Activated low-temperature carbonized fiber obtained without using chemical solvent, manufacturing method thereof, and adsorbent including same

Abstract

The present invention relates to: an activated low-temperature carbonized fiber physically activated without using a chemical solvent; a manufacturing method thereof; and an adsorbent including the activated low-temperature carbonized fiber. An activated low-temperature carbonized fiber according to an embodiment of the present invention includes micropores and mesopores on the surface and inside of the carbonized fiber, and has a specific surface area of 800 m2 / g to 4,000 m2 / g.

Description

Activated low-temperature carbonized fiber without using chemical solvent, method for producing the same, and adsorbent containing the same

[0001] The present invention relates to an active low-temperature carbonized fiber, a method for producing the same, and an adsorbent comprising the same, and more particularly, to a method for producing an active low-temperature carbonized fiber that exhibits improved adsorption performance for harmful gases such as iodine or carbon dioxide through a process of producing pores of micro-pore and meso-pore sizes by heat-treating a polymer precursor fiber in an oxygen, nitrogen, or carbon dioxide atmosphere.

[0002] Activated carbon fiber and activated carbon are carbon-based materials with a high specific surface area and excellent adsorption performance and adsorption speed for gaseous and liquid pollutants. They are high value-added materials used in various industrial fields such as water purification, air purification, deodorization, and adsorbents.

[0003] Activated carbon based on carbon black, pitch, and cellulose has high adsorption performance and is used in various fields such as water purification, air purification, deodorization, and adsorbents.

[0004] Activated carbon fibers possess excellent mechanical and electrical properties due to their continuous fibrous form and high degree of orientation of the carbon crystal planes. These properties are used in composite materials, energy storage and conversion devices, nuclear power generation, and the adsorption of gaseous and liquid waste from industrial activities. Both activated carbon and activated carbon fibers possess excellent adsorption performance due to their high surface area, but they differ in the following ways.

[0005] Typically, activated carbon is attached to a support. This is because activated carbon, in powder or pellet form, is not continuous and requires a support to ensure strength and protect the pore structure. This method requires additional processing, which has disadvantages in terms of process cost and lightweight adsorbent. In contrast, activated carbon fiber, due to its fibrous form, can inherently secure strength. Therefore, it eliminates the need for a support, allowing for lightweight materials, components, and equipment. This lack of a support is the most significant differentiator of activated carbon fiber. Supports complicate the activated carbon manufacturing process, increase manufacturing costs, and can also degrade adsorption performance.

[0006] In addition, activated carbon has limitations such as low process reproducibility and frequent replacement cycles due to the difficulty in controlling the pore structure and low durability, which leads to weak etching resistance. On the other hand, in the case of activated carbon fiber, the molecules are highly oriented during heat treatment from the polymer fiber stage, which is the precursor of the carbon fiber, so the proportion of crystalline carbon structure is high, and accordingly, it has high durability during activation, making it easy to form micropores belonging to micro-pores and meso-pores, and having high process reproducibility.

[0007] However, conventional activated carbon fibers are manufactured through a complex process that involves removing surface sizing of carbon fibers manufactured through high-temperature carbonization at 1,600°C to 3,000°C, immersing in strong acids, strong bases, and organic solvents for a certain period of time, and then performing additional heat treatment at 500°C to 1,000°C, which results in problems of high heat treatment costs and long process times.

[0008] Accordingly, there is a need for an adsorbent manufacturing process that satisfies high adsorption performance and durability with a simple process.

[0009] Meanwhile, industrial activities and the accompanying nuclear power and renewable energy generation are essential elements of human life, but the gaseous and liquid pollutants generated in the process, including carbon dioxide, radioactive waste, and heavy metals, pose a serious threat to the environment, and the treatment and reduction of such waste are emerging as important tasks worldwide.

[0010] In particular, iodine isotope I, one of the substances produced as a byproduct of nuclear fission in nuclear power generation 129 Wow I 131 When exposed to the human body, it can cause serious symptoms such as thyroid cancer or cell destruction, so it is important to absorb and recover the harmful gas quickly and efficiently to prevent exposure to it in real life.

[0011] Conventional methods that utilize chemical activation of carbon black, carbon fiber, and other materials used for gaseous and liquid pollutants, including carbon dioxide, radioactive waste, and heavy metals, have high production costs and concerns about environmental pollution due to the complex process and long time required. Furthermore, due to the limitations of the specific surface area and low adsorption rate, large amounts of adsorbent are required, resulting in high energy consumption and low efficiency. Therefore, the present invention, which manufactures activated low-temperature carbonized fibers without using chemical solvents and has high adsorption rate and adsorption capacity due to a microporous structure and heterogeneous element doping, as well as selective adsorption properties for hazardous gases, is expected to play a significant role in resolving environmental pollution problems caused by nuclear power generation and industrial activities in a sustainable manner.

[0012] The background technology described above is technology that the inventor possessed or acquired in the process of deriving the disclosure of the present invention, and cannot necessarily be said to be publicly known technology disclosed to the general public prior to the present application.

[0013] The present invention is intended to solve the above-described problems, and the purpose of the present invention is to provide an active low-temperature carbonized fiber having a high specific surface area and micropores and mesopores and capable of being manufactured through a simple process without using a chemical solvent, and a method for manufacturing the same.

[0014] Another object of the present invention is to provide an adsorbent comprising activated low-temperature carbonized fibers capable of capturing liquid / gaseous hazardous substances including carbon dioxide, radioactive waste (iodine, etc.), and heavy metals.

[0015] However, the problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0016] According to one embodiment of the present invention, the active low-temperature carbonized fiber includes micropores and mesopores on the surface and inside of the carbonized fiber, and has a specific surface area of ​​800 m 2 / g to 4,000 m 2 / g is.

[0017] In one embodiment, the micropores may have an average diameter of less than 2 nm, and the mesopores may have an average diameter of from 2 nm to 50 nm.

[0018] In one embodiment, the mesopores may include first pores, second pores, and third pores, wherein the first pores may have an average diameter of 20 nm to 30 nm, the second pores may have an average diameter of 30 nm to 40 nm, and the third pores may have an average diameter of 40 nm to 50 nm.

[0019] In one embodiment, the first pores may be distributed from 40% to 70%, the second pores may be distributed from 25% to 45%, and the third pores may be distributed from 5% to 15%.

[0020] In one embodiment, the active low-temperature carbon fiber may be a continuous fiber in length.

[0021] In one embodiment, the active low-temperature carbon fiber may contribute to promoting physical adsorption and chemical adsorption mechanisms of gaseous / liquid hazardous substances through doping with at least one heterogeneous element selected from the group consisting of oxygen (O), nitrogen (N), sulfur (S), phosphorus (P), boron (B), and fluorine (F).

[0022] A method for manufacturing an activated low-temperature carbonized fiber according to another embodiment of the present invention comprises the steps of stabilizing a polymer precursor to form a stabilized fiber; and low-temperature carbonizing and activating the stabilized fiber to form an activated low-temperature carbonized fiber including pores.

[0023] In one embodiment, the polymer precursor may include at least one selected from the group consisting of polyacrylo nitrile (PAN), polyimide, polybenz imidazole (PBI), polystyrene, polydivinylbenzene, polyvinylpyridine, polypyrrole, polythiophene, and polyaniline.

[0024] In one embodiment, the step of forming the stabilizing fiber may be performed in an air atmosphere at a temperature range of 200° C. to 500° C. for 60 minutes to 240 minutes.

[0025] In one embodiment, after the step of forming the stabilizing fiber, the step of cooling to room temperature in an air atmosphere may be further included.

[0026] In one embodiment, prior to the step of forming the active low-temperature carbon fiber including the above pores, the temperature may be increased at 3°C / min to 10°C / min in a nitrogen atmosphere.

[0027] In one embodiment, the step of forming the active low-temperature carbon fiber including the pores may be performed in a carbon dioxide atmosphere at a temperature range of 800°C to 1,100°C for 60 minutes to 300 minutes.

[0028] In one embodiment, after the step of forming the active low-temperature carbon fiber including the pores, the step of cooling to room temperature in a nitrogen atmosphere may be further included.

[0029] An adsorbent according to another embodiment of the present invention comprises an activated low-temperature carbonized fiber according to one embodiment of the present invention or an activated low-temperature carbonized fiber manufactured by a method for manufacturing an activated low-temperature carbonized fiber according to another embodiment.

[0030] In one embodiment, the adsorbent may adsorb a pollutant comprising at least one selected from the group consisting of carbon dioxide, iodine, a biochemical agent, and a heavy metal.

[0031] In one embodiment, the adsorbent may adsorb 310% or more of iodine or 2.0 mmol or more of carbon dioxide relative to the weight of the adsorbent under temperature conditions of 10° C. to 80° C.

[0032] According to one embodiment of the present invention, the activated low-temperature carbonized fibers include micropores and mesopores and have a high specific surface area without using a chemical solvent, thereby significantly improving the adsorption speed and adsorption amount for capturing iodine gas (nuclear gas waste) and carbon dioxide. The method for manufacturing the activated low-temperature carbonized fibers according to one embodiment of the present invention can reduce heat treatment costs and improve productivity by continuously performing low-temperature carbonization and activation, and can enhance economic efficiency through process omission. The continuous activated low-temperature carbonized fibers can also be utilized in energy storage and conversion devices such as supercapacitors and fuel cells due to their morphological uniformity and excellent specific surface area and electrical / thermal conductivity resulting from crystallinity.

[0033] Additionally, it is environmentally friendly as it does not use chemical solvents such as strong acids, strong bases, and organic solvents that were previously used.

[0034] An adsorbent according to one embodiment of the present invention can exhibit improved adsorption performance for gaseous and liquid pollutants.

[0035] Figure 1 is a flowchart showing a method for manufacturing an active low-temperature carbon fiber according to one embodiment of the present invention.

[0036] Figure 2 is a schematic diagram illustrating a method for manufacturing an active low-temperature carbonized fiber according to an embodiment of the present invention.

[0037] Figure 3 is a schematic diagram illustrating an iodine adsorption experiment method of an active low-temperature carbon fiber according to an embodiment of the present invention.

[0038] Hereinafter, embodiments are described in detail with reference to the attached drawings. However, the embodiments may be modified in various ways, and the scope of the patent application is not limited or restricted by these embodiments. It should be understood that all modifications, equivalents, or alternatives to the embodiments are included within the scope of the patent application.

[0039] The terms used in the examples are for illustrative purposes only and should not be construed as limiting. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but should be understood to not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0040] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the embodiments pertain. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0041]

[0042] In addition, when describing with reference to the attached drawings, identical components will be assigned the same reference numerals regardless of the drawing numbers, and redundant descriptions thereof will be omitted. When describing embodiments, if a detailed description of a related known technology is judged to unnecessarily obscure the gist of the embodiment, the detailed description will be omitted.

[0043] Additionally, in describing components of an embodiment, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by the terms.

[0044] Components included in one embodiment and components with common functions will be described using the same names in other embodiments. Unless otherwise stated, the descriptions given in one embodiment may also apply to other embodiments, and detailed descriptions will be omitted to the extent of overlap.

[0045]

[0046] Hereinafter, the active low-temperature carbon fiber of the present invention, its manufacturing method, and the adsorbent comprising the same will be described in detail with reference to examples and drawings. However, the present invention is not limited to these examples and drawings.

[0047]

[0048] According to one embodiment of the present invention, the active low-temperature carbonized fiber includes micropores and mesopores on the surface and inside of the carbonized fiber, and has a specific surface area of ​​800 m 2 / g to 4,000 m 2 / g is.

[0049] In general, active nanofibers have the characteristic of manufacturing 'nano-diameter fibers' by 'electrospinning' fibers, and thus have the characteristic of a 'non-woven fiber' type fiber manufacturing method that is completely different from the active low-temperature carbonized fiber of the present invention.

[0050] On the other hand, the present invention has the characteristic of manufacturing continuous fibers of 'Woven, Wovable fiber' of m to km scale by wet spinning or dry spinning the fibers into 'micro diameter fibers'.

[0051] The above active low-temperature carbonized fiber has a specific surface area of ​​800 m 2 / g to 4,000 m 2 / g; 800 m 2 / g to 3,500 m 2 / g; 800 m 2 / g to 3,000 m2 / g; 800 m 2 / g to 2,500 m 2 / g; 800 m 2 / g to 2,000 m 2 / g; 800 m 2 / g to 1,500 m 2 / g; 800 m 2 / g to 1,000 m 2 / g; 1,000 m 2 / g to 4,000 m 2 / g; 1,000 m 2 / g to 3,500 m 2 / g; 1,000 m 2 / g to 3,000 m 2 / g; 1,000 m 2 / g to 2,500 m 2 / g; 1,000 m 2 / g to 2,000 m 2 / g; 1,000 m 2 / g to 1,500 m 2 / g; 1,500 m 2 / g to 4,000 m 2 / g; 1,500 m 2 / g to 3,500 m 2 / g; 1,500 m 2 / g to 3,000 m 2 / g; 1,500 m 2 / g to 2,500 m 2 / g; 1,500 m 2 / g to 2,000 m 2 / g; 2,000 m 2 / g to 4,000 m 2 / g; 2,000 m 2 / g to 3,500 m 2 / g; 2,000 m 2 / g to 3,000 m 2 / g; 2,000 m 2 / g to 2,500 m 2 / g; 2,500 m 2 / g to 4,000 m 2 / g; 2,500 m 2 / g to 3,500 m 2 / g; 2,500 m 2 / g to 3,000 m 2 / g; 3,000 m 2 / g to 4,000 m 2 / g; 3,000 m 2 / g to 3,500 m 2 / g; or 3,500 m 2 / g to 4,000 m 2 It could be / g;

[0052] In one embodiment, the micropores may have an average diameter of less than 2 nm, and the mesopores may have an average diameter of from 2 nm to 50 nm.

[0053] In one embodiment, the mesopores may include first pores, second pores, and third pores.

[0054] The first pores may have an average diameter of 20 nm to 30 nm; 20 nm to 28 nm; 20 nm to 25 nm; 20 nm to 23 nm; 23 nm to 30 nm; 23 nm to 28 nm; 23 nm to 25 nm; 25 nm to 30 nm; 25 nm to 28 nm; 28 nm to 30 nm.

[0055] The first pores may have an average diameter of 30 nm to 40 nm; 30 nm to 38 nm; 30 nm to 35 nm; 30 nm to 33 nm; 33 nm to 40 nm; 33 nm to 38 nm; 33 nm to 35 nm; 35 nm to 40 nm; 35 nm to 38 nm; or 38 nm to 40 nm.

[0056] The third pores may have an average diameter of 40 nm to 50 nm; 40 nm to 48 nm; 40 nm to 45 nm; 40 nm to 43 nm; 43 nm to 50 nm; 43 nm to 48 nm; 43 nm to 45 nm; 45 nm to 50 nm; 45 nm to 48 nm; or 48 nm to 50 nm.

[0057] In one embodiment, the first pores may be distributed as 40% to 70%; 40% to 65%; 40% to 60%; 40% to 55%; 40% to 50%; 40% to 45%; 50% to 70%; 50% to 65%; 50% to 60%; 50% to 55%; 60% to 70%; 60% to 65%; or 65% to 70%.

[0058] The second pores may be distributed as 25% to 45%; 25% to 40%; 25% to 35%; 25% to 30%; 30% to 45%; 30% to 40%; 30% to 35%; or 40% to 45%.

[0059] The above third pores may be distributed as 5% to 15%; 5% to 10%; or 10% to 15%.

[0060] The diameter of the above-mentioned active low-temperature carbonized fiber may be 5 ㎛ to 10 ㎛ and the length may be continuous.

[0061] In one embodiment, the activated low-temperature carbonized fiber may be doped with a heterogeneous element, such as oxygen (O), nitrogen (N), sulfur (S), phosphorus (P), boron (B), or fluorine (F). The activated low-temperature carbonized fiber of the present invention is doped with an electron-rich heterogeneous element, such as oxygen or nitrogen, and thus has an effect of exhibiting an improved adsorption amount and adsorption rate for gaseous / liquid hazardous substances having the same electron acceptor properties. More specifically, the heterogeneous element doping may contribute to promoting hydrogen bonding, van der Waals bonding, and hydrophobic bonding among physical adsorption mechanisms, and redox reactions, coordination bonding, electrophilic aromatic substitution, Lewis acid-base interactions, and Coulomb interactions among chemical adsorption mechanisms during hazardous substance adsorption.

[0062] An active low-temperature carbon fiber according to one embodiment of the present invention includes micropores and mesopores and has a high specific surface area, so that it can greatly improve the adsorption speed and adsorption amount for capturing iodine gas (nuclear gas waste) and carbon dioxide.

[0063]

[0064] A method for manufacturing an activated low-temperature carbonized fiber according to another embodiment of the present invention comprises the steps of stabilizing a polymer precursor to form a stabilized fiber; and low-temperature carbonizing and activating the stabilized fiber to form an activated low-temperature carbonized fiber including pores.

[0065] According to the method for manufacturing an active low-temperature carbonized fiber of the present invention, since activation is performed after stabilization and carbonization in a state where crystal planes are arranged from the precursor fiber stage, the specific gravity of the crystalline carbon structure is high, and accordingly, when activation is performed, it is possible to manufacture an active low-temperature carbonized fiber that is easy to form micropores and mesopores and has high reproducibility, with high durability.

[0066] Figure 1 is a flowchart showing a method for manufacturing an active low-temperature carbon fiber according to one embodiment of the present invention.

[0067] Referring to FIG. 1, a method for manufacturing an active low-temperature carbonized fiber according to one embodiment includes a stabilizing fiber formation step (110), a low-temperature carbonized fiber and an active low-temperature carbonized fiber formation step (120).

[0068] The above stabilizing fiber formation step (110) is to form a stabilizing fiber by stabilizing a polymer precursor fiber.

[0069] Fibers can be manufactured by wet or dry spinning, heat treatment, and activation to apply tension to 'micro-diameter fibers' and 'woven, wovable fibers' on the meter to kilometer scale. The molecular chain structure oriented by the tension applied during heat treatment enables self-standing (no support required) and exhibits high physical properties that enable it to be woven into fabrics for large-area applications.

[0070] In one embodiment, the polymer precursor may include at least one selected from the group consisting of polyacrylo nitrile (PAN), polyimide, polybenz imidazole (PBI), polystyrene, polydivinylbenzene, polyvinylpyridine, polypyrrole, polythiophene, and polyaniline.

[0071] Preferably, the polymer precursor may be polyacrylonitrile (PAN).

[0072] In one embodiment, the step of forming the stabilizing fiber may be performed in an air atmosphere at a temperature range of 200°C to 500°C; 200°C to 400°C; 200°C to 300°C; 300°C to 500°C; 300°C to 400°C; or 400°C to 500°C; for 60 minutes to 240 minutes; 60 minutes to 180 minutes; 60 minutes to 120 minutes; 120 minutes to 240 minutes; 120 minutes to 180 minutes; or 180 minutes to 240 minutes.

[0073] When the stabilization process is performed in an air atmosphere, oxygen is doped into the fiber during the process, which has the advantage of promoting the carbonization process and the activation process, and the oxidized structure has the advantage of being stable during the carbonization and activation processes.

[0074] If the stabilization temperature is less than 200°C or the stabilization time is less than 60 minutes, the problem of the degree of oxygen doping inside the fiber being low and the stabilized structure being less developed may occur, causing the carbonization and activation processes to not proceed smoothly. If the stabilization temperature is more than 500°C or the stabilization time is more than 240 minutes, the problem of the structural stability being reduced and the final yield being reduced may occur due to the excessive stabilization.

[0075] Preferably, the stabilization process may be performed at a temperature range of 200°C to 400°C for 60 to 120 minutes.

[0076] In one embodiment, after the step of forming the stabilizing fiber, the step of cooling to room temperature in an air atmosphere may be further included.

[0077] When the cooling process is performed in an air atmosphere, there is an advantage of process convenience as no additional atmosphere change or post-treatment process is required.

[0078] In one embodiment, prior to the step of forming the active low-temperature carbon fiber including the above pores, the temperature may be increased in a nitrogen atmosphere at 3°C / min to 10°C / min; 3°C / min to 8°C / min; 3°C / min to 5°C / min; 5°C / min to 10°C / min; 5°C / min to 8°C / min or 8°C / min to 10°C / min.

[0079] Preferably, the heating temperature may be 3 ℃ / min to 8 ℃ / min.

[0080] When heated in a nitrogen atmosphere, there is an advantage in that a carbon structure is stably formed in an inert atmosphere and the formation of smooth micropores is promoted in the subsequent activation process.

[0081] The above-described active low-temperature carbonized fiber forming step (120) is to form an active low-temperature carbonized fiber including pores by low-temperature carbonizing and firing the above-described stabilized fiber.

[0082] Unlike chemical activation processes that have the disadvantages of secondary environmental pollution and equipment corrosion due to the use of activators such as NaOH and KOH, increased unit cost, and complex processes for removing residual salts, the activation process performed in a carbon dioxide atmosphere has the advantage of not requiring post-treatment processes such as solvent recovery, removal of residual salts, and equipment corrosion, and the unit cost of the activator is very low.

[0083] Conventional inventions that utilize carbon dioxide and water vapor as physical activators for carbon fibers have had difficulties in forming micropores or developing a high specific surface area compared to activation using chemical solvents. However, the present invention overcomes the limitations of micropores / low specific surface area of ​​such physical activation techniques by performing a low-temperature carbonization process while heating the fibers in the cyclization stage before the carbon crystal structure is formed in an inert atmosphere and then applying physical activation.

[0084]

[0085] In one embodiment, the step of forming the active low-temperature carbonized fiber including the pores is performed in a carbon dioxide atmosphere at a temperature range of 800°C to 1,100°C; 800°C to 1,000°C; 800°C to 900°C; 900°C to 1,100°C; 900°C to 1,000°C; 1,000°C to 1,100°C for 60 minutes to 300 minutes; 60 minutes to 240 minutes; 60 minutes to 180 minutes; 60 minutes to 120 minutes; 120 minutes to 300 minutes; 120 minutes to 240 minutes; 120 minutes to 180 minutes; 180 minutes to 300 minutes; 180 minutes to 240 minutes; or 240 minutes to 300 minutes; It may be performed during.

[0086] Preferably, the activation process may be performed at a temperature range of 800°C to 1,000°C for 60 to 240 minutes.

[0087]

[0088] In one embodiment, after the step of forming the active low-temperature carbon fiber including the pores, the step of cooling to room temperature in a nitrogen atmosphere may be further included.

[0089] When the cooling process is performed in a nitrogen atmosphere, there is an advantage of maintaining an inert atmosphere, thereby preventing collapse of the pore structure and ensuring the stability of the active low-temperature carbonized fiber.

[0090] According to one embodiment of the present invention, a method for manufacturing an active low-temperature carbonized fiber includes micropores and mesopores and has a specific surface area of ​​800 m 2 / g to 4,000 m 2 / g of active low-temperature carbon fibers can be manufactured.

[0091] The above active low-temperature carbonized fiber has a specific surface area of ​​800 m 2 / g to 4,000 m 2 / g; 800 m 2 / g to 3,500 m2 / g; 800 m 2 / g to 3,000 m 2 / g; 800 m 2 / g to 2,500 m 2 / g; 800 m 2 / g to 2,000 m 2 / g; 800 m 2 / g to 1,500 m 2 / g; 800 m 2 / g to 1,000 m 2 / g; 1,000 m 2 / g to 4,000 m 2 / g; 1,000 m 2 / g to 3,500 m 2 / g; 1,000 m 2 / g to 3,000 m 2 / g; 1,000 m 2 / g to 2,500 m 2 / g; 1,000 m 2 / g to 2,000 m 2 / g; 1,000 m 2 / g to 1,500 m 2 / g; 1,500 m 2 / g to 4,000 m 2 / g; 1,500 m 2 / g to 3,500 m 2 / g; 1,500 m 2 / g to 3,000 m 2 / g; 1,500 m 2 / g to 2,500 m 2 / g; 1,500 m 2 / g to 2,000 m 2 / g; 2,000 m 2 / g to 4,000 m 2 / g; 2,000 m 2 / g to 3,500 m 2 / g; 2,000 m 2 / g to 3,000 m 2 / g; 2,000 m 2 / g to 2,500 m 2 / g; 2,500 m 2 / g to 4,000 m 2 / g; 2,500 m 2 / g to 3,500 m 2 / g; 2,500 m 2 / g to 3,000 m 2 / g; 3,000 m 2 / g to 4,000 m 2 / g; 3,000 m 2 / g to 3,500 m 2 / g; or 3,500 m 2 / g to 4,000 m 2 It could be / g;

[0092] A method for manufacturing activated low-temperature carbonized fibers according to one embodiment of the present invention can reduce heat treatment costs and improve productivity by continuously performing low-temperature carbonization and activation, and can enhance economic efficiency by eliminating processes. Furthermore, it is environmentally friendly, as it does not use chemical solvents such as strong acids, strong bases, and organic solvents, which are conventionally used.

[0093]

[0094] An adsorbent according to another embodiment of the present invention comprises an activated low-temperature carbonized fiber according to one embodiment of the present invention or an activated low-temperature carbonized fiber manufactured by a method for manufacturing an activated low-temperature carbonized fiber according to another embodiment.

[0095] In one embodiment, the adsorbent may adsorb a pollutant comprising at least one selected from the group consisting of carbon dioxide, iodine, a biochemical agent, and a heavy metal.

[0096] In one embodiment, the adsorbent may adsorb 310% or more of iodine or 2.0 mmol or more of carbon dioxide relative to the weight of the adsorbent under temperature conditions of 10° C. to 80° C.

[0097] An adsorbent according to one embodiment of the present invention can exhibit improved adsorption performance for gaseous and liquid pollutants.

[0098]

[0099] Hereinafter, the present invention will be described in detail with reference to the following examples and comparative examples. However, the technical concept of the present invention is not limited or restricted thereby.

[0100]

[0101] [Example]

[0102] Experimental Example 1: Production of Activated Low-Temperature Carbonized Fibers

[0103] Figure 2 is a schematic diagram illustrating a method for manufacturing an active low-temperature carbonized fiber according to an embodiment of the present invention.

[0104] As illustrated in Fig. 2, first, 2,500 strands of PAN-based precursor fibers were used to manufacture stabilized fibers using a continuous heat treatment device consisting of seven sections. The stabilization process was performed by setting the temperature by heating air, and the air was heated using two band heaters and one blow heater for each section. The set temperatures of the seven sections were 180°C, 200°C, 210°C, 220°C, 240°C, 260°C, and 270°C, respectively, and a total elongation of 27% was performed so that a tension of approximately 25 MPa could be applied to each fiber strand in each section. The stabilization process was performed in an air atmosphere, and the fiber was allowed to pass through the heated sections for a total of 100 minutes at a maximum temperature of 270°C, at a speed of 13.2 m / h. Afterwards, it was cooled to room temperature in an air atmosphere.

[0105] Next, the stabilized fibers were cut into 15 cm pieces, 1 g each was aligned and placed in an alumina crucible, and then the temperature was increased to 800 °C, 850 °C, 900 °C, 950 °C, and 1,000 °C in a nitrogen atmosphere at 5 °C each. After reaching the corresponding temperatures, the atmosphere was replaced with a CO2 atmosphere and physical activation was performed for 180 minutes. Thereafter, the fibers were cooled to room temperature in a nitrogen atmosphere to produce activated low-temperature carbonized fibers.

[0106]

[0107] Experimental Example 2: Analysis of Pores and Specific Surface Area of ​​Activated Low-Temperature Carbonized Fibers

[0108] The properties of the activated low-temperature carbon fibers manufactured at each activation temperature are shown in Table 1 below.

[0109]

[0110] Activation temperature (℃) Micropore (~ 2 nm) ratio (%) Mesopore (2~50 nm) ratio (%) V total (cm 2 / g) specific surface area (cm) 2 / g)Yield(%)800---4.0056.27850100 %00.066223.4547.7590099.890.110.256820.0133.7595056.6843.301.5722982.3413.831,00034.1365.550.394538.354.76

[0111] Activation in a carbon dioxide atmosphere revealed that as the activation temperature increased, the proportion of mesopores increased, as did the pore volume and specific surface area. However, when the activation temperature exceeded 950°C, the pore volume and specific surface area decreased significantly, indicating that the pore structure collapses at activation temperatures above 950°C.

[0112] Therefore, when an active low-temperature carbon fiber is manufactured according to the present invention and activation is performed at 950°C, the specific surface area and the volume of pores required for adsorption can be maximized simultaneously.

[0113]

[0114] Experimental Example 3: Adsorbent Preparation

[0115] The activated low-temperature carbon fiber manufactured above was used as an iodine and carbon dioxide adsorbent without a separate treatment process after the manufacturing process was completed.

[0116]

[0117] Experimental Example 4: Iodine Adsorption

[0118] An experiment to adsorb iodine was performed using the adsorbent manufactured above.

[0119] Figure 3 is a schematic diagram illustrating an iodine adsorption experiment method of an active low-temperature carbon fiber according to an embodiment of the present invention.

[0120] In order to minimize interference of residual moisture, the adsorbent manufactured by Experimental Example 2 was dried overnight in a vacuum oven at 80°C, and then 5 mg of the adsorbent with moisture removed was placed in a heating / vacuum chamber. Then, 500 mg of iodine particles, which serve as a source of iodine vapor during the iodine adsorption test, were injected, and the gas manifold was opened and the system was kept closed.

[0121] After reacting at 80°C for 10 minutes, the mixture was cooled to room temperature, the mass of the adsorbent was measured, and the process was repeated until no more adsorption occurred.

[0122] Iodine adsorption performance was derived using the following equation.

[0123]

[0124] [In the above formula is the iodine adsorption performance,

[0125] Above is the weight of the adsorbent,

[0126] Above is the weight of the adsorbent to which iodine is adsorbed.]

[0127]

[0128] The iodine adsorption rate is the iodine adsorption performance derived from the above equation ( ) was derived from the rate of adsorption per hour up to 80% of the level.

[0129] At this time, when adsorbing liquid iodine rather than gaseous iodine, the adsorption performance can be derived through ASTM D1510 and ASTM D4607.

[0130]

[0131] Experimental Example 5: Analysis of Iodine Adsorption Performance of Activated Low-Temperature Carbon Fiber

[0132] Activation temperature (℃) Iodine adsorption performance (gg -1 )Iodine adsorption rate (K80%) (gh -1 )9001.371.839503.102.561,0001.682.99

[0133] The iodine adsorption performance was derived as an average value after at least 10 repeated experiments and is shown in Table 2 above. The adsorption performance was the best in the activated low-temperature carbonized fiber activated at 950°C, and this is proportional to the specific surface area and pore volume.

[0134]

[0135] Experimental Example 6: Carbon Dioxide Adsorption

[0136] An experiment to adsorb carbon dioxide was conducted using the adsorbent manufactured above.

[0137] The adsorbent was dried under vacuum conditions at 160°C for 12 hours to remove internal moisture and residual gases. Afterwards, 40 mg of the adsorbent was placed in a glass tube, and the carbon dioxide adsorption capacity was measured using a Triastar II 3020 surface area measuring device. The adsorption performance was confirmed at 760 mmHg and 25°C.

[0138]

[0139] Experimental Example 7: Analysis of carbon dioxide adsorption performance of activated low-temperature carbon fibers

[0140] Activation temperature (℃) Carbon dioxide adsorption performance (mmol g -1 )9002.289502.021,0000.80

[0141] The carbon dioxide adsorption performance is shown in Table 3 above, and excellent adsorption performance is shown in the activated low-temperature carbon fiber activated at 900 ℃ and 950 ℃.

[0142] Through the above experimental examples, the active low-temperature carbonized fibers of the present invention are manufactured by a method suitable for efficiently adsorbing various harmful gases, while simplifying the process and not using chemical solvents, and having a high specific surface area and micro- and meso-pore structures.

[0143]

[0144] Although the embodiments described above have been described with limited drawings, those skilled in the art will appreciate that various technical modifications and variations can be applied based on the above. For example, appropriate results can still be achieved even if the described techniques are performed in a different order than described, and / or components of the described systems, structures, devices, circuits, etc. are combined or combined in a different manner than described, or are replaced or substituted with other components or equivalents.

[0145] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims described below.

Claims

1. On the surface and inside of the carbon fiber, Contains micropores and mesopores, Surface area is 800 m 2 / g to 4,000 m 2 / g person, Activated low temperature carbon fiber.

2. In paragraph 1, The above micropores have an average diameter of less than 2 nm, The above mesopores are 2 nm to 50 nm, Activated low temperature carbon fiber.

3. In paragraph 1, The above mesopores include first pores, second pores and third pores, The above first pore has an average diameter of 20 nm to 30 nm, The above second pores have an average diameter of 30 nm to 40 nm, The above third pore has an average diameter of 40 nm to 50 nm, which includes, Activated low temperature carbon fiber.

4. In paragraph 3, The above first pores are distributed from 40% to 70%, The above second pores are distributed from 25% to 45%, The above third pore is distributed between 5% and 15%, Activated low temperature carbon fiber.

5. In paragraph 1, The above active low-temperature carbonized fibers are, The length is continuous, Activated low temperature carbon fiber.

6. In paragraph 1, The above active low-temperature carbonized fibers are, Contributes to promoting physical adsorption and chemical adsorption mechanisms of gaseous / liquid hazardous substances through doping with at least one heterogeneous element selected from the group consisting of oxygen (O), nitrogen (N), sulfur (S), phosphorus (P), boron (B), and fluorine (F). Activated low temperature carbon fiber.

7. A step of stabilizing a polymer precursor to form a stabilized fiber; and A step of low-temperature carbonizing and activating the above-mentioned stabilizing fibers to form active low-temperature carbonized fibers including pores; Including, Method for producing active low-temperature carbonized fiber.

8. In paragraph 7, The above polymer precursor is, Containing at least one selected from the group consisting of polyacrylo nitrile (PAN), polyimide, polybenz imidazole (PBI), polystyrene, polydivinylbenzene, polyvinylpyridine, polypyrrole, polythiophene, and polyaniline. Method for producing active low-temperature carbonized fiber.

9. In paragraph 7, The step of forming the above stabilizing fibers is: In an air atmosphere, the process is performed at a temperature range of 200°C to 500°C for 60 to 240 minutes. Method for producing active low-temperature carbonized fiber.

10. In paragraph 7, After the step of forming the above stabilizing fibers, In an air atmosphere, the step of cooling to room temperature; Including more, Method for producing active low-temperature carbonized fiber.

11. In paragraph 7, Prior to the step of forming an active low-temperature carbon fiber including the above pores, In a nitrogen atmosphere, the temperature is increased at a rate of 3 ℃ / min to 10 ℃ / min. Method for producing active low-temperature carbonized fiber.

12. In paragraph 7, The step of forming an active low-temperature carbon fiber including the above pores is: In a carbon dioxide atmosphere, the process is performed at a temperature range of 800°C to 1,100°C for 60 to 300 minutes. Method for producing active low-temperature carbonized fiber.

13. In paragraph 7, After the step of forming an active low-temperature carbon fiber including the above pores, a step of cooling to room temperature in a nitrogen atmosphere; Including more, Method for producing active low-temperature carbonized fiber.

14. An adsorbent comprising the active low-temperature carbonized fiber of paragraph 1.

15. In paragraph 14, The above adsorbent is, Adsorbing a pollutant comprising at least one selected from the group consisting of carbon dioxide, iodine, biochemical agents and heavy metals; absorbent.

16. In paragraph 14, The above adsorbent is, Adsorbing at least 310% of iodine or at least 2.0 mmol of carbon dioxide relative to the weight of the adsorbent under temperature conditions of 10°C to 80°C, absorbent.

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