2-chloro-3,3,3-trifluoropropene (HCFO-1233XF) and water azeotropic or azeotropic-like composition

Abstract

A heterogeneous azeotropic or azeotropic-like composition comprising 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water, which may comprise 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, and 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. Impurities including water can be separated from 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) using the azeotropic or azeotropic-like composition.

Description

Technology Field

[0001] The present disclosure relates to an azeotropic or azeotropic-like composition, in particular to an azeotropic or azeotropic-like composition comprising an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water. Background Technology

[0002] Hydrofluoroolefins (HFOs), such as tetrafluoropropenes including 2,3,3,3-tetrafluoropropene (HFO-1234yf), are known to be effective refrigerants, heat transfer media, propellants, foaming agents, blowing agents, gas dielectrics, disinfectant carriers, polymerization media, particulate removal fluids, carrier fluids, buffing abrasives, displacement desiccants, and power cycle working fluids. Unlike chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), which can potentially 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 low-toxicity, low-global-warming compound, thus meeting the increasingly stringent requirements for refrigerants in portable air conditioners. Therefore, compositions containing HFO-1234yf are among the materials currently under development for use in many of the aforementioned applications.

[0003] One manufacturing process for HFO-1234yf uses 1,1,2,3-tetrachloropropene (HCFC-1230xa) as a starting material. This process comprises the following three steps.

[0004] Step (1) 1230xa + 3HF --> 2-chloro-3,3,3-trifluoropropene(1233xf) + 3HCl in a gas-phase reactor charged with a solid catalyst;

[0005] step (2)1233xf + HF --> 2-chloro-1,1,1,2-tetrafluoropropane(244bb) in a liquid-phase reactor filled with a liquid catalyst; and

[0006] Step (3) 244 bb in gas phase or liquid phase --> 1234 yf + HCl

[0007] During the above process, by-products are generated and / or impurities, including water, may be present. To limit unwanted side reactions, it is desirable to have all reactants and intermediate products in the purest possible form. Therefore, a method to reduce impurities in reactants and intermediate products is desired. means of solving the problem

[0008] The present disclosure provides an azeotropic or azeotropic-like composition of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water.

[0009] It is well known in the art that it is impossible to predict the formation of azeotropic mixtures, and the inventors have unexpectedly discovered that 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water form an azeotropic or azeotropic-like composition, in particular a heterogeneous azeotropic or azeotropic-like composition.

[0010] The present disclosure provides a composition comprising an azeotropic or azeotropic-like composition essentially composed of an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, preferably wherein the azeotropic or azeotropic-like composition has a boiling point of about 12.0°C to 13.6°C, preferably about 13.1°C to 13.2°C at a pressure of about 12.5 psia to about 16.5 psia, preferably about 14.5 psia.

[0011] The azeotropic or azeotropic-like composition may essentially 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, preferably wherein the azeotropic or azeotropic-like composition is essentially composed of about 65 wt% to about 90 wt% of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and 10 wt% to about 35 wt% of water; preferably, the azeotropic or azeotropic-like composition is essentially composed of about 65.14 wt% to about 86.25 wt% of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and about 13.75 wt% to about 34.86 wt% of water. The azeotropic or azeotropic-like composition preferably has a boiling point of about 12.0°C to 13.6°C, preferably about 13.1°C to 13.2°C, at a pressure of about 12.5 psia to about 16.5 psia, preferably about 14.5 psia.

[0012] The present disclosure also provides a method for forming an azeotropic or azeotropic-like composition comprising the step of combining 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water to form an azeotropic or azeotropic-like composition essentially composed of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, preferably having a boiling point of about 12.0°C to 13.6°C at a pressure of about 12.5 psia to about 16.5 psia.

[0013] The present disclosure also provides a method for separating water-containing impurities from a composition comprising at least one impurity that may include 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, comprising the steps of: 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 applying the composition to conditions effective for forming an azeotropic or azeotropic-like composition that is essentially composed of, or composed of, 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water. The method includes the step of separating an azeotropic or azeotropic-like composition from a composition comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), wherein the separation step may include at least one of phase separation, distillation, drying, and fractionation.

[0014] In the above method, the step of changing the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water may include 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.

[0015] The present disclosure also includes the step of converting at least a portion of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) present in an azeotropic or azeotropic-like composition to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb); and

[0016] 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).

[0017] A method for manufacturing 2,3,3,3-tetrafluoropropene (HFO-1234yf) comprising

[0018] 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) present in an azeotrope or azeotrope-like composition can be separated from water before being 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 sensitive to the presence of water. Converting at least a portion of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) may involve reacting 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) with HF, preferably anhydrous HF, in the presence of a catalyst. The catalyst may preferably comprise a metal halide catalyst selected from SbCl5, SbF5, TiCl4, or a combination thereof, or a fluorosulfonic acid; and / or converting at least a portion 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 5-100°C, preferably 50-100°C. Converting at least a portion of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) may involve 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 in the presence of a phase transition catalyst, preferably an ammonium halide, preferably a trialkylammonium halide of tetraalkylammonium halide, preferably a trialkylammonium chloride of tetraalkylammonium chloride.The reaction can 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 conversion of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) can suitably occur at super-atmosphere pressure, atmospheric pressure, or sub-atmosphere pressure. Brief explanation of the drawing

[0019] Figure 1 is a plot of the boiling point versus percentage of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) in water. Specific details for implementing the invention

[0020] 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) are reacted with anhydrous hydrogen fluoride (HF) in a first gas phase reactor (fluorination reactor) to produce a mixture of at least 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 exiting the gas phase reactor may optionally contain additional components such as unreacted hydrogen fluoride (HF), heavy intermediates, 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244b), 1,1,1,2,2-pentafluoropropane (HFC-245cb), etc.

[0021] The reaction may be carried out in any reactor suitable for gas-phase fluorination. The reactor may be composed of a material that resists the corrosive effects of hydrogen fluoride and catalysts, such as Hastelloy®, Inconel®, Monel®, etc. In the case of a gas-phase process, the reactor is filled with a gas-phase fluorination catalyst. Any fluorination catalyst known in the art may be used in this process. Suitable catalysts include, but are not limited to, chromium, aluminum, cobalt, manganese, nickel, and iron oxides, hydroxides, halides, oxyhalides, inorganic salts thereof, and mixtures thereof in which any of these may optionally be halogenated. Combinations of catalysts suitable for the present invention include, but are not exclusive, Cr2O3, FeCl3 / C, Cr2O3 / Al2O3, Cr2O3 / AlF3, Cr2O3 / carbon, CoCl2 / Cr2O3 / Al2O3, NiCl2 / Cr2O3 / Al2O3, CoCl2 / AlF3, NiCl2 / AlF3, and mixtures thereof. A 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) oxides, such as crystalline chromium oxide or amorphous chromium oxide, are 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 excess but in an amount sufficient to induce the reaction.

[0022] 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 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 between HF and the compound of I, II, or III 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 yet another embodiment, about 200°C to about 300°C. In one embodiment, the reaction pressure is in the range of about 0 psig to about 500 psig; in another embodiment, about 20 psig to about 200 psig, and in a further embodiment, about 50 to about 100 psig.

[0023] 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 the range of about 1:1 to about 50:1 in one embodiment; in another embodiment, about 10:1 to about 50:1; and in a further embodiment, about 10:1 to about 20:1. In one embodiment, the reaction between 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 yet another embodiment, at a temperature of about 200°C to about 300°C. In one embodiment, the reaction pressure is in the range of about 0 psig to about 500 psig; in another embodiment, about 20 psig to about 200 psig, and in a further embodiment, about 50 to about 100 psig.

[0024] Similarly, where the compound of Formula II is 2,3,3,3-tetrachloro-1-propene (HCC-1230xf or 1230xf), in one embodiment, the molar ratio of HF to 1230xf in step 1 of the reaction is in the range of about 1:1 to about 50:1; in another embodiment, about 10:1 to about 50:1; and in yet another embodiment, about 10:1 to about 20:1. In one embodiment, the reaction between 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 yet another embodiment, at about 200°C to about 300°C. In one embodiment, the reaction pressure is in the range of about 0 psig to about 500 psig; In another implementation, it is about 20 psig to about 200 psig, and in yet another implementation, it is about 50 to about 100 psig.

[0025] Similarly, where 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 in the range of about 1:1 to about 50:1; in another embodiment, about 10:1 to about 50:1; and in yet another embodiment, about 10:1 to about 20:1. The reaction between HF and 240db is carried out at a temperature of about 200°C to about 600°C in one embodiment; at about 200°C to about 400°C in another embodiment, and at about 200°C to about 300°C in yet another embodiment. In one embodiment, the reaction pressure is in the range of about 0 psig to about 500 psig; in another embodiment, about 20 psig to about 200 psig; And in additional implementations, it is about 50 to about 100 psig.

[0026] The first step of the reaction is not necessarily limited to a gas phase reaction as described above, but may also be carried out using a liquid phase reaction or a combination of liquid and gas phases, as disclosed in U.S. Patent Application No. 20070197842, the contents of which are incorporated herein by reference. It is also considered that the reaction may be carried out batch-wise, continuous, or a combination thereof. In embodiments where the reaction involves a liquid phase reaction, the reaction may be catalytic or non-catalytic. Lewis acid catalysts, such as metal halide catalysts comprising antimony halide, tin halide, thallium halide, iron halide, and combinations of two or more of these, may be used. In certain embodiments, metal chlorides and metal fluorides comprising, but not limited to, SbCl5, SbCl3, SbF5, SnCl4, TiCl4, FeCl3, and combinations of two or more of these, are used.

[0027] The fluorination reaction may be performed to achieve a single or multiple-pass conversion rate of at least 1%, 5%, 10%, or about 20%. In a particular preferred embodiment of the invention, the starting reagent is converted to 1233xf in a single pass, wherein the reaction conditions achieve a conversion rate of more than 75%; in one embodiment, more than 85%; in another embodiment, more than 95%; and in yet another embodiment, more than 99%. To this end, the resulting effluent may contain small or trace amounts of unreacted starting material or may be substantially free of such compounds.

[0028] Fluorination reaction steps containing any intermediate effluent that may be present in a multi-stage reactor arrangement, the effluent from Step 1 is treated to achieve a desired degree of separation. For example, in an implementation where the reactor effluent contains 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), the effluent generally contains HCl, unreacted HF, and, if present, trace amounts of unreacted starting components (e.g., 1230xa, 1230xf, and / or 240db). The effluent may also contain one or more byproduct organics, 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) and 1,1,1,2,2-pentafluoropropane (245cb) and HFO-1234yf and combinations thereof. In further embodiments, the impurity is hydrogen fluoride. Other byproduct organics may also include, but are not limited to, dichlorotrifluoropropane (243) isomers and trichlorodifluoropropane (242) isomers and dimers derived from one or more starting compounds. As non-limiting examples, dimers derived from 1230xa include C6H3F6Cl, C6H3F7Cl2, C6F6Cl2, C6H8Cl2, C6F5Cl3, C6H3F2Cl5, etc.

[0029] After HCl is removed by distillation and a portion of HF is removed by phase separation, water is added to the remaining effluent of Step 1 in an effective amount to form an azeotropic or azeotropic-like mixture containing 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, which can subsequently be separated from the effluent containing impurities by the technique described herein. Subsequently, 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) is separated from water as described herein and then fed to the hydrofluoricing reactor of Step 2 discussed below.

[0030] In step 2 of the above-described 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 liquid form in a liquid-phase reactor that may be TFE or PFA-lined. This process may be carried out at a temperature range of about 70°C to about 120°C and a pressure range of about 50 to about 120 psig.

[0031] Any liquid-phase fluorination catalyst may be used in the present invention. A non-limiting 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, chromium fluoride halides, chromium fluoride 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.

[0032] If the catalyst becomes inactive, it can be easily regenerated by any means known in the art. One suitable method for regenerating the catalyst involves flowing a stream of chlorine through the catalyst. For example, about 0.002 to about 0.2 lb of chlorine per hour may be added to the liquid phase reaction per lb of 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.

[0033] Step 2 of the reaction in which the 244bb product is formed is not necessarily limited to a liquid-phase reaction and may be carried out using a gas-phase reaction or a combination of liquid and gas phases, as disclosed in U.S. Patent Application No. 20070197842, the contents of which are incorporated herein by reference. To this end, 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 brought into contact with a catalyst and a fluorinating agent. The catalyst may include a standard gas-phase agent used in such a reaction, and the fluorinating agent may include, but is not limited to, those generally known in the art such as hydrogen fluoride.

[0034] The effluent of the hydrofluorination reaction step (step 2), consisting mainly of 244bb and HF (and additionally small amounts of unreacted 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), overfluorinated byproduct 245cb, HCl, and Cl2), is treated to achieve the desired degree of separation and / or other treatment. For example, the product stream is fed into a light removal column, where a stream consisting mainly of 245cb, HCl, and Cl2 exits the top of the column and is sent to a thermal oxidizer (T-OX) for destruction. In one implementation, water is added to the bottom stream of the light removal column, which consists mainly of 244bb and HF (and additionally small amounts of unreacted 1233xf), to form an azeotrope 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 above, such as by distillation. In another embodiment, 244bb is also present in an azeotropic or azeotropic-like mixture composed of 1233xf and water. Then, 244bb is separated from 1233xf by techniques known in the art as described in U.S. Patent No. 8,252,965 (the contents of which are incorporated by reference). The separated 1233xf may be recycled back to the hydrofluoric acid reactor of step 2 as described above.

[0035] Step 3 of the process can be carried out in a gaseous or liquid phase. When producing HFO-1234yf in the gaseous phase, 244bb is fed to a second gaseous 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 catalytically dehydrochlorinating HCFC-244bb to produce HFO-1234yf; however, in one embodiment, the reactor contains a catalyst.

[0036] The catalyst may be a metal halide, a metal halide oxide, a neutral (or 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, and more preferably may include monovalent and divalent metal halides and mixtures / combinations thereof. The constituent metal may include, but is not limited to, Cr 3+ , Fe 3+ , Mg 2+ , Ca 2+ , Ni 2+ , Zn 2+ , Pd 2+ , Li + , Na + , K + , and Cs + Includes. Component halogens are not limited to, but include, , F - , Cl - , Br - , and I - Includes. 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. Halogenation treatment may include any treatment known in the prior art, in particular, treatment using HF, F2, HCl, Cl2, HBr, Br2, HI, and I2 as the halogenation source.

[0037] In one embodiment, neutral metals, i.e., zero-valence 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. Useful examples of metal alloys include, but are not limited to, SS 316, Monel ®400, Incoloy ® 825, Inconel ® 600, and Inconel ® 625 is included. These catalysts may be provided as individually supported or unsupported elements and / or as part of the reactor and / or reactor walls.

[0038] Exemplary but non-limiting catalysts include activated carbon, stainless steel (e.g., SS 316), and 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 be in the range of about 300 to about 550°C, and the reaction pressure may be in the range of about 0 to about 150 psig. The reactor effluent may be fed to a caustic scrubber or distillation column to remove HCl byproducts to produce an acid-free organic product, which may optionally undergo further purification using one or any combination of purification techniques known in the art.

[0039] Step 3 can also be performed 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 to dehydrochloride the 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb). The base may be a caustic base, preferably a caustic base selected from the group consisting of alkali metal hydroxides, alkali metal oxides, alkaline earth metal hydroxides, alkaline earth metal oxides, and combinations thereof. Preferred examples of 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 or solution form. If provided as a solution, the solvent is preferably water or an alcohol, preferably MeOH of EtOH. It is particularly desirable that KOH be provided as an aqueous solution containing about 5% to about 62% by weight, preferably 5% to 55% by weight of KOH. Liquid-phase dehydrochlorination is preferably carried out in an aqueous environment. With respect to liquid phase step 3, the aqueous environment is an environment in which the liquid-phase reaction mixture contains 5-80% by weight of water, preferably 10-60% by weight of water, more preferably 20-40% by weight of water. It is also particularly desirable to use a phase-transition catalyst when carrying out the reaction in an aqueous environment, as it is believed to support reactivity by promoting intimate contact between the base and 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb). Such phase transition catalysts may include, but are not limited to, crown ethers (e.g., 18-crown-6), onium salts (e.g., phosphonium salts or ammonium salts having a halide anion), cryptands (e.g., N[CH2CH2OCH2CH2OCH2CH2]3N), polyalkylene glycols (e.g., poly(ethylene glycol), derivatives thereof, and combinations thereof.In one embodiment, the phase transition catalyst is Aliquat 336. An onium salt, particularly an ammonium salt, is preferred. The ammonium salt is preferably an ammonium halide, preferably a trialkylammonium halide of a tetraalkylammonium halide, preferably a trialkylammonium chloride or a tetraalkylammonium chloride.

[0040] The liquid 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, and 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) can appropriately occur at superatmospheres, atmospheric pressure, or subatmospheres. These temperatures and pressures are particularly useful when carrying out Step 3 in the liquid phase using a base as described above.

[0041] WO-2011 / 139646 discloses additional experimental details for converting 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) in a liquid phase, the contents of which are incorporated herein.

[0042] An alternative process for manufacturing HFO-1234yf uses 1,2-dichloro-3,3,3-trifluoropropane (HCFC-243db) as a starting material and is carried out in gaseous and liquid phases. In this alternative, the process comprises the following three steps (wherein steps (2) and (3) are identical to the steps above).

[0043] Step (1): In the gas phase (with or without catalyst) 243 dB → 1233 xf + HCl or in the liquid phase (optional with phase transition catalyst and / or solvent and / or salt) 243 dB + base → 1233 xf + H2O

[0044] Step (2): 1233xf + HF → 244bb in a liquid-phase reactor filled with a liquid hydrofluorination catalyst; and

[0045] Step (3): In a gas phase reactor (with or without catalyst) or in the liquid phase, 244bb → 1234yf + HCl

[0046] In an alternative process in which the starting composition comprises 243db, 243db is dehydrohalogenated to produce a product mixture containing 1233xf. The dehydrohalogenation reaction is a dehydrochlorination reaction when the starting composition comprises 243db. The dehydrochlorination reaction is carried out in a reaction zone and may occur in the gas phase using a catalyst or in the liquid phase using a base and optionally a phase transition catalyst, and / or a solvent and / or a salt. For example, WO 2012 / 115934 discloses a gas phase reaction of 243db with a carbon catalyst. WO 2012 / 115938 discloses a gas phase reaction of 243db using a chromium oxyfluoride catalyst. WO 2017 / 044719 discloses the reaction of 243db with a fluorinated alkane in the presence of a fluorination catalyst to produce other compounds useful for producing 1233xf as well as 1234yf. WO 2017 / 044724 discloses the liquid-phase reaction of 243db with a corrosive agent. When the dehydrochlorination reaction is carried out in the gas phase, HCl is produced, whereas 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).

[0047] In an implementation where it is desirable to maintain conditions free of moisture and impurities during the synthesis of 1234yf, the reactants and intermediate products can be purified. For example, it is desirable to remove impurities, including water, from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf).

[0048] It has been found that 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water form heterogeneous azeotropic and azeotropic-like compositions or mixtures, and the present disclosure provides a heterogeneous azeotropic or azeotropic-like composition comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water. The azeotropic or azeotropic-like composition may essentially consist of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, or the azeotropic or azeotropic-like composition may consist of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water.

[0049] The inventors experimentally discovered that 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water form an azeotrope or azeotrope-like composition.

[0050] A heterogeneous azeotropic mixture consists of two liquid phases and one gas phase, all in equilibrium. For 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 constant pressure, the boiling point of the heterogeneous azeotropic mixture becomes lower than that of the lower boiling point component ("minimum boiling azeotropic mixture").

[0051] An "azeotrope" (or "azeotropic") composition is a unique combination of two or more components. An azeotropic mixture can be homogeneous (having a single liquid phase) or heterogeneous (having two liquid phases). Azeotropic compositions can be characterized in various ways. For example, at a given pressure, an azeotropic composition boils at a constant characteristic temperature that is higher than the higher boiling point component (maximum boiling point azeotropic mixture) or lower than the lower boiling point component (minimum boiling point azeotropic mixture). However, in the case of a heterogeneous azeotropic mixture, the boiling point of the azeotropic mixture is always lower than the boiling point of the lower boiling point component. At this characteristic temperature, a homogeneous azeotropic mixture has the same composition in both the gaseous and liquid phases. In the case of a heterogeneous azeotropic mixture, the composition of each of the two liquid and gaseous phases remains constant at this characteristic temperature upon boiling. An azeotropic mixture does not separate when boiling or evaporating. Therefore, the components of an azeotropic composition cannot separate during the phase change.

[0052] A homogeneous azeotropic composition is also characterized in that the bubble point pressure of the liquid phase at a characteristic azeotropic temperature is equal to the dew point pressure of the gas phase. The behavior of an azeotropic composition contrasts with the behavior of a non-azeotropic composition, in which the liquid composition changes significantly during boiling or evaporation.

[0053] However, those skilled in the art will understand that both the composition and boiling point of an azeotropic composition will vary to some extent at different pressures. Therefore, depending on temperature and / or pressure, an azeotropic composition may have various compositions. Accordingly, those skilled in the art will understand that an azeotropic composition can be defined using a compositional range rather than a fixed composition. Furthermore, an azeotropic mixture can be defined as the exact weight percentage of each component of the composition characterized by a fixed boiling point at a specific pressure.

[0054] An "azeotrope-like" composition is a composition of two or more components that behaves substantially as an azeotrope composition. Accordingly, for the purposes of this disclosure, an azeotrope-like composition is a combination of two or more different components that, in the case of a homogeneous azeotrope mixture, boils at a substantially constant temperature when in liquid form under a given pressure and provides a vapor composition substantially identical to the boiling liquid composition. In the case of a heterogeneous azeotrope mixture, two liquid phases are formed under a given pressure and will be covered by a vapor composition. Each of the two liquid phases and the gas phase remains substantially constant during boiling.

[0055] For the purposes of the present disclosure, the azeotropic-like composition is preferably a composition or range of compositions that boils at a temperature range of about 12.0°C to 13.6°C at a pressure of about 12.5 psia to about 16.5 psia.

[0056] Azeotropic or azeotropic-like compositions can be identified using a number of different methods.

[0057] For the purposes of this disclosure, azeotropic or azeotropic-like compositions are experimentally identified using a dilatometer (Walas, Phase Equilibria in Chemical Engineering, Butterworth-Heinemann, 1985, 533-544). The dilatometer is designed to measure the boiling point of a liquid very accurately by measuring the vapor-liquid equilibrium temperature.

[0058] 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 initially measured. Subsequently, a second component of the composition is added in varying amounts, and the boiling point of each of the obtained compositions is measured using a dilatometer at the constant pressure. In the case of a ternary azeotrope mixture, the initial composition consists of a binary blend, and a third component is added in varying amounts. The boiling point of each of the obtained ternary compositions is measured using a dilatometer at the constant pressure.

[0059] The measured boiling point is plotted against the composition of the tested composition, for example, in the case of a binary azeotropic mixture, against the amount of the second component added to the composition (expressed in weight% or mole%). The presence of an azeotropic composition can be confirmed by observing a maximum or minimum boiling temperature that is higher or lower than the boiling point of any component alone.

[0060] As recognized by those skilled in the art, identification of an azeotropic or azeotropic-like composition is achieved by comparing the change in the boiling point of the composition with respect to the boiling point of the first component when a second component is added to the first component. Therefore, it is not necessary to calibrate the system to the reported boiling point of a specific component in order to measure the change in boiling point.

[0061] As previously discussed, at the maximum or minimum boiling point, the composition of the gas phase will be the same as the composition of the liquid phase. Accordingly, the azeotropic-like composition is a composition of components that provides 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 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 a substantially constant boiling point, the composition of the gas phase will be substantially the same as the composition of the liquid phase.

[0062] The present disclosure provides an azeotropic or azeotropic-like composition comprising an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water to form an azeotropic or azeotropic-like composition. As used herein, the term "effective amount" is the amount of each component that results in the formation of an azeotropic or azeotropic-like composition when combined with other components.

[0063] The azeotropic or azeotropic-like composition of the present invention is essentially composed of a combination of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, or is composed of a combination of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water.

[0064] As used herein, the term “consisting essentially of” means, with respect to the components of an azeotropic or azeotropic-like composition or mixture, that said composition contains a component designated as an azeotropic or azeotropic-like ratio and may contain additional components, provided that the additional components do not form a new azeotropic or azeotropic-like system. For example, an azeotropic mixture essentially composed of two compounds forms a binary azeotropic mixture and may optionally include one or more additional components, provided that the additional components do not impart non-azeotropic properties to the mixture and do not form an azeotropic mixture with one or all of the compounds (e.g., do not form a triotropic or greater azeotropic mixture).

[0065] The present disclosure also provides a method for forming an azeotropic or azeotropic-like composition by mixing, combining, or blending an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water. Any wide 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, blended, or otherwise combined by hand and / or machine as part of a batch or continuous reaction and / or process, or through a combination of two or more such steps. The components may be provided in the required amount, for example, by weighing and then combining the amounts.

[0066] An azeotropic or azeotropic-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 also essentially consist of about 0.09 wt% to about 92.69 wt% 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and about 7.31 wt% to about 99.91 wt% water, or may consist of the same.

[0067] The present disclosure also provides a composition comprising an azeotropic or azeotropic-like composition. For example, a composition comprising at least about 14 weight% of an azeotropic or azeotropic-like composition, or at least about 21 weight% of an azeotropic or azeotropic-like composition, or at least about 25 weight% of an azeotropic or azeotropic-like composition, or at least about 70 weight% of an azeotropic or azeotropic-like composition, or at least about 90 weight% of an azeotropic or azeotropic-like composition, or at least 95 weight% of an azeotropic or azeotropic-like composition, or 99 weight% of an azeotropic or azeotropic-like composition is provided.

[0068] An azeotropic or azeotropic-like composition disclosed herein comprising, essentially consisting of, or consisting of, an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, or composed of, may be used to separate impurities from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf).

[0069] The preparation of an azeotropic or azeotropic-like composition comprising, essentially consisting of, or consisting of an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water is used for azeotropic distillation, for example, to remove impurities including water from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf).

[0070] In particular, an azeotropic or azeotropic-like composition comprising, essentially consisting of, or composed of an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water may be formed from a composition comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), water, and at least one impurity that may include water. After the formation of the azeotropic or azeotropic-like composition, the azeotropic or azeotropic-like composition may be separated from other chemical compounds by suitable methods such as distillation, phase separation, drying, or fractionation. Drying may be achieved by the addition of a drying agent such as a molecular sieve.

[0071] In one example, the present disclosure provides a method for separating impurities from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), comprising the steps of providing a primary composition of crude 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf); changing the relative amounts of 2-chloro-3,3,3-trifluoropropene and water; applying the primary composition to conditions effective for forming a secondary composition which is essentially composed of or an azeotropic or azeotropic-like composition composed 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. Afterwards, the secondary composition may undergo additional 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 include 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.

[0072] An azeotropic or azeotropic-like composition comprising, essentially consisting of, or composed of an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water can be used to produce 2,3,3,3-tetrafluoropropene (HFO-1234yf). For example, as described above, the azeotropic or azeotropic-like composition can be used to purify 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) prior to step 3 of the process. 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) removed from 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) through the formation of an azeotropic mixture may subsequently be converted to additional 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) before being converted to 2,3,3,3-tetrafluoropropene (HFO-1234yf). Similarly, if 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) is present in the crude product, for example, an azeotropic mixture or an azeotropic-like composition may be formed after step 3 by the dehydrofluorination of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) in step 3. Although not inevitable, it is also possible for azeotropic or azeotropic-like compositions to be formed in the reaction producing 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) from 1,2-dichloro-3,3,3-trifluoropropane (HCFC-243db). The presence of azeotropic or azeotropic-like compositions will depend on factors such as whether they are interfered with by other substances in which the azeotrope exists. Examples of how azeotropic or azeotropic-like compositions may be formed, although not inevitable, include the following:

[0073] When water is present as a solvent in the reaction, e.g., when the reaction is carried out in an aqueous environment, such as when a base is used in an aqueous solution.

[0074] When water evolves 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 formula: : CF3CHClCCH2Cl + - OH → CF3CCl=CH2+ Cl - + H2O. Those skilled in the art will understand that water molecules may be produced when other types of bases, especially caustic bases, are used.

[0075] The following non-limiting embodiments are provided to illustrate the invention.

[0076] Examples

[0077] Example 1 - Vapor-Liquid Equilibrium (VLE) Test

[0078] A quartz thermometer was mounted on a boiling point measuring device (ebulliometer) consisting of a vacuum jacketed tube with a dry ice cooling condenser at the top. The boiling point measuring device was initially filled with 14.11 g of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf). Then, water was added gradually, and the temperature of the mixture was recorded at each water increment. The temperature of the mixture reached a minimum value and then remained essentially constant as additional water was added, indicating the formation of a heterogeneous azeotropic mixture. The ambient pressure during the measurement was 14.5 psia. The composition of the mixture and the measured temperatures are shown in Table 1. The data in Table 1 are graphed in Figure 1.

[0079]

[0080] Example 2 - Measurement of Vapor-Liquid-Liquid Equilibrium (VLLE)

[0081] A 50:50 weight mixture of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water was prepared in a Teflon cell at 23°C. Two distinct phases were observed in the cell, indicating the formation of a heterogeneous azeotropic mixture. 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.

[0082]

[0083] Example 3 - Purification of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf)

[0084] In this embodiment, a composition comprising 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and an impurity which may be water is provided. An effective amount of water is added to the composition, and the composition is applied under conditions effective to essentially consist of an effective amount of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water, or to form an azeotropic or azeotropic-like composition composed thus. Then, the azeotropic or azeotropic-like composition is 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, a drying agent may be added to further dry it.

[0085] Example 4 - Separation of water as an impurity

[0086] In this embodiment, a composition is provided comprising a primary compound, such as 2-chloro-3,3,3-trifluoropropene (1233xf), along with water as an impurity. An effective amount of water is added to the composition, and the composition is essentially composed of an effective amount of 2-chloro-3,3,3-trifluoropropene (1233xf) and water, or is applied under conditions effective for forming an azeotropic or azeotropic-like composition composed thus. Then, the azeotropic or azeotropic-like composition is 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, a desiccant may be added to further dry it.

[0088] Example 5 - Separation of water as an impurity

[0089] In this embodiment, a composition is provided comprising a primary compound, such as 2-chloro-3,3,3-trifluoropropene (1233xf), along 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 applied under conditions effective to essentially consist of an effective amount of 2-chloro-3,3,3-trifluoropropene (1233xf) and water, or to form an azeotropic or azeotropic-like composition composed thus. Then, the azeotropic or azeotropic-like composition is 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, a drying agent may be added to further dry it.

[0090] Example 6 - Representative procedure for converting 1,2-dichloro-3,3,3-trifluoropropane (HCFC-243db) to 2-chloro-3,3,3-trifluoropropene (1233xf)

[0091] 86 g of 12 wt% NaOH solution and 36.5 g of 243 dB were loaded into a shaking tube reactor. The reactor was cooled to -10°C and briefly evacuated. It was then heated to 55°C without stirring. When the temperature reached 47°C, it was shaken and heated to 55°C. It was then maintained at ~55°C for 60 minutes. The expected mixing power was 30-40 HP / 1000 gallons. During the reaction, the pressure was continuously increased from 6.34 psig to 47 psig. Based on the temperature and pressure profiles, it was estimated that the reaction would reach a 98% conversion rate within approximately 25 minutes. The product was analyzed by GC-MS, and the results indicated that approximately 98% of the 243 dB was converted.

[0092]

[0093] Example 7 - Representative procedure for converting 2-chloro-3,3,3-trifluoropropene (1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb)

[0094] Approximately 327 g of HF, approximately 50 g of 1233xf, and approximately 75 g of SbCl5 were loaded into a 1 L autoclave. The reaction mixture was stirred at a temperature of approximately 80°C for approximately 3 hours under a pressure of approximately 620 psig. After the reaction, the reactor was cooled to approximately 0°C, and then approximately 300 ml of water was slowly added to the autoclave over a period of approximately 45 minutes. After the water was completely added under stirring, the reactor was cooled to room temperature, and then the overhead gas was transferred to another collection cylinder. The yield of CF3CFClCH3 was approximately 90% at a 1233xf conversion level of approximately 98%. Other major byproducts were CF3CF2CH3 (2%) and an unidentified isomer of the compound of general formula C4, C4H3Cl3F4 (8%).

[0095] Example 8 - Representative procedure for converting 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf)

[0096] The dehydrochlorination of HCFC-244bb was performed in a 1-liter Parr reactor equipped with a thermocouple and a magnetic stirrer. 15 g of Aliquat 336™ was added to the reactor. Then, the reactor was closed and the pressure was tested. Subsequently, 294 g of the organic mixture and 270 g of 45% KOH were added to the reactor. Analysis of the organic mixture using gas chromatography (GC) revealed 1234yf with 8.1 GC area%, 244bb with 89.5 GC area%, and 1233xf with 1.8 GC area%. Next, the stirrer was turned on and the reactor was heated to 55°C. Upon reaching 55°C (after approximately 2 hours), the pressure in the reactor was increased from an initial 10 psig to 55 psig. The reactor was maintained at 55°C for 4 hours, and the pressure was further increased to 78 psig. After the reaction was completed, GC analysis of the reactor organic matter content revealed 1234yf with 64.2 GC area%, 244bb with 33.2% GC area%, 1233xf with 2.2 GC area%, and an unknown substance with 0.4 GC area%.

[0097] The synthesis examples described above are included to illustrate the reaction and are not intended to explain whether an azeotropic mixture of the claimed azeotropic-like composition is present in the synthesis procedure.

[0098] Example 9 - Representative purification of HCFO-1233xf

[0099] A composition containing HCFO-1233xf and water is purified to provide a purified stream of HCFO-1233xf.

[0100] 1,000 kg of a mixture containing 926.9 kg of HCFO-1233xf and 73.1 kg of water, available at IMTP in Koch-Glitsch ®It is loaded into the reboiler of a batch distillation system consisting of a reboiler and a condenser packed in a multi-stage rectification section with random packing such as packing. The condenser is cooled with flow cooling water at approximately 5°C at the condenser inlet. 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 undergoing phase separation, and in phase separation, the aqueous phase is poured off from the top.

[0101] A batch distillation system is used to distill an overhead stream essentially containing an azeotropic mixture of HCFO-1233xf and water, leaving substantially HCFO-1233xf containing about 0.039 wt% water in the reboiler. See Table 3 for a summary. The material in the reboiler can be further dried by passing it through a desiccant such as a molecular sieve 3A.

[0102]

[0103] Under these conditions, the azeotropic composition is 68 wt% HCFO-1233xf. Any amount slightly exceeding the azeotropic ratio is recovered from the overhead.

[0104] This example illustrates a batch distillation method for purification, but it can be adapted by those skilled in the art for continuous distillation for purification.

[0105] Modes

[0106] Embodiment 1 is a composition comprising an azeotropic or azeotropic-like composition essentially composed of an effective amount of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water.

[0107] Embodiment 2 is a composition of Embodiment 1, wherein the azeotropic or azeotropic-like composition has a boiling point of about 12.0°C to 13.6°C at a pressure of about 12.5 psia to about 16.5 psia.

[0108] Embodiment 3 is a composition in which, in the composition of Embodiment 1 or Embodiment 2, the azeotrope or azeotrope-like composition is essentially composed 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.

[0109] Embodiment 4 is a method for forming an azeotropic or azeotropic-like composition, comprising the step of combining 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water to form an azeotropic or azeotropic-like composition essentially composed of an effective amount of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water, 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.

[0110] Embodiment 5 is a method of the method of Embodiment 4, wherein the combining step comprises combining 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.

[0111] Aspect 6 is a method for separating water-containing impurities from a composition comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and at least one impurity, comprising the steps of: 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 applying the composition to conditions effective for forming an azeotropic or azeotropic-like composition essentially composed of, or composed of, 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water; and separating the azeotropic or azeotropic-like composition from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf). It is a method for separating impurities that includes a separation step.

[0112] Embodiment 7 is a method of Embodiment 6, wherein the separating step comprises at least one of phase separation, distillation, drying, and fractionation.

[0113] Embodiment 8 is a method according to Embodiment 6 or Embodiment 7, further comprising the step of separating 2-chloro-3,3,3-trifluoropropene from water.

[0114] Embodiment 9 is a method in which, in any one of Embodiments 6-8, 2-chloro-3,3,3-trifluoropropene is separated from water using liquid-liquid phase separation.

[0115] Embodiment 10 is a method in which, in any one of Embodiments 6-9, 2-chloro-3,3,3-trifluoropropene is separated from water using distillation.

[0116] Embodiment 11 is a method in which, in any one of Embodiments 6-10, 2-chloro-3,3,3-trifluoropropene is separated from water using at least one drying agent.

[0117] Embodiment 12 is a method in which, in any one of Embodiments 6-11, water is first removed by liquid-liquid phase separation and then removed by a second method selected from the group consisting of distillation, one or more drying agents, and combinations thereof.

[0118] Embodiment 13 is a method in which, in any one of Embodiments 6-12, 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.

[0119] Embodiment 14 is a method in which, in any one of Embodiments 6-13, the step of changing the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water comprises adding water to the composition.

[0120] Embodiment 15 is a method in which, in any one of Embodiments 6-14, 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.

[0121] As used herein, the phrase “within any range defined between any two of the above values” literally means that any range may be selected from any two of the values ​​listed prior to this phrase, regardless of whether the values ​​are in the lower part of the list or the higher part of the list. For example, a pair of values ​​may be selected from two lower values, two higher values, or a lower value and a high value.

[0122] As used herein, the singular forms “a,” “an,” and “the” include the plural unless the context clearly indicates otherwise. Furthermore, when a quantity, concentration, or other value or parameter is given as a range, a preferred range, or a list of preferred upper and lower preferred values, this should be understood as specifically disclosing any range formed from any pair of any upper range or preferred value and any lower range or preferred value, regardless of whether the range is disclosed separately. Where a range of numerical values ​​is cited herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within the range. The ranges of this disclosure are not intended to be limited to the specific values ​​cited when defining the ranges.

[0123] As used herein, the phrase “within any range defined between any two of the above values” literally means that any range may be selected from any two of the values ​​listed before this phrase, regardless of whether the values ​​are in the lower part of the list or the higher part of the list. For example, a pair of values ​​may be selected from two lower values, two higher values, or a lower value and a high value.

[0124] It should be understood that the foregoing description is merely illustrative of the present disclosure. Various alternatives and modifications may be devised by those skilled in the art without departing from the scope of the present disclosure. Accordingly, the present disclosure is intended to include all such alternatives, modifications, and changes that fall within the scope of the appended claims.

Claims

Claim 1 A composition comprising an azeotropic or azeotropic-like composition essentially composed of 0.09 wt% to 92.69 wt% of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and 7.31 wt% to 99.91 wt% of water. Claim 2 A composition according to claim 1, wherein the azeotropic or azeotropic-like composition has a boiling point of 12.0°C to 13.6°C, or 13.1°C to 13.2°C at a pressure of 12.5 psia to 16.5 psia, or 14.5 psia. Claim 3 A composition according to claim 1, wherein the azeotrope or azeotrope-like composition is essentially composed of 65% to 90% by weight of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and 10% to 35% by weight of water. Claim 4 A composition according to claim 3, wherein the azeotrope or azeotrope-like composition is essentially composed of 65.14% to 86.25% by weight of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and 13.75% to 34.86% by weight of water. Claim 5 A method for forming an azeotropic or azeotropic-like composition comprising the step of combining 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water to form an azeotropic or azeotropic-like composition as defined in any one of claims 1 to 4. Claim 6 A method for separating impurities including water from a composition comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and at least one impurity, comprising the steps of: 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 applying the composition to conditions effective for forming an azeotropic or azeotropic-like composition defined in any one of claims 1 to 4; and separating the azeotropic or azeotropic-like composition from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf). Claim 7 A method for separating impurities according to claim 6, wherein the separation step comprises at least one of phase separation, distillation, and fractionation; and / or further comprises the step of separating 2-chloro-3,3,3-trifluoropropene from water using liquid-liquid phase separation, distillation, or at least one drying agent. Claim 8 A method for separating impurities according to claim 6, wherein water is first removed by liquid-liquid phase separation and then removed by a second method selected from the group consisting of distillation, one or more drying agents, and combinations thereof. Claim 9 In claim 7, 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 a composition; adding water to a composition; or adding both 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water to a composition, a method for separating impurities. Claim 10 A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf), comprising the steps of: converting at least a portion of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) present in an azeotrope or azeotrope-like composition defined in any one of claims 1 to 4 to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb); and converting at least a portion of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf). Claim 11 A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf) according to claim 10, wherein 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) is separated from water before being converted to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb). Claim 12 A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf) according to claim 10, wherein 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) is separated from water by a method defined in (i) or (ii) below before being converted to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb): (i) comprising at least one of phase separation, distillation and fractionation; and / or further comprising the step of separating 2-chloro-3,3,3-trifluoropropene from water using liquid-liquid phase separation, distillation or at least one drying agent; (ii) wherein water is first removed by liquid-liquid phase separation and then removed by a second method selected from the group consisting of distillation, one or more drying agents, and combinations thereof. Claim 13 A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf) according to claim 10, wherein the step of converting at least a portion 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 in the presence of a catalyst. Claim 14 A method for manufacturing 2,3,3,3-tetrafluoropropene (HFO-1234yf), wherein, in paragraph 13, HF is anhydrous HF. Claim 15 A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf), wherein, in claim 13, the catalyst comprises a metal halide catalyst, or a metal halide catalyst selected from SbCl5, SbF5, TiCl4, or a combination thereof, or a fluorosulfonic acid; and / or the step of converting at least a portion of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) is performed at 5-100°C, or 50-100°C. Claim 16 A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf), wherein, in claim 10, 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) comprises the step of reacting 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) with a base. Claim 17 A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf) according to claim 16, wherein the step of reacting 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) with a base is carried out in an aqueous environment in the presence of a phase transition catalyst, or in the presence of an ammonium halide, or in the presence of a trialkylammonium halide of a tetraalkylammonium halide, or in the presence of a trialkylammonium chloride of a tetraalkylammonium chloride. Claim 18 A method for preparing 2,3,3,3-tetrafluoropropene (HFO-1234yf) according to claim 16, wherein the base is a caustic base, an alkali metal hydroxide, KOH, or NaOH. Claim 19 A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf) according to claim 16, wherein the step of reacting 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) with a base is performed at a temperature of 0°C to 100°C, 20°C to 90°C, 50°C to 90°C, or 60°C to 80°C.

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