Conversion of chlorofluoropropanes and chlorofluoropropenes to more desirable fluoropropanes and fluoropropenes.

Abstract

To provide hydrofluoroolefins (HFOs), Cl-free propenes.SOLUTION: A composition includes HCFO-1224yd (CF3CF=CHCl), HFO-1234yf (CF3CF=CH2), HCFC-235cb (CF3CF2CH2Cl), HCFC-225ca (CF3CF2CHCl2), and F22E (CF3CF2CH=CHCF2CF3).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to chemical processes for the conversion of chlorofluoropropanes (HCFCs) and chlorofluoropropenes (CFOs) to more desirable fluoropropanes and fluoropropenes, in particular hydrofluoroolefins (HFOs), i.e. Cl-free propenes, and to intermediates from which these HFOs can be obtained. [Background technology]

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

[0003] [Patent Document 1] U.S. Patent No. 8,399,722 Summary of the Invention [Problem 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] Desirable hydrofluoropropenes include HFO-1234yf (CFCF=CH), HFO-1234ze (CFCH=CHF), and HFO-1225zc (CFCH=CF).

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

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

[0010] Typically, the reaction compound HCFC-225ca will be mixed with HCFC-225aa (CF3CCl2CHF2), so that HCFC-225aa will coexist with HCFC-225ca in the contacting and reacting step. Hydrogenation of HCFC-225aa results in reaction products including 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). 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, while 1234ze can be formed directly from 1224xe. When the intermediate is HCFC-235da, it can be converted to HFO-1234ze. When the intermediate is HCFC-245fa, it can be converted directly to HFO-1234ze.

[0012] When the reactant is either CFO-1214ya or 1224yd, or a mixture thereof, the reaction product contains HFO-1234yf. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The hydrogenation reactions (hydrogenation processes and intermediate processes) of the present invention are preferably carried out in the gas phase, in a corrosion resistant reaction vessel containing a catalytically effective amount of catalyst, at temperatures and pressures and contact times effective to produce the reaction outcome desired for the particular reaction. The hydrogenation reactions are preferably carried out at atmospheric, or elevated, or reduced 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, with or without a support (carrier). The catalyst used in a particular 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 a support is used as part of the catalyst, the Cu, Ru, Cu-Pd, Ni-Cu, or Ni-Pd can be loaded onto the support in any conventional manner used to load metals onto a 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 on 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, unless it actively participates in obtaining the desired outcome of the reaction. A preferred support is carbon, which may be treated to enhance its support function for the catalyst loaded thereon. One example of treatment is acid washing of the carbon.

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

[0016] The above description of the catalysts applies to each of the hydrogenation reactions involved in the hydrogenation process and, when these catalysts are used in the intermediate process, to each of the hydrogenation reactions 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 to form intermediates that can be directly or indirectly converted to the desired HFP propene. Other impurities may be unaffected 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 comprises the compound CF3CF=CH2 (HFO-1234yf).

[0019] The reaction product may also include 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, it 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 the compound CF3CF=CHCl to a reaction product containing CF3CF=CH2 is effectively an implementation 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 said compound CF3CF2CH2Cl to form the compound CF3CF=CHCl, and then hydrogenating said compound CF3CF=CHCl in the presence of the above-mentioned catalyst. Alternatively, the compound CF3CF2CH2Cl can be converted to CF3CF=CH2 by hydrogenating in the presence of the above-mentioned catalyst.

[0022] When the reaction compound contains HCFC-225ca, this compound will usually be accompanied by the compound CF3CCl2CHF2 (HCFC-225aa) in said contact and reaction in the presence of a catalyst, so that the reaction product will also contain at least one of the compounds CF3CCl=CHF (HCFO-1224xe), CF3CHClCHF2 (HCFC-235da), CF3CH2CF2H (HCFC-245fa), and CF3CH=CHF (HFO-1234ze) as hydrogenation reaction products of HCFC-225aa during the hydrogenation of HCFC-225ca. Both HCFO-1224xe and HFC-245fa are intermediates that form CF3CH=CHF (HFO-1234ze). The presence of HFO-1234ze in the reaction product means that this compound is 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 above catalyst to form a reaction product comprising at least one of the compounds CF3CH=CHF (HFO-1234ze) and CF3CHClCH2F (HCFC-244db).

[0024] When the reaction products comprise the compound CF3CHClCH2F (HCFC-244db), this compound is converted to reaction products comprising the compound CF3CH=CHF by dehydrochlorination of the compound CF3CHClCH2F.

[0025] When the reaction products include the compound CF3CHClCHF2 (HCFC-235da), this compound is converted to a reaction product that includes the compound CF3CH=CF2 or CF3CH=CHF. In one embodiment, HCFC-235da can be dehydrochlorinated to form a reaction product that includes 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 that includes HFO-1234ze.

[0026] When the reaction products include the compound CF3CH2CF2H (HCFC-245a), this compound can be dehydrofluorinated to form reaction products including CF3CH=CHF (HFO-1234ze).

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

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

[0029] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or any other variations thereof, are intended to cover non-exclusive inclusions. For example, a composition, process, method, article, or device that includes recited elements is not necessarily limited to only those elements, but may include other elements not expressly recited or inherent in such composition or process, method, article, device, etc. Furthermore, unless expressly stated to the contrary, "or" indicates an inclusive or, not an exclusive or. For example, condition A or B satisfies 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 exists).

[0030] The transitional phrase "consisting of" excludes any element, step, or ingredient not specified. When in a claim, such a phrase limits the claim to include materials other than those recited, except for impurities normally accompanying the material. When the phrase "consisting of" appears within a clause in the body of a claim rather than immediately following the preamble, the phrase limits only the elements set forth in 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 compositions, methods that include materials, steps, features, ingredients, or elements in addition to those literally disclosed, provided that these additionally included materials, steps, features, ingredients, or elements have a substantial effect on the basic and novel characteristic(s) of the claimed invention, particularly the mode of action for achieving the desired results of any process of the invention. The term "consisting essentially of" occupies intermediate ground between "comprising" and "consisting of."

[0032] It should be readily understood that where applicants have defined an invention, or portions thereof, with open-ended terms such as "comprising," the description should be construed to also include inventions using the terms "consisting essentially of" or "consisting of" (unless otherwise expressly stated).

[0033] Additionally, the use of "a" or "an" is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be interpreted as including one or at least one, and the singular also includes the plural unless it is clear that a different meaning is intended. EXAMPLES

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

[0035] Example 1 - Hydrogenation of 225ca to 1234y, 1224yd, and 235cb 10 cc of 10% Cu / C is placed in a 1.3 cm (1 / 2 inch) Hastelloy® C227 reactor. The catalyst is reduced with H2 at 250°C for 4 hours. Then HCFC-225ca (GC analysis of HCFC-225ca reaction mixture is in Table 1) is pumped at 3.11 sccm with H2 (10.5 sccm) at 325°C and 350°C at atmospheric pressure. The reaction product stream from the reactor 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 10 cc of 0.5%Pd-8.5%%Cu / C is placed in a 1.3 cm (1 / 2 inch) Hastelloy® C227 reactor. The catalyst is reduced with H2 at 400°C for 4 hours. Then 225ca / cb mixture (GC analysis of HCFC-225ca reaction mixture is in Table 1) is pumped at 3.11 sccm with H2 (10.5 sccm) at 125, 140, and 160°C at atmospheric pressure. Airflow from the reactor is analyzed by GC and GC-MS. 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.

[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 reactor. The catalyst is reduced with H2 at 250°C for 4 hours. 235cb is then pumped at 3.5 sccm with H2 (6 sccm) at 325C and 350C at atmospheric pressure. The air stream from the reactor is analyzed by GC and GC-MS. The test results are shown in Table 4. 235cb is converted to 1234yf with 88-90% selectivity.

[0042] [Table 4]

[0043] Example 4 - Hydrogenation of 225ca to 1234y, 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 reactor. The catalyst is reduced with H2 at 400°C for 4 hours. Then 225ca (GC analysis of the mixture is in Table 5) is pumped at 3.11 sccm with H2 (11 sccm) at 225, 250, 275, and 300C at atmospheric pressure. The air stream from the reactor 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] Example 5 - Hydrogenation of 1214ya to 1234y and 1224yd, Ni-Cu catalyst 10 cc of Johnson Matthey CP447 Ni-Cu / C is placed in a 1.3 cm (1 / 2 inch) Hastelloy® C227 reactor. The catalyst is reduced with H2 at 400°C for 4 hours. 1214ya is then pumped at 3.11 sccm with H2 (11 sccm) at 225, 250, 275, and 300°C at atmospheric pressure. The air stream from the reactor is analyzed by GC and GC-MS. 1234yf and 1224yd are produced in this reaction as shown in Table 7.

[0047] [Table 7]

[0048] Example 6 - Hydrogenation of 1214ya to 1234yf and 1224yd, 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 reactor. The catalyst is reduced with H2 at 400°C for 4 hours. 1214ya is then pumped at 3.11 sccm with H2 (10.5 sccm) at 125, 140, and 160°C at atmospheric pressure. The air stream from the reactor is analyzed by GC and GC-MS. 1234yf and 1224yd are produced as shown in Table 8.

[0049] [Table 8]

Claims

【Request 1】 HCFO-1224yd (CF 3 CF=CHCl), HFO-1234yf (CF 3 CF=CH 2 ), HCFC-235cb (CF 3 CF 2 CH 2 Cl), HCFC-225ca (CF 3 CF 2 CHCl 2 ), and F22E (CF 3 CF 2 CH=CHCF 2 CF 3 ). 【Request 2】 In addition, HCFC-225aa (CF 3 CCl 2 CHF 2 ) and HCFC-225cb (CF 2 ClCF 2 2. The composition of claim 1, comprising at least one of the following:

3. HCFC-225ca (CF 3 CF 2 CHCl 2 2. A method for producing the composition of claim 1 comprising the step of contacting a composition comprising HCFC-225aa (CF3CCl2CHF2) and HCFC-225cb (CF2ClCF2CHClF) with hydrogen. 【Request 4】 HCFC-225ca (CF 3 CF 2 CHCl 2 4. The method of claim 3, wherein the Ni-Cu carbon supported catalyst is reduced with hydrogen prior to the step of contacting the composition comprising HCFC-225aa (CF3CCl2CHF2) and HCFC-225cb (CF2ClCF2CHClF) with hydrogen. 【Request 5】 loading a Ni-Cu carbon supported catalyst into a reactor tube, contacting the loaded catalyst with hydrogen at 400° C., and reacting HCFC-225ca (CF 3 CF 2 CHCl 2 A composition containing HCFC-225aa (CF3CCl2CHF2) and HCFC-225cb (CF2ClCF2CHCIF) and hydrogen are contacted with the hydrotreating catalyst to produce HCFO-1224yd (CF 3 CF=CHCl), HFO-1234yf (CF 3 CF=CH 2 ), HCFC-235cb (CF 3 CF 2 CH 2 Cl), F22E (CF 3 CF 2 CH=CHCF 2 CF 3 ) and unreacted HCFC-225ca (CF 3 CF 2 CHCl 2 producing a product mixture comprising:

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