Abstract: A process is disclosed for purifying an impure HCl containing at least one saturated or olefinic impurity of the formula C.sub.a H.sub.b Cl.sub.c F.sub.d (wherein a is an integer from 1 to 4, b and c are each integers from 0 to 9, and d is an integer from 1 to 10; provided b+c+d=2a+2 for acyclic compounds and b+c+d=2a for cyclic compounds and olefinic compounds) which comprises the step of contacting the impure HCl with a sorbent for said impurities selected from activated carbons and inorganic molecular sieves (e.g., silicalites and zeolites) at a temperature and a pressure suitable for sorption for a period of time sufficient to remove a substantial amount of said impurities.

Abstract: Process for the recovery of hydrogen fluoride (HF) from a mixture, preferably an azeotropic mixture, of HF with water and/or an organic compound such as 134a, 125 or 133a, which comprises contacting the mixture with lithium fluoride or an alkaline earth metal fluoride to form a metal fluoride-hydrogen fluoride compound (e.g. lithium bifluoride, LiHF.sub.2), separating the compound and decomposing it to liberate hydrogen fluoride therefrom. The process is useful for recovering HF from azeotropic or azeotropic-like mixtures.

Abstract: A liquid and vapor phase processes for the production of difluoromethane in which the risk of exposure to, and equipment fouling from, chlorofluoromethane is reduced. This reduction is accomplished from removing a sidestream containing monochloromonofluoromethane from a fluorination process distillation column.

Abstract: A system for purification and generation of hydrofluoric acid on-site at a semiconductor device fabrication facility. An evaporation stage (optionally with arsenic oxidation) is followed by a fractionating column to remove most other impurities, an Ionic Purifier column to suppress contaminants not removed by the fractionating column, and finally the HF Supplier (HFS).

Abstract: The invention relates to a process for recycling waste which consists essentially of one or more plastics comprising polyvinyl chloride (PVC), in which:the waste is mixed with a heavy oil, in a reactor under an inert atmosphere, at an internal temperature of at least 300.degree. C., and the hydrogen chloride (HCl) which is evolved is collected;the contents of the reactor are then cracked at a temperature of at least 400.degree. C., and at least part of the gases which are evolved are extracted from the reactor;the contents of the reactor are then cooled and the residual solid product is collected.HCl, coke, hydrocarbon gases and various oils are thus mainly obtained.

Abstract: A process for separating HCl from pentafluoroethane, chloropentafluoroethane, chlorotrifluoroethane, trifluoromethane, and other fully saturated and unsaturated fluorocarbons, chlorofluorocarbons and chlorocarbons.

Abstract: A process is described by which numerous waste or by-product aqueous hydrochloric acid streams can be purified by contacting the aqueous hydrochloric acid with activated carbon to remove silicon containing impurities and thereby allowing the hydrochloric acid to be re-used for various applications.

Abstract: Reagent grade hydrochloric acid having an iron content of less than 200 p.p.b. is made from an industrial organic isocyanate manufacturing process by removing hydrogen chloride from organic isocyanates produced in the reaction between phosgene and an organic amine, converting the hydrogen chloride to concentrated aqueous hydrochloric acid, and contacting the acid with a strongly basic anion exchange resin.

Abstract: Highly purified ammonia for use in processes for the production of high-precision electronic components is prepared on-site by drawing ammonia vapor from a liquid ammonia reservoir, passing the vapor through a filter capable of filtering out particles of less than 0.005 micron in size, and scrubbing the filtered vapor in a high-pH aqueous scrubber.

Abstract: The disclosure relates to removing impurities from hexafluoroethane (CF.sub.3 CF.sub.3), also known as PerFluoroCarbon 116 (PFC-116) or FluoroCarbon 116 (FC-116), by using azeotropic distillation such that an overhead product containing an HCl-hexafluoroethane is formed, optionally combined with a phase separation step to break the HCl-hexafluoroethane azeotropic or azeotrope-like composition thereby permitting recovery of substantially pure hexafluoroethane. Unreacted hydrogen fluoride (HF) may be removed from hexafluoroethane during the above azeotropic distillation with HCl or alternatively by an azeotropic distillation wherein an HF-hexafluoroethane azeotropic or azeotrope-like composition exits overhead and substantially pure HF exits in the bottoms stream.

Abstract: A process for eliminating organic pollutant residues in the synthesis gas occurring during refuse gasification by the addition of oxygen, in which at least prepyrolyzed, carbon-containing refuse in compressed form is fed into a high temperature reactor, where a loosely heaped gasification bed is formed and is burnt below the same by oxygen addition. The resulting synthesis gas is drawn off from the top area of the high temperature reactor after an adequate residence time and into the residence zone. Additional oxygen is then jetted in temperature-regulated, partial quantities in such a way that the resulting possible partial combustion of the synthesis gas maintains its temperature above the gasification bed constant at approximately 1000.degree. C. Oxygen jetting takes place in such a way that a completely homogeneous gas mixing is ensured in the top area. For this purpose, several oxygen jets are arranged in the top area of the high temperature reactor and are axially and/or radially inclined thereto.

Abstract: A process for the separation of hydrogen fluoride (HF) and of difluoromethane (F32) by fractional distillation and/or condensation, in at least one stage, including in at least one stage obtaining a stream whose HF and F32 contents correspond.

Abstract: A process for producing refined hydrogen iodide having organic components of 0.2 ppm by volume or less and water of 0.1 ppm by volume or less by contacting crude hydrogen iodide with a zeolite is disclosed. Crude hydrogen iodide is obtained by reducing iodine with a hydrogenated naphthalene, wherein all of the iodine is dissolved in advance in a portion of the hydrogenated naphthalene to prepare an iodine solution, and the reaction is carried out while adding continuously or intermittently the iodine solution to the balance of the hydrogenated naphthalene. The same operation may be repeated in succession using unreacted hydrogenated naphthalene and fresh iodide. The zeolite is contacted in advance with crude hydrogen iodide, the amount of which is at least 1/3 (weight ratio) relative to the amount of the zeolite, to convert impurities of sulfur components contained in the zeolite to hydrogen sulfide, thereby removing the sulfur components.

Abstract: There is provided a process to recover phthalic anhydride from a plastic material which contains a phthalate ester as a plasticizer comprising the steps of:(a) heating the plastic material so that the plastic material is gasified to produce a first product,(b) contacting the first product with alumina catalyst so that the product is catalytically cracked to produce a first catalytically cracked product comprising phthalic anhydride; and(c) recovering phthalic anhydride from the first catalytically cracked product.

Abstract: A method and apparatus for preparing high purity hydrogen bromide, wherein a starting hydrogen bromide which contains impurities having low boiling points is supplied to an intermediate space. While the gas phase of the starting hydrogen bromide is allowed to ascend through an upper rectifying section, it is brought into contact with a first reflux solution flowing in the reverse direction. The uncondensed gas stored in an upper space is cooled and partly condensed. The condensed liquid is allowed to flow down through an upper rectifying section as the first reflux solution. The liquid-phase of the starting hydrogen bromide is mixed with the first reflux solution in the intermediate space and serves as a second reflux solution. The liquid stored in a lower space is heated and partly evaporated. The liquid stored in the lower space is supplied outside as high purity hydrogen bromide. The uncondensed gas stored in the upper space is discharged outside.

Abstract: Regeneration of hydrochloric acid by hydrolysis of iron chloride in aqueous solution employs a Pelletiser (5) after preconcentration of acid solution in a "Pre-Evaporator" (1). Pelletiser (5) controls pellet mixture to between 12% and 14% free water by recycling dried solids from Roaster (3), from Screen (7), or from dust removal Cyclone (9), and waste liquid from Preconcentrator (1). Preconcentrator (1) is contacted with superheated gas from Fluid Bed Roaster (3). Rotary Drier (6) dries pellets with a concurrent hot gas stream and the pellets are screened at (7) with oversize being sent to a Mill (8), undersize recycled to Pelletiser (5), and sized feed delivered to Roaster (3). HCl is produced as gas offtake from Preconcentrator (1) and passes via a demisting Cyclone into adiabatic Absorption Process section (11), where weak acid liquor and water (10) are added as required.

Abstract: The present invention provides a convenient method for separating hydrogen fluoride from a chemical mixture. More specifically, a method is provided in which hydrogen fluoride is separated from a chemical mixture containing at least one organic material by contacting the chemical mixture with a hydrogen fluoride binder. The hydrogen fluoride separated from the chemical mixture is readily recoverable from the hydrogen fluoride binder.

Abstract: A method of recycling and purifying cleaning chemicals used in the production of semiconductor circuits and containing hydrofluoric acid and or hydrochloric acid. Recycling of such chemicals is accomplished using separation and reconstitution steps Hydrofluoric acid and hydrochloric acid cannot be distilled directly from a chemical solution as they form azeotropes with water. A low vapor pressure substance such as sulfuric acid or phosphoric acid is used to break the azeotrope while increasing the purity of the recovered chemicals and decreasing disposal problems. The method is useable at the point of use of the chemicals.

Abstract: A process for treating an aqueous solution mainly containing nitric acid and hydrofluoric acid. The process involves distilling to provide an aqueous solution concentrated in nitric acid and hydrofluoric acid for the separation thereof, then separating by distillation.

Abstract: HF can be recovered from aqueous streams, particularly those which are dilute and have a concentration of HF lower than the azeotrope between HF and water. Such aqueous streams are contacted with carbon molecular sieves, preferably those having an average pore size of about 3.5 Angstroms, which adsorb both HF and water. When regenerated by heating, more dilute aqueous streams are desorbed at lower temperatures, followed by desorption of HF which is free of water, making possible a separation of HF and water and avoiding formation of the azeotrope.

Abstract: A process for removing water and/or carbon compounds from hydrogen fluoride by contacting the hydrogen fluoride to be purified with elemental fluorine.

Abstract: The invention relates to a process for separating HF contained in liquid mixtures comprising HCFC 123 and/or 124. The mixtures, enriched in C.sub.2 Cl.sub.4 up to a content of such compound of 20-75% by weight, is subjected to a treatment for separating liquid phases, thereby obtaining an acid phase very rich in Hf and an organic phase impoverished in HF, which is subjected to a flash, so obtaining a liquid phase containing 123, 124 and C.sub.2 Cl.sub.4, having a very low HF content, and a gas phase enriched in HF. As an alternative to flash, a separation in a distillation column can be carried out.

Abstract: An HCl adsorbent, and method of making and using the adsorbent, the adsorbent comprising an activated alumina promoted with an alkali metal in an amount such that if calculated as alkali metal oxide, the adsorbent contains at least about 5% by weight alkali metal oxide. The adsorbent is used for removal of HCl from a fluid stream.

Abstract: A process of pyrolyzing plastic waste feed streams containing polyvinyl chloride, polyethylene terephthalate, polystyrene and polyethylene to recover polystyrene HCl and terephthalic acid comprising: heating the plastic waste feed stream to a first temperature; adding an acid or base catalyst on an oxide or carbonate support; heating the plastic waste feed stream to pyrolyze polyethylene terephthalate and polyvinyl chloride; separating terephthalic acid or HCl; heating to a second temperature to pyrolyze polystyrene; separating styrene; heating the waste feed stream to a third temperature to pyrolyze polyethylene; and separating hydrocarbons.

Abstract: A process for disposing of bromofluorocarbons, bromochlorofluorocarbons, or mixtures of any of bromofluorocarbons, bromochlorofluorocarbons, fluorocarbons, or chlorofluorocarbons. The process comprises thermally cleaving halons, halon-containing fluorocarbons, or halon containing chlorofluorocarbons, cooling the resulting gas stream, oxidizing the resulting hydrogen bromide to bromine by feeding excess elemental chlorine into the gas stream, absorbing the resulting HF or HCl from the gas stream with recovery of hydrofluoric acid or hydrochloric acid, and finally separating elemental bromine and chlorine from each other by distillation or reducing both to give the salts.

Abstract: A method of removing chloride from phosphorus/vanadium/oxygen mixed oxide oxidation catalysts comprising treating a chloride containing catalyst comprising phosphorus, vanadium and oxygen with a stream of gas comprising oxygen, steam and an inert gas at flow rate and temperature and for a period of time to substantially reduce the amount of chloride in the catalyst.

Abstract: A purification method and apparatus for creating ultra-purity chemicals for semiconductor processing. The purification method includes a step of expanding an ESG chemical through an orifice (17) inside a condenser (21) to a partial condensed state for removing impurities from ESG chemical. During the expansion step, the higher boiling point impurities remain in the liquid phase and the impurities in the vapor phase are removed at least in part by a scavenging technique. After purification, the ultra-purified gas is transferred to a semiconductor manufacturing operation (24). The manufacturing operation includes both dry and wet processes. The method may also be integrated into a large volume on-site purification system (30), on-line point of use purifier (50), or small volume trans-filling purification system (70).

Abstract: The present invention discloses an extractive distillation process for separating HCl from pentafluoroethane, chloropentafluoroethane, chlorotrifluoroethane, trifluoromethane, and other fully saturated and unsaturated fluorocarbons, chlorofluorocarbons and chlorocarbons.

Abstract: A two step method of converting ferrous chloride from a pickling liquor to produce hydrochloric acid and ferric sulfate is disclosed. The ferrous chloride is first mixed with sulfuric acid to produce ferrous sulfate and HCl. The HCl is carried to an absorbtion tower where most of the HCl is collected and the remainder is returned to the reactor. The ferrous sulfate is separated from the sulfuric acid. The unreacted sulfuric acid is returned to the reactor and the ferrous sulfate is transported to a second reactor where it is reacted with sulfuric acid and air (O.sub.2) to produce ferric sulfate. The ferric sulfate is removed from the second reactor. Both reactions are carried out at relatively low temperatures under atmospheric pressures.

Abstract: The invention relates to a process for purifying industrial anhydrous hydrogen fluoride by means of oxygen difluoride.

Abstract: A method of removing a metal impurity, including the steps of: removing oxygen dissolved in a hydrofluoric-acid-containing chemical solution; and in order to remove a metal impurity contained in the hydrofluoric-acid-containing chemical solution free from the dissolved oxygen, bringing or circulating the hydrofluoric-acid-containing chemical solution into contact with or in a column filled with silicon granules to adsorb the metal impurity on the silicon granules.

Abstract: A process for preparing ultrapure hydrogen fluoride by contacting impure hydrogen fluoride with elemental fluorine in the presence of metal fluorides. The ultrapure hydrogen fluoride which can be obtained can be used in electronics or optics or for preparing fluorine-containing organic or inorganic compounds or ultrapure hydrofluoric acid.

Abstract: The invention provides a process for hydrotreating an organic feedstock containing oxygen compounds and a halogen component by means of removing the oxygen compounds with an adsorbent and then contacting the resulting organic feedstock having a reduced concentration of oxygen compounds and a gaseous recycle stream containing hydrogen with a hydrogenation catalyst in a hydrogenation reaction zone to produce an anhydrous liquid stream comprising hydrogenated hydrocarbonaceous compounds having a reduced concentration of halogen and a hydrogen halide compound. The resulting effluent from the hydrogenation zone is optionally separated to produce a hydrogenated hydrocarbonaceous stream having a reduced level of halogen and an anhydrous stream comprising a hydrogen halide compound.

Abstract: A process, for purification of a combustion flue gas from a garbage incineration plant having a chloride content and further contaminated with HF, SO.sub.2, NO.sub.

Abstract: The invention relates to the removal of detrimental metal ions represented by Cu ion from a hydrofluoric acid solution for use in the manufacturing of semiconductor devices to clean silicon wafer surfaces. The acid solution is brought into contact with silicon granules which are used for the adsorption of the detrimental metal ions. To enhance the adsorption power and the rate of adsorption, the silicon granules are treated in advance to deposit a metal which is lower in ionization tendency than silicon on the surface of each silicon granule so as to partly cover the silicon granule surface by the deposited metal. Particularly Au or Ag is suitable as the metal deposited on the silicon granules.

Abstract: A method is provided for recovering an anhydrous hydrogen fluoride product from uranium hexafluoride gas by initially reacting the uranium hexafluoride in a primary reactor with steam to produce a uranyl fluoride intermediate and a gaseous mixture of hydrogen fluoride and water. The uranyl fluoride intermediate is fed to a secondary reactor and reacted with water to produce a triuranium octoxide product for disposal, and a gaseous mixture of water, hydrogen fluoride and oxygen. The two mixtures from the primary and secondary reactors are combined and subsequently separated in a distillation column to obtain an anhydrous hydrogen fluoride product stream and an aqueous azeotropic recycle stream containing water and hydrogen fluoride which is vaporized and returned to the primary reactor as the steam feed.

Abstract: A process is described by which numerous waste or by-product aqueous hydrochloric acid streams can be purified by contacting the aqueous hydrochloric acid with a polystyrenic based resin to remove silicon containing impurities and thereby allowing the hydrochloric acid to be re-used for various applications.

Abstract: Disclosed herein is a method for producing plasters that contain chloride contents of less than 0.5% by weight from calcium-containing impure products or residues having a high chloride content (e.g., about 10% or higher based on the total product or residue weight). The method does not require the addition of fly ash, SiO.sub.2 or Al.sub.2 O.sub.3. The method comprises temperature and water-mediated conversion of calcium chloride to calcium oxide in the calcium-containing product or residue using water, steam and/or substances that generate water to obtain calcium oxide and hydrochloric acid; and sulfating calcium components in the product or residue using oxygen and sulfur-containing, largely calcium-free substances. The product so obtained is an anhydride plaster which can optionally be hydrated.

Abstract: Halogen-containing waste gases resulting from the dry etching step of the process of fabricating semiconductor devices are rendered harmless by removing the halogen compounds concomitant with said waste gases. Waste gases containing halogen compounds are treated by bringing them into contact first with activated carbon and then into contact with a member selected from the group consisting of an alkali agent and a ferric oxide, at a linear velocity of about 3-50 cm/min at ambient temperature, volume ratios of said activated carbon to the alkali agent or the ferric oxide in terms of a substantially dried base being about 2-4, and said alkali agent being selected from a group consisting of calcium hydroxide, calcium oxide, magnesium hydroxide and magnesium oxide.

Abstract: A process is disclosed for regenerating a spent liquid acid catalyst comprising the steps of:(a) providing a spent liquid acid catalyst comprising HF, sulfolane, and conjunct polymeric byproducts formed during the HF-catalyzed reaction of isoparaffin and olefin to form isoparafinnic alkylate;(b) providing a finely divided solid sorbent, wherein said solid sorbent preferentially and reversibly sorbs said conjunct polymeric byproducts from a mixture containing HF, sulfolane;(c) mixing said spent liquid acid catalyst of step (a) with said solid sorbent of step (b) by charging said spent liquid acid catalyst to the driving fluid inlet of an eductor and drawing a stream containing said solid sorbent into said eductor;(d) holding said mixture of step (c) in contact for time sufficient for said solid sorbent to preferentially sorb at least a portion of said conjunct polymeric byproducts from said spent liquid acid catalyst to produce a conjunct polymer-enriched sorbent and to regenerate said liquid acid catalyst; an

Abstract: A method of treating a gas based on fluorine and containing hydrofluoric acid, and which may optionally contain condensable gaseous compounds, especially uranium compounds, and non-condensable gases. The gas is refrigerated to obtain a gaseous component containing fluorine and any non-condensable gases present, and a liquid phase containing liquid HF and condensable compounds in solution and/or suspension. The liquid phase is filtered to recover the compounds in suspension.

Abstract: A method for processing chlorosilane distillation residues by hydrolysis with steam, in which the hydrolysis is carried out at escalating temperatures from about 130.degree. C. to at least 170.degree. C.

Abstract: A process for waste liquid-free processing of residues of chlorosilane distillations, wherein the residue is allowed to react with liquid hydrochloric acid accompanied by the release of hydrogen chloride, the resulting reaction mixture is allowed to coagulate, the solid phase is separated and dried and heat-treated, and the liquid phase and the condensed gaseous constituents are recycled into the process.

Abstract: A waste pickle which has been formed in the surface treatment of rolled stock consisting of steel and contains metal salts and acids and specifically contains nitric and hydrofluoric acids and nickel salts, chromium salts, and iron salts is subjected to an acid dialysis and a membrane electrolysis. To permit a recycling of free acids at a high rate and a recovering of the metals in a form in which they can directly be used in the melting process, the acid dialysis performed for a recovery of the free nitric acid and hydrofluoric acids is succeeded by a membrane electrolysis, in which the metals are recovered from the depleted effluent from the acid dialysis, which effluent has been depleted of free acid, and the enriched effluent from the acid dialysis, which enriched effluent has been enriched with free acids, and the effluent from the membrane electrolysis, which effluent has been depleted of metals, are subjected to an evaporation.

Abstract: The present invention relates to a process for the pretreatment of activated carbon, capable of being employed especially for the purification of concentrated solutions of hydrochloric acid.

Abstract: To remove phosgene from off-gases, the former is reacted in a washing zone with a liquid which contains or is composed of compounds of the formula ##STR1## where R.sub.1 and R.sub.2 are identical or different and are each aliphatic or cycloaliphatic alkyl of 1 to 8 carbons, or R.sub.1 and R.sub.2 are --(CH.sub.2).sub.n -- where n is 4 or 5, R.sub.3 is hydrogen or aliphatic or cycloaliphatic alkyl of 1 to 6 carbon atoms, or R.sub.1 or R.sub.2 and R.sub.3 are --(CH.sub.2).sub.m -- where m is 3, 4 or 5.The liquid can be regenerated by the addition of water, and the regenerated liquid can be returned to the washing zone.

Abstract: A process for separating and recovering an organic phase (e.g., fluorocarbons such as chlorofluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons and perfluorocarbons) from a feed stream of a mixture of fluorocarbons and hydrogen fluoride, wherein the mixture is characterized as forming at least one azeotrope or azeotrope-like composition involving at least one fluorocarbon and hydrogen fluoride, by passing the fluorocarbon/HF mixture feed stream through the feed side of a semipermeable membrane unit and then further separating a fluorocarbon-depleted hydrogen fluoride permeate stream and a fluorocarbon enriched residual stream exiting the membrane unit by conventional distillation. An essentially pure fluorocarbon phase and hydrogen fluoride phase are recovered from the distillation with the azeotrope or azeotrope-like distillate being recycled to the inlet of the semipermeable membrane unit.

Abstract: A residue from the production of chlorosilanes from raw silicon is treated with steam and aditionally with nitrogen-oxygen mixtures. The resulting residue has a lower chloride content.

Abstract: A chemical method of removing thiourea from spent hydrochloric acid cleaning solutions comprising the steps of: adjusting the pH to not less than 12 by addition of base to remove metal hydroxides; oxidizing thiourea to urea by the addition of at least a stoichimetric amount of oxidant per mole of thiourea; and further oxidizing urea to nonregulated/nonhazardous compounds by the addition of at least 3 moles of a hypochlorite per mole of urea. UV analysis confirms a greater than 98% removal of thiourea from solutions containing 0.4 to 2.7 wt. % thiourea after as little as 3 hours with an exotherm, .DELTA.t, of less than 105.degree. F.

Abstract: A process for removing halogen gases from a gas stream containing carbon dioxide such as flue gas from an industrial waste incinerator burning chlorinated organic wastes, the process includes seven steps. The first step is to flow fresh absorption liquor to a gas-liquid contactor (such as a column packed with pall rings) the fresh absorption liquor containing water, base and thiosulfate (such as sodium carbonate and sodium thiosulfate). The second step is to flow the gas stream to the gas-liquid contactor. The third step is to contact the fresh absorption liquor and the gas stream in the gas-liquid contactor to form a contacted gas stream and a contacted absorption liquor. The fourth step is to flow the contacted gas stream from the gas-liquid contactor to form an exhaust gas stream from the process. The fifth step is to flow the contacted absorption liquor from the gas-liquid contactor to form used absorption liquor.