619results about "Preparation by halogen addition" patented technology

Disclosed are processes for the production of fluorinated olefins, preferably adapted to commercialization of CF3CF═CH2 (1234yf). Three steps may be used in preferred embodiments in which a feedstock such as CCl2═CClCH2Cl (which may be purchased or synthesized from 1,2,3-trichloropropane) is fluorinated (preferably with HF in gas-phase in the presence of a catalyst) to synthesize a compound such as CF3CCl═CH2, preferably in a 80-96% selectivity. The CF3CCl═CH2 is preferably converted to CF3CFClCH3 (244-isomer) using a SbCl5 as the catalyst which is then transformed selectively to 1234yf, preferably in a gas-phase catalytic reaction using activated carbon as the catalyst. For the first step, a mixture of Cr2O3 and FeCl3 / C is preferably used as the catalyst to achieve high selectivity to CF3CCl═CH2 (96%). In the second step, SbCl5 / C is preferably used as the selective catalyst for transforming 1233xf to 244-isomer, CF3CFClCH3. The intermediates are preferably isolated and purified by distillation and used in the next step without further purification, preferably to a purity level of greater than about 95%.

A method for preparing 2,3,3,3-tetrafluoroprop-1-ene comprising (a) providing a starting composition comprising at least one compound having a structure selected from Formulae I, II and III:CX2═CCl—CH2X  (Formula I)CX3—CCl═CH2  (Formula II)CX3—CHCl—CH2X  (Formula III)wherein X is independently selected from F, Cl, Br, and I, provided that at least one X is not fluorine;(b) contacting said starting composition with a first fluorinating agent to produce a first intermediate composition comprising 2-chloro-3,3,3-trifluoropropene and a first chlorine-containing byproduct; (c) contacting said first intermediate composition with a second fluorinating agent to produce a second intermediate composition comprising 2-chloro-1,1,1,2-tetrafluoropropane and a second chlorine-containing byproduct; and (d) catalytically dehydrochlorinating at least a portion of said 2-chloro-1,1,1,2-tetrafluoropropane to produce a reaction product comprising 2,3,3,3-tetrafluoroprop-1-ene.

Disclosed are processes for the production of fluorinated olefins, preferably adapted to commercialization of CF3CF═CH2 (1234yf). Three steps may be used in preferred embodiments in which a feedstock such as CCl2═CClCH2Cl (which may be purchased or synthesized from 1,2,3-trichloropropane) is fluorinated (preferably with HF in gas-phase in the presence of a catalyst) to synthesize a compound such as CF3CCl═CH2, preferably in a 80-96% selectivity. The CF3CCl═CH2 is preferably converted to CF3CFClCH3 (244-isomer) using a SbCl5 as the catalyst which is then transformed selectively to 1234yf, preferably in a gas-phase catalytic reaction using activated carbon as the catalyst. For the first step, a mixture of Cr2O3 and FeCl3 / C is preferably used as the catalyst to achieve high selectivity to CF3CCl═CH2 (96%). In the second step, SbCl5 / C is preferably used as the selective catalyst for transforming 1233xf to 244-isomer, CF3CFClCH3. The intermediates are preferably isolated and purified by distillation and used in the next step without further purification, preferably to a purity level of greater than about 95%.

The invention provides an economic process for the manufacture of 1,3,3,3-tetrafluoropropene (HFC-1234ze) by a two stage process. A hydrofluorination of 1-chloro-3,3,3-trifluoropropene (HCFC-1233zd) into 1-chloro-1,3,3,3-tetrafluoropropane (HCFC-244fa) and 1,1,1,3,3-pentafluoropropane (HFC-245fa) is conducted, followed by the dehydrochlorination of HCFC-244fa and dehydrofluorination of HFC-245fa into HFC-1234ze.

The present invention relates to an improved method for manufacturing 2-chloro-3,3,3,-trifluoropropene (HCFC-1233xf) by reacting 1,1,2,3-tetrachloropropene, 1,1,1,2,3-pentachloropropane, and / or 2,3,3,3-tetrachloropropene with hydrogen fluoride, in a vapor phase reaction vessel in the presence of a vapor phase fluorination catalyst and stabilizer. HCFC-1233xf is an intermediate in the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf) which is a refrigerant with low global warming potential.

The present invention relates to an improved method for manufacturing 2-chloro-3,3,3,-trifluoropropene (HCFC-1233xf) by reacting 1,1,2,3-tetrachloropropene, 1,1,1,2,3-pentachloropropane, and / or 2,3,3,3-tetrachloropropene with hydrogen fluoride, in a vapor phase reaction vessel in the presence of a vapor phase fluorination catalyst and stabilizer. HCFC-1233xf is an intermediate in the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf) which is a refrigerant with low global warming potential.

Disclosed is a process for the synthesis of 1,3,3,3-tetrafluoropropene that comprises, in one preferred embodiment, providing a compound of the formula CF3CH2CHFX, wherein X is a selected from the group consisting of chlorine, bromine and iodine, and exposing said compound to reaction conditions effective to convert said compound to 1,3,3,3-tetrafluoropropene. Other processes for forming 1,3,3,3-tetrafluoropropene are also disclosed.

A process for producing a fluoroolefin of the formula: CF.sub.3CY.dbd.CX.sub.nH.sub.p wherein Y is a hydrogen atom or a halogen atom (i.e., fluorine, chlorine, bromine or iodine); X is a hydrogen atom or a halogen atom (i.e., fluorine, chlorine, bromine or iodine); n and p are integers independently equal to 0, 1 or 2, provided that (n+p)=2; comprising contacting, in the presence of a phase transfer catalyst, a compound of the formula: CF.sub.3C(R.sup.1.sub.aR.sup.2.sub.b) C(R.sup.3.sub.cR.sup.4.sub.d), wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently a hydrogen atom or a halogen selected from the group consisting of fluorine, chlorine, bromine and iodine, provided that at least one of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 is halogen and there is at least one hydrogen and one halogen on adjacent carbon atoms; a and b are independently=0, 1 or 2 and (a+b)=2; and c and d are independently=0, 1, 2 or 3 and (c+d)=3; and at least one alkali metal hydroxide. The alkali metal hydroxide can be, for example, potassium or sodium hydroxide and the phase transfer catalyst can be, for example, at least one: crown ether such as 18-crown-6 and 15-crown-5; or onium salt such as, quaternary phosphonium salt and quaternary ammonium salt. The olefin is useful, for example, as an intermediate for producing other industrial chemicals and as a monomer for producing oligomers and polymers.

The present invention discloses a manufacturing process to produce high purity 1234yf from 245eb, which preferably includes the removal of impurities present in 245eb raw material, the dehydrofluorination of 245eb, and the removal of impurities present in final crude product. The disclosed manufacturing process allows the production of a 1234yf product with lower the levels of 1225ye and / or trifluoropropene, preferably in amounts of less than about 500, and 50 ppm, respectively.

A catalyst composition is disclosed that includes chromium, oxygen, and at least two of gold, silver, and palladium as essential constituent elements. The amount of modifier metals (gold, silver, and / or palladium) in the composition is from about 0.05 atom % to about 10 atom % based on the total amount of chromium and modifier metals. Also disclosed is a process for changing the fluorine distribution (i.e., content and / or arrangement) in a hydrocarbon or halogenated hydrocarbon in the presence of the catalyst composition; and methods for preparing said catalyst composition. One preparation method involves (a) co-precipitating a solid by adding ammonium hydroxide (aqueous ammonia) to an aqueous solution of soluble salts of modifier metals and a soluble chromium salt that contains at least three moles of nitrate per mole of chromium in the solution and has a modifier metal content of from about 0.05 atom % to about 10 atom % of the total content of modifier metals and chromium in the solution to form an aqueous mixture containing co-precipitated solid; (b) drying the co-precipitated solid formed in (a); and (c) calcining the dried solid formed in (b) in an atmosphere containing at least 10% oxygen by volume. Another preparation method involves (a) impregnating solid chromium oxide with a solution of a soluble modifier metal salts; (b) drying the impregnated chromium oxide prepared in (a); and optionally; (c) calcining the dried solid. Yet another preparation method involves mixing multiple compositions, each comprising chromium, oxygen, and at least one modifier metal.

An improved continuous process for converting methane, natural gas, and other hydrocarbon feedstocks into one or more higher hydrocarbons, methanol, amines, or other products comprises continuously cycling through hydrocarbon halogenation, product formation, product separation, and electrolytic regeneration of halogen, optionally using an improved electrolytic cell equipped with an oxygen depolarized cathode.

A mixture comprising at least 1,1,1,3,3-pentafluoropropane and 1,1,1-trifluoro-3-chloro-2-propene is subjected to a distillation operation, and thereby, a distillate comprising an azeotropic composition consisting substantially of 1,1,1,3,3-pentafluoropropane and 1,1,1-trifluoro-3-chloro-2-propene is obtained and a bottom product comprising 1,1,1,3,3-pentafluoropropane or 1,1,1-trifluoro-3-chloro-2-propene which each is separated and purified.

Provided is a continuous process for preparing 1,1,2,3-tetrachloro-1-propene having the steps of catalytically dehydrochlorinating CH2ClCCl2CH2Cl in the gas phase to produce CHCl═CClCH2Cl; chlorinating the CHCl═CClCH2Cl to form CHCl2CCl2CH2Cl; and catalytically dehydrochlorinating the CHCl2CCl2CH2Cl in the gas phase to form CCl2═CClCH2Cl.

The invention refers to a process for the production of high-purity 1,2-dichloroethane from dissolved chlorine and dissolved ethylene, which are brought into contact with each other in a circulating liquid reaction fluid, which mainly consists of 1,2-dichlorethane and a catalyst and flows through at least one vertically arranged loop-type reaction section, both legs of the loop being connected to an overhead degassing vessel from where the reaction product is withdrawn either in gaseous or in liquid state or in both gaseous and liquid state, and numerous admixing sections being arranged in the leg of the loop in which the liquid rises, and each of these admixing sections having one upstream feed point for dissolved or gaseous ethylene and one downstream feed point for dissolved chlorine and, if required, the admixing sections featuring static mixers.

The invention relates to a method for producing high-purity 1,2-dichloroethane from dissolved chlorine and dissolved ethylene which are brought into contact with each other using a circulating liquid reaction medium which essentially consists of 1,2-dichloroethane and a catalyst and passes through at least one reaction loop. The two limbs of the loop are connected to a gas-phase stripping container which is arranged at the top and from which the reaction product is outwardly transferred either in a gaseous or liquid form or both in a gaseous form and in a liquid form. The addition points for the addition of chlorine and dissolved ethylene are arranged in the limb of the loop in which the liquid rises. The addition point for dissolved chlorine is always arranged downstream of the ethylene addition point. At least one addition point for liquid 1,2-dichloroethane follows each chlorine addition point, and the addition of the liquid 1,2-dichloroethane is carried out under kinetic energy which is high enough to enable a vigorous mixture of 1,2-dichloroethane, dissolved chlorine and ethylene to be carried out. Preferably, the liquid 1,2-dichloroethane is added by means of at least one jet mixer.

Compounds corresponding to formula (I)F2C=CFX(CY2)nBr (I)in which: X represents an atom of oxygen or no atom; Y represents an atom of hydrogen or of fluorine; and n is a whole natural number ranging from 0 to 10 inclusive, excluding bromotrifluoroethylene, 3-bromo-perfluoropropene, 4-bromo-1,1,2,-trifluorobutene, 4-bromo-perfluorobutene-1 and perfluoro(2-bromo-ethylvinyl ester), and their use in the synthesis of fluorinated copolymers then in the synthesis of homosulphonated fluorinated elastomers, exhibiting a low glass transition temperature.

A process for converting gaseous alkanes to olefins, higher molecular weight hydrocarbons or mixtures thereof wherein a gaseous feed containing alkanes is thermally reacted with a dry bromine vapor to form alkyl bromides and hydrogen bromide. Poly-brominated alkanes present in the alkyl bromides are further reacted with methane over a suitable catalyst to form mono-brominated species. The mixture of alkyl bromides and hydrogen bromide is then reacted over a suitable catalyst at a temperature sufficient to form olefins, higher molecular weight hydrocarbons or mixtures thereof and hydrogen bromide. Various methods are disclosed to remove the hydrogen bromide from the higher molecular weight hydrocarbons, to generate bromine from the hydrogen bromide for use in the process, and to selectively form mono-brominated alkanes in the bromination step.

Provided is a continuous process for preparing 1,1,2,3-tetrachloro-1-propene having the steps of catalytically dehydrochlorinating CH2ClCCl2CH2Cl in the gas phase to produce CHCl═CClCH2Cl; chlorinating the CHCl═CClCH2Cl to form CHCl2CCl2CH2Cl; and catalytically dehydrochlorinating the CHCl2CCl2CH2Cl in the gas phase to form CCl2═CClCH2Cl.

A method comprising: providing a halogen stream; providing an alkane stream; providing a decoking agent; and reacting at least a portion of the halogen stream with at least a portion of the alkane stream in the presence of a halogenation catalyst and the decoking agent to form a halogenated stream.

A method comprising: providing an alkyl halide stream; contacting at least some of the alkyl halides with a coupling catalyst to form a product stream comprising higher hydrocarbons and hydrogen halide; contacting the product stream with a solid reactant to remove at least a portion of the hydrogen halide from the product stream; and reacting the solid reactant with a source of oxygen to generate a corresponding halogen.

A process for converting gaseous alkanes to olefins, higher molecular weight hydrocarbons or mixtures thereof wherein a gaseous feed containing alkanes is reacted with a dry bromine vapor to form alkyl bromides and hydrobromic acid vapor. The mixture of alkyl bromides and hydrobromic acid is then reacted over a suitable catalyst at a temperature sufficient to form olefins, higher molecular weight hydrocarbons or mixtures thereof and hydrobromic acid vapor. Various methods are disclosed to remove the hydrobromic acid vapor from the higher molecular weight hydrocarbons, to generate bromine from the hydrobromic acid for use in the process, and to selectively form monobrominated alkanes in the bromination step.