CN1155577C - Process for extracting caprolactam and direct steam debenzolization - Google Patents
Process for extracting caprolactam and direct steam debenzolization Download PDFInfo
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- CN1155577C CN1155577C CNB011164123A CN01116412A CN1155577C CN 1155577 C CN1155577 C CN 1155577C CN B011164123 A CNB011164123 A CN B011164123A CN 01116412 A CN01116412 A CN 01116412A CN 1155577 C CN1155577 C CN 1155577C
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- benzene
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- open steam
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- JBKVHLHDHHXQEQ-UHFFFAOYSA-N epsilon-caprolactam Chemical compound O=C1CCCCCN1 JBKVHLHDHHXQEQ-UHFFFAOYSA-N 0.000 title claims abstract description 73
- 238000000034 method Methods 0.000 title claims abstract description 46
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 claims abstract description 393
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 58
- 238000000605 extraction Methods 0.000 claims abstract description 29
- 238000010438 heat treatment Methods 0.000 claims abstract description 28
- 238000004821 distillation Methods 0.000 claims abstract description 17
- AWSFEOSAIZJXLG-UHFFFAOYSA-N azepan-2-one;hydrate Chemical compound O.O=C1CCCCCN1 AWSFEOSAIZJXLG-UHFFFAOYSA-N 0.000 claims abstract description 14
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052742 iron Inorganic materials 0.000 claims abstract description 10
- -1 iron ions Chemical class 0.000 claims abstract description 10
- 239000002904 solvent Substances 0.000 claims abstract description 7
- 239000006227 byproduct Substances 0.000 claims abstract description 6
- 238000010025 steaming Methods 0.000 claims description 61
- 230000000694 effects Effects 0.000 claims description 28
- 239000000945 filler Substances 0.000 claims description 9
- 239000012071 phase Substances 0.000 claims description 8
- 230000001314 paroxysmal effect Effects 0.000 claims description 2
- 239000007791 liquid phase Substances 0.000 claims 1
- 239000000463 material Substances 0.000 abstract description 42
- 239000007788 liquid Substances 0.000 abstract description 14
- 238000010533 azeotropic distillation Methods 0.000 abstract description 2
- SLUNEGLMXGHOLY-UHFFFAOYSA-N benzene;hexane Chemical compound CCCCCC.C1=CC=CC=C1 SLUNEGLMXGHOLY-UHFFFAOYSA-N 0.000 abstract 3
- 238000005406 washing Methods 0.000 abstract 1
- 239000012535 impurity Substances 0.000 description 26
- 239000000243 solution Substances 0.000 description 25
- 241000282326 Felis catus Species 0.000 description 23
- 239000000047 product Substances 0.000 description 20
- 239000012808 vapor phase Substances 0.000 description 15
- 239000007864 aqueous solution Substances 0.000 description 11
- 238000005516 engineering process Methods 0.000 description 7
- 238000007670 refining Methods 0.000 description 5
- 238000007701 flash-distillation Methods 0.000 description 3
- 239000013589 supplement Substances 0.000 description 3
- VEFXTGTZJOWDOF-UHFFFAOYSA-N benzene;hydrate Chemical compound O.C1=CC=CC=C1 VEFXTGTZJOWDOF-UHFFFAOYSA-N 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- 230000001839 systemic circulation Effects 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 1
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 1
- 235000011130 ammonium sulphate Nutrition 0.000 description 1
- 239000001166 ammonium sulphate Substances 0.000 description 1
- IJQAOQPOJZUGIA-UHFFFAOYSA-N azepan-2-one benzene Chemical compound c1ccccc1.O=C1CCCCCN1 IJQAOQPOJZUGIA-UHFFFAOYSA-N 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 229910017053 inorganic salt Inorganic materials 0.000 description 1
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
Abstract
The invention relates to a process for debenzolizing caprolactam extraction liquid by utilizing direct steam. The benzene-hexane solution obtained after extraction of caprolactam or the benzene-hexane solution obtained after extraction and water washing is debenzolized, which is characterized in that steam is directly added into a benzene distillation tower through a steam distribution device, the benzene-hexane solution is subjected to single-effect or multi-effect azeotropic distillation through the benzene distillation tower, and the caprolactam water solution with solvent benzene removed is obtained at the tower bottom. The direct steam heating debenzolization adopted by the invention can fully utilize the low-pressure steam of the byproduct of the device, and the direct steam not only plays a role of a heating source for benzene distillation, but also can replace supplemented desalted water or process water to play a role of an entrainer. In order to avoid the iron ions from being brought into the system and stabilize the steam pressure entering the benzene distillation tower, a steam buffer tank is added and the material of the steam buffer tank is considered.
Description
The present invention relates to the novel process that hexanolactam extraction open steam takes off benzene.
In the existing hexanolactam extracting and refining technology, a kind of is that its benzene---own liquid carries out the water back extraction again after the extraction of hexanolactam benzene, obtains about 30% oneself---it is refining that the aqueous solution send the back operation to continue, and reclaims solvent benzol simultaneously, and time systemic circulation is used; Another kind is a benzene after the extraction of hexanolactam benzene---own liquid adding is taken off benzene as the water of entrainer by the benzene steaming tower component distillation, obtains about 90% oneself---, and the aqueous solution send the back operation to continue to make with extra care, and reclaims solvent benzol simultaneously and returns the systemic circulation use.
Yet, in above-mentioned hexanolactam extracting and refining technology, take off the benzene process and need consume a large amount of water vapors as the heating thermal source, adopt the benzene process of taking off of benzene water azeotropic distillation process, need in benzene steaming tower, to add de-salted water or process water, water-content during the benzene under the general a little higher than steaming benzene operating mode of its additional amount---water azeotropic is formed as the entrainer of benzene, it is very few to add the water yield, cause that to take off benzene incomplete, add hypervolia, cause the waste of adding water and heating steam.Therefore, in steaming the benzene process,, can reach the material balance and the heat balance of mutual coupling as long as rational technical process and control device are set.The present inventor is through research, find to adopt open steam to replace indirect steam, open steam had both played the effect of steaming benzene heating thermal source, can replace de-salted water or the process water added again, play the effect of entrainer, and the thermo-efficiency of open steam heating is much higher than the thermo-efficiency of indirect steam heating, thereby saves a large amount of steam and de-salted water or process water.
Benzene water component distillation in steaming the benzene process, for the temperature that prevents tower still caprolactam water solution too high, all adopt the vacuum distilling mode, therefore the open steam that is used to steam benzene both can adopt the open steam of being supplied with by heat distribution pipe network, also can the various low-pressure steam use device by-product or flash distillation, do not entered in the benzene steaming tower and worry that vapor pressure is low, this also provides effective way for the utilization of low-pressure steam such as the byproduct steam of hexanolactam device or flash-off steam.
Caprolactam product has strict requirement for its contained iron ion index, and steam-pipe is carbon steel material, whether has iron ion and brings system into and the quality of hexanolactam is impacted.We know, the iron ion content of the steam-pipe output under the normal circumstances is not high, even and a spot of iron ion is brought in the material system, under the operating mode of caprolactam refining process, iron ion is that the form with the higher inorganic salt of boiling point exists basically, the tower still that in the still-process of hexanolactam, is present in distillation tower substantially, tower still through the high boiling point tower is got back in the preceding operation with the form of vinasse, finally take out of outside the system by ammoniumsulphate soln or thick oily raffinate at extraction process, go and can not bring in the hexanolactam finished product of cat head, to quality of caprolactam without any influence.
In order to ensure quality of caprolactam under various conditions, avoiding the paroxysmal a large amount of iron ions of contingency to bring system into reaches in order to stablize the into vapor pressure of benzene steaming tower, among the present invention, be provided with the steam buffer jar of capturing device before open steam enters benzene steaming tower, this jar and subsequent material adopt corrosion resistant stainless steel.
In the present invention, open steam can join each position of benzene steaming tower, but being the best in the top that is added to benzene steaming tower tower bottoms phase and the gas-phase space between column plate or the filler bottom, for improving open steam and benzene---the mass-and heat-transfer intensity of own liquid in the benzene steaming tower, open steam enters in the benzene steaming tower by the steam distribution device of appropriate design.
Should be noted that, for open steam distillatory benzene steaming tower, the benzene concentration that contains of the benzene of its charging---own solution can be in 15～85% (weight), benzene---own liquid component distillation takes off the caprolactam refining technology of benzene without water stripping process step owing to adopt, part water-soluble impurity must be in taking off the benzene process from the benzene steaming tower cat head with benzene---the form of water is taken away by water, therefore, the benzene of charging---own liquid contain benzene concentration preferably more than 50%, discharge to guarantee to steam from the benzene steaming tower top makes the water-soluble impurity in the hexanolactam be able to effective removal.
And benzene steaming tower can be operated under normal pressure or vacuum state, and optimum operation pressure is 0.03～0.05Mpa (cutting off), the caprolactam water solution that benzene steaming tower tower still obtains contain own concentration usually 68～92%, it is 85～90% that the best contains own concentration.
In the present invention, the taking off benzene and can adopt the mode of single effect distillation or multi-effect distilling to remove solvent benzol of benzene---own solution, adopt the general former effects of multi-effect distilling can not add entrainer, open steam is added to last and imitates benzene steaming tower, and promptly general last imitated employing, and benzene---the mode of water component distillation is taken off benzene.
Multi-effect distilling also should be carried out the heat balance and the material balance of system, has made entrainer and part of heat energy effect and the open steam and the system balancing that add adapt.The benzene steaming tower that is preferably in last effect is provided with the indirect heater of external hanging type, under the system fluctuation situation, adjusts the water balance and the thermal equilibrium of benzene steaming tower by the heating steam amount of controlling plug-in indirect heater.
In conjunction with Fig. 1, we do concise and to the point being described below to technical process of the present invention.
The own preheater 2 of benzene---own solution is transported to benzene by pipe arrangement 1---after the hexanolactam extraction is preheating near after 55～60 ℃ of the top temperature of benzene steaming tower and enters the column plate of benzene steaming tower 4 or the liquid distribution device on filler top by pipe arrangement 3.
On the one hand, enter the steam buffer jar 6 that inside has capturing device from the hexanolactam device by-product of pipe arrangement 5 or 0.05Mpa (table) low-pressure steam of flash distillation, iron ion or mechanical impurity enter water sealed tank 7 with water of condensation, and the low-pressure steam that steam buffer jar 6 comes out enters the column plate that is arranged at benzene steaming tower 4 or filler below, the tower bottoms steam distribution device of gas-phase space between the top mutually by pipe arrangement 8.
On the other hand, the indirect heating steam of thermal source is added to the shell side of the plug-in indirect heater 10 of benzene steaming tower 4 by pipe arrangement 9 as a supplement, the benzene that cat head steams---the aqueous solution removes the condenser of back by pipe arrangement 11, and tower kettle product is discharged to removing the caprolactam water solution of benzene by pipe arrangement 12.
According to the present invention, adopt the open steam de-benzene process, can utilize low-pressure steam in a large number, save de-salted water or process water, and the mass conservation of final caprolactam product.
In order to specify technical process of the present invention, enumerate following embodiment and describe, but the present invention is not subjected to the restriction of these embodiment.
By hexanolactam extraction open steam single effect distillation de-benzene process flow process shown in Figure 1.
Charging: benzene---own solution 16435kg/h, wherein: benzene 12704kg/h, hexanolactam 3287kg/h, water 424kg/h, organic impurity 20kg/h
Benzene steaming tower overhead product: benzene---aqueous solution 14665kg/h, wherein: benzene 12704kg/h, water 1949kg/h, organic impurity 12kg/h
The benzene steaming tower tower kettle product: caprolactam water solution 3767kg/h, wherein: hexanolactam 3287kg/h, water 472kg/h, organic impurity 8kg/h
Benzene steaming tower tower top pressure 0.04Mpa (cutting off), 65 ℃ of top temperature, 102 ℃ of still temperature
The own preheater 2 of benzene---own solution 16435kg/h is transported to benzene by pipe arrangement 1---after the hexanolactam extraction is preheating near 55～60 ℃ of the top temperature of benzene steaming tower, enters the column plate of benzene steaming tower 4 or the liquid distribution device on filler top by pipe arrangement 3.
On the other hand, enter the steam buffer jar 6 that inside has capturing device from the lactan device by-product of pipe arrangement 5 or 0.05Mpa (table) the low-pressure steam 1997kg/h of flash distillation, iron ion or mechanical impurity enter water sealed tank 7 with water of condensation, and the open steam that the steam buffer jar comes out enters the column plate that is arranged at benzene steaming tower 4 or filler below, the tower bottoms steam distribution device of gas-phase space between the top mutually by pipe arrangement 8.
The indirect heating steam 2879kg/h of thermal source is added to the shell side of the plug-in indirect heater 10 of benzene steaming tower 4 by pipe arrangement 9 as a supplement, the benzene that cat head steams---water 14665kg/h removes the condenser of back by pipe arrangement 11, and tower kettle product is discharged to removing the caprolactam water solution 3767kg/h of benzene by pipe arrangement 12.
This technology is compared with whole employing indirect steam heating processes, has utilized low-pressure steam 1997kg/h, has saved de-salted water or the process water of 1997kg/h, and indirect heating steam has dropped to 2879kg/h by 5255kg/h, final caprolactam product mass conservation.
By hexanolactam extraction open steam economic benefits and social benefits distillation de-benzene process flow process shown in Figure 2.
Charging: benzene---own solution 16435kg/h, wherein: benzene 12704kg/h, hexanolactam 3287kg/h, water 424kg/h, organic impurity 20kg/h
1st effective evaporator cat head vapor-phase material: benzene---aqueous solution 4645kg/h, wherein: benzene 4234kg/h, water 407kg/h, organic impurity 4kg/h
1st effective evaporator tower still material: 11791kg/h, wherein: benzene 8470kg/h, hexanolactam 3287kg/h, water 17kg/h, organic impurity 17kg/h
Benzene steaming tower overhead product: benzene---aqueous solution 9770kg/h, wherein: benzene 8470kg/h, water 1292kg/h, organic impurity 8kg/h
The benzene steaming tower tower kettle product: caprolactam water solution 3718kg/h, wherein: hexanolactam 3287kg/h, water 422kg/h, organic impurity 9kg/h
Benzene steaming tower tower top pressure 0.04Mpa (cutting off), 64 ℃ of top temperature, 104 ℃ of still temperature
The vapor-phase material 4645kg/h that 1st effective evaporator 13 cats head steam enters benzene steaming tower reboiler 10 by pipe arrangement 16 as thermal source, and 1st effective evaporator 13 tower still material 11791kg/h enter the liquid distribution device of benzene steaming tower 4 by pipe arrangement 17.
Similarly to Example 1, the open steam 1714kg/h that comes out by steam buffer jar 6, enter by pipe arrangement 8 and to be arranged at benzene steaming tower 4 column plates or filler below, the tower bottoms steam distribution device of gas-phase space between the top mutually, the material benzene that cat head steams---water 9770kg/h, remove the condenser of back by pipe arrangement 11, tower kettle product is discharged to removing the caprolactam water solution 3718kg/h of benzene by pipe arrangement 12.
This technology is compared with the economic benefits and social benefits de-benzene process of whole employing indirect steam heating, utilized low-pressure steam 1714kg/h, saved de-salted water or the process water of 1714kg/h, indirect heating steam has dropped to 1770kg/h by 3913kg/h, final caprolactam product mass conservation.
By hexanolactam extraction open steam triple effect distillation de-benzene process flow process shown in Figure 3.
Charging: benzene---own solution 41098kg/h, wherein: benzene 31769kg/h, hexanolactam 8219kg/h, water 1062kg/h, organic impurity 48kg/h
1st effective evaporator cat head vapor-phase material: benzene---aqueous solution 8849kg/h, wherein: benzene 7775kg/h, water 1062kg/h, organic impurity 12kg/h
1st effective evaporator tower still material: 32249kg/h, wherein: benzene 23994kg/h, hexanolactam 8219kg/h, organic impurity 36kg/h
2nd effect evaporator cat head vapor-phase material: 11286kg/h all is a benzene
2nd effect evaporator tower still material: 20963kg/h, wherein: benzene 12708kg/h, hexanolactam 8219kg/h, organic impurity 36kg/h
Benzene steaming tower overhead product: benzene---aqueous solution 14565kg/h, wherein: benzene 12708kg/h, water 1850kg/h, organic impurity 7kg/h
The benzene steaming tower tower kettle product: caprolactam water solution 9190kg/h, wherein: hexanolactam 8219kg/h, water 942kg/h, organic impurity 29kg/h
Benzene steaming tower tower top pressure 0.04Mpa (cutting off), 66 ℃ of top temperature, 105 ℃ of still temperature
The vapor-phase material 8849kg/h that 1st effective evaporator 13 cats head steam enters 2nd effect evaporator reboiler 18 by pipe arrangement 16 as thermal source, and 1st effective evaporator 13 tower still material 32249kg/h enter the liquid distribution device of 2nd effect evaporator 19 by pipe arrangement 17.
The vapor-phase material 11286kg/h that 2nd effect evaporator 19 cats head steam all is a benzene, enters benzene steaming tower reboiler 10 by pipe arrangement 20 as thermal source, and 2nd effect evaporator 19 tower still material 20963kg/h enter the liquid distribution device of benzene steaming tower 4 by pipe arrangement 21.
Similarly to Example 1, the open steam 2792kg/h that comes out by steam buffer jar 6, enter by pipe arrangement 8 and to be arranged at benzene steaming tower 4 column plates or filler below, the tower bottoms steam distribution device of gas-phase space between the top mutually, the material benzene that cat head steams---water 14565kg/h, remove the condenser of back by pipe arrangement 11, tower kettle product is discharged to removing the caprolactam water solution 9190kg/h of benzene by pipe arrangement 12.
This technology is compared with the triple effect de-benzene process of whole employing indirect steam heating, utilized low-pressure steam 2972kg/h, saved de-salted water or the process water of 2972kg/h, indirect heating steam has dropped to 3500kg/h by 7215kg/h, final caprolactam product mass conservation.
By hexanolactam extraction open steam quadruple effect distillation de-benzene process flow process shown in Figure 4.
Charging: benzene---own solution 82196kg/h, wherein: benzene 63538kg/h, hexanolactam 16438kg/h, water 2124kg/h, organic impurity 96kg/h
1st effective evaporator cat head vapor-phase material: benzene---aqueous solution 12115kg/h, wherein: benzene 10219kg/h, water 1878kg/h, organic impurity 18kg/h
1st effective evaporator tower still material: 70081kg/h, wherein: benzene 53319kg/h, hexanolactam 16438kg/h, organic impurity 78kg/h
2nd effect evaporator cat head vapor-phase material: 19685kg/h, wherein: benzene 19437kg/h, water 246kg/h, organic impurity 2kg/h
2nd effect evaporator tower still material: 50396kg/h, wherein: benzene 33882kg/h, hexanolactam 16438kg/h, organic impurity 76kg/h
Triple-effect evaporator cat head vapor-phase material: 16644kg/h all is a benzene
Triple-effect evaporator tower still material: 33752kg/h, wherein: benzene 17238kg/h, hexanolactam 16438kg/h, organic impurity 76kg/h
Benzene steaming tower overhead product: benzene---aqueous solution 19819kg/h, wherein: benzene 17238kg/h, water 2569kg/h, organic impurity 12kg/h
The benzene steaming tower tower kettle product: caprolactam water solution 18258kg/h, wherein: hexanolactam 16438kg/h, water 1756kg/h, organic impurity 64kg/h
Benzene steaming tower tower top pressure 0.04Mpa (cutting off), 66 ℃ of top temperature, 106 ℃ of still temperature
The own preheater 2 of benzene---own solution 82196kg/h is transported to benzene by pipe arrangement 1---after the hexanolactam extraction enters in the tower after being preheating near the feed tray bubble point of approaching-single-effect evaporator 13, heating steam 5300kg/h enters material in the shell side heating tower of 1st effective evaporator reboiler 15 by pipe arrangement 14.
The vapor-phase material 12115kg/h that 1st effective evaporator 13 cats head steam enters 2nd effect evaporator reboiler 18 by pipe arrangement 16 as thermal source, and 1st effective evaporator 13 tower still material 7008kg/h enter the liquid distribution device of 2nd effect evaporator 19 by pipe arrangement 17.
The vapor-phase material 19685kg/h that 2nd effect evaporator 19 cats head steam enters triple-effect evaporator reboiler 22 by pipe arrangement 20 as thermal source, and 2nd effect evaporator 19 tower still material 50396kg/h enter the liquid distribution device of triple-effect evaporator 23 by pipe arrangement 21.
The vapor-phase material 16644kg/h that triple-effect evaporator 23 cats head steam all is a benzene, enters benzene steaming tower reboiler 10 by pipe arrangement 24 as thermal source, and triple-effect evaporator 23 tower still material 33752kg/h enter the liquid distribution device of benzene steaming tower 4 by pipe arrangement 25.
Similarly to Example 1, the open steam 4321kg/h that comes out by steam buffer jar 6, enter by pipe arrangement 8 and to be arranged at benzene steaming tower 4 column plates or filler below, the tower bottoms steam distribution device of gas-phase space between the top mutually, the material benzene that cat head steams---water 19819kg/h, remove the condenser of back by pipe arrangement 11, tower kettle product is discharged to removing the caprolactam water solution 18258kg/h of benzene by pipe arrangement 12.
This technology is compared with the quadruple effect de-benzene process of whole employing indirect steam heating, utilized low-pressure steam 4321kg/h, saved de-salted water or the process water of 4321kg/h, indirect heating steam has dropped to 5300kg/h by 10700kg/h, final caprolactam product mass conservation.
Fig. 1-the 4th is as the schema of the hexanolactam of typical embodiments of the present invention extraction open steam benzene-removing process.
Nomenclature is as follows among the figure.
1: supply with benzene---the pipe arrangement of own solution
2: benzene---own preheater
3: benzene---the pipe arrangement of own solution after the conveying preheating
4: benzene steaming tower
5: the pipe arrangement of supplying with open steam (low pressure)
6: the steam buffer jar
7: water sealed tank
8: the pipe arrangement of the open steam that the delivering vapor surge tank comes out
9: supply with the pipe arrangement of the indirect heating steam of thermal source as a supplement
10: the benzene steaming tower reboiler
11: benzene---the pipe arrangement of the aqueous solution of carrying the benzene steaming tower cat head to steam
12: the pipe arrangement of carrying the caprolactam water solution that removes benzene
13: 1st effective evaporator
14: the pipe arrangement of carrying heating steam
15: the 1st effective evaporator reboiler
16: the pipe arrangement of the vapor-phase material that conveying 1st effective evaporator cat head steams
17: the pipe arrangement of carrying 1st effective evaporator tower still material
18: the 2nd effect evaporator reboiler
19: 2nd effect evaporator
20: the pipe arrangement of the vapor-phase material that conveying 2nd effect evaporator cat head steams
21: the pipe arrangement of carrying 2nd effect evaporator tower still material
22: the triple-effect evaporator reboiler
23: triple-effect evaporator
24: the pipe arrangement of the vapor-phase material that conveying triple-effect evaporator cat head steams
25: the pipe arrangement of carrying triple-effect evaporator tower still material
Claims (8)
1, hexanolactam extraction open steam benzene-removing process, with the benzene that obtains after the hexanolactam extraction benzene of water washing---after the caprolactam solution or the extraction through---caprolactam solution takes off benzene, it is characterized in that, the heating of employing open steam, steam directly joins in the benzene steaming tower by the steam distribution device, benzene---caprolactam solution carries out single-action or multiple-effect component distillation by benzene steaming tower, and the tower still obtains removing the caprolactam water solution of solvent benzol.
2, the described hexanolactam extraction of claim 1 open steam benzene-removing process, wherein, described open steam adopts the steam of the inner by-product of hexanolactam device, perhaps adopts the steam that is produced by boiler.
3, the described hexanolactam extraction of claim 1 open steam benzene-removing process, wherein, open steam is added in the top and the gas-phase space between column plate or the filler bottom of benzene steaming tower still liquid phase.
4, the described hexanolactam extraction of claim 1 open steam benzene-removing process, wherein, bring a large amount of iron ions into for avoiding paroxysmal in the steam pipe system, inside is set before open steam enters benzene steaming tower has the capturing device and the steam buffer jar of division box automatically.
5, the described hexanolactam extraction of claim 1 open steam benzene-removing process, wherein, for open steam distillatory benzene steaming tower, the benzene concentration that contains of the benzene of its charging---caprolactam solution calculates by weight 15～85%.
6, the described hexanolactam extraction of claim 1 open steam benzene-removing process, wherein, benzene steaming tower is operated under normal pressure or vacuum state, and working pressure is absolute pressure 0.03～0.05Mpa.
7, the described hexanolactam extraction of claim 1 open steam benzene-removing process, wherein, by the benzene steaming tower indirect heater of plug-in form is set, under the system fluctuation situation, the heating steam amount of controlling plug-in indirect heater is adjusted the water balance and the thermal equilibrium of benzene steaming tower.
8, the described hexanolactam extraction of claim 1 open steam benzene-removing process, wherein, benzene---caprolactam solution adopts the mode of single-action or multi-effect distilling to remove solvent benzol, when adopting the mode of multi-effect distilling, former effects do not feed open steam, directly remove partial solvent benzene by distillation, the end is imitated and is adopted the open steam component distillation again.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB011164123A CN1155577C (en) | 2001-04-12 | 2001-04-12 | Process for extracting caprolactam and direct steam debenzolization |
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|---|---|---|---|
| CNB011164123A CN1155577C (en) | 2001-04-12 | 2001-04-12 | Process for extracting caprolactam and direct steam debenzolization |
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| CN1323786A CN1323786A (en) | 2001-11-28 |
| CN1155577C true CN1155577C (en) | 2004-06-30 |
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| CN103896841B (en) * | 2012-12-28 | 2018-11-09 | Cap Iii 有限公司 | The method for being recycled from organic solvent and purifying epsilon-caprolactams |
| CN111333577A (en) * | 2020-02-26 | 2020-06-26 | 福建永荣科技有限公司 | Brand-new caprolactam production system |
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