Conversion of chlorofluoropropanes and chlorofluoropropenes to more desirable fluoropropanes and fluoropropenes

Abstract

To provide compositions that yield better results in the production of HFO-1234yf.SOLUTION: The present invention provides a composition comprising: (i) at least one selected from the group consisting of HFO-1234yf (CF3CF=CH2), HFO-1234ze (CF3CH=CHF), and HFO-1225zc (CF3CH=CF2); (ii) at least one selected from the group consisting of HCFC-235cb (CH2ClCF2CF3), HCFC-225cb (CHClFCF2CClF2), HCFC-225ca (CHCl2CF2CF3), and HCFC-225aa (CF3CCl2CHF2); (iii) optionally, one of HCFO-1224yd (CF3CF=CHCl) and 1214ya (CF3CF=CCl2); and (iv) at least one selected from HCFO-1224xe (CF3CCl=CHF) and HCFC-235da (CF3CHClCHF2).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to the conversion of chlorofluoropropanes (HCFCs) and chlorofluoropropenes (CFPs) to more desirable fluoropropanes and fluoropropenes, particularly hydrofluoroolefins (HFOs), i.e., propenes without Cl, and to chemical processes for the conversion to intermediates from which these HFOs can be obtained.

Background Art

[0002] U.S. Patent No. 8,399,722 discloses that the hydrogenation of at least one of 1,1-dichloro-2,3,3,3-tetrafluoropropene (CF3CF = CCl2, 1214ya) and 1-chloro-2,3,3,3-tetrafluoropropene (CF3CF = CHCl, 1224yd) in the presence of a catalyst composed of Pd supported on a carbon carrier gives 2,3,3,3-tetrafluoropropene (CF3CF = CH2, 1234yf), which is promising as a refrigerant that does not contain chlorine and exhibits both a low ozone depletion potential and a low global warming potential. Example 2 discloses that the conversion rate of 1214ya to 1234yf is 75%, and this conversion rate can also be considered as the selectivity of this process. In Example 3, the selectivity decreased to 69%.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] What is desired are processes that provide better results in the production of HFO-1234yf and / or that provide HFO-1234ze (CFCH=CHF), 1,3,3,3-tetrafluoropropene), which is also chlorine-free and has refrigerant applications, and / or that open up new avenues for obtaining desirable HFOs, such as, for example, HFO-1234yf or HFO-1234ze. [Means for solving the problem]

[0005] The present invention provides a process comprising contacting and reacting a compound CF3CF2CHXCl (wherein X is H or Cl) or a compound CF3CF=CXCl (wherein X is H or Cl) with hydrogen in the presence of a catalyst consisting essentially of Cu, Ru, Cu-Pd, Ni-Cu, and Ni-Pd, resulting in a reaction product comprising a hydrofluoropropene or an intermediate convertible to said hydrofluoropropene. In the compound CF3CF2CHXCl, when X is H, the compound is HCFC-235cb, and when X is Cl, the compound is HCFC-225ca. In the compound CF3CF=CXCl, when X is H, the compound is HCFO-1224yd, and when X is Cl, the compound is CFO-1214ya. These are the reactive compounds in this hydrogenation process.

[0006] Another embodiment of the present invention is an intermediate process, i.e. a process for converting an intermediate obtained in a hydrogenation process into the desired hydrofluoropropene. The intermediate process includes, for example, reactions such as hydrogenation, dehydrochlorination, and dehydrofluorination. The catalyst used in the hydrogenation process is preferably the catalyst used in the hydrogenation reaction in the intermediate process.

[0007] Preferred hydrofluoropropenes include HFO-1234yf (CFCF=CH), HFO-1234ze (CFCH=CHF), and HFO-1225zc (CFCH=CF).

[0008] The reaction pathways (reactants / reaction products) involved in the hydrogenation process and the intermediate process are as follows.

[0009] When the reaction compound is HCFC-225ca, the reaction products include HFO-1234yf (CF2CF=CH2). The reaction products may also include at least one of HCFO-1224yd and HCFC-235cb (CF3CF2CH2Cl), which are intermediates capable of obtaining HFO-1234yf. HCFO-1224yd can be directly converted to HFO-1234yf. HCFC-235cb can be indirectly converted to HFO-1234yf by first converting to HCFO-1224yd, which is later converted to HFO-1234yf. HCFC-235cb can also be directly converted to HFO-1234yf. That is, the hydrogenation reaction products of HCFC-235cb include HFO-1234yf. This direct conversion can occur when HCFC-235cb is the reaction compound CF3CF2CHXCl (where X is H).

[0010] Normally, the reaction compound HCFC-225ca will be mixed with HCFC-225aa (CF3CCl2CHF2), whereby HCFC-225aa will coexist with HCFC-225ca in the contact and reaction steps. As a result of the hydrogenation of HCFC-225aa, reaction products containing at least one of HCFO-1224xe (CF3CCl=CHF), HCFC-235da (CF3CHClCHF2), and HCFC-245fa (CF3CH2CF2H), which are intermediates in the formation of HFO-1234ze (CF3CH=CHF), are produced. The hydrogenation of HCFC-225aa can also directly form HFO-1234ze.

[0011] When the intermediate is HCFO-1224xe, the reaction pathway to HFO-1234ze is to first form HCFC-244db (CF3CHClHCH2F) which can be converted to HFO-1234ze, although 1234ze can be formed directly from 1224xe. When the intermediate is HCFC-235da, this can be converted to HFO-1234ze. When the intermediate is HCFC-245fa, this can be directly converted to HFO-1234ze.

[0012] When the reaction compound is either one of CFO-1214ya or 1224yd or a mixture thereof, the reaction product contains HFO-1234yf.

Mode for Carrying Out the Invention

[0013] The hydrogenation reaction (hydrogenation process and intermediate process) of the present invention is preferably carried out in the gas phase in a corrosion-resistant reaction vessel containing a catalytically effective amount of a catalyst at a temperature, pressure and contact time effective to bring about the desired reaction results for a particular reaction. The hydrogenation reaction is preferably carried out at atmospheric pressure, or high pressure, or low pressure.

[0014] The hydrogenation catalyst in each hydrogenation reaction in the hydrogenation process consists essentially of Cu, Ru, Cu-Pd, Ni-Cu, or Ni-Pd, and may or may not have a support. The catalyst used in a specific hydrogenation reaction in the intermediate process may be different from the catalyst used in the hydrogenation reaction in the hydrogenation process, but these same catalysts are preferably used in the hydrogenation reaction in the intermediate process. The catalyst may include a support in each hydrogenation reaction. When the support is used as part of the catalyst, Cu, Ru, Cu-Pd, Ni-Cu, or Ni-Pd can be loaded onto the support by conventional methods used to load metals onto the support, including combinations of metals. For example, the catalyst can be prepared by any one of the deposition or impregnation methods of Cu, Ru, Cu-Pd, Ni-Cu, or Ni-Pd onto the support as generally described in Satterfield, "Heterogeneous Catalysts in Industrial Practice", 2nd ed. (McGraw-Hill, New York, 1991), pp. 87-112. The support is preferably inert under the reaction conditions if it does not actively participate in obtaining the desired result of the reaction. A preferred support is carbon, and the carbon may be treated to enhance its supporting function for the catalyst loaded on the carbon. An example of the treatment is acid washing of the carbon.

[0015] When the catalyst is Cu-Pd or Ni-Pd, preferably, Pd is present in a smaller amount compared to the weight of Cu or Ni. For example, when the catalyst is Cu-Pd, in one embodiment, the loading amount on the support is 0.1-20 wt% for Cu and 0.1-1.0 wt% for Pd. These same ratios can be applied to the Ni-Pd catalyst. When the catalyst is Ni-Cu, the molar ratio of these metals may range from 1:99 to 99:1. In one embodiment, the molar ratio of these metals is about 1:1.

[0016] The foregoing description of the catalyst applies to each hydrogenation reaction included in the hydrogenation process and, when these catalysts are used in an intermediate process, to each hydrogenation reaction of the intermediate process.

[0017] The reaction compounds HCFC-235cb, HCFC-225ca, HCFO-1224yd, and CFO-1214ya are each commercially available in various purities or can be prepared by known methods. Some impurities may participate in the hydrogenation reaction that forms intermediates that can be directly or indirectly converted to the desired HFP propene. Other impurities may not be affected by the reaction.

[0018] When the compound is CF3CF2CHXCl (wherein X is Cl), i.e., HCFC-225ca, the reaction product of the hydrogenation reaction in the presence of the above catalyst contains the compound CF3CF=CH2 (HFO-1234yf).

[0019] This reaction product may also contain at least one of the compounds CF3CF=CHCl (HCFO-1224yd) and CF3CF2CH2Cl (HCFC-235cb).

[0020] When the compound CF3CF=CHCl is present in the reaction product, this compound can be converted to the compound CF3CF=CH2, for example, by hydrogenation in the presence of a catalyst as described above. The catalyst may be the same as or different from the catalyst used to form the reaction product. The hydrogenation of CF3CF=CHCl to a reaction product containing CF3CF=CH2 is in fact the practice of the present invention when the reaction compound is CF3CF=CXCl (wherein X is H).

[0021] When the compound CF3CF2CH2Cl is present in the reaction product, this compound can be converted to the compound CF3CF=CH2 by first dehydrofluorinating the compound CF3CF2CH2Cl to form the compound CF3CF=CHCl, and then hydrogenating the compound CF3CF=CHCl in the presence of the catalyst described above. Alternatively, the compound CF3CF2CH2Cl can be converted to CF3CF=CH2 by hydrogenation in the presence of the catalyst described above.

[0022] When the reaction compound contains HCFC-225ca, this compound will generally be accompanied by the compound CF3CCl2CHF2 (HCFC-225aa) in the contact and reaction in the presence of a catalyst, such that the reaction product will also include, as the hydrogenation reaction product of HCFC-225aa upon hydrogenation of HCFC-225ca, at least one of the compounds CF3CCl=CHF (HCFO-1224xe), CF3CHClCHF2 (HCFC-235da), CF3CH2CF2H (HCFC-245fa), and CF3CH=CHF (HFO-1234ze). Both HCFO-1224xe and HFC-245fa are intermediates in the formation of CF3CH=CHF (HFO-1234ze). The presence of HFO-1234ze in the reaction product means that this compound was formed directly from the hydrogenation of HCFC-225aa.

[0023] When the reaction product compound is CF3CCl=CHF (HCFO-1224xe), this compound is hydrogenated in the presence of the catalyst described above to form a reaction product containing at least one of the compounds CF3CH=CHF (HFO-1234ze) and CF3CHClCH2F (HCFC-244db).

[0024] When the reaction product contains the compound CF3CHClCH2F (HCFC-244db), this compound is converted to a reaction product containing the compound CF3CH=CHF by dehydrochlorination of the compound CF3CHClCH2F.

[0025] When the reaction product contains the compound CF3CHClCHF2 (HCFC-235da), this compound is converted to a reaction product containing the compound CF3CH=CF2 or CF3CH=CHF. In one embodiment, HCFC-235da can be dehydrochlorinated to form a reaction product containing HFO-1225zc (CF3CH=CF2). In another embodiment, HCFC-235da is reacted with H2 to remove both Cl and F (dehydrohalogenation) to form a reaction product containing HFO-1234ze.

[0026] When the reaction product contains the compound CF3CH2CF2H (HCFC-245a), this compound can be defluorinated to form a reaction product containing CF3CH=CHF (HFO-1234ze).

[0027] When the reaction compound is CF3CF2CHXCl (where X is H), i.e., (HCFC-235cb), the reaction product with H2 contains the compound CF3CF=CH2 (HFO-1234yf).

[0028] When the reaction compound is CF3CF=CXCl (where X is Cl), or CF3CF=CXCl (where X is H), or a mixture of these reaction compounds, the reaction product of the hydrogenation reaction in the presence of the above catalyst contains the compound CF3CF=CH2. Thus, CFO-1214ya or HCFO 1224yd may be the reaction compound without containing the other, or these compounds may be present as a mixture of reaction compounds.

[0029] When used in the present invention, the terms "comprises", "comprising", "includes", "including", "has", "having", or any other variation thereof are intended to cover non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that includes the recited elements is not necessarily limited to only those elements, but may include other elements not expressly recited, or other elements inherent to such a composition, process, method, article, or apparatus. Further, unless expressly stated to the contrary, "or" means an inclusive or and not an exclusive or. For example, condition A or B is satisfied by any of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist).

[0030] The transitional phrase "consisting of" excludes any unspecified element, step, or ingredient. In the case of a claim, such a phrase limits the claim to the recited material excluding impurities ordinarily associated therewith. When the phrase "consisting of" appears not immediately following the preamble but within a clause of the body of the claim, the phrase limits only the elements set forth within that clause and does not exclude other elements from the scope of the claim as a whole.

[0031] The transitional phrase "consisting essentially of" is used to define a composition or method that includes materials, steps, features, components, or elements in addition to those literally disclosed, provided that these additionally included materials, steps, features, components, or elements do not materially affect the basic and novel characteristics of the claimed invention, particularly the manner of operation for achieving the desired result of any process of the present invention. The term "consisting essentially of" occupies an intermediate position between "comprising" and "consisting of".

[0032] It should be readily understood that when the applicant defines the invention or a part thereof in terms of non-limiting terms such as "comprising", the description (unless otherwise specified) should be construed to include inventions using the terms "consisting essentially of" or "consisting of".

[0033] Also, the use of "a" or "an" is employed to describe the elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the present invention. This description should be construed to include one or at least one, and the singular form also includes the plural form unless it is clear that the singular form has a different meaning.

Examples

[0034] The concepts described herein are further illustrated by the following examples, which do not limit the scope of the invention described in the claims.

[0035] Example 1 - Hydrogenation of 1234y, 1224yd, and 235cb to 225ca Place 10 cc of 10% Cu / C in a 1.3 cm (1 / 2 inch) Hastelloy® C227 reaction vessel. The catalyst is reduced with H2 at 250 °C for 4 hours. Then, HCFC-225ca (GC analysis of the HCFC-225ca reaction mixture is in Table 1) is fed at 3.11 sccm together with H2 (10.5 sccm) at 325 °C and 350 °C at atmospheric pressure. The reaction product gas stream from the reaction vessel is analyzed by GC and GC-MS. The results of the hydrogenation reaction are shown in Table 2. HFO-1234yf, HCFO-1224yd, and HCFC-235cb are the reaction products produced in this reaction.

[0036]

Table 1

[0037]

Table 2

[0038] Example 2 - Hydrogenation of HCFC-225ca, Cu-Pd Catalyst Place 10 cc of 0.5% Pd - 8.5% Cu / C in a 1.3 cm (1 / 2 inch) Hastelloy® C227 reaction vessel. The catalyst is reduced with H2 at 400 °C for 4 hours. Then, the 225ca / cb mixture (GC analysis of the HCFC-225ca reaction mixture is in Table 1) is fed at 3.11 sccm together with H2 (10.5 sccm) at 125, 140, and 160 °C at atmospheric pressure. The gas stream from the reaction vessel is analyzed by GC and GC-MS. The test results are shown in Table 3. HFO-1234yf, CFO-1224yd, and HCFC-235cb are produced in this reaction.

[0039]

Table 3

[0040] This example shows the conversion of 225ca and 1224yd to 1234yf, where 1224yd is an intermediate in forming 1234yf in this example.

[0041] Example 3 - Hydrogenation of HCFC - 235cb to HFO - 1234yf 10 cc of 10% Cu / C is placed in a 1.3 cm (1 / 2 inch) Hastelloy® C227 reaction vessel. The catalyst is reduced with H2 at 250 °C for 4 hours. Then, 235cb is fed at 3.5 sccm together with H2 (6 sccm) at 325 °C and 350 °C at atmospheric pressure. The gas stream from the reaction vessel is analyzed by GC and GC - MS. The test results are shown in Table 4. 235cb is converted to 1234yf with a selectivity of 88 - 90%.

[0042]

Table 4

[0043] Example 4 - Hydrogenation of 225ca to 1234yf, 1224yd, and 235cb, Ni - Cu catalyst 10 cc of Johnson Matthey CP447 Ni - Cu / C is placed in a 1.3 cm (1 / 2 inch) Hastelloy® C227 reaction vessel. The catalyst is reduced with H2 at 400 °C for 4 hours. Then, 225ca (GC analysis of the mixture is in Table 5) is fed at 3.11 sccm together with H2 (11 sccm) at 225, 250, 275, and 300 °C at atmospheric pressure. The gas stream from the reaction vessel is analyzed by GC and GC - MS. The test results are shown in Table 6. 1234yf, 1224yd, and 235cb are produced in this reaction.

[0044]

Table 5

[0045]

Table 6

[0046] Hydrogenation of 1214ya to 1234y and 1224yd in Example 5 - 1214ya, Ni - Cu catalyst 10 cc of Johnson Matthey CP447 Ni - Cu / C is placed in a 1.3 cm (1 / 2 inch) Hastelloy® C227 reaction vessel. The catalyst is reduced with H2 at 400 °C for 4 hours. Then, 1214ya is fed at atmospheric pressure at 225, 250, 275, and 300 °C with H2 (11 sccm) at 3.11 sccm. The gas stream from the reaction vessel is analyzed by GC and GC - MS. 1234yf and 1224yd are produced in this reaction as shown in Table 7.

[0047] [Table 7]

[0048] Hydrogenation of 1214ya to 1234yf and 1224yd in Example 6 - 1214ya, Pd - Cu catalyst 10 cc of 0.5% Pd - 8.5% Cu / C is placed in a 1.3 cm (1 / 2 inch) Hastelloy® C227 reaction vessel. The catalyst is reduced with H2 at 400 °C for 4 hours. Then, 1214ya is fed at atmospheric pressure at 125, 140, and 160 °C with H2 (10.5 sccm) at 3.11 sccm. The gas stream from the reaction vessel is analyzed by GC and GC - MS. 1234yf and 1224yd are produced as shown in Table 8.

[0049] [Table 8]

Claims

Claim 1 (i) At least one selected from the group consisting of HFO-1234yf (CF 3 CF=CH 2 ), HFO-1234ze (CF 3 CH=CHF), and HFO-1225zc (CF 3 CH=CF 2 ). (ii) At least one selected from the group consisting of HCFC-235cb (CH 2 ClCF 2 CF 3 ), HCFC-225cb (CHClFCF 2 CClF 2 ), HCFC-225ca (CHCl 2 CF 2 CF 3 ), and HCFC-225aa (CF 3 CCl 2 CHF 2 ), (iii) Optionally, one of HCFO-1224yd (CF 3 CF=CHCl) and 1214ya (CF 3 CF=CCl 2 ), and (iv) HCFO-1224xe (CF 3 CCl=CHF), and at least one of HCFC-235da (CF 3 CHClCHF 2 ), a composition comprising. Claim 2 CF 3 The composition according to claim 1, comprising CCl=CHF (HCFO-1224xe). Claim 3 HFO-1234yf (CF 3 CF=CH 2 ), HCFO-1224yd (CF 3 CF=CHCl), HCFC-225ca (CHCl 2 CF 2 CF 3 ), and a composition containing HCFO-1224xe (CF 3 CCl=CHF). Claim 4 HFO-1234yf (CF 3 CF=CH 2 ), HCFO-1224yd (CF 3 CF=CHCl), and CFO-1214ya (CF 3 CF=CCl 2 ) The composition according to claim 1, comprising Claim 5 HFO-1234yf (CF 3 CF=CH 2 ), HFO-1234ze (CF 3 CH=CHF), HCFO-1224yd (CF 3 CF=CHCl) and HCFC-225ca (CHCl 2 CF 2 CF 3 ) The composition according to claim 1, comprising Claim 6 HCFC-225ca (CHCl 2 CF 2 CF 3 ), HCFC-225aa (CF 3 CCI 2 CHF 2 ), and HCFC-245fa (CF 3 CH 2 CF 2 H), the composition according to claim 1. Claim 7 HFO-1234ze (CF 3 CH=CHF), HCFC-235cb (CF 3 CF 2 CH 2 Cl), HFC-245fa (CF 3 CH 2 CF 2 H) and a composition containing HCFO-1224xe (CF 3 CCl=CHF). Claim 8 HFO-1234yf (CF 3 CF=CH 2 ), HCFO-1224yd (CHCl 2 CF 2 CF 3 ), HCFC-225ca (CHCl 2 CF 2 CF 3 ), and HCFO-1224xe (CF 3 CCl=CHF), a composition consisting essentially of

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