528results about "Hydrogen fluoride" patented technology

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 herein are processes for the production of hydrofluoroolefins by dehydrofluorination. Also disclosed herein are processes for separation of hydrofluoroolefins from hydrofluorocarbons and from hydrogen fluoride.

Disclosed herein are azeotrope or near-azeotrope compositions comprising 2,3,3,3-tetrafluoropropene (HFC-1234yf) and hydrogen fluoride (HF). These compositions are useful in processes to produce and purify HFC-1234yf. Additionally, disclosed herein are processes for the manufacture of HFC-1234yf.

Disclosed herein are azeotrope and near-azeotrope compositions comprising E-1,3,3,3-tetrafluoropropene and hydrogen fluoride. These azeotrope and near-azeotrope compositions are useful in processes to produce E-1,3,3,3-tetrafluoropropene and in processes to purify E-1,3,3,3-tetrafluoropropene from mixtures of E-1,3,3,3-tetrafluoropropene with 1,1,1,3,3-pentafluoropropane and / or with hydrogen fluoride.

1,1,3,3,3-Pentafluoropropene (CF3CH═CF2, HFC-1225zc) can be produced by pyrolyzing 1,1,1,3,3,3-hexafluoropropane (CF3CH2CF3, HFC-236fa) in the absence of dehydrofluorination catalyst at temperatures of from about 700° C. to about 1000° C. and total pressures of about atmosphere pressure in an empty, tubular reactor, the interior surfaces of which comprise materials of construction resistant to hydrogen fluoride.

An integrated process for the manufacture of HFO trans-1,3,3,3-tetrafluoropropene (HFO trans-1234ze) by first catalytically dehydrofluorinating 1,1,1,3,3-pentafluoropropane to thereby produce a mixture of cis-1,3,3,3-tetrafluoropropene, trans-1,3,3,3-tetrafluoropropene and hydrogen fluoride. Then optionally recovering hydrogen fluoride, catalytically isomerizing cis-1234ze into trans-1234ze, and recovering trans-1,3,3,3-tetrafluoropropene.

According to the first characteristic of the present invention, there is provided a production process for 1,3,3,3-tetrafluoropropene including: the first step of reacting 1,1,1,3,3-pentachloropropane with hydrogen fluoride thereby obtaining 1-chloro-3,3,3-trifluoropropene; and the second step of reacting 1-chloro-3,3,3-trifluoropropene obtained in the first step with hydrogen fluoride in a gaseous phase in the presence of a fluorination catalyst. According to the second characteristic of the present invention, there is provided a dehydration process including bringing 1,3,3,3-tetrafluoropropene containing at least water into contact with zeolite.

Disclosed herein are azeotrope compositions comprising 1,2,3,3,3-pentafluoropropene and hydrogen fluoride. The azeotrope compositions are useful in processes to produce and in processes to purify 1,2,3,3,3-pentafluoropropene.

Disclosed herein are azeotrope or near-azeotrope compositions comprising 2,3,3,3-tetrafluoropropene (HFC-1234yf) and hydrogen fluoride (HF). These compositions are useful in processes to produce and purify HFC-1234yf. Additionally, disclosed herein are processes for the manufacture of HFC-1234yf.

Disclosed herein is a process to produce an azeotrope composition comprising a hydrofluoroolefin and hydrogen fluoride, said process comprising, dehydrofluorinating a hydrofluorocarbon containing at least one hydrogen and at least one fluorine on adjacent carbons, thereby forming a mixture comprising said hydrofluoroolefin, unreacted hydrofluorocarbon and hydrogen fluoride, and distilling the mixture to produce a distillate composition comprising an azeotrope composition containing said hydrofluoroolefin and hydrogen fluoride and a column bottoms composition comprising said hydrofluorocarbon essentially free of hydrogen fluoride. Also disclosed herein are processes for separation of hydrofluoroolefins from hydrofluorocarbons and from hydrogen fluoride.

The invention relates to azeotropic and azeotrope-like mixtures of 1,1,1-trifluoroethane (HFC-143a) and hydrogen fluoride and a process for separating the azeotrope-like mixtures. The compositions of the invention are useful as an intermediate in the production of HFC-143a. The latter is useful as a nontoxic, zero ozone depleting fluorocarbon useful as a solvent, blowing agent, refrigerant, cleaning agent and aerosol propellant.

A liquid phase process is disclosed for producing halogenated alkane adducts of the formula CAR1R2CBR3R4 (where A, B, R1, R2, R3, and R4 are as defined in the specification) which involves contacting a corresponding halogenated alkane, AB, with a corresponding olefin, CR1R2═CR3R4 in a dinitrile or cyclic carbonate ester solvent which divides the reaction mixture into two liquid phases and in the presence of a catalyst system containing (i) at least one catalyst selected from monovalent and divalent copper; and optionally (ii) a promoter selected from aromatic or aliphatic heterocyclic compounds which contain at least one carbon-nitrogen double bond in the heterocyclic ring. When hydrochlorofluorocarbons are formed, the chlorine content may be reduced by reacting the hydrochlorofluorocarbons with HF. New compounds disclosed include CF3CF2CCl2CH2CCl3, CF3CCl2CH2CH2Cl and CF3CCl2CH2CHClF. These compounds are useful as intermediates for producing hydrofluorocarbons. Azeotropes of CClF2CH2CF3 with HF and azeotropes of CF3CH2CHF2 with HF are also disclosed; as are process for producing such azeotropes. A process for purification of certain hydrofluorocarbons and / or chloro-precursors thereof from mixtures of such compounds with HF is also disclosed.

This invention provides a method for purifying HFO-1234yf by removing HF from a mixture of HFO-1234yf and HF under simple and economically advantageous conditions. According to the present invention, this is a purification method for 2,3,3,3-tetrafluoropropene, (1) the purification method comprising the step of subjecting a mixture comprising 2,3,3,3-tetrafluoropropene and hydrogen fluoride to extractive distillation in a distillation column A using an extractant, thereby obtaining a fraction I that contains 2,3,3,3-tetrafluoropropene and has a lower ratio of hydrogen fluoride to 2,3,3,3-tetrafluoropropene than that of the mixture, while obtaining a fraction II that contains hydrogen fluoride and has a lower ratio of 2,3,3,3-tetrafluoropropene to hydrogen fluoride than that of the mixture; (2) the extractant comprising at least one member selected from the group consisting of: (i) alcohols represented by ROH, wherein R is a C1-5 alkyl group, (ii) ethers represented by ROR′, wherein R and R′ are the same or different, and each is a C1-4 alkyl group, (iii) fluorinated alcohols represented by RfOH, wherein Rf is a C1-3 fluoroalkyl group, (iv) ketones represented by RCOR′, wherein R and R′ are the same or different, and each is a C1-4 alkyl group, (v) esters represented by RCOOR′, wherein R and R′ are the same or different, and each is a C1-4 alkyl group, (vi) polyols represented by R(OH)n, wherein R is a C1-4 alkyl group, and n is an integer of 2 to 3, and (vii) ethylene glycols represented by R1O(CH2CH2O)nR2, wherein R1 and R2 are the same or different, and each is hydrogen or a C1-4 alkyl group, and n is an integer of 1 to 3.

The present invention pertains to azeotropic and azeotrope-like compositions of the following three blends:1. Trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)), cis-1,3,3,3-tetrafluoropropene (HFO-1234ze(Z)) and hydrogen fluoride (HF);2. HFO-1234ze(E), 1,1,1,3,3-pentafluoropropane (HFC-245fa) and HF; and3. HFO-1234ze(Z), HFC-245fa and HF.These azeotropic and azeotrope-like compositions are useful as intermediates in the production of HFO-1234ze(E).

The invention discloses an environment-friendly separation and recovery method of fluorine in a fluorine-containing waste liquid. According to the invention, a magnesium-containing compound is added into the fluorine-containing waste liquid as a precipitation agent, such that fluorine in the waste liquid is selectively precipitated; filtering is carried out, and fluorine-removed liquid and magnesium fluoride precipitate are obtained; the fluorine-removed liquid is used in waste water recycling; the magnesium fluoride precipitate is decomposed with sulfuric acid, such that a series of compounds of fluorine are obtained; decomposition residue is subjected to a dissolution-crystallization treatment, such that magnesium sulfate crystals are obtained; the obtained magnesium sulfate crystals are returned and recycled in the fluorine selective precipitation process; the crystallization mother liquor of magnesium sulfate is returned to the dissolution-crystallization process or the magnesium fluoride precipitation decomposition process. The method has the advantages of simple process, simple operation, low production cost, and good fluorine-removing effect. With the method, fluorine resource utilization is realized. The method also has the advantages of no fluorine-containing waste production and no three-waste emission.

Provided is a novel method and system for preparing ultra-high-purity buffered-hydrofluoric acid or ammonium fluoride controlled concentration. The method comprises bubbling purified ammonia vapor into ultra-pure hydrofluoric acid. The inventive method and system can be used as an on-site subsystem in a semiconductor device fabrication facility for supplying the buffered-hydrofluoric acid and ammonium fluoride to points of use in the semiconductor device fabrication facility.

Provided are a novel system and method for delivery of a vapor phase product to a point of use, as well as a novel on-site chemical distribution system and method. The system for delivery of a vapor phase product includes a storage vessel containing a liquid chemical under its own vapor pressure, a column connected to receive the chemical in liquified state from the storage vessel, wherein the chemical is fractionated into a contaminated liquid heavy fraction and a purified light vapor fraction and a conduit connected to the column for removing the purified light vapor fraction therefrom. The system is connected to the point of use for introducing the purified vapor fraction thereto. Particular applicability is found in semiconductor manufacturing in the delivery of electronic specialty gases to one or more semiconductor processing tools.

Molecular fluorine may be generated and distributed on-site at a fabrication facility. A molecular fluorine generator may come in a variety of sizes to fit better the needs of the particular fabrication facility. The generator may service one process tool, a plurality of process tool along a process bay, the entire fabrication facility, or nearly any other configuration within the facility. The process can obviate the need and inherent risks with transporting or handling gas cylinders. The process can be used in conjunction with a cleaning or fabrication operation used in the electronics fabrication industry.

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.

In order to recycle the fluoride, calcium fluoride having a particle size and purity suitable for the production of hydrogen fluoride is recovered from the fluoride-containing effluent or the hydrofluoric acid-containing effluent. The method involves reacting a fluoride-containing effluent or a hydrofluoric acid-containing effluent with an aqueous solution of calcium chloride under acidic conditions formed by hydrochloric acid, under which calcium fluoride has a relatively high solubility. Calcium fluoride can be precipitated with high purity and large particle size. The hydrochloric acid residue from or formed by the reaction reacts with inexpensive calcium compounds such as calcium hydroxide, calcium oxide, and calcium carbonate to produce an aqueous calcium chloride solution that is reused to treat effluents containing hydrofluoric acid . The obtained calcium fluoride can be used as a raw material for producing hydrogen fluoride, and the remaining calcium chloride aqueous solution can be provided for other industrial purposes.

An improved radiation shielding material and storage systems for radioactive materials incorporating the same. The PYRolytic Uranium Compound (“PYRUC”) shielding material is preferably formed by heat and / or pressure treatment of a precursor material comprising microspheres of a uranium compound, such as uranium dioxide or uranium carbide, and a suitable binder. The PYRUC shielding material provides improved radiation shielding, thermal characteristic, cost and ease of use in comparison with other shielding materials. The shielding material can be used to form containment systems, container vessels, shielding structures, and containment storage areas, all of which can be used to house radioactive waste. The preferred shielding system is in the form of a container for storage, transportation, and disposal of radioactive waste. In addition, improved methods for preparing uranium dioxide and uranium carbide microspheres for use in the radiation shielding materials are also provided.

Provided are a novel system and method for delivery of a vapor phase product to a point of use, as well as a novel on-site chemical distribution system and method. The system for delivery of a vapor phase product includes a storage vessel containing a liquid chemical under its own vapor pressure, a column connected to receive the chemical in liquified state from the storage vessel, wherein the chemical is fractionated into a contaminated liquid heavy fraction and a purified light vapor fraction and a conduit connected to the column for removing the purified light vapor fraction therefrom. The system is connected to the point of use for introducing the purified vapor fraction thereto. Particular applicability is found in semiconductor manufacturing in the delivery of electronics specialty gases to one or more semiconductor processing tools.

The invention discloses a recycling method of waste cathode carbon blocks of an aluminum electrolysis cell. The method comprises the following steps: breaking, crushing and ball milling the waste cathode carbon block raw material of the aluminum electrolysis cell to form powder, and then adding hydrogen peroxide to remove cyanide; adding concentrated sulfuric acid to react to generate hydrogen fluoride gas, introducing the hydrogen fluoride gas into a condensation absorption tower, and circularly absorbing the hydrogen fluoride gas with deionized water or a low-concentration hydrofluoric acidsolution to obtain a 25-40% hydrofluoric acid product; neutralizing carbon powder by adding NaOH, filtering and drying the carbon powder to use as a raw material for processing a new cathode for recycling; finally, concentrating a large amount of sodium sulfate contained in filtrate to obtain sodium sulfate crystals. The recycling method has the advantages of advanced technology and obvious advantages, and realizes zero emission of environmental pollutants in the recycling process. The treated waste cathode carbon blocks can be reused to process new cathode carbon blocks, and the main harmfulcomponent fluorine in the original waste cathode carbon blocks is converted into high side addition hydrogen fluoride to realize the recycling of fluorine.

The present invention relates to a catalyst composition and a catalytic process for the destruction of PFC's and HFC's using a catalyst which comprises aluminum oxide that has preferably been stabilized through the addition of a stabilizing agent (such as titanium, zirconium, or cobalt, or mixtures of these elements). The addition of these elements to the aluminum oxide unexpectedly enhances the catalyst's stability without significantly altering the reactivity of the catalyst. The total amount of stabilizing agent added to the catalyst can be as low as 0.005 parts (by weight) stabilizing agent per part (by weight) aluminum oxide (Al2O3) or as great as 2 or more parts (by weight) stabilizing agent per part (by weight) aluminum oxide; so long as there is sufficient aluminum oxide available to effectively catalyze the destruction of the target PFC's and / or HFC±.

Production of trans-1,3,3,3-tetrafluoropropene by reacting 1-chloro-3,3,3-trifluoropropene with hydrogen fluoride to obtain a reaction product A containing formed trans-1,3,3,3-tetrafluoropropene, unreacted 1-chloro-3,3,3-trifloropropene and hydrogen fluoride, and by-product cis-1,3,3,3-tetrafluoropropene, 1,1,1,3,3-pentafluoropropane and hydrogen chloride; distilling reaction product A to recover a distillation bottom product containing 1-chloro-3,3,3-trifloropropene and hydrogen fluoride and supplying recovered distillation bottom product to the reacting step; recovering hydrogen fluoride from a residue B remaining after recovery of the distillation bottom product and supplying recovered hydrogen fluoride to the reacting step; contacting a residue C remaining after recovery of hydrogen fluoride with water or aqueous sodium hydroxide solution to separate hydrogen chloride; dehydrating a residue D remaining after separation of hydrogen chloride; and distilling a residue E remaining after the dehydration to obtain trans-1,3,3,3-tetrafluoropropene. The method reuses unreacted reactants and produces the target compound efficiently.