Selective adsorption of halocarbon impurities containing Cl, Br, and I in fluorocarbons or hydrofluorocarbons using adsorbents loaded with metal oxides

Abstract

A process for purifying a fluorocarbon or hydrofluorocarbon containing at least one undesirable halocarbon impurity includes flowing the fluorocarbon or hydrofluorocarbon through at least one adsorbent bed to selectively adsorb the at least one undesirable halocarbon impurity by physisorption and / or chemisorption, wherein the at least one adsorbent bed contains a metal oxide supported on an adsorbent in an inert atmosphere.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Application No. 17 / 192,421, filed March 4, 2021, which is incorporated herein by reference in its entirety for all purposes. Technical Field

[0003] This invention relates to a method for selectively adsorbing halogenated hydrocarbon impurities containing Cl, Br, and I from fluorocarbons (FC) or hydrofluorocarbons (HFC) using an adsorbent loaded with metal oxides, and particularly to a method for purifying fluorocarbons or hydrofluorocarbons and removing undesirable impurities.

[0004] background

[0005] In the chemical industry, standard fluorocarbons (FCs) or hydrofluorocarbons (HFCs), commonly used as refrigerants, are produced by fluorinating halogenated hydrocarbons or hydrocarbons containing Cl, Br, and I at elevated temperatures in the presence of a metal or metal oxide supported by a porous material such as silica (SiO2) or alumina (Al2O3) as a catalyst. This reaction process can result in numerous undesirable impurities (e.g., halogenated hydrocarbons containing Br or I) in the product as unreacted feedstocks or byproducts. While some of these compounds (primarily chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs)) are known to contribute to ozone depletion, they can also be toxic and harmful to processes when these ultrapure FC or HFC gases are used in the semiconductor industry. The reaction is as follows: Halogenated hydrocarbon (containing Cl, Br, or I) + F2 / HF → HFC + Byproducts.

[0006] For example, US 5545774, granted to V. Rao, discloses the production of 1,1,1,3,3,3-hexachloropropane (trade names 236fa or FE-36) by reacting 1,1,1,3,3,3,3-hexachloropropane with HF in the presence of a trivalent chromium compound supported on carbon at a temperature of about 250°C to 400°C. US 5574192, granted to VanDerPuy et al., discloses the production of 1,1,1,3,3-pentafluoropropane (245fa or HFC-245fa, also trade names Enovate and Genetron) by reacting HCFC compounds such as CCl3CH2CHCl2, CF3CH2CHCl2, and CFCl2CH2CHCl2 with HF in the presence of a fluorination catalyst such as a metal halide.

[0007] The use or presence of these impurities needs to be limited to various concentration levels ranging from percentages to ppm, depending on the severity of the damage caused by the aforementioned reasons. However, some of these contaminants may be difficult to separate using more widely used methods such as distillation due to their azeotropic interactions with the main product. Although different methods have been disclosed for separating key haloalkanes containing Cl, Br, and I from some HFC molecules (including those covered by this invention), a universal method has not yet been developed that can be applied to different molecules for all of the aforementioned impurities.

[0008] For example, J. Knapp's US 2012 / 0323054 discloses the separation of cis-1,1,1,4,4,4-hexafluoro-2-butene from a mixture containing one or more chlorofluoroolefins by adding an extractant. This solvent alters the relative volatility of the cis compound relative to the chloroolefin, making it relatively easier to purify using distillation.

[0009] P. Clayton's EP 0508631 A1 discloses a method for producing and purifying hydrofluoroalkanes from chlorinated compounds and halohydrofluoroalkanes by passing the vaporized compound through a solution of a complex metal hydride combined with an alkali metal hydride.

[0010] Wilmet et al.’s US 2004 / 0030204 discloses more general methods for purifying hydrofluoroalkanes, including different methods for removing olefinic impurities, including reaction with HF, treatment with Cl2 in the presence of an initiator, adsorption onto solid adsorbents (alumina and silica), distillation, and reactive distillation.

[0011] US 6815568 by Horiba et al. discloses a method for purifying octafluorocyclobutane by reacting a crude product containing chlorine impurities with a decomposing agent (iron oxide and alkaline earth metal compounds) at elevated temperatures, followed by adsorption with coal tar, molecular sieves, or activated carbon to obtain the product.

[0012] US 5852223 by Kohno et al. discloses a method for reducing CFCs in hydrofluoroalkanes by reacting the compound with H2 gas and using distillation to separate the mixture.

[0013] Many other patents claim protection for similar purification methods used for different fluorocarbons or hydrofluorocarbons.

[0014] A. Gabelman describes the basic operation, design, and mechanism of adsorption methods, including the regeneration of adsorbent beds, in Adsorption Basics, Parts 1 and 2 (2017 CEP, American Institute of Chemical Engineers). Adsorbent bed regeneration can be achieved by contacting the adsorbent with a gas or liquid containing little or no adsorbate (impurities), contacting the bed with a solvent having a higher affinity for the adsorbate, increasing the temperature of the adsorbent, or decreasing the pressure. Silica gel and activated alumina (Al₂O₃) can be used to dry gases or liquids. Silica gel can be regenerated at 120°C. Zeolite molecular sieves 3A, 4A, 5A, and 13X can be used to remove various impurities (including water) and can be regenerated at 200°C–300°C.

[0015] The use of adsorbents, including alumina and silica, to adsorb moisture, acid (HF and HCl) solvent vapors, and some other organic pollutants from HFCs is standard practice in the chemical industry. Other important applications involve metal oxides / metals on alumina or adsorbents for catalytic dehydrohalogenation to produce olefins or for the environmentally friendly decomposition of waste gases, similar to those mentioned in Sharratt et al.'s US 2015 / 126786A and Liu's CN 101293212A, respectively.

[0016] US 2879228 by Holeton et al. discloses the use of silica gel and alumina to remove partially fluorinated compounds from liquid-phase perfluorinated lubricants. KR 100317113 discloses the continuous removal of HF and halogenated hydrocarbon contaminants from HCl streams using tandem alumina and activated carbon columns. GB 2295101 by Leppard et al. discloses the removal of halogenated hydrocarbon contaminants from air streams using a χ(chi) alumina bed. Other common applications involve the use of adsorbents to remove oil or hydrocarbon contaminants from refrigerants.

[0017] Using ultra-high purity gases free of impurities is essential for any method requiring good quality control. Maintaining the purity of the feed gas is particularly critical for delicate processes involving the manufacture of semiconductor devices with extremely narrow tolerances, ensuring high production volumes. Distillation is a more conventional separation technique for achieving this, but it becomes extremely difficult when the volatility of the impurities is close to that of the matrix compound, or if the impurities form azeotropes / near-azeotropes with the desired product.

[0018] Therefore, methods for producing ultra-high purity FC or HFC gases free of impurities are still needed. Summary of the Invention

[0019] A method for purifying fluorocarbons or hydrofluorocarbons containing at least one undesirable halogenated hydrocarbon impurity is disclosed. The method includes the steps of: passing the fluorocarbon or hydrofluorocarbon through at least one adsorbent bed to selectively adsorb the at least one undesirable halogenated hydrocarbon impurity by physical adsorption and / or chemical adsorption, wherein the at least one adsorbent bed is in an inert atmosphere and contains a metal oxide supported on the adsorbent.

[0020] A method for purifying fluorocarbons or hydrofluorocarbons containing at least one undesirable halogenated hydrocarbon impurity is disclosed. The method includes the steps of: passing the fluorocarbon or hydrofluorocarbon through at least one adsorbent bed to selectively adsorb the at least one undesirable halogenated hydrocarbon impurity by physical adsorption and / or chemical adsorption, wherein the at least one adsorbent bed is in an inert atmosphere and contains a metal oxide supported on an adsorbent; and distilling the effluent stream of the at least one adsorbent bed to obtain purified fluorocarbons or hydrofluorocarbons.

[0021] Any of the disclosed methods may include one or more of the following aspects: The method further includes the step of distilling the effluent stream of the at least one adsorbent bed to obtain purified fluorocarbons or hydrofluorocarbons; The at least one undesirable halogenated hydrocarbon impurity includes chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and Cl-containing halides, Br-containing halides, I-containing halides, or combinations thereof; The at least one undesirable halohydrocarbon impurity includes halohydrocarbons containing carbon-bonded halogens with lower electronegativity than fluorine. The at least one undesirable halohydrocarbon impurity includes halohydrocarbons containing carbon-bonded halogens that have undergone adsorption and have a lower electronegativity than fluorine. The at least one undesirable halohydrocarbon impurity is a halohydrocarbon containing a carbon-bonded halogen with a lower electronegativity than fluorine. The at least one undesirable halohydrocarbon impurity is a halohydrocarbon containing a carbon-bonded halogen that has undergone adsorption and has a lower electronegativity than fluorine. Halogens with lower electronegativity than fluorine are Cl, Br and / or I; The at least one undesirable halocarbon impurity includes halocarbons containing Cl, Br and / or I bonded to carbon; The at least one undesirable halocarbon impurity includes halocarbons containing Cl, Br and / or I bonded to carbon that have undergone adsorption. The at least one undesirable halohydrocarbon impurity is a halohydrocarbon containing Cl, Br and / or I bonded to carbon; The at least one undesirable halohydrocarbon impurity is a halohydrocarbon containing Cl, Br and / or I bonded to carbon that has undergone adsorption. The at least one undesirable halogenated hydrocarbon impurity is a Cl-containing halide, a Br-containing halide, an I-containing halide, or a combination thereof; The at least one undesirable halocarbon impurity is a Cl-containing halocarbon, a Br-containing halocarbon, an I-containing halocarbon, or a combination thereof; The at least one undesirable halogenated hydrocarbon impurity is a chlorofluorocarbon (CFC) or a hydrochlorofluorocarbon (HCFC). The at least one undesirable halogenated hydrocarbon impurity is chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC). The at least one undesirable halogenated hydrocarbon impurity is a chlorofluorocarbon (CFC). The at least one undesirable halogenated hydrocarbon impurity is a chlorofluorocarbon (CFC). The least one undesirable halogenated hydrocarbon impurity is 2-chloro-1,1,1-trifluoroethane (C2H2F3Cl). The least one undesirable halogenated hydrocarbon impurity is 2-chloro-1,1,3-trifluoropropene (C3H2F3Cl). The least one undesirable halogenated hydrocarbon impurity is 2-chloro-1,1,1,2-tetrafluoropropane (C2HF4Cl). The least one undesirable halogenated hydrocarbon impurity is 2-chloro-1,1,1,3,3-pentafluoro-1-propene (C3F5Cl). The least one undesirable halogenated hydrocarbon impurity is 1,1,2-trichlorotrifluoroethane (C2F3Cl3). The least one undesirable halogenated hydrocarbon impurity is trichlorofluoromethane (CFCl3). The least one undesirable halogenated hydrocarbon impurity is 2,2-dichloro-1,1,1,-trifluoroethane (C2HF3Cl2). The at least one undesirable halogenated hydrocarbon impurity contains a halogen with a lower electronegativity than fluorine, such as Cl, Br, and I, wherein Cl, Br, and I are in C a Hb F c X d (Where a is 1-7, b is 0-13, c is 0-15, and d is 1-16) and C o F p X q (where o is 1-7, p is 0-15, and q is 1-16) is represented by "X" in the form; The at least one undesirable halogenated hydrocarbon impurity contains a halogen with a lower electronegativity than fluorine, such as Cl, Br, and I, wherein Cl, Br, and I are in C a F c X d (where a is 1-7, c is 0-15, and d is 1-16) and C o H p F q X r (where o is 1-7, p is 0-13, q is 0-15, and r is 1-16) is represented by "X"; Fluorinated hydrocarbons or hydrofluorocarbons are etching gases containing fluorocarbons and hydrofluorocarbons. Etching gases containing fluorocarbons and hydrofluorocarbons include, but are not limited to, CF4, CHF3, CH2F2, CH3F, C2F6, C2HF5, C3HF5, C3H2F4, C3H2F6, C3F8, C3F6, C4F8, C4F6, C4H2F4, C4H2F6, C5F8, C5HF7, and C6F6, including their isomers. Further examples of fluorocarbons and hydrofluorocarbon gases include, but are not limited to, C2H3F3, C2H2F4, C2H4F2, C2H4F2, C2H5F, C3H3F5, and C4F6. 10 C5F 12 C6F 14 and C7F 16 , including their isomers; The etching gases for fluorocarbons and hydrofluorocarbons are C3H2F6, 1,1,1,3,3,3-hexafluoropropane, and 236fa; The etching gases for fluorocarbons and hydrofluorocarbons are C3H3F5, 1,1,1,3,3-pentafluoropropane, and 245fa; Inert atmospheres are N2, H2, He, Ar, Xe, or combinations thereof; The at least one adsorbent bed is an adsorbent bed; The at least one adsorbent bed is two adsorbent beds placed in parallel; Each of the at least one adsorbent bed contains multiple beds connected in series; Each of the at least one adsorbent bed is a long bed with a desired size to purify and control the concentration of impurities in the output product; The adsorbent is silica, alumina, or molecular sieve; The metal oxide is CuO or MgO; The metal oxide is CuO supported on aluminum oxide; The flow rate of fluorocarbon or hydrofluorocarbon gas entering the adsorbent bed in the vapor phase ranges from 0.5 slm to 500 l / min; The flow rate of fluorocarbon or hydrofluorocarbon gas entering the adsorbent bed in the vapor phase ranges from 1 slm to 150 l / min; The flow rate of the fluorocarbon or hydrofluorocarbon liquid entering the adsorbent bed in the liquid phase ranges from 0.1 kg / h to 100 kg / h; The flow rate of fluorocarbon or hydrofluorocarbon liquids varies between 0.1 kg / h and 20 kg / h; The temperature range of the adsorbent bed is from -50°C to 150°C; The temperature range of the adsorbent bed is from 0°C to 50°C; pressure The purity of the purified fluorocarbons or hydrofluorocarbons is > 99.9%; The purity of the purified fluorocarbons or hydrofluorocarbons is > 99.99%; The concentration of halogenated hydrocarbon impurities in the feed of the hydrofluorocarbon or fluorocarbon to be purified is less than 5%; The concentration of halogenated hydrocarbon impurities in the feed of hydrofluorocarbons or fluorocarbons to be purified is less than 1000 ppm. The concentration of halogenated hydrocarbon impurities in the feed of hydrofluorocarbons or fluorocarbons to be purified is less than 500 ppm. The concentration of halogenated hydrocarbon impurities in the feed of hydrofluorocarbons or fluorocarbons to be purified is less than 200 ppm; The concentration of impurities in purified fluorocarbons or hydrofluorocarbons is < 1000 ppm; The concentration of impurities in purified fluorocarbons or hydrofluorocarbons is < 100 ppm; The concentration of impurities in purified fluorocarbons or hydrofluorocarbons is < 10 ppm; The concentration of impurities in purified fluorocarbons or hydrofluorocarbons is < 5 ppm; The concentration of impurities in purified fluorocarbons or hydrofluorocarbons is < 1 ppm; The concentration of impurities in the purified fluorocarbons or hydrofluorocarbons is < 0.1 ppm; The method further includes the step of regenerating the adsorbent bed by continuously passing purge gas through it at a temperature ranging from 25°C to 1000°C. The method further includes the step of regenerating the adsorbent bed by continuously passing purge gas through it at a temperature ranging from 200°C to 400°C. The pressure of the regeneration process ranges from 1 Torr to 100,000 Torr; The purging gas is selected from N2, H2, He, Ar, Xe, Kr or a combination of N2, H2, He, Ar, Xe and Kr; The purging gas is N2; The purging gas is H2; The purging gas is Ar; The purging gas is Xe; The purging gas is Kr; The purging gas is He; The purging gases are H2 and N2; The purging gases are H2 and N2, with H2 comprising a percentage of N2 between 0 and 100%. The purging gases are H2 and N2, with H2 comprising more than 3% of the N2; and The purging gas is a combination of N2, H2, He, Ar, Xe, and Kr.

[0022] A system for purifying fluorocarbons or hydrofluorocarbons containing at least one undesirable halogenated hydrocarbon impurity is disclosed. The system includes at least one adsorbent bed containing a metal oxide supported on an adsorbent in an inert atmosphere. The at least one adsorbent bed is adapted and configured to adsorb the at least one undesirable halogenated hydrocarbon impurity by physical adsorption and / or chemisorption. The disclosed system may include one or more of the following aspects: It further includes at least one distillation column adapted and configured to distill the effluent stream of the at least one adsorbent bed to obtain purified fluorocarbons or hydrofluorocarbons; The metal oxide is CuO or MgO; The loading percentage of metal oxides ranges from 0.1% to 99%; The loading percentage of metal oxides ranges from 5% to 50%; The adsorbents are silica, alumina, and molecular sieves; The operating temperature of at least one distillation column varies from -50°C to 150°C; The operating temperature of at least one distillation column varies from -20°C to 100°C; The at least one undesirable halogenated hydrocarbon impurity includes chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and Cl-containing halides, Br-containing halides, I-containing halides, or combinations thereof; The at least one undesirable halohydrocarbon impurity includes halohydrocarbons containing carbon-bonded halogens with lower electronegativity than fluorine. The at least one undesirable halohydrocarbon impurity includes halohydrocarbons containing carbon-bonded halogens that have undergone adsorption and have a lower electronegativity than fluorine. Halogens with lower electronegativity than fluorine are Cl, Br and / or I; The at least one undesirable halocarbon impurity includes halocarbons containing Cl, Br and / or I bonded to carbon; The at least one undesirable halocarbon impurity includes halocarbons containing Cl, Br and / or I bonded to carbon that have undergone adsorption. The at least one undesirable halogenated hydrocarbon impurity is a Cl-containing halide, a Br-containing halide, an I-containing halide, or a combination thereof; The at least one undesirable halocarbon impurity is a Cl-containing halocarbon, a Br-containing halocarbon, an I-containing halocarbon, or a combination thereof; The at least one undesirable halogenated hydrocarbon impurity includes chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). The at least one undesirable halogenated hydrocarbon impurity contains a halogen with a lower electronegativity than fluorine, such as Cl, Br, and I, wherein Cl, Br, and I are in C a H b F c X d (Where a is 1-7, b is 0-13, c is 0-15, and d is 1-16) and C o F p X q (where o is 1-7, p is 0-15, and q is 1-16) is represented by "X" in the form; The at least one undesirable halogenated hydrocarbon impurity contains a halogen with a lower electronegativity than fluorine, such as Cl, Br, and I, wherein Cl, Br, and I are in C a F c X d (where a is 1-7, c is 0-15, and d is 1-16) and C o H p F q X r (where o is 1-7, p is 0-13, q is 0-15, and r is 1-16) is represented by "X"; Fluorinated hydrocarbons or hydrofluorocarbons are etching gases containing fluorocarbons and hydrofluorocarbons. Etching gases containing fluorocarbons and hydrofluorocarbons include, but are not limited to, CF4, CHF3, CH2F2, CH3F, C2F6, C2HF5, C3HF5, C3H2F4, C3H2F6, C3F8, C3F6, C4F8, C4F6, C4H2F4, C4H2F6, C5F8, C5HF7, and C6F6, including their isomers. Further examples of fluorocarbons and hydrofluorocarbon gases include, but are not limited to, C2H3F3, C2H2F4, C2H4F2, C2H4F2, C2H5F, C3H3F5, and C4F6. 10 C5F 12 C6F 14 and C7F 16 , including their isomers; The etching gases for fluorocarbons and hydrofluorocarbons are C3H2F6, 1,1,1,3,3,3-hexafluoropropane, and 236fa; The etching gases for fluorocarbons and hydrofluorocarbons are C3H3F5, 1,1,1,3,3-pentafluoropropane, and 245fa; The at least one adsorbent bed is an adsorbent bed; The at least one adsorbent bed is two adsorbent beds placed in parallel; Each of the at least one adsorbent bed contains multiple beds connected in series; Each of the at least one adsorbent bed is a long bed of a desired size for purifying and controlling the concentration of impurities in the output product; and The adsorbent is silica, alumina, or molecular sieve. Attached Figure Description

[0023] To further understand the nature and purpose of the invention, reference should be made to the following detailed description in conjunction with the accompanying drawings, in which similar elements are given the same or similar reference numerals, and in the drawings: Figure 1 A block diagram illustrating an exemplary embodiment of the disclosed purification system is shown; and Figure 2 A block diagram of another exemplary embodiment of the disclosed purification system is shown.

[0024] Element number

[0025] Symbol Explanation

[0026] 102 Source Tube

[0027] 104 Adsorption Bed

[0028] 106 distillation column

[0029] 108 tubes

[0030] 110 pump

[0031] 112 Distillation Column

[0032] 114 tubes

[0033] 116 tubes

[0034] 120 Adsorption Bed

[0035] Abstract Symbol Explanation

[0036] 102 Source Tube

[0037] 104 Adsorption Bed

[0038] 106 distillation column

[0039] 108 tubes

[0040] 110 pump

[0041] 112 Distillation Column

[0042] 114 tubes

[0043] 116 tubes Detailed Implementation

[0044] A method is disclosed for the selective adsorption of halogenated hydrocarbon impurities containing Cl, Br, and I from fluorocarbons (FCs) or hydrofluorocarbons (HFCs) using an adsorbent loaded with metal oxides. More specifically, the disclosed method is a method for purifying fluorocarbons or hydrofluorocarbons and removing undesirable impurities. The disclosed purification method removes halogenated hydrocarbon contaminants or impurities containing Cl, Br, and / or I, which have lower electronegativity than fluorine, from fluorocarbons or hydrofluorocarbons. In one embodiment, the halogenated hydrocarbon contaminants or impurities contained in the fluorocarbons or hydrofluorocarbons may be chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs). These halogenated hydrocarbon contaminants or impurities are harmful to the application of hydrofluorocarbons or fluorocarbon gases and are also harmful to safety and the environment (e.g., ozone depletion and global warming). These halogenated hydrocarbon contaminants are difficult to remove in high yields using distillation in relatively simple unit operations. Some of these impurities may even be difficult to separate from hydrofluorocarbons or fluorocarbons by conventional distillation. Therefore, the disclosed purification method may be a viable and economical alternative by saving capital costs without compromising purification efficiency. Highly purified hydrofluorocarbons or fluorocarbons obtained through the disclosed purification methods can be used in the semiconductor industry, metal cleaning processes, and any related fields.

[0045] The disclosed method involves passing the fluorocarbon or hydrofluorocarbon gas to be purified through an adsorbent bed filled with metal oxide beads at a specific flow rate and temperature to selectively adsorb undesirable impurities by physical and / or chemical adsorption in an inert atmosphere free from any moisture contamination, thereby avoiding undesirable reactions with the product fluorocarbon. The inert atmosphere can be N2, H2, He, Ar, Xe, or combinations thereof. Using hydrogen in its pure form or a mixture with other gases described above to form a purge gas can be very effective in dehydroxylation and preparation of the adsorbent bed. This step can be followed by distillation of the adsorbent bed's effluent stream to obtain purified fluorocarbons or hydrofluorocarbons. The distillation step can remove other impurities unaffected by adsorption. Purified fluorocarbons or hydrofluorocarbons can be obtained solely by the passing step, or by a combination of the passing and distillation steps. The adsorbent bed described herein can include one or more adsorbent beds. For example, the adsorbent bed can be two adsorbent beds placed in parallel. Using the disclosed method, small amounts of the desired product can also be adsorbed, which can subsequently be removed during the regeneration process of the adsorbent bed. Using the disclosed method, key impurities in fluorocarbons or hydrofluorocarbons can be removed in an energy-efficient manner with high yield and recovery.

[0046] In the disclosed method, undesirable impurities containing carbon-bonded halogens Cl, Br, and / or I, which have lower electronegativity than fluorine, undergo adsorption. The remaining impurities should pose relatively less harm to the application and the environment and be easily separated by distillation. Therefore, undesirable impurities containing halides or halogenated hydrocarbons (i.e., containing Cl, Br, and I) in fluorocarbons or hydrofluorocarbons can be readily removed without reacting with the adsorbent and without compromising the yield.

[0047] Purified hydrofluorocarbons have the formula C x H y F z Where x is 1-7, y is 1-13 and z is 1-16, and the undesirable impurities in the feed gas contain halogens with lower electronegativity than fluorine, such as Cl, Br and I, where Cl, Br and I are in C a H b F c X d (Where a is 1-7, b is 0-13, c is 0-15, and d is 1-16) and C o F p X q (where o is 1-7, p is 0-15, and q is 1-16) is represented by “X”.

[0048] Purified fluorocarbons have the formula C x F zWhere x is 1-7 and z is 1-16, and the undesirable impurities in the feed gas contain halogens with lower electronegativity than fluorine, such as Cl, Br, and I, where Cl, Br, and I are in C a F c X d (where a is 1-7, c is 0-15, and d is 1-16) and C o H p F q X r (where o is 1-7, p is 0-13, q is 0-15, and r is 1-16) is represented by “X”.

[0049] Undesirable halogenated hydrocarbon impurities include Cl-containing halogenated hydrocarbons, Br-containing halogenated hydrocarbons, I-containing halogenated hydrocarbons, or combinations thereof, such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). Undesirable halogenated hydrocarbon impurities include halogenated hydrocarbons undergoing adsorption containing carbon-bonded halogens (e.g., Cl, Br, and / or I) with lower electronegativity than fluorine. Undesirable halogenated hydrocarbon impurities are halogenated hydrocarbons undergoing adsorption containing carbon-bonded halogens (e.g., Cl, Br, and / or I) with lower electronegativity than fluorine. Undesirable halogenated hydrocarbon impurities include halogenated hydrocarbons undergoing adsorption containing Cl, Br, and / or I bonded to carbon. Undesirable halogenated hydrocarbon impurities are halogenated hydrocarbons undergoing adsorption containing Cl, Br, and / or I bonded to carbon. Undesirable halogenated hydrocarbon impurities include Cl-containing halides, Br-containing halides, I-containing halides, or combinations thereof. Undesirable halogenated hydrocarbon impurities are Cl-containing halides, Br-containing halides, I-containing halides, or combinations thereof. Undesirable halogenated hydrocarbon impurities include Cl-containing halogenated hydrocarbons, Br-containing halogenated hydrocarbons, I-containing halogenated hydrocarbons, or combinations thereof. Undesirable halogenated hydrocarbon impurities can be chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), such as 2-chloro-1,1,1-trifluoroethane (C2H2F3Cl), 2-chloro-1,1,3-trifluoropropene (C3H2F3Cl), 2-chloro-1,1,1,2-tetrafluoropropane (C2HF4Cl), 2-chloro-1,1,1,3,3-pentafluoro-1-propene (C3F5Cl), 1,1,2-trichlorotrifluoroethane (C2F3Cl3), trichlorofluoromethane (CFCl3), and 2,2-dichloro-1,1,1-trifluoroethane (C2HF3Cl2).

[0050] Fluorinated hydrocarbons (FHH) and hydrofluorocarbons (HFCs) have traditionally been used in a wide variety of applications, including as foaming agents in the preparation of foams and insulation materials, fire extinguishing systems and fire extinguishers, refrigerants, heat transfer media, dielectric gases, chemical industry applications, metal smelting, and as plasma etching gases, primarily for silicon and silicon-containing materials, in the semiconductor industry.

[0051] Exemplary fluorocarbon and hydrofluorocarbon etching gases requiring purification may include, but are not limited to, CF4, CHF3, CH2F2, CH3F, C2F6, C2HF5, C3HF5, C3H2F4, C3H2F6, C3F8, C3F6, C4F8, C4F6, C4H2F4, C4H2F6, C5F8, C5HF7, and C6F6, including their isomers. Further examples of fluorocarbon and hydrofluorocarbon gases include, but are not limited to, C2H3F3, C2H2F4, C2H4F2, C2H4F2, C2H5F, C3H3F5, and C4F6. 10 C5F 12 C6F 14 and C7F 16 , including their isomers.

[0052] In this article, C3H2F6 (chemical name 1,1,1,3,3,3-hexafluoropropane, 236fa) is widely used in a variety of applications, including as a foaming agent and fire extinguishing agent. C3H3F5 (chemical name 1,1,1,3,3-pentafluoropropane, 245fa) is widely used as a foaming agent for producing closed-cell spray foam insulation materials.

[0053] The fluorocarbons or hydrofluorocarbons to be purified are fed in liquid or gaseous form (up to, but not limited to, 100 kg / h). However, it is important to note that residence time can vary significantly between liquid-solid and gas-solid adsorption. Those skilled in the art will understand that the feed rate and phase can be varied based on production rate, adsorbent selectivity, desired yield, bed size, and residence time. A longer residence time in the liquid phase than in the gaseous phase can lead to lower recovery rates due to undesirable side reactions between the desired hydrofluorocarbons or fluorocarbons and the adsorbent or metal oxide. Selectivity can be adjusted by means of the metal oxide, its loading percentage, adsorbent type, and flow rate. A gaseous feed is preferred if the feed is relatively pure and the concentration of impurities in the feed is not high, as it improves the yield and recovery of the main product.

[0054] The instability of fluorocarbons or hydrofluorocarbons when using metals and metal oxides is a well-known topic and common information in the safety data sheets (SDS) of these compounds. Some of the adsorbent materials in the disclosed methods are commonly used as catalysts for the defluorination of these compounds at elevated temperatures used in substitution or elimination reactions. However, when the disclosed adsorption methods are carried out in a controlled manner at room temperature with ideal residence times, selectively removing undesirable impurities without any byproducts can be an effective and useful tool.

[0055] Figure 1A block diagram illustrating an exemplary embodiment of the purification system disclosed according to the present invention is shown. A feed gas containing undesirable impurities from a source cylinder 102 or a storage tank (not shown) is fed into an adsorbent bed 104 at a desired flow rate (see below) and a desired temperature to optimize adsorption capacity and selectivity. The source cylinder 102 or storage tank (not shown) may be heated to the desired temperature to achieve the desired flow rate. The feed gas may be any fluorocarbon or hydrofluorocarbon gas containing halogenated impurities (e.g., Cl, Br, and I) with lower electronegativity than fluorine. The adsorbent bed 104 is filled with an adsorbent containing metal oxide beads in an inert atmosphere. The adsorbent bed 104 may be any adsorbent containing metal oxides (silica, alumina, etc.). Preferably, the adsorbent bed 104 contains metal oxides such as CuO, MgO, etc., supported on an adsorbent such as silica, alumina, or a molecular sieve. In one embodiment, the metal oxide is CuO supported on aluminum. The loading percentage of these metal oxides may vary from 0.1% to 99%. Preferably, the loading percentage of these metal oxides can be from 5% to 50%. The temperature of the adsorbent bed 104 can range from -50°C to 150°C; preferably, the temperature of the adsorbent bed 104 can range from 0°C to 50°C. The flow rate of the fluorocarbon or hydrofluorocarbon gas can vary from 0.5 slm to 500 l / min. For liquid feed, the flow rate of the fluorocarbon or hydrofluorocarbon liquid can vary between 0.1 kg / h and 100 kg / h. Preferably, the flow rate of the fluorocarbon or hydrofluorocarbon gas can vary from 1 slm to 150 slm, and for liquid feed, the flow rate of the fluorocarbon or hydrofluorocarbon liquid can vary between 0.1 kg / h and 20 kg / h. Undesirable halogenated hydrocarbon impurities containing chlorine, bromine, or iodine can be removed from the feed fluorocarbon or hydrofluorocarbon gas through the adsorbent bed 104.

[0056] The output or outlet stream from adsorbent bed 104 contains the purified fluorocarbons or hydrofluorocarbons and light impurities such as non-condensable gases (e.g., N2 and CO2) and volatile impurities (FC or HFC) (having a boiling point lower than the purified fluorocarbons or hydrofluorocarbons) and heavy impurities (having a boiling point higher than the products). A first distillation column 106 separates the light impurities from the products and heavy impurities. The outlet of adsorbent bed 104 may include a particulate filtration system (not shown). The particulate filter may be made of, but is not limited to, stainless steel, nickel, Hastelloy, or PTFE. The particulate filter can remove particles larger than, but not limited to, about 1 nm. Commercial filters include, for example, filters from the Entegris Wafergard or Pall Corporation Gaskleen series. The output from adsorbent bed 104 is fed to an additional purification bed containing molecular sieves or silica to remove moisture, and then to a first distillation column 106 operating under optimized conditions (see below) to separate the light impurities from adsorbent bed 104 from the products and heavy impurities. The light impurities enter cartridge 108. The product and heavy impurities are discharged from distillation column 106 and pumped by pump 110 to distillation column 112. Those skilled in the art will understand that various packing materials are used in the distillation column, including but not limited to Heli-Pak, ceramic saddles, Raschig rings, balls (Teflon or glass), wire mesh, and specialized structured packing materials. Subsequently, since the product's boiling point is lower than that of the heavy impurities, the product exits from the top of distillation column 112 and is collected by a condenser (not shown) in cylinder 114 or storage tank (not shown) and valve bottle (not shown) for analysis and packaging. Heavy impurities are discharged from the bottom of distillation column 112 and are then collected as waste in cylinder 116 or storage tank (not shown). Depending on the impurities contained in the feed fluorocarbons or hydrofluorocarbons, a series of distillation columns may be applied after adsorbent bed 104. It is generally known in the field of distillation that additional equipment, such as additional pumps, flow controllers, valves, pressure sensors, sensors, filters, etc., can be used.

[0057] The operating temperatures of distillation columns 106 and 112 can vary from -50°C to 150°C. Preferably, the operating temperatures of distillation columns 106 and 112 can vary from -20°C to 100°C.

[0058] By using the disclosed purification The adsorption method involves adsorption followed by distillation to reduce or completely remove unwanted impurities, resulting in a purified fluorocarbon or hydrofluorocarbon product with a purity > 99.9%. Preferably, this is achieved by using the disclosed... purificationThe adsorption method reduces or completely removes unwanted impurities through adsorption followed by distillation, and the purity of the purified fluorocarbon or hydrofluorocarbon product is >99.99%.

[0059] The concentration of halogenated hydrocarbon impurities in the feed gas of the hydrofluorocarbon or fluorocarbon to be purified is less than 5. Preferably, the concentration of undesirable impurities in the feed gas can be < 1000 ppm. More preferably, the concentration of undesirable impurities in the feed gas can be < 500 ppm. Even more preferably, the concentration of undesirable impurities in the feed gas can be < 200 ppm.

[0060] The concentration of undesirable impurities in the purified fluorocarbon or hydrofluorocarbon product can be < 1000 ppm. Preferably, the concentration of undesirable impurities in the purified fluorocarbon or hydrofluorocarbon product can be < 100 ppm. Preferably, the concentration of undesirable impurities in the purified fluorocarbon or hydrofluorocarbon product can be < 10 ppm. Preferably, the concentration of undesirable impurities in the purified fluorocarbon or hydrofluorocarbon product can be < 5 ppm. More preferably, the concentration of undesirable impurities in the purified fluorocarbon or hydrofluorocarbon product can be < 1 ppm. Even more preferably, the concentration of undesirable impurities in the purified fluorocarbon or hydrofluorocarbon product can be < 0.1 ppm. The feed gas and product gas and their impurities can be analyzed using a variety of analytical instruments, including gas chromatography with detectors such as thermal conductivity detectors (TCD), photoionization detectors (PID), and pulsed discharge ionization detectors (PDHID), mass spectrometry (MS), etc. Other detectors may include FTIR, humidity analyzers such as Meeco Iceman or other P2O5-based analyzers, and cavity ring-down spectrometers (CRDS). It should be understood that each analyzer can detect different impurities and operates within different detection limits. Analyzers can be used to detect impurities along... Figure 1 The exemplary purification system shown in the figure is analyzed at points including, but not limited to, source cylinder 102, outlet of adsorbent bed 104, different positions on distillation columns 106 and 112, cylinder 114 and collection cylinder 116 or storage tank (not shown), and a second adsorbent bed 120 connected in parallel with 104. Figure 2 (As shown in the diagram). These analyzers can be used to analyze gas or liquid stream samples from a process, either directly or in a separate collection container. These analyses can be used to modify process conditions within a distillation column or to determine the breakthrough point of an adsorbent bed. The breakthrough point is defined as the point at which some of the adsorbate begins to pass through the adsorbent bed without being adsorbed.

[0061] The adsorbent bed 104 is regenerated at high temperature and under a continuous purge gas containing H2 in the remainder of an inert gas such as He, N2, Ar, Xe, Kr, but more preferably N2. An exemplary continuous purge gas may contain both H2 and N2. The term regeneration, as used herein, can refer to the process of first preparing the adsorbent bed, or the process of removing impurities that have been reversibly adsorbed onto the adsorbent bed after it has been used for a period of time, reached saturation capacity, or balanced with the feed stream. The temperature of the adsorbent bed 104 during regeneration can vary from 25°C to 1000°C. The adsorbent bed can be regenerated as follows: Figure 2 The system depicted in the diagram is regenerated, with two parallel beds 104 and 120 and a switching system allowing one bed to be regenerated while the other is being purified. Alternatively, the used adsorbent bed can be moved to a separate system (not shown) for regeneration. Preferably, the temperature of the adsorbent bed during regeneration can vary from 200°C to 400°C. The regeneration temperature can be selected based on the specific materials in the adsorbent bed and the nature of the adsorbed impurities. The N2 purge flow rate during regeneration is greater than 100 sccm. Preferably, the N2 purge flow rate during regeneration is greater than 500 sccm. It should be understood that the gas flow rate during regeneration can vary depending on the size of the adsorbent bed. The pressure of the regeneration process can range from 1 Torr to 100,000 Torr. Those skilled in the art will recognize that the pressure of the regeneration process can be selected based on the specific impurities adsorbed on the adsorbent bed. The purge gases H2 and N2 have a percentage of H2 in N2 between 0% and 100%. Using H2 at < 4% in N2 in the regeneration process can have some advantages, since H2 concentrations greater than about 4% in N2 are considered flammable. However, since the flammability limit depends on the inert gas used, those skilled in the art can use different concentrations of H2 in the regeneration process.

[0062] Depending on the quality of the feed gas, adsorbent beds 104 and 120 may contain multiple beds in series or a single long bed of desired size to purify and control the concentration of impurities in the output product.

[0063] Example

[0064] The following non-limiting examples are provided to further illustrate embodiments of the invention. However, these examples are not intended to cover all cases, nor are they intended to limit the scope of the invention described herein.

[0065] Example 1

[0066] One adsorbent bed consisted of copper oxide (CuO) on alumina (13%) from Sigma Aldrich (product number: 417971-250G). Another original adsorbent bed without metal oxide loading was activated alumina from Delta Adsorbents (product number: Activated Alumina AA400G). The physical dimensions of both adsorbents, with and without metal oxide loading, were similar (i.e., 14–28 mesh), and both were regenerated prior to adsorption under N2 purging at 300°C for approximately 5 hours at a flow rate of 500 sccm, with a residence time of approximately 46 seconds. A hydrofluorocarbon gas, C3H2F6 (236 fa), containing CFC impurities (including 2-chloro-1,1,1-trifluoroethane (C2H2F3Cl), trichlorofluoromethane (CFCl3), and 2-chloro-1,1,1,3,3-pentafluoro-1-propene (C3F5Cl)), was passed through an adsorbent bed in the gas phase at room temperature. After passing through an adsorbent bed supported by CuO, the concentration of 2-chloro-1,1,1-trifluoroethane (C2H2F3Cl), one of the impurities in the feed hydrofluorocarbon gas C3H2F6 (236 fa), decreased from approximately 42 ppm to < 1 ppm. Another impurity in the feed fluorocarbon or hydrofluorocarbon gas, trichlorofluoromethane (CFCl3), decreased from approximately 139 ppm to < 1 ppm. Similarly, another impurity, 2-chloro-1,1,1,3,3-pentafluoro-1-propene (C3F5Cl), decreased from 67 ppm to < 1 ppm. When the same feed gas was passed through a pristine alumina bed without metal oxide loading, these impurities in the feed gas, 2-chloro-1,1,1-trifluoroethane (C2H2F3Cl) and trichlorofluoromethane (CFCl3), decreased to 23 ppm and 46 ppm, respectively. All impurities were measured using gas chromatography-mass spectrometry.

[0067] Example 2

[0068] At room temperature, gaseous C3H3F5 (245fa) was passed in the gas phase through an alumina adsorbent bed supported on CuO. The concentration of one of the impurities, 1,1,2-trichlorotrifluoroethane (C2F3Cl3), decreased from 284 ppm to < 1 ppm, while the concentration of 2-chloro-1,1,3-trifluoropropene (C3H2F3Cl) decreased from 969 ppm to < 1 ppm. The concentration of 2,2-dichloro-1,1,1-trifluoroethane (C2HF3Cl2) also decreased from 16 ppm in the feed gas to < 1 ppm in the product. However, after a single pass through an adsorbent bed containing copper oxide supported on alumina, the concentration of 2-chloro-1,1,1,2-tetrafluoroethane (C2HF4Cl) decreased from 530 ppm to 45 ppm.

[0069] Example 3

[0070] The adsorbent bed can be regenerated with pure N2, pure H2, or a mixture of H2 and N2. Studies evaluating and comparing the capacity of adsorbent beds regenerated with pure N2 and with 3.5% H2 in the balance N2 (at a flow rate of 1000 sccm at 300°C) showed that when the bed was regenerated with a mixture of N2 and H2, the adsorption capacity for removing the 2-chloro-1,1,1-trifluoroethane (C2H2F3Cl) impurity from 236fa increased by >10× (10-fold) compared to using only N2 (i.e., the bed regenerated with only N2). The breakthrough point of this impurity in 236fa at 100 sccm through the bed occurred at 45 minutes, while the adsorbent bed regenerated with 3.5% H2 in the balance N2, tested at the same flow rate, reached its breakthrough point after 480 minutes.

[0071] Example 4

[0072] During the distillation of 236fa gas at room temperature using a fractional distillation column (4' length and 2" diameter) and Propak packing, some of the chlorine impurities were observed to form an azeotropic mixture with 236fa, leading to difficulties in purification. In particular, the two impurities 2-chloro-1,1,1-trifluoroethane (C2H2F3Cl) (feed concentration 29 ppm) and 2-chloro-1,1,1,3,3-pentafluoro-1-propene (C3F5Cl) (feed concentration 47 ppm) did not show much separation when passing through the distillation column and could only be reduced to 27 ppm and 42 ppm, respectively.

[0073] Example 5

[0074] Similar to the examples above, when purifying 245 fa gas using the same distillation column, the chlorine impurities 1,1,2-trichlorotrifluoroethane (C2F3Cl3) and 2,2-dichloro-1,1,1-trifluoroethane (C2HF3Cl2) form an azeotropic mixture with 245 fa, resulting in minimal separation. For example, after a single distillation at a reboiler temperature of 58°C, the concentration of 1,1,2-trichlorotrifluoroethane (C2F3Cl3) decreased from 110 ppm to 60 ppm, while the concentrations of 2,2-dichloro-1,1,1-trifluoroethane (C2HF3Cl2) decreased only from 6 ppm and 5 ppm, respectively.

[0075] In this document, references to "an embodiment" or "embodiment" mean that a particular feature, structure, or characteristic described with respect to that embodiment may be included in at least one embodiment of the invention. The phrase "in an embodiment" appearing in different places in the specification does not necessarily refer to the same embodiment in all instances, and individual or alternative embodiments are not necessarily mutually exclusive with other embodiments. The foregoing also applies to the term "implementation".

[0076] As used herein, the article “a / an” as used in this application and the appended claims should generally be interpreted as meaning “a / an or a plurality of”, unless otherwise stated or clearly indicated from the context.

[0077] As used herein, “about” or “around or approximately” in the text or claims means ± 10% of the value.

[0078] As used herein, the term “regeneration” can refer to the process of preparing the adsorbent bed for the first time, or the process of removing impurities that have been reversibly adsorbed onto the adsorbent bed after the adsorbent bed has been used for a period of time, reached saturation capacity, or balanced with the feed flow.

[0079] This article uses the standard abbreviations of elements from the periodic table. It should be understood that elements can be referred to using these abbreviations (e.g., F for fluorine, H for hydrogen, C for carbon, etc.).

[0080] A unique CAS registry number (i.e., "CAS") assigned by the Chemical Abstracts Service is provided to identify the specific molecule disclosed.

[0081] As used herein, the term "alkyl group" refers to a saturated or unsaturated functional group containing only carbon and hydrogen atoms. As used herein, the term "alkyl" refers to a saturated functional group containing only carbon and hydrogen atoms. An alkyl group is a type of hydrocarbon. Additionally, the term "alkyl" refers to a straight-chain, branched, or cyclic alkyl group. Examples of straight-chain alkyl groups include, but are not limited to, methyl, ethyl, propyl, butyl, etc. Examples of branched alkyl groups include, but are not limited to, tert-butyl. Examples of cyclic alkyl groups include, but are not limited to, cyclopropyl, cyclopentyl, cyclohexyl, etc.

[0082] As used herein, the word “exemplary” is used to mean serving as an instance, example, or illustration. Any aspect or design described as “exemplary” in this document is not to be construed as preferred or advantageous over other aspects or designs. Rather, the use of the word “exemplary” is intended to present the concept in a specific manner.

[0083] Furthermore, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless otherwise stated or clear from the context, "X adopts A or B" is intended to mean any natural inclusive arrangement. That is, if X adopts A; X adopts B; or X adopts both A and B, then "X adopts A or B" is satisfied in any of the foregoing cases.

[0084] The word “comprising” in the claims is an open-ended transitional term, meaning that the subsequently defined claim elements are a non-exclusive list, i.e., anything else may be additionally included and remain within the scope of “comprising.” “Comprising” is defined herein as necessary to encompass the more restrictive transitional terms “substantially consists of” and “consisting of”; therefore, “comprising” can be replaced by “substantially consists of” or “consisting of” and remain within the clearly defined scope of “comprising.”

[0085] In the claims, "provide" is defined as meaning to supply, provide, make available, or prepare something. The steps can, conversely, be performed by any actor in the absence of explicit language in the claims.

[0086] A range may be expressed herein as from about one specific value and / or to about another specific value. When such a range is expressed, it should be understood that another embodiment is from one specific value and / or to another specific value, together with all combinations within the range. Any and all ranges listed herein include their endpoints (i.e., x = 1 to 4, or x in the range from 1 to 4, including x = 1, x = 4, and x = any number in between), regardless of whether the term "inclusive" is used.

[0087] As used herein, when used in the context of describing an R group, the term "independently" should be understood to mean that the subject R group is chosen independently not only relative to other R groups with the same or different subscripts or superscripts, but also relative to any additional kind of the same R group. For example, in the formula MR 1 x (NR 2 R 3 ) (4-x) In the case where x is 2 or 3, two or three R 1 Groups may (but need not) be identical to each other or with R 2 Or R 3 The same. Furthermore, it should be understood that, unless otherwise specified, the values ​​of the R group are independent of each other when used in different formulas.

[0088] As used herein, the term “exemplary” is used to mean serving as an instance, example, or illustration. Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, the use of the term “exemplary” is intended to present the concept in a specific manner.

[0089] While the subject matter described herein can be described in the context of illustrative implementations to address one or more computing application features / operations of a computing application with user interaction components, the subject matter is not limited to these specific embodiments. Rather, the techniques described herein can be applied to any suitable type of user interaction component execution management methods, systems, platforms, and / or devices.

[0090] It should be understood that many additional changes in details, materials, steps, and arrangements of parts that have been described and elucidated to explain the nature of the invention can be made by those skilled in the art within the principles and scope of the invention as set forth in the appended claims. Therefore, the invention is not intended to be limited to the specific embodiments given above and / or in the drawings.

[0091] Although embodiments of the invention have been shown and described, those skilled in the art can modify them without departing from the spirit or teachings of the invention. The embodiments described herein are exemplary and not limiting. Many variations and modifications of the compositions and methods are possible and are within the scope of the invention. Therefore, the scope of protection is not limited to the embodiments described herein, but is defined only by the following claims, the scope of which should include all equivalents of the subject matter of the claims.

Claims

1. A method for purifying fluorocarbons or hydrofluorocarbons containing at least one undesirable halocarbon impurity, the method comprising: The fluorocarbon or hydrofluorocarbon is passed through at least one adsorbent bed to selectively adsorb the at least one undesirable halogenated hydrocarbon impurity by physical adsorption and / or chemical adsorption, wherein the at least one adsorbent bed is in an inert atmosphere and contains a metal oxide CuO supported on the adsorbent. The at least one adsorbent bed is regenerated by continuously passing a purge gas through it at a temperature ranging from 25°C to 1000°C, the purge gas being H2 or H2 contained in a balance inert gas selected from He, N2, Ar, Xe or Kr.

2. The method of claim 1, further comprising: Distill the effluent stream from at least one adsorbent bed to obtain purified fluorocarbons or hydrofluorocarbons.

3. The method as described in claim 1, wherein, The at least one undesirable halocarbon impurity is a Cl-containing halocarbon, a Br-containing halocarbon, an I-containing halocarbon, or a combination thereof.

4. The method of claim 1, wherein, The adsorbent is silica, alumina, or molecular sieve.

5. The method of claim 1, wherein, The temperature range of the adsorbent bed is from -50°C to 150°C.

6. The method of claim 1, wherein, The at least one adsorbent bed is regenerated by continuously passing purge gas through it at a temperature ranging from 200°C to 400°C.

7. The method according to any one of claims 1 to 6, wherein, The concentration of impurities in the purified fluorocarbons or hydrofluorocarbons is < 1000 ppm.

8. A method for purifying fluorocarbons or hydrofluorocarbons containing at least one undesirable halogenated hydrocarbon impurity, the method comprising: The fluorocarbon or hydrofluorocarbon is passed through at least one adsorbent bed to selectively adsorb the at least one undesirable halogenated hydrocarbon impurity by physical adsorption and / or chemical adsorption, wherein the at least one adsorbent bed is in an inert atmosphere and contains a metal oxide CuO supported on the adsorbent; and Distillation of the effluent stream from at least one adsorbent bed yields purified fluorocarbons or hydrofluorocarbons. The at least one adsorbent bed is regenerated by continuously passing a purge gas through it at a temperature ranging from 25°C to 1000°C, the purge gas being H2 or H2 contained in a balance inert gas selected from He, N2, Ar, Xe or Kr.

9. The method of claim 8, wherein, The at least one adsorbent bed is regenerated by continuously passing purge gas through it at a temperature ranging from 200°C to 400°C.

10. The method of claim 8 or 9, wherein, The concentration of impurities in the purified fluorocarbons or hydrofluorocarbons is <1000 ppm.

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