System for purification and regeneration of oil-soluble liquids using highly selective polymeric porous filter

Abstract

The present invention relates to a system for regenerating oil-soluble liquids using a highly selective polymer porous filter, comprising: a storage tank for collecting and storing an oil-soluble liquid from a collection tank; a filter unit for purifying the oil-soluble liquid transferred from the storage tank; a wastewater tank for collecting moisture separated from the oil-soluble liquid through the filter unit; and a purification tank for transferring and storing the purified oil purified through the filter unit. According to the present invention, the time required for purifying fat-soluble liquids can be shortened through real-time purification, and the area of ​​the installation site can be minimized through the miniaturization of the equipment.

Description

Technology Field

[0001] The present invention relates to a system for regenerating oil-soluble liquids using a highly selective polymer porous filter, and more specifically, to a system for regenerating oil-soluble liquids using a highly selective polymer porous filter that can reduce the time required for purifying oil-soluble liquids through real-time purification and minimize the installation area by miniaturizing the equipment. Background Technology

[0002] Various industrial oils used throughout industrial sites, such as lubricants, coolants, and cleaning oils, are discharged as oil-soluble liquids due to the contamination of various impurities and moisture during use or storage. The proper purification and regeneration of these oil-soluble liquids are required not only for the maintenance of industrial facilities but also for environmental safety and resource recycling.

[0003] For example, in the case of agricultural oils such as tractor engine oil, condensation may form on the inner walls of storage tanks or drums due to external temperature fluctuations during long-term storage, or moisture may be mixed in by humidity from the air entering through vents. Furthermore, oils mixed with certain bio-components have high hygroscopicity and absorb moisture more easily; this leads to quality degradation issues, such as water accumulating inside the oil, reduced performance of additives, and corrosion.

[0004] Furthermore, industrial lubricants, such as gear oil used in industrial facilities, are prone to contaminating with moisture along with wear particles, oxides, and fine solid foreign substances during operation; failure to properly remove these contaminants can lead to a shortened equipment lifespan and performance degradation. Moreover, in situations requiring environmental pollution response, such as marine oil spills, technology capable of rapidly and efficiently separating and purifying moisture and various pollutants contained in oil is necessary.

[0005] Meanwhile, in the case of laundry solvents used in the dry cleaning process, moisture remaining inside the laundry or temperature differences occurring during the process can be mixed into the organic solvent; if the moisture content increases, serious problems such as reduced washing performance and the generation of unpleasant odors may occur.

[0006] As such, oil-soluble liquids are contaminated with moisture and complex impurities through various pathways depending on the usage environment and application; therefore, precipitation and heating methods are widely used as general purification techniques to remove these contaminants. The precipitation method separates water and oil contained in the oil-soluble liquid by gravity using the difference in specific gravity. While it has the advantage of a simple structure and does not require complex equipment, it has the disadvantages of requiring sufficient precipitation time and a large installation space. The heating method evaporates moisture by utilizing the difference in boiling points between oil and water. Although it enables relatively rapid moisture removal, it requires additional processes to remove suspended solids during the process, and there is a risk that the oil itself may degrade due to the heat.

[0007] These existing purification methods have focused primarily on moisture removal, which has limited their ability to effectively and simultaneously remove complex impurities, such as solid foreign matter, microcontaminants, and oxides, contained in oil-soluble liquids. Consequently, there is a growing need for an oil-soluble liquid regeneration system utilizing a real-time, highly selective polymer porous filter that goes beyond simple moisture removal to simultaneously eliminate both moisture and complex impurities from oil-soluble liquids generated in various industries, while simultaneously improving purification efficiency, shortening processing time, and reducing installation space through equipment miniaturization. Prior art literature

[0008] Republic of Korea Registered Patent No. 10-2202494 The problem to be solved

[0009] The objective of the present invention is to solve the aforementioned conventional problems by providing a regeneration system for fat-soluble liquids using a highly selective polymer porous filter that can reduce the time required for purifying fat-soluble liquids through real-time purification and minimize the installation area by miniaturizing the equipment. means of solving the problem

[0010] The above objective is achieved, according to the present invention, by a fat-soluble liquid regeneration system using a highly selective polymer porous filter comprising: a storage tank for collecting and storing a fat-soluble liquid from a collection tank; a filter unit for purifying the fat-soluble liquid transferred from the storage tank; a wastewater tank for collecting moisture separated from the fat-soluble liquid through the filter unit; and a purification tank for transferring and storing the purified oil purified through the filter unit.

[0011] In addition, the present invention further includes a tank for controlling the viscosity of the oil-soluble liquid transferred from the storage tank, and the filter unit can purify the oil-soluble liquid transferred from the tank.

[0012] In addition, the above tank may be equipped with a stirring unit for stirring the contained oil-soluble liquid.

[0013] In addition, the present invention may further include a heating unit for heating the oil-soluble liquid.

[0014] In addition, the above water tank and the above wastewater tank can be connected to the above collection tank.

[0015] In addition, a valve is provided between the filter unit and the wastewater tank to control the amount of moisture collected in the wastewater tank.

[0016] In addition, the present invention may further include a pretreatment unit for performing pretreatment on the oil-soluble liquid.

[0017] In addition, the above filter unit may be provided in multiple numbers and connected in series.

[0018] In addition, the above filter unit may be provided in multiple numbers and connected in parallel. Effects of the invention

[0019] According to the present invention, the time required for purifying fat-soluble liquids can be shortened through real-time purification, and the area of ​​the installation site can be minimized through the miniaturization of the equipment.

[0020] In addition, according to the present invention, oil-soluble liquids can be effectively purified based on a polymer porous filter having extremely oleophilic and water-repellent properties.

[0021] Meanwhile, the effects of the present invention are not limited to those mentioned above, and various effects may be included within the scope obvious to a person skilled in the art from the contents described below. Brief explanation of the drawing

[0022] FIG. 1 illustrates an overall oil-soluble liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, and FIG. 2 illustrates another example of a lipid-soluble liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, and FIG. 3 illustrates a tank of a lipid-soluble liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, and FIG. 4 is a side view of the tank and filter section of a lipid-soluble liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, and FIG. 5 illustrates a graph showing the change in kinematic viscosity according to temperature of an oil-soluble liquid in an oil-soluble liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, and FIG. 6 is a block diagram of a method for manufacturing an extremely hydrophilic polymer porous substrate of a lipophilic liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, and FIG. 7 is a schematic diagram of a method for manufacturing an extremely hydrophilic polymer porous substrate of a lipophilic liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, and FIG. 8 is a flowchart of a method for manufacturing an extremely hydrophilic polymer porous substrate of a lipophilic liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, and FIG. 9 is a schematic diagram of a polymer porous filter of a lipophilic liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, and FIG. 10 is a diagram showing a polymer porous filter of a lipophilic liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention. Specific details for implementing the invention

[0023] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings.

[0024] In addition, when describing embodiments of the present invention, if it is determined that a detailed description of related known configurations or functions would hinder understanding of the embodiments of the present invention, such detailed description is omitted.

[0025] In addition, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the embodiments of the present invention. These terms are used merely to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by such terms.

[0027] Now, with reference to the attached drawings, a system for regenerating a lipid-soluble liquid (100) using a highly selective polymer porous filter according to one embodiment of the present invention will be described in detail.

[0028] FIG. 1 illustrates an overall oil-soluble liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, FIG. 2 illustrates another example of an oil-soluble liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, FIG. 3 illustrates a water tank of an oil-soluble liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, FIG. 4 is a side view of the water tank and filter section of an oil-soluble liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, and FIG. 5 illustrates a graph showing the change in kinematic viscosity of an oil-soluble liquid according to temperature in an oil-soluble liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention.

[0029] Referring to FIGS. 1 to 4, a lipid-soluble liquid regeneration system (100) using a highly selective polymer porous filter according to one embodiment of the present invention may include a collection tank (110), a storage tank (120), a water tank (130), a heating unit (140), a filter unit (150), a pretreatment unit (160), a posttreatment unit (161), a wastewater tank (170), a valve (180), and / or a purification tank (190).

[0030] However, each of the above components may be selectively applied as a component unit depending on the state of the oil-soluble liquid to be processed and the required purification quality, or may be configured to include additional components.

[0031] The collection tank (110) is a collection tank where oil-soluble liquid recovered from an industrial site is collected before being transferred to a storage tank (120), and is optionally provided and connected to allow fluid to flow into the storage tank (120).

[0032] Here, oil-soluble liquids refer to liquids that are used in various ways, such as lubricating oils, gear oils, cooling oils, cleaning oils, and / or organic solvents for laundry, or liquids that have been spilled, such as marine oil spills, and are in a state where moisture and / or various impurities have been mixed in due to the usage environment, storage conditions, and / or external ingress; it refers to the state prior to being utilized as a regenerable fluid through a purification process.

[0033] The collection tank (110) is connected to the storage tank (120) so that fluid can flow smoothly, and in the present invention, the connection method can be made through a fluid transfer connecting pipe, such as a Y-shaped pipe, for example. However, it is not limited thereto, and various shapes of connecting pipes may be applied depending on the configuration and installation environment of the oil-soluble liquid regeneration system (100) using a highly selective polymer porous filter.

[0034] In addition, at least one connecting pipe in the present invention may be equipped with a pump for controlling the transfer flow rate and / or pressure.

[0035] The pump can be controlled to allow the oil-soluble liquid to move smoothly to the storage tank (120) by setting the necessary transfer conditions according to the viscosity, temperature, contamination level, etc. of the oil-soluble liquid, and the pump can be provided as various types of pumps, such as a gear pump, a rotary pump, and / or a diaphragm pump suitable for transferring high-viscosity liquids, but is not limited thereto.

[0036] The storage tank (120) is configured to temporarily store the oil-soluble liquid transferred from the collection tank (110) and can be connected to the collection tank (110) and / or filter unit (150) so that fluid can flow through them.

[0037] Specifically, the storage tank (120) is connected to the collection tank (110) so that fluid can flow to receive the oil-soluble liquid from the collection tank (110), and can also be connected to the filter unit (150) so that fluid can flow to transfer the stored oil-soluble liquid to the filter unit (150). At this time, at least one connecting pipe is equipped with a pump so that the oil-soluble liquid can be transferred.

[0038] Meanwhile, when the present invention is configured to include a water tank (130), the storage tank (120) is connected to the water tank (130) so that fluid can flow through it, and the water tank (130) can be connected to a filter unit (150). In this case, the oil-soluble liquid stored in the storage tank (120) can be transferred to the water tank (130) by a pump provided in the connecting pipe connecting the storage tank (120) and the water tank (130).

[0039] The tank (130) receives the oil-soluble liquid transferred from the storage tank (120) and controls the viscosity of the oil-soluble liquid, and can be connected to the storage tank (120), the filter unit (150) and / or the collection tank (110) so that fluid can flow through them, respectively.

[0040] The tank (130) may more specifically include a container part (131) and / or a stirring part (133).

[0041] The container section (131) provides a space for receiving a lipid-soluble liquid transferred from the storage tank (120) via a pump, the upper part is connected to the storage tank (120) and / or filter section (150) so that fluid can flow, and the lower part may have an outlet formed therein.

[0042] This container part (131) may basically have a cylindrical shape, and the lower part may include an inclined surface to induce natural flow of the oil-soluble liquid and accumulation of sludge. For example, the lower part may be formed in a funnel shape, and a discharge port may be provided at the end so that sludge can be effectively discharged.

[0043] Meanwhile, the discharge port formed at the bottom of the container (131) can be connected to the collection tank (110) so that fluid can flow, and the connecting pipe may be equipped with a pump. This is intended to discharge sludge from the water tank (130) and at the same time improve the recovery rate of refined oil through a circulation structure.

[0044] The stirring unit (133) is installed inside the container unit (131) to prevent sedimentation of solids in the stored oil-soluble liquid.

[0045] The stirring part (133) can be formed in the shape of a stirrer bar that can be rotated by a rotating shaft, for example, and can also be implemented in various forms of blade-type, impeller-type, or paddle-type stirring blade structures depending on the viscosity of the oil-soluble liquid or operating conditions, but the shape and driving method of the stirring part (133) can be selected according to the system structure and the characteristics of the oil to be processed, and is not limited to the above examples.

[0046] In addition, the stirring section (133) is positioned above the discharge port at the bottom of the container section (131) where sludge is mainly accumulated, that is, at a position relatively higher than the sludge, so as to provide a uniform stirring effect throughout the entire oil-soluble liquid without directly disturbing the sludge.

[0047] The heating unit (140) is configured to ensure fluidity or improve sedimentation efficiency by maintaining the oil-soluble liquid at a set temperature, and, for example, can be provided in a heating wire manner and wound in a spiral shape along the outer surface of the container unit (131).

[0048] However, the heating part (140) is not limited to the spiral shape described above and can be implemented in various shapes, such as a plate-type heater attached to the outer wall of the container part (131), a rod-type heater inserted inside the container, or a jacket-type heating structure using a fluid-circulating heat medium.

[0049] Furthermore, the heating unit (140) may be provided as an independent module in a connecting pipe through which fluid flows, as a separate configuration from the container unit (131).

[0050] When purifying a high-viscosity oil-soluble liquid of 100 cSt or more, this heating unit (140) maintains the temperature of the oil-soluble liquid at 40°C to 80°C, preferably about 60°C, thereby allowing the oil-soluble liquid to move smoothly within the system and efficiently separate from contaminants.

[0051] Figure 5 shows a graph of the change in kinematic viscosity according to temperature of an oil-soluble liquid in an oil-soluble liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention.

[0052] Referring to Fig. 5, heating was performed on various types of oil-soluble liquids with different viscosities within a certain temperature range, and the resulting change in viscosity was measured.

[0053] Based on the viscosity-temperature correlation data of the oils measured in this way, an appropriate heating temperature range can be derived to ensure that a specific oil-soluble liquid can be smoothly transported and purified.

[0054] For example, when a lipid-soluble liquid with a kinematic viscosity of about 140 cSt at 40°C was heated through a water bath (130), it was confirmed that the kinematic viscosity of the lipid-soluble liquid decreased to about 50 cSt when the temperature reached 60°C.

[0055] That is, in the present invention, for a lipid-soluble liquid having a kinematic viscosity of 100 cSt or more and 500 cSt or less at 40°C, the internal temperature of the water bath (130) can be set and maintained at a maximum of 60°C to minimize energy consumption and prevent aging caused by heat.

[0056] The oil-soluble liquid heated through the heating unit (140) described above is transferred to the filter unit (150) through a pump provided in a connecting pipe connected to the filter unit (150), and a precision filtration process can be performed in the filter unit (150).

[0057] The filter unit (150) is configured to purify a fat-soluble liquid transferred from a water tank (130) and can be connected to a storage tank (120), a wastewater tank (170), and / or a purification tank (190) so that fluid can flow through them, respectively. Meanwhile, if a water tank (130) is provided, the filter unit (150) can be connected to a water tank (130), a wastewater tank (170), and / or a purification tank (190) so that fluid can flow through them, respectively.

[0058] The oil-soluble liquid is transferred to each housing (151) of the filter unit (150) via a pump, and complex impurities such as solid foreign matter, fine contaminants, oxides and / or moisture are removed through the filter (152) inside the housing (151).

[0059] At this time, it is preferable that the pump used be able to provide a flow rate of at least 50 mL / min, and the maximum flow rate may be adjusted according to the size of each housing (151) constituting the filter section (150) or the viscosity of the oil-soluble liquid to be purified.

[0060] In particular, when the flow rate of the pump is relatively small, it is preferable that the connecting pipe be installed with a slope in a direction that induces gravity flow so that a uniform amount of oil-soluble liquid can be distributed to the housing (151) of each filter unit (150). This pipe slope structure can prevent purification deviations caused by flow rate imbalance and contribute to improving the impurity separation efficiency in each housing (151).

[0061] The filter section (150) more specifically includes at least one housing (151) and / or a filter (152) installed in each housing (151).

[0062] The filter (152) may be provided as a polymer porous filter (152) having extreme hydrophilicity that selectively allows only oil to pass through and blocks moisture.

[0063] From now on, a method for manufacturing a polymer porous substrate having extreme hydrophilicity will be explained in detail with reference to the attached drawings.

[0064] FIG. 6 is a block diagram of a method for manufacturing an extremely hydrophilic polymer porous substrate of a lipophilic liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, FIG. 7 is a schematic diagram of a method for manufacturing an extremely hydrophilic polymer porous substrate of a lipophilic liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, and FIG. 8 is a flowchart of a method for manufacturing an extremely hydrophilic polymer porous substrate of a lipophilic liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention.

[0065] Referring to FIGS. 6 to 8, a method for manufacturing a polymer porous substrate having extreme hydrophilicity may include the steps of preparing a porous substrate (S210), performing plasma etching (S220), and coating the porous substrate with a polymer coating (S230).

[0066] In the step (S210) of preparing a porous substrate (210), a porous substrate (210) may be prepared that is formed in a three-dimensional shape extending in the planar direction and the height direction, has an internal space formed in at least a part, and has a plurality of pores formed inside or on the surface.

[0067] In one embodiment, the porous substrate (210) may be a polymer substrate comprising at least one of polypropylene, polytetrafluoroethylene, and polyethylene.

[0068] In one embodiment, the porous substrate (210) may include at least one of a nonwoven fabric, a fabric, a sponge, and a fiber.

[0069] The porous substrate (210) may have a uniform thickness from the internal space to the surface exposed to the outside on at least one side. For example, the internal space of the porous substrate (210) may be formed in a shape corresponding to the shape of the porous substrate (210), so that the thickness between the internal space on one side of the porous substrate (210) may be uniform.

[0070] The size of the pores of the porous substrate (210) can be set to 5㎛ or more and 200㎛ or less, taking into account the viscosity of the fluid and separation performance.

[0071] A porous substrate (210) according to one embodiment has a cylindrical shape with a circular cross-section extending in the height direction, and a through hole may be formed in which at least a portion of the interior is penetrated in the height direction. In one embodiment, the thickness between the bottom surface of the cylindrical porous substrate (210) and the bottom surface of the internal space formed by the through hole may be uniform, and the thickness between the side surface of the porous substrate (210) and the side surface of the internal space formed by the through hole may be uniform.

[0072] In one embodiment, the porous substrate (210) was described as having a cylindrical shape with a through hole formed inside, but the shape of the porous substrate (210) is not limited to the illustrated example and can be applied in various shapes.

[0073] In the step (S220) of performing plasma etching, a microstructure or nanostructure can be formed on the porous substrate (210).

[0074] In one embodiment, the step (S220) of performing plasma etching may perform reactive-ion etching (RIE) on a porous substrate (210) using a double electrode with an etching gas containing oxygen (O2) gas or a mixed gas of oxygen (O2) and CF4.

[0075] In one embodiment, by controlling the conditions and / or processing time of the reactive ion etching process, a composite structure in which various types of microstructures and / or nanostructures are combined can be formed on a porous substrate (210).

[0076] In one embodiment, the step (S220) of performing plasma etching can be performed with a power of 100W to 1000W and can be performed within a processing time of 3 minutes to 30 minutes.

[0077] For example, if the power is less than 100W, the plasma energy is not supplied sufficiently, so surface modification is insufficient and the desired micro-nano composite structure may not be formed, while conversely, if the power exceeds 1000W, excessive damage to the substrate surface or collapse of the pore structure may occur.

[0078] In addition, if the processing time is less than 3 minutes, the degree of surface modification may be insufficient, which may result in reduced adhesion of the subsequent polymer coating layer, and if it exceeds 30 minutes, the mechanical strength and durability of the substrate may be reduced due to excessive etching. Therefore, in the step of performing plasma etching, a power of 100W to 1000W and a processing time of 3 minutes to 30 minutes may be optimal conditions for ensuring a balance between forming a surface structure and maintaining the physical properties of the substrate.

[0079] Plasma etching performed under these conditions can form a complex of microstructures of several micrometers in size and nanostructures of tens to hundreds of nanometers in size on the surface, and can significantly increase the surface area.

[0080] In addition, a large amount of hydroxyl (OH) functional groups are generated on the surface during the processing process, temporarily maximizing hydrophilicity. As a result, the contact angle with water can be reduced to about 1° or less, and this extremely hydrophilic state allows the polymer coating solution to penetrate deep into the substrate, thereby increasing the uniformity and adhesion of the coating layer.

[0081] Meanwhile, reactive ion etching is an etching method that combines physical impact and chemical reaction by making the gas into a plasma state and using an upper electrode and a lower electrode to collide the gas in the plasma state with the porous substrate (210). For example, reactive ions (e.g., fluorine) in the etching gas can be collided with the porous substrate (210).

[0082] In one embodiment, the reactive ion etching process may be performed through a device comprising a stage in which a workpiece is installed inside a vacuum chamber, a gas introduction means for introducing an etching gas into a vacuum chamber in a vacuum atmosphere, a plasma generation means for generating a plasma that ionizes the introduced etching gas inside the vacuum chamber, and a high-frequency power source connected to the stage via an output line to apply a bias potential to the workpiece. In one embodiment, high-frequency power of different frequencies may be supplied to a first electrode (inner electrode) and a second electrode (outer electrode) installed in a state of mutual insulation on the stage using two high-frequency power sources.

[0083] In one embodiment, the method may further include the step of applying an epoxy silane primer before coating with a polymer coating solution after performing plasma etching. Plasma treatment helps to increase the adhesion of the subsequent coating layer by activating the filter surface energy to temporarily generate hydrophilic functional groups and improving surface roughness and polarity. However, this plasma effect gradually decreases over time, and especially in the case of non-polar polymer materials, there is a possibility that the adhesion of the coating layer may become uneven because sufficient chemical bonding does not occur on the surface.

[0084] To compensate for these limitations, an epoxy silane primer can be applied. Epoxy silanes generally possess a Si-OR structure and form strong covalent bonds with the substrate surface by creating siloxane bonds through hydrolysis and condensation reactions with the -OH groups on the substrate surface. Additionally, the epoxy groups form additional chemical bonds with the functional groups of the upper hydrophobic coating layer, resulting in the formation of a double-bond structure. Through this process, the adhesion and chemical bond stability between the coating layer and the substrate are significantly improved, and the uniformity and durability of the coating can also be enhanced.

[0085] In one embodiment, if there is a lack of surface -OH bonding sites after plasma treatment, the bonding sites can be increased through the polymerization of APS (3-aminopropyltriethoxysilane) and BIS (N,N'-methylenebisacrylamide), and then a hydrophobic coating can be applied to enhance the bonding properties. The plasma etching process generates hydroxyl groups (-OH) on the surface of the substrate to provide bonding sites for the subsequent silane coating, but in some polymer materials or under insufficient plasma treatment conditions, the surface -OH density is low, which may reduce the bonding density of the silane coating layer.

[0086] In this case, if APS is applied first, the amino groups (-NH2) of APS form siloxane bonds with surface -OH, thereby introducing amino functional groups to the surface. Subsequently, when BIS is polymerized, the amino groups of APS and the acrylamide groups of BIS react to form a cross-linked network, and in this process, additional reactive functional groups are generated on the surface, increasing the number of bonding sites in the hydrophobic coating layer. As a result, the APS and BIS polymer layer acts as an intermediate layer between the substrate and the hydrophobic coating, which can improve the adhesion, uniformity, and durability of the coating layer.

[0087] The step of coating with a polymer coating solution according to one embodiment (S230) may include the step of immersing a porous substrate in a crosslinking solution and / or drying the porous substrate while heating.

[0088] In one embodiment, the crosslinking solution may include C14 to C18 alkylsilanes. The C14 to C18 alkylsilanes may have a trichlorosilane or trialkoxysilane head group and may include C18 alkylsilanes such as octadecyltrichlorosilane (OTS), octadecyltrimethoxysilane (ODMS), or octadecyltriethoxysilane (ODES), for example, and may include tetradecyl (C14) or hexadecyl (C16) alkylsilanes.

[0089] In one embodiment, the crosslinking solution may exclude fluorinated alkylsilanes and use non-fluorinated alkylsilanes. Fluorinated alkylsilanes (e.g., PFOTS, perfluoro-SAM) have a very low critical surface tension of about 6 mN / m to 13 mN / m, so they exhibit water repellency (oleophobic) not only against water but also against oil, and thus may be unsuitable for the purpose of oil-water separation filters that require oil permeation and precipitation.

[0090] In one embodiment, the crosslinking solution may exclude difunctional or monofunctional silanes having SiX2 or SiX1 head groups (e.g., ODMDCS, ODMS) and use a trifunctional silane having a SiX3 head group. Since difunctional or monofunctional silanes lack binding sites and thus have low crosslinking density and water and heat resistance, which may be disadvantageous in terms of long-term durability, it may be desirable to use a trifunctional silane capable of forming high-density crosslinks through reaction sites.

[0091] C14 to C18 alkylsilanes have a chemical structure having a straight-chain alkyl group (R) and a SiX3 head group (X=Cl or OR', R'=C1-C3 alkyl group), and can form a self-assembled monolayer (SAM) aligned on the substrate surface by reacting with a hydroxyl group (OH) generated by plasma etching to form a siloxane (-Si-O-Si-) network.

[0092] In particular, when using C18 alkylsilanes, a -CH3 terminal SAM is formed at the end of the straight-chain alkyl group, controlling the critical surface tension to approximately 20 mN / m to 21 mN / m. This provides optimal conditions for exhibiting high affinity for oils (diesel, lubricating oil, cutting fluid, etc.) and strong water repellency. Additionally, trifunctional silanes having a SiX3 head group can improve the durability and reproducibility of the coating layer by forming multi-point bonds (multi-point crosslinking) through three reaction sites.

[0093] For example, referring to FIGS. 6 to 8, a porous substrate having hydroxyl groups (OH) formed on its surface through plasma etching has increased hydrophilicity, so extreme hydrophilicity characteristics can be imparted by applying a crosslinking solution thereon.

[0094] In one embodiment, the crosslinking solution is composed of a polymer having a surface energy of 23 mN / m to 30 mN / m and can be composed such that the contact angle with oil, including diesel, lubricating oil and cutting oil, is 10 degrees or less.

[0095] For example, if the surface energy is less than 23 mN / m, the wettability with oil is excessively low, which may reduce oil permeability, and if the surface energy exceeds 30 mN / m, the wettability with water increases, which may reduce water-repellent performance.

[0096] Therefore, by being composed of a polymer having a surface energy of 23 mN / m to 30 mN / m, it may be a range that can simultaneously satisfy oil permeability and water barrier properties.

[0097] Accordingly, for general oils such as diesel, lubricating oil, and cutting oil with a surface energy of 32 mN / m or less, the contact angle can be formed to be 10° or less.

[0098] In one embodiment, the crosslinking solution can impart extreme hydrophilicity by minimizing the contact area with water and having a contact angle with water of 150 degrees or more.

[0099] A porous substrate that has undergone a plasma etching process has hydroxyl groups (OH) formed on its surface, which greatly increases hydrophilicity, and by coating the porous substrate in this state with a crosslinking solution containing C14 to C18 alkylsilanes, the surface of the substrate can be modified into a water-repellent surface in which the contact area with water is minimized.

[0100] The above alkylsilane forms a Cassie-Baxter state by combining the hydrophobicity of the straight-chain alkyl group and the roughness effect of the micro-nano composite structure, which causes water droplets to exist floating on the air layer of the structure on the surface, thereby exhibiting superhydrophobicity.

[0101] Accordingly, the crosslinking solution can be formulated so that the contact angle with water on the porous substrate (220) is 150° or more, and such a contact angle means that the surface repels water extremely, and can typically be classified as a 'superhydrophobic' state.

[0102] In the step of drying the porous substrate (230) while heating according to one embodiment, the porous substrate (230) may be dried in an oven at 40 to 80 degrees. In one embodiment, a cross-linking polymerization reaction may be performed by heating and drying the porous substrate (230) for 2 to 6 hours.

[0103] The method for manufacturing an extremely hydrophilic polymer porous substrate of the present invention may further include the step of immersing a porous substrate (230) coated with a polymer coating solution in a waterproof coating solution and the step (S240) of drying the porous substrate (240) immersed in the waterproof coating solution while heating.

[0104] A porous substrate (230) that has undergone plasma etching and polymer coating already has an extremely hydrophilic property that can selectively separate oil and water, but since this property may be contaminated by contaminants, sludge, fine particles, etc. in the oil during long-term use, or the surface properties may gradually deteriorate during repeated washing and drying of the substrate, a waterproof coating step can be added to improve the durability and anti-contamination performance of the porous substrate (240).

[0105] The waterproof coating solution can further increase the contact angle with water, so that water droplets do not stay on the surface of the porous substrate (240) but roll off easily, thereby preventing moisture from adhering to the surface of the substrate for a long time and minimizing the possibility of moisture penetrating into the substrate. In addition, the waterproof coating layer is formed thinly and uniformly on the micro-nano composite structure of the substrate surface, so that the duration of water repellency on the surface can be extended without affecting the existing oil permeability performance.

[0106] The step (S240) of drying a porous substrate (240) immersed in a waterproof coating solution while heating can be performed by immersing the porous substrate (240) in a waterproof coating solution and then heating and drying it at an appropriate temperature. In this step, the coating layer can chemically or physically bond with the surface of the substrate to provide wear resistance and chemical resistance, and accordingly, the filter surface is resistant to contamination and wetting, and can maintain its initial extremely hydrophilic properties for a long period even during repeated use and washing processes.

[0107] FIG. 9 is a schematic diagram of a polymer porous filter of a lipophilic liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention, and FIG. 10 is a diagram showing a polymer porous filter of a lipophilic liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention.

[0108] Referring to FIGS. 9 and 10, the polymer porous filter (152) of the present invention may be composed of a porous substrate (240) formed in a three-dimensional shape extending in the planar direction and the height direction, and having an internal space formed in at least a part thereof.

[0109] A polymer porous filter (152) can be manufactured by a process of performing plasma etching to form microstructures or nanostructures on a porous substrate (210), immersing the porous substrate (220), in which hydroxyl groups (OH) are generated by plasma etching and wettability is improved, in a crosslinking solution containing C14 to C18 alkylsilanes, and coating the porous substrate (230) with a polymer coating solution, which includes a process of drying while heating.

[0110] The crosslinking solution may include C18 alkylsilanes such as octadecyltrichlorosilane, octadecyltrimethoxysilane, or octadecyltriethoxysilane, for example, and may also include tetradecyl (C14) or hexadecyl (C16) alkylsilanes.

[0111] In one embodiment, a polymer porous filter (152) can be manufactured by the process of immersing the porous substrate (230) coated with a polymer coating solution in a waterproof coating solution and drying the porous substrate (240) immersed in the waterproof coating solution while heating.

[0112] In one embodiment, the polymer porous filter (152) can be manufactured by drying at 40°C or higher and 80°C or lower for 2 hours or more and 6 hours or less.

[0113] In one embodiment, the polymer porous filter (152) may have a uniform thickness from the internal space to the surface exposed to the outside on at least one side.

[0114] In one embodiment, the polymer porous filter (152) has a cylindrical shape with a circular cross-section extending in the height direction, and a through hole (H) may be formed in which at least a portion of the interior is penetrated in the height direction. In one embodiment, the thickness (t) between the side surface of the cylindrical wastewater treatment filter and the side surface of the internal space formed by the through hole (H) may be uniform.

[0115] In one embodiment, the polymer porous filter (152) may have a contact angle with oil of 10 degrees or less and a contact angle with water of 150 degrees or more.

[0116] As described above, the method for manufacturing an extremely hydrophilic polymer porous substrate according to one embodiment of the present invention maximizes the hydrophilicity of the surface by forming microstructures or nanostructures on the surface of the porous substrate through plasma etching, and then imparts extreme hydrophilicity by coating with a crosslinking solution containing C14 to C18 alkylsilanes, thereby providing significantly improved water separation performance and durability compared to the conventional method of removing water in non-aqueous solutions.

[0117] In particular, the alkylsilane has a trichlorosilane or trialkoxysilane head group and forms a -CH3-terminated self-assembled monolayer (SAM) at the end of the straight-chain alkyl group to form a critical surface tension of 20 mN / m to 21 mN / m, thereby simultaneously optimizing the affinity for oil and water repellency, and the multi-point crosslinking structure through the SiX3 head group can significantly improve the durability and reproducibility of the coating layer.

[0118] In addition, by further including the steps of immersing a porous substrate coated with a polymer coating solution in a waterproof coating solution and drying the porous substrate immersed in the waterproof coating solution while heating, water droplets can be made to roll off easily without remaining on the surface of the porous substrate, thereby preventing moisture from adhering to the surface of the substrate for a long time and minimizing the possibility of moisture penetrating into the interior of the substrate.

[0119] The housing (151) may be formed as a single unit, but may be configured as a plurality as needed to improve purification efficiency and secure processing capacity, and each housing (151) may be arranged in a series or parallel structure according to the system design, which will be described later.

[0120] At this time, each housing (151) includes a head portion and a main body portion.

[0121] The head section is formed with an inlet and an outlet for inflow and outflow, and is installed on the upper part of the main body to seal the interior.

[0122] The main body provides a space in which the above-described extremely hydrophilic polymer porous filter (152), pre-treatment filter, and / or post-treatment filter are installed. The main body forms a structure in which fluid passes through the filter (152) while stably supporting the filter (152), and acts as a central component responsible for the purification function of the entire filter section (150).

[0123] Meanwhile, if the filter (152) is the above-described extremely hydrophilic polymer porous filter (152), a discharge hole for discharging moisture may be formed in the lower part of the main body.

[0124] When the filter (152) is an extremely hydrophilic polymer porous filter (152), the separation of the oil phase and the water phase is performed more precisely, and the moisture that does not pass through the filter (152) gradually accumulates at the bottom of the main body of the housing (151). As the separation process proceeds, if moisture continues to accumulate at the bottom, problems may occur such as the pressure inside the housing (151) rising or the functional coating layer formed on the surface of the filter (152) being destroyed.

[0125] Accordingly, by periodically or automatically discharging moisture through the discharge hole provided at the bottom of the main body, the increase in internal pressure and damage to the filter (152) can be prevented, thereby improving separation efficiency and increasing the lifespan of the filter (152).

[0126] Meanwhile, in the present invention, the filter unit (150) may be optionally provided in multiple numbers and connected in a serial manner.

[0127] Specifically, the serial method can be applied when high purity of the final refined oil is required. For example, the filter unit (150) may be configured such that two or more housings (151) are connected in series, and purification can be performed in stages so that relatively large solid foreign substances and contaminants are removed first in the upstream housing (151), and fine contaminants or residual moisture are additionally removed in the downstream housing (151). According to this configuration, the purification stages can be adjusted to match the target quality, and it can contribute to securing a purification quality that is difficult to achieve with a single housing alone.

[0128] Alternatively, in the present invention, the filter unit (150) may be optionally provided in multiple numbers and connected in a parallel manner.

[0129] Specifically, the parallel method can be applied when increased throughput is required. For example, the filter unit (150) may be configured such that a plurality of housings (151) are connected in parallel, and the oil-soluble liquid may be distributed to each housing (151) to be purified simultaneously. At this time, the connecting pipes may be installed with an incline in a direction that induces gravity flow so that the oil-soluble liquid flowing into each housing (151) is distributed uniformly, thereby mitigating purification deviations caused by flow rate imbalance and contributing to securing the overall processing capacity.

[0130] Meanwhile, the present invention may optionally further include a pretreatment unit (160). The pretreatment unit (160) may be optionally provided when the oil-soluble liquid has a high degree of contamination, high viscosity, or high particle concentration. In this case, the pretreatment unit (160) may be positioned between the storage tank (120) and the filter unit (150) or between the water tank (130) and the filter unit (150) so that the oil-soluble liquid is pretreated before flowing into the filter unit (150).

[0131] Furthermore, the present invention may optionally include a post-treatment unit (161). The post-treatment unit (161) is configured to remove odors, pigments, or trace contaminants that may remain in the oil-soluble liquid purified through the filter unit (150) via a post-treatment filter, and may be used for the purpose of improving the quality of the final purified oil and satisfying the usage conditions or related reuse standards of the purified oil. In this case, the post-treatment unit (161) may be positioned between the filter unit (150) and the purification tank (190) so that the purified oil-soluble liquid is additionally treated before flowing into the purification tank (190).

[0132] The wastewater tank (170) is a storage container for collecting moisture discharged through the outlet of the filter unit (150), and can be connected to the filter unit (150) and the collection tank (110) so that fluid can flow through them, respectively.

[0133] The wastewater tank (170) can be implemented in various shapes, and for example, when it is integrally provided in a reservoir manner at the bottom of the filter section (150), the internal structure can be formed by dividing it into partition structures so as to selectively separate and contain only the oil components floating on the top.

[0134] This structure can contribute to increasing the recovery rate of refined oil and reducing resource waste by selectively recovering only the oil components in the upper layer using the difference in specific gravity between oil and water.

[0135] Additionally, a general storage container such as a drum can be used as the wastewater tank (170), and in this case, since the fluid flow rate is relatively slow, it can be additionally helpful to uniformly separate or collect residual oil components through a distributor structure located at the top of the tank.

[0136] Additionally, an on / off valve (180) may be installed in the connecting pipe between the filter section (150) and the wastewater tank (170), and this may operate in a configuration for controlling the opening and closing of the discharge of water.

[0137] Furthermore, the wastewater tank (170) may be configured to be connected to a detection unit capable of detecting when a certain amount of water is collected and automatically opening the corresponding valve (180) or generating a warning signal.

[0138] For example, capacitive or resistive methods may be applied; the former precisely measures the rise in liquid level by utilizing changes in the dielectric constant of moisture, while the latter detects the presence of moisture contact through changes in electrical resistance between sensor electrodes.

[0139] According to this configuration, when a specific water level is reached, the wastewater discharge valve (180) is automatically opened, or visual and auditory warning signals are provided to the manager, thereby preventing in advance problems such as an increase in internal pressure and malfunction of the filter unit (150) that may occur due to excessive accumulation of moisture.

[0140] Meanwhile, the wastewater tank (170) can be connected to the collection tank (110) so that fluid can flow, and this is to effectively re-collect oil components recoverable in the refining process to improve the recovery rate of the entire system.

[0141] That is, as the water separated from the filter unit (150) flows into the wastewater tank (170), a small amount of oil component partially contained in the water may remain floating on the surface of the wastewater, and this oil component can be selectively separated and collected through the upper structure or separation device of the wastewater tank (170), then transferred back to the collection tank (110) and reintroduced into the purification process.

[0142] The purification tank (190) is a storage container in which purified oil is transferred and stored through the filter section (150), and is connected to the filter section (150) so that fluid can flow.

[0143] In addition to the function of storing and stabilizing the refined oil for a certain period of time, the refining tank (190) may additionally be provided with a configuration to prevent or remove moisture condensation that may occur during the process of cooling the refined oil to room temperature as needed.

[0144] For example, the refining tank (190) may be equipped with a cooling device or a heat exchanger to gradually lower the temperature of the refined oil, and in conjunction with this, a water separation device or a discharge line may be provided to remove moisture condensed on the surface or inside of the refined oil.

[0145] This composition contributes to maintaining the quality of refined oil and ensuring stability during reuse by preventing the phenomenon where refined oil absorbs moisture due to the temperature difference with the external temperature.

[0147] Although all components constituting the embodiments of the present invention have been described above as being combined or operating in combination, the present invention is not necessarily limited to such embodiments. That is, within the scope of the purpose of the present invention, all components may be selectively combined in one or more ways to operate.

[0148] Furthermore, terms such as "include," "compose," or "have" described above, unless specifically stated otherwise, mean that the relevant component may be inherent; therefore, they should be interpreted as allowing for the inclusion of additional components rather than excluding them. All terms, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains, unless otherwise defined. Commonly used terms, such as those defined in advance, should be interpreted in accordance with their meaning in the context of the relevant technology and should not be interpreted in an ideal or overly formal sense unless explicitly defined in the present invention.

[0149] Furthermore, the above description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention.

[0150] Accordingly, the embodiments disclosed in this invention are intended to illustrate, not limit, the technical concept of the invention, and the scope of the technical concept of the invention is not limited by these embodiments. The scope of protection of this invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of this invention. Explanation of the symbols

[0151] 100: Oil-soluble liquid regeneration system using a highly selective polymer porous filter according to one embodiment of the present invention 110 : Collection Team 120 : Storage tank 130 : Aquarium 131 : Courage Department 133 : Stirring section 140 : Heating part 150 : Filter section 151 : Housing 152 : Filter H: Through hole 160 : Preprocessing section 161 : Post-processing section 210 : Porous substrate 220: Plasma-etched porous substrate 230: Porous substrate coated with a polymer coating 240 : Porous substrate coated with a waterproof coating 170 : Wastewater tank 180 : Valve 190: Refining tank

Claims

Claim 1 A system for regenerating a fat-soluble liquid using a highly selective polymer porous filter, comprising: a storage tank for collecting and storing a fat-soluble liquid from a collection tank; a water tank for receiving the fat-soluble liquid transferred from the storage tank; a heating unit for heating the fat-soluble liquid; a filter unit for purifying the fat-soluble liquid transferred from the water tank; a wastewater tank for collecting moisture separated from the fat-soluble liquid through the filter unit; and a purification tank for receiving and storing purified oil purified through the filter unit, wherein the water tank includes a container unit that provides a space for receiving the fat-soluble liquid and has a lower portion formed in a funnel shape with a discharge port for sludge discharge provided at the end of the inclined surface of the lower portion, and a stirring unit disposed above the discharge port for stirring the fat-soluble liquid, wherein the heating unit is formed in a spiral shape wound along the outer surface of the container unit, and the filter unit includes a housing and a filter installed in the housing, wherein the filter is provided as a polymer porous filter having extreme hydrophilicity. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 A fat-soluble liquid regeneration system using a highly selective polymer porous filter according to claim 1, wherein the water tank and the wastewater tank are connected to the collection tank. Claim 6 A system for regenerating oil-soluble liquids using a highly selective polymer porous filter according to claim 1, characterized in that a valve is provided between the filter section and the wastewater tank to control the amount of moisture collected in the wastewater tank. Claim 7 A system for regenerating a lipid-soluble liquid using a highly selective polymer porous filter, wherein the system further comprises a pretreatment unit for performing pretreatment on the lipid-soluble liquid according to claim 1. Claim 8 A system for regenerating oil-soluble liquids using highly selective polymer porous filters, wherein the filter section is provided in a plurality and connected in series, in accordance with claim 1. Claim 9 A system for regenerating oil-soluble liquids using highly selective polymer porous filters, wherein the filter section is provided in a plurality and connected in parallel according to claim 1.

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