Azeotropes of 3-chloro-3, 3-difluoro-1-propene, 3, 3, 3-trifluoropropene and hydrogen fluoride

Abstract

Disclosed herein is an azeotropic or near-azeotropic composition comprising HCFO-1242zf, HFO-1243zf, and HF, and a method for preparing the azeotropic or near-azeotropic composition.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 426,604, filed on November 18, 2022, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] FIELD OF THE DISCLOSURE

[0004] The present disclosure relates to a method for separating mixtures of hydrogen fluoride (HF), chlorofluoroolefins (HCFO) and fluoroolefins (HFO) and their combinations. More specifically, the present disclosure relates to mixtures containing 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf; CClF 2 CH=CH 2 ), 3,3,3-trifluoropropylene (HFO-1243zf; CF 3 CH=CH 2 ) and HF, and a method for separating such a mixture. Background Art

[0005] The refrigeration industry has been working hard for the past few decades to find replacement refrigerants for the ozone-depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) that are being phased out by the Montreal Protocol. The solution for most refrigerant manufacturers has been to commercialize hydrofluorocarbon (HFC) refrigerants. These new HFC refrigerants (HFC-134a), which are currently the most widely used, have zero ozone depletion potential and are therefore not affected by the current Montreal Protocol phase-out regulations.

[0006] In addition to the ozone depletion problem, global warming is another environmental issue. However, many HFC alternative refrigerants tend to have high global warming potential (GWP). For example, the GWP of HFC-134a is 1430. Therefore, there is still a need to meet both low ozone depletion and low global warming potential heat transfer compositions. Certain hydrofluoroolefins (HFOs) meet these two goals. Therefore, it is necessary to provide a method for manufacturing halogenated hydrocarbons and fluoroolefins that do not contain chlorine and also have lower global warming potential.

[0007] The chemical manufacture of fluoroolefins is typically a multi-step process that produces an intermediate mixture of HFCs, HCFCs, hydrochlorofluoroolefins (HCFOs) and / or HFOs and hydrogen fluoride (HF). The separation of such mixtures is not always easy to achieve. Existing distillation and decantation methods are generally ineffective for the separation of these compounds.

[0008] Aqueous scrubbing can be effective but requires the use of large amounts of scrubbing solution, additional equipment, and produces excess waste and a wet product that must then be dried. Thus, new methods for separating HF and fluoroolefins, hydrofluoroolefins, hydrochlorofluoroolefins, hydrochlorofluorocarbons and / or hydrofluorocarbons are needed. Summary of the invention

[0009] In some embodiments, the invention disclosed herein is directed to a method for separating components of a process stream comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf), 3,3,3-trifluoropropene (HFO-1243zf), and HF and forming an HF-rich stream comprising an azeotrope or near-azeotrope of HCFO-1242zf and HF.

[0010] In some embodiments, the invention disclosed herein relates to a method for distilling a process stream comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf), 3,3,3-trifluoropropene (HFO-1243zf), and a molar excess of HF based on the 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) and 3,3,3-trifluoropropene (HFO-1243zf) content of the stream into a bottoms stream comprising HF substantially free of 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) and 3,3,3-trifluoropropene (HFO-1243zf) and a distillate stream comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf), 3,3,3-trifluoropropene (HFO-1243zf), and HF.

[0011] In some embodiments, the invention disclosed herein is directed to a process for forming multiple azeotropes, the process comprising: condensing a distillate stream of 3,3,3-trifluoropropene (HFO-1243zf) and chloro-3,3-difluoro-1-propene (HCFO-1242zf) containing a molar excess of HF, the distillate stream forming an HFO-1243zf / HF azeotrope or near-azeotrope and an HCFO-1242zf / HF azeotrope or near-azeotrope.

[0012] In some embodiments, the invention disclosed herein is directed to a process for forming a mixture comprising an azeotrope or a near-azeotrope of HCFO-1242zf / HF and HCFO-1243zf / HF.

[0013]

[0013] Disclosed herein, in some embodiments, is a method for decanting a first stream comprising a mixture of an azeotrope or near-azeotrope, a first HCFO-1242zf / HF azeotrope or near-azeotrope, and a second HCFO-1243zf / HF azeotrope or near-azeotrope.

[0014] In some embodiments, disclosed herein is a process for forming an HF-rich azeotrope or near-azeotrope and an HF-lean azeotrope or near-azeotrope, wherein the HF-rich azeotrope or near-azeotrope comprises HFO-1242zf / HF and the HF-lean azeotrope or near-azeotrope comprises HCFO-1243zf / HF.

[0015] Disclosed herein, in some embodiments, is a process for distilling a stream comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf), 3,3,3-trifluoropropene (HFO-1243zf), and a molar excess of HF sufficient to form a heteroazeotrope or near-azeotrope mixture and to form a heteroazeotrope or near-azeotrope distillate stream.

[0016]

[0013] Disclosed herein, in some embodiments, is a method for forming and using an azeotropic mixture of HCFO-1242zf / HF.

[0017]

[0013] Disclosed herein, in some embodiments, is a process for contacting a feed or product stream with a HCFO-1242zf / HF azeotrope or near-azeotrope to remove HCFO-1242zf.

[0018]

[0013] Disclosed herein, in some embodiments, are compositions comprising an azeotrope or a near-azeotrope of HCFO-1242zf and HF.

[0019]

[0013] Disclosed herein, in some embodiments, are compositions comprising heterogeneous HF containing an azeotrope or a near-azeotrope.

[0020] Disclosed herein, in some embodiments, are mixtures of HFO-1243zf / HF and HCFO-1242zf / HF azeotropes and near-azeotropes.

[0021]

[0013] Process embodiments disclosed herein use one or more distillation columns, condensers, and decanters to form, produce, and / or use a HCFO-1242zf / HF azeotrope or near-azeotrope.

[0022] In one embodiment of the invention, HFO-1243zf, HCFO-1242zf, and a HF stream containing sufficient HF (i.e., a molar excess sufficient to form a mixture of different azeotropes or near-azeotropes each containing HF) are passed to and through a distillation column under conditions for forming a first distillate stream comprising azeotropes or near-azeotropes of HFO-1242zf and HFO-1243zf with HF.

[0023] In another embodiment of the invention, HFO-1243zf, HCFO-1242zf, and a HF stream containing sufficient HF (i.e., a molar excess sufficient to form a mixture of HFO-1242zf / HF azeotrope or near-azeotrope and HFO-1243zf / HF azeotrope or near-azeotrope) are passed to and through a distillation column under conditions for forming a first distillate stream comprising HFO-1242zf and HFO-1243zf and an azeotrope or near-azeotrope with HF upon undergoing a phase change from vapor to liquid.

[0024] In one embodiment of the invention, HFO-1243zf, HCFO-1242zf, and a HF stream containing sufficient HF (i.e., a molar excess sufficient to form a mixture of HFO-1242zf / HF azeotrope or near-azeotrope and HFO-1243zf / HF azeotrope or near-azeotrope) are passed to and through a distillation column under conditions to form a first distillate stream comprising HFO-1242zf and HFO-1243zf and an azeotrope or near-azeotrope with HF and a first bottoms stream substantially free of HF that is present in the distillation column for HCFO-1242zf and HFO-1243zf.

[0025] In one embodiment, a mixture of an HFO-1242zf / HF azeotrope or near-azeotrope and an HFO-1243zf / HF azeotrope or near-azeotrope is formed.

[0026] Another embodiment disclosed herein is directed to a process comprising: distilling a process stream of HFO-1242zf, HFO-1243zf, and HF, recovering a first distillate stream and a first bottoms stream consisting essentially of HF free of HFO-1243zf and HFO-1242zf, and condensing and converting the first distillate stream into an HF-rich liquid stream and an HF-depleted liquid stream comprising HFO-1242zf and HF and HFO-1243zf and HF, respectively.

[0027] In another process embodiment, the present disclosure provides a process for separating 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) from an HCFO-1242zf-rich stream comprising HCFO-1242zf and HF, the process involving distillation, condensation and / or cooling, and decantation, wherein the HCFO-1242zf-rich stream from the decantation is distilled in a second distillation column under such boiling conditions that HFO-1243zf and an azeotrope or a near-azeotrope of HCFO-1242zf with HF are removed from the top of the column as a second distillate stream, and HCFO-1242zf and HFO-1243zf are removed from the bottom of the second distillation column as a second bottoms stream substantially free of HF.

[0028] The process also includes subjecting the second bottoms stream to a third distillation column to form a HCFO-1242zf stream that is substantially free of HFO-1243zf.

[0029] In another embodiment of the present invention, the present disclosure provides an azeotrope or near-azeotrope composition comprising an azeotrope or near-azeotrope of 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) and 3,3,3-trifluoropropene (HFO-1243zf) with HF.

[0030] In yet another process embodiment, the present disclosure provides a process for separating 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) from a process stream comprising HCFO-1242zf, 3,3,3-trifluoropropene (HFO-1243zf) / HF, and a molar excess of HF (i.e., an amount of HF sufficient to form an azeotrope or near-azeotrope). The process comprises subjecting the process stream to distillation in a first distillation column under boiling conditions sufficient to remove excess HF as a bottoms stream but leaving sufficient HF in the distillate stream to permit the formation of both an HFO-1243zf / HF azeotrope or near-azeotrope and an HFO-1242zf / HF azeotrope or near-azeotrope. The process also includes forming a first distillate stream from the first distillation column comprising an azeotropic or near-azeotropic composition of HCFO-1242zf, HFO-1243zf, and HF and a first bottoms stream of HF that is substantially free of HCFO-1242zf and HFO-1243zf.

[0031] In another process embodiment, the HCFO-1242zf, HFO-1243zf and HF distillate is condensed and cooled, and then decanted to form a stream rich in HCFO-1242zf (HF lean) and a stream rich in HF (HCFO-1242zf lean). The process also includes: subjecting the HCFO-1242zf-rich stream to distillation under boiling conditions in a second distillation tower to form an azeotrope of HCFO-1242zf and HFO-1243zf with HF. The process also includes: forming a second distillate stream containing an azeotropic or near-azeotropic composition of HCFO-1242zf, HFO-1243zf and HF from the second distillation tower and a second bottoms stream of HCFO-1242zf and HFO-1243zf substantially free of HF. The process also includes subjecting the second bottoms stream to a third standard distillation column using methods known in the art to form a HCFO-1242zf stream that is substantially free of HFO-1243zf.

[0032] In another embodiment of the present invention, a heterogeneous HF-azeotrope is described.

[0033] Other embodiments disclosed herein are as follows:

[0034] Embodiment 1 An azeotropic or near-azeotropic composition comprises 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) and hydrogen fluoride (HF).

[0035] Embodiment 2 An azeotropic or near-azeotropic composition according to Embodiment 1, wherein the azeotropic or near-azeotropic composition comprises about 9.8 mol % to about 70.6 mol % HCFO-1242zf and about 90.2 mol % to about 29.4 mol % HF.

[0036] Embodiment 3 An azeotropic or near-azeotropic composition according to any one of the embodiments disclosed herein, wherein the azeotropic or near-azeotropic composition has a vapor pressure of about 6.5 psia (44.8 kPa) to about 29.8 psia (205.5 kPa) at a temperature of about -10°C to about 30°C.

[0037] Embodiment 4 An azeotropic or near-azeotropic composition according to any one of the embodiments disclosed herein, wherein the azeotropic or near-azeotropic composition comprises about 38.0 mol% HCFO-1242zf and about 62.0 mol% HF.

[0038] Embodiment 5 An azeotropic or near-azeotropic composition according to any one of the embodiments disclosed herein, wherein the azeotropic or near-azeotropic composition has a vapor pressure of about 25.9 psia at a temperature of about 20°C.

[0039] Embodiment 6 An azeotropic or near-azeotropic composition according to any one of the embodiments disclosed herein, wherein the azeotropic or near-azeotropic composition is prepared by weighing the desired amounts of HCFO-1242zf and HF and thereafter combining them in a suitable container.

[0040] Embodiment 7 An azeotropic or near-azeotropic composition according to any of the embodiments disclosed herein, wherein the azeotropic or near-azeotropic composition consists essentially of HCFO-1242zf and HF.

[0041] Embodiment 8 A composition comprising an azeotropic or near-azeotropic composition according to any one of the embodiments disclosed herein and 3,3,3-trifluoropropene (HFO-1243zf).

[0042] Embodiment 9 A composition comprising an azeotropic or near-azeotropic composition according to any one of the embodiments disclosed herein and 1,1,1,3-tetrafluoropropane (HFC-254fb).

[0043] Embodiment 10 A composition according to any one of the embodiments disclosed herein, wherein the composition further comprises one or more additional components selected from the group consisting of: 3-chloro-3,3,-difluoropropene (HCFO-1242zf; CF 2 Cl-CH=CH 2 ), dichlorodifluoromethane (CFC-12; CCl 2 F 2 ), chlorotrifluoromethane (CFC-13; CClF 3 ), 1,1,1-trifluoroethane (HFC-143a; CF 3 -CH 3 ), 2-chloro-1,1,1-trifluoropropane (HCFC-253db; CF 3 -CHCl-CH 3 ), 3-chloro-1,1,1-trifluoropropane (HCFC-253fb; CF 3 -CH 2 -CH 2 Cl), 1,1,1,2-tetrafluoropropane (HFC-254eb; CF 3 -CHF-CH 3 ), 1,1,1-trifluoropropane (HFC-263fb; CF 3 CH 2 CH 3 ), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf; CF 3 -CCl=CH 2 ), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd; CF 3 -CH 2 =CHCl), isomers of trichloropropylene (HCO-1240; C 3 H 3 Cl 3 ) and their combinations.

[0044] Embodiment 11 An azeotropic or near-azeotropic composition comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf), 3,3,3-trifluoropropene (HFO-1243zf), and hydrogen fluoride (HF).

[0045] Embodiment 12 A composition comprising a mixture of an azeotrope or a near-azeotrope of 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) and hydrogen fluoride (HF) and an azeotrope or a near-azeotrope of 3,3,3-trifluoropropene (HFO-1243zf) and HF.

[0046] Embodiment 13 A composition according to any one of the embodiments disclosed herein, wherein the HCFO-1242zf and HF portion of the azeotropic or near-azeotropic composition comprises from about 9.8 mol % to about 70.6 mol % HCFO-1242zf and from about 90.2 mol % to about 29.4 mol % HF.

[0047] Embodiment 14 A composition according to any one of the embodiments disclosed herein, wherein the HCFO-1242zf and HF portions of the azeotropic or near-azeotropic composition have a vapor pressure of about 6.5 psia (44.8 kPa) to about 29.8 psia (205.5 kPa) at a temperature of about -10°C to about 30°C.

[0048] Embodiment 15 A composition according to any one of the embodiments disclosed herein, wherein the HCFO-1242zf and HF portion of the azeotropic or near-azeotropic composition comprises about 38.0 mol% HCFO-1242zf and about 62.0 mol% HF.

[0049] Embodiment 16 A composition according to any one of the embodiments disclosed herein, wherein the HCFO-1242zf and HF portion of the azeotropic or near-azeotropic composition has a vapor pressure of about 25.9 psia at a temperature of about 20°C.

[0050] Embodiment 17 The composition according to any of the embodiments disclosed herein, further comprising 1,1,1,3-tetrafluoropropane (HFC-254fb).

[0051] The foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as defined in the appended claims.

[0052] Other features and benefits of any one or more of the embodiments described herein will be apparent from the following detailed description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Embodiments are illustrated in the accompanying drawings to improve understanding of the concepts presented herein.

[0054] Figure 1 is a schematic representation of an embodiment of an azeotropic distillation for separating HCFO-1242zf from a mixture containing HCFO-1242zf, HFO-1243zf, and HF.

[0055] Figure 2Another embodiment of the azeotropic distillation for separating HCFO-1242zf from a mixture containing HCFO-1242zf, HFO-1243zf, and HF is illustrated.

[0056] Figure 3 Yet another embodiment of the azeotropic distillation for separating HCFO-1242zf from a mixture containing HCFO-1242zf, HFO-1243zf, and HF is illustrated.

[0057] The skilled person will understand that the objects in the drawings are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the sizes of some of the objects in the drawings may be exaggerated relative to other objects to help improve the understanding of the embodiments. DETAILED DESCRIPTION

[0058] High purity 3,3,3-trifluoropropene (HFO-1243zf) is desired for subsequent downstream conversion into hydrofluorocarbons, hydrochlorofluorocarbons, fluoroolefins and hydrochlorofluoroolefins, including but not limited to HFO-1234ze and HFO-1234yf, or as a refrigerant or refrigerant component. The gas phase reaction of 1,1,1,3-tetrachloropropane (HCC-250fb) and HF in the absence or presence of a catalyst at a molar excess concentration of HF:250fb will result in high yields of HFO-1243zf and other products with a lower degree of fluorination (such as HCFO-1242zf), as disclosed in U.S. Pat. No. 6,329,559, the disclosure of which is incorporated herein by reference in its entirety. The multi-step process for producing HFO-1234yf from HFO-1243zf also includes using HCFC-250fb as a starting material for producing HFO-1243zf by fluorination, as disclosed in US 8,318,992, the disclosure of which is incorporated herein by reference in its entirety. The molar ratio of HF:250fb used to produce HFO-1243zf is between 3:1 and at least about 50:1.

[0059] It has been observed that low-boiling azeotropes or near-azeotropes of HFO-1243zf are formed from product streams comprising HFO-1243zf and HF, as disclosed in International Application WO2009105517, the disclosure of which is incorporated herein by reference in its entirety. The data in Table 1 illustrate that the molar ratio of HF / 1243zf in the azeotrope is about 1:3.

[0060] It has been surprisingly found that HCFO-1242zf forms low boiling azeotropes or near azeotropes with HF and that they can be used to produce HF substantially free of HCFO-1242zf and HFO-1243zf in a single distillation even though HCFO-1242zf has a very similar boiling point to HF (only 1°C different at atmospheric pressure).

[0061] It is therefore unexpected that an HCFO-1242zf / HF azeotrope or near-azeotrope would form which is HF-rich and contains about 62.0 mole % HF at a vapor pressure of 25.9 psia and a temperature of 20°C.

[0062] Before addressing the details of the embodiments described below, some terms are defined or clarified.

[0063] By "azeotropic" composition is meant a constant boiling liquid blend of two or more substances that behaves as a single substance. Generally speaking, an azeotrope is a phenomenon where a composition comprises two or more molecular species such that the relative volatility between any binary pair of components is unity. That is, the composition of a boiling liquid mixture that exhibits an azeotrope is the same as the resulting vapor phase.

[0064]

[0065] Where: αij is the relative volatility between component i and component j, Ki is the K factor of component i, Kj is the K factor of component j, yi and xi are the vapor and liquid mole fractions of component i, and yj and xj are the vapor and liquid mole fractions of component j.

[0066] Additionally, the temperature of a boiling mixture exhibiting an azeotropic phenomenon is constant at constant pressure. When it can be distilled (or condensed) without changing the composition, the system is azeotropic. The concept of a "quasi-azeotrope" or a system exhibiting a "near-azeotropic phenomenon" is generally known as a system that is close enough to the azeotropic phenomenon so that the composition of the liquid phase and the gas phase in the phase equilibrium has a very similar composition, so that the boiling temperature only rises to a small extent during the boiling process. Therefore, all relative volatilities of all i-, binary pairs of the system in the above equation will be very close to one. Therefore, one way to characterize an azeotropic composition is that the vapor produced by partially evaporating or distilling a liquid has the same composition as the evaporated or distilled liquid, that is, the admixture distills / refluxes without a change in composition. Constant boiling compositions are characterized by azeotropy because they exhibit a maximum or minimum boiling point compared to non-azeotropic mixtures of the same components. Azeotropic compositions are also characterized by a minimum or maximum value of the vapor pressure of the mixture relative to the vapor pressure of the pure components at a constant temperature.

[0067] By "azeotrope-like" compositions (sometimes also referred to as "near-azeotrope") is meant a constant boiling or substantially constant boiling liquid admixture of two or more substances that behaves as a single substance. Another way to characterize an azeotrope-like or near-azeotrope composition is that, at a particular temperature, the bubble point vapor pressure and the dew point vapor pressure of the composition are substantially the same. An azeotrope-like or near-azeotrope composition may also be characterized by the area adjacent to a maximum or minimum vapor pressure at a given temperature in a graph of the composition's vapor pressure as a function of the mole fractions of the components in the composition.

[0068] As disclosed herein, the terms "azeotrope-like composition" and "near-azeotrope composition" should be understood to mean a composition wherein the difference between the bubble point pressure ("BP") and the dew point pressure ("DP") of the composition at a particular temperature is less than or equal to 5% based on the bubble point pressure (i.e., [(BP-DP) / BP]×100≤5), and more preferably a composition wherein the difference between the bubble point pressure ("BP") and the dew point pressure ("DP") of the composition at a particular temperature is less than or equal to 3% based on the bubble point pressure (i.e., [(BP-DP) / BP]×100 is 3).

[0069] For azeotropic compositions, there is usually a range of compositions around the azeotropic point, with the maximum boiling azeotrope having a higher boiling point at a specific pressure than the pure components of the composition at that pressure and a lower vapor pressure at a specific temperature than the pure components of the composition at that temperature, and the minimum boiling azeotrope having a lower boiling point at a specific pressure than the pure components of the composition at that pressure and a higher vapor pressure at a specific temperature than the pure components of the composition at that temperature. The higher or lower boiling temperatures and vapor pressures of the pure components are caused by unexpected intermolecular forces between and among the molecules of the composition, which may be a combination of repulsive and attractive forces (such as van der Waals forces) and hydrogen bonding.

[0070] It is well-recognized in the art that when an azeotropic liquid composition is subjected to boiling at different pressures, the boiling point of the azeotropic composition and the amount of each component can change. Therefore, an azeotropic composition can be defined based on the unique relationship that exists between the components or based on the exact amounts of each component of a composition characterized by a fixed boiling point at a specific pressure. Azeotropes or azeotrope-like compositions of two or more compounds can be characterized by defining a composition characterized by a boiling point at a given pressure, thereby providing an identifying characteristic without unduly limiting the scope of the present invention by a specific numerical composition that is limited by and only as accurate as the available analytical equipment.

[0071] It is also well recognized in the art that a system is defined as forming an azeotrope-like or near-azeotrope composition when the relative volatility of the system approaches 1.0. The relative volatility is the ratio of the volatility of the first component to the volatility of the second component. The ratio of the mole fraction of a component in vapor form to the mole fraction of the component in liquid form is the volatility of the component.

[0072] To determine the relative volatility of any two compounds, a method known as the PTx method can be used. In this procedure, the total absolute pressure in a pore of known volume is measured at a constant temperature for various compositions of the two compounds. The use of the PTx method is described in detail in "Phase Equilibrium in Process Design," by Harold R. Null, Wiley-Interscience Publisher, 1970, pp. 124-126, which is hereby incorporated by reference.

[0073] These measurements can be converted to equilibrium vapor and liquid compositions in the PTx cell by using an activity coefficient equation model, such as the non-random two-liquid (NRTL) equation, to account for liquid phase non-ideality. The use of activity coefficient equations, such as the NRTL equation, is described in detail in "The Properties of Gases and Liquids", Fourth Edition, McGrawHill, Reid, Prausnitz and Poling, pp. 241-387, and "Phase Equilibria in Chemical Engineering", Butterworth Publishers, 1985, Stanley M. Walas, pp. 165-244. Both of the foregoing references are hereby incorporated by reference. Without wishing to be bound by any theory or explanation, it is believed that the NRTL equations together with the PTx cell data can adequately predict the relative volatility of the HFO-1243zf-containing compositions and HCFO-1242zf-containing compositions of the present disclosure under conditions other than those under which the measurements were made, and thus can predict the behavior of these mixtures in multi-stage separation equipment (such as distillation columns). See, for example, U.S. Pat. No. 8,486,293 and International Publication No. WO2009105517, the disclosures of each of which are incorporated herein by reference, which rely on PTx data to predict mixtures (e.g., mixtures of 254eb and 1234zf with HF).

[0074] In accordance with the present invention, the conditions and compositions of the HF / HCFO-1242zf azeotrope calculated as described above are provided in Table A below.

[0075] Table A

[0076] HF / HFCO-1242zf

[0077] Temperature, °C Pressure, psia HF mol% HFCO-1242zf mole % -10 6.5 90.2 9.8 -5 9.1 86.0 14.0 0 12.4 82.3 17.7 5 16.1 79.3 20.7 10 19.9 76.3 23.7 15 23.4 71.9 28.1 20 25.9 62.0 38.0 25 27.8 45.3 54.7 30 29.8 29.4 70.6

[0078] Based on these discoveries, the present invention provides an azeotropic or near-azeotropic composition comprising, consisting of, or consisting essentially of about 9.8 mol % to about 70.6 mol % HCFO-1242zf and about 90.2 mol % to about 29.4 mol % HF.

[0079] In some embodiments, the present invention provides an azeotropic or near-azeotropic composition comprising, consisting of, or consisting essentially of about 9.8 mol % to about 70.6 mol % HCFO-1242zf and about 90.2 mol % to about 29.4 mol % HF, and having a boiling point of about 30° C. at about 29.8 psia (205.5 kPa) to about -10° C. at about 6.5 psia (44.8 kPa).

[0080] As used herein, the term "azeotrope" is meant to refer to azeotrope compositions, azeotrope-like compositions, azeotrope compositions, and / or near-azeotrope compositions.

[0081] Process equipment and associated feed lines, discharge lines, and associated units for all methods disclosed herein may be constructed of materials resistant to hydrogen fluoride. Typical materials of construction well known in the art include stainless steel (especially austenitic stainless steel) and well-known high nickel alloys (such as Nickel copper alloy, Nickel-based alloys and nickel-chromium alloy).

[0082] By so-called azeotropic distillation is meant a process in which a distillation column is operated under conditions that cause one or more azeotropic or azeotrope-like compositions to form, and thereby facilitate separation of the components of a mixture. Azeotropic distillation can occur when only the components of the mixture to be separated are distilled or when an entrainer is added that forms an azeotrope with one or more of the components of the initial mixture. An entrainer that acts in this manner (that is, an entrainer that forms an azeotrope with one or more of the components of the mixture to be separated, thereby facilitating separation of those components by distillation) is more commonly referred to as an entrainer or an azeotropic entrainer.

[0083] In conventional or azeotropic distillation, a conventional reflux condenser can be used to condense the overhead stream or distillate stream leaving the tower. At least a portion of the condensed stream can be returned to the top of the tower as reflux, and the remainder can be recovered as a product or used for optional processing. The ratio of the condensed material returned to the top of the tower as reflux to the material removed as distillate is generally referred to as the reflux ratio. The compounds and entrainer leaving the tower as distillate or distillation bottoms stream can then be passed into a stripping tower or a second distillation tower for separation using conventional distillation, or can be separated by other methods (such as decantation). If desired, the entrainer can then be recycled back to the first distillation tower for reuse. In some embodiments, the composition and separation method contain no or substantially no added entrainer.

[0084] The specific conditions that can be used to practice the present invention depend on many parameters, such as the diameter of the distillation column, the feed point, the number of separation trays in the column, etc. In some embodiments, the operating pressure of the distillation system can be in the range of about 5 psia to about 500 psia (34 kPa to 3450 kPa), in another embodiment, in the range of about 20 psia to about 400 psia (140 kPa to 2760 kPa). Generally, increasing the reflux ratio results in increased purity of the distillate stream, but generally the reflux ratio is in the range of about 1 / 1 to about 200 / 1. The temperature of the condenser located near the top of the column is generally sufficient to substantially completely condense the distillate discharged from the top of the column, or the temperature required to achieve the desired reflux ratio by partial condensation.

[0085] As used herein, "substantially free" means that the composition contains less than about 100 ppm (molar basis), less than about 10 ppm, or less than about 1 ppm of a specified component. If the composition is substantially free of more than one component, the total concentration of these components is less than about 100 ppm, less than about 10 ppm, or less than about 1 ppm.

[0086] Hydrogen fluoride (HF, anhydrous) is a commercially available chemical or can be produced by methods known in the art.

[0087] By "molar excess of HF" is meant the amount of HF in excess of that necessary to form an azeotrope or near-azeotrope with the organics (HFC or HFO) present in the composition. The molar amount of HF will vary depending upon the organics present in the composition to be separated and the separation conditions. For a given composition, a molar excess of HF is the amount of HF that is greater than the amount of HF required to form an azeotrope (or near-azeotrope mixture) with each organic compound in the composition.

[0088] As used herein, the terms "comprises," "includes," "has," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that includes a list of elements is not necessarily limited to only those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. In addition, unless expressly indicated to the contrary, "or" refers to an inclusive or and not an exclusive or. For example, a condition A or B satisfies one of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist).

[0089] The transitional phrase "consisting of" excludes any unspecified elements, steps, or ingredients. If in a claim, protection would not be included for materials other than those recited, except for impurities normally associated therewith. When the phrase "consisting of" appears in a clause in the body of a claim, rather than immediately following a preamble, it limits only the elements recited in that clause; other elements are not excluded from the claim as a whole.

[0090] The transitional phrase "consisting essentially of" is used to define a composition, method, or process that includes materials, steps, features, components, or elements in addition to those disclosed in the document, provided that these additionally included materials, steps, features, components, or elements do not significantly affect the basic and novel characteristics of the claimed invention, especially the mode of action for achieving the desired result of any of the processes of the invention. The term "consisting essentially of" is intermediate between "comprising" and "consisting of."

[0091] In addition, the use of "a" or "an" is used to describe elements and components described herein. This is just for convenience and to give a general sense of the scope of the invention. The description should be understood to include one or at least one and the singular also includes the plural unless it is obvious that there is another meaning.

[0092] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those of ordinary skill in the art to which the present invention belongs. Although methods and materials similar to or equivalent to the methods and materials described herein can be used in the practice or testing of the embodiments of the present disclosure, suitable methods and materials are described below. Unless citing a specific paragraph, all publications, patent applications, patents and other references mentioned herein are incorporated herein by reference in their entirety. If a conflict occurs, this specification and the definitions included therein shall prevail. In addition, materials, methods and examples are only illustrative and are not intended to be limiting.

[0093] Described herein is a method for separating HCFO-1242zf, HFO-1243zf and HF from a composition comprising HCFO-1242zf, HFO-1243zf and HF. The method comprises subjecting the composition to a first distillation step to form a column (first) distillate composition capable of forming an azeotrope or near-azeotrope composition of HCFO-1242zf / HF and HFO-1243zf / HF, and a bottom HF stream composition substantially free of HCFO-1242zf and HFO-1243zf. In this context, substantially free means less than about 1000 ppm, less than about 500 ppm, less than about 100 ppm or less than about 10 ppm.

[0094] Described herein are azeotropic and near-azeotropic compositions comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) or 3,3,3-trifluoropropene (HFO-1243zf), each with hydrogen fluoride (HF).

[0095] Also described herein are compositions comprising HCFO-1242zf, HFO-1243zf, and HF to be separated.

[0096] In some embodiments, the composition comprising HCFO-1242zf, HFO-1243zf, and HF is a process stream.

[0097] In some embodiments, the composition to be separated contains additional HCFO-1242zf or HF in excess of that necessary to form an azeotropic or azeotrope-like composition.

[0098] In some embodiments, the separation method is used to produce 3,3,3-trifluoropropene (HFO-1243zf, CF 3 CH=CH 2 In some embodiments, the production of HFO-1243zf is used to produce 2,3,3,3-tetrafluoropropene (HFO-1234yf; CF 3 CF=CH 2 ). In some embodiments, the separation method separates a process stream that is a reaction product stream of a reaction method for producing HFO-1243zf. In some embodiments, the reaction method separates a process stream that is a reaction product stream of a reaction method for producing HFO-1243zf. 3 CH 2 CH 2 Fluorination of 2-nitropropene (2-nitropropene) (Cl) produces HFO-1243zf.

[0099] HFO-1243zf can be prepared by fluorinating HCC-250fb with HF over a fluorination catalyst such as chromium fluoride / alumina or a chromium oxide catalyst. HCC-250fb can be prepared by methods known in the art such as described in U.S. Pat. Nos. 4,605,802 and 5,705,779, the disclosures of each of which are hereby incorporated by reference in their entirety, by the addition reaction of carbon tetrachloride and ethylene.

[0100] In addition to excess HF and HFO-1243zf products, the reaction product stream obtained by fluorinating HCC-250fb with HF may contain HCFO-1242zf and other intermediate products. Other intermediate products may include one or more of the following: 3-chloro-3,3,-difluoropropene (HCFO-1242zf; CF 2 Cl-CH=CH 2 ), dichlorodifluoromethane (CFC-12; CCl 2 F 2 ), chlorotrifluoromethane (CFC-13; CClF 3 ), 1,1,1-trifluoroethane (HFC-143a; CF 3 -CH 3 ), 2-chloro-1,1,1-trifluoropropane (HCFC-253db; CF 3 -CHCl-CH 3 ), 3-chloro-1,1,1-trifluoropropane (HCFC-253fb; CF 3 -CH 2 -CH 2 Cl), 1,1,1,2-tetrafluoropropane (HFC-254eb; CF 3 -CHF-CH 3 ), 1,1,1-trifluoropropane (HFC-263fb; CF 3 CH 2 CH 3 ), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf; CF 3 -CCl=CH 2 ), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd; CF 3 -CH 2 =CHCl), isomers of trichloropropylene (HCO-1240; C 3 H 3 Cl 3 ) or a combination thereof.

[0101] It has been found that HFO-1243zf forms a binary azeotropic composition with HF, as disclosed in International Application Publication No. WO2009 / 105517, the disclosure of which is incorporated herein by reference in its entirety. At 29.8°C and 106.6 psia (735 kPa), the azeotropic composition comprises about 72.0 mol% HFO-1243zf and about 28.0 mol% HF. In addition, at 79.7°C and 363 psia (2503 kPa), the azeotropic composition comprises about 76.2 mol% HFO-1243zf and about 23.8 mol% HF.

[0102] Surprisingly, it has been found that HCFO-1242zf also forms a binary azeotrope with HF.

[0103] For purposes of this disclosure, an "effective amount" is defined as the amount of each component in the compositions of the present invention that, when combined, results in the formation of an azeotropic or azeotrope-like composition. This definition includes the amount of each component, which may vary depending on the pressure applied to the composition, as long as the azeotropic or azeotrope-like composition continues to exist at different pressures, but may have different boiling points. Thus, an effective amount includes the amount of each component of the compositions of the present invention that forms an azeotropic or azeotrope-like composition at temperatures or pressures other than those described herein, such as may be expressed as a weight percentage.

[0104] For the purposes of this disclosure, azeotropy or constant boiling are also intended to mean substantially azeotropic or substantially constant boiling. In other words, within the meaning of these terms are included not only the true azeotropes described above, but also other compositions containing the same components in different proportions, which are true azeotropes at other temperatures and pressures, as well as those equivalent compositions that are part of the same azeotropic system and are azeotropes-like in their properties. As is well known in the art, there are a range of compositions containing the same components as azeotropes, which not only exhibit substantially equivalent properties for refrigeration and other applications, but also exhibit substantially equivalent properties to true azeotropic compositions in terms of constant boiling characteristics or the tendency not to separate or fractionate when boiling.

[0105] In practice, constant-boiling admixtures that may occur in many cases may be characterized by any of several criteria, depending on the conditions chosen: The composition may be defined as an azeotrope of A, B, C (and D ...), since the term "azeotrope" is both limiting and restrictive, and effective amounts of A, B, C (and D ...) are required for this unique composition of matter (which is a constant-boiling composition). It is well known to those skilled in the art that at different pressures, the composition of a given azeotrope will vary at least to some extent, and changes in pressure will also change the boiling temperature at least to some extent. Thus, an azeotrope of A, B, C (and D) represents a unique type of relationship, but with a variable composition that depends on temperature and / or pressure. Therefore, a range of compositions rather than a fixed composition is often used to define an azeotrope. The composition may be defined as a specific weight percent relationship or mole percent relationship of A, B, C, and D, recognizing that such specific values ​​indicate only one specific relationship, and that in fact, a range of such relationships represented by A, B, C (and D) actually exists for a given azeotrope, varying as a function of pressure. The azeotrope of A, B, C (and D) can be characterized by defining a composition characterized by a boiling point at a given pressure, thereby giving an identifying characteristic without unduly limiting the scope of the invention by a specific numerical composition which is limited by and is only as accurate as the available analytical equipment.

[0106] When two azeotropes are present, the composition can be defined as an azeotrope of A being HFO-1243zf / HF and B being HCFO-1242zf / HF, or vice versa, since the term "azeotrope" is both limiting and restrictive, and for this unique composition of matter, which is a constant boiling composition, such effective amounts of A and B are required. It is well known to those skilled in the art that at different pressures, the composition of a given azeotrope will vary at least to some extent, and that changes in pressure will also change the boiling temperature at least to some extent. Thus, an azeotrope of A and B represents a unique type of relationship, but with a variable composition that depends on temperature and / or pressure. Therefore, a range of compositions, rather than fixed compositions, is often used to define azeotropes. The composition can be defined as a specific weight percent relationship or mole percent relationship of A and B, recognizing that such specific values ​​indicate only one specific relationship. A range of such relationships represented by A and B actually exist for a given azeotrope, varying under the influence of pressure. The azeotrope of A and B can be characterized by defining a composition characterized by a boiling point at a given pressure, thereby giving an identifying characteristic without unduly limiting the scope of the invention by a specific numerical composition which is limited by and only as accurate as available analytical equipment.

[0107] The azeotrope or azeotrope-like compositions of the present disclosure can be prepared by any convenient method, including mixing or combining the desired amounts. A preferred method is to weigh the desired component amounts and thereafter combine them in a suitable container. Another preferred method is to use the azeotrope or azeotrope-like composition as the distillate stream of a distillation column.

[0108] Some fluoroolefins have been found to form azeotrope compositions with HF. Typically, fluoroolefin / HF azeotrope compositions boil at a lower temperature than the corresponding pure compounds. Several examples of such fluoroolefin / HF azeotropes are disclosed, for example, in International Application No. WO2009 / 105517, the disclosure of which is incorporated herein by reference in its entirety.

[0109] Unexpectedly, HCFO-1242zf will form azeotropes or azeotrope-like compositions with HF, and it has been unexpectedly observed that, in some cases, azeotrope compositions comprising fluoroolefins and HF can form two liquid phases upon condensation and / or cooling. These two phases comprise a chlorofluoroolefin-rich phase and an HF-rich phase. This phase behavior allows for unique separation schemes utilizing liquid-liquid separation (such as decantation) of these two phases, which is not possible with many saturated hydrofluorocarbons, which do not typically phase separate in the same manner.

[0110] In some embodiments, a method for separating hydrogen fluoride (HF) from a composition (e.g., a process stream) comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf), 3,3,3-trifluoropropene (HFO-1243zf), and a molar excess of HF is provided. The method comprises subjecting the process stream to distillation in a first distillation column under boiling conditions of an azeotrope of HCFO-1242zf / HF and HFO-1243zf / HF, wherein a molar excess of HF is used to produce both azeotropes. The method also comprises forming a first distillate stream comprising an azeotropic or near-azeotropic composition of HCFO-1242zf / HF and HFO-1243zf / HF from the first distillation column and a first bottoms stream of HF that is substantially free of HCFO-1242zf and HFO-1243zf.

[0111] In some embodiments, the method of the above paragraphs further comprises condensing, cooling, and decanting the first distillate stream to form an HF-rich stream, for example, an HCFO-1242zf / HF-rich stream.

[0112] In some embodiments, the process further comprises subjecting the HCFO-1242zf / HF-rich stream to distillation in a second distillation column under boiling conditions of an azeotrope of HCFO-1242zf / HF and HFO-1243zf / HF, and forming a second distillate stream from the second distillation column comprising an azeotropic or near-azeotropic composition of HCFO-1242zf / HF and HFO-1243zf / HF and a second bottoms stream of HCFO-1242zf and HFO-1243zf that is substantially free of HF.

[0113] In some embodiments, the method further includes subjecting the second bottoms stream to a third distillation column to form a HCFO-1242zf stream that is substantially free of HFO-1243zf.

[0114] In some embodiments, the method further comprises combining the first distillate stream with the second distillate stream prior to decanting.

[0115] In some embodiments, the process stream is a product stream from the fluorination reaction of 1,1,1,3-tetrachloropropane (HCC-250fb) with HF to produce HFO-1243zf.

[0116] In some embodiments, the method includes: subjecting a process stream (such as a process stream provided by the fluorination of HCC-250fb) to distillation in a first distillation column under boiling conditions of an azeotrope of HCFO-1242zf-HF and HFO-1243zf-HF. The method also includes forming a first distillate stream from the first distillation column comprising a molar excess of HF to provide an azeotropic or near-azeotropic composition of both HCFO-1242zf and HF and HFO-1243zf and HF, and a first bottoms stream of HCFO-1242zf and HFO-1243zf that is substantially free of HF. The method also includes sequentially condensing and decanting the distillate, while the first bottoms stream is substantially pure HF, containing up to about 50 ppm of HCFO-1242zf and trace amounts of HFO-1243zf, preferably less than about 1 ppm of HCFO-1242zf.

[0117] In some embodiments, the HCFO-1242zf-rich stream is formed by decanting an azeotropic or near-azeotropic composition of HCFO-1242zf, HFO-1243zf, and HF.

[0118] In some embodiments, a method for separating 3-chloro-3,3-difluoro-1-propylene (HCFO-1242zf) from a process stream comprising HCFO-1242zf, 3,3,3-trifluoropropylene (HFO-1243zf) and a molar excess of hydrogen fluoride (HF) is provided. The method includes subjecting the HFO-1243zf process stream to distillation in a first distillation column under boiling conditions of an azeotrope of HCFO-1242zf, HFO-1243zf and HF. The method also includes forming a first distillate stream of a composition comprising an azeotrope or near-azeotrope of HCFO-1242zf / HF and HCFO-1243zf / HF and an excess of HF from the first distillation column and a first HF bottoms stream substantially free of HCFO-1242zf and HFO-1243zf. The method also includes condensing, cooling and decanting the first distillate stream to form a HF-rich stream and a HCFO-1242zf-rich stream. The method also includes subjecting the HCFO-1242zf-rich stream to distillation under boiling conditions of HCFO-1242zf / HF and HFO-1243zf / HF azeotropes in a second distillation tower. The method also includes forming a second distillate stream of an azeotropic or near-azeotropic composition of HCFO-1242zf / HF and HFO-1243zf / HF from the second distillation tower and a second bottom stream of HCFO-1242zf and HFO-1243zf substantially free of HF. The method also includes subjecting the second bottom stream to a third distillation tower using standard distillation techniques to form a HCFO-1242zf stream substantially free of HFO-1243zf.

[0119] In some embodiments, the process stream containing HFO-1242zf and HFO-1243zf is a reaction product stream of a reaction process for producing HFO-1243zf by fluorination of 1,1,1,3-tetrachloropropane (HCC-250fb) with HF, and optionally includes 1,1,1,3-tetrafluoropropane (HFC-254fb).

[0120] In some embodiments, the first distillate stream and the second distillate stream of any of the above paragraphs comprise an azeotropic or near-azeotropic composition comprising from about 9.8 mol% to about 70.6 mol% HCFO-1242zf and from about 90.2 mol% to about 29.4 mol% HF.

[0121] In some embodiments, the first distillate stream and the second distillate stream of any of the above paragraphs comprise an azeotropic or near-azeotropic composition comprising from about 9.8 mol% to about 70.6 mol% HCFO-1242zf and from about 90.2 mol% to about 29.4 mol% HF, and having a vapor pressure of from about 6.5 psia to about 29.8 psia at a temperature of from about -10°C to about 30°C.

[0122] In some embodiments, the first distillate stream comprises about 38.0 mole % HCFO-1242zf and about 62.0 mole % HF, and has a vapor pressure of about 25.9 psia at a temperature of about 20 °C.

[0123] In some embodiments, an azeotropic or near-azeotropic composition comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf), 3,3,3-trifluoropropene (HFO-1243zf), and hydrogen fluoride (HF) is provided.

[0124] In some embodiments, an azeotropic or near-azeotropic composition comprising HCFO-1242zf and HF is provided.

[0125] In some embodiments, the azeotropic or near-azeotropic composition comprises from about 9.8 mol % to about 70.6 mol % HCFO-1242zf and from about 90.2 mol % to about 29.4 mol % HF.

[0126] In some embodiments, the azeotropic or near-azeotropic composition comprises about 9.8 mol % to about 70.6 mol % HCFO-1242zf and about 90.2 mol % to about 29.4 mol % HF, and has a vapor pressure of about 6.5 psia to about 29.8 psia at a temperature of about -10°C to about 30°C.

[0127] In some embodiments, the azeotropic or near-azeotropic composition comprises about 38.0 mole percent HCFO-1242zf and about 62.0 mole percent HF, and has a vapor pressure of about 25.9 psia at a temperature of about 20°C.

[0128] In some embodiments, the azeotropic or near-azeotropic composition further comprises 1,1,1,3-tetrafluoropropane (HFC-254fb).

[0129] In some embodiments, the HCFO-1242zf and HF portion of the azeotropic or near-azeotropic composition of HCFO-1242zf, HFO-1243zf, and HF comprises from about 9.8 mol % to about 70.6 mol % HCFO-1242zf and from about 90.2 mol % to about 29.4 mol % HF.

[0130] In some embodiments, the HCFO-1242zf and HF portion of an azeotropic or near-azeotropic composition of HCFO-1242zf, HFO-1243zf, and HF comprises from about 9.8 mol % to about 70.6 mol % HCFO-1242zf and from about 90.2 mol % to about 29.4 mol % HF with a vapor pressure of from about 6.5 psia to about 29.8 psia at a temperature of from about -10°C to about 30°C.

[0131] In some embodiments, the HCFO-1242zf and HF portion of the azeotropic or near-azeotropic composition of HCFO-1242zf, HFO-1243zf, and HF comprises about 38.0 mole % HCFO-1242zf and about 62.0 mole % HF with a vapor pressure of about 25.9 psia at a temperature of about 20°C.

[0132] In some embodiments, the first and second distillation columns are operated at about 14.7 psia (101 kPa) to about 300 psia (2068 kPa), with an overhead temperature of about -50°C to about 200°C and a bottom temperature of about -30°C to about 220°C. In another embodiment, the pressure will be in the range of about 50 psia (345 kPa) to about 250 psia (1724 kPa), with an overhead temperature of about -25°C to about 100°C and a bottom temperature of about 0°C to about 150°C.

[0133] In the separation processes described herein that include more than one distillation column, these distillation columns may all be operated at the same pressure and / or temperature or at different pressures and / or temperatures.

[0134] In the case where the composition to be separated is a reaction product stream formed by fluorinating HCC-250fb with HF, it is desirable to recycle any unreacted HCFO-1242zf back into the reactor so that it can be converted to HFO-1243zf. However, it is necessary to remove HFO-1243zf from the unreacted HCFO-1242zf prior to recycling so as not to inhibit the equilibrium reaction. It is also necessary to remove HF from HFO-1243zf and HCFO-1242zf to allow them to be used as reagents in a fluorination reaction or another reaction or as a refrigerant or in other applications.

[0135] Other Implementations

[0136] A first distillate stream is formed comprising HFO-1243zf, HCFO-1242zf and a molar excess of HF.

[0137] A first distillate stream is formed comprising HFO-1243zf, HCFO-1242zf, and sufficient HF to form an azeotrope or near-azeotrope of HCFO-1242zf / HF and HFO-1243zf / HF.

[0138] The first distillate HFO-1243zf, HCFO-1242zf, and sufficient HF are condensed to form an azeotrope or near azeotrope of HCFO-1242zf / HF and HFO-1243zf / HF.

[0139] An azeotrope or a near-azeotrope of at least one of HCFO-1242zf / HF and HFO-1243zf / HF is recovered.

[0140] A heterogeneous azeotrope is produced.

[0141] Heterogeneous azeotropes of HFO-1243zf / HF and HFO-1242zf / HF are produced.

[0142] The first distillate containing HFO-1243zf, HCFO-1242zf and sufficient HF is condensed and decanted, and the HCFO-1242zf / HF and HFO-1243zf / HF azeotropes or near-azeotropes are recovered.

[0143] An HFO-1242zf-rich phase and an HCFO-1242zf-lean phase are formed, and the HFO-1242zf-rich phase is recycled.

[0144] An HF-rich phase comprising HFO-1242zf / HF is formed and is recycled to the first distillation column.

[0145] The distillation column is operated at a pressure greater than about 14.7 psig, preferably between about 14.7 psig and about 500 psig, more preferably between about 30 psig and about 150 psig to form a first distillate comprising HFO-1243zf, HCFO-1242zf, and sufficient HF.

[0146] The second distillation is operated wherein the HCFO-1242zf-rich stream is at boiling conditions of the HCFO-1242zf and HFO-1243z azeotrope and forms a second distillate stream from the second distillation column comprising an azeotropic or near-azeotropic composition of HCFO-1242zf, HFO-1243zf, and HF and a second bottoms stream substantially free of HF-1242zf and HFO-1243zf.

[0147] The second bottoms stream of HCFO-1242zf and HFO-1243zf substantially free of HF is subjected to distillation in a third distillation column to form a HCFO-1242zf stream substantially free of HFO-1243zf.

[0148] A process of combining a first distillate stream of HFO-1243zf, HCFO-1242zf, and HF sufficient to form a heteroazeotrope with a second distillate stream comprising an azeotropic or near-azeotropic composition of HCFO-1242zf, HFO-1243zf, and HF and forming a heteroazeotrope or near-azeotrope upon condensation.

[0149] A first distillate stream and a second distillate stream are formed, the second distillate stream comprising from about 9.8 mole % to about 70.6 mole % HCFO-1242zf and from about 90.2 mole % to about 29.4 mole % HF and having a vapor pressure of from about 6.5 psia (44.8 kPa) to about 29.8 psia (205.5 kPa) at a temperature of from about -10°C to about 30°C.

[0150] A first distillate stream and a second distillate stream comprising about 38.0 mole % HCFO-1242zf and about 62.0 mole % HF are formed at a temperature of about 20°C and a vapor pressure of about 25.9 psia.

[0151] 3-Chloro-3,3-difluoro-1-propene (HCFO-1242zf) is separated from an HCFO-1242zf-rich stream comprising HCFO-1242zf, 3,3,3-trifluoropropene (HFO-1243zf), and hydrogen fluoride (HF).

[0152] A first distillate stream comprising about 9.8 mol % to about 70.6 mol % HCFO-1242zf and about 90.2 mol % to about 29.4 mol % HF is formed, obtained, and recovered at a temperature of about -10°C to about 30°C at a vapor pressure of about 6.5 psia to about 29.8 psia.

[0153] A first distillate stream comprising about 38.0 mole % HCFO-1242zf and about 62.0 mole % HF is formed, obtained, and recovered at a temperature of about 20°C and a vapor pressure of about 25.9 psia.

[0154] An azeotropic or near-azeotropic composition comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf), 3,3,3-trifluoropropene (HFO-1243zf), and hydrogen fluoride (HF) is obtained at a temperature of about -10°C to about 30°C at a vapor pressure of about 6.5 psia to about 29.8 psia, the azeotropic or near-azeotropic composition comprising, consisting of, or consisting essentially of about 9.8 mole % to about 70.6 mole % HCFO-1242zf and about 90.2 mole % to about 29.4 mole % HF.

[0155] An azeotropic or near-azeotropic composition comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf), 3,3,3-trifluoropropene (HFO-1243zf), and hydrogen fluoride (HF) is obtained at a temperature of about 20° C. and a vapor pressure of about 25.9 psia, the azeotropic or near-azeotropic composition comprising, consisting of, or consisting essentially of about 38.0 mole percent HCFO-1242zf and about 62.0 mole percent HF.

[0156] Those skilled in the art will appreciate that any of the aforementioned embodiments may be combined with each other in any manner.

[0157] In the foregoing description, the concepts have been described with reference to specific embodiments. However, those skilled in the art recognize that various modifications and changes may be made without departing from the scope of the invention as set forth in the following claims. However, benefits, advantages, solutions to problems, and any features that may cause any benefit, advantage, or solution to occur or become more apparent are not to be construed as key, essential, or essential features of any or all of the claims.

[0158] Accordingly, the specification and drawings should be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention. Note that not all of the above-described actions are required in the general description or in the embodiments, that a portion of a specific action may not be required, and that one or more additional actions may be performed in addition to those described. Further, the order in which the actions are listed is not necessarily the order in which they are performed.

[0159] It should be understood that certain features described in the context of separate embodiments herein for clarity may also be provided in combination in a single embodiment. Conversely, various features described in the context of a single embodiment for simplicity may also be provided individually or in any secondary combination. In addition, references to values ​​described in ranges include each value within the range.

[0160] Various aspects and embodiments have been described above and are exemplary only and not limiting. After reading this specification, skilled artisans appreciate that other aspects and embodiments are possible without departing from the scope of the present invention.

Claims

1. An azeotropic or near-azeotropic composition comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) and hydrogen fluoride (HF).

2. The azeotropic or near-azeotropic composition of claim 1, wherein the azeotropic or near-azeotropic composition comprises from about 9.8 mol % to about 70.6 mol % HCFO-1242zf and from about 90.2 mol % to about 29.4 mol % HF.

3. The azeotropic or near-azeotropic composition of any one of claims 1 to 2, wherein the azeotropic or near-azeotropic composition has a vapor pressure of about 6.5 psia (44.8 kPa) to about 29.8 psia (205.5 kPa) at a temperature of about -10°C to about 30°C.

4. The azeotropic or near-azeotropic composition of any one of claims 1 to 3, wherein the azeotropic or near-azeotropic composition comprises about 38.0 mole % HCFO-1242zf and about 62.0 mole % HF.

5. The azeotropic or near-azeotropic composition of any one of claims 1 to 4, wherein the azeotropic or near-azeotropic composition has a vapor pressure of about 25.9 psia at a temperature of about 20°C.

6. The azeotropic or near-azeotropic composition according to any one of claims 1 to 5, wherein the azeotropic or near-azeotropic composition is prepared by weighing the desired amounts of HCFO-1242zf and HF and thereafter combining them in a suitable container.

7. The azeotropic or near-azeotropic composition of any one of claims 1 to 6, wherein the azeotropic or near-azeotropic composition consists essentially of HCFO-1242zf and HF.

8. A composition comprising the azeotropic or near-azeotropic composition according to any one of claims 1 to 7 and 3,3,3-trifluoropropene (HFO-1243zf).

9. A composition comprising the azeotropic or near-azeotropic composition according to any one of claims 1 to 8 and 1,1,1,3-tetrafluoropropane (HFC-254fb).

10. The composition according to any one of claims 1 to 9, wherein the composition further comprises one or more additional components selected from the group consisting of: 3-chloro-3,3,-difluoropropene (HCFO-1242zf; CF2Cl-CH=CH2), dichlorodifluoromethane (CFC-12; CCl2F2), chlorotrifluoromethane (CFC-13; CClF3), 1,1,1-trifluoroethane (HFC-143a; CF3-CH3), 2-chloro-1,1,1-trifluoropropane (HCFC-253db; CF3-CHCl-CH3), 3-chloro-1,1,1 -trifluoropropane (HCFC-253fb; CF3-CH2-CH2Cl), 1,1,1,2-tetrafluoropropane (HFC-254eb; CF3-CHF-CH3), 1,1,1-trifluoropropane (HFC-263fb; CF3CH2CH3), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf; CF3-CCl=CH2), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd; CF3-CH2=CHCl), isomers of trichloropropene (HCO-1240; C3H3Cl3) and combinations thereof.

11. An azeotropic or near-azeotropic composition comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf), 3,3,3-trifluoropropene (HFO-1243zf) and hydrogen fluoride (HF).

12. A composition comprising a mixture of an azeotrope or a near-azeotrope containing 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) and hydrogen fluoride (HF) and an azeotrope or a near-azeotrope containing 3,3,3-trifluoropropene (HFO-1243zf) and HF.

13. The composition of any one of claims 11 or 12, wherein the HCFO-1242zf and HF portion of the azeotropic or near-azeotropic composition comprises from about 9.8 mol% to about 70.6 mol% HCFO-1242zf and from about 90.2 mol% to about 29.4 mol% HF.

14. The composition of any one of claims 11 to 13, wherein the HCFO-1242zf and HF portions of the azeotropic or near-azeotropic composition have a vapor pressure of about 6.5 psia (44.8 kPa) to about 29.8 psia (205.5 kPa) at a temperature of about -10°C to about 30°C.

15. The composition of any one of claims 11 to 14, wherein the HCFO-1242zf and HF portion of the azeotropic or near-azeotropic composition comprises about 38.0 mole % HCFO-1242zf and about 62.0 mole % HF.

16. The composition of any one of claims 11 to 15, wherein the HCFO-1242zf and HF portion of the azeotropic or near-azeotropic composition has a vapor pressure of about 25.9 psia at a temperature of about 20°C.

17. The composition of any one of claims 11 to 16, further comprising 1,1,1,3-tetrafluoropropane (HFC-254fb).

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