Azeotropic properties and azeotropic-like compositions of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and their uses.

Abstract

An azeotropic or azeotropic-like composition comprising an effective amount of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a). Methods for separating the azeotropic or azeotropic-like composition and / or utilizing the composition in extraction and pressure swing distillation are also disclosed in connection with a method for producing 1,1,2-trifluoroethane (HFC-143).

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 63 / 465,512, filed on May 10, 2023, entitled "AZEOTROPE AND AZEOTROPE - LIKE COMPOSITIONS OF 1,1,2 - TRICHLORO - 1,2,2 - TRIFLUOROETHANE (CFC - 113) AND 1,1,2 - TRIFLUOROETHANE (HFC - 143) AND APPLICATIONS THEREOF", and claims the priority of U.S. Patent Application No. 18 / 658,355, filed on May 8, 2024, both of which are hereby incorporated by reference in their entirety.

[0002] (Field of the Invention) The present disclosure relates to azeotropic and azeotrope - like compositions, particularly azeotropic and azeotrope - like compositions consisting essentially of 1 - chloro - 1,2 - difluoroethane (HCFC - 142a) and 1,1,2 - trichloro - 1,2,2 - trifluoroethane (CFC - 113), and to the uses or applications of these compositions.

Background Art

[0003] Fluorocarbon fluids have desirable properties for use as heat transfer media, immersion coolants, liquid or gaseous dielectrics, industrial refrigerants, and other applications.

[0004] For example, 1,2-difluoroethylene (HFO-1132) has recently been found to have increasing utility for a variety of uses. HFO-1132 may exist as a mixture of two geometric isomers (E or trans isomer and Z or cis isomer), which may be used separately or together in various proportions. Potential end uses of HFO-1132 include refrigerants used alone or in blends with other components, solvents for organic materials, and refrigerants as chemical intermediates in the synthesis of other halogenated hydrocarbon solvents. Improved methods for producing HFO-1132, particularly HFO-1132E, are desired.

[0005] Azeotropic and azeotropic-like compositions may be encountered during the production of fluorocarbon fluids, and understanding any such azeotropic or azeotropic-like composition can help improve the efficiency of the production process. [Overview of the Initiative]

[0006] This disclosure provides homogeneous azeotropic or azeotropic-like compositions with minimum boiling points, essentially comprising 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a), as well as uses or applications of these compositions.

[0007] In one embodiment, the present disclosure provides an azeotropic or azeotropic-like composition essentially consisting of effective amounts of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a).

[0008] In another form, the present disclosure provides a method for producing 1,1,2-trifluoroethane (HFC-143), comprising: hydrogenating 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) with hydrogen (H2) to form a product mixture comprising 1,1,2-trifluoroethane (HFC-143) and an effective amount of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113); and separating 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) to provide a product composition comprising 1,1,2-trifluoroethane (HFC-143). [Brief explanation of the drawing]

[0009] [Figure 1] This is a process flow diagram for separating 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a). [Figure 2] This graph shows the PTx measurement values ​​of azeotropic or azeotropic-like compositions of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) at an average temperature of 49.5°C. [Figure 3] This is a schematic diagram of an apparatus for separating azeotropic or azeotropic-like compositions of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) by pressure swing distillation. [Figure 4] This is a schematic diagram of an apparatus for separating azeotropic or azeotropic-like compositions of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) by extractive distillation. [Modes for carrying out the invention]

[0010] This disclosure provides homogeneous azeotropic or azeotropic-like compositions with minimum boiling points, essentially consisting of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113, also referred to herein as R113) and 1-chloro-1,2-difluoroethane (HCFC-142a, also referred to herein as R142a), as well as uses or applications of these compositions.

[0011] I. Description of azeotropic or azeotropic compositions An "azeotropic" composition is a specific combination of two or more components. Azeotropic compositions can be characterized in various ways. For example, at a given pressure, an azeotropic composition boils either at a constant characteristic temperature higher than the component with the higher boiling point (maximum boiling point azeotrope) or at a constant characteristic temperature lower than the component with the lower boiling point (minimum boiling point azeotrope). At this characteristic temperature, the same composition exists in both the gas and liquid phases. Azeotropic compositions do not separate during boiling or evaporation. Therefore, the components of an azeotropic composition cannot be separated during phase transition.

[0012] Azeotropic compositions are also characterized in that, at their characteristic azeotropic temperature, the boiling point pressure of the liquid phase (bubble point pressure) is the same as the dew point pressure of the vapor phase.

[0013] The behavior of azeotropic compositions is in contrast to that of non-azeotropic compositions, where the liquid composition changes to a considerable extent during boiling or evaporation.

[0014] For the purposes of this disclosure, an azeotropic composition is characterized as a composition that boils at a constant characteristic temperature lower than the boiling points of two or more components (a minimum boiling point azeotrope), thereby having the same composition in both the gas and liquid phases.

[0015] However, those skilled in the art will understand that at different pressures, both the composition and boiling point of an azeotropic composition will change to some extent. Therefore, depending on the temperature and / or pressure, an azeotropic composition may have a variable composition. Thus, those skilled in the art will understand that an azeotropic composition can be defined using a compositional range rather than a fixed composition. Furthermore, an azeotrope can also be defined in terms of the precise weight percentage of each component of a composition characterized by a fixed boiling point at a particular pressure.

[0016] An "azeotropic" composition is a composition of two or more components that behave substantially as an azeotropic composition. Therefore, for the purposes of this disclosure, an azeotropic composition is a combination of two or more different components that boil at substantially a constant temperature when in liquid form under a given pressure and provide a vapor composition substantially identical to that of the boiling liquid composition.

[0017] Azeotropic or azeotropic-like compositions can be identified using a number of different methods.

[0018] Static vapor-liquid equilibrium is a class of experimental techniques that can also be used to identify the presence of azeotropic and azeotropic-like compositions. One such technique known as the PTx method involves collecting measurements of the total saturation pressure ("P") exerted by a mixture of known composition ("x") at a fixed temperature ("T") and cell volume. (Walas, Phase Equilibria in Chemical Engineering, Butterworth-Heinemann, 1985, pp. 537). Using data collected from PTx experiments, as well as the pure component properties of the mixture's constituent elements, the thermodynamic properties of the mixture can be precisely characterized by fitting the interaction parameters of the components into clearly defined thermodynamic equations. One such equation is the non-random two-liquid (NRTL) activity coefficient model described by Renon and Prausnitz (Local Compositions in Thermodynamic Excess Functions for Liquid Mixtures, AIChE Journal, Vol.14, January 1968, pp.135-144).

[0019] The presence of azeotropes and their corresponding compositions can be observed by plotting saturation pressure measurements from PTx data and the saturation pressure described by NRTL as a function of composition. For a given temperature (isotherm), the presence of an azeotropic composition is identified by observing a maximum or minimum value at total pressure greater than or less than the pure saturation pressure of any single component.

[0020] As used herein, with respect to the components of an azeotropic or azeotrope-like composition or mixture, the term "consisting essentially of" means that the composition contains the indicated components in an azeotropic or azeotrope-like ratio and may contain additional components, provided that the additional components do not form a new azeotropic or azeotrope-like system. For example, an azeotropic mixture consisting essentially of two compounds forms a binary azeotrope and may optionally contain one or more additional components, provided that the additional components do not make the mixture non-azeotropic and do not form an azeotrope with either or both of the compounds (e.g., do not form azeotropes of three or more components).

[0021] As used herein, the term "about", when used in connection with the recited weight percentages of the components of the present composition, includes a deviation of ±0.3% from the recited weight percentage.

[0022] As used herein, the singular forms "a", "an", and "the" include the plural unless the context clearly dictates otherwise. Further, when an amount, concentration, or other value or parameter is given as a range, a preferred range, or an enumeration of upper preferred values and lower preferred values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or upper preferred value and any lower range limit or lower preferred value, whether or not the ranges are separately disclosed. When numerical ranges are recited herein, unless otherwise stated, the ranges are intended to include their endpoints, as well as all integers and fractions within the ranges. The scope of the present disclosure is not intended to be limited to the specific values recited when defining the ranges.

[0023] As noted above, in the case of an azeotrope, at the maximum or minimum boiling point, the composition of the vapor phase is the same as that of the liquid phase. Thus, an azeotrope-like composition is a composition of components that provides a substantially constant minimum or maximum boiling point, at which substantially constant boiling point, the composition of the vapor phase is substantially the same as that of the liquid phase.

[0024] II. Azeotropic or azeotrope-like compositions of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a), and uses thereof The present disclosure provides a homogeneous azeotropic or azeotrope-like composition having a minimum boiling point, comprising effective amounts of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a). In particular, the present disclosure provides a homogeneous azeotropic or azeotrope-like composition having a minimum boiling point, consisting essentially of effective amounts of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a). The present disclosure provides a homogeneous azeotropic or azeotrope-like composition having a minimum boiling point, consisting of effective amounts of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a).

[0025] The azeotropic or azeotrope-like composition may comprise from about 42.2 wt% to about 58.5 wt% of 1-chloro-1,2-difluoroethane (HCFC-142a) and from about 57.8 wt% to about 41.5 wt% of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) at a temperature of about 19.7 °C to about 80.0 °C and a pressure of about 8.9 to about 61.8 psia. The azeotropic or azeotrope-like composition may consist essentially of from about 42.2 wt% to about 58.5 wt% of 1-chloro-1,2-difluoroethane (HCFC-142a) and from about 57.8 wt% to about 41.5 wt% of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) at a temperature of about 19.7 °C to about 80.0 °C and a pressure of about 8.9 to about 61.8 psia. The azeotropic or azeotrope-like composition may consist of from about 42.2 wt% to about 58.5 wt% of 1-chloro-1,2-difluoroethane (HCFC-142a) and from about 57.8 wt% to about 41.5 wt% of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) at a temperature of about 19.7 °C to about 80.0 °C and a pressure of about 8.9 to about 61.8 psia.

[0026] The azeotropic or azeotropic composition, at a pressure of approximately 18.5 psia, consists of approximately 36.9% to 68.3% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a) and approximately 31.7% to 63.1% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), more specifically, approximately 41.6% to 52.1% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a) and approximately 47.9% to 58.4% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane. It may contain chloro-1,2-difluoroethane (HCFC-142a) in an amount of approximately 43.9% to 49.3% by weight and approximately 50.7% to 56.1% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and even more specifically approximately 46.5% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a) and approximately 53.5% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113).

[0027] The azeotropic or azeotropic composition, at a pressure of about 18.5 psia, consists of about 36.9% to 68.3% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a) and about 31.7% to 63.1% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), more specifically, about 41.6% to 52.1% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a) and about 47.9% to 58.4% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane. It can essentially consist of ethane (CFC-113), more specifically, about 43.9% to 49.3% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a) and about 50.7% to 56.1% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and even more specifically, about 46.5% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a) and about 53.5% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113).

[0028] The azeotropic or azeotropic composition, at a pressure of approximately 18.5 psia, consists of approximately 36.9% to 68.3% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a) and approximately 31.7% to 63.1% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), more specifically, approximately 41.6% to 52.1% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a) and approximately 47.9% to 58.4% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane. It may consist of oleethane (CFC-113), more specifically, about 43.9% to 49.3% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a) and about 50.7% to 56.1% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and even more specifically, about 46.5% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a) and about 53.5% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113).

[0029] In other words, the composition, at a pressure of about 18.5 psia, is based on the total weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) in an azeotropic or azeotropic composition, in a large amount of about 63.1% by weight, or about 58.4% by weight, or about 56.1% by weight, or about 53.5% by weight, or about 31.7% by weight. It may contain 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) in amounts of approximately 47.9% by weight, or about 50.7% by weight, or in amounts of any two of the above-mentioned endpoints, for example, about 31.7% to about 63.1% by weight, about 47.9% to about 58.4% by weight, about 50.7% to about 56.1% by weight, and / or about 53.5% by weight.

[0030] In other words, the composition, at a pressure of about 18.5 psia, is based on the total weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) in an azeotropic or azeotropic composition, in a large amount of about 63.1% by weight, or about 58.4% by weight, or about 56.1% by weight, or about 53.5% by weight, or about 31.7% by weight. It may essentially consist of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) in amounts of approximately 47.9% by weight, or less, or in amounts of any two of the above values ​​as endpoints, for example, approximately 31.7% to approximately 63.1% by weight, approximately 47.9% to approximately 58.4% by weight, approximately 50.7% to approximately 56.1% by weight, and / or approximately 53.5% by weight.

[0031] In other words, the composition, at a pressure of about 18.5 psia, is based on the total weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) in an azeotropic or azeotropic composition, in a large amount of about 63.1% by weight, or about 58.4% by weight, or about 56.1% by weight, or about 53.5% by weight, or about 31.7% by weight. It may consist of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) in amounts of % by weight, or less than about 47.9% by weight, or about 50.7% by weight, or any two of the above values ​​as endpoints, for example, about 31.7% by weight to about 63.1% by weight, about 47.9% by weight to about 58.4% by weight, about 50.7% by weight to about 56.1% by weight, and / or about 53.5% by weight.

[0032] In other words, the composition may contain 1-chloro-1,2-difluoroethane (HCFC-142a) in amounts of about 68.3% by weight, or about 52.1% by weight, or about 49.3% by weight, or about 46.5% by weight, based on the total weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) of an azeotropic or azeotropic composition, in large amounts of about 68.3% by weight, or about 52.1% by weight, or about 49.3% by weight, or about 46.5% by weight, or in small amounts of about 36.9% by weight, or about 41.6% by weight, or about 43.9% by weight, or any two of the above values ​​as endpoints, for example, about 36.9% by weight to about 68.3% by weight, about 41.6% by weight to about 52.1% by weight, about 43.9% by weight to about 49.3% by weight, and / or about 46.5% by weight.

[0033] In other words, the composition may consist essentially of 1-chloro-1,2-difluoroethane (HCFC-142a) in amounts of about 68.3% by weight, or about 52.1% by weight, or about 49.3% by weight, or about 46.5% by weight, or in amounts of about 36.9% by weight, or about 41.6% by weight, or about 43.9% by weight, or in amounts of any two of the above values ​​as endpoints, for example, about 36.9% by weight to about 68.3% by weight, about 41.6% by weight to about 52.1% by weight, about 43.9% by weight to about 49.3% by weight, and / or about 46.5% by weight.

[0034] In other words, the composition may consist of 1-chloro-1,2-difluoroethane (HCFC-142a) in amounts of about 68.3% by weight, or about 52.1% by weight, or about 49.3% by weight, or about 46.5% by weight, based on the total weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) of an azeotropic or azeotropic composition, in large amounts of about 68.3% by weight, or about 52.1% by weight, or about 49.3% by weight, or about 46.5% by weight, or in small amounts of about 36.9% by weight, or about 41.6% by weight, or about 43.9% by weight, or any two of the above values ​​as endpoints, for example, about 36.9% by weight to about 68.3% by weight, about 41.6% by weight to about 52.1% by weight, about 43.9% by weight to about 49.3% by weight, and / or about 46.5% by weight.

[0035] The composition may have azeotropic or azeotropic-like properties at temperatures within any range encompassed by any two of the aforementioned endpoints, such as approximately 19.7°C, approximately 29.6°C, approximately 39.3°C, approximately 49.5°C, approximately 59.2°C, approximately 69.8°C, and / or approximately 80.0°C, or approximately 19.7°C to approximately 80.0°C.

[0036] The composition may have azeotropic or azeotropic-like properties at pressures of about 8.9 psia, about 13.1 psia, about 18.5 psia, about 25.9 psia, about 35.0 psia, 47.3 psia, and / or about 61.8 psia, or at any range of pressures encompassed by any two of the aforementioned values ​​as endpoints, such as about 8.9 psia to about 61.8 psia.

[0037] Specifically, as shown in Table 1 below, the azeotropic or azeotropic-like compositions of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) can correlate with pressure (psia) and saturation temperature.

[0038] In column (i) of Table 1 below, temperature glide is the difference between the saturated vapor temperature and the saturated liquid temperature at a fixed pressure in thermodynamic equilibrium. Therefore, azeotropic compositions have a temperature glide of zero, and azeotropic-like compositions may have a temperature glide that is substantially close to zero. A temperature glide of less than 0.5°C is substantially close to zero, and therefore compositions that satisfy such a temperature glide are identified as azeotropic-like. Using this method, the relative compositions in column (i) of Table 1 below, which can be considered to represent the broadest azeotropic-like composition range, were determined.

[0039] In column (ii) of Table 1 below, relative volatility is defined as the ratio of the vapor composition to the liquid composition of the most volatile component at a fixed pressure in thermodynamic equilibrium, compared to the ratio of the vapor composition to the liquid composition of the less volatile component. Therefore, azeotropic compositions have a relative volatility of 1.0, and azeotropic-like compositions have a relative volatility substantially close to 1.0. A relative volatility of 1.1 is substantially close to 1.0, and therefore, compositions satisfying such a relative volatility were identified as azeotropic-like. Using this method, the relative compositions in column (ii) of Table 1 below, which can be considered to be in the intermediate azeotropic-like composition range, were determined.

[0040] In column (iii) of Table 1 below, a relative volatility of 1.05 is substantially close to 1.0, and therefore, compositions satisfying such relative volatility are considered azeotropic. This can be considered the narrowest range of azeotropic compositions.

[0041] Column (1) of Table 1 below lists azeotropic compositions (minimal boiling point azeotropes) that, at a given pressure, boil at a specific characteristic temperature lower than that of components with lower boiling points. At this characteristic temperature, the same composition exists in both the gas and liquid phases. Therefore, the components of the azeotropic composition cannot be separated during the phase change and are considered an azeotropic composition. Such compositional values ​​are shown in Column (1) of Table 1 below, corresponding to each pressure and saturation temperature.

[0042] Therefore, and from the above viewpoint, azeotropic or azeotropic-like compositions of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) may contain any of the values ​​listed in each of the columns (1), (i), (ii), or (iii) of each row in Table 1 below.

[0043] In another embodiment, azeotropic or azeotropic-like compositions of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) may essentially consist of any of the values ​​listed in each of the columns (1), (i), (ii), or (iii) of each row in Table 1 below.

[0044] In further embodiments, azeotropic or azeotropic-like compositions of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) may consist of any of the values ​​listed in each of the columns (1), (i), (ii), or (iii) in each row of Table 1 below.

[0045] [Table 1]

[0046] III. Formation of E-1,2-difluoroethylene (HFO-1132E) It has been found that azeotropic or azeotropic-like compositions of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) may be formed during the production of E-1,2-difluoroethylene (HFO-1132E) or otherwise encountered.

[0047] In particular, azeotropic or azeotropic-like compositions of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) may be formed in or otherwise encountered in a method for producing E-1,2-difluoroethylene (HFO-1132E) from 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) according to the following three-step scheme or process ("Scheme 1").

[0048] Scheme 1 comprises the following three steps: (i) hydrogenating 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) to produce 1,1,2-trifluoroethane (HFC-143); (ii) dehydrofluorinating 1,1,2-trifluoroethane (HFC-143) to produce a mixture of trans-1,2-difluoroethylene (HFO-1132E) and cis-1,2-difluoroethylene (HFO-1132Z); and (iii) isomerizing cis-1,2-difluoroethylene (HFO-1132Z) to trans-1,2-difluoroethylene (HFO-1132E).

[0049] The following are schematic formulas for the three steps of Scheme 1. Scheme 1 (i)CFCl2-CF2Cl(CFC-113)+H2→CFH2-CF2H(HFC-143)+HCl (ii) CFH2 - CF2H → Trans-CFH = CHF(HFO-1132E) + Cis-CFH = CFH(HFO-1132Z) + HF (iii) cis-CFH=CFH(HFO-1132Z) → trans-CFH=CHF(HFO-1132E)

[0050] Step (i) may proceed via a 1,1,2-trifluoroethene intermediate, in which 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) is first hydrogenated to produce 1,1,2-trifluoroethene as an intermediate, and then this intermediate itself is hydrogenated to produce 1,1,2-trifluoroethane (HFC-143).

[0051] An azeotropic or azeotropic-like composition of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) is formed in step (i) of Scheme 1 above. Here, 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) is considered a desirable intermediate, and the separation of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and subsequent recirculation into the hydrogenation process of step (i) can improve the overall recovery of the 1,1,2-trifluoroethane (HFC-143) product. Specifically, by recirculating the desired intermediate, the reaction in step (i) proceeds to its final completion, converting the desired intermediate into the 1,1,2-trifluoroethane (HFC-143) product. 1-chloro-1,2-difluoroethane (HCFC-142a), another component in the azeotropic or azeotropic-like composition, is considered an undesirable by-product, and the separation and removal of 1-chloro-1,2-difluoroethane (HCFC-142a) as a by-product can increase the overall recovery rate of the 1,1,2-trifluoroethane (HFC-143) product. Therefore, it may be important to use or utilize such azeotropic or azeotropic-like compositions of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) to improve the operation of Scheme 1 and produce E-1,2-difluoroethylene (HFO-1132E) in the desired amount or purity. For example, by separating the azeotropic or azeotropic composition of (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), 1-chloro-1,2-difluoroethane (HCFC-142a) can be substantially removed from 1,1,2-trifluoroethane (HFC-143), and by recirculating 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) into the hydrogenation process of step (i), the recovery purity of 1,1,2-trifluoroethane (HFC-143) can be increased.

[0052] The separation step may include transporting the product mixture to a first column having a first pressure, collecting a first bottom product from the first column, and transporting the first distillate from the first column to a second column having a second pressure to provide a second distillate and a second bottom product, wherein the second distillate contains an azeotropic or azeotropic composition. The pressure of the first column may be lower than the pressure of the second column, in which case the first bottom product essentially consists of 1-chloro-1,2-difluoroethane (HCFC-142a) and the second bottom product essentially consists of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113). Alternatively, the pressure in the first column may be higher than the pressure in the second column, in which case the bottom product of the first column will essentially consist of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and the bottom product of the second column will essentially consist of 1-chloro-1,2-difluoroethane (HCFC-142a). The separation step may include an additional step of recycling the second distillate back into the first column.

[0053] Alternatively, the separation step may include transporting the product mixture and the adjunct fluid to a first column; collecting a first distillate from the first column containing a first component of the azeotropic or azeotropic-like composition; collecting a first bottom product from the first column containing a mixture of the adjunct and a second component of the azeotropic or azeotropic-like composition; transporting the first bottom product to a second column to separate the adjunct from the second component of the azeotropic or azeotropic-like composition; and removing a composition essentially consisting of the second component of the azeotropic or azeotropic-like composition from the second column as a second distillate. The first component of the azeotropic or azeotropic-like composition may consist of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and the second component of the azeotropic or azeotropic-like composition may consist of 1-chloro-1,2-difluoroethane (HCFC-142a). Alternatively, the first component of the azeotropic or azeotropic-like composition may consist of 1-chloro-1,2-difluoroethane (HCFC-142a), and the second component of the azeotropic or azeotropic-like composition may consist of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113). The separation step may include an additional step of recirculating the second column bottom product, which is essentially composed of the adjuvant, from the second column to the first column.

[0054] For example, as shown in Figure 1, the inlet flow 110 to process 100 containing at least the reactant from step (i): CFCl2-CF2Cl(CFC-113)+H2 can be mixed with a recirculating flow 116, which will be described in more detail herein, to form a reagent flow 112. Generally, the recirculating flow 116 may contain the desired intermediate 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113). After mixing, the reagent flow 112 can be sent to the first unit operation 105.

[0055] The first unit operation 105 may be a hydrogenation reactor, in which step (i) of scheme 1 is carried out. Here, the first unit operation 105 may be a tubular reactor made of a temperature-resistant and / or corrosion-resistant material such as nickel and its alloys, including Hastelloy (e.g., Hastelloy C276), Inconel (e.g., Inconel 600), Incoloy, and Monel, and the vessel may be lined with a fluoropolymer. The hydrogenation reaction of step (i) may be carried out in the gas phase or vapor phase, and the reactor may be first cleaned by flowing an inert gas such as nitrogen, followed by loading with a catalyst. The catalyst may contain metals such as palladium, platinum, rhodium, ruthenium, iron, cobalt, or nickel. More specifically, the catalyst may contain palladium metal, platinum metal, or a combination of palladium metal and platinum metal. The catalyst may be supported on a suitable carrier such as carbon or alumina. For example, the catalyst may be palladium on a carbon support, platinum on a carbon support, and / or palladium or platinum on an alumina support.

[0056] The reagent stream 112 flows through the catalyst bed in the first unit operation 105 (for example, either upward or downward) and undergoes the hydrogenation reaction of step (i) of scheme 1. Here, the reaction temperature may be as low as about 100°C, about 125°C, about 150°C, about 200°C, about 250°C, or as high as about 300°C, about 350°C, about 400°C, or within any range encompassed by any two of the aforementioned values ​​as endpoints, such as about 100°C to about 250°C, or about 150°C to about 200°C. The temperature may preferably be about 100°C to about 350°C, more preferably about 200°C to about 300°C. The contact time between the reactant and the catalyst may be as short as about 0.1 seconds, about 1 second, about 5 seconds, about 10 seconds, about 15 seconds, or about 20 seconds, or as long as about 25 seconds, about 30 seconds, about 40 seconds, about 50 seconds, about 60 seconds, or about 120 seconds, and may be within any approximate range or range encompassed by the two aforementioned values ​​as endpoints. For example, the contact time may preferably be from about 1 second to about 120 seconds. The pressure may be as low as about 1 psig, about 3 psig, about 5 psig, about 10 psig, about 15 psig, about 20 psig, about 30 psig, about 35 psig, or about 40 psig, or may be as high as about 90 psig, about 100 psig, about 120 psig, about 150 psig, about 200 psig, or about 250 psig, or about 300 psig, or may be within any range encompassed by the two aforementioned values ​​as endpoints. For example, the pressure may preferably be about 10 psig to about 300 psig.

[0057] After the reaction, the reagent stream 112 forms a product stream 114 containing one or a combination of HCl, 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), 1,1,2-trifluoroethane (HFC-143), and 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and azeotropic or azeotropic-like compositions. As described above, 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) may be considered a desirable intermediate. Therefore, the separation of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) from 1,1,2-trifluoroethane (HFC-143) and the subsequent recirculation of 1,2-trichloro-1,2,2-trifluoroethane (CFC-113) into the reagent stream 112 may be desirable to improve the recovery of 1,1,2-trifluoroethane (HFC-143) and lead to improved production of E-1,2-difluoroethylene (HFO-1132E).

[0058] Specifically, upon exiting the first unit operation 105, the product stream 114 may enter the second unit operation 107. The second unit operation 107 may separate the components of the azeotropic or azeotropic composition of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) from each other by means of, for example, pressure swing distillation, extractive distillation, permeation vaporization, adsorption, such as pressure swing adsorption, membrane separation, etc. Pressure swing distillation is described in more detail specifically in Section IV, and extractive distillation is described in more detail specifically in Section V, both of which are provided herein.

[0059] After separation, HCl and 1,1,2-trifluoroethane (HFC-143) are recovered in recovery stream 118, and the desired intermediate of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) is recycled back to process 100 as recirculation stream 116. Undesirable by-product 1-chloro-1,2-difluoroethane (HCFC-142a) is recovered in recovery stream 120. The amount or purity of 1,1,2-trifluoroethane (HFC-143) in recovery stream 118 may be, for example, greater than 90 mol%, greater than 95 mol%, greater than 97 mol%, greater than 99 mol%, or greater than 99.5 mol%, based on the total number of moles of organic components in the composition. The amount of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) in the recovered stream 118 may be less than 5000 ppm, less than 3000 ppm, less than 2000 ppm, less than 1000 ppm, less than 500 ppm, or less than 250 ppm, for example, based on the total number of moles of organic components in the composition. The amount of 1-chloro-1,2-difluoroethane (HCFC-142a) in the recovered stream 118 may be less than 5000 ppm, less than 3000 ppm, less than 2000 ppm, less than 1000 ppm, less than 500 ppm, or less than 250 ppm, for example, based on the total number of moles of organic components in the composition.

[0060] As described above, the recirculating stream 116, containing substantially all of the 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), can be mixed with the inlet stream 110 when forming the reagent stream 112. Here, the separated and recirculated 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) may be added along with the components of the inlet stream 110 to reduce the amount of replenishment 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) required for the reaction process, and thus improve the operation of Scheme 1. Although not shown, the recovery stream 118 may then be sent to further unit operations to separate HCl from 1,1,2-trifluoroethane (HFC-143), and the unit operations may be one or a combination thereof, such as an absorption unit, an adsorption unit, a membrane separator, a cryogenic separator, a subsequent chemical reactor, or a distillation unit. After removing HCl from 1,1,2-trifluoroethane (HFC-143), 1,1,2-trifluoroethane (HFC-143) may be used as the reactant in step (ii).

[0061] IV. Separation of azeotropic and azeotropic-like compositions of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) by pressure swing distillation The disclosure also provides a method for separating azeotropic and azeotropic-like compositions of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) by pressure swing distillation, as discussed below and in Example 3.

[0062] In the first step, a mixture of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) is transported to a first low-pressure column having a first pressure to obtain a first distillate and a first bottom product. The first bottom product is a concentrated stream of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) collected from the bottom of the low-pressure column. The first distillate is an azeotropic or azeotropic-like composition of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a), which is collected from the top of the low-pressure column and transported to the second high-pressure column to obtain the second distillate from the top of the high-pressure column and the second bottom product from the bottom of the high-pressure column. The second bottom product is a concentrated stream of 1-chloro-1,2-difluoroethane (HCFC-142a), which is collected from the high-pressure column. The 1.2 distillate contains an azeotropic or azeotropic-like composition essentially consisting of an effective amount of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a), which may be recirculated and returned to the low-pressure column.

[0063] The above process may be modified to reverse the order of the low-pressure and high-pressure columns, in which case the high-pressure column is the second column and the low-pressure column is the -1.2 column. When modified in this way, the bottom product of the first column is a concentrated stream of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and the bottom stream of the second column is a concentrated stream of 1-chloro-1,2-difluoroethane (HCFC-142a).

[0064] A schematic diagram of an exemplary separation apparatus is shown in Figure 3. Referring to this figure, a mixture of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) is fed to a first low-pressure column 12 as feed stream 10. The low-pressure column 12 yields a first distillate stream 14 which is an azeotropic or azeotropic-like composition of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a), and a first bottom product 16 which may be concentrated with HCFC-142a or may essentially consist of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113). The first distillate flow 14 is then transported to the high-pressure column 18 to obtain a second distillate flow 22, which is an azeotropic or azeotropic-like composition of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a), and a second bottom product 20. The second bottom product 20 is either concentrated with 1-chloro-1,2-difluoroethane (HCFC-142a) or essentially consists of 1-chloro-1,2-difluoroethane (HCFC-142a). The second distillate flow 22 may optionally be returned to the feed flow 10 and thereby recirculated to the low-pressure column 12.

[0065] According to this method, if an azeotropic or azeotropic-like composition of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) is formed during the production of E-1,2-dichloroethane (HFO-1132E) according to scheme 1, for example, then the azeotropic or azeotropic-like composition of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) can be used to produce a desired intermediate product and / or a desired final product, for example. After separation from E-1,2-dichloroethane (HFO-1132E), the azeotropic or azeotropic-like composition of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) can be separated into its constituent components, 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a), which can then be recycled back to the appropriate location in the manufacturing process.

[0066] V. Separation of azeotropic and azeotropic-like compositions of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) by extractive distillation. This disclosure provides a method for separating azeotropic and azeotropic-like compositions of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) by extractive distillation, as discussed below and in Example 4. A schematic diagram of an exemplary separation apparatus is shown in Figure 4.

[0067] In the first step, a product stream 24 (which may be the same as product stream 114, see Figure 1) containing at least an azeotropic or azeotropic-like composition of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) is transported to an extraction column 26 together with an adsorbent fluid 28. The adsorbent fluid 28 is a composition in which one of the components of the azeotropic or azeotropic-like composition of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) has a higher affinity for the adsorbent fluid compared to the other component. Here, one of the components of the azeotropic or azeotropic-like composition dissolves more readily in the adsorbent fluid 28 than the other component. Therefore, the azeotropic or azeotropic-like composition may be separated into its individual components based on the difference in affinity / solubility using the azeotropic fluid 28, and thus, each component of the azeotropic or azeotropic-like composition may be selectively separated using this method. For example, the conjugate fluid 28 may have a higher affinity for 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and can act as a selective solute for 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) in the azeotropic or azeotropic-like composition. In another example, the conjugate fluid 28 may have a higher affinity for 1-chloro-1,2-difluoroethane (HCFC-142a) and can act as a selective solute for 1-chloro-1,2-difluoroethane (HCFC-142a) in the azeotropic or azeotropic-like composition.

[0068] The extraction column 26 is operated with operating parameters (temperature and pressure) such that the mixture of the first / dissolved component of the azeotropic or azeotropic-like composition and the accompanying fluid 28 is separated from the second component of the azeotropic or azeotropic-like composition. For example, if the accompanying fluid 28 has a higher affinity for 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and the accompanying fluid 28 are recovered in the bottom product 34 from the extraction column 26, while concentrated 1-chloro-1,2-difluoroethane (HCFC-142a) is recovered as distillate 30. In another example, if the conjugate fluid 28 has a higher affinity for 1-chloro-1,2-difluoroethane (HCFC-142a), 1-chloro-1,2-difluoroethane (HCFC-142a) and the conjugate fluid 28 are recovered in the bottom product 34, and the concentrated 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) is recovered as distillate 30.

[0069] In the second step, the bottom product 34, which contains each of the dissolved first component of the azeotropic or azeotropic-like composition and the mixture with the conjugate fluid, is transported to the recovery column 32. The recovery column 32 is operated with operating parameters (temperature and pressure) such that the conjugate fluid and the dissolved component of the azeotropic or azeotropic-like composition are separated from each other, where the concentrated conjugate fluid is recovered from the extraction column 32 as the bottom product 36, and either the concentrated 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) or 1-chloro-1,2-difluoroethane (HCFC-142a)) is recovered as the distillate 38. The recovered concentrated conjugate fluid can be recycled as described above and used as the conjugate fluid 28 in the extraction column 26. [Examples]

[0070] Example 1: Measurement and characterization of azeotropic properties and azeotropic-like compositions of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) The azeotropic properties and azeotropic-like compositions of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a) were measured using a set of volume-calibrated PTx cells. Mixtures of CFC-113 and HCFC-142a were prepared by gravimetric analysis in an evacuated PTx cell, and two cells were retained to measure each pure component. After preparation, each of up to eight cells with different compositions was inserted into a constant temperature chamber. Within the chamber, each cell was mounted on an instrumentation manifold equipped with a calibrated pressure transducer and a resistance temperature detector (RTD), providing a means to measure and record the total saturation pressure of the contents of each cell at its local temperature.

[0071] To establish equilibrium at the target temperature, the chamber setpoint is adjusted to maintain an average temperature of 49.5°C (T) across all PTx cells. avg The following was obtained. Once each cell reached an equilibrium where its temperature and pressure remained stable for several hours, the local temperature and saturation pressure of each cell were recorded. From these pressure-temperature-composition data, the binary interaction parameters of CFC-113 and HCFC-142a for a non-random two-liquid (NRTL) activity coefficient model were identified. Based on the data shown in Table 2, an azeotropic composition of approximately 51.0 wt% CFC-113 and approximately 49.0 wt% HCFC-142a with a minimum boiling point was formed, as indicated by the maximum pressure shown in Figure 2.

[0072] [Table 2]

[0073] Example 2 - Azeotropic locus The procedure of Example 1 was repeated for each of the temperatures shown in Table 3 below to generate azeotropes and azeotrope-like composition ranges.

[0074] Table 3 below contains azeotropic and azeotropic-like compositions of HCFC-142a and CFC-113.

[0075] [Table 3]

[0076] Based on the above data, temperature glide and relative volatility were applied to determine azeotropic properties and azeotropic-like compositions.

[0077] The thermal glide and relative volatility of a mixture can be derived from thermodynamic measurements, such as those collected via PTx, according to the mass balance and thermodynamic constraints. Several methods for deriving thermal glide from thermodynamic measurements are described in Sandler, SI (2006). Chapter 10: Vapor-Liquid Equilibrium in Mixtures. In Chemical, Biochemical, and Engineering Thermodynamics (4th ed., pp. 489-574), and include constraining thermodynamic consistency by the basic Gibbs-Duhem relation, as well as elucidating the vapor phase composition from the measurements by a combination of mass balance and equilibrium criteria (often called the Rachford-Rice equation or algorithm). This derivation confirms the relationship between equilibrium composition, temperature, and pressure, making it possible to evaluate thermal glide and relative volatility.

[0078] For a given composition, thermal glide is, by definition, the difference between the saturated vapor temperature and the saturated liquid temperature at a fixed pressure in thermodynamic equilibrium. Therefore, azeotropic compositions have a thermal glide of zero, and azeotropic-like compositions have a thermal glide that is substantially close to zero. A thermal glide of less than 0.5°C is substantially close to zero, and therefore, compositions satisfying such a thermal glide are considered azeotropic-like. This represents a broad azeotropic-like range.

[0079] Relative volatility, by definition, is the ratio of the vapor-to-liquid composition of the most volatile component to the vapor-to-liquid composition of the less volatile component at a fixed pressure in thermodynamic equilibrium. Therefore, azeotropic compositions have a relative volatility of 1.0, and azeotropic-like compositions have a relative volatility substantially close to 1.0. A relative volatility of 1.1 is substantially close to 1.0, and therefore compositions satisfying such a relative volatility are identified as azeotropic-like. This represents an intermediate azeotropic-like range.

[0080] Furthermore, a relative volatility of 1.05 is substantially close to 1.0, and therefore, compositions satisfying such relative volatility were identified as azeotropic. This represents a narrow azeotropic range.

[0081] Example 3 - Pressure Swing Separation A well-known consequence of azeotropic mixtures is that their components cannot be completely separated in a single, continuous distillation operation. For example, the separation of a 30 / 70% by mass mixture of 1-chloro-1,2-difluoroethane (HFCF-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) by a continuous distillation column held at 25.9 psia, exhibiting azeotropic behavior as described in Example 1, would be constrained by the composition between the HCFC-142a endpoint and the azeotropic composition, making it impossible to produce CFC-113 of a purity higher than 51.0% by weight. To overcome this fundamental barrier of azeotropes and achieve both purer HCFC-142a and HCFC-113, different separation strategies must be implemented.

[0082] As described in Example 2, the azeotropic compositions of HCFC-142a and CFC-113 are pressure-sensitive. This sensitivity can be utilized to support better separation by pressure swing distillation. In this system, the pressure-sensitive azeotrope is separated using two distillation columns in sequence, one at any relatively low pressure and the other at any relatively high pressure. The columns may be arranged so that the low-pressure column is first in sequence, or the high-pressure column may be first in sequence. For the purposes of this example, referring to Figure 3, the columns are arranged so that the low-pressure column is first in sequence.

[0083] A mixture of HCFC-142a and CFC-113 is first distilled at low pressure. The specific composition of the mixture may be adjusted as needed. For the purposes of this representative example, a mixture containing 42% by mass of HCFC-142a and 58% by mass of CFC-113 is used. Referring to Figure 3, this mixture (flow 10) is fed into the distillation column 12 at any low pressure.

[0084] The feed composition in flow 10 has not yet reached its azeotropic point with respect to the column pressure. Therefore, the mixture may separate into one component of the mixture and a fraction concentrated in the azeotropic or azeotropic-like composition. Here, the fraction concentrated with the high-boiling-point component CFC-113 is collected as the bottom product, shown as flow 16 in Figure 3. The azeotropic or azeotropic-like composition is the distillate from the low-pressure column 12 shown in Figure 3. This mixture is then passed to column 18 at an arbitrary high pressure, following flow 14 in Figure 3.

[0085] When the composition of flow 14 is brought to the high pressure of column 18, its composition relative to the high-pressure azeotropic composition is lower at this point. This allows for the collection of a fraction in which the other components of the mixture are concentrated. In this embodiment, the fraction in which HFCF-142a is concentrated is collected as the bottom product shown as flow 20 in Figure 3. Similar to the low-pressure column, the distillate contains an azeotropic mixture or an azeotropic-like mixture. This mixture may be recirculated and mixed with the low-pressure column feed following flow 22 in Figure 3.

[0086] In this way, the azeotrope barrier is addressed using the composition's sensitivity to column conditions, producing two streams in which one of the components is concentrated. It is important to note that the details of this embodiment are intended to be illustrative. Depending on the context of the mixture, the column conditions and configuration can be designed to support almost any desired purity of HCFC-142a and / or CFC-113.

[0087] Example 4: Extractive Distillation The azeotropic or azeotropic-like compositions of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,2-dichloro-1,1,2-trifluoroethane (HCFC-123a) are separated by extractive distillation. First, a stream containing the azeotropic or azeotropic compositions of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) is fed into a first distillation column along with an adsorbent fluid. The extraction column is operated at appropriate temperature and pressure. The first distillation column functions as an extraction column, and one of the components of the azeotropic or azeotropic composition (e.g., component A) and the adsorbent fluid are recovered in the bottom product from the extraction column, while the other component of the azeotropic or azeotropic composition (e.g., component B) is recovered. Here, the adjunct fluid is selected based on various thermodynamic properties, including the difference in affinity between component A and component B that dissolve in the adjunct fluid, so that substantially all of component A dissolves in the adjunct fluid, while component B is hardly soluble or not soluble at all. The column is operated based on the thermodynamic difference between the adjunct / component A and component B, as described in relation to "Example 3: Pressure Swing Distillation". The extraction column is operated so that the distillate contains substantially all of component B and the bottom product contains substantially all of the adjunct fluid and dissolved component A.

[0088] The recovered adjunct fluid and dissolved component A are fed into a second recovery column operated at appropriate temperature and pressure. The recovery column separates the adjunct fluid from component A based on thermodynamic difference, as described in relation to "Example 3: Pressure Swing Distillation." Here, substantially all of the adjunct fluid is recovered in the bottom product from the recovery column, and substantially all of component A is recovered in the distillate. The recovered adjunct fluid is then recycled to the extraction column.

[0089] Example 5: A process for separating 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) from 1-chloro-1,2-difluoroethane (HCFC-142a) in the process of producing 1,1,2-trifluoroethane (HFC-143). A reagent stream containing CFCl2-CF2Cl (CFC-113) and hydrogen (H2) is supplied to the hydrogenation reactor. The hydrogenation reactor is operated at a temperature of 200°C to 300°C, a pressure of 10 psig to 200 psig, and a contact time of 1 second to 60 seconds. The hydrogenation reactor contains a platinum-containing catalyst on a carbon support. After the reaction, the product stream from the reaction is analyzed by a boiling point meter, as in Examples 1 to 4 above. The product stream has been found to contain at least HCl and an azeotropic or azeotropic-like composition of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113). Specifically, azeotropic or azeotropic-like compositions of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) have been found to contain approximately 41.5% to 57.8% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and approximately 42.4% to 58.5% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a). The azeotropic or azeotropic-like composition of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) in the product stream is then separated into individual components, where 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) are separated from each other. For example, the azeotropic or azeotropic-like composition of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) is separated by either pressure swing distillation or extractive distillation, as described with reference to Examples 3 and 4 above. 1-Chloro-1,2-difluoroethane (HCFC-142a) is removed during the separation process, and the resulting product stream contains HCl and 1,1,2-trifluoroethane (HFC-143). HCl is then removed. The final recovered product is found to contain 90 mol% to 99.5 mol% of 1,1,2-trifluoroethane (HFC-143).

[0090] manner Embodiment 1 is an azeotropic or azeotropic-like composition essentially consisting of effective amounts of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a).

[0091] Embodiment 2 is an azeotropic or azeotropic-like composition according to either the preceding or subsequent embodiment, essentially consisting of about 31.7% to about 63.1% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and about 36.9% to about 68.3% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a).

[0092] Embodiment 3 is an azeotropic or azeotropic-like composition according to either the preceding or subsequent embodiment, essentially consisting of about 47.9% to about 58.4% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and about 41.6% to about 52.1% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a).

[0093] Embodiment 4 is an azeotropic or azeotropic-like composition according to either the preceding or subsequent embodiment, essentially consisting of about 50.7% to about 56.1% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and about 43.9% to about 49.3% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a).

[0094] Embodiment 5 is an azeotropic or azeotropic-like composition according to either the preceding or subsequent embodiment, essentially consisting of about 53.5% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and about 46.5% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a).

[0095] Embodiment 6 is an azeotropic or azeotropic-like composition according to either the preceding or subsequent embodiment, wherein the azeotropic or azeotropic-like composition has a boiling point ranging from about 19.7°C at a pressure of about 8.9 psia to about 80.0°C at a pressure of about 61.8 psia.

[0096] Embodiment 7 is a method for producing 1,1,2-trifluoroethane (HFC-143), comprising hydrogenating 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) with hydrogen (H2) to form a product mixture, wherein the product mixture comprises 1,1,2-trifluoroethane (HFC-143) and an azeotropic or azeotropic-like composition essentially consisting of an effective amount of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and hydrogenation and an effective amount of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoro The present invention provides a method comprising: separating an essentially azeotropic or azeotropic-like composition from roethane (CFC-113); separating 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) from 1,1,2-trifluoroethane (HFC-143) to provide a product composition containing 1,1,2-trifluoroethane (HFC-143); and separating 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) to provide a product composition containing 1,1,2-trifluoroethane (HFC-143).

[0097] Embodiment 8 is a method according to any of the preceding or subsequent embodiments, further comprising recirculating 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) to a hydrogenation step.

[0098] Embodiment 9 is a method according to any of the preceding or subsequent embodiments, wherein the first separation step comprises conveying a product mixture to a first column having a first pressure, collecting a first bottom product from the first column, and conveying a first distillate from the first column to a second column having a second pressure to provide a second distillate and a second bottom product, wherein the second distillate contains an azeotropic or azeotropic composition.

[0099] Embodiment 10 is a method according to any of the preceding or subsequent embodiments, wherein the pressure in the first column is lower than the pressure in the second column, the first column bottom product consists essentially of 1-chloro-1,2-difluoroethane (HCFC-142a), and the second column bottom product consists essentially of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113).

[0100] Embodiment 11 is a method according to either the earlier or later embodiment, wherein the pressure in the first column is higher than the pressure in the second column, the first column bottom product consists essentially of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and the second column bottom product consists essentially of 1-chloro-1,2-difluoroethane (HCFC-142a).

[0101] Embodiment 12 is a method according to any of the preceding or subsequent embodiments, which includes an additional step of recirculating the second distillate to the first column.

[0102] Embodiment 13 is a method according to any of the preceding or subsequent embodiments, wherein the first separation step comprises: transporting the product mixture and the conjugate fluid to a first column; collecting a first distillate from a first column containing a first component of an azeotropic or azeotropic-like composition; collecting a first bottom product from a first column containing a mixture of the conjugate and a second component of an azeotropic or azeotropic-like composition; transporting the first bottom product to a second column to separate the conjugate from the second component of an azeotropic or azeotropic-like composition; and removing the composition containing the second component of an azeotropic or azeotropic-like composition as a second distillate from a second column.

[0103] Embodiment 14 is a method according to either the preceding or subsequent embodiment, wherein the first component of the azeotropic or azeotropic-like composition essentially consists of 1-chloro-1,2-difluoroethane (HCFC-142a), and the second component of the azeotropic or azeotropic-like composition essentially consists of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113).

[0104] Embodiment 15 is a method according to either the preceding or subsequent embodiment, wherein the first component of the azeotropic or azeotropic-like composition essentially consists of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and the second component of the azeotropic or azeotropic-like composition essentially consists of 1-chloro-1,2-difluoroethane (HCFC-142a).

[0105] Embodiment 16 is an azeotropic or azeotropic-like composition produced by any one of the methods of Embodiments 6 to 15.

[0106] Embodiment 17 is a composition comprising an azeotropic or azeotropic-like composition that is essentially derived from any of Embodiments 1 to 6, or obtained from any of Embodiments 7 to 15.

[0107] Embodiment 18 is a composition comprising 1,1,2-trifluoroethane (HFC-143) produced by any of the methods of Embodiments 7 to 15.

Claims

1. An azeotropic or azeotropic-like composition essentially consisting of effective amounts of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and 1-chloro-1,2-difluoroethane (HCFC-142a).

2. The azeotropic or azeotropic-like composition according to claim 1, comprising essentially about 31.7% to about 63.1% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and about 36.9% to about 68.3% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a).

3. The azeotropic or azeotropic-like composition according to claim 1, comprising essentially about 47.9% to about 58.4% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and about 41.6% to about 52.1% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a).

4. The azeotropic or azeotropic-like composition according to claim 1, comprising essentially about 50.7% to about 56.1% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and about 43.9% to about 49.3% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a).

5. The azeotropic or azeotropic-like composition according to claim 1, comprising essentially about 53.5% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and about 46.5% by weight of 1-chloro-1,2-difluoroethane (HCFC-142a).

6. The azeotropic or azeotropic composition according to claim 1, wherein the azeotropic or azeotropic-like composition has a boiling point ranging from about 19.7°C at a pressure of about 8.9 psia to about 80.0°C at a pressure of about 61.8 psia.

7. A method for producing 1,1,2-trifluoroethane (HFC-143), 1,1,2-Trichloro-1,2,2-trifluoroethane (CFC-113) is converted to hydrogen (H ２ Hydrogenation involves hydrogenating with a product mixture, wherein the product mixture comprises an azeotropic or azeotropic-like composition essentially consisting of 1,1,2-trifluoroethane (HFC-143) and effective amounts of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and Separating the azeotropic or azeotropic-like composition, which is essentially composed of effective amounts of 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), A method comprising separating 1-chloro-1,2-difluoroethane (HCFC-142a) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) from 1,1,2-trifluoroethane (HFC-143) to provide a product composition containing 1,1,2-trifluoroethane (HFC-143).

8. The method according to claim 7, further comprising recirculating the 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) to the hydrogenation step.

9. The first separation step is, The product mixture is transported to a first tower having a first pressure, Collecting the first column base product from the first column, The first distillate is transported from the first column to a second column having a second pressure to provide a second distillate and a second column bottom product, wherein the second distillate contains the azeotropic or azeotropic-like composition, and the transport is carried out accordingly. The method according to claim 7, comprising collecting a second column bottom product from the second column.

10. The method according to claim 9, wherein the pressure in the first column is lower than the pressure in the second column, the first column bottom product consists essentially of 1-chloro-1,2-difluoroethane (HCFC-142a), and the second column bottom product consists essentially of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113).

11. The method according to claim 9, wherein the pressure in the first column is higher than the pressure in the second column, the first column bottom product consists essentially of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and the second column bottom product consists essentially of 1-chloro-1,2-difluoroethane (HCFC-142a).

12. The method according to claim 9, further comprising the additional step of recirculating the second distillate to the first column.

13. The first separation step is, The product mixture and the accompanying fluid are transported to the first column. The first distillate is collected from the first column containing the first component of the azeotropic or azeotropic-like composition, The first column bottom product is collected from the first column containing a mixture of the adjuvant and the second component of the azeotropic or azeotropic-like composition, In order to separate the adjuvant from the second component of the azeotropic or azeotropic-like composition, the first column bottom product is transported to the second column, The method according to claim 7, comprising removing a composition containing the second component of the azeotropic or azeotropic-like composition from the second column as a second distillate.

14. The method according to claim 13, wherein the first component of the azeotropic or azeotropic-like composition essentially consists of 1-chloro-1,2-difluoroethane (HCFC-142a), and the second component of the azeotropic or azeotropic-like composition essentially consists of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113).

15. The method according to claim 13, wherein the first component of the azeotropic or azeotropic-like composition essentially consists of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and the second component of the azeotropic or azeotropic-like composition essentially consists of 1-chloro-1,2-difluoroethane (HCFC-142a).

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