CN1795171A - Continuous process for preparing caprolactam - Google Patents
Continuous process for preparing caprolactam Download PDFInfo
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- CN1795171A CN1795171A CN 200480014190 CN200480014190A CN1795171A CN 1795171 A CN1795171 A CN 1795171A CN 200480014190 CN200480014190 CN 200480014190 CN 200480014190 A CN200480014190 A CN 200480014190A CN 1795171 A CN1795171 A CN 1795171A
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Abstract
The invention relates to a continuous process for preparing caprolactam by Beckmann rearrangement of cyclohexanone oxime, said process comprising a) feeding (i) oleum and (ii) cyclohexanone oxime into a first reaction mixture comprising caprolactam, sulfuric acid and SO3, b) feeding (iii) a portion of the first reaction mixture and (iv) cyclohexanone oxime into a second reaction mixture comprising caprolactam, sulfuric acid and SO3, c) withdrawing a portion of the second reaction mixture, wherein the process further comprises obtaining the cyclohexanone oxime that is fed to the reaction mixtures by: 1) preparing an organic medium comprising cyclohexanone oxime dissolved in an organic solvent 2) separating, by distillation, cyclohexanone oxime from said organic medium.
Description
The Beckmann that the present invention relates to be used for by cyclohexanone-oxime resets the continuation method for preparing hexanolactam, and described method comprises:
A) with (i) oleum and (ii) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3First reaction mixture in;
B) will be (iii) first reaction mixture a part and (iv) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3Second reaction mixture in; And
C) part of described second reaction mixture of taking-up.
Hexanolactam can be reset by the Beckmann of cyclohexanone-oxime and prepare.Such Beckmann resets can comprise hexanolactam, sulfuric acid and SO by cyclohexanone-oxime is mixed into
3Reaction mixture in realize.In such method, sulfuric acid and SO
3It is the catalyzer that cyclohexanone-oxime transforms to hexanolactam.Known such conversion is instantaneous generation.
A kind of like this method has been described in US-A-3953438.In this method, comprise the cyclohexanone-oxime of 4.9wt.% water and comprise 25wt.%SO
3Oleum be fed to continuously and comprise first of circulating reaction material and reset in the district, make the circulating reaction material have sulfuric acid+SO of 1.45
3To the weight ratio of hexanolactam and the SO of 5.9wt.%
3Content.Equal in the reaction mass in the first catalytically rearranging district to be taken out continuously, and be fed into and comprise second of circulating reaction material and reset the district to its part of feed.The cyclohexanone-oxime that comprises 4.9wt.% water also is fed to second continuously and is reset the circulating reaction material in district.The second circulating reaction material of resetting the district has sulfuric acid+SO of 1.14
3To the weight ratio of hexanolactam and the SO of 3.2wt.%
3Content.Equal in the reaction mass in the second catalytically rearranging district to be removed to its part of feed.
In US-A-3953438, describe described oxime and can comprise the water that is up to 6wt.%.Though the value of the water of 0.1wt.% is mentioned as lower limit, in fact, disclosed method is finished under high water-content in this patent, that is, in all embodiment, the oxime that comprises 4.9wt.% water is used.Do not provide the method for the water-content that how to reduce described oxime.
In the method for US-A-3953438, need have the oleum of higher oleum intensity.Therefore, need a large amount of SO
3To obtain desired hexanolactam productive rate.
The objective of the invention is to improve productive rate, use more a spot of relatively SO simultaneously
3
This purpose has been implemented, because present method also comprises the cyclohexanone-oxime that obtains as follows to be fed in the reaction mixture:
1) preparation comprise the organic medium that is dissolved in the cyclohexanone-oxime in the organic solvent and
2) by distilling from described organic medium cyclohexanone oxime.
Have been found that the method for the present invention of utilizing, need to add the SO of less amount
3Obtain the high yield of hexanolactam.Add a large amount of SO
3Be disadvantageous, because, or must be at oleum (H
2SO
4/ SO
3Mixture) uses high SO in
3Concentration, and consider and because the danger that oleum distributes increases and because the flowability of oleum descends, this is disadvantageous from the viewpoint of economy, or, at the SO that still in oleum, uses relatively low concentration
3The time, for the oxime of every deal, a large amount of oleums must be fed in the neutralized rearrangement mixture, and this causes forming a large amount of byproducts (ammonium sulfate) in N-process subsequently.
In the method for the invention, or for the SO that adds the specified rate in this technology to
3, can obtain higher hexanolactam productive rate, or SO still less
3Need be added and obtain given hexanolactam productive rate.In addition, utilize method of the present invention, or for the SO that adds the specified rate in this technology to
3, can obtain the gained hexanolactam that quality improves, or SO still less
3Need be added the hexanolactam that obtains given quality.
The cyclohexanone-oxime that is fed to reaction mixture obtains as follows:
1) preparation comprise the organic medium that is dissolved in the cyclohexanone-oxime in the organic solvent and
2) by distilling from described organic medium cyclohexanone oxime.
Preparation comprises the organic medium that is dissolved in the cyclohexanone-oxime in the organic solvent and preferably realizes as follows: the mode with adverse current in reaction zone (after this being called the synthetic district of cyclohexanone-oxime) contacts the solution stream of pimelinketone in organic solvent with the water solution flow of the phosphate buffered of hydroxylammonium, wherein said organic solvent also is the solvent of cyclohexanone-oxime; And take out the organic medium be dissolved in the cyclohexanone-oxime the described organic solvent from reaction zone.The organic solvent that is particularly useful for making the method for cyclohexanone-oxime is toluene and benzene.Preferably, toluene is used as organic solvent.The aqueous reaction medium of phosphate buffered is circulation continuously between synthetic district of hydroxylammonium and the synthetic district of cyclohexanone-oxime preferably.In the synthetic district of hydroxylammonium,, form hydroxylammonium by with hydrogen catalysis reduction nitrate ion or nitrogen protoxide.In the synthetic district of cyclohexanone-oxime, hydroxylammonium that forms in the synthetic district of hydroxylammonium and pimelinketone reaction are to form cyclohexanone-oxime.Can synthesize cyclohexanone oxime the aqueous reaction medium of distinguishing from being recycled to hydroxylammonium then.Comprise the organic medium that is dissolved in the formed cyclohexanone-oxime the described organic solvent from the reaction zone taking-up, and can be with its distillation with recycle-water content less than 2wt.%, preferably less than 1wt.%, more preferably even less than 0.2wt.% and even be more preferably less than the cyclohexanone-oxime of 0.1wt.%.The cyclohexanone-oxime of described recovery is fed in the reaction mixture in the method according to this invention.
Organic medium generally comprises cyclohexanone-oxime, described organic solvent and optional pimelinketone.Comprise at organic medium under the situation of pimelinketone, the concentration of pimelinketone can be higher than 0.1wt% in organic medium, preferably is higher than 0.5wt%, most preferably is higher than 1wt%.The concentration of pimelinketone can be lower than 10wt.% in organic medium, preferably is lower than 5wt.%.The concentration of cyclohexanone-oxime can be higher than 5wt.% in organic medium, preferably is higher than 10wt.%, more preferably is higher than 25wt.%, and can be lower than 60wt.%, is preferably lower than 50wt.%.The concentration of organic solvent can be higher than 40wt.% in organic medium, preferably is higher than 50wt.%, and can be lower than 95wt.%, preferably is lower than 90wt.%.
In the method for the invention, realize by distillation from described organic medium cyclohexanone oxime.Distillation can realize in any suitable manner.Distillation can be finished with any suitable post or the combination of a plurality of posts.In one embodiment, separate by distillatory and comprise that the distillation organic medium is to obtain as the organic solvent of cut (crown product) with as the cyclohexanone-oxime of bottoms.Cyclohexanone-oxime, for example as bottoms obtained, can for example comprise less than 2wt.%, preferably less than 1wt.%, be more preferably less than 0.2wt.%, be more preferably less than the water of 0.1wt.%, and can be fed into first reaction mixture, second reaction mixture and the 3rd optional reaction mixture.Distillation can be carried out under any suitable temperature, for example between 35 and 115 ℃, preferably between 50 and 100 ℃, and can under any suitable pressure, carry out, for example 0.006 and 0.020MPa between, preferably 0.012 and 0.020MPa between.Temperature as used herein is meant the temperature in the top of carrying out the distillatory post therein.Pressure as used herein is meant the pressure in the top of carrying out the distillatory post therein.Carry out distillatory embodiment and in GB-A-1303739 and EP-A-5291, description is arranged.
One preferred embodiment in, described method comprises:
A) with (i) oleum and (ii) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3First reaction mixture in; B) will be (iii) first reaction mixture a part and (iv) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3Second reaction mixture in; C) part of described second reaction mixture of taking-up; D) will (part of v) described second reaction mixture and (vi) cyclohexanone-oxime is fed to and comprises hexanolactam, sulfuric acid and SO
3The 3rd reaction mixture in; E) part of described the 3rd reaction mixture of taking-up; And wherein, described method also comprises the cyclohexanone-oxime that obtains to be incorporated into reaction mixture as follows:
1) preparation comprises the organic medium that is dissolved in the cyclohexanone-oxime in the organic solvent;
2) by distilling from described organic medium cyclohexanone oxime.
Preferably, first reaction mixture, second reaction mixture and if applicable, the 3rd reaction mixture is held circulation.
In such multistage rearrangement, Beckmann in each stage reset preferably by at from previous stage the cyclic reaction mixture that (if any) taken out amount continuously with cyclohexanone-oxime with discretely oleum (fs) is fed to cyclic reaction mixture with it, and the amount of the cyclic reaction mixture of the amount (fs) by taking out the amount that equals cyclohexanone-oxime and oleum continuously at the amount of the cyclic reaction mixture that is incorporated into cyclic reaction mixture that takes out from previous stage (if any), and, comprising hexanolactam by continuously described amount being fed to next stage (if any), sulfuric acid and SO
3Cyclic reaction mixture in realize.The amount that the final stage of resetting in the multistage, a part of taking out cyclic reaction mixture, a described part equal cyclohexanone-oxime adds the amount of taking out and be introduced in the cyclic reaction mixture the circulating mixture of final stage from previous stage; Reclaim hexanolactam from a described part.
First reaction mixture, second reaction mixture and the 3rd optional reaction mixture comprise hexanolactam, sulfuric acid and SO
3The mol ratio M of reaction mixture is defined as (n
SO3+ n
H2SO4)/n
Cap, wherein, n
SO3SO in the=reaction mixture
3Amount, unit is mol (1mol SO
3Corresponding to 80g), n
H2SO4H in the=reaction mixture
2SO
4Amount, unit is mol (1mol H
2SO
4Corresponding to 98g), and n
CapThe amount of hexanolactam in the=reaction mixture, unit is mol (the 1mol hexanolactam is corresponding to 113g).SO
3Content (wt.%) be meant with respect to comprising sulfuric acid, SO
3SO with the reaction mixture total amount (g) of hexanolactam
3Amount (g).
In a preferred embodiment mode, be rearranged in two stages that are connected in series and finish.In this embodiment, hexanolactam preferably obtains by the successive method, and described method comprises:
A) with (i) oleum and (ii) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3First reaction mixture in;
B) will be (iii) first reaction mixture a part and (iv) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3Second reaction mixture in, the mol ratio M of wherein said second reaction mixture is between 1.0 and 1.4 and the SO of described second reaction mixture
3Content is higher than 6wt.%, more preferably is higher than 8wt.% and even more preferably is higher than the SO of 10wt.% and described second reaction mixture
3Content preferably is lower than 20wt.%, more preferably less than 18wt.% and even more preferably less than 16wt.%;
C) part of described second reaction mixture of taking-up reclaims hexanolactam from a described part, and wherein, described method also comprises the cyclohexanone-oxime that obtains to be incorporated into reaction mixture as follows:
1) preparation comprises the organic medium that is dissolved in the cyclohexanone-oxime in the organic solvent;
2) by distilling from described organic medium cyclohexanone oxime.Preferably, first reaction mixture and second reaction mixture keep circulation.
In one even preferred embodiment of the present invention, be rearranged in the three phases that is connected in series and finish.In this embodiment, hexanolactam preferably obtains by the successive method, and described method comprises:
A) with (i) oleum and (ii) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3First reaction mixture in;
B) will be (iii) first reaction mixture a part and (iv) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3Second reaction mixture in;
C) part of described second reaction mixture of taking-up;
D) will (part of v) described second reaction mixture and (vi) cyclohexanone-oxime is fed to and comprises hexanolactam, sulfuric acid and SO
3The 3rd reaction mixture in, the mol ratio M of wherein said the 3rd reaction mixture is between 1.0 and 1.4 and the SO of described the 3rd reaction mixture
3Content is higher than 6wt.%, more preferably is higher than 8wt.% and even more preferably is higher than the SO of 10wt.% and described the 3rd reaction mixture
3Content preferably is lower than 18wt.%, more preferably less than 17wt.% and even more preferably less than 16wt.%;
E) part of described the 3rd reaction mixture of taking-up reclaims hexanolactam from a described part, and wherein, described method also comprises the cyclohexanone-oxime that obtains to be incorporated into reaction mixture as follows:
1) preparation comprises the organic medium that is dissolved in the cyclohexanone-oxime in the organic solvent;
2) by distilling from described organic medium cyclohexanone oxime.Preferably, first reaction mixture, second reaction mixture and the 3rd reaction mixture keep circulation.
In the final stage of resetting in multistage particularly with low like this mol ratio and high SO
3The content operation is favourable, because the low mol ratio in the final stage of multistage rearrangement causes forming a spot of ammonium sulfate, the high SO under low like this mol ratio simultaneously in N-process subsequently
3Amount causes the raising of hexanolactam productive rate, and causes the raising of the quality of resulting hexanolactam.
Mol ratio M is preferably different in each reaction mixture.Molar ratio M in first, second of Shi Yonging and the 3rd (if applicable) reaction mixture will be called as M (1), M (2) and M (3) respectively in this article.SO in first, second and the 3rd (if applicable) reaction mixture used herein
3Concentration will be called as C respectively
SO3(1), C
SO3(2) and C
SO3(3).Temperature in first, second and the 3rd (if applicable) reaction mixture used herein will be called as T (1), T (2) and T (3) respectively.M value used herein, SO
3Concentration value and temperature value specifically are meant the value in the resulting reaction mixture after cyclohexanone-oxime is fed in the reaction mixture.
Comprise hexanolactam, sulfuric acid and SO
3The SO of reaction mixture
3Content preferably be higher than the SO of 6wt.%
3, more preferably be higher than the SO of 8wt.%
3, and even more preferably be higher than 10wt.%.Since practical, the SO of reaction mixture
3Content is usually less than 20wt.%, for example less than 18wt.%, for example less than 17wt.%.The mol ratio M of reaction mixture is preferably between 1 and 2.2, more preferably between 1.1 and 1.9.
The temperature of carrying out the Beckmann rearrangement is preferably between 70 and 130 ℃, and more preferably, this temperature is between 70 and 120 ℃.
Can be fed to the different stages by cyclohexanone-oxime with appropriate vol, and by applying the suitable SO of having of appropriate amount
3The oleum of concentration can obtain M and SO
3The preferred value of concentration.
Preferably, M (2) is lower than M (1).Preferably, M (3) is lower than M (2).
In a preferred implementation, M (1) is between 1.2 and 2.2, is preferably between 1.4 and 1.9, more preferably between 1.5 and 1.8.Preferably, C
SO3(1) be 3 and 20wt.% between, more preferably be higher than 5wt.% and more preferably be higher than 6wt.%.The C that increases
SO3(1) advantage of value is C
SO3(2) can in second reaction mixture, remain height, and oleum need not be fed to second reaction mixture.C
SO3(1), and even is more preferably less than 17wt.% preferably less than 18wt.%.Preferably, T (1) is between 70 and 130 ℃, more preferably is between 70 and 120 ℃.
In a preferred implementation, M (2) is between 1.0 and 1.6, preferably between 1.2 and 1.5.Preferably, C
SO3(2) be 2 and 20wt.% between, more preferably be higher than 6wt.%, more preferably be higher than 8wt.%.Find the C that in the scope of above-mentioned M (2), increases surprisingly
SO3(2) concentration causes obviously higher productive rate.C
SO3(2), even be more preferably less than 16wt.% preferably less than 18wt.%.Preferably, T (2) is between 70 and 130 ℃, more preferably is between 80 and 120 ℃.
In a preferred implementation, M (3) is between 1.0 and 1.4, is preferably between 1.0 and 1.3.Preferably, C
SO3(3) be 4 and 18wt.% between, preferably be higher than 6wt.%, more preferably be higher than 8wt.%.Find the C that in the scope of above-mentioned M (3), increases surprisingly
SO3(3) concentration causes obviously higher productive rate.C
SO3(3), even be more preferably less than 16wt.% preferably less than 17wt.%.Preferably, T (3) is between 70 and 130 ℃, more preferably is between 80 and 120 ℃.
Can obtain M value and SO in any suitable method
3Content value.In a preferred implementation, this method is a successive method, comprises keeping the reaction mixture circulation, will comprise sulfuric acid and SO
3Mixture (for example oleum), perhaps comprise hexanolactam, sulfuric acid and SO
3Reaction mixture be fed in the cyclic reaction mixture, and take out the part of cyclic reaction mixture.Can select to be fed to and comprise sulfuric acid and SO in the cyclic reaction mixture
3Amount, its SO of mixture
3The amount of content and cyclohexanone-oxime makes the M and the SO of reaction mixture
3Content has preferred value.Oleum can have any suitable SO
3Concentration, for example 18 to 35wt.% SO
3
In the method for the invention, be rearranged in carrying out in a plurality of stages that are connected in series, wherein, in each next stage, the mol ratio M of reaction mixture preferably reduces.Preferably, be rearranged at least two that are connected in series, more preferably carry out in the three phases at least.Can in any suitable manner oleum be fed in the reaction mixture.Preferably, applied all oleums are fed in first reaction mixture, and preferably, and cyclohexanone-oxime is fed into first, second and if applicable in the 3rd reaction mixture.Preferably, the amount that is fed into the cyclohexanone-oxime in first reaction mixture is greater than the amount that is fed into the cyclohexanone-oxime in second reaction mixture, and the amount that is fed into if applicable, the cyclohexanone-oxime in second reaction mixture is greater than the amount that is fed into the cyclohexanone-oxime in the 3rd reaction mixture.This is favourable, because because the lower mol ratio in each next stage, the productive rate of hexanolactam reduced in each next stage.With the amount that reduces by the stage cyclohexanone-oxime being fed to each stage causes keeping the overall high yield of hexanolactam under the situation that forms ammonium sulfate byproduct relatively still less.Preferably, be fed into first and second reaction mixtures and if applicable 60 to 95wt.% in the total amount of the cyclohexanone-oxime in the 3rd reaction mixture be fed in first reaction mixture.Preferably, be fed into first and second reaction mixtures and if applicable 5 to 40wt.% in the total amount of the cyclohexanone-oxime in the 3rd reaction mixture be fed in second reaction mixture.If applicable, preferably, be fed into 2 to 15wt.% in the total amount of the cyclohexanone-oxime in first, second and the 3rd reaction mixture and be fed in the 3rd reaction mixture.
Preferably, Yi Fen cyclohexanone-oxime is incorporated at least 10 parts by volume continuously by volume, more preferably at least 20 parts the reaction mixture.
Cyclohexanone-oxime preferably is fed in the reaction mixture with the form of liquid melts.
Cyclohexanone-oxime and oleum (with cyclohexanone-oxime discretely) preferably be introduced into via tripper.Preferably, cyclohexanone-oxime is mixed consumingly with reaction mixture.Be used for that the appropriate method of cyclohexanone-oxime and reaction mixture is for example had description at US-A-3601318 and EP-A-15617.In a preferred embodiment of the present invention, utilization is mixed into reaction mixture as the mixing equipment that Fig. 2 described with cyclohexanone-oxime.In Fig. 2, mixing equipment comprises cylindrical tube 101, and described pipe 101 constriction in the 101a of first part arrives line mouth 101b, and broadening in second section 101c outside line mouth 101b.The second section 101c of pipe is connected to second pipe 102.In the line mouth, there are a plurality of openings 103 that are connected with feed chamber 104.Cyclohexanone-oxime is supplied via feed chamber 104, and is fed in the reaction mixture by opening 103.Mixing equipment comprises closure member 105, utilizes closure member 105 open and close opening 103 independently.Mixing equipment also comprises the relative traverse baffle 106 of outlet with pipe 101.Tube opening is in collection container B, and described collection container B has wall 110, overflow port 111 and exports 112.Leave pipe 102 reaction mixture and be collected among the collection container B, and part leaves collection container B via pipeline 112, further being circulated, and part is fed in the subsequent reaction mixture via overflow port 111 or is used to reclaim hexanolactam.In a preferred embodiment of the present invention, described mixing equipment comprises: (i) pipe, and described reaction mixture can flow through described pipe; (ii) center on a plurality of passages that described pipe is arranged, described access portal is in described pipe, described method comprises: make described reaction mixture by described pipe, and cyclohexanone-oxime is fed to described reaction mixture by in the described passage one or more, wherein the Re of reaction mixture＞5000 are preferably greater than 10000, and Re is a Reynolds number, be defined as ρ VD/ η, wherein
The density of ρ=the be fed into described reaction mixture of described pipe (units/m3),
The speed of the described reaction mixture of V=, V is defined as W/A, and wherein W is the flow rate (m of unit that is fed into the described reaction mixture in the described pipe
3/ s), A is that described pipe is at cross-sectional area (the unit m of described access portal to the place, plane of described pipe
2),
The diameter (m of unit) that the described pipe of D=is located to the plane of described pipe in described access portal,
η=the be fed into viscosity (Pas of unit) of the described reaction mixture in the described pipe.
Obtaining reaction mixture recovery hexanolactam from the end the Beckmann in stage resets can be undertaken by currently known methods.Preferably, neutralize with ammoniacal liquor obtaining reaction mixture during in the end the Beckmann in stage resets, and the ammonium sulfate that will form is thus removed from caprolactam solution.Caprolactam solution can be purified by already known processes.
Embodiment
Fig. 1 shows the preferable configuration that is used in the rearrangement of three stages, comprises first recycle system, second recycle system and third circulation system.First recycle system comprises mixing equipment A1, collection container B1, pump C1 and water cooler D1, and first reaction mixture keeps circulation via pipeline 1.Second recycle system comprises mixing equipment A2, collection container B2, pump C2 and water cooler D2, and second reaction mixture keeps circulation via pipeline 11.Third circulation system comprises mixing equipment A3, collection container B3, pump C3 and water cooler D3, and the 3rd reaction mixture keeps circulation via pipeline 21.Cyclohexanone-oxime and oleum are fed in first reaction mixture via pipeline 2 and pipeline 3 respectively.The part of first reaction mixture is taken out from collection container B1 via pipeline 4, and is fed in second reaction mixture.Cyclohexanone-oxime is fed in second reaction mixture via pipeline 12.The part of second reaction mixture is taken out from collection container B2 via pipeline 14, and is fed in the 3rd reaction mixture.Cyclohexanone-oxime is fed in the 3rd reaction mixture via pipeline 22.The part of the 3rd reaction mixture is taken out from collection container B3 via pipeline 24.This process quilt carries out continuously.
Fig. 2 shows the mixing equipment that is preferably used as mixing equipment A1, mixing equipment A2 and mixing equipment A3.
Below specific embodiment only will be considered to explanation to rest part of the present disclosure, and do not limit.In an embodiment, the productive rate of hexanolactam is determined as follows.Extract sample from leaving the reaction mixture of resetting final stage.Described productive rate (amount that is fed into the formed hexanolactam of cyclohexanone-oxime in the reaction mixture of every deal) is determined as follows.With the vitriol oil (20ml, 96wt.%) and the K of 15g
2SO
4Add the first part (0.2 gram) of each sample to the HgO of 0.7 gram.Utilize the Kjeldahl method to determine the nitrogen content of gained acidic mixture, calculate the volumetric molar concentration (TN) of the nitrogen in the first part of sample thus.The second section chloroform extraction of each sample.This method is based on the fact that hexanolactam enters the chloroform phase.Impurity is retained in aqueous phase.Analyze nitrogen content by the Kjeldahl method, calculate the volumetric molar concentration (RN) of the nitrogen in the second section of sample thus through the water of extraction.Productive rate is pressed following calculating:
The % productive rate=(1-RN/TN) * 100
Be used as the specific absorption (E at the 290nm place of the quality indication of gained hexanolactam
290Nm) determine as follows:
Leave the reaction mixture of resetting final stage and neutralize with ammonia, and the separating obtained hexanolactam water that contains.Utilize the 1cm cuvette to measure the isolating specific absorption (caprolactam solution of pressing 70wt.% calculates) that contains the hexanolactam water at the wavelength place of 290nm.
Embodiment 1
This is the embodiment by the prepared in reaction cyclohexanone-oxime of buffered hydroxylammonium phosphate solution and pimelinketone in the presence of toluene.
Use is according to the method for Fig. 3, time per unit, and following hydroxylammonium salt solution is fed into counter-current reactor A via pipeline 1:
The NH of 65 kilomols
2OHH
3PO
4
The NH of 97 kilomols
4H
2PO
4
The H of 38 kilomols
3PO
4
The NH of 191 kilomols
4NO
3With
The H of 3184 kilomols
2O
Described solution is from the azanol synthesis phase, wherein, with under the help of nitrate ion hydrogen in medium of the form supply of the nitric acid of 55wt.% and be reduced into azanol in the presence of platinum catalyst, described medium is cushioned under the help of the combination of phosphoric acid salt and phosphoric acid.The pH of solution is 2.1.
The pimelinketone solution and the toluene flow point of 65 kilomols in addition do not enter into described reactor A via pipeline 2 and 3, and wherein said toluene stream comprises:
The toluene of 400 kilomols,
The pimelinketone of 9 kilomols,
The oxime of 2 kilomols and
The H of 5 kilomols
2O.
Temperature in the reactor A is maintained at 70 ℃.
Contain oxime toluene product flow and be discharged to the distillation column C that is provided with heater coil 5 via pipeline 4 from reactor.Described product flow comprises:
The toluene of 400 kilomols,
The oxime of 65 kilomols and
The H of 20 kilomols
2O.
In post C, finish separating of oxime and toluene.Via the oxime of pipeline 6 discharge time per units 65 kilomols, toluene (400 kilomol) and water (20 kilomol) are discharged to column extractor B via pipeline 7 simultaneously.
To column extractor B, the described aqueous solution comprises time per unit via pipeline 8 drainage water solution:
The NH of 191 kilomols
4NO
3
97 kilomol NH
4H
2PO
4
103 kilomol H
3PO
4
9 kilomol pimelinketone
2 kilomol oximes and
3234 kilomol H
2O.
After removing the toluene that is dissolved in wherein by stripping again, the aqueous solution of discharging from column extractor B has following composition:
97 kilomol NH
4H
2PO
4
The NH of 191 kilomols
4NO
3
103 kilomol H
3PO
4With
3249 kilomol H
2O.
This solution is recycled to the azanol synthesis phase, to serve as at the reaction medium of nitric acid in the reduction of azanol.
Comprise water at the resulting oxime of post C less than 1000ppm.Described oxime is used to given below
Embodiment 2-4.
Comparative experiment A
Use device as Fig. 1 and 2 described.7.1t/hr the oxime that comprises 4.7% water (2) and the SO that comprises 25wt.% of 9.2t/hr
3Oleum (3) be fed into fs of system for rearranging.By first reaction mixture is lowered to 77 ℃ water cooler (D1) with the rate loop of 400t/hr by temperature wherein, the temperature in the pump receptacle (C1) is remained on 102 ℃.The mixing equipment (A1) that described oxime transmitted beam head piece diameter is 51mm (101b) is mixed in circulation first reaction mixture, and mixing equipment is provided with 16 passages (diameter 3mm).Cyclohexanone-oxime is fed by 8 passages (8 in the described passage are in make-position).The speed of circulating mixture is 40m/s in the line mouth, and the speed that cyclohexanone-oxime is fed to cyclic reaction mixture is 41m/s.Reactor ejecta (4) is sent to the subordinate phase of system for rearranging, and at this, the oxime in the identical source of 1.9t/hr is added (12).In second and the phase III of system for rearranging, oxime is mixed in round-robin second and the 3rd reaction mixture by mixing equipment (being respectively A2 and A3), described mixing equipment is as employed in the fs, but its size be applicable to second and the phase III in lower treatment capacity.Cycle rate is 150t/hr, and water cooler (D2) temperature out is 72 ℃, and reactor is 86 ℃ of operations down.At last, reactor ejecta (14) is sent to the phase III of system for rearranging, and at this, the oxime of 1.1t/hr is added (22).Operating temperature still is 86 ℃, by the cycle rate of 100t/hr and 76 ℃ water cooler (D3) temperature out control.
The mol ratio M of first, second and the 3rd reaction mixture is respectively 1.68,1.32 and 1.18, corresponds respectively to 1.46,1.15 and 1.02 weight ratio.The weight ratio of reaction mixture is defined as (SO in the reaction mixture
3Amount add H in the reaction mixture
2SO
4Amount)/reaction mixture in the amount of hexanolactam.The first,, the SO of the second and the 3rd reaction mixture
3Concentration is respectively: 4.8%, 2.1% and 0.8%.The method that utilization provides is above determined the overall yield of 3 stage system for rearranging: 98.9%.Extinctivity at the 290nm place is 3.54 (determining by the method that provides above).
Embodiment 2
Repeat the contrast experiment, difference is, uses the prepared cyclohexanone-oxime according to embodiment 1.Oxime also almost equates with Comparative experiment A to three feeding rates of resetting the stage.The feeding rate of described oleum is not conditioned, and causes oleum to compare lower with Comparative experiment A to the consumption ratio of oxime.Cycle rate is retained as in the Comparative experiment A, and cooling temperature is by being regulated a little, so as temperature of reactor can be remained on Comparative experiment A in par.The mol ratio of first, second and the 3rd reaction mixture is respectively 1.58,1.24 and 1.11.The SO of first, second and the 3rd reaction mixture
3Concentration is respectively 14.2%, 12.7% and 12.0%, and utilizes the method that provides above to determine that overall yield measured in the ejecta of the 3rd reactor is 99.4%.Extinctivity (determining by the method that provides above) at the 290nm place is 0.65.
Embodiment 3
Repeat Comparative experiment A, difference is, use is according to the prepared cyclohexanone-oxime of embodiment 1, and in order to guarantee the consumption ratio of similar oleum to oxime, oleum with mol ratio measured in three phases each near or the mode that is same as from the value of Comparative experiment A be reduced.Cycle rate is retained as in the Comparative experiment A, and cooling temperature is by being regulated a little, so as temperature of reactor can be remained on Comparative experiment A in par.The SO of first, second and the 3rd reaction mixture
3Concentration is respectively 14.5%, 13.0% and 12.3%.The method that utilization provides above determines that overall yield measured in the 3rd reactor outlet is 99.5%.Extinctivity (determining by the method that provides above) at the 290nm place is 0.65.
The raising of the increase that relatively the showing of Comparative experiment A and embodiment 2 uses oxime prepared in accordance with the present invention to cause the hexanolactam productive rate and the quality of gained hexanolactam.The feasible amount that can reduce of use oxime prepared in accordance with the present invention that relatively shows of embodiment 2 and embodiment 3 for the oleum that oxime added of every deal, the lower mol ratio ammonium sulfate of the lower amount in neutralization subsequently (and cause thus) that causes the reaction mixture in the stage in the end, and the quality of the productive rate of hexanolactam and gained hexanolactam is further improved.
Embodiment 4
Repeat Comparative experiment A, difference is, uses the prepared cyclohexanone-oxime according to embodiment 1, and uses the SO that comprises less than 9wt.%
3Oleum.Constant to three oxime feeding rates of resetting the stage.For guarantee to Comparative experiment A in similar oleum to the consumption ratio of oxime, the feeding rate of oleum finally is set at 10t/hr, be implemented in each in the three phases mol ratio all near or be same as value from Comparative experiment A.
Cycle rate is retained as in the Comparative experiment A, and cooling temperature is by being regulated a little, so as temperature of reactor can be remained on Comparative experiment A in par.The SO of first, second and the 3rd reaction mixture
3Concentration is respectively 5.0%, 4.4% and 4.2%.The method that utilization provides above determines that overall yield measured in the 3rd reactor outlet is 99.3%.Extinctivity (determining by the method that provides above) at the 290nm place is 1.06.
Relatively showing of Comparative experiment A and embodiment 4 uses feasible can the use of oxime prepared in accordance with the present invention to have lower SO
3The oleum of content, the productive rate of hexanolactam and the quality of gained hexanolactam are further improved simultaneously.
Claims (14)
1. the Beckmann by cyclohexanone-oxime resets the continuation method for preparing hexanolactam, and described method comprises:
A) with (i) oleum and (ii) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3First reaction mixture in;
B) will be (iii) described first reaction mixture a part and (iv) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3Second reaction mixture in;
C) part of described second reaction mixture of taking-up, wherein, described method also comprises the cyclohexanone-oxime that obtains to be fed into described reaction mixture as follows:
1) preparation comprises the organic medium that is dissolved in the cyclohexanone-oxime in the organic solvent;
2) by distilling from described organic medium cyclohexanone oxime.
2. the method for claim 1, described method also comprises:
D) will (part of v) described second reaction mixture and (vi) cyclohexanone-oxime is fed to and comprises hexanolactam, sulfuric acid and SO
3The 3rd reaction mixture in; With
E) part of described the 3rd reaction mixture of taking-up.
3. as each described method among the claim 1-2, wherein, the cyclohexanone-oxime that is fed into described reaction mixture comprises the water less than 1wt.%.
4. as each described method among the claim 1-2, wherein, the cyclohexanone-oxime that is fed into described reaction mixture comprises the water less than 0.1wt.%.
5. method according to any one of claims 1 to 4 wherein, comprises hexanolactam, sulfuric acid and SO
3The SO of described reaction mixture
3Content is 6wt.% at least.
6. method according to any one of claims 1 to 4 wherein, comprises hexanolactam, sulfuric acid and SO
3The SO of described reaction mixture
3Content is 8wt.% at least.
7. method according to any one of claims 1 to 4 wherein, comprises hexanolactam, sulfuric acid and SO
3The SO of described reaction mixture
3Content is 10wt.% at least.
8. as each described method in the claim 1 to 7, wherein, the SO of described oleum
3Content is between 18wt.% and the 35wt.%.
9. method according to any one of claims 1 to 4, wherein, described method comprises:
A) with (i) oleum and (ii) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3First reaction mixture in;
B) will be (iii) first reaction mixture a part and (iv) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3Second reaction mixture in, the mol ratio M of wherein said second reaction mixture is between 1.0 and 1.4 and the SO of described second reaction mixture
3Content is higher than 6wt.%;
C) part of described second reaction mixture of taking-up reclaims hexanolactam from a described part.
10. method as claimed in claim 9, wherein, the SO of described second reaction mixture
3Content is higher than 8wt.%.
11. method as claimed in claim 9, wherein, the SO of described second reaction mixture
3Content is higher than 10wt.%.
12. method according to any one of claims 1 to 4, wherein, described method comprises:
A) with (i) oleum and (ii) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3First reaction mixture in;
B) will be (iii) first reaction mixture a part and (iv) cyclohexanone-oxime be fed to and comprise hexanolactam, sulfuric acid and SO
3Second reaction mixture in;
C) part of described second reaction mixture of taking-up;
D) will (part of v) described second reaction mixture and (vi) cyclohexanone-oxime is fed to and comprises hexanolactam, sulfuric acid and SO
3The 3rd reaction mixture in, the mol ratio M of wherein said the 3rd reaction mixture is between 1.0 and 1.4 and the SO of described the 3rd reaction mixture
3Content is higher than 6wt.%;
E) part of described the 3rd reaction mixture of taking-up reclaims hexanolactam from a described part.
13. method as claimed in claim 12, wherein, the SO of described the 3rd reaction mixture
3Content is higher than 8wt.%.
14. method as claimed in claim 12, wherein, the SO of described the 3rd reaction mixture
3Content is higher than 10wt.%.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP03076591.1 | 2003-05-23 | ||
| EP03076590.3 | 2003-05-23 | ||
| EP03076589.5 | 2003-05-23 | ||
| EP03076592.9 | 2003-05-23 | ||
| EP03076590 | 2003-05-23 |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410381352.6A Division CN104262223A (en) | 2003-05-23 | 2004-05-17 | Continuous Process For Preparing Caprolactam |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1795171A true CN1795171A (en) | 2006-06-28 |
Family
ID=34923942
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200480014190 Pending CN1795171A (en) | 2003-05-23 | 2004-05-17 | Continuous process for preparing caprolactam |
| CNB2004800142613A Expired - Lifetime CN100410240C (en) | 2003-05-23 | 2004-05-17 | Continuous process for preparing caprolactam |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2004800142613A Expired - Lifetime CN100410240C (en) | 2003-05-23 | 2004-05-17 | Continuous process for preparing caprolactam |
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| Country | Link |
|---|---|
| CN (2) | CN1795171A (en) |
| ES (1) | ES2363138T3 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102746228A (en) * | 2012-07-23 | 2012-10-24 | 福建锦江石化有限公司 | Method for producing caprolactam |
| CN103896838A (en) * | 2012-12-28 | 2014-07-02 | 帝斯曼知识产权资产管理有限公司 | Method and equipment for continuously producing epsilon-hexanolactam |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101117326B (en) * | 2006-07-31 | 2010-12-22 | 中国石油化工股份有限公司 | Method for preparing aminocaprolactam by catalysis of nicotinic acid in ionic liquid |
| CN103073497B (en) * | 2011-10-26 | 2015-04-22 | 中国石油化工股份有限公司 | Method and device for preparing caprolactam through cyclohexanone oxime rearrangement reaction |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3914217A (en) * | 1974-11-13 | 1975-10-21 | Allied Chem | Process for the preparation of lactams |
| KR970706249A (en) * | 1995-07-20 | 1997-11-03 | 미우라 아끼라 | Process for preparing epsilon-caprolactam (PROCESS FOR THE PREPARATION OF EPSILON-CAPROLACTAM) |
-
2004
- 2004-05-17 ES ES04739353T patent/ES2363138T3/en not_active Expired - Lifetime
- 2004-05-17 CN CN 200480014190 patent/CN1795171A/en active Pending
- 2004-05-17 CN CNB2004800142613A patent/CN100410240C/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102746228A (en) * | 2012-07-23 | 2012-10-24 | 福建锦江石化有限公司 | Method for producing caprolactam |
| CN103896838A (en) * | 2012-12-28 | 2014-07-02 | 帝斯曼知识产权资产管理有限公司 | Method and equipment for continuously producing epsilon-hexanolactam |
| CN103896838B (en) * | 2012-12-28 | 2018-03-23 | Cap Iii 有限公司 | The method and apparatus of continuous production ε caprolactams |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1795172A (en) | 2006-06-28 |
| ES2363138T3 (en) | 2011-07-21 |
| CN100410240C (en) | 2008-08-13 |
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