SINGLE-STAGE PROCESS FOR MANUFACTURING TRIFLUORIOIODOMETHANAN FROM TRIFLUOROACETYL HALIDE, HYDROGEN AND IODINE

Abstract

This description provides a process for producing trifluoroiodomethane (CF3I). The process includes supplying vapor-phase reactants, including trifluoroacetyl halide, hydrogen, and iodine; heating the vapor-phase reactants; and reacting the heated vapor-phase reactants in the presence of a catalyst to produce trifluoroiodomethane. The catalyst is a transition metal.

Description

Field of Invention This description relates to processes for producing trifluoroiodomethane (CF3I). Specifically, this description relates to catalysts and integrated processes for producing trifluoroiodomethane. Background of the Invention Trifluoroiodomethane (CF3I) is a useful compound in commercial applications, such as a refrigerant or fire suppressant. It is an environmentally acceptable compound with a low global warming potential and a low ozone depletion potential. Trifluoroiodomethane can replace more environmentally harmful materials. Methods for preparing trifluoroiodomethane are known. For example, U.S. Patent No. 7,132,578 (Mukhopadhyay et al.) describes a one-step catalytic process for producing trifluoroiodomethane from trifluoroacetyl chloride. However, the source of iodine is iodine fluoride (IF). Iodine fluoride is relatively unstable and decomposes above 0 °C to I₂ and IF₅. It is also possible that iodine fluoride is not available in commercially useful quantities. QQ ! «nn / Lznz / E / YILI Ref. 325575 In another example, U.S. Patent No. 7,196,236 (Mukhopadhyay et al.) describes a catalytic process for producing trifluoroiodomethane using reagents comprising an iodine source, such as hydrogen iodide, at least a stoichiometric amount of oxygen, and a CF3R reagent, where R is selected from the group consisting of —COOH, —COX, —CHO, —COOR2, and —SO2X, where R2 is an alkyl group and X is chlorine, bromine, or iodine. The hydrogen iodide, which can be produced by the reaction, is oxidized by at least a stoichiometric amount of oxygen, yielding water and iodine for economical recycling. Several other processes are mentioned in the literature for producing CF3I from trifluoroacetyl chloride with hydrogen iodide in a vapor-phase reaction. However, the production of CF3I from trifluoroacetyl chloride and hydrogen iodide requires an additional step to produce hydrogen iodide. This description introduces a single-stage process for producing CF3I by co-feeding trifluoroacetyl halide, hydrogen, and iodine in a reactor with a catalyst. Summary of the Invention The present description provides processes for producing trifluoroiodomethane from hydrogen (H2), elemental iodine (I2) and a trifluoroacetyl halide (CF3C(O)X). In one embodiment, the present invention provides a process for producing trifluoroiodomethane (CF3I). The process includes providing vapor-phase reactants comprising trifluoroacetyl halide, hydrogen, and iodine, heating the vapor-phase reactants, and reacting the heated vapor-phase reactants in the presence of a catalyst to produce trifluoroiodomethane. The catalyst comprises a transition metal. In another embodiment, the present invention provides a process for producing trifluoroiodomethane (CF3I). The process includes the steps of reacting a trifluoroacetyl halide, hydrogen, and iodine in the vapor phase at a temperature of approximately 200 °C to approximately 600 °C in the presence of a catalyst to produce a product stream comprising trifluoroiodomethane, unreacted trifluoroacetyl halide, unreacted hydrogen, unreacted iodine, hydrogen halide, and hydrogen iodide. The catalyst includes a transition metal. The process further includes removing at least some of the unreacted iodine from the product stream by cooling the product stream to condense the iodine from the vapor phase and recycling the condensed iodine to the reaction step. The aforementioned characteristics and others in the description, as well as the way to achieve them, will become more evident and better understood with reference to the following description of modalities. Brief Description of the Figures Figure 1 is a process flow diagram showing a process 10 for manufacturing trifluoroiodomethane. Detailed Description of the Invention This description provides a one-step process for the fabrication of trifluoroiodomethane (CF3I) from trifluoroacetyl halide (CF3C(O)X), hydrogen (H2), and iodine (I2), including the use of a transition metal catalyst. The reaction at approximately 200 °C to approximately 600 °C in the presence of the transition metal catalyst has been found to provide efficient fabrication of trifluoroiodomethane from these readily available reagents. Efficiency is further enhanced by recycling the reagents. As described herein, trifluoroiodomethane is produced in a one-stage process in which the reactants trifluoroacetyl halide, hydrogen (H2), and iodine (I2) are fed together into a reactor in the presence of a catalyst at a reaction temperature of approximately 200 °C to approximately 600 °C. All reactants are anhydrous. It is preferred that the reactants contain as little water as possible because water in the reaction can favor side reaction pathways that lead to the formation of undesirable byproducts, such as trifluoromethane (CF3H). qq / «nn / Lznz / E / YiAi Trifluoroacetyl halide is substantially free of water. That is, the water in trifluoroacetyl halide is present by weight in an amount less than approximately 500 parts per million, approximately 300 ppm, approximately 200 ppm, approximately 100 ppm, approximately 50 ppm, approximately 30 ppm, approximately 20 ppm, or approximately 10 ppm, or less than any value defined between any two of the foregoing values. Preferably, the water in trifluoroacetyl halide is present by weight in an amount less than approximately 100 ppm. More preferably, the water in trifluoroacetyl halide is present by weight in an amount less than approximately 30 ppm. Most preferably, the water in trifluoroacetyl halide is present by weight in an amount less than approximately 10 ppm. qq / «nn / ίζηζ / Ε / γίΛΐ Iodine is substantially free of water. That is, the water in iodine is present by weight in an amount less than approximately 500 ppm, approximately 300 ppm, approximately 200 ppm, approximately 100 ppm, approximately 50 ppm, approximately 30 ppm, approximately 20 ppm, or approximately 10 ppm, or less than any value defined between any two of the foregoing values. Preferably, the water in iodine is present by weight in an amount less than approximately 100 ppm. Preferably, the water in the iodine is in a weight amount (qq / "nn / Lznz / E / YiAi) less than approximately 30 ppm. With maximum preference, The water in iodine is present by weight in an amount less than approximately 10 ppm. Hydrogen is substantially free of water. That is, the water in hydrogen is present by weight in an amount less than approximately 500 ppm, approximately 300 ppm, approximately 200 ppm, approximately 100 ppm, approximately 50 ppm, approximately 30 ppm, approximately 20 ppm, or approximately 10 ppm, or less than any value defined between any two of the above values. Preferably, the water in the hydrogen is present in an amount by weight less than approximately 100 ppm. More preferably, the water in the hydrogen is present in an amount by weight less than approximately 30 ppm. Most preferably, the water in the hydrogen is present in an amount by weight less than approximately 10 ppm. Trifluoroacetyl halide is selected from the group consisting of trifluoroacetyl fluoride (CF3C(O)F), trifluoroacetyl chloride (CF3C(O)C1), trifluoroacetyl bromide (CF3C(O)Br), and any combination thereof. Preferably, trifluoroacetyl halide comprises trifluoroacetyl chloride. More preferably, trifluoroacetyl halide consists essentially of trifluoroacetyl chloride. Most preferably, trifluoroacetyl halide consists of trifluoroacetyl chloride. Trifluoroacetyl chloride, for example, is readily available in commercial quantities from Halocarbon Products Corporation, Peachtree Corners, Georgia, or Solvay SA, Brussels, Belgium, for example. Hydrogen is commercially available from Air Products, Allentown, PA. Solid iodine is commercially available from SQM, Santiago, Chile, or Kanto Natural Gas Development Co., Ltd., Chiba, Japan. The reactants may be provided for the reaction in a hydrogen-to-iodine molar ratio of at least approximately 0.1:1, approximately 0.2:1, approximately 0.3:1, approximately 0.4:1, approximately 0.5:1, approximately 0.6:1, approximately 0.7:1, approximately 0.8:1, approximately 0.9:1, or approximately 1:1, or at most 1.1:1, 1.2:1, 1.5:1, 2:1, 2.5:1, 3:1, 4:1, or 5:1, or within any defined range between any two of the above values, such as approximately 0.1:1 to approximately 5:1, approximately 0.2:1 to approximately 4:1, approximately 0.3:1 to approximately 3:1, approximately 0.4:1 to approximately 2.5:1, approximately 0.5:1 to approximately 2:1, approximately 0.5:1 to approximately 1.5:1, approximately 0.7:1 to approximately 1.2:1, approximately 0.8:1 to approximately 1.1:1, or approximately 0.9:1 to approximately 1:1, for example.Preferably, the hydrogen-to-iodine molar ratio is approximately 0.1:1 to approximately 1:1. More preferably, the hydrogen-to-iodine molar ratio is approximately 0.3:1 to approximately 0.8:1. Most preferably, the hydrogen-to-iodine molar ratio is approximately 0.5:1 to approximately 0.7:1. A hydrogen-to-iodine molar ratio less than 1 has been found to provide significantly better yields than ratios greater than 1. Without wishing to be limited by any theory, it is believed that with a hydrogen-to-iodine molar ratio less than 1, little hydrogen is available for competing side reactions that form undesirable byproducts from trifluoroacetyl halide, such as CF3H and CH3I. The reactants may be provided for the reaction in a hydrogen-to-trifluoroacetyl halide molar ratio of at least approximately 0.002:1, approximately 0.004:1, approximately 0.006:1, approximately 0.008:1, approximately 0.01:1, approximately 0.02:1, approximately 0.03:1, approximately 0.04:1, or at most approximately 0.05:1, approximately 0.07:1, approximately 0.09:1, approximately 0.1:1, approximately 0.2:1, approximately 0.3:1, approximately 0.4:1, approximately 0.5:1, or approximately 1:1, or within any defined range between any two of the above values, such as approximately 0.002:1 to approximately 1:1, approximately 0.004:1 to approximately 0.5:1 1, approximately 0.006:1 to approximately 0.4:1, or approximately 0.01:1 to 0.1:1, for example. Preferably, the molar ratio of hydrogen to trifluoroacetyl halide is approximately 0.01:1 to approximately 0.05:1. The reactants react in the presence of a catalyst contained within a reactor to produce a product stream comprising trifluoroiodomethane and the reaction byproducts carbon monoxide (CO) and hydrogen halide (HX), according to the following Equation 1: Eq. 1: 2CF3C(O)X + H2+ I2 → 2CF3I + 2HX + 2CO where X is fluoride, chloride, or bromide, depending on the trifluoroacetyl halide reagent chosen. Therefore, the hydrogen halide is hydrogen fluoride (HF), hydrogen chloride (HCl), and / or hydrogen fluoride (HBr). It is believed that within the reactor, hydrogen and iodine react to form hydrogen iodide (HI) in situ, which then reacts almost immediately with trifluoroacetyl halide to form trifluoroiodomethane. Competing side reactions may produce byproducts such as trifluoromethane (CF3H), iodomethane (CH3I), and trifluoroacetyl iodide (TFAI), for example. The reactor may be a heated tube reactor, such as a fixed-bed tubular reactor, which includes a tube containing the catalyst. The tube may be made of a metal such as stainless steel, nickel, and / or a nickel alloy, such as a nickel-molybdenum alloy, a nickel-chromium-molybdenum alloy, or a nickel-copper alloy. The tube reactor is heated, thereby also heating the catalyst. Alternatively, the reactor may be any type of packed reactor. The reaction is carried out substantially free of oxygen (O2). That is, the oxygen during the reaction, by weight, is less than approximately 500 parts per million, approximately 300 ppm, approximately 200 ppm, approximately 100 ppm, approximately 50 ppm, approximately 30 ppm, approximately 20 ppm, approximately 10 ppm, approximately 5 ppm, approximately 3 ppm, approximately 2 ppm, or approximately 1 ppm, or less than any value defined between any two of the foregoing values. Preferably, the oxygen during the reaction is less than approximately 100 ppm. More preferably, the oxygen during the reaction is less than approximately 10 ppm. Most preferably, the oxygen during the reaction is less than approximately 3 ppm.It is preferable to have as little oxygen as possible during the reaction because it can oxidize at least some of the hydrogen iodide to form iodine and water before the hydrogen iodide can react to form trifluoroiodomethane, thus reducing the efficiency of the process. qq / «nn / Lznz / E / YiAi The catalyst includes a transition metal. Preferably, the transition metal includes the non-precious transition metals nickel, cobalt, or iron, or the precious transition metals rhodium, iridium, platinum, palladium, or any combination thereof. More preferably, the transition metal consists essentially of nickel, platinum, palladium, or combinations thereof. Most preferably, the transition metal consists essentially of palladium. The catalyst may include a support for the transition metal. Preferably, the support includes carbon, aluminum oxide (Al2O3), silica gel (SiO2), silicon carbide (SiC), or combinations thereof. Most preferably, the support consists essentially of aluminum oxide. The amount of transition metal on the catalyst surface, as a percentage of the total combined weight of the transition metal and support, may be, at a minimum, approximately 0.01 percent by weight (% wt), approximately 0.02% by weight, approximately 0.1% by weight, approximately 0.3% by weight, approximately 0.5% by weight, approximately 0.7% by weight, approximately 1% by weight, approximately 2% by weight, approximately 4% by weight, or at most approximately 6% by weight, approximately 8% by weight, approximately 10% by weight, approximately 15% by weight, approximately 20% by weight, approximately 21% by weight, approximately 25% by weight, approximately 30% by weight, or approximately 40% by weight, or within any defined range between any two of the above values, such as approximately 0.01% by weight to approximately 40% by weight, approximately 0.0.2 wt. to approximately 30 wt., approximately 0.1 wt. to approximately 25 wt., approximately 0.3 wt. to approximately 20 wt., approximately 0.5 wt. to approximately 15 wt., approximately 0.7 wt. to approximately 10 wt., approximately 1 wt. to approximately 8 wt., approximately 2 wt. to approximately 6 wt., approximately 1 wt. to approximately 4 wt., or approximately 0.3 wt. to approximately 0.7 wt., for example. Preferably, the amount of a non-precious transition metal on the catalyst surface is approximately 5 wt. to approximately 35 wt. More preferably, the amount of a non-precious transition metal on the catalyst surface is approximately 10 wt. to approximately 30 wt.With the highest preference, the amount of a non-precious transition metal on the catalyst surface is approximately 20 wt% to approximately 30 wt%. Preferably, the amount of a precious transition metal on the catalyst surface is approximately 0.1 wt% to approximately 5 wt%. With a higher preference, the amount of a precious transition metal on the catalyst surface is approximately 0.3 wt% to approximately 1 wt%. With the highest preference, the amount of a precious transition metal on the catalyst surface is approximately 0.3 wt% to approximately 0.7 wt%. The reactants can be in contact with the catalyst for a contact time of at least approximately 0.1 seconds, 1 second, approximately 2 seconds, approximately 4 seconds, approximately 6 seconds, approximately 8 seconds, approximately 10 seconds, approximately 15 seconds, approximately 20 seconds, approximately 25 seconds, or approximately 30 seconds or at most approximately 40 seconds, approximately 50 seconds, approximately 60 seconds, approximately 70 seconds, approximately 80 seconds, approximately 100 seconds, approximately 120 seconds, or approximately 1,200 seconds, or within any defined interval between any two of the above values, such as approximately 0.1 second to approximately 1,200 seconds, approximately 2 seconds to approximately 120 seconds, approximately 4 seconds to approximately 100 seconds, approximately 6 seconds to approximately 80 seconds, approximately 8 seconds to approximately 70 seconds. QQ ! «nn / Lznz / E / YILI approximately 10 seconds to approximately 60 seconds, approximately 15 seconds to approximately 50 seconds, approximately 20 seconds to approximately 40 seconds, approximately 20 seconds to approximately 30 seconds, approximately 10 seconds to approximately 20 seconds, or approximately 100 seconds to approximately 120 seconds, For example. Preferably, the reactants are in contact with the catalyst for a contact time of approximately 1 second to approximately 100 seconds. More preferably, the reactants are in contact with the catalyst for a contact time of approximately 2 seconds to approximately 50 seconds. Most preferably, the reactants are in contact with the catalyst for a contact time of approximately 10 seconds to approximately 30 seconds. The reaction is carried out at a temperature of at least approximately 200 °C, approximately 250 °C, approximately 300 °C, approximately 320 °C, approximately 330 °C, approximately 340 °C, approximately 350 °C, or up to a temperature of at most approximately 360 °C, approximately 370 °C, approximately 380 °C, approximately 390 °C, approximately 400 °C, 500 °C, or approximately 600 °C, or within any defined interval between any two of the above values, such as approximately 200 °C to approximately 600°C, approximately 250°C to approximately 500°C, approximately 300°C to approximately 400°C, approximately 320°C to approximately 390°C, approximately 340°C to approximately 380°C, approximately 350°C to approximately 370°C, or approximately 340°C to approximately 360°C, for example. Preferably, the QQ ! «nn / Lznz / E / YILI reagents are heated to a temperature of approximately 300 °C to approximately 400 °C. More preferably, the reagents are heated to a temperature of approximately 320 °C to approximately 360 °C. Most preferably, the reagents are heated to a temperature of approximately 340 °C to approximately 360 °C. Pressure is not critical. Suitable operating pressures range from approximately 10 kPa to approximately 4000 kPa, and preferably from approximately 100 kPa to approximately 350 kPa. The composition of organic compounds in the product stream leaving the reactor can be measured by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The graph areas provided by GC analysis for each organic compound can be combined to provide a percentage GC area (% GC area) of total organic compounds for each organic compound as a measure of the relative concentrations of organic compounds in the product stream. The concentration of trifluoroiodomethane in the product stream leaving the reactor, as a % of GC area of ​​total organic compounds excluding trifluoroacetyl halide, may be at least approximately 10%, approximately 15%, approximately 20%, approximately 25%, approximately 30%, approximately 35%, approximately 40%, approximately 45%, approximately 50%, approximately 55%, or approximately 60%, or may be at most approximately 65%, approximately 70%, approximately 75%, approximately 80%, approximately 85%, approximately 90%, approximately 95%, or approximately 99%, or within any defined interval between any two of the above values, such as approximately 10% to approximately 99%, approximately 20% to approximately 95%, approximately 30% to approximately 90%, approximately 40% to approximately 85%, approximately 45% to approximately 80%.approximately 50% to approximately 75%, approximately 55% to approximately 70%, approximately 60% to approximately 65%, approximately 90% to approximately 99%, or approximately 95% to approximately 99%, for example. Preferably, the concentration of trifluoroiodomethane in the product stream is approximately 30% to approximately 99%. More preferably, the concentration of trifluoroiodomethane in the product stream is approximately 70% to approximately 99%. Most preferably, the concentration of trifluoroiodomethane in the product stream is approximately 90% to approximately 99%. The product stream is directed from the reactor to one or more iodine removal vessels, where it is cooled to allow unreacted iodine to condense, removing at least some of the iodine from the product stream for recycling as a reagent. The product stream may be cooled to a temperature below the boiling point of iodine but above its melting point to condense the iodine into liquid form. Alternatively, or additionally, the product stream leaving the reactor may be cooled to a temperature below the melting point of iodine to recover the iodine in solid form. The product stream may then proceed from the iodine removal vessel to one or more additional iodine removal vessels to remove further unreacted iodine for recycling. The product stream can be directed from one or more vessels for iodine removal to a heavy compound distillation column to separate by-products from the heated hydrogen can be controlled by a gas flow controller 28. TFAC 16 can be supplied to a TFAC 30 preheater, where the TFAC is heated to a selected reaction temperature. The flow rate of the heated TFAC vapor can be controlled by a gas flow controller 32. The heated hydrogen flow and the heated TFAC flow can be combined in a mixing valve 34, which can then be combined with the iodine vapor flow in another mixing valve 36. Alternatively, the heated hydrogen flow, the heated TFAC flow, and the iodine flow can be combined in a single mixing valve. The heated mixture of iodine vapor, hydrogen, and TFAC is supplied to a reactor 38. The hot mixture of iodine vapor, hydrogen, and TFAC reacts in the presence of a catalyst 40 contained within reactor 38 to produce a crude product stream. The catalyst 40 is any of the catalysts described herein. The crude product stream may include trifluoroiodomethane, unreacted hydrogen, unreacted iodine, unreacted TFAC, and reaction byproducts such as HI, CO, CF3H, TFAI, HC1, and CH3I, for example. The raw product stream is fed to an iodine removal vessel 44. In the iodine removal vessel, the raw product stream is cooled to a temperature below the boiling point of iodine to condense at least some of the iodine and separate it from the raw product stream. The iodine collected in the iodine removal vessel 44 forms an iodine recycle stream 46. The iodine recycle stream 46 is fed to the iodine condenser 20 for iodine recycling. The raw product stream can be further cooled in the first iodine removal vessel 44 to a temperature below the melting point of iodine to further separate iodine from the raw product stream and deposit at least some of the iodine as a solid within the iodine removal vessel 44. Subsequently, the iodine removal vessel 44 can be disconnected and the solid iodine can be heated to liquefy the iodine for the iodine recycling stream 46. Although a single iodine 44 removal vessel is shown, it is understood that the iodine 44 removal vessel may include two or more iodine 44 removal vessels operating in a parallel configuration, two or more iodine 44 removal vessels operating in a series configuration, and any combination thereof. It is further understood that the iodine 44 removal vessel may include multiple trains of iodine 44 removal vessels, such that at least one train is operating while another train is offline to remove solid iodine qq / «nn / Lznz / E / YiAi in order to provide continuous operation while collecting the iodine in solid form. The crude product stream is fed from the iodine removal vessel 44 to a heavy compound distillation column 48. The heavy compound distillation column 48 is configured for the separation of heavy organic compounds, such as CH3I and TFAI, from light organic compounds, such as CF3I, unreacted TFAC, and byproducts such as HI, CO, CF3H, and HC1. A bottom stream 50, which includes the heavy organic compounds from the heavy compound distillation column 48, can be fed to a vessel (not shown). The heavy organic components in the vessel can be discarded or further distilled to recover the components for later use or sale. An overhead stream 52, comprising the light organic compounds from the heavy compound distillation column 48, which includes CF3I, TFAC, CF3H, HC1, HI, H2, and CO, is directed to a light compound distillation column 54 to separate the higher-boiling compounds, such as TFAC, HI, and CF3I, from the lower-boiling compounds, such as CF3H, HC1, CO, and H2. An overhead stream 56 from the light compound distillation column 54, comprising CF3H, HC1, CO, and H2, can be supplied to the scrubber (not shown) for the removal of HC1, and then supplied to a thermal oxidant (not shown) for the oxidation of CF3H, CO, and H2. A lower stream 58, containing CF3I, TFAC, and HI from the light compound distillation column 54, is fed to a recycle column 60. The recycle column 60 can be configured to separate CF3I from TFAC and HI. An upper stream 62 from the recycle column 60, containing TFAC and HI, forms a TFAC / HI recycle stream. The TFAC / HI recycle stream 62 is fed to the TFAC preheater 30 for recycling the TFAC and HI. Although a single recycle column 60 is illustrated, it is understood that the recycle column 60 can include two or more recycle columns operating in series, in parallel, or any combination thereof to achieve the desired separation efficiency. A lower stream 64, containing CF3I and trace amounts of light and heavy organic compounds, from the recycling column 60 is fed to a first product column 66. The first product column 66 is configured to separate the CF3I from the trace amount of light organic compounds. An upper stream 68 from the first product column 66, containing the light organic compounds and some CF3I, can be recycled to the lower stream 58 fed to the recycling column 60 for recovery. Additional CF3I. An understream 70 containing CF3I and the heavy organic compounds from the first product column 66 is fed to a second product column 72. The CF3I product is collected from an overstream 74 of the second product column 72. An understream 76 containing some CF3I and heavy organic compounds from the second product column 72 can be recycled to the understream 58 fed to the recycling column 60 to recover additional CF3I. Although this invention has been described as relating to illustrative designs, the present invention may be further modified within the spirit and scope of this description. Furthermore, this application seeks to cover such deviations from the present description as arise in the known or customary practice of the art to which this invention belongs. As used in this description, the phrase "within any defined interval between any two of the above values" literally means that any interval can be selected from any two of the values ​​listed before that phrase, regardless of whether the values ​​are at the bottom or top of the list. For example, a pair of values ​​can be selected from two lower values, two higher values, or one lower and one higher value. EXAMPLES Examples 1-4: Production of CF3I from trifluoroacetyl chloride (TFAC), hydrogen, and elemental iodine The following examples illustrate the fabrication of trifluoroiodomethane from TFAC, hydrogen, and iodine according to Equation 1 described above. A three-quarter-inch-long Inconel 600 tube was used as the reactor and charged with 11 inches of either Johnson Matthey's 0.1 wt. Pd / Al₂O₃ catalyst or BASF's 0.5 wt. Pd / Al₂O₃ catalyst. The reactor was preheated to 350 °C. A certain amount of TFAC and H₂ was co-fed into a TFAC / H₂ preheater, as shown in the table below, and then fed into an I₂ vaporizer initially charged with 1000 grams of solid iodine. The temperature of the I₂ vaporizer was controlled at 150–165 °C, generating I₂ vapor. Next, the mixture of I2 vapor, TFAC vapor, and H2 vapor was fed into the heated fixed-bed tubular reactor that was loaded with the catalyst.The reactor effluent was passed through a two-stage I2 collector to capture any unreacted I2 in a solid form and was then fed into a deionized water scrubber to capture unreacted TFAC, as well as HC1 and HI generated during the reaction. Periodically, samples of the deionized water treatment plant effluent were taken, and the composition of the organic compounds in the samples was measured using gas chromatography (GC). The graph areas provided by the GC analysis for each of the organic compounds were combined to provide a percentage GC area (% GC area) of the total organic compounds. At the end of the reaction run time, the system was shut down, and the weight loss in the iodine vaporizer and the weight gain in the iodine removal vessels were measured to determine an iodine feed rate. The iodine feed rate was compared to the hydrogen feed rate to determine an average molar ratio of H₂:I₂ fed to the reactor. A residence time in the reactor was calculated based on the combined feed rates of hydrogen, iodine, and TFA. The results for each example are shown in Table 1. For each example, Table 1 shows the amount of palladium in the aluminum oxide catalyst used, the TFAC feed index, the H2 feed index, the average molar feed ratio of H2 to I2, the average molar feed ratio of TFAC to HI, the residence time, and the % GC area for CF3I, CF3H, and CH3I at the end of the test. Examples 1, 3, and 4 were run for 24 hours, and Example 2 was run for 20 hours. As shown in Table 1, the examples with an average molar feed ratio of H2 to I2 less than 1:1 and with an average molar feed ratio of H2 to TFAC less than 0.05:1 produced substantially better selectivity for CF3I.It also appears that a higher amount of palladium on the support improves selectivity for CF3I when the average molar feed ratio of H2a I2 is less than 1:1 and the average molar feed ratio of H2a TFAC is less than 0.05:1. qq / «nn / Lznz / E / YiAi Table 1 Ex. no. Pd / Al2O3 (% by weight) TFAC feed rate (g / h) H2 feed rate (ml / min) H2:l2 H2:TFAC Residence time (s) CF3I (% area per GC) CF3H (% area per GC) CH3I (% area per GC) 1 0.1 13.4 20 0.53:1 0.02:1 15.4 77.5 4.5 0.3 2 0.1 7.0 40 1.18:1 0.09:1 16.0 49.7 21.3 14.7 3 0.5 7.5 40 1.16:1 0.07:1 15.7 38.4 17.1 38.7 4 0.5 13.4 20 0.62:1 0.02:1 16.3 94.9 0.5 1.1 Aspects Aspect 1 is a process for producing trifluoroiodomethane (CF3I). The process includes providing vapor-phase reactants comprising trifluoroacetyl halide, hydrogen, and iodine; heating the vapor-phase reactants; and reacting the heated vapor-phase reactants in the presence of a catalyst to produce trifluoroiodomethane. The catalyst comprises a transition metal. Aspect 2 is the process of Aspect 1, wherein the trifluoroacetyl halide comprises less than approximately 500 ppm by weight of water. Aspect 3 is the process of Aspect 1, wherein the trifluoroacetyl halide comprises less than approximately 100 ppm by weight of water. Aspect 4 is the process of Aspect 1, wherein the trifluoroacetyl halide comprises less than approximately 30 ppm by weight of water. Aspect 5 is the process of Aspect 1, wherein the trifluoroacetyl halide comprises less than approximately 10 ppm by weight of water. Aspect 6 is the process of any of Aspects 1-5, where hydrogen comprises less than approximately 500 ppm by weight of water. Aspect 7 is the process of any of Aspects 1-5, where hydrogen comprises less than approximately 100 ppm by weight of water. Aspect 8 is the process of any of Aspects 1-5, where hydrogen comprises less than approximately 30 ppm by weight of water. Aspect 9 is the process of any of Aspects 1-5, where hydrogen comprises less than approximately 10 ppm by weight of water. Aspect 10 is the process of any of Aspects 1-9, where the iodine comprises less than approximately 500 ppm by weight of water. Aspect 11 is the process of any of Aspects 1-9, where iodine comprises less than approximately 100 ppm by weight of water. Aspect 12 is the process of any of Aspects 1-9, where iodine comprises less than approximately 30 ppm by weight of water. Aspect 13 is the process of any of Aspects 1-9, where iodine comprises less than approximately 10 ppm by weight of water. Aspect 14 is the process of any of Aspects 1-13, where at the stage of providing, a molar ratio of hydrogen to iodine is from approximately 0.1:1 to approximately 5:1. Aspect 15 is the process of any of Aspects 1-13, where at the stage of providing, a molar ratio of hydrogen to iodine is from approximately 0.1:1 to approximately 1:1. Aspect 16 is the process of any of Aspects 1-13, where at the stage of providing, a molar ratio of hydrogen to iodine is from approximately 0.3:1 to approximately 0.8:1. Aspect 17 is the process of any of Aspects 1-13, where at the stage of providing, a molar ratio of hydrogen to iodine is approximately 0.5:1 to qq / «nn / Lznz / E / YiAi approximately 0.7:1. Aspect 18 is the process of any of Aspects 1-17, wherein at the stage of providing, a molar ratio of hydrogen to trifluoroacetyl halide is from approximately 0.002:1 to approximately 1:1. Aspect 19 is the process of any of Aspects 1-17, wherein at the stage of providing, a molar ratio of hydrogen to trifluoroacetyl halide is from approximately 0.01:1 to approximately 0.05:1. Aspect 20 is the process of any of Aspects 1-19, where at the provisioning stage, the vapor-phase reactants comprise less than approximately 500 ppm by weight of oxygen. Aspect 21 is the process of any of Aspects 1-19, wherein at the provisioning stage, the vapor-phase reactants comprise less than approximately 100 ppm by weight of oxygen. Aspect 22 is the process of any of Aspects 1-19, wherein at the provisioning stage, the vapor-phase reactants comprise less than approximately 10 ppm by weight of oxygen. Aspect 23 is the process of any of Aspects 1-19, where at the provisioning stage, the vapor-phase reactants comprise less than approximately 3 ppm by weight of oxygen. qq / «nn / Lznz / E / YiAi Aspect 24 is the process of any of Aspects 1-23, wherein the transition metal includes at least one selected from the group of nickel, cobalt, iron, rhodium, iridium, platinum, and palladium. Aspect 25 is the process of any of Aspects 1-23, where the transition metal consists essentially of nickel, platinum, palladium, or combinations thereof. Aspect 26 is the process of any of Aspects 1-23, where the transition metal consists essentially of nickel, platinum, palladium, or combinations thereof. Aspect 27 is the process of any of Aspects 1-23, where the transition metal consists essentially of palladium. Aspect 28 is the process of any of Aspects 1-27, wherein the catalyst further comprises a support that includes at least one selected from the group of an aluminum oxide support, a carbon support, a silica gel support, and a silicon carbide support. Aspect 29 is the process of any of Aspects 1-27, wherein the catalyst further comprises a support consisting essentially of an aluminum oxide support. Aspect 30 is the process of either Aspect 28 or 29, wherein the amount of transition metal on the catalyst surface is approximately 0.01 wt% to approximately 40 wt% of the total metal weight. QQ ! «nn / Lznz / E / YILI transition and support. Aspect 31 is the process of Aspect 30, wherein the transition metal includes at least one selected from the group of nickel, cobalt, iron, or combinations thereof, and the amount of transition metal on the catalyst surface is approximately 5 wt% to approximately 35 wt% of the total weight of the transition metal and support. Aspect 32 is the process of Aspect 30, wherein the transition metal includes at least one selected from the group of nickel, cobalt, iron, or combinations thereof, and the amount of transition metal on the catalyst surface is approximately 10 wt% to approximately 30 wt% of the total weight of the transition metal and support. Aspect 33 is the process of Aspect 30, wherein the transition metal includes at least one selected from the group of nickel, cobalt, iron, or combinations thereof, and the amount of transition metal on the catalyst surface is approximately 20 wt to approximately 30 wt of the total weight of the transition metal and support. Aspect 34 is the process of Aspect 30, where the transition metal includes nickel, the support includes aluminum oxide, and the nickel is approximately 21% by weight of the QQ ! «nn / Lznz / E / YILI total weight of nickel and aluminum oxide. Aspect 35 is the process of Aspect 30, wherein the transition metal includes at least one selected from the group of rhodium, iridium, platinum, palladium, or combinations thereof, and the amount of transition metal on the catalyst surface is approximately 0.1 wt% to approximately 5 wt% of the total weight of the transition metal and support. Aspect 36 is the process of Aspect 30, wherein the transition metal includes at least one selected from the group of rhodium, iridium, platinum, palladium, or combinations thereof, and the amount of transition metal on the catalyst surface is approximately 0.3 wt% to approximately 1 wt% of the total weight of the transition metal and support. Aspect 37 is the process of Aspect 30, wherein the transition metal includes at least one selected from the group of rhodium, iridium, platinum, palladium, or combinations thereof, and the amount of transition metal on the catalyst surface is approximately 0.3 wt to approximately 0.7 wt of the total weight of the transition metal and support. Aspect 38 is the process of Aspect 30, wherein the transition metal includes palladium, the support includes aluminum oxide, and the palladium is approximately 0.5% by weight of the total weight of palladium and aluminum oxide. Aspect 39 is the process of any of Aspects 1-38, wherein the vapor-phase reactants are heated to a temperature of approximately 200 °C to approximately 600 °C. Aspect 40 is the process of any of Aspects 1-38, whereby the vapor-phase reactants are heated to a temperature of approximately 300 °C to approximately 400 °C. Aspect 41 is the process of any of Aspects 1-38, whereby the vapor-phase reactants are heated to a temperature of approximately 320 °C to approximately 360 °C. Aspect 42 is the process of any of Aspects 1-38, whereby the vapor-phase reactants are heated to a temperature of approximately 340 °C to approximately 360 °C. Aspect 43 is the process of any of Aspects 1-42, where in the reacting stage, the contact time of the vapor-phase reactants with the catalyst is from approximately 0.1 seconds to approximately 1200 seconds. Aspect 44 is the process of any of Aspects 1-42, wherein in the reacting stage, a contact time of the vapor-phase reactants with the catalyst qq / «nn / Lznz / E / YiAi is from approximately 1 second to approximately 100 seconds. Aspect 45 is the process of any of Aspects 1-42, where in the reacting stage, the contact time of the vapor-phase reactants with the catalyst is approximately 2 seconds to approximately 50 seconds. Aspect 46 is the process of any of Aspects 1-42, where in the reacting stage, the contact time of the vapor-phase reactants with the catalyst is approximately 10 seconds to approximately 30 seconds. Aspect 47 is the process of any of Aspects 1-46, further comprising the additional steps of separating unreacted hydrogen iodide from the product stream and returning unreacted hydrogen iodide to the reactant stream. Aspect 48 is the process of any of Aspects 1-47, where the process is a continuous process. Aspect 49 is the process of any of Aspects 1-47, where the process is a discontinuous process. Aspect 51 is the process of any of Aspects 1-49, wherein the trifluoroacetyl halide is selected from the group consisting of trifluoroacetyl fluoride, trifluoroacetyl chloride, trifluoroacetyl bromide, and any combination thereof. Aspect 52 is the process of any of the Aspects 1-49, wherein the trifluoroacetyl halide comprises trifluoroacetyl chloride. Aspect 53 is the process of any of Aspects 1-49, wherein the trifluoroacetyl halide consists essentially of trifluoroacetyl chloride. Aspect 54 is the process of any of Aspects 1-49, wherein the trifluoroacetyl halide consists of trifluoroacetyl chloride. Aspect 55 is a process for producing trifluoroiodomethane (CF3I). The process includes the following steps: reacting a trifluoroacetyl halide, hydrogen, and iodine in the vapor phase at a temperature of approximately 200 °C to approximately 600 °C in the presence of a catalyst to produce a product stream comprising trifluoroiodomethane, unreacted trifluoroacetyl halide, unreacted hydrogen, unreacted iodine, and hydrogen iodide. The catalyst comprises a transition metal. At least some of the unreacted iodine is removed from the product stream by cooling the product stream to condense the vapor-phase iodine. The condensed iodine is then recycled to the reaction stage. Aspect 56 is the process of Aspect 55, wherein the trifluoroacetyl halide comprises less than approximately 500 ppm by weight of water. Aspect 57 is the process of Aspect 55, wherein the trifluoroacetyl halide comprises less than approximately 100 ppm by weight of water. Aspect 58 is the process of Aspect 55, wherein the trifluoroacetyl halide comprises less than approximately 30 ppm by weight of water. Aspect 59 is the process of Aspect 55, wherein the trifluoroacetyl halide comprises less than approximately 10 ppm by weight of water. Aspect 60 is the process of any of Aspects 55-59, where hydrogen comprises less than approximately 500 ppm by weight of water. Aspect 61 is the process of any of Aspects 55-59, where hydrogen comprises less than approximately 100 ppm by weight of water. Aspect 62 is the process of any of Aspects 55-59, where hydrogen comprises less than approximately 30 ppm by weight of water. Aspect 63 is the process of any of Aspects 55-59, where hydrogen comprises less than approximately 10 ppm by weight of water. Aspect 64 is the process of any of Aspects 55-63, where iodine comprises less than approximately 500 ppm by weight of water. Aspect 65 is the process of any of Aspects 55-63, wherein the iodine comprises less than approximately qq / «nn / Lznz / E / YiAi 100 ppm by weight of water. Aspect 66 is the process of any of Aspects 55-63, where iodine comprises less than approximately 30 ppm by weight of water. Aspect 67 is the process of any of Aspects 55-63, where iodine comprises less than approximately 10 ppm by weight of water. Aspect 68 is the process of any of Aspects 55-67, where the molar ratio of hydrogen to iodine is from approximately 0.1:1 to approximately 5:1. Aspect 69 is the process of any of Aspects 55-67, where the molar ratio of hydrogen to iodine is from approximately 0.1:1 to approximately 1:1. Aspect 70 is the process of any of Aspects 55-67, where the molar ratio of hydrogen to iodine is approximately 0.3:1 to approximately 0.8:1. Aspect 71 is the process of any of Aspects 55-67, where the molar ratio of hydrogen to iodine is approximately 0.5:1 to approximately 0.7:1. Aspect 72 is the process of any of Aspects 55-71, wherein the molar ratio of hydrogen to trifluoroacetyl halide is from approximately 0.002:1 to approximately 1:1. Aspect 73 is the process of any of Aspects 55-71, wherein a molar ratio of hydrogen to trifluoroacetyl halide is from approximately 0.01:1 to approximately 0.05:1. Aspect 74 is the process of any of Aspects 55-73, wherein the vapor-phase reactants comprise less than approximately 500 ppm by weight of oxygen. Aspect 75 is the process of any of Aspects 55-73, wherein the vapor-phase reactants comprise less than approximately 100 ppm by weight of oxygen. Aspect 76 is the process of any of Aspects 55-73, wherein the vapor-phase reactants comprise less than approximately 10 ppm by weight of oxygen. Aspect 77 is the process of any of Aspects 55-73, wherein the vapor-phase reactants comprise less than approximately 3 ppm by weight of oxygen. Aspect 78 is the process of any of Aspects 55-77, wherein the transition metal includes at least one selected from the group of nickel, cobalt, iron, rhodium, iridium, platinum, and palladium. Aspect 79 is the process of any of Aspects 55-77, where the transition metal consists essentially of nickel, platinum, palladium, or combinations thereof. Aspect 80 is the process of any of Aspects 55-77, where the transition metal consists essentially of nickel, platinum, palladium, or combinations thereof. Aspect 81 is the process of any of the Aspects qq / «nn / Lznz / E / YiAi 55-77, where the transition metal consists essentially of palladium. Aspect 82 is the process of any of Aspects 55-81, wherein the catalyst further comprises a support that includes at least one selected from the group of an aluminum oxide support, a carbon support, a silica gel support, and a silicon carbide support. Aspect 83 is the process of any of Aspects 55-81, wherein the catalyst comprises, in addition to a support, essentially consisting of an aluminum oxide support. Aspect 84 is the process of either Aspect 82 or 83, wherein the amount of transition metal on the catalyst surface is from approximately 0.01 wt% to approximately 40 wt% of the total weight of the transition metal and support. Aspect 85 is the process of Aspect 84, wherein the transition metal includes at least one selected from the group of nickel, cobalt, iron, or combinations thereof, and the amount of transition metal on the catalyst surface is approximately 5 wt% to approximately 35 wt% of the total weight of the transition metal and support. Aspect 86 is the process of Aspect 84, wherein the transition metal includes at least one selected from the group of nickel, cobalt, iron, or combinations thereof, and the amount of transition metal on the catalyst surface is approximately 10 wt% to approximately 30 wt% of the total weight of the transition metal and support. Aspect 87 is the process of Aspect 84, wherein the transition metal includes at least one selected from the group of nickel, cobalt, iron, or combinations thereof, and the amount of transition metal on the catalyst surface is approximately 20 wt to approximately 30 wt of the total weight of the transition metal and support. Aspect 88 is the process of Aspect 84, wherein the transition metal includes nickel, the support includes aluminum oxide, and the nickel is approximately 21% by weight of the total weight of nickel and aluminum oxide. Aspect 89 is the process of Aspect 84, wherein the transition metal includes at least one selected from the group of rhodium, iridium, platinum, palladium, or combinations thereof, and the amount of transition metal on the catalyst surface is approximately 0.1 wt% to approximately 5 wt% of the total weight of the transition metal and support. Aspect 90 is the process of Aspect 84, wherein the transition metal includes at least one selected from the group of rhodium, iridium, platinum, palladium, or combinations thereof, and the amount of transition metal on the catalyst surface is approximately 0.3 wt% to approximately 1 wt% of the total weight of the transition metal and support. Aspect 91 is the process of Aspect 84, wherein the transition metal includes at least one selected from the group of rhodium, iridium, platinum, palladium, or combinations thereof, and the amount of transition metal on the catalyst surface is approximately 0.3 wt to approximately 0.7 wt of the total weight of the transition metal and support. Aspect 92 is the process of Aspect 84, wherein the transition metal includes palladium, the support includes aluminum oxide, and the palladium is approximately 0.5% by weight of the total weight of palladium and aluminum oxide. Aspect 93 is the process of any of Aspects 55-92, wherein the vapor-phase reactants are heated to a temperature of approximately 300 °C to approximately 400 °C. Aspect 94 is the process of any of Aspects 55-92, wherein the vapor-phase reactants are heated to a temperature of approximately 320 °C to approximately 360 °C. Aspect 95 is the process of any of Aspects 55-92, in which the vapor-phase reactants are heated to QQ! «nn / Lznz / Ε / ΥΙΛΙ a temperature of approximately 340 °C to approximately 360 °C. Aspect 96 is the process of any of Aspects 55-95, where in the reacting stage, the contact time of the vapor-phase reactants with the catalyst is from approximately 0.1 seconds to approximately 1200 seconds. Aspect 97 is the process of any of Aspects 55-95, where in the reacting stage, the contact time of the vapor-phase reactants with the catalyst is from approximately 1 second to approximately 100 seconds. Aspect 98 is the process of any of Aspects 55-95, where in the reacting stage, the contact time of the vapor-phase reactants with the catalyst is approximately 2 seconds to approximately 50 seconds. Aspect 99 is the process of any of Aspects 55-95, where in the reacting stage, the contact time of the vapor-phase reactants with the catalyst is approximately 10 seconds to approximately 30 seconds. Aspect 100 is the process of any of Aspects 55-99, wherein the process further comprises the additional steps of separating unreacted trifluoroacetyl halide from the product stream; and recycling the separated trifluoroacetyl halide to the reaction stage. Aspect 101 is the process of any of Aspects 55-100, wherein the process further comprises the additional steps of separating unreacted hydrogen iodide from the product stream; and recycling the separated hydrogen iodide to the reaction stage. Aspect 102 is the process of any of Aspects 55-101, where the process is a continuous process. Aspect 103 is the process of any of Aspects 55-101, where the process is a discontinuous process. Aspect 104 is the process of any of Aspects 55-103, wherein the trifluoroacetyl halide is selected from the group consisting of trifluoroacetyl fluoride, trifluoroacetyl chloride, trifluoroacetyl bromide, and any combination thereof. Aspect 105 is the process of any of Aspects 55-103, wherein the trifluoroacetyl halide comprises trifluoroacetyl chloride. Aspect 106 is the process of any of Aspects 55-103, wherein the trifluoroacetyl halide consists essentially of trifluoroacetyl chloride. Aspect 107 is the process of any of Aspects 55-103, wherein the trifluoroacetyl halide consists of trifluoroacetyl chloride. It is hereby stated that, as of this date, the best method known to the applicant for putting the aforementioned invention into practice is the one that is clear from the present description of the invention.

Claims

1. A process for producing trifluoroiodomethane (CF3I), characterized in that it comprises: providing vapor-phase reactants comprising trifluoroacetyl halide, hydrogen, and iodine; heating the vapor-phase reactants; and reacting the heated vapor-phase reactants in the presence of a catalyst to produce trifluoroiodomethane, the catalyst comprising a transition metal.

2. The process according to claim 1, characterized in that at the provisioning step, the trifluoroacetyl halide, iodine, and hydrogen each comprise less than approximately 500 ppm by weight of water.

3. The process according to claim 1 or 2, characterized in that at the proportioning step, a molar ratio of hydrogen to iodine is from approximately 0.1:1 to approximately 5:

1.

4. The process according to any of claims 1-3, characterized in that the transition metal includes at least one selected from the group of nickel, cobalt, iron, rhodium, iridium, platinum, and palladium.

5. The process according to claim 4, characterized in that the catalyst further comprises a support including at least one selected from the group of an aluminum oxide support, a carbon support, a silica gel support, and a silicon carbide support.

6. The process according to claim 5, characterized in that the transition metal is from approximately 0.1% by weight to approximately 40% by weight of the total weight of the transition metal and the support.

7. The process according to claim 6, characterized in that the transition metal includes palladium, the support includes aluminum oxide, and the palladium is approximately 0.5% by weight of the total weight of the palladium and aluminum oxide.

8. The process according to claim 6, characterized in that the transition metal includes nickel, the support includes aluminum oxide, and the nickel is approximately 21% by weight of the total weight of the nickel and aluminum oxide.

9. The process according to any of claims 1-8, characterized in that the vapor phase reactants are heated to a temperature of approximately 200 °C to approximately 600 °C.

10. The process according to any of claims 1-9, characterized in that it further comprises the additional steps of: separating the unreacted iodine from the trifluoroiodomethane; and returning the unreacted iodine to the providing step.