CN103864689A - Method for preparing caprolactam - Google Patents
Method for preparing caprolactam Download PDFInfo
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- CN103864689A CN103864689A CN201310661049.7A CN201310661049A CN103864689A CN 103864689 A CN103864689 A CN 103864689A CN 201310661049 A CN201310661049 A CN 201310661049A CN 103864689 A CN103864689 A CN 103864689A
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- phlegma
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- ammonium sulfate
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D223/00—Heterocyclic compounds containing seven-membered rings having one nitrogen atom as the only ring hetero atom
- C07D223/02—Heterocyclic compounds containing seven-membered rings having one nitrogen atom as the only ring hetero atom not condensed with other rings
- C07D223/06—Heterocyclic compounds containing seven-membered rings having one nitrogen atom as the only ring hetero atom not condensed with other rings with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D223/08—Oxygen atoms
- C07D223/10—Oxygen atoms attached in position 2
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
- C01C1/00—Ammonia; Compounds thereof
- C01C1/24—Sulfates of ammonium
- C01C1/242—Preparation from ammonia and sulfuric acid or sulfur trioxide
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
- C07D201/02—Preparation of lactams
- C07D201/04—Preparation of lactams from or via oximes by Beckmann rearrangement
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
- C07D201/16—Separation or purification
Abstract
The invention discloses a method for preparing caprolactam, which is a method for purifying the condensate obtained in the step of evaporating and crystallizing a water-containing ammonium sulfate phase, wherein the water-containing ammonium sulfate phase is obtained through a Beckmann rearrangement reaction using cyclohexanone-oxime in the presence of sulfuric acid. The method at least comprises steps of extracting and stripping the water-containing ammonium sulfate phase to obtain the condensate, wherein the condensate can be at least partially purified; the condensate purified by the purifying step can be at least partially led into the process.
Description
Technical field
The present invention relates to a kind of method of preparing hexanolactam, in the method, formed ammoniumsulphate soln and can from described ammoniumsulphate soln, obtain ammonia sulfate crystal and phlegma in crystallisation step.
Background technology
Here " method of hexanolactam " refers to prepare method steps comprehensive of hexanolactam.Therefore, the production method of hexanolactam also comprises those steps that are applied to the intermediates of preparing hexanolactam.Method of the present invention is not limited to arbitrary special lactan.The preferred ε-caprolactam of lactan.
US3,264,060 disclose the method that lactan comprises hexanolactam of producing.In the method, under the existence of sulfuric acid, reset cycloalkanone oxime by Beckmann rearrangement, thereby obtained a kind of neutralized rearrangement mixture containing lactan.Subsequently, under the existence of water, neutralized rearrangement mixture is neutralized with ammoniacal liquor in neutral zone, thereby obtain a kind of mixture that contains the solution and aqeous thick lactan phase of aqueous ammonium sulfate.Then, by mutually separated from one another solution and aqeous aqueous ammonium sulfate thick lactan.
Ammoniumsulphate soln is inputted in vaporizer mutually, in this vaporizer at ammoniumsulphate soln the moisture in mutually by part evaporation sulfate precipitate ammonium crystal simultaneously.In described process, the mother liquor of generation contains remaining unprecipitated ammonium sulfate.Thereby in next processing step, utilize the effect of for example separating centrifuge ammonia sulfate crystal to be separated from mother liquor to reclaim(ed) sulfuric acid ammonium crystal.Then add the remaining mother liquor of thin up, and the mother liquor of dilution is transported to neutral zone.It can be the phlegma that the transpiring moisture condensation of vaporizer is obtained for the water diluting.
WO00/66561 discloses the method for preparing hexanolactam, has formed ammoniumsulphate soln and can obtain ammonia sulfate crystal and phlegma is purified to phlegma simultaneously and returns it to the production process of hexanolactam from described ammoniumsulphate soln in the method in crystallisation step.Described ammoniumsulphate soln is preferably with forming in ammoniacal liquor or aqueous ammonia He during Beckmann rearrangement mixture, and wherein said Beckmann rearrangement mixture is that cyclohexanone-oxime utilizes Beckmann rearrangement to form in the process of hexanolactam to obtain under the existence of sulfuric acid.
The phlegma of not purifying in ammonium sulfate crystallization process is turned back to and in caprolactam production process, causes having higher concentration organic pollutant and produce compared with the hexanolactam of high absorbance, and described data are measured according to ISO7059.Before phlegma turns back to the production technique of hexanolactam, purification phlegma is to produce enough pure hexanolactam.
Can adopt Different treatments to carry out the purification of phlegma, comprise the combination by Activated carbon separation, for example ozonize of oxide treatment or hydrogen peroxide treatment, UV irradiation, ion-exchanger, polymer absorbing agent, biopurification, membrane sepn, extraction or distillation and these technology as described in WO00/66561.
In an option of described method, in the evaporative crystallizer that produces ammonia sulfate crystal, form vaporize water and be condensed into phlegma, this phlegma of purifying, the neutral zone of the neutralized rearrangement mixture that the purification phlegma of this acquisition can be applicable to obtain by Beckmann rearrangement.In the embodiment 1 of WO00/66561, in ammoniacal liquor, add the phlegma of purification and extra deionized water, wherein said ammoniacal liquor is imported into neutral zone.
Have now found that implementing the disclosed purifying technique of WO00/66561 can make the hexanolactam producing have enough low absorbancy, measures according to ISO7059.Therefore, as known to the skilled person, the hexanolactam that polymerization produces and detect nylon-6 with usual method, can produce the nylon-6 of high-quality.
But the method for purification that it is found that the disclosed phlegma of WO00/66561 is not still the method for an efficient economy.Although disclosed method of purification is not removed most pollutent and via the hexanolactam that has produced better quality containing the preferred purification of active-carbon bed strainer in WO00/66561, but utilize the quantity of pollutent in the phlegma of active-carbon bed removal very large, and need the frequency of displacement or regenerated carbon bed too high and uneconomical.
Except pollutent, hexanolactam can evaporate during ammonium sulfate crystallization and due to the existence of hexanolactam in phlegma, hexanolactam also can be by active-carbon bed absorption.Thereby described hexanolactam can improve to the adsorptive power of arbitrary pollutent the frequency that activated carbon beds need to be replaced or regenerate by restricted activity charcoal bed.In addition, due to being abandoned of the gac with crossing, thereby gac can cause the minimizing of hexanolactam ultimate production to increase cost to the absorption of hexanolactam.
As everyone knows, the contaminant problems of hexanolactam is very serious in the time that phlegma returns to caprolactam production process.But, if phlegma is not turned back to the production technique of hexanolactam, just need in technique, add the not water of homology.This can greatly improve the consumption of water, thereby causes the raising of cost and the increase of carrying capacity of environment.
Nowadays we have found a kind of method that reduces pollutant load in phlegma and therefore can maximum degree degree have extended life-span of the strainer using.
Summary of the invention
The present invention relates to a kind of method of preparing hexanolactam, in the method, limited the use of unnecessary water, reduce or eliminated the problem that hexanolactam is pure not and extended to greatest extent life-span of liquor condensate filter.
Target of the present invention is the extraction step by introduce extra ammoniumsulphate soln before crystallization processes and stripping step subsequently and phlegma is purified to realize before phlegma is turned back to preparing process of caprolactam.
Therefore, the invention provides a kind of method that the phlegma obtaining in the evaporative crystallization step of aqueous ammonium sulfate phase is purified, wherein said aqueous ammonium sulfate is mutually under the existence of water, reaction mixture is obtained with ammonia neutralization, this reaction mixture is under the existence of sulfuric acid, to utilize the Beckmann rearrangement of cyclohexanone-oxime to obtain, and said method comprising the steps of:
1) under existing, sulfuric acid carries out the Beckmann rearrangement of cyclohexanone-oxime;
2) with aqueous ammonia neutralization procedure 1) product obtained an aqueous ammonium sulfate phase and a crude caprolactam phase;
3) from the crude caprolactam aqueous ammonium sulfate phase that is separated out;
4) by organic solvent extraction crude caprolactam phase;
5) by the isolated aqueous ammonium sulfate phase of organic solvent extraction;
6) the stripped aqueous ammonium sulfate of stripping obtains a steam stripped aqueous ammonium sulfate phase and the organic solvent phase containing organic substance mutually;
7) steam stripped aqueous ammonium sulfate is carried out to crystallization mutually, this crystallisation step contains evaporation of water;
8) at least in part condensation from the moisture evaporating of step 7) and the phlegma of generation is implemented to purification step at least in part;
9) at least in part the phlegma of purifying in step 8) is introduced to step 2).
The term " at least in part " here refers at least 50% weight, is more preferably at least 75% weight, is most preferably at least 85% weight, is especially at least 90% weight.
Have at present a lot of methods of producing hexanolactam, wherein ammoniumsulphate soln is formed in single or multiple processing step.In production technique, may obtain successively pimelinketone, cyclohexanone-oxime and hexanolactam from benzene or toluene.Under the condition that ammoniumsulphate soln can pass through to exist at water, obtain with for example ammonia neutralization Beckmann rearrangement mixture, wherein said Beckmann rearrangement mixture is obtainable in the process of cyclohexanone-oxime via Beckmann rearrangement formation hexanolactam under the condition existing at sulfuric acid.Ammoniumsulphate soln also can form in the process of preparing azanol, and described azanol is for being formed the reaction of cyclohexanone-oxime by pimelinketone.
The production method that method of the present invention is not limited to any hexanolactam is also not limited to the processing step of any formation ammoniumsulphate soln.The production method of described hexanolactam comprises according to so-called (improved) Raschig technology, based on nitric oxide production hydrogenation technology, based on ammonia oxidation technology and
the method of intermediate prepared by technology.In these production technologies one or more may with the condition existing at sulfuric acid under implement a step and multistep Beckmann rearrangement technology combine.Thereby conventionally form ammoniumsulphate soln with the reaction mixture obtaining after ammonia neutralization Beckmann rearrangement.
Then, from the crude caprolactam aqueous ammonium sulfate phase that is separated out.
For reaching certain purity, the aqueous ammonium sulfate phase that need separate with organic solvent extraction.Preferably, organic solvent can be toluene or benzene, is most preferably wherein benzene.This extraction step has been removed hexanolactam and other organic pollutants mutually from aqueous ammonium sulfate.
Then, thus this stripped aqueous ammonium sulfate phase of stripping has produced a steam stripped aqueous ammonium sulfate phase and an organic solvent phase.Utilize the vapour stream can the stripped aqueous ammonium sulfate phase of stripping.Can following current or the stripped aqueous ammonium sulfate phase of adverse current stripping, and preferred adverse current stripping.For steam, can use any inertia steam, but preferably water steam.Stripping carries out conventionally in packing tower or tray column.
The organic hexanolactam being obtained by organic solvent extraction in step 4) may process to produce high-quality hexanolactam mutually in a lot of approach.One of these approach are included in the phase containing aqueous caprolactam with acquisition that contains organic hexanolactam containing stripping in water, optional hexanolactam is carried out ion exchange treatment, the processing of hydrogenation impurity, distills and anhydrate and finally distillation processing after this strip stage.
Another one approach comprises cleaning containing organic hexanolactam phase, distillation to be removed organic solvent, hydrogenation impurity, distills to anhydrate, distill and remove lighting end and finally distill hexanolactam.
Preferably water or alkaline moisture solution cleaning step 4) in organic solvent extraction obtain organic hexanolactam phase.The alkali concn of described aqueous solution with respect to the water yield generally between 0.01% weight to 5% weight.Preferably, alkali concn is 0.1-2% weight.Preferably water or with the water cleaning that contains the alkaline solution that alkali content is extremely low.Conventionally using alkalescence (alkaline earth) oxyhydroxide and/or carbonate as alkali.Preferably use sodium hydroxide or potassium hydroxide.
Those skilled in the art can determine the water yield of cleaning containing the phase of organic hexanolactam.In general,, with respect to the amount of organic phase, the described water yield is 0.1-5% weight.Preferably, with respect to the amount of organic phase, the described water yield is 0.5-2% weight.Organic phase usually evaporates the water increasing in organic phase and organic phase after cleaning.Thereby form hexanolactam/water mixture.The 85-99.9% weight that in this mixture, the content of hexanolactam is gross weight.So the water yield is 0.1-15% weight here.
The further purification of hexanolactam/water mixture can adopt multiple technological method, for example, use ion-exchanger, sorbent material or method for hydrogenation.Preferably, hydrogenated caprolactam/water mixture is further purified.Utilize art processes can implement hydrogenation.EP0635487 has described a suitable method for hydrogenation.
In order to obtain pure anhydrous hexanolactam, water can be distilled out from hexanolactam.Finally, utilize distillation that high boiling point composition is removed from the dry hexanolactam obtaining.
Another advantage of the present invention is, from step 5) and step 6) mutually recovery and reuse in process of production of organic solvent.
Preferably, step 5) organic solvent at least part of extraction step 4 that can be used for after being condensed) crude caprolactam phase;
Preferably, step 6) organic solvent be recovered mutually after at least in part for purification step 4) crude caprolactam phase.
Preferably, step 6) organic solvent be recovered mutually after and use it at least in part extraction step 5) aqueous ammonium sulfate phase.
Step 9) obtain do not purify phlegma contain organic pollutant, this pollutent comprises the such as material such as cyclohexanone-oxime, aniline, especially octahydro azophenlyene.In the phlegma of not purifying, especially with forming with neutralized rearrangement mixture the organic pollutant of having found high density in ammoniumsulphate soln in ammoniacal liquor or aqueous ammonia, especially the octahydro azophenlyene of high density, wherein said neutralized rearrangement mixture is that the condition cyclohexanone-oxime existing at sulfuric acid generates in hexanolactam process and obtains via Beckmann rearrangement.
Step 9) the above-mentioned pollutent that exists is wondrous in the phlegma that obtains because to crystallisation step 8) add from step 6) aqueous sulfuric acid ammonium solution in do not find described pollutent.In default of the rationale of science, can think that the precursor of above-mentioned organic pollutant is present in the ammoniumsulphate soln that joins in crystallizer and at crystallisation step 7) in formed above-mentioned organic pollutant.In addition, surprisingly step 8) in the phlegma that obtains contain for example organic pollutant of octahydro azophenlyene, described pollutent is at the about 100kPa of 1bar() there is the boiling point of 355-365 ℃ under pressure.There is octahydro azophenlyene in not wishing phlegma in people in the time considering crystallizer operation temperature as described below, because it has higher boiling point.
Steam stripped aqueous ammonium sulfate is implemented to crystallisation step 7 mutually), this step contains evaporation of water.
The method according to this invention, utilizes transpiring moisture to obtain mutually ammonia sulfate crystal from aqueous ammonium sulfate at crystallisation step.This usually realizes in crystallizer.The 18th part 44-55 page of " Perry's Chemical Engineers Handbook " that the example of crystallizer can be write referring to Don W.Green and James O.Maloney for 1997.The service temperature of crystallizer and pressure are not strict.Crystallizer is 20-80 ℃ in temperature conventionally, and pressure is that 20mbar (about 2kPa) operates to the condition of 8bar (about 800kPa).Preferably, the service temperature of crystallizer is 40-130 ℃, and operation pressure is that 50mbar (about 5kPa) is between 2bar (about 200kPa).
The ammonium sulfate concentrations of the ammonium sulfate that adds crystallizer in is mutually generally 25%-50% weight, is especially 35%-45% weight.The chemical oxygen demand (COD) that joins ammonium sulfate phase in crystallizer (is used KMnO
4oxidation style is measured) be generally 0.1-20g/kg, be preferably 0.2-15g/kg, be especially 0.3-10g/kg.
Therefore, in crystallisation step, thereby the condensation in step 8) of the vaporize water of step 7) obtains phlegma.Can realize above-mentioned condensation with for example heat exchanger cooling vaporize water.
The water of condensation of step 8) contains nearly 5mg/kg octahydro azophenlyene, is measured by HPLC (UV E290mm), preferably reaches 3mg/kg octahydro azophenlyene, is most preferably nearly 1mg/kg octahydro azophenlyene.
Then phlegma is implemented to purification step.The purification of phlegma can realize by number of ways.Preferably purify with gac.Also be possible by above-mentioned technology and oxide treatment combination.Oxide treatment for example comprises, ozonize and/or hydrogen peroxide treatment, and/or UV radiation treatment.Utilization well known to a person skilled in the art above-mentioned technology purification of aqueous steam." the Handbook of Separation Process Technology " that edited by Ronald W.Rousseau of John Wiley & Sons publishing company publication in 1987 described a lot of such purification techniquess.With the purification of gac as described in 651-653 page." Chemical Engineer's Handbook " the 4th version of being edited by John H.Perry that McGraw-Hill publishing company publishes has been inquired into absorption and ion-exchanger.
In the present invention, preferably adopt gac to purify.Preferably granular carbon, this is because its size, surface-area and drooping characteristic aspect are more balanced.Especially preferably Norit ROX 0.8, Chemviron Filtrasorb 300, YH Shell 20-40, the Ji Bei Yanshan Mountain, Chengde YH-11 Shell 10-24 of gac company limited and the YH Shell 8-16 of Huaibei gac carbon company.
The reduction of each and any organic composition concentration is all favourable.Preferably, the octahydro azophenlyene that the purification phlegma of step 8) contains <3mg/kg, be more preferably <1mg/kg, be most preferably <0.5mg/kg, especially be <0.02mg/kg, measured by HPLC (UV E290nm).
Preferably, in technique of the present invention, for the consumption of the gac of the phlegma of purifying (fresh or regeneration) for being less than 1kg hexanolactam per ton, more preferably less than 0.7kg hexanolactam per ton, be more preferably and be less than 0.5kg hexanolactam per ton, be most preferably less than 0.25kg hexanolactam per ton.
The phlegma of purifying turns back to hexanolactam and produces and make hexanolactam than not carrying out phlegma purification in technique but the hexanolactam of the identical production technique generation of other steps is purer.The purity that the phlegma of purifying according to the present invention permission phlegma turns back to while hexanolactam in production technique is without any serious reduction.According to the present invention, phlegma is returned and can greatly reduce water consumption.
In method of the present invention, the phlegma of purification can be returned to the different steps in hexanolactam preparation process.The example in phlegma stage that may turn back to of purifying comprises the preparatory phase of preparatory phase, the cyclohexanone-oxime of azanol, neutralization and the hexanolactam purification phase of neutralized rearrangement mixture that Beckmann rearrangement obtains.
One embodiment of the invention have been set forth the hexanolactam obtaining according to the inventive method.
Obtain by the inventive method the hexanolactam producing and preferably contain <3mg/kg octahydro azophenlyene, more preferably <1mg/kg, most preferably <0.5mg/kg, especially be <0.2mg/kg, measure (UV E290nm) by HPLC.
Therefore, we can find to work as for economic aim is by the overtime of trying one's best the duration of service of gac, extraction aqueous sulfuric acid ammonium solution, the concentration of carrying out subsequently the stripped aqueous sulfuric acid ammonium solution of stripping and part being evaporated to the phlegma producing after steam stripped aqueous sulfuric acid ammonium solution and carries out purification and can greatly reduce octahydro azophenlyene in the concentration of concentration, particularly unsaturated compounds of organic pollutant and phlegma.
Accompanying drawing explanation
The present invention more fully explains by following figure.
Fig. 1 has described prior art, as WO00/66561 institute example.
Fig. 2 has set forth the embodiment of the inventive method.
In Fig. 1, add Beckmann rearrangement mixture [1] and aqueous ammonia [4] to neutral zone [A].In neutral zone [A], obtain the neutralise mixt that contains aqueous sulfuric acid ammonium solution and moisture crude caprolactam.Carry neutralise mixt [5] to separator [B], aqueous sulfuric acid ammonium solution and moisture crude caprolactam are separated from each other by being separated there.Moisture crude caprolactam [6] and aqueous sulfuric acid ammonium solution [7] leave separator [B].Ammoniumsulphate soln [7] enters crystallizing field [E] subsequently.One or more crystallizers and one or more liquid-brilliant separating device are contained in crystallizing field [E].The ammonia sulfate crystal that crystallizing field [E] forms leaves crystallizing field [E] with streamer [13].Optionally, remove the mother liquor in streamer [17].The water condensation of crystallizing field [E] evaporation is condensed into phlegma.Phlegma [14] is transported to adsorption zone [F].Adsorption zone [F] is made up of one or more equipment that is full of gac.
From adsorption zone, [F] discharges the phlegma [15] of purifying.In the phlegma [15] of purifying, add deionized water [16], thereby obtain the current [3] that mix.Add gaseous state or aqueous ammonia [2] to streamer [3], thereby obtain the aqueous ammonia [4] that can be used for neutral zone [A].Utilize afterwards extraction purification of aqueous crude caprolactam [6] (Fig. 1 does not show) in organic solvent.
In Fig. 2, add Beckmann rearrangement mixture [1] and aqueous ammonia [4] to neutral zone [A].In neutral zone [A], obtain the neutralise mixt that contains aqueous sulfuric acid ammonium solution and moisture crude caprolactam.Carry neutralise mixt [5] to separator [B], aqueous sulfuric acid ammonium solution and moisture crude caprolactam are separated from each other by being separated there.Moisture crude caprolactam [6] and aqueous sulfuric acid ammonium solution [7] leave separator [B].In extractor [C], use the organic solvent extraction aqueous sulfuric acid ammonium solution [7] joining in [8].The organic streamer that contains organic solvent, hexanolactam and organic pollutant is left by [9] and for the extraction (Fig. 2 does not show) of moisture crude caprolactam.The stripped aqueous sulfuric acid ammonium solution of stripping [10] in stripping tower [D] afterwards.Remove any remaining organic solvent and after condensation, can use it for the extraction of moisture crude caprolactam or the extraction (Fig. 2 does not show) of aqueous sulfuric acid ammonium solution by line [11].
Steam stripped ammoniumsulphate soln [12] enters crystallizing field [E].One or more crystallizers and one or more liquid-brilliant separating device are contained in crystallizing field [E].The ammonia sulfate crystal that crystallizing field [E] forms leaves crystallizing field [E] with streamer [13].Optionally, remove the mother liquor in streamer [17].By the water-cooled phlegma that congeals into of crystallizing field [E] evaporation.Phlegma [14] is transported to adsorption zone [F].Adsorption zone [F] is made up of one or more equipment that is full of gac.
From adsorption zone, [F] discharges the phlegma [15] of purifying.In the phlegma [15] of purifying, add deionized water [16], thereby obtain the current [3] that mix.
Add gaseous state or aqueous ammonia [2] to streamer [3], thereby obtain aqueous ammonia [4], this aqueous ammonia [4] can be used for neutral zone [A] subsequently.
Then use organic solvent extraction purification of aqueous crude caprolactam [6] (Fig. 2 does not show).
Embodiment
The present invention further illustrates by following embodiment, but is not limited to this.
In the present embodiment, described method as shown in Figure 2.
According to DSM
in the business cyclohexanone-oxime production plant of technical work, utilize hydrogen that the nitrate reduction that is dissolved in aqueous solution is become to azanol.The azanol obtaining reacts with pimelinketone and produces cyclohexanone-oxime.After purification cyclohexanone-oxime, thereby being mixed with excessive oleum, the cyclohexanone-oxime of acquisition converts thereof into hexanolactam (17 tons of hexanolactams of average production per hour).Add Beckmann rearrangement mixture [1] and the aqueous ammonia [4] of acquisition to neutral zone [A].The temperature of neutral zone [A] remains on 50 ℃.Obtain at neutral zone [A] neutralise mixt that contains aqueous ammonium sulfate and moisture crude caprolactam.The pH of neutralise mixt is 4.5.
By neutralise mixt [5] input separator [B], aqueous sulfuric acid ammonium solution and moisture crude caprolactam are separated from each other by being separated in separator.Crude caprolactam phase streamer [6] is made up of the water of 30% weight and the hexanolactam of 70% weight, and aqueous ammonium sulfate [7] phase streamer leaves separator [B] simultaneously, and this aqueous ammonium sulfate is made up of the ammonium sulfate of 42% weight and the water of 58% weight.
Aqueous ammonium sulfate [7] the mutually content of middle hexanolactam is 1% weight.Aqueous ammonium sulfate [7] extracts and adds almost purified petroleum benzin by line [8] simultaneously in the extractor [C] of counter-current operation.The organic streamer that contains benzene, hexanolactam and organic pollutant leaves extractor [C] the extraction for crude caprolactam by line [9].
Stripped aqueous ammonium sulfate is left and is entered subsequently steam stripped tower [D] by line [10] from the bottom of extractor [C].The COD(KMnO of stripped aqueous sulfuric acid ammonium solution [10]
4the chemical oxygen demand (COD) that oxidation style is measured) be 2250ppm weight.Benzene in stripped aqueous sulfuric acid ammonium solution [10] and the concentration of hexanolactam are respectively 35 and 30ppm weight.In steam stripped tower [D], remove nearly all benzene by line [11].The benzene of removing by line [11] reclaims and again utilizes in the process of purification hexanolactam and ammonium sulfate phase.In steam stripped aqueous ammonium sulfate [12], the content of benzene is lower than 0.1ppm weight.
Then steam stripped aqueous ammonium sulfate [12] enters crystallizing field [E].Crystallizing field [E] is made up of one group of Oslo type evaporative crystallizer, and its service temperature is 50-110 ℃, pressure be 100mbar (about 10kPa) between 1.1bar (about 110kPa) and separating centrifuge as liquid-brilliant separating device.
The ammonia sulfate crystal that crystallizing field [E] forms leaves crystallizing field [E] with streamer [13].Remove the mother liquor in streamer [17].By the water-cooled of the crystallizing field evaporation phlegma [14] that congeals into.In phlegma [14], the concentration of octahydro azophenlyene is 0.52mg/kg, is measured by HPLC (UV E290nm).Adsorption zone [F] is made up of the pillar that is full of activated carbon granule of two parallel runnings.Norit ROX0.8(steam activation, acid elution, the gac of extrusion pressing type) as sorbent material.The effective volume that flows into each pillar is 0.5m
3gac phlegma per ton (=1800m per hour
3gac phlegma per ton is per second).The temperature of phlegma [14] is about 65 ℃.The amount of the phlegma of activated carbon treatment is month 2.7 tons of hexanolactams per ton.
From adsorption zone, [F] discharges the phlegma [15] of purifying.In the phlegma [15] of purifying, the concentration of octahydro azophenlyene is lower than 0.01mg/kg, is measured by HPLC (UV E290nm).
In the phlegma [15] of purifying, add deionized water [16], thereby obtain current [3].
Then purify by the moisture crude caprolactam of line [6] removal according to the technology in WO98/49140.The hexanolactam obtaining has the octahydro azophenlyene of concentration lower than 0.01mg/kg, is measured by HPLC (UV E290nm).
Through 36 months by a definite date, the gac of adsorption zone [F] can be reduced to the concentration of octahydro azophenlyene in phlegma [14] lower than 0.01mg/kg(and be measured by HPLC (UV E290nm)).During this period of time, with the gac in new material substitution adsorption zone [F].In the described time period, produce the hexanolactam of high-quality.The consumption of fresh gac is about 0.1kg hexanolactam per ton.
Comparative Examples A
As described in Example 1, unique difference is stripped aqueous sulfuric acid ammonium solution [10] not to be carried out to stripping the method.Stripped aqueous sulfuric acid ammonium solution [10] directly joins in crystallizing field [E].The aqueous sulfuric acid ammonium solution [10] of extraction has the every m of average about 2250gram
3the COD(KMnO of aqueous sulfuric acid ammonium solution of extraction
4the chemical oxygen demand (COD) that oxidation style is measured) content.This comprises the benzene of the 35ppm weight of HPLC (UV E290nm) mensuration.
Water in crystallizing field [E] is evaporated subsequently to be condensed.Except water, volatile compound is also all evaporated and is condensed.Phlegma [14] also contains the volatile compound of condensation except containing water, comprises benzene and octahydro azophenlyene.
In described comparative example, simulate the saturated time of gac that makes adsorption zone [F].Saturated gac is no longer purified to the phlegma of input.In general, gac occurring completely has just had been found that before saturated and has penetrated (incomplete absorption).
Make gac in adsorption zone [F] required time that reaches capacity be less than 2100hrs.This is the continuous production lower than 3 months.
By the duration of service (36 months) of gac in the adsorption zone [F] described in embodiment 1 and result (3 months) contrast that Comparative Examples A is simulated, clearly show and introduce steam stripped device [D] and prolongation duration of service of gac can be exceeded to 12 times.The consumption of fresh gac is about 1.2kg hexanolactam per ton.
Comparative example B
As described in Example 1, unique difference is aqueous sulfuric acid ammonium solution [7] do not extracted and also it does not carried out to stripping subsequently the method.Described method as shown in Figure 1.Add aqueous sulfuric acid ammonium solution [7] to crystallizing field [E].Organic content in aqueous sulfuric acid ammonium solution [7] is on average about 1% weight.Described organic substance is mainly hexanolactam.
The interior water in crystallizing field [E] is evaporated subsequently to be condensed.Except water, volatile compound is also all evaporated and is condensed.Evaporation composition and any residuals from crystallizer are all finally in phlegma [14].Therefore, phlegma [14] can contain water and residual component, comprises the volatile component of hexanolactam and condensation, comprises octahydro azophenlyene.Analyze and show that hexanolactam and 6-aminocaprolc acid calculate together between 1000 to 2000ppm weight.(6-aminocaprolc acid is the linear response product of hexanolactam and water).
In described comparative example, simulate the saturated time of gac that makes adsorption zone [F].Saturated gac is no longer purified to the phlegma of input.In general, gac occurring completely has just had been found that before saturated and has penetrated (incomplete absorption).
Make gac in adsorption zone [F] required time that reaches capacity be less than 125hrs.This is only the continuous production of 5 days.
By the duration of service of gac in the adsorption zone [F] described in embodiment 1 and result contrast that comparative example B simulates, clearly show and introduce extractor [C] and steam stripped tower [D] can exceed 200 times by prolongation duration of service of gac.The consumption of fresh gac is about 22kg hexanolactam per ton.
Claims (14)
1. the method for the phlegma obtaining in the evaporative crystallization step of a purification of aqueous ammonium sulfate phase, wherein said aqueous ammonium sulfate is to obtain with ammonia neutralization reaction mixture under the existence of water mutually, this reaction mixture is under the existence of sulfuric acid, to utilize the Beckmann rearrangement of cyclohexanone-oxime to obtain, and said method comprising the steps of:
1) under existing, sulfuric acid carries out the Beckmann rearrangement of cyclohexanone-oxime;
2) with aqueous ammonia neutralization procedure 1) product obtained an aqueous ammonium sulfate phase and a crude caprolactam phase;
3) isolate aqueous ammonium sulfate phase from crude caprolactam mutually;
4) by organic solvent extraction crude caprolactam phase;
5) produce mutually stripped aqueous ammonium sulfate phase and comprise organic organic phase with the isolated aqueous ammonium sulfate of organic solvent extraction;
6) the stripped aqueous ammonium sulfate of stripping obtains a steam stripped aqueous ammonium sulfate phase and the phase containing organic substance mutually;
7) steam stripped aqueous ammonium sulfate is carried out to crystallization mutually, this step contains evaporation of water;
8) implement at least in part purification step by the condensate moisture of the evaporation from step 7) and by the phlegma of generation at least in part;
9) at least in part the phlegma of purifying in step 8) is introduced to step 2).
2. method according to claim 1 is wherein carried out the neutralization of step 1) product in water with ammonia.
3. method according to claim 1, wherein carries out the extraction of isolated aqueous ammonium sulfate phase with benzene.
4. method, wherein step 5 according to claim 1) organic phase can be used for extraction step 4) crude caprolactam phase;
5. method, wherein recycling step 6 according to claim 1) the phase containing organic substance and use it at least in part purification step 4) crude caprolactam phase.
6. method, wherein recycling step 6 according to claim 1) the phase containing organic substance and use it at least in part extraction step 5) aqueous ammonium sulfate phase.
7. method according to claim 1, wherein utilizes active-carbon bed purification step 8) phlegma.
8. method according to claim 1, wherein, for purification step 8) the fresh gac of phlegma or the consumption of regenerated carbon that obtain be to be less than 1kg hexanolactam per ton.
9. method according to claim 1, wherein, for purification step 8) the fresh gac of phlegma or the consumption of regenerated carbon that obtain be to be less than 0.5kg hexanolactam per ton.
10. method according to claim 1, wherein the phlegma of step 8) contains 5mg/kg octahydro azophenlyene altogether.
11. methods according to claim 1, the octahydro azophenlyene that wherein the purification phlegma of step 8) contains <3mg/kg.
12. methods according to claim 1, the octahydro azophenlyene that wherein the purification phlegma of step 9) contains <0.2mg/kg.
13. hexanolactams that obtain according to method described in claim 1-12.
The octahydro azophenlyene that 14. hexanolactams according to claim 13 contain <3mg/kg.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105061311A (en) * | 2015-08-13 | 2015-11-18 | 江苏三鼎石化科技有限公司 | Caprolactam refining technology |
| CN107118156A (en) * | 2017-06-26 | 2017-09-01 | 山东清创化工有限公司 | A kind of caprolactam separation and purification technique |
| CN108341763A (en) * | 2018-04-24 | 2018-07-31 | 河北美邦工程科技股份有限公司 | A kind of caprolactam crystallization purifications |
| CN115052835A (en) * | 2020-02-07 | 2022-09-13 | Cap Iii 有限公司 | Industrial scale ammonium sulfate production |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54128589A (en) * | 1978-03-29 | 1979-10-05 | Mitsubishi Chem Ind Ltd | Recovery of epsilon-caprolactam |
| CN1235595A (en) * | 1996-09-02 | 1999-11-17 | Dsm有限公司 | Preparation of 'epsilon'-caprolactam |
| WO2000066561A1 (en) * | 1999-04-29 | 2000-11-09 | Dsm N.V. | Process for the preparation of caprolactam |
| CN1332158A (en) * | 2000-06-27 | 2002-01-23 | 住友化学工业株式会社 | Prep. of epsilon-hexanolactam |
| CN101613311A (en) * | 2008-06-25 | 2009-12-30 | 中国石油化学工业开发股份有限公司 | From neutralized rearrangement mixture, reclaim the system and method for hexanolactam |
| CN102234248A (en) * | 2010-04-23 | 2011-11-09 | 中国石油化工股份有限公司 | Impurity extraction method for caprolactam production |
| CN102452982A (en) * | 2010-10-15 | 2012-05-16 | 中国石油化工股份有限公司 | Method for purifying epsilon-caprolactam and method for preparing epsilon-caprolactam |
| CN102584703A (en) * | 2012-01-16 | 2012-07-18 | 武汉大学 | Extraction method for removing trace impurities from caprolactam water solution |
| CN102675176A (en) * | 2012-05-31 | 2012-09-19 | 中国天辰工程有限公司 | Method for producing caprolactam by taking high-purity benzene as raw material |
-
2013
- 2013-12-09 CN CN201310661049.7A patent/CN103864689B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54128589A (en) * | 1978-03-29 | 1979-10-05 | Mitsubishi Chem Ind Ltd | Recovery of epsilon-caprolactam |
| CN1235595A (en) * | 1996-09-02 | 1999-11-17 | Dsm有限公司 | Preparation of 'epsilon'-caprolactam |
| WO2000066561A1 (en) * | 1999-04-29 | 2000-11-09 | Dsm N.V. | Process for the preparation of caprolactam |
| CN1332158A (en) * | 2000-06-27 | 2002-01-23 | 住友化学工业株式会社 | Prep. of epsilon-hexanolactam |
| CN101613311A (en) * | 2008-06-25 | 2009-12-30 | 中国石油化学工业开发股份有限公司 | From neutralized rearrangement mixture, reclaim the system and method for hexanolactam |
| CN102234248A (en) * | 2010-04-23 | 2011-11-09 | 中国石油化工股份有限公司 | Impurity extraction method for caprolactam production |
| CN102452982A (en) * | 2010-10-15 | 2012-05-16 | 中国石油化工股份有限公司 | Method for purifying epsilon-caprolactam and method for preparing epsilon-caprolactam |
| CN102584703A (en) * | 2012-01-16 | 2012-07-18 | 武汉大学 | Extraction method for removing trace impurities from caprolactam water solution |
| CN102675176A (en) * | 2012-05-31 | 2012-09-19 | 中国天辰工程有限公司 | Method for producing caprolactam by taking high-purity benzene as raw material |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105061311A (en) * | 2015-08-13 | 2015-11-18 | 江苏三鼎石化科技有限公司 | Caprolactam refining technology |
| CN105061311B (en) * | 2015-08-13 | 2017-12-01 | 江苏三鼎石化科技有限公司 | A kind of process for refining of caprolactam |
| CN107118156A (en) * | 2017-06-26 | 2017-09-01 | 山东清创化工有限公司 | A kind of caprolactam separation and purification technique |
| CN108341763A (en) * | 2018-04-24 | 2018-07-31 | 河北美邦工程科技股份有限公司 | A kind of caprolactam crystallization purifications |
| CN108341763B (en) * | 2018-04-24 | 2020-12-01 | 河北美邦工程科技股份有限公司 | Caprolactam crystallization and purification method |
| CN115052835A (en) * | 2020-02-07 | 2022-09-13 | Cap Iii 有限公司 | Industrial scale ammonium sulfate production |
| CN115052835B (en) * | 2020-02-07 | 2024-05-07 | Capiii有限公司 | Industrial-scale ammonium sulfate production |
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|---|---|
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