An azeotrope or azeotropic composition of 2-chloro-3,3,3-trifluoropropene (HCFO-1233XF) and water.

Abstract

This application relates to azeotropic or azeotropic compositions of 2-chloro-3,3,3-trifluoropropene and water. A non-homogeneous azeotropic or azeotropic composition comprising 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water may contain 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 pressure of about 12.0 psia to about 16.5 psia. o C to approximately 13.6 o The boiling point of C. The azeotrope or azeotropic composition can be used to separate impurities including water from 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf).

Description

Technical Field

[0001] This disclosure relates to azeotropic or azeotropic compositions, particularly azeotropic or azeotropic compositions comprising effective amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water. Background Technology

[0002] Hydrofluoroolefins (HFOs), such as tetrafluoropropylene, including 2,3,3,3-tetrafluoropropylene (HFO-1234yf), are known to be effective refrigerants, heat transfer media, propellants, foaming agents, blowing agents, gaseous dielectrics, pesticide carriers, polymerization media, particulate removal fluids, carrier fluids, polishing abrasives, displacement desiccants, and power cycle working fluids. Unlike chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), which can both deplete the Earth's ozone layer, HFOs pose no threat to the ozone layer. HFO-1234yf has also been shown to be a low-toxicity, low-global-warming compound, and therefore meets the increasingly stringent requirements for refrigerants in automotive air conditioning systems. Therefore, compositions containing HFO-1234yf belong to the category of materials being developed for use in many of the aforementioned applications.

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

[0004] Step (1) In a gas-phase reactor containing a solid catalyst, 1230xa + 3HF → 2-chloro-3,3,3-trifluoropropene (1233xf) + 3HCl;

[0005] Step (2) In a liquid-phase reactor containing a liquid catalyst, 1233xf + HF → 2-chloro-1,1,1,2-tetrafluoropropane (244bb); and

[0006] Step (3) in a gas-phase reactor or in the liquid phase: 244 bb → 1234yf + HCl.

[0007] During the aforementioned process, byproducts and / or impurities, including water, may be generated. It is desirable that all reactants and intermediates be in the purest possible form to limit undesirable side reactions. Therefore, methods to reduce impurities in reactants and intermediates are needed. Summary of the Invention

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

[0009] It is generally accepted in the art that the formation of azeotropes is unpredictable, and the inventors of this invention have unexpectedly discovered that 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water form azeotropic or azeotropic compositions, particularly non-homogeneous azeotropic or azeotropic compositions.

[0010] This disclosure provides a composition comprising an azeotropic or azeotropic composition substantially consisting of an effective amount of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, preferably wherein the azeotropic or azeotropic composition has a pressure of about 12.0 at a pressure of about 12.5 psia to about 16.5 psia, preferably about 14.5 psia. o C to approximately 13.6 o C. Preferably around 13.1 o C to approximately 13.2 o Boiling point of C.

[0011] The azeotropic or azeotropic-like composition may consist substantially 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 consists substantially of about 65 wt% to about 90 wt% of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and about 10 wt% to about 35 wt% of water; preferably the azeotropic or azeotropic-like composition consists substantially 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 composition preferably 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.

[0012] This disclosure also provides a method for forming an azeotrope or azeotropic-like composition, comprising combining 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water to form a composition substantially consisting of effective amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, and preferably having a pressure of about 12.0 psia at a pressure of about 12.5 psia to about 16.5 psia. o C to approximately 13.6 o The steps of creating an azeotrope or azeotropic composition with boiling point C.

[0013] This disclosure further provides a method for separating impurities (including water) from a composition comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and at least one impurity (which may include water), comprising the following steps:

[0014] Provide a composition comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and at least one impurity; vary the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, and subject the composition to conditions that effectively form an azeotrope or azeotropic-like composition, the azeotrope or azeotropic-like composition consisting substantially of or of effective amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water; and separate the azeotrope 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.

[0015] In the aforementioned 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.

[0016] This disclosure also provides a method for preparing 2,3,3,3-tetrafluoropropylene (HFO-1234yf), which includes:

[0017] At least some of the 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) present in the azeotropic or azeotropic composition is converted to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb); and

[0018] At least some of the 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) is converted into 2,3,3,3-tetrafluoropropene (HFO-1234yf).

[0019] Prior to conversion to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), it is advantageous to separate 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) present in the azeotropic or azeotropic composition from water, as this 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 water-sensitive catalyst. The conversion of at least some of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) may comprise reacting 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) with HF, preferably anhydrous HF, in the presence of a catalyst. The catalyst may include a metal halide catalyst, preferably selected from SbCl5, SbF5, TiCl4 or combinations thereof, or fluorosulfonic acid; and / or the conversion of at least some 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) can be carried out at 5-100 o C. Preferred size: 50-100 o The reaction is carried out at a temperature of C. The conversion of at least some 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 trialkylammonium halide or a tetraalkylammonium halide, preferably a trialkylammonium chloride or a tetraalkylammonium chloride. The reaction may preferably be carried out at about 0°C. o C - Approximately 100 o C. Preferably about 20 o C-approx. 90 o C. Preferred 50 o C-approx. 90 o C. Preferred 60 o C-approx. 80 o The conversion of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) can be carried out at ultra-atmospheric pressure, atmospheric pressure, or below atmospheric pressure. Attached Figure Description

[0020] Figure 1 This is a graph showing the percentage of boiling point relative to the concentration of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) in water. Detailed Implementation

[0021] In the first step (as described 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 can be carried out at a temperature of about 200°C to about 400°C and a pressure of about 0 psig to about 200 psig. The effluent stream leaving 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-244bb), 1,1,1,2,2-pentafluoropropane (HFC-245cb), etc.

[0022] The reaction can be carried out in any reactor suitable for gas-phase fluorination. The reactor can be made of materials resistant to the corrosion of hydrogen fluoride and catalysts, such as Hastelloy. ® Inconel ® Monel ® The reactor is constructed as follows. In the case of a gas-phase method, the reactor is filled with a gas-phase fluorination catalyst. Any fluorination catalyst known in the art can be used in this method. Suitable catalysts include, but are not limited to, oxides, hydroxides, halides, oxyhalides, inorganic salts of chromium, aluminum, cobalt, manganese, nickel, and iron, any of which may optionally be halogenated. The set of catalysts suitable for use in this invention nonexclusively includes Cr2O3, FeCl3 / C, Cr2O3 / Al2O3, Cr2O3 / AlF3, Cr2O3 / carbon, CoCl2 / Cr2O3 / Al2O3, NiCl2 / Cr2O3 / Al2O3, CoCl2 / AlF3, NiCl2 / AlF3, and mixtures thereof. Chromium oxide / aluminum oxide catalysts are 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, with amorphous chromium oxide being the most preferred. Chromium oxide (Cr2O3) is a commercially available material, available in various particle sizes. A fluorination catalyst with a purity of at least 98% is preferred. The fluorination catalyst is present in excess, but at least in an amount sufficient to drive the reaction.

[0023] In one embodiment, the molar ratio of hydrogen fluoride (HF) to the compound of formula I, II, or III in step 1 reaction is from about 1:1 to about 50:1 in one embodiment; from about 10:1 to about 50:1 in another embodiment; and from about 10:1 to about 20:1 in a further embodiment. In one embodiment, the reaction between HF and the compound of formula I, II, or III is carried out at about 200°C. o C to approximately 600 o C, in another implementation, in approximately 200 o C to approximately 400 o C, in another implementation, in approximately 200 o C to approximately 300 o The reaction is carried out at a temperature of C. In one embodiment, the reaction pressure is from about 0 psig to about 500 psig; in another embodiment, it is from about 20 psig to about 200 psig; and in a further embodiment, it is from about 50 psig to about 100 psig.

[0024] For example, when the compound of Formula I is 1230xa, in one embodiment, the molar ratio of HF to 1230xa in reaction step 1 is about 1:1 to about 50:1; in another embodiment, it is about 10:1 to about 50:1; and in a further embodiment, it is about 10:1 to about 20:1. In one embodiment, the reaction between HF and 1230xa is carried out at about 200°C. o C to approximately 600 o C, in another implementation, in approximately 200 o C to approximately 400 o C, in another implementation, in approximately 200 o C to approximately 300 o The reaction is carried out at a temperature of C. In one embodiment, the reaction pressure is from about 0 psig to about 500 psig; in another embodiment, it is from about 20 psig to about 200 psig; and in a further embodiment, it is from about 50 psig to about 100 psig.

[0025] Similarly, when 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 reaction step 1 is about 1:1 to about 50:1; in another embodiment, it is about 10:1 to about 50:1; and in yet another embodiment, it is about 10:1 to about 20:1. In one embodiment, the reaction between HF and 1230xf is carried out at about 200 °C. o C to approximately 600 oC, in another implementation, in approximately 200 o C to approximately 400 o C and in another implementation in approximately 200 o C to approximately 300 o The reaction is carried out at a temperature of C. In one embodiment, the reaction pressure is from about 0 psig to about 500 psig; in another embodiment, it is from about 20 psig to about 200 psig; and in yet another embodiment, it is from about 50 psig to about 100 psig.

[0026] 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 reaction step 1 is about 1:1 to about 50:1; in another embodiment, it is about 10:1 to about 50:1; and in yet another embodiment, it is about 10:1 to about 20:1. In one embodiment, the reaction between HF and 240db is carried out at about 200 °C. o C to approximately 600 o C, in another implementation, in approximately 200 o C to approximately 400 o C and in another implementation in approximately 200 o C to approximately 300 o The reaction is carried out at a temperature of C. In one embodiment, the reaction pressure is from about 0 psig to about 500 psig; in another embodiment, it is from about 20 psig to about 200 psig; and in a further embodiment, it is from about 50 psig to about 100 psig.

[0027] 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, such as those disclosed in U.S. Patent Application Publication No. 20070197842, the contents of which are incorporated herein by reference. It is also contemplated that the reaction may be carried out batch, continuously, or in a combination thereof. For embodiments in which the reaction includes a liquid-phase reaction, the reaction may be catalytic or non-catalytic. Lewis acid catalysts may be used, such as metal halide catalysts, including antimony halides, tin halides, thallium halides, iron halides, and combinations of two or more of these. In some embodiments, metal chlorides and metal fluorides are used, including but not limited to SbCl5, SbCl3, SbF5, SnCl4, TiCl4, FeCl3, and combinations of two or more of these.

[0028] The fluorination reaction can be carried out to obtain a single-pass or multi-pass conversion of at least 1% or higher, 5% or higher, 10% or higher, or about 20% or higher. In some preferred embodiments of the invention, the starting reactants are converted to 1233xf in a single pass, wherein the reaction conditions achieve a conversion of greater than 75%, greater than 85% in one embodiment, greater than 95% in another embodiment, and greater than 99% in yet another embodiment. In view of this, the resulting effluent contains small or trace amounts of unreacted starting material, or may be substantially free of these compounds.

[0029] The effluent from the fluorination reaction step (Step 1), including any intermediate effluents that may be present in a multi-stage reactor configuration, is treated to achieve the desired separation. For example, in an embodiment where the reactor effluent contains 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), the effluent will typically also contain HCl, unreacted HF, and trace amounts (if any) of unreacted starting components (e.g., 1230xa, 1230xf, and / or 240db). The effluent may also contain one or more byproduct organic compounds, such as under-fluorinated and / or over-fluorinated intermediates. Non-limiting examples of underfluorinated intermediates include trichlorofluoropropene (1231) isomers and 2,3-dichloro-3,3-difluoropropene (1232xf), and non-limiting examples of perfluorinated 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 a further embodiment, the impurity is hydrogen fluoride. Other byproduct organics may also include, but are not limited to, dichlorotrifluoropropane (243) isomers and trichlorodifluoropropane (242) isomers, as well as dimers derived from one or more starting compounds. As non-limiting examples, dimers derived from 1230xa include, but are not limited to, C6H3F6Cl, C6H3F7Cl2, C6F6Cl2, C6H8Cl2, C6F5Cl3, C6H3F2Cl5, etc.

[0030] After removing HCl by distillation and a portion of HF by phase separation, water is added in an effective amount to the remaining effluent from step 1 to form an azeotrope or azeotropic-like mixture comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water. This azeotrope or azeotropic-like mixture can then be separated from the effluent containing its impurities using the techniques described herein. 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) is then separated from water as described herein, and then fed into the hydrofluorination reactor of step 2, discussed below.

[0031] In step 2 of the method described above 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 can be carried out in a liquid phase in a liquid-phase reactor, which may be TFE or PFA-lined. Such a method can be performed at approximately 70°C. o C to approximately 120 o The temperature range of C is neutralized at pressures ranging from approximately 50 psig to approximately 120 psig.

[0032] Any liquid-phase fluorination catalyst can be used in this 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, fluorides of SbCl5, fluorides of SbCl3, fluorides of SnCl4, fluorides of TaCl5, fluorides of TiCl4, fluorides of NbCl5, fluorides of MoCl6, fluorides of FeCl3, or combinations thereof. Antimony pentachloride is the preferred choice.

[0033] If the catalyst becomes deactivated, it can be readily regenerated by any means known in the art. A suitable method for regenerating a catalyst involves passing a chlorine feed stream through the catalyst. For example, for each pound of liquid-phase fluorination catalyst, approximately 0.002 to approximately 0.2 pounds of chlorine per hour can be added to the liquid-phase reaction. This can be done, for example, at approximately 65... o C to approximately 100 o The temperature is maintained at C for approximately 1 to 2 hours or continuously.

[0034] Reaction step 2, which forms the 244bb product, is not limited to a liquid-phase reaction, but can also be carried out using a gas-phase reaction or a combination of liquid and gas phases, as disclosed in U.S. Patent Application Publication No. 20070197842, the contents of which are incorporated herein by reference. For this purpose, the feed stream containing 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) is preheated to approximately 50 °C. o C to approximately 400 oThe temperature is set to C, and the mixture is brought into contact with the catalyst and the fluorinating agent. The catalyst may include standard gaseous reagents used for this reaction, and the fluorinating agent may include those commonly known in the art, such as, but not limited to, hydrogen fluoride.

[0035] The effluent from the hydrofluorination reaction step (step 2) is treated to achieve the desired separation and / or other treatments. The effluent consists primarily of 244bb and HF (plus a small amount of unreacted 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), the perfluorination byproduct 245cb, HCl, and Cl2). For example, the product stream is fed into a light matter removal tower, where the stream, primarily composed of 245cb, HCl, and Cl2, exits from the top of the tower and is sent to a thermal oxidizer (T-OX) for destruction. In one embodiment, water is added to the bottom stream of the light matter removal tower, which consists primarily of 244bb and HF (plus a small amount of unreacted 1233xf), to form an azeotrope or azeotropic mixture containing 1233xf and water. In one embodiment, 244bb is not present in the mixture, in which case 1233xf is separated from water using techniques known in the art, such as distillation, as described above. In another embodiment, 244bb is also present in the azeotrope or azeotropic mixture containing 1233xf and water. The 244bb is then separated from the 1233xf using techniques known in the art (e.g., described in U.S. Patent No. 8,252,965, the contents of which are incorporated herein by reference). The separated 1233xf can be recycled back to the hydrofluorination reactor of step 2 as described above.

[0036] Step 3 of the method can be carried out in the gas phase or the liquid phase. When preparing HFO-1234yf in the gas phase, 244bb is fed into a second gas-phase reactor (dehydrochlorination reactor) to dehydrochlorinate it, in order to prepare 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 prepare HFO-1234yf; however, in one embodiment, the reactor contains the catalyst.

[0037] The catalyst can be a bulk or supported metal halide, a metal halide oxide, a neutral (or zero oxidation state) metal or metal alloy, or activated carbon. Metal halide or metal oxide catalysts may include, but are 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. Component metals include, but are not limited to, Cr. 3+ Fe 3+ Mg 2+ Ca 2+ Ni2+ Zn 2+ Pd 2+ Li + Na + K + and Cs + The halogen components 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. Halogenation treatments can include any of those known in the art, particularly those using HF, F2, HCl, Cl2, HBr, Br2, HI, and I2 as halogen sources.

[0038] 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 above metals as alloys or mixtures. The catalyst can be supported or unsupported. Useful examples of metal alloys include, but are not limited to, SS 316, Monel... ® 400, Incoloy ® 825, Inconel ® 600 and Inconel ® 625. These catalysts can be provided as discrete supported or unsupported elements and / or as part of the reactor and / or reactor wall.

[0039] 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 is approximately 300°C. o C to approximately 550 o C, and the reaction pressure can be from about 0 psig to about 150 psig. The reactor effluent can be fed into an alkaline scrubber or distillation column to remove HCl byproducts to produce an acid-free organic product, which can optionally be further purified using one or any combination of purification techniques known in the art.

[0040] Step 3 can also be carried out 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 dehydrochlorinating 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) using a base. The base can be a caustic base, preferably selected from 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 can be added to the reaction in solid form or in solution. When provided in solution, the solvent is preferably water or alcohol, preferably MeOH or EtOH. KOH is particularly preferred and is preferably provided as an aqueous solution, preferably containing about 5% to about 62% by weight of KOH, preferably 5% to 55% by weight of KOH. Liquid-phase dehydrochlorination is preferably carried out in an aqueous environment. In the case of liquid-phase step 3, an aqueous environment is one in which the liquid-phase reaction mixture contains 5% to 80% by weight of water, preferably 10% to 60% by weight of water, and more preferably 20% to 40% by weight of water. A phase-transfer catalyst is also preferred, particularly when the reaction is carried out in an aqueous environment, as it is believed to contribute to reactivity by promoting close contact between the base and 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb). Such a phase-transfer catalyst may include, but is not limited to, crown ethers (e.g., octadecyl-crown-6), onium salts (e.g., phosphonium or ammonium salts having a halide anion), cavitary ligands (e.g., N[CH2CH2OCH2CH2OCH2CH2]3N), polyalkylene glycols (e.g., poly(ethylene glycol)), their 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 an ammonium halide, more preferably a trialkylammonium halide or a tetraalkylammonium halide, and more preferably a trialkylammonium chloride or a tetraalkylammonium chloride.

[0041] The liquid phase variant in step 3 is preferably at about 0 o C to approximately 100 o C. Preferably about 20 o C to approximately 90 o C. Preferred 50 o C to approximately 90 o C. Preferred 60 o C to approximately 80 oThe conversion of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) can suitably occur at above atmospheric pressure, atmospheric pressure, or below atmospheric pressure. These temperatures and pressures are particularly useful when step 3 is carried out in the liquid phase using a base as described above.

[0042] WO-2011 / 139646 discloses further experimental details of the conversion of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) in the liquid phase, the contents of which are incorporated herein by reference.

[0043] An alternative method for preparing HFO-1234yf uses 1,2-dichloro-3,3,3-trifluoropropane (HCFC-243db) as a starting material and is carried out in both the gas and liquid phases. In this alternative method, the method comprises the following three steps (where steps (2) and (3) are the same as those described above):

[0044] Step (1): In the gas phase (with or without a catalyst) 243db → 1233xf + HCl or in the liquid phase (optionally with a phase transfer catalyst, and / or solvent and / or salt) 243db + base → 1233xf + H2O;

[0045] Step (2): In a liquid-phase reactor containing a liquid hydrofluorination catalyst, 1233xf + HF → 244bb; and

[0046] Step (3): 244bb → 1234yf + HCl in a gas-phase reactor (with or without a catalyst) or in the liquid phase.

[0047] In the alternative method, the starting composition contains 243db, which 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 in a reaction zone and can occur in the gas phase using a catalyst or in the liquid phase using a base and optionally a phase-transfer catalyst and / or solvent and / or salt. For example, WO 2012 / 115934 discloses the gas-phase reaction of 243db with a carbon catalyst. WO 2012 / 115938 discloses the gas-phase reaction of 243db with a chromium fluoride catalyst. WO 2017 / 044719 discloses the reaction of 243db with fluorinated alkanes in the presence of a fluorination catalyst to prepare 1233xf and other compounds that can be used to prepare 1234yf. WO 2017 / 044724 discloses the liquid-phase reaction of 243db with a caustic base. If the dehydrochlorination reaction is carried out in the gas phase, HCl is produced; on the other hand, when the dehydrochlorination reaction is carried out in the liquid phase, no HCl is produced. When starting with a compound having formula (III), other methods can be used, as those skilled in the art will know.

[0048] For embodiments where it is desirable to maintain a moisture- and impurity-free environment during the synthesis of 1234yf, the reactants and intermediates can be purified. For example, it is ideal to remove impurities (including water) from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf).

[0049] It has been found that 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water form non-homogeneous azeotropic and azeotropic compositions or mixtures, and this disclosure provides non-homogeneous azeotropic or azeotropic compositions comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water. The azeotropic or azeotropic compositions may consist substantially of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, or the azeotropic or azeotropic compositions may consist of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water.

[0050] The inventors of this invention have discovered through experiments that 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water form an azeotrope or azeotropic-like composition.

[0051] A non-homogeneous azeotrope consists of two liquid phases, each in equilibrium, and one gas phase. For a non-homogeneous azeotrope at a given temperature and pressure, the composition of each of the two liquid phases and the composition of the gas phase remain constant. If a non-homogeneous azeotrope is formed, at constant pressure, the boiling point of the non-homogeneous azeotrope will be lower than that of the lower boiling point component (“lowest boiling point azeotrope”).

[0052] An azeotropic (or "azeotropic") composition is a unique combination of two or more components. An azeotrope can be homogeneous (having one 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 above the higher boiling point component (maximum boiling point azeotrope) or below the lower boiling point component (minimum boiling point azeotrope). However, in the case of a heterogeneous azeotrope, the boiling point of the azeotrope will always be lower than that of the lower boiling point component. At this characteristic temperature, a homogeneous azeotrope has the same composition in both the gas and liquid phases. In the case of a heterogeneous azeotrope, at this characteristic temperature, the composition of each of the two liquid phases and the gas phase will remain constant upon boiling. An azeotropic composition does not fractionate upon boiling or evaporation. Therefore, the components of an azeotropic composition cannot be separated during phase transition.

[0053] A characteristic of homogeneous azeotropic compositions is that, at the characteristic azeotropic temperature, the bubble point pressure of the liquid phase is the same as the dew point pressure of the gas phase. Azeotropic compositions behave in the opposite way to non-azeotropic compositions, where the liquid composition of non-azeotropic compositions changes significantly during boiling or evaporation.

[0054] However, those skilled in the art will understand that the composition and boiling point of an azeotropic composition will vary to some extent under different pressures. Therefore, an azeotropic composition can have a variable composition depending on temperature and / or pressure. Consequently, those skilled in the art will understand that a range of compositions, rather than a fixed composition, can be used to define an azeotropic composition. Furthermore, an azeotrope can be defined by the precise weight percentage of each component in a composition characterized by a fixed boiling point at a specified pressure.

[0055] An "azeotropic-like" composition is a composition of two or more components that behaves substantially the same as an azeotropic composition. Therefore, for the purposes of this disclosure, an azeotropic-like composition is a combination of two or more different components that, in the case of a homogeneous azeotrope, will boil at a substantially constant temperature when in liquid form at a given pressure, and will provide a vapor composition substantially the same as that of a liquid composition undergoing boiling. In the case of a non-homogeneous azeotrope, two liquid phases are formed at a given pressure, both of which will be covered by the vapor composition. Each of the two liquid phases and the vapor phase will remain substantially constant upon boiling.

[0056] For the purposes of this disclosure, the azeotropic composition is preferably prepared at a pressure of about 12.0 psia to about 16.5 psia. o C to approximately 13.6 o A composition or series of compositions that boils within a temperature range of C.

[0057] Azeotropic or azeotropic compositions can be identified using many different methods.

[0058] For the purposes of this disclosure, the azeotropic or azeotropic compositions were experimentally identified using a boiling point riser (Walas, Phase Equilibria in Chemical Engineering, Butterworth-Heinemann, 1985, 533-544). The boiling point riser is designed to provide an extremely accurate measurement of the liquid boiling point by measuring the gas-liquid equilibrium temperature.

[0059] The boiling point of each component is measured individually at constant pressure. As those skilled in the art will understand, for binary azeotropic or azeotropic compositions, the boiling point of one component of the composition is initially measured. Then, a second component of the composition is added in varying amounts, and the boiling point of each resulting composition is measured at the constant pressure using a boiling point rise meter. In the case of ternary azeotropes, the initial composition will contain a binary blend, and a third component is added in varying amounts. The boiling point of each resulting ternary composition is measured at the constant pressure using a boiling point rise meter.

[0060] Plot the measured boiling points relative to the composition of the tested composition, for example, for a binary azeotrope, relative to the amount (expressed as weight % or mole %) of the second component added to the composition. The presence of an azeotropic composition can be identified by observing the highest or lowest boiling temperature above or below the boiling point of any individual component.

[0061] As those skilled in the art will understand, the identification of an azeotropic or azeotropic composition is performed by comparing the change in the boiling point of the composition relative to the boiling point of the first component when the 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.

[0062] As previously stated, at the highest or lowest boiling point, the composition of the gas phase will be the same as that of the liquid phase. Therefore, the azeotropic composition provides a substantially constant lowest or highest boiling point (i.e., about 12.0 pssia) at a pressure of about 12.5 pssia to about 16.5 pssia, preferably about 14.5 pssia. o C to approximately 13.6 o C. Preferably around 13.1 o C to approximately 13.2 o A composition of components (the boiling point of C) at which the composition of the gas phase will be substantially the same as the composition of the liquid phase at a substantially constant boiling point.

[0063] This disclosure provides azeotropic or azeotropic-like compositions comprising effective amounts 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, when combined with another component, results in the formation of an azeotropic or azeotropic-like composition.

[0064] The azeotropic or azeotropic composition of the present invention may consist essentially of a combination of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, or a combination of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water.

[0065] As used herein, for the components of an azeotropic or azeotropic-like composition or mixture, the term "consistently of..." means that the composition contains a specified component in 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 consisting essentially of two compounds is one of those that form a binary azeotrope, which may optionally contain one or more additional components provided that the additional components do not render the mixture non-azeotropic and do not form an azeotrope with any one or two of the compounds (e.g., not forming a ternary or higher-order azeotrope).

[0066] This disclosure also provides a method for forming an azeotropic or azeotropic composition by mixing, combining, or blending effective amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water. Any of the rich variety of methods known in the art for combining two or more components to form a composition can be used in the method of this invention. For example, 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water can be mixed, blended, or combined manually and / or by machine as part of a batch or continuous reaction and / or method, or by a combination of two or more such steps. The components can be provided in the desired amount, for example by weighing and then combining the amounts.

[0067] It has approximately 12.0 at pressures ranging from approximately 12.5 psia to approximately 16.5 psia. o C to approximately 13.6 o The azeotropic or azeotropic composition with a boiling point of C may also consist substantially of or be composed 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.

[0068] This disclosure also provides compositions comprising the azeotropic or azeotropic-like compositions. For example, compositions are provided comprising at least about 14% by weight of the azeotropic or azeotropic-like composition, or at least about 21% by weight of the azeotropic or azeotropic-like composition, or at least about 25% by weight of the azeotropic or azeotropic-like composition, or at least about 70% by weight of the azeotropic or azeotropic-like composition, or at least about 90% by weight of the azeotropic or azeotropic-like composition, or at least 95% by weight of the azeotropic or azeotropic-like composition, or at least about 99% by weight of the azeotropic or azeotropic-like composition.

[0069] The azeotropic or azeotropic compositions disclosed herein, comprising effective amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, substantially composed of or composed of thereof, can be used to separate impurities from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf).

[0070] Preparation of an azeotropic or azeotropic composition comprising, substantially comprising, or comprising of, effective amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water, such that separation techniques such as azeotropic distillation can be used to remove impurities (including water) from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf).

[0071] Specifically, an azeotropic or azeotropic composition comprising, substantially composed of, or consisting of, 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), water, and at least one impurity (which may include water) can be formed from a composition comprising 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water. After the formation of the azeotropic or azeotropic composition, it can be separated from other compounds by suitable methods, such as distillation, phase separation, drying, or fractional distillation. Drying can be achieved by adding a desiccant such as a molecular sieve.

[0072] In one example, this disclosure provides a method for separating an impurity from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), the method comprising the steps of: providing a primary composition of crude 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf); altering the relative amounts of 2-chloro-3,3,3-trifluoropropene and water; subjecting the primary composition to conditions that effectively form a secondary composition, said secondary composition being an azeotropic or azeotropic-like composition consisting essentially of, or of effective amounts of, 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water; and separating the secondary composition from the primary composition by separation techniques such as phase separation, distillation, or fractionation. Thereafter, the secondary composition may undergo further separation, purification, or drying steps to obtain purified 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf). The steps 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 and water to the composition.

[0073] The azeotropic or azeotropic composition comprising, substantially comprising, or consisting 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, prior to step 3 of the method, the azeotropic or azeotropic composition can be used to purify 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb). 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) removed from 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) by forming the azeotrope can then be converted to further 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), which is subsequently 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 by the defluorination of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) in step 3, the azeotropic or azeotropic-like composition may be formed after step 3. Although not inevitable, the azeotropic or azeotropic-like composition may also be formed in the reaction to prepare 2-chloro-3,3,3-trifluoropropane (HCFO-1233xf) from 1,2-dichloro-3,3,3-trifluoropropane (HCFC-243db). The presence of the azeotropic or azeotropic-like composition will depend on factors such as whether the azeotropic properties are disrupted by other substances present. Although not inevitable, examples of how the azeotropic or azeotropic-like composition may form include the following:

[0074] • When water is present as a solvent in the reaction, for example when the reaction is carried out in an aqueous environment, such as when the base is used in an aqueous solution.

[0075] • When water is precipitated during the reaction. For example, in the presence or absence of water as a solvent, the dehydrochlorination of HCFC-243db with hydroxide ions will precipitate water molecules according to the following equation: CF3CHClCCH2Cl + - OH → CF3CCl=CH2 + Cl - + H2O. Those skilled in the art will understand that when other types of alkali, especially caustic alkali, are used, water molecules may be precipitated.

[0076] The following non-limiting embodiments are used to illustrate the present invention.

[0077] Example

[0078] Example 1 - Vapor-Liquid Equilibrium (VLE) Study

[0079] A boiling point riser, consisting of a vacuum-jacketed tube with a dry ice-cooled condenser at the top, was equipped with a quartz thermometer. The boiling point riser was initially loaded with 14.11 g of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf). Water was then added incrementally, and the temperature of the mixture was recorded at each water increment. The mixture temperature reached a minimum and then remained substantially constant with the addition of further water, indicating the formation of a non-homogeneous azeotrope. The ambient pressure during the measurements was 14.5 psia. The mixture composition and measured temperatures are shown in Table 1. The data in Table 1 are illustrated in... Figure 1 middle.

[0080] Table 1

[0081] Weight % HCFO-1233xf water by weight <![CDATA[Temperature( o °C)]]> 100 0.00 13.44 99.65 0.35 13.26 98.95 1.05 13.23 97.58 2.42 13.20 95.6 4.40 13.18 93.07 6.93 13.17 90.68 9.32 13.17 86.25 13.75 13.15 82.23 17.77 13.14 78.56 21.44 13.14 75.21 24.79 13.14 71.77 28.23 13.14 68.30 31.70 13.14 65.14 34.86 13.14

[0082] Example 2 - Gas-Liquid-Liquid Balance (VLLE) Measurement

[0083] 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 separate phases were observed in the cell, indicating the formation of a non-homogeneous azeotrope. The upper (water-rich) and lower (2-chloro-3,3,3-trifluoropropene (HCFO-1233xf)) phases were separated and analyzed. The compositions of the two phases are shown in Table 2 below.

[0084] Table 2

[0085] Components Upper phase weight % Lower phase weight % HCFO-1233xf 0.09 92.69 water 99.91 7.31

[0086] Example 3 - Purification of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf)

[0087] In this embodiment, a composition comprising 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and impurities (which may be water) is provided. An effective amount of water is added to the composition, and the composition is subjected to conditions conducive to the formation of an azeotropic or azeotropic-like composition, which consists essentially of or of an effective amount of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water. The azeotropic or azeotropic-like composition is then separated from the composition containing the major compound by separation techniques such as phase separation, distillation, and / or fractionation. Once 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) has been separated, it can be further dried by adding a desiccant.

[0088] Example 4 - Separation of water as impurities

[0089] In this embodiment, a composition is provided comprising a major compound, such as 2-chloro-3,3,3-trifluoropropene (1233xf), and water as an impurity. An effective amount of water is added to the composition, and the composition is subjected to conditions that effectively form an azeotropic or azeotropic-like composition consisting essentially of, or consisting of, an effective amount of, 2-chloro-3,3,3-trifluoropropene (1233xf) and water. The azeotropic or azeotropic-like composition is then separated from the composition containing the major compound by separation techniques such as phase separation, distillation, and / or fractionation. Once 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) has been separated, it can be further dried by adding a desiccant.

[0090] Example 5 - Separation of water as impurities

[0091] In this embodiment, a composition is provided comprising a major compound, such as 2-chloro-3,3,3-trifluoropropene (1233xf), and 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 that effectively form an azeotropic or azeotropic-like composition consisting essentially of, or consisting of, an effective amount of, 2-chloro-3,3,3-trifluoropropene (1233xf) and water. The azeotropic or azeotropic-like composition is then separated from the composition containing the major compound by separation techniques such as phase separation, distillation, and / or fractionation. Once 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) has been separated, it can be further dried by adding a desiccant.

[0092] Example 6 - Conversion of 1,2-dichloro-3,3,3-trifluoropropane (HCFC-243db) to 2-chloro-3,3,3-trifluoropropane Representative processes of alkene (1233xf)

[0093] 86 g of 12 wt% NaOH solution and 36.5 g of 243 dB were charged into a shaker-tube reactor. The reactor was cooled to -10 °C and briefly evacuated. It was then heated to 55 °C without stirring. Once the temperature reached 47 °C, it was shaken and heated to 55 °C. It was then maintained at ~55 °C for 60 minutes. The estimated 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 curves, it was estimated that 98% conversion was achieved in approximately 25 minutes. The product was analyzed by GC-MS, and the analysis showed that approximately 98% of the 243 dB was converted.

[0094] compound GC area % HCFO-1233xf 96.97% HCFO-1233zd 0.11% HCFC-243fa 0.43% HCFC-243db 1.06% HCFC-233ab 1.00% other 0.43%

[0095] Example 7 - Conversion of 2-chloro-3,3,3-trifluoropropene (1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane Representative process of (HCFC-244bb)

[0096] Approximately 327 g of HF, approximately 50 g of 1233xf, and approximately 75 g of SbCl5 were charged into a 1-L autoclave. The reaction mixture was stirred at 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 approximately 45 minutes. After the water was completely added with stirring, the reactor was cooled to room temperature, and then the top gas was transferred to another collection container. 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 C4 compound of the general formula C4H3Cl3F4 (8%).

[0097] Example 8 - Conversion of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) to 2,3,3,3-tetrafluoropropene Representative process of (HFO-1234yf)

[0098] Dehydrochlorination of HCFC-244bb was carried out in a 1-liter Parr reactor equipped with a thermocouple and a magnetic stirrer. 15 grams of Aliquat 336 were added. TM Add to the reactor. Then shut down the reactor and test the pressure. Then add 294 g of the organic mixture and 270 g of 45% KOH 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. Then turn on the stirrer and heat the reactor to 55°C. When (approximately 2 hours) 55°C is reached, the pressure in the reactor increases from the initial 10 psig to 55 psig. The reactor is maintained at 55°C for 4 hours, and the pressure is further increased to 78 psig. GC analysis of the organic contents in the reactor after the reaction is complete showed 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.

[0099] The above synthetic examples are included to illustrate the reaction, and not as a comment on the presence of the claimed azeotropic or azeotropic composition in the synthesis process.

[0100] Example 9 - Representative purification of HCFO-1233xf

[0101] The composition containing HCFO-1233xf and water is purified to provide a purified HCFO-1233xf stream.

[0102] 1000 kg of a mixture (containing 926.9 kg of HCFO-1233xf and 73.1 kg of water) was charged into the reboiler of a batch distillation system consisting of a reboiler, a multi-stage rectification section, and a condenser. The multi-stage rectification section was filled with random packing material, such as IMTP available from Koch-Glitsch. ® Packing material. Approximately 5g of packing material is used at the condenser inlet. o C's flowing cooling water cools the condenser. The reboiler has a half-tube jacket for steam. The reboiler charge can be an organic phase of a mixture of HCFO-1233xf and water undergoing phase separation, with the aqueous phase precipitating to the top.

[0103] The batch distillation system is used to distill the top stream of an azeotrope that substantially contains HCFO-1233xf and water, leaving HCFO-1233xf substantially containing about 0.039% by weight of water in the reboiler. Please refer to the summary in Table 3. The substance in the reboiler can be further dried by passing it through a desiccant such as 3A molecular sieve.

[0104] Table 3 - Composition

[0105] Reboiler charge (kg) Distillate(kg) Bottom material (kg) HCFO-1233xf 926.9 158.0* 768.9 water 73.1 72.8 0.3

[0106] Under these conditions, the azeotropic composition was 68 wt% HCFO-1233xf. Slightly more substances than the azeotrope were recovered at the top.

[0107] Although this embodiment illustrates purification in a batch distillation scheme, those skilled in the art can modify it for continuous distillation purification.

[0108] all aspects

[0109] Aspect 1 is a composition comprising an azeotropic or azeotropic composition consisting essentially of effective amounts of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water.

[0110] Aspect 2 is the composition of aspect 1, wherein the azeotropic or azeotropic-like composition has a content of about 12.0 at a pressure of about 12.5 psia to about 16.5 psia. o C to approximately 13.6 o Boiling point of C.

[0111] Aspect 3 is a composition of aspect 1 or aspect 2, wherein the azeotropic or azeotropic 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.

[0112] Aspect 4 is a method for forming an azeotropic or azeotropic composition, comprising the step of combining 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water to form an azeotropic or azeotropic composition substantially consisting of effective amounts of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water and having a pressure of about 12.0 psia at about 12.5 psia to about 16.5 psia. o C to approximately 13.6 o Boiling point of C.

[0113] Aspect 5 is the method of aspect 4, wherein the combination 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.

[0114] Aspect 6 is a method for separating an impurity, including water, from a composition comprising 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and at least one impurity, comprising the steps of: 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 (HFCO-1233xf) and water; subjecting the composition to conditions that effectively form an azeotropic or azeotropic-like composition consisting substantially of or composed of effective amounts of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and water; and separating the azeotropic or azeotropic-like composition from 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf).

[0115] Aspect 7 is a method of aspect 6, wherein the separation step includes at least one of phase separation, distillation and fractionation.

[0116] Aspect 8 further includes separating 2-chloro-3,3,3-trifluoropropene from water according to the method of aspect 6 or aspect 7.

[0117] Aspect 9 is a method of any one of Aspects 6-8, wherein 2-chloro-3,3,3-trifluoropropene is separated from water using liquid-liquid phase separation.

[0118] Aspect 10 is a method of any one of Aspects 6-9, wherein distillation is used to separate 2-chloro-3,3,3-trifluoropropene from water.

[0119] Aspect 11 is a method of any one of Aspects 6-10, wherein 2-chloro-3,3,3-trifluoropropene is separated from water using at least one drying agent.

[0120] Aspect 12 is a method of 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 distillation, one or more drying agents and combinations thereof.

[0121] Aspect 13 is a method of any one of Aspects 6-12, 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.

[0122] Aspect 14 is a method of any one of Aspects 6-13, wherein the step of changing the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water includes adding water to the composition.

[0123] Aspect 15 is a method of any one of Aspects 6-14, 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.

[0124] As used herein, the phrase “any range between any two of the foregoing values” literally means that any range can be selected from any two values ​​listed preceding such a phrase, regardless of whether the values ​​are in the lower or higher part of the list. For example, a pair of values ​​can be selected from two lower values, two higher values, or a lower value and a higher value.

[0125] As used herein, the singular forms “an,” “a,” and “the” include the plural, unless the context explicitly specifies otherwise. Furthermore, when quantities, concentrations, or other values ​​or parameters are given as intervals, preferred ranges, or lists of preferred upper and lower limits, this should be understood as specifically disclosing all intervals formed by any pair of any upper or preferred value and any lower or preferred value, regardless of whether the interval is disclosed individually. When numerical intervals are referenced herein, unless otherwise stated, the interval is intended to include its endpoints and all integers and fractions within that interval. When an interval is defined, the scope of disclosure is not intended to be limited to the specific values ​​listed.

[0126] As used herein, the phrase “any range between any two of the foregoing values” literally means that any range can be selected from any two values ​​listed preceding such a phrase, regardless of whether the values ​​are in the lower or higher part of the list. For example, a pair of values ​​can be selected from two lower values, two higher values, or a lower value and a higher value.

[0127] It should be understood that the foregoing description is merely illustrative of this disclosure. Various alternatives and modifications can be devised by those skilled in the art without departing from this disclosure. Therefore, this disclosure is intended to cover all such alternatives, modifications, and variations that fall within the scope of the appended claims.

Claims

1. An azeotropic or azeotropic composition comprising 65.14 wt% to 90.68 wt% of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and 9.32 wt% to 34.86 wt% of water, wherein the azeotropic or azeotropic composition has a strength of 12.0 at a pressure of 12.5 psia to 16.5 psia. o C to 13.6 o Boiling point of C.

2. The azeotropic or azeotropic-like composition according to claim 1, wherein the azeotropic or azeotropic-like composition has a density of 13.14 at a pressure of 14.5 psia. o C to 13.17 o Boiling point of C.

3. The azeotropic or azeotropic composition according to claim 1, wherein the azeotropic or azeotropic composition comprises 65.14 wt% to 82.23 wt% of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and 17.77 wt% to 34.86 wt% of water, and has a pH of 13.14 at a pressure of 14.5 psia. o Boiling point of C.

4. The azeotropic or azeotropic composition according to claim 1, wherein the azeotropic or azeotropic composition comprises 68.30% to 78.56% by weight of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and 21.44% to 31.70% by weight of water, and has a pH of 13.14 at a pressure of 14.5 psia. o Boiling point of C.

5. The azeotropic or azeotropic composition according to claim 1, wherein the azeotropic or azeotropic composition comprises 71.77% to 82.23% by weight of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and 17.77% to 28.23% by weight of water, and has a pH of 13.14 at a pressure of 14.5 psia. o Boiling point of C.

6. A method for forming an azeotropic or azeotropic composition, comprising the step of combining 65.14 wt% to 90.68 wt% of 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) with 9.32 wt% to 34.86 wt% of water to form the azeotropic or azeotropic composition of claim 1 or 2, wherein the azeotropic or azeotropic composition has a pressure of 12.0 at a pressure of 12.5 psia to 16.5 psia. o C to 13.6 o Boiling point of C.

7. A method for separating an impurity comprising water from 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and at least one impurity from a composition comprising 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and at least one impurity, the method comprising the steps of: A composition comprising 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) and at least one impurity is provided; By altering the relative amounts of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and water and subjecting the composition to conditions that effectively form the azeotropic or azeotropic composition of claim 1 or 2; and The azeotrope or azeotropic-like composition was separated from 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf). The separation steps include at least one of phase separation, distillation, and fractionation.

8. The method according to claim 7, further comprising separating 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf) from water.

9. The method of claim 7, wherein liquid-liquid phase separation is used to separate 2-chloro-3,3,3-trifluoropropene from water.

10. The method of claim 7, wherein distillation is used to separate 2-chloro-3,3,3-trifluoropropene from water.

11. The method of claim 7, wherein at least one desiccant is used to separate 2-chloro-3,3,3-trifluoropropene from water.

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

13. The method of claim 7, 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.

14. The method of claim 7, 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.

15. The method of claim 7, 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.

16. A method for preparing 2,3,3,3-tetrafluoropropylene (HFO-1234yf), comprising: The method according to any one of claims 7 to 15 is used to obtain 2-chloro-3,3,3-trifluoropropene (HFCO-1233xf); At least some of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) is converted to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb); and At least some of the 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) is converted into 2,3,3,3-tetrafluoropropene (HFO-1234yf).

17. The method of claim 16, wherein converting 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) into 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.

18. The method of claim 17, wherein the HF is anhydrous.

19. The method of claim 17, wherein: The catalyst comprises a metal halide catalyst selected from SbCl5, SbF5, TiCl4, or combinations thereof, or fluorosulfonic acid; and / or At least some of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) was converted to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) at 5-100 °C. o The temperature is C.

20. The method of claim 16, wherein converting at least some of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) into 2,3,3,3-tetrafluoropropene (HFO-1234yf) comprises reacting 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) with a base.

21. The method of claim 20, wherein the reaction with the base is carried out in an aqueous environment.

22. The method of claim 20, wherein the reaction with the base is carried out in the presence of a phase-transfer catalyst, ammonium halide.

23. The method of claim 22, wherein the ammonium halide is a trialkylammonium halide or a tetraalkylammonium halide.

24. The method of claim 23, wherein the trialkylammonium halide or tetraalkylammonium halide is trialkylammonium chloride or tetraalkylammonium chloride.

25. The method of claim 20, wherein the base is a caustic base.

26. The method according to claim 25, wherein the caustic alkali is an alkali metal hydroxide.

27. The method according to claim 26, wherein the alkali metal hydroxide is KOH or NaOH.

28. The method of claim 20, wherein the reaction is carried out at 0-100°C. o The temperature is C.

29. The method of claim 28, wherein the reaction is carried out at 20-90°C. o The temperature is C.

30. The method of claim 28, wherein the reaction is carried out at 50-90°C. o The temperature is C.

31. The method of claim 28, wherein the reaction is carried out at 60-80°C. o The temperature is C.

32. The method according to claim 19, wherein: The conversion of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) occurs at 50-100 °C. o The temperature is C.

33. A method for preparing 2,3,3,3-tetrafluoropropylene (HFO-1234yf), comprising: A composition of products that converts 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) into 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), which also contains some HCFO-1233xf; Water is added to the HCFC-244bb product composition and the composition is subjected to conditions that effectively form an azeotropic or azeotropic composition according to claim 1 or 2; Separation of azeotropic or azeotropic-like compositions from HCFC-244bb; and At least some HCFC-244bb will be converted into 2,3,3,3-tetrafluoropropylene (HFO-1234yf).

34. The method of claim 33, wherein converting 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) into 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.

35. The method of claim 34, wherein the HF is anhydrous.

36. The method of claim 34, wherein: The catalyst comprises a metal halide catalyst selected from SbCl5, SbF5, TiCl4, or combinations thereof, or fluorosulfonic acid; and / or At least some of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) was converted to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) at 5-100 °C. o The temperature is C.

37. The method of claim 33, wherein converting at least some of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) into 2,3,3,3-tetrafluoropropene (HFO-1234yf) comprises reacting 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) with a base.

38. The method of claim 37, wherein the reaction with the base is carried out in an aqueous environment.

39. The method of claim 37, wherein the reaction with the base is carried out in the presence of a phase-transfer catalyst, ammonium halide.

40. The method of claim 39, wherein the ammonium halide is a trialkylammonium halide or a tetraalkylammonium halide.

41. The method of claim 40, wherein the trialkylammonium halide or tetraalkylammonium halide is trialkylammonium chloride or tetraalkylammonium chloride.

42. The method of claim 37, wherein the base is a caustic base.

43. The method according to claim 42, wherein the caustic alkali is an alkali metal hydroxide.

44. The method according to claim 43, wherein the alkali metal hydroxide is KOH or NaOH.

45. The method of claim 37, wherein the reaction is carried out at 0-100°C. o The temperature is C.

46. ​​The method of claim 45, wherein the reaction is carried out at 20-90°C. o The temperature is C.

47. The method of claim 45, wherein the reaction is carried out at 50-90°C. o The temperature is C.

48. The method of claim 45, wherein the reaction is carried out at 60-80°C. o The temperature is C.

49. The method of claim 36, wherein: The conversion of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) occurs at 50-100 °C. o The temperature is C.

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