System and method for reducing impurity formation during the dehydrochlorination of 244bb to 1234yf

Abstract

This provides various manufacturing processes for the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf or 1234yf). [Solution] A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf) comprises: providing a feed containing 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) and at least one impurity; removing the at least one impurity from the feed until the feed contains less than 200 ppm of the at least one impurity; and dehydrochlorinating the HCFC-244bb in the feed to form a product stream containing HFO-1234yf. Such a method may enable improved yields in the production of 1234yf and subsequent processes, a more economical process, and reduced waste.

Description

[Technical Field]

[0001] This disclosure relates to a method and system for reducing the formation of impurities during the production of HFO-1234yf. More specifically, this disclosure relates to a method for reducing the formation of impurities during the dehydrochlorination of 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb or 244bb) to form 2,3,3,3-tetrafluoropropene (HFO-1234yf or 1234yf). [Background technology]

[0002] Hydrofluoroolefins (HFOs), such as tetrafluoropropene, are known to be effective refrigerants, fire extinguishing agents, heat transfer fluids, propellants, foaming agents, gaseous dielectrics, sterilizer carriers, polymerization media, particulate removal fluids, liquid carriers, buffing abrasives, displacement drying agents, and power circulation working fluids. Due to suspected environmental problems associated with the use of some of these fluids, including their relatively high global warming potential, it is desirable to use fluids with the lowest possible global warming potential (GWP), in addition to having a zero ozone depletion potential (ODP). Therefore, developing environmentally friendly materials for the aforementioned applications is of considerable interest.

[0003] Hydrofluoroolefins (HFOs), which have zero ozone depletion and a low global warming potential, have been identified as potentially fulfilling this need. However, the toxicity, boiling point, and other physical properties of such chemicals vary considerably from isomer to isomer. One HFO with useful properties is 2,3,3,3-tetrafluoropropene (HFO-1234yf or 1234yf).

[0004] HFO-1234yf has been shown to be a low-toxicity, low-global-warming compound, and therefore can increasingly meet the stringent requirements for refrigerants in mobile air conditioning. Accordingly, compositions containing HFO-1234yf are present among the materials being developed for use in many of the aforementioned applications.

[0005] Various methods for producing HFO-1234yf are known, such as those described in U.S. Patent No. 8,058,486, titled "INTEGRATED PROCESS TO PRODUCE 2,3,3,3-TETRAFLUOROPROPENE" (issued November 15, 2011), U.S. Patent No. 8,975,454, titled "PROCESS FOR PRODUCING 2,3,3,3-TETRAFLUOROPROPENE" (issued March 10, 2015), and U.S. Patent No. 8,766,020, titled "PROCESS FOR PRODUCING 2,3,3,3-TETRAFLUOROPROPENE" (issued July 1, 2014), and these methods are incorporated herein by reference. [Overview of the project]

[0006] This disclosure provides various manufacturing processes for the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf or 1234yf). Such methods may enable improved yields in the production of 1234yf and subsequent processes, more economical processes, and reduced waste.

[0007] According to various aspects of this disclosure, a method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf) is provided, which involves 2-chloro-1,1,1,2-tetrafluoropropene The method may include providing a feed containing (HCFC-244bb) and at least one heavy organic impurity having a boiling point higher than about 15°C, removing at least one impurity from the feed until the feed contains less than 200 ppm of the at least one impurity, and dehydrochlorinating the HCFC-244bb in the feed to form a product stream containing HFO-1234yf. In certain embodiments, it is preferable to remove at least one impurity from the feed until the feed contains less than 100 ppm of the at least one impurity, and more preferably to remove at least one impurity from the feed until the feed contains less than 50 ppm of the at least one impurity.

[0008] In some embodiments, at least one impurity is 1,1,1,3-tetrachloropropane (HCFC-253fb), 1,1,1,3,3-pentafluoropropane (HFC-245fa), chlorohexafluorobutene (HFO-1326 isomer), hexafluorobutene (HFO-1336 isomer), pentafluorobutene (HFO-1345 isomer), heptafluorobutene (HFO-1327 isomer), 2,3-dichloro-1,1,1,2-tetrafluoropropane (HFC-234bb), chlorotetrafluoropropene (HCFO-1224 isomer), tetrafluorohexane (HFC-5-11-4 isomer), tetrafluoropropane (HFC- (254 isomer), chlorohexafluorobutane (HFC-346 isomer), octafluoropentane (HFC-458 isomer), chlorotrifluoropropene (HCFO-1233 isomer), (E)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)), 2-chloro-1,1,1,3,3-pentafluoropropane (HCFC-235da), octafluorohexene, 3-chloro-1,1,1,2-tetrafluoropropane (HFC-244eb), 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), (Z)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z)), C5H2F 10 Isomers, C6H2F8 isomers, C6H4F8 isomers, decafluorobutane (C4F 10 ), C6H3F7 isomer, C6H3F9 isomer, dichlorodifluoropropene (HCFO-1232 isomer), dichlorotrifluoropropene (HCFO-1223 isomer), dichlorotetrafluoropropane (HCFC-234 isomer), dichlorotrifluoropropane (HCFC-243 isomer), trichlorotrifluoropropane (HCFC-233 isomer), C6H3Cl2F7 isomer, trichlorodifluoropropane (HCFC-242 isomer), C8H3F7 isomer, tar, or at least one of these combinations.

[0009] Various methods may further include treating the product stream containing HFO-1234yf with at least one of the following: a column containing HCl, a column containing water, a column containing a caustic solution, a scrubber, a dryer, a distillation column, or a combination thereof.

[0010] Several methods for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf) may also include providing a feed containing 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) and at least one impurity, dehydrochlorinating HCFC-244bb in the feed to form a product stream containing HFO-1234yf, and controlling the formation of 1140, 1243zf or a combination thereof below a predetermined threshold. In various embodiments, this may include removing 1,1,1,3-tetrachloropropane (HCFC-253fb) before dehydrochlorinating HCFC-244bb in the feed. [Brief explanation of the drawing]

[0011] By referring to the following description of exemplary embodiments of the present disclosure in conjunction with the attached drawings, the above and other features and objectives of the present disclosure, as well as the methods for achieving them, will become clearer, and the present disclosure itself will be better understood.

[0012] [Figure 1A] This is a process flow diagram illustrating an exemplary portion of the manufacturing process for 2,3,3,3-tetrafluoropropene (HFO-1234yf).

[0013] [Figure 1B] This process flow diagram is similar to the process flow shown in Figure 1A, but with the addition of a third distillation column in series.

[0014] [Figure 1C]It is a process flow diagram similar to the process flow shown in Figure 1A, showing an exemplary part of the manufacturing process of 2,3,3,3-tetrafluoropropene (HFO-1234yf) using a side draw from a distillation column.

[0015] [Figure 2] It is a process flow diagram showing Step 3 of an exemplary process for manufacturing HFO-1234yf.

[0016] [Figure 3] Illustrates a part of a method for manufacturing HFO-1234yf during the control of the formation of 1140, 1243zf and combinations thereof according to various embodiments.

[0017] [Figure 4] Illustrates a method for manufacturing HFO-1234yf according to various embodiments.

[0018] [Figure 5] It is a chart illustrating 244bb conversion data using two different 244bb feed materials.

[0019] Corresponding reference characters indicate corresponding parts throughout several figures. The drawings represent embodiments of the present disclosure, but the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present disclosure. The illustrations described herein illustrate exemplary embodiments of the present disclosure in various forms, and such illustrations should not be construed as limiting the scope of the present disclosure in any way.

Embodiments for Carrying Out the Invention

[0020] As briefly described above, the present disclosure provides various methods and systems for the manufacture of 2,3,3,3-tetrafluoropropene (HFO-1234yf or 1234yf). The manufacture of HFO-1234yf from 1,1,2,3-tetrachloropropene (TCP) and hydrogen fluoride can be generalized in a three-step process.

[0021] 2-chloro-1,1,1,2-tetrafluoropropane Step 1 can be understood as generating 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) from 1,1,2,3-tetrachloropropene (1230xa) in a vapor-phase reactor according to the following reaction scheme.

Chemical formula

[0022] Step 2 can be understood as generating 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) from 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) according to the following reaction scheme. propene (HCFO-1233xf)

Chemical formula

[0023] Step 3 can be understood as generating 2,3,3,3-tetrafluoropropene (HFO-1234yf) from 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) in a reactor such as a vapor-phase reactor according to the following reaction scheme.

Chemical formula

[0024] While we do not wish to be bound by any particular operating theory, certain aspects of the present invention are based on the observation and understanding that the presence of certain impurities has been found to be detrimental and unfavorable during the specific dehydrochlorination reaction of certain dehydrochlorination initiators, such as 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf) by step 3 above.

[0025] For example, the presence of 3-chloro-1,1,1-trifluoropropane (HCFC-253fb or 253fb) in the reactor of step 3 may result in the formation and / or presence of elevated levels of both 3,3,3-trifluoropropene (HFO-1243zf or 1243zf) and vinyl chloride (1140), which may subsequently be found in the crude 1234yf product. The presence of 1243zf and 1140 impurities is undesirable because separating 1243zf and 1140 from 1234yf is difficult, as it may result in extra yield loss during the final purification step.

[0026] Furthermore, the presence of high boiler and tar (long-chain halogenated hydrocarbons) formed as by-reactions in the reactor of step 3 is thought to cause or contribute to excessive coking of the reactor in step 3, leading to premature deactivation of the reactor. A non-limiting example of high boiler is C4F 10 , C5H2F 10 Isomers include, but are not limited to, various tetrafluorohexane isomers, C6H3F7 isomers, C6H3Cl2F7 isomers, C6H2F8 isomers, C6H4F8 isomers, C6H3F9 isomers, various octafluorohexene isomers, and C8H3F7 isomers. These high boilers may further react to form tar, which can condense to form a dark brown or black viscous liquid upon cooling.

[0027] Therefore, for the feed to the reactor in step 3, reducing specific impurities, as well as / or reducing and separating tar, high boiler, and precursors of these materials, can enable a more economical process, improved uptime, higher yield, and improved use of the reactor's metal surfaces. Next, this may also allow the process to be carried out under milder conditions, which may also help prevent the formation of undesirable by-products.

[0028] The embodiments disclosed below are not intended to be exhaustive or to limit this disclosure to the exact forms disclosed in the following detailed description. Rather, the embodiments are selected and described so that those skilled in the art can utilize their teachings.

[0029] When used herein, the modifier “approximately” in relation to a quantity includes the stated value and has a meaning determined by the context (for example, it includes at least the degree of error associated with the measurement of a particular quantity). When used in the context of a range, the modifier “approximately” should also be understood to disclose a range defined by the absolute values ​​of two endpoints. For example, the range “approximately 2 to approximately 4” also discloses the range “2 to 4”.

[0030] Figure 1A is a process flow diagram illustrating exemplary manufacturing process flow 1 according to various embodiments. The HF feed 5 and 1233xf feed 3 (from step 1) may be combined, for example, with any pipe or container, such as a combination flow valve 28, and may be heated by a heat exchanger 24 and then supplied to reactor 2 as flow 7. In reactor 2, which can be shown as a liquid-phase reactor in Figure 1A, HCFC-244bb is produced as briefly described above as step 2. After the reaction of step 2 has taken place in reactor 2, the HCFC-244bb crude product flow 9 is sent to a catalyst stripper column 4, where the catalyst is separated and returned to reactor 2 in a return flow 18. After processing in the catalyst stripper column 4 and heat exchanger 22, the removed HCFC-244bb crude product flow 11 is sent to a light distillation column 6. In a light distillation column, the light boiler is distilled as a light top flow 13, while the light bottom flow 15 may be cooled by a heat exchanger 16 and sent to a phase separator 8 via flow 24, where HF is separated from the light bottom flow 15 containing HCFC-244bb. The HF phase may then be recycled back to the reactor of step 2 as a recirculated HF flow 19, and the liquid flow 17 containing HCFC-244bb may be sent to one or more distillation columns.

[0031] Figure 1A illustrates the initial liquid stream 17 delivered to the distillation column 10, which in this embodiment is exemplified as an azeotropic distillation column. In other embodiments, the distillation column 10 may include non-azeotropic distillation.

[0032] In the azeotropic distillation column 10, HCFO-1233xf can be removed from a liquid stream of HCFC-244bb using azeotropic distillation. As used herein, the term azeotropic distillation is used in a broad sense to include distillation processes involving one or more azeotropes or azeotropic-like mixtures of two or more fluids. For this purpose, a third stream, such as unreacted reagents and / or by-products from step 3, may be provided by a recirculating stream 29 to form an azeotropic mixture or azeotropic composition, which is then isolated from the composition. More specifically, the presence of a third component (e.g., HF) may form a ternary azeotropic mixture and / or a binary azeotropic mixture with HCFO-1233xf and / or HCFC-244bb. Various azeotropic mixtures can be separated from the solution using standard separation means, such as distillation in the azeotropic distillation column 10, such that a significant portion of HCFC-244bb remains in the solution at the bottom 21.

[0033] In various embodiments of this disclosure, compositions are provided that include effective amounts of HF, light organic, heavy organic, or combinations thereof to form an azeotropic or azeotropic mixture-like composition. As used herein, the term “effective amount” refers to the amount of each component that, when combined with other components, results in the formation of an azeotrope or azeotrope-like mixture. As used herein, the terms “heterophase azeotrope” and “heterogeneous azeotrope” include azeotrope-like compositions that include a vapor phase present simultaneously with two liquid phases.

[0034] Such azeotropic mixtures and methods for azeotropic separation or distillation may further include those disclosed in U.S. Patent No. 7,803,283 and U.S. Patent Publication Nos. 2010 / 0187088 and 2009 / 0256110, the contents of which are all incorporated herein by reference.

[0035] The azeotropic column bottom 21 can then be isolated as purified HCFC-244bb in the heavy distillation column 12, which may not substantially contain 253FB, and as other heavy impurities, indicated as the purified HCFC-244bb top flow 27, which can be sent for further processing (e.g., step 3) and / or stored in tank 60. The top flow 23 from the column can then be returned and recirculated for reuse in step 2 in reactor 2, and can be combined with the feed flow 7 in a pipe or container, for example, using a combined flow valve 28.

[0036] Finally, the bottom 25 of the heavy distillation column 12, which may contain enriched 253fb and tar and / or other heavy boilers, is then collected and may be subjected to additional recovery to improve yield and / or waste. As used herein, the term “heavy boiler” may include organic compositions having a boiling point higher than 244bb, which typically has a boiling point of about 14–15°C. For example, in some embodiments, the heavy organic may have a boiling point above about 15°C. Examples of heavy organics include HCFC-253fb, C4F 10 , C5H2F 10 Examples include isomers, various tetrafluorohexane isomers, C6H3F7 isomers, C6H3Cl2F7 isomers, C6H2F8 isomers, C6H4F8 isomers, C6H3F9 isomers, various octafluorohexene isomers, C8H3F7 isomers, tar, or combinations thereof.

[0037] Therefore, in some embodiments, such as the process flow diagrams shown in Figures 1A and 1B, the removed impurities are 1-chloro-3,3,3-trifluoropropane (HCFC-253fb), 1,1,1,3,3-pentafluoropropane (HFC-245fa), chlorohexafluorobutene (HFO-1326 isomer), hexafluorobutene (HFO-1336 isomer), pentafluorobutene (HFO-1345 isomer), heptafluorobutene (HFO-1327 isomer), 2,3-dichloro-1,1,1,2-tetrafluoropropane (HFC-234bb), chlorotetrafluoropropene (HCFO-1224 isomer), tetrafluorohexane (HFC-5-11-4 isomer), and Trafluoropropane (HFC-254 isomer), chlorohexafluorobutane (HFC-346 isomer), octafluoropentane (HFC-458 isomer), chlorotrifluoropropene (HCFO-1233 isomer), (E)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)), 2-chloro-1,1,1,3,3-pentafluoropropane (HCFC-235da), octafluorohexene, 3-chloro-1,1,1,2-tetrafluoropropane (HFC-244eb), 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), (Z)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z)), C5H2F 10 Isomers, C6H2F8 isomers, C6H4F8 isomers, decafluorobutane (C4F 10 ), C6H3F7 isomer, C6H3F9 isomer, dichlorodifluoropropene (HCFO-1232 isomer), dichlorotrifluoropropene (HCFO-1223 isomer), dichlorotetrafluoropropane (HCFC-234 isomer), dichlorotrifluoropropane (HCFC-243 isomer), trichlorotrifluoropropane (HCFC-233 isomer), C It may contain at least one of the following: 6H3Cl2F7 isomer, trichlorodifluoropropane (HCFC-242 isomer), C8H3F7 isomer, tar, or a combination thereof.

[0038] In some embodiments, such as the process flow 30 shown in Figure 1B, which includes many embodiments similar to or identical to that of Figure 1A, the bottom 25 of the heavy distillation column 12 may be further separated by a distillation column 32, etc. In some embodiments, the heavy recovery distillation column 32 may further separate the high boiler and tar from the heavy distillation column 12 into the top 33 and bottom 35. In various embodiments, the heavy recovery distillation column 32 may operate by batch distillation, and in other embodiments, the distillation column 32 may operate by continuous distillation. Also, in some embodiments, the purified product 244bb or partially purified product 244bb may be stored in a storage container such as a storage container 60.

[0039] In several embodiments, such as the process flow 40 shown in Figure 1C, which includes many embodiments similar to or identical to that of Figure 1A, the separation of the refined product 244bb using a side draw 47 from the distillation column 10 is illustrated. In some embodiments, the use of a side draw may be beneficial due to differences in separation within various trays of the distillation column 10, resulting from high boiler temperatures and vapor pressure differences between the tar and the refined product 244bb.

[0040] Figure 2 illustrates a process flow diagram 70 showing the production of 1234yf from a feed containing purified product 244bb and at least one impurity. The process flow diagram 70 in Figure 2 includes an input stream 27 containing HCFC-244bb, which may contain at least one of the aforementioned impurities, as illustrated in the descriptions of Figures 1A and 1B.

[0041] Next, the composition containing HCFC-244bb and at least one of the aforementioned impurities may be heated in a heat exchanger 24 and sent to a dehydrochlorination reactor 72 to produce 1234yf (step 3, briefly described above). The reaction product stream 75 containing 1234yf can then be sent to a recirculation column 62, where the bottom 63 can be returned to the reactor 72 and / or recirculated back to the azeotropic distillation column 10 of step 2 as the stream 29 in Figures 1A and 1B, and the top 65 may be sent to be purified by an HCl stream 67 in an HCl column 64. The HCl purification stream 69 may then be purified by a solution stream 77 in a scrubber 74. The solution stream 77 is not particularly limited and may be water, or a solution such as a caustic solution or an acidic solution, such as a solution containing sulfuric acid. The purified product stream 79 may then be sent to a dryer 76 containing an acid, such as concentrated sulfuric acid, a solid desiccant or a mixture of solid desiccants, or a combination of concentrated sulfuric acid and a desiccant(s) to remove any remaining scrub solution / moisture. A pre-cooling step may be incorporated between the scrubber 74 and the dryer 76 to differentially condense the water vapor in order to conserve the desiccant in the dryer 76.

[0042] Next, the dried product stream 81 may be distilled in the light distillation column 78, where the light top stream 83 passes through the heat exchanger 22 and is reused or removed. The light bottom stream 85 may be heated or cooled via the heat exchanger 26 and may be further distilled in the product distillation column 80. The purified 1234yf stream 87 may be processed through the heat exchanger 22, stored in a container 82, and / or recycled. The bottom product stream 29 may be heated in the heat exchanger 26, returned to the product distillation column 80 and recycled, and / or removed for disposal.

[0043] In some embodiments, the formation of 1140, 1243zf, or combinations thereof may be controlled to below a predetermined threshold in the effluent of the reactor in step 3 (shown as dehydrochlorination reactor 72 in Figure 2). In various embodiments, 1140, 1243z The formation of f, and combinations thereof, may be controlled by the selective removal of their precursors, such as 253fb.

[0044] While not limited to any particular theory, it is thought that an increase in the amount of 253fb may result in an increase in the amounts of 1243zf, 1140, and combinations thereof, including other by-reactants. It has been found that an increase in the level of 253fb may result in an increase in undesirable side reactions that can adversely affect the yield, such as the formation of 1140 and 1243zf in reaction schemes I and II below. [ka]

[0045] Therefore, in various embodiments, the amounts of 1243zf, 1140, and combinations thereof may be controlled to fall below a predetermined threshold. For example, limiting the amount of HCFC-253fb using one of the aforementioned separation processes, such as distillation, can help control the amount of HFO-1243zf and 1140 produced. For example, in some embodiments, HCFC-253fb may be removed by distillation or a series of distillations, as shown in Figures 1A and 1B.

[0046] For example, in some embodiments, the amount of HCFC-253fb may be reduced to levels less than about 200 ppm, less than about 100 ppm, less than about 50 ppm, or less than about 30 ppm. This may then help limit the formation of HFO-1243zf and 1140, but this is due to the fact that precursors for these aforementioned compounds are not available (as shown in schemes I and II).

[0047] For example, in some embodiments, the formation of 1140 may be controlled to less than about 200 ppm, less than about 100 ppm, less than about 50 ppm, or less than about 30 ppm by limiting the presence of HCFC-253fb.

[0048] Similarly, in some embodiments, the formation of 1243zf may also be controlled by limiting the presence of HCFC-253fb. Thus, HFO-1243zf The formation of [the substance] was controlled (minimized) to levels of less than approximately 200 ppm, less than approximately 100 ppm, less than approximately 80 ppm, or less than approximately 50 ppm.

[0049] Furthermore, in some embodiments, the combination of 1140 and 1243zf may be controlled to an amount less than about 300 ppm, less than about 200 ppm, less than about 100 ppm, or less than 80 ppm. For example, in various embodiments, controlling the formation of 1140 and 1243zf can be achieved by removing 253fb before performing step 3, for example by removing 253fb from the feed stream to step 3, and thus the feed stream has an amount of 253fb less than about 200 ppm, less than about 100 ppm, less than about 50 ppm, or less than 30 ppm.

[0050] Therefore, methods for producing 2,3,3,3-tetrafluoropropene may include the methods shown in Figures 3 and 4. Figure 3 shows method 101 for producing 2,3,3,3-tetrafluoropropene, which may include providing a feed containing 244bb and at least one impurity (step 110), removing at least one impurity from the feed until the feed contains at least one impurity below a predetermined threshold (e.g., less than about 200 ppm, less than about 100 ppm, less than about 50 ppm, and less than about 30 ppm) (step 120), and dehydrochlorinating the 244bb in the feed to form a product stream containing 1234yf (step 130).

[0051] Figure 4 illustrates another method for producing 2,3,3,3-tetrafluoropropene according to various embodiments. Method 301 may include steps 110 and 130 described above. Method 301 may also include a step (step 140) to control the formation of 1243zf, 1140, or combinations thereof to below a predetermined threshold. In various embodiments, this can be achieved by removing 253fb to a predetermined threshold.

[0052] Dehydrochlorination of HCFC-244bb can be carried out in a temperature range of 200°C to 800°C, preferably 300°C to 600°C, more preferably 425°C to 525°C, and a pressure range of 0 to 300 psig, preferably 5 to 200 psig, more preferably 20 to 100 psig. The residence time of HCFC-244bb in the reactor may be in the range of about 1 second to about 320 seconds, but longer or shorter times can be used.

[0053] As described above and shown in various process flow diagrams, the removal of at least one impurity may involve the use of one or more different separation or manufacturing processes. Exemplary processes include decanting, centrifugation, liquid-liquid extraction, distillation, flash distillation, partial vaporization, partial condensation, or a combination thereof. The separation process may be carried out in a multi-stage distillation column, which can be operated in a continuous or batch process, for example, in batch mode or continuous mode. In some embodiments, the separation of impurities can be achieved by side drawing from the distillation column.

[0054] In some embodiments, the product stream containing 1234yf may be further processed. For example, in some embodiments, some separated or further processed streams may be recycled to improve the overall yield of the process. For example, in some embodiments, unreacted 2-chloro-1,1,1,2-tetrafluoropropane may be recycled after dehydrochlorination by using a recirculation column.

[0055] Further processing is not particularly limited and may include various procedures having multiple unit operations, such as HCl recovery columns, caustic scrubbers, sulfuric acid drying columns, and product purification columns. [Examples]

[0056] Example 1 The objective of the following examples was to demonstrate the feasibility of removing 253fb and other high boilers from the 244bb crude product. Batch distillation was performed using an Oldershaw batch column with 15 tray glasses at a 1:1 RR (magnetic flux ratio). Approximately 3. Eight pounds of 244bb crude were packed into a glass still. Four distillates were cut during distillation, and after distillation, a nearly black residue remained in the reboiler. As shown in Table 1, compared to the initial 244bb crude, 253fb and other heavy components were significantly reduced in the distillate while being enriched in the reboiler (compared to 145 ppm of 253fb in the initial 244bb crude, cuts 1-3 contained less than 5 ppm of 253fb, cut 4 contained 89.0 ppm of 253fb, while the reboiler residue had 9551 ppm of 253fb. Compared to approximately 1.25% of other heavy components, cuts 1-3 contained less than 0.65% of other heavy components, cut 4 contained approximately 1.23% of other heavy components, while the reboiler residue had 21.66% of other heavy components). These results indicate that 253fb and other heavy components could be effectively reduced by distillation. [Table 1]

[0057] In Table 1 above, "other light compounds" refers to compounds with a boiling point lower than 244bb that do not contain 1233xf (for example, non-limiting examples include tetrafluoropropene (HFO-1234 isomer), pentafluoropropene (HFO-1225 isomer), heptafluorobutene, and 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124)).

[0058] In Table 1 above, "other heavy substances" refers to components having a boiling point higher than 244bb other than 253fb (non-limiting examples include 1,1,1,3,3-pentafluoropropane (HFC-245fa), chlorohexafluorobutene (HFO-1326 isomers), hexafluorobutene (HFO-1336 isomers), pentafluorobutene (HFO-1345 isomers), heptafluorobutene (HFO-1327 isomers), 2,3-dichloro-1,1,1,2-tetrafluoropropane (HFC-234bb), chlorotetrafluoropropene (HCFO-1224 isomers), tetrafluorohexane (HFC-5-11-4 isomers), tetrafluoropropane (HFC-254 isomers), chlorohexafluorobutane (HFC-346 isomers), octafluoropentane (HFC-458 isomers), chlorotrifluoropropene (HCFO-1233 isomers), (E)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)), 2-chloro-1,1,1,3,3-pentafluoropropane (HCFC-235da), octafluorohexene, 3-chloro-1,1,1,2-tetrafluoropropane (HFC-244eb), 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), (Z)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z)), C5H2F 10 isomers, C6H2F8 isomers, C6H4F8 isomers, decafluorobutane (C4F 10 )、C6H3F7 isomers, C6H3F9 isomers, dichlorodifluoropropene (HCFO-1232 isomers), dichlorotrifluoropropene (HCFO-122 3 isomers), dichlorotetrafluoropropane (HCFC-234 isomers), dichlorotrifluoropropane (HCFC-243 isomers), trichlorotrifluoropropane (HCFC-233 isomers), C6H3Cl2F7 isomers, trichlorodifluoropropane (HCFC-242 isomers), C8H3F7 isomers, and tar). Example 2

[0059] The objective of the following examples was to demonstrate the feasibility of removing high boiler from 244bb crude product. Batch distillation was performed in a distillation column consisting of a 10-gallon jacketed reboiler, a 2-inch inner diameter × 8-foot height column packed with Monel Pro-Pak® column packing, and a shell and tube condenser. The column had approximately 35–40 theoretical plates. The distillation column was equipped with temperature, pressure, and differential pressure transmitters. The distillate velocity was measured using a Coriolis flow meter.

[0060] Approximately 98 pounds of crude 244bb was packed into an S1 distillation column. Its composition is shown in Table 2. Distillation was then started and carried out at a pressure of approximately 12–15 psig. 92 pounds of purified 244bb distillate were recovered. The 244bb distillate was analyzed. Its composition is shown in Table 2. As shown in Table 2, 253fb was completely removed after distillation, but the total amount of other heavy components was significantly reduced.

[0061] After distillation was complete, approximately 3 pounds of black reboiler residue was discharged from the reboiler. Subsequently, 92 pounds of the purified 244 bb distillate were used as feedstock for the dehydrochlorination reaction experiment. [Table 2]

[0062] In Table 2 above, "other light compounds" refers to compounds with boiling points lower than 244bb other than 1233xf (non-limiting examples include tetrafluoropropene (HFO-1234 isomer), pentafluoropropene (HFO-1225 isomer), heptafluorobutene, and 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124)).

[0063] In Table 2 above, "other heavy compounds" refers to compounds with boiling points higher than 244bb other than 253fb (non-limiting examples include 1,1,1,3,3-pentafluoropropane (HFC-245fa), chlorohexafluorobutene (HFO-1326 isomer), hexafluorobutene (HFO-1336 isomer), pentafluorobutene (HFO-1345 isomer), heptafluorobutene (HFO-1327 isomer), 2,3-dichloro-1,1,1,2-tetrafluoropropane (HFC-234bb), chlorotetrafluoropropene (HCFO-1224 isomer), and tetrafluorohexane (HFC-5-1 (1-4 isomers), tetrafluoropropane (HFC-254 isomer), chlorohexafluorobutane (HFC-346 isomer), octafluoropentane (HFC-458 isomer), chlorotrifluoropropene (HCFO-1233 isomer), (E)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)), 2-chloro-1,1,1,3,3-pentafluoropropane (HCFC-235da), octafluorohexene, 3-chloro-1,1,1,2-tetrafluoropropane (HFC-244eb), 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), (Z )-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z)), C5H2F 10 Isomers, C6H2F8 isomers, C6H4F8 isomers, decafluorobutane (C4F 10 Examples include C6H3F7 isomers, C6H3F9 isomers, dichlorodifluoropropene (HCFO-1232 isomer), dichlorotrifluoropropene (HCFO-1223 isomer), dichlorotetrafluoropropane (HCFC-234 isomer), dichlorotrifluoropropane (HCFC-243 isomer), trichlorotrifluoropropane (HCFC-233 isomer), C6H3Cl2F7 isomer, trichlorodifluoropropane (HCFC-242 isomer), C8H3F7 isomer, and tar. Example 3

[0064] Two 11.5-inch Inconel® 625 tubes (3 / 4-inch outer diameter, 0.035-inch wall thickness) were used as reactors for the reaction in step 3 (dehydrochlorination of HCFC-244bb to produce HFO-1234yf) and were installed in parallel in an electrical box oven. After heating the tube reactors to a given temperature by N2 purging, the starting material containing HCFC-244bb and other impurities was supplied into each tube reactor, with each supply independently controlled by a mass flow meter and controller. The pressure of each reactor was independently controlled by a pressure control system including a pressure transducer and control valve. The effluent from both reactors was routed through a scrubber containing a 10% KOH solution to neutralize the HCl produced during the process. Samples were periodically taken from the sample port using a sample bag containing a constant amount of deionized H2O before the crude product reached the scrubber solution.

[0065] In one reactor, undistilled 244bb crude, which had the same composition as the 244bb crude in Example 2 (see Table 2 for its composition), was used as the starting material.

[0066] In the other reactors, distilled 244bb (see Table 2 for its composition), which was the 244bb distillate from Example 2, was used as the starting material.

[0067] Both reactors were operated under the same reaction conditions (480°C, 70 psig, and a residence time of 80 seconds, with a feed rate of 43 g / h equivalent to that), and the conversion data of 244 bb is shown in Figure 5.

[0068] The reactor using crude 244bb as the starting material experienced a significant outlet plug gauge after 24 hours of operation. Visual inspection revealed that a tar-like black solid had packed into the reactor outlet. After removing the tar-like material, the outlet was plugged again. The reaction was restarted after 8 hours. After removing the tar-like material, a third plug gauge was observed. The reaction was restarted after 16 hours. The conversion of 244bb was very low and unstable when using crude 244bb as the starting material. On the other hand, when the reactor was operated using distilled 244bb as the starting material, it was possible to maintain high and stable activity after the induction period without any operational problems. In addition, when crude 244bb was used as the starting material, the normalized HFO-1243zf and 1140 concentrations in the reactor effluent were 159 ppm and 247 ppm, respectively. For 244bb distilled as the starting material, the average normalized concentrations of HFO-1243zf and HCC-1140 in the reactor effluent were 75 ppm and 30 ppm, respectively. Example 4

[0069] The distilled 244bb described in Example 2 was supplied to one of the reactors described in Example 3 at 465°C and 70 psig at a supply rate of 21.5 g / h (equivalent to a residence time of 164 seconds). GC analysis revealed that the average normalized concentrations of HFO-1243zf and HCC-1140 in the reactor effluent were 56 ppm and 38 ppm, respectively. Example 5

[0070] The 244bb distilled as described in Example 2 was subjected to a 43g / h rate at 465°C and 70psig. The mixture was supplied to one of the reactors described in Example 3 at a supply rate equivalent to a residence time of 82 seconds. GC analysis revealed that the average normalized concentrations of HFO-1243zf and HCC-1140 in the reactor effluent were 71 ppm and 27 ppm, respectively. Example 6

[0071] The distilled 244bb described in Example 2 was supplied to one of the reactors described in Example 3 at 480°C and 70 psig at a supply rate of 21.5 g / h (equivalent to a residence time of 161 seconds). GC analysis revealed that the average normalized concentrations of HFO-1243zf and HCC-1140 in the reactor effluent were 59 ppm and 98 ppm, respectively. Example 7

[0072] In Example 2, the distilled 244bb was supplied to one of the reactors described above at 480°C and 58 psig at a supply rate of 43 g / h (equivalent to a residence time of 69 seconds). GC analysis revealed that the average normalized concentrations of HFO-1243zf and HCC-1140 in the reactor effluent were 68 ppm and 21 ppm, respectively. Example 8

[0073] Under the same reaction conditions as described in Example 3, an initiating material containing 27 ppm HFC-253fb, 98.46% 244bb, and 0.84% ​​1233xf was supplied to one of the reactors. GC analysis revealed that the mean normalized concentrations of HFO-1243zf and HCC-1140 in the reactor effluent were 63 ppm and 42 ppm, respectively. Example 9

[0074] Under the same reaction conditions as described in Example 3, an initiating material containing 41 ppm HFC-253fb, 98.42% 244bb, and 0.85% 1233xf was supplied to one of the reactors. GC analysis revealed that the mean normalized concentrations of HFO-1243zf and HCC-1140 in the reactor effluent were 78 ppm and 44 ppm, respectively. Example 10

[0075] Under the same reaction conditions as described in Example 3, an initiating material containing 53 ppm HFC-253fb, 97.32% 244bb, and 1.47% 1233xf was supplied to one of the reactors. GC analysis revealed that the mean normalized concentrations of HFO-1243zf and HCC-1140 in the reactor effluent were 120 ppm and 165 ppm, respectively. Example 11

[0076] Under the same reaction conditions as described in Example 3, a plant-based starting material (after removal of heavy components by distillation) containing 14 ppm HFC-253fb, 98.59% 244bb, and 1.03% 1233xf was supplied to one of the reactors. GC analysis revealed that the mean normalized concentrations of HFO-1243zf and HCC-1140 in the reactor effluent were 48 ppm and 23 ppm, respectively.

[0077] Although this disclosure has been described as having exemplary designs, this disclosure may be further modified within the spirit and scope of this disclosure. Accordingly, this application is intended to encompass any variations, uses, or adaptations of this disclosure that utilize its general principles. Furthermore, this application is intended to encompass any such deviations from this disclosure that belong to known or customary practices in the art to which the invention relates.

[0078] Furthermore, the connecting lines shown in the various drawings included herein are intended to illustrate exemplary functional relationships and / or physical connections between various elements. Actual systems may have numerous alternatives. It should be noted that additional functional relationships or physical connections may exist. However, benefits, advantages, solutions to problems, and any elements that may produce or make more prominent any benefits, advantages, or solutions should not be interpreted as important, necessary, or essential features or elements. Accordingly, the scope is merely a limitation of the attached claims, and any reference to a single element is intended to mean "one or more" rather than "one and only" unless expressly stated. Furthermore, where a phrase similar to "at least one of A, B, or C" is used in the claims, it is intended to be interpreted as meaning that in some embodiments A may exist alone, in some embodiments B may exist alone, in some embodiments C may exist alone, or any combination of elements A, B, or C, e.g., A and B, A and C, B and C, or A and B and C may exist in one embodiment.

[0079] In the detailed description herein, references such as “one embodiment,” “a certain embodiment,” and “exemplary embodiment” indicate that the embodiments described may include certain features, structures, or characteristics, but not all embodiments may necessarily include those specific features, structures, or characteristics. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, where certain features, structures, or characteristics are described in relation to one embodiment, it is presented that this is within the scope of the knowledge of those skilled in the art, along with the interest of the disclosure in that such features, structures, or characteristics may be affected in relation to other embodiments, whether explicitly described or not. After reading the description, methods of carrying out the disclosure in alternative embodiments will be apparent to those skilled in the art.

[0080] Furthermore, any elements, components, or steps of a method in this disclosure are intended for the public, regardless of whether such elements, components, or steps of a method are expressly enumerated in the claims. No claim element in this specification should be construed under Section 112(f) of the U.S. Patent Act unless such element is expressly enumerated using the phrase “means.” When used herein, the terms “comprises,” “comprising,” or any other variation thereof are intended to encompass non-exclusive inclusion. The diagram illustrates that a process, method, article, or apparatus containing a list of elements does not include only those elements, but may include other elements that are not explicitly enumerated or are inherent to such a process, method, article, or apparatus.

Claims

1. A method for producing 2,3,3,3-tetrafluoropropene (HFO-1234yf), 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) and 2-Chloro-1,1,1,3,3-pentafluoropropane (HCFC-235da) To provide supplies including, The process involves removing 2-chloro-1,1,1,3,3-pentafluoropropane (HCFC-235da) from the feed by distillation until the feed contains less than 200 ppm of 2-chloro-1,1,1,3,3-pentafluoropropane (HCFC-235da), The HCFC-244bb in the feed is dehydrochlorinated to form a product stream containing HFO-1234yf, A method that includes this.

2. The feedstock is 1-chloro-3,3,3-trifluoropropane (HCFC-253fb), 1,1,1,3,3-pentafluoropropane (HFC-245fa), chlorohexafluorobutene (HFO-1326 isomers), hexafluorobutene (HFO-1336 isomers), pentafluorobutene (HFO-1345 isomers), heptafluorobutene (HFO-1327 isomers), 2,3-dichloro-1,1,1,2-tetrafluoropropane (HCFC-234bb), chlorotetrafluoropropene (HCFO-1224 isomers), tetrafluorohexane (HFC-5-11-4 isomers), tetrafluoropropane (HFC-254 isomers), chlorohexafluorobutane (HFC-346 isomers), octafluoropentane (HFC-458 isomers), chlorotrifluoropropene (HCFO-1233 isomers), (E)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)), octafluorohexene, 3-chloro-1,1,1,2-tetrafluoropropane (HFC-244eb), 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), (Z)-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z)), C ８ , ６ , ３ , ３ , ９ , ７ , ６ , ６ , ３ , ４ , １０ , ２ H ２ F １０ isomers, C ６ H ２ F ８ isomers, C ６ H ４ F ８ isomers, decafluorobutane (C ４ F １０ ), C ６ H ３ F ７ isomers, C ６ H ３ F ９ isomers, dichlorodifluoropropene (HCFO-1232 isomers), dichlorotrifluoropropene (HCFO-1223 isomers), dichlorotetrafluoropropane (HCFC-234 isomers), dichlorotrifluoropropane (HCFC-243 isomers), trichlorotrifluoropropane (HCFC-233 isomers), C ６ H<​​​ ７ Isomer, trichlorodifluoropropane (HCFC-242 isomer), C ８ H ３ F ７ The method according to claim 1, further comprising at least one of isomers, tars, or combinations thereof.

3. The method according to claim 1, wherein the supply further comprises HCFC-253fb.

4. The method according to claim 1, wherein 2-chloro-1,1,1,3,3-pentafluoropropane (HCFC-235da) is removed from the feed by distillation until the feed contains less than 100 ppm of 2-chloro-1,1,1,3,3-pentafluoropropane (HCFC-235da).

5. The method according to claim 1, wherein 2-chloro-1,1,1,3,3-pentafluoropropane (HCFC-235da) is removed from the feed by distillation until the feed contains less than 50 ppm of 2-chloro-1,1,1,3,3-pentafluoropropane (HCFC-235da).

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