Method for removing hi / i2 / hi3 from trifluoroacetyl iodide (tfa i) feedstock and pyrolysis reactor effluent

Abstract

A method of producing trifluoroiodomethane (CF3I) includes providing a feedstock comprising trifluoroacetyl iodide (TFAI), passing the feedstock through at least one column loaded with a carbon-containing material to remove hydrogen iodide (HI), hydrogen triiodide (HI3), and iodine (I2) from the feedstock, and providing the feedstock to a reactor to produce a trifluoroiodomethane product stream. Another method of producing trifluoroiodomethane (CF3I) includes providing a feedstock comprising trifluoroacetyl iodide (TFAI) to a reactor to produce a trifluoroiodomethane product stream, and passing the trifluoroiodomethane product stream from the reactor through at least one column loaded with a carbon-containing material to remove hydrogen iodide (HI), hydrogen triiodide (HI3), and iodine (I2) from the trifluoroiodomethane product stream.

Description

[0001] This application is a divisional application of the invention application with application number "202180069919.4" and invention title "Method for removing HI / I2 / HI3 from trifluoroacetyl iodine (TFAI) feedstock and effluent from pyrolysis reactor".

[0002] Cross-references to related applications This application claims priority to U.S. Patent Application No. 17 / 495,511, filed October 6, 2021, which in turn claims priority to Provisional Application No. 63 / 091,727, filed October 14, 2020, both of which are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure relates to a method for producing trifluoroiodomethane (CF3I). Specifically, this disclosure relates to an improved method for producing trifluoroiodomethane from trifluoroacetyl iodide (TFAI) by removing hydrogen-containing and iodine-containing substances from a trifluoroacetyl iodide (TFAI) feedstock and from the reactor effluent. Background Technology

[0004] Trifluoromethyl iodide (CF3I), also known as perfluoromethyl iodide, trifluoromethyl iodide, or iodine trifluoromethane, is a compound that can be used commercially as a refrigerant or fire extinguishing agent. CF3I is an environmentally acceptable compound with low global warming and ozone depletion potentials. CF3I can replace more environmentally harmful substances.

[0005] Methods for preparing trifluoroiodomethane are known. For example, US Patent No. 7,132,578 (Mukhopadhyay et al.) discloses a one-step catalytic method for producing trifluoroiodomethane from trifluoroacetyl chloride. However, the iodine source is iodine fluoride (IF). Iodine fluoride is relatively unstable and decomposes into I₂ and IF₅ above 0°C. Iodine fluoride may also not be available in commercially available quantities.

[0006] For example, US Patent No. 7,196,236 (Mukhopadhyay et al.) discloses a catalytic method for producing trifluoroiodomethane using a reactant comprising an iodine source such as hydrogen iodide, at least a stoichiometric amount of oxygen, and a reactant CF3R (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 produced by this reaction can be oxidized by at least a stoichiometric amount of oxygen to produce water and iodine for economical recycling. Several other methods are cited in the literature for the preparation of trifluoroiodomethane (CF3I) from trifluoroacetyl chloride and hydrogen iodide in a vapor-phase reaction.

[0007] For example, U.S. Patent Application No. 16 / 549,412 discloses a two-step method for producing trifluoroiodomethane from trifluoroacetyl chloride. This method involves reacting CF3COCl + HI... The first step in the preparation of trifluoroacetyl iodide via the reaction of CF3COI + HCl. The second step in the preparation of trifluoroiodomethane via the reaction of CF3I + CO is composed of [missing information]. This method offers higher selectivity for trifluoroiodomethane (CF3I) than other methods.

[0008] In developing the aforementioned two-step process, the applicant discovered that even in the purified trifluoroacetyl iodide (TFAI) feed, one, two, or all three of the following impurities—HI, I2, and HI3—are present. During the conversion of trifluoroacetyl iodide (TFAI) to trifluoroiodomethane (CF3I), the presence of these hydrogen-containing substances such as HI and HI3 leads to an increase in the formation of byproducts such as CF3H (HFC-23). ​​Furthermore, the presence of iodine-containing substances such as I2 and HI3, along with additional I2 formed during the reaction, results in increased equipment corrosion and / or operational difficulties, including flow, pressure control, and clogging problems. These outcomes are unfavorable from the perspective of reduced productivity of the desired product and increased operating costs. Therefore, a method is needed to remove HI / I2 / HI3 from the trifluoroacetyl iodide (TFAI) feedstock and to remove I2 from the reactor effluent from step 2. Summary of the Invention

[0009] This disclosure provides a method for producing trifluoroiodomethane (CF3I) from a feedstock containing trifluoroacetyl iodide (TFAI).

[0010] In one embodiment, the present invention provides a method for producing trifluoroiodomethane (CF3I), the method comprising: providing a feedstock comprising trifluoroacetyl iodide (TFAI); passing the feedstock through at least one tower loaded with carbonaceous material to remove hydrogen iodide (HI), hydrogen triiodide (HI3), and iodine (I2) from the feedstock; and providing the feedstock to a reactor to produce a trifluoroiodomethane product stream.

[0011] In another embodiment, the present invention provides a method for producing trifluoroiodomethane (CF3I), the method comprising: providing a feedstock comprising trifluoroacetyl iodide (TFAI); providing the feedstock to a reactor to produce a trifluoroiodomethane product stream; and passing the trifluoroiodomethane product stream from the reactor through at least one tower loaded with carbon-containing material to remove hydrogen iodide (HI), hydrogen triiodide (HI3), and iodine (I2) from the trifluoroiodomethane product stream.

[0012] The above and other features of this disclosure, as well as the ways in which they are implemented, will become more apparent and better understood by referring to the following description of the implementation scheme. Attached Figure Description

[0013] Figure 1 The changes in selectivity for trifluoroiodide methane (CF3I) are shown using waste activated carbon towers and fresh activated carbon towers.

[0014] Figure 2 The changes in selectivity for trifluoromethane (CF3H) are shown using waste activated carbon towers and fresh activated carbon towers. Detailed Implementation

[0015] This disclosure provides a method for removing hydrogen-containing and iodine-containing substances from the trifluoroacetyl iodide (TFAI) feedstock and from the reactor effluent during the conversion of trifluoroacetyl iodide (TFAI) to trifluoroiodomethane (CF3I).

[0016] As disclosed in U.S. Patent Application No. 16 / 549,412, trifluoroiodimethane (CF3I) can be formed by the decomposition of trifluoroacetyl iodide (TFAI) according to the following formula 1: Formula 1: CF3COI CF3I + CO.

[0017] The reaction can be carried out in a heated tube reactor, which comprises tubes made of metals such as stainless steel, nickel, and / or nickel alloys such as nickel-chromium alloys, nickel-molybdenum alloys, nickel-chromium-molybdenum alloys, or nickel-copper alloys. The tubes within the reactor can be heated. The reactor can also comprise any type of packed bed reactor. The packing material can be a catalyst or an inert material that improves heat transfer and promotes mixing of reactants and products.

[0018] The reaction can be carried out at a temperature of about 200°C or higher, about 250°C or higher, about 300°C or higher, about 350°C or higher, about 400°C or lower, about 450°C or lower, about 500°C or lower, about 550°C or lower, about 600°C or lower, or in any range covering these endpoints. Preferably, the temperature is from about 300°C to about 500°C. More preferably, the temperature is from about 350°C to about 450°C.

[0019] The reaction can be carried out at pressures of about 0 psig or higher, about 5 psig or higher, about 20 psig or higher, about 50 psig or higher, about 70 psig or higher, about 100 psig or higher, about 150 psig or lower, about 200 psig or lower, about 225 psig or lower, about 250 psig or lower, about 275 psig or lower, about 300 psig, or any range including these endpoints. Preferably, the reaction is carried out at pressures of about 5 psig to about 275 psig. More preferably, the reaction is carried out at pressures of about 10 psig to about 250 psig.

[0020] The contact time of the reaction can be about 0.1 seconds or more, about 1 second or more, about 5 seconds or more, about 10 seconds or more, about 60 seconds or more, about 100 seconds or less, about 150 seconds or less, about 200 seconds or less, about 250 seconds or less, about 300 seconds or less, about 600 seconds or less, or within any range covering these endpoints. Preferably, the contact time of the reaction is from about 0.1 seconds to about 60 seconds. More preferably, the contact time of the reaction is from about 0.1 seconds to about 10 seconds.

[0021] The reaction can be carried out in the presence of a catalyst. The catalyst may include stainless steel, nickel, nickel-chromium alloys, nickel-chromium-molybdenum alloys, nickel-copper alloys, copper, alumina, silicon carbide, platinum, palladium, rhenium, activated carbon (such as Norit PK 3-5, Calgon, or Shirasagi carbon), or combinations thereof. Alternatively, the reaction can be carried out in the absence of a catalyst.

[0022] Without wishing to be bound by any particular operational theory, certain aspects of this disclosure are based on the observation and understanding that the presence of certain hydrogen-containing substances, including HI and HI3, during the reaction leads to an increase in the formation of some byproducts such as CF3H (HFC-23) and iodine (I2) according to Equation 2: Equation 2: CF3COI + HI / HI3 CF3H + CO + I2.

[0023] The formation of trifluoromethane (CF3H) is undesirable because it inevitably leads to a reduced yield of the target product, trifluoroiodomethane (CF3I). Similarly, the formation of iodine (I2) in the trifluoroacetyl iodide (TFAI) feed stream via the aforementioned side reactions during the decomposition of TFAI is also undesirable, as the formation of solid iodine (I2) causes increased equipment corrosion and operational problems such as clogging.

[0024] It has been found that hydrogen-containing and iodine-containing substances, including HI, HI3, and I2, can be reduced and / or removed from the trifluoroacetyl iodide (TFAI) feed stream and reactor effluent stream through an adsorption process on a carbon-containing material. This method results in improved selectivity of trifluoroacetyl iodide (CF3I) relative to trifluoromethane (CF3H) and reduced operational problems such as clogging.

[0025] This disclosure provides a method using at least one tower loaded with a carbonaceous material. The tower can be positioned such that hydrogen-containing and iodine-containing substances, such as HI, HI3, and I2, can be removed from the trifluoroacetyl iodide (TFAI) feedstock before it enters the reaction chamber to form trifluoroiodomethane (CF3I), as shown in Formula 1 above. Without being bound by theory, removing these substances from the trifluoroiodomethane feedstock limits undesirable side reactions leading to the formation of trifluoromethane (CF3H), as shown in Formula 2. Therefore, the selectivity of the reaction to the desired trifluoroiodomethane (CF3I) can be improved. Furthermore, the formation of iodine (I2) can be limited, thereby limiting operational problems such as clogging and corrosion.

[0026] In one embodiment, at least one tower loaded with carbonaceous material is installed, allowing the trifluoroacetyl iodine (TFAI) feedstock to be recycled through the tower before being fed to the reactor. In another embodiment, at least one tower loaded with carbonaceous material is installed in the trifluoroacetyl iodine (TFAI) feed line, and the trifluoroacetyl iodine (TFAI) feedstock passes through the tower before being fed to the reactor. In yet another embodiment, at least one tower loaded with carbonaceous material is installed in the trifluoroacetyl iodine (TFAI) feed line, allowing the trifluoroacetyl iodine (TFAI) feedstock to be recycled through the tower before being fed to the reactor, and the trifluoroacetyl iodine (TFAI) feedstock passes through the tower before being fed to the reactor.

[0027] Trifluoroacetyl iodine (TFAI) passing through at least one column loaded with carbonaceous material before being fed to the reactor can be in liquid form, vapor form, or any combination of both. Preferably, TFAI is in liquid form. The column is operated at temperatures as low as about 0°C, about 10°C, about 20°C, about 30°C, or about 40°C, or as high as about 50°C, about 60°C, about 70°C, about 80°C, about 90°C, or about 100°C, or any range defined between any two of the foregoing values, such as, for example, about 0°C to about 100°C, about 10°C to about 90°C, about 20°C to about 80°C, about 30°C to about 70°C, about 40°C to about 60°C, about 50°C to about 70°C, about 40°C to about 50°C, about 60°C to about 90°C, about 0°C to about 60°C, or about 20°C to about 40°C. Preferably, the column is operated at a temperature of about 0°C to about 60°C. More preferably, the tower is operated at a temperature of about 20°C to about 40°C.

[0028] The column operates at pressures slightly above the reactor pressure or at pressures as low as about 0 psig, about 5 psig, about 20 psig, about 50 psig, about 70 psig, or about 100 psig, or as high as about 150 psig, about 200 psig, about 250 psig, or about 300 psig, or any pressure within any range defined between any two of the foregoing values, such as, for example, about 0 psig to about 300 psig, about 5 psig to about 250 psig, about 20 psig to about 200 psig, about 50 psig to about 150 psig, about 5 psig to about 100 psig, about 20 psig to about 70 psig, or about 150 psig to about 250 psig. Preferably, the column operates at a pressure of about 5 psig to about 250 psig. More preferably, the column operates at a pressure of about 10 psig to about 100 psig.

[0029] Stable and controllable flow of trifluoroacetyl iodide (TFAI) can be achieved by passing it through at least one column loaded with carbonaceous material before it is fed into the reactor. Furthermore, compared to methods that do not use at least one column loaded with carbonaceous material, a relative flow of trifluoroacetyl iodide methane (CF3I) to trifluoromethane (CF2) can be achieved. 3- Higher selectivity for H).

[0030] This disclosure also provides a method in which at least one additional tower loaded with carbonaceous material is installed in the reactor effluent line. Specifically, a first tower loaded with carbonaceous material is installed such that hydrogen-containing and iodine-containing substances, such as hydrogen iodide (HI), hydrogen triiodide (HI3), and iodine (I2), can be removed from the trifluoroacetyl iodide (TFAI) feedstock as described above before entering the reactor, and a second tower loaded with carbonaceous material is installed in the reactor effluent line. In this method, the first tower can be installed in the trifluoroacetyl iodide (TFAI) feedstock to remove hydrogen-containing and iodine-containing substances, and the second tower can be installed in the reactor effluent line to remove hydrogen-containing and iodine-containing substances, including iodine (I2), from the desired trifluoroiodomethane (CF3I) product stream. Iodine (I2) can be additionally formed in undesirable side reactions, as shown in Formula 2. By passing the reactor effluent stream through the tower loaded with carbonaceous material to remove iodine (I2), the formation of solid iodine (I2) is prevented, thereby limiting operational problems such as equipment blockage and corrosion.

[0031] In this method, the first column operates as described above, and the second column operates at temperatures as low as about 0°C, about 10°C, about 20°C, about 30°C, or about 40°C, or as high as about 50°C, about 60°C, about 70°C, about 80°C, about 90°C, or about 100°C, or any temperature within any range defined between any two of the foregoing values, such as, for example, about 0°C to about 100°C, about 10°C to about 90°C, about 20°C to about 80°C, about 30°C to about 70°C, about 40°C to about 60°C, about 50°C to about 70°C, about 40°C to about 50°C, about 60°C to about 90°C, about 40°C to about 80°C, or about 50°C to about 70°C. Preferably, the second column operates at a temperature of about 40°C to about 80°C. More preferably, the second column operates at a temperature of about 50°C to about 70°C.

[0032] This disclosure also provides a method in which at least one tower loaded with carbonaceous material is installed in a reactor effluent line, as described above. The tower operates as described above. In this method, no tower is placed such that hydrogen-containing and iodine-containing substances, such as HI, HI3, and I2, can be removed from the trifluoroacetyl iodine (TFAI) feedstock before it enters the reactor.

[0033] Suitable carbon-containing materials may include activated carbon, carbon black, and carbon molecular sieves. When using activated carbon, it is preferred to have an iodine value higher than 500 (surface area greater than 900 m²). 2 Activated carbon with an iodine value of 500 (approximately 100 g / g) is preferred. The iodine value can be determined, for example, by ASTM D4607. When using carbon black, an iodine value higher than 500 (surface area greater than 400 m²) is preferred. 2 Those carbon blacks ( / g). Iodine value can be determined, for example, by ASTM D1510-16. When using carbon molecular sieves, those with an average pore size greater than 2 Å are preferred.

[0034] As used in this article, the phrase “any range between any two of the preceding values” literally means that any range can be selected from any two values ​​listed before such a phrase, regardless of whether these values ​​are in the lower or higher part of the list. For example, a pair of values ​​can be selected from two lower values, two higher values, or a lower value and a higher value.

[0035] As used herein, the modifier “approximately” when used with a quantity includes the value and has a meaning indicated by the context (e.g., it includes at least the degree of error associated with the measurement of the particular quantity). When used in the context of a range, the modifier “approximately” should also be considered as publicly defining a range by the absolute values ​​of its two endpoints.

[0036] The following non-limiting embodiments are used to illustrate this disclosure. Example

[0037] Example 1: Analysis of treated trifluoroacetyl iodine (TFAI) 29.2g of iodine with a BET surface area of ​​1225m² was packed into a stainless steel tower with an outer diameter of 1 inch and a length of 9 inches. 2 / g fresh Norit ROX 0.8 activated carbon. Prepare two 300mL collection cylinders. The first cylinder is connected to the outlet of the trifluoroacetyl iodine (TFAI) feed line and placed in a Dewar flask filled with wet ice and set on a balance. The TFAI flow is started at 0.25 lb / hr and passed through an activated carbon (AC) column at room temperature. This flow is then directed to a scrubber large container until liquid is observed entering the large container, indicating that the entire feed line is filled with liquid. Next, the feed flow path is switched to the collection cylinder for approximately 3 hours, totaling approximately 0.75 lb, as confirmed by the increase in weight on the balance. The cylinder is isolated and replaced with the second cylinder, and the flow of TFAI to the new collection cylinder is restarted. The two collection cylinders of TFAI are used together with the cylinder containing the original TFAI feed for various analyses, including I2 titration and 1 H NMR.

[0038] The iodine concentration was determined by adding the sample to 36 g of deionized water, mixing, adding 4.0 g of KI, mixing again, and titrating with sodium thiosulfate. The result was obtained by Proton NMR (…). 1 The 1H-NMR method involves transferring the sample into a thick-walled, valved NMR tube containing deuterated chloroform (CDCl3) with a calibrated tetramethylsilane (TMS) standard to determine the concentrations of hydrogen- and iodine-containing substances. The concentrations of identified components in the sample are calculated based on the integrated values ​​of the sample peaks. The sample analysis is performed using a 300 MHz field strength.

[0039] The concentrations of I2 and other hydrogen-containing substances and iodine-containing substances such as HI and HI3 were compared before and after treatment with an activated carbon (AC) tower. The results of these analyses are shown in Table 1 below.

[0040] Table 1 .

[0041] Example 2 - Changes in selectivity when using spent activated carbon and fresh activated carbon The selectivity of trifluoroiodomethane (CF3I) and trifluoromethane (CF3H) was tested using spent and fresh activated carbon. The decomposition reaction of Equation 1 was continuously carried out at 390°C, 25 psig, 0.25 lb / h, and 2.4 seconds (contact time) while simultaneously reducing the concentration of hydrogen-containing impurities in the TFAI feedstock by passing liquid trifluoroacetyl iodide (TFAI) through a column packed with 29.4 g of Norit ROX 0.8 activated carbon (AC) at room temperature. AC effectively absorbed hydrogen-containing impurities, such as HI and HI3, from the TFAI feedstock, improving selectivity for the desired trifluoroiodomethane (CF3I) product while minimizing the formation of trifluoromethane (CF3H). Once the activated carbon was depleted, hydrogen-containing impurities such as HI and HI3 from the TFAI feedstock were fed into the reactor along with the feedstock. Figure 1 As shown in section 10, once the AC column is depleted, the selectivity of trifluoromethane (CF3I) decreases by approximately 2%. Once the spent AC is replaced with fresh AC, the selectivity of trifluoromethane (CF3I) immediately returns to its original level, as... Figure 1 Section 12 is shown.

[0042] like Figure 2 As shown in section 14, once AC is depleted, the formation of trifluoromethane (CF3H) increases by approximately 1.1%. Upon replacement of the spent AC with fresh AC, the selectivity for trifluoromethane (CF3H) immediately returns to its original level, as... Figure 2 Section 16 is shown.

[0043] Example 3 - Effect of filtered raw materials on product selectivity Next, the effectiveness of using activated carbon (AC) to remove hydrogen-containing impurities such as HI and HI3, as well as iodine (I2), from trifluoroacetyl iodide (TFAI) was tested. The decomposition reaction according to Equation 1 above was carried out at 300 °C, 25 psig, a TFAI feed rate of 0.25 lb / h, and a contact time of 4.9 seconds. 29.5 g of fresh Norit ROX 0.8 activated carbon (AC) was loaded into a 1-inch outer diameter × 9-inch length stainless steel column, which, along with a bypass loop surrounding the column, was installed in the TFAI feed line. Liquid TFAI feed was passed through the column at room temperature (“run”). Gas chromatography (GC) data of the reactor and reactor effluent were collected over 48 hours. The average selectivity for trifluoroacetyl iodide methane (CF3I) was 99.62%. The major byproduct was trifluoromethane (CF3H).

[0044] Next, the same trifluoroacetyl iodide (TFAI) feedstock was used untreated (i.e., bypassed the AC tower, "bypass") and under the same reaction conditions as described above for approximately 48 hours. The average selectivity for trifluoroiodide methane (CF3I) decreased to 99.33%, while the selectivity for the same major impurity (trifluoromethane, CF3H) increased.

[0045] The experiments were repeated with different trifluoroacetyl iodine (TFAI) feedstocks, and the same trend was observed. The test results are shown in Table 2 below. The tests indicate that using an AC tower installed on the trifluoroacetyl iodine (TFAI) feedline results in improved selectivity for trifluoroiodomethane (CF3I), while the trifluoroacetyl iodine (TFAI) conversion remains at a comparable level.

[0046] Table 2 *Others include trifluoroacetyl fluoride, C2F5I, etc.

[0047] The activated carbon tower used in Example 2 was removed from the trifluoroacetyl iodine (TFAI) pipeline, and the AC was discharged and weighed. After use, the activated carbon weighed 2.7 times its initial weight, indicating that it had adsorbed a large amount of substances present in the trifluoroacetyl iodine (TFAI) feed. The AC was further analyzed by TGA-MS (thermogravimetric analysis-mass spectrometry) to determine the nature of the adsorbed substances. As shown in Table 3, the substances desorbed during TGA included I2, HI, and trifluoroacetyl iodine (TFAI). The absence of HI3 among the detected substances may be due to its instability upon heating, during which HI3 can decompose into HI and iodine (I2).

[0048] Table 3 Analytes m / z Peak intensity* Notes <![CDATA[CF3]]> 69 8.36E-11 <![CDATA[CF3 fragment]]> I 127 7.78E-10 Fragment I HI 128 1.98E-11 HI molecules <![CDATA[CF3I]]> 196 1.80E-11 <![CDATA[CF3I molecule or TFAI fragment**]]> <![CDATA[I2]]> 254 8.12E-10 <![CDATA[I2 molecule]]> The higher the peak intensity, the higher the concentration of the analyte. This is more likely to represent the CF3I fragment from the TFAI molecule, assuming the TFAI feed passes through the AC tower.

[0049] These results, together with those of Example 1, demonstrate that AC can be used to remove I2, HI, and HI3 from trifluoroacetyl iodine (TFAI) feedstock.

[0050] Example 4 - The effect of combining filtered raw materials and filtered effluent The reaction was carried out under the same conditions as described in Example 3, wherein an activated carbon (AC) tower was installed on the trifluoroacetyl iodine (TFAI) feed line as described in Example 3. During the reaction, the reactor outlet line was confined by solid I₂ crystals (precipitated from the gas-phase reactor effluent) on average every 38 hours. A tower filled with Norit ROX 0.8 activated carbon (AC) was installed in the reactor outlet line and maintained at 60°C during operation without altering the other conditions. In this case, the average time before iodine crystal-induced confinement in the reactor outlet line increased to over 100 hours due to iodine (I₂) adsorption by AC.

[0051] The activated carbon tower used above was removed from the reactor outlet line, and the waste AC was analyzed by TGA-MS (thermogravimetric analysis-mass spectrometry) to determine the properties of the adsorbed substances. As shown in Table 4, the substances desorbed during TGA included I2, HI, and trifluoroacetyl iodine (TFAI). The absence of HI3 among the detected substances may be due to its instability upon heating, during which HI3 can decompose into HI and iodine (I2).

[0052] Table 4 Analytes m / z Peak intensity* Notes <![CDATA[CF3]]> 69 1.94E-11 <![CDATA[CF3 fragment]]> I 127 1.23E-9 Fragment I HI 128 9.01E-11 HI molecules <![CDATA[CF3I]]> 196 7.98E-12 <![CDATA[CF3I molecule and / or TFAI fragment**]]> <![CDATA[I2]]> 254 1.63E-9 <![CDATA[I2 molecule]]> The higher the peak intensity, the higher the concentration of the analyte. This could represent CF3I molecules and TFAI fragments, as both CF3I and TFAI are present in the reactor effluent stream.

[0053] These results, together with those of Example 1, demonstrate that AC can be used to remove I2, HI, and HI3 from the reactor effluent when trifluoroacetyl iodide (TFAI) is converted to trifluoroiodomethane (CF3I).

[0054] Example 5: The effect of filtered effluent In this embodiment, the column loaded with activated carbon (AC) as described in Example 3 was not installed on the trifluoroacetyl iodine (TFAI) feed line. The column was filled with Norit ROX 0.8 activated carbon (AC) and installed in the reactor outlet line. The reaction outlet line could be maintained at 60°C during operation without altering the other conditions. Therefore, the average time before iodine crystal-induced confinement in the reactor outlet line may be increased due to iodine (I₂) adsorption by AC.

[0055] aspect Aspect 1 is a method for producing trifluoroiodomethane (CF3I). The method includes: providing a feedstock containing trifluoroacetyl iodide (TFAI); passing the feedstock through at least one tower loaded with carbonaceous material to remove hydrogen iodide (HI), hydrogen triiodide (HI3), and iodine (I2) from the feedstock; and providing the feedstock to a reactor to produce a trifluoroiodomethane product stream.

[0056] Aspect 2 is the method according to aspect 1, wherein passing the raw material through at least one tower loaded with carbonaceous material comprises: passing the raw material through the at least one tower just before it is to be provided to the reactor.

[0057] Aspect 3 is the method according to aspect 1, wherein passing the raw material through at least one tower loaded with carbonaceous material comprises: recirculating the raw material through the at least one tower before providing the raw material to the reactor.

[0058] Aspect 4 is the method according to aspect 1, wherein the at least one tower loaded with carbon-containing material comprises at least two towers, and passing the raw material through the at least one tower loaded with carbon-containing material comprises: recirculating the raw material through one of the two towers before it is about to be supplied to the reactor, and then passing the raw material through the other of the two towers.

[0059] Aspect 5 is the method according to any one of aspects 1 to 4, wherein the at least one tower is operated at a temperature of about 0°C to about 100°C.

[0060] Aspect 6 is the method according to any one of aspects 1 to 4, wherein the at least one tower is operated at a temperature of about 0°C to about 60°C.

[0061] Aspect 7 is the method according to any one of aspects 1 to 4, wherein the at least one tower is operated at a temperature of about 20°C to about 40°C.

[0062] Aspect 8 is the method according to any one of aspects 1 to 7, wherein the at least one tower is operated at a pressure of about 0 psig to about 300 psig.

[0063] Aspect 9 is the method according to any one of aspects 1 to 7, wherein the at least one tower is operated at a pressure of about 5 psig to about 250 psig.

[0064] Aspect 10 is the method according to any one of aspects 1 to 7, wherein the at least one tower is operated at a pressure of about 10 psig to about 100 psig.

[0065] Aspect 11 is the method according to any one of aspects 1 to 10, wherein the carbon-containing material is selected from the group consisting of activated carbon, carbon black and carbon molecular sieves.

[0066] Aspect 12 is the method according to aspect 11, wherein the carbon-containing material comprises an iodine value of at least 500 and a surface area of ​​at least 900 m². 2 / g of activated carbon.

[0067] Aspect 13 is the method according to aspect 11, wherein the carbon-containing material comprises an iodine value of at least 500 and a surface area of ​​at least 400 m². 2 / g of carbon black.

[0068] Aspect 14 is the method according to aspect 11, wherein the carbon-containing material comprises a carbon molecular sieve with a pore size of at least about 2 Å.

[0069] Aspect 15 is a method according to any one of aspects 1 to 14, wherein at least one tower loaded with carbon-containing material is at least one first tower, and the method further comprises: passing the trifluoroiodomethane product stream from the reactor through at least one second tower loaded with carbon-containing material to remove hydrogen iodide (HI), hydrogen triiodide (HI3) and iodine (I2) from the trifluoroiodomethane product stream.

[0070] Aspect 16 is the method according to aspect 15, wherein the at least one first tower operates at a temperature of about 0°C to about 100°C, and the second tower operates at a temperature of about 0°C to about 100°C.

[0071] Aspect 17 is the method according to aspect 15, wherein the at least one first tower operates at a temperature of about 0°C to about 60°C, and the second tower operates at a temperature of about 40°C to about 80°C.

[0072] Aspect 18 is the method according to aspect 15, wherein the at least one first tower operates at a temperature of about 20°C to about 40°C, and the second tower operates at a temperature of about 50°C to about 70°C.

[0073] Aspect 19 is the method according to any one of aspects 15 to 18, wherein the carbon-containing material in the at least one second tower is selected from the group consisting of activated carbon, carbon black and carbon molecular sieves.

[0074] Aspect 20 is the method according to aspect 19, wherein the carbon-containing material in the at least one second tower comprises an iodine value of at least 500 and a surface area of ​​at least 900 m². 2 / g of activated carbon.

[0075] Aspect 21 is the method according to aspect 19, wherein the carbon-containing material in the at least one second tower comprises an iodine value of at least 500 and a surface area of ​​at least 400 m². 2 / g of carbon black.

[0076] Aspect 22 is the method according to aspect 19, wherein the carbon-containing material in the at least one second tower comprises a carbon molecular sieve with a pore size of at least about 2 Å.

[0077] Aspect 23 is a method for producing trifluoroiodomethane (CF3I). The method includes: providing a feedstock comprising trifluoroacetyl iodide (TFAI); providing the feedstock to a reactor to produce a trifluoroiodomethane product stream; and passing the trifluoroiodomethane product stream from the reactor through at least one tower loaded with carbon-containing material to remove hydrogen iodide (HI), hydrogen triiodide (HI3), and iodine (I2) from the trifluoroiodomethane product stream.

[0078] Aspect 24 is the method according to aspect 23, wherein the at least one tower operates at a temperature of about 0°C to about 100°C.

[0079] Aspect 25 is the method according to aspect 23, wherein the at least one tower operates at a temperature of about 40°C to about 80°C.

[0080] Aspect 26 is the method according to aspect 23, wherein the at least one tower operates at a temperature of about 50°C to about 70°C.

[0081] Aspect 27 is the method according to any one of aspects 23 to 26, wherein the carbon-containing material is selected from the group consisting of activated carbon, carbon black and carbon molecular sieves.

[0082] Aspect 28 is the method according to aspect 27, wherein the carbon-containing material comprises an iodine value of at least 500 and a surface area of ​​at least 900 m². 2 / g of activated carbon.

[0083] Aspect 29 is the method according to aspect 27, wherein the carbon-containing material comprises an iodine value of at least 500 and a surface area of ​​at least 400 m². 2 / g of carbon black.

[0084] Aspect 30 is the method according to aspect 27, wherein the carbon-containing material comprises a carbon molecular sieve with a pore size of at least about 2 Å.

[0085] Aspect 31 is a method for producing trifluoroiodomethane (CF3I). The method includes: providing a feedstock comprising trifluoroacetyl iodide (TFAI); passing the feedstock through at least one column loaded with a carbon-containing material to remove hydrogen iodide (HI), hydrogen triiodide (HI3), and iodine (I2) from the feedstock; and providing the feedstock to a reactor to produce a trifluoroiodomethane product stream. The at least one column operates at a temperature of about 20°C to about 40°C. The at least one column operates at a pressure of about 10 psig to about 100 psig. The carbon-containing material comprises an iodine value of at least 500 and a surface area of ​​at least 900 m². 2 / g of activated carbon, with an iodine value of at least 500 and a surface area of ​​at least 400m². 2 / g of carbon black, or carbon molecular sieves with a pore size of at least about 2 Å.

[0086] Aspect 32 is the method according to aspect 31, wherein passing the raw material through at least one tower loaded with carbon-containing material comprises: passing the raw material through the at least one tower before it is about to be supplied to the reactor; passing the raw material through at least one tower loaded with carbon-containing material comprises: recycling the raw material through the at least one tower before it is about to be supplied to the reactor; or passing the raw material through at least one tower loaded with carbon-containing material comprises: recycling the raw material through one of two towers before it is about to be supplied to the reactor, and then passing the raw material through the other of the two towers.

[0087] Aspect 33 is the method according to aspect 31 or aspect 32, wherein at least one column loaded with carbon-containing material is at least one first column, and the method further comprises: passing the trifluoroiodomethane product stream from the reactor through at least one second column loaded with carbon-containing material to remove hydrogen iodide (HI), hydrogen triiodide (HI3), and iodine (I2) from the trifluoroiodomethane product stream. The at least one first column operates at a temperature of about 20°C to about 40°C, and the second column operates at a temperature of about 50°C to about 70°C. The at least one first column operates at a pressure of about 10 psig to about 100 psig. The carbon-containing material in the first column comprises an iodine value of at least 500 and a surface area of ​​at least 900 m². 2 / g of activated carbon, with an iodine value of at least 500 and a surface area of ​​at least 400m². 2 / g of carbon black, or carbon molecular sieves with a pore size of at least about 2 Å. The carbon-containing material in the second column comprises an iodine value of at least 500 and a surface area of ​​at least 900 m². 2 / g of activated carbon, with an iodine value of at least 500 and a surface area of ​​at least 400m². 2 / g of carbon black, or carbon molecular sieves with a pore size of at least about 2 Å.

[0088] Aspect 34 is a method for producing trifluoroiodomethane (CF3I). The method includes: providing a feedstock comprising trifluoroacetyl iodide (TFAI); providing the feedstock to a reactor to produce a trifluoroiodomethane product stream; and passing the trifluoroiodomethane product stream from the reactor through at least one column loaded with a carbon-containing material to remove hydrogen iodide (HI), hydrogen triiodide (HI3), and iodine (I2) from the trifluoroiodomethane product stream. The at least one column operates at a temperature of about 50°C to about 70°C. The carbon-containing material comprises an iodine value of at least 500 and a surface area of ​​at least 900 m². 2 / g of activated carbon, with an iodine value of at least 500 and a surface area of ​​at least 400m². 2 / g of carbon black, or carbon molecular sieves with a pore size of at least about 2 Å.

Claims

1. A method for producing trifluoroiodomethane (CF3I), the method comprising: Provide raw materials containing trifluoroacetyl iodine (TFAI); The raw material is passed through at least one tower loaded with carbonaceous material to remove hydrogen iodide (HI), hydrogen triiodide (HI3), and iodine (I2) from the raw material; and The raw material is fed to the reactor to produce a trifluoroiodomethane product stream.

2. The method of claim 1, wherein passing the raw material through at least one tower loaded with a carbon-containing material comprises: The raw material is passed through at least one tower just before it is supplied to the reactor.

3. The method of claim 1, wherein passing the raw material through at least one tower loaded with a carbon-containing material comprises: The raw material is recycled through the at least one tower before being supplied to the reactor.

4. The method of claim 1, wherein the at least one tower loaded with carbon-containing material comprises at least two towers, and passing the raw material through the at least one tower loaded with carbon-containing material comprises: Before the raw material is supplied to the reactor, it is recycled through one of the two towers, and then through the other of the two towers.

5. The method of claim 1, wherein the at least one tower operates at a temperature of about 0°C to about 100°C.

6. The method of claim 1, wherein the at least one tower operates at a pressure of about 0 psig to about 300 psig.

7. The method of claim 1, wherein at least one tower loaded with carbonaceous material is at least one first tower, and the method further comprises: The trifluoroiodomethane product stream from the reactor is passed through at least one second tower loaded with carbon-containing material to remove hydrogen iodide (HI), hydrogen triiodide (HI3), and iodine (I2) from the trifluoroiodomethane product stream.

8. The method of claim 7, wherein the at least one first tower operates at a temperature of about 0°C to about 100°C, and the second tower operates at a temperature of about 0°C to about 100°C.

9. A method for producing trifluoroiodomethane (CF3I), the method comprising: A feedstock containing trifluoroacetyl iodide (TFAI) is fed into the reactor to produce a trifluoroiodomethane product stream; as well as The trifluoroiodomethane product stream from the reactor is passed through at least one tower loaded with carbon-containing material to remove hydrogen iodide (HI), hydrogen triiodide (HI3), and iodine (I2) from the trifluoroiodomethane product stream.

10. The method of claim 9, wherein the at least one tower operates at a temperature of about 0°C to about 100°C.

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