CN104876805B - A kind of preparation technology of the 2,5-chlorophenesic acid for mass production - Google Patents
A kind of preparation technology of the 2,5-chlorophenesic acid for mass production Download PDFInfo
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Abstract
The present invention provides the preparation technology of a kind of 2,5-chlorophenesic acids for mass production, and it includes the continuous rectification recovery with substrate and solvent of the preparation of catalyst, Isosorbide-5-Nitrae-dichloro-benzenes one-step synthesis method target product and product 2,5-chlorophenesic acid.Catalyst of the present invention can significantly improve efficiency and the yield of synthetic reaction, reduces production cost, and heavy component reduces, and is beneficial to later separation purification work.The present invention is by carrying out rectification separating-purifying to synthesis product, obtain product 2, the purity of 5-chlorophenesic acid is more than 99.7%, reclaim the raw material 1 obtained, the purity of 4-dichloro-benzenes, solvent and water both is greater than 99%, the raw material, the solvent that reclaim can be directly used for next group synthetic reaction, reduce production cost, are beneficial to environmental protection.
Description
Technical field
The preparation method that the present invention relates to 2,5-chlorophenesic acids.It is more particularly related to one is with Isosorbide-5-Nitrae-dichloro-benzenes for raw material, efficiently synthesize 2,5-chlorophenesic acids by single step reaction, then it is carried out multistep continuous rectification and prepare the mass production technique of high-purity 2,5-chlorophenesic acid.
Background technology
2,5-chlorophenesic acids are the intermediate of a kind of important pesticide, medicine, dyestuff, nitrogen fertilizer potentiating agent and leather fungicide etc..At present, 2,5-chlorophenesic acids are used for the synthesis of the chloro-2-methoxybenzoic acid of herbicide 3,6-bis-(Dicamba).
The method preparing 2,5-chlorophenesic acids at present, mainly has 1,2,4-trichloro-benzenes Hydrolyze method and 2,5-dichloroaniline diazonium Hydrolyze method.But 1,2,4-trichloro-benzenes Hydrolyze method requires over high temperature and high pressure hydrolysis and prepares, and can use substantial amounts of bronsted lowry acids and bases bronsted lowry, produce substantial amounts of three industrial wastes, and product is the mixture of isomers in preparation process, follow-up is not readily separated purification, industrial cost is high.2,5-dichloroaniline diazonium Hydrolyze method can use a large amount of sulphuric acid and nitrite, equipment corrosion is serious, energy consumption is high, it is difficult to recycles and processes, contaminated environment, additionally substrate 2, the preparation process of 5-dichloroaniline relates to nitration reaction, and equipment is not only had higher requirement by the use of a large amount of sulphuric acid and nitrite, also exacerbates the harm to environment.
In order to solve this defect, prior art prepares 2 for raw material by catalytic oxidation with Isosorbide-5-Nitrae-dichloro-benzenes, the method of 5-chlorophenesic acid, adopting heteropoly acid, heteropolyacid salt or its support type is catalyst, and its reaction scheme is short, simple to operate, almost environmentally safe, but catalytic effect is undesirable, catalyst reclaims difficulty, and does not disclose its follow-up purification refine technique, therefore, preparation technology of the prior art is all not suitable for mass production.
Summary of the invention
Result as various extensive and careful researchs and experiment, present inventors have found that, with 1,4-dichloro-benzenes is raw material, is synthesized in the technical process of 2,5-chlorophenesic acids by single step reaction catalytic oxidation, adopt ferrovanadium sinter can significantly improve catalytic efficiency as catalyst, improve the yield of 2,5-chlorophenesic acids, and the problem such as recovery and product purity that the present invention is directed to reactant mixture Raw, solvent etc. proposes a kind of rationally efficient continuous rectification separation method.
Therefore, it is an object of the invention to solve at least the above and/or defect, and the advantage that at least will be described later is provided.
It is a further object of the present invention to provide the synthetic method of a kind of 2,5-chlorophenesic acids, it is with Isosorbide-5-Nitrae-dichloro-benzenes for raw material, efficient can obtain catalytic oxidation synthesis 2,5-chlorophenesic acids by single step reaction, and product yield is high, low for equipment requirements and environmentally safe.
A further object of the present invention is the mixed composition obtained for described synthetic reaction, it is provided that a kind of efficiently method for subsequent processing, is ensureing on the basis that 2,5-chlorophenesic acid purity are higher, is improving organic efficiency and the purity of raw material, solvent etc..
In order to realize these purposes according to the present invention and further advantage, it is provided that the preparation method of a kind of 2,5-chlorophenesic acids, it comprises the following steps:
Step one: by the Fe of 1/800～1/100 weight portionxVyOzWith in the acetic acid that the polyphosphoric acids of 1/80～1/10 weight portion joins 1/50～1/10 weight portion, at 50～65 DEG C, stirring 5～10min, is subsequently adding and described FexVyOzMol ratio is the peracetic acid of 0.3～1.2, continues stirring 15～25min, obtains activating solution；
Step 2: the acetic acid of the Isosorbide-5-Nitrae-dichloro-benzenes of 1 weight portion and 3～12 weight portions is stirred to mix homogeneously at the temperature not higher than 30 DEG C, is subsequently adding described activating solution, obtains reactant liquor；
Step 3: at 30～75 DEG C of temperature, adds in described reactant liquor by the peracetic acid that mol ratio is 0.5～5 with described Isosorbide-5-Nitrae-dichloro-benzenes, and time for adding is 1.5～6h, after dropwising, continues stirring 1h；It is subsequently added and sodium sulfite or sodium sulfite that described peracetic acid mol ratio is 0.5～0.8, stirs 5min, filter, obtain filtrate；
Step 4: by least three rectifying column, described filtrate is come separating-purifying, described rectifying column includes the first rectifying column, the Second distillation column being connected in parallel by pipeline respectively and the 3rd rectifying column with described first rectifying column；
Wherein, the charging flow velocity of described first rectifying column is 7000～8500kg/h, and feeding temperature is 80～100 DEG C, and feed pressure is 35～45kPa；
The charging flow velocity of described Second distillation column is 2500～4000kg/h, and feeding temperature is 70～85 DEG C, and feed pressure is 25～35kPa；
The charging flow velocity of described 3rd rectifying column is 200～500kg/h, and feeding temperature is 100～120 DEG C, and feed pressure is 8～12kP.
Preferably, in step one, described FexVyOzAddition be 1/500～1/200 weight portion, the amount that described polyphosphoric acids adds is 1/50～1/30 weight portion, and the amount that acetic acid described in step 2 adds is 5～8 weight portions, and the mol ratio of peracetic acid described in step 3 and described Isosorbide-5-Nitrae-dichloro-benzenes is 1.2～3.5.Described catalyst is sinter FexVyOz, after peroxide pre-treatment and activation, catalysis activity significantly improves, and catalytic efficiency is also obviously improved, and when the amount of substrate Isosorbide-5-Nitrae-dichloro-benzenes is constant, the addition of required catalyst reduces 12～20 times.
Preferably, described filtrate is entering before rectifying column at least through an evaporating kettle to deviate from heavy constituent, and to prevent restructuring etching apparatus, the charging flow velocity of described evaporating kettle is 6000～9000kg/h, and feeding temperature is 30～35 DEG C, and pressure is 400～550kPa.
Preferably, between described first rectifying column and described Second distillation column, also it is disposed with stripper and Isosorbide-5-Nitrae-dichloro-benzenes treating column, in order to the refining purity reclaiming Isosorbide-5-Nitrae-dichloro-benzenes and improving product further.
Preferably, described first rectifying column is combination tower, top is 2 sections of packed towers, bottom is the number of plates is the partitioned column of 33 layers, packed tower has higher mass transfer and separating effect relative to plate column, tower height can be reduced, but cost is also higher, for the component of the present invention the first rectifying column charging be water, acetic acid, 1,4-dichloro-benzenes and described 2, the practical situation of the mixture of 5-chlorophenesic acid, is designed to top packed tower, the structure of bottom plate column, can effectively increase treating capacity, ensureing on the basis of the certain separation efficiency of material component, reduce tower height, reduce energy consumption；
Described first rectifying column bottom is partitioned column mechanism, by the main body of tower is divided into two, make three components carry out mass transfer, heat transfer in tower simultaneously, realize the separation of three components simultaneously, described first rectifying column tower top deviates from waste water, the mixture extracting acetic acid and water in tower out enters described Second distillation column, tower reactor obtain described 1,4-dichloro-benzenes and described 2, the mixture of 5-chlorophenesic acid enters described stripper, and this tower structure completes the separation task generally needing two conventional towers just can complete, greatly reduce energy expenditure.
Preferably, the number of plates of described Second distillation column is 70 layers, it is refined further and obtains the acetic acid that purity is higher, in reacting in order to recovery to next batch, and Second distillation column tower top deviates from waste water and flows to described first tower bottom of rectifying tower with gas phase, waste water condensation releases heat in order to heat the first rectifying column, saves energy consumption；
Described 3rd rectifying column is 3 sections of packed towers.3rd rectifying column obtains product 2,5-chlorophenesic acid in order to separate, and owing to the requirement of product purity is higher, and packed tower has higher mass-transfer efficiency compared with plate column, therefore the present invention selects packed tower to reduce tower height, it is ensured that product purity；Packed tower is designed as 3 sections, the purity of product 2, the 5-chlorophenesic acid obtained is more than 99.7%, and filler disjunction is too many, the tower internals such as required distributor and redistributor also can increase accordingly, increase cost, but filler segmentation is very little, wall stream effect easily occurs, reduce separation efficiency, when filler only has 2 sections, the purity of product 2, the 5-chlorophenesic acid obtained only has 99.1%.
Preferably, the number of plates of described stripper is 10 layers, in order to the acetic acid in the mixed liquor of Isosorbide-5-Nitrae-dichloro-benzenes and 2,5-chlorophenesic acids and water to be further separated out；Described Isosorbide-5-Nitrae-dichloro-benzenes treating column is 3 sections of packed towers, makes substrate Isosorbide-5-Nitrae-dichloro-benzenes and product 2,5-chlorophenesic acid is efficiently separated, wherein, and described 1, the charging flow velocity of 4-dichloro-benzenes treating column is 1000～1600kg/h, and feeding temperature is 120～150 DEG C, and pressure is 30～45kPa.
Wherein the preparation technology of catalyst ferrovanadium sinter is: weigh the Fe of corresponding weight in proportion2O3And V2O5, ground 1～2 hour, obtained micron powder, ground powder is preheated one hour in 550 DEG C, in nitrogen and atmosphere that hydrogen volume ratio is 19: 1, calcination 3 hours at 1200 DEG C, obtain ferrovanadium sinter, after natural cooling, the sinter that ball milling obtains to its particle diameter is 70～80nm, wash 3 times with deionized water, dry, obtain catalyst ferrovanadium sinter.
Wherein work as Fe2O3And V2O5Mass ratio when being 5: 9, sintered product is: Fe5V8O27.5；Work as Fe2O3And V2O5Mass ratio when being 1: 3, sinter is: Fe2V5O15.5；Work as Fe2O3And V2O5Mass ratio when being 1: 2, sinter is: Fe7V12O40.5。
The present invention at least includes following beneficial effect:
(1) by the pretreatment to catalyst, catalytic performance and the catalytic effect of catalyst can be effectively improved, thus improve efficiency and the yield of one-step synthesis reaction；
(2) catalyst of the present invention and adjuvant are after pretreatment, and when raw material input amount is constant, catalyst and the required amount added of adjuvant significantly reduce, and reduce production cost, and heavy component reduces, and is beneficial to later separation purification work；
(3) waste water that Second distillation column tower top is deviate from flows to described first tower bottom of rectifying tower with gas phase, and waste water condensation liberated heat may be used to heating the first rectifying column, saves energy consumption；
(4) first rectifying column bottoms are partitioned column, by the main body of tower is divided into two so that three components carry out mass transfer, heat transfer in tower, realize the separation of three components simultaneously simultaneously, complete the separation task generally needing two conventional towers just can complete, greatly reduce energy expenditure；
(5) by synthesis product is carried out rectification separating-purifying, obtain product 2, the purity of 5-chlorophenesic acid is more than 99.7%, reclaim the raw material 1 obtained, 4-dichloro-benzenes, solvent and water purity both are greater than 99%, reclaim raw material, solvent can be directly used for next group synthetic reaction, reduces production cost, is beneficial to environmental protection；
(6) synthesis step of the present invention only has a step, and route is short, reacts without High Temperature High Pressure, and reaction condition is gentle, low for equipment requirements, and technological operation is simple, and in product preparation process, almost no waste discharge, environmentally friendly, is beneficial to industrialized production.
Part is embodied by the further advantage of the present invention, target and feature by description below, and part is also by by being understood by those skilled in the art the research of the present invention and practice.
Detailed description of the invention
Below in conjunction with embodiment, the present invention is described in further detail, to make those skilled in the art can implement according to this with reference to description word.
Should be appreciated that used herein such as " have ", existence or the interpolation of other elements one or more or its combination do not allotted in " comprising " and " including " term.
<example 1>
Fe by 0.00125 weight portion5V8O27.5With in the acetic acid that the polyphosphoric acids of 0.025 weight portion joins 1/50 weight portion, at 55 DEG C, stirring 5min, adds 0.0033 × 10 afterwards-4The peracetic acid of weight portion, after continuing stirring 20min, obtains activating solution；
The acetic acid of the Isosorbide-5-Nitrae-dichloro-benzenes of 1 weight portion and 3 weight portions is stirred to mix homogeneously at the temperature of 25 DEG C, is subsequently adding activating solution, obtains reactant liquor；
At 35 DEG C of temperature, dropping in reactant liquor by the peracetic acid of 0.0034 weight portion, time for adding is 1.5h, after dropwising, continues stirring 0.5h；It is subsequently added the sodium sulfite of 0.2 weight portion, stirs 5min, filter, obtain filtrate；
Above-mentioned filtrate is joined in evaporating kettle with the speed of 6000kg/h, its feeding temperature is 30 DEG C, pressure is 400kPa, to remove the heavy constituents such as phosphoric acid in mother solution, tar, catalyst, for the recovery of phosphoric acid, catalyst, the gas phase that evaporating kettle is deviate from enters the first rectifying column, and wherein charging flow velocity is 7000kg/h, feeding temperature is 80 DEG C, and feed pressure is 35kPa；First rectifying column is combination tower, top is 2 sections of packed towers, bottom is the number of plates is the partitioned column of 30 layers, first rectifying column tower top deviates from waste water with the speed of 550kg/h, the mixture extracting acetic acid and water in tower out enters Second distillation column, Isosorbide-5-Nitrae-dichloro-benzenes and the mixture of 2,5-chlorophenesic acids that tower reactor obtains enter stripper.
The number of plates of Second distillation column is 60 layers, and its charging flow velocity is 2500kg/h, and feeding temperature is 70 DEG C, and pressure is 25kPa；Second distillation column tower top deviates from waste water with the speed of 190kg/h, tower reactor reclaims with the speed of 3500kg/h and obtains acetic acid, wherein the isolated gas phase of the tower top of Second distillation column flows to the left side tower reactor heating of the first partition in tower, and self the condensed waste water that becomes flows out, and saves energy consumption.
The number of plates of stripper is 12 layers, and top gaseous phase enters tower reactor on the right side of the first rectifying tower dividing plate, and tower bottoms enters 1 with the flow velocity of 1000kg/h, 4-dichloro-benzenes treating column, wherein Isosorbide-5-Nitrae-dichloro-benzenes treating column is 3 sections of packed towers, its feeding temperature is 120 DEG C, and pressure is 30kPa；Isosorbide-5-Nitrae-dichloro-benzenes treating column tower top isolates Isosorbide-5-Nitrae-dichloro-benzenes with the speed of 890kg/h, and tower bottoms enters the 3rd rectifying column with 200kg/h, and wherein the 3rd rectifying column is 3 sections of packed towers, and its feeding temperature is 100 DEG C, and pressure is 8kPa；3rd rectifying tower ejects light component and returns Isosorbide-5-Nitrae-dichloro-benzenes treating column, goes out product 2,5-chlorophenesic acid product with the velocity separation of 250kg/h in tower, and tower reactor goes out heavy constituent, returns evaporating kettle.
The product 2 that final rectification obtains, the purity of 5-chlorophenesic acid is 99.7%, the purity reclaiming the acetic acid obtained is 99.3%, and the purity reclaiming the Isosorbide-5-Nitrae-dichloro-benzenes obtained is 99.3%, wherein there are 2,5-chlorophenesic acid 0.33 part, reclaims and obtains 0.58 part of raw material Isosorbide-5-Nitrae-dichloro-benzenes, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid is 70.9%.
<example 2>
Fe by 0.01 weight portion5V8O27.5With in the acetic acid that the polyphosphoric acids of 0.1 weight portion joins 1/10 weight portion, at 65 DEG C, stirring 10min, adds 0.0071 × 10 afterwards-3The peracetic acid of weight portion, after continuing stirring 20min, obtains activating solution；
The acetic acid of the Isosorbide-5-Nitrae-dichloro-benzenes of 1 weight portion and 12 weight portions is stirred to mix homogeneously at the temperature of 30 DEG C, is subsequently adding activating solution, obtains reactant liquor；
At 75 DEG C of temperature, dropping in reactant liquor by the peracetic acid of 0.017 weight portion, time for adding is 6h, after dropwising, continues stirring 0.5h；It is subsequently added the sodium sulfite of 0.98 weight portion, stirs 5min, filter, obtain filtrate；
Above-mentioned filtrate is joined in evaporating kettle with the speed of 9000kg/h, its feeding temperature is 35 DEG C, pressure is 550kPa, to remove the heavy constituents such as phosphoric acid in mother solution, tar, catalyst, for the recovery of phosphoric acid, catalyst, the gas phase that evaporating kettle is deviate from enters the first rectifying column, and wherein charging flow velocity is 8500kg/h, feeding temperature is 100 DEG C, and feed pressure is 45kPa；First rectifying column is combination tower, top is 2 sections of packed towers, bottom is the number of plates is the partitioned column of 30 layers, first rectifying column tower top deviates from waste water with the speed of 710kg/h, the mixture extracting acetic acid and water in tower out enters Second distillation column, Isosorbide-5-Nitrae-dichloro-benzenes and the mixture of 2,5-chlorophenesic acids that tower reactor obtains enter stripper.
The number of plates of Second distillation column is 60 layers, and its charging flow velocity is 4000kg/h, and feeding temperature is 85 DEG C, and pressure is 35kPa；Second distillation column tower top deviates from waste water with the speed of 210kg/h, tower reactor reclaims with the speed of 5500kg/h and obtains acetic acid, wherein the isolated gas phase of the tower top of Second distillation column flows to the left side tower reactor heating of the first partition in tower, and self the condensed waste water that becomes flows out, and saves energy consumption.
The number of plates of stripper is 12 layers, and top gaseous phase enters tower reactor on the right side of the first rectifying tower dividing plate, and tower bottoms enters 1 with the flow velocity of 1600kg/h, 4-dichloro-benzenes treating column, wherein Isosorbide-5-Nitrae-dichloro-benzenes treating column is 3 sections of packed towers, its feeding temperature is 150 DEG C, and pressure is 45kPa；Isosorbide-5-Nitrae-dichloro-benzenes treating column tower top isolates Isosorbide-5-Nitrae-dichloro-benzenes with the speed of 930kg/h, and tower bottoms enters the 3rd rectifying column with 500kg/h, and wherein the 3rd rectifying column is 3 sections of packed towers, and its feeding temperature is 120 DEG C, and pressure is 12kPa；3rd rectifying tower ejects light component and returns Isosorbide-5-Nitrae-dichloro-benzenes treating column, goes out product 2,5-chlorophenesic acid product with the velocity separation of 300kg/h in tower, and tower reactor goes out heavy constituent, returns evaporating kettle.
The product 2 that final rectification obtains, the purity of 5-chlorophenesic acid is 99.7%, the purity reclaiming the acetic acid obtained is 99.2%, and the purity reclaiming the Isosorbide-5-Nitrae-dichloro-benzenes obtained is 99.3%, wherein there are 2,5-chlorophenesic acid 0.35 part, reclaims and obtains 0.61 part of raw material Isosorbide-5-Nitrae-dichloro-benzenes, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid is 80.9%
<example 3>
Fe by 0.006 weight portion5V8O27.5With in the acetic acid that the polyphosphoric acids of 0.05 weight portion joins 1/30 weight portion, at 60 DEG C, stirring 8min, adds 0.0064 × 10 afterwards-3The peracetic acid of weight portion, after continuing stirring 20min, obtains activating solution；
The acetic acid of the Isosorbide-5-Nitrae-dichloro-benzenes of 1 weight portion and 8 weight portions is stirred to mix homogeneously at the temperature of 28 DEG C, is subsequently adding activating solution, obtains reactant liquor；
At 50 DEG C of temperature, dropping in reactant liquor by the peracetic acid of 0.031 weight portion, time for adding is 4, after dropwising, continues stirring 0.5h；It is subsequently added the sodium sulfite of 1.72 weight portions, stirs 5min, filter, obtain filtrate；
Above-mentioned filtrate is joined in evaporating kettle with the speed of 7500kg/h, its feeding temperature is 32 DEG C, pressure is 470kPa, to remove the heavy constituents such as phosphoric acid in mother solution, tar, catalyst, for the recovery of phosphoric acid, catalyst, the gas phase that evaporating kettle is deviate from enters the first rectifying column, and wherein charging flow velocity is 7800kg/h, feeding temperature is 90 DEG C, and feed pressure is 40kPa；First rectifying column is combination tower, top is 2 sections of packed towers, bottom is the number of plates is the partitioned column of 30 layers, first rectifying column tower top deviates from waste water with the speed of 660kg/h, the mixture extracting acetic acid and water in tower out enters Second distillation column, Isosorbide-5-Nitrae-dichloro-benzenes and the mixture of 2,5-chlorophenesic acids that tower reactor obtains enter stripper.
The number of plates of Second distillation column is 60 layers, and its charging flow velocity is 3200kg/h, and feeding temperature is 80 DEG C, and pressure is 30kPa；Second distillation column tower top deviates from waste water with the speed of 210kg/h, tower reactor reclaims with the speed of 5200kg/h and obtains acetic acid, wherein the isolated gas phase of the tower top of Second distillation column flows to the left side tower reactor heating of the first partition in tower, and self the condensed waste water that becomes flows out, and saves energy consumption.
The number of plates of stripper is 12 layers, and top gaseous phase enters tower reactor on the right side of the first rectifying tower dividing plate, and tower bottoms enters 1 with the flow velocity of 1300kg/h, 4-dichloro-benzenes treating column, wherein Isosorbide-5-Nitrae-dichloro-benzenes treating column is 3 sections of packed towers, its feeding temperature is 135 DEG C, and pressure is 40kPa；Isosorbide-5-Nitrae-dichloro-benzenes treating column tower top isolates Isosorbide-5-Nitrae-dichloro-benzenes with the speed of 910kg/h, and tower bottoms enters the 3rd rectifying column with 350kg/h, and wherein the 3rd rectifying column is 3 sections of packed towers, and its feeding temperature is 110 DEG C, and pressure is 10kPa；3rd rectifying tower ejects light component and returns Isosorbide-5-Nitrae-dichloro-benzenes treating column, goes out product 2,5-chlorophenesic acid product with the velocity separation of 270kg/h in tower, and tower reactor goes out heavy constituent, returns evaporating kettle.
The product 2 that final rectification obtains, the purity of 5-chlorophenesic acid is 99.8%, the purity reclaiming the acetic acid obtained is 99.2%, and the purity reclaiming the Isosorbide-5-Nitrae-dichloro-benzenes obtained is 99.2%, wherein there are 2,5-chlorophenesic acid 0.33 part, reclaims and obtains 0.60 part of raw material Isosorbide-5-Nitrae-dichloro-benzenes, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid is 74.4%.
<example 4>
Fe by 0.01 weight portion2V5O15.5With in the acetic acid that the polyphosphoric acids of 0.1 weight portion joins 1/10 weight portion, at 65 DEG C, stirring 10min, adds 0.013 × 10 afterwards-3The peracetic acid of weight portion, after continuing stirring 20min, obtains activating solution；
The acetic acid of the Isosorbide-5-Nitrae-dichloro-benzenes of 1 weight portion and 12 weight portions is stirred to mix homogeneously at the temperature of 30 DEG C, is subsequently adding activating solution, obtains reactant liquor；
At 75 DEG C of temperature, dropping in reactant liquor by the peracetic acid of 0.017 weight portion, time for adding is 6h, after dropwising, continues stirring 0.5h；It is subsequently added the sodium sulfite of 0.98 weight portion, stirs 5min, filter, obtain filtrate；
Above-mentioned filtrate is joined in evaporating kettle with the speed of 6000kg/h, its feeding temperature is 30 DEG C, pressure is 400kPa, to remove the heavy constituents such as phosphoric acid in mother solution, tar, catalyst, for the recovery of phosphoric acid, catalyst, the gas phase that evaporating kettle is deviate from enters the first rectifying column, and wherein charging flow velocity is 7000kg/h, feeding temperature is 80 DEG C, and feed pressure is 35kPa；First rectifying column is combination tower, top is 2 sections of packed towers, bottom is the number of plates is the partitioned column of 30 layers, first rectifying column tower top deviates from waste water with the speed of 550kg/h, the mixture extracting acetic acid and water in tower out enters Second distillation column, Isosorbide-5-Nitrae-dichloro-benzenes and the mixture of 2,5-chlorophenesic acids that tower reactor obtains enter stripper.
The number of plates of Second distillation column is 60 layers, and its charging flow velocity is 2500kg/h, and feeding temperature is 70 DEG C, and pressure is 25kPa；Second distillation column tower top deviates from waste water with the speed of 190kg/h, tower reactor reclaims with the speed of 3500kg/h and obtains acetic acid, wherein the isolated gas phase of the tower top of Second distillation column flows to the left side tower reactor heating of the first partition in tower, and self the condensed waste water that becomes flows out, and saves energy consumption.
The number of plates of stripper is 12 layers, and top gaseous phase enters tower reactor on the right side of the first rectifying tower dividing plate, and tower bottoms enters 1 with the flow velocity of 1000kg/h, 4-dichloro-benzenes treating column, wherein Isosorbide-5-Nitrae-dichloro-benzenes treating column is 3 sections of packed towers, its feeding temperature is 120 DEG C, and pressure is 30kPa；Isosorbide-5-Nitrae-dichloro-benzenes treating column tower top isolates Isosorbide-5-Nitrae-dichloro-benzenes with the speed of 890kg/h, and tower bottoms enters the 3rd rectifying column with 200kg/h, and wherein the 3rd rectifying column is 3 sections of packed towers, and its feeding temperature is 100 DEG C, and pressure is 8kPa；3rd rectifying tower ejects light component and returns Isosorbide-5-Nitrae-dichloro-benzenes treating column, goes out product 2,5-chlorophenesic acid product with the velocity separation of 250kg/h in tower, and tower reactor goes out heavy constituent, returns evaporating kettle.
The product 2 that final rectification obtains, the purity of 5-chlorophenesic acid is 99.7%, the purity reclaiming the acetic acid obtained is 99.1%, and the purity reclaiming the Isosorbide-5-Nitrae-dichloro-benzenes obtained is 99.3%, wherein there are 2,5-chlorophenesic acid 0.21 part, reclaims and obtains 0.6 part of raw material Isosorbide-5-Nitrae-dichloro-benzenes, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid is 47.3%.
<example 5>
Fe by 0.01 weight portion7V12O40.5With in the acetic acid that the polyphosphoric acids of 0.1 weight portion joins 1/10 weight portion, at 65 DEG C, stirring 10min, adds 0.0048 × 10 afterwards-3The peracetic acid of weight portion, after continuing stirring 20min, obtains activating solution；
The acetic acid of the Isosorbide-5-Nitrae-dichloro-benzenes of 1 weight portion and 12 weight portions is stirred to mix homogeneously at the temperature of 30 DEG C, is subsequently adding activating solution, obtains reactant liquor；
At 75 DEG C of temperature, dropping in reactant liquor by the peracetic acid of 0.017 weight portion, time for adding is 6h, after dropwising, continues stirring 0.5h；It is subsequently added the sodium sulfite of 0.98 weight portion, stirs 5min, filter, obtain filtrate；
Above-mentioned filtrate is joined in evaporating kettle with the speed of 6000kg/h, its feeding temperature is 30 DEG C, pressure is 400kPa, to remove the heavy constituents such as phosphoric acid in mother solution, tar, catalyst, for the recovery of phosphoric acid, catalyst, the gas phase that evaporating kettle is deviate from enters the first rectifying column, and wherein charging flow velocity is 7000kg/h, feeding temperature is 80 DEG C, and feed pressure is 35kPa；First rectifying column is combination tower, top is 2 sections of packed towers, bottom is the number of plates is the partitioned column of 30 layers, first rectifying column tower top deviates from waste water with the speed of 550kg/h, the mixture extracting acetic acid and water in tower out enters Second distillation column, Isosorbide-5-Nitrae-dichloro-benzenes and the mixture of 2,5-chlorophenesic acids that tower reactor obtains enter stripper.
The number of plates of Second distillation column is 60 layers, and its charging flow velocity is 2500kg/h, and feeding temperature is 70 DEG C, and pressure is 25kPa；Second distillation column tower top deviates from waste water with the speed of 190kg/h, tower reactor reclaims with the speed of 3500kg/h and obtains acetic acid, wherein the isolated gas phase of the tower top of Second distillation column flows to the left side tower reactor heating of the first partition in tower, and self the condensed waste water that becomes flows out, and saves energy consumption.
The number of plates of stripper is 12 layers, and top gaseous phase enters tower reactor on the right side of the first rectifying tower dividing plate, and tower bottoms enters 1 with the flow velocity of 1000kg/h, 4-dichloro-benzenes treating column, wherein Isosorbide-5-Nitrae-dichloro-benzenes treating column is 3 sections of packed towers, its feeding temperature is 120 DEG C, and pressure is 30kPa；Isosorbide-5-Nitrae-dichloro-benzenes treating column tower top isolates Isosorbide-5-Nitrae-dichloro-benzenes with the speed of 890kg/h, and tower bottoms enters the 3rd rectifying column with 200kg/h, and wherein the 3rd rectifying column is 3 sections of packed towers, and its feeding temperature is 100 DEG C, and pressure is 8kPa；3rd rectifying tower ejects light component and returns Isosorbide-5-Nitrae-dichloro-benzenes treating column, goes out product 2,5-chlorophenesic acid product with the velocity separation of 250kg/h in tower, and tower reactor goes out heavy constituent, returns evaporating kettle.
The product 2 that final rectification obtains, the purity of 5-chlorophenesic acid is 99.8%, the purity reclaiming the acetic acid obtained is 99.2%, and the purity reclaiming the Isosorbide-5-Nitrae-dichloro-benzenes obtained is 99.5%, wherein there are 2,5-chlorophenesic acid 0.27 part, reclaims and obtains 0.63 part of raw material Isosorbide-5-Nitrae-dichloro-benzenes, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid is 65.8%.
In order to the effect of the present invention is described, inventor provides comparative experiments as follows:
<comparative example 1>
Not to catalyst Fe5V8O27.5Carrying out pretreatment with adjuvant polyphosphoric acids, be added directly in the homogeneous mixture of Isosorbide-5-Nitrae-dichloro-benzenes and acetic acid, all the other parameters are identical with example 1, and technical process is also identical.Finally being rectifying to obtain 2,5-chlorophenesic acid 0.26 part, reclaim and obtain 0.6 part of raw material Isosorbide-5-Nitrae-dichloro-benzenes, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid only has 58.6%.
<comparative example 2>
In this comparative example, adjuvant polyphosphoric acids and solvent acetic acid are respectively adopted other materials and are replaced, and carry out single factor test contrast test with example 3, and all the other parameters are identical with example 3, technical process is also identical, and different auxiliary auxiliary agent and the solvent impact on synthesizing reaction yield are in Table 1.
The impact on synthesis reaction yield of table 1 different catalysts, adjuvant and solvent
<comparative example 3>
When Rectification Tower Design, the first rectifying column bottom is not provided with partitioned column, and all the other parameters are identical with example 3, and technical process is also identical.The product 2 that final rectification obtains, the purity of 5-chlorophenesic acid is 93.3%, the purity reclaiming the acetic acid obtained is 90.2%, and the purity reclaiming the Isosorbide-5-Nitrae-dichloro-benzenes obtained is 90.7%, wherein there are 2,5-chlorophenesic acid 0.29 part, reclaims and obtains 0.54 part of raw material Isosorbide-5-Nitrae-dichloro-benzenes, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid is 56.9%.
<comparative example 4>
Different feed states can make to change from the quantity of steam of feedboard rising and the amount of liquid of decline, thus having influence on separation efficiency, in this comparative example, carry out the first rectifying column respectively, Second distillation column, 3rd rectifying column, 1, single factor test contrast test (the charging flow velocity only for one of them rectifying column of the charging parameter of 4-dichloro-benzenes treating column and example 3, a parameter in feeding temperature and feed pressure is changed), all the other parameters are identical with example 3, technical process is also identical, the concrete charging parameter of rectifying column and separating effect are in Table 2.
The charging parameter of table 2 rectifying column and separating effect
<comparative example 5>
Different feed states can make to change from the quantity of steam of feedboard rising and the amount of liquid of decline, thus having influence on separation efficiency, in this comparative example, carry out the first rectifying column respectively, Second distillation column, 3rd rectifying column, 1, single factor test contrast test (the charging flow velocity only for one of them rectifying column of the charging parameter of 4-dichloro-benzenes treating column and example 3, a parameter in feeding temperature and feed pressure is changed), all the other parameters are identical with example 3, technical process is also identical, the concrete charging parameter of rectifying column and separating effect are in Table 3.
The charging parameter of table 3 rectifying column and separating effect
From the various embodiments described above and comparative example it can be seen that, in instances, 2, in the synthetic reaction of 5-chlorophenesic acid, owing to catalyst and adjuvant have been carried out pretreatment, its effect is significantly higher than in comparative example to be directly added into catalyst and the adjuvant of not pretreatment, and the first rectifying column bottom is designed as partitioned column, and its rectification and purification effect is substantially better than in comparative example to be not provided with the structure of partitioned column.
Comparative example 1 is compared with example, and comparative example adopts not pretreated catalyst and adjuvant, and its product yield is 58.6%, is substantially less than in embodiment 1 product yield of 70.9%.
Comparative example 2 is compared with embodiment, owing to have employed catalyst Fe in example 35V8O27.5, adjuvant polyphosphoric acids and solvent acetic acid, the yield of product is significantly higher than in comparative example to be respectively adopted the situation of other substitute materials.
Comparative example 3 is compared with embodiment, first rectifying column bottom is not provided with partitioned column, organic solvent and the purity of raw material that the product obtained and recovery obtain all substantially reduce, and owing to separating effect declines, portioned product and feedstock portions are taken away by impurity such as solvents, the amount of the product obtained also declines to some extent, and product yield reduces.
Comparative example 4 is compared with embodiment, and the flow velocity of each rectifying column charging, temperature and pressure are below scope disclosed in this invention, the too low phenomenon of leakage that may result in of the flow velocity of rectifying column charging, reduces rectification effect；The too low thermic load that can increase evaporating kettle at the bottom of tower of feeding temperature, reduces the refrigeration duty of overhead condenser, affects tower body temperature, changes vapor liquid equilibrium；Feed pressure is too low, and tower top heavy component content can be too high, affects separator purity, from table 2 it can be seen that the flow velocity of each rectifying column charging, temperature and pressure are lower than scope disclosed in this invention, rectification effect can be affected, causing that separator purity declines, product yield reduces.
Comparative example 5 is compared with embodiment, the flow velocity of each rectifying column charging, temperature and pressure are all higher than scope disclosed in this invention, the too high change tower top of flow velocity of rectifying column charging and the temperature of tower reactor, ring vapor liquid equilibrium in tower, the too high refrigeration duty that can increase overhead condenser of feeding temperature, reduce the thermic load of overhead condenser, affect tower body temperature, change vapor liquid equilibrium；Feed pressure is too high, and at the bottom of tower, Light ends content can be too high, affects separator purity, from table 3 it can be seen that the flow velocity of each rectifying column charging, temperature and pressure are higher than scope disclosed in this invention, rectification effect also can be affected, causing that separator purity declines, product yield reduces.
Visible, by using a certain amount of oxidant that catalyst and adjuvant are carried out pretreatment, catalytic performance and the catalytic effect of catalyst can be effectively improved, significantly improve efficiency and the yield of synthetic reaction；
In addition, first rectifying column bottom is the number of plates is the partitioned column structure of 30 layers, by the main body of tower is divided into two so that three components carry out mass transfer, heat transfer in tower, realize the separation of three components simultaneously simultaneously, first rectifying column tower top deviates from waste water, extracting the mixture of solvent and water in tower out, tower reactor obtains Isosorbide-5-Nitrae-dichloro-benzenes and 2, the mixture of 5-chlorophenesic acid, and greatly reduce energy expenditure；
Additionally, catalyst of the present invention and adjuvant are after pretreatment, when raw material input amount is constant, owing to the required amount added of the raising of catalytic efficiency, catalyst and adjuvant all significantly reduces, reduce production cost, and heavy component reduces, it is beneficial to later separation purification work；
Additionally, synthesis step of the present invention only has a step, route is short, reacts without High Temperature High Pressure, and reaction condition is gentle, low for equipment requirements, and technological operation is simple, and in product preparation process, almost no waste discharge, environmentally friendly, is beneficial to industrialized production.
Although embodiment of the present invention are disclosed as above, but it is not restricted in description and embodiment listed utilization.It can be applied to various applicable the field of the invention completely.For those skilled in the art, it is easily achieved other amendment.Therefore, under the general concept limited without departing substantially from claim and equivalency range, the present invention is not limited to specific details and shown here as the embodiment with description.
Claims (9)
1. the preparation technology for 2,5-chlorophenesic acids of mass production, it is characterised in that comprise the following steps:
Step one: by the Fe of 1/800～1/100 weight portionxVyOzWith in the acetic acid that the polyphosphoric acids of 1/80～1/10 weight portion joins 1/50～1/10 weight portion, at 50～65 DEG C, stirring 5～10min, is subsequently adding and described FexVyOzMol ratio is the peracetic acid of 0.3～1.2, continues stirring 15～25min, obtains activating solution；
Wherein, described FexVyOzIn, 2≤x≤7,5≤y≤12,15.5≤z≤40.5；
Step 2: the acetic acid of the Isosorbide-5-Nitrae-dichloro-benzenes of 1 weight portion and 3～12 weight portions is stirred to mix homogeneously at the temperature not higher than 30 DEG C, is subsequently adding described activating solution, obtains reactant liquor；
Step 3: at 30～75 DEG C of temperature, adds in described reactant liquor by the peracetic acid that mol ratio is 0.5～5 with described Isosorbide-5-Nitrae-dichloro-benzenes, and time for adding is 1.5～6h, after dropwising, continues stirring 1h；It is subsequently added and sodium sulfite or sodium sulfite that described peracetic acid mol ratio is 0.5～0.8, stirs 5min, filter, obtain filtrate；
Step 4: by least three rectifying column, described filtrate is come separating-purifying, described rectifying column includes the first rectifying column, the Second distillation column being connected in parallel by pipeline respectively and the 3rd rectifying column with described first rectifying column；
Wherein, the charging flow velocity of described first rectifying column is 7000～8500kg/h, and feeding temperature is 80～100 DEG C, and feed pressure is 35～45kPa；
The charging flow velocity of described Second distillation column is 2500～4000kg/h, and feeding temperature is 70～85 DEG C, and feed pressure is 25～35kPa；
The charging flow velocity of described 3rd rectifying column is 200～500kg/h, and feeding temperature is 100～120 DEG C, and feed pressure is 8～12kPa.
2. the preparation technology of 2, the 5-chlorophenesic acids for mass production as claimed in claim 1, it is characterised in that described FexVyOzFor Fe5V8O27.5。
3. the preparation technology of 2, the 5-chlorophenesic acids for mass production as claimed in claim 1, it is characterised in that in step one, described FexVyOzAddition be 1/500～1/200 weight portion, the amount that described polyphosphoric acids adds is 1/50～1/30 weight portion, and the amount that acetic acid described in step 2 adds is 5～8 weight portions, and the mol ratio of peracetic acid described in step 3 and described Isosorbide-5-Nitrae-dichloro-benzenes is 1.2～3.5.
4. the preparation technology of 2, the 5-chlorophenesic acids for mass production as claimed in claim 1, it is characterised in that described filtrate before entering rectifying column at least through an evaporating kettle to deviate from heavy component.
5. the preparation technology of 2, the 5-chlorophenesic acids for mass production as claimed in claim 4, it is characterised in that the charging flow velocity of described evaporating kettle is 6000～9000kg/h, and feeding temperature is 30～35 DEG C, and pressure is 400～550kPa.
6. as claimed in claim 1 for the 2 of mass production, the preparation technology of 5-chlorophenesic acid, it is characterized in that, stripper and 1 also it is disposed with between described first rectifying column and described Second distillation column, 4-dichloro-benzenes treating column, in order to the refining purity reclaiming Isosorbide-5-Nitrae-dichloro-benzenes and improving product further.
7. as claimed in claim 6 for the 2 of mass production, the preparation technology of 5-chlorophenesic acid, it is characterized in that, described first rectifying column is combination tower, and top is 2 sections of packed towers, bottom is the number of plates is the partitioned column of 33 layers, described first rectifying column tower top deviates from waste water, tower is extracted out described acetic acid and water mixture enter described Second distillation column, tower reactor obtain described 1, the mixed liquor of 4-dichloro-benzenes and described 2,5-chlorophenesic acids enters described stripper.
8. the preparation technology of 2, the 5-chlorophenesic acids for mass production as claimed in claim 1, it is characterised in that the number of plates of described Second distillation column is 70 layers, and described 3rd rectifying column is 3 sections of packed towers.
9. as claimed in claim 6 for the 2 of mass production, the preparation technology of 5-chlorophenesic acid, it is characterized in that, the number of plates of described stripper is 10 layers, described 1,4-dichloro-benzenes treating column is 3 sections of packed towers, wherein, the charging flow velocity of described Isosorbide-5-Nitrae-dichloro-benzenes treating column is 1000～1600kg/h, feeding temperature is 120～150 DEG C, and pressure is 30～45kPa.
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