CN113354528A - Production method of phenylacetic acid - Google Patents
Production method of phenylacetic acid Download PDFInfo
- Publication number
- CN113354528A CN113354528A CN202110630753.0A CN202110630753A CN113354528A CN 113354528 A CN113354528 A CN 113354528A CN 202110630753 A CN202110630753 A CN 202110630753A CN 113354528 A CN113354528 A CN 113354528A
- Authority
- CN
- China
- Prior art keywords
- phenylacetic acid
- toluene
- tower
- reaction
- water
- 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.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/10—Preparation of carboxylic acids or their salts, halides or anhydrides by reaction with carbon monoxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D3/00—Halides of sodium, potassium or alkali metals in general
- C01D3/04—Chlorides
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D3/00—Halides of sodium, potassium or alkali metals in general
- C01D3/14—Purification
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/584—Recycling of catalysts
Abstract
The invention discloses a method for producing phenylacetic acid, belonging to the technical field of phenylacetic acid production; the production method of phenylacetic acid comprises the following steps: preparing raw materials, mixing the raw materials, carrying out synthetic reaction, carrying out oil-water phase separation, carrying out acidification reaction, crystallizing, centrifuging, drying, MVR, purifying condensed water and rectifying toluene; the invention replaces sodium cyanide with carbon monoxide, reduces two highly toxic materials of sodium cyanide and phenylacetonitrile in the production process, has lower cost and better product quality, and can be used in wider fields because of no cyanide; the method realizes catalyst recycling, material recycling and water recycling, has advanced technology, advanced concept, advanced equipment and extremely strong system compatibility, and avoids the discharge of process wastewater.
Description
Technical Field
The invention relates to the technical field of phenylacetic acid production, in particular to a production method of phenylacetic acid.
Background
Phenylacetic acid is an important fine chemical intermediate for medicines, spices and the like, and belongs to the field of fine chemical engineering. In the medical aspect, the phenylacetic acid is mainly used for producing penicillin, and is also used for preparing sedative anti-depression drug amitriptyline, epileptic drug phenobarbital and the like. In the industrial aspect, phenylacetic acid is commonly used for preparing high-performance curing agents for engineering plastics, fluorescent whitening agents, developers for fuel and photosensitive materials, and the like. In addition, phenylacetic acid is edible spice which is allowed to be used in China, and is mainly used for producing foods, detergents, cleaning agents, cosmetics, tobaccos and beverages.
The production method of phenylacetic acid can be up to dozens of methods, and some methods are due to main raw material costThe price of the product is higher than or close to that of the phenylacetic acid product, and the product has no great practical significance, such as a acetophenone method, a benzyl alcohol method, a phenylacetate ethyl hydrolysis method, a benzaldehyde method, a trichloroethylene hydrolysis method and the like. The currently industrially employed or industrially valuable production methods mainly include: benzyl cyanide hydrolysis, CO carbonylation, benzene-acetic anhydride, ethylbenzene oxidation, benzyl sodium, benzene-formaldehyde carbonylation, phenylacetamide hydrolysis (Vigregor process), benzyl chloride-CO2The electrolytic method is eight, and only the phenylacetonitrile hydrolysis method, the phenylacetamide method and the CO carbonylation method are used for realizing industrial production.
At present, the benzyl cyanide hydrolysis method is mostly adopted, the benzyl cyanide hydrolysis method technology is lagged behind, the production cost is high, the pollution of three wastes is serious, the product quality is poor, toxic cyanide exists to influence the use of downstream products, and in order to replace the benzyl cyanide hydrolysis method, domestic enterprises simulate foreign technologies and successfully develop the carbonylation method process route. However, the traditional carbonylation method must add a cocatalyst (such as ferroferric oxide and the like) and a phase transfer catalyst (such as quaternary ammonium salt and the like), catalytic metals must be prepared again after each batch of reaction, so that production equipment is more, a process route is long, the scale of a device is small, and with the reduction of the raw material cost of the phenylacetonitrile hydrolysis method and the enlargement of the scale of the device, the carbonylation method gradually loses the cost advantage in the competition of the phenylacetonitrile hydrolysis method and finally becomes dull. With the successive shut-down or production change of only a few domestic carbonylation industrial devices, the hydrolysis of phenylacetonitrile has been the pattern for a whole day in the phenylacetic acid industry. Because of the monopoly advantage of the raw materials of a few enterprises, the benzyl cyanide hydrolysis method gradually forms oligopolism, but serious three-waste pollution still can not be treated, and the quality and the application field of the product are limited.
Disclosure of Invention
The present invention has been made to solve the above problems occurring in the prior art, and an object of the present invention is to provide a process for producing phenylacetic acid.
In order to achieve the purpose, the invention provides the following technical scheme:
a phenylacetic acid production process comprising the steps of:
s1, preparing raw materials: preparing raw materials of benzyl chloride, carbon monoxide, monobasic alkali, monobasic acid, toluene and a catalyst;
s2, mixing the raw materials: adding benzyl chloride, monobasic alkali, toluene and a catalyst into a premixing tank for premixing;
s3, synthesis reaction: transferring the premixed raw materials to a reaction tower, introducing carbon monoxide, and carrying out carbonylation synthesis reaction;
s4, oil-water phase separation: performing oil-water separation on a product of the carbonylation synthesis reaction to obtain a water phase and an oil phase;
s5, acidification reaction: transferring the water phase to an acidification kettle, and adding monobasic acid for acidification;
s6, crystallization: sending the acidified product into a crystallizer, and cooling to 15-20 ℃ to separate out phenylacetic acid crystals;
s7, centrifugation: centrifuging and washing the crystallized product to obtain a wet product of phenylacetic acid; filtering the centrifuged mother liquor to remove solid components, returning the concentrated solution to a crystallization system, cooling the crystallization system, adding monobasic alkali for neutralization to ensure that the pH value reaches 9-11%, and sending the solution to a brine tank for later use;
s8, drying: sending the wet phenylacetic acid product into a fluidized bed for drying to obtain a phenylacetic acid finished product, and treating a drying tail gas;
s9, MVR: sending the saline water in the saline water tank into an MVR system for evaporation concentration to obtain a sodium chloride crystal mixed solution, centrifugally washing to obtain a sodium chloride byproduct, sending the evaporated condensed water into an evaporation condensing tank for storage, and treating the evaporated tail gas;
s10, condensed water purification: adsorbing and purifying the evaporated condensed water by using macroporous resin to reduce the toluene content to below 1 ppm;
s11, toluene rectification: and (3) feeding part of the oil phase into a toluene tower, distilling out toluene at the normal pressure of 120 ℃, condensing the toluene, feeding the toluene into a toluene recovery tank, and feeding the residual tower bottom liquid after distillation into a batch tower to distill out the benzyl alcohol.
As a further scheme of the invention: the benzyl chloride in the S1 is in an industrial grade, and the content is more than 99.5%; the content of carbon monoxide is more than 95 percent, and the content of oxygen is less than 30 ppm; the monobasic alkali is sodium hydroxide or potassium hydroxide, and the monobasic acid is hydrochloric acid.
As a further scheme of the invention: the reaction temperature in the S3 is 65-75 ℃, and the reaction pressure is 1.8-2.5 MPa.
As a further scheme of the invention: and S4, separating by adopting a centrifugal method, wherein the temperature of the water phase and the oil phase after separation is 58-68 ℃.
As a further scheme of the invention: and heating the temperature in the acidification kettle in the S5 to 80-90 ℃ before acidification, wherein the temperature after acidification is not lower than 76.5 ℃, and the pH value after acidification is 1-2.
As a further scheme of the invention: the drying temperature in the S8 is 50-70 ℃.
As a further scheme of the invention: the rectification in the S11 is as follows: transferring the bottom liquid of the toluene tower to a first batch tower, rectifying at 145 ℃ and under-0.098 MPa to obtain benzyl chloride, and transferring the benzyl chloride to a toluene recovery tank; the bottom liquid of the first batch tower is transferred to a second batch tower, and the benzyl alcohol byproduct is rectified at 150 ℃ and-0.098 MPa.
Compared with the prior art, the invention has the beneficial effects that:
1. the carbon monoxide replaces sodium cyanide, so that two highly toxic materials of sodium cyanide and phenylacetonitrile in the production process are reduced, the cost is lower, the product quality is better, and the carbon monoxide can be used in wider fields due to no cyanide.
2. The catalyst recycling, the material recycling and the water recycling are realized, the technology is advanced, the concept is advanced, the equipment is advanced, the system compatibility is strong, and the discharge of process wastewater is avoided; the byproduct NaCl can be used for producing ionic membrane caustic soda or soda ash, so that a large amount of solid waste is avoided, and comprehensive utilization of resources and circular economy are realized; the process hazardous waste is only 0.1-0.2% of the yield of the main product, and green and clean production is realized.
3. By adopting the recyclable catalyst and the tower type continuous system, the traditional kettle type batch reaction is abandoned, the defect that the catalyst cannot be directly recycled by the traditional carbonylation method is overcome, the continuity and the large scale of the reaction system are realized, and the automation level and the safety and the reliability of the system are improved.
4. Because the cost of raw materials is reduced, large-scale and automatic, the comprehensive cost of the product is greatly reduced, and the market competitiveness of the product is improved.
Detailed Description
The technical solution of the present patent will be described in further detail with reference to the following embodiments.
Example 1
A phenylacetic acid production process comprising the steps of:
s1, preparing raw materials:
preparing raw materials of benzyl chloride, sodium hydroxide, carbon monoxide, hydrochloric acid, toluene and a catalyst, wherein the raw materials are provided by public works, storage tanks or matched projects; the benzyl chloride is of industrial grade, the content is more than 99.5 percent, and the content of impurities is controlled; the sodium hydroxide is ionic membrane caustic soda, and can be solid sodium hydroxide, 50% sodium hydroxide or 32% sodium hydroxide; carbon monoxide is supplied by an external device, such as carbon monoxide prepared by natural gas conversion, carbon monoxide prepared by water gas separation, carbon monoxide prepared by methanol cracking, carbon monoxide prepared by coke, carbon monoxide prepared by calcium carbide tail gas, carbon monoxide prepared by yellow phosphorus tail gas and the like, wherein the carbon monoxide content is required to be more than 95%, and the oxygen content is required to be less than 30 ppm; hydrochloric acid is a byproduct of chlor-alkali synthesis, other harmful impurities are avoided, the product quality is ensured, industrial hydrochloric acid with the mass percentage concentration of 31% is selected as the hydrochloric acid, and the process is not influenced by 5-10% fluctuation of the concentration; toluene is used as a solvent, does not participate in the reaction and meets the requirements of national standards; the catalyst is a composite component of palladium compound and ligand, and is special for carbonylation synthesis of phenylacetic acid.
S2, mixing the raw materials:
adding benzyl chloride, sodium hydroxide, toluene and a catalyst into a premixing tank for premixing;
benzyl chloride comes from a raw material storage tank, and a small amount of benzyl chloride comes from unreacted materials in the subsequent synthesis (and is recycled by toluene);
sodium hydroxide is prepared with water to a concentration of 10-13%, and under normal production conditions, MVR evaporation condensed water (which may not be purified) is used for preparation;
the toluene is recycled (from a toluene recovery tank) under normal conditions, and only a small amount of toluene is needed to be supplemented by a toluene storage tank;
the catalyst is recycled under normal conditions, and only a small amount of supplement is needed intermittently;
various materials containing the reaction materials in the subsequent process, including maintenance, accident discharging and the like, can be added into the process under the condition of ensuring the material proportioning range, so that the discharge of the materials in a production system is avoided;
the temperature of the materials is not specially adjusted when the source is not used and the temperature is between the ambient temperature and 80 ℃;
the materials are pumped or self-pressurized according to the proportion and enter a premixing tank for mixing.
S3, synthesis reaction:
transferring mixed liquid obtained by mixing raw materials into a reaction tower, introducing carbon monoxide, and carrying out carbonylation synthesis reaction, wherein the chemical reaction formula is as follows:
C6H5CH2Cl+2Na0H+CO→C6H5CH2C00Na+NaC1+H20
separating unreacted carbon monoxide from the materials in the reaction tower through a gas-liquid separation device;
specifically, the mixed liquid is pumped into a reaction tower by a pump with the pressure of 2.0-2.5Mpa, preheated to 65-75 ℃ before entering the tower, enters a gas-liquid mixer at the bottom after entering the tower, and is efficiently mixed with carbon monoxide simultaneously entering the gas-liquid mixer at a high speed, so that gas and various liquids are fully mixed with a catalyst; after mixing, the mixture is flushed out from the bottom of the gas-liquid mixer, and the mixture turns back (passes through a gap between the inner wall of the reaction tower and the shell of the gas-liquid mixer) to move to the upper part of the tower when meeting the tower wall at the bottom of the reaction tower, and special internals are arranged in the tower to avoid gas-liquid layering, so that the reaction efficiency is increased; after the reaction liquid reaches the upper part, the reaction liquid enters a gas-liquid separator, carbon monoxide is separated from the reaction materials through gas-liquid separation, the separated carbon monoxide enters a next-stage reaction tower or is discharged out of a reaction system, and the separated liquid materials are circularly reacted or enter the next-stage reaction tower or enter the next procedure after the reaction is finished;
wherein, the reaction temperature is as follows: 65-75 ℃, reaction pressure: 1.8-2.5 Mpa;
the phenylacetic acid synthesis reaction is a micro-endothermic reaction, the temperature is controlled by steam heating through a fresh material inlet tower preheater and a circulating reaction material preheater, and the reaction pressure is jointly controlled by liquid material pumping pressure and carbon monoxide inlet tower pressure; the reaction tower is in multi-stage series connection or multi-stage parallel series connection, the multi-stage series connection aims at improving the reaction rate and the utilization rate of carbon monoxide, and the parallel connection aims at improving the reaction load of a single stage; 1-10 ten thousand tons, which can be realized by three-stage series connection, wherein the structure and size of each stage of tower are basically the same, the reaction temperature is basically the same, the pressure is slightly influenced by the carbon monoxide pressure difference, the temperature and the pressure are kept in the allowable range of reaction conditions, the reverse time of each tower is controlled between 40 and 120 minutes, the material circulation amount of each tower is about the total feeding amount per hour, and the reaction end point is that the pH value is between 9 and 12.
Liquid materials and carbon monoxide are fed in a reverse direction, and by taking three-stage series connection as an example, the liquid materials go to a first-stage-second-stage-next procedure, and the carbon monoxide goes to a third-stage-second-first-stage-tail gas treatment procedure (after condensation and water removal, the carbon monoxide is sent to a whole plant tail gas treatment system); the temperature of the reaction mass to be fed to the next step is about 62-72 ℃.
S4, oil-water phase separation:
carrying out oil-water separation on the reactant of S3 to respectively obtain a water phase and an oil phase;
separation principle: the synthesis reactant from S3, comprising toluene (1), trace benzyl chloride (2), trace benzyl alcohol (3), other trace organic by-products or impurities (4), catalyst (5), sodium phenylacetate (6), NaCl (7), trace sodium hydroxide (8), water (9), forms an organic layer (oil phase), an interfacial layer and an inorganic layer (aqueous phase) if left to stand for about 10 minutes, (1) (2) (3) (4) is present almost completely in the oil phase, (6) (7) (8) (9) is present almost completely in the aqueous phase, (5) is at the interface where the oil phase and the aqueous phase are separated, the specific gravities of the organic layer (oil phase), interfacial layer and inorganic layer (aqueous phase) are respectively slightly 0.88, 0.92, 1.07; due to the difference of specific gravity, the separation can be carried out by a standing method and a centrifugal method, the standing method has long time, low efficiency and discontinuity, and is suitable to be used as an auxiliary means in details; the centrifugal method has high efficiency, continuous operation and automation, and is a better choice, so the centrifugal method is mainly selected in the scheme;
separation requirements: dividing (1), (2), (3), (4) and (5) into oil phases, dividing (6), (7), (8) and (9) into water phases, and dividing a small amount of water phase materials into the oil phases in order to ensure that the water phases contain no oil phase materials as much as possible;
selecting centrifugal separation equipment: a centrifugal extraction separator or a disc centrifuge can be selected, both the devices are mature and reliable, and a sizing device can be selected;
and (3) separation post-treatment: the water phase enters a water phase storage tank, and after standing for a certain time, a trace amount of oil phase is accumulated on the top of the storage tank and can be periodically or automatically extracted and separated again or transferred to an oil phase storage tank; conveying the materials to the next procedure from the lower part of the water phase storage tank; the oil phase enters an oil phase storage tank, and is kept stand for a certain time, so that the water phase and the catalyst can be accumulated to the bottom of the storage tank (the amount is small and the catalyst is not required to be in a separated state), and the top of the storage tank is relatively pure organic matters (toluene, benzyl chloride, benzyl alcohol, other organic byproducts and impurities); continuously conveying the materials to a toluene recovery tank from the lower part of the oil phase storage tank to realize the recycling of toluene and catalyst; meanwhile, in order to separate by-products and impurities such as benzyl alcohol and the like generated in the synthesis reaction, a certain proportion (5-20%) of the by-products and the impurities are extracted from the upper part of the oil phase storage tank to a toluene rectifying tower;
the temperature of the separated water phase and oil phase materials is about 58-68 ℃.
S5, acidification reaction:
transferring the water phase obtained in the step S4 to an acidification kettle, and adding hydrochloric acid for acidification, wherein the reaction formula is as follows:
C6H5CH2C00Na+HC1→C6H5CH2C00H+NaC1
the sodium phenylacetate generated by the synthesis reaction is acidified to be phenylacetic acid;
in order to realize full acidification and accelerate acidification speed, the reaction materials are heated; meanwhile, in order to ensure the crystallization quality, the crystallization in the acidification stage is avoided, and the temperature after the reaction is not lower than the phenylacetic acid melting temperature of 76.5 ℃; before the water phase material enters the acidification kettle, heating to 80-90 ℃ by using a heat exchanger, and then carrying out acidification reaction with hydrochloric acid;
mixing part of hydrochloric acid and a heated water phase material through a tubular mixer, then feeding the mixture into an acidification kettle, wherein the acidification kettle is provided with a stirrer, slowly stirring the mixture to fully mix and react the materials, and simultaneously supplementing hydrochloric acid to control the final pH value to be between 1 and 2; the reaction and retention time of the materials in the acidification kettle are controlled to be 20-60 minutes;
the materials qualified in the reaction are conveyed to the next working procedure from the bottom.
S6, crystallization:
feeding the acidified material of S5 into a crystallizer, cooling to 15-20 ℃, and crystallizing and separating out phenylacetic acid;
the temperature of the acidified material from S5 is 70-85 ℃, phenylacetic acid is in a molten state, the temperature of the material is reduced to 15-20 ℃ through multi-stage temperature reduction, the multi-stage temperature reduction is to avoid rapid crystallization of the phenylacetic acid and blockage of equipment, and meanwhile, different cooling media are conveniently utilized to realize energy conservation; the first stage adopts circulating water (the temperature is about 32 ℃), and the temperature of the materials is reduced to 45-55 ℃; the second stage adopts the centrifugate (the temperature is about 15-20 ℃) after crystallization, and the temperature of the materials is reduced to 25-35 ℃; the third stage adopts chilled water (the temperature is about 5 ℃) to reduce the temperature of the materials to 15-20 ℃;
the lower the final crystallization temperature, the less phenylacetic acid is dissolved in the solution, reducing the amount to be subjected to the subsequent process.
S7, centrifugation:
centrifuging and washing the crystallized product obtained from the S6 to obtain a wet product of phenylacetic acid;
because the phenylacetic acid content after crystallization is low (8-15%), and the proportion of the phenylacetic acid (1.09) is close to the proportion of the solution (1.06-1.08), a flat vertical scraper automatic lower discharging centrifuge is selected in the embodiment, pure water (from purified MVR evaporation condensed water) is used for enhanced washing in the centrifugation process, impurities such as NaCl, HCl, toluene and the like in the product are reduced to improve the product quality, the water content is controlled to be not higher than 5% so as to facilitate subsequent drying, and the wet phenylacetic acid is sent to the next process;
filtering the centrifuged mother liquor by an automatic precision filter to remove solid components, returning concentrated liquor (containing the solid components) to a crystallization system, cooling the clear liquor serving as the crystallization system, adding sodium hydroxide for neutralization to enable the pH value to reach 9-11%, and entering a saline water storage tank for MVR;
if the content of phenylacetic acid and toluene in the clear liquid is higher, a set of macroporous resin adsorption system can be added before adding alkali for neutralization, and most of phenylacetic acid and toluene can be adsorbed and returned to the front end.
S8, drying:
drying the wet phenylacetic acid product obtained in the step S7 through a fluidized bed to obtain a finished phenylacetic acid product;
according to the characteristics of peculiar smell and low melting point of phenylacetic acid, the fluidized bed drying needs to meet the following requirements: the drying equipment must be totally closed to avoid gas leakage; the drying temperature is controlled to be about 50-70 ℃ so that the product is not melted;
the dry tail gas firstly needs to recycle phenylacetic acid dust through a cyclone dust collector and a bag-type dust collector, and directly enters a product or is recrystallized; the dedusted gas is washed by alkali liquor for two or more times, so that organic matters in the tail gas are further reduced, and the washing liquid is recycled to the previous working procedure; and (4) the washed tail gas enters a tail gas treatment system for treatment, and the tail gas treatment system adopts the existing resin adsorption treatment mode.
S9、MVR：
Pumping the brine in the brine storage tank to an MVR system for evaporation and concentration to obtain a sodium chloride crystal mixed solution, and performing centrifugal washing to obtain a sodium chloride byproduct;
the MVR system selects a material resistant to NaCl corrosion and strengthens washing in the crystallization process; selecting a pusher centrifuge, and washing with pure water (from purified MVR evaporation condensed water) during centrifugation to reduce the content of NaCl and impurities as byproducts, so as to meet the quality requirement of the salt for the ionic membrane caustic soda or the soda ash; returning the centrifugal mother liquor to the phase separation process or before the acidification process according to 3-5% so as to circulate and remove the concentrated sodium phenylacetate, the trace catalyst and other impurities;
the evaporation condensed water of the MVR enters an evaporation condensing tank for storage;
after cooling and dewatering the non-condensable tail gas of MVR, the non-condensable tail gas enters a tail gas treatment system for treatment, and the tail gas treatment system adopts the existing resin adsorption treatment mode.
S10, condensed water purification:
as sodium hydroxide and hydrochloric acid are brought into water, water is generated in the reaction process, and the water in the process is excessive; the water is evaporated and condensed by MVR, and the evaporated and condensed water contains toluene (500-10000 ppm); in order to enable the evaporated condensate water to be used for steam, phenylacetic acid centrifugal washing, NaCl centrifugal washing, circulating water supplementing water, discharging other items for comprehensive utilization and the like, the scheme utilizes macroporous resin to adsorb and purify the evaporated condensate water so as to reduce the toluene content to below 1 ppm; part is directly recycled to the process system without purification; the toluene recovered by the resin is absorbed and returned to the toluene recovery tank for recycling.
S11, toluene rectification:
toluene materials (containing byproducts such as benzyl alcohol and impurities) from the oil phase storage tank are condensed in a toluene tower at 120 ℃ and distilled under normal pressure to be sent to a toluene recovery tank for recycling; transferring the residual tower bottom liquid after the toluene tower distillation into a batch tower process to refine and distill a benzyl alcohol byproduct;
wherein, the batch tower process is as follows:
the intermittent tower procedure comprises a first intermittent tower and a second intermittent tower, wherein the bottom liquid of the toluene tower is transferred to the first intermittent tower, the benzyl chloride is rectified at 145 ℃ and-0.098 MPa, and the benzyl chloride is transferred to a toluene recovery tank for recycling; the tower bottom liquid of the first batch tower is transferred to a second batch tower, and benzyl alcohol by-product is rectified at 150 ℃ and-0.098 MPa; the residual tower bottom liquid of the second batch tower is a byproduct which can not be separated and utilized and other impurities, is the only production process hazardous waste generation point of the system, is about 0.1-0.2 percent of the output of the phenylacetic acid, and is sent to qualified units for disposal.
Example 2
A phenylacetic acid production process comprising the steps of:
s1, preparing raw materials:
preparing raw materials of benzyl chloride, potassium hydroxide, carbon monoxide, hydrochloric acid, toluene and a catalyst, wherein the raw materials are provided by public works, storage tanks or matched projects; the benzyl chloride is of industrial grade, the content is more than 99.5 percent, and the content of impurities is controlled; the potassium hydroxide is solid potassium hydroxide; carbon monoxide is supplied by an external device, such as carbon monoxide prepared by natural gas conversion, carbon monoxide prepared by water gas separation, carbon monoxide prepared by methanol cracking, carbon monoxide prepared by coke, carbon monoxide prepared by calcium carbide tail gas, carbon monoxide prepared by yellow phosphorus tail gas and the like, wherein the carbon monoxide content is required to be more than 95%, and the oxygen content is required to be less than 30 ppm; hydrochloric acid is a byproduct of chlor-alkali synthesis, other harmful impurities are avoided, the product quality is ensured, industrial hydrochloric acid with the mass percentage concentration of 31% is selected as the hydrochloric acid, and the process is not influenced by 5-10% fluctuation of the concentration; toluene is used as a solvent, does not participate in the reaction and meets the requirements of national standards; the catalyst is a composite component of palladium compound and ligand, and is special for carbonylation synthesis of phenylacetic acid.
S2, mixing the raw materials:
adding benzyl chloride, potassium hydroxide, toluene and a catalyst into a premixing tank for premixing;
benzyl chloride comes from a raw material storage tank, and a small amount of benzyl chloride comes from unreacted materials in the subsequent synthesis (and is recycled by toluene);
potassium hydroxide is prepared with water to a concentration of 14% -18%, and under normal production conditions, MVR evaporation condensed water (which may not be purified) is used for preparation;
the toluene is recycled (from a toluene recovery tank) under normal conditions, and only a small amount of toluene is needed to be supplemented by a toluene storage tank;
the catalyst is recycled under normal conditions, and only a small amount of supplement is needed intermittently;
various materials containing the reaction materials in the subsequent process, including maintenance, accident discharging and the like, can be added into the process under the condition of ensuring the material proportioning range, so that the discharge of the materials in a production system is avoided;
the temperature of the materials is not specially adjusted when the source is not used and the temperature is between the ambient temperature and 80 ℃;
the materials are pumped or self-pressurized according to the proportion and enter a premixing tank for mixing.
S3, synthesis reaction:
transferring mixed liquid obtained by mixing raw materials into a reaction tower, introducing carbon monoxide, and carrying out carbonylation synthesis reaction, wherein the chemical reaction formula is as follows:
C6H5CH2Cl+2K0H+CO→C6H5CH2C00K+KC1+H20
separating unreacted carbon monoxide from the materials in the reaction tower through a gas-liquid separation device;
specifically, the mixed liquid is pumped into a reaction tower by a pump with the pressure of 2.0-2.5Mpa, preheated to 65-75 ℃ before entering the tower, enters a gas-liquid mixer at the bottom after entering the tower, and is efficiently mixed with carbon monoxide simultaneously entering the gas-liquid mixer at a high speed, so that gas and various liquids are fully mixed with a catalyst; after mixing, the mixture is flushed out from the bottom of the gas-liquid mixer, and the mixture turns back (passes through a gap between the inner wall of the reaction tower and the shell of the gas-liquid mixer) to move to the upper part of the tower when meeting the tower wall at the bottom of the reaction tower, and special internals are arranged in the tower to avoid gas-liquid layering, so that the reaction efficiency is increased; after the reaction liquid reaches the upper part, the reaction liquid enters a gas-liquid separator, carbon monoxide is separated from the reaction materials through gas-liquid separation, the separated carbon monoxide enters a next-stage reaction tower or is discharged out of a reaction system, and the separated liquid materials are circularly reacted or enter the next-stage reaction tower or enter the next procedure after the reaction is finished;
wherein, the reaction temperature is as follows: 65-75 ℃, reaction pressure: 1.8-2.5 Mpa;
the phenylacetic acid synthesis reaction is a micro-endothermic reaction, the temperature is controlled by steam heating through a fresh material inlet tower preheater and a circulating reaction material preheater, and the reaction pressure is jointly controlled by liquid material pumping pressure and carbon monoxide inlet tower pressure; the reaction tower is in multi-stage series connection or multi-stage parallel series connection, the multi-stage series connection aims at improving the reaction rate and the utilization rate of carbon monoxide, and the parallel connection aims at improving the reaction load of a single stage; 1-10 ten thousand tons, which can be realized by three-stage series connection, wherein the structure and size of each stage of tower are basically the same, the reaction temperature is basically the same, the pressure is slightly influenced by the carbon monoxide pressure difference, the temperature and the pressure are kept in the allowable range of reaction conditions, the reverse time of each tower is controlled between 40 and 120 minutes, the material circulation amount of each tower is about the total feeding amount per hour, and the reaction end point is that the pH value is between 9 and 12.
Liquid materials and carbon monoxide are fed in a reverse direction, and by taking three-stage series connection as an example, the liquid materials go to a first-stage-second-stage-next procedure, and the carbon monoxide goes to a third-stage-second-first-stage-tail gas treatment procedure (after condensation and water removal, the carbon monoxide is sent to a whole plant tail gas treatment system); the temperature of the reaction mass to be fed to the next step is about 62-72 ℃.
S4, oil-water phase separation:
carrying out oil-water separation on the reactant of S3 to respectively obtain a water phase and an oil phase;
separation principle: the synthesis reactant from S3, comprising toluene (1), trace benzyl chloride (2), trace benzyl alcohol (3), other trace organic by-products or impurities (4), catalyst (5), potassium phenylacetate (6), KCl (7), trace potassium hydroxide (8), water (9), forms an organic layer (oil phase), an interfacial layer and an inorganic layer (aqueous phase) if left to stand for about 10 minutes, (1) (2) (3) (4) is almost completely present in the oil phase, (6) (7) (8) (9) is almost completely present in the aqueous phase, (5) is at the interface where the oil phase and the aqueous phase are separated, and the specific gravities of the organic layer (oil phase), interfacial layer and inorganic layer (aqueous phase) are respectively slightly 0.88, 0.92, 1.07; due to the difference of specific gravity, the separation can be carried out by a standing method and a centrifugal method, the standing method has long time, low efficiency and discontinuity, and is suitable to be used as an auxiliary means in details; the centrifugal method has high efficiency, continuous operation and automation, and is a better choice, so the centrifugal method is mainly selected in the scheme;
separation requirements: dividing (1), (2), (3), (4) and (5) into oil phases, dividing (6), (7), (8) and (9) into water phases, and dividing a small amount of water phase materials into the oil phases in order to ensure that the water phases contain no oil phase materials as much as possible;
selecting centrifugal separation equipment: a centrifugal extraction separator or a disc centrifuge can be selected, both the devices are mature and reliable, and a sizing device can be selected;
and (3) separation post-treatment: the water phase enters a water phase storage tank, and after standing for a certain time, a trace amount of oil phase is accumulated on the top of the storage tank and can be periodically or automatically extracted and separated again or transferred to an oil phase storage tank; conveying the materials to the next procedure from the lower part of the water phase storage tank; the oil phase enters an oil phase storage tank, and is kept stand for a certain time, so that the water phase and the catalyst can be accumulated to the bottom of the storage tank (the amount is small and the catalyst is not required to be in a separated state), and the top of the storage tank is relatively pure organic matters (toluene, benzyl chloride, benzyl alcohol, other organic byproducts and impurities); continuously conveying the materials to a toluene recovery tank from the lower part of the oil phase storage tank to realize the recycling of toluene and catalyst; meanwhile, in order to separate by-products and impurities such as benzyl alcohol and the like generated in the synthesis reaction, a certain proportion (5-20%) of the by-products and the impurities are extracted from the upper part of the oil phase storage tank to a toluene rectifying tower;
the temperature of the separated water phase and oil phase materials is about 58-68 ℃.
S5, acidification reaction:
transferring the water phase obtained in the step S4 to an acidification kettle, and adding hydrochloric acid for acidification, wherein the reaction formula is as follows:
C6H5CH2C00K+HC1→C6H5CH2C00H+KC1
the potassium phenylacetate generated by the synthesis reaction is acidified to be phenylacetic acid;
in order to realize full acidification and accelerate acidification speed, the reaction materials are heated; meanwhile, in order to ensure the crystallization quality, the crystallization in the acidification stage is avoided, and the temperature after the reaction is not lower than the phenylacetic acid melting temperature of 76.5 ℃; before the water phase material enters the acidification kettle, heating to 80-90 ℃ by using a heat exchanger, and then carrying out acidification reaction with hydrochloric acid;
mixing part of hydrochloric acid and a heated water phase material through a tubular mixer, then feeding the mixture into an acidification kettle, wherein the acidification kettle is provided with a stirrer, slowly stirring the mixture to fully mix and react the materials, and simultaneously supplementing hydrochloric acid to control the final pH value to be between 1 and 2; the reaction and retention time of the materials in the acidification kettle are controlled to be 20-60 minutes;
the materials qualified in the reaction are conveyed to the next working procedure from the bottom.
S6, crystallization:
feeding the acidified material of S5 into a crystallizer, cooling to 15-20 ℃, and crystallizing and separating out phenylacetic acid;
the temperature of the acidified material from S5 is 70-85 ℃, phenylacetic acid is in a molten state, the temperature of the material is reduced to 15-20 ℃ through multi-stage temperature reduction, the multi-stage temperature reduction is to avoid rapid crystallization of the phenylacetic acid and blockage of equipment, and meanwhile, different cooling media are conveniently utilized to realize energy conservation; the first stage adopts circulating water (the temperature is about 32 ℃), and the temperature of the materials is reduced to 45-55 ℃; the second stage adopts the centrifugate (the temperature is about 15-20 ℃) after crystallization, and the temperature of the materials is reduced to 25-35 ℃; the third stage adopts chilled water (the temperature is about 5 ℃) to reduce the temperature of the materials to 15-20 ℃;
the lower the final crystallization temperature, the less phenylacetic acid is dissolved in the solution, reducing the amount to be subjected to the subsequent process.
S7, centrifugation:
centrifuging and washing the crystallized product obtained from the S6 to obtain a wet product of phenylacetic acid;
because the phenylacetic acid content after crystallization is low (8-15%), and the proportion of the phenylacetic acid (1.09) is close to the proportion of the solution (1.06-1.08), a flat vertical scraper automatic lower discharging centrifuge is selected in the embodiment, pure water (from purified MVR evaporation condensed water) is used for enhanced washing in the centrifugation process, impurities such as NaCl, HCl, toluene and the like in the product are reduced to improve the product quality, the water content is controlled to be not higher than 5% so as to facilitate subsequent drying, and the wet phenylacetic acid is sent to the next process;
filtering the centrifuged mother liquor by an automatic precision filter to remove solid components, returning concentrated liquor (containing the solid components) to a crystallization system, cooling the clear liquor serving as the crystallization system, then adding potassium hydroxide for neutralization to enable the pH value to reach 9-11%, and entering a saline water storage tank for MVR;
if the content of phenylacetic acid and toluene in the clear liquid is higher, a set of macroporous resin adsorption system can be added before adding alkali for neutralization, and most of phenylacetic acid and toluene can be adsorbed and returned to the front end.
S8, drying:
drying the wet phenylacetic acid product obtained in the step S7 through a fluidized bed to obtain a finished phenylacetic acid product;
according to the characteristics of peculiar smell and low melting point of phenylacetic acid, the fluidized bed drying needs to meet the following requirements: the drying equipment must be totally closed to avoid gas leakage; the drying temperature is controlled to be about 50-70 ℃ so that the product is not melted;
the dry tail gas firstly needs to recycle phenylacetic acid dust through a cyclone dust collector and a bag-type dust collector, and directly enters a product or is recrystallized; the dedusted gas is washed by alkali liquor for two or more times, so that organic matters in the tail gas are further reduced, and the washing liquid is recycled to the previous working procedure; and (4) the washed tail gas enters a tail gas treatment system for treatment.
S9、MVR：
Pumping the brine in the brine storage tank to an MVR system for evaporation and concentration to obtain a potassium chloride crystal mixed solution, and performing centrifugal washing to obtain a potassium chloride byproduct;
the MVR system selects a material resistant to NaCl corrosion and strengthens washing in the crystallization process; selecting a pusher centrifuge, and washing with pure water (from purified MVR evaporation condensed water) during centrifugation to reduce the content of NaCl and impurities as byproducts, so as to meet the quality requirement of the salt for the ionic membrane caustic soda or the soda ash; returning the centrifugal mother liquor to the phase separation process or before the acidification process according to 3-5% so as to circulate and remove the concentrated potassium phenylacetate, the trace catalyst and other impurities;
the evaporation condensed water of the MVR enters an evaporation condensing tank for storage;
after cooling and dewatering the non-condensable tail gas of MVR, the non-condensable tail gas enters a whole-plant tail gas treatment system.
S10, condensed water purification:
the potassium hydroxide and the hydrochloric acid bring water into the reaction process, so that the water in the process is excessive; the water is evaporated and condensed by MVR, and the evaporated and condensed water contains toluene (500-10000 ppm); in order to enable the evaporated condensate water to be used for steam, phenylacetic acid centrifugal washing, NaCl centrifugal washing, circulating water supplementing water, discharging other items for comprehensive utilization and the like, the scheme utilizes macroporous resin to adsorb and purify the evaporated condensate water so as to reduce the toluene content to below 1 ppm; part is directly recycled to the process system without purification; the toluene recovered by the resin is absorbed and returned to the toluene recovery tank for recycling.
S11, toluene rectification:
toluene materials (containing byproducts such as benzyl alcohol and impurities) from the oil phase storage tank are condensed in a toluene tower at 120 ℃ and distilled under normal pressure to be sent to a toluene recovery tank for recycling; transferring the residual tower bottom liquid after the toluene tower distillation into a batch tower process to refine and distill a benzyl alcohol byproduct;
wherein, the batch tower process is as follows:
the intermittent tower procedure comprises a first intermittent tower and a second intermittent tower, wherein the bottom liquid of the toluene tower is transferred to the first intermittent tower, the benzyl chloride is rectified at 145 ℃ and-0.098 MPa, and the benzyl chloride is transferred to a toluene recovery tank for recycling; the tower bottom liquid of the first batch tower is transferred to a second batch tower, and benzyl alcohol by-product is rectified at 150 ℃ and-0.098 MPa; the residual tower bottom liquid of the second batch tower is a byproduct which can not be separated and utilized and other impurities, is the only production process hazardous waste generation point of the system, is about 0.1-0.2 percent of the output of the phenylacetic acid, and is sent to qualified units for disposal.
Comparative example 1
The prior art phenylacetonitrile hydrolysis production was used as comparative example 1, and the phenylacetic acid project pollutant emissions are summarized in the following table.
10000t/a phenylacetic acid project pollutant discharge summary table
By comparison, in the examples 1 and 2, the residual tower bottom liquid of the second batch tower is a byproduct which cannot be separated and utilized and other impurities, is the only production method hazardous waste generation point of the system, and is about 0.1-0.2% of the output of the phenylacetic acid; the current hydrolysis method of phenylacetonitrile generates a large amount of waste water and waste gas.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.
Claims (7)
1. A phenylacetic acid production method is characterized by comprising the following steps:
s1, preparing raw materials: preparing raw materials of benzyl chloride, carbon monoxide, monobasic alkali, monobasic acid, toluene and a catalyst;
s2, mixing the raw materials: adding benzyl chloride, monobasic alkali, toluene and a catalyst into a premixing tank for premixing;
s3, synthesis reaction: transferring the premixed raw materials to a reaction tower, introducing carbon monoxide, and carrying out carbonylation synthesis reaction;
s4, oil-water phase separation: performing oil-water separation on a product of the carbonylation synthesis reaction to obtain a water phase and an oil phase;
s5, acidification reaction: transferring the water phase to an acidification kettle, and adding monobasic acid for acidification;
s6, crystallization: sending the acidified product into a crystallizer, and cooling to 15-20 ℃ to separate out phenylacetic acid crystals;
s7, centrifugation: centrifuging and washing the crystallized product to obtain a wet product of phenylacetic acid; filtering the centrifuged mother liquor to remove solid components, returning the concentrated solution to a crystallization system, cooling the crystallization system, adding monobasic alkali for neutralization to ensure that the pH value reaches 9-11%, and sending the solution to a brine tank for later use;
s8, drying: sending the wet phenylacetic acid product into a fluidized bed for drying to obtain a phenylacetic acid finished product, and treating a drying tail gas;
s9, MVR: sending the saline water in the saline water tank into an MVR system for evaporation concentration to obtain a sodium chloride crystal mixed solution, centrifugally washing to obtain a sodium chloride byproduct, sending the evaporated condensed water into an evaporation condensing tank for storage, and treating the evaporated tail gas;
s10, condensed water purification: adsorbing and purifying the evaporated condensed water by using macroporous resin to reduce the toluene content to below 1 ppm;
s11, toluene rectification: and (3) feeding part of the oil phase into a toluene tower, distilling out toluene at the normal pressure of 120 ℃, condensing the toluene, feeding the toluene into a toluene recovery tank, and feeding the residual tower bottom liquid after distillation into a batch tower to distill out the benzyl alcohol.
2. The phenylacetic acid production method according to claim 1, wherein the benzyl chloride in the S1 is industrial grade with a content of more than 99.5%; the content of carbon monoxide is more than 95 percent, and the content of oxygen is less than 30 ppm; the monobasic alkali is sodium hydroxide or potassium hydroxide, and the monobasic acid is hydrochloric acid.
3. The production method of phenylacetic acid according to claim 1, wherein the reaction temperature in said S3 is 65 to 75 ℃ and the reaction pressure is 1.8 to 2.5 MPa.
4. The method for producing phenylacetic acid according to claim 1, wherein said S4 is separated by centrifugation, and the temperature of the water phase and the oil phase after separation is 58-68 ℃.
5. The method for producing phenylacetic acid according to claim 1, wherein the temperature in said acidification kettle before acidification in S5 is heated to 80-90 ℃, the temperature after acidification is not lower than 76.5 ℃, and the pH value after acidification is 1-2.
6. The production method of phenylacetic acid according to claim 1, wherein said drying temperature in S8 is 50 to 70 ℃.
7. The phenylacetic acid production process according to claim 1, wherein the rectification in the S11 is: transferring the bottom liquid of the toluene tower to a first batch tower, rectifying at 145 ℃ and under-0.098 MPa to obtain benzyl chloride, and transferring the benzyl chloride to a toluene recovery tank; the bottom liquid of the first batch tower is transferred to a second batch tower, and the benzyl alcohol byproduct is rectified at 150 ℃ and-0.098 MPa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110630753.0A CN113354528A (en) | 2021-06-07 | 2021-06-07 | Production method of phenylacetic acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110630753.0A CN113354528A (en) | 2021-06-07 | 2021-06-07 | Production method of phenylacetic acid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113354528A true CN113354528A (en) | 2021-09-07 |
Family
ID=77532869
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110630753.0A Pending CN113354528A (en) | 2021-06-07 | 2021-06-07 | Production method of phenylacetic acid |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113354528A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115300929A (en) * | 2022-08-15 | 2022-11-08 | 四川信乙化工有限公司 | Crystallization equipment and method for phenylacetic acid production |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE753756A (en) * | 1969-07-23 | 1971-01-22 | Montedison Spa | PHENYLACETIC ACID PREPARATION PROCESS |
| BE863040A (en) * | 1977-01-18 | 1978-07-18 | Montedison Spa | NEW PROCESS FOR THE PREPARATION OF PHENYLACETIC ACID |
| CN1039241A (en) * | 1988-07-05 | 1990-01-31 | 中国科学院兰州化学物理所 | Process for preparing phenylacetic acid by chlorobenzyl carbonylation under normal pressure |
| US20070010696A1 (en) * | 2005-07-08 | 2007-01-11 | Ramazanova Elmira M | Method of preparation of methyl-benzyl-ketone |
| WO2007049148A2 (en) * | 2005-07-08 | 2007-05-03 | Property Development Corporation International; Ltd., Inc. | Methods of preparing phenylacetic acid |
| CN105692996A (en) * | 2016-02-24 | 2016-06-22 | 湖北绿色家园精细化工股份有限公司 | Novel process for treating industrial wastewater with benzyl alcohol |
| CN106865706A (en) * | 2017-03-14 | 2017-06-20 | 湖北科林博伦新材料有限公司 | A kind of toluene oxidation method prepares the treatment and circulation utilization method in phenmethylol technique containing organic matter salt solution |
| CN108997106A (en) * | 2018-07-30 | 2018-12-14 | 麻城市天恒商贸有限公司 | The preparation method of phenylacetic acid |
| CN109438215A (en) * | 2018-11-12 | 2019-03-08 | 西南化工研究设计院有限公司 | A kind of method of carbonylation synthesis phenylacetic acid |
| CN109516622A (en) * | 2018-11-16 | 2019-03-26 | 山东聊城中盛蓝瑞化工有限公司 | The treatment process of high-salt wastewater in a kind of benzyl alcohol production system |
| CN111440061A (en) * | 2019-01-16 | 2020-07-24 | 姜林 | Preparation method of phenoxyacetic acid |
-
2021
- 2021-06-07 CN CN202110630753.0A patent/CN113354528A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE753756A (en) * | 1969-07-23 | 1971-01-22 | Montedison Spa | PHENYLACETIC ACID PREPARATION PROCESS |
| BE863040A (en) * | 1977-01-18 | 1978-07-18 | Montedison Spa | NEW PROCESS FOR THE PREPARATION OF PHENYLACETIC ACID |
| CN1039241A (en) * | 1988-07-05 | 1990-01-31 | 中国科学院兰州化学物理所 | Process for preparing phenylacetic acid by chlorobenzyl carbonylation under normal pressure |
| US20070010696A1 (en) * | 2005-07-08 | 2007-01-11 | Ramazanova Elmira M | Method of preparation of methyl-benzyl-ketone |
| WO2007049148A2 (en) * | 2005-07-08 | 2007-05-03 | Property Development Corporation International; Ltd., Inc. | Methods of preparing phenylacetic acid |
| CN105692996A (en) * | 2016-02-24 | 2016-06-22 | 湖北绿色家园精细化工股份有限公司 | Novel process for treating industrial wastewater with benzyl alcohol |
| CN106865706A (en) * | 2017-03-14 | 2017-06-20 | 湖北科林博伦新材料有限公司 | A kind of toluene oxidation method prepares the treatment and circulation utilization method in phenmethylol technique containing organic matter salt solution |
| CN108997106A (en) * | 2018-07-30 | 2018-12-14 | 麻城市天恒商贸有限公司 | The preparation method of phenylacetic acid |
| CN109438215A (en) * | 2018-11-12 | 2019-03-08 | 西南化工研究设计院有限公司 | A kind of method of carbonylation synthesis phenylacetic acid |
| CN109516622A (en) * | 2018-11-16 | 2019-03-26 | 山东聊城中盛蓝瑞化工有限公司 | The treatment process of high-salt wastewater in a kind of benzyl alcohol production system |
| CN111440061A (en) * | 2019-01-16 | 2020-07-24 | 姜林 | Preparation method of phenoxyacetic acid |
Non-Patent Citations (1)
| Title |
|---|
| 刘华平等: "苯乙酸合成研究进展", 《山东化工》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115300929A (en) * | 2022-08-15 | 2022-11-08 | 四川信乙化工有限公司 | Crystallization equipment and method for phenylacetic acid production |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1153754C (en) | Production of aromatic polycarboxylic acids | |
| CN103113208B (en) | The continuous production processes of calcium formiate is prepared by calcium hydroxide carbonylation | |
| CN102755759B (en) | Continuous reaction rectification process and rectification equipment for synthesizing isopropyl alcohol | |
| CN102503014A (en) | Treatment method of glycerin wastewater containing salt | |
| CN101429288A (en) | Method for treating process liquid generated in production process of polyphenylene sulfide | |
| CN102241606A (en) | Clean production method of N-cyanoethylaniline | |
| CN108715574A (en) | A method of synthesis '-biphenyl diphenol | |
| CN113354528A (en) | Production method of phenylacetic acid | |
| CN105111074B (en) | A kind of alkali decrement waste water solid residue esterification recoverying and utilizing method | |
| CN114191837A (en) | Device and method for separating methanol-benzene-acetonitrile azeotrope system by extractive distillation | |
| CN1745913A (en) | Recovering treatment of hydrated hydrazine by-product saline-alkali by urea method | |
| CN105480948B (en) | A kind of aliphatic acid or fat acyl chloride chlorination production byproduct in process object hydrogen chloride circulation utilization method and system | |
| CN113548954A (en) | Phenylacetic acid preparation system | |
| CN101157646A (en) | Method for producing monomer aminocaprolactam by using nylon 6 waste and old material | |
| CN209193736U (en) | A kind for the treatment of process device of high-salt wastewater | |
| CN110746293B (en) | Process for preparing p-toluic acid by continuous catalytic oxidation | |
| CN110818556A (en) | Method for producing high-purity 2-chloro-6-fluorobenzoyl chloride by using waste residues | |
| CN1166616C (en) | Process and apparatus for purifying raw lactic acid | |
| CN105749967A (en) | Method for preparing tributyl citrate in presence of bamboo-charcoal-based solid sulfonic acid catalyst | |
| CN101525287B (en) | Method for refining sebacic acid | |
| CN107129103B (en) | Comprehensive treatment and utilization process and method for furfural production wastewater | |
| CN109205934A (en) | A kind for the treatment of process device and method of high-salt wastewater | |
| CN219518808U (en) | Green chlorine hydrogen internal consumption absorption system in foaming agent production | |
| CN211445568U (en) | Production device of malonic acid | |
| CN104744254A (en) | Method for recovering hydroxyacetate from waste water of phenoxyacetic acid pesticides |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |