Azeotrope or azeotrope-like compositions of 2-chloro-3,3,3-trifluoropropene (hcfo-1233xf) and water

Abstract

To provide an azeotrope for separating impurities including water, from 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf).SOLUTION: There is provided a heterogenous azeotrope or azeotrope-like compositions comprising 2-chloro-3,3,3- trifluoropropene (HFCO-1233xf) and water which may include from about 0.09 wt.% to about 92.69 wt.% 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and from about 7.31 wt.% to about 99.91 wt.% water and having a boiling point between about 12.0°C and about 13.6°C at a pressure of between about 12.5 psia and about 16.5 psia.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001]

[0001] This disclosure relates to an azeotropic mixture or azeotrope-like composition, and more particularly, to an azeotropic mixture or azeotrope-like composition containing an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water.

Background Art

[0002]

[0002] Hydrofluoroolefins (HFOs) such as tetrafluoropropene containing 2,3,3,3-tetrafluoropropene (HFO-1234yf) are known to be effective refrigerants, heat transfer media, propellants, foaming agents, blowing agents, gas dielectrics, sterilant carriers, polymerization media, particle removal fluids, carrier fluids, buffing abrasives, replacement desiccants, and power cycle working fluids. Unlike chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), which can both damage the Earth's ozone layer, HFOs do not pose a threat to the ozone layer. HFO-1234yf has also been shown to be a compound with low toxicity and a low global warming potential, and thus can meet the increasingly stringent requirements for refrigerants in mobile air conditioning units. Therefore, compositions containing HFO-1234yf are one of the materials being developed for use in many of the aforementioned applications.

[0003]

[0003] One method for manufacturing HFO-1234yf uses 1,1,2,3-tetrachloropropene (HCFC-1230xa) as a starting material. This method includes the following three steps: Step (1) 1230xa + 3HF -> 2-chloro-3,3,3-trifluoropropene (1233xf) + 3HCl in a gas-phase reactor filled with a solid catalyst, Step (2) 1233xf + HF -> 2-chloro-1,1,1,2-tetrafluoropropane (244bb) in a liquid-phase reactor filled with a liquid catalyst, and Step (3) 244bb -> 1234yf + HCl in a gas-phase reactor or in the liquid phase.

[0004] During the above method, by-products may be generated and / or impurities containing water may be present. In order to limit unwanted side reactions, it is desirable to have all reactants and intermediate products in the highest possible purity form. Therefore, a method for reducing impurities in reactants and intermediate products is desired.

Summary of the Invention

[0005]

[0004] The present disclosure provides an azeotropic mixture or azeotrope-like composition of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water.

[0005] It is well recognized in the art that it is impossible to predict the formation of an azeotropic mixture. The inventors unexpectedly discovered that 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water form an azeotropic mixture or an azeotrope-like composition, specifically, a heterogeneous azeotropic mixture or an azeotrope-like composition.

[0006]

[0006] The present disclosure provides a composition comprising an azeotropic mixture or azeotrope-like composition consisting essentially of an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water. Preferably, the azeotropic mixture or azeotrope-like composition has a boiling point of about 12.0 °C to about 13.6 °C, preferably about 13.1 °C to about 13.2 °C at a pressure of about 12.5 psia to about 16.5 psia, preferably about 14.5 psia.

[0007]

[0007] The azeotropic mixture or azeotrope-like composition may consist essentially of from about 0.09 wt.% to about 92.69 wt.% of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and from about 7.31 wt.% to about 99.91 wt.% of water. Preferably, the azeotropic mixture or azeotrope-like composition consists essentially of from about 65 wt.% to about 90 wt.% of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and from about 10 wt.% to about 35 wt.% of water. More preferably, the azeotropic mixture or azeotrope-like composition consists essentially of from about 65.14 wt.% to about 86.25 wt.% of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and from about 13.75 wt.% to about 34.86 wt.% of water. The azeotropic mixture or azeotrope-like composition preferably has a boiling point of from about 12.0 °C to about 13.6 °C, preferably from about 13.1 °C to about 13.2 °C, at a pressure of from about 12.5 psia to about 16.5 psia, preferably about 14.5 psia.

[0008]

[0008] The present disclosure also provides a method of forming an azeotropic mixture or azeotrope-like composition, the method comprising combining 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water to form an azeotropic mixture or azeotrope-like composition consisting essentially of an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water and having a boiling point of from about 12.0 °C to about 13.6 °C at a pressure of from about 12.5 psia to about 16.5 psia.

[0009]

[0009] The present disclosure provides a method for separating impurities containing water from a composition that may contain 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and at least one impurity containing water, the method comprising the steps of preparing a composition containing 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and at least one impurity, changing the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, and applying to the composition conditions effective to form an azeotropic or azeotrope-like mixture consisting essentially of or consisting of effective amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, and separating the azeotropic or azeotrope-like mixture from the composition containing 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), wherein the separating step may include at least one of phase separation, distillation, drying, and fractionation.

[0010]

[0010] In the above method, the step of changing the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water may involve adding 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to the composition, adding water to the composition, or adding both 2-chloro-3,3,3-trifluoropropene (trifluropropene) (HCFO-1233xf) and water to the composition.

[0011]

[0011] The present disclosure provides a method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf), converting at least a portion of the 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) present in the azeotropic or azeotrope-like mixture to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), The step of converting at least a portion of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) and A method including this is also provided.

[0012] The 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) present in the azeotropic mixture or azeotrope-like composition may be separated from water and then converted to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), which is beneficial because it means that 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) can be converted to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) in the presence of a catalyst that is weak to the presence of water. The step of converting at least a part of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) may include reacting 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) with HF, preferably anhydrous HF, in the presence of a catalyst. The catalyst may preferably include a metal halide catalyst selected from SbCl5, SbF5, TiCl4 or a combination thereof, or is fluorosulfonic acid, and / or the step of converting at least a part of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) may be carried out at a temperature of 5 to 100 °C, preferably 50 to 100 °C. The step of converting at least a part of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) may include reacting 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) with a base, a caustic base, preferably an alkali metal hydroxide, preferably KOH or NaOH. The reaction is preferably carried out in an aqueous environment, preferably in the presence of a phase transfer catalyst, preferably an ammonium halide, preferably a tetraalkylammonium halide or a trialkylammonium halide, preferably tetraalkylammonium chloride or trialkylammonium chloride.The reaction may preferably be carried out at a temperature of about 0 °C to about 100 °C, preferably about 20 °C to about 90 °C, preferably about 50 °C to about 90 °C, preferably about 60 °C to about 80 °C. The step of converting 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) may be suitably carried out at a pressure above atmospheric pressure, atmospheric pressure, or below atmospheric pressure.

Brief Description of the Drawings

[0013]

Figure 1

[0013] It is a graph showing a plot of the boiling point against the percentage of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) in water.

Modes for Carrying Out the Invention

[0014]

[0014] In the first step (above), starting materials such as 1,1,2,3-tetrachloropropene (“HCO-1230xa” or “1230xa”) and / or 1,1,1,2,3-pentachloropropane (“HCC-240db” or “240db”) and / or 2,3,3,3-tetrachloropropane (HCO-1230xf) react with anhydrous hydrogen fluoride (HF) in a first gas-phase reactor (fluorination reactor) to produce at least a mixture of HCFO-1233xf (2-chloro-3,3,3-trifluoropropene) and HCl. The reaction may be carried out at a temperature of about 200 °C to about 400 °C and a pressure of about 0 to about 200 psig. The effluent stream from the gas-phase reactor may optionally contain further components such as unreacted hydrogen fluoride (HF), heavy intermediates, 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), 1,1,1,2,2-pentafluoropropane (HFC-245cb), etc.

[0015]

[0015] The reaction may be carried out in any reactor suitable for gas-phase fluorination reactions. The reactor is made of hydrogen fluoride and Hastelloy (registered trademark), Inconel (registered trademark), It may be constructed of materials resistant to the corrosive action of catalysts such as Monel (registered trademark). In the case of the gas-phase method, the reactor is filled with a gas-phase fluorination catalyst. Any fluorination catalyst known in the art may be used in this method. Suitable catalysts include, but are not limited to, oxides, hydroxides, halides, oxyhalides of chromium, aluminum, cobalt, manganese, nickel and iron, their inorganic salts and mixtures thereof, any of which may optionally be halogenated. Combinations of catalysts suitable for the present invention non-exclusively include Cr2O3, FeCl3 / C, Cr2O3 / Al2O3, Cr2O3 / AlF3, Cr2O3 / carbon, CoCl2 / Cr2O3 / Al2O3, NiCl2 / Cr2O3 / Al2O3, CoCl2 / AlF3, NiCl2 / AlF3 and mixtures thereof. The chromium oxide / aluminum oxide catalyst is described in U.S. Patent No. 5,155,082, the contents of which are incorporated herein by reference. Chromium(III) oxide such as crystalline chromium oxide or amorphous chromium oxide is preferred, and amorphous chromium oxide is most preferred. Chromium oxide (Cr2O3) is a commercially available material available in various particle sizes. A fluorination catalyst having a purity of at least 98% is preferred. The fluorination catalyst is present in an excess amount, but in an amount sufficient to at least drive the reaction.

[0016]

[0016] In one embodiment, the molar ratio of hydrogen fluoride (HF) to the compound of formula I, II or III in the step 1 reaction is in the range of about 1:1 to about 50:1 in one embodiment, about 10:1 to about 50:1 in another embodiment, and about 10:1 to about 20:1 in a further embodiment. In one embodiment, the reaction of HF with the compound of I, II or III is carried out at a temperature of about 200°C to about 600°C, about 200°C to about 400°C in another embodiment, and about 200°C to about 300°C in another embodiment. The reaction pressure is in the range of about 0 psig to about 500 psig in one embodiment, about 20 psig to about 200 psig in another embodiment, and about 50 to about 100 psig in a further embodiment.

[0017]

[0017] For example, when the compound of formula I is 1230xa, the molar ratio of HF to 1230xa in step 1 of the reaction is, in one embodiment, from about 1:1 to about 50:1, in another embodiment from about 10:1 to about 50:1, and in yet another embodiment in the range of about 10:1 to about 20:1. In one embodiment, the reaction of HF and 1230xa is carried out at a temperature of about 200 °C to about 600 °C, in another embodiment about 200 °C to about 400 °C, and in another embodiment about 200 °C to about 300 °C. The reaction pressure is, in one embodiment, in the range of about 0 psig to about 500 psig, in another embodiment about 20 psig to about 200 psig, and in yet another embodiment about 50 to about 100 psig.

[0018]

[0018] Similarly, when the compound of formula II is 2,3,3,3 - tetrachloro - 1 - propene (HCC - 1230xf or 1230xf), the molar ratio of HF to 1230xf in step 1 of the reaction is, in one embodiment, from about 1:1 to about 50:1, in another embodiment from about 10:1 to about 50:1, and in yet another embodiment in the range of about 10:1 to about 20:1. In one embodiment, the reaction of HF and 1230xf is carried out at a temperature of about 200 °C to about 600 °C, in another embodiment about 200 °C to about 400 °C, and in another embodiment about 200 °C to about 300 °C. The reaction pressure is, in one embodiment, in the range of about 0 psig to about 500 psig, in another embodiment about 20 psig to about 200 psig, and in another embodiment about 50 to about 100 psig.

[0019]

[0019] Similarly, when the compound of formula III is 1,1,1,2,3 - pentachloropropane (HCC - 240db or 240db), the molar ratio of HF to 240db in step 1 of the reaction is from about 1:1 to about 50:1, in another embodiment from about 10:1 to about 50:1, and in another embodiment in the range of about 10:1 to about 20:1. The reaction of HF and 240db is carried out, in one embodiment, at a temperature of about 200 °C to about 600 °C, in another embodiment about 200 °C to about 400 °C, and in another embodiment about 200 °C to about 300 °C. The reaction pressure is, in one embodiment, in the range of about 0 psig to about 500 psig, in another embodiment about 20 psig to about 200 psig, In certain embodiments, it ranges from about 50 to about 100 psig.

[0020]

[0020] The first step of the reaction is not necessarily limited to a gas-phase reaction as described above, and as disclosed in U.S. Patent Application Publication No. 20070197842, the contents of which are incorporated herein by reference, it may be carried out using a liquid-phase reaction or a combination of liquid and gas phases. It is also contemplated that the reaction may be carried out batchwise, continuously, or a combination thereof. In embodiments where the reaction involves a liquid-phase reaction, the reaction may or may not be catalyzed. Lewis acid catalysts such as metal halide catalysts including antimony halides, tin halides, thallium halides, iron halides, and combinations of two or more thereof are available. In certain embodiments, metal chlorides and metal fluorides including, but not limited to, SbCl5, SbCl3, SbF5, SnCl4, TiCl4, FeCl3, and combinations of two or more thereof are utilized.

[0021]

[0021] The fluorination reaction may be carried out to achieve at least 1% or more, 5% or more, 10% or more, or about 20% or more single or multi-pass conversion. In certain preferred embodiments of the present invention, the starting reagent is converted to 1233xf in a single pass, and the reaction conditions achieve a conversion of more than 75%, in one embodiment more than 85%, in another embodiment more than 95%, and in another embodiment more than 99%. For this purpose, the resulting effluent may contain little or trace amounts of unreacted starting materials or may be substantially free of such compounds.

[0022]

[0022] The effluent from step 1, which is a fluorination reaction step and contains any intermediate effluent that may be present in the multi-stage reactor device, is processed to achieve a desired degree of separation. For example, in embodiments where the reactor effluent contains 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), the effluent generally also contains HCl, unreacted HF, and, if any, trace amounts of unreacted starting components (e.g., 1230xa, 1230xf, and / or 240db). The effluent may also contain one or more by-product organic substances such as underfluorinated and / or overfluorinated intermediates. Non-limiting examples of underfluorinated intermediates include trichlorofluoropropene (1231) isomers and 2,3-dichloro-3,3-difluoropropene (1232xf), and non-limiting examples of overfluorinated intermediates include 2-chloro-1,1,1,2-tetrafluoropropane (244bb), 1,1,1,2,2-pentafluoropropane (245cb), and HFO-1234yf and combinations thereof. In further embodiments, the impurity is hydrogen fluoride. Other by-product organic substances may include, but are not limited to, dichlorotrifluoropropane (243) isomers, and trichlorodifluoropropane (242) isomers, and dimers derived from one or more of the starting compounds. As non-limiting examples, dimers derived from 1230xa include, but are not limited to, C6H3F6Cl, C6H3F7Cl2, C6F6Cl2, C6H8Cl2, C6F5Cl3, C6H3F2Cl5, etc.

[0023]

[0023] After HCl is removed by distillation and a portion of HF is removed by phase separation, water is added to the remaining effluent from step 1 in an amount effective to form an azeotropic mixture or azeotrope-like mixture containing 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, and then may be separated from the effluent along with its impurities by the techniques described herein. The 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) is then separated from the water as described herein and then fed to the hydrogen fluoride reactor of step 2, which is discussed below.

[0024]

[0024] In step 2 of the aforementioned method for forming 2,3,3,3-tetrafluoroprop-1-ene, purified 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) is converted to 2-chloro-1,1,1,2-tetrafluoropropane (244bb). In one embodiment, this step may be carried out in the liquid phase in a liquid phase reactor which may be lined with TFE or PFA. Such a method may be carried out at a temperature range of about 70 °C to about 120 °C and a pressure in the range of about 50 to about 120 psig. Any liquid phase fluorination catalyst may be used in the present invention. A non-exhaustive list includes Lewis acids, transition metal halides, transition metal oxides, Group IVb metal halides, Group Vb metal halides, or combinations thereof. Non-exclusive examples of liquid phase fluorination catalysts are antimony halides, tin halides, tantalum halides, titanium halides, niobium halides, and molybdenum halides, iron halides, fluorinated chromium halides, fluorinated chromium oxides or combinations thereof. Specific non-exclusive examples of liquid phase fluorination catalysts are SbCl5, SbCl3, SbF5, SnCl4, TaCl5, TiCl4, NbCl5, MoCl6, FeCl3, fluorinated species of SbCl5, fluorinated species of SbCl3, fluorinated species of SnCl4, fluorinated species of TaCl5, fluorinated species of TiCl4, fluorinated species of NbCl5, fluorinated species of MoCl6, fluorinated species of FeCl3, or combinations thereof. Antimony pentachloride is most preferred.

[0025]

[0025] When deactivated, the catalyst can be readily regenerated by any means known in the art. One suitable method of regenerating the catalyst involves passing a stream of chlorine through the catalyst. For example, about 0.91 g (0.002 lb) to about 90.7 g (0.2 lb) of chlorine per hour may be added to the liquid phase reaction per 453.6 g (1 pound) of the liquid phase fluorination catalyst. This may be carried out, for example, at a temperature of about 65 °C to about 100 °C for about 1 to about 2 hours, or continuously.

[0026]

[0026] When deactivated, the catalyst can be readily regenerated by any means known in the art. One suitable method of regenerating the catalyst involves passing a stream of chlorine through the catalyst. For example, about 0.91 g (0.002 lb) to about 90.7 g (0.2 lb) of chlorine per hour may be added to the liquid phase reaction per 453.6 g (1 pound) of the liquid phase fluorination catalyst. This may be carried out, for example, at a temperature of about 65 °C to about 100 °C for about 1 to about 2 hours, or continuously.

[0027]

[0027] The second step of the reaction in which the 244bb product is formed is not necessarily limited to a liquid-phase reaction, and as disclosed in U.S. Patent Application Publication No. 20070197842, the contents of which are incorporated herein by reference, it may be carried out using a gas-phase reaction or a combination of liquid and gas phases. For this purpose, a feed stream containing 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) is preheated to a temperature of about 50°C to about 400°C and contacted with a catalyst and a fluorinating agent. The catalyst may include standard gas-phase agents used in such reactions, and the fluorinating agent may include those generally known in the art, including but not limited to hydrogen fluoride.

[0028]

[0028] The effluent from the hydrofluorination reaction step (step 2), which mainly consists of 244bb and HF (and also a small amount of unreacted 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), perfluorinated by-product 245cb, HCl, and Cl2), is treated to achieve a desired degree of separation and / or other processing. For example, the product stream is fed to a lights removal column, where a stream mainly consisting of 245cb, HCl, and Cl2 exits from the top of the column and is sent to a thermal oxidizer (T-OX) for decomposition. In one embodiment, water is added to the bottoms stream of the lights removal column, which mainly consists of 244bb and HF (and also a small amount of unreacted 1233xf), to form an azeotropic or azeotrope-like mixture composed of 1233xf and water. In one embodiment, 244bb is not present in this mixture, in which case 1233xf is separated from water by techniques known in the art as described earlier herein, such as distillation. In another embodiment, 244bb is also present in the azeotropic or azeotrope-like mixture composed of 1233xf and water. Then 244bb is separated from 1233xf by techniques known in the art, such as those described in U.S. Patent No. 8,252,965, the content of which is incorporated herein by reference. The separated 1233xf may be recycled back to the hydrofluoronation reactor of step 2 as described earlier.

[0029]

[0029] Step 3 of this method may be carried out in the gas phase or the liquid phase. When producing HFO -1234yf in the gas phase, 244bb is fed to a second gas-phase reactor (dehydrochlorination reactor) to be dehydrochlorinated to produce the desired product 2,3,3,3-tetrafluoroprop-1-ene (1234yf). This reactor may optionally contain a catalyst capable of dehydrochlorinating HCFC-244bb with a catalyst to produce HFO-1234yf, but in one embodiment, the reactor contains a catalyst.

[0030]

[0030] The catalyst may be a metal halide, a metal halide oxide, a neutral (i.e., zero oxidation state) metal or metal alloy, or activated carbon in bulk or supported form. The metal halide or metal oxide catalyst may include, but is not limited to, monovalent, divalent, and trivalent metal halides, oxides, and mixtures / combinations thereof, more preferably monovalent and divalent metal halides and mixtures / combinations thereof. The component metals may include, but are not limited to, Cr 3+ , Fe 3+ , Mg 2+ , Ca 2+ , Ni 2+ , Zn 2+ , Pd 2+ , Li + , Na + , K + , and Cs + . The component halogens may include, but are not limited to, F - , Cl - , Br - , and I - . Examples of useful monovalent or divalent metal halides include, but are not limited to, LiF, NaF, KF, CsF, MgF2, CaF2, LiCl, NaCl, KCl, and CsCl. The halogenation treatment may include any of those known in the prior art, particularly those utilizing HF, F2, HCl, Cl2, HBr, Br2, HI, and I2 as the halogenation source.

[0031]

[0031] In one aspect, neutral metals, i.e., zero-valent metals, metal alloys, and mixtures thereof are used. Useful metals include, but are not limited to, Pd, Pt, Rh, Fe, Co, Ni, Cu, Mo, Cr, Mn, and combinations of the foregoing as alloys or mixtures. The catalyst may or may not be supported. Examples of useful metal alloys include, but are not limited to, SS316, Monel® 400, Incoloy® 825, Inconel® 600, and Inconel® 625. Such catalysts may be provided as individual supported or unsupported elements and / or as part of and / or as the walls of the reactor.

[0032]

[0032] Exemplary but non-limiting catalysts include activated carbon, stainless steel (e.g., SS316), austenitic nickel-based alloys (e.g., Inconel® 625), nickel, fluorinated 10% CsCl / MgO, and 10% CsCl / MgF2, etc. In one embodiment, the reaction temperature may range from about 300 to about 550 °C and the reaction pressure may range from about 0 to about 150 psig. The reactor effluent may be fed to a caustic scrubber or distillation column to remove HCl by-products, producing an acid-free organic product, which may optionally undergo further purification using one or any combination of purification techniques known in the art.

[0033]

[0033] Step 3 can be carried out even in the liquid phase. The conversion of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) can be carried out, for example, by using a base for dehydrochlorination of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb). The base may be a caustic base and is preferably selected from the group consisting of alkali metal hydroxides, alkali metal oxides, alkaline earth metal hydroxides, alkaline earth metal oxides and combinations thereof. Examples of preferred caustic bases are KOH, NaOH, LiOH, Mg(OH)2, Ca(OH)2, CaO and combinations thereof. The caustic base may be added to the reaction in solid form or as a solution. When supplied as a solution, the solvent is preferably water or an alcohol, preferably MeOH or EtOH. KOH is particularly preferred and is preferably supplied as an aqueous solution, preferably an aqueous solution containing from about 5 wt.% to about 62 wt.%, preferably 5 wt.% to 55 wt.% of KOH. The dehydrochlorination in the liquid phase is preferably carried out in an aqueous environment. In the context of the liquid phase Step 3, the aqueous environment is an environment in which the counter reaction mixture contains from 5 to 80 wt.%, preferably from 10 to 60 wt.%, more preferably from 20 to 40 wt.% of water. Since it is considered that the reactivity is assisted by promoting the intimate contact between the base and 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), it is also preferable to utilize a phase transfer catalyst, particularly when carrying out the reaction in an aqueous environment. Such phase transfer catalysts include, but are not limited to, crown ethers (e.g., 18-crown-6), onium salts (e.g., phosphonium salts or ammonium salts having halide anions), cryptands (e.g., N[CH2C H2OCH2CH2OCH2CH2]3N), polyalkylene glycols (e.g., poly( It may contain ethylene glycol), its derivatives, and combinations thereof. In one embodiment, the phase transfer catalyst is Aliquat 336. Onium salts, especially ammonium salts, are preferred. The ammonium salt is preferably ammonium halide, preferably tetraalkylammonium halide or trialkylammonium halide, preferably trialkylammonium chloride or tetraalkylammonium chloride.

[0034]

[0034] The liquid phase version of Step 3 is preferably carried out at a temperature of about 0 °C to about 100 °C, preferably about 20 °C to about 90 °C, preferably about 50 °C to about 90 °C, preferably about 60 °C to about 80 °C. The conversion of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) may be suitably carried out at a pressure above atmospheric pressure, atmospheric pressure, or below atmospheric pressure. These temperatures and pressures are particularly useful when carrying out Step 3 in a liquid phase with a base, as described above.

[0035]

[0035] WO-2011 / 139646, the content of which is incorporated herein, discloses further details of experiments for converting 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) in a liquid phase.

[0036]

[0036] An alternative method for making HFO-1234yf utilizes 1,2-dichloro-3,3,3-trifluoropropane (HCFC-243db) as a starting material and is carried out in the gas phase and liquid phase. In this alternative method, the method includes the following three steps (Steps (2) and (3) are the same as those above): Step (1): 243db → 1233xf + HCl in the gas phase (with or without a catalyst) or 243db + base → 1233xf + H2O in the liquid phase (optionally with a phase transfer catalyst and / or a solvent and / or a salt).

[0037] Step (2): In a liquid-phase reactor loaded with a liquid hydrogen fluoride catalyst, 1233xf + HF → 244bb, and Step (3): 244bb → 1234yf + HCl in a gas-phase reactor (with or without a catalyst) or in a liquid phase.

[0038]

[0037] In an alternative process where the starting composition contains 243db, 243db is dehydrohalogenated to produce a product mixture containing 1233xf. When the starting composition contains 243db, the dehydrohalogenation reaction is a dehydrochlorination reaction. The dehydrochlorination reaction is carried out within a reaction compartment, in the gas phase with a catalyst, or in the liquid phase with a base and optionally a phase transfer catalyst, and / or a solvent and / or a salt. For example, WO2012 / 115934 discloses the gas-phase reaction of 243db with a carbon catalyst. WO2012 / 115938 discloses the gas-phase reaction of 243db with a chromium oxyfluoride catalyst. WO2017 / 044719 discloses the reaction of 243db with a fluorinated alkane in the presence of a fluorination catalyst to produce 1233xf, and further discloses other compounds useful for producing 1234yf. WO2017 / 044724 discloses the liquid-phase reaction of 243db with a caustic alkali. When the dehydrochlorination reaction is carried out in the gas phase, HCl is produced, while when the dehydrochlorination reaction is carried out in the liquid phase, HCl is not produced. As is known to those skilled in the art, other methods may be used when starting with a compound having formula (III).

[0039]

[0038] In a preferred embodiment where it is desirable to maintain moisture- and impurity-free conditions during the synthesis of 1234yf, the reactants and intermediate products may be purified. For example, it is desirable to remove impurities containing water from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf).

[0040]

[0039] It has been found that 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water form a heterogeneous azeotropic mixture and an azeotrope-like composition or mixture, and the present disclosure provides a heterogeneous azeotropic mixture or an azeotrope-like composition comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water. The azeotropic mixture or azeotrope-like composition may consist essentially of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, or the azeotropic mixture or azeotrope-like composition may consist of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water.

[0041]

[0040] The inventors have experimentally found that 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water form an azeotropic mixture or an azeotrope-like composition.

[0042]

[0041] A heterogeneous azeotropic mixture consists of two liquid phases and one gas phase in equilibrium. In a heterogeneous azeotropic mixture at a given temperature and pressure, the composition of each of the two liquid phases and the composition of the gas phase remain constant. When a heterogeneous azeotropic mixture is formed, at a constant pressure, the boiling point of the heterogeneous azeotropic mixture is lower than that of the lower-boiling component ("minimum-boiling azeotropic mixture").

[0043]

[0042] An "azeotropic mixture" (or "azeotropy") composition is a unique combination of two or more components. An azeotropic mixture can be either homogeneous (having one liquid phase) or heterogeneous (having two liquid phases). Azeotropic mixture compositions can be characterized in various ways. For example, at a given pressure, an azeotropic mixture composition boils at a certain characteristic temperature that is either above the higher-boiling component (maximum-boiling azeotropic mixture) or below the lower-boiling component (minimum-boiling azeotropic mixture). However, in the case of a heterogeneous azeotropic mixture, the boiling point of the azeotropic mixture is always below the boiling point of the lower-boiling component. At this characteristic temperature, a homogeneous azeotropic mixture has the same composition in both the gas phase and the liquid phase. In the case of a heterogeneous azeotropic mixture, at this characteristic temperature, the composition of each of the two liquid phases and the gas phase remains constant during boiling. An azeotropic mixture composition does not fractionate upon boiling or evaporation. Therefore, the components of an azeotropic mixture composition cannot be separated during a phase transition.

[0044]

[0043] A homogeneous azeotropic mixture composition is also characterized in that at the characteristic azeotropic mixture temperature, the boiling point pressure of the liquid phase is the same as the dew point pressure of the gas phase. The behavior of an azeotropic mixture composition is in contrast to that of a non-azeotropic mixture composition in which the liquid composition changes to a significant extent during boiling or evaporation.

[0045]

[0044] However, those skilled in the art understand that at different pressures, both the composition and the boiling point of an azeotropic mixture composition vary to some extent. Therefore, depending on the temperature and / or pressure, an azeotropic mixture composition can have a variable composition. Therefore, those skilled in the art understand that a composition range, rather than a fixed composition, can be used to define an azeotropic mixture composition. Furthermore, an azeotropic mixture is characterized by a fixed boiling point at a specific pressure. It can be defined in terms of the exact weight percentages of the components of the composition.

[0046]

[0045] An "azeotrope-like" composition is a composition of two or more components that behaves substantially as an azeotropic mixture. Thus, for the purposes of the present disclosure, an azeotrope-like composition, in the case of a homogeneous azeotrope, boils at a substantially constant temperature if in liquid form under a given pressure, and results in a gas composition that is substantially the same as the liquid composition undergoing boiling, and is a combination of two or more different components. In the case of a heterogeneous azeotrope, two liquid phases covered by a gas composition are formed under a given pressure. Each of the two liquid phases and the gas phase remain substantially constant during boiling.

[0047]

[0046] For the purposes of the present disclosure, an azeotrope-like composition is preferably a composition or range of compositions that boils in a temperature range of about 12.0 °C to 13.6 °C and at a pressure of about 12.5 psia to about 16.5 psia.

[0048]

[0047] An azeotrope or azeotrope-like composition can be identified using a plurality of different methods.

[0048] For the purposes of the present disclosure, an azeotrope or azeotrope-like composition is identified experimentally using an ebulliometer (Walas, Phase Equilibria in Chemical Engineering, Butterworth-Heinemann, 1985, 533-544). An ebulliometer is designed to provide a very accurate measurement of the boiling point of a liquid by measuring the temperature of the vapor-liquid equilibrium.

[0049]

[0049] The boiling point of each component alone is measured at a constant pressure. As will be understood by those skilled in the art, in the case of a binary azeotrope or azeotrope-like composition, the boiling point of one of the components of the composition is measured first. Then a second component of the composition is added in various amounts, and the boiling point of each of the resulting compositions is measured using an ebulliometer at the said constant pressure. In the case of a ternary azeotrope, the first composition contains a binary mixture, and a third component is added in various amounts. The boiling point of each of the resulting ternary compositions is measured using an ebulliometer at the said constant pressure.

[0050]

[0050] The measured boiling point is plotted against the composition of the composition being tested, e.g., in a binary azeotropic mixture, the amount of the second component added to the composition (expressed either as weight % or mole %). The presence of an azeotropic mixture composition can be identified by observation of a maximum or minimum boiling point that is above or below the boiling point of either of the components alone.

[0051]

[0051] As will be understood by those skilled in the art, the identification of an azeotropic mixture or an azeotrope-like composition is made by comparing the boiling point change of the composition when a second component is added to the first component, against the boiling point of the first component. Thus, the system need not be calibrated to the reported boiling points of the specific components in order to measure the boiling point change.

[0052]

[0052] As previously discussed, at the maximum or minimum boiling point, the composition of the gas phase is the same as the composition of the liquid phase. Thus, an azeotrope-like composition is a composition of components that results in a substantially constant minimum or maximum boiling point, i.e., a boiling point of about 12.0 °C to about 13.6 °C, preferably about 13.1 °C to about 13.2 °C, at a pressure of about 12.5 psia to about 16.5 psia, preferably about 14.5 psia, and at that substantially constant boiling point, the composition of the gas phase is substantially the same as the composition of the liquid phase.

[0053]

[0053] The present disclosure provides an azeotropic mixture or an azeotrope-like composition comprising an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water for forming an azeotropic mixture or an azeotrope-like composition. As used herein, the term "eff ective amount" is the amount of each component that, when combined with the other components, results in the formation of an azeotropic mixture or an azeotrope-like composition.

[0054]

[0054] This azeotropic mixture or azeotrope-like composition may consist essentially of a combination of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, or may consist of a combination of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water.

[0055]

[0055] As used herein, the term "consisting essentially of" with respect to the components of an azeotropic mixture or azeotrope-like composition or mixture means that the composition contains the indicated components in an azeotropic or azeotrope-like ratio and may contain additional components, provided that the additional components do not form a new azeotropic or azeotrope-like system. For example, an azeotropic mixture consisting essentially of two compounds may optionally contain one or more additional components, provided that the additional components do not make the mixture non-azeotropic and do not form an azeotrope with either or both of the compounds (e.g., do not form a ternary or higher azeotrope), and is an azeotropic mixture that forms a binary azeotrope.

[0056]

[0056] The present disclosure also provides a method of forming an azeotropic mixture or azeotrope-like composition by mixing, combining, or admixing an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water. Any of a variety of methods known in the art for combining two or more components to form a composition may be used in this method. For example, 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water may be mixed, admixed, or otherwise combined by hand and / or mechanically as part of a batch or continuous reaction and / or process, or by a combination of two or more such steps. The components may be supplied in the required amounts, for example, by weighing and then combining the amounts.

[0057] An azeotropic mixture or azeotrope-like composition having a boiling point of about 12.0 °C to about 13.6 °C at a pressure of about 12.5 psia to about 16.5 psia may consist essentially of, or may consist of, about 0.09 wt.% to about 92.69 wt.% of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and about 7.31 wt.% to about 99.91 wt.% of water.

[0058]

[0058] The present disclosure also provides a composition comprising an azeotropic mixture or an azeotrope-like composition. For example, a composition comprising at least about 14 wt.% of an azeotropic mixture or an azeotrope-like composition, or at least about 21 wt.% of an azeotropic mixture or an azeotrope-like composition, or at least about 25 wt.% of an azeotropic mixture or an azeotrope-like composition, or at least about 70 wt.% of an azeotropic mixture or an azeotrope-like composition, or at least about 90 wt.% of an azeotropic mixture or an azeotrope-like composition, or at least 95 wt.% of an azeotropic mixture or an azeotrope-like composition, 99 wt.% of an azeotropic mixture or an azeotrope-like composition is provided.

[0059]

[0059] An azeotropic mixture or an azeotrope-like composition, which comprises an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water and consists essentially of or consists of these, can be used to separate impurities from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf).

[0060]

[0060] The preparation of an azeotropic or azeotrope-like composition, which comprises an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water and consists essentially of or consists of these, enables separation techniques such as azeotropic distillation that are used to remove impurities containing water from 2-chloro-3,3,3-trifluoropropene (HC FO-1233xf).

[0061]

[0061] In particular, an azeotropic mixture or azeotrope-like composition comprising an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, consisting essentially of or consisting of these, may be formed from a composition comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), water, and at least one impurity that may contain water. Following the formation of the azeotropic mixture or azeotrope-like composition, the azeotropic mixture or azeotrope-like composition may be separated from other chemical compounds by suitable methods such as distillation, phase separation, drying, or fractionation. Drying may be accomplished by the addition of a desiccant such as molecular sieves.

[0062]

[0062] In one example, the present disclosure provides a method for separating impurities from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), the method comprising preparing a primary composition of unpurified 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), changing the relative amounts of 2-chloro-3,3,3-trifluoropropene and water, and subjecting the primary composition to conditions effective to form a secondary composition that is an azeotropic mixture or azeotrope-like composition consisting essentially of or consisting of an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, and separating the secondary composition from the primary composition by a separation technique such as phase separation, distillation, or fractionation. The secondary composition may then be subjected to further separation, purification, or drying steps to obtain purified 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf). The step of changing the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water may involve adding 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to the composition, adding water to the composition, or adding both 2-chloro-3,3,3-trifluoropropene to the composition.

[0063] An azeotropic mixture or azeotrope-like composition comprising an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, consisting essentially of or consisting of these, can be used for the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf). For example, as previously explained, an azeotropic mixture or azeotrope-like composition can be used to purify 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) before step 3 of this process. By formation of the azeotropic mixture, 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) removed from 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) can subsequently be converted to further 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) and then to 2,3,3,3-tetrafluoropropene (HFO-1234yf). Similarly, for example, if 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) is present in the unpurified product due to dehydrofluorination of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) in step 3, an azeotropic mixture or azeotrope-like composition may be formed after step 3. Although not inevitable, an azeotropic mixture or azeotrope-like composition may also occur in the reaction to produce 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) from 1,2-dichloro-3,3,3-trifluoropropane (HCFC-243db). The presence of an azeotropic mixture or azeotrope-like composition depends on factors such as whether the azeotropy is hindered by other substances present. Although not inevitable, examples of how an azeotropic mixture or azeotrope-like composition may occur include the following: · When water is present as a solvent during the reaction, for example, when a base is used in an aqueous solution such as when the reaction is carried out in an aqueous environment.

[0064] · When water is generated in the reaction. For example, when HCFC-243db is dehydrochlorinated with hydroxide ions in the presence or absence of water as a solvent, water molecules are generated according to the following equation: CF3CHClCCH2Cl + - OH → CF3CCl=CH2 + Cl - + H2O. Those skilled in the art will understand that water molecules may be generated when other types of bases, especially caustic bases, are used.

[0065]

[0064] The following non-limiting examples serve to illustrate the present invention.

Example

[0066] Example 1 - Vapor-Liquid Equilibrium (VLE) Study

[0065] A cryometer consisting of a tube with a vacuum jacket having a dry ice cooling condenser at the top was equipped with a quartz thermometer. First, 14.11 grams of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) was loaded into the cryometer. Then water was added incrementally and the temperature of the mixture was recorded for each increase in water. The mixture temperature reached a minimum value and then remained substantially constant while further water was added, indicating the formation of a heterogeneous azeotrope. The ambient pressure during the measurement was 14.5 psia. The mixture composition and the measured temperatures are shown in Table 1. The data in Table 1 is illustrated in Figure 1.

[0067]

Table 1

[0068] Example 2 - Vapor-Liquid-Liquid Equilibrium (VLLE) Measurement

[0066] A 50:50 by weight mixture of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water was prepared at 23 °C in a Teflon® cell. Two separate phases were observed in the cell, indicating that an immiscible azeotrope was formed. The upper (water-rich) and lower (2-chloro-3,3,3-trifluoropropene (HCFO-1233xf)-rich) phases were separated and analyzed. The compositions of the two phases are shown in Table 2 below. are shown.

[0069]

Table 2

[0070] Example 3 - Purification of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf)

[0067] In this example, a composition containing 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and possible impurities such as water is provided. An effective amount of water is added to the composition, and the composition is subjected to conditions effective to form an azeotrope or azeotrope-like composition consisting essentially of or consisting of an effective amount of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water. The azeotrope or azeotrope-like composition is then separated from the composition containing the primary compound by separation techniques such as phase separation, distillation, and / or fractionation. Once 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) is separated, it may be further dried by the addition of a desiccant.

[0071] Example 4 - Separation of Water as an Impurity

[0068] In this example, a composition containing a primary compound such as 2-chloro-3,3,3-trifluoropropene (1233xf) is prepared together with water as an impurity. An effective amount of water is added to the composition, and the composition is subjected to conditions effective to form an azeotropic mixture or azeotrope-like composition consisting essentially of or consisting of an effective amount of 2-chloro-3,3,3-trifluoropropene (1233xf) and water. The azeotropic mixture or azeotrope-like composition is then separated from the composition containing the primary compound by separation techniques such as phase separation, distillation, and / or fractionation. When 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) is separated, it may be further dried by the addition of a drying agent.

[0072] Example 5 - Separation of Water as an Impurity

[0069] In this example, a composition containing a primary compound such as 2-chloro-3,3,3-trifluoropropene (1233xf) is prepared together with water as an impurity. An effective amount of 2-chloro-3,3,3-trifluoropropene (1233xf) is added to the composition, and the composition is subjected to conditions effective to form an azeotropic mixture or azeotrope-like composition consisting essentially of or consisting of an effective amount of 2-chloro-3,3,3-trifluoropropene (1233xf) and water. The azeotropic mixture or azeotrope-like composition is then separated from the composition containing the primary compound by separation techniques such as phase separation, distillation, and / or fractionation. When 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) is separated, it may be further dried by the addition of a drying agent.

[0073] Example 6 - Representative Procedure for Converting 1,2-dichloro-3,3,3-trifluoropropane (HCFC-243db) to 2-chloro-3,3,3-trifluoropropene (1233xf)

[0070] 86 g of a 12 wt% NaOH solution and 36.5 g of 243db were charged into a shaking tube reactor. The reactor was cooled to -10 °C and evacuated briefly. Then it was left without stirring at 55 It was heated to ℃. When the temperature reached 47 °C, it was shaken and heated to 55 °C. Then it was held at about 55 °C for 60 minutes. The estimated mixing power was 30 - 40 HP / 3785 L (1000 gallons). During the reaction, the pressure continuously increased from 6.34 psig to 47 psig. Based on the temperature and pressure profiles, the reaction was estimated to reach 98% conversion in about 25 minutes. The product was analyzed by GC-MS, and the analysis showed that about 98% of 243db was converted.

[0074]

Table 3

[0075] Typical procedure for converting 7-chloro-3,3,3-trifluoropropene (1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb)

[0071] Approximately 327 grams of HF, approximately 50 grams of 1233xf, and approximately 75 grams of SbCl5 were charged into a 1-L autoclave. The reaction mixture was stirred at a pressure of about 620 psig and a temperature of about 80 °C for about 3 hours. After the reaction, the reactor was cooled to about 0 °C, and then about 300 ml of water was slowly added to the autoclave over a period of about 45 minutes. After the water was completely added with stirring, the reactor was cooled to room temperature, and then the overhead gas was transferred to another collection cylinder. The yield of CF3CFClCH3 was about 90% at a 1233xf conversion level of about 98%. The other main by-products were CF3CF2CH3 (2%) and an unspecified isomer of a C4 compound of the general formula C4H3Cl3F4 (8%).

[0076] Typical procedure for converting 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf)

[0072] The dehydrochlorination of HCFC-244bb was carried out in a 1-liter Parr reactor equipped with a thermocouple and a magnetic stirrer. 15 g of Aliquat 336 (trademark) was added to the reactor. The reactor was then closed and the pressure was tested. Thereafter, 294 g of an organic mixture and 270 g of 45% KOH were added to the reactor. Analysis of the organic mixture using gas chromatography (GC) showed 8.1 GC area% of 1234yf, 89.5 GC area% of 244bb, and 1.8 GC area% of 1233xf. The stirrer was then operated and the reactor was heated to 55 °C. When 55 °C was reached (after about 2 hours), the pressure in the reactor increased from an initial 10 psig to 55 psig. The reactor was held at 55 °C for 4 hours and the pressure further increased to 78 psig. GC analysis of the organic content of the reactor after the reaction was completed, showing 64.2 GC area% of 1234yf, 33.2 GC area% of 244bb, 2.2 GC area% of 1233xf, and 0.4 GC area% of an unknown substance.

[0077] The synthetic examples described above are included to illustrate the reactions and are not an indication of whether the claimed azeotropic or azeotrope-like compositions are present during the synthetic procedures. Example 9 - Representative Purification of HCFO-1233xf

[0073] A composition containing HCFO-1233xf and water is purified to yield a purified stream of HCFO-123 3xf.

[0078]

[0074] 1000 kg of a mixture containing 926.9 kg of HCFO-1233xf and 73.1 kg of water is charged to the reboiler of a batch distillation facility consisting of a multi-stage rectification section packed with random packing such as IMTP (registered trademark) packing available from Koch-Glitsch and a condenser. The condenser is cooled with flowing water cooled to about 5 °C at the inlet to the condenser. The reboiler has a half-pipe jacket for steam. The reboiler charge may be the organic phase of a mixture of HCFO-1233xf and water that has been subjected to phase separation and from which the aqueous phase has been removed by decantation from the top.

[0079]

[0075] A batch distillation facility is used to distill the overhead stream substantially containing the azeotropic mixture of HCFO-1233xf and water, and HCFO-1233xf containing about 0.039 wt% of water remains substantially in the reboiler. Refer to Table 3 for an overview. The material in the reboiler may be further dried by passing through a desiccant such as 3A molecular sieve.

[0080]

Table 4

[0081] This example shows purification by a batch distillation mechanism, which may be adapted by those skilled in the art for continuous distillation for purification. Aspect

[0076] Aspect 1 is a composition comprising an azeotropic mixture or azeotrope-like composition consisting essentially of an effective amount of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water.

[0082]

[0077] Aspect 2 is the composition of Aspect 1, wherein the azeotropic mixture or azeotrope-like composition has a boiling point of about 12.0 °C to about 13.6 °C at a pressure of about 12.5 psia to about 16.5 psia.

[0083]

[0078] Aspect 3 is the composition of Aspect 1 or Aspect 2, wherein the azeotropic mixture or azeotrope-like composition consists essentially of about 0.09 wt.% to about 92.69 wt.% of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and about 7.31 wt.% to about 99.91 wt.% of water.

[0084] Aspect 4 is a method for forming an azeotropic mixture or an azeotrope-like composition, comprising combining 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water to form an azeotropic mixture or an azeotrope-like composition consisting essentially of an effective amount of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water and having a boiling point of about 12.0 °C to about 13.6 °C at a pressure of about 12.5 psia to about 16.5 psia.

[0085] Aspect 5 is the method of Aspect 4, wherein the combining step comprises combining from about 0.09 wt.% to about 92.69 wt.% of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and from about 7.31 wt.% to about 99.91 wt.% of water.

[0086] Aspect 6 is a method for separating water-containing impurities from 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) in a composition comprising 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and at least one impurity, comprising providing a composition comprising 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and at least one impurity; changing the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water and applying to the composition conditions effective to form an azeotropic mixture or an azeotrope-like composition consisting essentially of or consisting of an effective amount of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water; and separating the azeotropic mixture or azeotrope-like composition from the 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf).

[0087] Aspect 7 is the method of Aspect 6, wherein the separating step comprises at least one of phase separation, distillation, and fractionation. Aspect 8 is the method according to aspect 6 or aspect 7, further comprising the step of separating 2-chloro-3,3,3-trifluoropropene from water.

[0088] Aspect 9 is the method according to any one of aspects 6 to 8, wherein 2-chloro-3,3,3-trifluoropropene is separated from water using liquid-liquid phase separation. Aspect 10 is the method according to any one of aspects 6 to 9, wherein 2-chloro-3,3,3-trifluoropropene is separated from water using distillation.

[0089] Aspect 11 is the method according to any one of aspects 6 to 10, wherein 2-chloro-3,3,3-trifluoropropene is separated from water using at least one desiccant. Aspect 12 is the method according to any one of aspects 6 to 11, wherein water is first removed by liquid-liquid phase separation and then by a second method selected from the group consisting of distillation, one or more desiccants, and combinations thereof.

[0090] Aspect 13 is the method according to any one of aspects 6 to 12, wherein the step of changing the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water comprises adding 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to the composition.

[0091] Aspect 14 is the method according to any one of aspects 6 to 13, wherein the step of changing the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water comprises adding water to the composition.

[0092] Aspect 15 is the method according to any one of aspects 6 to 14, wherein the step of changing the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water comprises adding both 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water to the composition.

[0093] As used herein, the phrase "within any range defined as being between any two of the above values" means that any range extends from any two of the values recited preceding such phrase, regardless of whether that value is the lower of the recited items or the higher of the recited items. For example, a pair of values may be selected from the smaller of two values, the larger of two values, or a smaller and a larger value.

[0094]

[0092] As used herein, the singular forms "a", "an" and "the" include the plural unless the context clearly dictates otherwise. Furthermore, when an amount, concentration, or other value or parameter is given as either a range, a preferred range, or a list of upper and lower preferred values, this should be understood to specifically disclose all ranges formed from any upper range limit or preferred value and any pair of lower range limit or preferred values, regardless of whether the ranges are separately disclosed. When a numerical range is recited herein, unless otherwise specified, the range is intended to include its endpoints, and all integers and fractions within the range. It is not intended that the scope of the present disclosure be limited to the specific values recited in defining the range.

[0095]

[0093] As used herein, the phrase "within any range defined as between any two of the above values" literally means that any range may be selected from any two of the values listed preceding such phrase, regardless of whether the values are the lower of the enumeration or the higher of the enumeration. For example, a pair of values may be selected from two lower values, two higher values, or a lower value and a higher value.

[0096] It should be understood that the foregoing specification is merely illustrative of the present disclosure. Various alternative and modified forms may be devised by those skilled in the art without departing from the present disclosure. Accordingly, the present disclosure is intended to embrace all such alternative, modified, and changed forms that fall within the scope of the appended claims.

Claims

1. A composition comprising an azeotropic mixture or azeotrope-like composition consisting essentially of an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water.

2. The composition according to claim 1, wherein the azeotropic mixture or azeotrope-like composition has a boiling point of about 12.0 °C to about 13.6 °C, preferably about 13.1 °C to about 13.2 °C, at a pressure of about 12.5 psia to about 16.5 psia, preferably about 14.5 psia.

3. The azeotropic mixture or azeotrope-like composition consists essentially of about 0.09 wt.% to about 92.69 wt.% of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and about 7.31 wt.% to about 99.91 wt.% of water, preferably the azeotropic mixture or azeotrope-like composition consists essentially of about 65 wt.% to about 90 wt.% of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and about 10 wt.% to about 35 wt.% of water, preferably the azeotropic mixture or azeotrope-like composition consists essentially of about 65.14 wt.% to about 86.25 wt.% of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and about 13.75 wt.% to about 34.86 wt.% of water, The composition according to claim 1 or 2.

4. A method of forming an azeotropic mixture or azeotrope-like composition, comprising combining 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water and forming the azeotropic mixture or azeotrope-like composition according to any one of claims 1 to 3.

5. A method for separating water-containing impurities from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) from a composition comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and at least one impurity, comprising providing a composition comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and at least one impurity, changing the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water and subjecting the composition to conditions effective to form the azeotropic mixture or azeotrope-like composition according to any one of claims 1 to 3. The step of separating an azeotropic mixture or an azeotrope-like composition from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) A method comprising.

6. The separation step includes at least one of phase separation, distillation, and fractionation, and / or The method further includes a step of separating 2-chloro-3,3,3-trifluoropropene from water by liquid-liquid phase separation, distillation, or using at least one desiccant. The method according to claim 5.

7. The method according to claim 5, wherein water is first removed by liquid-liquid phase separation and then by a second method selected from the group consisting of distillation, one or more desiccants, and combinations thereof.

8. The step of changing the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water comprises Adding 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to the composition, Adding water to the composition, or Adding both 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water to the composition The method according to claim 6.

9. A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf), comprising Converting at least a portion of the 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) present in the azeotropic mixture or azeotrope-like composition according to any of claims 1 to 3 to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb); Converting at least a portion of the 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf); A method comprising.

10. The method according to claim 9, wherein 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) is preferably separated from water by the method according to claim 6 or 7 and then converted to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb).

11. The step of converting at least a part of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) comprises reacting 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) with HF, preferably anhydrous HF, in the presence of a catalyst, according to the method of claim 9 or 10.

12. The catalyst is preferably SbCl ５ , SbF ５ , TiCl ４ or a combination thereof, or is a fluorosulfonic acid; and / or The step of converting at least a part of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) is carried out at a temperature of 5 to 100 °C, preferably 50 to 100 °C, according to the method of claim 11.

13. The step of converting at least a part of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) comprises reacting 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) with a base preferably in an aqueous environment, preferably in the presence of a phase transfer catalyst, preferably an ammonium halide, preferably a tetraalkylammonium halide or a trialkylammonium halide, preferably a tetraalkylammonium chloride or a trialkylammonium chloride, and / or preferably, the base is a caustic base, preferably an alkali metal hydroxide, preferably KOH or NaOH, and / or preferably carried out at a temperature of about 0 °C to about 100 °C, preferably about 20 °C to about 90 °C, preferably about 50 °C to about 90 °C, preferably about 60 °C to about 80 °C, according to the method of any one of claims 9 to 12.

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