CN108863833A - 2- nitro -4- acetyl-anisidine, its separation method and device - Google Patents
2- nitro -4- acetyl-anisidine, its separation method and device Download PDFInfo
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- CN108863833A CN108863833A CN201810729956.3A CN201810729956A CN108863833A CN 108863833 A CN108863833 A CN 108863833A CN 201810729956 A CN201810729956 A CN 201810729956A CN 108863833 A CN108863833 A CN 108863833A
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C231/00—Preparation of carboxylic acid amides
- C07C231/12—Preparation of carboxylic acid amides by reactions not involving the formation of carboxamide groups
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C231/00—Preparation of carboxylic acid amides
- C07C231/22—Separation; Purification; Stabilisation; Use of additives
- C07C231/24—Separation; Purification
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C233/00—Carboxylic acid amides
- C07C233/01—Carboxylic acid amides having carbon atoms of carboxamide groups bound to hydrogen atoms or to acyclic carbon atoms
- C07C233/16—Carboxylic acid amides having carbon atoms of carboxamide groups bound to hydrogen atoms or to acyclic carbon atoms having the nitrogen atom of at least one of the carboxamide groups bound to a carbon atom of a hydrocarbon radical substituted by singly-bound oxygen atoms
- C07C233/24—Carboxylic acid amides having carbon atoms of carboxamide groups bound to hydrogen atoms or to acyclic carbon atoms having the nitrogen atom of at least one of the carboxamide groups bound to a carbon atom of a hydrocarbon radical substituted by singly-bound oxygen atoms with the substituted hydrocarbon radical bound to the nitrogen atom of the carboxamide group by a carbon atom of a six-membered aromatic ring
- C07C233/25—Carboxylic acid amides having carbon atoms of carboxamide groups bound to hydrogen atoms or to acyclic carbon atoms having the nitrogen atom of at least one of the carboxamide groups bound to a carbon atom of a hydrocarbon radical substituted by singly-bound oxygen atoms with the substituted hydrocarbon radical bound to the nitrogen atom of the carboxamide group by a carbon atom of a six-membered aromatic ring having the carbon atom of the carboxamide group bound to a hydrogen atom or to a carbon atom of an acyclic saturated carbon skeleton
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Abstract
The present invention is about a kind of 2- nitro -4- acetyl-anisidine, its separation method and device, which be made after carrying out mixed acid nitrification as raw material using p acetamidoanisol, which specifically includes following steps：Step 1, the mixture after p acetamidoanisol and mixed acid nitrification is diluted with water to h 2 so 4 concentration is 28%~38%；Step 2, the mixture after diluting in step 1 is cooled to -25 DEG C~-5 DEG C, carries out the precipitation of crude product；Step 3, mixture after cooling in step 2 is filtered, solid phase is crude product 2- nitro -4- acetyl-anisidine.Waste and the big problem of subsequent acid pickle processing difficulty present method solves product in the prior art, and the product particle size that can control precipitation is conducive to the sedimentation and separation of product at 50~200 μm.
Description
Technical field
The present invention relates to the separation methods and equipment therefor of a kind of organic nitration product, and in particular to 2- nitro -4- acetyl
The method and equipment therefor that aminoanisole is precipitated from sulfuric acid.
Background technique
2- amino -4- acetyl-anisidine is the important intermediate of a variety of disperse dyes, and structural formula is as follows：
Producing one of main technique of 2- amino -4- acetyl-anisidine is using paraphenetidine as raw material, with ice
Acetic acid carries out acetylization reaction, and nitration mixture (sulfuric acid and nitric acid) progress nitration reaction is added in reaction product, and (sulfuric acid is reaction medium, no
Participate in reaction), nitration product is passed through hydrogen in the presence of a catalyst and is restored, and finally obtains product 2- amino -4- acetyl ammonia
Base methyl phenyl ethers anisole.The quality of product not only can be improved compared with traditional handicraft (iron powder reducing) for the technique, while can increase product
Yield.But the sulfuric acid of high concentration is applied in the nitration reaction of this technique, and in order to nitration product is precipitated from solution with
The hydro-reduction of next step is carried out, current usual way is to be diluted with water reaction product, i.e., to nitration product (concentrated sulfuric acid, 2-
Nitro -4- acetyl-anisidine, water) it is diluted with water, since 2- nitro -4- acetyl-anisidine (NMA) is soluble in dense sulphur
Acid and be insoluble in water, therefore, after being diluted with water reaction product NMA can be made to start gradually to be precipitated, and the water being added is more, i.e. sulfuric acid
Concentration is lower, and the amount of precipitation of product NMA is more, also therefore, can generate a large amount of acid-bearing wastewater in the process.Ordinary circumstance
Under, to enable NMA to be sufficiently precipitated, the useless containing acid of 5% sulfuric acid can be contained to this by the concentration dilution of sulfuric acid to 5% or so
The post-processing approach of water is mainly the following：It recycles, neutralisation treatment and be applied directly to sulfuric acid quality requirement after concentration
In not high other production processes, wherein the method recycled after concentration can consume more energy, in actual production not
Ideal economic benefit can be generated；Lime mainly is added for neutralisation treatment or salkali waste is neutralized, and is to useless there are also enterprise
Be passed through in acid solution ammonia or be added liquefied ammonia production ammonium sulfate, but these methods all can secondary generation solid waste, can not be effective
Thoroughly solve problem of environmental pollution；And sulfuric acid concentration after diluting is lower, amount is big and contains organic impurities, it is difficult to be matched to conjunction
Other suitable production processes, and also contain organic impurities in the Waste Sulfuric Acid after dilution, it is also possible to the production process for using it is produced
Raw adverse effect, therefore the third method is also and non-process dilute sulfuric acid completely safe plan.As it can be seen that how to generate in processing production process
Dilute sulfuric acid up to the present there are no very good solution methods, also, the sulfuric acid concentration after being diluted is lower, the corruption to equipment
Corrosion is also bigger, to production process and a big hidden danger.
Secondly, above-mentioned NMA separation method is usually precipitated under normal temperature conditions, precipitation process takes a long time and analyses
Product granularity out is smaller, is easy to form suspension in the solution, is more time-consuming so as to cause subsequent precipitating and filter process
And the product residual rate in acid solution is also larger.
In view of the above problems, how to enable that product NMA is largely precipitated and sulfuric acid concentration will not be diluted to very low and product
Granularity cannot be too small, is particularly important.For Chen Jia in " 2- nitro -4- acetyl-anisidine Study on Crystallization Process ", Ningxia is big
Master thesis is learned, in 12-17 page, 38-50 pages and page 62, when disclosing sulfuric acid mass fraction and being greater than 60%, the dissolution of NMA
Degree starts to increase rapidly, and when sulfuric acid mass fraction is less than or equal to 60%, with the reduction of sulfuric acid mass fraction, NMA's is molten
Xie Du reduces seldom.Illustrate that industrial dilute sulphuric acid concentration has been precipitated to 60%, the NMA overwhelming majority, and dilute sulphuric acid solution
It to concentration 60%, is retained in sulfuric acid solution containing NMA3.5%, NMA, and as sulfuric acid solution concentration cycles are to nitrifying workshop section
It continues to use, has no waste.Although this method can energy saving and water resource, in the concentration engineering of sulfuric acid, sulfuric acid
When concentration reaches certain value, there can be very strong dehydration property, being mixed in organic matter therein can be carbonized, not only cannot be sharp again
With can also be brought a great deal of trouble to the concentration of sulfuric acid, and be 10,000 tons/year of enterprise, 3.5% loss for industrial production capacity
350 tons of 2- nitro -4- acetyl-anisidines will be wasted by meaning enterprise every year, therefore this method is industrially and infeasible；
By the disclosure of the paper it is found that it does not recommend that product is precipitated under conditions of 0 DEG C, even and at 0 DEG C
Product is precipitated, when by sulfuric acid solution concentration dilution to 60%, wherein still containing 0.85% NMA, this ratio is in actual work
It is still not to be allowed in industry production.Meanwhile in order to overcome the problems, such as that product precipitation granularity is small, which is utilized Metastable zone reason
By having studied influence of the rate of temperature fall to product particle size size under conditions of 0 DEG C or more, but be precipitated under the conditions of in this way
The effect is unsatisfactory for product grain size.
Summary of the invention
It is existing to solve the purpose of the present invention is to provide a kind of separation method of 2- nitro -4- acetyl-anisidine
The problem of 2- nitro -4- acetyl-anisidine cannot sufficiently be precipitated and undersized is precipitated in technology.
The object of the invention is also to provide a kind of devices that 2- nitro -4- acetyl-anisidine is precipitated.
The object of the invention is also to provide a kind of 2- nitro -4- acetyl-anisidines being precipitated by the above method.
To achieve the above object, the present invention provides a kind of separation method of 2- nitro -4- acetyl-anisidine, the 2- nitre
Base -4- acetyl-anisidine is made after carrying out mixed acid nitrification as raw material using p acetamidoanisol, separation method tool
Body includes the following steps：
Step 1, p acetamidoanisol is diluted with water to h 2 so 4 concentration with the mixture after mixed acid nitrification is
28%~38%；
Step 2, the mixture after diluting in step 1 is cooled to -25 DEG C~-5 DEG C, carries out the precipitation of crude product；
Step 3, the mixture after cooling in step 2 for having carried out crude product precipitation is filtered, solid phase is crude product
2- nitro -4- acetyl-anisidine.
The separation method of 2- nitro -4- acetyl-anisidine of the present invention, it is preferred that mixture passes through in step 1
The concentration of sulfuric acid is 30%~36% after dilution.
The separation method of 2- nitro -4- acetyl-anisidine of the present invention, it is preferred that after being diluted in step 2
Mixture is cooled to -20 DEG C~-10 DEG C.
The separation method of 2- nitro -4- acetyl-anisidine of the present invention, it is preferred that in step 2 to dilution after
Mixture it is cooling during, during -5 DEG C are cooled to -15 DEG C, rate of temperature fall is 3~6 DEG C/h, -15 DEG C be cooled to -
During 25 DEG C, rate of temperature fall is 2~4 DEG C/h.
The separation method of 2- nitro -4- acetyl-anisidine of the present invention, it is preferred that in step 2 to dilution after
Mixture it is cooling during, during -10 DEG C are cooled to -20 DEG C, rate of temperature fall is 3~6 DEG C/h.
The separation method of 2- nitro -4- acetyl-anisidine of the present invention, wherein the analysis of crude product in step 2
The time is 40~100min out.
The separation method of 2- nitro -4- acetyl-anisidine of the present invention, wherein be cooled to described in step 2
Indirectly cooling, cooling medium is liquid nitrogen or dry ice.
The separation method of 2- nitro -4- acetyl-anisidine of the present invention, wherein water described in step 1 is to steam
Distilled water.
To achieve the above object, the present invention also provides a kind of device that 2- nitro -4- acetyl-anisidine is precipitated, applications
In the separation method of above-mentioned 2- nitro -4- acetyl-anisidine, including：
One thinning tank, for diluting p acetamidoanisol and the mixture after mixed acid nitrification；
One cooling device, for the mixture after the p acetamidoanisol and mixed acid nitrification after cooling dilution；
The mixing after the p acetamidoanisol and mixed acid nitrification of crude product has been precipitated for separating in one filter device
Object；And
One controller, for control in dilution device dilute after p acetamidoanisol and mixed acid nitrification after mixing
The concentration of sulfuric acid, cooling temperature and rate of temperature fall in cooling device in object.
The device of the present invention that 2- nitro -4- acetyl-anisidine is precipitated, it is preferred that the cooling in cooling device
Medium is liquid nitrogen or dry ice.
The present invention also provides a kind of 2- nitro -4- acetyl-anisidines that method described above is precipitated.
Beneficial effects of the present invention：
With the method for the invention it is achieved that product 2- nitro -4- acetyl-anisidine is higher by (28% in sulfuric acid concentration
~38%) it is largely precipitated in the case where, the residual quantity of product can be controlled 0.0055% hereinafter, solving existing in acid pickle
Have in technology because in acid pickle product residual quantity it is high caused by asking of increasing of product waste and subsequent acid pickle processing difficulty
Topic, and the product particle size that can control precipitation is conducive to the sedimentation and separation of product at 50~200 μm.
Detailed description of the invention
Fig. 1 is the technological process block-diagram of 2- nitro -4- acetyl-anisidine purification process of the present invention.
Fig. 2 is the flow chart of the recovery method of nitrating wasting acid of the present invention.
Fig. 3 is same temperature condition, the precipitation situation schematic diagram of product NMA under different sulfuric acid concentrations；
Fig. 4 is identical sulfuric acid concentration, the precipitation situation schematic diagram of product NMA under different Precipitation Temperatures.
Wherein, appended drawing reference：
8 strippers
18 phase separators
26,28,30,32,34 evaporator
26A, 28A, 30A, 32A, 34A overhead fraction condenser
R101 nitration reaction kettle
E105 heat exchanger
V101 level-one steams sour kettle
V102 second level steams sour kettle
V103 three-level steams sour kettle
V104 level Four steams sour kettle
V105 spent acidic water pot
Y101 filter device
T101 level-one foam removal tower
T102 second level foam removal tower
T103 three-level foam removal tower
T104 level Four foam removal tower
One device for cooling of E101a level-one
Two device for cooling of E101b level-one
One device for cooling of E102a second level
Two device for cooling of E102b second level
One device for cooling of E103a three-level
Two device for cooling of E103b three-level
One device for cooling of E104a level Four
Two device for cooling of E104b level Four
V1~V4 alkali liquid tank
Specific embodiment
It elaborates below to the embodiment of the present invention：The present embodiment carries out under the premise of the technical scheme of the present invention
Implement, gives detailed embodiment and process, but protection scope of the present invention is not limited to following embodiments, following implementation
Test method without specific conditions in example, usually according to normal condition, involved concentration, if being matter without specified otherwise
Measure concentration.
2- nitro -4- acetyl-anisidine according to the present invention is mixed by raw material of p acetamidoanisol
It is made after acid nitrification, the process that the present invention nitrifies the mixture of p acetamidoanisol and nitric acid, sulfuric acid is not
It is particularly limited, can realize the method that p acetamidoanisol and nitration mixture carry out nitration reaction, example in the prior art
It can such as carry out as follows：
By 98% concentrated nitric acid and 93% concentrated sulfuric acid example 1 in molar ratio:1~7:1 is configured to nitration mixture, by acetparaminosalol
Methyl phenyl ethers anisole is added in nitration reaction kettle, is then slowly added dropwise and carries out nitration reaction, p acetamidoanisol and nitric acid into nitration mixture
Molar ratio be 1:1~1:1.5, in 50~100 DEG C of progress nitration reactions, the reaction time is 0.2~4h.
After the completion of nitration reaction, reaction product 2- nitro -4- acetyl-anisidine is dissolved in the concentrated sulfuric acid, to make 2- nitre
Base -4- acetyl-anisidine is separated with the concentrated sulfuric acid, and prior art is that will contain product 2- nitro -4- acetylamino at room temperature
The concentrated sulfuric acid of methyl phenyl ethers anisole is diluted with water, until product 2- nitro -4- acetyl-anisidine almost all is precipitated, sulfuric acid at this time
Concentration is 5% or so.
The separation method of 2- nitro -4- acetyl-anisidine provided by the present invention, specially：It first will be to acetyl ammonia
It is 28%~38% that mixture after base methyl phenyl ethers anisole and mixed acid nitrification, which adds distilled water to be diluted to h 2 so 4 concentration,；Then pass through liquid
Mixture after dilution is cooled to -25 DEG C~-5 DEG C by nitrogen or dry ice indirectly, carries out the precipitation of crude product, be precipitated the time be 40~
100min, be precipitated after the completion of filter solid phase 2- nitro -4- acetyl-anisidine crude product, liquid phase is acid pickle.
In order to enable 2- nitro -4- acetyl-anisidine to be sufficiently precipitated, the concentration for just having to reduce sulfuric acid (will make
Sulfuric acid concentration is down to 5% or so), and the concentration for reducing sulfuric acid increases the difficulty of subsequent acid processing, also will increase to equipment
Corrosivity, and the concentration of acid solution will be improved in order to simplify subsequent sour treatment process, and can thus make acid solution
In 2- nitro -4- acetyl-anisidine content increase, lead to the waste of product, while also will increase the post-processing of acid solution
(there are coking problems) in difficulty, but if sulfuric acid concentration makes for 28%~38% can under the conditions of -25 DEG C~-5 DEG C of temperature
So that 2- nitro -4- acetyl-anisidine almost all is precipitated, 2- nitro -4- acetyl-anisidine is residual in acid solution
Allowance is below 0.0055%.
To keep the product grain granularity being precipitated bigger, preferably in the cooling procedure to mixture, -5 DEG C are cooled to -15 DEG C
During, rate of temperature fall is 3~6 DEG C/h, and during -15 DEG C are cooled to -25 DEG C, rate of temperature fall is 2~4 DEG C/h.
Eduction rate, energy consumption and subsequent dilute sulfuric acid processing difficulty, the sulfuric acid concentration after dilution for comprehensively considering product may be used also
Think 30%~36%, it can also be -20 DEG C~-10 DEG C that cooling temperature, which is precipitated,.
The present invention also provides a kind of devices that 2- nitro -4- acetyl-anisidine is precipitated, applied to above-mentioned 2- nitro -
The separation method of 4- acetyl-anisidine, including：
One thinning tank, for diluting p acetamidoanisol and the mixture after mixed acid nitrification；
One cooling device, for the mixture after the p acetamidoanisol and mixed acid nitrification after cooling dilution；
The mixing after the p acetamidoanisol and mixed acid nitrification of crude product has been precipitated for separating in one filter device
Object；And
One controller, for control in dilution device dilute after p acetamidoanisol and mixed acid nitrification after mixing
The concentration of sulfuric acid, cooling temperature and rate of temperature fall in cooling device in object.
The device of the present invention that 2- nitro -4- acetyl-anisidine is precipitated, it is preferred that the cooling in cooling device
Medium is liquid nitrogen or dry ice.
After crude product 2- nitro -4- acetyl-anisidine is precipitated by the above method and step, also need to crude product into
The further washing of row purifies and carries out concentration and recovery to generated dilute sulfuric acid, and above-mentioned mesh can be realized by the following method
's.
Washing purifying to crude product
Level-one washing step
Cleaning solution in second level washing liquid tank is inputted in product tank by way of from top to bottom spraying, solid phase is slightly produced
Object carries out level-one washing, in the level-one cleaning solution input level-one washing liquid tank after washing；
Second level washing step
Cleaning solution in three-level washing liquid tank is inputted in product tank by way of from top to bottom spraying, is washed to through level-one
Solid phase crude product after washing carries out second level washing, and the second level cleaning solution after washing inputs second level washing liquid tank；
Three-level washing step
Cleaning solution in level Four washing liquid tank is inputted in product tank by way of from top to bottom spraying, is washed to through second level
Solid phase crude product after washing carries out three-level washing, and the three-level cleaning solution after washing inputs three-level washing liquid tank；
……
N-1 grades of washing steps
Cleaning solution in N grades of washing liquid tanks is inputted in product tank by way of from top to bottom spraying, is washed to through N-2 grades
Solid phase crude product after washing carries out N-1 grades of washings, and the N-1 grade cleaning solution after washing inputs N-1 grades of washing liquid tanks；
N grades of washing steps
It will be inputted in product tank by way of from top to bottom spraying from extraneous processed soft water, washed to through N-1 grades
Solid phase crude product after washing carries out N grades of washings, and the N grade cleaning solution after washing inputs N grades of washing liquid tanks, after N grades of washings
Solid phase crude product is pure 2- nitro -4- acetyl-anisidine, can enter subsequent processing and use；
Wherein, 5≤N≤9；If the h 2 so 4 concentration of cleaning solution is greater than or equal to 25% in level-one washing liquid tank, with
Spent acid mother liquor mixes the recycling technique for entering nitrating wasting acid as nitrating wasting acid；If cleaning solution in level-one washing liquid tank
H 2 so 4 concentration < 25%, then continue to carry out level-one washing to next group solid phase crude product, until h 2 so 4 concentration is big
In or equal to 25%.
Fig. 1 is the technological process block-diagram of 2- nitro -4- acetyl-anisidine purification process of the present invention.
The recycling step of nitrating wasting acid
Cleaning solution in spent acid mother liquor and level-one washing liquid tank is mixed to get nitrating wasting acid, includes matter in the nitrating wasting acid
The sulfuric acid that concentration is 25%~38% is measured, nitric acid of the mass concentration less than 0.1% and mass concentration are 0.2%~0.5%
Organic matter.The nitrating wasting acid recycles wherein sulfuric acid using the method for multi-step pressure reduction concentration, and this method comprises the following steps：
Heat exchange steps
So that nitrating wasting acid is carried out heat exchange with the hot concentrated sulfuric acid that is concentrated to get from the multi-step pressure reduction, be preheated to temperature be 80~
100℃；
Level-one distilation steps
To be introduced into level-one by the nitrating wasting acid of preheating to steam in sour kettle, and be 110~125 DEG C in temperature, pressure for 20KPa~
It is distilled under conditions of 28KPa, the mass concentration that control level-one steams sulfuric acid in sour bottom portion outflow acid is 55%~59%；
Secondary distillation step
Level-one is steamed into the nitrating wasting acid after sour kettle distillation and introduces the sour kettle of second level steaming, is 130~140 DEG C in temperature, pressure is
Distilled under conditions of 15KPa~25KPa, control second level steam the mass concentration of sulfuric acid in sour bottom portion outflow acid be 65%~
68%；
Three-stage distillation step
Second level is steamed into the nitrating wasting acid after sour kettle distillation and introduces the sour kettle of three-level steaming, is 185~200 DEG C in temperature, pressure is
Distilled under conditions of 8KPa~12KPa, control three-level steam the mass concentration of sulfuric acid in sour bottom portion outflow acid be 78%~
82%；
Four-stage distillation step
Three-level is steamed into the nitrating wasting acid after sour kettle distillation and introduces the sour kettle of level Four steaming, is 185~200 DEG C in temperature, pressure is
It is distilled under conditions of 2KPa~5KPa, the mass concentration that control level Four steams sulfuric acid in sour bottom portion outflow acid is greater than or equal to
93%, it is the hot concentrated sulfuric acid that the multi-step pressure reduction is concentrated to get which, which steams the acid that sour bottom portion is flowed out, is recycled for acetyl
The nitrification of aminoanisole and nitration mixture；
In addition, this method further includes a filtration step, which is that level-one or second level or three-level are steamed to sour kettle distillation
Nitrating wasting acid afterwards introduces ceramic membrane filter device and is filtered.
Filtration step of the present invention is preferably after three-stage distillation step and before Four-stage distillation step, the filtering
Step is that the nitrating wasting acid introducing ceramic membrane filter device after three-level to be steamed to sour kettle distillation is filtered, filtered nitrating wasting acid
Continue the sour kettle of introducing level Four steaming to be distilled.
It is all the sour kettle of horizontal steaming that the level-one, second level, three-level and level Four, which steam sour kettle, steams acid in level-one, second level, three-level and level Four
Kettle middle and lower part is all provided with multiple groups heater, and the heating temperature of the multiple groups heater is successively increased by sequence from top to bottom
It is high.
Nitrating wasting acid enters foam removal tower, part in the steam at different levels for steaming and generating in sour kettle by distillation, from sour kettle top portion is steamed
Steam is flowed back into after the condensation of foam removal tower in the sour kettle of steaming, and uncooled steam enters condensation after multistage cooling device condensed
Liquid inputs in spent acidic water pot, on-condensible gas base extraction.
Fig. 2 is the flow chart of the recovery method of nitrating wasting acid of the present invention.The recovery method of nitrating wasting acid of the present invention, can be with
It is described below in detail：
Heat exchange steps
In heat exchanger E105, thermal material in nitrating wasting acid and technical process is subjected to heat exchange, thermal material can be from
The hot concentrated sulfuric acid that the multi-step pressure reduction is concentrated to get is also possible to other heat in the waste water in spent acidic water pot or technical process
Material, being preheated to temperature is 80~100 DEG C.
Level-one distilation steps
It is steamed level-one is introduced by the nitrating wasting acid of preheating in sour kettle V101, is 110~125 DEG C in temperature, pressure is
It is distilled under conditions of 20KPa~28KPa, the steam for distilling generation steams sour kettle top portion from level-one and enters level-one foam removal tower
T101, some vapor flow back into level-one and steam sour kettle after condensing in level-one foam removal tower, uncooled steam enters one cold charge of level-one
It sets E101a and two device for cooling E101b of level-one is condensed, condensate liquid inputs in spent acidic water pot V105, and fixed gas inputs alkali
It is absorbed in flow container V1 with lye；After distillation, nitrating wasting acid steams the sour bottom kettle V101 from level-one and flows out in kettle, control outflow acid
The mass concentration of middle sulfuric acid is 55%~59%.
Secondary distillation step
Level-one is steamed into the nitrating wasting acid after sour kettle distillation and introduces the sour kettle V102 of second level steaming, is 130~140 DEG C in temperature, pressure
Power is distilled under conditions of being 15KPa~25KPa, and the steam for distilling generation steams sour kettle top portion from second level and enters second level foam removal tower
T102, some vapor flow back into second level and steam sour kettle after condensing in second level foam removal tower, uncooled steam enters one cold charge of second level
It sets E102a and two device for cooling E102b of second level is condensed, condensate liquid inputs in spent acidic water pot V105, and fixed gas inputs alkali
It is absorbed in flow container V2 with lye；After distillation, nitrating wasting acid steams the sour bottom kettle V102 from second level and flows out in kettle, control outflow acid
The mass concentration of middle sulfuric acid is 65%~68%.
Three-stage distillation step
Second level is steamed into the nitrating wasting acid after sour kettle distillation and introduces the sour kettle V103 of three-level steaming, is 185~200 DEG C in temperature, pressure
Power is distilled under conditions of being 8KPa~12KPa, and the steam for distilling generation steams sour kettle top portion from three-level and enters three-level foam removal tower
T103, some vapor flow back into three-level and steam sour kettle after condensing in three-level foam removal tower, uncooled steam enters one cold charge of three-level
It sets E103a and two device for cooling E103b of three-level is condensed, condensate liquid inputs in spent acidic water pot V105, and fixed gas inputs alkali
It is absorbed in flow container V3 with lye；After distillation, nitrating wasting acid steams the sour bottom kettle V103 from three-level and flows out in kettle, control outflow acid
The mass concentration of middle sulfuric acid is 78%~82%.
Four-stage distillation step
Three-level is steamed into the nitrating wasting acid after sour kettle distillation and introduces the sour kettle V104 of level Four steaming, is 185~200 DEG C in temperature, pressure
Power is distilled under conditions of being 2KPa~5KPa, and the steam for distilling generation steams sour kettle top portion from level Four and enters level Four foam removal tower
T104, some vapor flow back into level Four and steam sour kettle after condensing in level Four foam removal tower, uncooled steam enters one cold charge of level Four
It sets E104a and two device for cooling E104b of level Four is condensed, condensate liquid inputs in spent acidic water pot V105, and fixed gas inputs alkali
It is absorbed in flow container V4 with lye；After distillation, nitrating wasting acid steams the sour bottom kettle V104 from level Four and flows out in kettle, control outflow acid
The mass concentration of middle sulfuric acid is greater than or equal to 93%, and the acid which steams sour bottom portion outflow is that the multi-step pressure reduction is concentrated to get
Hot concentrated sulfuric acid, circulation be used for p acetamidoanisol and nitration mixture nitrification；
In addition, this method further includes a filtration step, which is that level-one or second level or three-level are steamed to sour kettle distillation
Nitrating wasting acid afterwards is introduced into ceramic membrane filter device Y101 and is filtered, after which preferably steams sour kettle distillation for three-level
Nitrating wasting acid be filtered.
It is all the sour kettle of horizontal steaming that the level-one, second level, three-level and level Four, which steam sour kettle, steams acid in level-one, second level, three-level and level Four
Kettle middle and lower part is all provided with multiple groups heater, and the heating temperature of the multiple groups heater is successively increased by sequence from top to bottom
It is high.
Ceramic membrane filter device of the invention, including a shell and a ceramic membrane filter unit, the ceramic membrane filter list
Member is flat, tubular type or Porous Ceramics Membrane, and the shell is set in outside the ceramic membrane filter unit, there is one between the two
Fixed gap, shell are equipped with feeding inlet and discharge port, are provided with feeding inlet and discharge port on ceramic membrane filter unit.Operation ceramics
When film filter, steams sour bottom portion outflow acid and entered by the feed inlet being arranged on the ceramic membrane filter unit, pass through ceramics
After film, the discharge port outflow being arranged from shell carries out continuing to distill into the sour kettle of next stage steaming.Sour bottom portion is steamed from level Four to flow
Hot concentrated sulfuric acid out is directly used in after can carrying out heat exchange with the nitrating wasting acid for not entering the sour kettle of level-one steaming also to acetyl ammonia
The nitrification of base methyl phenyl ethers anisole and nitration mixture can also be added after oxidant carries out oxidative decoloration processing to it and be used further to acetylaminobenzene
The nitrification of methyl ether and nitration mixture, the present invention are not particularly limited oxidant, if it is able to satisfy present invention process condition, such as
Hydrogen peroxide, fenton reagent etc..
Condensate liquid obtained in one device for cooling of level-one is compared with the condensate liquid of other condensing units, containing organic matter, and its
The organic matter that the condensate liquid of his condensing unit is practically free of organic matter or contains is extremely micro, if by obtaining in one device for cooling of level-one
To condensate liquid be passed through as the condensate liquid of other condensing units in spent acidic water pot, will affect waste water in spent acidic water pot
It recycles, therefore preferably condensate liquid obtained in one device for cooling of level-one is collected separately or is individually handled, do not show in Fig. 2
Out.Waste water can be used for the technical process such as the dilution precipitation of nitration product, the washing of product in spent acidic water pot.
The recovery method of nitrating wasting acid of the present invention can carry out in a continuous manner, can also be in an intermittent fashion
It carries out, the present invention is not particularly limited this.
The recovery method of nitrating wasting acid of the present invention, wherein steaming acid kettle control preferably by the way of indirect heating
Temperature processed.
In the following, according to examples illustrate the present invention.
Embodiment 1
The preparation of 2- nitro -4- acetyl-anisidine
By 98% concentrated nitric acid and 93% concentrated sulfuric acid in molar ratio 2:1 is configured to nitration mixture, by p acetamidoanisol
It is added in nitration reaction kettle, is then slowly added dropwise and carries out nitration reaction, mole of p acetamidoanisol and nitric acid into nitration mixture
Than being 1:1.2, nitration reaction, reaction time 1.5h are carried out at 80 DEG C.
The precipitation of 2- nitro -4- acetyl-anisidine
Distilled water is added into the nitration product mixture of above-mentioned preparation, sulfuric acid is diluted to 24%, it then will be after dilution
Mixture is cooled to -20 DEG C, during -5 DEG C are cooled to -15 DEG C with liquid nitrogen, and rate of temperature fall is 3 DEG C/h, -15 DEG C be cooled to -
During 25 DEG C, rate of temperature fall is 2 DEG C/h, and cooling temperature 60min is kept to be precipitated, and filters, obtains solid 2- nitro -4- second
Acylamino- methyl phenyl ethers anisole.
Embodiment 2-20
In addition to change dilution after sulfuric acid concentration, to the cooling temperature and rate of temperature fall of mixture other than, other conditions are same
Embodiment 1, specific data are see table 1, table 2 and table 3.
Table 1
Table 2
Table 3
Examples 1 to 9 is different sulfuric acid concentration under the conditions of same temperature, the precipitation situation of product NMA, the production of precipitation
Object NMA granular size is 280~371 μm, and NMA is precipitated under the conditions of -20 DEG C it can be seen from Fig. 1 and table 1, with sulfuric acid
The increase of concentration, the residual of product NMA is in increasing trend in acid solution, but all in all, residual quantity is seldom, and every 100g acid is molten
The product NMA of 0.0018~0.0052g is only remained in liquid；Embodiment 10~15 is different precipitation temperature under same sulfuric acid concentration
Degree, the precipitation situation of product NMA, when by sulfuric acid, to be diluted to concentration be 30% by Fig. 2 and table 2 it can be seen from, temperature is lower, sour
Remaining product NMA content is fewer in solution, also, refers to the data of embodiment 10, when being precipitated under the conditions of 0 DEG C, although
The content of NMA is relatively low, but is also significantly larger than NMA residual quantity in acid solution when Precipitation Temperature is -5 DEG C~-30 DEG C；Embodiment
The Precipitation Temperature that 16~21 experiment condition is -5~-25 DEG C, the product grain size of 28~28% sulfuric acid solubility, precipitation are
203~395 μm, and as can be seen from Table 3, the precipitation of the product overwhelming majority may be implemented, the product residual quantity in sulfuric acid solution is very
It is few.
Comparative example 1
The preparation of 2- nitro -4- acetyl-anisidine
The preparation method is the same as that of Example 1 for product.
The precipitation of 2- nitro -4- acetyl-anisidine
Distilled water is added into the nitration product mixture of above-mentioned preparation, sulfuric acid is diluted to 60%, then with rate of temperature fall
Solution temperature is down to 5 DEG C for the speed of 6 DEG C/h, continues 60min cooling time, filters, obtains solid 2- nitro -4- acetylamino
Methyl phenyl ethers anisole.
Comparative example 2~6
Other than the rate of temperature fall of dilution and Precipitation Temperature make change, remaining is identical as comparative example 1, and concrete outcome is shown in
Table 4.
Table 4
Comparative example 1-6 is the temperature of solution to be reduced with certain rate of temperature fall, then in 5 DEG C~25 DEG C temperature ranges
Product NMA is precipitated, the particle size of precipitation is 48~127 μm, and product is residual in sulfuric acid solution it can be seen from data in table 4
Allowance is 0.0630~0.5540%.
As can be seen from the above embodiments, with the method for the invention it is achieved that product 2- nitro -4- acetyl amino phenyl first
Ether is largely precipitated in the case where sulfuric acid concentration higher (28%~38%), and the residual quantity of product can control in acid pickle
0.0055% hereinafter, solve in the prior art because in acid pickle product residual quantity it is high caused by product waste and subsequent useless
The problem of acid solution processing difficulty increases, and the product particle size that can control precipitation is conducive to the heavy of product at 200~400 μm
Drop and separation.
Certainly, the present invention can also have other various embodiments, without deviating from the spirit and substance of the present invention, ripe
Various corresponding changes and modifications, but these corresponding changes and modifications can be made according to the present invention by knowing those skilled in the art
It all should belong to the protection scope of the claims in the present invention.
Claims (11)
1. a kind of separation method of 2- nitro -4- acetyl-anisidine, which is to second
Acylamino- methyl phenyl ethers anisole is to be made after raw material carries out mixed acid nitrification, which is characterized in that the separation method specifically includes following steps：
Step 1, the mixture after p acetamidoanisol and mixed acid nitrification is diluted with water to h 2 so 4 concentration is 28%
~38%；
Step 2, the mixture after diluting in step 1 is cooled to -25 DEG C~-5 DEG C, carries out the precipitation of crude product；
Step 3, the mixture after cooling in step 2 for having carried out crude product precipitation is filtered, solid phase is crude product 2- nitre
Base -4- acetyl-anisidine.
2. the separation method of 2- nitro -4- acetyl-anisidine according to claim 1, which is characterized in that in step 1
The concentration of mixture sulfuric acid after diluting is 30%~36%.
3. the separation method of 2- nitro -4- acetyl-anisidine according to claim 1 or 2, which is characterized in that step
Mixture after dilution is cooled to -20 DEG C~-10 DEG C in 2.
4. the separation method of 2- nitro -4- acetyl-anisidine according to claim 1 or 2, which is characterized in that step
During cooling down in 2 to the mixture after dilution, during -5 DEG C are cooled to -15 DEG C, rate of temperature fall is 3~6 DEG C/h, -
During 15 DEG C are cooled to -25 DEG C, rate of temperature fall is 2~4 DEG C/h.
5. the separation method of 2- nitro -4- acetyl-anisidine according to claim 3, which is characterized in that in step 2
During cooling to the mixture after dilution, during -10 DEG C are cooled to -20 DEG C, rate of temperature fall is 3~6 DEG C/h.
6. the separation method of 2- nitro -4- acetyl-anisidine described in any one according to claim 1~5, feature
It is, the precipitation time of crude product is 40~100min in step 2.
7. the separation method of 2- nitro -4- acetyl-anisidine described in any one according to claim 1~6, feature
It is, indirect cooling is cooled to described in step 2, and cooling medium is liquid nitrogen or dry ice.
8. the separation method of 2- nitro -4- acetyl-anisidine described in any one according to claim 1~7, feature
It is, water described in step 1 is distilled water.
9. a kind of device that 2- nitro -4- acetyl-anisidine is precipitated, which is characterized in that be applied to described in 1~8 any one
2- nitro -4- acetyl-anisidine separation method, including：
Thinning tank, for diluting p acetamidoanisol and the mixture after mixed acid nitrification；
Cooling device, for the mixture after the p acetamidoanisol and mixed acid nitrification after cooling dilution；
The mixture after the p acetamidoanisol and mixed acid nitrification of crude product has been precipitated for separating in filter device；And
Controller, for control in dilution device dilute after p acetamidoanisol and mixed acid nitrification after mixture in sulphur
The concentration of acid, cooling temperature and rate of temperature fall in cooling device.
10. the device according to claim 9 that 2- nitro -4- acetyl-anisidine is precipitated, which is characterized in that cooling dress
Cooling medium in setting is liquid nitrogen or dry ice.
11. the 2- nitro -4- acetyl-anisidine that method according to any one of claims 1 to 8 is precipitated.
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Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN85109473A (en) * | 1985-12-23 | 1986-10-08 | 化工部沈阳化工研究院 | The synthetic method of 2-nitro-4-acetylaminohydroxyphenylarsonic acid benzene-'beta '-methoxy ether |
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2018
- 2018-07-05 CN CN201810729956.3A patent/CN108863833A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN85109473A (en) * | 1985-12-23 | 1986-10-08 | 化工部沈阳化工研究院 | The synthetic method of 2-nitro-4-acetylaminohydroxyphenylarsonic acid benzene-'beta '-methoxy ether |
Non-Patent Citations (1)
| Title |
|---|
| 陈佳: "2-硝基-4-乙酰氨基苯甲醚结晶过程研究", 《万方数据知识服务平台》 * |
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