Abstract: Chlorine is produced by oxidizing byproduced hydrogen chloride. An offgas containing hydrogen chloride as a byproduct is reacted with oxygen at 300.degree.-500.degree. C. in the presence of a catalyst which contains chromic oxide (Cr.sub.2 O.sub.3) as a principal component. The resulting gas is cooled rapidly and then washed with water to recover vaporized chromium. The hydrogen chloride is then absorbed in water to recover it as an aqueous hydrochloric acid solution. The still remaining portion of the resultant gas is washed with sulfuric acid to remove water from the same, followed by compression and cooling. The resulting liquefied chlorine is separated. The still remaining gas composed principally of oxygen is thereafter returned to the oxidation step.

Abstract: A continuous process for the extraction of bromine from a bromine-rich brine in high efficiency while dramatically reducing the steam requirement for the distillation by operating a contact tower under vacuum. The contact tower is designed to operate near the boiling point of the feed brine so that only stripping steam is needed to remove elemental bromine from the brine.

Abstract: A process for obtaining hydrogen and oxygen from water in a two stage process including a first electrolysis stage performed in a two chamber cell wherein the chambers are separated by a membrane. Iodine is introduced into the cathodic chamber and hydrogen iodide is formed therein. Oxygen is formed in the anodic chamber and is removed as a product. The membrane conducts hydrogen ions and prevents the passage of the products HI and oxygen. In a second phase, hydrogen iodide is separated and removed from the cathodic chamber and is thermally decomposed into hydrogen and iodine. The iodine is recycled to the cathodic chamber and the hydrogen is recovered as a product.

Abstract: A process for oxidizing hydrogen halides having substantially no sulfur impurities by means of a catalytically active molten salt is disclosed. A mixture of the subject hydrogen halide and an oxygen bearing gas is contacted with a molten salt containing an oxidizing catalyst and alkali metal normal sulfates and pyrosulfates to produce an effluent gas stream rich in the elemental halogen and substantially free of sulfur oxide gases.

Abstract: A method for producing iodine or iodine derivatives which comprises oxidizing ammonium iodide with oxygen or oxygen-containing gas in a medium comprising a transition metal compound, a weak acid and water to produce the iodine or iodine derivatives.The iodine and iodine derivatives are useful as medical and agricultural chemicals, dyes, pigments, intermediates thereof and the like.

Abstract: Liquid hydrogen iodide is decomposed to form hydrogen and iodine in the presence of water using a soluble catalyst. Decomposition is carried out at a temperature between about 350.degree. K. and about 525.degree. K. and at a corresponding pressure between about 25 and about 300 atmospheres in the presence of an aqueous solution which acts as a carrier for the homogeneous catalyst. Various halides of the platinum group metals, particularly Pd, Rh and Pt, are used, particularly the chlorides and iodides which exhibit good solubility. After separation of the H.sub.2, the stream from the decomposer is countercurrently extracted with nearly dry HI to remove I.sub.2. The wet phase contains most of the catalyst and is recycled directly to the decomposition step. The catalyst in the remaining almost dry HI-I.sub.2 phase is then extracted into a wet phase which is also recycled. The catalyst-free HI-I.sub.2 phase is finally distilled to separate the HI and I.sub.2. The HI is recycled to the reactor; the I.sub.

Abstract: This invention relates to improvements in the execution of catalytic processes wherein chlorine in high state of purity is produced by reacting hydrogen chloride containing organic impurities with oxygen.

Abstract: A process for converting chloride salts and sulfuric acid to sulfate salts and elemental chlorine is disclosed. A chloride salt and sulfuric acid are combined in a furnace where they react to produce a sulfate salt and hydrogen chloride. Hydrogen chloride from the furnace contacts a molten salt mixture containing an oxygen compound of vanadium, an alkali metal sulfate and an alkali metal pyrosulfate to recover elemental chlorine. In the absence of an oxygen-bearing gas during the contacting, the vanadium is reduced, but is regenerated to its active higher valence state by separately contacting the molten salt mixture with an oxygen-bearing gas.

Abstract: Hydrogen iodide is efficiently decomposed to hydrogen and iodine by treatment in the liquid phase with a platinum group metal catalyst. At temperatures between about 0.degree. C. and about 150.degree. C. and pressures sufficiently high to maintain the liquid phase, at least about 50 percent of the hydrogen iodide present can be decomposed at a reasonable rate of reaction. The hydrogen which is created is easily separated as a gas. Exemplary catalysts include platinum particles and supported catalysts, such as ruthenium on a titania substrate and platinum on a barium sulfate substrate.

Abstract: A thermochemical process for producing hydrogen comprises the step of reacting CoO with BaO or Ba(OH).sub.2 in the presence of steam to produce H.sub.2 and novel double oxides of Ba and Co having the empirical formulas BaCoO.sub.2.33 and Ba.sub.2 CoO.sub.3.33. The double oxide can be reacted with H.sub.2 O to form Co.sub.3 O.sub.4 and Ba(OH).sub.2 which can be recycled to the original reaction. The Co.sub.3 O.sub.4 is converted to CoO by either of two procedures. In one embodiment Co.sub.3 O.sub.4 is heated, preferably in steam, to form CoO. In another embodiment Co.sub.3 O.sub.4 is reacted with aqueous HCl solution to produce CoCl.sub.2 and Cl.sub.2. The CoCl.sub.2 is reacted with H.sub.2 O to form CoO and HCl and the CoO is recycled to the initial reaction step. The Cl.sub.2 can be reacted with H.sub.2 O to produce HCl. HCl can be recycled for reaction with Co.sub.3 O.sub.4.

Abstract: A process for producing chlorine from ammonium chloride which comprises vaporizing ammonium chloride, contacting the vapors with a metal selected from the group consisting of tin, zinc and cadmium whereby a metal chloride is formed and then electrolyzing the metal chloride in the presence of a fused salt electrolyte. The ammonium chloride is preferably obtained from the Solvay soda ash process and the process for producing chlorine is integrated with the Solvay process. The integrated process produces chlorine at a substantial energy savings and without calcium chloride being produced as a by-product.

Abstract: In a process for making chlorine electrolytically in which a build-up of nitrogen trichloride occurs in the bottoms of cooling apparatus, a method and apparatus is provided wherein the nitrogen trichloride is dissolved in an organic solvent such as carbon tetrachloride, the chlorine removed, and the solution treated to destroy the otherwise hazardous nitrogen trichloride. The solvent is then separated and recycled to avoid environmentally undesirable waste products.

Abstract: Hydrogen chloride and oxygen are contacted with a molten mixture of cuprous and cupric chloride in a oxidation reaction zone to enrich the cupric chloride content of the melt, and the melt introduced into a dechlorination zone wherein gaseous chlorine is removed from the melt. The oxidation reactor is operated at a pressure higher than the dechlorination reactor, and molten salt circulation rates are controlled in a manner such that the cupric chloride content and temperature of the salt introduced into the dechlorination reaction zone are higher than the cupric chloride concentration and temperature of the melt introduced into the oxidation reactor.

Abstract: A process for the preparation of bromine and hydrogen bromide, which comprises reacting ammonium bromide with an oxygen containing gas at temperatures of from 200.degree. to 800.degree. C in the presence of oxidation catalysts is disclosed. Catalysts based on platinum group metals favor formation of HBr. Most other metal catalysts cause chiefly formation of bromine.

Abstract: A process for oxidizing hydrogen halides by means of a catalytically active molten salt is disclosed. The subject hydrogen halide is contacted with a molten salt containing an oxygen compound of vanadium and alkali metal sulfates and pyrosulfates to produce an effluent gas stream rich in the elemental halogen. The reduced vanadium which remains after this contacting is regenerated to the active higher valence state by contacting the spent molten salt with a stream of oxygen-bearing gas.

Abstract: A process for the preparation of bromine and hydrogen bromide, which comprises reacting ammonium bromide with an oxygen containing gas at temperatures of from 200.degree. to 800.degree. C. in the presence of oxidation catalysts is disclosed. Catalysts based on platinum group metals favor formation of HBr. Most other metal catalysts cause chiefly formation of bromine.

Abstract: This invention relates to an improved process for preparing cyanogen chloride by reacting chlorine and hydrogen cyanide in a manganous chloride-containing aqueous medium to form gaseous cyanogen chloride and dissolved hydrogen chloride and to the subsequent conversion of the hydrogen chloride to chlorine employing manganese dioxide and nitric acid as cyclic reagents.

Abstract: A method for efficient production of hydrogen by thermochemical decomposition of water by use of tri-iron tetraoxide and hydrogen bromide as main cyclic reaction media.

Abstract: Hydrogen and sulfur are produced from hydrogen sulfide by reacting the latter with iodine in an aqueous solution of hydriodic acid, recovering the sulfur thus formed, removing any unreacted hydrogen sulfide from the solution, rectifying said solution thereby to obtain hydrogen iodide and a residual hydriodic acid solution and thermally dissociating the hydrogen iodide to form hydrogen and iodine. The hydrogen is separated by diffusion and recovered. The unreacted hydrogen sulfide thus removed, the residual solution and the iodine are recycled.

Abstract: Chlorine dioxide is produced in a continuous process by reaction of sodium chlorate and hydrochloric acid. The reaction medium is maintained at its boiling point under subatmospheric pressure and the resulting steam is used to dilute the chlorine dioxide and chlorine and remove the same from the reaction zone. Sodium chloride is deposited from the reaction medium in the reaction zone. The mole ratio of chlorate to chloride in the reaction medium, and the temperature of the reaction medium are controlled within narrow limits to provide high efficiency of production of chlorine dioxide.

Abstract: A process for removing hydrogen sulfide and/or mercaptans from hydrogen sulfide and/or mercaptans-containing gases using aqueous iodine slurry and/or solution to recover elemental sulfur as one product and to generate hydriodic acid which is dehydrated, pressurized, and decomposed into iodine for recycling and into hydrogen for recovering as another product.

Abstract: Bromine is continuously produced by simultaneously feeding an aqueous solution of bromide or hydrobromic acid and chlorine gas into the top of a contact tower which is separated into an upper reaction section and a lower distillation section, having a gas outlet port therebetween; and feeding steam from the bottom of the tower whereby free bromine formed in the upper reaction port section and free bromine distilled from the lower distillation tower section are recovered through said bromine outlet port, wherein the aqueous solution containing bromide or hydrobromic acid is heated at lower than 80.degree. C in the reaction section and the solution is heated to higher than 90.degree. C in the distillation section.

Abstract: Bromine is prepared by a method which comprises contacting hydrogen peroxide with an aqueous solution containing bromide ion and rapidly removing the bromine as it is formed. This method is particularly suitable for obtaining bromine from seawater, using the conventional intermediate, bromosulfuric solution.

Abstract: Chlorine or bromine are produced from the respective hydrogen halide in a reaction system, wherein a stoichiometric excess of active nitrogen is maintained within the reaction system over the amount of hydrogen halide in the system. Preferably the reaction system is a single tower wherein sulfuric acid is introduced to the top of the tower where it absorbs the active nitrogen while conditions are so set that at the bottom of the tower the gases, introduced there, strip the active nitrogen away from the acid. It is a further characteristic of the process, that the nitrogen compounds stripped at the bottom, are mainly stripped as a mixture of nitrogen monoxide and nitrogen dioxide. A major portion of the nitrogen monoxide stripped, is oxidized with the oxygen, present in the gases fed in the bottom, to form nitrogen dioxide. If hydrogen halide is fed in the bottom, it will also strip nitrogen compounds, but mostly in the form of nitrosyl-halide.

Abstract: A method for the thermochemical production of hydrogen from water is disclosed in which barium iodide, carbon dioxide, ammonia and water are allowed to react with one another and give rise to barium carbonate and ammonium iodide, the ammonium iodide thus produced is thermally decomposed to produce hydrogen, iodine and ammonia, and the hydrogen thus produced is recovered as the product. The by-produced barium carbonate is allowed to react with the iodine remaining after the separation of hydrogen thereby to produce barium iodide, carbon dioxide and oxygen, and the barium iodide and carbon dioxide are recycled to the reaction system. The ammonia which remains after the separation of hydrogen is also recycled to the reaction system. By causing the by-products occurring in the various reactions to be recycled to the relevant reaction systems, hydrogen is efficiently produced from water at a reaction temperature of not more than 800.degree. C.

Abstract: Calcium hydroxide and iodine are reacted with each other in the presence of water to produce calcium iodate and calcium iodide, the former of which precipitates from the reaction solution and is obtained by filtration and the latter of which is thereafter separated from the filtrate by evaporation separation. The calcium iodate is heated until it is converted into calcium oxide, whereafter there ensues generation of a mixed gas of iodine and oxygen. The mixed gas is cooled causing the iodine component thereof to solidify and pure oxygen gas is consequently liberated to be obtained as one product. The calcium iodide is solidified and subsequently heated under a current of steam to cause it to undergo conversion into calcium oxide with liberation of hydrogen iodide gas. The hydrogen iodide gas thus liberated is then separated by a known method into iodine and hydrogen which is obtained as another product.

Abstract: Pure liquid bromine is produced directly from an acidic aqueous bromide mother liquor by reacting it with about 80 to about 90% of the amount of chlorine stoichiometrically equivalent to the bromide present in the whole supplied mother liquor and collecting the liquid bromine which separates out of solution; the remaining mother liquor free from liquid bromine is steam distilled in the presence of sufficient chlorine to convert the rest of the bromide to bromine and to condense crude liquid bromine which is purified by washing with sufficient fresh mother liquor. Production capacity is increased by about 20% compared to conventional process in which all the bromine is submitted to steam distillation.

Abstract: An improvement in the continuous process for oxidizing hydrogen chloride to chlorine with an aqueous mixture of nitric and sulfuric acids, which acids are subsequently regenerated, the improvement concerned primarily with maintaining critical water control of from 23.0 to 27.5 percent, by weight, during the oxidation reaction to form the chlorine and from 27.5 to 30.0 percent during the reaction wherein the nitric and sulfuric acids are regenerated; and with maintaining the mol ratio of HCl to HNO.sub.3 at about 2 to 1 during the oxidation reaction to form the chlorine.