WO2015160531A2

WO2015160531A2 - Process for the production of 1,1,1,2,2-pentafluoro- 3-chloropropane

Info

Publication number: WO2015160531A2
Application number: PCT/US2015/024218
Authority: WO
Inventors: Xuehui Sun; Douglas R. Leach
Original assignee: The Chemours Company Fc, Llc
Priority date: 2014-04-16
Filing date: 2015-04-03
Publication date: 2015-10-22
Also published as: WO2015160531A3

Abstract

A process for the manufacture of CF3CF2CH2Cl comprising contacting CH2ClF with CF2=CF2 in the presence of a catalytically effective amount of an aluminum halide composition having a bulk formula of AlClxBryF3-x-y wherein the average value of x is 0 to 3, the average value of y is 0 to 3-x, provided that the average values of x and y are not both 0, to produce CF3CF2CH2Cl with a selectivity of at least 70%.

Description

TITLE

PROCESS FOR THE PRODUCTION OF 1 ,1 ,1 ,2,2-PENTAFLUORO-

3-CHLOROPROPANE BACKGROUND INFORMATION

Field of the Disclosure

This disclosure relates in general to processes for the production of fluorinated olefins such as 2,3,3,3-tetrafluoropropene, and fluorocarbons which can be readily converted into such fluorinated olefins.

Description of the Related Art

The fluorocarbon industry has been working for the past few decades to find replacement refrigerants for the ozone depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) being phased out as a result of the Montreal Protocol. The solution for many applications has been the commercialization of hydrofluorocarbon (HFC) compounds for use as refrigerants, solvents, fire extinguishing agents, blowing agents and propellants. These new compounds, such as HFC refrigerants, HFC-134a and HFC-125 being the most widely used at this time, have zero ozone depletion potential and thus are not affected by the current regulatory phase-out as a result of the Montreal Protocol.

In addition to ozone depleting concerns, global warming is another environmental concern in many of these applications. Thus, there is a need for compositions that meet both low ozone depletion standards as well as having low global warming potentials. Certain hydrofluoroolefins are believed to meet both goals. Thus there is a need for manufacturing processes that provide halogenated hydrocarbons and fluoroolefins that contain no chlorine that also have a low global warming potential.

There is also considerable interest in developing new refrigerants with reduced global warming potential for the mobile air-conditioning market.

HFC-1234yf (CF₃CF=CH₂) and HFC-1234ze (CF₃CH=CHF) , both having zero ozone depletion and low global warming potential, have been identified as potential refrigerants. U. S. Patent Publication No.

2006/0106263 A1 discloses the production of HFC-1234yf by a catalytic vapor phase dehydrofluorination of CF3CF2CH3 or CF3CHFCH2F, and of HFC-1234ze (mixture of E- and Z- isomers) by a catalytic vapor phase dehydrofluorination of CF3CH2CHF2.

There is a continuing need for more selective and efficient manufacturing processes for the production of HFC-1234yf.

SUMMARY

The present invention provides a process for making CH2CICF2CF5 (HCFC-235cb). The process comprises reacting CH2CIF (HCFC-31 ) with CF2=CF2 (TFE) in a reaction zone in the presence of a catalytically effective amount of an aluminum halide composition having a bulk formula of AICIxBr_yF3-x-_y wherein the average value of x is 0 to 3, the average value of y is 0 to 3-x, provided that the average values of x and y are not both 0 with a selectivity to HCFC-235cb of at least 70%. The foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as defined in the appended claims.

DETAILED DESCRIPTION

In one embodiment, the present invention provides a process for making CH2CICF2CF5 (HCFC-235cb). The process comprises reacting CH2CIF (HCFC-31 ) with CF2=CF2 (TFE) in a reaction zone in the presence of a catalytically effective amount of an aluminum halide composition having a bulk formula of AICI_xBr_yF3-x-_y wherein the average value of x is 0 to 3, the average value of y is 0 to 3-x, provided that the average values of x and y are not both 0 with a selectivity to HCFC-235cb of at least 70%.

In another embodiment, the selectivity to HCFC-235cb is at least 80%. In yet another embodiment, the process is conducted at a

temperature of from 25°C to 40°C

Many aspects and embodiments have been described above and are merely exemplary and not limiting. After reading this specification, skilled artisans appreciate that other aspects and embodiments are possible without departing from the scope of the invention. Other features and benefits of any one or more of the embodiments will be apparent from the following detailed description, and from the claims.

The present invention provides a process for making HCFC-235cb. The process comprises reacting HCFC-31 with TFE in a reaction zone in the presence of an aluminum halide composition having a bulk formula of AICIxBr_yF3-x-_y wherein the average value of x is 0 to 3, the average value of y is 0 to 3-x, provided that the average values of x and y are not both 0. It has been found in accordance with this invention that the HCFC-235cb can be produced with high selectivity of at least 70%, as calculated as a percentage of the amount of HCFC-235cb as compared to the total amount of C3 products, including other isomers of HCFC-235, HCFC- 236cb, and any isomers of HCFC-225, any of which may be produced as by-products. In another embodiment, the selectivity to HCFC-2235cb is at least 80%.

Of note are embodiments wherein x is from about 0.10 to 3.00 and y is 0. Aluminum halide compositions of this type are known; see U. S. Patent Nos. 5,157,171 and 5,162,594. In some cases HCFC-31 may be employed in the formation of the aluminum halide composition. In other embodiment, trichlorofluoromethane (CFC-1 1 ) is employed in the formation of the aluminum halide composition. Thus, in some

embodiments, use of sufficient excess of HCFC-31 enables the production of AICIxF3-x in s/ft/ from anhydrous aluminum chloride so that a fluorine- containing catalyst is obtained.

The addition reaction involving HCFC-31 and TFE is based on a stoichiometry of 1 mole of HCFC-31 per mole of TFE. However, an excess of either reactant may be used as desired. Typically, the mole ratio of TFE to HCFC-31 is about 1 .5 or less (e.g., from about 0.3:1 to about 1 .1 :1 ).

The process can be conducted batchwise or in a continuous manner. In the continuous mode, a mixture of HCFC-31 and TFE may be passed through or over a bed or body of the aluminum halide composition (which may be under agitation) at suitable temperature and pressure to form a product stream, and the desired products (e.g., HCFC-235cb) may be recovered from the stream by conventional methods such as fractional distillation.

In the batch process, the reactants and the aluminum halide composition may be combined in a suitable reactor to form a reaction mixture, and the mixture held at a suitable temperature and pressure (normally under agitation) until a desired degree of conversion is obtained. In one embodiment, the reactor is initially charged with the aluminum halide composition, and optionally with a diluent, and the HCFC-31 and TFE are fed in the desired mole ratio (as separate streams or as a combined stream) into the reactor and maintained therein until the reaction is substantially complete. If the reactor is fed with HCFC-31 and the aluminum halide composition prior to the substantial absence of the TFE, the reactor and ingredients is preferably kept relatively cold (e.g., between about -78°C and 10°C) to discourage disproportionation of the HCFC-31 to fluorine-substituted methanes having a different fluorine content.

The process may be practiced with or without a solvent or diluent for the HCFC-31 and TFE. Typically, the HCFC-31 and TFE are diluted; however, the diluent may be primarily the HCFC-235cb produced in the addition reaction. Solvents which may be used include chlorocarbons (e.g., , and CCU), hydrochlorofluorocarbons (e.g., CHCI2CF3 and mixtures of dichloropentafluoropropanes such as CHCI2C2F5 and CHCIFCF2CCIF2), and chlorofluorocarbons (e.g., CCIF2CCIF2), and mixtures thereof.

In one embodiment, the addition reaction zone temperature is typically in the range of from about 25°C to about 40°C. In another embodiment the addition reaction zone temperature is in the range of from about 30°C to about 40°C.

The reaction pressure may vary widely but normally the reaction is carried out at elevated pressures, particularly pressures generated autogenously in conformity with the reaction temperature employed. The pressure may be adjusted by controlling the amount of unreacted HCFC- 31 and TFE. At normally employed temperatures, the reaction time is typically between about 0.2 hour and 12 hours.

The amount of aluminum halide composition employed is typically in the range of from about 1 to 20 weight percent, based on the weight of the HCFC-31 reactant.

The effluent from the reaction zone (continuous or batch) typically includes HCFC-235cb, unreacted HCFC-31 and/or TFE, other HCFC-235 isomers such as CH2FCF2CCIF2. The effluent may also include one or more by-products such as CH2CI2 and CH2CICF2CCIF2. The reaction products may be recovered from the reaction zone by use of conventional means such as filtration and/or distillation. In batch mode, it is normally convenient to separate the reaction products from the aluminum halide composition and to use the separated aluminum halide composition in subsequent reactions.

As used herein, the terms "comprises," "comprising," "includes,"

"including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

Also, use of "a" or "an" are 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 read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

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

The concepts described herein will be further described in the following examples, which do not limit the scope of the invention described in the claims.

LEGEND

215aa is CF3CCI2CCIF2 215cb is CF3CF2CCI3

216cb is CCI2FCF2CF3 225ca is CHCI2CF2CF3

235cb is CH2CICF2CF3 235cc is CH2FCF2CCIF2

244 is C₃H₃CIF 245cb is CF3CF2CH3

254eb is CF3CHFCH3 263fb is CF3CH2CH3

1234yf is CF₃CF=CH₂

Example 1

Example 1 demonstrates the reaction of chlorofluoromethane with tetrafluoroethylene at 35°C.

A 400 ml Hastelloy C shaker tube was charged with 5 g of modified aluminum chloride. The tube was cooled down to -10° C and evacuated.

The tube was then charged with 30.8g (0.45mol) of HFC-31 and 30 g (0.3 mol) of TFE. Then the reaction mixture was stirred at 35° C for 6 hours.

The continue drop of pressure from 194 psig to 50 psig indicated the progress of reaction. 60g product was collected after filtrate off the catalyst and analyzed by GC-MS. The analytical results were given in units of GC area% in Table 1 below. The selectivity of 235cab at 35C is about 77%. TABLE 1 GC analysis of product

Comprative Example 1

Comparative example 1 illustrates the reaction of

chlorofluoromethane with tetrafluoroethylene at 60°C.

A 400 ml_ Hastelloy™ C shaker tube was charged with AICI3 (1 .6 g,

0.012 mole) and 20 g of a mixture of dichloropentafluoropropanes as a reaction solvent. The tube was cooled to -78°C, evacuated, purged with nitrogen three times, and then charged with HCFC-31 (20.6 g, 0.30 mole).

The tube was then placed in a barricaded shaker and charged with TFE

(10.0 g, 0.10 mole). The temperature in the tube was increased to 39°C.

Additional TFE was added (10.0 g, 0.20 mole total charge) and the temperature increased to 50°C and held at 50°C for six hours. The pressure in the tube decreased from a maximum of 176 psig (1315 kPa) to

65 psig (549 kPa). The resulting product mixture weighed 41 .2 grams.

Analysis of the product by ¹ H NMR indicated the major products as shown in TABLE 2.

TABLE 2

Note that not all of the activities described above in the general description or the examples are required, that a portion of a specific activity may not be required, and that one or more further activities may be performed in addition to those described. Still further, the order in which activities are listed are not necessarily the order in which they are performed.

In the foregoing specification, the concepts have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of invention.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.

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

Claims

CLAIMS What is claimed is:

1 . A process for the manufacture of CF3CF2CH2CI comprising:

contacting CH2CIF with CF2=CF2 in the presence of a catalytically effective amount of an aluminum halide composition having a bulk formula of AICI_xBr_yF3-x-_y wherein the average value of x is 0 to 3, the average value of y is 0 to 3-x, provided that the average values of x and y are not both 0, to produce CF3CF2CH2CI with a selectivity of at least 70%.

2. The process of claim 1 , wherein the process is conducted at a

temperature of from 25°C to 40°C.

3. The process of claim 1 , wherein said selectivity for CF3CF2CH2CI is at least 80%.