAOYSA-N hexanenitrile Chemical compound CCCCCC#N AILKHAQXUAOOFU-UHFFFAOYSA-N 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- CKRLKUOWTAEKKX-UHFFFAOYSA-N 4,5,6,7-tetrahydro-2h-benzotriazole Chemical compound C1CCCC2=NNN=C21 CKRLKUOWTAEKKX-UHFFFAOYSA-N 0.000 description 2
- 238000006237 Beckmann rearrangement reaction Methods 0.000 description 2
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- 229920002302 Nylon 6,6 Polymers 0.000 description 2
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical group O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- URRHWTYOQNLUKY-UHFFFAOYSA-N [AlH3].[P] Chemical group [AlH3].[P] URRHWTYOQNLUKY-UHFFFAOYSA-N 0.000 description 2
- 235000011037 adipic acid Nutrition 0.000 description 2
- 239000001361 adipic acid Substances 0.000 description 2
- AWSFEOSAIZJXLG-UHFFFAOYSA-N azepan-2-one;hydrate Chemical compound O.O=C1CCCCCN1 AWSFEOSAIZJXLG-UHFFFAOYSA-N 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- VEFXTGTZJOWDOF-UHFFFAOYSA-N benzene;hydrate Chemical compound O.C1=CC=CC=C1 VEFXTGTZJOWDOF-UHFFFAOYSA-N 0.000 description 2
- 230000005587 bubbling Effects 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 238000012856 packing Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 239000000126 substance Substances 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
- 238000007738 vacuum evaporation Methods 0.000 description 2
- 238000003809 water extraction Methods 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
- TYNIJIXWHNNKNQ-UHFFFAOYSA-N 1,4-xylene;hydrate Chemical compound O.CC1=CC=C(C)C=C1 TYNIJIXWHNNKNQ-UHFFFAOYSA-N 0.000 description 1
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- PGTXKIZLOWULDJ-UHFFFAOYSA-N [Mg].[Zn] Chemical compound [Mg].[Zn] PGTXKIZLOWULDJ-UHFFFAOYSA-N 0.000 description 1
- HYWKVFVQRGEFCH-UHFFFAOYSA-N [O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[PH6+3] Chemical compound [O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[PH6+3] HYWKVFVQRGEFCH-UHFFFAOYSA-N 0.000 description 1
- UGACIEPFGXRWCH-UHFFFAOYSA-N [Si].[Ti] Chemical group [Si].[Ti] UGACIEPFGXRWCH-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000010306 acid treatment Methods 0.000 description 1
- 229910000287 alkaline earth metal oxide Inorganic materials 0.000 description 1
- CSDREXVUYHZDNP-UHFFFAOYSA-N alumanylidynesilicon Chemical group [Al].[Si] CSDREXVUYHZDNP-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- WASPOUDNZOOSEW-UHFFFAOYSA-N benzene toluene hydrate Chemical compound CC1=CC=CC=C1.C1=CC=CC=C1.O WASPOUDNZOOSEW-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 231100000481 chemical toxicant Toxicity 0.000 description 1
- FIMJSWFMQJGVAM-UHFFFAOYSA-N chloroform;hydrate Chemical compound O.ClC(Cl)Cl FIMJSWFMQJGVAM-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- BJZJDEOGMBZSLE-UHFFFAOYSA-N cyclohexane;hydrate Chemical compound O.C1CCCCC1 BJZJDEOGMBZSLE-UHFFFAOYSA-N 0.000 description 1
- 125000000113 cyclohexyl group Chemical group [H]C1([H])C([H])([H])C([H])([H])C([H])(*)C([H])([H])C1([H])[H] 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- PKMNZOFQIRXQDO-UHFFFAOYSA-N heptane;hexane Chemical compound CCCCCC.CCCCCCC PKMNZOFQIRXQDO-UHFFFAOYSA-N 0.000 description 1
- 125000005842 heteroatom Chemical group 0.000 description 1
- -1 hexane-normal heptane-water Chemical compound 0.000 description 1
- JYVHOGDBFNJNMR-UHFFFAOYSA-N hexane;hydrate Chemical compound O.CCCCCC JYVHOGDBFNJNMR-UHFFFAOYSA-N 0.000 description 1
- 239000003456 ion exchange resin Substances 0.000 description 1
- 229920003303 ion-exchange polymer Polymers 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 238000006068 polycondensation reaction Methods 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000011946 reduction process Methods 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000012430 stability testing Methods 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- CMQCNTNASCDNGR-UHFFFAOYSA-N toluene;hydrate Chemical compound O.CC1=CC=CC=C1 CMQCNTNASCDNGR-UHFFFAOYSA-N 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
- 239000002918 waste heat Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C253/00—Preparation of carboxylic acid nitriles
- C07C253/20—Preparation of carboxylic acid nitriles by dehydration of carboxylic acid amides
-
- 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
- B01D11/0488—Flow sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/009—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping in combination with chemical reactions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
- B01D3/143—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
- B01D3/143—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step
- B01D3/148—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step in combination with at least one evaporator
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C253/00—Preparation of carboxylic acid nitriles
- C07C253/32—Separation; Purification; Stabilisation; Use of additives
- C07C253/34—Separation; Purification
-
- 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
-
- 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
-
- 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
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00002—Chemical plants
- B01J2219/00004—Scale aspects
- B01J2219/00006—Large-scale industrial plants
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
本发明提出了一种以环己酮肟液相重排产物制氨基己腈的节能装置和方法，所述装置和方法将环己酮肟液相重排并经氨水中和后的含有硫铵、水的己内酰胺原料液经萃取后直接精馏、过滤、浓缩后进入氨化反应器反应制备氨基己腈。与现有技术相比，本发明整合并优化了己内酰胺的精制与氨化反应，消除了水反萃取、离子交换、多效蒸发水和精馏己内酰胺等多个单元步骤，极大简化工艺流程，大幅节约能耗和投资，降低6‑氨基己腈的生产成本，并且适量萃取剂进入氨化反应过程能一定程度上降低原料己内酰胺的聚合以及抑制副反应结焦物对催化剂的包裹污染，从而提高产品收率并延长催化剂寿命。
The present invention proposes an energy-saving device and method for preparing aminocapronitrile with a cyclohexanone oxime liquid phase rearrangement product, wherein the device and method rearrange the cyclohexanone oxime liquid phase and the caprolactam raw material liquid containing ammonium sulfate and water after neutralization in ammonia water is directly distilled, filtered, and concentrated after extraction to enter an aminating reactor for reaction to prepare aminocapronitrile. Compared with the prior art, the present invention integrates and optimizes the refining and aminating reaction of caprolactam, eliminates multiple unit steps such as water back extraction, ion exchange, multi-effect evaporation of water and distillation of caprolactam, greatly simplifies the process flow, greatly saves energy consumption and investment, reduces the production cost of 6-aminocapronitrile, and an appropriate amount of extractant enters the aminating reaction process to reduce the polymerization of raw material caprolactam and suppress the encapsulation pollution of the catalyst by the side reaction coke product to a certain extent, thereby improving the product yield and extending the catalyst life.
Description
Technical Field
The invention belongs to the technical field of green chemical preparation, and particularly relates to an energy-saving device and an energy-saving method for preparing aminocapronitrile by using a cyclohexanone oxime liquid-phase rearrangement product.
Background
Nylon 66 is a versatile polymer material, and its excellent properties have been used in steadily increasing amounts in recent years. Nylon 66 is made by polycondensation of hexamethylenediamine and adipic acid.
The existing production process of hexamethylenediamine mainly comprises a butadiene method, an acrylonitrile method and an adipic acid method, but has the defects of high usage of toxic chemicals, high energy consumption, low product selectivity and the like. In contrast, the caprolactam process uses caprolactam as a raw material, and 6-aminocapronitrile is produced after ammonification and dehydration, and then hexamethylenediamine is produced by hydrogenation. The caprolactam method for preparing hexamethylenediamine has the advantages of simple reaction steps, environment-friendly process, sufficient raw material supply, high product selectivity and the like.
At present, the main production process of caprolactam is to use benzene as a raw material to prepare cyclohexanone, then use hydroxylamine to prepare cyclohexanone oxime, then use fuming sulfuric acid to perform Beckmann rearrangement to generate a caprolactam sulfuric acid mixture, and finally generate crude caprolactam liquid containing ammonium sulfate through neutralization and crystallization. In the crude caprolactam liquid containing ammonium sulfate, 60-70% of caprolactam is the rest of impurities such as ammonium sulfate, water, cyclohexanone, benzene, toluene, cyclohexanol and the like, and in order to improve the purity and quality of the caprolactam, a caprolactam refining unit is needed to purify the caprolactam to obtain refined caprolactam.
The current caprolactam refining process flow comprises the steps of benzene extraction, water back extraction, ion exchange, caprolactam hydrogenation, multi-effect evaporation, caprolactam rectification and the like. The extraction refining is an important link of caprolactam refining, firstly, using organic solvent (usually benzene) to extract crude caprolactam solution containing ammonium sulfate to remove most of water-soluble impurities, then using water to reextract caprolactam benzene solution to remove partial residual organic impurities to obtain caprolactam water solution, using ion exchange and hydrogenation to further remove organic impurities containing unsaturated bonds, then using multiple-effect evaporation to remove water in the caprolactam water solution, and finally rectifying caprolactam to obtain high-quality caprolactam product. It is apparent from the above steps that the refining of caprolactam requires the distillation of the extractant benzene and water, and that caprolactam also requires gasification, which requires a large amount of energy consumption, and that the wastewater discharge is increased due to the introduction of a large amount of water in the water washing and stripping steps.
The prior art about caprolactam refining and caprolactam ammonification mainly aims at optimizing a single reaction process flow or developing a new catalyst, for example, a caprolactam refining device is reported by a patent CN201620239506.2, which consists of an extraction tower, a refining tower, a hydrogenation reactor, a light removal tower, a distillation device, and does not need steps of water back extraction, ion exchange, evaporation and the like, a device for reducing steam consumption in the caprolactam refining process is reported by a patent CN202220658386.5, steam and circulating water consumption is reduced by fully utilizing heat energy of the top of the tower, a caprolactam refining method is reported by a patent CN201711000196.4, the working procedures comprise extraction of an extractant, water back extraction and ion exchange of a hydrogen peroxide wash extractant solution, prolonging the service life of an ion exchange resin, a caprolactam refining device with low energy consumption is reported by a patent CN201621187626.9, compared with the traditional caprolactam refining process, an alkaline washing tower, an acid washing tower, a light removal tower, water extraction and evaporation and the like are not needed, waste water generation is reduced, an alkaline earth metal oxide, an excessive metal oxide, silicon oxide and aluminum oxide are reported by a patent CN113083270A, 6-aminocapronitrile is prepared by using a phosphorus nitrate molecular sieve as a nitric acid, and a catalyst is prepared by soaking nickel and nickel in the nitric acid molecular sieve. CN16617690a reports a device and a method for preparing 6-aminocapronitrile from crude caprolactam, which uses some crude caprolactam containing water and impurities to replace the currently refined caprolactam as a raw material, prepares 6-aminocapronitrile by vacuum evaporation dehydration, vacuum evaporation caprolactam and gas ammonia jet pressurization technology, and reduces the energy consumption of once rectifying, gasifying and refining of caprolactam.
Although the technology is optimized for the technological process, the energy consumption and the raw material requirements are locally reduced, the defects of complicated technological steps, more wastewater discharge and higher production cost still exist.
Disclosure of Invention
Aiming at the problems of the prior art, the invention provides a novel, simplified, low-energy-consumption, low-pollution and high-feasibility device and method for producing 6-aminocapronitrile, which are characterized in that an extracting agent is used for extracting crude caprolactam liquid containing ammonium sulfate after cyclohexanone oxime liquid phase rearrangement to obtain a crude caprolactam-extracting agent mixed solution, and then azeotropic dehydration and extractive agent distillation recovery are carried out to directly carry out ammoniation reaction to obtain 6-aminocapronitrile product liquid.
The invention reduces the steps of water back extraction, ion exchange, hydrogenation, multi-effect evaporation and other high-energy consumption and high-pollution caprolactam refining, and greatly reduces the energy consumption and the production cost. Besides the selectivity of the catalyst, the yield of the aminocapronitrile in the caprolactam ammonification process is mainly influenced by liquid phase polymerization of caprolactam under the condition of water, particularly, the boiling point of the caprolactam is high, the evaporation is required to be more than 260 ℃, and the aminocapronitrile starts to produce polymerization reaction under the condition of water content at 130 ℃, so that water control and gasification under the condition of low water content as much as possible are the most effective means for improving the yield of the aminocapronitrile. The invention utilizes the water content of the crude caprolactam-extractant mixed liquor after azeotropic dehydration to be controlled below 100ppm, compared with the water content of the high-grade caprolactam directly used as a raw material in the prior art, the method can greatly reduce the polymerization risk of caprolactam in the heating gasification process, meanwhile, the experiment proves that the organic impurities except for sulfides in the crude caprolactam-extractant mixed liquor have little influence on the conversion rate and selectivity of the ammoniation reaction, the existence of a proper amount of extractant in the ammoniation process can also relieve the polymerization of caprolactam in the evaporation process and inhibit the wrapping pollution of side reaction cokes on the catalyst, thereby being beneficial to improving the selectivity of 6-aminocapronitrile, and besides, part of extractant can be used as an entrainer for the dehydration link of the follow-up aminocapronitrile, and is also very beneficial to reducing the water content of a system and reducing the generation of various polymers in the rectification process, so that the method has extremely high economic benefit in the field of preparing new nylon materials.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
an energy-saving device for preparing aminocapronitrile by using a cyclohexanone oxime liquid-phase rearrangement product comprises an extraction device, a first rectifying device, a filter, a concentration system and a reaction system,
The inlet of the extraction device is connected with an extractant and raw material liquid, the raw material liquid is caprolactam liquid containing water, ammonium sulfate and organic impurities,
The oil phase outlet of the extraction device is directly connected with the first rectifying device, the tower kettle outlet of the first rectifying device is connected with the filter,
The liquid phase outlet of the filter is connected with the concentration system,
The outlet of the tower kettle of the concentration system is connected with the reaction system,
The reaction system comprises a reactor and a second rectifying device which are sequentially arranged, wherein the reactor is a caprolactam ammoniation reactor, and a tower kettle outlet of the second rectifying device is a crude aminocapronitrile mixed solution outlet. The reaction mixed solution containing NH 3, water, 6-aminocapronitrile, caprolactam and light and heavy component impurities is obtained at the outlet of the reactor, and after dehydration by a second rectifying device, the obtained crude aminocapronitrile mixed solution can be connected with an aminocapronitrile refining system. The aminocapronitrile refining system is of the prior art.
Preferably, the extraction device is a sieve plate extraction tower, a filler extraction tower, a modified pulse sieve plate tower or a rotary disk extraction tower.
Preferably, the water phase outlet of the extraction device is connected with the wastewater treatment device.
Preferably, the top outlet of the first rectifying device is connected with a delaminator, more preferably, the oil phase outlet of the delaminator is connected with the inlet of the extracting device, and the water phase outlet of the delaminator is connected with the wastewater treatment device. The extractant and water forming azeotropy are extracted from the top of the first rectifying device, and the extractant of the oil phase can be recycled after layering by the layering device, so that the cost is further saved.
More preferably, the wastewater treatment device is a rectifying tower, and the top outlet of the rectifying tower is connected with the extraction device. The waste water treatment device recycles a small amount of extractant in the recovered waste water through rectification separation, further saves cost and ensures that the waste water reaches the discharge standard.
Preferably, the concentration system is a single-effect evaporation system, a multi-effect evaporation system, a single-tower rectification system or a multi-tower rectification system. The concentration system with lower relative cost is selected according to the actual production condition, so that the cost can be further saved.
Preferably, the top outlet of the concentration system is connected with the extraction device. The extractant is obtained by separating the top of the concentration system, and can be recycled, thereby further saving the cost.
Preferably, the reactor is a fixed bed reactor or a fluidized bed reactor.
Preferably, the reaction system further comprises a mixing evaporator arranged before the reactor. The reaction raw materials are mixed in the form of a gas phase in a mixing evaporator.
Preferably, the reaction system further comprises a cooling separator arranged between the reactor and the second rectifying device, and a liquid phase outlet of the cooling separator is connected with the second rectifying device. And cooling and separating the reactor discharge by a cooling separator, and sending the separated feed liquid into a second rectifying device.
More preferably, the gas phase outlet of the cooling separator is connected to the mixing evaporator. The ammonia gas which is obtained by cooling the separator and is not completely reacted can be recycled as the reaction raw material, thereby further saving the cost.
Preferably, a rectification deamination tower is further arranged between the second rectification device and the reactor, the tower bottom of the rectification deamination tower is connected with the second rectification device, and the tower top of the rectification deamination tower is communicated with the mixing evaporator. The rectification deamination tower is used for removing ammonia gas which is not completely reacted and remains, and can be recycled as a reaction raw material, so that the cost is further saved.
More preferably, the cooling separator is disposed before the rectification deamination column.
Preferably, the top outlet of the second rectifying device is connected with a second separator. More preferably, the oil phase outlet of the second separator is connected with the inlet of the extraction device, and the water phase outlet of the second separator is connected with the wastewater treatment device. Similar to the first rectifying device, the extractant forming azeotropy and water produced in the reaction are extracted from the top of the second rectifying device, and after layering by the second layering device, the extractant of the oil phase can be recycled, thereby further saving the cost.
The invention further provides a method for preparing aminocapronitrile by using a cyclohexanone oxime liquid-phase rearrangement product, which comprises the following steps:
(1) Adding an organic extractant into the raw material liquid for extraction, wherein the obtained oil phase is caprolactam extraction solution;
the raw material liquid is a material liquid obtained by neutralizing a cyclohexanone oxime heavy liquid with ammonia;
(2) Directly rectifying the caprolactam extraction solution to remove water and part of organic extractant, so as to obtain a caprolactam mixture containing impurities;
(3) Filtering the caprolactam mixture containing impurities to remove the impurities, and concentrating to remove most or all of the extractant to obtain caprolactam liquid;
(4) Feeding the caprolactam liquid into a reactor for ammonification reaction to obtain a reaction mixture;
(5) And (3) rectifying the reaction mixture to remove water, so as to obtain a crude aminocapronitrile mixed solution.
In the prior art, feed liquid obtained by neutralizing the cyclohexanone oxime heavy liquor through ammonia is caprolactam solution which is obtained by subjecting cyclohexanone oxime to Beckmann rearrangement under fuming sulfuric acid treatment and then carrying out an ammonia neutralization step and contains more ammonium sulfate, water and other small amount of organic impurities.
The solution is used as a raw material, and is directly rectified and separated after being extracted by an organic extractant without conventional treatment steps such as back extraction, so that a large amount of wastewater can be avoided from being generated after a large amount of water is introduced, an azeotropic system can be formed by the extractant and the water to reduce the rectification temperature, on one hand, the rectification energy consumption is reduced, on the other hand, the water in the system can be effectively removed, and the obtained tower kettle discharge is very easy to separate out and separate a small amount of ammonium sulfate dissolved in the water contained in the extract, and most or even all of the extractant can be removed by a concentration system after the filtering treatment. In the ammonification reaction process, a small amount of residual extractant can not only not influence the reaction, but also relieve the polymerization of caprolactam in the vaporization process and inhibit the wrapping pollution of side reaction cokes on the catalyst, and water generated in the reaction after the reaction can form an azeotropic system, so that the water in the system is effectively removed with low energy consumption, and the product is finally obtained with high efficiency, high selectivity and low cost.
Preferably, the concentration of caprolactam in the caprolactam extraction solution in the step (1) is 5-40% by mass, and preferably 15-30%.
Preferably, the raw material liquid is derived from hydroxylamine process of cyclohexanone or hydroxylamine-free process of cyclohexanone.
Preferably, the hydroxylamine process of cyclohexanone is a raschig process, an HSO process, a DSM/HPO process or a NO reduction process.
Preferably, the hydroxylamine-free process of cyclohexanone is an alpha extractant process or a photonitrosation process.
Preferably, the organic extractant in step (1) is an organic substance that forms an azeotrope with water and is not miscible with water. More preferably, the organic extractant is one or a mixture of several of benzene, toluene, xylene, chloroform, carbon tetrachloride, cyclohexane, methylcyclohexane or methylcyclopentane.
Preferably, the operation pressure of the top of the rectifying tower in the step (2) is 30-120 KPa, the operation temperature of the top of the tower is 45-80 ℃, and the operation temperature of the bottom of the tower is 70-120 ℃. The first rectifying tower adopts low-pressure steam or steam condensate water with the temperature higher than that of the tower kettle by more than 10 ℃ as a heat source, and the second rectifying tower adopts saturated steam with the temperature higher than that of the tower kettle by more than 5 ℃ as a heat source.
Preferably, in the step (3), the content of caprolactam in the caprolactam liquid is 50-99.9% by mass, and the preferred range is 75-99.9%. The balance of organic extractant and organic impurities. The content of the extractant in the caprolactam extraction solution is comprehensively determined according to the water content of an ammoniation reaction product, the azeotrope composition of the extractant and water and the steam energy consumption, and if benzene is adopted as the extractant, the benzene content is preferably 20-30%, if toluene is adopted, the toluene content is preferably 10-20%, and if benzene and toluene are adopted as the compound extractant, the benzene content is preferably 10-20%, and the toluene content is preferably 5-10%.
The ammonification of caprolactam can be carried out according to the conventional technology in the art, and the invention is not particularly limited, namely caprolactam and ammonia are mixed according to a certain proportion and are introduced into a reactor, and the ammonification is carried out under the catalysis condition.
The reaction pressure of caprolactam ammonification is 90-1000 KPa.
The reaction temperature of caprolactam ammonification is 250-400 ℃.
The reaction space velocity of the ammonification of caprolactam is 0.5-5 h -1.
The molar ratio of caprolactam to ammonia in the caprolactam ammonification reaction is 1:5-150.
In the rectification stage, the reaction mixture containing NH 3, water, 6-aminocapronitrile, caprolactam and light and heavy component impurities is subjected to the reaction, the residual extractant in the previous step forms an azeotrope with water, and the water content after rectification can be reduced to be within 200ppm, so that a dehydrated crude aminocapronitrile mixed solution is obtained.
The invention has the beneficial effects that:
The invention couples caprolactam refining and caprolactam ammonification reaction, reduces the steps of back extraction, ion exchange and hydrogenation of waste water and the steps of multi-effect evaporation and distillation with high energy consumption on the premise of not influencing the production data (raw material conversion rate and product selectivity) of preparing 6-aminocapronitrile by caprolactam ammonification, thereby providing a new technological process for preparing 6-aminocapronitrile by taking crude caprolactam as a raw material.
(1) The invention skillfully utilizes the characteristics that azeotropic dehydration removes water-soluble impurities such as ammonium sulfate and the like which have influence on the ammonification reaction from a system, and impurities contained in the residual caprolactam extraction solution have no influence on the ammonification reaction, directly skips the links of high energy consumption and high pollution such as water extraction, multi-effect evaporation, ion exchange, hydrogenation, caprolactam refining and the like, simplifies the steps, reduces the energy consumption, reduces the production of wastewater and the like.
(2) The organic extractant adopted by the invention is favorable for dispersing caprolactam, is not easy to polymerize and coke in the gasification process, inhibits side reactions and the wrapping and pollution of sticky cokes to the catalyst, is favorable for the continuity and stability of ammonification reaction, and can improve the product yield and prolong the service life of the catalyst.
(3) The water content of the system of the caprolactam extraction solution after azeotropic dehydration can be controlled below 100ppm, and the water content of caprolactam in a better product is much lower than 700ppm, so that the polymerization risk of caprolactam in the heating gasification process before reaction can be greatly reduced.
(4) According to the invention, a small amount of organic extractant can be left in the raw materials before the ammonification reaction, and after the residual small amount of organic extractant participates in the ammonification reaction, an azeotrope can be formed with water generated in the reaction in a subsequent separation process, so that the water content in the reaction product is reduced to below 200ppm from 700-1000 ppm of common rectification dehydration by azeotropic dehydration, the polymerization of unreacted caprolactam in a tower bottom in a subsequent refining unit is greatly reduced, and the overall yield of 6-aminocapronitrile is improved.
Drawings
FIG. 1 is a schematic diagram of the apparatus of example 1.
Fig. 2 is a schematic view of the apparatus of example 2.
FIG. 3 is a chromatogram of the crude aminocapronitrile mixture obtained by the reaction in example 1.
Wherein 1 is an extraction device, 2 is a wastewater treatment device, 3 is a first rectification device, 4 is a layering device, 5 is a filter, 6 is a first rectification recovery tower, 7 is a second rectification recovery tower, 8 is a mixed evaporator, 9 is a reactor, 10 is a cooling separator, 11 is a rectification deamination tower, 12 is a second rectification device, and 13 is a second layering device.
Detailed Description
The raw materials adopted in the embodiments of the invention are specifically as follows:
The device adopted by each embodiment of the invention comprises an extraction device 1, a first rectifying device 3, a filter 5, a concentration system and a reaction system, wherein an inlet of the extraction device 1 is connected with an extractant and a raw material liquid, the raw material liquid is caprolactam liquid containing water, ammonium sulfate and organic impurities, an oil phase outlet of the extraction device 1 is connected with the first rectifying device 3, a tower kettle outlet of the first rectifying device 3 is connected with the filter 5, a liquid phase outlet of the filter 5 is connected with the concentration system, a tower kettle outlet of the concentration system is connected with the reaction system, the reaction system comprises a reactor 9 and a second rectifying device 12 which are sequentially arranged, the reactor 9 is a caprolactam ammoniation reactor, and a tower kettle outlet of the second rectifying device 12 is a crude aminocapronitrile mixed liquid outlet.
The water phase outlet of the extraction device 1 is connected with the wastewater treatment device 2.
The top outlet of the first rectifying device 3 is connected with a layering device 4, the oil phase outlet of the layering device 4 is connected with the inlet of the extraction device 1, and the water phase outlet of the layering device 4 is connected with the wastewater treatment device 2.
The wastewater treatment device 2 is a rectifying tower, and an outlet at the top of the tower is connected with the extraction device 1.
The top outlet of the concentration system is connected with the extraction device 1.
The reaction system further comprises a mixing evaporator 8 arranged before the reactor 9.
The reaction system further comprises a cooling separator 10 arranged between the reactor 9 and the second rectifying device 12, wherein a liquid phase outlet of the cooling separator 10 is connected with the second rectifying device 12.
The gas phase outlet of the cooling separator 10 is connected to the mixing evaporator 8.
A rectification deamination tower 11 is further arranged between the second rectification device 12 and the reactor 9, the tower bottom of the rectification deamination tower 11 is connected with the second rectification device 12, and the tower top of the rectification deamination tower 11 is communicated with the mixing evaporator 8.
The cooling separator 10 is arranged before the rectifying deamination tower 11.
The top outlet of the second rectifying device 12 is connected with a second separator 13. The oil phase outlet of the second separator 13 is connected with the inlet of the extraction device 1, and the water phase outlet of the second separator 13 is connected with the wastewater treatment device 2.
Example 1
(1) The method comprises the steps of taking ammonium sulfate-containing caprolactam liquid obtained by a cyclohexanone oxime rearrangement process as a raw material liquid, using benzene as an extracting agent, carrying out countercurrent extraction by taking a rotary disc extraction tower as an extracting device, obtaining an ammonium sulfate-containing aqueous solution at the tower bottom, and obtaining a crude caprolactam benzene solution with the mass fraction of 25% of caprolactam at the tower top, wherein the water content is 3%, ammonium sulfate is dissolved in water, and organic impurities comprise 180ppm of cyclohexane, 68ppm of cyclohexene, 41ppm of cyclopentanone, 78ppm of methylcyclopentane and the like.
(2) The crude caprolactam benzene solution enters a first rectifying device 3, is operated under normal pressure, the temperature of the top of the tower is 68 ℃ and the temperature of the bottom of the tower is 92 ℃,2 kg of secondary low-pressure steam is used as a heat source, the azeotrope of water and benzene extracted from the top of the tower enters a layering device 4, water and oil are separated in the layering device 4, an oil phase returns to an extraction device 1 for recycling, and a water phase enters a wastewater treatment device 2. The mixture at the bottom of the first rectifying device 3 is filtered by a filter 5 to remove solid particles such as precipitated ammonium sulfate, and the like, so that a benzene-hexane mixed solution with caprolactam concentration of 41.2% is obtained and enters a concentration system.
(3) The concentration system is a three-effect evaporation system, a benzene-hexane mixed solution with caprolactam concentration of 80% is obtained after part of benzene is evaporated, and the evaporated benzene is cooled and recycled by a rotary disc extraction tower.
(4) Gasifying a benzene-hexane mixed solution with caprolactam concentration of 80% and then feeding the solution into an ammoniation fixed bed reactor, wherein a catalyst is activated alumina, the reaction temperature is 330 ℃, the feeding mole ratio of ammonia to caprolactam is 24:1, the airspeed is 0.8h -1, the once-through caprolactam conversion rate is 67.3%, the selectivity of 6-aminocapronitrile is 96.9%, the benzene content in the product is 18.8% by mass fraction, the water content is 7.8% by mass fraction, the positions of cyclohexane and methylcyclopentane still have peaks in liquid chromatography, the cyclohexanone and cyclohexene are not converted into other byproducts, and the average once-through caprolactam conversion rate is 66.7% and the average selectivity of 6-aminocapronitrile is 96.7% in a catalyst stability test of 200 hours.
(5) A comparison experiment is carried out on 80% benzene and hexane mixed solution prepared from commercial reagent grade benzene and excellent caprolactam, wherein the reaction temperature is 330 ℃ in the same ammonification fixed bed reactor, the feeding mole ratio of ammonia gas to caprolactam is 24:1, the airspeed is 0.8h -1, the once-through caprolactam conversion rate is 67.8%, and the 6-aminocapronitrile selectivity is 96.3%.
(6) A commercial high-grade caprolactam is adopted for a comparison experiment, wherein the reaction temperature is 330 ℃ in the same ammonification fixed bed reactor, the feeding mole ratio of ammonia gas and caprolactam is 24:1, the airspeed is 0.8h -1, the single-pass caprolactam conversion rate is 66.8%, the 6-aminocapronitrile selectivity is 96.1%, the single-pass caprolactam average conversion rate is 65.6% and the 6-aminocapronitrile average selectivity is 96.0% in a catalyst stability test of 200 hours.
(7) The reacted feed liquid is cooled by a cooling separator 10, deaminated by a rectifying deamination tower 11 and enters a second rectifying device 12, the operation is carried out under the negative pressure of 2KPa, benzene-water azeotropic liquid, water, light component and other mixed liquid are obtained at the top of the tower, the oil phase part is returned to the second rectifying device 12 to carry water as reflux after layering by a second layering device 13, part of the oil phase part returns to a turntable extraction tower, the water phase enters a wastewater treatment device 2, the water content at the bottom of the second rectifying device 12 is 120ppm (the water content after rectifying and dewatering treatment of the feed liquid obtained by the reaction in the prior art is about 500-600 ppm), the 6-aminocapronitrile with the purity of 99.5% is obtained by a deamination capronitrile refining system of the material after the water removal, and unreacted caprolactam is recovered and returns to an evaporation system to continue the reaction.
Example 2
(1) The method comprises the steps of taking ammonium sulfate-containing caprolactam liquid obtained by a cyclohexanone oxime rearrangement process as a raw material liquid, using benzene as an extracting agent, carrying out countercurrent extraction in a 20-layer sieve plate tower, obtaining an ammonium sulfate-containing aqueous solution at the tower bottom, and obtaining a crude caprolactam benzene solution with the mass fraction of 30% of caprolactam at the tower top, wherein the water content is 3.5%, ammonium sulfate is dissolved in the water, and organic impurities comprise 120ppm of cyclohexane, 40ppm of cyclohexene, 52ppm of methylcyclohexane, 35ppm of 4,5,6, 7-tetrahydro-1H-benzotriazole and the like.
(2) The crude caprolactam benzene solution enters a first rectifying device 3, is operated under negative pressure at 70KPa, the temperature of the top of the tower is 68 ℃ and the temperature of the bottom of the tower is 78 ℃, 5kg of steam condensate is used as a heat source, an azeotrope of water extracted from the top of the tower and benzene enters a delaminator 4, water and oil are separated in the delaminator 4, an oil phase returns to an extraction device 1 for recycling, a water phase enters a wastewater treatment device 2, solid particles such as ammonium sulfate and the like are removed from a mixture at the bottom of the first rectifying device 3 through a filter 5, and then the obtained benzene and hexane mixed solution with caprolactam concentration of 35.7% is sent to a concentration system.
(3) The concentration system is a double-tower rectification system consisting of two vacuum rectification towers, wherein the first rectification recovery tower 6 is operated at 50KPa, the tower top temperature is 58.7 ℃, the tower bottom temperature is 95 ℃, the caprolactam content in the tower bottom solution is 85.2%, 2 kg of waste heat steam is used as a heat source, 90% of benzene is recovered, the second rectification recovery tower 7 is operated at 50KPa, the tower top temperature is 58.7 ℃, the tower bottom temperature is 204 ℃, the tower bottom obtains caprolactam with the benzene content of about 0.5% and the purity of 99.5%, and the distilled benzene is cooled and then recycled to the extraction device 1.
(4) The caprolactam with the purity of 99.5 percent is gasified and then enters an ammoniation fixed bed reactor, the catalyst is active alumina, the reaction temperature is 330 ℃, the feeding mole ratio of ammonia gas to caprolactam is 18:1, the airspeed is 0.8H -1, the once-through caprolactam conversion rate is 61.7%, the selectivity of 6-aminocapronitrile is 95.7%, the benzene content in the product is 0.5 percent by mass fraction, the water content is 8.81 percent by mass fraction, the positions of original cyclohexane and methylcyclopentane in liquid chromatography still have tiny peaks, cyclohexene does not appear, and the positions of the peaks of 4,5,6, 7-tetrahydro-1H-benzotriazole and a plurality of hetero peaks are overlapped and are difficult to judge.
(5) The reacted feed liquid is cooled by a cooling separator 10, deaminated by a rectifying deamination tower 11 and enters a second rectifying device 12, the operation is carried out under the negative pressure of 3KPa, benzene-water azeotropic liquid is obtained at the top of the tower, the oil phase part is returned to the second rectifying device 12 as reflux after layering by a second layering device 13 and is provided with water, part of the oil phase part is returned to an extraction device 1, the water phase enters a wastewater treatment device 2, the water content at the bottom of the second rectifying device 12 is 450ppm, the caprolactam content is 38.3%, the aminocapronitrile is 58.5%, the balance is light and heavy component impurities, the material deamination capronitrile refining system is used for preparing 6-aminocapronitrile with the purity of 99.5%, and unreacted caprolactam is returned to an evaporation system after being recovered and continuously participates in the reaction.
Example 3
(1) The method comprises the steps of taking ammonium sulfate-containing caprolactam liquid obtained by a cyclohexanone oxime rearrangement process as a raw material liquid, using toluene as an extracting agent, carrying out countercurrent extraction in a filler extraction tower, obtaining an ammonium sulfate-containing aqueous solution at the tower bottom, and obtaining a crude caprolactam toluene solution with the mass fraction of caprolactam of 40%, wherein the water content is 4.1%, ammonium sulfate is dissolved in water, and organic impurities comprise 220ppm of cyclohexane, 128ppm of cyclohexene, 71ppm of cyclopentanone, 12ppm of cyclohexanol, 92ppm of methylcyclohexane and the like.
(2) The crude caprolactam toluene solution enters a first rectifying device 3 for azeotropic dehydration, the operation is carried out under 60KPa, the temperature of the top of the tower is 69.5 ℃, the temperature of the tower kettle is 108 ℃, the secondary low-pressure steam at 124 ℃ is adopted as a heat source, the azeotrope of water extracted from the top of the tower and toluene enters a layering device 4, water and oil are separated in the layering device 4, the oil phase returns to an extraction device 1 for recycling, and the water phase enters a wastewater treatment device 2. The mixture at the bottom of the first rectifying device 3 is filtered by a filter 5 to remove solid particles such as ammonium sulfate which are precipitated, and then toluene mixed solution with caprolactam concentration of 50% is obtained and enters a concentration system.
(3) The concentration system is a three-effect evaporation system, a toluene caprolactam mixed solution with 90% of caprolactam concentration is obtained after part of toluene is evaporated, and the evaporated toluene is cooled and then returned to the extraction tower for recycling.
(4) Gasifying a mixed solution in toluene with 90% of caprolactam concentration, then feeding the gasified mixed solution into an ammonification fixed bed reactor, wherein the catalyst is activated alumina, the reaction temperature is 330 ℃, the feeding mole ratio of ammonia gas to caprolactam is 18:1, the airspeed is 0.8h -1, the once-through caprolactam conversion rate is 62.3%, the selectivity of 6-aminocapronitrile is 96.5%, the toluene content in the product is 9.4% by mass percent, the water content is 8.1% by mass percent, no peak exists at the positions of raw cyclohexane and methylcyclopentane in liquid chromatography, the raw cyclohexane, the methylcyclopentane are separated completely in the evaporation concentration stage, and cyclohexanone, cyclohexanol and cyclohexene are not seen and are converted into other byproducts.
(5) A comparison experiment is carried out on 90% toluene caprolactam mixed solution prepared from commercial reagent grade toluene and excellent caprolactam, wherein the reaction temperature is 330 ℃ in the same ammonification fixed bed reactor, the feeding mole ratio of ammonia gas to caprolactam is 18:1, the airspeed is 0.8h -1, the once-through caprolactam conversion rate is 62.7%, and the 6-aminocapronitrile selectivity is 95.8%.
(6) The reacted feed liquid is cooled by a cooling separator 10, deaminated by a rectifying deamination tower 11 and enters a second rectifying device 12, the operation is carried out under the negative pressure of 2KPa, toluene-water azeotropic liquid, water, light component and other mixed liquid are obtained at the top of the tower, the oil phase part is returned to the second rectifying device 12 as reflux after layering by a second layering device 13 and is carried with water, part of the oil phase part returns to an extraction tower, the water phase enters a wastewater treatment device 2, the water content at the bottom of the second rectifying device 12 is 150ppm, the deaminated material after the water removal is subjected to the refining system of the deaminated material to obtain 6-aminocapronitrile with the purity of 99.5%, and unreacted caprolactam is returned to an evaporation system to continue to participate in the reaction after being recovered.
Example 4
(1) The method comprises the steps of taking ammonium sulfate-containing caprolactam liquid obtained by a cyclohexanone oxime rearrangement process as raw material liquid, taking toluene and benzene mixed solvent as an extracting agent, wherein the volume ratio is 1:1, extracting in a bubbling tower with an upper-stage structured packing as a static mixer and a jet micro-bubble type middle section, wherein 3 layers of sieve plates are arranged at the lower section, obtaining an ammonium sulfate-containing aqueous solution at the tower bottom, obtaining a crude caprolactam extracting agent solution with the mass fraction of 40% of caprolactam at the tower top, wherein the water content is 4.3%, ammonium sulfate is dissolved in water, and organic impurities comprise 90ppm of cyclohexane, 56ppm of cyclohexene, 32ppm of cyclopentanone, 15ppm of cyclohexanol and the like.
(2) The crude caprolactam extractant solution enters a first rectifying device 3, is operated under 80KPa, the temperature of the top of the tower is 59.6 ℃, the temperature of the tower is 108.7 ℃, 5kg of steam condensate is used as a heat source, the azeotrope of water extracted from the top of the tower and the extractant enters a delaminator 4, water and oil are separated in the delaminator 4, an oil phase returns to an extraction device 1 for recycling, a water phase enters a wastewater treatment device 2, solid particles such as ammonium sulfate and the like are removed from a mixture at the bottom of the first rectifying device 3 through a filter 5, and a mixed solution with caprolactam concentration of 42.8%, toluene of 47.5% and benzene of 9.7% is obtained and enters a concentration system.
(3) The concentration system is a three-effect evaporation system, a mixed solution with caprolactam concentration of 90% is obtained after part of the extractant is evaporated, and the evaporated extractant is cooled and then returned to the extraction tower for recycling.
(4) The caprolactam mixed solution with 90 percent of caprolactam concentration is gasified and then enters an ammoniation fixed bed reactor, the catalyst is activated alumina, the reaction temperature is 330 ℃, the feeding mole ratio of ammonia gas to caprolactam is 18:1, the airspeed is 0.8h -1, the once-through caprolactam conversion rate is 62.7%, the selectivity of 6-aminocapronitrile is 95.9%, the toluene content in the product is 9.5% by mass percent, the water content is 8.1% by mass percent, the positions of raw cyclohexane and methylcyclopentane do not have peaks in liquid chromatography, the raw cyclohexane and methylcyclopentane should be separated completely in the evaporation concentration stage, and the cyclohexanone, the cyclohexanol and the cyclohexene are not seen.
(5) The reacted feed liquid is cooled by a cooling separator 10, deaminated by a rectifying deamination tower 11 and enters a second rectifying device 12, the operation is carried out under the negative pressure of 2KPa, benzene-toluene-water azeotropic liquid and mixed liquid of water, light components and the like are obtained at the top of the tower, the oil phase part is returned to the second rectifying device 12 as reflux after layering by a second layering device 13 and is provided with water, the water phase part is returned to an extraction device 1, the water phase enters a wastewater treatment device 2, the water content at the bottom of the second rectifying device 12 is 170ppm, the deamination nitrile refining system of the dehydrated material is used for preparing 6-aminocapronitrile with the purity of 99.5%, and unreacted caprolactam is returned to an evaporation system for continuous participation in the reaction after recovery.
Example 5
(1) The method comprises the steps of taking ammonium sulfate-containing caprolactam liquid obtained by a cyclohexanone oxime rearrangement process as a raw material liquid, using cyclohexane as an extracting agent, carrying out countercurrent extraction in a rotary disc extraction tower, obtaining an ammonium sulfate-containing aqueous solution at the tower bottom, and obtaining a crude caprolactam cyclohexane solution with the mass fraction of 30% of caprolactam at the tower top, wherein the water content is 3.4%, ammonium sulfate is dissolved in the water, and organic impurities comprise 72ppm of cyclohexene, 48ppm of cyclopentanone, 34ppm of cyclohexanol, 78ppm of methylcyclohexane and the like.
(2) The crude caprolactam cyclohexane solution enters a first rectifying device 3, is operated under normal pressure, the temperature of the top of the tower is 64.9 ℃ and the temperature of the bottom of the tower is 90 ℃,2 kg of secondary low-pressure steam is used as a heat source, the azeotrope of water and cyclohexane extracted from the top of the tower enters a delaminator 4, water and oil are separated in the delaminator 4, the oil phase returns to an extraction tower for recycling, and the water phase enters a wastewater treatment device 2. The mixture at the bottom of the first rectifying device 3 is filtered by a filter 5 to remove solid particles such as precipitated ammonium sulfate and the like, so that caprolactam cyclohexane solution with caprolactam concentration of 34% is obtained and enters a concentration system.
(3) The concentration system is a three-effect evaporation system, a caprolactam cyclohexane solution with the caprolactam concentration of 75% is obtained after part of cyclohexane is evaporated, and the evaporated cyclohexane is recycled by a rotary disc extraction tower after being cooled.
(4) Gasifying caprolactam cyclohexane solution with caprolactam purity of 75% and then feeding the gasified caprolactam solution into an ammonification fixed bed reactor, wherein a catalyst is titanium silicon molecular sieve, the reaction temperature is 360 ℃, the feeding mole ratio of ammonia gas and caprolactam is 24:1, the airspeed is 2.4h -1, the once-through caprolactam conversion rate is 68.4%, the selectivity of 6-aminocapronitrile is 95.8%, the cyclohexane content of the product is 23.8% by mass percent, the water content is 8.2% by mass percent, the position of original methylcyclopentane in liquid chromatography still has a peak, and cyclohexanone, cyclohexanol and cyclohexene are not seen and are converted into other byproducts.
(5) A comparison experiment is carried out by adopting a 75% caprolactam cyclohexane solution prepared from commercial reagent-grade cyclohexane and excellent caprolactam, wherein the reaction temperature is 360 ℃ in the same ammonification fixed bed reactor, the feeding mole ratio of ammonia gas and caprolactam is 24:1, the airspeed is 2.4h -1, the once-through caprolactam conversion rate is 67.7%, the 6-aminocapronitrile selectivity is 95.7%, and the once-through caprolactam average conversion rate is 67.1% and the 6-aminocapronitrile average selectivity is 95.4% in a catalyst stability test of 200 hours.
(6) A commercial high-grade caprolactam is adopted for a comparison experiment, wherein the reaction temperature is 360 ℃, the feeding mole ratio of ammonia gas and caprolactam is 24:1, the airspeed is 2.4h -1, the single-pass caprolactam conversion rate is 68.0%, the 6-aminocapronitrile selectivity is 95.5%, and in a catalyst stability test of 200 hours, the single-pass caprolactam average conversion rate is 65.5%, and the 6-aminocapronitrile average selectivity is 95.4%.
(7) The reacted feed liquid is cooled by a cooling separator 10, deaminated by a rectifying deamination tower 11 and enters a second rectifying device 12, the operation is carried out under the negative pressure of 2KPa, cyclohexane-water azeotropic liquid, water, light components and other mixed liquid are obtained at the top of the tower, the oil phase part is returned to the second rectifying device 12 as reflux after layering by a second layering device 13 and is provided with water, the oil phase part is returned to a turntable extraction tower, the water phase enters a wastewater treatment device 2, the water content at the bottom of the second rectifying device 12 is 80ppm, the deamination nitrile refining system of the dehydrated material is used for preparing 6-aminocapronitrile with the purity of 99.5%, and unreacted caprolactam is returned to an evaporation system for continuous participation in the reaction after recovery.
Example 6
(1) The method comprises the steps of taking ammonium sulfate-containing caprolactam liquid obtained by a cyclohexanone oxime rearrangement process as a raw material liquid, using methylcyclohexane as an extracting agent, carrying out countercurrent extraction in a filler extraction tower, obtaining an ammonium sulfate-containing aqueous solution at the tower bottom, and obtaining a crude caprolactam methylcyclohexane solution with the mass fraction of 5% of caprolactam at the tower top, wherein the water content is 0.7%, ammonium sulfate is dissolved in the water, and organic impurities comprise 210ppm of cyclohexane, 135ppm of cyclohexene, 28ppm of cyclopentanone, 22ppm of cyclohexanol and the like.
(2) The crude caprolactam methylcyclohexane solution enters a first rectifying device 3, is operated under normal pressure, the temperature of the top of the tower is 69 ℃, the temperature of the bottom of the tower is 106 ℃, secondary low-pressure steam at 126 ℃ is used as a heat source, the azeotrope of water extracted from the top of the tower and methylcyclohexane enters a layering device 4, water and oil are separated in the layering device 4, an oil phase returns to an extraction device 1 for recycling, and a water phase enters a wastewater treatment device 2. The mixture at the bottom of the first rectifying device 3 is filtered by a filter 5 to remove solid particles such as precipitated ammonium sulfate, so that caprolactam methylcyclohexane solution with caprolactam concentration of 8.5% is obtained and enters a concentration system.
(3) The concentration system is a three-effect evaporation system, a caprolactam methylcyclohexane solution with caprolactam concentration of 85% is obtained after part of methylcyclohexane is evaporated, and the evaporated methylcyclohexane is cooled and then returned to the extraction tower for recycling.
(4) Gasifying caprolactam methyl cyclohexane solution with caprolactam concentration of 85% and feeding the gasified caprolactam methyl cyclohexane solution into an ammonification fixed bed reactor, wherein the catalyst is titanium dioxide rich in oxygen vacancies, the reaction temperature is 400 ℃, the feeding mole ratio of ammonia to caprolactam is 20:1, the airspeed is 0.5h -1, the once-through caprolactam conversion rate is 84.8%, the 6-aminocapronitrile selectivity is 94.6%, the methyl cyclohexane content in the product is 14.1% by mass fraction, the water content is 10.2% by mass fraction, the raw cyclohexane, cyclohexene, cyclohexanone and cyclohexanol in the liquid chromatography are not seen, the raw cyclohexane, cyclohexene, cyclohexanone and cyclohexanol are separated cleanly or converted into other byproducts in a solvent distillation recovery link, and the once-through caprolactam average conversion rate is 84.4% and the 6-aminocapronitrile average selectivity is 94.5% after the catalyst stability test for 200 hours.
(5) A comparison experiment is carried out by adopting a caprolactam methylcyclohexane solution of 85% prepared by commercial reagent grade methylcyclohexane and excellent product caprolactam, wherein the reaction temperature is 400 ℃ in the same ammonification fixed bed reactor, the feeding mole ratio of ammonia gas and caprolactam is 20:1, the airspeed is 0.5h -1, the once-through caprolactam conversion rate is 85.1%, and the 6-aminocapronitrile selectivity is 94.3%.
(6) A commercial high-grade caprolactam is adopted for a comparison experiment, wherein the reaction temperature is 400 ℃ in the same ammonification fixed bed reactor, the feeding mole ratio of ammonia and caprolactam is 20:1, the airspeed is 0.5h -1, the single-pass caprolactam conversion rate is 84.9%, the 6-aminocapronitrile selectivity is 94.6%, the single-pass caprolactam average conversion rate is 84.1% and the 6-aminocapronitrile average selectivity is 94.3% after the catalyst stability test for 200 hours;
(7) The reacted feed liquid is cooled by a cooling separator 10, deaminated by a rectifying deamination tower 11 and enters a second rectifying device 12, the operation is carried out under the negative pressure of 2KPa, water-methylcyclohexane azeotropic liquid and mixed liquid of water, light components and the like are obtained at the top of the tower, the oil phase part is returned to the second rectifying device 12 as reflux after layering by a second layering device 13 and is provided with water, the part returns to an extraction tower, the water phase enters a wastewater treatment device 2, the water content at the bottom of the second rectifying device 12 is 130ppm, the deamination nitrile refining system of the dehydrated material is used for preparing 6-aminocapronitrile with the purity of 99.5%, and unreacted caprolactam is returned to an evaporation system for continuous participation in the reaction after recovery.
Example 7
(1) The method comprises the steps of taking ammonium sulfate-containing caprolactam liquid obtained by a cyclohexanone oxime rearrangement process as a raw material liquid, using carbon tetrachloride as an extracting agent, carrying out countercurrent extraction in a 20-layer sieve plate tower, obtaining an ammonium sulfate-containing aqueous solution at the top of the tower when a water phase is at an upper layer and an oil phase is at a lower layer due to larger carbon tetrachloride density, and obtaining a crude ammonium sulfate-containing caprolactam carbon tetrachloride solution with a caprolactam mass fraction of 25% at the bottom of the tower, wherein the water content is 1.6%, ammonium sulfate is dissolved in the water, and organic impurities comprise 90ppm cyclohexane, 36ppm cyclohexene, 38ppm methylcyclohexane and 28ppm methylcyclopentane.
(2) The crude caprolactam carbon tetrachloride solution enters a first rectifying device 3, is operated under normal pressure, the temperature of the top of the tower is 68.7 ℃, the temperature of the bottom of the tower is 90 ℃,5 kg of steam condensate is used as a heat source, the azeotrope of water extracted from the top of the tower and carbon tetrachloride enters a layering device 4, water and oil are separated in the layering device 4, the carbon tetrachloride has higher density than water, at the moment, the water phase is at the upper layer, the oil phase is at the lower layer, the oil phase returns to the extraction tower for recycling, and the water phase enters a wastewater treatment device 2. The mixture at the bottom of the first rectifying device 3 is filtered by a filter 5 to remove solid particles such as precipitated ammonium sulfate, so that caprolactam carbon tetrachloride solution with caprolactam concentration of 27.8% is obtained and enters a concentration system.
(3) The concentration system is a double-tower rectification system consisting of two vacuum rectification towers, wherein the first rectification recovery tower 6 is operated at 50KPa, the tower top temperature is 56 ℃, the tower bottom temperature is 111 ℃, the caprolactam content in the tower bottom solution is 75.7%, 2 kg of secondary steam is used as a heat source, 80% of carbon tetrachloride of the total solvent is recovered, the second rectification recovery tower is operated at 50KPa, the tower top temperature is 56 ℃, the tower bottom temperature is 229 ℃, the tower bottom obtains caprolactam with the carbon tetrachloride content of about 0.8% and the purity of 99.2%, and the distilled carbon tetrachloride is recycled by the extraction device 1 after being cooled.
(4) Gasifying caprolactam with purity of 99.2%, then feeding the gasified caprolactam into an ammoniation fixed bed reactor, wherein the catalyst is a phosphorus-aluminum molecular sieve supported palladium catalyst, the reaction temperature is 280 ℃, the feeding mole ratio of ammonia to caprolactam is 36:1, the airspeed is 1.0h -1, the once-through caprolactam conversion rate is 46.5%, the selectivity of 6-aminocapronitrile is 99.6%, the carbon tetrachloride content in the product is 0.75% by mass, the water content is 6.86% by mass, and the positions of raw cyclohexane, methylcyclohexane and methylcyclopentane in the liquid chromatography still have peaks, and cyclohexene is not seen and converted into byproducts.
(5) The reacted feed liquid is cooled by a cooling separator 10, enters a second rectifying device 12 after deamination by a rectifying deamination tower 11, is operated under the negative pressure of 1.5KPa, after the material at the top of the tower is layered, the lower layer oil phase part (carbon tetrachloride with higher density than water) returns to the second rectifying device 12 as reflux to carry water, part of the water returns to an extraction device 1, the water phase enters a wastewater treatment device 2, the water content at the bottom of the second rectifying device 12 is 390ppm, the deamination refining system of the material after the water removal is used for preparing the 6-aminocapronitrile with the purity of 99.5%, and unreacted caprolactam returns to an evaporation system to continuously participate in the reaction after being recovered.
Example 8
(1) The method comprises the steps of taking ammonium sulfate-containing caprolactam liquid obtained by a cyclohexanone oxime rearrangement process as a raw material liquid, using paraxylene as an extracting agent, carrying out countercurrent extraction in a rotary disc extraction tower, obtaining an ammonium sulfate-containing aqueous solution at the tower bottom, and obtaining a crude ammonium sulfate-containing caprolactam paraxylene solution with the mass fraction of 20% at the tower top, wherein the water content is 1.5%, ammonium sulfate is dissolved in the water, and organic impurities comprise 80ppm of cyclohexane, 34ppm of cyclohexene, 25ppm of cyclohexanone, 40ppm of methylcyclopentane and the like.
(2) The crude caprolactam paraxylene solution enters a first rectifying device 3, is operated under the negative pressure of 50KPa, the temperature of the top of the tower is 87 ℃, the temperature of the bottom of the tower is 124 ℃,5 kg of saturated steam is adopted as a heat source, the azeotrope of water extracted from the top of the tower and paraxylene enters a layering device 4, water and oil are separated in the layering device 4, the oil phase returns to an extraction tower for recycling, and the water phase enters a wastewater treatment device 2. The mixture at the bottom of the first rectifying device 3 is filtered by a filter 5 to remove solid particles such as precipitated ammonium sulfate and the like, so that a caprolactam paraxylene solution with caprolactam concentration of 21% is obtained, and the caprolactam paraxylene solution enters a concentration system.
(3) The concentration system is a double-effect evaporation system, and the caprolactam paraxylene solution with the caprolactam concentration of 92% is obtained after part of paraxylene is evaporated, and the evaporated paraxylene is recycled by the extraction device 1 after being cooled.
(4) Gasifying a caprolactam paraxylene solution with a caprolactam concentration of 92% and then feeding the gasified caprolactam paraxylene solution into an ammoniation fixed bed reactor, wherein a catalyst is silicon-aluminum bimetallic oxide, the reaction temperature is 360 ℃, the feeding mole ratio of ammonia to caprolactam is 42:1, the airspeed is 2.4h -1, the once-through caprolactam conversion rate is 65.3%, the selectivity of 6-aminocapronitrile is 96.5%, the paraxylene content in the product is 7.5% by mass and the water content is 8.7% by mass, the raw cyclohexane, methylcyclopentane, cyclohexene and cyclohexanone in the liquid chromatography are not seen, the raw cyclohexane, the methylcyclopentane, the cyclohexene and the cyclohexanone are separated cleanly or converted into other byproducts in a solvent distillation recovery link, and the once-through caprolactam conversion rate is 64.7% and the selectivity of 6-aminocapronitrile is 96.3% after the catalyst stability test for 200 hours.
(5) A comparison experiment is carried out on 92% of caprolactam paraxylene solution prepared from commercial reagent grade paraxylene and excellent product caprolactam, wherein the reaction temperature is 360 ℃ in the same ammonification fixed bed reactor, the feeding mole ratio of ammonia gas and caprolactam is 42:1, the airspeed is 2.4h -1, the once-through caprolactam conversion rate is 65.6%, and the 6-aminocapronitrile selectivity is 96.0%.
(6) A comparison experiment is carried out by adopting commercial high-grade caprolactam, wherein the reaction temperature is 360 ℃ in the same ammonification fixed bed reactor, the feeding mole ratio of ammonia gas and caprolactam is 42:1, the airspeed is 2.4h -1, the single-pass caprolactam conversion rate is 65.3%, and the 6-aminocapronitrile selectivity is 96.1%. After 200 hours of catalyst stability testing, the once-through caprolactam conversion was 63.8% and the 6-aminocapronitrile selectivity was 96.2%;
(7) The reacted feed liquid is cooled by a cooling separator 10, deaminated by a rectifying deamination tower 11 and enters a second rectifying device 12, the operation is carried out under the negative pressure of 2KPa, p-xylene-water azeotropic liquid and mixed liquid of water, light components and the like are obtained at the top of the tower, the oil phase part is returned to the second rectifying device 12 to carry water as reflux after layering by the second separator 13, part of the oil phase part returns to a turntable extraction tower, the water phase enters a wastewater treatment device 2, the water content at the bottom of the second rectifying device 12 is 180ppm, the caprolactam content is 34.7%, the aminocapronitrile is 62.5%, the rest is light component impurities, the material deamination capronitrile refining system after the material is dehydrated is used for preparing 6-aminocapronitrile with the purity of 99.5%, and unreacted caprolactam is returned to an evaporation system to continuously participate in the reaction after being recovered.
Example 9
(1) Extracting a caprolactam liquid containing ammonium sulfate, which is obtained by a cyclohexanone oxime rearrangement process, in a bubbling tower containing upper-stage structured packing as a static mixer and spraying microbubbles at the middle stage, wherein the lower stage is provided with 3 layers of sieve plates, an aqueous solution containing ammonium sulfate is obtained at the tower bottom, a crude caprolactam extractant solution containing 30% of caprolactam in mass fraction is obtained at the tower top, wherein the water content is 3.2%, ammonium sulfate is dissolved in water, and organic impurities comprise 63ppm of cyclohexene, 40ppm of cyclohexanone, 21ppm of cyclohexanol, 18ppm of methylcyclohexane and the like;
(2) The crude caprolactam extractant solution enters a first rectifying device 3, is operated under normal pressure, the temperature of the top of the tower is 64 ℃, the temperature of the bottom of the tower is 105 ℃,5 kg of steam condensate is adopted as a heat source, the mixture of water extracted from the top of the tower and extractant enters a layering device 4, water and oil are separated in the layering device 4, an oil phase returns to an extraction tower for recycling, and the water phase enters a wastewater treatment device 2. The mixture at the bottom of the first rectifying device 3 is filtered by a filter 5 to remove solid particles such as ammonium sulfate which are precipitated, and then a mixed solution with caprolactam concentration of 38.1%, n-hexane of 10.5% and n-heptane of 51.4% is obtained and enters a concentration system.
(3) The concentration system adopts a three-effect evaporation system, a mixed solution with caprolactam concentration of 88% is obtained after part of the extractant is evaporated, and the evaporated extractant is cooled and then returned to the extraction tower for recycling.
(4) Gasifying a caprolactam mixed solution with caprolactam concentration of 88%, then entering an ammoniation fluidized bed reactor, wherein a catalyst is mesoporous alumina, the reaction temperature is 325 ℃, the feeding mole ratio of ammonia gas to caprolactam is 24:1, the space velocity is 0.8h -1, the once-through caprolactam conversion rate is 59.7%, the selectivity of 6-aminocapronitrile is 97.5%, the n-hexane n-heptane content in the product is 11.3% by mass, the water content is 7.7% by mass, and the methyl cyclohexane position in the liquid chromatograph still has peaks, and the rest is not seen.
(5) The reacted feed liquid is cooled by a cooling separator 10, deaminated by a rectifying deamination tower 11 and enters a second rectifying device 12, the operation is carried out under the negative pressure of 2KPa, normal hexane-normal heptane-water azeotropic liquid and mixed liquid of water, light components and the like are obtained at the top of the tower, the oil phase part after layering returns to the second rectifying device 12 with water as reflux, part returns to an extraction tower, the water phase enters a wastewater treatment device 2, the water content at the bottom of the second rectifying device 12 is 160ppm, the deaminated material is subjected to deamination to obtain 6-aminocapronitrile with the purity of 99.5%, and unreacted caprolactam is recovered and returns to an evaporation system to continuously participate in the reaction.
Example 10
(1) The method comprises the steps of taking ammonium sulfate-containing caprolactam liquid obtained by a cyclohexanone oxime rearrangement process as a raw material liquid, using chloroform as an extracting agent, carrying out countercurrent extraction in a rotary disk extraction tower, obtaining an ammonium sulfate-containing aqueous solution at the top of the rotary disk extraction tower, and obtaining a crude caprolactam chloroform solution with 15% of caprolactam mass fraction at the bottom of the tower, wherein the water content is 1.3%, ammonium sulfate is dissolved in water, and organic impurities comprise 190ppm of cyclohexane, 63ppm of cyclohexene, 38ppm of cyclohexanone, 66ppm of methylcyclohexane, 42ppm of ethylcyclopentane and the like.
(2) The crude caprolactam chloroform solution enters a first rectifying device 3, is operated under normal pressure, the temperature of the top of the tower is 57 ℃, the temperature of the tower bottom is 70.2 ℃,2 kg of secondary low-pressure steam is used as a heat source, the azeotrope of water and chloroform extracted from the top of the tower enters a delaminator 4, water and oil are separated in the delaminator 4, the water phase is arranged on an upper oil layer, the oil phase returns to an extraction tower for recycling under the lower oil phase, and the water phase enters a wastewater treatment device 2. The mixture at the bottom of the first rectifying device 3 is filtered by a filter 5 to remove solid particles such as precipitated ammonium sulfate, so that a caprolactam chloroform mixed solution with caprolactam concentration of 17.5% is obtained and enters a concentration system.
(3) The concentration system is a three-effect evaporation system, a chloroform mixed solution with caprolactam concentration of 84% is obtained after part of chloroform is evaporated, and the evaporated chloroform is cooled and recycled by a rotary disc extraction tower.
(4) Gasifying a mixed solution with caprolactam concentration of 84% and then entering an ammoniation fixed bed reactor, wherein the catalyst is a phosphorus-aluminum molecular sieve supported zinc-magnesium catalyst, the reaction temperature is 350 ℃, the feeding mole ratio of ammonia to caprolactam is 26:1, the airspeed is 1.5h -1, the once-through caprolactam conversion rate is 66.8%, the 6-aminocapronitrile selectivity is 97.1%, the chloroform content in the product is 15.1% by mass and the water content is 8.1% by mass, and the positions of raw cyclohexane, methylcyclopentane and ethylcyclopentane still have peaks in the liquid chromatography, and the cyclohexanone and cyclohexene are not found and are converted into other byproducts.
(5) A comparison experiment is carried out on 84% mixed solution prepared from commercial reagent-grade chloroform and high-grade caprolactam, wherein the reaction temperature is 350 ℃ in the same ammonification fixed bed reactor, the feeding mole ratio of ammonia gas to caprolactam is 26:1, the airspeed is 1.5h -1, the once-through caprolactam conversion rate is 66.5%, and the 6-aminocapronitrile selectivity is 96.8%.
(6) The reacted feed liquid is cooled by a cooling separator 10, deaminated by a rectifying deamination tower 11 and enters a second rectifying device 12, the operation is carried out under the negative pressure of 2KPa, chloroform-water azeotropic liquid, water, light component and other mixed liquid are obtained at the top of the tower, the oil phase part is returned to the second rectifying device 12 as reflux after layering by a second layering device 13 and is carried with water, the oil phase part is returned to a turntable extraction tower, the water phase enters a wastewater treatment device 2, the water content at the bottom of the second rectifying device 12 is 170ppm, the deamination nitrile refining system of the dehydrated material is used for preparing 6-aminocapronitrile with the purity of 99.5%, and unreacted caprolactam is returned to an evaporation system for continuous participation in the reaction after recovery.
Claims (18)
1. An energy-saving device for preparing aminocapronitrile by using a cyclohexanone oxime liquid-phase rearrangement product is characterized by comprising an extraction device (1), a first rectifying device (3), a filter (5), a concentration system and a reaction system,
The inlet of the extraction device (1) is connected with an extractant and a raw material liquid, the raw material liquid is caprolactam liquid containing water, ammonium sulfate and organic impurities,
The oil phase outlet of the extraction device (1) is directly connected with the first rectifying device (3), the tower bottom outlet of the first rectifying device (3) is connected with the filter (5), and the tower top outlet of the first rectifying device (3) is connected with the layering device (4);
the liquid phase outlet of the filter (5) is connected with the concentration system,
The outlet of the tower kettle of the concentration system is connected with the reaction system,
The reaction system comprises a reactor (9) and a second rectifying device (12) which are sequentially arranged, wherein the reactor (9) is a caprolactam ammoniation reactor, and a tower kettle outlet of the second rectifying device (12) is a crude aminocapronitrile mixed solution outlet.
2. Energy saving device according to claim 1, characterized in that the extraction device (1) is a sieve plate extraction column, a packed extraction column, a modified pulsed sieve plate column or a rotating disc extraction column.
3. The energy saving device according to claim 1, characterized in that the water phase outlet of the extraction device (1) is connected to a wastewater treatment device (2).
4. The energy saving device according to claim 1, characterized in that the oil phase outlet of the separator (4) is connected to the inlet of the extraction device (1), and the water phase outlet of the separator (4) is connected to the wastewater treatment device (2).
5. The energy saving device of claim 1, wherein the concentration system is a single effect evaporation system, a multiple effect evaporation system, a single tower rectification system, or a multi-tower rectification system.
6. Energy saving device according to claim 1, characterized in that the reactor (9) is a fixed bed reactor or a fluidized bed reactor.
7. The energy saving device according to claim 1, characterized in that the reaction system further comprises a mixing evaporator (8) arranged before the reactor (9).
8. The energy saving device according to claim 1, characterized in that the reaction system further comprises a cooling separator (10) arranged between the reactor (9) and the second rectifying device (12), the liquid phase outlet of the cooling separator (10) being connected to the second rectifying device (12).
9. The energy-saving device according to claim 7, characterized in that a rectification deamination tower (11) is further arranged between the second rectification device (12) and the reactor (9), a tower bottom of the rectification deamination tower (11) is connected with the second rectification device (12), and a tower top of the rectification deamination tower (11) is communicated with the mixing evaporator (8).
10. The energy saving device according to claim 1, characterized in that the top outlet of the second rectifying device (12) is connected to a second separator (13).
11. A process for producing aminocapronitrile from a liquid-phase rearrangement product of cyclohexanone oxime, comprising the steps of:
(1) Adding an organic extractant into the raw material liquid for extraction, wherein the obtained oil phase is caprolactam extraction solution;
the raw material liquid is a material liquid obtained by neutralizing a cyclohexanone oxime heavy liquid with ammonia;
(2) Directly rectifying the caprolactam extraction solution to remove water and part of organic extractant, so as to obtain a caprolactam mixture containing impurities;
(3) Filtering the caprolactam mixture containing impurities to remove the impurities, and concentrating to remove part or all of the extractant to obtain caprolactam liquid;
(4) Feeding the caprolactam liquid into a reactor for ammonification reaction to obtain a reaction mixture;
(5) And rectifying the reaction mixture to remove water, so as to obtain a crude aminocapronitrile mixed solution.
12. The method of claim 11, wherein the caprolactam concentration in the caprolactam extraction solution in step (1) is 5-40% by mass.
13. The method of claim 12, wherein the caprolactam concentration in the caprolactam extraction solution in step (1) is 15-30% by mass.
14. The method of claim 11, wherein the organic extractant in step (1) is an organic compound that forms an azeotrope with water and is immiscible with water.
15. The method of claim 14, wherein the organic extractant in step (1) is one or more of benzene, toluene, xylene, chloroform, carbon tetrachloride, cyclohexane, methylcyclohexane, or methylcyclopentane.
16. The method according to claim 11, wherein the rectification in step (2) has a top operating pressure of 30 to 120kpa, a top operating temperature of 45 to 80 ℃ and a bottom operating temperature of 70 to 120 ℃.
17. The method according to claim 11, wherein the caprolactam content in the caprolactam liquid in the step (3) is 50-99.9% by mass.
18. The method of claim 17, wherein the caprolactam content in the caprolactam liquid in the step (3) is 75-99.9% by mass.
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| RU1777600C (en) * | 1991-02-25 | 1992-11-23 | Владимир Александрович Линев | Method for separating caprolactam from used-up trichloroethylene in caprolactam production |
| DE4446907A1 (en) * | 1994-12-27 | 1996-07-04 | Basf Ag | Process for the preparation of a hydrogenation catalyst |
| TW420662B (en) * | 1996-02-17 | 2001-02-01 | Du Pont | Recovery of <epsilon>-caprolactam |
| CN101781232B (en) * | 2010-01-29 | 2012-09-05 | 河北瑞通美邦工程有限公司 | Preparation process of cyclohexanone-oxime |
| US11149001B2 (en) * | 2016-12-06 | 2021-10-19 | Toray Industries, Inc. | Method for producing ϵ-caprolactam |
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| US20230407094A1 (en) * | 2022-06-21 | 2023-12-21 | Ascend Performance Materials Operations Llc | Asphalt additives with multiple amines |
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| CN115710198A (en) * | 2022-11-11 | 2023-02-24 | 聊城鲁西聚酰胺新材料科技有限公司 | Method for preparing 6-aminocapronitrile |
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