CN106083596B - A kind of method that continuous nitrification prepares 2,5- dichloronitrobenzenes - Google Patents
A kind of method that continuous nitrification prepares 2,5- dichloronitrobenzenes Download PDFInfo
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- CN106083596B CN106083596B CN201610408055.5A CN201610408055A CN106083596B CN 106083596 B CN106083596 B CN 106083596B CN 201610408055 A CN201610408055 A CN 201610408055A CN 106083596 B CN106083596 B CN 106083596B
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- acid
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- dichloronitrobenzenes
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- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C201/00—Preparation of esters of nitric or nitrous acid or of compounds containing nitro or nitroso groups bound to a carbon skeleton
- C07C201/06—Preparation of nitro compounds
- C07C201/08—Preparation of nitro compounds by substitution of hydrogen atoms by nitro groups
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Abstract
The invention discloses a kind of methods that continuous nitrification prepares 2,5 dichloronitrobenzenes, include the following steps：Using the kettle-type continuous reaction of three-level, sulfuric acid, paracide in nitric acid and extraction kettle adds in simultaneously carries out nitration reaction in first order nitrating pot, nitrification liquid, which is sequentially entered by the lifter that each nitrating pot carries in next stage nitrating pot, to react, after third level nitrating pot completes reaction, detach oil phase and sour phase, oil phase is neutralized, washing and dehydration obtain 2, 5 dichloronitrobenzenes, first order nitrating pot is recycled back in part spent acid in sour phase, remaining spent acid enters extraction kettle, isolated acidity paracide and extraction spent acid after paracide extracts, extraction spent acid is concentrated to enter recycled in first order nitrating pot into concentrated vitriol and acid paracide.The present invention is eliminated nitration mixture process for preparation, simplifies technological process, can be realized nitration reaction serialization, nitrification liquid separation serialization and spent acid extraction serialization using automation control.
Description
Technical field
The invention belongs to the synthesis fields of 2,5- dichloronitrobenzenes, are related to a kind of continuous nitrification and prepare 2,5- dichloronitrobenzenes
Method.
Background technology
2,5- dichloronitrobenzenes are important chemical intermediate, mainly for the production of 2,5- dichloroanilines, large red-based g G,
Red base 3GL, fast red rl and triclosan (2,4,4- tri- chloro- 2- dihydroxy diphenyl ethers) etc., in addition, being alternatively arranged as nitrogen fertilizer potentiating agent
To improve rice yield.
Industrialized production 2 at present, 5- dichloronitrobenzenes using batch production process, are made bottom acid with sulfuric acid, are added in two
Then chlorobenzene is added dropwise nitric acid, the mixed acid nitrification that sulfuric acid is prepared, neutralizes, washs, being dehydrated and to obtain 2,5- dichloronitrobenzene products.Intermittently
There are production capacity is low, labor intensity is big, working environment is poor, consumption of raw materials is high, production cost is high, three-protection design amount for production technology
It is big to wait series of problems.Using continuous process, with reference to automation control means, can effectively solve the above problems.Chinese patent
Application 201310601213.5 discloses a kind of acid and applies mechanically the method that serialization nitrification prepares 2,5- dichloronitrobenzenes, and this method is protected
Nitration mixture preparation process is stayed, nitration mixture and paracide will nitrify simultaneously into the kettle-type continuous reactor part serialization of three-level
Reaction terminates a large amount of spent acid generated after being layered all extraction concentrations, and then set is used for the mixed acid nitrification of lower batch, and the method is given up
Sour treating capacity is big, increases spent acid processing cost.In addition, in traditional handicraft, oil phase acid boundary will appear emulsion layer, patent
Though CN104649910A by controlling dehydrating value of sulfuric acid and reaction temperature, only generates a small amount of emulsion layer, emulsion does not obtain
To basic control.
Therefore, it is necessary to develop new technique, simplify continuous process prepared by 2,5- dichloronitrobenzenes, farthest subtract
The generation of few emulsion layer improves the utilization rate of raw material, reduces spent acid processing cost.
Invention content
For current 2,5- dichloronitrobenzenes production technology without whole serializations, spent acid internal circulating load is big, the sour phase boundary of oil phase
There is emulsion layer in face, the present invention provides a kind of method that continuous nitrification prepares 2,5- dichloronitrobenzenes, using continuous
Nitrification prepares 2,5- dichloronitrobenzenes, and this method uses automation control, eliminates nitration mixture process for preparation, simplify technique stream
Journey can realize nitration reaction serialization, nitrification liquid separation serialization and spent acid extraction serialization.
Technical scheme is as follows：
A kind of method that continuous nitrification prepares 2,5- dichloronitrobenzenes, is as follows：It is kettle-type continuous using three-level
It reacts, the paracide in sulfuric acid, nitric acid and extraction kettle adds in simultaneously carries out nitration reaction in first order nitrating pot, nitrification liquid leads to
It crosses the lifter that each nitrating pot carries and sequentially enters and reacted in next stage nitrating pot, control nitration reaction temperature is 58~68 DEG C,
It is 3~4 that modulus is reacted in nitrating pots at different levels, and sulfuric acid concentration is 82~83%, after third level nitrating pot completes reaction, separation oil
Mutually and sour phase, oil phase is neutralized, washing and dehydration obtain 2,5- dichloronitrobenzenes, and first is recycled back in the part spent acid in sour phase
Grade nitrating pot, remaining spent acid enter extraction kettle, isolated acidity paracide and extraction spent acid, extraction after paracide extracts
Take spent acid under vacuum, kettle temperature control be condensed into the concentrated vitriol of content >=97% at 290~320 DEG C, concentrated vitriol and
Acid paracide enters recycled in first order nitrating pot.
In the present invention, the reaction modulus refers to sour phase and the volume ratio of oil phase.
In the present invention, use mass fraction for 97% sulfuric acid and mass fraction be 98% nitric acid as raw material.
For the present invention using the kettle-type continuous reaction of three-level, it is 1.00~1.05 to control the molar ratio of nitric acid and paracide:
1, the molar ratio of sulfuric acid and nitric acid is 1.08~1.35:1.
In a specific embodiment of the present invention, third level nitrating pot is completed after reacting, separation oil phase and sour phase, in sour phase
It is recycled back to first order nitrating pot in 80% spent acid to apply mechanically, 20% spent acid enters extraction kettle.
In three-level autoclave continuous nitrification reaction process, in order to ensure that reaction is normal, control it is di-nitrated wait side reactions and
Inhibiting emulsion, the temperature of control first order nitrating pot is 58~62 DEG C, and the temperature of second level nitrating pot is 65~68 DEG C, the
The temperature of three-level nitrating pot is 65~68 DEG C, and the temperature of extraction kettle is 68~70 DEG C.
In the present invention, the specific method of oil phase neutralization, washing and dehydration is：65~70 DEG C of dropwise addition, quality in oil phase
Score is 8% sodium carbonate hydrothermal solution, neutralizes pH to 8~9, stratification, it is 7~8 that oil reservoir, which heats water washing to pH, is distilled
It is dehydrated to obtain 2,5- dichloronitrobenzenes.
In the present invention, the specific method for extracting waste acid concentration is：Extraction spent acid is evacuated to -0.090Mpa, is warming up to 290
~320 DEG C are distilled, and obtain the concentrated vitriol of content >=97%.
From tape lifter, and third level nitrating pot is reaction, separating one-piece, extraction kettle is nitrating pot in the present invention
Extraction, separating one-piece.
Compared with prior art, the present invention has following remarkable result：
1st, cancel acid preparing device, sulfuric acid, nitric acid add in first order nitrating pot simultaneously, and paracide adds in extraction kettle, optimization
Technological process；
2nd, the equal tape lifter of nitrating pot at different levels has reaction, enhanced feature, and third level nitrating pot and extraction kettle, which also carry, to be divided
From device, has automatic separation, device structure is compact, and floor space is small；
3rd, 80% spent acid after the separation of third level nitrating pot nitrification liquid enters recycled in first order nitrating pot, improves
Reaction modulus in nitrating pot, improves mass transfer condition, is conducive to control di-nitrated side reactions of Denging, eliminates emulsion；
4th, the reaction temperature of modulus, sulfuric acid concentration and each nitrating pot is reacted by control, reduces di-nitrated grade for side reactions,
And inhibiting the generation of emulsion, obtained 2,5- dichloronitrobenzenes product quality is stablized.
Description of the drawings
Fig. 1 is the process flow chart that the continuous nitrification of the present invention prepares the method for 2,5- dichloronitrobenzenes.
Specific embodiment
With reference to embodiment and attached drawing, the invention will be further described.
Embodiment 1
1st, process units is composed using 3 nitrating pots and 1 extraction kettle, and 3 nitrating pot total volumies are respectively
2.5m3、1.5m3、1.5m3, dischargeable capacity is respectively：1.2m3、1.1m3、1.1m3；Extraction kettle total volume is 1.5m3, dischargeable capacity
For 1.1m3, 1 is controlled in the process#58~62 DEG C of nitrating pot temperature, 2#65~68 DEG C of nitrating pot temperature；3#Nitrating pot temperature 65~68
℃；68~70 DEG C of extraction kettle temperature；React modulus 3~4, sulfuric acid concentration 82~83%.To extraction kettle into 320L/h paracide,
Kettle to be extracted has acid paracide to flow into 1#Nitrating pot, to 1#Nitrating pot throws 97% sulfuric acid of 175L/h, 98% nitre of 120L/h
Acid, nitrification liquid is promoted to next stage nitrating pot successively by each kettle lifter, finally 3#Reaction, separation are completed in nitrating pot,
Oil phase itrated compound and spent acid are obtained, 80% spent acid returns 1#Nitrating pot recycled, 20% flow to extraction kettle.
2nd, washing is neutralized：Oil phase itrated compound is added dropwise in 65~70 DEG C of 8% sodium carbonate hydrothermal solution and PH to 8~9, stands and divides
Layer, PH to 7~8, oil reservoir distillation dehydration obtain 2,5- dichloronitrobenzenes to oil reservoir heating water washing twice, and gas chromatographic analysis is contained
The 2,5- dichloronitrobenzene finished products of amount >=99.5%.
3rd, nitrating wasting acid is gone in distillation still, is evacuated to -0.090Mpa, and heating distillation obtains for 290~320 DEG C to kettle temperature
The concentrated vitriol of content >=97%.
4th, gelled acid is applied mechanically：To extraction kettle into 320L/h paracide, kettle to be extracted has acid paracide to flow into 1#Nitre
Change kettle, to 1#Nitrating pot throws 175L/h concentrated vitriols, 120L/h98% nitric acid, and nitrification liquid is promoted to successively by each kettle lifter
Next stage nitrating pot, finally 3#Reaction, separation are completed in nitrating pot, obtains oil phase itrated compound and spent acid, 80% spent acid returns 1#Nitre
Change kettle recycled, 20% flow to extraction kettle, applies mechanically 5 batches, as a result such as table 1.
1 acid-spending strength of table and reaction modulus apply mechanically continuous nitrification and spent acid the influence of rear product quality
As known from Table 1, by control in nitrating pot react modulus between 3~4, sulfuric acid concentration between 82~83%,
For 2, the 5- dichloronitrobenzene contents being prepared more than 99.5%, dinitro class by-products content is few, after continuous nitrification reaction
There is no emulsions.
Claims (7)
1. a kind of method that continuous nitrification prepares 2,5- dichloronitrobenzenes, which is characterized in that be as follows：Using three-level kettle
Formula continuous reaction, the paracide in sulfuric acid, nitric acid and extraction kettle adds in simultaneously carries out nitration reaction in first order nitrating pot,
Nitrification liquid, which is sequentially entered by the lifter that each nitrating pot carries in next stage nitrating pot, to react, and control nitration reaction temperature is 58
~68 DEG C, reaction modulus is 3~4 in nitrating pots at different levels, and sulfuric acid concentration is 82~83%, completes to react in third level nitrating pot
Afterwards, separation oil phase and sour phase, oil phase is neutralized, washing and dehydration obtain 2,5- dichloronitrobenzenes, in the part spent acid in sour phase
Be recycled back to first order nitrating pot, remaining spent acid enters extraction kettle, after paracide extracts it is isolated acidity paracide and
Extract spent acid, extraction spent acid under vacuum, kettle temperature control the concentrated vitriol of content >=97% is condensed at 290~320 DEG C,
Concentrated vitriol and acid paracide enter recycled in first order nitrating pot.
2. the method that continuous nitrification according to claim 1 prepares 2,5- dichloronitrobenzenes, which is characterized in that described the
The temperature of level-one nitrating pot is 58~62 DEG C, and the temperature of second level nitrating pot is 65~68 DEG C, and the temperature of third level nitrating pot is
65~68 DEG C, the temperature of extraction kettle is 68~70 DEG C.
3. the method that continuous nitrification according to claim 1 prepares 2,5- dichloronitrobenzenes, which is characterized in that using quality
The nitric acid that the sulfuric acid and mass fraction that score is 97% are 98% is as raw material.
4. the method that continuous nitrification according to claim 1 prepares 2,5- dichloronitrobenzenes, which is characterized in that control nitric acid
Molar ratio with paracide is 1.00~1.05:1, the molar ratio of sulfuric acid and nitric acid is 1.08~1.35:1.
5. the method that continuous nitrification according to claim 1 prepares 2,5- dichloronitrobenzenes, which is characterized in that third level nitre
Change kettle to complete after reacting, separation oil phase and sour phase, being recycled back to first order nitrating pot in 80% spent acid in sour phase applies mechanically, and 20% is useless
Acid enters extraction kettle.
6. the method that continuous nitrification according to claim 1 prepares 2,5- dichloronitrobenzenes, which is characterized in that the oil
Mutually the specific method of neutralization, washing and dehydration is：In oil phase be added dropwise 65~70 DEG C, mass fraction be 8% sodium carbonate heat
Aqueous solution neutralizes pH to 8~9, stratification, and it is 7~8 that oil reservoir, which heats water washing to pH, and distillation dehydration obtains 2,5- dichloro nitros
Benzene.
7. the method that continuous nitrification according to claim 1 prepares 2,5- dichloronitrobenzenes, which is characterized in that the extraction
The specific method for taking waste acid concentration is：Extraction spent acid is evacuated to -0.090Mpa, is warming up to 290~320 DEG C and is distilled, is obtained
To the concentrated vitriol of content >=97%.
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| CN107417536A (en) * | 2017-04-10 | 2017-12-01 | 浙江工业大学 | Method and special device for continuous mono-nitration reaction of o-dichlorobenzene |
| CN110845338B (en) * | 2018-08-21 | 2022-09-06 | 中国石油化工股份有限公司 | Method for extracting and separating 2, 5-dichloronitrobenzene by adopting composite ionic liquid |
| CN110054566A (en) * | 2019-04-08 | 2019-07-26 | 淮海工学院 | The method of mesitylene continuous nitrification production 2,4,6- trimethyl nitrobenzene |
| CN111929375A (en) * | 2020-07-20 | 2020-11-13 | 江苏云阳集团药业有限公司 | Method for detecting and analyzing content of 2, 5-dichloronitrobenzene in clozapine bulk drug and methodological verification |
| CN112778136B (en) * | 2021-01-11 | 2023-07-14 | 南通江山农药化工股份有限公司 | 2, 5-dichloronitrobenzene and microchannel continuous synthesis process thereof |
| CN115433091A (en) * | 2021-10-18 | 2022-12-06 | 江苏隆昌化工有限公司 | Method for synthesizing 2, 5-dichloronitrobenzene through continuous flow tubular reaction |
| CN113861033A (en) * | 2021-11-03 | 2021-12-31 | 江苏海洋大学 | Process for preparing 1-nitronaphthalene by continuous low-temperature nitration |
| CN115611745A (en) * | 2022-09-26 | 2023-01-17 | 浙江闰土股份有限公司 | Method for continuously producing 3, 4-dichloronitrobenzene |
| CN115521207B (en) * | 2022-10-08 | 2023-10-13 | 中建安装集团有限公司 | Continuous production C 9 H 3 Cl 2 F 6 NO 3 Is a process and device for the production of a metal product |
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Effective date of registration: 20210105 Address after: No. 417-631, comprehensive building, comprehensive bonded zone, Lianyungang Economic and Technological Development Zone, China (Jiangsu) pilot Free Trade Zone, Lianyungang City, Jiangsu Province 224500 Patentee after: Jiangsu Tuofu Engineering Design Research Co.,Ltd. Address before: No.108, Tongguan South Road, Haizhou District, Lianyungang City, Jiangsu Province 222000 Patentee before: MARINE RESOURCES DEVELOPMENT INSTITUTE OF JIANGSU (LIANYUNGANG) |