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

Abstract

Disclosed herein are azeotropic or near-azeotropic compositions comprising HCFO-1242zf, HFO-1243zf, and HF.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 63 / 426,604, filed November 18, 2022, the disclosure of which is incorporated herein by reference in its entirety.

[0002] FIELD OF THE INVENTION The present disclosure relates to a process for separating mixtures of hydrogen fluoride (HF), chlorofluoroolefins (HCFOs), and fluoroolefins (HFOs). More specifically, the present disclosure relates to mixtures containing 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf; CCIFCH=CH), 3,3,3-trifluoropropene (HFO-1243zf; CFCH=CH), and HF, and processes for separating these mixtures. [Background technology]

[0003] The refrigeration industry has been working for the past several decades to find replacement refrigerants for the ozone-depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) that are being phased out as a result of the Montreal Protocol. The solution for most refrigerant producers has been to commercialize hydrofluorocarbon (HFC) refrigerants. The most widely used of these new HFC refrigerants today, HFC-134a, has an ozone depletion potential of zero and is therefore not affected by the current regulations that are being phased out as a result of the Montreal Protocol.

[0004] In addition to the problem of ozone depletion, another environmental issue is global warming. 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 for heat transfer compositions that meet both low ozone depletion potential and low global warming potential. Certain hydrofluoroolefins (HFOs) meet both goals. Therefore, there is a need for a manufacturing process that provides hydrogenated hydrocarbons and fluoroolefins that do not contain chlorine and also have low global warming potential.

[0005] The chemical production of fluoroolefins is typically a multi-step process that can produce intermediate mixtures of HFCs, HCFCs, hydrochlorofluoroolefins (HCFOs), and / or HFOs, and hydrogen fluoride (HF). Separation of such mixtures is not always easily accomplished. Existing methods of distillation and decantation are frequently ineffective at separating these compounds. Summary of the Invention [Problem to be solved by the invention]

[0006] While aqueous scrubbing can be effective, it requires large amounts of scrubbing solution, the use of additional equipment, and produces excessive waste and a wet product that must then be dried. Therefore, new methods are needed to separate HF from fluoroolefins, hydrofluoroolefins, hydrochlorofluoroolefins, hydrochlorofluorocarbons, and / or hydrofluorocarbons. [Means for solving the problem]

[0007] In some embodiments, the invention disclosed herein relates to a process 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 to form an HF-enriched stream comprising an azeotropic or near-azeotropic mixture of HCFO-1242zf and HF.

[0008] In some embodiments, the invention disclosed herein relates to a process 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 bottom stream comprising HF that is 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.

[0009] In some embodiments, the invention disclosed herein relates to a process for forming multiple azeotropic mixtures 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, wherein HFO-1243zf / HF azeotropic or near-azeotropic mixtures and HCFO-1242zf / HF azeotropic or near-azeotropic mixtures are formed.

[0010] In some embodiments, the invention disclosed herein relates to a process for forming a mixture of azeotropic or near-azeotropic mixtures comprising HCFO-1242zf / HF and HCFO-1243zf / HF.

[0011] In some embodiments, disclosed herein is a process for decanting a first stream comprising a mixture of an azeotropic or near-azeotropic mixture, a first HCFO-1242zf / HF azeotropic or near-azeotropic mixture, and a second HCFO-1243zf / HF azeotropic or near-azeotropic mixture.

[0012] In some embodiments, disclosed herein are processes for forming an HF-rich azeotropic or near-azeotropic mixture and an HF-lean azeotropic or near-azeotropic mixture, wherein the HF-rich azeotropic or near-azeotropic mixture comprises HFO-1242zf / HF and the HF-lean azeotropic or near-azeotropic mixture comprises HCFO-1243zf / HF.

[0013] In some embodiments, disclosed herein 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 mixture of a heterogeneous azeotropic or near-azeotropic mixture, and forming a distillate stream of a heterogeneous azeotropic or near-azeotropic mixture.

[0014] In some embodiments, disclosed herein are processes for forming and using HCFO-1242zf / HF azeotropic mixtures.

[0015] In some embodiments, disclosed herein are processes for removing HCFO-1242zf by contacting a feed or product stream with an HCFO-1242zf / HF azeotropic or near-azeotropic mixture.

[0016] In some embodiments, disclosed herein are compositions comprising HCFO-1242zf azeotropic or near-azeotropic mixtures with HF.

[0017] In some embodiments, disclosed herein are compositions comprising heterogeneous HF-containing azeotropic or near-azeotropic mixtures.

[0018] In some embodiments, mixtures of HFO-1243zf / HF and HCFO-1242zf / HF azeotropic and near-azeotropic mixtures are disclosed herein.

[0019] Embodiments of the processes disclosed herein use one or more distillation columns, condensers, and decanters to form, produce, and / or use HCFO-1242zf / HF azeotropic or near-azeotropic mixtures.

[0020] In one embodiment of the present invention, HFO-1243zf, HCFO-1242zf, and HF streams containing sufficient HF (i.e., sufficient molar excess to form a mixture of different azeotropic or near-azeotropic mixtures, each containing HF) are conveyed to and passed through a distillation column under conditions to form a first distillate stream comprising an azeotropic or near-azeotropic mixture of HFO-1242zf and HFO-1243zf with HF.

[0021] In another embodiment of the invention, an HFO-1243zf, HCFO-1242zf, and HF stream containing sufficient HF (i.e., a sufficient molar excess to form a mixture of HFO-1242zf / HF and HFO-1243zf / HF azeotropic or near-azeotropic mixtures) is conveyed to and passed through a distillation column under conditions to form, upon changing phase from a vapor to a liquid, a first distillate stream comprising HFO-1242zf and HFO-1243zf and azeotropic or near-azeotropic mixtures with HF.

[0022] In one embodiment of the present invention, an HFO-1243zf, HCFO-1242zf, and HF stream containing sufficient HF (i.e., a sufficient molar excess to form a mixture of HFO-1242zf / HF and HFO-1243zf / HF azeotropic or near-azeotropic mixtures) is conveyed to and passed through a distillation column under conditions to form a first distillate stream comprising HFO-1242zf and HFO-1243zf and azeotropic or near-azeotropic mixtures with HF, and a first bottom stream of HF essentially free of HCFO-1242zf and HFO-1243zf present in the distillation column.

[0023] In one embodiment, a mixture of HFO-1242zf / HF and HFO-1243zf / HF azeotropic or near-azeotropic mixtures is formed.

[0024] Another embodiment disclosed herein relates 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-lean liquid stream comprising HFO-1242zf and HF and HFO-1243zf and HF, respectively.

[0025] 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, comprising distillation, condensation, and / or cooling, and decantation, wherein the HCFO-1242zf-rich stream from the decantation is distilled in a second distillation column under boiling conditions such that an azeotropic or near-azeotropic mixture of HFO-1242zf and HCFO-1242zf with HF is removed overhead 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 essentially free of HF.

[0026] The process further includes subjecting the second bottoms stream to a third distillation column to form an HCFO-1242zf stream that is essentially free of HFO-1243zf.

[0027] In another embodiment of the present invention, the present disclosure provides an azeotropic or near-azeotropic mixture composition comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) and 3,3,3-trifluoropropene (HFO-1243zf) azeotropic or near-azeotropic mixture with HF.

[0028] In a further process embodiment, the present disclosure provides a process for separating 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) from a process stream containing HCFO-1242zf, 3,3,3-trifluoropropene (HFO-1243zf) / HF, and a molar excess of HF (i.e., a sufficient amount of HF to form an azeotropic or near-azeotropic mixture). The process comprises subjecting the process stream to distillation in a first distillation column under boiling conditions sufficient to remove the excess HF as a bottom stream, but sufficient HF remaining in the distillate stream to allow the formation of both an HFO-1243zf / HF azeotropic or near-azeotropic mixture and an HFO-1242zf / HF azeotropic or near-azeotropic mixture. The process also includes forming a first distillate stream comprising an azeotropic or near-azeotropic composition of HCFO-1242zf, HFO-1243zf, and HF, and a first bottoms stream of HF essentially free of HCFO-1242zf and HFO-1243zf from the first distillation column.

[0029] In another process embodiment, the HCFO-1242zf, HFO-1243zf, and HF distillate is condensed and cooled, then decanted to form an HCFO-1242zf-rich (HF-lean) stream and an HF-rich (HCFO-1242zf-rich) stream. The process further includes subjecting the HCFO-1242zf-rich stream to distillation in a second distillation column under boiling conditions to form an azeotropic mixture of HCFO-1242zf and HFO-1243zf with HF. The process further includes forming a second distillate stream comprising an azeotropic or near-azeotropic composition of HCFO-1242zf, HFO-1243zf, and HF, and a second bottom stream of HCFO-1242zf and HFO-1243zf essentially free of HF from the second distillation column. The process also further includes subjecting the second bottoms stream to a third standard distillation column using methods known in the art to form an HCFO-1242zf stream that is essentially free of HFO-1243zf.

[0030] In another embodiment of the present invention, heterogeneous HF azeotropes are described.

[0031] Further embodiments disclosed herein are as follows.

[0032] Embodiment 1. An azeotropic or near-azeotropic composition comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) and hydrogen fluoride (HF).

[0033] Embodiment 2. The azeotropic or near-azeotropic composition of embodiment 1, wherein the azeotropic or near-azeotropic composition comprises from about 9.8 to about 70.6 mole percent HCFO-1242zf and from about 90.2 to about 29.4 mole percent HF.

[0034] Embodiment 3. The azeotropic or near-azeotropic composition of any one of the embodiments disclosed herein, wherein the azeotropic or near-azeotropic composition has 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.

[0035] Embodiment 4. The azeotropic or near-azeotropic composition of 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.

[0036] Embodiment 5. The azeotropic or near-azeotropic composition of 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.

[0037] Embodiment 6. The azeotropic or near-azeotropic composition of any one of the embodiments disclosed herein, wherein the azeotropic or near-azeotropic composition is prepared by weighing out the desired amounts of HCFO-1242zf and HF, and then combining them in a suitable container.

[0038] Embodiment 7. The azeotropic or near-azeotropic composition of any one of the embodiments disclosed herein, wherein the azeotropic or near-azeotropic composition consists essentially of HCFO-1242zf and HF.

[0039] Embodiment 8. A composition comprising the azeotropic or near-azeotropic composition of any one of the embodiments disclosed herein and 3,3,3-trifluoropropene (HFO-1243zf).

[0040] Embodiment 9. A composition comprising the azeotropic or near-azeotropic composition of any one of the embodiments disclosed herein and 1,1,1.3-tetrafluoropropane (HFC-254fb).

[0041] Embodiment 10. The composition comprises 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-tetra ... 1,1,1-trifluoropropane (HFC-263fb; CFCHCH), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf; CF-CCl=CH), 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd; CF-CH=CHCl), isomers of trichloropropene (HCO-1240; CHClCl), and combinations thereof.

[0042] 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).

[0043] Embodiment 12. A composition comprising a mixture of an azeotropic or near-azeotropic mixture comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) and hydrogen fluoride (HF), and an azeotropic or near-azeotropic mixture comprising 3,3,3-trifluoropropene (HFO-1243zf) and HF.

[0044] Embodiment 13. The composition of 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 to about 70.6 mole percent HCFO-1242zf and from about 90.2 to about 29.4 mole percent HF.

[0045] Embodiment 14. The composition of 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.

[0046] Embodiment 15. The composition of 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.

[0047] Embodiment 16. The composition of 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 25.9 psia at a temperature of about 20° C.

[0048] Embodiment 17. The composition of any one of the embodiments disclosed herein, further comprising 1,1,1,3-tetrafluoropropane (HFC-254fb).

[0049] 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.

[0050] Other features and advantages of any one or more of the embodiments described herein will become apparent from the following detailed description, the accompanying drawings, and the claims. [Brief explanation of the drawings]

[0051] To facilitate an understanding of the concepts presented herein, embodiments are illustrated in the accompanying drawings. [Figure 1] Illustrates an embodiment of azeotropic distillation for separating HCFO-1242zf from a mixture containing HCFO-1242zf, HFO-1243zf, and HF. [Figure 2] 1 illustrates another embodiment of azeotropic distillation for separating HCFO-1242zf from a mixture containing HCFO-1242zf, HFO-1243zf, and HF. [Figure 3] Illustrates a further embodiment of azeotropic distillation for separating HCFO-1242zf from a mixture containing HCFO-1242zf, HFO-1243zf, and HF.

[0052] Those skilled in the art will appreciate that objects in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale, for example, the dimensions of some of the objects in the figures may be exaggerated relative to other objects to help improve understanding of the embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0053] High-purity 3,3,3-trifluoropropene (HFO-1243zf) is desirable for subsequent downstream conversion to hydrofluorocarbons, hydrochlorofluorocarbons, fluoroolefins, and hydrochlorofluoroolefins, including, but not limited to, HFO-1234ze and HFO-1234yf, or as a refrigerant or refrigerant component. The vapor-phase reaction of 1,1,1,3-tetrachloropropane (HCC-250fb) with HF, in the absence or presence of a catalyst, at a molar excess of HF:250fb, provides high yields of HFO-1243zf and other products with lower degrees of fluorination, such as HCFO-1242zf, as disclosed in U.S. Patent No. 6,329,559, the disclosure of which is incorporated herein by reference in its entirety. Multi-step processes for producing HFO-1234yf from HFO-1243zf also include using HCFC-250fb as a starting material to produce HFO-1243zf by fluorination, as disclosed in U.S. Patent No. 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 from 3:1 to at least about 50:1.

[0054] As disclosed in WO 2009105517, the disclosure of which is incorporated herein by reference in its entirety, it has been observed that a low-boiling azeotropic or near-azeotropic mixture of HFO-1243zf is formed from a product stream comprising HFO-1243zf and HF. The data in Table 1 indicate that the molar ratio of HF / 1243zf in the azeotropic mixture is about 1:3.

[0055] Surprisingly, it has been found that HCFO-1242zf forms low-boiling azeotropic or near-azeotropic mixtures with HF and can be used to produce HF essentially 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. difference at atmospheric pressure).

[0056] Therefore, the formation of an HCFO-1242zf / HF azeotropic or near-azeotropic mixture that is HF-enriched and contains about 62.0 mole percent HF at a vapor pressure of 25.9 psia and a temperature of 20° C. was unexpected.

[0057] Before going into the details of the embodiments described below, some terms will be defined or clarified.

[0058] "Azeotropic" composition refers to a constant-boiling liquid mixture of two or more substances that behaves as a single substance. In general, an azeotrope is a phenomenon in which a composition contains two or more molecular species such that the relative volatility between the components of any binary pair is uniform. That is, the composition of a boiling liquid mixture that exhibits an azeotropy is identical to the vapor phase that is produced.

[0059]

number

[0060] Furthermore, the temperature of a boiling mixture, which exhibits an azeotropic mixture, remains constant at a constant pressure. A system is azeotropic if it can be distilled (or condensed) without a change in composition. The concept of a system exhibiting "azeotrope-like" or "near-azeotropic" is commonly known as a system in which the liquid and vapor phases at phase equilibrium are very similar in composition and the boiling temperature is close enough to an azeotrope that the boiling temperature increases only slightly during the boiling process. Thus, all relative volatilities for all binary component pairs i to j in the system in the above equation are very close to unity. Thus, one way to characterize an azeotropic composition is that the vapor produced by partial evaporation or distillation of a liquid has the same composition as the liquid from which it was evaporated or distilled (i.e., the mixture can be distilled / refluxed without a change in composition). Constant-boiling compositions are characterized as azeotropic because they exhibit a maximum or minimum boiling point compared to non-azeotropic mixtures of the same components. Azeotropic compositions are also characterized by the minimum or maximum value of the vapor pressure of the mixture relative to the vapor pressure of each undiluted component at a constant temperature.

[0061] An "azeotrope-like" composition (sometimes referred to as a "near-azeotrope") refers to a constant-boiling or substantially constant-boiling liquid mixture of two or more substances that behaves as a single substance. Another way to characterize an azeotropic or near-azeotrope composition is that the bubble-point vapor pressure and dew-point vapor pressure of the composition at a particular temperature are substantially the same. An azeotropic or near-azeotrope composition can also be characterized by the area adjacent to the maximum or minimum vapor pressure in a plot of the vapor pressure of the composition at a given temperature as a function of the mole fraction of the components in the composition.

[0062] As disclosed herein, the terms "azeotrope-like composition" and "near-azeotrope composition" shall be understood to mean a composition in which the difference between the bubble point pressure ("BP") and the dew point pressure ("DP") of the composition at a particular temperature is 5 percent or less, based on the bubble point pressure, i.e., [(BP-DP) / BP] x 100≦5; more preferably, a composition in which the difference between the bubble point pressure ("BP") and the dew point pressure ("DP") of the composition at a particular temperature is 3 percent or less, based on the bubble point pressure, i.e., [(BP-DP) / BP] x 100 is 3.

[0063] For azeotropic compositions, there is usually some range of compositions around the azeotropic point, with the highest boiling point azeotrope having a higher boiling point at a particular pressure than the pure components of the composition at that pressure and a lower vapor pressure at a particular temperature than the pure components of the composition at that temperature, and the lowest boiling point azeotrope having a lower boiling point at a particular pressure than the pure components of the composition at that pressure and a higher vapor pressure at a particular temperature than the pure components of the composition at that temperature. Boiling points and vapor pressures above or below the pure components are caused by unexpected intermolecular forces between the molecules of the composition, which can be a combination of repulsive and attractive forces such as van der Waals forces and hydrogen bonding.

[0064] It is recognized in the art that when an azeotropic liquid composition is subjected to boiling at various pressures, both the boiling point and the amount of each component of the azeotropic composition can change. Thus, an azeotropic composition can be defined in terms of the unique relationship that exists between the components, or in terms of the precise amounts of each component that result in a composition characterized by a constant boiling point at a particular pressure. Azeotropic or azeotrope-like compositions of two or more compounds can be characterized by defining the composition as characterized by its boiling point at a given pressure, thereby providing a distinguishing feature without unduly limiting the scope of the invention with specific numerical compositions, which are limited, but only as accurate, by available analytical equipment.

[0065] It is also recognized in the art that a system is defined as forming an azeotropic or near-azeotropic composition when the relative volatility of the system approaches 1.0. Relative volatility is the ratio of the volatility of a first component to the volatility of a second component. The ratio of the mole fraction of a component in the vapor to the mole fraction of the component in the liquid is the volatility of the component.

[0066] 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 cell 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," Wiley-Interscience Publishers, 1970, by Harold R. Null, pp. 124-126, which is incorporated herein by reference.

[0067] These measurements can be converted to equilibrium vapor and liquid compositions in the PTx cell to represent liquid-phase nonideal systems, for example, by using activity coefficient equation models such as the Non-Random, Two-Liquid (NRTL) equation. For example, the use of activity coefficient equations such as the NRTL equation is described in detail in "The Properties of Gases and Liquids," 4th Edition, McGraw Hill, by Reid, Prausnitz, and Poling, pp. 241-387, and "Phase Equilibria in Chemical Engineering," Butterworth Publishers, 1985, by Stanley M. Walas, pp. 165-244. Both of the above references are incorporated herein by reference. Without wishing to be bound by any theory or explanation, it is believed that the NRTL equation, in conjunction with PTx cell data, can satisfactorily predict the relative volatility of the HFO-1243zf- and HCFO-1242zf-containing compositions of the present disclosure at conditions other than those at which the measurements were made, and thus can predict the behavior of these mixtures in multistage separation equipment such as distillation columns. See, e.g., U.S. Pat. No. 8,486,293 and 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.

[0068] The conditions and compositions of the HF / HCFO-1242zf azeotropic mixtures according to the present invention, calculated as above, are provided in Table A below.

[0069] [Table 1]

[0070] Based on these findings, the present invention provides azeotropic or near-azeotropic compositions comprising, consisting of, or consisting essentially of from about 9.8 to about 70.6 mole percent HCFO-1242zf and from about 90.2 to about 29.4 mole percent HF.

[0071] In some embodiments, the present invention provides azeotropic or near-azeotropic compositions comprising, consisting of, or consisting essentially of from about 9.8 to about 70.6 mole percent HCFO-1242zf and from about 90.2 to about 29.4 mole percent HF, and having a boiling point of from about 30° C. at about 29.8 psia (205.5 kPa) to about −10° C. at about 6.5 psia (44.8 kPa).

[0072] As used herein, the term "azeotrope" is meant to refer to azeotrope compositions, azeotrope-like compositions, azeotropic and / or near-azeotrope compositions.

[0073] Process equipment for all processes disclosed herein, as well as associated supply lines, discharge lines, and related units, may be constructed from materials resistant to hydrogen fluoride. Typical materials of construction known in the art include stainless steel (especially austenitic) and well-known high-nickel alloys, such as Monel® nickel-copper alloy, Hastelloy® nickel-based alloy, and Inconel® nickel-chromium alloy.

[0074] Azeotropic distillation refers to a process operated under conditions that result in the formation of one or more azeotropic or azeotrope-like compositions, thereby facilitating the 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 azeotropic mixture with one or more of the components of the original mixture. Entrainers that act in this manner, i.e., that form an azeotropic mixture with one or more of the components of the mixture to be separated and thus facilitate the separation of those components by distillation, are more commonly referred to as azeotropic agents or azeotropic entrainers.

[0075] In conventional or azeotropic distillation, the overhead or distillate stream exiting the column can be condensed using a conventional reflux condenser. At least a portion of this condensed stream can be returned to the top of the column as reflux, and the remainder is recovered as product or for optional processing. The ratio of the condensed material returned to the top of the column as reflux to the material removed as distillate is commonly referred to as the reflux ratio. The compounds and entrainers exiting the column as distillate or distillation bottoms can then be passed to a stripper or second distillation column for separation using conventional distillation, or can be separated by other methods such as decantation. If desired, the entrainers can then be recycled back to the first distillation column for reuse. In some embodiments, the compositions and separation processes do not include, or are essentially free of, added entrainers.

[0076] The specific conditions that can be used to practice this invention depend on several parameters, including, among others, the diameter of the distillation column, the feed point, and the number of separation stages within the column. In some embodiments, the operating pressure of the distillation system can range from about 5 to about 500 psia (34 to 3450 kPa), and in other embodiments, from about 20 to about 400 psia (140 to 2760 kPa). Generally, increasing the reflux ratio increases the purity of the distillate stream, but reflux ratios generally range from about 1 / 1 to about 200 / 1. The temperature of the condenser located adjacent to the top of the column is typically sufficient to substantially completely condense the distillate exiting the top of the column, or as needed to achieve the desired reflux ratio by partial condensation.

[0077] As used herein, "essentially free" means that the composition contains less than about 100 ppm (on a molar basis), less than about 10 ppm, or less than about 1 ppm of the specified component. If the composition is essentially free of two or more components, the total concentration of those components is less than about 100 ppm, less than about 10 ppm, or less than about 1 ppm.

[0078] Hydrogen fluoride (HF, anhydrous) is a commercially available chemical or can be generated by methods known in the art.

[0079] "Molar excess of HF" means the amount of HF in excess of the amount necessary to form an azeotropic or near-azeotropic mixture with the organics (HFCs or HFOs) present in the composition. The molar amount of HF varies as a function of the organics present in the composition being separated and the separation conditions. A molar excess of HF for a given composition is the amount of HF that is greater than the amount of HF required to form an azeotropic mixture (or near-azeotropic mixture) with each organic compound in the composition.

[0080] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," 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 in such process, method, article, or apparatus. Furthermore, unless expressly stated to the contrary, "or" refers to an inclusive "or," not an exclusive "or." For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or absent), A is false (or absent) and B is true (or present), and both A and B are true (or present).

[0081] The transitional phrase "consisting of" excludes any unspecified element, step, or ingredient. In the context of a claim, such a phrase closes the claim to including materials other than those recited, except for impurities normally accompanying the materials. When the phrase "consists of" appears within a clause in the body of a claim rather than immediately following the introductory section, the phrase is limited to only the elements recited in that clause and does not exclude other elements from the claim as a whole.

[0082] The transitional phrase "consisting essentially of" is used to define compositions, methods, and compositions that include materials, steps, mechanisms, ingredients, or elements in addition to those literally disclosed, provided that these additionally included materials, steps, mechanisms, components, or elements do not materially affect the basic and novel characteristics of the claimed invention, particularly the mechanism of action for achieving any desired result of the inventive process. The term "consisting essentially of" occupies intermediate ground between "comprising" and "consisting of."

[0083] Additionally, the use of "a" or "an" is used to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be interpreted to include one or at least one, and the singular also includes the plural unless it is clear that a different meaning is intended.

[0084] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety, unless a specific passage is cited. In case of conflict, the present specification, including definitions, will control. Furthermore, the materials, methods, and examples are illustrative only and are not intended to be limiting.

[0085] Described herein is a process for separating HCFO-1242zf, HFO-1243zf, and HF from a composition comprising HCFO-1242zf, HFO-1243zf, and HF. The process includes subjecting the composition to a first distillation step to form a column (first) distillate composition capable of forming an azeotropic or near-azeotropic mixture composition of HCFO-1242zf / HF and HFO-1243zf / HF, and a column bottoms HF stream composition that is essentially free of HCFO-1242zf and HFO-1243zf. In this context, essentially free means less than about 1000 ppm, less than about 500 ppm, less than about 100 ppm, or less than about 10 ppm.

[0086] Described herein are azeotropic or 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).

[0087] Also described herein are compositions comprising HCFO-1242zf, HFO-1243zf, and HF to be separated.

[0088] In some embodiments, the composition comprising HCFO-1242zf, HFO-1243zf, and HF is a process stream.

[0089] In some embodiments, the composition being separated contains additional HCFO-1242zf or HF beyond the amount necessary to form an azeotrope or azeotrope-like composition.

[0090] In some embodiments, the separation process is part of a general process for producing 3,3,3-trifluoropropene (HFO-1243zf, CFCH=CH). In some embodiments, the production of HFO-1243zf can be part of a general process for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf; CFCF=CH). In some embodiments, the separation process separates a process stream that is a reaction product stream of a reaction process to produce HFO-1243zf. In some embodiments, the reaction process produces HFO-1243zf by the fluorination of 1,1,1,3-tetrachloropropane (HCC-250fb; CCl-CHCHCl).

[0091] HFO-1243zf can be made by the fluorination of HCC-250fb with HF over a fluorination catalyst such as a chromium fluoride / alumina or chromium oxide catalyst. HCC-250fb can be made by the addition reaction of carbon tetrachloride and ethylene by processes known in the art, such as those described in U.S. Pat. Nos. 4,605,802 and 5,705,779, the disclosures of each of which are incorporated herein by reference in their entireties.

[0092] The reaction product stream from the fluorination of HCC-250fb with HF may contain, in addition to excess HF and HFO-1243zf products, HCFO-1242zf and other intermediate products, such as 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-CH2C). HCl), 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), or combinations thereof.

[0093] HFO-1243zf is known to form a binary azeotropic composition with HF, as disclosed in International Application Publication No. 2009 / 105517, the disclosure of which is incorporated herein by reference in its entirety. The azeotropic composition comprises about 72.0 mol % HFO-1243zf and about 28.0 mol % HF at 29.8°C and 106.6 psia (735 kPa). Additionally, the azeotropic composition comprises about 76.2 mol % HFO-1243zf and about 23.8 mol % HF at 79.7°C and 363 psia (2503 kPa).

[0094] Surprisingly, it has been found that HCFO-1242zf also forms a binary azeotropic mixture with HF.

[0095] For purposes of this disclosure, an "effective amount" is defined as the amount of each component of the compositions of the present invention that, when combined, forms an azeotropic or azeotrope-like composition. This definition includes the amounts of each component, which may vary depending on the pressure applied to the composition, so long as the azeotropic or azeotrope-like composition continues to exist at different pressures (although the boiling points may differ). Thus, an effective amount includes the amount (which may be expressed, for example, by weight percent) of each component of the compositions of the present disclosure that forms an azeotropic or azeotrope-like composition at temperatures or pressures other than those described herein.

[0096] For the purposes of this disclosure, azeotropic compositions or constant boiling points are also intended to mean essentially azeotropic compositions or essentially constant boiling points. In other words, these terms include not only the true azeotropic mixtures described above, but also other compositions containing the same components in different proportions that are true azeotropic mixtures at other temperatures and pressures, as well as equivalent compositions that are part of the same azeotropic composition system and are azeotrope-like in their properties. As is well recognized in the art, there is a range of compositions containing the same components as azeotropes that not only exhibit essentially equivalent properties for refrigeration and other applications, but also essentially equivalent properties to true azeotropic compositions in terms of constant boiling point properties or tendency not to separate or fractionate upon boiling.

[0097] Depending on the conditions selected, it is possible to actually characterize a constant-boiling mixture, which can appear under many guises, by any of several criteria. A composition may be defined as an azeotropic mixture of A, B, C (and D, ...). This is because the very term "azeotropic mixture" is simultaneously definitive and restrictive, requiring effective amounts of A, B, C (and D, ...) for this unique composition to be a constant-boiling composition. It is well known to those skilled in the art that at different pressures, the composition of a given azeotropic mixture will vary, at least to some extent, and that changes in pressure will also change the boiling point temperature, at least to some extent. Thus, an azeotropic mixture of A, B, C (and D) exhibits a unique type of relationship, but with a composition that varies with temperature and / or pressure. Therefore, a range of compositions, rather than a fixed composition, is often used to define an azeotropic mixture. While a composition may be defined as a particular weight or mole percent relationship of A, B, C, and D, it is recognized that such specific values ​​represent only one particular relationship, and that in fact a series of such relationships represented by A, B, C (and D) actually exist for a given azeotropic mixture that varies with the influence of pressure. An azeotropic mixture of A, B, C (and D) may define the composition as an azeotrope characterized by its boiling point at a given pressure, thereby indicating a distinguishing feature without unduly limiting the scope of the invention with a specific numerical composition, which is limited by, and only as accurate as, available analytical equipment.

[0098] When two azeotropes exist, the composition can be defined as an azeotropic mixture of A, which is HFO-1243zf / HF, and B, which is HCFO-1242zf / HF, or vice versa, precisely because the term "azeotrope" is simultaneously definitive and restrictive, requiring effective amounts of A and B for this unique composition to be a constant-boiling composition. It is well known to those skilled in the art that at different pressures, the composition of a given azeotropic mixture will vary at least to some extent, and that changes in pressure will also change the boiling point temperature to at least some extent. Thus, an azeotropic mixture of A and B will exhibit a unique type of relationship, but with a composition that varies with temperature and / or pressure. Thus, a range of compositions, rather than a fixed composition, is often used to define an azeotrope. While a composition can be defined as a specific weight or mole percent relationship between A and B, it is recognized that such specific values ​​represent only one particular relationship, and that in reality, a series of such relationships, represented by A and B, actually exist for a given azeotropic mixture that varies with the influence of pressure. Azeotropic mixtures of A and B can be characterized by defining the composition as an azeotrope characterized by its boiling point at a given pressure, thereby providing a distinguishing feature without unduly limiting the scope of the invention with specific numerical compositions, which are limited by, and only as accurate as, available analytical equipment.

[0099] The azeotropic or azeotrope-like compositions of the present invention can be prepared by any convenient method, including mixing or combining the desired amounts. One preferred method is to weigh out the desired amounts of the components and then mix them in a suitable container. Another preferred method is to use the azeotropic or azeotrope-like composition as the distillate stream of a distillation column.

[0100] It has been discovered that some fluoroolefins form azeotropic compositions with HF. Generally, fluoroolefin / HF azeotropic mixture compositions boil at a lower temperature than the corresponding pure compounds. Some examples of such fluoroolefin / HF azeotropic mixtures are disclosed, for example, in International Publication No. 2009 / 105517, the disclosure of which is incorporated herein by reference in its entirety.

[0101] It was unexpected that HCFO-1242zf forms azeotropic or azeotrope-like compositions with HF, and it has been unexpectedly observed that in some cases, azeotropic compositions comprising fluoroolefins and HF can form two liquid phases when condensed and / or cooled. The two phases include a chlorofluoroolefin-rich phase and an HF-rich phase. This phase behavior enables unique separation schemes that utilize two-phase liquid-liquid separation (such as decantation) that are not possible with many saturated hydrofluorocarbons, which generally do not phase separate in the same manner.

[0102] In some embodiments, a process 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 process includes subjecting the process stream to distillation in a first distillation column under boiling conditions for HCFO-1242zf / HF and HFO-1243zf / HF azeotropic mixtures, using a molar excess of HF to produce both azeotropes. The process also includes forming a first distillate stream comprising an azeotropic or near-azeotropic composition of HCFO-1242zf / HF and HFO-1243zf / HF, and forming a first bottom stream of HF essentially free of HCFO-1242zf and HFO-1243zf from the first distillation column.

[0103] In some embodiments, the process of the above paragraph further comprises condensing, cooling, and decanting the first distillate stream to form an HF-rich stream, for example, an HCFO-1242zf / HF-rich stream.

[0104] In some embodiments, the process further comprises subjecting the HCFO-1242zf-HF-enriched stream to distillation in a second distillation column under boiling conditions for an HCFO-1242zf / HF and HFO-1243zf / HF azeotropic mixture, and forming a second distillate stream comprising an azeotropic or near-azeotropic mixture composition of HCFO-1242zf / HF and HFO-1243zf / HF, and a second bottom stream of HCFO-1242zf and HFO-1243zf essentially free of HF from the second distillation column.

[0105] In some embodiments, the process further comprises subjecting the second bottoms stream to a third distillation column to form an HCFO-1242zf stream that is essentially free of HFO-1243zf.

[0106] In some embodiments, the process further comprises combining the first distillate stream with the second distillate stream prior to decanting.

[0107] 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.

[0108] In some embodiments, the process comprises subjecting a process stream, such as that provided by the fluorination of HCC-250fb, to distillation in a first distillation column under boiling conditions for an HCFO-1242zf- and HFO-1243zf-HF azeotropic mixture. The process also comprises forming a first distillate stream comprising a molar excess of HF to provide an azeotropic or near-azeotropic composition of HCFO-1242zf and HF and HFO-1243zf and HF, and a first bottoms stream of HCFO-1242zf and HFO-1243zf essentially free of HF from the first distillation column. The process further comprises continuously condensing and decanting the distillate, while the first bottoms stream is essentially pure HF containing up to about 50 ppm HCFO-1242zf and trace amounts of HFO-1243zf, preferably less than about 1 ppm HCFO-1242zf.

[0109] In some embodiments, the HCFO-1242zf-enriched stream is formed by decanting an azeotropic or near-azeotropic composition of HCFO-1242zf, HFO-1243zf, and HF.

[0110] In some embodiments, a process for separating 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) from a process stream containing HCFO-1242zf, 3,3,3-trifluoropropene (HFO-1243zf), and a molar excess of hydrogen fluoride (HF) is provided. The process includes subjecting the HFO-1243zf process stream to distillation in a first distillation column under boiling conditions for an azeotropic mixture of HCFO-1242zf, HFO-1243zf, and HF. The process also includes forming a first distillate stream containing an azeotropic or near-azeotropic mixture composition of HCFO-1242zf / HF and HCFO-1243zf / HF and excess HF, and a first bottom stream of HF essentially free of HCFO-1242zf and HFO-1243zf from the first distillation column. The process further includes condensing, cooling, and decanting the first distillate stream to form an HF-enriched stream and an HCFO-1242zf-enriched stream. The process further includes subjecting the HCFO-1242zf-enriched stream to distillation in a second distillation column under boiling conditions for the HCFO-1242zf / HF and HFO-1243zf / HF azeotropic mixtures. The process further includes forming a second distillate stream 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 essentially free of HF from the second distillation column. The process also includes subjecting the second bottoms stream to a third distillation column using standard distillation techniques to form an HCFO-1242zf stream essentially free of HFO-1243zf.

[0111] 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 the fluorination of 1,1,1,3-tetrachloropropane (HCC-250fb) with HF, and optionally includes 1,1,1,3-tetrafluoropropane (HFC-254fb).

[0112] 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 to about 70.6 mole percent HCFO-1242zf and from about 90.2 to about 29.4 mole percent HF.

[0113] 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 to about 70.6 mole percent HCFO-1242zf and from about 90.2 to about 29.4 mole percent 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.

[0114] In some embodiments, the first distillate stream and the second distillate stream comprise about 38.0 mol % HCFO-1242zf and about 62.0 mol % HF and have a vapor pressure of about 25.9 psia at a temperature of about 20°C.

[0115] In some embodiments, an azeotropic or near-azeotropic composition is provided comprising 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf), 3,3,3-trifluoropropene (HFO-1243zf), and hydrogen fluoride (HF).

[0116] In some embodiments, an azeotropic or near-azeotropic composition comprising HCFO-1242zf and HF is provided.

[0117] In some embodiments, the azeotropic or near-azeotropic composition comprises from about 9.8 to about 70.6 mole percent HCFO-1242zf and from about 90.2 to about 29.4 mole percent HF.

[0118] In some embodiments, the azeotropic or near-azeotropic compositions comprise from about 9.8 to about 70.6 mole percent HCFO-1242zf and from about 90.2 to about 29.4 mole percent HF, and have 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.

[0119] In some embodiments, the azeotropic or near-azeotropic composition comprises about 38.0 mol % HCFO-1242zf and about 62.0 mol % HF and has a vapor pressure of about 25.9 psia at a temperature of about 20°C.

[0120] In some embodiments, the azeotropic or near-azeotropic composition further comprises 1,1,1,3-tetrafluoropropane (HFC-254fb).

[0121] 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 to about 70.6 mole percent HCFO-1242zf and from about 90.2 to about 29.4 mole percent HF.

[0122] 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 to about 70.6 mole percent HCFO-1242zf and from about 90.2 to about 29.4 mole percent HF, and has 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.

[0123] 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 mol % HCFO-1242zf and about 62.0 mol % HF and has a vapor pressure of about 25.9 psia at a temperature of about 20° C.

[0124] In some embodiments, the first and second distillation columns operate 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 bottoms temperature of about -30°C to about 220°C. In other embodiments, the pressure ranges from 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 bottoms temperature of about 0°C to about 150°C.

[0125] In separation processes described herein that include two or more distillation columns, the distillation columns may all operate at the same pressure and / or temperature, or at different pressures and / or temperatures.

[0126] When the composition being separated is a reaction product stream formed by the fluorination of HCC-250fb with HF, it is desirable to recycle any unreacted HCFO-1242zf back to the reactor so that it can be converted to HFO-1243zf. However, the HFO-1243zf needs to be removed from the unreacted HCFO-1242zf before being recycled so as not to inhibit the equilibrium reaction. It is also necessary to remove HF from the HFO-1243zf and HCFO-1242zf so that it can be used as a reagent in the fluorination reaction or another reaction, or as a refrigerant, or in other applications.

[0127] Other embodiments forming a first distillate stream comprising HFO-1243zf, HCFO-1242zf, and a molar excess of HF;

[0128] Forming a first distillate stream comprising HFO-1243zf, HCFO-1242zf, and sufficient HF to form an azeotropic or near-azeotropic mixture of HCFO-1242zf / HF and HFO-1243zf / HF.

[0129] The first distillate HFO-1243zf, HCFO-1242zf, and sufficient HF are condensed to form an azeotropic or near-azeotropic mixture of HCFO-1242zf / HF and HFO-1243zf / HF.

[0130] Recovering an azeotropic or near-azeotropic mixture of at least one of HCFO-1242zf / HF and HFO-1243zf / HF.

[0131] Generates a heterogeneous azeotropic mixture.

[0132] Heterogeneous azeotropic mixtures of HFO-1243zf / HF and HFO-1242zf / HF were formed.

[0133] The first distillate, containing HFO-1243zf, HCFO-1242zf, and sufficient HF, is condensed and decanted to recover HCFO-1242zf / HF and HFO-1243zf / HF azeotropic or near-azeotropic mixtures.

[0134] An HFO-1242zf-rich phase and an HCFO-1242zf-lean phase are formed, and the HFO-1242zf-rich phase is recycled.

[0135] An HF-rich phase containing HFO-1242zf / HF is formed and recycled to the first distillation column.

[0136] The distillation column is operated at a pressure greater than about 14.7 psig, preferably from about 14.7 psig to about 500 psig, and more preferably from about 30 psig to about 150 psig to form a first distillate comprising HFO-1243zf, HCFO-1242zf, and sufficient HF.

[0137] and operating a second distillation of the HCFO-1242zf-enriched stream under boiling conditions for the HCFO-1242zf and HFO-1243z azeotropic mixture to form a second distillate stream comprising an azeotropic or near-azeotropic composition of HCFO-1242zf, HFO-1243zf, and HF, and a second bottoms stream of HCFO-1242zf and HFO-1243zf essentially free of HF from the second distillation column.

[0138] The second bottoms stream of essentially HF-free HCFO-1242zf and HFO-1243zf is subjected to distillation in a third distillation column to form an HCFO-1242zf stream that is essentially HFO-1243zf-free.

[0139] A process in which a first distillate stream of HFO-1243zf, HCFO-1242zf, and sufficient HF is combined with a second distillate stream comprising an azeotropic or near-azeotropic composition of HCFO-1242zf, HFO-1243zf, and HF to form a heterogeneous azeotropic or near-azeotropic mixture upon condensation.

[0140] forming a first distillate stream and a second distillate stream comprising from about 9.8 to about 70.6 mole percent HCFO-1242zf and from about 90.2 to about 29.4 mole percent 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.

[0141] forming a first distillate stream comprising about 38.0 mol % HCFO-1242zf and about 62.0 mol % HF and a second distillate stream at a temperature of about 20° C. and a vapor pressure of about 25.9 psia;

[0142] 3-chloro-3,3-difluoro-1-propene (HCFO-1242zf) is separated from an HCFO-1242zf-rich stream containing HCFO-1242zf, 3,3,3-trifluoropropene (HFO-1243zf), and hydrogen fluoride (HF).

[0143] forming, obtaining, and recovering a first distillate stream comprising from about 9.8 to about 70.6 mole percent HCFO-1242zf and from about 90.2 to about 29.4 mole percent HF at a temperature of from about −10° C. to about 30° C. and a vapor pressure of from about 6.5 psia to about 29.8 psia;

[0144] forming, obtaining, and recovering a first distillate stream comprising about 38.0 mol % HCFO-1242zf and about 62.0 mol % HF at a temperature of about 20° C. and a vapor pressure of about 25.9 psia;

[0145] 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 and a vapor pressure of about 6.5 psia to about 29.8 psia, the composition comprising, consisting essentially of, or consisting of about 9.8 to about 70.6 mole percent HCFO-1242zf and about 90.2 to about 29.4 mole percent HF.

[0146] 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 composition comprising, consisting essentially of, or consisting of about 38.0 mol % HCFO-1242zf and about 62.0 mol % HF.

[0147] It will be understood by those skilled in the art that any of the foregoing embodiments may be combined with each other in any manner.

[0148] In the foregoing specification, the concepts of the present invention have been described with reference to specific embodiments. However, those skilled in the art will recognize that various modifications and changes can be made without departing from the scope of the present invention as set forth in the following claims. However, these benefits, advantages, solutions to problems, and any features that may give rise to or make more obvious any benefit, advantage, or solution are not to be construed as essential, necessary, or essential features in any or all of the claims.

[0149] Accordingly, the specification and figures are to 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. It should be noted that not all of the operations or examples described above in the general description are required, some of the specific operations may not be required, and one or more additional operations may be performed in addition to the operations described. Furthermore, the order in which the operations are listed is not necessarily the order in which they are performed.

[0150] It should be understood that certain features that are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Further, references to values ​​stated in ranges include each and every value within that range.

[0151] Numerous aspects and embodiments have been described above, and these are merely illustrative and not limiting. After reading this specification, skilled artisans will appreciate that other aspects and embodiments are possible without departing from the scope of the invention.

Claims

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

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

3. 3. The azeotropic or near-azeotropic composition of claim 1, wherein the azeotropic or near-azeotropic composition has 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.

4. 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 mol % HCFO-1242zf and about 62.0 mol % HF.

5. 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. 6. The azeotropic or near-azeotropic composition of 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 then 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 contains 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 trichloropropene (HCO-1240; C ３ H ３ Cl ３ 10. The composition of any one of claims 1 to 9, further comprising one or more additional ingredients selected from the group consisting of:

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

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

14. 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 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.

15. 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 mol % HCFO-1242zf and about 62.0 mol % HF.

16. 16. The composition of any one of claims 11 to 15, wherein the HCFO-1242zf and HF portions of the azeotropic or near-azeotropic composition have 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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