Abstract: A process and apparatus for removing sulfur oxide from combustion gas to form Na.sub.2 SO.sub.4 and for reducing the harmful effects of Na.sub.2 SO.sub.4 on auxiliary heat exchangers in which a sodium compound is injected into the hot combustion gas forming liquid Na.sub.2 SO.sub.4 in a gas-gas reaction and the resultant gas containing Na.sub.2 SO.sub.4 is cooled to below about 1150.degree. K. to form particles of Na.sub.2 SO.sub.4 prior to contact with at least one heat exchanger with the cooling being provided by the recycling of combustion gas from a cooled zone downstream from the introduction of the cooling gas.

Abstract: Cuprous chloride, which is contained in a reduced leach solution or pregnant liquor, can be recovered as a complex salt of alkali metal chloride, such as potassium chloride, or alkaline earth metal chloride or ammonium chloride. The salts are produced by oxidation of a copper ore, such as chalcopyrite, with ferric chloride and cupric chloride, and after removal of insolubles, by adding sufficient metallic copper to the solution to reduce cupric ions to cuprous ions so as to provide a solution containing 1.5 to 2.5 molal potassium chloride, or other metal or ammonium chloride, and cooling the resultant saturated solution to precipitate the potassium chloride-cuprous chloride complex salts and recovering the complex salts. Also provided as a method for recovery of pure copper metal by electrolysis of solutions derived from the complex salts wherein the impurities are diverted to an anode loop which is separated from the cathode loop by a diaphragm.

Abstract: Catalytic desulfurization process of an acid gas containing H.sub.2 S, and optionally a total quantity of at most 3% by volume of CS.sub.2 and/or COS, by contacting said acid gas and oxygen or air with a catalyst based on titanium oxide, at temperatures between 100.degree. C. and 600.degree. C. The catalyst used comprises, in addition to the titanium oxide, a sulfate of alkaline earth metal selected from Ca, Sr, Ba and Mg. Application to the desulfurization of acid gases, which in particular contain less than 15% by volume of H.sub.2 S, and therefore cannot be treated in conventional sulfur plants.

Abstract: The present invention provides a process for the continuous production of chlorine dioxide by the reaction of hydrochloric acid with an alkali metal chlorate solution, which is obtained by means of an electrolysis plant from a chlorate solution containing alkali metal chloride circulating in the process, together with cathodically-formed hydrogen, in a cascade reactor with the introduction of air, wherein the reaction of the alkali metal chlorate solution with the hydrochloric acid is carried out under reduced pressure and chlorine gas separated off from the reaction product is reacted with the cathodically-formed hydrogen with the introduction of external chlorine gas to give the required amount of hydrochloric acid.

Abstract: A process is described for preventing the formation of thiosulfate in oxidative hydrogen sulfide scrubbings. For this purpose, an aqueous alkaline scrubbing agent, containing an oxidizing agent, is used, the hydrogen sulfide being absorbed from the scrubbing agent in a scrubbing column and oxidized principally to elementary sulfur with reduction of the oxidizing agent. Subsequently, the scrubbing agent is regenerated for reuse by exposure to an oxygen-containing gas for the reoxidation of the oxidizing agent. A thiocyanate is added to the scrubbing agent, advantageously in a concentration of 0.06 to 0.5 mol/l, preferably 0.3 to 0.4 mol/l.

Abstract: A process for the removal of hydrogen sulfide from a variety of gas streams is disclosed. The gas stream containing the sour gases is contacted with a reactant solution comprising iron (Fe III) lignosulfonate. The hydrogen sulfide is converted to sulfur, and the reactant is reduced. The process may be cyclic, and may include sulfur removal and regeneration of the reactant.

Abstract: A hardened product prepared by mixing cement with limestone or dolomite and hardening it by incorporating water can be used as a heat medium for a fluidized bed heating furnace and also act as a preferred desulfurizing agent having a high desulfurizing performance which can effectively absorb to eliminate the sulfur components in exhaust or product gases from the heating furnace.The strength as the heat medium and the desulfurizing performance can further be increased by setting the cement content in the mixture between 10-70% by weight and the particle size for the mixture between 0.7 and 2.0 mm.Furthermore, the desulfurizing agent can be produced preferably by previously setting the particle size of the mixture to less than 0.3 mm and then adding 5-20% by weight of the seed material between 0.3 mm and 1.2 mm in particle size, followed by pelletization.

Abstract: A process for the removal of acid gases which are reactive with ethylene oxide from a gas mixture containing carbon dioxide, comprises contacting the gas mixture with ethylene carbonate containing sufficient amount of ethylene oxide, whereby the ethylene oxide reacts chemically with the acid gases to produce reaction products which are more easily removable from the gas mixture.

Abstract: A method for the wet treatment of combustion exhaust gases comprising SO.sub.2 and HCl, the method comprising detecting an amount of HCl in the exhaust gas and feeding, to an exhaust gas treating tower, a sodium salt in an amount corresponding to at least the detected amount of HCl so that all the HCl is able to be converted into NaCl in the exhaust gas treating tower, along with CaCO.sub.3 or Ca(OH).sub.2 used as an SO.sub.2 absorbent.

Abstract: A process for afterburning and purifying process exhaust gases, which contain combustible constituents, wherein the process exhaust gases and the oxygen-containing gases required for a combustion are separately supplied to a fluidized bed reactor of a circulating fluidized bed. In the fluidized bed reactor, the gas velocity is adjusted to 2 to 10 m/s (empty pipe velocity), the mean suspension density is adjusted to 0.1 to 10 kg/m.sup.3, the temperature is adjusted to 700.degree. to 1100.degree. C., and the stoichiometric ratio of gas-purifying agent having a particle size d.sub.p 50 of 30 to 200 .mu.m to pollutant contained in the process exhaust gas or formed by the combustion is adjusted to 1.2 to 3.0, calculated as Ca:S. The entrained solids in the gases from the fluidized-bed reactor are recycled to the reactor at a rate of at least 5 times the weight of solids contained in the fluidized bed reactor per hour.

Abstract: CO.sub.2 and, where relevant, H.sub.2 S are removed from natural gases which contain CO.sub.2 and may or may not contain H.sub.2 S by a process in which the said natural gases are treated, in an absorption stage at from 40.degree. to 100.degree. C., with an aqueous absorption liquid containing from 20 to 70% by weight of methyldiethanolamine, the treated natural gases are taken off at the top of the absorption stage, the aqueous absorption liquid laden with CO.sub.2 and, where relevant, H.sub.2 S is taken off at the bottom of the absorption stage and then regenerated in one or more flash stages, and the regenerated absorption liquid is recycled to the absorption stage.

Abstract: For the simultaneous absorption and oxidation of hydrogen sulfide, gaseous mixtures substantially free of molecular oxygen are scrubbed in a first stage with an aqueous, alkaline scrubbing agent containing pentavalent vanadium as the oxidizing medium. The hydrogen sulfide is absorbed by the scrubbing agent and oxidized to elemental sulfur with reduction of pentavalent vanadium to tetravalent vanadium. The thus-reduced scrubbing agent is then regenerated in a separate second stage in the presence of an amine promoter by reoxidation of the tetravalent vanadium with molecular oxygen, and reused.

Abstract: An integrated process for modifying the H.sub.2 /CO ratio in specified gaseous streams is disclosed, the process being characterized by bulk removal of H.sub.2 S, adjustment of H.sub.2 /CO ratio by water gas (or carbon monoxide) shift, and removal of remaining H.sub.2 S. CO.sub.2 may be recovered, and the process may be operated to produce a gas comprising principally hydrogen.

Abstract: An integrated process for modifying the H.sub.2 /CO ratio in specified gaseous streams is disclosed, the process being characterized by bulk removal of H.sub.2 S, adjustment of H.sub.2 /CO ratio by water gas (or carbon monoxide) shift, and removal of remaining H.sub.2 S. CO.sub.2 may be recovered, and the process may be operated to produce a gas comprising principally hydrogen.

Abstract: A carbon monoxide-contaminated breathable gas (that is a gas or gas mixture containing sufficient oxygen to support human life) is purified by bringing it into contact with a bed of a catalyst, whereby to oxidize carbon monoxide to carbon dioxide and reduce the carbon monoxide contamination of gas, the catalyst being a promoted tin IV oxide-support precious metal catalyst in which the promoter is one or more metals of group 1b, 3b, 7bb and 8 of the Periodic Table (especially copper, nickel, manganese, silica or lanthanum) and the precious metal is platinum, palladium, rhodium, iridium or ruthenium.

Abstract: A composition to absorb mercury vapor and suppress the formation of the vapor. The composition comprises a carrier liquid, for example water, an alcohol or glycol, copper ions, for example copper sulphate and thiosulphate ions, for example sodium thiosulphate. The absorbent is efficient and clean in use.

Abstract: An absorbent for the dry removal of sulfur dioxide and other noxious and toxic components from a combustion flue gas which consists essentially of at least one finely divided alkaline-earth compound and an additive selected from the group which consists of at least one carboxylic acid or an alkali metal, alkaline-earth metal or ammonium salt thereof.

Abstract: A process for the separation of volatile chlorine compounds from exhaust gases resulting from the chlorination of titanium-containing raw material by the treatment of the exhaust gases with an aqueous media in several stages and the absorption of the volatile chlorine compounds in the aqueous media. In the first stage, the exhaust gases are contacted with an aqueous solution of titanium oxide chloride and, in the subsequent second stage, the exhaust gases are contacted with water to obtain hydrochloric acid of useful concentration.

Abstract: An exhaust fume desulfurization process is disclosed which comprises the steps of contacting an off-gas containing SO.sub.2 with a slurry containing calcium and manganese compounds, introducing a gas containing oxygen into the slurry, detecting the amount of the absorption of oxygen by the slurry, and regulating the amount of manganese present in the slurry based upon the amount of oxygen absorbed by the slurry. The desulfurization rate is correspondingly adjusted and the desulfurized gas product is recovered.

Abstract: A method for reducing the hydrogen sulfide, hydrogen polysulfides and/or ash content of molten sulfur is disclosed. The subject invention is directed at the addition of an effective amount of a degassing agent selected from the class consisting of inorganic phosphorous compounds, urea and urea derivatives without the necessity for also adding sulfur dioxide to the molten sulfur.