253 results about "Azeotrope" patented technology

The invention discloses a water-based environment-friendly coating and local printing transfer paper thereof, and particularly relates to the technical field of water-based environment-friendly coatings. The water-based environment-friendly coating is prepared from a water-based epoxy ester dispersion, an organic silicon modified polyvinyl butyral emulsion, a gas-phase method aluminum oxide nano dispersion, a fluorocarbon surfactant, a self-crosslinking polyether thickening agent and a propylene glycol methyl ether acetate-water azeotropic quick-drying auxiliary agent. According to the coating, through cooperation of specific components and process control, the drying speed is remarkably increased, the surface drying time is shortened, meanwhile, shrinkage cavities are eliminated, the hardness of the coating is enhanced, and the edge transfer precision is improved. Corona treatment is adopted for the corresponding local printing transfer paper, gravure precise coating, infrared pre-drying and gradient hot air drying are matched, and finally clear separation and transfer of a coating are achieved through infrared laser scanning. The whole system is a water-based formula, is environment-friendly and safe, is suitable for the field of high-end printing, and has the comprehensive advantages of high drying speed, high precision, strong adhesive force, simplified process and the like.

The invention relates to a vinyl acetate refining system and method, and the system comprises: an azeotropic tower for extracting a vinyl acetate azeotrope from the top of the azeotropic tower, extracting a water-containing acetic acid material flow from the bottom of the azeotropic tower, and extracting an ethyl acetate material flow from the side line of the azeotropic tower; the azeotrope tower reflux unit is used for separating the vinyl acetate azeotrope into an azeotrope organic phase and an azeotrope water phase; the dehydration unit is used for carrying out light component and vinyl acetate separation on an azeotrope organic phase output by the azeotropic tower reflux unit, so as to realize light component recovery and vinyl acetate finished product recovery; the ethyl acetate treatment unit is used for carrying out ethyl acetate separation and vinyl acetate component recovery on the ethyl acetate material flow through the ethyl acetate treatment unit; and the vinyl acetate material flow output end of the ethyl acetate treatment unit is connected with the input end of the azeotropic tower, so that the vinyl acetate material flow flows back to the azeotropic tower. The method provided by the invention can realize separation of each component in the vinyl acetate crude product, significantly improves process stability, reduces separation difficulty, and reduces energy consumption at the same time.

The invention relates to an ethanol upgrading device and method, the device is used for upgrading ethanol containing a small amount of ethyl acetate, the device comprises a low-pressure rectification unit, a pumping unit and a high-pressure rectification unit which are connected in sequence, a variable-pressure rectification principle is adopted, azeotrope composition is changed only through a variable-pressure mode, reasonable process parameters are matched, and the quality of ethanol is improved. The purified ethanol is extracted from the low-pressure rectification unit, and the ethanol with higher ethyl acetate content is extracted from the high-pressure rectification unit, so that a large amount of ethanol is prevented from being evaporated to the high-pressure rectification unit, the energy consumption is obviously reduced, the production cost is reduced, and the economic benefit is improved.

Provided in the present application are a heat-absorbing material and a preparation method therefor, a heat-absorbing part, a battery assembly and an electric device. The heat-absorbing material comprises a carrier, an entrainer and a phase-change component, wherein the phase-change component and the entrainer form a negative azeotrope. The entrainer and the phase-change component in the heat-absorbing material of the present application form a negative azeotrope, such that the phase-change component undergoes phase change when the temperature is lower than the phase-change temperature of the phase-change component, thereby absorbing heat, realizing a heat-absorbing effect, improving the heat-absorbing response speed of the heat-absorbing material, and further improving the usage safety of the battery assembly.

The invention provides novel azeotrope-like compositions and separation processes utilizing the same. An azeotrope-like composition comprising 1,2-difluoroethylene (HFO-1132) and hydrogen fluoride. An azeotrope-like composition comprising 1,1,2-trifluoroethylene (HFO-1123) and hydrogen fluoride. A separation process for a composition comprising at least one member selected from the group consisting of trans-1,2-difluoroethylene (HFO-1132(E)), cis-1,2-difluoroethylene (HFO-1132(Z)), and 1,1,2-trifluoroethylene (HFO-1123) and hydrogen fluoride.

The invention relates to the technical field of alkyl anthracene production, and discloses a separation method of an anthracene alkylation reaction product, which comprises the following steps: pretreating the anthracene alkylation reaction product to remove part of anthracene; mixing the pretreated product with an entrainer, and rectifying at the temperature of 100-250 DEG C and the pressure of 1-120 kPa to obtain a light component I and a heavy component I; the light component I contains an azeotrope of a reaction solvent and an entrainer in the anthracene alkylation reaction product; the heavy component I is rectified at the temperature of 100-300 DEG C and the pressure of 0.5-100 kPa, and a light component II and a heavy component II are obtained; the light component II contains an azeotrope of anthracene and an entrainer; and carrying out cooling crystallization on the heavy component II, and carrying out solid-liquid separation to obtain alkyl anthracene. By adopting the separation method provided by the invention, the system can stably operate for a long time, and meanwhile, higher yield and purity of anthracene and alkyl anthracene can be realized.

The invention relates to a method and system for preparing isobutene from tert-butyl alcohol, and the method comprises the following steps: S1, hydrolyzing initial tert-butyl alcohol to obtain a first product containing water, isobutene and unreacted tert-butyl alcohol; s2, performing membrane permeation separation on the first product to obtain a water permeate and a retentate containing isobutene and unreacted tert-butyl alcohol; s3, performing flash evaporation separation on the retentate to obtain gas-phase isobutene and liquid-phase tert-butyl alcohol; circulating the liquid-phase tert-butyl alcohol and repeating the steps S1 to S3 until the total conversion rate of the initial tert-butyl alcohol reaches a preset value; rectifying the liquid-phase tert-butyl alcohol, all water permeates and all gas-phase isobutene obtained in the last-stage circulation to obtain high-purity isobutene, water-tert-butyl alcohol azeotrope and wastewater; the water-tert-butyl alcohol azeotrope is extracted from the side line of the rectifying stripping section and returns to S2 for recycling. Through cyclic coupling of hydrolysis, membrane permeation separation, flash separation and rectification, high-purity isobutene is obtained, the conversion rate of tert-butyl alcohol is high, and the discharge amount of wastewater is low.

Azeotropic or azeotrope-like compositions, particularly azeotropic or azeotrope-like compositions consisting essentially of or consisting of (Z)-1-chloro-2,3,3-trifluoroprop-1-ene (HCFO-1233yd(Z)), ethanol, and each of methanol, as well as azeotropic or azeotrope-like compositions consisting essentially of or consisting of (Z)-1-chloro-2,3,3-trifluoroprop-1-ene (HCFO-1233yd(Z)), ethanol, and 1,2-trans-dichloroethylene (trans-DCE), and azeotropic or azeotrope-like compositions consisting essentially of or consisting of (Z)-1-chloro-2,3,3-trifluoroprop-1-ene (HCFO-1233yd(Z)), methanol, and 1,2-trans-dichloroethylene (trans-DCE), and solvent uses of the aforementioned compositions.

The disclosed method for recovering N-methyl pyrrolidone from complex waste liquid includes the following processes: pumping the NMP-containing waste liquid into a rectification one-effect tower after vacuum dehydration in a dehydration tower, condensing and collecting NMP at the top of the tower, and pumping the tower bottom into a rectification two-effect tower; obtaining NMP at the top of the rectification two-effect tower, sending the liquid residue to a depolymerization reactor after evaporation of the gas phase in a thin film evaporator, and condensing and condensing; performing side line extraction on the rectification two-effect tower and injecting sulfolane to extract heavy components, separating after mixing, returning the light phase to the rectification two-effect tower, and sending the heavy phase to a regeneration tower; collecting NMP-water azeotrope at the top of the regeneration tower to return to the dehydration tower, collecting sulfolane at the side line to return to the extraction cycle, and sending the concentrated residue at the bottom to the depolymerization reactor; sending the depolymerization gas obtained from the depolymerization reactor to a quenching tower, sending the cooling liquid of the quenching tower to a light-removing tower, sending the overhead product of the light-removing tower to sewage treatment, and collecting NMP at the tower bottom. The recovery treatment method has reasonable and efficient process flow, and has higher NMP yield for complex NMP-containing waste liquid.

A process of thermal management fluid reclamation is provided. The process includes collecting at least one recovered thermal management fluid including at least a first refrigerant compound and a second refrigerant compound to form a collected thermal management fluid; and forming a blend constituent from the collected thermal management fluid in the absence of distillation or substantially in the absence of distillation. The blend constituent is azeotropic, azeotrope-like, or close-boiling. The blend constituent is configured to be combined with (i) one or more refrigerant compounds, and / or (ii) one or more blends comprising two or more refrigerant compounds, for formation of a thermal management fluid product.

The present application relates to acetonitrile recovery field, in particular to a kind of acetonitrile waste liquid separation and recovery method and device. The method includes steps: the pH of the acetonitrile waste liquid is adjusted to 6 8; the acetonitrile waste liquid having a pH adjusted to 6 8 is sent to the first distillation tower, and rectification obtains one-level separation acetonitrile; the one-level separation acetonitrile is sent to a gas-liquid separator, and secondary separation acetonitrile is obtained after separation; the secondary separation acetonitrile is sent to a permeation vaporization membrane assembly, and tertiary separation acetonitrile is obtained after separation; the tertiary separation acetonitrile is sent to the second distillation tower, and rectification obtains acetonitrile. The present application removes the water in acetonitrile-water azeotrope by a gas-liquid separator and a permeation vaporization membrane assembly, and two kinds of equipment have low working energy consumption, and water content can be reduced to less than 0.1% after being used in combination; in addition, only two rectifications need to be carried out before and after, and the equipment used is less than that of existing separation method, and structure is simple and compact, and whole process does not need to introduce new substances (such as extractants, adsorbents, etc.), effectively reducing recovery cost.

The utility model relates to the technical field of petrochemical engineering, and discloses a C4 integrated device which comprises a countercurrent multistage reactor, a reduced pressure rectifying tower and an azeotropic rectifying tower which are arranged on the same straight line, a mixed C4 feeding hole and a catalyst feeding hole are formed in one side of the countercurrent multi-stage reactor, the bottom end of the countercurrent multi-stage reactor is connected with a reactor discharging pipe, and one end, far away from the reduced pressure rectifying tower, of the reactor discharging pipe is connected with a feeding hole of the reduced pressure rectifying tower; through the pressure transmitter, the component analysis probe and the temperature sensor, the temperature, pressure and component change in the azeotropic rectifying tower can be monitored in real time, so that the temperature gradient in the azeotropic rectifying tower can be adjusted by controlling the flow of cooling liquid and the flow of steam, the probability of C4 azeotrope interference is reduced, and temperature capture can be carried out on key positions such as a rectifying section and a stripping section.

An azeotrope or azeotrope-like composition consists essentially of an effective amount of 1-chloro-1, 1-difluoroethane (HCFC-142b) and 1, 1, 2-trifluoroethane (HFC-143), and a method for producing the azeotrope or azeotrope-like composition. Also disclosed are methods for separating azeotrope or azeotrope-like compositions and / or utilizing the same in extraction and pressure swing distillation in conjunction with methods of making 1, 1, 2-trifluoroethane (HFC-143).

The invention discloses a rectification device and method for separating and purifying normal propyl alcohol-isopropyl alcohol-tetrahydrofuran-water azeotrope, relates to the field of separation and purification, and provides a novel rectification tower which is internally provided with two vertical partition plates, ethylene oxide is used as a reaction solvent, ethylene glycol is used as an extraction agent, and the normal propyl alcohol-isopropyl alcohol-tetrahydrofuran-water azeotrope is separated and purified. The separation and purification of the n-propanol-isopropanol-tetrahydrofuran-water azeotrope are realized in the rectifying tower, the process flow is short, the separation effect is good, the thermal efficiency is high, the energy consumption is low, the emission of carbon dioxide is less, the equipment investment is less, the occupied area is small, the obtained n-propanol, isopropanol and tetrahydrofuran are high in purity, the practicability is strong, and the sustainable development is favorably realized. Compared with the traditional multi-stage extractive distillation, the rectifying tower disclosed by the invention has the advantages that the heat utilization efficiency is improved, the equipment investment is reduced by about 40-50%, the occupied area is reduced by about 50-60%, and the construction cost is effectively saved.

Minimum-boiling, heterogeneous azeotropic and azeotrope-like compositions including 1,1,2,2,3-pentachloropropane (HCC-240aa) and hydrogen fluoride (HF), as well as methods for using these azeotropic or azeotrope-like compositions in the production of trifluorochloropropenes.

Specifically, a process for controlling heavies in a recycle catalyst stream for use in a continuous hydroformylation process in which olefins are converted with synthesis gas in the presence of a hydroformylation catalyst to form an aldehyde product stream, followed by separation of the catalyst for recycle to the hydroformylation step, comprises removing a crude product stream from a hydroformylation reaction zone, the crude product stream comprising one or more aldehyde products, one or more heavy by-products, a transition metal-organophosphorus ligand complex catalyst, one or more unconverted reactants, and one or more inert lights; providing a water stream; combining the water stream with the crude product stream into an azeotropic vaporizer; removing from the vaporizer an overhead gas stream comprising the one or more aldehyde products, the one or more unconverted reactants, the one or more inert lights, a portion of the water, and a portion of the heavy by-products; a liquid recycle catalyst stream to be sent to the reaction zone, the liquid recycle catalyst stream comprising the transition metal-organophosphorus ligand complex catalyst, a remainder of the aldehyde product, and a remainder of the heavy by-products, as a residue stream from the azeotropic vaporizer, wherein at least 25% of the aldehyde product recovered in the overhead gas stream from the condenser is removed as a water azeotrope.

The utility model discloses a bio-based 1, 4-butanediol production process system which comprises an esterification unit, a hydrogenation unit, a tetrahydrofuran refining unit, a gamma-butyrolactone extraction unit, an azeotrope extraction unit and a 1, 4-butanediol refining unit which are communicated in sequence. The discharge end of the azeotrope extraction unit is sequentially connected with a post-treatment unit and a gamma-butyrolactone refining unit; the discharging end of the gamma-butyrolactone refining unit is communicated with the feeding end of the hydrogenation unit. According to the utility model, the azeotrope liquid containing BDO is subjected to dehydrogenation reaction to generate post-treatment liquid containing GBL, the post-treatment liquid is mixed with the byproduct GBL crude liquid, and the GBL reuse liquid is obtained through light component removal, heavy component removal and purification. The obtained GBL reuse liquid is returned to the previous procedure, and BDO is regenerated through hydrogenation reaction, so that the total yield of BDO in the process is improved.

Disclosed is a process for the preparation of triacetonamine (TAA), the process comprising (i) reacting acetone and ammonia to produce a reaction product comprising TAA, acetone, isopropylideneacetone, and TMDP; (ii) directing the reaction product to an acetone separation column to obtain an unreacted acetone stream; and a first bottoms stream; (iii) directing the first bottoms stream to an azeotrope separation column to obtain an azeotrope distillate stream comprising an aqueous azeotrope of isopropylideneacetone and TMDP; and a second bottoms stream; (iv) directing the second bottoms stream to a medium boil substance separation column to obtain a medium boil stream; and a third bottoms stream; (v) directing the third bottoms stream to a refining column to obtain pure TAA as a distillate stream; (vi) subjecting the azeotrope distillate stream to phase separation to obtain an organic phase and an aqueous phase; directing the organic phase to a TMDP separation column to obtain a recyclable distillate stream comprising isopropylideneacetone and a bottoms stream comprising TMDP; and (vii) at least partially recycling the unreacted acetone stream, the medium boil stream and the recycle distillate stream to step (i); and discarding the TMDP bottoms stream.

The invention belongs to the technical field of separation and purification, and particularly relates to a method for separating a methanol-dimethyl carbonate azeotrope system, which adopts a system for separating a methanol-dimethyl carbonate azeotrope and adopts a eutectic solvent as an extracting agent for extractive distillation. The hydrogen bond acceptor of the deep-eutectic solvent is choline chloride, and the hydrogen bond donor of the deep-eutectic solvent is malonic acid or urea. According to the method, the choline chloride deep eutectic solvent which is lower in cost, simpler and more convenient to prepare and more environmentally friendly is selected as the extracting agent, systematic process parameter optimization and equipment configuration design are carried out according to the high-viscosity characteristic of the choline chloride deep eutectic solvent, and stable, efficient and long-period operation of the high-viscosity green solvent in the continuous extractive distillation process is successfully achieved; the target of separating the methanol and the dimethyl carbonate from the binary mixture is achieved, the final yield of the methanol and the dimethyl carbonate can reach 99% or above, the product purity can reach 99.5% or above, and compared with a traditional solvent separation method, the energy consumption is greatly reduced, the equipment cost is saved, and the method is suitable for industrial production. The strict standard of the high-end chemical industry and the fine chemical industry on the raw material purity can be reached.

The invention relates to the technical field of acetonitrile rectification and purification, and discloses a resource recycling method of acetonitrile in acetonitrile-containing wastewater, which comprises the following steps: firstly, adding a certain amount of dilute sulphuric acid into a raw material tank, and adjusting the pH value to 5-5.5; pumping the raw materials from a raw material tank to a light component removal tower, and removing low-boiling-point impurities in the raw materials; pumping tower bottoms of the light component removal tower into a dehydration tower, and carrying out preliminary dehydration treatment; steam at the top of the dehydrating tower directly enters a membrane separation system for membrane separation dehydration to obtain a mixture of acetonitrile and isopropanol with the water content being less than or equal to 0.03 wt%; pumping an acetonitrile and isopropanol mixture produced by the membrane separation system into an impurity removal tower, and separating out an acetonitrile and isopropanol azeotrope; and finally pumping acetonitrile in a tower kettle of the impurity removal tower to a product tower, further decoloring and purifying, and extracting an acetonitrile product from the top of the tower. By combining a conventional rectification process and a membrane separation process, the acetonitrile in the acetonitrile-containing wastewater is subjected to resource recovery, and finally the acetonitrile product with the water content being less than or equal to 0.03 wt.% and the effective purity being 99.9% or above is obtained.

Provided are azeotrope and azeotrope-like compositions between HFO-1252zc, HFC-263fb, HF, and H2O, which are present in a process for the preparation or purification of HFO-1252zc, and methods for the preparation or purification of HFO-1252zc, HFC-263fb, HF, and H2O. Also provided are methods of forming and using these azeotrope and azeotrope-like compositions.

The application provides a dehydration method of an aqueous triethylene glycol solution, a dehydration method and device of natural gas, and the dehydration method of the aqueous triethylene glycol solution is performed by using a dehydration device, the dehydration device comprises a stripping tower and a reboiler connected in sequence, and the dehydration method comprises the following steps: making the aqueous triethylene glycol solution enter the reboiler, and performing azeotropy with an azeotrope agent in the reboiler to obtain a dehydrated triethylene glycol system and a compatible gas product of water and the azeotrope agent generated by azeotropy respectively; wherein the azeotrope agent comprises cyclohexane; making the triethylene glycol system enter the stripping tower, and performing stripping with stripping gas entering the stripping tower in countercurrent contact, and outputting the triethylene glycol system from the stripping tower after stripping, the dehydration method can further reduce the water content of the triethylene glycol, and the dehydration method has the advantages of low toxicity, high efficiency, low energy consumption and the like.

The invention discloses a separation system and a separation method of a dichloromethane, ethanol and methanol aqueous solution multi-element azeotropic system. The separation system comprises three stages of rectifying towers connected in series; a reflux pipeline with a condenser is connected to a tower top extraction port of each stage of rectifying tower, and the reflux pipeline corresponding to the first stage of rectifying tower is also connected with a mixer for mixing tower top extraction substances of the first stage of rectifying tower with water and a phase splitter for separating oil and water in the mixer; a water phase outlet of the phase splitter and a tower kettle extraction opening of the first-stage rectifying tower are respectively connected with a feeding opening of the second-stage rectifying tower; a methanol extraction opening is formed in the side line of the second-stage rectifying tower; a tower kettle extraction opening of the second-stage rectifying tower is connected with a feeding opening of the third-stage rectifying tower; and a device for separating ethanol and water is connected to a tower top extraction port of the third-stage rectifying tower. The method provided by the invention can effectively separate the dichloromethane, ethanol and methanol aqueous solution multi-element azeotropic system, and the obtained dichloromethane, ethanol and methanol products have high purity.

The invention provides a continuous extractive distillation separation method of a p-xylene-propanol azeotropic mixture, and belongs to the technical field of separation. According to the method disclosed by the invention, any two of dibutyl phthalate, N-methyl pyrrolidone and sulfolane are used as extracting agents. The method comprises the following steps: adding a mixed raw material solution of p-xylene and propanol into an extraction tower, then adding an extraction agent, carrying out extractive distillation, extracting a propanol product from the top of the tower, introducing an extraction tower bottom product containing the extraction agent and p-xylene into a solvent recovery tower, and after distillation, extracting a p-xylene product from the top of the tower and discharging the extraction agent from the bottom of the solvent recovery tower; and introducing the extraction agent into the extraction tower for cyclic utilization. The method provided by the invention realizes the separation of the p-xylene-propanol azeotropic mixture, has high separation efficiency, is easy to regenerate and is environment-friendly, and the mass fraction of p-xylene in the separated propanol can be greater than or equal to 99.9%.

The invention provides a heat pump rectification system for recycling DMAC (dimethylacetamide) through double-tower coupling rectification, impurity removal and desalination and a method for recycling DMAC through impurity removal and desalination. The heat pump rectification system comprises a rectification tower, a compressor, an evaporator, a condensate water tank, a reboiler and a pump. The method comprises the following steps: rectifying in a first tower: preheating a mixed material containing DMAC, water, ethyl acetate and salt, feeding the preheated mixed material into the first tower, extracting an ethyl acetate-water azeotrope from the top of the tower, and enriching a DMAC-water-salt mixed solution from the bottom of the tower; and second-tower rectification and purification: conveying the first-stage tower kettle liquid to a second-stage tower for deep separation, extracting process water from the tower top, extracting a DMAC finished product with the purity reaching the standard from a tower side line, concentrating and crystallizing the second-stage tower kettle high-salt-content solution, and feeding the concentrated and crystallized solution into a centrifugal machine to realize solid-liquid separation of inorganic salt. Through the double-tower heat pump coupling design, first-stage tower top steam is used as a heat source of a first-tower reboiler after being heated by a compressor, and more steam is saved compared with a traditional steam heating process.

The invention discloses a continuous mixing and batching system for methylamine synthesis, and relates to the technical field of methylamine synthesis, the continuous mixing and batching system comprises a methanol storage tank, a liquid ammonia storage tank, an azeotrope storage tank, a mixed amine storage tank and a mixing kettle, the methanol storage tank, the liquid ammonia storage tank, the azeotrope storage tank and the mixed amine storage tank are connected with the mixing kettle through pipelines, a low-temperature heat exchanger, a start vaporizer, a three-stage high-temperature heat exchanger, a reactor, a rectifying tower and a tail gas absorption tower are arranged at the rear section of the mixing kettle. According to the invention, all component materials firstly enter the feeding premixer through the feeding pipeline, and the atomization nozzle, located at one end of the feeding premixer, of the feeding pipeline atomizes the materials and then impacts and mixes the materials, so that an efficient premixing effect is achieved. When the first stirring mixer located on the outer side of the stirring shaft and located in the feeding premixer rotates along with the stirring shaft, the stirring resistance can be reduced, and the material mixing uniformity can be further improved through impact and mesh dispersion.

The present application relates to a kind of methyl isopropyl ketone production device and process for floor coating, belong to methyl isopropyl ketone production device and process technical field.It includes reaction rectifying tower, first refining tower, second refining tower, third refining tower;Reaction rectifying tower includes first kettle from bottom to top, reaction rectifying tower distillation section, reaction rectifying tower reaction section, reaction rectifying tower rectification section;First refining tower includes second kettle, first distillation section, first rectification section;Second refining tower includes third kettle, second distillation section, third rectification section;Third refining tower includes fourth kettle, fourth distillation section, fourth rectification section.The present application uses reaction rectification process, reaction and separation are coupled, isobutyric acid conversion rate is more than 90%;Using double-effect distillation integrated heat, energy consumption is reduced by 40-50%;Combining azeotrope and liquid-liquid phase separation technology, product purity can reach more than 99%, with the advantages of low by-product, low investment, low energy consumption.

The present application relates to a kind of continuous catalytic rectification ester exchange production propylene glycol monomethyl ether acetate processes, including PO catalytic rectification tower, PM catalytic rectification tower, MeOAc recovery tower, PMA refining tower, PO catalytic rectification tower is generated using PO and methanol reaction PM;PM is sent into PM catalytic rectification tower and occurs ester exchange reaction with MeOAc, and PMA is generated;The MeOAc, MeOH mixture obtained from PM catalytic rectification tower top is sent into MeOAc recovery tower and is separated, and the MeOAC and MeOH azeotrope of recovery tower top is recycled to PO catalytic rectification tower and is fully utilized MeOH, and the MeOAc of column bottom is recycled to PM catalytic rectification tower and participates in reaction;PMA refining tower separates the PMA obtained from PM catalytic rectification tower bottom and a small amount of PM, and the PM of refining tower top is recycled to PM catalytic rectification tower, and the PMA product of column bottom is obtained with high purity.Process operation is simple, process conversion rate and selectivity are high, catalyst can be recycled, post-treatment separation is simple, and have good industrial application prospect.