Method for removing haloalkyne impurities from a (hydro)carbon composition

Abstract

To provide methods for removing reaction by-products from (hydro)halocarbon compounds.SOLUTION: A method comprises contacting a composition comprising a (hydro)halocarbon and a compound of formula Rf-C≡CX with a basic solution comprising an alkali metal hydroxide, an alkaline earth metal hydroxide, an alkali metal alkoxide, and / or an alkaline earth metal alkoxide so as to reduce the concentration of Rf-C≡CX. In the formula, Rf is a perfluorinated alkyl group, and X is H, F, Cl, Br, or I. The basic solution has a concentration of 0.1 to 10 M. The (hydro)halocarbon is a hydrohalopropene selected from CF3CH=CHCl(HCFO-1233zd), CF3CCl=CH2(HCFO-1233xf), CF3CH=CHF(HFO-1234ze), and / or CF3CF=CH2(HFO-1234yf).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for reducing the concentration of a compound of the formula R f -C≡CX in a composition containing at least one (hydro)halocarbon.

Background Art

[0002] The listing or discussion of prior published documents herein should not necessarily be taken as an admission that those documents are part of the state of the art or common general knowledge.

[0003] (Hydro)halocarbons are commonly used as materials for refrigerants or propellants and as blowing agents. Over the past 20 years, the types of (hydro)halocarbons used in these applications have changed because some of these materials (e.g., dichlorodifluoromethane, CFC-12) deplete the Earth's ozone layer, while others (e.g., 1,1,1,2-tetrafluoroethane, HFC-134a) have been found to have an unacceptably large impact as greenhouse gases.

[0004] Hydro(chloro)fluoroolefins have emerged as a group of compounds that can address these problems by providing good performance as refrigerants, propellant materials and / or blowing agents, while also having a low ozone depletion potential and a low global warming potential.

[0005] For example, (hydro)fluoroalkenes such as 2,3,3,3-tetrafluoropropene (HFO-1234yf) are increasingly being considered as working fluids in applications such as cooling, heat pumps, foaming, fire extinguishants / flame retardants, propellants and dissolution (e.g., plasma cleaning and etching). However, the methods used to produce (hydro)fluoroalkenes can lead to the formation of toxic and / or other undesirable by-products.

[0006] In the preparation of hydro(chloro)fluoroolefins, at the high temperatures (e.g., above 300 °C) that are normally considered necessary to achieve commercially desirable reaction rates, many side reactions can occur, including dehydrohalogenation, hydrohalogenation, and rearrangement. Thus, the crude product mixture emerging from the reaction train can contain many chemical species in addition to the feedstock and the desired product.

[0007] For example, HFO-1234yf can be dehydrofluorinated under the reaction conditions under which it is prepared, yielding 3,3,3-trifluoropropyne (trifluoromethylacetylene, TFMA). By-products such as TFMA can be produced only in small amounts relative to the desired product (e.g., HFO-1234yf), but the presence of such by-products in an HFO-1234yf composition can impair its toxicity, (chemical / oxidative) stability, and / or compatibility with components of a cooling system such as hoses or lubricants. Thus, in some applications, very low impurity levels are required. Unfortunately, some of the chemical species produced have physical properties very similar to, or associate with, the desired (hydro)halocarbon compound, rendering conventional separation methods such as distillation or phase separation ineffective. DISCLOSURE OF THE INVENTION

[0008] Accordingly, there is a need for a novel method for removing reaction by-products from (hydro)halocarbon compounds.

[0009] In a first aspect of the invention, a composition comprising a (hydro)halocarbon and a compound of the formula R f -C≡CX is contacted with a basic solution comprising a hydroxide, an alkoxide, and / or an amide to reduce the concentration of R f -C≡CX, wherein R f is a perfluorinated alkyl group and X is H, F, Cl, Br, or I.

[0010] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or any other variation thereof are intended to cover 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 disjunction and not an exclusive disjunction. For example, the condition "A or B" is satisfied by any one of the following: A is true (or present) and B is false (or absent), A is false (or absent) and B is true (or present), and both A and B are true (or present).

[0011] Also, the use of "a" or "an" is employed to describe elements and components 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 form also includes the plural form unless it is obvious that it means otherwise.

[0012] Unless defined otherwise, 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. In case of conflict, the present specification, including definitions, will control. 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, the preferred methods and materials are described below. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

[0013] When a quantity, concentration, or other value or parameter is given as any of a list of ranges, preferred ranges, or preferred upper and / or lower limits, it is to be understood as specifically disclosing all ranges formed by any pair of any upper limit or preferred upper limit and any lower limit or preferred lower limit, whether or not the ranges are separately disclosed. When a numerical range is recited in this specification, unless otherwise stated, the range is intended to include its endpoints, as well as all integers and rational numbers within the range. Unless otherwise specified, all percentage values are by weight.

[0014] The term “(hydro)halocarbon” refers to any saturated or unsaturated hydrocarbon in which at least one hydrogen atom (optionally all hydrogen atoms) is replaced by a fluorine atom, chlorine atom, bromine atom, and / or iodine atom. In preferred embodiments, the (hydro)halocarbon is unsaturated. For the avoidance of doubt, a composition containing a (hydro)halocarbon (and a compound of formula R f -C≡CX) may contain a single (hydro)halocarbon compound or a plurality of such compounds.

[0015] In preferred embodiments, the (hydro)halocarbon is a hydrofluoroolefin (HFO). Preferably, the (hydro)halocarbon is a C 3~4 hydrohaloalkene such as a C 3~7 (hydro)haloalkene. Examples of C 3~4 hydrohaloalkenes include hydrofluoropropene, hydrochlorofluoropropene, hydrofluorobutene, hydrochlorofluorobutene, and (hydro)fluoropropene. Advantageously, the (hydro)halocarbon is a hydrohalopropene.

[0016] In one embodiment, the hydrohalopropene is tetrafluoropropene and / or chlorotrifluoropropene. Preferred tetrafluoropropenes are 2,3,3,3-tetrafluoropropene (CF3CF=CH2, HFO-1234yf) and / or E, Z or E / Z-1,3,3,3-tetrafluoropropene (CF3CH=CHF, HFO-1234ze). Preferred chlorotrifluoropropenes are E, Z or E / Z-1-chloro-3,3,3-trifluoropropene (CF3CH=CHCl, HCFO-1233zd) and / or 2-chloro-3,3,3-trifluoropropene (CF3CCl=CH2, HCFO-1233xf).

[0017] HFO-1234ze may exist as one of two configurational isomers, E or Z. HFO-1234ze, as used herein, refers to the isomers, E-HFO-1234ze or Z-HFO-1234ze, and any combination or mixture of such isomers.

[0018] HCFO-1233zd may also exist as one of two configurational isomers, E or Z. HCFO-1233zd, as used herein, refers to these isomers, E-HCFO-1233zd or Z-HCFO-1233zd, and any combination or mixture of such isomers.

[0019] Formula R f in the compound of -C≡CX f is usually a C 1~5 perfluorinated alkyl group, preferably a C 1~2 perfluorinated alkyl group such as a perfluorinated methyl group. In one embodiment, X = H, F or Cl, preferably H and Cl. Preferred compounds of formula R f -C≡CX are 1-chloro-3,3,3-trifluoropropyne (CF3C≡CCl) and 3,3,3-trifluoropropyne (CF3C≡CCl, trifluoromethylacetylene, TFMA).

[0020] Alkynes such as TFMA are known to be producible by dehydrohalogenation of hydrohaloalkenes with a base. See, for example, pages 1530 - 1532 of the 6th edition of “March’s Advanced Organic Chemistry” and European Patent No. 2143702 (A). Based on such teachings, a composition containing a (hydro)halocarbon and a compound of the formula R f -C≡CX is contacted with a basic solution containing a hydroxide, an alkoxide and / or an amide, and it would be expected that the concentration of R f -C≡C would rather increase. However, surprisingly, it has been found that when using a basic solution containing a hydroxide, an alkoxide and / or an amide, at least a part of the compound of the formula R f -C≡CX can be effectively removed from the above composition.

[0021] To avoid doubt, it should be understood that the contacting step of the present invention is different from any conventional process that may have been carried out to prepare the (hydro)halocarbon. For example, the dehydrohalogenation of the corresponding C 3~7 hydro(halo)fluoroalkene with a basic solution containing hydroxide ions to prepare C 3~7 (hydro)fluoroalkene is known. See, for example, WO 2008 / 075017. The contacting step of the method of the present invention is separate from any reaction step in which a C f -C≡CX compound is also produced, whether or not such a compound is produced, in which a C 3~7 (hydro)fluoroalkene (or other (hydro)halocarbon) as described in WO 2008 / 075017 is produced.

[0022] In the method of the present invention, the basic solution containing a hydroxide, an alkoxide and / or an amide is R f-C≡CX concentration is reduced. Preferably, the base is one or more of an alkali metal hydroxide, alkoxide or amide, an alkaline earth metal hydroxide, alkoxide or amide, and NR4OH, where R is independently H, C 1~10 an alkyl group, an aryl group (e.g., a phenyl group, a naphthyl group or a pyridinyl group) or an arylalkyl group (e.g., a benzyl group or a C 1~10 alkyl-substituted phenyl group).

[0023] Advantageously, the base is selected from potassium hydroxide (KOH), sodium hydroxide (NaOH), calcium hydroxide (Ca(OH)2), ammonium hydroxide (NH4OH), potassium methoxide, sodium methoxide, potassium ethoxide, sodium ethoxide and sodium amide (NaNH2). In a preferred embodiment, the base is sodium ethoxide, KOH, NaOH or Ca(OH)2. Preferably, the base is KOH, NaOH or Ca(OH)2. KOH and NaOH are currently the most preferred.

[0024] The basic solution containing hydroxide, alkoxide and / or amide used in the contacting step of the present invention usually has a concentration of about 0.1 to about 10M, preferably about 0.2 to about 5M, such as about 0.5 to about 3M, about 0.5 to about 2M, or about 0.6 to about 2M. Without being bound by theory, the specified concentration is high enough for the reaction with the compound of formula R f -C≡CX and low enough not to react with (hydro)halocarbons (e.g., not to form further R f -C≡CX). f -C≡CX is considered to be low enough so as not to generate).

[0025] Moreover, a lower concentration of the basic solution is considered to have the advantage of reducing the possibility of precipitation of any corresponding fluoride salts (e.g., NaF, KF, etc.).

[0026] Generally, solvents for basic solutions containing hydroxides, alkoxides and / or amides used in the contacting step are selected from water (i.e., aqueous solutions), alcohols (e.g., methanol, ethanol and n - propanol and i - propanol), diols, polyols (e.g., polyalkylene glycols such as PEG300), polar aprotic solvents (e.g., diglyme and N - methylpyrrolidone), ethers and cyclic ethers (e.g., diethyl ether, dibutyl ether, tetrahydrofuran), esters (e.g., methyl acetate, ethyl acetate, etc.), straight - chain alkanes, branched alkanes and cyclic alkanes (e.g., cyclohexane, methylcyclohexane), their fluorinated derivatives (e.g., hexafluoroisopropanol, perfluorotetrahydrofuran), and mixtures of the above. In a preferred embodiment, the solvent is selected from water, alcohols and mixtures thereof. The currently preferred solvent is water alone or water combined with any of the above as a co - solvent.

[0027] The contacting step of the present invention is usually carried out at a temperature of about 0 to about 100 °C, preferably about 20 to about 60 °C, such as about 10 to about 80 °C. The method may be carried out at sub - atmospheric pressure, atmospheric pressure or super - atmospheric pressure, preferably at atmospheric pressure or super - atmospheric pressure. Suitable pressures include 0 bar to about 30 bar, preferably about 1 to about 5 or about 10 bar, such as about 0.5 bar to about 20 bar.

[0028] The composition is usually contacted with a basic solution containing hydroxides, alkoxides and / or amides for about 1 second to about 4 hours, preferably about 10 seconds to about 3 hours, preferably about 2 to about 100 minutes, about 5 to about 80 or about 10 to about 60 minutes (e.g., about 15 to about 45 minutes), such as about 1 minute to about 180 minutes. This so - called residence time has been demonstrated to be an important parameter in the method of the present invention, along with other variables such as the temperature of the contacting step and the concentration of the basic solution containing hydroxides, alkoxides and / or amides (described later in this specification).

[0029] (Hydro)halocarbons and formula R fA composition containing a compound of -C≡CX can be in the liquid or gas phase (preferably the gas phase) when contacted with a basic solution containing a hydroxide, an alkoxide, and / or an amide.

[0030] Before contacting with a basic solution containing a hydroxide, an alkoxide, and / or an amide, the composition preferably contains at least about 90 wt% of a (hydro)halocarbon, such as at least about 95 wt%, 98 wt%, 99 wt%, or 99.5 wt% of a (hydro)halocarbon.

[0031] Before contacting with a basic solution containing a hydroxide and / or an amide, the composition usually contains about 10000 ppm or less of the formula R, such as 5000 ppm or less. f -C≡CX contains a compound. Preferably, before contacting the composition with a basic solution containing a hydroxide, an alkoxide, and / or an amide, the formula R is about 4000 ppm, 3000 ppm, 2000 ppm, 1000 ppm, 800 ppm, 700 ppm, 600 ppm, or 500 ppm or less. f -C≡CX contains a compound.

[0032] In the (hydro)halocarbon-containing composition, the amount of the compound of the formula R f -C≡CX is usually reduced by at least about 20 wt% of the composition, preferably at least about 50 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, or 95 wt% or more by the method of the present invention.

[0033] After contacting with a basic solution containing a hydroxide, an alkoxide, and / or an amide, the composition usually contains 0 to about 1000 ppm of the formula R, such as 0 to about 500 ppm. f -C≡CX contains a compound. Preferably, after contacting the composition with a basic solution containing a hydroxide, an alkoxide, and / or an amide, the formula R is less than about 400 ppm, 300 ppm, 200 ppm, 100 ppm, 50 ppm, 40 ppm, 30 ppm, 20 ppm, 10 ppm, or 5 ppm or less. f -C≡CX contains a compound.

[0034] In one embodiment, the contacting step is carried out in the presence of a phase transfer catalyst. As used herein, the term "phase transfer catalyst" means a substance that facilitates the transfer of a chemical substance from one phase to another. The phase transfer catalyst can be ionic or neutral and is typically selected from the group consisting of crown ethers, onium salts, cryptands, and polyalkylene glycols and their derivatives (e.g., their fluorinated derivatives).

[0035] Generally, the amount of catalyst used is from about 0.001 to about 20% by weight of the composition, such as from about 0.01 to about 10% by weight, for example, from about 0.5 to about 5% by weight.

[0036] Crown ethers are cyclic molecules in which ether groups are linked by dimethylene bonds. Useful crown ethers include 18-crown-6, 15-crown-5, and 12-crown-4. Derivatives of the above crown ethers, such as dibenzyl-18-crown-6, dicyclohexanyl-18-crown-6, dibenzyl-24-crown-8, and dibenzyl-12-crown-4, are also useful. Other compounds similar to crown ethers and useful for the same purpose are compounds that differ by substituting one or more oxygen atoms with other types of donor atoms, particularly N or S. All of the above fluorinated derivatives may also be used.

[0037] Cryptands are another class of compounds useful as phase transfer catalysts in base-induced dehydrohalogenation. They are three-dimensional polymacrocyclic chelators formed by joining bridge structures with chains containing appropriately spaced donor atoms. The donor atoms in the bridges may all be O, N, or S, or the compounds may be mixed donor macrocycles in which the bridge strands contain a combination of such donor atoms. Suitable cryptands include bicyclic molecules obtained by joining nitrogen bridgeheads with chains of (-OCH2CH2-) groups, as in, for example, [2.2.2] cryptand (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane, available under the trade names Kryptand 222 and Kryptofix 222).

[0038] Onium salts which may be used as catalysts in the base dehydrohalogenation process include quaternary phosphonium salts and quaternary ammonium salts, each of which can be represented by the formula R 1 R 2 R 3 R 4 P + Z - and R 1 R 2 R 3 R 4 N + Z - In these formulas, R 1 , R 2 , R 3 and R 4 Each of the following is typically, independently, C 1~10 Alkyl groups, aryl groups (e.g., phenyl, naphthyl or pyridinyl groups) or arylalkyl groups (e.g., benzyl or C 1~10 alkyl-substituted phenyl group; Z - is a halide or other suitable counterion (e.g., hydrogen sulfate).

[0039] Specific examples of such phosphonium salts and quaternary ammonium salts include tetramethylammonium chloride, tetramethylammonium bromide, benzyltriethylammonium chloride, methyltrioctylammonium chloride (commercially available under the trademarks Aliquat 336 and Adogen 464), tetra-n-butylammonium chloride, tetra-n-butylammonium bromide, tetra-n-butylammonium hydrogensulfate, tetra-n-butylphosphonium chloride, tetraphenylphosphonium bromide, tetraphenylphosphonium chloride, triphenylmethylphosphonium bromide, and triphenylmethylphosphonium chloride. Benzyltriethylammonium chloride is preferred for use under strongly basic conditions. Quaternary ammonium chloride salts are preferred onium salt groups for use as phase transfer catalysts, such as Aliquat 336.

[0040] Other useful onium salts include onium salts that exhibit high-temperature stability (e.g., up to about 200 °C), such as 4-dialkylaminopyridinium salts, tetraphenylarsonium chloride, bis[tris(dimethylamino)phosphine]iminium chloride, and tetrakis[tris(dimethylamino)phosphineiminio]phosphonium chloride.

[0041] Polyalkylene glycol compounds useful as phase transfer catalysts have the formula R 6 O(R 5 O) m R 7 and can be represented by the formula, where R 5 is an alkylene group, and R 1~10 and R 6 and R 7 are each independently H, a C 1~10 alkyl group, an aryl group (e.g., a phenyl group, a naphthyl group, or a pyridinyl group), or an arylalkyl group (e.g., a benzyl group or a C 1~10 alkyl-substituted phenyl group), and m is an integer of 2 or more. Preferably, R 6 and R 7Both are identical and, for example, they may both be H.

[0042] Such polyalkylene glycols include diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, diisopropylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol and tetramethylene glycol, monoalkyl glycol ethers such as monomethyl ether, monoethyl ether, monopropyl ether and monobutyl ether of such glycols, dialkyl ethers such as tetraethylene glycol dimethyl ether and pentaethylene glycol dimethyl ether, phenyl ether, benzyl ether of such glycols, and polyalkylene glycols such as polyethylene glycol (average molecular weight about 300) and polyethylene glycol (average molecular weight about 400), and dialkyl (e.g., dimethyl, dipropyl, dibutyl) ethers of such polyalkylene glycols.

[0043] Combinations of phase transfer catalysts from one group among the above groups, and combinations or mixtures from two or more groups may also be useful.

[0044] In one embodiment, a composition comprising a (hydro)halocarbon and a compound of the formula R f -C≡CX may be a product stream from a process for producing a (hydro)halocarbon. Thus, the composition typically contains a desired or desired (hydro)halocarbon such as a hydrohalopropene (e.g., tetrafluoropropene, e.g., HFO-1234yf or HFO-1234ze, and / or chlorotrifluoropropene, e.g., HCFO-1233zd or HCFO-1233xf) and one or more (undesired) (hydro)halocarbon by-products. The method can be carried out as a batch reaction, a continuous reaction or a semi-continuous reaction.

[0045] For example, examples of such (hydro)halocarbon by-products in the production method of tetrafluoropropene (for example, HFO-1234yf) and / or chlorotrifluoropropene (for example, HCFO-1233xf) include pentafluoropropene (for example, CF3CFH=CFH, HFO-1225ye), pentafluoropropane (for example, HFC-245eb and / or HFC-245fa and / or HFC-245cb), chlorotetrafluoropropane (for example, HCFC-244bb), and hexafluoropropane (for example, CF3CFHCF2H, HFC-236ea).

[0046] Surprisingly, the contacting step of the present invention is not only effective in reducing the concentration of the compound of formula R f -C≡CX, but has also been found to be effective in reducing the concentration of one or more by-products present in the composition containing the target (hydro)halocarbon, the compound of formula R f -C≡CX and the (hydro)halocarbon by-products. Thereby, the selectivity and / or yield of the desired (hydro)halocarbon is increased. Preferably, the concentration of any saturated (hydro)halocarbon by-product is reduced relative to the desired (hydro)halocarbon.

[0047] The amount of (hydro)halocarbon by-products in the desired (hydro)halocarbon-containing composition is usually reduced by at least about 20% by weight, preferably at least about 50% by weight, 60% by weight, 70% by weight, 80% by weight, 90% by weight, or 95% by weight or more of the composition in the method of the present invention.

[0048] After contacting with a basic solution containing hydroxide, alkoxide and / or amide, the composition usually contains a compound of (hydro)carbon by-products in the range of 0 to about 1000 ppm, such as 0 to about 500 ppm. Preferably, after contacting with a basic solution containing hydroxide, alkoxide and / or amide, the composition contains less than about 400 ppm, 300 ppm, 200 ppm, 100 ppm, 50 ppm, 40 ppm, 30 ppm, 20 ppm, 10 ppm, or 5 ppm of (hydro)carbon by-products.

[0049] In a second aspect of the present invention, (i) Optionally in the presence of HF and / or a catalyst, converting a starting material into a composition containing a (hydro)carbon and a compound of the formula R f -C≡CX, wherein R f is a perfluorinated alkyl group and X is H, F, Cl, Br, or I, and (ii) contacting the composition with a basic solution containing hydroxide, alkoxide and / or amide to reduce the concentration of the compound of the formula R f -C≡CX, and (iii) recovering the (hydro)carbon, A method for preparing a (hydro)carbon is provided, which includes the above steps.

[0050] For the sake of avoiding ambiguity, for example, the above information related to the invention of the first aspect regarding the composition containing a (hydro)carbon and a compound of the formula R f -C≡CX and the step of contacting is also applicable to the second aspect of the present invention. Further embodiments of the second aspect of the present invention will be described below.

[0051] The conversion of the starting material to (hydro)carbon and R f -C≡CX impurities in step (i) preferably includes a hydrogenation reaction, a dehydrohalogenation reaction, an isomerization reaction and / or a fluorination reaction.

[0052] In one embodiment, the (hydro)carbon and the formula R fA composition containing a -C≡CX compound is prepared by a hydrogenation reaction.

[0053] Such hydrogenation reaction(s) may be carried out in the liquid phase or the gas phase, preferably the gas phase, usually at a temperature of about -50 to about 275 °C. The preferred temperature for liquid-phase hydrogenation is about -50 to about 50 °C, for example, about 15 to about 40 °C. The preferred temperature for gas-phase hydrogenation is about 0 to about 250 °C, such as about 20 to about 200 °C, for example, about 50 to about 150 °C.

[0054] The hydrogenation reaction(s) may be carried out in the presence of a fluorinated polar aprotic solvent, especially when carried out in the liquid phase. Suitable solvents include HFC (e.g., 134a) and PFC (e.g., perfluorodecalin).

[0055] The hydrogenation reaction(s) may be carried out at atmospheric pressure, subatmospheric pressure or superatmospheric pressure, preferably superatmospheric pressure. For example, the hydrogenation may be carried out at a pressure of about 0 to about 40 bara, such as about 1 to about 30 bara, for example, about 5 to about 20 bara.

[0056] The hydrogen:reactant ratio is preferably about 0.1:1 to about 40:1, such as about 1:1 to about 20:1, preferably about 1.1:1 to about 10:1, for example, 1.5:1 to about 5:1.

[0057] The hydrogenation reaction(s) is / are usually carried out in the presence of a catalyst. Suitable hydrogenation catalysts include catalysts containing transition metals nickel (Ni), palladium (Pd), platinum (Pt), rhenium (Re), rhodium (Rh), ruthenium (Ru) and mixtures thereof. Such catalysts may be supported on, for example, alumina, titania, silica, zirconia, fluorides thereof, calcium fluoride, carbon or barium sulfate, or the catalyst may be unsupported, such as Pd metal produced by reduction of, for example, Raney Ni or PdO2. Examples of catalysts suitable for use in the present invention include Pd / alumina, Pd / barium sulfate, Pd / C and chlorotris(triphenylphosphine)rhodium(I). Preferably, the catalyst is palladium supported on carbon (Pd / C) or chlorotris(triphenylphosphine)rhodium(I) (Wilkinson's catalyst) or platinum supported on alumina (Pt / Al2O3) or Adams' catalyst, PtO2, which is reduced to platinum metal in situ. When Pd / C is used as the catalyst, Pd is present in an amount of about 0.01 to about 10 wt% of the catalyst, such as about 0.1 to about 5 wt%.

[0058] The hydrogenation catalyst is usually used in an amount of about 0.01 to about 30 wt%, such as about 0.1 to about 10 wt%, based on the total weight of the components constituting steps (a) and (c). When Pd / C is used as the catalyst, Pd is present in an amount of about 0.01 to about 10 wt% of the catalyst, such as about 0.1 to about 5 wt%.

[0059] In the gas phase, the contact time of the catalyst may be about 1 to about 200 seconds, such as about 2 to about 150 seconds. In the liquid phase, the contact time with the accompanying catalyst is preferably about 1 to about 180 minutes, such as about 2 to about 60 minutes.

[0060] In one embodiment, a composition comprising a (hydro)halocarbon and a compound of the formula R f -C≡CX is prepared by a dehydrohalogenation reaction.

[0061] The dehydrohalogenation reaction thermally decomposes the starting material to give a (hydro)halocarbon and a compound of the formula Rf It may also be carried out by producing a composition containing a compound of -C≡CX. As used herein, the terms "pyrolysing" or "pyrolysis" include the meaning of chemical changes caused by heating in the absence of a catalyst. The absence of a catalyst includes the meaning that a material or process that increases the reaction rate by reducing the activation energy of the pyrolysis process is not added to the pyrolysis reactor.

[0062] For pyrolysis, any suitable reactor can be used, such as a cylindrical tube that can be either linear or coiled. Preferred pyrolysis reactors include reactors in which the gas flow through the reactor is partially obstructed to cause backmixing, i.e., turbulent flow, thereby promoting gas mixing and good heat transfer. This partial obstruction can conveniently be obtained by placing a packing inside the reactor to fill its cross-section or by using perforated baffles. The reactor packing can be granular or fibrous and has an open structure such as Raschig rings or other packings with a high free volume to avoid coke accumulation, minimize pressure drop, and allow a generally free gas flow. In some embodiments of the present invention, the reactor packing is in a cartridge arrangement for easy insertion and removal. In some embodiments of the present invention, the pyrolysis reactor is substantially empty, which means that the free volume of the reaction zone (the volume of the reaction zone minus the volume of the material constituting the reactor packing) is at least about 80%, preferably at least about 90%, more preferably at least about 95%. In some embodiments, the pyrolysis reactor is made of a corrosion-resistant material including stainless steel, Hastelloy®, Inconel®, Monel®, gold, or gold-plated, or quartz.

[0063] The dehydrohalogenation reaction of step (i) preferably includes a dehydrofluorination process and / or dehydrochlorination, depending on the starting materials and the corresponding (hydro)halocarbon products. The temperature of the dehydrofluorination pyrolysis is usually higher than that of the dehydrochlorination pyrolysis. For example, the dehydrofluorination pyrolysis may be carried out at a temperature of about 600 °C to about 900 °C, and the dehydrochlorination pyrolysis may be carried out at a temperature of about 400 °C to about 700 °C.

[0064] In one embodiment, the dehydrohalogenation reaction is catalyzed. Such a reaction may be carried out in the liquid phase or the gas phase, preferably the gas phase. A temperature of about -25 to about 700 °C may be used. The preferred temperature for the liquid phase is about 0 to about 180 °C, for example, about 15 to about 120 °C. The preferred temperature for the dehydrohalogenation in the gas phase is about 100 to about 650 °C, such as about 200 to about 600 °C, for example, about 300 to about 500 °C.

[0065] The catalyzed dehydrohalogenation reaction may be carried out at atmospheric pressure, sub-atmospheric pressure or super-atmospheric pressure, preferably atmospheric pressure or super-atmospheric pressure. For example, the dehydrohalogenation may be carried out at a pressure of about 0 to about 40 bara, such as about 1 to about 30 bara, for example, about 1 or 5 to about 20 bara.

[0066] Preferably, the catalyst is stable in the presence of HF and / or HCl. Suitable catalysts include metal catalysts and carbon-based catalysts such as activated carbon (including acid-washed carbon, activated carbon, and three-dimensional matrix carbonaceous materials), main group (e.g., alumina-based catalysts), and chromia-based catalysts (e.g., zinc / chromia) or nickel-based catalysts (e.g., nickel mesh) containing transition metals. Examples of such catalysts include alumina, fluorinated alumina, aluminum fluoride, aluminum fluoride chloride; metal compounds supported on alumina, fluorinated alumina, aluminum fluoride, or aluminum fluoride chloride; chromium oxide (Cr2O3), fluorinated chromium oxide, and cubic chromium trifluoride; oxides, fluorides, and oxyfluorides of magnesium, zinc, and mixtures of magnesium and zinc and / or aluminum; lanthanum oxide and fluorinated lanthanum oxide; carbon, and metal compounds supported on carbon. The metal compound can be an oxide, fluoride, and oxyfluoride of at least one metal selected from the group consisting of sodium, potassium, rubidium, cesium, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, chromium, iron, cobalt, rhodium, nickel, copper, zinc, and mixtures thereof. In some embodiments of the present invention, the dehydrohalogenation catalyst comprises an alkali metal salt supported on chromium oxide.

[0067] The catalyst used may be used in an amount of about 0.01 to about 50% by weight, such as about 0.1 to about 30%, for example, about 0.5 to about 20% based on the weight of the reactant. The contact time with the catalyst in the catalytic reaction is preferably about 1 to about 500 seconds, such as about 5 to about 400 seconds.

[0068] Dehydrohalogenation can be carried out in any suitable apparatus such as a static mixer, a stirred tank reactor, or a stirred gas-liquid separation vessel. Preferably, the apparatus is made of one or more corrosion-resistant materials such as Hastelloy® or Inconel®. The method may be carried out batchwise or (semi)continuously, preferably (semi)continuously.

[0069] In one embodiment, a composition comprising a (hydro)halocarbon and a compound of the formula R f -C≡CX is prepared by an isomerization reaction. Suitable reaction conditions and catalysts include those described above for the dehydrohalogenation reaction, optionally at somewhat lower temperatures. Suitable conditions for the isomerization reaction are described, for example, in WO 2008 / 125825 and WO 2015 / 059500. The term "isomerization reaction" includes structural isomerization and geometric isomerization, such as the structural isomerization of CF2CH=CF2 (HFO-1234zc) to 1234ze and the geometric isomerization of Z-HFO-1234ze to E-HFO-1234ze.

[0070] In one embodiment, a composition comprising a (hydro)halocarbon and a compound of the formula R f -C≡CX is prepared by a fluorination reaction. Suitable reaction conditions and catalysts include those described above for the dehydrohalogenation reaction, but include those in the presence of a fluorinating agent such as HF. Usually, HF is present in a molar excess relative to the starting material, for example, in an amount of about 1:1 to about 70:1, preferably about 2:1 to about 60:1, about 3:1 to about 50:1, such as about 5:1 to about 40:1. Suitable conditions for the fluorination reaction are described, for example, in EP 2154122(A) and WO 2011 / 077394.

[0071] The (hydro)halocarbon produced in step (i) may be a C 3~7 (hydro)haloalkene, preferably a hydrohalopropene, such as chlorotrifluoropropene and / or tetrafluoropropene.

[0072] Preferably, the starting material comprises one or more of CCl3CH2CCl2H (HFC-240fa), CF3CH2CFClH (HCFC-244fa), CF3CH2CF2H (HFC-245fa), CF3CF2CH3 (HFC-245cb), CF3CFHCFH2 (HFC-245eb), CF3CFClCH3 (HCFC-244bb), HCFO-1233xf, tetrachloropropene (HCO-1230), Z-HFO-1234ze, Z-HCFO-1233zd, HFO-1234zc, and CCl3CClHCClH2 (HFC-240db). The starting material may also be CF3CHClCH2Cl (HCFC-243db).

[0073] Advantageously, the hydrohalopropene is HCFO-1233zd and / or HFO-1234ze, and the starting material comprises one or more of CCl3CH2CCl2H (HFC-240fa), CF3CH2CFClH (HCFC-244fa), and CF3CH2CF2H (HFC-245fa) as described, for example, in U.S. Patent Application Publication No. 2014 / 228600, which is incorporated herein by reference. In a further embodiment, the hydrohalopropene can be E-HCFO-1233zd and the starting material comprises E-HCFO-1233zd, or the hydrohalopropene can be E-HFO-1234ze and the starting material comprises one or more of Z-HFO-1234ze or HFO-1234zc.

[0074] Preferably, the hydrohalopropene is HFO-1234yf, and the starting material comprises one or more of CF3CF2CH3 (HFC-245cb), CF3CFHCFH2 (HFC-245eb), CF3CFClCH3 (HCFC-244bb), HCFO-1233xf, tetrachloropropene (HCO-1230), CCl3CClHCClH2 (HFC-240db) as described in International Publication Nos. 2008 / 04096 and 2010 / 123154, which are incorporated herein by reference. The starting material for preparing HFP-1234yf may also be CF3CHClCH2Cl (HCFC-243db).

[0075] Advantageously, the hydrohalopropene is HCFO-1233xf, and the starting materials include tetrachloropropene (HCO-1230) and / or CCl3CClHCClH2 (HFC-240db) as described in International Publication No. WO 2011 / 077394, which is incorporated herein by reference.

[0076] Preferably, the (hydro)halocarbon is HCFC-244bb, and the starting materials include one or more of HCFO-1233xf, tetrachloropropene (HCO-1230), and CCl3CClHCClH2 (HFC-240db) as described in International Publication No. WO 2007 / 125199, which is incorporated herein by reference.

[0077] In some embodiments of the present invention, a composition comprising a (hydro)halocarbon and a compound of formula R f -C≡CX is mixed in a container equipped with an agitator with a basic solution containing a hydroxide, an alkoxide, and / or an amide, optionally in the presence of a suitable solvent. For example, a (hydro)halocarbon containing R f -C≡CX impurities may be contacted with a basic solution containing a hydroxide, an alkoxide, and / or an amide under a suitable amount of pressure to maintain the liquid phases of the (hydro)halocarbon and the basic solution containing the hydroxide, the alkoxide, and / or the amide. The contents of the contact vessel may be stirred so that contact can occur between the (hydro)halocarbon and the basic solution containing the hydroxide, the alkoxide, and / or the amide.

[0078] In some embodiments, the contacting step can be carried out by contacting a mixed gas of the (hydro)halocarbon and the R f -C≡CX impurities with a basic solution containing an oxide, an alkoxide, and / or an amide. For example, the (hydro)halocarbon and the R fA mixture containing -C≡CX impurities may be bubbled as a gas into a basic solution containing a hydroxide, an alkoxide, and / or an amide in a stirred vessel. Subsequently, the (hydro)halocarbon can exit the contact vessel and optionally pass through a condenser where further purification or recovery can occur.

[0079] In some embodiments, the contacting step is carried out in a column filled with a material such as a helix, a ring, a saddle, a sphere, or other shaped bodies made of glass, plastic, or ceramic. The (hydro)halocarbon and R f A mixture containing -C≡CX impurities enters the bottom of the column as a vapor. A basic solution containing a hydroxide, an alkoxide, and / or an amide enters the top of the column, for example, by a pump connected to a reservoir of the basic solution containing a hydroxide, an alkoxide, and / or an amide. Subsequently, the R in the (hydro)halocarbon f -C≡CX impurities are removed by contacting with a basic solution containing a hydroxide, an alkoxide, and / or an amide within the column, and the (hydro)halocarbon vapor passes through the top of the column with reduced R f -C≡CX impurities and are then collected. The basic solution containing a hydroxide, an alkoxide, and / or an amide passes through the bottom of the column and returns to the reservoir.

[0080] The (hydro)halocarbon is recovered in step (iii) by any suitable means, for example, including distillation and / or phase separation.

[0081] The method of the present invention may include one or more additional purification steps such as distillation, condensation, washing, phase separation, acid removal, polishing, and / or drying.

[0082] HF and optionally HCl may be present in the composition obtained from the conversion step. Preferably, at least a portion of the HF, and optionally HCl, in the composition is removed prior to the contacting step. The acid can be removed, for example, by flash separation, aqueous washing and / or distillation. If bulk removal of HF is carried out prior to the contacting step (ii), the residual HF (and optionally HCl) is advantageously removed by the contacting step.

[0083] When the basic solution containing hydroxide, alkoxide and / or amide used in step (ii) is aqueous, it is preferred to have a drying step. Drying of the (hydro)halocarbon can be achieved by known methods such as treatment with sulfuric acid and / or contact with a porous medium such as silica, an aluminum-containing adsorbent (e.g., zeolite) or activated carbon.

[0084] As will be understood by those skilled in the art, any of the preferred and alternative embodiments presented above may be applicable to any of the described aspects of the present invention.

[0085] The present invention will be illustrated by the following non-limiting examples.

Examples

[0086] Experimental section

[0087] A feed mixture was prepared by adding TFMA (2.5 g) to HFO-1234yf (499.98 g). This mixture containing 0.50 wt% TFMA was used in all experiments.

[0088] The solid base was accurately weighed into a 100 mL Hastelloy C22 autoclave and dissolved in deionized water of known weight. When used, a phase transfer catalyst was also added at this point. The container was sealed, purged with nitrogen, and depressurized. The container was then pressurized (4 - 4.5 Barg) with an HFO-1234yf / TFMA feed mixture. The contents of the container were then stirred at 1000 rpm and heated to the desired temperature over 4 - 5 minutes. After reaching the desired temperature, samples of the gas in the headspace of the container were periodically removed and analyzed by gas chromatography.

[0089] Results

[0090] Experiments were conducted using various basic reagents at different concentrations and temperatures, both in the presence and absence of a phase transfer catalyst (Aliquat 336). The results are shown in Tables 1 - 8.

[0091] [Table 1]

[0092] [Table 2]

[0093] [Table 3]

[0094] [Table 4]

[0095] [Table 5]

[0096] [Table 6]

[0097]

Table 7

[0098]

Table 8

[0099] It can be understood that treatment with a base is very effective in reducing the absolute concentration of TFMA in the mixture and increasing the HFO-1234yf content of the mixture relative to the total TFMA.

[0100] After treatment with a base, reduction of other trace impurities was also observed. The results of the reduction of other impurities are summarized in Tables 9 and 10.

[0101]

Table 9

[0102]

Table 10

[0103] Therefore, the method of the present invention is also effective in reducing the levels of R-1225ye(Z), R-236ea and R-245eb in a composition containing HFO-1234yf.

[0104] Experimental section

[0105] The feed mixture was prepared by adding TFMA (1.25 g) to HFO (250 g). These mixtures containing 0.50 wt% TFMA were used in all experiments.

[0106] In a typical cleaning experiment, the base was accurately weighed into a 100 mL Hastelloy C22 autoclave and dissolved in deionized water or solvent of known weight. If used, any additional additives, such as KF or catalyst, were also added at this point. The vessel was then sealed, purged with nitrogen, depressurized, and heated to the desired temperature over 5 minutes. After reaching the temperature, the vessel was then pressurized with an HFO / TFMA feed mixture. The contents of the vessel were then stirred at 1000 rpm, and samples of the gas in the headspace of the vessel were periodically removed and analyzed by gas chromatography.

[0107] Results

[0108] Experiments were conducted using various basic reagents and hydrofluoroolefins (HFOs). The results are shown in Tables 11 to 15.

[0109] [Table 11]

[0110] [Table 12]

[0111] [Table 13]

[0112] [Table 14]

[0113] [Table 15]

[0114] It can be understood that treatment with the base is very effective in reducing the absolute concentration of TFMA in its mixture with a certain range of HFOs and increasing the HFO content of the mixture relative to the total TFMA.

[0115] The present invention encompasses the following aspects. [Aspect 1] (Hydro)halocarbon and a compound of formula R f -C≡CX are contacted with a basic solution containing a hydroxide, an alkoxide, and / or an amide to reduce the concentration of R f -C≡CX, where R f is a perfluorinated alkyl group and X is H, F, Cl, Br, or I. [Aspect 2] The compound of formula R f -C≡CX is 3,3,3-trifluoropropyne (trifluoromethylacetylene, TFMA) in the method according to Aspect 1. [Aspect 3] The solution is an aqueous solution in the method according to Aspect 1 or 2. [Aspect 4] The solution contains one or more of a hydroxide, an alkoxide, or an amide of an alkali metal, a hydroxide or an amide of an alkaline earth metal, or NR4OH, where R is independently H, C 1~10 alkyl group, aryl group (e.g., phenyl group, naphthyl group, or pyridinyl group), or arylalkyl group (e.g., benzyl group or C 1~10 alkyl-substituted phenyl group) in the method according to any one of Aspects 1 to 3. [Aspect 5] The solution contains one or more of potassium hydroxide (KOH), sodium hydroxide (NaOH), or calcium hydroxide (Ca(OH)2) in the method according to any one of Aspects 1 to 4. [Aspect 6] The solution has a concentration of about 0.1 to about 10 M, preferably about 0.2 to about 5 M, such as about 0.5 to about 3 M in the method according to any one of Aspects 1 to 5. [Aspect 7] The (hydro)halocarbon is C 3~7 (hydro)haloalkene, preferably hydrohalopropene in the method according to any one of Aspects 1 to 6. [Aspect 8] The method according to embodiment 7, wherein the hydrohalopropene is chlorotrifluoropropene and / or tetrafluoropropene. [Embodiment 9] The method according to embodiment 8, wherein the chlorotrifluoropropene is CF3CH=CHCl (HCFO-1233zd) and / or CF3CCl=CH2 (HCFO-1233xf). [Embodiment 10] The method according to embodiment 8, wherein the tetrafluoropropene is CF3CH=CHF (HFO-1234ze) and / or CF3CF=CH2 (HFO-1234yf). [Embodiment 11] The method according to any one of embodiments 1 to 10, which is carried out in the presence of a phase transfer catalyst. [Embodiment 12] The method according to any one of embodiments 1 to 11, which is carried out at a temperature of about 0 to about 100°C, preferably about 10 to about 80°C, such as about 20 to about 60°C. [Embodiment 13] The method according to any one of embodiments 1 to 12, having a contact time between the composition and the solution of about 1 second to about 4 hours, preferably about 10 seconds to about 3 hours, such as about 1 minute to about 180 minutes. [Embodiment 14] The method according to any one of embodiments 1 to 13, wherein the composition is in the gas phase at least before contacting with the solution. [Embodiment 15] The method according to any one of embodiments 1 to 14, wherein the composition contains at least about 90% by weight, preferably at least about 95% by weight of the (hydro)halocarbon before the step of contacting. [Embodiment 16] The method according to any one of embodiments 1 to 15, wherein the composition contains about 10,000 ppm or less, preferably about 5,000 ppm or less, such as about 1,000 ppm or less of the compound of the formula R f -C≡CX before the step of contacting. [Embodiment 17] The R in the composition fThe method according to any one of aspects 1 to 16, wherein the amount of the compound of -C≡CX is reduced by at least about 50% by weight, preferably at least about 70% by weight, such as at least about 90% by weight. [Aspect 18] After the step of contacting, the resulting composition contains from 0 to about 500 ppm, preferably from 0 to about 100 ppm, such as from 0 to about 10 ppm, of the compound of the formula R f -C≡CX, the method according to any one of aspects 1 to 17. [Aspect 19] (Hydro)halocarbon and the composition containing the compound of the formula R f -C≡CX further contains an undesired (hydro)halocarbon, and contacting the composition with the basic solution containing a hydroxide, an alkoxide and / or an amide reduces the concentration of the undesired (hydro)halocarbon, the method according to any one of aspects 1 to 18. [Aspect 20] The method according to aspect 19, wherein the undesired (hydro)halocarbon is selected from pentafluoropropene, pentafluoropropane, chlorotetrafluoropropane, hexafluoropropane and mixtures thereof. [Aspect 21] The method according to aspect 20, wherein the undesired (hydro)halocarbon is one or more of CF3CFH=CFH (HFO-1225ye), HFC-245eb, HFC-245fa, HFC-245cb, HCFC-244bb and HFC-236ea. [Aspect 22] The method according to any one of aspects 19 to 21, wherein the amount of the undesired (hydro)halocarbon in the composition is reduced by at least about 50% by weight, preferably at least about 70% by weight, such as at least about 90% by weight. [Aspect 23] After the step of contacting, the resulting composition contains from 0 to about 500 ppm, preferably from 0 to about 100 ppm, such as from 0 to about 10 ppm, of the compound of the undesired (hydro)halocarbon, the method according to any one of aspects 19 to 22. [Aspect 24] The method according to any one of aspects 1 to 23, wherein the composition is a product stream from a process for producing the (hydro)halocarbon. [Aspect 25] The method according to aspect 24, combined with one or more additional purification steps. [Aspect 26] (i) Optionally in the presence of HF and / or a catalyst, converting a starting material into a composition comprising a (hydro)halocarbon and a compound of the formula R f -C≡CX, wherein R f is a perfluorinated alkyl group and X is H, F, Cl, Br, or I, (ii) contacting the composition with a basic solution comprising a hydroxide, an alkoxide and / or an amide to reduce the concentration of the compound of the formula R f -C≡CX, (iii) recovering the (hydro)halocarbon, A method for preparing a (hydro)halocarbon, comprising: [Aspect 27] The method according to aspect 26, wherein the compound of the formula R f -C≡CX is 3,3,3-trifluoropropyne (trifluoromethylacetylene, TFMA). [Aspect 28] The method according to aspect 26 or 27, wherein the solution is an aqueous solution. [Aspect 29] The solution comprises one or more of a hydroxide, an alkoxide or an amide of an alkali metal, a hydroxide or an amide of an alkaline earth metal, or NR4OH, wherein R is independently H, C 1~10 an alkyl group, an aryl group (e.g., a phenyl group, a naphthyl group or a pyridinyl group) or an arylalkyl group (e.g., a benzyl group or a C 1~10 alkyl-substituted phenyl group), the method according to any one of aspects 26 to 28. [Aspect 30] The method according to aspect 29, wherein the solution contains one or more of potassium hydroxide (KOH), sodium hydroxide (NaOH) or calcium hydroxide (Ca(OH)2). [Aspect 31] The method according to any one of Aspects 26 to 30, wherein the solution has a concentration of about 0.1 to about 10 M, preferably about 0.2 to about 5 M, such as about 0.5 to about 3 M. [Aspect 32] The (hydro)halocarbon is C 3~7 (Hydro)haloalkene, preferably hydrohalopropene, the method according to any one of Aspects 26 to 31. [Aspect 33] The method according to Aspect 32, wherein the hydrohalopropene is chlorotrifluoropropene and / or tetrafluoropropene. [Aspect 34] The method according to Aspect 33, wherein the starting material comprises one or more of CCl3CH2CCl2H (HFC-240fa), CF3CH2CFClH (HCFC-244fa), CF3CH2CF2H (HFC-245fa), CF3CF2CH3 (HFC-245cb), CF3CFHCFH2 (HFC-245eb), CF3CFClCH3 (HCFC-244bb), CF3CHClCH2Cl (HCFC-243db), HCFO-1233xf, tetrachloropropene (HCO-1230), Z-HFO-1234ze, Z-HCFO-1233zd, HFO-1234zc or CCl3CClHCClH2 (HFC-240db). [Aspect 35] The method according to Aspect 33, wherein the hydrohalopropene is HCFO-1233zd and / or HFO-1234ze, and the starting material comprises one or more of CCl3CH2CCl2H (HFC-240fa), CF3CH2CFClH (HCFC-244fa) or CF3CH2CF2H (HFC-245fa). [Aspect 36] The method according to embodiment 33, wherein the hydrohalopropene is HFO-1234yf and the starting material comprises one or more of CF3CF2CH3 (HFC-245cb), CF3CFHCFH2 (HFC-245eb), CF3CFClCH3 (HCFC-244bb), CF3CHClCH2Cl (HCFC-243db), HCFO-1233xf, tetrachloropropene (HCO-1230), or CCl3CClHCClH2 (HFC-240db). [Embodiment 37] The method according to embodiment 33, wherein the hydrohalopropene is HCFO-1233xf and the starting material comprises tetrachloropropene (HCO-1230) and / or CCl3CClHCClH2 (HFC-240db). [Embodiment 38] The method according to embodiment 33, wherein the (hydro)halocarbon is HCFC-244bb and the starting material comprises one or more of HCFO-1233xf, tetrachloropropene (HCO-1230), or CCl3CClHCClH2 (HFC-240db). [Embodiment 39] The method according to any one of embodiments 26 to 38, wherein the contacting step is carried out in the presence of a phase transfer catalyst. [Embodiment 40] The method according to any one of embodiments 26 to 39, wherein the contacting step is carried out at a temperature of about 0 to about 100 °C, preferably about 10 to about 80 °C, such as about 20 to about 60 °C. [Embodiment 41] The method according to any one of embodiments 26 to 40, wherein the contacting step has a contact time between the composition and the solution of about 1 second to about 4 hours, preferably about 10 seconds to about 3 hours, such as about 1 minute to about 180 minutes. [Embodiment 42] The method according to any one of embodiments 26 to 41, wherein the composition is in the gas phase at least before contacting with the solution. [Embodiment 43] The method according to any one of embodiments 26 to 42, wherein the composition comprises at least about 90% by weight, preferably at least about 95% by weight, of the (hydro)halocarbon before the contacting step. [Aspect 44] Before the step of bringing into contact, the composition contains a compound of the formula R-C≡CX, such as 1000 ppm or less, preferably 5000 ppm or less, more preferably 10000 ppm or less, of the method according to any one of Aspects 26 to 43. f -C≡CX, of the method according to any one of Aspects 26 to 43. [Aspect 45] The amount of the compound of the formula R-C≡CX in the composition is reduced by at least about 50% by weight, preferably at least about 70% by weight, more preferably at least about 90% by weight, in the step of bringing into contact, of the method according to any one of Aspects 26 to 44. f -C≡CX, of the method according to any one of Aspects 26 to 44. [Aspect 46] After the step of bringing into contact, the resulting composition contains a compound of the formula R-C≡CX of 0 to about 10 ppm, preferably 0 to about 100 ppm, more preferably 0 to about 500 ppm, of the method according to any one of Aspects 26 to 45. f -C≡CX, of the method according to any one of Aspects 26 to 45. [Aspect 47] The method according to any one of Aspects 26 to 46, further comprising one or more additional purification steps. [Aspect 48] HF is present in the composition obtained from the step of converting, of the method according to any one of Aspects 26 to 47. [Aspect 49] At least a part of the HF in the composition is removed before the step of bringing into contact, of the method according to Aspect 48.

Claims

1. A method for reducing the concentration of a compound of the formula Rf-C≡CX, comprising a (hydro)halocarbon and a compound of the formula R ｆ -C≡CX is contacted with a basic solution comprising a hydroxide of an alkali metal, a hydroxide of an alkaline earth metal, an alkoxide of an alkali metal, and / or an alkoxide of an alkaline earth metal to reduce the concentration of R ｆ -C≡CX, wherein R ｆ is a perfluorinated alkyl group and X is H, F, Cl, Br, or I, the basic solution has a concentration of 0.1 to 10 M, and the (hydro)halocarbon is CF ３ CH=CHCl (HCFO-1233zd), CF ３ CCl=CH ２ (HCFO-1233xf), CF ３ CH=CHF (HFO-1234ze), and / or CF ３ CF=CH ２ (HFO-1234yf), which is a hydrohalopropene selected from the group consisting of: (Hydro)halocarbons and formula R ｆ The composition containing a compound of -C≡CX further contains an unwanted (hydro)halocarbon, and contacting the composition with the basic solution containing a hydroxide of an alkali metal, a hydroxide of an alkaline earth metal, an alkoxide of an alkali metal, and / or an alkoxide of an alkaline earth metal reduces the concentration of the unwanted (hydro)halocarbon, and the unwanted (hydro)halocarbon is CF ３ CF=CFH (HFO-1225ye), HFC-245eb, HFC-245fa, HFC-245cb, HCFC-244bb and one or more of HFC-236ea, method.

2. Said formula R ｆ The method according to claim 1, wherein the compound of -C≡CX is 3,3,3-trifluoropropyne (trifluoromethylacetylene, TFMA).

3. The method according to claim 1 or 2, wherein the solution is an aqueous solution.

4. The method according to any one of claims 1 to 3, wherein the solution contains one or more of potassium hydroxide (KOH), sodium hydroxide (NaOH), or calcium hydroxide (Ca(OH) ２ ).

5. The method according to any one of claims 1 to 4, wherein the solution has a concentration of 0.2 to 5 M.

6. The method according to claim 5, wherein the solution has a concentration of 0.5 to 3 M.

7. The method according to any one of claims 1 to 6, which is carried out in the presence of a phase transfer catalyst.

8. The method according to any one of claims 1 to 7, which is carried out at a temperature of 0 to 100 °C.

9. The method according to claim 8, which is carried out at a temperature of 10 to 80 °C.

10. The method according to claim 9, which is carried out at a temperature of 20 to 60 °C.

11. The method according to any one of claims 1 to 10, having a contact time between the composition and the solution of 1 second to 4 hours.

12. The method according to claim 11, having a contact time between the composition and the solution of 10 seconds to 3 hours.

13. The method according to claim 12, having a contact time between the composition and the solution of 1 minute to 180 minutes.

14. The method according to any one of claims 1 to 13, wherein the composition is in the gas phase at least before contacting with the solution.

15. The method according to any one of claims 1 to 14, wherein the composition contains at least 90% by weight of the (hydro)halocarbon before the step of contacting.

16. The method according to claim 15, wherein the composition contains at least 95% by weight of the (hydro)halocarbon before the step of contacting.

17. Before the step of contacting, the composition contains a compound of the formula R ｆ -C≡CX in an amount of 10,000 ppm or less. The method according to any one of claims 1 to 16.

18. Before the step of contacting, the composition contains a compound of the formula R ｆ -C≡CX at 5000 ppm or less. The method according to claim 17.

19. The composition contains, prior to the step of bringing into contact, 1000 ppm or less of the compound of the formula R ｆ -C≡CX, the method according to claim 18.

20. The amount of the compound of the formula R ｆ -C≡CX in the composition is reduced by at least 50% by weight, the method according to any one of claims 1 to 19.

21. The amount of the compound of the formula R ｆ -C≡CX in the composition is reduced by at least 70% by weight, the method according to claim 20.

22. The amount of the compound of the formula R ｆ -C≡CX in the composition is reduced by at least 90% by weight, the method according to claim 21.

23. After the step of bringing into contact, the resulting composition contains from 0 to 500 ppm of the compound of the formula R ｆ -C≡CX, the method according to any one of claims 1 to 22.

24. After the step of bringing into contact, the resulting composition contains 0 to 100 ppm of the compound of the formula R ｆ -C≡CX, the method according to claim 23.

25. After the step of bringing into contact, the resulting composition contains 0 to 10 ppm of the compound of the formula R ｆ -C≡CX, the method according to claim 24.

26. The method according to any one of claims 1 to 25, wherein the amount of the undesired (hydro)halocarbon in the composition is reduced by at least 20% by weight.

27. The method according to claim 26, wherein the amount of the undesired (hydro)halocarbon in the composition is reduced by at least 50% by weight.

28. The method according to claim 27, wherein the amount of the undesired (hydro)halocarbon in the composition is reduced by at least 70% by weight.

29. The method according to claim 28, wherein the amount of the undesired (hydro)halocarbon in the composition is reduced by at least 90% by weight.

30. The method according to any one of claims 1 to 29, wherein after the step of bringing into contact, the resulting composition contains 0 to 500 ppm of said compound of said undesired (hydro)halocarbon.

31. The method according to claim 30, wherein after the step of bringing into contact, the resulting composition contains 0 to 100 ppm of said compound of said undesired (hydro)halocarbon.

32. The method according to claim 31, wherein after the step of bringing into contact, the resulting composition contains 0 to 10 ppm of said compound of said undesired (hydro)halocarbon.

33. The method according to any one of claims 1 to 32, wherein the composition is a product stream from a process for producing said (hydro)halocarbon.

34. The method according to claim 33, combined with one or more additional purification steps.

35. (i) Optionally in the presence of HF and / or a catalyst, convert the starting material to obtain an intermediate composition different from the starting material, comprising a (hydro)halocarbon and a compound of the formula R ｆ -C≡CX, wherein R ｆ is a perfluorinated alkyl group and X is H, F, Cl, Br, or I, and the (hydro)halocarbon is CF ３ CH=CHCl (HCFO-1233zd), CF ３ CCl=CH ２ (HCFO-1233xf), CF ３ CH=CHF (HFO-1234ze), and / or CF ３ CF=CH ２ (HFO-1234yf), a hydrohalopropene selected therefrom, and the intermediate composition comprising the (hydro)halocarbon and the compound of the formula R ｆ -C≡CX further comprises an undesired (hydro)halocarbon, and the undesired (hydro)halocarbon is one or more of CF ３ CF=CFH (HFO-1225ye), HFC-245eb, HFC-245fa, HFC-245cb, HCFC-244bb and HFC-236ea; (ii) contacting the intermediate composition with a basic solution comprising a hydroxide of an alkali metal, a hydroxide of an alkaline earth metal, an alkoxide of an alkali metal, and / or an alkoxide of an alkaline earth metal to reduce the concentration of the compound of the formula R ｆ -C≡CX and the concentration of the unwanted (hydro)halocarbon, and the basic solution has a concentration of 0.1 to 10 M; (iii) recovering said (hydro)halocarbon, A method for preparing a (hydro)halocarbon, comprising:

36. Said formula R ｆ The method according to claim 35, wherein the compound of -C≡CX is 3,3,3-trifluoropropyne (trifluoromethylacetylene, TFMA).

37. The method according to claim 35 or 36, wherein the solution is an aqueous solution.

38. The method according to any one of claims 35 to 37, wherein the solution contains one or more of potassium hydroxide (KOH), sodium hydroxide (NaOH), or calcium hydroxide (Ca(OH) ２ ).

39. The method according to any one of claims 35 to 38, wherein the solution has a concentration of 0.2 to 5 M.

40. The method according to claim 39, wherein the solution has a concentration of 0.5 to 3 M.

41. wherein the starting material is CCl ３ CH ２ CCl ２ H (HFC-240fa), CF ３ CH ２ CFClH (HCFC-244fa), CF ３ CH ２ CF ２ H (HFC-245fa), CF ３ CF ２ CH ３ (HFC-245cb), CF ３ CFHCFH ２ (HFC-245eb), CF ３ CFClCH ３ (HCFC-244bb), CF ３ CHClCH ２ Cl (HCFC-243db), HCFO-1233xf, tetrachloropropene (HCO-1230), Z-HFO-1234ze, Z-HCFO-1233zd, HFO-1234zc or CCl ３ CClHCCClH ２ (HFC-240db), the method according to any one of claims 35 to 40, comprising one or more of them.

42. The hydrohalopropene is HCFO-1233zd and / or HFO-1234ze, and the starting material is CCl ３ CH ２ CCl ２ H (HCFC-240fa), CF ３ CH ２ CFClH (HCFC-244fa) or CF ３ CH ２ CF ２ H (HFC-245fa), and the method according to claim 41, comprising one or more of them.

43. The hydrohalopropene is HFO-1234yf, and the starting material is CF ３ CF ２ CH ３ (HFC-245cb), CF ３ CFHCFH ２ (HFC-245eb), CF ３ CFClCH ３ (HCFC-244bb), CF ３ CHClCH ２ Cl (HCFC-243db), HCFO-1233xf, tetrachloropropene (HCO-1230) or CCl ３ CClHCCClH ２ The method according to claim 41, comprising one or more of (HFC-240db).

44. The hydrohalopropene is HCFO-1233xf, and the starting material is tetrachloropropene (HCO-1230) and / or CCl ３ CClHCCIH ２ The method according to any one of claims 35 to 40, comprising (HFC-240db).

45. The method according to any one of claims 35 to 44, wherein the step of bringing into contact is carried out in the presence of a phase transfer catalyst.

46. The method according to any one of claims 35 to 45, wherein the step of bringing into contact is carried out at a temperature of 0 to 100 °C.

47. The method according to claim 46, wherein the step of bringing into contact is carried out at a temperature of 10 to 80 °C.

48. The method according to claim 47, wherein the step of bringing into contact is carried out at a temperature of 20 to 60 °C.

49. The method according to any one of claims 35 to 48, wherein the step of bringing into contact has a contact time between the intermediate composition and the solution of 1 second to 4 hours.

50. The method according to claim 49, wherein the step of bringing into contact has a contact time between the intermediate composition and the solution of 10 seconds to 3 hours.

51. The method according to claim 50, wherein the step of bringing into contact has a contact time between the intermediate composition and the solution of 1 minute to 180 minutes.

52. The method according to any one of claims 35 to 51, wherein the intermediate composition is in the gas phase at least before contacting with the solution.

53. The method according to any one of claims 35 to 52, wherein the intermediate composition contains at least 90% by weight of the (hydro)halocarbon before the step of contacting.

54. The method according to claim 53, wherein the intermediate composition contains at least 95% by weight of the (hydro)halocarbon before the step of contacting.

55. Before the step of bringing into contact, the intermediate composition contains, at 10,000 ppm or less, the compound of the formula R ｆ -C≡CX, the method according to any one of claims 35 to 54.

56. The intermediate composition contains, prior to the contacting step, 5000 ppm or less of the compound of the formula R ｆ -C≡CX, the method according to claim 55.

57. The method according to claim 56, wherein the intermediate composition contains, prior to the step of bringing into contact, a compound of the formula R ｆ -C≡CX in an amount of 1000 ppm or less.

58. The amount of the compound of the formula R ｆ -C≡CX in the intermediate composition is reduced by at least 50% by weight in the contacting step, the method according to any one of claims 35 to 57.

59. The amount of the compound of the formula R ｆ -C≡CX in the intermediate composition is reduced by at least 70% by weight in the step of bringing them into contact, the method according to claim 58.

60. The amount of the compound of the formula R ｆ -C≡CX in the intermediate composition is reduced by at least 90% by weight in the step of bringing them into contact, the method according to claim 59.

61. After the step of bringing into contact, the resulting composition contains 0 to 500 ppm of the compound of the formula R ｆ -C≡CX, the method according to any one of claims 35 to 60.

62. After the step of bringing into contact, the resulting composition contains 0 to 100 ppm of the compound of the formula R ｆ -C≡CX, the method according to claim 61.

63. After the step of bringing into contact, the resulting composition contains 0 to 10 ppm of the compound of the formula R ｆ -C≡CX, the method according to claim 62.

64. The method according to any one of claims 35 to 63, further comprising one or more additional purification steps.

65. The method according to any one of claims 35 to 64, wherein HF is present in the intermediate composition obtained from the step of converting.

66. The method according to claim 65, wherein at least a part of the HF in the intermediate composition is removed before the step of contacting.

67. The step of contacting is carried out by contacting a gaseous intermediate composition containing the (hydro)halocarbon and the compound of R ｆ -C≡CX with the basic solution, and the method according to any one of claims 1 to 66.

68. The method according to claim 67, wherein the intermediate composition containing the (hydro)halocarbon and the compound of Rf-C≡CX is bubbled as a gas into the basic solution in a stirring vessel.

69. The method according to claim 68, wherein the (hydro)halocarbon is discharged from the vessel through a condenser.

70. The method according to any one of claims 1 to 69, further comprising a step of drying the (hydro)halocarbon.

71. The method according to claim 70, wherein the drying of the (hydro)halocarbon is performed by treatment with sulfuric acid and / or contact with a porous medium.

Images