CN110449031A - A kind of device and method separating organic liquid impurities - Google Patents

Abstract

The application belongs to the technical field of separation and purification chemical industry, and in particular relates to a device and method for separating organic liquid impurities, removing particulate impurities, colored impurities, large molecular weight impurities, gel-type impurities in a solvent system through molecular sieving and dissolution diffusion Impurities, inorganic salts, etc., as well as substances with suitable molecular weights that are screened or enriched by molecular weight selection, etc.; the core components of the device include buffer tanks, feed pumps, membrane separation equipment, etc.; feed pumps are used for feeding and provide appropriate temperature and temperature. pressure; organic nanofiltration membranes are arranged in the membrane separation equipment, and separation is carried out based on separation membranes with different pore sizes through the difference in molecular weight or separation based on the difference in dissolution and diffusion rates of different substances in the membrane; the device occupies a small area, Energy saving, high purification efficiency and wide applicability, it can be used independently or embedded in existing equipment, and has broad application prospects in the fields of general chemical and electronic chemical raw materials.

Description

A device and method for separating organic liquid impurities

technical field

The application belongs to the technical field of separation and purification chemicals, and in particular relates to a device and method for separating organic liquid impurities.

Background technique

In a narrow sense, organic compounds are mainly composed of carbon and hydrogen elements, and are certain carbon-containing compounds, but do not include carbon oxides, sulfides, carbonic acid, carbonates, cyanides, thiocyanates, cyanates, Carbides, carboranes, metal alkyls, metal carbonyls, metal organic ligand complexes, etc. Organic matter is the material basis for life, and all living organisms contain organic compounds. Fats, amino acids, proteins, sugars, heme, chlorophyll, enzymes, hormones, etc. Metabolism in organisms and genetic phenomena of organisms involve the transformation of organic compounds. In addition, many substances closely related to human life, such as oil, natural gas, cotton, dyes, chemical fibers, plastics, plexiglass, natural and synthetic drugs, etc., are closely related to organic compounds.

The purity of organic compounds and the content of impurities have a very large impact on their performance and application, even a decisive impact, such as the purity of drugs, the purity of monomers used in polymer preparation, etc., all have extremely high purity Require. With the increasingly strict environmental protection requirements and the continuous progress of my country's economy and society, the requirements for high-end chemicals with high purity and low impurity content are also increasing. Generally speaking, the removal of impurities in organic matter mainly includes the following methods: 1) Larger particulate matter can be removed by filtration; 2) If the organic matter is liquid, it can be removed by distillation, rectification, fractionation, molecular distillation, etc. Separation and purification; 3) The product is solid and can be purified by recrystallization; 4) The product is colored and can be purified by activated carbon adsorption; 5) If it is macromolecules and monomers or oligomers, it can be purified by precipitation or dialysis Purification; 6) Moisture can be removed by azeotropic or desiccant methods; 7) Other methods. The comprehensive application of these methods can preliminarily purify most of the organic matter to a certain degree of purity, such as analytical purity, chemical purity and so on. However, when lower levels of impurities are required or cannot be achieved by conventional methods, such as microgels and trace oligomers in polymer monomers, pigments in natural products, extremely low and extremely low levels in mobile phases for HPLC When fine solid particles or multiple impurities coexist in the system to be removed at one time, and the traditional methods cannot be realized or the realization cost is very high, new green and energy-saving purification methods and devices are very necessary.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the present application provides a device and method for separating organic liquid impurities, so as to realize the removal of some special requirements of high purity, environmental sensitivity, and the removal of impurities that cannot be achieved by conventional methods, or the energy consumption is very high, At the same time, the device is simple in structure, controllable in cost, occupies less space, and has great potential for industrialization.

In order to achieve the above purpose, the solution of this application is:

A device for separating organic liquid impurities, comprising a raw material tank, a buffer tank, a feeding pump, and a membrane separation device connected by pipelines in sequence;

Wherein, the raw material tank is used to store the organic liquid to be separated; the buffer tank is used to directly form the organic liquid to be separated into the feed liquid or add organic solvent to dilute the organic liquid to be separated into the feed liquid; the feed pump is used to The size and flow of the organic nanofiltration membrane in the membrane separation equipment are adjusted to the temperature and pressure of the feed liquid to form the feed liquid; the membrane separation equipment is provided with an organic nanofiltration membrane to separate and purify the feed liquid and form a retentate and permeate.

The intercepted liquid can be injected into the buffer tank and mixed with the organic liquid to be separated, and then separated and filtered again, or directly recovered through the intercepted liquid discharge recovery pipeline. Thus, the retentate can be divided into the retentate circulating fluid and the retentate effluent. Among them, the intercepted circulating liquid is circulated into the buffer tank and mixed with the organic liquid to be separated, and then continues to pass through the organic nanofiltration membrane in the membrane separation equipment for circulating separation, and the intercepted material liquid can be directly discharged.

The permeate can also be directly collected as required, or further purified; the permeate can be further purified by common separation methods, such as distillation, rectification, fractionation, molecular distillation, recrystallization, etc. Apparatus and method for separating organic liquid impurities.

Further, the permeate end and/or the retention end of the membrane separation equipment can be connected to the buffer tank through pipelines, so that a circulating separation system is further formed between the membrane separation equipment, the buffer tank and the feed pump, so that the permeate from the membrane separation equipment And/or the retentate is returned to the buffer tank and mixed with the organic liquid to be separated to form the feed liquid again, the feed liquid is then adjusted by the feed pump to adjust the temperature and pressure to form the membrane feed liquid, and the membrane feed liquid then enters the membrane separation equipment, The retentate and permeate are formed under the action of the organic nanofiltration membrane.

Further, the device for separating organic liquid impurities provided by the present application can also be provided with multi-stage separation, that is, a plurality of devices for separating organic liquid impurities can be connected in series, so that the permeate of the upper stage is used as the organic solution to be separated in the next stage. Enter the next stage device for further separation and purification. The number of stages of the specific multi-stage separation membrane equipment is designed according to the actual needs.

Further, the membrane separation equipment can also be connected to a conventional separation device to further separate and purify the permeate.

In this application, organic nanofiltration membranes of various materials and types that are resistant to organic solvents can be used; as an example and not a limitation, PuraMem membranes from Evonik Specialty Chemicals (Shanghai) Co., Ltd. can be used. Differently, polyimide substrates or polyacrylonitrile membranes can be selected. The size of various membranes and the molecular weight of sieving can be determined according to the components to be purified and separated.

In this application, each section of pipelines and valves are made of special steel or special steel lined with Teflon.

The device of the present application can be used independently, or can be integrated into various existing chemical production and purification equipment containing organic solvents to realize the enrichment, separation, purification and other operations of raw materials in the production process.

The application also provides a method for separating organic liquid impurities, comprising:

S1. Pass the raw material liquid through a common filtration device to remove large particles and obtain the organic solvent to be separated, so as to avoid damage to the organic nanofiltration membrane;

S2. The organic solution to be separated described in step S1 is directly formed into a feed liquid, or is diluted as required under the action of an organic solvent to form a feed liquid;

S3. The feed liquid obtained in step S2 is subjected to temperature and pressure adjustment by the feed pump to form a film feed liquid;

S4. The membrane feed liquid obtained in step S3 is separated and purified through an organic nanofiltration membrane to obtain a retentate and a permeate.

Further, after step S4, it also includes:

S5. Return the retentate obtained in step S4 to step S2, and further mix with the organic solution to be separated described in step S2 to form a feed solution.

As long as the intercepted liquid obtained in step S4 remains homogeneous, the intercepted liquid can be determined according to the specific requirements of the actual interception rate, and the appropriate proportion or all of the intercepted liquid can be returned to step S2 and separated again.

Further, after step S4, it also includes:

S6. Separate and purify the permeate obtained in step S4 through an organic nanofiltration membrane again.

When separating and purifying again to reduce the impurity content, the corresponding temperature and pressure parameters can be changed according to requirements.

Further, after step S4, it also includes:

S7. The permeate obtained in step S4 is again subjected to distillation, or rectification, or fractionation, or molecular distillation, or recrystallization for separation and purification.

In this application, the organic solution to be separated may be an organic solution formed by a pure solvent or a mixed solvent containing ultra-fine and ultra-low content of solid particle impurities; it may also be an organic solution containing high molecular weight such as oligomers and microgels The polymerizable monomer solution of impurities; it can also be an organic solvent extract solution containing natural products; it can also be an organic solution containing a large amount of impurities such as waste lubricating oil, and other organic solutions that will not damage the membrane.

Further, the weight percentage of organic compounds in the organic solution to be separated is at least 80%; more preferably 90%; still more preferably 95%.

Further, the temperature of the film feeding liquid in step S3 is -30°C to 100°C, more preferably -10°C to 70°C; still more preferably 10°C to 50°C.

Further, the pressure of the film feeding liquid in step S3 is 5 bar to 70 bar; more preferably 20 bar to 60 bar; still more preferably 30 bar to 50 bar. Since there is no pressure behind the inlet membrane, the transmembrane pressure difference is the pressure in front of the inlet membrane.

Further, the temperature and pressure in step S3 are adjusted according to the size and flow rate of the organic nanofiltration membrane in step S4. The basis of adjustment is to adjust by detecting the working curves of different solutions under different pressures.

Further, the area of the organic nanofiltration membrane described in step S4 can meet the requirements of the amount of separation without waste, which is determined according to the amount of the separated organic solution and the ratio of interception/permeability, as well as specific working conditions.

In the present application, the organic nanofiltration membranes used may be the same or different according to the separation principle and the properties of the target product.

Due to the adoption of the above scheme, the beneficial effects of the present application are:

The device provided by the application adopts an organic nanofiltration membrane to realize the separation and purification of organic compounds, the energy required is mainly electric energy for changing the temperature and pressure of the feed liquid, and the power consumption is greatly saved compared with traditional distillation; and The device is compact and occupies a small area, and can be embedded in various existing chemical production and purification production lines as a new structural unit to purify some special impurities in a targeted manner.

The method provided in this application shows great advantages for some temperature-sensitive compounds, such as the purification of traditional Chinese medicine extracts, the purification of compounds containing polymerizable double bonds, etc., and even the key technical problems that cannot be solved by traditional processes are also It can be solved by this method, such as the removal of ultra-fine and ultra-low content of solid particles in organic solvents.

In a word, the present application can simplify many traditional separation and purification methods, can effectively reduce the cost of separation, and is simple and convenient to use, has a high degree of automation, and occupies a small space. Separations that are not easily achieved in many traditional separation methods, such as color removal after extraction of natural products, removal of high molecular weight impurities in polymerizable monomers, and removal of microgels, etc., all show high practicability by using the present application. At the same time, the application shows huge market potential in the separation of common chemical products and the purification of electronic-grade chemical products, has great market application prospects, and has extensive practicability for the upgrading of many traditional chemical industry products.

Description of drawings

Fig. 1 is a kind of schematic flow sheet of the device for separating organic liquid impurities provided by the embodiment of the application;

Figure 2 shows the morphology of the samples before and after the separation of waste lubricating oil by using the method for separating organic liquid impurities provided by the present application; left: before membrane separation; right: after membrane separation.

Description of reference numbers:

1 raw material tank, 11 organic solution to be separated, 2 buffer tank, 21 feed liquid, 3 feed pump, 31 film feed liquid, 4 membrane separation equipment, 41 retentate liquid, 411 retentate circulating liquid, 412 retentate discharge liquid, 42 osmotic fluid.

Detailed ways

The present application will be further described below with reference to specific embodiments. It should be pointed out that the following examples are only used to illustrate the application but not to limit the scope of application of the application. Several modifications and other applications can also be made without departing from the concept of the present application. These all belong to the protection scope of the present application.

As shown in Figure 1, a device for separating organic liquid impurities includes a raw material tank 1, a buffer tank 2, a feed pump 3, and a membrane separation device 4 connected by pipelines in sequence.

The raw material tank 1 is used to store the organic liquid 11 to be separated; the buffer tank 2 is used to directly form the organic liquid 11 to be separated into the feed liquid 21 or add an organic solvent to dilute the organic liquid 11 to be separated into the feed liquid 21 The feed pump 3 is used to adjust the temperature and pressure of the feed liquid 21 according to the size and flow rate of the organic nanofiltration membrane in the membrane separation device 4 to form a membrane feed liquid 31; the membrane separation device is provided with an organic nanofiltration membrane for according to The principles of molecular osmosis and molecular weight sieving separate impurities from the membrane feed liquid 31 .

In this application, the organic liquid 11 to be separated in the raw material tank 1 enters the buffer tank 2 to directly form the feed liquid 21, or is diluted under the action of an organic solvent to form the feed liquid 21, and the feed liquid 21 is adjusted by the feed pump 3 After the temperature and pressure, the membrane inlet liquid 31 is formed. After entering the membrane separation device 4, the membrane inlet liquid 31 forms a retentate 41 and a permeate 42 under the action of the organic nanofiltration membrane.

In this application, when the viscosity of the organic liquid 11 to be separated is greater than 500cp, an organic solvent can be used for dilution; the organic solvent can be alcohols, esters, ethers, aromatic hydrocarbons, or alkanes, etc.

The principle of action of the organic nanofiltration membrane is that the organic liquid to be separated is contacted with the organic nanofiltration membrane at a certain temperature and pressure, and the organic nanofiltration membrane has different permeability for the components existing in the organic liquid, which can make the organic nanofiltration membrane to be separated. Each component in the organic liquid passes through the organic nanofiltration membrane at different rates, that is, permeates through the organic nanofiltration membrane, and the driving force for permeating the membrane is mainly the transmembrane pressure difference, that is, the pressure difference on both sides of the membrane; Under the action of the pressure difference, the components with faster permeation rate pass through the organic nanofiltration membrane and become permeate, while the components with slower permeation rate are enriched on the interception side and become interception liquid.

The intercepted liquid 41 can be injected into the buffer tank 2 and mixed with the organic liquid 11 to be separated, and then separated and filtered again, or directly recovered through the intercepted liquid discharge recovery pipeline. Thus, the retentate liquid 41 can be divided into a retentate circulating liquid 411 and a retentate effluent liquid 412 . Among them, the intercepted circulating liquid 411 is circulated into the buffer tank 2 and mixed with the organic liquid 11 to be separated, and then continues to pass through the organic nanofiltration membrane in the membrane separation device 4 for circulating separation, and the intercepted feed liquid 412 can be directly discharged.

In this application, the retention end of the membrane separation device 4 can also be connected to the buffer tank 2 through a pipeline, so that a circulating separation system is further formed between the membrane separation device 4, the buffer tank 2 and the feed pump 3, so that the The shut-off circulating liquid 411 of the equipment 4 returns to the buffer tank 2 and is mixed with the organic liquid 11 to be separated to form the feed liquid 21, and the feed liquid 21 is then adjusted by the feed pump 3 to form the film feeding liquid 31 after adjusting the temperature and pressure. The liquid 31 then enters the membrane separation device 4, and forms a retentate 41 and a permeate 42 under the action of the organic nanofiltration membrane.

Further, a three-way valve and a branch pipeline can be used to connect the membrane separation device 4 to the buffer tank 2 and the intercepted liquid discharge recovery pipeline respectively, and the direction of the intercepted liquid 41 can be controlled through the three-way valve.

The permeate 42 can also be directly collected as required, or further purified; the further purification of the permeate 42 can adopt common separation methods, such as distillation, rectification, fractionation, molecular distillation, recrystallization, etc., and the application can also be used. The provided apparatus and method for separating organic liquid impurities are performed.

In this application, the permeate end of the membrane separation device 4 can be connected to the buffer tank 2 through a pipeline, so that a circulating separation system is further formed between the membrane separation device 4, the buffer tank 2 and the feed pump 3, so that the The permeate 42 of 4 is returned to the buffer tank 2 and mixed with the organic liquid 11 to be separated to form the feed liquid 21, and the feed liquid 21 is then adjusted by the feed pump 3 to form a film feeding liquid 31 after adjusting the temperature and pressure, and the film feeding liquid 31 Then enter the membrane separation device 4, and form a retentate 41 and a permeate 42 under the action of the organic nanofiltration membrane.

Further, a three-way valve and a branch pipeline can be used to connect the membrane separation device 4 to the buffer tank 2 and the permeate discharge recovery pipeline respectively, and the direction of the permeate 42 is controlled by the three-way valve.

Further, the device for separating organic liquid impurities provided by the present application can also be provided with multi-stage separation, that is, a plurality of devices for separating organic liquid impurities can be connected in series, so that the permeate of the upper stage is used as the organic solution to be separated in the next stage. Enter the next stage device for further separation and purification. The number of stages of the specific multi-stage separation membrane equipment is designed according to the actual needs.

Further, the membrane separation device 4 can also be connected to a conventional separation device to further separate and purify the permeate 42 .

In this application, organic nanofiltration membranes of various materials and types that are resistant to organic solvents can be used; as an example and not a limitation, PuraMem membranes from Evonik Specialty Chemicals (Shanghai) Co., Ltd. can be used. Differently, polyimide substrates or polyacrylonitrile membranes can be selected. The size of various membranes and the molecular weight of sieving can be determined according to the components to be purified and separated.

In this application, each section of pipelines and valves are made of special steel or special steel lined with Teflon.

The device of the present application can be used independently, or can be integrated into various existing chemical production and purification equipment containing organic solvents to realize the enrichment, separation, purification and other operations of raw materials in the production process.

A method for separating organic liquid impurities provided by the application, comprising:

S1. Pass the raw material liquid through a common filtration device to remove large particles and obtain the organic solvent to be separated, so as to avoid damage to the organic nanofiltration membrane;

S2. The organic solution to be separated described in step S1 is directly formed into a feed liquid, or is diluted as required under the action of an organic solvent to form a feed liquid;

S3. The feed liquid obtained in step S2 is subjected to temperature and pressure adjustment by the feed pump to form a film feed liquid;

S4. The membrane feed liquid obtained in step S3 is separated and purified through an organic nanofiltration membrane to obtain a retentate and a permeate.

Further, after step S4, it can also include:

S5. Return the retentate obtained in step S4 to step S2, and further mix with the organic solution to be separated described in step S2 to form a feed solution.

Preferably, as long as the intercepted liquid obtained in step S4 remains homogeneous, the intercepted liquid can be determined in an appropriate proportion according to the specific requirements of the actual interception rate, or all return to step S2 and be separated again.

Further, after step S4, it can also include:

S6. Separate and purify the permeate obtained in step S4 through an organic nanofiltration membrane again.

When separating and purifying again to reduce the impurity content, the corresponding temperature and pressure parameters can be changed according to requirements.

Further, after step S4, it can also include:

S7. The permeate obtained in step S4 is again subjected to distillation, or rectification, or fractionation, or molecular distillation, or recrystallization for separation and purification.

Further, the organic solution to be separated can be in the organic solution formed by pure solvent or mixed solvent containing ultrafine and ultra-low content of solid particle impurities; it can also be in the organic solution containing high molecular weight impurities such as oligomers and microgels. Polymeric monomer solution; it can also be an organic solvent extract solution containing natural products; it can also be an organic solution containing a large amount of impurities such as waste lubricating oil, and other organic solutions that will not damage the membrane.

Further, the weight percentage of organic compounds in the organic solution to be separated is at least 80%; more preferably 90%; still more preferably 95%.

Further, the temperature of the film feeding liquid in step S3 is -30°C to 100°C, more preferably -10°C to 70°C; still more preferably 10°C to 50°C.

Further, the pressure of the film feeding liquid in step S3 is 5 bar to 70 bar; more preferably 20 bar to 60 bar; still more preferably 30 bar to 50 bar. Since there is no pressure behind the inlet membrane, the transmembrane pressure difference is the pressure in front of the inlet membrane.

Further, the temperature and pressure in step S3 are adjusted according to the size and flow rate of the organic nanofiltration membrane in step S4. The basis of adjustment is to adjust by detecting the working curves of different solutions under different pressures.

Further, the area of the organic nanofiltration membrane described in step S4 can meet the requirements of the amount of separation without waste, which is determined according to the amount of the separated organic solution and the ratio of interception/permeability, as well as specific working conditions.

In the present application, the organic nanofiltration membranes used may be the same or different according to the separation principle and the properties of the target product. If it is an organic solution formed by purifying ultra-fine and ultra-low content of solid particle impurities or mixed solvents in the organic solution, it can be selected according to the molecular weight of the organic solvent molecules in the organic solution, and the transmittance can be selected under the condition of ensuring the interception rate. High membrane; if it is to purify a polymerizable monomer solution containing high molecular weight impurities such as oligomers and microgels, or an organic solvent extract solution containing natural products, it can be selected according to the difference between molecules and retained impurities ; When purifying organic solutions with a lot of impurities such as waste lubricating oil, choose a membrane that can pass through most of the recyclable lubricating oil. In addition, in a two-stage or multi-stage device, the first stage can select a membrane that filters out impurities, and the second stage can select a membrane that recovers the solvent.

Application Example 1: Separation of ultra-fine and ultra-low content of solid particle impurities in pure solvents or various organic solutions

The organic solution to be separated after preliminary purification by the conventional separation method first enters the buffer tank to form the feed solution, and then the pressure, temperature, and injection speed of the feed pump are set according to various specific performance parameters of the subsequent organic nanofiltration membrane. The membrane inlet liquid is formed, and the membrane inlet liquid is separated and purified by the organic nanofiltration membrane. Because the solid particles cannot diffuse into the organic nanofiltration membrane, the purified solvent or solution forms a permeate to obtain the product, and the retentate is the separated solid containing solid. For the concentrated liquid of particles, if it is necessary to further improve the yield, the circulating liquid of the intercepted liquid can be returned to the buffer tank by the circulating device and further separated until the appropriate yield is reached.

In this application example, the solid particle impurities in the isopropanol solution are separated, and each kilogram of the solution contains 1-10 mg of solid particle impurities in nanometer to micron order, and these remaining solid particle impurities cannot be realized by conventional filtration and centrifugation operations. The technical solution provided in this application is used for membrane separation and purification. The organic nanofiltration membrane adopts Evonik PuraMemFlux membrane module. The temperature of the membrane inlet liquid is room temperature, the pressure is 20bar, the filtration flux is 40LMH (liters per square meter hour), and the particles The removal rate is over 99%.

Application Example 2: Separation of Colored Impurities in Natural Product Extracts and/or Concentration of Extracts

Taking the extract of antibacterial components of honeysuckle leaves as an example, the solvent is absolute ethanol. After routine extraction, the color of the ethanol sample after evaporation is brown, and the target separation product is a light-colored powder. The technical solution provided in this application is used for membrane separation and purification. The organic nanofiltration membrane adopts Evonik DuraMem 500 membrane module. The ethanol extract directly enters the membrane separation equipment. The permeate is further subjected to conventional heating and concentration to obtain product crystals. The extraction of such natural products can use elevated temperature to remove ethanol.

The other type is the extraction of temperature-sensitive natural products, such as the extraction of Nobel Prize-winning artemisinin. The extraction liquids such as ethanol and ether cannot be concentrated by heating distillation or the product concentration is too low by heating distillation, and the vacuum distillation time is too low. If the time is too long, such temperature-sensitive natural products can be further extracted by intercepting biological macromolecules using the separation technology provided in this application, thereby realizing the concentration and purification of natural products. Taking the extraction of astragaloside IV from Astragalus as an example, the permeate (concentration 1-2%) obtained by the first-stage membrane separation is used as a new feed solution, the natural product astragaloside IV is an organic macromolecule, and the second-stage separation selection can permeate The separation membrane with too small molecular weight adopts Evonik PuraMem Flux membrane module, the temperature of the membrane inlet liquid is -10℃, the pressure is 30bar, and the filtration flux is 8LMH. The intercepted liquid is circulated into the buffer tank again until the intercepted liquid is nearly saturated, and is led out from the outlet of the intercepted liquid, and the product is obtained after low-temperature recrystallization or vacuum distillation of ethanol.

Application Example 3: Separation of high molecular weight impurities, such as microgels, in polymerized monomers such as pentaerythritol tetraacrylate

Polymeric monomers such as pentaerythritol tetraacrylate have a wide range of uses in functional coatings such as UV curing due to their high functionality. The curing system with such monomers has high functionality and leads to high polymerization speed and cross-linking degree. Therefore, the preparation efficiency of the coating is high, the hardness is high, and it has many advantages. However, the synthesis of such monomers is usually prepared by acid-catalyzed dehydration reaction, which inevitably involves the generation of crosslinks and oligomers and microgels mixed into the monomers. The result is that the viscosity of the ester system, which should be very low in nature, increases and is limited in many applications, such as flow coating or spray coating in UV curing. However, such impurities have good compatibility with monomers. These high-functional monomers have high boiling points and are prone to thermal polymerization. They cannot be purified by conventional vacuum distillation methods. The membrane separation method provides a possible choice. The specific implementation process is as follows:

A two-stage membrane separation device is used for separation. The pentaerythritol tetraacrylate produced by a domestic company was formulated into a 50wt% tetrahydrofuran solution as the initial feed solution. First, a separation membrane with a suitable molecular weight was selected, and Evonik PuraMem Flux membrane module was used. The temperature of the membrane solution was room temperature and the pressure was 30bar. , filtration efficiency 20LMH. The permeate enters the second-stage separation device. This time, a small molecular weight separation membrane is used, and Evonik's PuraMemSelective membrane module is used. The separation membrane can allow tetrahydrofuran to pass through and retain pentaerythritol tetraacrylate to achieve solvent removal. The liquid temperature is room temperature, the pressure is 30Bar, and the filtration flux is 35LMH. In this application example, the tetrahydrofuran obtained by infiltration is recycled and directly returned to the buffer tank of the first-stage separation device, and the separated intercepted liquid is returned to the second-stage buffer tank for further solvent recovery until recovery. The rate reached 98%, that is, the concentration of pentaerythritol tetraacrylate was increased to 98%. At the same time, the intercepted liquid produced in the first-stage separation is also returned to the first-stage buffer tank for secondary separation. Since the pure tetrahydrofuran separated by the second-stage membrane separation device is added back to the first-stage buffer tank, the concentration of pentaerythritol is further reduced, and impurities with large molecular weight and microgels will not be adsorbed on the membrane surface. After the second separation Afterwards, the intercepted liquid is mainly high-viscosity impurities, and the permeate containing pentaerythritol tetraacrylate continues to enter the second-stage membrane separation device for separation. In general, after the secondary membrane separation, 95% of tetrahydrofuran can be recycled and applied, and the separation yield of the target monomer is also 95%.

Application example 4: waste lubricating oil regeneration pretreatment

Lubricating oil is an indispensable lubricant in the operation of various types of machinery. The recycling of waste lubricating oil has always been a hot issue of concern, because only about 10%-20% of waste lubricating oil is non-renewable impurities, and the rest is non-renewable impurities. Part of it can still be regenerated into base oil. Recycling and reusing the base oil that has not deteriorated in waste lubricating oil is not only conducive to protecting the environment, reducing pollution, but also promoting the healthy development of the environmental protection industry. Here is a waste lubricating oil treatment method based on membrane separation technology, which can treat macromolecular substances, additives, colloids, asphaltenes and other impurities in waste lubricating oil. The resulting yellow to tan product can be used for further refining.

The waste lubricating oil that has been heated and precipitated to remove mechanical impurities and moisture, as shown on the left side of Figure 2, is first separated as an organic liquid to be separated, using Evonik PuraMem Flux membrane module, the separation membrane can retain macromolecular colloids, Impurities such as asphaltenes are allowed to permeate the lubricating oil base oil substances, so as to realize the removal of impurities. The temperature of the liquid entering the membrane is 60 degrees Celsius, the pressure is 50bar, the filtration flux is 5LMH, and the removal rate of macromolecular colloid and asphaltene is greater than 95%. . The obtained yellow to brown permeate can be used as a raw material for further refining of the regenerated base oil. Since Figure 2 is a black and white image, the true color of the permeate is not shown on the right side of Figure 2. The key technical indicators before and after separation are shown in Table 1.

Table 1 Comparison of key indicators of waste lubricating oil and permeate

waste lubricating oil permeate carbon residue 1.72% 0.02% calcium 230ppm 19.2ppm manganese 365ppm 40.3ppm chromium 129ppm 11.8ppm

In summary, the present application discloses the removal of ultra-fine and ultra-low content of solid particle impurities in organic solvents; the removal of colored impurities in natural product recovery; the removal of large molecular weight impurities in temperature-sensitive polymerizable monomers and the preparation process. The method of microgel impurities, separation of impurities such as recrystallization and co-precipitation; and the regeneration and pretreatment of waste lubricating oil. And relying on these experiments, the whole device was invented, from the pretreatment of the separated components to the subsequent purification of the concentrate and permeate and other supporting equipment. The whole device occupies a small area, saves energy, has high efficiency and wide applicability, and has broad application prospects in the field of general chemical and electronic chemical raw materials. Therefore, it can be used in the production of organic matter with special requirements, especially the purification and production of products that cannot be heated and require very low impurity content, or the improvement of the impurity removal process under the condition of high energy consumption by conventional methods.

The above description of the embodiments is provided to facilitate understanding and use of the present application by those of ordinary skill in the art. It will be apparent to those skilled in the art that various modifications to these embodiments can be readily made, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present application is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art according to the principles of the present application without departing from the scope of the present application should all fall within the protection scope of the present application.

Claims (10)

1. it is a kind of separate organic liquid impurities device, it is characterised in that: including pass sequentially through piping connection head tank (1), Surge tank (2), feed pump (3), membrane separation plant (4)；

Wherein, head tank (1) is to store organic liquid to be separated (11)；Surge tank (2) is to by organic liquor to be separated Body (11), which directly forms feeding liquid (21) or organic solvent is added, is diluted to feeding liquid (21) for organic liquid (11) to be separated； Feed pump (3) is used for according to the size of organic nanofiltration membrane, the temperature and pressure of flow adjustment feeding liquid (21) in membrane separation plant (4) Power is formed into film liquid (31)；Organic nanofiltration membrane is provided in membrane separation plant, separating-purifying will be carried out simultaneously into film liquid (31) Form trapped fluid (41) and penetrating fluid (42).

2. the device of separation organic liquid impurities according to claim 1, it is characterised in that: the infiltration of membrane separation plant (4) End and/or retention end are connect by pipeline with surge tank (2) thoroughly, make membrane separation plant (4), surge tank (2), feed pump (3) it Between further constitute multi-cycle separation system, return to penetrating fluid (42) and/or trapped fluid (41) from membrane separation plant (4) Formation feeding liquid (21) again is mixed in surge tank (2) with organic liquid (11) to be separated, feeding liquid (21) is using charging It is formed after pump (3) adjustment temperature and pressure into film liquid (31), membrane separation plant (4) is entered back into film liquid (31), in organic nanofiltration Trapped fluid (41) and penetrating fluid (42) are formed under film effect.

3. the device of separation organic liquid impurities according to claim 1, it is characterised in that: the pipeline is special steel The special steel material of material or inner liner polytetrafluoroethylene is prepared.

4. a kind of method for separating organic liquid impurities characterized by comprising

S1. material liquid is removed into big particulate matter by common filter device and obtains organic solvent to be separated, to avoid Organic nanofiltration membrane is destroyed；

S2. organic solution to be separated described in step S1 is directly formed into feeding liquid, or under organic solvent effect as requested It is diluted to form feeding liquid；

S3. the feeding liquid that step S2 is obtained is adjusted to be formed into film liquid by feed pump progress temperature and pressure；

S4. separating-purifying is carried out by organic nanofiltration membrane into film liquid by what step S3 was obtained, obtains trapped fluid and penetrating fluid.

5. the method for separation organic liquid impurities according to claim 4, it is characterised in that: after step S4 further include:

The obtained penetrating fluid of step S4 and/or trapped fluid are back in step S2, further with it is to be separated described in step S2 Organic solution carries out being mixed to form feeding liquid.

6. the method for separation organic liquid impurities according to claim 4, it is characterised in that: after step S4 further include:

The obtained penetrating fluid of step S4 and/or trapped fluid are passed through into distillation or rectifying or fractionation or molecular distillation or recrystallization Mode further purify.

7. the method for separation organic liquid impurities according to claim 4, it is characterised in that: described to be separated organic molten Liquid is in the organic solutions of formation such as pure solvent or the mixed solvent of the solid particle polluter containing superfine, super low loading； Or the polymerizable type monomer solution containing the high molecular weight impurity such as oligomer, microgel；Or contain the organic of natural products Solvent extractable matter solution；Or the organic solution containing waste lubricating oil etc. with a large amount of impurity.

8. the method for separation organic liquid impurities according to claim 7, it is characterised in that: described to be separated organic molten The weight percent of organic compound is at least 80% in liquid.

9. the method for separation organic liquid impurities according to claim 4, it is characterised in that: temperature of the step S3 into film liquid It is -30 DEG C to 100 DEG C.

10. the method for separation organic liquid impurities according to claim 4, it is characterised in that: pressure of the step S3 into film liquid Power is 5bar to 70bar.