Adsorbent for gas removal and gas removal filter including the same

Abstract

An adsorbent for removing ammonia according to exemplary embodiments may comprise an adsorption carrier and an organic acid attached to the surface of the adsorption carrier. The ratio of breakthrough times represented by Formula 1 of the adsorbent for removing ammonia may be less than 1.2.

Description

Technology Field

[0001] The present invention relates to an adsorbent for gas removal and a gas removal filter containing the same. More specifically, it relates to an adsorbent for ammonia gas removal and a gas removal filter containing the same. Background Technology

[0003] Organic and inorganic hazardous gases cause environmental pollution and exert toxicity on the human respiratory and nervous systems.

[0004] Chemical filters are being installed and operated to remove harmful gases such as Volatile Organic Compounds (VOCs).

[0005] In particular, ammonia gas causes a foul odor and can cause dermatitis upon contact with the skin, and excessive ammonia gas inhaled into the respiratory system can lead to death.

[0006] For example, various methods have been proposed to remove harmful gases, including ammonia. For instance, a method of removal using chemical filters made from materials such as activated carbon, ion exchange resin, nonwoven fabric, and hot melt is known.

[0007] However, chemical filters equipped with ion exchange resins have limitations in removing compounds with specific chemical properties (e.g., ammonia).

[0008] Therefore, there is a need for research and development on adsorbents and gas removal filters capable of easily removing compounds with specific chemical properties (e.g., ammonia).

[0009] For example, Korean Patent Publication No. 10-2021-0076011 discloses a catalyst-adsorbent filter for removing air pollutants including ammonia. Prior art literature

[0011] Korean Patent Publication No. 10-2021-0076011 The problem to be solved

[0012] One objective of the present invention is to provide an adsorbent for gas removal that selectively removes specific gases.

[0013] One objective of the present invention is to provide a gas removal filter comprising the above-mentioned adsorbent for gas removal. means of solving the problem

[0015] An adsorbent for gas removal according to exemplary embodiments may comprise an adsorption carrier and an organic acid attached to the surface of the adsorption carrier. The ratio of breakthrough times represented by Formula 1 below for the adsorbent for gas removal may be less than 1.2.

[0016] [Equation 1]

[0017]

[0018] In Formula 1, BT N This may be the time until the removal rate of the ammonia reaches 70% when 100 ppm of ammonia is flowed through 20 cc of a gas removal adsorbent at a flow rate of 0.3 m / s.

[0019] In Formula 1, BT A.N The time may be until the removal rate of ammonia reaches 70% when 100 ppm of ammonia is flowed at a flow rate of 0.3 m / s after 20 cc of a gas removal adsorbent is exposed for 24 hours to a gas in which the concentration of propylene glycol monomethyl ether acetate (PGMEA) is maintained at 50 ppm to 100 ppm.

[0020] In some embodiments, when 100 ppm of ammonia is flowed through 20 cc of the gas removal adsorbent at a flow rate of 0.3 m / s, the time until the removal rate of the ammonia reaches 70% may be 700 minutes to 1,500 minutes.

[0021] In some embodiments, when 20 cc of the gas removal adsorbent is exposed for 24 hours to a gas in which the concentration of PGMEA is maintained at 50 ppm to 100 ppm, and then 100 ppm of ammonia is flowed at a flow rate of 0.3 m / s, the time until the removal rate of the ammonia reaches 70% may be 600 minutes to 1,400 minutes.

[0022] In some embodiments, the organic acid may include a carboxyl group. The number of carboxyl groups included in the organic acid may be at least two.

[0023] In some embodiments, the content of the carboxyl group in the total weight of the organic acid may be 50% to 80% by weight.

[0024] In some embodiments, the solubility of the organic acid in water may be 500 g / L to 1,400 g / L under temperature conditions of 20 ℃.

[0025] In some embodiments, the acid-ionization constant (pKa) of the organic acid may be 2.7 to 3.4.

[0026] In some embodiments, the standard enthalpy of formation (H) of the organic acid f °) can be -1,200 kJ / mol to -600 kJ / mol.

[0027] In some embodiments, the standard Gibbs free energy of formation (G) of the organic acid f °) can be -1,000 kJ / mol to -500 kJ / mol.

[0028] In some embodiments, the adsorption carrier may comprise at least one of silica, zeolite, cordierite, and alumina.

[0029] In some embodiments, the particle size of the adsorption carrier may be 40 mesh to 60 mesh.

[0030] In some embodiments, the organic acid may be adhered to the surface of the adsorption carrier.

[0031] In some embodiments, the specific surface area of ​​the ammonia removal adsorbent is 650 m² 2 / g to 800 m 2 It can be / g.

[0032] In some embodiments, the content of the organic acid in the total weight of the ammonia removal adsorbent may be 5% to 65% by weight.

[0033] A gas removal filter according to exemplary embodiments may include a gas removal filter body, a gas inlet disposed at one end of the gas removal filter body, a gas outlet disposed at the other end of the gas removal filter body, and the above-described gas removal adsorbent filled in the gas removal filter body. Effects of the invention

[0035] According to exemplary embodiments, the adsorbent for gas removal may comprise a carrier and an organic acid. The organic acid can effectively adsorb basic gases. For example, the acid functional groups contained in the organic acid can effectively adsorb basic substances such as ammonia. Accordingly, basic harmful gases can be effectively removed.

[0036] According to exemplary embodiments, the organic acid may contain carbon in a predetermined amount. Accordingly, the organic acid can be stably bound to the carrier. Accordingly, the structural stability of the gas removal adsorbent can be improved. Therefore, the durability of the gas removal adsorbent can be improved.

[0037] The above carrier may include porous ceramic. Accordingly, the specific surface area of ​​the gas removal adsorbent may be increased. Therefore, the removal efficiency of harmful gases by the gas removal adsorbent may be improved. Brief explanation of the drawing

[0039] FIG. 1 is a schematic cross-sectional view showing a gas removal filter according to exemplary embodiments. Specific details for implementing the invention

[0040] An adsorbent for gas removal according to exemplary embodiments may include an adsorption carrier and an organic acid. Additionally, a gas removal filter according to exemplary embodiments may include the adsorbent for gas removal.

[0041] Hereinafter, the present disclosure will be described in detail with reference to the attached drawings. However, this is merely illustrative and the present disclosure is not limited to the specific embodiments described illustratively.

[0042] According to exemplary embodiments, the adsorbent for gas removal may comprise an adsorption carrier and an organic acid. For example, the organic acid may be attached to the surface of the adsorption carrier. The organic acid may comprise carbon, oxygen, and hydrogen. For example, the organic acid may comprise an acid functional group comprising carbon, oxygen, and hydrogen.

[0043] The above acid functional group may have a high adsorption capacity for basic substances. Accordingly, the gas removal adsorbent containing the above organic acid may have a high adsorption rate for basic harmful gases. Therefore, the gas removal adsorbent containing the organic acid can remove basic harmful gases.

[0044] In some embodiments, the organic acid may be attached to the adsorption carrier by chemical bonding. For example, the organic acid may be chemically bonded to a material constituting the adsorption carrier through hydrogen bonding or covalent bonding, etc. Accordingly, the organic acid can be stably fixed on the adsorption carrier.

[0045] In some embodiments, the organic acid may include a carboxyl group. Since the organic acid includes a carboxyl group, the organic acid may be an acid that is neither excessively strong nor weak. Accordingly, the adsorption capacity of the organic acid for harmful gases having weak basicity (e.g., ammonia gas) may be increased.

[0046] In some embodiments, the number of carboxyl groups included in the organic acid may be at least 2, 2 to 5, or 2 to 3. Within this range, the adsorption capacity of the organic acid for harmful gases may increase, while the adsorption capacity for propylene glycol monomethyl ether acetate (PGMEA) may decrease.

[0047] In some embodiments, the content of the carboxyl group in the total weight of the organic acid may be 50% to 80% by weight, 50% to 70% by weight, or 55% to 70% by weight. Within the above content range, the acidity of the organic acid can be maintained so that it is neither excessively strong nor excessively weak. Additionally, the proportion of acid functional groups contained in the organic acid can be sufficiently increased. Accordingly, the number of sites where basic harmful gases (e.g., ammonia gas) can be adsorbed can be increased. Therefore, the adsorption rate of the gas removal adsorbent containing the organic acid for harmful gases can be improved.

[0048] In some embodiments, the solubility of the organic acid in water may be 500 g / L to 1,400 g / L, 500 g / L to 1,000 g / L, or 500 g / L to 700 g / L. For example, the solubility may be the solubility measured at 20°C. Within the above range, the strength of the organic acid is appropriately maintained so that the adsorption rate for basic harmful gases can be improved. Accordingly, the adsorption rate of a gas removal adsorbent containing the organic acid for harmful gases can be improved.

[0049] In some embodiments, the acid-ionization constant (pKa) of the organic acid may be 2.7 to 3.4, 2.85 to 3.4, or 3 to 3.4. Within the above range, the solubility described above can be achieved, and the acid strength can be appropriately maintained. Accordingly, the adsorption rate of the gas removal adsorbent containing the organic acid for harmful gases can be improved.

[0050] In some embodiments, the standard enthalpy of formation (Hf°) of the organic acid may be -1,200 kJ / mol to -600 kJ / mol, -1,200 kJ / mol to -900 kJ / mol, or -1,200 kJ / mol to -800 kJ / mol. Within this range, a stable state can be maintained even when the organic acid is bound to a carrier. Accordingly, the lifespan of the gas removal adsorbent can be improved.

[0051] In some embodiments, the standard Gibbs free energy of formation (Gf°) of the organic acid may be -1,000 kJ / mol to -500 kJ / mol, -1,000 kJ / mol to -600 kJ / mol, or -1,000 kJ / mol to -700 kJ / mol. Within this range, the stability of the organic acid may be further improved. For example, the stability of the organic acid may be further improved by satisfying the standard Gibbs free energy of formation within the range along with the standard enthalpy of formation within the range. Accordingly, the lifespan of the adsorbent for gas removal may be further improved.

[0052] In some embodiments, the organic acid may include at least one selected from the group consisting of citric acid, malic acid, tartaric acid, malonic acid, aconitic acid, fumaric acid, and oxalic acid. . Accordingly, the adsorption rate of harmful gases of the gas removal adsorbent containing the above organic acid can be improved.

[0053] In one embodiment, the organic acid may include at least one selected from the group consisting of citric acid, malic acid, tartaric acid, and malonic acid. Accordingly, the adsorption rate of harmful gases of the gas removal adsorbent containing the organic acid may be further improved, while the adsorption rate of gases other than the target harmful gases may be reduced.

[0054] In some embodiments, the adsorption carrier may be an adsorption carrier comprising a porous material. For example, the adsorption carrier may include silica, zeolite, cordierite, alumina, activated carbon, titania, magnesia, etc. The above materials may be used alone or in combination of two or more. Accordingly, the specific surface area of ​​the gas removal adsorbent comprising the adsorption carrier may be increased.

[0055] In one embodiment, the adsorption carrier may include at least one of silica, zeolite, cordierite, and alumina. Accordingly, the specific surface area of ​​the gas removal adsorbent comprising the adsorption carrier may be further increased.

[0056] In some embodiments, the particle size of the adsorption carrier may be 40 mesh to 60 mesh, 45 mesh to 60 mesh, or 45 mesh to 55 mesh. For example, if the particle size of the adsorption carrier is excessively small, the pressure required for harmful gas to pass through the gas removal adsorbent may be high. Consequently, the flow rate of the gas may be slowed down. For example, if the particle size of the adsorption carrier is excessively large, the surface area of ​​the gas removal adsorbent may be reduced. Consequently, the efficiency of removing harmful gas may be reduced. Within the above particle size range, it is possible to suppress the reduction in the flow rate of harmful gas passing through the gas removal adsorbent while improving the harmful gas removal performance of the gas removal adsorbent containing the adsorption carrier.

[0057] In some embodiments, the organic acid may be adhered to the surface of the adsorption carrier. For example, the organic acid may be bound to and positioned on the surface of the adsorption carrier. Accordingly, the organic acid can be stably incorporated into the adsorbent for ammonia removal. Additionally, the organic acid can come into contact with the harmful gas, allowing the adsorption reaction of the weakly basic harmful gas through the organic acid to be stably performed.

[0058] In some embodiments, the specific surface area of ​​the ammonia removal adsorbent is 650 m² 2 / g to 800 m 2 / g, 650 m 2 / g to 750 m 2 / g, or 650 m 2 / g to 700 m 2 It can be / g.

[0059] As used herein, the term "specific surface area" refers to the BET specific surface area measured by the BET (Brunaucr-Emmett-Teller) method.

[0060] Within the above specific surface area range, the specific surface area of ​​the ammonia removal adsorbent can be maintained at a sufficiently high level. In addition, when harmful gases pass through the ammonia removal adsorbent, the reduction in flow rate caused by an excessively high pressure drop can be suppressed. Accordingly, harmful gases can be sufficiently adsorbed and removed by the ammonia removal adsorbent.

[0061] In one embodiment, the specific surface area of ​​an ammonia removal adsorbent containing silica may be within the above range.

[0062] In some embodiments, the silica included in the ammonia removal adsorbent may be Type A silica according to KS T 1084. For example, it may be Type A silica according to KS T 1084 satisfying the specific surface area described above. Accordingly, even when relative humidity is low, the adsorption power and adsorption capacity of the ammonia removal adsorbent can be improved together, and the removal efficiency of harmful gases can be improved.

[0063] In some embodiments, the content of the organic acid in the total weight of the adsorbent for ammonia removal may be 5% to 65% by weight, 5% to 30% by weight, 10% to 30% by weight, 10% to 20% by weight, or 15% to 20% by weight.

[0064] Within the above content range, organic acids can be formed across the entire area of ​​the adsorption carrier. Furthermore, the organic acids may not become excessively abundant to block the pores of the adsorption carrier. Accordingly, the specific surface area of ​​the ammonia removal adsorbent may increase, thereby improving adsorption efficiency.

[0065] In exemplary embodiments, a porous material comprising at least one of silica, zeolite, cordierite, and alumina may be prepared as a carrier for adsorption. A solution in which an organic acid is dispersed and / or dissolved in a solvent may be prepared. By introducing the porous material into the solvent and impregnating the organic acid onto the outer surface of the porous material and the inner surface of the internal pores, a gas removal adsorbent comprising the porous material and the organic acid may be prepared.

[0066] In one embodiment, the solvent may be water or an organic solvent. The organic solvent may include butanol, alcohol, acetone, etc.

[0067] In exemplary embodiments, the ratio of breakthrough times represented by Formula 1 below for the gas removal adsorbent may be less than 1.2.

[0068] [Equation 1]

[0069]

[0070] In Formula 1, BT N This may be the time until the removal rate of the ammonia reaches 70% when 100 ppm of ammonia is flowed through 20 cc of a gas removal adsorbent at a flow rate of 0.3 m / s.

[0071] In Formula 1, BT A.N The time may be until the removal rate of ammonia reaches 70% when 100 ppm of ammonia is flowed at a flow rate of 0.3 m / s after 20 cc of a gas removal adsorbent is exposed for 24 hours to a gas in which the concentration of propylene glycol monomethyl ether acetate (PGMEA) is maintained at 50 ppm to 100 ppm.

[0072] The above PGMEA may correspond to a solvent used in the manufacture of semiconductors, etc. Therefore, the above PGMEA does not correspond to the target hazardous gas of the gas removal adsorbent. However, the above PGMEA corresponds to a basic gas. Therefore, generally, the gas removal adsorbent for removing basic gases adsorbs or decomposes the above PGMEA together with, for example, ammonia gas, thereby removing a high proportion of the PGMEA that does not correspond to the target hazardous gas. Furthermore, when PGMEA is decomposed and removed, acetic acid may be generated. Consequently, foul odors may occur.

[0073] If the ratio of breakthrough time expressed by Equation 1 is 1.2 or higher, the adsorption rate of the gas removal adsorbent for PGMEA or the decomposition rate of PGMEA may be high. Therefore, if the ratio of breakthrough time is 1.2 or higher, PGMEA, which is not the target hazardous gas, may be removed at a high rate.

[0074] Within the above-mentioned breakdown time range, the decomposition rate of PGMEA decreases, and the removal rate of harmful gases, such as ammonia, can be improved. Accordingly, the selective removal efficiency of the gas removal adsorbent for harmful gases can be improved, and the generation of acetic acid, etc., due to the decomposition of PGMEA is suppressed, thereby preventing the occurrence of odors.

[0075] In some embodiments, the ratio of breakthrough times represented by Formula 1 may be greater than 0 and less than 1.2, 0.5 to 1.19, 1 to 1.19, or 1.1 to 1.19. Within the above ranges, the selective removal efficiency for harmful gases may be further improved, and the amount of unnecessary gas (e.g., acetic acid) generated by side reactions may be reduced.

[0076] In one embodiment, when 100 ppm of ammonia is flowed through 20 cc of a gas removal adsorbent at a flow rate of 0.3 m / s, the time until the removal rate of the ammonia reaches 70% may be 700 minutes or more, 700 minutes to 1,500 minutes, or 730 minutes to 1,500 minutes. Within the above range, the gas removal adsorbent can sufficiently remove harmful gases (e.g., ammonia).

[0077] In one embodiment, when 20 cc of a gas removal adsorbent is exposed for 24 hours to a gas in which the concentration of propylene glycol monomethyl ether acetate (PGMEA) is maintained at 50 ppm to 100 ppm, and then 100 ppm of ammonia is flowed at a flow rate of 0.3 m / s, the time until the removal rate of the ammonia reaches 70% may be 600 minutes or more, 600 minutes to 1,400 minutes, or 630 minutes to 1,400 minutes. Within the above range, harmful gases (e.g., ammonia) can be sufficiently removed while reducing the removal selectivity for gases other than the target gas (e.g., PGMEA).

[0078] FIG. 1 is a schematic cross-sectional view showing a gas removal filter according to exemplary embodiments.

[0079] Referring to FIG. 1, the gas removal filter (100) may include a gas inlet (120), a gas removal filter body (110), and a gas outlet (130).

[0080] A gas removal filter (100) according to exemplary embodiments may include a gas inlet (120) into which gas is introduced, a gas removal filter body (110) capable of adsorbing specific harmful gases among the gas, and a gas discharge part (130) into which residual gas from which the specific harmful gases have been removed is discharged. For example, the gas removal filter body (110) may include the gas removal adsorbent (150) described above, so that the specific harmful gas can be removed by being adsorbed onto the gas removal adsorbent (150). For example, the gas inlet (120) may be positioned at one end of the gas removal filter body (110). For example, the gas discharge part (130) may be positioned at the other end of the gas removal filter body (110), which is opposite to the one end.

[0081] In some embodiments, the gas removal filter (100) can remove basic harmful gases among the harmful gases contained in the gas by adsorbing them. For example, the gas removal adsorbent (150) contained in the gas removal filter body (110) can remove ammonia gas by adsorbing it.

[0082] For example, gas may be introduced into one end of the gas removal filter (100) (e.g., gas inlet (120)) and harmful gases among the gas may be removed in the gas removal filter body (110). The residual gas from which harmful gases have been removed may be discharged through the other end (e.g., gas outlet (130)).

[0084] Hereinafter, preferred embodiments are presented to aid in understanding the present invention; however, these embodiments are merely illustrative of the invention and are not intended to limit the appended claims. It is obvious to those skilled in the art that various changes and modifications to the embodiments are possible within the scope and spirit of the invention, and that such variations and modifications fall within the scope of the appended claims.

[0086] Examples and Comparative Examples

[0087] (1) Example 1

[0088] Silica with an average particle size of about 50 mesh (actually 20–40 mesh) was prepared as an adsorption carrier. An organic acid was dispersed in alcohol to prepare a support solution.

[0089] The above-mentioned adsorption carrier was introduced into a support solution in which an organic acid was dispersed, and the organic acid was supported on the adsorption carrier.

[0090] Subsequently, an adsorption carrier loaded with organic acid was dried to prepare an adsorbent for gas removal.

[0091] The specific surface area of ​​the above-mentioned adsorption carrier is 650 m² 2 / g to 800 m 2 / g was.

[0092] The organic acid supported on the adsorption carrier was citric acid, and the organic acid was included in 15% by weight of the total weight of the gas removal adsorbent.

[0093] 20 cc of the manufactured gas removal adsorbent was filled into a cylindrical gas removal filter body. A gas removal filter was manufactured by attaching a gas inlet and a gas outlet to each end of the filled gas removal filter body.

[0094] (2) Examples 2 to 4

[0095] A gas removal adsorbent and a gas removal filter were prepared in the same manner as in Example 1, except that the specific surface area of ​​the adsorption carrier, the type of organic acid supported on the adsorption carrier, and the content of the organic acid in the total weight of the gas removal adsorbent were changed as shown in Table 1 below.

[0096] (3) Comparative Examples 1 to 3

[0097] A gas removal adsorbent and a gas removal filter were prepared in the same manner as in Example 1, except that the type of organic acid supported on the adsorption carrier was changed as shown in Table 1 below.

[0099] division Types of loaded organic acids Content of organic acid (weight%) of total weight of gas removal adsorbent Example 1 A1 15 Example 2 A2 15 Example 3 A3 15 Example 4 A4 15 Comparative Example 1 A5 15 Comparative Example 2 A6 15 Comparative Example 3 A7 15

[0100] The specific components listed in Table 1 are as follows.

[0101] A1: Citric acid

[0102] A2: Malic acid

[0103] A3: Tartaric acid

[0104] A4: Malonic acid

[0105] A5: Formic acid

[0106] A6: Glycylic acid (glycine acid)

[0107] A7: Acetic acid (C4H6O5)

[0109] Evaluation Example 1

[0110] (1) Measurement of organic acid solubility

[0111] The solubility of the organic acids used in the examples and comparative examples at 20°C was measured by referring to the Ceondo GmbH (Germany) website.

[0112] If the solubility at 20 ℃ is 500 g / L or higher, it was indicated as "miscible".

[0113] (2) Measurement of the acid-ionization constant (pKa) of organic acids

[0114] The pKa of the organic acids used in the examples and comparative examples was measured by referring to the Ceondo GmbH (Germany) website.

[0115] (3) Standard enthalpy of formation of organic acids (H f °) and standard Gibbs free energy of formation (G f °) Calculate

[0116] Standard enthalpy of formation (H) of the organic acid used in the examples and comparative examples f °) and standard Gibbs free energy of formation (G f °) was calculated by referring to the Ceondo GmbH (Germany) website.

[0117] Measured or calculated solubility of organic acids, acid-ionization constant (pKa), standard enthalpy of formation (H f °) and standard Gibbs free energy of formation (G f °) is indicated in Table 2 below.

[0119] division Number of carboxyl groups Solubility (g / L) pKa H f °(kJ / mol) G f °(kJ / mol) Example 1 3 Miscibility 3.13 -1,122.6 -931.6 Example 2 2 Miscibility 3.40 -813.0 -687.9 Example 3 2 Miscibility 2.89 -970.5 -827.2 Example 4 2 Miscibility 2.83 -634.9 -557.1 Comparative Example 1 1 Miscibility 3.75 -379.2 -351.2 Comparative Example 2 1 249 2.34 -390.5 -233.3 Comparative Example 3 1 Miscibility 4.75 -435.4 -376.9

[0120] Referring to Table 2, the organic acids used in the examples had two or more carboxyl groups, a solubility of 500 g / L or more, a pKa of 2 to 3.7, and standard enthalpy of formation and standard Gibbs free energy of formation were -1,500 kJ / mol to -600 kJ / mol and -1,400 kJ / mol to -500 kJ / mol, respectively.

[0121] The number of carboxyl groups of the organic acids used in the comparative examples was 1.

[0123] Experimental Example 1

[0124] (1) Breakthrough time for ammonia (BT N )

[0125] The time from when ammonia gas begins to pass through the gas removal filter according to the above-described embodiments and comparative examples until breakthrough occurs and the removal efficiency reaches 70% (breakthrough time, BT N , min) was measured.

[0126] Specifically, while introducing a gas containing ammonia gas at a concentration of 100 ppm into a gas removal filter at a flow rate of 0.3 m / s under conditions of 23±2℃ and 45±5% relative humidity, the breakthrough time (BT N ) was measured.

[0127] (2) Breakthrough time to ammonia after PGMEA exposure (BT A.N )

[0128] The gas removal adsorbent of the gas removal filter according to the above-described examples and comparative examples was exposed for 24 hours to a gas in which the concentration of propylene glycol monomethyl ether acetate (PGMEA) was maintained at 50 ppm to 100 ppm.

[0129] Afterwards, the exposed gas removal adsorbent was filled into the gas removal filter, and ammonia gas was passed through.

[0130] The time from when ammonia gas begins to pass through until breakthrough occurs and the removal efficiency reaches 70% (breakthrough time, BT A.N , min) was measured.

[0131] Specifically, while introducing a gas containing ammonia gas at a concentration of 100 ppm into a gas removal filter at a flow rate of 0.3 m / s under conditions of 23±2℃ and 45±5% relative humidity, the breakthrough time (BT N ) was measured.

[0132] (3) Calculation of breakthrough time ratio

[0133] BT measured in (1) and (2) above N and BT A.N Using [this], the breakthrough time ratio was calculated through Equation 1 below.

[0134] [Equation 1]

[0135]

[0136] (4) Amount of acetic acid produced

[0137] After ammonia gas passed through the gas removal filter according to the above-described embodiments and comparative examples, the gas discharged from the gas discharge section of the gas removal filter was collected, and the acetic acid content was measured.

[0138] The evaluation results are shown in Table 3 below.

[0140] BT N (minute) BT A.N (minute) Breakthrough time ratio Acetic acid production (ppb) Example 1 750 646 1.160 3.8 to 4.0 Example 2 880 765 1.115 2.5 to 3.0 Example 3 837 795 1.053 4.0 to 5.8 Example 4 715 666 1.074 14.5 to 16.0 Comparative Example 1 427 355 1.203 800 or more Comparative Example 2 151 63 2.397 0.4 to 0.6 Comparative Example 3 443 330 1.342 1,000 or more

[0141] In the examples where the breakthrough time ratio was less than 1.2, the breakthrough time for ammonia was long, and even when exposed to PGMEA, the rate of reduction in breakthrough time was low. In addition, the amount of acetic acid produced was 16 or less.

[0142] In Examples 1 and 2, where the carboxyl group content was 70% to 80% by weight of the total weight of the organic acid, the amount of acetic acid produced was reduced.

[0143] In comparative examples where the ratio of breakthrough time was greater than 1.2, the breakthrough time for ammonia was reduced compared to the examples, and the rate of reduction in breakthrough time after exposure to PGMEA was increased compared to the examples. Explanation of the symbols

[0145] 100: Gas removal filter 110: Gas removal filter body 120: Gas inlet 130: Gas outlet 150: Adsorbent for gas removal

Claims

Claim 1 An adsorbent for gas removal comprising: a carrier for adsorption; and an organic acid attached to the surface of the carrier for adsorption, wherein the organic acid comprises a carboxyl group and the number of carboxyl groups included in the organic acid is at least two or more, wherein the content of the organic acid in the total weight of the adsorbent is 10% to 30% by weight, and the breakthrough time ratio represented by Formula 1 below is less than 1.2: [Formula 1] (In Equation 1, BT N ⅓ is the time until the removal rate of the ammonia reaches 70% when 100 ppm of ammonia is flowed through 20 cc of gas removal adsorbent at a flow rate of 0.3 m / s, and BT A.N (This is the time until the removal rate of ammonia reaches 70% when 100 ppm of ammonia is flowed at a flow rate of 0.3 m / s after 20 cc of gas removal adsorbent is exposed for 24 hours to a gas in which the concentration of propylene glycol monomethyl ether acetate (PGMEA) is maintained at 50 ppm to 100 ppm) Claim 2 A gas removal adsorbent according to claim 1, wherein when 100 ppm of ammonia is flowed through 20 cc of the gas removal adsorbent at a flow rate of 0.3 m / s, the time until the removal rate of the ammonia reaches 70% is 700 minutes to 1,500 minutes. Claim 3 A gas removal adsorbent according to claim 1, wherein 20 cc of the gas removal adsorbent is exposed for 24 hours to a gas in which the concentration of PGMEA is maintained at 50 ppm to 100 ppm, and then 100 ppm of ammonia is flowed at a flow rate of 0.3 m / s, the time until the removal rate of the ammonia reaches 70% is 600 minutes to 1,400 minutes. Claim 4 A gas removal adsorbent according to claim 1, wherein 20 cc of the gas removal adsorbent is exposed for 24 hours to a gas in which the concentration of propylene glycol monomethyl ether acetate (PGMEA) is maintained at 50 ppm to 100 ppm, and then 100 ppm of ammonia is flowed at a flow rate of 0.3 m / s, the amount of acetic acid produced is 16 ppm or less. Claim 5 A gas removal adsorbent according to claim 1, wherein the content of the carboxyl group in the total weight of the organic acid is 50% to 80% by weight. Claim 6 A gas removal adsorbent according to claim 1, wherein the solubility of the organic acid in water is 500 g / L to 1,400 g / L under temperature conditions of 20 ℃. Claim 7 A gas removal adsorbent according to claim 1, wherein the acid-ionization constant (pKa) of the organic acid is 2.7 to 3.

4. Claim 8 In claim 1, the standard enthalpy of formation (H) of the organic acid f A gas removal adsorbent having a gamma of -1,200 kJ / mol to -600 kJ / mol. Claim 9 In claim 1, the standard Gibbs free energy of formation (G) of the organic acid f A gas removal adsorbent having a gamma of -1,000 kJ / mol to -500 kJ / mol. Claim 10 A gas removal adsorbent according to claim 1, wherein the adsorption carrier comprises at least one of silica, zeolite, cordierite, and alumina. Claim 11 A gas removal adsorbent according to claim 1, wherein the particle size of the adsorption carrier is 40 mesh to 60 mesh. Claim 12 The gas removal adsorbent of claim 1, wherein the organic acid is adhered to the surface of the adsorption carrier. Claim 13 In claim 1, the specific surface area of ​​the gas removal adsorbent is 650 m² 2 / g to 800 m 2 Adsorbent for gas removal, with a phosphorus content of 1g. Claim 14 delete Claim 15 A gas removal filter comprising: a gas removal filter body; a gas inlet portion disposed at one end of the gas removal filter body; a gas outlet portion disposed at the other end of the gas removal filter body; and a gas removal adsorbent according to claim 1 filled in the gas removal filter body.

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