CN104876805A - Preparation process for mass production of 2, 5-dichlorophenol - Google Patents
Preparation process for mass production of 2, 5-dichlorophenol Download PDFInfo
- Publication number
- CN104876805A CN104876805A CN201510336996.8A CN201510336996A CN104876805A CN 104876805 A CN104876805 A CN 104876805A CN 201510336996 A CN201510336996 A CN 201510336996A CN 104876805 A CN104876805 A CN 104876805A
- Authority
- CN
- China
- Prior art keywords
- tower
- acid
- dichlorobenzene
- rectifying tower
- nitrae
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/60—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by oxidation reactions introducing directly hydroxy groups on a =CH-group belonging to a six-membered aromatic ring with the aid of other oxidants than molecular oxygen or their mixtures with molecular oxygen
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
- C07C37/70—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment
- C07C37/74—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment by distillation
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Catalysts (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Heterocyclic Carbon Compounds Containing A Hetero Ring Having Oxygen Or Sulfur (AREA)
Abstract
The invention provides a preparation process for mass production of 2, 5-dichlorophenol. The method comprises the steps of preparing a catalyst; synthesizing a target product through 1, 4-dichlorobenzene by the one-step method; continuously rectifying the product 2, 5-dichlorophenol; recovering a substrate and a solvent. According to the preparation process, the catalyst can obviously increase the synthesizing reaction efficiency and yield; the production cost can be reduced; the heavy components can be decreased; therefore, the subsequent separating and purifying works can be conveniently carried out; the product of the synthetic reaction is rectified, separated and purified, so that the purity of the product 2, 5-dichlorophenol is more than 99.7%; the purity of the recovered raw material, namely, 1, 4-dichlorobenzene and the purity of the solvent and water are more than 99%; the recovered raw material and the solvent can be directly used in the next synthetic reaction; therefore, the production cost can be reduced, and the environment can be protected.
Description
Technical field
The present invention relates to the preparation method of 2,5-chlorophenesic acid.More particularly, the present invention relates to a kind of with Isosorbide-5-Nitrae-dichlorobenzene for raw material, efficiently synthesize 2,5-chlorophenesic acid by single step reaction, then the mass production technique that multistep continuous rectification prepares high purity 2,5-chlorophenesic acid carried out to it.
Background technology
2,5-chlorophenesic acid is the intermediate of a kind of important agricultural chemicals, medicine, dyestuff, nitrogen fertilizer potentiating agent and leather fungicide etc.At present, 2,5-chlorophenesic acid is used for the synthesis of the chloro-O-Anisic Acid of weedicide 3,6-bis-(Dicamba).
The method of current preparation 2,5-chlorophenesic acid, mainly contains 1,2,4-trichlorobenzene hydrolysis method and 2,5-dichlorphenamide bulk powder diazonium hydrolysis method.But 1,2,4-trichlorobenzene hydrolysis method needs to be obtained by high temperature and high pressure hydrolysis, can use a large amount of bronsted lowry acids and bases bronsted lowries in preparation process, produces a large amount of three industrial wastes, and product is the mixture of isomers, and follow-up not easily separating-purifying, industrial cost is high.2,5-dichlorphenamide bulk powder diazonium hydrolysis method can use a large amount of sulfuric acid and nitrite, serious to equipment corrosion, energy consumption is high, is difficult to recycle and process, contaminate environment, substrate 2 in addition, the preparation process of 5-dichlorphenamide bulk powder relates to nitration reaction, and the use of a large amount of sulfuric acid and nitrite is not only had higher requirement to equipment, also exacerbates the harm to environment.
In order to solve this defect, in prior art with Isosorbide-5-Nitrae-dichlorobenzene for raw material prepares 2 by catalyzed oxidation, the method of 5-chlorophenesic acid, adopt heteropolyacid, heteropolyacid salt or its loading type to be catalyzer, its reaction scheme is short, simple to operate, almost environmentally safe, but catalytic effect is undesirable, catalyst recovery difficulty, and its follow-up purification refine technique is not disclosed, therefore, preparation technology of the prior art is all not suitable for mass production.
Summary of the invention
As the result of various extensive and careful research and experiment, the present inventor has been found that, with 1,4-dichlorobenzene is raw material, in the technological process by single step reaction catalyzed oxidation synthesis 2,5-chlorophenesic acid, adopt ferrovanadium sinter can significantly improve catalytic efficiency as catalyzer, improve the yield of 2,5-chlorophenesic acid, and the problems such as the recovery of reaction mixture Raw, solvent etc. and product purity that the present invention is directed to propose a kind of rationally continuous rectification separation method efficiently.
Therefore, an object of the present invention is to solve at least the problems referred to above and/or defect, and the advantage will illustrated at least is below provided.
Another object of the present invention is to provide a kind of synthetic method of 2,5-chlorophenesic acid, its with Isosorbide-5-Nitrae-dichlorobenzene for raw material, by single step reaction can be efficient catalyzed oxidation synthesis 2,5-chlorophenesic acid, product yield is high, low for equipment requirements and environmentally safe.
Another object of the present invention is the mixed composition obtained for described building-up reactions, provides a kind of efficient method for subsequent processing, on the basis that guarantee 2,5-chlorophenesic acid purity is higher, improves organic efficiency and the purity of raw material, solvent etc.
In order to realize according to these objects of the present invention and other advantage, provide a kind of preparation method of 2,5-chlorophenesic acid, it comprises the following steps:
Step one: by the Fe of 1/800 ~ 1/100 weight part
xv
yo
zjoin in the acetic acid of 1/50 ~ 1/10 weight part with the polyphosphoric acid of 1/80 ~ 1/10 weight part, at 50 ~ 65 DEG C, stir 5 ~ 10min, then add and described Fe
xv
yo
zmol ratio is the Peracetic Acid of 0.3 ~ 1.2, continues stirring 15 ~ 25min, obtains activation solution;
Step 2: the Isosorbide-5-Nitrae-dichlorobenzene of 1 weight part and the acetic acid of 3 ~ 12 weight parts are stirred at not higher than the temperature of 30 DEG C and mix, then add described activation solution, obtain reaction solution;
Step 3: at 30 ~ 75 DEG C of temperature, the Peracetic Acid being 0.5 ~ 5 by the mol ratio with described Isosorbide-5-Nitrae-dichlorobenzene adds in described reaction solution, and time for adding is 1.5 ~ 6h, after dropwising, continues to stir 1h; Add subsequently with described Peracetic Acid mol ratio be 0.5 ~ 0.8 sodium bisulfite or S-WAT, stir 5min, filter, obtain filtrate;
Step 4: described filtrate is carried out separating-purifying by least three rectifying tower, described rectifying tower comprises the first rectifying tower, the Second distillation column be connected in parallel by pipeline with described first rectifying tower respectively and the 3rd rectifying tower;
Wherein, the charging flow velocity of described first rectifying tower 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 tower is 200 ~ 500kg/h, and feeding temperature is 100 ~ 120 DEG C, and feed pressure is 8 ~ 12kP.
Preferably, in step one, described Fe
xv
yo
zadd-on be 1/500 ~ 1/200 weight part, the amount that described polyphosphoric acid adds is 1/50 ~ 1/30 weight part, the amount that acetic acid described in step 2 adds is 5 ~ 8 weight parts, and the mol ratio of Peracetic Acid described in step 3 and described Isosorbide-5-Nitrae-dichlorobenzene is 1.2 ~ 3.5.Described catalyzer is sinter Fe
xv
yo
z, after superoxide pre-treatment and activation, catalytic activity significantly improves, and catalytic efficiency also obviously promotes, and when the amount of substrate Isosorbide-5-Nitrae-dichlorobenzene is constant, the add-on of required catalyzer reduces 12 ~ 20 times.
Preferably, described filtrate before entering rectifying tower at least through an evaporating kettle to deviate from heavy constituent, with prevent recombinate 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 tower and described Second distillation column, be also disposed with stripping tower and Isosorbide-5-Nitrae-dichlorobenzene treating tower, in order to further refine and reclaim Isosorbide-5-Nitrae-dichlorobenzene and the purity improving product.
Preferably, described first rectifying tower is combination tower, top is 2 sections of packing towers, to be stage number be in the bottom partitioned column of 33 layers, packing tower has higher mass transfer and separating effect relative to tray column, tower height can be reduced, but cost is also higher, component for the charging of the present invention first rectifying tower is water, acetic acid, 1, 4-dichlorobenzene and described 2, the practical situation of the mixture of 5-chlorophenesic acid, be designed to top packing tower, the structure of bottom tray column, effectively can increase treatment capacity, on the basis ensureing the certain separation efficiency of material component, reduce tower height, reduce energy consumption,
Described first rectifying tower bottom is partitioned column mechanism, be divided into two by the main body tower, make three components in tower, carry out mass transfer, heat transfer simultaneously, realize the separation of three components simultaneously, described first rectifying tower 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-dichlorobenzene and described 2, the mixture of 5-chlorophenesic acid enters described stripping tower, and this tower structure completes the separation task usually needing two conventional towers just can complete, and greatly reduces energy expenditure.
Preferably, the stage number of described Second distillation column is 70 layers, it is refined further and obtains the higher acetic acid of purity, in order to recovery in next batch reaction, and Second distillation column tower top is deviate from waste water and is flowed to described first tower bottom of rectifying tower with gas phase, waste water condensation releases heat in order to heat the first rectifying tower, saves energy consumption;
Described 3rd rectifying tower is 3 sections of packing towers.3rd rectifying tower obtains product 2,5-chlorophenesic acid in order to be separated, and due to higher to the requirement of product purity, and packing tower has higher mass-transfer efficiency compared with tray column, therefore the present invention selects packing tower to reduce tower height, ensures product purity; Packing tower is designed to 3 sections, the purity of product 2, the 5-chlorophenesic acid obtained is greater than 99.7%, and filler disjunction is too many, the column internalss such as required sparger and redistributor also can correspondingly increase, increase cost, but filler segmentation very little, easily occurs wall stream effect, 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 stage number of described stripping tower is 10 layers, in order to the acetic acid in the mixed solution of Isosorbide-5-Nitrae-dichlorobenzene and 2,5-chlorophenesic acid and water to be separated further; Described Isosorbide-5-Nitrae-dichlorobenzene treating tower is 3 sections of packing towers, makes substrate Isosorbide-5-Nitrae-dichlorobenzene and product 2,5-chlorophenesic acid is effectively separated, wherein, and described 1, the charging flow velocity of 4-dichlorobenzene treating tower is 1000 ~ 1600kg/h, and feeding temperature is 120 ~ 150 DEG C, and pressure is 30 ~ 45kPa.
Wherein the preparation technology of catalyzer ferrovanadium sinter is: the Fe taking corresponding weight in proportion
2o
3and V
2o
5, ground 1 ~ 2 hour, obtained micron powder, by ground powder in 550 DEG C of preheatings one hour, be calcination 3 hours at 1200 DEG C in the atmosphere of 19: 1 at nitrogen and hydrogen volume ratio, obtain ferrovanadium sinter, after naturally cooling, the sinter that ball milling obtains to its particle diameter is 70 ~ 80nm, wash 3 times with deionized water, dry, obtain catalyzer ferrovanadium sinter.
Wherein work as Fe
2o
3and V
2o
5mass ratio when being 5: 9, sintered product is: Fe
5v
8o
27.5; Work as Fe
2o
3and V
2o
5mass ratio when being 1: 3, sinter is: Fe
2v
5o
15.5; Work as Fe
2o
3and V
2o
5mass ratio when being 1: 2, sinter is: Fe
7v
12o
40.5.
The present invention at least comprises following beneficial effect:
(1) by the pre-treatment to catalyzer, effectively can improve catalytic performance and the catalytic effect of catalyzer, thus improve efficiency and the yield of one-step synthesis reaction;
(2) catalyzer of the present invention and auxiliary are after pretreatment, and when raw material input amount is constant, the amount added needed for catalyzer and auxiliary obviously reduces, and reduces 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 in order to heat the first rectifying tower, can save energy consumption;
(4) first rectifying tower bottoms are partitioned column, be divided into two by the main body tower, make three components in tower, carry out mass transfer, heat transfer simultaneously, realize the separation of three components simultaneously, complete the separation task usually needing two conventional towers just can complete, greatly reduce energy expenditure;
(5) by carrying out rectifying separation purification to synthesis reaction product, obtain product 2, the purity of 5-chlorophenesic acid is greater than 99.7%, reclaim the raw material 1 obtained, 4-dichlorobenzene, solvent and water purity are all greater than 99%, recovery raw material, solvent can be directly used in next batch building-up reactions, reduce production cost, are beneficial to environmental protection;
(6) synthesis step of the present invention only has a step, and route is short, reacts without the need to High Temperature High Pressure, and reaction conditions 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 suitability for industrialized production.
Part is embodied by explanation below by other advantage of the present invention, target and feature, part also will by research and practice of the present invention by those skilled in the art is understood.
Embodiment
Below in conjunction with embodiment, the present invention is described in further detail, can implement according to this with reference to specification sheets word to make those skilled in the art.
Should be appreciated that used hereinly such as " to have ", other element one or more do not allotted in " comprising " and " comprising " term or the existence of its combination or interpolation.
< example 1>
By the Fe of 0.00125 weight part
5v
8o
27.5join in the acetic acid of 1/50 weight part with the polyphosphoric acid of 0.025 weight part, at 55 DEG C, stir 5min, after add 0.0033 × 10
-4the Peracetic Acid of weight part, after continuing to stir 20min, obtains activation solution;
Isosorbide-5-Nitrae-the dichlorobenzene of 1 weight part and the acetic acid of 3 weight parts are stirred at the temperature of 25 DEG C and mix, then add activation solution, obtain reaction solution;
At 35 DEG C of temperature, drop in reaction solution by the Peracetic Acid of 0.0034 weight part, time for adding is 1.5h, after dropwising, continues to stir 0.5h; Add the S-WAT of 0.2 weight part subsequently, stir 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 constituent such as phosphoric acid, tar, catalyzer in mother liquor, for the recovery of phosphoric acid, catalyzer, the gas phase that evaporating kettle is deviate from enters the first rectifying tower, and wherein charging flow velocity is 7000kg/h, feeding temperature is 80 DEG C, and feed pressure is 35kPa; First rectifying tower is combination tower, top is 2 sections of packing towers, to be stage number be in the bottom partitioned column of 30 layers, first rectifying tower 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, the mixture of Isosorbide-5-Nitrae-dichlorobenzene that tower reactor obtains and 2,5-chlorophenesic acid enters stripping tower.
The stage number 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 vapor phase stream of the tower top of Second distillation column is to the left side tower reactor heating of the first partition in tower, self becomes wastewater streams through condensation and goes out, save energy consumption.
The stage number of stripping tower 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-dichlorobenzene treating tower, wherein Isosorbide-5-Nitrae-dichlorobenzene treating tower is 3 sections of packing towers, its feeding temperature is 120 DEG C, and pressure is 30kPa; Isosorbide-5-Nitrae-dichlorobenzene treating tower tower top isolates Isosorbide-5-Nitrae-dichlorobenzene with the speed of 890kg/h, and tower bottoms enters the 3rd rectifying tower with 200kg/h, and wherein the 3rd rectifying tower is 3 sections of packing towers, and its feeding temperature is 100 DEG C, and pressure is 8kPa; 3rd rectifying tower ejects light constituent and returns Isosorbide-5-Nitrae-dichlorobenzene treating tower, and go out product 2,5-chlorophenesic acid product with the velocity separation of 250kg/h in tower, tower reactor goes out heavy constituent, returns evaporating kettle.
The product 2 that final rectifying 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-dichlorobenzene obtained is 99.3%, wherein obtain 2 altogether, 5-chlorophenesic acid 0.33 part, reclaims and obtains 0.58 part of raw material Isosorbide-5-Nitrae-dichlorobenzene, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid is 70.9%.
< example 2>
By the Fe of 0.01 weight part
5v
8o
27.5join in the acetic acid of 1/10 weight part with the polyphosphoric acid of 0.1 weight part, at 65 DEG C, stir 10min, after add 0.0071 × 10
-3the Peracetic Acid of weight part, after continuing to stir 20min, obtains activation solution;
Isosorbide-5-Nitrae-the dichlorobenzene of 1 weight part and the acetic acid of 12 weight parts are stirred at the temperature of 30 DEG C and mix, then add activation solution, obtain reaction solution;
At 75 DEG C of temperature, drop in reaction solution by the Peracetic Acid of 0.017 weight part, time for adding is 6h, after dropwising, continues to stir 0.5h; Add the sodium bisulfite of 0.98 weight part subsequently, stir 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 constituent such as phosphoric acid, tar, catalyzer in mother liquor, for the recovery of phosphoric acid, catalyzer, the gas phase that evaporating kettle is deviate from enters the first rectifying tower, and wherein charging flow velocity is 8500kg/h, feeding temperature is 100 DEG C, and feed pressure is 45kPa; First rectifying tower is combination tower, top is 2 sections of packing towers, to be stage number be in the bottom partitioned column of 30 layers, first rectifying tower 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, the mixture of Isosorbide-5-Nitrae-dichlorobenzene that tower reactor obtains and 2,5-chlorophenesic acid enters stripping tower.
The stage number 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 vapor phase stream of the tower top of Second distillation column is to the left side tower reactor heating of the first partition in tower, self becomes wastewater streams through condensation and goes out, save energy consumption.
The stage number of stripping tower 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-dichlorobenzene treating tower, wherein Isosorbide-5-Nitrae-dichlorobenzene treating tower is 3 sections of packing towers, its feeding temperature is 150 DEG C, and pressure is 45kPa; Isosorbide-5-Nitrae-dichlorobenzene treating tower tower top isolates Isosorbide-5-Nitrae-dichlorobenzene with the speed of 930kg/h, and tower bottoms enters the 3rd rectifying tower with 500kg/h, and wherein the 3rd rectifying tower is 3 sections of packing towers, and its feeding temperature is 120 DEG C, and pressure is 12kPa; 3rd rectifying tower ejects light constituent and returns Isosorbide-5-Nitrae-dichlorobenzene treating tower, and go out product 2,5-chlorophenesic acid product with the velocity separation of 300kg/h in tower, tower reactor goes out heavy constituent, returns evaporating kettle.
The product 2 that final rectifying 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-dichlorobenzene obtained is 99.3%, wherein obtain 2 altogether, 5-chlorophenesic acid 0.35 part, reclaims and obtains 0.61 part of raw material Isosorbide-5-Nitrae-dichlorobenzene, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid is 80.9%
< example 3>
By the Fe of 0.006 weight part
5v
8o
27.5join in the acetic acid of 1/30 weight part with the polyphosphoric acid of 0.05 weight part, at 60 DEG C, stir 8min, after add 0.0064 × 10
-3the Peracetic Acid of weight part, after continuing to stir 20min, obtains activation solution;
Isosorbide-5-Nitrae-the dichlorobenzene of 1 weight part and the acetic acid of 8 weight parts are stirred at the temperature of 28 DEG C and mix, then add activation solution, obtain reaction solution;
At 50 DEG C of temperature, drop in reaction solution by the Peracetic Acid of 0.031 weight part, time for adding is 4, after dropwising, and continues to stir 0.5h; Add the S-WAT of 1.72 weight parts subsequently, stir 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 constituent such as phosphoric acid, tar, catalyzer in mother liquor, for the recovery of phosphoric acid, catalyzer, the gas phase that evaporating kettle is deviate from enters the first rectifying tower, and wherein charging flow velocity is 7800kg/h, feeding temperature is 90 DEG C, and feed pressure is 40kPa; First rectifying tower is combination tower, top is 2 sections of packing towers, to be stage number be in the bottom partitioned column of 30 layers, first rectifying tower 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, the mixture of Isosorbide-5-Nitrae-dichlorobenzene that tower reactor obtains and 2,5-chlorophenesic acid enters stripping tower.
The stage number 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 vapor phase stream of the tower top of Second distillation column is to the left side tower reactor heating of the first partition in tower, self becomes wastewater streams through condensation and goes out, save energy consumption.
The stage number of stripping tower 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-dichlorobenzene treating tower, wherein Isosorbide-5-Nitrae-dichlorobenzene treating tower is 3 sections of packing towers, its feeding temperature is 135 DEG C, and pressure is 40kPa; Isosorbide-5-Nitrae-dichlorobenzene treating tower tower top isolates Isosorbide-5-Nitrae-dichlorobenzene with the speed of 910kg/h, and tower bottoms enters the 3rd rectifying tower with 350kg/h, and wherein the 3rd rectifying tower is 3 sections of packing towers, and its feeding temperature is 110 DEG C, and pressure is 10kPa; 3rd rectifying tower ejects light constituent and returns Isosorbide-5-Nitrae-dichlorobenzene treating tower, and go out product 2,5-chlorophenesic acid product with the velocity separation of 270kg/h in tower, tower reactor goes out heavy constituent, returns evaporating kettle.
The product 2 that final rectifying 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-dichlorobenzene obtained is 99.2%, wherein obtain 2 altogether, 5-chlorophenesic acid 0.33 part, reclaims and obtains 0.60 part of raw material Isosorbide-5-Nitrae-dichlorobenzene, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid is 74.4%.
< example 4>
By the Fe of 0.01 weight part
2v
5o
15.5join in the acetic acid of 1/10 weight part with the polyphosphoric acid of 0.1 weight part, at 65 DEG C, stir 10min, after add 0.013 × 10
-3the Peracetic Acid of weight part, after continuing to stir 20min, obtains activation solution;
Isosorbide-5-Nitrae-the dichlorobenzene of 1 weight part and the acetic acid of 12 weight parts are stirred at the temperature of 30 DEG C and mix, then add activation solution, obtain reaction solution;
At 75 DEG C of temperature, drop in reaction solution by the Peracetic Acid of 0.017 weight part, time for adding is 6h, after dropwising, continues to stir 0.5h; Add the sodium bisulfite of 0.98 weight part subsequently, stir 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 constituent such as phosphoric acid, tar, catalyzer in mother liquor, for the recovery of phosphoric acid, catalyzer, the gas phase that evaporating kettle is deviate from enters the first rectifying tower, and wherein charging flow velocity is 7000kg/h, feeding temperature is 80 DEG C, and feed pressure is 35kPa; First rectifying tower is combination tower, top is 2 sections of packing towers, to be stage number be in the bottom partitioned column of 30 layers, first rectifying tower 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, the mixture of Isosorbide-5-Nitrae-dichlorobenzene that tower reactor obtains and 2,5-chlorophenesic acid enters stripping tower.
The stage number 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 vapor phase stream of the tower top of Second distillation column is to the left side tower reactor heating of the first partition in tower, self becomes wastewater streams through condensation and goes out, save energy consumption.
The stage number of stripping tower 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-dichlorobenzene treating tower, wherein Isosorbide-5-Nitrae-dichlorobenzene treating tower is 3 sections of packing towers, its feeding temperature is 120 DEG C, and pressure is 30kPa; Isosorbide-5-Nitrae-dichlorobenzene treating tower tower top isolates Isosorbide-5-Nitrae-dichlorobenzene with the speed of 890kg/h, and tower bottoms enters the 3rd rectifying tower with 200kg/h, and wherein the 3rd rectifying tower is 3 sections of packing towers, and its feeding temperature is 100 DEG C, and pressure is 8kPa; 3rd rectifying tower ejects light constituent and returns Isosorbide-5-Nitrae-dichlorobenzene treating tower, and go out product 2,5-chlorophenesic acid product with the velocity separation of 250kg/h in tower, tower reactor goes out heavy constituent, returns evaporating kettle.
The product 2 that final rectifying 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-dichlorobenzene obtained is 99.3%, wherein obtain 2 altogether, 5-chlorophenesic acid 0.21 part, reclaims and obtains 0.6 part of raw material Isosorbide-5-Nitrae-dichlorobenzene, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid is 47.3%.
< example 5>
By the Fe of 0.01 weight part
7v
12o
40.5join in the acetic acid of 1/10 weight part with the polyphosphoric acid of 0.1 weight part, at 65 DEG C, stir 10min, after add 0.0048 × 10
-3the Peracetic Acid of weight part, after continuing to stir 20min, obtains activation solution;
Isosorbide-5-Nitrae-the dichlorobenzene of 1 weight part and the acetic acid of 12 weight parts are stirred at the temperature of 30 DEG C and mix, then add activation solution, obtain reaction solution;
At 75 DEG C of temperature, drop in reaction solution by the Peracetic Acid of 0.017 weight part, time for adding is 6h, after dropwising, continues to stir 0.5h; Add the sodium bisulfite of 0.98 weight part subsequently, stir 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 constituent such as phosphoric acid, tar, catalyzer in mother liquor, for the recovery of phosphoric acid, catalyzer, the gas phase that evaporating kettle is deviate from enters the first rectifying tower, and wherein charging flow velocity is 7000kg/h, feeding temperature is 80 DEG C, and feed pressure is 35kPa; First rectifying tower is combination tower, top is 2 sections of packing towers, to be stage number be in the bottom partitioned column of 30 layers, first rectifying tower 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, the mixture of Isosorbide-5-Nitrae-dichlorobenzene that tower reactor obtains and 2,5-chlorophenesic acid enters stripping tower.
The stage number 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 vapor phase stream of the tower top of Second distillation column is to the left side tower reactor heating of the first partition in tower, self becomes wastewater streams through condensation and goes out, save energy consumption.
The stage number of stripping tower 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-dichlorobenzene treating tower, wherein Isosorbide-5-Nitrae-dichlorobenzene treating tower is 3 sections of packing towers, its feeding temperature is 120 DEG C, and pressure is 30kPa; Isosorbide-5-Nitrae-dichlorobenzene treating tower tower top isolates Isosorbide-5-Nitrae-dichlorobenzene with the speed of 890kg/h, and tower bottoms enters the 3rd rectifying tower with 200kg/h, and wherein the 3rd rectifying tower is 3 sections of packing towers, and its feeding temperature is 100 DEG C, and pressure is 8kPa; 3rd rectifying tower ejects light constituent and returns Isosorbide-5-Nitrae-dichlorobenzene treating tower, and go out product 2,5-chlorophenesic acid product with the velocity separation of 250kg/h in tower, tower reactor goes out heavy constituent, returns evaporating kettle.
The product 2 that final rectifying 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-dichlorobenzene obtained is 99.5%, wherein obtain 2 altogether, 5-chlorophenesic acid 0.27 part, reclaims and obtains 0.63 part of raw material Isosorbide-5-Nitrae-dichlorobenzene, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid is 65.8%.
In order to effect of the present invention is described, contriver provides comparative experiments as follows:
< comparative example 1>
Not to catalyst Fe
5v
8o
27.5carry out pre-treatment with auxiliary polyphosphoric acid, directly join in the uniform mixture of Isosorbide-5-Nitrae-dichlorobenzene and acetic acid, identical with example 1 of all the other parameters, technological process is also identical.Finally obtain 2,5-chlorophenesic acid 0.26 part through rectifying, reclaim and obtain 0.6 part of raw material Isosorbide-5-Nitrae-dichlorobenzene, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid only has 58.6%.
< comparative example 2>
In this comparative example, auxiliary polyphosphoric acid and solvent acetic acid adopt other materials to replace respectively, and carry out single factor test simultaneous test with example 3, all the other parameters are identical with example 3, technological process is also identical, and different auxiliary auxiliary agent and solvent are on synthesizing the impact of reaction yield in table 1.
Table 1 different catalysts, auxiliary and solvent are on the impact of synthesis reaction yield
< comparative example 3>
When Rectification Tower Design, the first rectifying tower bottom does not arrange partitioned column, and identical with example 3 of all the other parameters, technological process is also identical.The product 2 that final rectifying 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-dichlorobenzene obtained is 90.7%, wherein obtain 2 altogether, 5-chlorophenesic acid 0.29 part, reclaims and obtains 0.54 part of raw material Isosorbide-5-Nitrae-dichlorobenzene, the yield (deduction reclaims raw material) of product 2,5-chlorophenesic acid is 56.9%.
< comparative example 4>
Different feed states can make the amount of liquid of quantity of steam and the decline of rising from feed plate change, thus have influence on separation efficiency, in this comparative example, carry out the first rectifying tower respectively, Second distillation column, 3rd rectifying tower, 1, the charging parameter of 4-dichlorobenzene treating tower and the single factor test simultaneous test of example 3 are (only for the charging flow velocity of one of them rectifying tower, a parameter in feeding temperature and feed pressure changes), identical with example 3 of all the other parameters, technological process is also identical, the concrete charging parameter of rectifying tower and separating effect are in table 2.
The charging parameter of table 2 rectifying tower and separating effect
< comparative example 5>
Different feed states can make the amount of liquid of quantity of steam and the decline of rising from feed plate change, thus have influence on separation efficiency, in this comparative example, carry out the first rectifying tower respectively, Second distillation column, 3rd rectifying tower, 1, the charging parameter of 4-dichlorobenzene treating tower and the single factor test simultaneous test of example 3 are (only for the charging flow velocity of one of them rectifying tower, a parameter in feeding temperature and feed pressure changes), identical with example 3 of all the other parameters, technological process is also identical, the concrete charging parameter of rectifying tower and separating effect are in table 3.
The charging parameter of table 3 rectifying tower and separating effect
Can find out from the various embodiments described above and comparative example, in instances, 2, in the building-up reactions of 5-chlorophenesic acid, owing to having carried out pre-treatment to catalyzer and auxiliary, its Be very effective is higher than directly adding not pretreated catalyzer and auxiliary in comparative example, the first rectifying tower bottom is designed to partitioned column, and its rectification and purification successful is better than the structure not arranging partitioned column in comparative example.
Comparative example 1 is compared with example, and comparative example adopts not pretreated catalyzer and auxiliary, and its product yield is 58.6%, significantly lower than in embodiment 1 70.9% product yield.
Comparative example 2 compared with embodiment, owing to have employed catalyst Fe in example 3
5v
8o
27.5, auxiliary polyphosphoric acid and solvent acetic acid, the yield of product is significantly higher than the situation adopting other substitute materials in comparative example respectively.
Comparative example 3 is compared with embodiment, first rectifying tower bottom does not arrange partitioned column, the purity of the organic solvent that the product obtained and recovery obtain and raw material all obviously reduces, and due to separating effect decline, 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 tower charging, temperature and pressure are all lower than scope disclosed in this invention, and the flow velocity of rectifying tower charging is too low may cause the phenomenon of leakage, reduces rectification effect; The too low thermal 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 isolate purity, as can be seen from Table 2, the flow velocity of each rectifying tower charging, temperature and pressure, lower than scope disclosed in this invention, can affect rectification effect, cause isolate purity to decline, product yield reduces.
Comparative example 5 is compared with embodiment, the flow velocity of each rectifying tower charging, temperature and pressure are all higher than scope disclosed in this invention, the too high change tower top of flow velocity of rectifying tower 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 thermal 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 isolate purity, as can be seen from Table 3, the flow velocity of each rectifying tower charging, temperature and pressure, higher than scope disclosed in this invention, also can affect rectification effect, cause isolate purity to decline, product yield reduces.
Visible, by using a certain amount of oxygenant to carry out pre-treatment to catalyzer and auxiliary, effectively can improve catalytic performance and the catalytic effect of catalyzer, significantly improving efficiency and the yield of building-up reactions;
In addition, the partitioned column structure of 30 layers that to be stage number be in first rectifying tower bottom, be divided into two by the main body tower, make three components in tower, carry out mass transfer, heat transfer simultaneously, realize the separation of three components simultaneously, first rectifying tower tower top deviates from waste water, extract the mixture of solvent and water in tower out, tower reactor obtains Isosorbide-5-Nitrae-dichlorobenzene and 2, the mixture of 5-chlorophenesic acid, and greatly reduce energy expenditure;
In addition, catalyzer of the present invention and auxiliary after pretreatment, when raw material input amount is constant, due to the raising of catalytic efficiency, the amount added needed for catalyzer and auxiliary all obviously reduces, and reduces production cost, and heavy component reduces, and is beneficial to later separation purification work;
In addition, synthesis step of the present invention only has a step, and route is short, reacts without the need to High Temperature High Pressure, and reaction conditions 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 suitability for industrialized production.
Although embodiment of the present invention are open as above, it is not restricted to listed in specification sheets and embodiment utilization.It can be applied to various applicable the field of the invention completely.For those skilled in the art, can easily realize other amendment.Therefore do not deviating under the universal that claim and equivalency range limit, the present invention is not limited to specific details and illustrates here and the embodiment described.
Claims (10)
1. one kind for the preparation technology of 2,5-chlorophenesic acid of mass production, it is characterized in that, comprises the following steps:
Step one: by the Fe of 1/800 ~ 1/100 weight part
xv
yo
zjoin in the acetic acid of 1/50 ~ 1/10 weight part with the polyphosphoric acid of 1/80 ~ 1/10 weight part, at 50 ~ 65 DEG C, stir 5 ~ 10min, then add and described Fe
xv
yo
zmol ratio is the Peracetic Acid of 0.3 ~ 1.2, continues stirring 15 ~ 25min, obtains activation solution;
Step 2: the Isosorbide-5-Nitrae-dichlorobenzene of 1 weight part and the acetic acid of 3 ~ 12 weight parts are stirred at not higher than the temperature of 30 DEG C and mix, then add described activation solution, obtain reaction solution;
Step 3: at 30 ~ 75 DEG C of temperature, the Peracetic Acid being 0.5 ~ 5 by the mol ratio with described Isosorbide-5-Nitrae-dichlorobenzene adds in described reaction solution, and time for adding is 1.5 ~ 6h, after dropwising, continues to stir 1h; Add subsequently with described Peracetic Acid mol ratio be 0.5 ~ 0.8 sodium bisulfite or S-WAT, stir 5min, filter, obtain filtrate;
Step 4: described filtrate is carried out separating-purifying by least three rectifying tower, described rectifying tower comprises the first rectifying tower, the Second distillation column be connected in parallel by pipeline with described first rectifying tower respectively and the 3rd rectifying tower;
Wherein, the charging flow velocity of described first rectifying tower 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 tower is 200 ~ 500kg/h, and feeding temperature is 100 ~ 120 DEG C, and feed pressure is 8 ~ 12kPa.
2., as claimed in claim 1 for the preparation technology of 2,5-chlorophenesic acid of mass production, it is characterized in that, described Fe
xv
yo
zin, 2≤x≤7,5≤y≤12,15.5≤z≤40.5.
3., as claimed in claim 2 for the preparation technology of 2,5-chlorophenesic acid of mass production, it is characterized in that, described Fe
xv
yo
zfor Fe
5v
8o
27.5.
4., as claimed in claim 1 for the preparation technology of 2,5-chlorophenesic acid of mass production, it is characterized in that, in step one, described Fe
xv
yo
zadd-on be 1/500 ~ 1/200 weight part, the amount that described polyphosphoric acid adds is 1/50 ~ 1/30 weight part, the amount that acetic acid described in step 2 adds is 5 ~ 8 weight parts, and the mol ratio of Peracetic Acid described in step 3 and described Isosorbide-5-Nitrae-dichlorobenzene is 1.2 ~ 3.5.
5., as claimed in claim 1 for the preparation technology of 2,5-chlorophenesic acid of mass production, it is characterized in that, described filtrate before entering rectifying tower at least through an evaporating kettle to deviate from heavy component.
6., as claimed in claim 5 for the preparation technology of 2,5-chlorophenesic acid of mass production, it is characterized 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.
7. as claimed in claim 1 for 2 of mass production, the preparation technology of 5-chlorophenesic acid, it is characterized in that, stripping tower and 1 is also disposed with between described first rectifying tower and described Second distillation column, 4-dichlorobenzene treating tower, in order to further refine and reclaim Isosorbide-5-Nitrae-dichlorobenzene and the purity improving product.
8. as claimed in claim 7 for 2 of mass production, the preparation technology of 5-chlorophenesic acid, it is characterized in that, described first rectifying tower is combination tower, and top is 2 sections of packing towers, to be stage number be in the bottom partitioned column of 33 layers, described first rectifying tower tower top deviates from waste water, and the mixture extracting described acetic acid and water in tower out enters described Second distillation column, tower reactor obtain described 1, the mixed solution of 4-dichlorobenzene and described 2,5-chlorophenesic acid enters described stripping tower.
9., as claimed in claim 1 for the preparation technology of 2,5-chlorophenesic acid of mass production, it is characterized in that, the stage number of described Second distillation column is 70 layers, and described 3rd rectifying tower is 3 sections of packing towers.
10. as claimed in claim 7 for 2 of mass production, the preparation technology of 5-chlorophenesic acid, it is characterized in that, the stage number of described stripping tower is 10 layers, described 1,4-dichlorobenzene treating tower is 3 sections of packing towers, wherein, the charging flow velocity of described Isosorbide-5-Nitrae-dichlorobenzene treating tower is 1000 ~ 1600kg/h, feeding temperature is 120 ~ 150 DEG C, and pressure is 30 ~ 45kPa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510336996.8A CN104876805B (en) | 2015-06-15 | 2015-06-15 | A kind of preparation technology of the 2,5-chlorophenesic acid for mass production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510336996.8A CN104876805B (en) | 2015-06-15 | 2015-06-15 | A kind of preparation technology of the 2,5-chlorophenesic acid for mass production |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104876805A true CN104876805A (en) | 2015-09-02 |
| CN104876805B CN104876805B (en) | 2016-07-06 |
Family
ID=53944525
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510336996.8A Active CN104876805B (en) | 2015-06-15 | 2015-06-15 | A kind of preparation technology of the 2,5-chlorophenesic acid for mass production |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104876805B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107129426A (en) * | 2016-02-29 | 2017-09-05 | 南京工业大学 | Preparation method of 2, 5-dichlorophenol |
| CN109134203A (en) * | 2018-09-18 | 2019-01-04 | 四川大学 | A method of 2,5- chlorophenesic acid is prepared by activated carbon containing iron catalysis 1,4- dichloro benzene hydroxylation |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5648562A (en) * | 1994-08-03 | 1997-07-15 | Sandoz Ltd. | Oxidation process |
| WO1998047843A1 (en) * | 1997-04-17 | 1998-10-29 | Novartis Ag | Process for the hydroxylation of 1,4-dichlorobenzene |
| US6274776B1 (en) * | 1995-12-12 | 2001-08-14 | Syngenta Participations | Oxidation process |
-
2015
- 2015-06-15 CN CN201510336996.8A patent/CN104876805B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5648562A (en) * | 1994-08-03 | 1997-07-15 | Sandoz Ltd. | Oxidation process |
| US6274776B1 (en) * | 1995-12-12 | 2001-08-14 | Syngenta Participations | Oxidation process |
| WO1998047843A1 (en) * | 1997-04-17 | 1998-10-29 | Novartis Ag | Process for the hydroxylation of 1,4-dichlorobenzene |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107129426A (en) * | 2016-02-29 | 2017-09-05 | 南京工业大学 | Preparation method of 2, 5-dichlorophenol |
| CN107129426B (en) * | 2016-02-29 | 2021-01-26 | 南京工业大学 | Preparation method of 2, 5-dichlorophenol |
| CN109134203A (en) * | 2018-09-18 | 2019-01-04 | 四川大学 | A method of 2,5- chlorophenesic acid is prepared by activated carbon containing iron catalysis 1,4- dichloro benzene hydroxylation |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104876805B (en) | 2016-07-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP4049748A1 (en) | Gas-liquid bubbling bed reactor, reaction system and method for synthesizing carbonate | |
| CN1202072C (en) | Prodn. process of high pureness xylylene amine | |
| CN108129267B (en) | Low-temperature full-continuous reaction system and application | |
| KR20070015780A (en) | Azeotropic Distillation Process for Separating Acetic Acid, Methyl Acetate and Water | |
| CN104961630B (en) | Preparation method of 2, 5-dichlorophenol | |
| CN102452934B (en) | Preparation method of sec-butyl acetate | |
| CN104387236B (en) | A kind of propilolic alcohol, 1,4-butynediols and methenamine three coproduction continuous producing method | |
| CN115160109B (en) | Method for separating glycol and glycol diacetate by using sulfolane as entrainer | |
| CN102372567A (en) | Method for producing ethene by ethanol dehydration | |
| CN104876805B (en) | A kind of preparation technology of the 2,5-chlorophenesic acid for mass production | |
| CN103848739A (en) | Production method of high-purity dimethyl fumarate | |
| CN112125802A (en) | Extractive distillation separation system and method for ethyl acetate-isopropanol-water mixture | |
| CN1307109C (en) | Method for recovering aromatic carboxylic acid in waste water | |
| CN109704990B (en) | Refining method of high-purity acetonitrile | |
| CN114100551B (en) | Production device and production process of dimeric thiohexafluoroacetone | |
| CN109678690B (en) | Production process for co-production of methyl isobutyl ketone and diisobutyl ketone | |
| CN104262189A (en) | Method for liquid-phase preparation of high-purity N, N-diethylformamide | |
| CN107021969A (en) | The method that catalysis oxidation prepares biotin precursor ketone acid | |
| EP4119532B1 (en) | Method for preraring isopropyl alcohol | |
| CN109280040A (en) | A kind of continuous production processes of in the mixed solvent synthesis hexahydrophthalic anhydride | |
| EP4122908B1 (en) | Method for preparing isopropyl alcohol | |
| EP4249464A1 (en) | Method for preparing acrylic acid | |
| CN115589781B (en) | Method for preparing isopropanol | |
| CN109422705B (en) | Method for catalytically synthesizing piperazine and triethylene diamine from ethylenediamine under solvent-free condition | |
| EP4361124A1 (en) | Method for preparing acrylic acid |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| EXSB | Decision made by sipo to initiate substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |